fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/slab.h>
  25 #include <linux/init.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/backing-dev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/ctype.h>
  38 #include <linux/log2.h>
  39 #include <linux/crc16.h>
  40 #include <linux/dax.h>
  41 #include <linux/cleancache.h>
  42 #include <linux/uaccess.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/freezer.h>
  46
  47 #include "ext4.h"
  48 #include "ext4_extents.h"       /* Needed for trace points definition */
  49 #include "ext4_jbd2.h"
  50 #include "xattr.h"
  51 #include "acl.h"
  52 #include "mballoc.h"
  53 #include "fsmap.h"
  54
  55 #define CREATE_TRACE_POINTS
  56 #include <trace/events/ext4.h>
  57
  58 static struct ext4_lazy_init *ext4_li_info;
  59 static struct mutex ext4_li_mtx;
  60 static struct ratelimit_state ext4_mount_msg_ratelimit;
  61
  62 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  63                              unsigned long journal_devnum);
  64 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
  65 static int ext4_commit_super(struct super_block *sb, int sync);
  66 static void ext4_mark_recovery_complete(struct super_block *sb,
  67                                         struct ext4_super_block *es);
  68 static void ext4_clear_journal_err(struct super_block *sb,
  69                                    struct ext4_super_block *es);
  70 static int ext4_sync_fs(struct super_block *sb, int wait);
  71 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  72 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  73 static int ext4_unfreeze(struct super_block *sb);
  74 static int ext4_freeze(struct super_block *sb);
  75 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  76                        const char *dev_name, void *data);
  77 static inline int ext2_feature_set_ok(struct super_block *sb);
  78 static inline int ext3_feature_set_ok(struct super_block *sb);
  79 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  80 static void ext4_destroy_lazyinit_thread(void);
  81 static void ext4_unregister_li_request(struct super_block *sb);
  82 static void ext4_clear_request_list(void);
  83 static struct inode *ext4_get_journal_inode(struct super_block *sb,
  84                                             unsigned int journal_inum);
  85
  86 /*
  87  * Lock ordering
  88  *
  89  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
  90  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  91  *
  92  * page fault path:
  93  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  94  *   page lock -> i_data_sem (rw)
  95  *
  96  * buffered write path:
  97  * sb_start_write -> i_mutex -> mmap_sem
  98  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  99  *   i_data_sem (rw)
 100  *
 101  * truncate:
 102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 103  *   i_mmap_rwsem (w) -> page lock
 104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
 105  *   transaction start -> i_data_sem (rw)
 106  *
 107  * direct IO:
 108  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
 109  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
 110  *   transaction start -> i_data_sem (rw)
 111  *
 112  * writepages:
 113  * transaction start -> page lock(s) -> i_data_sem (rw)
 114  */
 115
 116 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 117 static struct file_system_type ext2_fs_type = {
 118         .owner          = THIS_MODULE,
 119         .name           = "ext2",
 120         .mount          = ext4_mount,
 121         .kill_sb        = kill_block_super,
 122         .fs_flags       = FS_REQUIRES_DEV,
 123 };
 124 MODULE_ALIAS_FS("ext2");
 125 MODULE_ALIAS("ext2");
 126 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
 127 #else
 128 #define IS_EXT2_SB(sb) (0)
 129 #endif
 130
 131
 132 static struct file_system_type ext3_fs_type = {
 133         .owner          = THIS_MODULE,
 134         .name           = "ext3",
 135         .mount          = ext4_mount,
 136         .kill_sb        = kill_block_super,
 137         .fs_flags       = FS_REQUIRES_DEV,
 138 };
 139 MODULE_ALIAS_FS("ext3");
 140 MODULE_ALIAS("ext3");
 141 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 142
 143 static int ext4_verify_csum_type(struct super_block *sb,
 144                                  struct ext4_super_block *es)
 145 {
 146         if (!ext4_has_feature_metadata_csum(sb))
 147                 return 1;
 148
 149         return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
 150 }
 151
 152 static __le32 ext4_superblock_csum(struct super_block *sb,
 153                                    struct ext4_super_block *es)
 154 {
 155         struct ext4_sb_info *sbi = EXT4_SB(sb);
 156         int offset = offsetof(struct ext4_super_block, s_checksum);
 157         __u32 csum;
 158
 159         csum = ext4_chksum(sbi, ~0, (char *)es, offset);
 160
 161         return cpu_to_le32(csum);
 162 }
 163
 164 static int ext4_superblock_csum_verify(struct super_block *sb,
 165                                        struct ext4_super_block *es)
 166 {
 167         if (!ext4_has_metadata_csum(sb))
 168                 return 1;
 169
 170         return es->s_checksum == ext4_superblock_csum(sb, es);
 171 }
 172
 173 void ext4_superblock_csum_set(struct super_block *sb)
 174 {
 175         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 176
 177         if (!ext4_has_metadata_csum(sb))
 178                 return;
 179
 180         es->s_checksum = ext4_superblock_csum(sb, es);
 181 }
 182
 183 void *ext4_kvmalloc(size_t size, gfp_t flags)
 184 {
 185         void *ret;
 186
 187         ret = kmalloc(size, flags | __GFP_NOWARN);
 188         if (!ret)
 189                 ret = __vmalloc(size, flags, PAGE_KERNEL);
 190         return ret;
 191 }
 192
 193 void *ext4_kvzalloc(size_t size, gfp_t flags)
 194 {
 195         void *ret;
 196
 197         ret = kzalloc(size, flags | __GFP_NOWARN);
 198         if (!ret)
 199                 ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
 200         return ret;
 201 }
 202
 203 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 204                                struct ext4_group_desc *bg)
 205 {
 206         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 207                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 208                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 209 }
 210
 211 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 212                                struct ext4_group_desc *bg)
 213 {
 214         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 215                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 216                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 217 }
 218
 219 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 220                               struct ext4_group_desc *bg)
 221 {
 222         return le32_to_cpu(bg->bg_inode_table_lo) |
 223                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 224                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 225 }
 226
 227 __u32 ext4_free_group_clusters(struct super_block *sb,
 228                                struct ext4_group_desc *bg)
 229 {
 230         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 231                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 232                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 233 }
 234
 235 __u32 ext4_free_inodes_count(struct super_block *sb,
 236                               struct ext4_group_desc *bg)
 237 {
 238         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 239                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 240                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 241 }
 242
 243 __u32 ext4_used_dirs_count(struct super_block *sb,
 244                               struct ext4_group_desc *bg)
 245 {
 246         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 247                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 248                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 249 }
 250
 251 __u32 ext4_itable_unused_count(struct super_block *sb,
 252                               struct ext4_group_desc *bg)
 253 {
 254         return le16_to_cpu(bg->bg_itable_unused_lo) |
 255                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 256                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 257 }
 258
 259 void ext4_block_bitmap_set(struct super_block *sb,
 260                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 261 {
 262         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 263         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 264                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 265 }
 266
 267 void ext4_inode_bitmap_set(struct super_block *sb,
 268                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 269 {
 270         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 271         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 272                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 273 }
 274
 275 void ext4_inode_table_set(struct super_block *sb,
 276                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 277 {
 278         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 279         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 280                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 281 }
 282
 283 void ext4_free_group_clusters_set(struct super_block *sb,
 284                                   struct ext4_group_desc *bg, __u32 count)
 285 {
 286         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 287         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 288                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 289 }
 290
 291 void ext4_free_inodes_set(struct super_block *sb,
 292                           struct ext4_group_desc *bg, __u32 count)
 293 {
 294         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 295         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 296                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 297 }
 298
 299 void ext4_used_dirs_set(struct super_block *sb,
 300                           struct ext4_group_desc *bg, __u32 count)
 301 {
 302         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 303         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 304                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 305 }
 306
 307 void ext4_itable_unused_set(struct super_block *sb,
 308                           struct ext4_group_desc *bg, __u32 count)
 309 {
 310         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 311         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 312                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 313 }
 314
 315
 316 static void __save_error_info(struct super_block *sb, const char *func,
 317                             unsigned int line)
 318 {
 319         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 320
 321         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 322         if (bdev_read_only(sb->s_bdev))
 323                 return;
 324         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 325         es->s_last_error_time = cpu_to_le32(get_seconds());
 326         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 327         es->s_last_error_line = cpu_to_le32(line);
 328         if (!es->s_first_error_time) {
 329                 es->s_first_error_time = es->s_last_error_time;
 330                 strncpy(es->s_first_error_func, func,
 331                         sizeof(es->s_first_error_func));
 332                 es->s_first_error_line = cpu_to_le32(line);
 333                 es->s_first_error_ino = es->s_last_error_ino;
 334                 es->s_first_error_block = es->s_last_error_block;
 335         }
 336         /*
 337          * Start the daily error reporting function if it hasn't been
 338          * started already
 339          */
 340         if (!es->s_error_count)
 341                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 342         le32_add_cpu(&es->s_error_count, 1);
 343 }
 344
 345 static void save_error_info(struct super_block *sb, const char *func,
 346                             unsigned int line)
 347 {
 348         __save_error_info(sb, func, line);
 349         ext4_commit_super(sb, 1);
 350 }
 351
 352 /*
 353  * The del_gendisk() function uninitializes the disk-specific data
 354  * structures, including the bdi structure, without telling anyone
 355  * else.  Once this happens, any attempt to call mark_buffer_dirty()
 356  * (for example, by ext4_commit_super), will cause a kernel OOPS.
 357  * This is a kludge to prevent these oops until we can put in a proper
 358  * hook in del_gendisk() to inform the VFS and file system layers.
 359  */
 360 static int block_device_ejected(struct super_block *sb)
 361 {
 362         struct inode *bd_inode = sb->s_bdev->bd_inode;
 363         struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
 364
 365         return bdi->dev == NULL;
 366 }
 367
 368 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
 369 {
 370         struct super_block              *sb = journal->j_private;
 371         struct ext4_sb_info             *sbi = EXT4_SB(sb);
 372         int                             error = is_journal_aborted(journal);
 373         struct ext4_journal_cb_entry    *jce;
 374
 375         BUG_ON(txn->t_state == T_FINISHED);
 376
 377         ext4_process_freed_data(sb, txn->t_tid);
 378
 379         spin_lock(&sbi->s_md_lock);
 380         while (!list_empty(&txn->t_private_list)) {
 381                 jce = list_entry(txn->t_private_list.next,
 382                                  struct ext4_journal_cb_entry, jce_list);
 383                 list_del_init(&jce->jce_list);
 384                 spin_unlock(&sbi->s_md_lock);
 385                 jce->jce_func(sb, jce, error);
 386                 spin_lock(&sbi->s_md_lock);
 387         }
 388         spin_unlock(&sbi->s_md_lock);
 389 }
 390
 391 /* Deal with the reporting of failure conditions on a filesystem such as
 392  * inconsistencies detected or read IO failures.
 393  *
 394  * On ext2, we can store the error state of the filesystem in the
 395  * superblock.  That is not possible on ext4, because we may have other
 396  * write ordering constraints on the superblock which prevent us from
 397  * writing it out straight away; and given that the journal is about to
 398  * be aborted, we can't rely on the current, or future, transactions to
 399  * write out the superblock safely.
 400  *
 401  * We'll just use the jbd2_journal_abort() error code to record an error in
 402  * the journal instead.  On recovery, the journal will complain about
 403  * that error until we've noted it down and cleared it.
 404  */
 405
 406 static void ext4_handle_error(struct super_block *sb)
 407 {
 408         if (sb->s_flags & MS_RDONLY)
 409                 return;
 410
 411         if (!test_opt(sb, ERRORS_CONT)) {
 412                 journal_t *journal = EXT4_SB(sb)->s_journal;
 413
 414                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 415                 if (journal)
 416                         jbd2_journal_abort(journal, -EIO);
 417         }
 418         if (test_opt(sb, ERRORS_RO)) {
 419                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 420                 /*
 421                  * Make sure updated value of ->s_mount_flags will be visible
 422                  * before ->s_flags update
 423                  */
 424                 smp_wmb();
 425                 sb->s_flags |= MS_RDONLY;
 426         }
 427         if (test_opt(sb, ERRORS_PANIC)) {
 428                 if (EXT4_SB(sb)->s_journal &&
 429                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 430                         return;
 431                 panic("EXT4-fs (device %s): panic forced after error\n",
 432                         sb->s_id);
 433         }
 434 }
 435
 436 #define ext4_error_ratelimit(sb)                                        \
 437                 ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),     \
 438                              "EXT4-fs error")
 439
 440 void __ext4_error(struct super_block *sb, const char *function,
 441                   unsigned int line, const char *fmt, ...)
 442 {
 443         struct va_format vaf;
 444         va_list args;
 445
 446         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 447                 return;
 448
 449         if (ext4_error_ratelimit(sb)) {
 450                 va_start(args, fmt);
 451                 vaf.fmt = fmt;
 452                 vaf.va = &args;
 453                 printk(KERN_CRIT
 454                        "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 455                        sb->s_id, function, line, current->comm, &vaf);
 456                 va_end(args);
 457         }
 458         save_error_info(sb, function, line);
 459         ext4_handle_error(sb);
 460 }
 461
 462 void __ext4_error_inode(struct inode *inode, const char *function,
 463                         unsigned int line, ext4_fsblk_t block,
 464                         const char *fmt, ...)
 465 {
 466         va_list args;
 467         struct va_format vaf;
 468         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 469
 470         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 471                 return;
 472
 473         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 474         es->s_last_error_block = cpu_to_le64(block);
 475         if (ext4_error_ratelimit(inode->i_sb)) {
 476                 va_start(args, fmt);
 477                 vaf.fmt = fmt;
 478                 vaf.va = &args;
 479                 if (block)
 480                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 481                                "inode #%lu: block %llu: comm %s: %pV\n",
 482                                inode->i_sb->s_id, function, line, inode->i_ino,
 483                                block, current->comm, &vaf);
 484                 else
 485                         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
 486                                "inode #%lu: comm %s: %pV\n",
 487                                inode->i_sb->s_id, function, line, inode->i_ino,
 488                                current->comm, &vaf);
 489                 va_end(args);
 490         }
 491         save_error_info(inode->i_sb, function, line);
 492         ext4_handle_error(inode->i_sb);
 493 }
 494
 495 void __ext4_error_file(struct file *file, const char *function,
 496                        unsigned int line, ext4_fsblk_t block,
 497                        const char *fmt, ...)
 498 {
 499         va_list args;
 500         struct va_format vaf;
 501         struct ext4_super_block *es;
 502         struct inode *inode = file_inode(file);
 503         char pathname[80], *path;
 504
 505         if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
 506                 return;
 507
 508         es = EXT4_SB(inode->i_sb)->s_es;
 509         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 510         if (ext4_error_ratelimit(inode->i_sb)) {
 511                 path = file_path(file, pathname, sizeof(pathname));
 512                 if (IS_ERR(path))
 513                         path = "(unknown)";
 514                 va_start(args, fmt);
 515                 vaf.fmt = fmt;
 516                 vaf.va = &args;
 517                 if (block)
 518                         printk(KERN_CRIT
 519                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 520                                "block %llu: comm %s: path %s: %pV\n",
 521                                inode->i_sb->s_id, function, line, inode->i_ino,
 522                                block, current->comm, path, &vaf);
 523                 else
 524                         printk(KERN_CRIT
 525                                "EXT4-fs error (device %s): %s:%d: inode #%lu: "
 526                                "comm %s: path %s: %pV\n",
 527                                inode->i_sb->s_id, function, line, inode->i_ino,
 528                                current->comm, path, &vaf);
 529                 va_end(args);
 530         }
 531         save_error_info(inode->i_sb, function, line);
 532         ext4_handle_error(inode->i_sb);
 533 }
 534
 535 const char *ext4_decode_error(struct super_block *sb, int errno,
 536                               char nbuf[16])
 537 {
 538         char *errstr = NULL;
 539
 540         switch (errno) {
 541         case -EFSCORRUPTED:
 542                 errstr = "Corrupt filesystem";
 543                 break;
 544         case -EFSBADCRC:
 545                 errstr = "Filesystem failed CRC";
 546                 break;
 547         case -EIO:
 548                 errstr = "IO failure";
 549                 break;
 550         case -ENOMEM:
 551                 errstr = "Out of memory";
 552                 break;
 553         case -EROFS:
 554                 if (!sb || (EXT4_SB(sb)->s_journal &&
 555                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 556                         errstr = "Journal has aborted";
 557                 else
 558                         errstr = "Readonly filesystem";
 559                 break;
 560         default:
 561                 /* If the caller passed in an extra buffer for unknown
 562                  * errors, textualise them now.  Else we just return
 563                  * NULL. */
 564                 if (nbuf) {
 565                         /* Check for truncated error codes... */
 566                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 567                                 errstr = nbuf;
 568                 }
 569                 break;
 570         }
 571
 572         return errstr;
 573 }
 574
 575 /* __ext4_std_error decodes expected errors from journaling functions
 576  * automatically and invokes the appropriate error response.  */
 577
 578 void __ext4_std_error(struct super_block *sb, const char *function,
 579                       unsigned int line, int errno)
 580 {
 581         char nbuf[16];
 582         const char *errstr;
 583
 584         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 585                 return;
 586
 587         /* Special case: if the error is EROFS, and we're not already
 588          * inside a transaction, then there's really no point in logging
 589          * an error. */
 590         if (errno == -EROFS && journal_current_handle() == NULL &&
 591             (sb->s_flags & MS_RDONLY))
 592                 return;
 593
 594         if (ext4_error_ratelimit(sb)) {
 595                 errstr = ext4_decode_error(sb, errno, nbuf);
 596                 printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 597                        sb->s_id, function, line, errstr);
 598         }
 599
 600         save_error_info(sb, function, line);
 601         ext4_handle_error(sb);
 602 }
 603
 604 /*
 605  * ext4_abort is a much stronger failure handler than ext4_error.  The
 606  * abort function may be used to deal with unrecoverable failures such
 607  * as journal IO errors or ENOMEM at a critical moment in log management.
 608  *
 609  * We unconditionally force the filesystem into an ABORT|READONLY state,
 610  * unless the error response on the fs has been set to panic in which
 611  * case we take the easy way out and panic immediately.
 612  */
 613
 614 void __ext4_abort(struct super_block *sb, const char *function,
 615                 unsigned int line, const char *fmt, ...)
 616 {
 617         struct va_format vaf;
 618         va_list args;
 619
 620         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 621                 return;
 622
 623         save_error_info(sb, function, line);
 624         va_start(args, fmt);
 625         vaf.fmt = fmt;
 626         vaf.va = &args;
 627         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
 628                sb->s_id, function, line, &vaf);
 629         va_end(args);
 630
 631         if ((sb->s_flags & MS_RDONLY) == 0) {
 632                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 633                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 634                 /*
 635                  * Make sure updated value of ->s_mount_flags will be visible
 636                  * before ->s_flags update
 637                  */
 638                 smp_wmb();
 639                 sb->s_flags |= MS_RDONLY;
 640                 if (EXT4_SB(sb)->s_journal)
 641                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 642                 save_error_info(sb, function, line);
 643         }
 644         if (test_opt(sb, ERRORS_PANIC)) {
 645                 if (EXT4_SB(sb)->s_journal &&
 646                   !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
 647                         return;
 648                 panic("EXT4-fs panic from previous error\n");
 649         }
 650 }
 651
 652 void __ext4_msg(struct super_block *sb,
 653                 const char *prefix, const char *fmt, ...)
 654 {
 655         struct va_format vaf;
 656         va_list args;
 657
 658         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
 659                 return;
 660
 661         va_start(args, fmt);
 662         vaf.fmt = fmt;
 663         vaf.va = &args;
 664         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 665         va_end(args);
 666 }
 667
 668 #define ext4_warning_ratelimit(sb)                                      \
 669                 ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), \
 670                              "EXT4-fs warning")
 671
 672 void __ext4_warning(struct super_block *sb, const char *function,
 673                     unsigned int line, const char *fmt, ...)
 674 {
 675         struct va_format vaf;
 676         va_list args;
 677
 678         if (!ext4_warning_ratelimit(sb))
 679                 return;
 680
 681         va_start(args, fmt);
 682         vaf.fmt = fmt;
 683         vaf.va = &args;
 684         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 685                sb->s_id, function, line, &vaf);
 686         va_end(args);
 687 }
 688
 689 void __ext4_warning_inode(const struct inode *inode, const char *function,
 690                           unsigned int line, const char *fmt, ...)
 691 {
 692         struct va_format vaf;
 693         va_list args;
 694
 695         if (!ext4_warning_ratelimit(inode->i_sb))
 696                 return;
 697
 698         va_start(args, fmt);
 699         vaf.fmt = fmt;
 700         vaf.va = &args;
 701         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
 702                "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
 703                function, line, inode->i_ino, current->comm, &vaf);
 704         va_end(args);
 705 }
 706
 707 void __ext4_grp_locked_error(const char *function, unsigned int line,
 708                              struct super_block *sb, ext4_group_t grp,
 709                              unsigned long ino, ext4_fsblk_t block,
 710                              const char *fmt, ...)
 711 __releases(bitlock)
 712 __acquires(bitlock)
 713 {
 714         struct va_format vaf;
 715         va_list args;
 716         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 717
 718         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
 719                 return;
 720
 721         es->s_last_error_ino = cpu_to_le32(ino);
 722         es->s_last_error_block = cpu_to_le64(block);
 723         __save_error_info(sb, function, line);
 724
 725         if (ext4_error_ratelimit(sb)) {
 726                 va_start(args, fmt);
 727                 vaf.fmt = fmt;
 728                 vaf.va = &args;
 729                 printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 730                        sb->s_id, function, line, grp);
 731                 if (ino)
 732                         printk(KERN_CONT "inode %lu: ", ino);
 733                 if (block)
 734                         printk(KERN_CONT "block %llu:",
 735                                (unsigned long long) block);
 736                 printk(KERN_CONT "%pV\n", &vaf);
 737                 va_end(args);
 738         }
 739
 740         if (test_opt(sb, ERRORS_CONT)) {
 741                 ext4_commit_super(sb, 0);
 742                 return;
 743         }
 744
 745         ext4_unlock_group(sb, grp);
 746         ext4_handle_error(sb);
 747         /*
 748          * We only get here in the ERRORS_RO case; relocking the group
 749          * may be dangerous, but nothing bad will happen since the
 750          * filesystem will have already been marked read/only and the
 751          * journal has been aborted.  We return 1 as a hint to callers
 752          * who might what to use the return value from
 753          * ext4_grp_locked_error() to distinguish between the
 754          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 755          * aggressively from the ext4 function in question, with a
 756          * more appropriate error code.
 757          */
 758         ext4_lock_group(sb, grp);
 759         return;
 760 }
 761
 762 void ext4_update_dynamic_rev(struct super_block *sb)
 763 {
 764         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 765
 766         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 767                 return;
 768
 769         ext4_warning(sb,
 770                      "updating to rev %d because of new feature flag, "
 771                      "running e2fsck is recommended",
 772                      EXT4_DYNAMIC_REV);
 773
 774         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 775         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 776         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 777         /* leave es->s_feature_*compat flags alone */
 778         /* es->s_uuid will be set by e2fsck if empty */
 779
 780         /*
 781          * The rest of the superblock fields should be zero, and if not it
 782          * means they are likely already in use, so leave them alone.  We
 783          * can leave it up to e2fsck to clean up any inconsistencies there.
 784          */
 785 }
 786
 787 /*
 788  * Open the external journal device
 789  */
 790 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 791 {
 792         struct block_device *bdev;
 793         char b[BDEVNAME_SIZE];
 794
 795         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 796         if (IS_ERR(bdev))
 797                 goto fail;
 798         return bdev;
 799
 800 fail:
 801         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 802                         __bdevname(dev, b), PTR_ERR(bdev));
 803         return NULL;
 804 }
 805
 806 /*
 807  * Release the journal device
 808  */
 809 static void ext4_blkdev_put(struct block_device *bdev)
 810 {
 811         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 812 }
 813
 814 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
 815 {
 816         struct block_device *bdev;
 817         bdev = sbi->journal_bdev;
 818         if (bdev) {
 819                 ext4_blkdev_put(bdev);
 820                 sbi->journal_bdev = NULL;
 821         }
 822 }
 823
 824 static inline struct inode *orphan_list_entry(struct list_head *l)
 825 {
 826         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 827 }
 828
 829 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 830 {
 831         struct list_head *l;
 832
 833         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 834                  le32_to_cpu(sbi->s_es->s_last_orphan));
 835
 836         printk(KERN_ERR "sb_info orphan list:\n");
 837         list_for_each(l, &sbi->s_orphan) {
 838                 struct inode *inode = orphan_list_entry(l);
 839                 printk(KERN_ERR "  "
 840                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 841                        inode->i_sb->s_id, inode->i_ino, inode,
 842                        inode->i_mode, inode->i_nlink,
 843                        NEXT_ORPHAN(inode));
 844         }
 845 }
 846
 847 #ifdef CONFIG_QUOTA
 848 static int ext4_quota_off(struct super_block *sb, int type);
 849
 850 static inline void ext4_quota_off_umount(struct super_block *sb)
 851 {
 852         int type;
 853
 854         /* Use our quota_off function to clear inode flags etc. */
 855         for (type = 0; type < EXT4_MAXQUOTAS; type++)
 856                 ext4_quota_off(sb, type);
 857 }
 858 #else
 859 static inline void ext4_quota_off_umount(struct super_block *sb)
 860 {
 861 }
 862 #endif
 863
 864 static void ext4_put_super(struct super_block *sb)
 865 {
 866         struct ext4_sb_info *sbi = EXT4_SB(sb);
 867         struct ext4_super_block *es = sbi->s_es;
 868         int aborted = 0;
 869         int i, err;
 870
 871         ext4_unregister_li_request(sb);
 872         ext4_quota_off_umount(sb);
 873
 874         flush_workqueue(sbi->rsv_conversion_wq);
 875         destroy_workqueue(sbi->rsv_conversion_wq);
 876
 877         if (sbi->s_journal) {
 878                 aborted = is_journal_aborted(sbi->s_journal);
 879                 err = jbd2_journal_destroy(sbi->s_journal);
 880                 sbi->s_journal = NULL;
 881                 if ((err < 0) && !aborted)
 882                         ext4_abort(sb, "Couldn't clean up the journal");
 883         }
 884
 885         ext4_unregister_sysfs(sb);
 886         ext4_es_unregister_shrinker(sbi);
 887         del_timer_sync(&sbi->s_err_report);
 888         ext4_release_system_zone(sb);
 889         ext4_mb_release(sb);
 890         ext4_ext_release(sb);
 891
 892         if (!(sb->s_flags & MS_RDONLY) && !aborted) {
 893                 ext4_clear_feature_journal_needs_recovery(sb);
 894                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 895         }
 896         if (!(sb->s_flags & MS_RDONLY))
 897                 ext4_commit_super(sb, 1);
 898
 899         for (i = 0; i < sbi->s_gdb_count; i++)
 900                 brelse(sbi->s_group_desc[i]);
 901         kvfree(sbi->s_group_desc);
 902         kvfree(sbi->s_flex_groups);
 903         percpu_counter_destroy(&sbi->s_freeclusters_counter);
 904         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 905         percpu_counter_destroy(&sbi->s_dirs_counter);
 906         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
 907         percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
 908 #ifdef CONFIG_QUOTA
 909         for (i = 0; i < EXT4_MAXQUOTAS; i++)
 910                 kfree(sbi->s_qf_names[i]);
 911 #endif
 912
 913         /* Debugging code just in case the in-memory inode orphan list
 914          * isn't empty.  The on-disk one can be non-empty if we've
 915          * detected an error and taken the fs readonly, but the
 916          * in-memory list had better be clean by this point. */
 917         if (!list_empty(&sbi->s_orphan))
 918                 dump_orphan_list(sb, sbi);
 919         J_ASSERT(list_empty(&sbi->s_orphan));
 920
 921         sync_blockdev(sb->s_bdev);
 922         invalidate_bdev(sb->s_bdev);
 923         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 924                 /*
 925                  * Invalidate the journal device's buffers.  We don't want them
 926                  * floating about in memory - the physical journal device may
 927                  * hotswapped, and it breaks the `ro-after' testing code.
 928                  */
 929                 sync_blockdev(sbi->journal_bdev);
 930                 invalidate_bdev(sbi->journal_bdev);
 931                 ext4_blkdev_remove(sbi);
 932         }
 933         if (sbi->s_ea_inode_cache) {
 934                 ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
 935                 sbi->s_ea_inode_cache = NULL;
 936         }
 937         if (sbi->s_ea_block_cache) {
 938                 ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
 939                 sbi->s_ea_block_cache = NULL;
 940         }
 941         if (sbi->s_mmp_tsk)
 942                 kthread_stop(sbi->s_mmp_tsk);
 943         brelse(sbi->s_sbh);
 944         sb->s_fs_info = NULL;
 945         /*
 946          * Now that we are completely done shutting down the
 947          * superblock, we need to actually destroy the kobject.
 948          */
 949         kobject_put(&sbi->s_kobj);
 950         wait_for_completion(&sbi->s_kobj_unregister);
 951         if (sbi->s_chksum_driver)
 952                 crypto_free_shash(sbi->s_chksum_driver);
 953         kfree(sbi->s_blockgroup_lock);
 954         kfree(sbi);
 955 }
 956
 957 static struct kmem_cache *ext4_inode_cachep;
 958
 959 /*
 960  * Called inside transaction, so use GFP_NOFS
 961  */
 962 static struct inode *ext4_alloc_inode(struct super_block *sb)
 963 {
 964         struct ext4_inode_info *ei;
 965
 966         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 967         if (!ei)
 968                 return NULL;
 969
 970         ei->vfs_inode.i_version = 1;
 971         spin_lock_init(&ei->i_raw_lock);
 972         INIT_LIST_HEAD(&ei->i_prealloc_list);
 973         spin_lock_init(&ei->i_prealloc_lock);
 974         ext4_es_init_tree(&ei->i_es_tree);
 975         rwlock_init(&ei->i_es_lock);
 976         INIT_LIST_HEAD(&ei->i_es_list);
 977         ei->i_es_all_nr = 0;
 978         ei->i_es_shk_nr = 0;
 979         ei->i_es_shrink_lblk = 0;
 980         ei->i_reserved_data_blocks = 0;
 981         ei->i_da_metadata_calc_len = 0;
 982         ei->i_da_metadata_calc_last_lblock = 0;
 983         spin_lock_init(&(ei->i_block_reservation_lock));
 984 #ifdef CONFIG_QUOTA
 985         ei->i_reserved_quota = 0;
 986         memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
 987 #endif
 988         ei->jinode = NULL;
 989         INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
 990         spin_lock_init(&ei->i_completed_io_lock);
 991         ei->i_sync_tid = 0;
 992         ei->i_datasync_tid = 0;
 993         atomic_set(&ei->i_unwritten, 0);
 994         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
 995         return &ei->vfs_inode;
 996 }
 997
 998 static int ext4_drop_inode(struct inode *inode)
 999 {
1000         int drop = generic_drop_inode(inode);
1001
1002         trace_ext4_drop_inode(inode, drop);
1003         return drop;
1004 }
1005
1006 static void ext4_i_callback(struct rcu_head *head)
1007 {
1008         struct inode *inode = container_of(head, struct inode, i_rcu);
1009         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1010 }
1011
1012 static void ext4_destroy_inode(struct inode *inode)
1013 {
1014         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1015                 ext4_msg(inode->i_sb, KERN_ERR,
1016                          "Inode %lu (%p): orphan list check failed!",
1017                          inode->i_ino, EXT4_I(inode));
1018                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1019                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
1020                                 true);
1021                 dump_stack();
1022         }
1023         call_rcu(&inode->i_rcu, ext4_i_callback);
1024 }
1025
1026 static void init_once(void *foo)
1027 {
1028         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1029
1030         INIT_LIST_HEAD(&ei->i_orphan);
1031         init_rwsem(&ei->xattr_sem);
1032         init_rwsem(&ei->i_data_sem);
1033         init_rwsem(&ei->i_mmap_sem);
1034         inode_init_once(&ei->vfs_inode);
1035 }
1036
1037 static int __init init_inodecache(void)
1038 {
1039         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1040                                              sizeof(struct ext4_inode_info),
1041                                              0, (SLAB_RECLAIM_ACCOUNT|
1042                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1043                                              init_once);
1044         if (ext4_inode_cachep == NULL)
1045                 return -ENOMEM;
1046         return 0;
1047 }
1048
1049 static void destroy_inodecache(void)
1050 {
1051         /*
1052          * Make sure all delayed rcu free inodes are flushed before we
1053          * destroy cache.
1054          */
1055         rcu_barrier();
1056         kmem_cache_destroy(ext4_inode_cachep);
1057 }
1058
1059 void ext4_clear_inode(struct inode *inode)
1060 {
1061         invalidate_inode_buffers(inode);
1062         clear_inode(inode);
1063         dquot_drop(inode);
1064         ext4_discard_preallocations(inode);
1065         ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1066         if (EXT4_I(inode)->jinode) {
1067                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1068                                                EXT4_I(inode)->jinode);
1069                 jbd2_free_inode(EXT4_I(inode)->jinode);
1070                 EXT4_I(inode)->jinode = NULL;
1071         }
1072 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1073         fscrypt_put_encryption_info(inode, NULL);
1074 #endif
1075 }
1076
1077 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1078                                         u64 ino, u32 generation)
1079 {
1080         struct inode *inode;
1081
1082         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1083                 return ERR_PTR(-ESTALE);
1084         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1085                 return ERR_PTR(-ESTALE);
1086
1087         /* iget isn't really right if the inode is currently unallocated!!
1088          *
1089          * ext4_read_inode will return a bad_inode if the inode had been
1090          * deleted, so we should be safe.
1091          *
1092          * Currently we don't know the generation for parent directory, so
1093          * a generation of 0 means "accept any"
1094          */
1095         inode = ext4_iget_normal(sb, ino);
1096         if (IS_ERR(inode))
1097                 return ERR_CAST(inode);
1098         if (generation && inode->i_generation != generation) {
1099                 iput(inode);
1100                 return ERR_PTR(-ESTALE);
1101         }
1102
1103         return inode;
1104 }
1105
1106 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1107                                         int fh_len, int fh_type)
1108 {
1109         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1110                                     ext4_nfs_get_inode);
1111 }
1112
1113 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1114                                         int fh_len, int fh_type)
1115 {
1116         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1117                                     ext4_nfs_get_inode);
1118 }
1119
1120 /*
1121  * Try to release metadata pages (indirect blocks, directories) which are
1122  * mapped via the block device.  Since these pages could have journal heads
1123  * which would prevent try_to_free_buffers() from freeing them, we must use
1124  * jbd2 layer's try_to_free_buffers() function to release them.
1125  */
1126 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1127                                  gfp_t wait)
1128 {
1129         journal_t *journal = EXT4_SB(sb)->s_journal;
1130
1131         WARN_ON(PageChecked(page));
1132         if (!page_has_buffers(page))
1133                 return 0;
1134         if (journal)
1135                 return jbd2_journal_try_to_free_buffers(journal, page,
1136                                                 wait & ~__GFP_DIRECT_RECLAIM);
1137         return try_to_free_buffers(page);
1138 }
1139
1140 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1141 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1142 {
1143         return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1144                                  EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1145 }
1146
1147 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1148                                                         void *fs_data)
1149 {
1150         handle_t *handle = fs_data;
1151         int res, res2, credits, retries = 0;
1152
1153         /*
1154          * Encrypting the root directory is not allowed because e2fsck expects
1155          * lost+found to exist and be unencrypted, and encrypting the root
1156          * directory would imply encrypting the lost+found directory as well as
1157          * the filename "lost+found" itself.
1158          */
1159         if (inode->i_ino == EXT4_ROOT_INO)
1160                 return -EPERM;
1161
1162         res = ext4_convert_inline_data(inode);
1163         if (res)
1164                 return res;
1165
1166         /*
1167          * If a journal handle was specified, then the encryption context is
1168          * being set on a new inode via inheritance and is part of a larger
1169          * transaction to create the inode.  Otherwise the encryption context is
1170          * being set on an existing inode in its own transaction.  Only in the
1171          * latter case should the "retry on ENOSPC" logic be used.
1172          */
1173
1174         if (handle) {
1175                 res = ext4_xattr_set_handle(handle, inode,
1176                                             EXT4_XATTR_INDEX_ENCRYPTION,
1177                                             EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1178                                             ctx, len, 0);
1179                 if (!res) {
1180                         ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1181                         ext4_clear_inode_state(inode,
1182                                         EXT4_STATE_MAY_INLINE_DATA);
1183                         /*
1184                          * Update inode->i_flags - e.g. S_DAX may get disabled
1185                          */
1186                         ext4_set_inode_flags(inode);
1187                 }
1188                 return res;
1189         }
1190
1191         res = dquot_initialize(inode);
1192         if (res)
1193                 return res;
1194 retry:
1195         res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1196                                      &credits);
1197         if (res)
1198                 return res;
1199
1200         handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1201         if (IS_ERR(handle))
1202                 return PTR_ERR(handle);
1203
1204         res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1205                                     EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1206                                     ctx, len, 0);
1207         if (!res) {
1208                 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1209                 /* Update inode->i_flags - e.g. S_DAX may get disabled */
1210                 ext4_set_inode_flags(inode);
1211                 res = ext4_mark_inode_dirty(handle, inode);
1212                 if (res)
1213                         EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1214         }
1215         res2 = ext4_journal_stop(handle);
1216
1217         if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1218                 goto retry;
1219         if (!res)
1220                 res = res2;
1221         return res;
1222 }
1223
1224 static bool ext4_dummy_context(struct inode *inode)
1225 {
1226         return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1227 }
1228
1229 static unsigned ext4_max_namelen(struct inode *inode)
1230 {
1231         return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1232                 EXT4_NAME_LEN;
1233 }
1234
1235 static const struct fscrypt_operations ext4_cryptops = {
1236         .key_prefix             = "ext4:",
1237         .get_context            = ext4_get_context,
1238         .set_context            = ext4_set_context,
1239         .dummy_context          = ext4_dummy_context,
1240         .is_encrypted           = ext4_encrypted_inode,
1241         .empty_dir              = ext4_empty_dir,
1242         .max_namelen            = ext4_max_namelen,
1243 };
1244 #else
1245 static const struct fscrypt_operations ext4_cryptops = {
1246         .is_encrypted           = ext4_encrypted_inode,
1247 };
1248 #endif
1249
1250 #ifdef CONFIG_QUOTA
1251 static const char * const quotatypes[] = INITQFNAMES;
1252 #define QTYPE2NAME(t) (quotatypes[t])
1253
1254 static int ext4_write_dquot(struct dquot *dquot);
1255 static int ext4_acquire_dquot(struct dquot *dquot);
1256 static int ext4_release_dquot(struct dquot *dquot);
1257 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1258 static int ext4_write_info(struct super_block *sb, int type);
1259 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1260                          const struct path *path);
1261 static int ext4_quota_on_mount(struct super_block *sb, int type);
1262 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1263                                size_t len, loff_t off);
1264 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1265                                 const char *data, size_t len, loff_t off);
1266 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1267                              unsigned int flags);
1268 static int ext4_enable_quotas(struct super_block *sb);
1269 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1270
1271 static struct dquot **ext4_get_dquots(struct inode *inode)
1272 {
1273         return EXT4_I(inode)->i_dquot;
1274 }
1275
1276 static const struct dquot_operations ext4_quota_operations = {
1277         .get_reserved_space     = ext4_get_reserved_space,
1278         .write_dquot            = ext4_write_dquot,
1279         .acquire_dquot          = ext4_acquire_dquot,
1280         .release_dquot          = ext4_release_dquot,
1281         .mark_dirty             = ext4_mark_dquot_dirty,
1282         .write_info             = ext4_write_info,
1283         .alloc_dquot            = dquot_alloc,
1284         .destroy_dquot          = dquot_destroy,
1285         .get_projid             = ext4_get_projid,
1286         .get_inode_usage        = ext4_get_inode_usage,
1287         .get_next_id            = ext4_get_next_id,
1288 };
1289
1290 static const struct quotactl_ops ext4_qctl_operations = {
1291         .quota_on       = ext4_quota_on,
1292         .quota_off      = ext4_quota_off,
1293         .quota_sync     = dquot_quota_sync,
1294         .get_state      = dquot_get_state,
1295         .set_info       = dquot_set_dqinfo,
1296         .get_dqblk      = dquot_get_dqblk,
1297         .set_dqblk      = dquot_set_dqblk,
1298         .get_nextdqblk  = dquot_get_next_dqblk,
1299 };
1300 #endif
1301
1302 static const struct super_operations ext4_sops = {
1303         .alloc_inode    = ext4_alloc_inode,
1304         .destroy_inode  = ext4_destroy_inode,
1305         .write_inode    = ext4_write_inode,
1306         .dirty_inode    = ext4_dirty_inode,
1307         .drop_inode     = ext4_drop_inode,
1308         .evict_inode    = ext4_evict_inode,
1309         .put_super      = ext4_put_super,
1310         .sync_fs        = ext4_sync_fs,
1311         .freeze_fs      = ext4_freeze,
1312         .unfreeze_fs    = ext4_unfreeze,
1313         .statfs         = ext4_statfs,
1314         .remount_fs     = ext4_remount,
1315         .show_options   = ext4_show_options,
1316 #ifdef CONFIG_QUOTA
1317         .quota_read     = ext4_quota_read,
1318         .quota_write    = ext4_quota_write,
1319         .get_dquots     = ext4_get_dquots,
1320 #endif
1321         .bdev_try_to_free_page = bdev_try_to_free_page,
1322 };
1323
1324 static const struct export_operations ext4_export_ops = {
1325         .fh_to_dentry = ext4_fh_to_dentry,
1326         .fh_to_parent = ext4_fh_to_parent,
1327         .get_parent = ext4_get_parent,
1328 };
1329
1330 enum {
1331         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1332         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1333         Opt_nouid32, Opt_debug, Opt_removed,
1334         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1335         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1336         Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1337         Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1338         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1339         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1340         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1341         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1342         Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1343         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1344         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1345         Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1346         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1347         Opt_inode_readahead_blks, Opt_journal_ioprio,
1348         Opt_dioread_nolock, Opt_dioread_lock,
1349         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1350         Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1351 };
1352
1353 static const match_table_t tokens = {
1354         {Opt_bsd_df, "bsddf"},
1355         {Opt_minix_df, "minixdf"},
1356         {Opt_grpid, "grpid"},
1357         {Opt_grpid, "bsdgroups"},
1358         {Opt_nogrpid, "nogrpid"},
1359         {Opt_nogrpid, "sysvgroups"},
1360         {Opt_resgid, "resgid=%u"},
1361         {Opt_resuid, "resuid=%u"},
1362         {Opt_sb, "sb=%u"},
1363         {Opt_err_cont, "errors=continue"},
1364         {Opt_err_panic, "errors=panic"},
1365         {Opt_err_ro, "errors=remount-ro"},
1366         {Opt_nouid32, "nouid32"},
1367         {Opt_debug, "debug"},
1368         {Opt_removed, "oldalloc"},
1369         {Opt_removed, "orlov"},
1370         {Opt_user_xattr, "user_xattr"},
1371         {Opt_nouser_xattr, "nouser_xattr"},
1372         {Opt_acl, "acl"},
1373         {Opt_noacl, "noacl"},
1374         {Opt_noload, "norecovery"},
1375         {Opt_noload, "noload"},
1376         {Opt_removed, "nobh"},
1377         {Opt_removed, "bh"},
1378         {Opt_commit, "commit=%u"},
1379         {Opt_min_batch_time, "min_batch_time=%u"},
1380         {Opt_max_batch_time, "max_batch_time=%u"},
1381         {Opt_journal_dev, "journal_dev=%u"},
1382         {Opt_journal_path, "journal_path=%s"},
1383         {Opt_journal_checksum, "journal_checksum"},
1384         {Opt_nojournal_checksum, "nojournal_checksum"},
1385         {Opt_journal_async_commit, "journal_async_commit"},
1386         {Opt_abort, "abort"},
1387         {Opt_data_journal, "data=journal"},
1388         {Opt_data_ordered, "data=ordered"},
1389         {Opt_data_writeback, "data=writeback"},
1390         {Opt_data_err_abort, "data_err=abort"},
1391         {Opt_data_err_ignore, "data_err=ignore"},
1392         {Opt_offusrjquota, "usrjquota="},
1393         {Opt_usrjquota, "usrjquota=%s"},
1394         {Opt_offgrpjquota, "grpjquota="},
1395         {Opt_grpjquota, "grpjquota=%s"},
1396         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1397         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1398         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1399         {Opt_grpquota, "grpquota"},
1400         {Opt_noquota, "noquota"},
1401         {Opt_quota, "quota"},
1402         {Opt_usrquota, "usrquota"},
1403         {Opt_prjquota, "prjquota"},
1404         {Opt_barrier, "barrier=%u"},
1405         {Opt_barrier, "barrier"},
1406         {Opt_nobarrier, "nobarrier"},
1407         {Opt_i_version, "i_version"},
1408         {Opt_dax, "dax"},
1409         {Opt_stripe, "stripe=%u"},
1410         {Opt_delalloc, "delalloc"},
1411         {Opt_lazytime, "lazytime"},
1412         {Opt_nolazytime, "nolazytime"},
1413         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1414         {Opt_nodelalloc, "nodelalloc"},
1415         {Opt_removed, "mblk_io_submit"},
1416         {Opt_removed, "nomblk_io_submit"},
1417         {Opt_block_validity, "block_validity"},
1418         {Opt_noblock_validity, "noblock_validity"},
1419         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1420         {Opt_journal_ioprio, "journal_ioprio=%u"},
1421         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1422         {Opt_auto_da_alloc, "auto_da_alloc"},
1423         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1424         {Opt_dioread_nolock, "dioread_nolock"},
1425         {Opt_dioread_lock, "dioread_lock"},
1426         {Opt_discard, "discard"},
1427         {Opt_nodiscard, "nodiscard"},
1428         {Opt_init_itable, "init_itable=%u"},
1429         {Opt_init_itable, "init_itable"},
1430         {Opt_noinit_itable, "noinit_itable"},
1431         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1432         {Opt_test_dummy_encryption, "test_dummy_encryption"},
1433         {Opt_nombcache, "nombcache"},
1434         {Opt_nombcache, "no_mbcache"},  /* for backward compatibility */
1435         {Opt_removed, "check=none"},    /* mount option from ext2/3 */
1436         {Opt_removed, "nocheck"},       /* mount option from ext2/3 */
1437         {Opt_removed, "reservation"},   /* mount option from ext2/3 */
1438         {Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1439         {Opt_removed, "journal=%u"},    /* mount option from ext2/3 */
1440         {Opt_err, NULL},
1441 };
1442
1443 static ext4_fsblk_t get_sb_block(void **data)
1444 {
1445         ext4_fsblk_t    sb_block;
1446         char            *options = (char *) *data;
1447
1448         if (!options || strncmp(options, "sb=", 3) != 0)
1449                 return 1;       /* Default location */
1450
1451         options += 3;
1452         /* TODO: use simple_strtoll with >32bit ext4 */
1453         sb_block = simple_strtoul(options, &options, 0);
1454         if (*options && *options != ',') {
1455                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1456                        (char *) *data);
1457                 return 1;
1458         }
1459         if (*options == ',')
1460                 options++;
1461         *data = (void *) options;
1462
1463         return sb_block;
1464 }
1465
1466 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1467 static const char deprecated_msg[] =
1468         "Mount option \"%s\" will be removed by %s\n"
1469         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1470
1471 #ifdef CONFIG_QUOTA
1472 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1473 {
1474         struct ext4_sb_info *sbi = EXT4_SB(sb);
1475         char *qname;
1476         int ret = -1;
1477
1478         if (sb_any_quota_loaded(sb) &&
1479                 !sbi->s_qf_names[qtype]) {
1480                 ext4_msg(sb, KERN_ERR,
1481                         "Cannot change journaled "
1482                         "quota options when quota turned on");
1483                 return -1;
1484         }
1485         if (ext4_has_feature_quota(sb)) {
1486                 ext4_msg(sb, KERN_INFO, "Journaled quota options "
1487                          "ignored when QUOTA feature is enabled");
1488                 return 1;
1489         }
1490         qname = match_strdup(args);
1491         if (!qname) {
1492                 ext4_msg(sb, KERN_ERR,
1493                         "Not enough memory for storing quotafile name");
1494                 return -1;
1495         }
1496         if (sbi->s_qf_names[qtype]) {
1497                 if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1498                         ret = 1;
1499                 else
1500                         ext4_msg(sb, KERN_ERR,
1501                                  "%s quota file already specified",
1502                                  QTYPE2NAME(qtype));
1503                 goto errout;
1504         }
1505         if (strchr(qname, '/')) {
1506                 ext4_msg(sb, KERN_ERR,
1507                         "quotafile must be on filesystem root");
1508                 goto errout;
1509         }
1510         sbi->s_qf_names[qtype] = qname;
1511         set_opt(sb, QUOTA);
1512         return 1;
1513 errout:
1514         kfree(qname);
1515         return ret;
1516 }
1517
1518 static int clear_qf_name(struct super_block *sb, int qtype)
1519 {
1520
1521         struct ext4_sb_info *sbi = EXT4_SB(sb);
1522
1523         if (sb_any_quota_loaded(sb) &&
1524                 sbi->s_qf_names[qtype]) {
1525                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1526                         " when quota turned on");
1527                 return -1;
1528         }
1529         kfree(sbi->s_qf_names[qtype]);
1530         sbi->s_qf_names[qtype] = NULL;
1531         return 1;
1532 }
1533 #endif
1534
1535 #define MOPT_SET        0x0001
1536 #define MOPT_CLEAR      0x0002
1537 #define MOPT_NOSUPPORT  0x0004
1538 #define MOPT_EXPLICIT   0x0008
1539 #define MOPT_CLEAR_ERR  0x0010
1540 #define MOPT_GTE0       0x0020
1541 #ifdef CONFIG_QUOTA
1542 #define MOPT_Q          0
1543 #define MOPT_QFMT       0x0040
1544 #else
1545 #define MOPT_Q          MOPT_NOSUPPORT
1546 #define MOPT_QFMT       MOPT_NOSUPPORT
1547 #endif
1548 #define MOPT_DATAJ      0x0080
1549 #define MOPT_NO_EXT2    0x0100
1550 #define MOPT_NO_EXT3    0x0200
1551 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1552 #define MOPT_STRING     0x0400
1553
1554 static const struct mount_opts {
1555         int     token;
1556         int     mount_opt;
1557         int     flags;
1558 } ext4_mount_opts[] = {
1559         {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1560         {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1561         {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1562         {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1563         {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1564         {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1565         {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1566          MOPT_EXT4_ONLY | MOPT_SET},
1567         {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1568          MOPT_EXT4_ONLY | MOPT_CLEAR},
1569         {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1570         {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1571         {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1572          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1573         {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1574          MOPT_EXT4_ONLY | MOPT_CLEAR},
1575         {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1576          MOPT_EXT4_ONLY | MOPT_CLEAR},
1577         {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1578          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1579         {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1580                                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1581          MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1582         {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1583         {Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1584         {Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1585         {Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1586         {Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1587          MOPT_NO_EXT2},
1588         {Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1589          MOPT_NO_EXT2},
1590         {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1591         {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1592         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1593         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1594         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1595         {Opt_commit, 0, MOPT_GTE0},
1596         {Opt_max_batch_time, 0, MOPT_GTE0},
1597         {Opt_min_batch_time, 0, MOPT_GTE0},
1598         {Opt_inode_readahead_blks, 0, MOPT_GTE0},
1599         {Opt_init_itable, 0, MOPT_GTE0},
1600         {Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1601         {Opt_stripe, 0, MOPT_GTE0},
1602         {Opt_resuid, 0, MOPT_GTE0},
1603         {Opt_resgid, 0, MOPT_GTE0},
1604         {Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1605         {Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1606         {Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1607         {Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1608         {Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1609         {Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1610          MOPT_NO_EXT2 | MOPT_DATAJ},
1611         {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1612         {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1613 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1614         {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1615         {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1616 #else
1617         {Opt_acl, 0, MOPT_NOSUPPORT},
1618         {Opt_noacl, 0, MOPT_NOSUPPORT},
1619 #endif
1620         {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1621         {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1622         {Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1623         {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1624         {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1625                                                         MOPT_SET | MOPT_Q},
1626         {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1627                                                         MOPT_SET | MOPT_Q},
1628         {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1629                                                         MOPT_SET | MOPT_Q},
1630         {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1631                        EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1632                                                         MOPT_CLEAR | MOPT_Q},
1633         {Opt_usrjquota, 0, MOPT_Q},
1634         {Opt_grpjquota, 0, MOPT_Q},
1635         {Opt_offusrjquota, 0, MOPT_Q},
1636         {Opt_offgrpjquota, 0, MOPT_Q},
1637         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1638         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1639         {Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1640         {Opt_max_dir_size_kb, 0, MOPT_GTE0},
1641         {Opt_test_dummy_encryption, 0, MOPT_GTE0},
1642         {Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1643         {Opt_err, 0, 0}
1644 };
1645
1646 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1647                             substring_t *args, unsigned long *journal_devnum,
1648                             unsigned int *journal_ioprio, int is_remount)
1649 {
1650         struct ext4_sb_info *sbi = EXT4_SB(sb);
1651         const struct mount_opts *m;
1652         kuid_t uid;
1653         kgid_t gid;
1654         int arg = 0;
1655
1656 #ifdef CONFIG_QUOTA
1657         if (token == Opt_usrjquota)
1658                 return set_qf_name(sb, USRQUOTA, &args[0]);
1659         else if (token == Opt_grpjquota)
1660                 return set_qf_name(sb, GRPQUOTA, &args[0]);
1661         else if (token == Opt_offusrjquota)
1662                 return clear_qf_name(sb, USRQUOTA);
1663         else if (token == Opt_offgrpjquota)
1664                 return clear_qf_name(sb, GRPQUOTA);
1665 #endif
1666         switch (token) {
1667         case Opt_noacl:
1668         case Opt_nouser_xattr:
1669                 ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1670                 break;
1671         case Opt_sb:
1672                 return 1;       /* handled by get_sb_block() */
1673         case Opt_removed:
1674                 ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1675                 return 1;
1676         case Opt_abort:
1677                 sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1678                 return 1;
1679         case Opt_i_version:
1680                 sb->s_flags |= MS_I_VERSION;
1681                 return 1;
1682         case Opt_lazytime:
1683                 sb->s_flags |= MS_LAZYTIME;
1684                 return 1;
1685         case Opt_nolazytime:
1686                 sb->s_flags &= ~MS_LAZYTIME;
1687                 return 1;
1688         }
1689
1690         for (m = ext4_mount_opts; m->token != Opt_err; m++)
1691                 if (token == m->token)
1692                         break;
1693
1694         if (m->token == Opt_err) {
1695                 ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1696                          "or missing value", opt);
1697                 return -1;
1698         }
1699
1700         if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1701                 ext4_msg(sb, KERN_ERR,
1702                          "Mount option \"%s\" incompatible with ext2", opt);
1703                 return -1;
1704         }
1705         if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1706                 ext4_msg(sb, KERN_ERR,
1707                          "Mount option \"%s\" incompatible with ext3", opt);
1708                 return -1;
1709         }
1710
1711         if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1712                 return -1;
1713         if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1714                 return -1;
1715         if (m->flags & MOPT_EXPLICIT) {
1716                 if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1717                         set_opt2(sb, EXPLICIT_DELALLOC);
1718                 } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1719                         set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1720                 } else
1721                         return -1;
1722         }
1723         if (m->flags & MOPT_CLEAR_ERR)
1724                 clear_opt(sb, ERRORS_MASK);
1725         if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1726                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1727                          "options when quota turned on");
1728                 return -1;
1729         }
1730
1731         if (m->flags & MOPT_NOSUPPORT) {
1732                 ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1733         } else if (token == Opt_commit) {
1734                 if (arg == 0)
1735                         arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1736                 sbi->s_commit_interval = HZ * arg;
1737         } else if (token == Opt_debug_want_extra_isize) {
1738                 sbi->s_want_extra_isize = arg;
1739         } else if (token == Opt_max_batch_time) {
1740                 sbi->s_max_batch_time = arg;
1741         } else if (token == Opt_min_batch_time) {
1742                 sbi->s_min_batch_time = arg;
1743         } else if (token == Opt_inode_readahead_blks) {
1744                 if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1745                         ext4_msg(sb, KERN_ERR,
1746                                  "EXT4-fs: inode_readahead_blks must be "
1747                                  "0 or a power of 2 smaller than 2^31");
1748                         return -1;
1749                 }
1750                 sbi->s_inode_readahead_blks = arg;
1751         } else if (token == Opt_init_itable) {
1752                 set_opt(sb, INIT_INODE_TABLE);
1753                 if (!args->from)
1754                         arg = EXT4_DEF_LI_WAIT_MULT;
1755                 sbi->s_li_wait_mult = arg;
1756         } else if (token == Opt_max_dir_size_kb) {
1757                 sbi->s_max_dir_size_kb = arg;
1758         } else if (token == Opt_stripe) {
1759                 sbi->s_stripe = arg;
1760         } else if (token == Opt_resuid) {
1761                 uid = make_kuid(current_user_ns(), arg);
1762                 if (!uid_valid(uid)) {
1763                         ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1764                         return -1;
1765                 }
1766                 sbi->s_resuid = uid;
1767         } else if (token == Opt_resgid) {
1768                 gid = make_kgid(current_user_ns(), arg);
1769                 if (!gid_valid(gid)) {
1770                         ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1771                         return -1;
1772                 }
1773                 sbi->s_resgid = gid;
1774         } else if (token == Opt_journal_dev) {
1775                 if (is_remount) {
1776                         ext4_msg(sb, KERN_ERR,
1777                                  "Cannot specify journal on remount");
1778                         return -1;
1779                 }
1780                 *journal_devnum = arg;
1781         } else if (token == Opt_journal_path) {
1782                 char *journal_path;
1783                 struct inode *journal_inode;
1784                 struct path path;
1785                 int error;
1786
1787                 if (is_remount) {
1788                         ext4_msg(sb, KERN_ERR,
1789                                  "Cannot specify journal on remount");
1790                         return -1;
1791                 }
1792                 journal_path = match_strdup(&args[0]);
1793                 if (!journal_path) {
1794                         ext4_msg(sb, KERN_ERR, "error: could not dup "
1795                                 "journal device string");
1796                         return -1;
1797                 }
1798
1799                 error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1800                 if (error) {
1801                         ext4_msg(sb, KERN_ERR, "error: could not find "
1802                                 "journal device path: error %d", error);
1803                         kfree(journal_path);
1804                         return -1;
1805                 }
1806
1807                 journal_inode = d_inode(path.dentry);
1808                 if (!S_ISBLK(journal_inode->i_mode)) {
1809                         ext4_msg(sb, KERN_ERR, "error: journal path %s "
1810                                 "is not a block device", journal_path);
1811                         path_put(&path);
1812                         kfree(journal_path);
1813                         return -1;
1814                 }
1815
1816                 *journal_devnum = new_encode_dev(journal_inode->i_rdev);
1817                 path_put(&path);
1818                 kfree(journal_path);
1819         } else if (token == Opt_journal_ioprio) {
1820                 if (arg > 7) {
1821                         ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1822                                  " (must be 0-7)");
1823                         return -1;
1824                 }
1825                 *journal_ioprio =
1826                         IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1827         } else if (token == Opt_test_dummy_encryption) {
1828 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1829                 sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1830                 ext4_msg(sb, KERN_WARNING,
1831                          "Test dummy encryption mode enabled");
1832 #else
1833                 ext4_msg(sb, KERN_WARNING,
1834                          "Test dummy encryption mount option ignored");
1835 #endif
1836         } else if (m->flags & MOPT_DATAJ) {
1837                 if (is_remount) {
1838                         if (!sbi->s_journal)
1839                                 ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1840                         else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1841                                 ext4_msg(sb, KERN_ERR,
1842                                          "Cannot change data mode on remount");
1843                                 return -1;
1844                         }
1845                 } else {
1846                         clear_opt(sb, DATA_FLAGS);
1847                         sbi->s_mount_opt |= m->mount_opt;
1848                 }
1849 #ifdef CONFIG_QUOTA
1850         } else if (m->flags & MOPT_QFMT) {
1851                 if (sb_any_quota_loaded(sb) &&
1852                     sbi->s_jquota_fmt != m->mount_opt) {
1853                         ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1854                                  "quota options when quota turned on");
1855                         return -1;
1856                 }
1857                 if (ext4_has_feature_quota(sb)) {
1858                         ext4_msg(sb, KERN_INFO,
1859                                  "Quota format mount options ignored "
1860                                  "when QUOTA feature is enabled");
1861                         return 1;
1862                 }
1863                 sbi->s_jquota_fmt = m->mount_opt;
1864 #endif
1865         } else if (token == Opt_dax) {
1866 #ifdef CONFIG_FS_DAX
1867                 ext4_msg(sb, KERN_WARNING,
1868                 "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1869                         sbi->s_mount_opt |= m->mount_opt;
1870 #else
1871                 ext4_msg(sb, KERN_INFO, "dax option not supported");
1872                 return -1;
1873 #endif
1874         } else if (token == Opt_data_err_abort) {
1875                 sbi->s_mount_opt |= m->mount_opt;
1876         } else if (token == Opt_data_err_ignore) {
1877                 sbi->s_mount_opt &= ~m->mount_opt;
1878         } else {
1879                 if (!args->from)
1880                         arg = 1;
1881                 if (m->flags & MOPT_CLEAR)
1882                         arg = !arg;
1883                 else if (unlikely(!(m->flags & MOPT_SET))) {
1884                         ext4_msg(sb, KERN_WARNING,
1885                                  "buggy handling of option %s", opt);
1886                         WARN_ON(1);
1887                         return -1;
1888                 }
1889                 if (arg != 0)
1890                         sbi->s_mount_opt |= m->mount_opt;
1891                 else
1892                         sbi->s_mount_opt &= ~m->mount_opt;
1893         }
1894         return 1;
1895 }
1896
1897 static int parse_options(char *options, struct super_block *sb,
1898                          unsigned long *journal_devnum,
1899                          unsigned int *journal_ioprio,
1900                          int is_remount)
1901 {
1902         struct ext4_sb_info *sbi = EXT4_SB(sb);
1903         char *p;
1904         substring_t args[MAX_OPT_ARGS];
1905         int token;
1906
1907         if (!options)
1908                 return 1;
1909
1910         while ((p = strsep(&options, ",")) != NULL) {
1911                 if (!*p)
1912                         continue;
1913                 /*
1914                  * Initialize args struct so we know whether arg was
1915                  * found; some options take optional arguments.
1916                  */
1917                 args[0].to = args[0].from = NULL;
1918                 token = match_token(p, tokens, args);
1919                 if (handle_mount_opt(sb, p, token, args, journal_devnum,
1920                                      journal_ioprio, is_remount) < 0)
1921                         return 0;
1922         }
1923 #ifdef CONFIG_QUOTA
1924         /*
1925          * We do the test below only for project quotas. 'usrquota' and
1926          * 'grpquota' mount options are allowed even without quota feature
1927          * to support legacy quotas in quota files.
1928          */
1929         if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1930                 ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1931                          "Cannot enable project quota enforcement.");
1932                 return 0;
1933         }
1934         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1935                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1936                         clear_opt(sb, USRQUOTA);
1937
1938                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1939                         clear_opt(sb, GRPQUOTA);
1940
1941                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1942                         ext4_msg(sb, KERN_ERR, "old and new quota "
1943                                         "format mixing");
1944                         return 0;
1945                 }
1946
1947                 if (!sbi->s_jquota_fmt) {
1948                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1949                                         "not specified");
1950                         return 0;
1951                 }
1952         }
1953 #endif
1954         if (test_opt(sb, DIOREAD_NOLOCK)) {
1955                 int blocksize =
1956                         BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1957
1958                 if (blocksize < PAGE_SIZE) {
1959                         ext4_msg(sb, KERN_ERR, "can't mount with "
1960                                  "dioread_nolock if block size != PAGE_SIZE");
1961                         return 0;
1962                 }
1963         }
1964         return 1;
1965 }
1966
1967 static inline void ext4_show_quota_options(struct seq_file *seq,
1968                                            struct super_block *sb)
1969 {
1970 #if defined(CONFIG_QUOTA)
1971         struct ext4_sb_info *sbi = EXT4_SB(sb);
1972
1973         if (sbi->s_jquota_fmt) {
1974                 char *fmtname = "";
1975
1976                 switch (sbi->s_jquota_fmt) {
1977                 case QFMT_VFS_OLD:
1978                         fmtname = "vfsold";
1979                         break;
1980                 case QFMT_VFS_V0:
1981                         fmtname = "vfsv0";
1982                         break;
1983                 case QFMT_VFS_V1:
1984                         fmtname = "vfsv1";
1985                         break;
1986                 }
1987                 seq_printf(seq, ",jqfmt=%s", fmtname);
1988         }
1989
1990         if (sbi->s_qf_names[USRQUOTA])
1991                 seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1992
1993         if (sbi->s_qf_names[GRPQUOTA])
1994                 seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1995 #endif
1996 }
1997
1998 static const char *token2str(int token)
1999 {
2000         const struct match_token *t;
2001
2002         for (t = tokens; t->token != Opt_err; t++)
2003                 if (t->token == token && !strchr(t->pattern, '='))
2004                         break;
2005         return t->pattern;
2006 }
2007
2008 /*
2009  * Show an option if
2010  *  - it's set to a non-default value OR
2011  *  - if the per-sb default is different from the global default
2012  */
2013 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2014                               int nodefs)
2015 {
2016         struct ext4_sb_info *sbi = EXT4_SB(sb);
2017         struct ext4_super_block *es = sbi->s_es;
2018         int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
2019         const struct mount_opts *m;
2020         char sep = nodefs ? '\n' : ',';
2021
2022 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2023 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2024
2025         if (sbi->s_sb_block != 1)
2026                 SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2027
2028         for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2029                 int want_set = m->flags & MOPT_SET;
2030                 if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2031                     (m->flags & MOPT_CLEAR_ERR))
2032                         continue;
2033                 if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2034                         continue; /* skip if same as the default */
2035                 if ((want_set &&
2036                      (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2037                     (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2038                         continue; /* select Opt_noFoo vs Opt_Foo */
2039                 SEQ_OPTS_PRINT("%s", token2str(m->token));
2040         }
2041
2042         if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2043             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2044                 SEQ_OPTS_PRINT("resuid=%u",
2045                                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
2046         if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2047             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2048                 SEQ_OPTS_PRINT("resgid=%u",
2049                                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
2050         def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2051         if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2052                 SEQ_OPTS_PUTS("errors=remount-ro");
2053         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2054                 SEQ_OPTS_PUTS("errors=continue");
2055         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2056                 SEQ_OPTS_PUTS("errors=panic");
2057         if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2058                 SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2059         if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2060                 SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2061         if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2062                 SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2063         if (sb->s_flags & MS_I_VERSION)
2064                 SEQ_OPTS_PUTS("i_version");
2065         if (nodefs || sbi->s_stripe)
2066                 SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2067         if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2068                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2069                         SEQ_OPTS_PUTS("data=journal");
2070                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2071                         SEQ_OPTS_PUTS("data=ordered");
2072                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2073                         SEQ_OPTS_PUTS("data=writeback");
2074         }
2075         if (nodefs ||
2076             sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2077                 SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2078                                sbi->s_inode_readahead_blks);
2079
2080         if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2081                        (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2082                 SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2083         if (nodefs || sbi->s_max_dir_size_kb)
2084                 SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2085         if (test_opt(sb, DATA_ERR_ABORT))
2086                 SEQ_OPTS_PUTS("data_err=abort");
2087
2088         ext4_show_quota_options(seq, sb);
2089         return 0;
2090 }
2091
2092 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2093 {
2094         return _ext4_show_options(seq, root->d_sb, 0);
2095 }
2096
2097 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2098 {
2099         struct super_block *sb = seq->private;
2100         int rc;
2101
2102         seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2103         rc = _ext4_show_options(seq, sb, 1);
2104         seq_puts(seq, "\n");
2105         return rc;
2106 }
2107
2108 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2109                             int read_only)
2110 {
2111         struct ext4_sb_info *sbi = EXT4_SB(sb);
2112         int res = 0;
2113
2114         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2115                 ext4_msg(sb, KERN_ERR, "revision level too high, "
2116                          "forcing read-only mode");
2117                 res = MS_RDONLY;
2118         }
2119         if (read_only)
2120                 goto done;
2121         if (!(sbi->s_mount_state & EXT4_VALID_FS))
2122                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2123                          "running e2fsck is recommended");
2124         else if (sbi->s_mount_state & EXT4_ERROR_FS)
2125                 ext4_msg(sb, KERN_WARNING,
2126                          "warning: mounting fs with errors, "
2127                          "running e2fsck is recommended");
2128         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2129                  le16_to_cpu(es->s_mnt_count) >=
2130                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2131                 ext4_msg(sb, KERN_WARNING,
2132                          "warning: maximal mount count reached, "
2133                          "running e2fsck is recommended");
2134         else if (le32_to_cpu(es->s_checkinterval) &&
2135                 (le32_to_cpu(es->s_lastcheck) +
2136                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2137                 ext4_msg(sb, KERN_WARNING,
2138                          "warning: checktime reached, "
2139                          "running e2fsck is recommended");
2140         if (!sbi->s_journal)
2141                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2142         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2143                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2144         le16_add_cpu(&es->s_mnt_count, 1);
2145         es->s_mtime = cpu_to_le32(get_seconds());
2146         ext4_update_dynamic_rev(sb);
2147         if (sbi->s_journal)
2148                 ext4_set_feature_journal_needs_recovery(sb);
2149
2150         ext4_commit_super(sb, 1);
2151 done:
2152         if (test_opt(sb, DEBUG))
2153                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2154                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2155                         sb->s_blocksize,
2156                         sbi->s_groups_count,
2157                         EXT4_BLOCKS_PER_GROUP(sb),
2158                         EXT4_INODES_PER_GROUP(sb),
2159                         sbi->s_mount_opt, sbi->s_mount_opt2);
2160
2161         cleancache_init_fs(sb);
2162         return res;
2163 }
2164
2165 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2166 {
2167         struct ext4_sb_info *sbi = EXT4_SB(sb);
2168         struct flex_groups *new_groups;
2169         int size;
2170
2171         if (!sbi->s_log_groups_per_flex)
2172                 return 0;
2173
2174         size = ext4_flex_group(sbi, ngroup - 1) + 1;
2175         if (size <= sbi->s_flex_groups_allocated)
2176                 return 0;
2177
2178         size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2179         new_groups = kvzalloc(size, GFP_KERNEL);
2180         if (!new_groups) {
2181                 ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2182                          size / (int) sizeof(struct flex_groups));
2183                 return -ENOMEM;
2184         }
2185
2186         if (sbi->s_flex_groups) {
2187                 memcpy(new_groups, sbi->s_flex_groups,
2188                        (sbi->s_flex_groups_allocated *
2189                         sizeof(struct flex_groups)));
2190                 kvfree(sbi->s_flex_groups);
2191         }
2192         sbi->s_flex_groups = new_groups;
2193         sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2194         return 0;
2195 }
2196
2197 static int ext4_fill_flex_info(struct super_block *sb)
2198 {
2199         struct ext4_sb_info *sbi = EXT4_SB(sb);
2200         struct ext4_group_desc *gdp = NULL;
2201         ext4_group_t flex_group;
2202         int i, err;
2203
2204         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2205         if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2206                 sbi->s_log_groups_per_flex = 0;
2207                 return 1;
2208         }
2209
2210         err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2211         if (err)
2212                 goto failed;
2213
2214         for (i = 0; i < sbi->s_groups_count; i++) {
2215                 gdp = ext4_get_group_desc(sb, i, NULL);
2216
2217                 flex_group = ext4_flex_group(sbi, i);
2218                 atomic_add(ext4_free_inodes_count(sb, gdp),
2219                            &sbi->s_flex_groups[flex_group].free_inodes);
2220                 atomic64_add(ext4_free_group_clusters(sb, gdp),
2221                              &sbi->s_flex_groups[flex_group].free_clusters);
2222                 atomic_add(ext4_used_dirs_count(sb, gdp),
2223                            &sbi->s_flex_groups[flex_group].used_dirs);
2224         }
2225
2226         return 1;
2227 failed:
2228         return 0;
2229 }
2230
2231 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2232                                    struct ext4_group_desc *gdp)
2233 {
2234         int offset = offsetof(struct ext4_group_desc, bg_checksum);
2235         __u16 crc = 0;
2236         __le32 le_group = cpu_to_le32(block_group);
2237         struct ext4_sb_info *sbi = EXT4_SB(sb);
2238
2239         if (ext4_has_metadata_csum(sbi->s_sb)) {
2240                 /* Use new metadata_csum algorithm */
2241                 __u32 csum32;
2242                 __u16 dummy_csum = 0;
2243
2244                 csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2245                                      sizeof(le_group));
2246                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2247                 csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2248                                      sizeof(dummy_csum));
2249                 offset += sizeof(dummy_csum);
2250                 if (offset < sbi->s_desc_size)
2251                         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2252                                              sbi->s_desc_size - offset);
2253
2254                 crc = csum32 & 0xFFFF;
2255                 goto out;
2256         }
2257
2258         /* old crc16 code */
2259         if (!ext4_has_feature_gdt_csum(sb))
2260                 return 0;
2261
2262         crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2263         crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2264         crc = crc16(crc, (__u8 *)gdp, offset);
2265         offset += sizeof(gdp->bg_checksum); /* skip checksum */
2266         /* for checksum of struct ext4_group_desc do the rest...*/
2267         if (ext4_has_feature_64bit(sb) &&
2268             offset < le16_to_cpu(sbi->s_es->s_desc_size))
2269                 crc = crc16(crc, (__u8 *)gdp + offset,
2270                             le16_to_cpu(sbi->s_es->s_desc_size) -
2271                                 offset);
2272
2273 out:
2274         return cpu_to_le16(crc);
2275 }
2276
2277 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2278                                 struct ext4_group_desc *gdp)
2279 {
2280         if (ext4_has_group_desc_csum(sb) &&
2281             (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2282                 return 0;
2283
2284         return 1;
2285 }
2286
2287 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2288                               struct ext4_group_desc *gdp)
2289 {
2290         if (!ext4_has_group_desc_csum(sb))
2291                 return;
2292         gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2293 }
2294
2295 /* Called at mount-time, super-block is locked */
2296 static int ext4_check_descriptors(struct super_block *sb,
2297                                   ext4_fsblk_t sb_block,
2298                                   ext4_group_t *first_not_zeroed)
2299 {
2300         struct ext4_sb_info *sbi = EXT4_SB(sb);
2301         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2302         ext4_fsblk_t last_block;
2303         ext4_fsblk_t block_bitmap;
2304         ext4_fsblk_t inode_bitmap;
2305         ext4_fsblk_t inode_table;
2306         int flexbg_flag = 0;
2307         ext4_group_t i, grp = sbi->s_groups_count;
2308
2309         if (ext4_has_feature_flex_bg(sb))
2310                 flexbg_flag = 1;
2311
2312         ext4_debug("Checking group descriptors");
2313
2314         for (i = 0; i < sbi->s_groups_count; i++) {
2315                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2316
2317                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2318                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2319                 else
2320                         last_block = first_block +
2321                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2322
2323                 if ((grp == sbi->s_groups_count) &&
2324                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2325                         grp = i;
2326
2327                 block_bitmap = ext4_block_bitmap(sb, gdp);
2328                 if (block_bitmap == sb_block) {
2329                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2330                                  "Block bitmap for group %u overlaps "
2331                                  "superblock", i);
2332                 }
2333                 if (block_bitmap < first_block || block_bitmap > last_block) {
2334                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2335                                "Block bitmap for group %u not in group "
2336                                "(block %llu)!", i, block_bitmap);
2337                         return 0;
2338                 }
2339                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2340                 if (inode_bitmap == sb_block) {
2341                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2342                                  "Inode bitmap for group %u overlaps "
2343                                  "superblock", i);
2344                 }
2345                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2346                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2347                                "Inode bitmap for group %u not in group "
2348                                "(block %llu)!", i, inode_bitmap);
2349                         return 0;
2350                 }
2351                 inode_table = ext4_inode_table(sb, gdp);
2352                 if (inode_table == sb_block) {
2353                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2354                                  "Inode table for group %u overlaps "
2355                                  "superblock", i);
2356                 }
2357                 if (inode_table < first_block ||
2358                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2359                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2360                                "Inode table for group %u not in group "
2361                                "(block %llu)!", i, inode_table);
2362                         return 0;
2363                 }
2364                 ext4_lock_group(sb, i);
2365                 if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2366                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2367                                  "Checksum for group %u failed (%u!=%u)",
2368                                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2369                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2370                         if (!(sb->s_flags & MS_RDONLY)) {
2371                                 ext4_unlock_group(sb, i);
2372                                 return 0;
2373                         }
2374                 }
2375                 ext4_unlock_group(sb, i);
2376                 if (!flexbg_flag)
2377                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2378         }
2379         if (NULL != first_not_zeroed)
2380                 *first_not_zeroed = grp;
2381         return 1;
2382 }
2383
2384 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2385  * the superblock) which were deleted from all directories, but held open by
2386  * a process at the time of a crash.  We walk the list and try to delete these
2387  * inodes at recovery time (only with a read-write filesystem).
2388  *
2389  * In order to keep the orphan inode chain consistent during traversal (in
2390  * case of crash during recovery), we link each inode into the superblock
2391  * orphan list_head and handle it the same way as an inode deletion during
2392  * normal operation (which journals the operations for us).
2393  *
2394  * We only do an iget() and an iput() on each inode, which is very safe if we
2395  * accidentally point at an in-use or already deleted inode.  The worst that
2396  * can happen in this case is that we get a "bit already cleared" message from
2397  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2398  * e2fsck was run on this filesystem, and it must have already done the orphan
2399  * inode cleanup for us, so we can safely abort without any further action.
2400  */
2401 static void ext4_orphan_cleanup(struct super_block *sb,
2402                                 struct ext4_super_block *es)
2403 {
2404         unsigned int s_flags = sb->s_flags;
2405         int ret, nr_orphans = 0, nr_truncates = 0;
2406 #ifdef CONFIG_QUOTA
2407         int quota_update = 0;
2408         int i;
2409 #endif
2410         if (!es->s_last_orphan) {
2411                 jbd_debug(4, "no orphan inodes to clean up\n");
2412                 return;
2413         }
2414
2415         if (bdev_read_only(sb->s_bdev)) {
2416                 ext4_msg(sb, KERN_ERR, "write access "
2417                         "unavailable, skipping orphan cleanup");
2418                 return;
2419         }
2420
2421         /* Check if feature set would not allow a r/w mount */
2422         if (!ext4_feature_set_ok(sb, 0)) {
2423                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2424                          "unknown ROCOMPAT features");
2425                 return;
2426         }
2427
2428         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2429                 /* don't clear list on RO mount w/ errors */
2430                 if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2431                         ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2432                                   "clearing orphan list.\n");
2433                         es->s_last_orphan = 0;
2434                 }
2435                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2436                 return;
2437         }
2438
2439         if (s_flags & MS_RDONLY) {
2440                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2441                 sb->s_flags &= ~MS_RDONLY;
2442         }
2443 #ifdef CONFIG_QUOTA
2444         /* Needed for iput() to work correctly and not trash data */
2445         sb->s_flags |= MS_ACTIVE;
2446
2447         /*
2448          * Turn on quotas which were not enabled for read-only mounts if
2449          * filesystem has quota feature, so that they are updated correctly.
2450          */
2451         if (ext4_has_feature_quota(sb) && (s_flags & MS_RDONLY)) {
2452                 int ret = ext4_enable_quotas(sb);
2453
2454                 if (!ret)
2455                         quota_update = 1;
2456                 else
2457                         ext4_msg(sb, KERN_ERR,
2458                                 "Cannot turn on quotas: error %d", ret);
2459         }
2460
2461         /* Turn on journaled quotas used for old sytle */
2462         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2463                 if (EXT4_SB(sb)->s_qf_names[i]) {
2464                         int ret = ext4_quota_on_mount(sb, i);
2465
2466                         if (!ret)
2467                                 quota_update = 1;
2468                         else
2469                                 ext4_msg(sb, KERN_ERR,
2470                                         "Cannot turn on journaled "
2471                                         "quota: type %d: error %d", i, ret);
2472                 }
2473         }
2474 #endif
2475
2476         while (es->s_last_orphan) {
2477                 struct inode *inode;
2478
2479                 /*
2480                  * We may have encountered an error during cleanup; if
2481                  * so, skip the rest.
2482                  */
2483                 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2484                         jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2485                         es->s_last_orphan = 0;
2486                         break;
2487                 }
2488
2489                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2490                 if (IS_ERR(inode)) {
2491                         es->s_last_orphan = 0;
2492                         break;
2493                 }
2494
2495                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2496                 dquot_initialize(inode);
2497                 if (inode->i_nlink) {
2498                         if (test_opt(sb, DEBUG))
2499                                 ext4_msg(sb, KERN_DEBUG,
2500                                         "%s: truncating inode %lu to %lld bytes",
2501                                         __func__, inode->i_ino, inode->i_size);
2502                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2503                                   inode->i_ino, inode->i_size);
2504                         inode_lock(inode);
2505                         truncate_inode_pages(inode->i_mapping, inode->i_size);
2506                         ret = ext4_truncate(inode);
2507                         if (ret)
2508                                 ext4_std_error(inode->i_sb, ret);
2509                         inode_unlock(inode);
2510                         nr_truncates++;
2511                 } else {
2512                         if (test_opt(sb, DEBUG))
2513                                 ext4_msg(sb, KERN_DEBUG,
2514                                         "%s: deleting unreferenced inode %lu",
2515                                         __func__, inode->i_ino);
2516                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2517                                   inode->i_ino);
2518                         nr_orphans++;
2519                 }
2520                 iput(inode);  /* The delete magic happens here! */
2521         }
2522
2523 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2524
2525         if (nr_orphans)
2526                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2527                        PLURAL(nr_orphans));
2528         if (nr_truncates)
2529                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2530                        PLURAL(nr_truncates));
2531 #ifdef CONFIG_QUOTA
2532         /* Turn off quotas if they were enabled for orphan cleanup */
2533         if (quota_update) {
2534                 for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2535                         if (sb_dqopt(sb)->files[i])
2536                                 dquot_quota_off(sb, i);
2537                 }
2538         }
2539 #endif
2540         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2541 }
2542
2543 /*
2544  * Maximal extent format file size.
2545  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2546  * extent format containers, within a sector_t, and within i_blocks
2547  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2548  * so that won't be a limiting factor.
2549  *
2550  * However there is other limiting factor. We do store extents in the form
2551  * of starting block and length, hence the resulting length of the extent
2552  * covering maximum file size must fit into on-disk format containers as
2553  * well. Given that length is always by 1 unit bigger than max unit (because
2554  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2555  *
2556  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2557  */
2558 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2559 {
2560         loff_t res;
2561         loff_t upper_limit = MAX_LFS_FILESIZE;
2562
2563         /* small i_blocks in vfs inode? */
2564         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2565                 /*
2566                  * CONFIG_LBDAF is not enabled implies the inode
2567                  * i_block represent total blocks in 512 bytes
2568                  * 32 == size of vfs inode i_blocks * 8
2569                  */
2570                 upper_limit = (1LL << 32) - 1;
2571
2572                 /* total blocks in file system block size */
2573                 upper_limit >>= (blkbits - 9);
2574                 upper_limit <<= blkbits;
2575         }
2576
2577         /*
2578          * 32-bit extent-start container, ee_block. We lower the maxbytes
2579          * by one fs block, so ee_len can cover the extent of maximum file
2580          * size
2581          */
2582         res = (1LL << 32) - 1;
2583         res <<= blkbits;
2584
2585         /* Sanity check against vm- & vfs- imposed limits */
2586         if (res > upper_limit)
2587                 res = upper_limit;
2588
2589         return res;
2590 }
2591
2592 /*
2593  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2594  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2595  * We need to be 1 filesystem block less than the 2^48 sector limit.
2596  */
2597 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2598 {
2599         loff_t res = EXT4_NDIR_BLOCKS;
2600         int meta_blocks;
2601         loff_t upper_limit;
2602         /* This is calculated to be the largest file size for a dense, block
2603          * mapped file such that the file's total number of 512-byte sectors,
2604          * including data and all indirect blocks, does not exceed (2^48 - 1).
2605          *
2606          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2607          * number of 512-byte sectors of the file.
2608          */
2609
2610         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2611                 /*
2612                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2613                  * the inode i_block field represents total file blocks in
2614                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2615                  */
2616                 upper_limit = (1LL << 32) - 1;
2617
2618                 /* total blocks in file system block size */
2619                 upper_limit >>= (bits - 9);
2620
2621         } else {
2622                 /*
2623                  * We use 48 bit ext4_inode i_blocks
2624                  * With EXT4_HUGE_FILE_FL set the i_blocks
2625                  * represent total number of blocks in
2626                  * file system block size
2627                  */
2628                 upper_limit = (1LL << 48) - 1;
2629
2630         }
2631
2632         /* indirect blocks */
2633         meta_blocks = 1;
2634         /* double indirect blocks */
2635         meta_blocks += 1 + (1LL << (bits-2));
2636         /* tripple indirect blocks */
2637         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2638
2639         upper_limit -= meta_blocks;
2640         upper_limit <<= bits;
2641
2642         res += 1LL << (bits-2);
2643         res += 1LL << (2*(bits-2));
2644         res += 1LL << (3*(bits-2));
2645         res <<= bits;
2646         if (res > upper_limit)
2647                 res = upper_limit;
2648
2649         if (res > MAX_LFS_FILESIZE)
2650                 res = MAX_LFS_FILESIZE;
2651
2652         return res;
2653 }
2654
2655 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2656                                    ext4_fsblk_t logical_sb_block, int nr)
2657 {
2658         struct ext4_sb_info *sbi = EXT4_SB(sb);
2659         ext4_group_t bg, first_meta_bg;
2660         int has_super = 0;
2661
2662         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2663
2664         if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2665                 return logical_sb_block + nr + 1;
2666         bg = sbi->s_desc_per_block * nr;
2667         if (ext4_bg_has_super(sb, bg))
2668                 has_super = 1;
2669
2670         /*
2671          * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2672          * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2673          * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2674          * compensate.
2675          */
2676         if (sb->s_blocksize == 1024 && nr == 0 &&
2677             le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2678                 has_super++;
2679
2680         return (has_super + ext4_group_first_block_no(sb, bg));
2681 }
2682
2683 /**
2684  * ext4_get_stripe_size: Get the stripe size.
2685  * @sbi: In memory super block info
2686  *
2687  * If we have specified it via mount option, then
2688  * use the mount option value. If the value specified at mount time is
2689  * greater than the blocks per group use the super block value.
2690  * If the super block value is greater than blocks per group return 0.
2691  * Allocator needs it be less than blocks per group.
2692  *
2693  */
2694 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2695 {
2696         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2697         unsigned long stripe_width =
2698                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2699         int ret;
2700
2701         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2702                 ret = sbi->s_stripe;
2703         else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2704                 ret = stripe_width;
2705         else if (stride && stride <= sbi->s_blocks_per_group)
2706                 ret = stride;
2707         else
2708                 ret = 0;
2709
2710         /*
2711          * If the stripe width is 1, this makes no sense and
2712          * we set it to 0 to turn off stripe handling code.
2713          */
2714         if (ret <= 1)
2715                 ret = 0;
2716
2717         return ret;
2718 }
2719
2720 /*
2721  * Check whether this filesystem can be mounted based on
2722  * the features present and the RDONLY/RDWR mount requested.
2723  * Returns 1 if this filesystem can be mounted as requested,
2724  * 0 if it cannot be.
2725  */
2726 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2727 {
2728         if (ext4_has_unknown_ext4_incompat_features(sb)) {
2729                 ext4_msg(sb, KERN_ERR,
2730                         "Couldn't mount because of "
2731                         "unsupported optional features (%x)",
2732                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2733                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2734                 return 0;
2735         }
2736
2737         if (readonly)
2738                 return 1;
2739
2740         if (ext4_has_feature_readonly(sb)) {
2741                 ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2742                 sb->s_flags |= MS_RDONLY;
2743                 return 1;
2744         }
2745
2746         /* Check that feature set is OK for a read-write mount */
2747         if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2748                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2749                          "unsupported optional features (%x)",
2750                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2751                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2752                 return 0;
2753         }
2754         /*
2755          * Large file size enabled file system can only be mounted
2756          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2757          */
2758         if (ext4_has_feature_huge_file(sb)) {
2759                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2760                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2761                                  "cannot be mounted RDWR without "
2762                                  "CONFIG_LBDAF");
2763                         return 0;
2764                 }
2765         }
2766         if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2767                 ext4_msg(sb, KERN_ERR,
2768                          "Can't support bigalloc feature without "
2769                          "extents feature\n");
2770                 return 0;
2771         }
2772
2773 #ifndef CONFIG_QUOTA
2774         if (ext4_has_feature_quota(sb) && !readonly) {
2775                 ext4_msg(sb, KERN_ERR,
2776                          "Filesystem with quota feature cannot be mounted RDWR "
2777                          "without CONFIG_QUOTA");
2778                 return 0;
2779         }
2780         if (ext4_has_feature_project(sb) && !readonly) {
2781                 ext4_msg(sb, KERN_ERR,
2782                          "Filesystem with project quota feature cannot be mounted RDWR "
2783                          "without CONFIG_QUOTA");
2784                 return 0;
2785         }
2786 #endif  /* CONFIG_QUOTA */
2787         return 1;
2788 }
2789
2790 /*
2791  * This function is called once a day if we have errors logged
2792  * on the file system
2793  */
2794 static void print_daily_error_info(unsigned long arg)
2795 {
2796         struct super_block *sb = (struct super_block *) arg;
2797         struct ext4_sb_info *sbi;
2798         struct ext4_super_block *es;
2799
2800         sbi = EXT4_SB(sb);
2801         es = sbi->s_es;
2802
2803         if (es->s_error_count)
2804                 /* fsck newer than v1.41.13 is needed to clean this condition. */
2805                 ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2806                          le32_to_cpu(es->s_error_count));
2807         if (es->s_first_error_time) {
2808                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2809                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2810                        (int) sizeof(es->s_first_error_func),
2811                        es->s_first_error_func,
2812                        le32_to_cpu(es->s_first_error_line));
2813                 if (es->s_first_error_ino)
2814                         printk(KERN_CONT ": inode %u",
2815                                le32_to_cpu(es->s_first_error_ino));
2816                 if (es->s_first_error_block)
2817                         printk(KERN_CONT ": block %llu", (unsigned long long)
2818                                le64_to_cpu(es->s_first_error_block));
2819                 printk(KERN_CONT "\n");
2820         }
2821         if (es->s_last_error_time) {
2822                 printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2823                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2824                        (int) sizeof(es->s_last_error_func),
2825                        es->s_last_error_func,
2826                        le32_to_cpu(es->s_last_error_line));
2827                 if (es->s_last_error_ino)
2828                         printk(KERN_CONT ": inode %u",
2829                                le32_to_cpu(es->s_last_error_ino));
2830                 if (es->s_last_error_block)
2831                         printk(KERN_CONT ": block %llu", (unsigned long long)
2832                                le64_to_cpu(es->s_last_error_block));
2833                 printk(KERN_CONT "\n");
2834         }
2835         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2836 }
2837
2838 /* Find next suitable group and run ext4_init_inode_table */
2839 static int ext4_run_li_request(struct ext4_li_request *elr)
2840 {
2841         struct ext4_group_desc *gdp = NULL;
2842         ext4_group_t group, ngroups;
2843         struct super_block *sb;
2844         unsigned long timeout = 0;
2845         int ret = 0;
2846
2847         sb = elr->lr_super;
2848         ngroups = EXT4_SB(sb)->s_groups_count;
2849
2850         for (group = elr->lr_next_group; group < ngroups; group++) {
2851                 gdp = ext4_get_group_desc(sb, group, NULL);
2852                 if (!gdp) {
2853                         ret = 1;
2854                         break;
2855                 }
2856
2857                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2858                         break;
2859         }
2860
2861         if (group >= ngroups)
2862                 ret = 1;
2863
2864         if (!ret) {
2865                 timeout = jiffies;
2866                 ret = ext4_init_inode_table(sb, group,
2867                                             elr->lr_timeout ? 0 : 1);
2868                 if (elr->lr_timeout == 0) {
2869                         timeout = (jiffies - timeout) *
2870                                   elr->lr_sbi->s_li_wait_mult;
2871                         elr->lr_timeout = timeout;
2872                 }
2873                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2874                 elr->lr_next_group = group + 1;
2875         }
2876         return ret;
2877 }
2878
2879 /*
2880  * Remove lr_request from the list_request and free the
2881  * request structure. Should be called with li_list_mtx held
2882  */
2883 static void ext4_remove_li_request(struct ext4_li_request *elr)
2884 {
2885         struct ext4_sb_info *sbi;
2886
2887         if (!elr)
2888                 return;
2889
2890         sbi = elr->lr_sbi;
2891
2892         list_del(&elr->lr_request);
2893         sbi->s_li_request = NULL;
2894         kfree(elr);
2895 }
2896
2897 static void ext4_unregister_li_request(struct super_block *sb)
2898 {
2899         mutex_lock(&ext4_li_mtx);
2900         if (!ext4_li_info) {
2901                 mutex_unlock(&ext4_li_mtx);
2902                 return;
2903         }
2904
2905         mutex_lock(&ext4_li_info->li_list_mtx);
2906         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2907         mutex_unlock(&ext4_li_info->li_list_mtx);
2908         mutex_unlock(&ext4_li_mtx);
2909 }
2910
2911 static struct task_struct *ext4_lazyinit_task;
2912
2913 /*
2914  * This is the function where ext4lazyinit thread lives. It walks
2915  * through the request list searching for next scheduled filesystem.
2916  * When such a fs is found, run the lazy initialization request
2917  * (ext4_rn_li_request) and keep track of the time spend in this
2918  * function. Based on that time we compute next schedule time of
2919  * the request. When walking through the list is complete, compute
2920  * next waking time and put itself into sleep.
2921  */
2922 static int ext4_lazyinit_thread(void *arg)
2923 {
2924         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2925         struct list_head *pos, *n;
2926         struct ext4_li_request *elr;
2927         unsigned long next_wakeup, cur;
2928
2929         BUG_ON(NULL == eli);
2930
2931 cont_thread:
2932         while (true) {
2933                 next_wakeup = MAX_JIFFY_OFFSET;
2934
2935                 mutex_lock(&eli->li_list_mtx);
2936                 if (list_empty(&eli->li_request_list)) {
2937                         mutex_unlock(&eli->li_list_mtx);
2938                         goto exit_thread;
2939                 }
2940                 list_for_each_safe(pos, n, &eli->li_request_list) {
2941                         int err = 0;
2942                         int progress = 0;
2943                         elr = list_entry(pos, struct ext4_li_request,
2944                                          lr_request);
2945
2946                         if (time_before(jiffies, elr->lr_next_sched)) {
2947                                 if (time_before(elr->lr_next_sched, next_wakeup))
2948                                         next_wakeup = elr->lr_next_sched;
2949                                 continue;
2950                         }
2951                         if (down_read_trylock(&elr->lr_super->s_umount)) {
2952                                 if (sb_start_write_trylock(elr->lr_super)) {
2953                                         progress = 1;
2954                                         /*
2955                                          * We hold sb->s_umount, sb can not
2956                                          * be removed from the list, it is
2957                                          * now safe to drop li_list_mtx
2958                                          */
2959                                         mutex_unlock(&eli->li_list_mtx);
2960                                         err = ext4_run_li_request(elr);
2961                                         sb_end_write(elr->lr_super);
2962                                         mutex_lock(&eli->li_list_mtx);
2963                                         n = pos->next;
2964                                 }
2965                                 up_read((&elr->lr_super->s_umount));
2966                         }
2967                         /* error, remove the lazy_init job */
2968                         if (err) {
2969                                 ext4_remove_li_request(elr);
2970                                 continue;
2971                         }
2972                         if (!progress) {
2973                                 elr->lr_next_sched = jiffies +
2974                                         (prandom_u32()
2975                                          % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2976                         }
2977                         if (time_before(elr->lr_next_sched, next_wakeup))
2978                                 next_wakeup = elr->lr_next_sched;
2979                 }
2980                 mutex_unlock(&eli->li_list_mtx);
2981
2982                 try_to_freeze();
2983
2984                 cur = jiffies;
2985                 if ((time_after_eq(cur, next_wakeup)) ||
2986                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2987                         cond_resched();
2988                         continue;
2989                 }
2990
2991                 schedule_timeout_interruptible(next_wakeup - cur);
2992
2993                 if (kthread_should_stop()) {
2994                         ext4_clear_request_list();
2995                         goto exit_thread;
2996                 }
2997         }
2998
2999 exit_thread:
3000         /*
3001          * It looks like the request list is empty, but we need
3002          * to check it under the li_list_mtx lock, to prevent any
3003          * additions into it, and of course we should lock ext4_li_mtx
3004          * to atomically free the list and ext4_li_info, because at
3005          * this point another ext4 filesystem could be registering
3006          * new one.
3007          */
3008         mutex_lock(&ext4_li_mtx);
3009         mutex_lock(&eli->li_list_mtx);
3010         if (!list_empty(&eli->li_request_list)) {
3011                 mutex_unlock(&eli->li_list_mtx);
3012                 mutex_unlock(&ext4_li_mtx);
3013                 goto cont_thread;
3014         }
3015         mutex_unlock(&eli->li_list_mtx);
3016         kfree(ext4_li_info);
3017         ext4_li_info = NULL;
3018         mutex_unlock(&ext4_li_mtx);
3019
3020         return 0;
3021 }
3022
3023 static void ext4_clear_request_list(void)
3024 {
3025         struct list_head *pos, *n;
3026         struct ext4_li_request *elr;
3027
3028         mutex_lock(&ext4_li_info->li_list_mtx);
3029         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3030                 elr = list_entry(pos, struct ext4_li_request,
3031                                  lr_request);
3032                 ext4_remove_li_request(elr);
3033         }
3034         mutex_unlock(&ext4_li_info->li_list_mtx);
3035 }
3036
3037 static int ext4_run_lazyinit_thread(void)
3038 {
3039         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3040                                          ext4_li_info, "ext4lazyinit");
3041         if (IS_ERR(ext4_lazyinit_task)) {
3042                 int err = PTR_ERR(ext4_lazyinit_task);
3043                 ext4_clear_request_list();
3044                 kfree(ext4_li_info);
3045                 ext4_li_info = NULL;
3046                 printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3047                                  "initialization thread\n",
3048                                  err);
3049                 return err;
3050         }
3051         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3052         return 0;
3053 }
3054
3055 /*
3056  * Check whether it make sense to run itable init. thread or not.
3057  * If there is at least one uninitialized inode table, return
3058  * corresponding group number, else the loop goes through all
3059  * groups and return total number of groups.
3060  */
3061 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3062 {
3063         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3064         struct ext4_group_desc *gdp = NULL;
3065
3066         for (group = 0; group < ngroups; group++) {
3067                 gdp = ext4_get_group_desc(sb, group, NULL);
3068                 if (!gdp)
3069                         continue;
3070
3071                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3072                         break;
3073         }
3074
3075         return group;
3076 }
3077
3078 static int ext4_li_info_new(void)
3079 {
3080         struct ext4_lazy_init *eli = NULL;
3081
3082         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3083         if (!eli)
3084                 return -ENOMEM;
3085
3086         INIT_LIST_HEAD(&eli->li_request_list);
3087         mutex_init(&eli->li_list_mtx);
3088
3089         eli->li_state |= EXT4_LAZYINIT_QUIT;
3090
3091         ext4_li_info = eli;
3092
3093         return 0;
3094 }
3095
3096 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3097                                             ext4_group_t start)
3098 {
3099         struct ext4_sb_info *sbi = EXT4_SB(sb);
3100         struct ext4_li_request *elr;
3101
3102         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3103         if (!elr)
3104                 return NULL;
3105
3106         elr->lr_super = sb;
3107         elr->lr_sbi = sbi;
3108         elr->lr_next_group = start;
3109
3110         /*
3111          * Randomize first schedule time of the request to
3112          * spread the inode table initialization requests
3113          * better.
3114          */
3115         elr->lr_next_sched = jiffies + (prandom_u32() %
3116                                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3117         return elr;
3118 }
3119
3120 int ext4_register_li_request(struct super_block *sb,
3121                              ext4_group_t first_not_zeroed)
3122 {
3123         struct ext4_sb_info *sbi = EXT4_SB(sb);
3124         struct ext4_li_request *elr = NULL;
3125         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3126         int ret = 0;
3127
3128         mutex_lock(&ext4_li_mtx);
3129         if (sbi->s_li_request != NULL) {
3130                 /*
3131                  * Reset timeout so it can be computed again, because
3132                  * s_li_wait_mult might have changed.
3133                  */
3134                 sbi->s_li_request->lr_timeout = 0;
3135                 goto out;
3136         }
3137
3138         if (first_not_zeroed == ngroups ||
3139             (sb->s_flags & MS_RDONLY) ||
3140             !test_opt(sb, INIT_INODE_TABLE))
3141                 goto out;
3142
3143         elr = ext4_li_request_new(sb, first_not_zeroed);
3144         if (!elr) {
3145                 ret = -ENOMEM;
3146                 goto out;
3147         }
3148
3149         if (NULL == ext4_li_info) {
3150                 ret = ext4_li_info_new();
3151                 if (ret)
3152                         goto out;
3153         }
3154
3155         mutex_lock(&ext4_li_info->li_list_mtx);
3156         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3157         mutex_unlock(&ext4_li_info->li_list_mtx);
3158
3159         sbi->s_li_request = elr;
3160         /*
3161          * set elr to NULL here since it has been inserted to
3162          * the request_list and the removal and free of it is
3163          * handled by ext4_clear_request_list from now on.
3164          */
3165         elr = NULL;
3166
3167         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3168                 ret = ext4_run_lazyinit_thread();
3169                 if (ret)
3170                         goto out;
3171         }
3172 out:
3173         mutex_unlock(&ext4_li_mtx);
3174         if (ret)
3175                 kfree(elr);
3176         return ret;
3177 }
3178
3179 /*
3180  * We do not need to lock anything since this is called on
3181  * module unload.
3182  */
3183 static void ext4_destroy_lazyinit_thread(void)
3184 {
3185         /*
3186          * If thread exited earlier
3187          * there's nothing to be done.
3188          */
3189         if (!ext4_li_info || !ext4_lazyinit_task)
3190                 return;
3191
3192         kthread_stop(ext4_lazyinit_task);
3193 }
3194
3195 static int set_journal_csum_feature_set(struct super_block *sb)
3196 {
3197         int ret = 1;
3198         int compat, incompat;
3199         struct ext4_sb_info *sbi = EXT4_SB(sb);
3200
3201         if (ext4_has_metadata_csum(sb)) {
3202                 /* journal checksum v3 */
3203                 compat = 0;
3204                 incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3205         } else {
3206                 /* journal checksum v1 */
3207                 compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3208                 incompat = 0;
3209         }
3210
3211         jbd2_journal_clear_features(sbi->s_journal,
3212                         JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3213                         JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3214                         JBD2_FEATURE_INCOMPAT_CSUM_V2);
3215         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3216                 ret = jbd2_journal_set_features(sbi->s_journal,
3217                                 compat, 0,
3218                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3219                                 incompat);
3220         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3221                 ret = jbd2_journal_set_features(sbi->s_journal,
3222                                 compat, 0,
3223                                 incompat);
3224                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3225                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3226         } else {
3227                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3228                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3229         }
3230
3231         return ret;
3232 }
3233
3234 /*
3235  * Note: calculating the overhead so we can be compatible with
3236  * historical BSD practice is quite difficult in the face of
3237  * clusters/bigalloc.  This is because multiple metadata blocks from
3238  * different block group can end up in the same allocation cluster.
3239  * Calculating the exact overhead in the face of clustered allocation
3240  * requires either O(all block bitmaps) in memory or O(number of block
3241  * groups**2) in time.  We will still calculate the superblock for
3242  * older file systems --- and if we come across with a bigalloc file
3243  * system with zero in s_overhead_clusters the estimate will be close to
3244  * correct especially for very large cluster sizes --- but for newer
3245  * file systems, it's better to calculate this figure once at mkfs
3246  * time, and store it in the superblock.  If the superblock value is
3247  * present (even for non-bigalloc file systems), we will use it.
3248  */
3249 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3250                           char *buf)
3251 {
3252         struct ext4_sb_info     *sbi = EXT4_SB(sb);
3253         struct ext4_group_desc  *gdp;
3254         ext4_fsblk_t            first_block, last_block, b;
3255         ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
3256         int                     s, j, count = 0;
3257
3258         if (!ext4_has_feature_bigalloc(sb))
3259                 return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3260                         sbi->s_itb_per_group + 2);
3261
3262         first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3263                 (grp * EXT4_BLOCKS_PER_GROUP(sb));
3264         last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3265         for (i = 0; i < ngroups; i++) {
3266                 gdp = ext4_get_group_desc(sb, i, NULL);
3267                 b = ext4_block_bitmap(sb, gdp);
3268                 if (b >= first_block && b <= last_block) {
3269                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3270                         count++;
3271                 }
3272                 b = ext4_inode_bitmap(sb, gdp);
3273                 if (b >= first_block && b <= last_block) {
3274                         ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3275                         count++;
3276                 }
3277                 b = ext4_inode_table(sb, gdp);
3278                 if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3279                         for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3280                                 int c = EXT4_B2C(sbi, b - first_block);
3281                                 ext4_set_bit(c, buf);
3282                                 count++;
3283                         }
3284                 if (i != grp)
3285                         continue;
3286                 s = 0;
3287                 if (ext4_bg_has_super(sb, grp)) {
3288                         ext4_set_bit(s++, buf);
3289                         count++;
3290                 }
3291                 j = ext4_bg_num_gdb(sb, grp);
3292                 if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3293                         ext4_error(sb, "Invalid number of block group "
3294                                    "descriptor blocks: %d", j);
3295                         j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3296                 }
3297                 count += j;
3298                 for (; j > 0; j--)
3299                         ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3300         }
3301         if (!count)
3302                 return 0;
3303         return EXT4_CLUSTERS_PER_GROUP(sb) -
3304                 ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3305 }
3306
3307 /*
3308  * Compute the overhead and stash it in sbi->s_overhead
3309  */
3310 int ext4_calculate_overhead(struct super_block *sb)
3311 {
3312         struct ext4_sb_info *sbi = EXT4_SB(sb);
3313         struct ext4_super_block *es = sbi->s_es;
3314         struct inode *j_inode;
3315         unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3316         ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3317         ext4_fsblk_t overhead = 0;
3318         char *buf = (char *) get_zeroed_page(GFP_NOFS);
3319
3320         if (!buf)
3321                 return -ENOMEM;
3322
3323         /*
3324          * Compute the overhead (FS structures).  This is constant
3325          * for a given filesystem unless the number of block groups
3326          * changes so we cache the previous value until it does.
3327          */
3328
3329         /*
3330          * All of the blocks before first_data_block are overhead
3331          */
3332         overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3333
3334         /*
3335          * Add the overhead found in each block group
3336          */
3337         for (i = 0; i < ngroups; i++) {
3338                 int blks;
3339
3340                 blks = count_overhead(sb, i, buf);
3341                 overhead += blks;
3342                 if (blks)
3343                         memset(buf, 0, PAGE_SIZE);
3344                 cond_resched();
3345         }
3346
3347         /*
3348          * Add the internal journal blocks whether the journal has been
3349          * loaded or not
3350          */
3351         if (sbi->s_journal && !sbi->journal_bdev)
3352                 overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3353         else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3354                 j_inode = ext4_get_journal_inode(sb, j_inum);
3355                 if (j_inode) {
3356                         j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3357                         overhead += EXT4_NUM_B2C(sbi, j_blocks);
3358                         iput(j_inode);
3359                 } else {
3360                         ext4_msg(sb, KERN_ERR, "can't get journal size");
3361                 }
3362         }
3363         sbi->s_overhead = overhead;
3364         smp_wmb();
3365         free_page((unsigned long) buf);
3366         return 0;
3367 }
3368
3369 static void ext4_set_resv_clusters(struct super_block *sb)
3370 {
3371         ext4_fsblk_t resv_clusters;
3372         struct ext4_sb_info *sbi = EXT4_SB(sb);
3373
3374         /*
3375          * There's no need to reserve anything when we aren't using extents.
3376          * The space estimates are exact, there are no unwritten extents,
3377          * hole punching doesn't need new metadata... This is needed especially
3378          * to keep ext2/3 backward compatibility.
3379          */
3380         if (!ext4_has_feature_extents(sb))
3381                 return;
3382         /*
3383          * By default we reserve 2% or 4096 clusters, whichever is smaller.
3384          * This should cover the situations where we can not afford to run
3385          * out of space like for example punch hole, or converting
3386          * unwritten extents in delalloc path. In most cases such
3387          * allocation would require 1, or 2 blocks, higher numbers are
3388          * very rare.
3389          */
3390         resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3391                          sbi->s_cluster_bits);
3392
3393         do_div(resv_clusters, 50);
3394         resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3395
3396         atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3397 }
3398
3399 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3400 {
3401         char *orig_data = kstrdup(data, GFP_KERNEL);
3402         struct buffer_head *bh;
3403         struct ext4_super_block *es = NULL;
3404         struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3405         ext4_fsblk_t block;
3406         ext4_fsblk_t sb_block = get_sb_block(&data);
3407         ext4_fsblk_t logical_sb_block;
3408         unsigned long offset = 0;
3409         unsigned long journal_devnum = 0;
3410         unsigned long def_mount_opts;
3411         struct inode *root;
3412         const char *descr;
3413         int ret = -ENOMEM;
3414         int blocksize, clustersize;
3415         unsigned int db_count;
3416         unsigned int i;
3417         int needs_recovery, has_huge_files, has_bigalloc;
3418         __u64 blocks_count;
3419         int err = 0;
3420         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3421         ext4_group_t first_not_zeroed;
3422
3423         if ((data && !orig_data) || !sbi)
3424                 goto out_free_base;
3425
3426         sbi->s_blockgroup_lock =
3427                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3428         if (!sbi->s_blockgroup_lock)
3429                 goto out_free_base;
3430
3431         sb->s_fs_info = sbi;
3432         sbi->s_sb = sb;
3433         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3434         sbi->s_sb_block = sb_block;
3435         if (sb->s_bdev->bd_part)
3436                 sbi->s_sectors_written_start =
3437                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3438
3439         /* Cleanup superblock name */
3440         strreplace(sb->s_id, '/', '!');
3441
3442         /* -EINVAL is default */
3443         ret = -EINVAL;
3444         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3445         if (!blocksize) {
3446                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3447                 goto out_fail;
3448         }
3449
3450         /*
3451          * The ext4 superblock will not be buffer aligned for other than 1kB
3452          * block sizes.  We need to calculate the offset from buffer start.
3453          */
3454         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3455                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3456                 offset = do_div(logical_sb_block, blocksize);
3457         } else {
3458                 logical_sb_block = sb_block;
3459         }
3460
3461         if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3462                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3463                 goto out_fail;
3464         }
3465         /*
3466          * Note: s_es must be initialized as soon as possible because
3467          *       some ext4 macro-instructions depend on its value
3468          */
3469         es = (struct ext4_super_block *) (bh->b_data + offset);
3470         sbi->s_es = es;
3471         sb->s_magic = le16_to_cpu(es->s_magic);
3472         if (sb->s_magic != EXT4_SUPER_MAGIC)
3473                 goto cantfind_ext4;
3474         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3475
3476         /* Warn if metadata_csum and gdt_csum are both set. */
3477         if (ext4_has_feature_metadata_csum(sb) &&
3478             ext4_has_feature_gdt_csum(sb))
3479                 ext4_warning(sb, "metadata_csum and uninit_bg are "
3480                              "redundant flags; please run fsck.");
3481
3482         /* Check for a known checksum algorithm */
3483         if (!ext4_verify_csum_type(sb, es)) {
3484                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3485                          "unknown checksum algorithm.");
3486                 silent = 1;
3487                 goto cantfind_ext4;
3488         }
3489
3490         /* Load the checksum driver */
3491         if (ext4_has_feature_metadata_csum(sb) ||
3492             ext4_has_feature_ea_inode(sb)) {
3493                 sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3494                 if (IS_ERR(sbi->s_chksum_driver)) {
3495                         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3496                         ret = PTR_ERR(sbi->s_chksum_driver);
3497                         sbi->s_chksum_driver = NULL;
3498                         goto failed_mount;
3499                 }
3500         }
3501
3502         /* Check superblock checksum */
3503         if (!ext4_superblock_csum_verify(sb, es)) {
3504                 ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3505                          "invalid superblock checksum.  Run e2fsck?");
3506                 silent = 1;
3507                 ret = -EFSBADCRC;
3508                 goto cantfind_ext4;
3509         }
3510
3511         /* Precompute checksum seed for all metadata */
3512         if (ext4_has_feature_csum_seed(sb))
3513                 sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3514         else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3515                 sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3516                                                sizeof(es->s_uuid));
3517
3518         /* Set defaults before we parse the mount options */
3519         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3520         set_opt(sb, INIT_INODE_TABLE);
3521         if (def_mount_opts & EXT4_DEFM_DEBUG)
3522                 set_opt(sb, DEBUG);
3523         if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3524                 set_opt(sb, GRPID);
3525         if (def_mount_opts & EXT4_DEFM_UID16)
3526                 set_opt(sb, NO_UID32);
3527         /* xattr user namespace & acls are now defaulted on */
3528         set_opt(sb, XATTR_USER);
3529 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3530         set_opt(sb, POSIX_ACL);
3531 #endif
3532         /* don't forget to enable journal_csum when metadata_csum is enabled. */
3533         if (ext4_has_metadata_csum(sb))
3534                 set_opt(sb, JOURNAL_CHECKSUM);
3535
3536         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3537                 set_opt(sb, JOURNAL_DATA);
3538         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3539                 set_opt(sb, ORDERED_DATA);
3540         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3541                 set_opt(sb, WRITEBACK_DATA);
3542
3543         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3544                 set_opt(sb, ERRORS_PANIC);
3545         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3546                 set_opt(sb, ERRORS_CONT);
3547         else
3548                 set_opt(sb, ERRORS_RO);
3549         /* block_validity enabled by default; disable with noblock_validity */
3550         set_opt(sb, BLOCK_VALIDITY);
3551         if (def_mount_opts & EXT4_DEFM_DISCARD)
3552                 set_opt(sb, DISCARD);
3553
3554         sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3555         sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3556         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3557         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3558         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3559
3560         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3561                 set_opt(sb, BARRIER);
3562
3563         /*
3564          * enable delayed allocation by default
3565          * Use -o nodelalloc to turn it off
3566          */
3567         if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3568             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3569                 set_opt(sb, DELALLOC);
3570
3571         /*
3572          * set default s_li_wait_mult for lazyinit, for the case there is
3573          * no mount option specified.
3574          */
3575         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3576
3577         if (sbi->s_es->s_mount_opts[0]) {
3578                 char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3579                                               sizeof(sbi->s_es->s_mount_opts),
3580                                               GFP_KERNEL);
3581                 if (!s_mount_opts)
3582                         goto failed_mount;
3583                 if (!parse_options(s_mount_opts, sb, &journal_devnum,
3584                                    &journal_ioprio, 0)) {
3585                         ext4_msg(sb, KERN_WARNING,
3586                                  "failed to parse options in superblock: %s",
3587                                  s_mount_opts);
3588                 }
3589                 kfree(s_mount_opts);
3590         }
3591         sbi->s_def_mount_opt = sbi->s_mount_opt;
3592         if (!parse_options((char *) data, sb, &journal_devnum,
3593                            &journal_ioprio, 0))
3594                 goto failed_mount;
3595
3596         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3597                 printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3598                             "with data=journal disables delayed "
3599                             "allocation and O_DIRECT support!\n");
3600                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3601                         ext4_msg(sb, KERN_ERR, "can't mount with "
3602                                  "both data=journal and delalloc");
3603                         goto failed_mount;
3604                 }
3605                 if (test_opt(sb, DIOREAD_NOLOCK)) {
3606                         ext4_msg(sb, KERN_ERR, "can't mount with "
3607                                  "both data=journal and dioread_nolock");
3608                         goto failed_mount;
3609                 }
3610                 if (test_opt(sb, DAX)) {
3611                         ext4_msg(sb, KERN_ERR, "can't mount with "
3612                                  "both data=journal and dax");
3613                         goto failed_mount;
3614                 }
3615                 if (ext4_has_feature_encrypt(sb)) {
3616                         ext4_msg(sb, KERN_WARNING,
3617                                  "encrypted files will use data=ordered "
3618                                  "instead of data journaling mode");
3619                 }
3620                 if (test_opt(sb, DELALLOC))
3621                         clear_opt(sb, DELALLOC);
3622         } else {
3623                 sb->s_iflags |= SB_I_CGROUPWB;
3624         }
3625
3626         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3627                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3628
3629         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3630             (ext4_has_compat_features(sb) ||
3631              ext4_has_ro_compat_features(sb) ||
3632              ext4_has_incompat_features(sb)))
3633                 ext4_msg(sb, KERN_WARNING,
3634                        "feature flags set on rev 0 fs, "
3635                        "running e2fsck is recommended");
3636
3637         if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3638                 set_opt2(sb, HURD_COMPAT);
3639                 if (ext4_has_feature_64bit(sb)) {
3640                         ext4_msg(sb, KERN_ERR,
3641                                  "The Hurd can't support 64-bit file systems");
3642                         goto failed_mount;
3643                 }
3644
3645                 /*
3646                  * ea_inode feature uses l_i_version field which is not
3647                  * available in HURD_COMPAT mode.
3648                  */
3649                 if (ext4_has_feature_ea_inode(sb)) {
3650                         ext4_msg(sb, KERN_ERR,
3651                                  "ea_inode feature is not supported for Hurd");
3652                         goto failed_mount;
3653                 }
3654         }
3655
3656         if (IS_EXT2_SB(sb)) {
3657                 if (ext2_feature_set_ok(sb))
3658                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3659                                  "using the ext4 subsystem");
3660                 else {
3661                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3662                                  "to feature incompatibilities");
3663                         goto failed_mount;
3664                 }
3665         }
3666
3667         if (IS_EXT3_SB(sb)) {
3668                 if (ext3_feature_set_ok(sb))
3669                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3670                                  "using the ext4 subsystem");
3671                 else {
3672                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3673                                  "to feature incompatibilities");
3674                         goto failed_mount;
3675                 }
3676         }
3677
3678         /*
3679          * Check feature flags regardless of the revision level, since we
3680          * previously didn't change the revision level when setting the flags,
3681          * so there is a chance incompat flags are set on a rev 0 filesystem.
3682          */
3683         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3684                 goto failed_mount;
3685
3686         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3687         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3688             blocksize > EXT4_MAX_BLOCK_SIZE) {
3689                 ext4_msg(sb, KERN_ERR,
3690                        "Unsupported filesystem blocksize %d (%d log_block_size)",
3691                          blocksize, le32_to_cpu(es->s_log_block_size));
3692                 goto failed_mount;
3693         }
3694         if (le32_to_cpu(es->s_log_block_size) >
3695             (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3696                 ext4_msg(sb, KERN_ERR,
3697                          "Invalid log block size: %u",
3698                          le32_to_cpu(es->s_log_block_size));
3699                 goto failed_mount;
3700         }
3701
3702         if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3703                 ext4_msg(sb, KERN_ERR,
3704                          "Number of reserved GDT blocks insanely large: %d",
3705                          le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3706                 goto failed_mount;
3707         }
3708
3709         if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3710                 err = bdev_dax_supported(sb, blocksize);
3711                 if (err)
3712                         goto failed_mount;
3713         }
3714
3715         if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3716                 ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3717                          es->s_encryption_level);
3718                 goto failed_mount;
3719         }
3720
3721         if (sb->s_blocksize != blocksize) {
3722                 /* Validate the filesystem blocksize */
3723                 if (!sb_set_blocksize(sb, blocksize)) {
3724                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3725                                         blocksize);
3726                         goto failed_mount;
3727                 }
3728
3729                 brelse(bh);
3730                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3731                 offset = do_div(logical_sb_block, blocksize);
3732                 bh = sb_bread_unmovable(sb, logical_sb_block);
3733                 if (!bh) {
3734                         ext4_msg(sb, KERN_ERR,
3735                                "Can't read superblock on 2nd try");
3736                         goto failed_mount;
3737                 }
3738                 es = (struct ext4_super_block *)(bh->b_data + offset);
3739                 sbi->s_es = es;
3740                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3741                         ext4_msg(sb, KERN_ERR,
3742                                "Magic mismatch, very weird!");
3743                         goto failed_mount;
3744                 }
3745         }
3746
3747         has_huge_files = ext4_has_feature_huge_file(sb);
3748         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3749                                                       has_huge_files);
3750         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3751
3752         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3753                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3754                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3755         } else {
3756                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3757                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3758                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3759                     (!is_power_of_2(sbi->s_inode_size)) ||
3760                     (sbi->s_inode_size > blocksize)) {
3761                         ext4_msg(sb, KERN_ERR,
3762                                "unsupported inode size: %d",
3763                                sbi->s_inode_size);
3764                         goto failed_mount;
3765                 }
3766                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3767                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3768         }
3769
3770         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3771         if (ext4_has_feature_64bit(sb)) {
3772                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3773                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3774                     !is_power_of_2(sbi->s_desc_size)) {
3775                         ext4_msg(sb, KERN_ERR,
3776                                "unsupported descriptor size %lu",
3777                                sbi->s_desc_size);
3778                         goto failed_mount;
3779                 }
3780         } else
3781                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3782
3783         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3784         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3785
3786         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3787         if (sbi->s_inodes_per_block == 0)
3788                 goto cantfind_ext4;
3789         if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3790             sbi->s_inodes_per_group > blocksize * 8) {
3791                 ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3792                          sbi->s_blocks_per_group);
3793                 goto failed_mount;
3794         }
3795         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3796                                         sbi->s_inodes_per_block;
3797         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3798         sbi->s_sbh = bh;
3799         sbi->s_mount_state = le16_to_cpu(es->s_state);
3800         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3801         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3802
3803         for (i = 0; i < 4; i++)
3804                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3805         sbi->s_def_hash_version = es->s_def_hash_version;
3806         if (ext4_has_feature_dir_index(sb)) {
3807                 i = le32_to_cpu(es->s_flags);
3808                 if (i & EXT2_FLAGS_UNSIGNED_HASH)
3809                         sbi->s_hash_unsigned = 3;
3810                 else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3811 #ifdef __CHAR_UNSIGNED__
3812                         if (!(sb->s_flags & MS_RDONLY))
3813                                 es->s_flags |=
3814                                         cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3815                         sbi->s_hash_unsigned = 3;
3816 #else
3817                         if (!(sb->s_flags & MS_RDONLY))
3818                                 es->s_flags |=
3819                                         cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3820 #endif
3821                 }
3822         }
3823
3824         /* Handle clustersize */
3825         clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3826         has_bigalloc = ext4_has_feature_bigalloc(sb);
3827         if (has_bigalloc) {
3828                 if (clustersize < blocksize) {
3829                         ext4_msg(sb, KERN_ERR,
3830                                  "cluster size (%d) smaller than "
3831                                  "block size (%d)", clustersize, blocksize);
3832                         goto failed_mount;
3833                 }
3834                 if (le32_to_cpu(es->s_log_cluster_size) >
3835                     (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3836                         ext4_msg(sb, KERN_ERR,
3837                                  "Invalid log cluster size: %u",
3838                                  le32_to_cpu(es->s_log_cluster_size));
3839                         goto failed_mount;
3840                 }
3841                 sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3842                         le32_to_cpu(es->s_log_block_size);
3843                 sbi->s_clusters_per_group =
3844                         le32_to_cpu(es->s_clusters_per_group);
3845                 if (sbi->s_clusters_per_group > blocksize * 8) {
3846                         ext4_msg(sb, KERN_ERR,
3847                                  "#clusters per group too big: %lu",
3848                                  sbi->s_clusters_per_group);
3849                         goto failed_mount;
3850                 }
3851                 if (sbi->s_blocks_per_group !=
3852                     (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3853                         ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3854                                  "clusters per group (%lu) inconsistent",
3855                                  sbi->s_blocks_per_group,
3856                                  sbi->s_clusters_per_group);
3857                         goto failed_mount;
3858                 }
3859         } else {
3860                 if (clustersize != blocksize) {
3861                         ext4_warning(sb, "fragment/cluster size (%d) != "
3862                                      "block size (%d)", clustersize,
3863                                      blocksize);
3864                         clustersize = blocksize;
3865                 }
3866                 if (sbi->s_blocks_per_group > blocksize * 8) {
3867                         ext4_msg(sb, KERN_ERR,
3868                                  "#blocks per group too big: %lu",
3869                                  sbi->s_blocks_per_group);
3870                         goto failed_mount;
3871                 }
3872                 sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3873                 sbi->s_cluster_bits = 0;
3874         }
3875         sbi->s_cluster_ratio = clustersize / blocksize;
3876
3877         /* Do we have standard group size of clustersize * 8 blocks ? */
3878         if (sbi->s_blocks_per_group == clustersize << 3)
3879                 set_opt2(sb, STD_GROUP_SIZE);
3880
3881         /*
3882          * Test whether we have more sectors than will fit in sector_t,
3883          * and whether the max offset is addressable by the page cache.
3884          */
3885         err = generic_check_addressable(sb->s_blocksize_bits,
3886                                         ext4_blocks_count(es));
3887         if (err) {
3888                 ext4_msg(sb, KERN_ERR, "filesystem"
3889                          " too large to mount safely on this system");
3890                 if (sizeof(sector_t) < 8)
3891                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3892                 goto failed_mount;
3893         }
3894
3895         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3896                 goto cantfind_ext4;
3897
3898         /* check blocks count against device size */
3899         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3900         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3901                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3902                        "exceeds size of device (%llu blocks)",
3903                        ext4_blocks_count(es), blocks_count);
3904                 goto failed_mount;
3905         }
3906
3907         /*
3908          * It makes no sense for the first data block to be beyond the end
3909          * of the filesystem.
3910          */
3911         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3912                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3913                          "block %u is beyond end of filesystem (%llu)",
3914                          le32_to_cpu(es->s_first_data_block),
3915                          ext4_blocks_count(es));
3916                 goto failed_mount;
3917         }
3918         blocks_count = (ext4_blocks_count(es) -
3919                         le32_to_cpu(es->s_first_data_block) +
3920                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3921         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3922         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3923                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3924                        "(block count %llu, first data block %u, "
3925                        "blocks per group %lu)", sbi->s_groups_count,
3926                        ext4_blocks_count(es),
3927                        le32_to_cpu(es->s_first_data_block),
3928                        EXT4_BLOCKS_PER_GROUP(sb));
3929                 goto failed_mount;
3930         }
3931         sbi->s_groups_count = blocks_count;
3932         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3933                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3934         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3935                    EXT4_DESC_PER_BLOCK(sb);
3936         if (ext4_has_feature_meta_bg(sb)) {
3937                 if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3938                         ext4_msg(sb, KERN_WARNING,
3939                                  "first meta block group too large: %u "
3940                                  "(group descriptor block count %u)",
3941                                  le32_to_cpu(es->s_first_meta_bg), db_count);
3942                         goto failed_mount;
3943                 }
3944         }
3945         sbi->s_group_desc = kvmalloc(db_count *
3946                                           sizeof(struct buffer_head *),
3947                                           GFP_KERNEL);
3948         if (sbi->s_group_desc == NULL) {
3949                 ext4_msg(sb, KERN_ERR, "not enough memory");
3950                 ret = -ENOMEM;
3951                 goto failed_mount;
3952         }
3953
3954         bgl_lock_init(sbi->s_blockgroup_lock);
3955
3956         /* Pre-read the descriptors into the buffer cache */
3957         for (i = 0; i < db_count; i++) {
3958                 block = descriptor_loc(sb, logical_sb_block, i);
3959                 sb_breadahead(sb, block);
3960         }
3961
3962         for (i = 0; i < db_count; i++) {
3963                 block = descriptor_loc(sb, logical_sb_block, i);
3964                 sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3965                 if (!sbi->s_group_desc[i]) {
3966                         ext4_msg(sb, KERN_ERR,
3967                                "can't read group descriptor %d", i);
3968                         db_count = i;
3969                         goto failed_mount2;
3970                 }
3971         }
3972         if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3973                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3974                 ret = -EFSCORRUPTED;
3975                 goto failed_mount2;
3976         }
3977
3978         sbi->s_gdb_count = db_count;
3979         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3980         spin_lock_init(&sbi->s_next_gen_lock);
3981
3982         setup_timer(&sbi->s_err_report, print_daily_error_info,
3983                 (unsigned long) sb);
3984
3985         /* Register extent status tree shrinker */
3986         if (ext4_es_register_shrinker(sbi))
3987                 goto failed_mount3;
3988
3989         sbi->s_stripe = ext4_get_stripe_size(sbi);
3990         sbi->s_extent_max_zeroout_kb = 32;
3991
3992         /*
3993          * set up enough so that it can read an inode
3994          */
3995         sb->s_op = &ext4_sops;
3996         sb->s_export_op = &ext4_export_ops;
3997         sb->s_xattr = ext4_xattr_handlers;
3998         sb->s_cop = &ext4_cryptops;
3999 #ifdef CONFIG_QUOTA
4000         sb->dq_op = &ext4_quota_operations;
4001         if (ext4_has_feature_quota(sb))
4002                 sb->s_qcop = &dquot_quotactl_sysfile_ops;
4003         else
4004                 sb->s_qcop = &ext4_qctl_operations;
4005         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4006 #endif
4007         memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4008
4009         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4010         mutex_init(&sbi->s_orphan_lock);
4011
4012         sb->s_root = NULL;
4013
4014         needs_recovery = (es->s_last_orphan != 0 ||
4015                           ext4_has_feature_journal_needs_recovery(sb));
4016
4017         if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
4018                 if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4019                         goto failed_mount3a;
4020
4021         /*
4022          * The first inode we look at is the journal inode.  Don't try
4023          * root first: it may be modified in the journal!
4024          */
4025         if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4026                 err = ext4_load_journal(sb, es, journal_devnum);
4027                 if (err)
4028                         goto failed_mount3a;
4029         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
4030                    ext4_has_feature_journal_needs_recovery(sb)) {
4031                 ext4_msg(sb, KERN_ERR, "required journal recovery "
4032                        "suppressed and not mounted read-only");
4033                 goto failed_mount_wq;
4034         } else {
4035                 /* Nojournal mode, all journal mount options are illegal */
4036                 if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4037                         ext4_msg(sb, KERN_ERR, "can't mount with "
4038                                  "journal_checksum, fs mounted w/o journal");
4039                         goto failed_mount_wq;
4040                 }
4041                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4042                         ext4_msg(sb, KERN_ERR, "can't mount with "
4043                                  "journal_async_commit, fs mounted w/o journal");
4044                         goto failed_mount_wq;
4045                 }
4046                 if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4047                         ext4_msg(sb, KERN_ERR, "can't mount with "
4048                                  "commit=%lu, fs mounted w/o journal",
4049                                  sbi->s_commit_interval / HZ);
4050                         goto failed_mount_wq;
4051                 }
4052                 if (EXT4_MOUNT_DATA_FLAGS &
4053                     (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4054                         ext4_msg(sb, KERN_ERR, "can't mount with "
4055                                  "data=, fs mounted w/o journal");
4056                         goto failed_mount_wq;
4057                 }
4058                 sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4059                 clear_opt(sb, JOURNAL_CHECKSUM);
4060                 clear_opt(sb, DATA_FLAGS);
4061                 sbi->s_journal = NULL;
4062                 needs_recovery = 0;
4063                 goto no_journal;
4064         }
4065
4066         if (ext4_has_feature_64bit(sb) &&
4067             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4068                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
4069                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4070                 goto failed_mount_wq;
4071         }
4072
4073         if (!set_journal_csum_feature_set(sb)) {
4074                 ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4075                          "feature set");
4076                 goto failed_mount_wq;
4077         }
4078
4079         /* We have now updated the journal if required, so we can
4080          * validate the data journaling mode. */
4081         switch (test_opt(sb, DATA_FLAGS)) {
4082         case 0:
4083                 /* No mode set, assume a default based on the journal
4084                  * capabilities: ORDERED_DATA if the journal can
4085                  * cope, else JOURNAL_DATA
4086                  */
4087                 if (jbd2_journal_check_available_features
4088                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4089                         set_opt(sb, ORDERED_DATA);
4090                 else
4091                         set_opt(sb, JOURNAL_DATA);
4092                 break;
4093
4094         case EXT4_MOUNT_ORDERED_DATA:
4095         case EXT4_MOUNT_WRITEBACK_DATA:
4096                 if (!jbd2_journal_check_available_features
4097                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4098                         ext4_msg(sb, KERN_ERR, "Journal does not support "
4099                                "requested data journaling mode");
4100                         goto failed_mount_wq;
4101                 }
4102         default:
4103                 break;
4104         }
4105
4106         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4107             test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4108                 ext4_msg(sb, KERN_ERR, "can't mount with "
4109                         "journal_async_commit in data=ordered mode");
4110                 goto failed_mount_wq;
4111         }
4112
4113         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4114
4115         sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4116
4117 no_journal:
4118         if (!test_opt(sb, NO_MBCACHE)) {
4119                 sbi->s_ea_block_cache = ext4_xattr_create_cache();
4120                 if (!sbi->s_ea_block_cache) {
4121                         ext4_msg(sb, KERN_ERR,
4122                                  "Failed to create ea_block_cache");
4123                         goto failed_mount_wq;
4124                 }
4125
4126                 if (ext4_has_feature_ea_inode(sb)) {
4127                         sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4128                         if (!sbi->s_ea_inode_cache) {
4129                                 ext4_msg(sb, KERN_ERR,
4130                                          "Failed to create ea_inode_cache");
4131                                 goto failed_mount_wq;
4132                         }
4133                 }
4134         }
4135
4136         if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4137             (blocksize != PAGE_SIZE)) {
4138                 ext4_msg(sb, KERN_ERR,
4139                          "Unsupported blocksize for fs encryption");
4140                 goto failed_mount_wq;
4141         }
4142
4143         if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4144             !ext4_has_feature_encrypt(sb)) {
4145                 ext4_set_feature_encrypt(sb);
4146                 ext4_commit_super(sb, 1);
4147         }
4148
4149         /*
4150          * Get the # of file system overhead blocks from the
4151          * superblock if present.
4152          */
4153         if (es->s_overhead_clusters)
4154                 sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4155         else {
4156                 err = ext4_calculate_overhead(sb);
4157                 if (err)
4158                         goto failed_mount_wq;
4159         }
4160
4161         /*
4162          * The maximum number of concurrent works can be high and
4163          * concurrency isn't really necessary.  Limit it to 1.
4164          */
4165         EXT4_SB(sb)->rsv_conversion_wq =
4166                 alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4167         if (!EXT4_SB(sb)->rsv_conversion_wq) {
4168                 printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4169                 ret = -ENOMEM;
4170                 goto failed_mount4;
4171         }
4172
4173         /*
4174          * The jbd2_journal_load will have done any necessary log recovery,
4175          * so we can safely mount the rest of the filesystem now.
4176          */
4177
4178         root = ext4_iget(sb, EXT4_ROOT_INO);
4179         if (IS_ERR(root)) {
4180                 ext4_msg(sb, KERN_ERR, "get root inode failed");
4181                 ret = PTR_ERR(root);
4182                 root = NULL;
4183                 goto failed_mount4;
4184         }
4185         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4186                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4187                 iput(root);
4188                 goto failed_mount4;
4189         }
4190         sb->s_root = d_make_root(root);
4191         if (!sb->s_root) {
4192                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
4193                 ret = -ENOMEM;
4194                 goto failed_mount4;
4195         }
4196
4197         if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4198                 sb->s_flags |= MS_RDONLY;
4199
4200         /* determine the minimum size of new large inodes, if present */
4201         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4202             sbi->s_want_extra_isize == 0) {
4203                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4204                                                      EXT4_GOOD_OLD_INODE_SIZE;
4205                 if (ext4_has_feature_extra_isize(sb)) {
4206                         if (sbi->s_want_extra_isize <
4207                             le16_to_cpu(es->s_want_extra_isize))
4208                                 sbi->s_want_extra_isize =
4209                                         le16_to_cpu(es->s_want_extra_isize);
4210                         if (sbi->s_want_extra_isize <
4211                             le16_to_cpu(es->s_min_extra_isize))
4212                                 sbi->s_want_extra_isize =
4213                                         le16_to_cpu(es->s_min_extra_isize);
4214                 }
4215         }
4216         /* Check if enough inode space is available */
4217         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4218                                                         sbi->s_inode_size) {
4219                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4220                                                        EXT4_GOOD_OLD_INODE_SIZE;
4221                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
4222                          "available");
4223         }
4224
4225         ext4_set_resv_clusters(sb);
4226
4227         err = ext4_setup_system_zone(sb);
4228         if (err) {
4229                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
4230                          "zone (%d)", err);
4231                 goto failed_mount4a;
4232         }
4233
4234         ext4_ext_init(sb);
4235         err = ext4_mb_init(sb);
4236         if (err) {
4237                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4238                          err);
4239                 goto failed_mount5;
4240         }
4241
4242         block = ext4_count_free_clusters(sb);
4243         ext4_free_blocks_count_set(sbi->s_es,
4244                                    EXT4_C2B(sbi, block));
4245         err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4246                                   GFP_KERNEL);
4247         if (!err) {
4248                 unsigned long freei = ext4_count_free_inodes(sb);
4249                 sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4250                 err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4251                                           GFP_KERNEL);
4252         }
4253         if (!err)
4254                 err = percpu_counter_init(&sbi->s_dirs_counter,
4255                                           ext4_count_dirs(sb), GFP_KERNEL);
4256         if (!err)
4257                 err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4258                                           GFP_KERNEL);
4259         if (!err)
4260                 err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4261
4262         if (err) {
4263                 ext4_msg(sb, KERN_ERR, "insufficient memory");
4264                 goto failed_mount6;
4265         }
4266
4267         if (ext4_has_feature_flex_bg(sb))
4268                 if (!ext4_fill_flex_info(sb)) {
4269                         ext4_msg(sb, KERN_ERR,
4270                                "unable to initialize "
4271                                "flex_bg meta info!");
4272                         goto failed_mount6;
4273                 }
4274
4275         err = ext4_register_li_request(sb, first_not_zeroed);
4276         if (err)
4277                 goto failed_mount6;
4278
4279         err = ext4_register_sysfs(sb);
4280         if (err)
4281                 goto failed_mount7;
4282
4283 #ifdef CONFIG_QUOTA
4284         /* Enable quota usage during mount. */
4285         if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4286                 err = ext4_enable_quotas(sb);
4287                 if (err)
4288                         goto failed_mount8;
4289         }
4290 #endif  /* CONFIG_QUOTA */
4291
4292         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4293         ext4_orphan_cleanup(sb, es);
4294         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4295         if (needs_recovery) {
4296                 ext4_msg(sb, KERN_INFO, "recovery complete");
4297                 ext4_mark_recovery_complete(sb, es);
4298         }
4299         if (EXT4_SB(sb)->s_journal) {
4300                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4301                         descr = " journalled data mode";
4302                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4303                         descr = " ordered data mode";
4304                 else
4305                         descr = " writeback data mode";
4306         } else
4307                 descr = "out journal";
4308
4309         if (test_opt(sb, DISCARD)) {
4310                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
4311                 if (!blk_queue_discard(q))
4312                         ext4_msg(sb, KERN_WARNING,
4313                                  "mounting with \"discard\" option, but "
4314                                  "the device does not support discard");
4315         }
4316
4317         if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4318                 ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4319                          "Opts: %.*s%s%s", descr,
4320                          (int) sizeof(sbi->s_es->s_mount_opts),
4321                          sbi->s_es->s_mount_opts,
4322                          *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4323
4324         if (es->s_error_count)
4325                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4326
4327         /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4328         ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4329         ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4330         ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4331
4332         kfree(orig_data);
4333         return 0;
4334
4335 cantfind_ext4:
4336         if (!silent)
4337                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4338         goto failed_mount;
4339
4340 #ifdef CONFIG_QUOTA
4341 failed_mount8:
4342         ext4_unregister_sysfs(sb);
4343 #endif
4344 failed_mount7:
4345         ext4_unregister_li_request(sb);
4346 failed_mount6:
4347         ext4_mb_release(sb);
4348         if (sbi->s_flex_groups)
4349                 kvfree(sbi->s_flex_groups);
4350         percpu_counter_destroy(&sbi->s_freeclusters_counter);
4351         percpu_counter_destroy(&sbi->s_freeinodes_counter);
4352         percpu_counter_destroy(&sbi->s_dirs_counter);
4353         percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4354 failed_mount5:
4355         ext4_ext_release(sb);
4356         ext4_release_system_zone(sb);
4357 failed_mount4a:
4358         dput(sb->s_root);
4359         sb->s_root = NULL;
4360 failed_mount4:
4361         ext4_msg(sb, KERN_ERR, "mount failed");
4362         if (EXT4_SB(sb)->rsv_conversion_wq)
4363                 destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4364 failed_mount_wq:
4365         if (sbi->s_ea_inode_cache) {
4366                 ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4367                 sbi->s_ea_inode_cache = NULL;
4368         }
4369         if (sbi->s_ea_block_cache) {
4370                 ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4371                 sbi->s_ea_block_cache = NULL;
4372         }
4373         if (sbi->s_journal) {
4374                 jbd2_journal_destroy(sbi->s_journal);
4375                 sbi->s_journal = NULL;
4376         }
4377 failed_mount3a:
4378         ext4_es_unregister_shrinker(sbi);
4379 failed_mount3:
4380         del_timer_sync(&sbi->s_err_report);
4381         if (sbi->s_mmp_tsk)
4382                 kthread_stop(sbi->s_mmp_tsk);
4383 failed_mount2:
4384         for (i = 0; i < db_count; i++)
4385                 brelse(sbi->s_group_desc[i]);
4386         kvfree(sbi->s_group_desc);
4387 failed_mount:
4388         if (sbi->s_chksum_driver)
4389                 crypto_free_shash(sbi->s_chksum_driver);
4390 #ifdef CONFIG_QUOTA
4391         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4392                 kfree(sbi->s_qf_names[i]);
4393 #endif
4394         ext4_blkdev_remove(sbi);
4395         brelse(bh);
4396 out_fail:
4397         sb->s_fs_info = NULL;
4398         kfree(sbi->s_blockgroup_lock);
4399 out_free_base:
4400         kfree(sbi);
4401         kfree(orig_data);
4402         return err ? err : ret;
4403 }
4404
4405 /*
4406  * Setup any per-fs journal parameters now.  We'll do this both on
4407  * initial mount, once the journal has been initialised but before we've
4408  * done any recovery; and again on any subsequent remount.
4409  */
4410 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4411 {
4412         struct ext4_sb_info *sbi = EXT4_SB(sb);
4413
4414         journal->j_commit_interval = sbi->s_commit_interval;
4415         journal->j_min_batch_time = sbi->s_min_batch_time;
4416         journal->j_max_batch_time = sbi->s_max_batch_time;
4417
4418         write_lock(&journal->j_state_lock);
4419         if (test_opt(sb, BARRIER))
4420                 journal->j_flags |= JBD2_BARRIER;
4421         else
4422                 journal->j_flags &= ~JBD2_BARRIER;
4423         if (test_opt(sb, DATA_ERR_ABORT))
4424                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4425         else
4426                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4427         write_unlock(&journal->j_state_lock);
4428 }
4429
4430 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4431                                              unsigned int journal_inum)
4432 {
4433         struct inode *journal_inode;
4434
4435         /*
4436          * Test for the existence of a valid inode on disk.  Bad things
4437          * happen if we iget() an unused inode, as the subsequent iput()
4438          * will try to delete it.
4439          */
4440         journal_inode = ext4_iget(sb, journal_inum);
4441         if (IS_ERR(journal_inode)) {
4442                 ext4_msg(sb, KERN_ERR, "no journal found");
4443                 return NULL;
4444         }
4445         if (!journal_inode->i_nlink) {
4446                 make_bad_inode(journal_inode);
4447                 iput(journal_inode);
4448                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4449                 return NULL;
4450         }
4451
4452         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4453                   journal_inode, journal_inode->i_size);
4454         if (!S_ISREG(journal_inode->i_mode)) {
4455                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
4456                 iput(journal_inode);
4457                 return NULL;
4458         }
4459         return journal_inode;
4460 }
4461
4462 static journal_t *ext4_get_journal(struct super_block *sb,
4463                                    unsigned int journal_inum)
4464 {
4465         struct inode *journal_inode;
4466         journal_t *journal;
4467
4468         BUG_ON(!ext4_has_feature_journal(sb));
4469
4470         journal_inode = ext4_get_journal_inode(sb, journal_inum);
4471         if (!journal_inode)
4472                 return NULL;
4473
4474         journal = jbd2_journal_init_inode(journal_inode);
4475         if (!journal) {
4476                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4477                 iput(journal_inode);
4478                 return NULL;
4479         }
4480         journal->j_private = sb;
4481         ext4_init_journal_params(sb, journal);
4482         return journal;
4483 }
4484
4485 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4486                                        dev_t j_dev)
4487 {
4488         struct buffer_head *bh;
4489         journal_t *journal;
4490         ext4_fsblk_t start;
4491         ext4_fsblk_t len;
4492         int hblock, blocksize;
4493         ext4_fsblk_t sb_block;
4494         unsigned long offset;
4495         struct ext4_super_block *es;
4496         struct block_device *bdev;
4497
4498         BUG_ON(!ext4_has_feature_journal(sb));
4499
4500         bdev = ext4_blkdev_get(j_dev, sb);
4501         if (bdev == NULL)
4502                 return NULL;
4503
4504         blocksize = sb->s_blocksize;
4505         hblock = bdev_logical_block_size(bdev);
4506         if (blocksize < hblock) {
4507                 ext4_msg(sb, KERN_ERR,
4508                         "blocksize too small for journal device");
4509                 goto out_bdev;
4510         }
4511
4512         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4513         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4514         set_blocksize(bdev, blocksize);
4515         if (!(bh = __bread(bdev, sb_block, blocksize))) {
4516                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4517                        "external journal");
4518                 goto out_bdev;
4519         }
4520
4521         es = (struct ext4_super_block *) (bh->b_data + offset);
4522         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4523             !(le32_to_cpu(es->s_feature_incompat) &
4524               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4525                 ext4_msg(sb, KERN_ERR, "external journal has "
4526                                         "bad superblock");
4527                 brelse(bh);
4528                 goto out_bdev;
4529         }
4530
4531         if ((le32_to_cpu(es->s_feature_ro_compat) &
4532              EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4533             es->s_checksum != ext4_superblock_csum(sb, es)) {
4534                 ext4_msg(sb, KERN_ERR, "external journal has "
4535                                        "corrupt superblock");
4536                 brelse(bh);
4537                 goto out_bdev;
4538         }
4539
4540         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4541                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4542                 brelse(bh);
4543                 goto out_bdev;
4544         }
4545
4546         len = ext4_blocks_count(es);
4547         start = sb_block + 1;
4548         brelse(bh);     /* we're done with the superblock */
4549
4550         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4551                                         start, len, blocksize);
4552         if (!journal) {
4553                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
4554                 goto out_bdev;
4555         }
4556         journal->j_private = sb;
4557         ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4558         wait_on_buffer(journal->j_sb_buffer);
4559         if (!buffer_uptodate(journal->j_sb_buffer)) {
4560                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4561                 goto out_journal;
4562         }
4563         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4564                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
4565                                         "user (unsupported) - %d",
4566                         be32_to_cpu(journal->j_superblock->s_nr_users));
4567                 goto out_journal;
4568         }
4569         EXT4_SB(sb)->journal_bdev = bdev;
4570         ext4_init_journal_params(sb, journal);
4571         return journal;
4572
4573 out_journal:
4574         jbd2_journal_destroy(journal);
4575 out_bdev:
4576         ext4_blkdev_put(bdev);
4577         return NULL;
4578 }
4579
4580 static int ext4_load_journal(struct super_block *sb,
4581                              struct ext4_super_block *es,
4582                              unsigned long journal_devnum)
4583 {
4584         journal_t *journal;
4585         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4586         dev_t journal_dev;
4587         int err = 0;
4588         int really_read_only;
4589
4590         BUG_ON(!ext4_has_feature_journal(sb));
4591
4592         if (journal_devnum &&
4593             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4594                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4595                         "numbers have changed");
4596                 journal_dev = new_decode_dev(journal_devnum);
4597         } else
4598                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4599
4600         really_read_only = bdev_read_only(sb->s_bdev);
4601
4602         /*
4603          * Are we loading a blank journal or performing recovery after a
4604          * crash?  For recovery, we need to check in advance whether we
4605          * can get read-write access to the device.
4606          */
4607         if (ext4_has_feature_journal_needs_recovery(sb)) {
4608                 if (sb->s_flags & MS_RDONLY) {
4609                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
4610                                         "required on readonly filesystem");
4611                         if (really_read_only) {
4612                                 ext4_msg(sb, KERN_ERR, "write access "
4613                                         "unavailable, cannot proceed");
4614                                 return -EROFS;
4615                         }
4616                         ext4_msg(sb, KERN_INFO, "write access will "
4617                                "be enabled during recovery");
4618                 }
4619         }
4620
4621         if (journal_inum && journal_dev) {
4622                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4623                        "and inode journals!");
4624                 return -EINVAL;
4625         }
4626
4627         if (journal_inum) {
4628                 if (!(journal = ext4_get_journal(sb, journal_inum)))
4629                         return -EINVAL;
4630         } else {
4631                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4632                         return -EINVAL;
4633         }
4634
4635         if (!(journal->j_flags & JBD2_BARRIER))
4636                 ext4_msg(sb, KERN_INFO, "barriers disabled");
4637
4638         if (!ext4_has_feature_journal_needs_recovery(sb))
4639                 err = jbd2_journal_wipe(journal, !really_read_only);
4640         if (!err) {
4641                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4642                 if (save)
4643                         memcpy(save, ((char *) es) +
4644                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4645                 err = jbd2_journal_load(journal);
4646                 if (save)
4647                         memcpy(((char *) es) + EXT4_S_ERR_START,
4648                                save, EXT4_S_ERR_LEN);
4649                 kfree(save);
4650         }
4651
4652         if (err) {
4653                 ext4_msg(sb, KERN_ERR, "error loading journal");
4654                 jbd2_journal_destroy(journal);
4655                 return err;
4656         }
4657
4658         EXT4_SB(sb)->s_journal = journal;
4659         ext4_clear_journal_err(sb, es);
4660
4661         if (!really_read_only && journal_devnum &&
4662             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4663                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4664
4665                 /* Make sure we flush the recovery flag to disk. */
4666                 ext4_commit_super(sb, 1);
4667         }
4668
4669         return 0;
4670 }
4671
4672 static int ext4_commit_super(struct super_block *sb, int sync)
4673 {
4674         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4675         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4676         int error = 0;
4677
4678         if (!sbh || block_device_ejected(sb))
4679                 return error;
4680         /*
4681          * If the file system is mounted read-only, don't update the
4682          * superblock write time.  This avoids updating the superblock
4683          * write time when we are mounting the root file system
4684          * read/only but we need to replay the journal; at that point,
4685          * for people who are east of GMT and who make their clock
4686          * tick in localtime for Windows bug-for-bug compatibility,
4687          * the clock is set in the future, and this will cause e2fsck
4688          * to complain and force a full file system check.
4689          */
4690         if (!(sb->s_flags & MS_RDONLY))
4691                 es->s_wtime = cpu_to_le32(get_seconds());
4692         if (sb->s_bdev->bd_part)
4693                 es->s_kbytes_written =
4694                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4695                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4696                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4697         else
4698                 es->s_kbytes_written =
4699                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4700         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4701                 ext4_free_blocks_count_set(es,
4702                         EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4703                                 &EXT4_SB(sb)->s_freeclusters_counter)));
4704         if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4705                 es->s_free_inodes_count =
4706                         cpu_to_le32(percpu_counter_sum_positive(
4707                                 &EXT4_SB(sb)->s_freeinodes_counter));
4708         BUFFER_TRACE(sbh, "marking dirty");
4709         ext4_superblock_csum_set(sb);
4710         if (sync)
4711                 lock_buffer(sbh);
4712         if (buffer_write_io_error(sbh)) {
4713                 /*
4714                  * Oh, dear.  A previous attempt to write the
4715                  * superblock failed.  This could happen because the
4716                  * USB device was yanked out.  Or it could happen to
4717                  * be a transient write error and maybe the block will
4718                  * be remapped.  Nothing we can do but to retry the
4719                  * write and hope for the best.
4720                  */
4721                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4722                        "superblock detected");
4723                 clear_buffer_write_io_error(sbh);
4724                 set_buffer_uptodate(sbh);
4725         }
4726         mark_buffer_dirty(sbh);
4727         if (sync) {
4728                 unlock_buffer(sbh);
4729                 error = __sync_dirty_buffer(sbh,
4730                         REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4731                 if (error)
4732                         return error;
4733
4734                 error = buffer_write_io_error(sbh);
4735                 if (error) {
4736                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4737                                "superblock");
4738                         clear_buffer_write_io_error(sbh);
4739                         set_buffer_uptodate(sbh);
4740                 }
4741         }
4742         return error;
4743 }
4744
4745 /*
4746  * Have we just finished recovery?  If so, and if we are mounting (or
4747  * remounting) the filesystem readonly, then we will end up with a
4748  * consistent fs on disk.  Record that fact.
4749  */
4750 static void ext4_mark_recovery_complete(struct super_block *sb,
4751                                         struct ext4_super_block *es)
4752 {
4753         journal_t *journal = EXT4_SB(sb)->s_journal;
4754
4755         if (!ext4_has_feature_journal(sb)) {
4756                 BUG_ON(journal != NULL);
4757                 return;
4758         }
4759         jbd2_journal_lock_updates(journal);
4760         if (jbd2_journal_flush(journal) < 0)
4761                 goto out;
4762
4763         if (ext4_has_feature_journal_needs_recovery(sb) &&
4764             sb->s_flags & MS_RDONLY) {
4765                 ext4_clear_feature_journal_needs_recovery(sb);
4766                 ext4_commit_super(sb, 1);
4767         }
4768
4769 out:
4770         jbd2_journal_unlock_updates(journal);
4771 }
4772
4773 /*
4774  * If we are mounting (or read-write remounting) a filesystem whose journal
4775  * has recorded an error from a previous lifetime, move that error to the
4776  * main filesystem now.
4777  */
4778 static void ext4_clear_journal_err(struct super_block *sb,
4779                                    struct ext4_super_block *es)
4780 {
4781         journal_t *journal;
4782         int j_errno;
4783         const char *errstr;
4784
4785         BUG_ON(!ext4_has_feature_journal(sb));
4786
4787         journal = EXT4_SB(sb)->s_journal;
4788
4789         /*
4790          * Now check for any error status which may have been recorded in the
4791          * journal by a prior ext4_error() or ext4_abort()
4792          */
4793
4794         j_errno = jbd2_journal_errno(journal);
4795         if (j_errno) {
4796                 char nbuf[16];
4797
4798                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4799                 ext4_warning(sb, "Filesystem error recorded "
4800                              "from previous mount: %s", errstr);
4801                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4802
4803                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4804                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4805                 ext4_commit_super(sb, 1);
4806
4807                 jbd2_journal_clear_err(journal);
4808                 jbd2_journal_update_sb_errno(journal);
4809         }
4810 }
4811
4812 /*
4813  * Force the running and committing transactions to commit,
4814  * and wait on the commit.
4815  */
4816 int ext4_force_commit(struct super_block *sb)
4817 {
4818         journal_t *journal;
4819
4820         if (sb->s_flags & MS_RDONLY)
4821                 return 0;
4822
4823         journal = EXT4_SB(sb)->s_journal;
4824         return ext4_journal_force_commit(journal);
4825 }
4826
4827 static int ext4_sync_fs(struct super_block *sb, int wait)
4828 {
4829         int ret = 0;
4830         tid_t target;
4831         bool needs_barrier = false;
4832         struct ext4_sb_info *sbi = EXT4_SB(sb);
4833
4834         if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4835                 return 0;
4836
4837         trace_ext4_sync_fs(sb, wait);
4838         flush_workqueue(sbi->rsv_conversion_wq);
4839         /*
4840          * Writeback quota in non-journalled quota case - journalled quota has
4841          * no dirty dquots
4842          */
4843         dquot_writeback_dquots(sb, -1);
4844         /*
4845          * Data writeback is possible w/o journal transaction, so barrier must
4846          * being sent at the end of the function. But we can skip it if
4847          * transaction_commit will do it for us.
4848          */
4849         if (sbi->s_journal) {
4850                 target = jbd2_get_latest_transaction(sbi->s_journal);
4851                 if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4852                     !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4853                         needs_barrier = true;
4854
4855                 if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4856                         if (wait)
4857                                 ret = jbd2_log_wait_commit(sbi->s_journal,
4858                                                            target);
4859                 }
4860         } else if (wait && test_opt(sb, BARRIER))
4861                 needs_barrier = true;
4862         if (needs_barrier) {
4863                 int err;
4864                 err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4865                 if (!ret)
4866                         ret = err;
4867         }
4868
4869         return ret;
4870 }
4871
4872 /*
4873  * LVM calls this function before a (read-only) snapshot is created.  This
4874  * gives us a chance to flush the journal completely and mark the fs clean.
4875  *
4876  * Note that only this function cannot bring a filesystem to be in a clean
4877  * state independently. It relies on upper layer to stop all data & metadata
4878  * modifications.
4879  */
4880 static int ext4_freeze(struct super_block *sb)
4881 {
4882         int error = 0;
4883         journal_t *journal;
4884
4885         if (sb->s_flags & MS_RDONLY)
4886                 return 0;
4887
4888         journal = EXT4_SB(sb)->s_journal;
4889
4890         if (journal) {
4891                 /* Now we set up the journal barrier. */
4892                 jbd2_journal_lock_updates(journal);
4893
4894                 /*
4895                  * Don't clear the needs_recovery flag if we failed to
4896                  * flush the journal.
4897                  */
4898                 error = jbd2_journal_flush(journal);
4899                 if (error < 0)
4900                         goto out;
4901
4902                 /* Journal blocked and flushed, clear needs_recovery flag. */
4903                 ext4_clear_feature_journal_needs_recovery(sb);
4904         }
4905
4906         error = ext4_commit_super(sb, 1);
4907 out:
4908         if (journal)
4909                 /* we rely on upper layer to stop further updates */
4910                 jbd2_journal_unlock_updates(journal);
4911         return error;
4912 }
4913
4914 /*
4915  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4916  * flag here, even though the filesystem is not technically dirty yet.
4917  */
4918 static int ext4_unfreeze(struct super_block *sb)
4919 {
4920         if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))
4921                 return 0;
4922
4923         if (EXT4_SB(sb)->s_journal) {
4924                 /* Reset the needs_recovery flag before the fs is unlocked. */
4925                 ext4_set_feature_journal_needs_recovery(sb);
4926         }
4927
4928         ext4_commit_super(sb, 1);
4929         return 0;
4930 }
4931
4932 /*
4933  * Structure to save mount options for ext4_remount's benefit
4934  */
4935 struct ext4_mount_options {
4936         unsigned long s_mount_opt;
4937         unsigned long s_mount_opt2;
4938         kuid_t s_resuid;
4939         kgid_t s_resgid;
4940         unsigned long s_commit_interval;
4941         u32 s_min_batch_time, s_max_batch_time;
4942 #ifdef CONFIG_QUOTA
4943         int s_jquota_fmt;
4944         char *s_qf_names[EXT4_MAXQUOTAS];
4945 #endif
4946 };
4947
4948 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4949 {
4950         struct ext4_super_block *es;
4951         struct ext4_sb_info *sbi = EXT4_SB(sb);
4952         unsigned long old_sb_flags;
4953         struct ext4_mount_options old_opts;
4954         int enable_quota = 0;
4955         ext4_group_t g;
4956         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4957         int err = 0;
4958 #ifdef CONFIG_QUOTA
4959         int i, j;
4960 #endif
4961         char *orig_data = kstrdup(data, GFP_KERNEL);
4962
4963         /* Store the original options */
4964         old_sb_flags = sb->s_flags;
4965         old_opts.s_mount_opt = sbi->s_mount_opt;
4966         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4967         old_opts.s_resuid = sbi->s_resuid;
4968         old_opts.s_resgid = sbi->s_resgid;
4969         old_opts.s_commit_interval = sbi->s_commit_interval;
4970         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4971         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4972 #ifdef CONFIG_QUOTA
4973         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4974         for (i = 0; i < EXT4_MAXQUOTAS; i++)
4975                 if (sbi->s_qf_names[i]) {
4976                         old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4977                                                          GFP_KERNEL);
4978                         if (!old_opts.s_qf_names[i]) {
4979                                 for (j = 0; j < i; j++)
4980                                         kfree(old_opts.s_qf_names[j]);
4981                                 kfree(orig_data);
4982                                 return -ENOMEM;
4983                         }
4984                 } else
4985                         old_opts.s_qf_names[i] = NULL;
4986 #endif
4987         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4988                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4989
4990         if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4991                 err = -EINVAL;
4992                 goto restore_opts;
4993         }
4994
4995         if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4996             test_opt(sb, JOURNAL_CHECKSUM)) {
4997                 ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4998                          "during remount not supported; ignoring");
4999                 sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5000         }
5001
5002         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5003                 if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5004                         ext4_msg(sb, KERN_ERR, "can't mount with "
5005                                  "both data=journal and delalloc");
5006                         err = -EINVAL;
5007                         goto restore_opts;
5008                 }
5009                 if (test_opt(sb, DIOREAD_NOLOCK)) {
5010                         ext4_msg(sb, KERN_ERR, "can't mount with "
5011                                  "both data=journal and dioread_nolock");
5012                         err = -EINVAL;
5013                         goto restore_opts;
5014                 }
5015                 if (test_opt(sb, DAX)) {
5016                         ext4_msg(sb, KERN_ERR, "can't mount with "
5017                                  "both data=journal and dax");
5018                         err = -EINVAL;
5019                         goto restore_opts;
5020                 }
5021         } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5022                 if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5023                         ext4_msg(sb, KERN_ERR, "can't mount with "
5024                                 "journal_async_commit in data=ordered mode");
5025                         err = -EINVAL;
5026                         goto restore_opts;
5027                 }
5028         }
5029
5030         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5031                 ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5032                 err = -EINVAL;
5033                 goto restore_opts;
5034         }
5035
5036         if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5037                 ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5038                         "dax flag with busy inodes while remounting");
5039                 sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5040         }
5041
5042         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5043                 ext4_abort(sb, "Abort forced by user");
5044
5045         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
5046                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
5047
5048         es = sbi->s_es;
5049
5050         if (sbi->s_journal) {
5051                 ext4_init_journal_params(sb, sbi->s_journal);
5052                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5053         }
5054
5055         if (*flags & MS_LAZYTIME)
5056                 sb->s_flags |= MS_LAZYTIME;
5057
5058         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
5059                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5060                         err = -EROFS;
5061                         goto restore_opts;
5062                 }
5063
5064                 if (*flags & MS_RDONLY) {
5065                         err = sync_filesystem(sb);
5066                         if (err < 0)
5067                                 goto restore_opts;
5068                         err = dquot_suspend(sb, -1);
5069                         if (err < 0)
5070                                 goto restore_opts;
5071
5072                         /*
5073                          * First of all, the unconditional stuff we have to do
5074                          * to disable replay of the journal when we next remount
5075                          */
5076                         sb->s_flags |= MS_RDONLY;
5077
5078                         /*
5079                          * OK, test if we are remounting a valid rw partition
5080                          * readonly, and if so set the rdonly flag and then
5081                          * mark the partition as valid again.
5082                          */
5083                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5084                             (sbi->s_mount_state & EXT4_VALID_FS))
5085                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
5086
5087                         if (sbi->s_journal)
5088                                 ext4_mark_recovery_complete(sb, es);
5089                 } else {
5090                         /* Make sure we can mount this feature set readwrite */
5091                         if (ext4_has_feature_readonly(sb) ||
5092                             !ext4_feature_set_ok(sb, 0)) {
5093                                 err = -EROFS;
5094                                 goto restore_opts;
5095                         }
5096                         /*
5097                          * Make sure the group descriptor checksums
5098                          * are sane.  If they aren't, refuse to remount r/w.
5099                          */
5100                         for (g = 0; g < sbi->s_groups_count; g++) {
5101                                 struct ext4_group_desc *gdp =
5102                                         ext4_get_group_desc(sb, g, NULL);
5103
5104                                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5105                                         ext4_msg(sb, KERN_ERR,
5106                "ext4_remount: Checksum for group %u failed (%u!=%u)",
5107                 g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5108                                                le16_to_cpu(gdp->bg_checksum));
5109                                         err = -EFSBADCRC;
5110                                         goto restore_opts;
5111                                 }
5112                         }
5113
5114                         /*
5115                          * If we have an unprocessed orphan list hanging
5116                          * around from a previously readonly bdev mount,
5117                          * require a full umount/remount for now.
5118                          */
5119                         if (es->s_last_orphan) {
5120                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
5121                                        "remount RDWR because of unprocessed "
5122                                        "orphan inode list.  Please "
5123                                        "umount/remount instead");
5124                                 err = -EINVAL;
5125                                 goto restore_opts;
5126                         }
5127
5128                         /*
5129                          * Mounting a RDONLY partition read-write, so reread
5130                          * and store the current valid flag.  (It may have
5131                          * been changed by e2fsck since we originally mounted
5132                          * the partition.)
5133                          */
5134                         if (sbi->s_journal)
5135                                 ext4_clear_journal_err(sb, es);
5136                         sbi->s_mount_state = le16_to_cpu(es->s_state);
5137                         if (!ext4_setup_super(sb, es, 0))
5138                                 sb->s_flags &= ~MS_RDONLY;
5139                         if (ext4_has_feature_mmp(sb))
5140                                 if (ext4_multi_mount_protect(sb,
5141                                                 le64_to_cpu(es->s_mmp_block))) {
5142                                         err = -EROFS;
5143                                         goto restore_opts;
5144                                 }
5145                         enable_quota = 1;
5146                 }
5147         }
5148
5149         /*
5150          * Reinitialize lazy itable initialization thread based on
5151          * current settings
5152          */
5153         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5154                 ext4_unregister_li_request(sb);
5155         else {
5156                 ext4_group_t first_not_zeroed;
5157                 first_not_zeroed = ext4_has_uninit_itable(sb);
5158                 ext4_register_li_request(sb, first_not_zeroed);
5159         }
5160
5161         ext4_setup_system_zone(sb);
5162         if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5163                 ext4_commit_super(sb, 1);
5164
5165 #ifdef CONFIG_QUOTA
5166         /* Release old quota file names */
5167         for (i = 0; i < EXT4_MAXQUOTAS; i++)
5168                 kfree(old_opts.s_qf_names[i]);
5169         if (enable_quota) {
5170                 if (sb_any_quota_suspended(sb))
5171                         dquot_resume(sb, -1);
5172                 else if (ext4_has_feature_quota(sb)) {
5173                         err = ext4_enable_quotas(sb);
5174                         if (err)
5175                                 goto restore_opts;
5176                 }
5177         }
5178 #endif
5179
5180         *flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5181         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5182         kfree(orig_data);
5183         return 0;
5184
5185 restore_opts:
5186         sb->s_flags = old_sb_flags;
5187         sbi->s_mount_opt = old_opts.s_mount_opt;
5188         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5189         sbi->s_resuid = old_opts.s_resuid;
5190         sbi->s_resgid = old_opts.s_resgid;
5191         sbi->s_commit_interval = old_opts.s_commit_interval;
5192         sbi->s_min_batch_time = old_opts.s_min_batch_time;
5193         sbi->s_max_batch_time = old_opts.s_max_batch_time;
5194 #ifdef CONFIG_QUOTA
5195         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5196         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5197                 kfree(sbi->s_qf_names[i]);
5198                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5199         }
5200 #endif
5201         kfree(orig_data);
5202         return err;
5203 }
5204
5205 #ifdef CONFIG_QUOTA
5206 static int ext4_statfs_project(struct super_block *sb,
5207                                kprojid_t projid, struct kstatfs *buf)
5208 {
5209         struct kqid qid;
5210         struct dquot *dquot;
5211         u64 limit;
5212         u64 curblock;
5213
5214         qid = make_kqid_projid(projid);
5215         dquot = dqget(sb, qid);
5216         if (IS_ERR(dquot))
5217                 return PTR_ERR(dquot);
5218         spin_lock(&dquot->dq_dqb_lock);
5219
5220         limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5221                  dquot->dq_dqb.dqb_bsoftlimit :
5222                  dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5223         if (limit && buf->f_blocks > limit) {
5224                 curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5225                 buf->f_blocks = limit;
5226                 buf->f_bfree = buf->f_bavail =
5227                         (buf->f_blocks > curblock) ?
5228                          (buf->f_blocks - curblock) : 0;
5229         }
5230
5231         limit = dquot->dq_dqb.dqb_isoftlimit ?
5232                 dquot->dq_dqb.dqb_isoftlimit :
5233                 dquot->dq_dqb.dqb_ihardlimit;
5234         if (limit && buf->f_files > limit) {
5235                 buf->f_files = limit;
5236                 buf->f_ffree =
5237                         (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5238                          (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5239         }
5240
5241         spin_unlock(&dquot->dq_dqb_lock);
5242         dqput(dquot);
5243         return 0;
5244 }
5245 #endif
5246
5247 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5248 {
5249         struct super_block *sb = dentry->d_sb;
5250         struct ext4_sb_info *sbi = EXT4_SB(sb);
5251         struct ext4_super_block *es = sbi->s_es;
5252         ext4_fsblk_t overhead = 0, resv_blocks;
5253         u64 fsid;
5254         s64 bfree;
5255         resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5256
5257         if (!test_opt(sb, MINIX_DF))
5258                 overhead = sbi->s_overhead;
5259
5260         buf->f_type = EXT4_SUPER_MAGIC;
5261         buf->f_bsize = sb->s_blocksize;
5262         buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5263         bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5264                 percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5265         /* prevent underflow in case that few free space is available */
5266         buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5267         buf->f_bavail = buf->f_bfree -
5268                         (ext4_r_blocks_count(es) + resv_blocks);
5269         if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5270                 buf->f_bavail = 0;
5271         buf->f_files = le32_to_cpu(es->s_inodes_count);
5272         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5273         buf->f_namelen = EXT4_NAME_LEN;
5274         fsid = le64_to_cpup((void *)es->s_uuid) ^
5275                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5276         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5277         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5278
5279 #ifdef CONFIG_QUOTA
5280         if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5281             sb_has_quota_limits_enabled(sb, PRJQUOTA))
5282                 ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5283 #endif
5284         return 0;
5285 }
5286
5287
5288 #ifdef CONFIG_QUOTA
5289
5290 /*
5291  * Helper functions so that transaction is started before we acquire dqio_sem
5292  * to keep correct lock ordering of transaction > dqio_sem
5293  */
5294 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5295 {
5296         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5297 }
5298
5299 static int ext4_write_dquot(struct dquot *dquot)
5300 {
5301         int ret, err;
5302         handle_t *handle;
5303         struct inode *inode;
5304
5305         inode = dquot_to_inode(dquot);
5306         handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5307                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5308         if (IS_ERR(handle))
5309                 return PTR_ERR(handle);
5310         ret = dquot_commit(dquot);
5311         err = ext4_journal_stop(handle);
5312         if (!ret)
5313                 ret = err;
5314         return ret;
5315 }
5316
5317 static int ext4_acquire_dquot(struct dquot *dquot)
5318 {
5319         int ret, err;
5320         handle_t *handle;
5321
5322         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5323                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5324         if (IS_ERR(handle))
5325                 return PTR_ERR(handle);
5326         ret = dquot_acquire(dquot);
5327         err = ext4_journal_stop(handle);
5328         if (!ret)
5329                 ret = err;
5330         return ret;
5331 }
5332
5333 static int ext4_release_dquot(struct dquot *dquot)
5334 {
5335         int ret, err;
5336         handle_t *handle;
5337
5338         handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5339                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5340         if (IS_ERR(handle)) {
5341                 /* Release dquot anyway to avoid endless cycle in dqput() */
5342                 dquot_release(dquot);
5343                 return PTR_ERR(handle);
5344         }
5345         ret = dquot_release(dquot);
5346         err = ext4_journal_stop(handle);
5347         if (!ret)
5348                 ret = err;
5349         return ret;
5350 }
5351
5352 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5353 {
5354         struct super_block *sb = dquot->dq_sb;
5355         struct ext4_sb_info *sbi = EXT4_SB(sb);
5356
5357         /* Are we journaling quotas? */
5358         if (ext4_has_feature_quota(sb) ||
5359             sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5360                 dquot_mark_dquot_dirty(dquot);
5361                 return ext4_write_dquot(dquot);
5362         } else {
5363                 return dquot_mark_dquot_dirty(dquot);
5364         }
5365 }
5366
5367 static int ext4_write_info(struct super_block *sb, int type)
5368 {
5369         int ret, err;
5370         handle_t *handle;
5371
5372         /* Data block + inode block */
5373         handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5374         if (IS_ERR(handle))
5375                 return PTR_ERR(handle);
5376         ret = dquot_commit_info(sb, type);
5377         err = ext4_journal_stop(handle);
5378         if (!ret)
5379                 ret = err;
5380         return ret;
5381 }
5382
5383 /*
5384  * Turn on quotas during mount time - we need to find
5385  * the quota file and such...
5386  */
5387 static int ext4_quota_on_mount(struct super_block *sb, int type)
5388 {
5389         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5390                                         EXT4_SB(sb)->s_jquota_fmt, type);
5391 }
5392
5393 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5394 {
5395         struct ext4_inode_info *ei = EXT4_I(inode);
5396
5397         /* The first argument of lockdep_set_subclass has to be
5398          * *exactly* the same as the argument to init_rwsem() --- in
5399          * this case, in init_once() --- or lockdep gets unhappy
5400          * because the name of the lock is set using the
5401          * stringification of the argument to init_rwsem().
5402          */
5403         (void) ei;      /* shut up clang warning if !CONFIG_LOCKDEP */
5404         lockdep_set_subclass(&ei->i_data_sem, subclass);
5405 }
5406
5407 /*
5408  * Standard function to be called on quota_on
5409  */
5410 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5411                          const struct path *path)
5412 {
5413         int err;
5414
5415         if (!test_opt(sb, QUOTA))
5416                 return -EINVAL;
5417
5418         /* Quotafile not on the same filesystem? */
5419         if (path->dentry->d_sb != sb)
5420                 return -EXDEV;
5421         /* Journaling quota? */
5422         if (EXT4_SB(sb)->s_qf_names[type]) {
5423                 /* Quotafile not in fs root? */
5424                 if (path->dentry->d_parent != sb->s_root)
5425                         ext4_msg(sb, KERN_WARNING,
5426                                 "Quota file not on filesystem root. "
5427                                 "Journaled quota will not work");
5428                 sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5429         } else {
5430                 /*
5431                  * Clear the flag just in case mount options changed since
5432                  * last time.
5433                  */
5434                 sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5435         }
5436
5437         /*
5438          * When we journal data on quota file, we have to flush journal to see
5439          * all updates to the file when we bypass pagecache...
5440          */
5441         if (EXT4_SB(sb)->s_journal &&
5442             ext4_should_journal_data(d_inode(path->dentry))) {
5443                 /*
5444                  * We don't need to lock updates but journal_flush() could
5445                  * otherwise be livelocked...
5446                  */
5447                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5448                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5449                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5450                 if (err)
5451                         return err;
5452         }
5453
5454         lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5455         err = dquot_quota_on(sb, type, format_id, path);
5456         if (err) {
5457                 lockdep_set_quota_inode(path->dentry->d_inode,
5458                                              I_DATA_SEM_NORMAL);
5459         } else {
5460                 struct inode *inode = d_inode(path->dentry);
5461                 handle_t *handle;
5462
5463                 /*
5464                  * Set inode flags to prevent userspace from messing with quota
5465                  * files. If this fails, we return success anyway since quotas
5466                  * are already enabled and this is not a hard failure.
5467                  */
5468                 inode_lock(inode);
5469                 handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5470                 if (IS_ERR(handle))
5471                         goto unlock_inode;
5472                 EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5473                 inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5474                                 S_NOATIME | S_IMMUTABLE);
5475                 ext4_mark_inode_dirty(handle, inode);
5476                 ext4_journal_stop(handle);
5477         unlock_inode:
5478                 inode_unlock(inode);
5479         }
5480         return err;
5481 }
5482
5483 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5484                              unsigned int flags)
5485 {
5486         int err;
5487         struct inode *qf_inode;
5488         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5489                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5490                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5491                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5492         };
5493
5494         BUG_ON(!ext4_has_feature_quota(sb));
5495
5496         if (!qf_inums[type])
5497                 return -EPERM;
5498
5499         qf_inode = ext4_iget(sb, qf_inums[type]);
5500         if (IS_ERR(qf_inode)) {
5501                 ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5502                 return PTR_ERR(qf_inode);
5503         }
5504
5505         /* Don't account quota for quota files to avoid recursion */
5506         qf_inode->i_flags |= S_NOQUOTA;
5507         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5508         err = dquot_enable(qf_inode, type, format_id, flags);
5509         iput(qf_inode);
5510         if (err)
5511                 lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5512
5513         return err;
5514 }
5515
5516 /* Enable usage tracking for all quota types. */
5517 static int ext4_enable_quotas(struct super_block *sb)
5518 {
5519         int type, err = 0;
5520         unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5521                 le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5522                 le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5523                 le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5524         };
5525         bool quota_mopt[EXT4_MAXQUOTAS] = {
5526                 test_opt(sb, USRQUOTA),
5527                 test_opt(sb, GRPQUOTA),
5528                 test_opt(sb, PRJQUOTA),
5529         };
5530
5531         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5532         for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5533                 if (qf_inums[type]) {
5534                         err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5535                                 DQUOT_USAGE_ENABLED |
5536                                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5537                         if (err) {
5538                                 for (type--; type >= 0; type--)
5539                                         dquot_quota_off(sb, type);
5540
5541                                 ext4_warning(sb,
5542                                         "Failed to enable quota tracking "
5543                                         "(type=%d, err=%d). Please run "
5544                                         "e2fsck to fix.", type, err);
5545                                 return err;
5546                         }
5547                 }
5548         }
5549         return 0;
5550 }
5551
5552 static int ext4_quota_off(struct super_block *sb, int type)
5553 {
5554         struct inode *inode = sb_dqopt(sb)->files[type];
5555         handle_t *handle;
5556         int err;
5557
5558         /* Force all delayed allocation blocks to be allocated.
5559          * Caller already holds s_umount sem */
5560         if (test_opt(sb, DELALLOC))
5561                 sync_filesystem(sb);
5562
5563         if (!inode || !igrab(inode))
5564                 goto out;
5565
5566         err = dquot_quota_off(sb, type);
5567         if (err || ext4_has_feature_quota(sb))
5568                 goto out_put;
5569
5570         inode_lock(inode);
5571         /*
5572          * Update modification times of quota files when userspace can
5573          * start looking at them. If we fail, we return success anyway since
5574          * this is not a hard failure and quotas are already disabled.
5575          */
5576         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5577         if (IS_ERR(handle))
5578                 goto out_unlock;
5579         EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5580         inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5581         inode->i_mtime = inode->i_ctime = current_time(inode);
5582         ext4_mark_inode_dirty(handle, inode);
5583         ext4_journal_stop(handle);
5584 out_unlock:
5585         inode_unlock(inode);
5586 out_put:
5587         lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5588         iput(inode);
5589         return err;
5590 out:
5591         return dquot_quota_off(sb, type);
5592 }
5593
5594 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5595  * acquiring the locks... As quota files are never truncated and quota code
5596  * itself serializes the operations (and no one else should touch the files)
5597  * we don't have to be afraid of races */
5598 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5599                                size_t len, loff_t off)
5600 {
5601         struct inode *inode = sb_dqopt(sb)->files[type];
5602         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5603         int offset = off & (sb->s_blocksize - 1);
5604         int tocopy;
5605         size_t toread;
5606         struct buffer_head *bh;
5607         loff_t i_size = i_size_read(inode);
5608
5609         if (off > i_size)
5610                 return 0;
5611         if (off+len > i_size)
5612                 len = i_size-off;
5613         toread = len;
5614         while (toread > 0) {
5615                 tocopy = sb->s_blocksize - offset < toread ?
5616                                 sb->s_blocksize - offset : toread;
5617                 bh = ext4_bread(NULL, inode, blk, 0);
5618                 if (IS_ERR(bh))
5619                         return PTR_ERR(bh);
5620                 if (!bh)        /* A hole? */
5621                         memset(data, 0, tocopy);
5622                 else
5623                         memcpy(data, bh->b_data+offset, tocopy);
5624                 brelse(bh);
5625                 offset = 0;
5626                 toread -= tocopy;
5627                 data += tocopy;
5628                 blk++;
5629         }
5630         return len;
5631 }
5632
5633 /* Write to quotafile (we know the transaction is already started and has
5634  * enough credits) */
5635 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5636                                 const char *data, size_t len, loff_t off)
5637 {
5638         struct inode *inode = sb_dqopt(sb)->files[type];
5639         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5640         int err, offset = off & (sb->s_blocksize - 1);
5641         int retries = 0;
5642         struct buffer_head *bh;
5643         handle_t *handle = journal_current_handle();
5644
5645         if (EXT4_SB(sb)->s_journal && !handle) {
5646                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5647                         " cancelled because transaction is not started",
5648                         (unsigned long long)off, (unsigned long long)len);
5649                 return -EIO;
5650         }
5651         /*
5652          * Since we account only one data block in transaction credits,
5653          * then it is impossible to cross a block boundary.
5654          */
5655         if (sb->s_blocksize - offset < len) {
5656                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5657                         " cancelled because not block aligned",
5658                         (unsigned long long)off, (unsigned long long)len);
5659                 return -EIO;
5660         }
5661
5662         do {
5663                 bh = ext4_bread(handle, inode, blk,
5664                                 EXT4_GET_BLOCKS_CREATE |
5665                                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5666         } while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5667                  ext4_should_retry_alloc(inode->i_sb, &retries));
5668         if (IS_ERR(bh))
5669                 return PTR_ERR(bh);
5670         if (!bh)
5671                 goto out;
5672         BUFFER_TRACE(bh, "get write access");
5673         err = ext4_journal_get_write_access(handle, bh);
5674         if (err) {
5675                 brelse(bh);
5676                 return err;
5677         }
5678         lock_buffer(bh);
5679         memcpy(bh->b_data+offset, data, len);
5680         flush_dcache_page(bh->b_page);
5681         unlock_buffer(bh);
5682         err = ext4_handle_dirty_metadata(handle, NULL, bh);
5683         brelse(bh);
5684 out:
5685         if (inode->i_size < off + len) {
5686                 i_size_write(inode, off + len);
5687                 EXT4_I(inode)->i_disksize = inode->i_size;
5688                 ext4_mark_inode_dirty(handle, inode);
5689         }
5690         return len;
5691 }
5692
5693 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5694 {
5695         const struct quota_format_ops   *ops;
5696
5697         if (!sb_has_quota_loaded(sb, qid->type))
5698                 return -ESRCH;
5699         ops = sb_dqopt(sb)->ops[qid->type];
5700         if (!ops || !ops->get_next_id)
5701                 return -ENOSYS;
5702         return dquot_get_next_id(sb, qid);
5703 }
5704 #endif
5705
5706 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5707                        const char *dev_name, void *data)
5708 {
5709         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5710 }
5711
5712 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5713 static inline void register_as_ext2(void)
5714 {
5715         int err = register_filesystem(&ext2_fs_type);
5716         if (err)
5717                 printk(KERN_WARNING
5718                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5719 }
5720
5721 static inline void unregister_as_ext2(void)
5722 {
5723         unregister_filesystem(&ext2_fs_type);
5724 }
5725
5726 static inline int ext2_feature_set_ok(struct super_block *sb)
5727 {
5728         if (ext4_has_unknown_ext2_incompat_features(sb))
5729                 return 0;
5730         if (sb->s_flags & MS_RDONLY)
5731                 return 1;
5732         if (ext4_has_unknown_ext2_ro_compat_features(sb))
5733                 return 0;
5734         return 1;
5735 }
5736 #else
5737 static inline void register_as_ext2(void) { }
5738 static inline void unregister_as_ext2(void) { }
5739 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5740 #endif
5741
5742 static inline void register_as_ext3(void)
5743 {
5744         int err = register_filesystem(&ext3_fs_type);
5745         if (err)
5746                 printk(KERN_WARNING
5747                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5748 }
5749
5750 static inline void unregister_as_ext3(void)
5751 {
5752         unregister_filesystem(&ext3_fs_type);
5753 }
5754
5755 static inline int ext3_feature_set_ok(struct super_block *sb)
5756 {
5757         if (ext4_has_unknown_ext3_incompat_features(sb))
5758                 return 0;
5759         if (!ext4_has_feature_journal(sb))
5760                 return 0;
5761         if (sb->s_flags & MS_RDONLY)
5762                 return 1;
5763         if (ext4_has_unknown_ext3_ro_compat_features(sb))
5764                 return 0;
5765         return 1;
5766 }
5767
5768 static struct file_system_type ext4_fs_type = {
5769         .owner          = THIS_MODULE,
5770         .name           = "ext4",
5771         .mount          = ext4_mount,
5772         .kill_sb        = kill_block_super,
5773         .fs_flags       = FS_REQUIRES_DEV,
5774 };
5775 MODULE_ALIAS_FS("ext4");
5776
5777 /* Shared across all ext4 file systems */
5778 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5779
5780 static int __init ext4_init_fs(void)
5781 {
5782         int i, err;
5783
5784         ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5785         ext4_li_info = NULL;
5786         mutex_init(&ext4_li_mtx);
5787
5788         /* Build-time check for flags consistency */
5789         ext4_check_flag_values();
5790
5791         for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5792                 init_waitqueue_head(&ext4__ioend_wq[i]);
5793
5794         err = ext4_init_es();
5795         if (err)
5796                 return err;
5797
5798         err = ext4_init_pageio();
5799         if (err)
5800                 goto out5;
5801
5802         err = ext4_init_system_zone();
5803         if (err)
5804                 goto out4;
5805
5806         err = ext4_init_sysfs();
5807         if (err)
5808                 goto out3;
5809
5810         err = ext4_init_mballoc();
5811         if (err)
5812                 goto out2;
5813         err = init_inodecache();
5814         if (err)
5815                 goto out1;
5816         register_as_ext3();
5817         register_as_ext2();
5818         err = register_filesystem(&ext4_fs_type);
5819         if (err)
5820                 goto out;
5821
5822         return 0;
5823 out:
5824         unregister_as_ext2();
5825         unregister_as_ext3();
5826         destroy_inodecache();
5827 out1:
5828         ext4_exit_mballoc();
5829 out2:
5830         ext4_exit_sysfs();
5831 out3:
5832         ext4_exit_system_zone();
5833 out4:
5834         ext4_exit_pageio();
5835 out5:
5836         ext4_exit_es();
5837
5838         return err;
5839 }
5840
5841 static void __exit ext4_exit_fs(void)
5842 {
5843         ext4_destroy_lazyinit_thread();
5844         unregister_as_ext2();
5845         unregister_as_ext3();
5846         unregister_filesystem(&ext4_fs_type);
5847         destroy_inodecache();
5848         ext4_exit_mballoc();
5849         ext4_exit_sysfs();
5850         ext4_exit_system_zone();
5851         ext4_exit_pageio();
5852         ext4_exit_es();
5853 }
5854
5855 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5856 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5857 MODULE_LICENSE("GPL");
5858 module_init(ext4_init_fs)
5859 module_exit(ext4_exit_fs)