fs/f2fs/super.c

   1 /*
   2  * fs/f2fs/super.c
   3  *
   4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   5  *             http://www.samsung.com/
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/fs.h>
  14 #include <linux/statfs.h>
  15 #include <linux/buffer_head.h>
  16 #include <linux/backing-dev.h>
  17 #include <linux/kthread.h>
  18 #include <linux/parser.h>
  19 #include <linux/mount.h>
  20 #include <linux/seq_file.h>
  21 #include <linux/proc_fs.h>
  22 #include <linux/random.h>
  23 #include <linux/exportfs.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/f2fs_fs.h>
  26 #include <linux/sysfs.h>
  27
  28 #include "f2fs.h"
  29 #include "node.h"
  30 #include "segment.h"
  31 #include "xattr.h"
  32 #include "gc.h"
  33
  34 #define CREATE_TRACE_POINTS
  35 #include <trace/events/f2fs.h>
  36
  37 static struct proc_dir_entry *f2fs_proc_root;
  38 static struct kmem_cache *f2fs_inode_cachep;
  39 static struct kset *f2fs_kset;
  40
  41 enum {
  42         Opt_gc_background,
  43         Opt_disable_roll_forward,
  44         Opt_discard,
  45         Opt_noheap,
  46         Opt_user_xattr,
  47         Opt_nouser_xattr,
  48         Opt_acl,
  49         Opt_noacl,
  50         Opt_active_logs,
  51         Opt_disable_ext_identify,
  52         Opt_inline_xattr,
  53         Opt_inline_data,
  54         Opt_flush_merge,
  55         Opt_nobarrier,
  56         Opt_err,
  57 };
  58
  59 static match_table_t f2fs_tokens = {
  60         {Opt_gc_background, "background_gc=%s"},
  61         {Opt_disable_roll_forward, "disable_roll_forward"},
  62         {Opt_discard, "discard"},
  63         {Opt_noheap, "no_heap"},
  64         {Opt_user_xattr, "user_xattr"},
  65         {Opt_nouser_xattr, "nouser_xattr"},
  66         {Opt_acl, "acl"},
  67         {Opt_noacl, "noacl"},
  68         {Opt_active_logs, "active_logs=%u"},
  69         {Opt_disable_ext_identify, "disable_ext_identify"},
  70         {Opt_inline_xattr, "inline_xattr"},
  71         {Opt_inline_data, "inline_data"},
  72         {Opt_flush_merge, "flush_merge"},
  73         {Opt_nobarrier, "nobarrier"},
  74         {Opt_err, NULL},
  75 };
  76
  77 /* Sysfs support for f2fs */
  78 enum {
  79         GC_THREAD,      /* struct f2fs_gc_thread */
  80         SM_INFO,        /* struct f2fs_sm_info */
  81         NM_INFO,        /* struct f2fs_nm_info */
  82         F2FS_SBI,       /* struct f2fs_sb_info */
  83 };
  84
  85 struct f2fs_attr {
  86         struct attribute attr;
  87         ssize_t (*show)(struct f2fs_attr *, struct f2fs_sb_info *, char *);
  88         ssize_t (*store)(struct f2fs_attr *, struct f2fs_sb_info *,
  89                          const char *, size_t);
  90         int struct_type;
  91         int offset;
  92 };
  93
  94 static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type)
  95 {
  96         if (struct_type == GC_THREAD)
  97                 return (unsigned char *)sbi->gc_thread;
  98         else if (struct_type == SM_INFO)
  99                 return (unsigned char *)SM_I(sbi);
 100         else if (struct_type == NM_INFO)
 101                 return (unsigned char *)NM_I(sbi);
 102         else if (struct_type == F2FS_SBI)
 103                 return (unsigned char *)sbi;
 104         return NULL;
 105 }
 106
 107 static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
 108                         struct f2fs_sb_info *sbi, char *buf)
 109 {
 110         unsigned char *ptr = NULL;
 111         unsigned int *ui;
 112
 113         ptr = __struct_ptr(sbi, a->struct_type);
 114         if (!ptr)
 115                 return -EINVAL;
 116
 117         ui = (unsigned int *)(ptr + a->offset);
 118
 119         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
 120 }
 121
 122 static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
 123                         struct f2fs_sb_info *sbi,
 124                         const char *buf, size_t count)
 125 {
 126         unsigned char *ptr;
 127         unsigned long t;
 128         unsigned int *ui;
 129         ssize_t ret;
 130
 131         ptr = __struct_ptr(sbi, a->struct_type);
 132         if (!ptr)
 133                 return -EINVAL;
 134
 135         ui = (unsigned int *)(ptr + a->offset);
 136
 137         ret = kstrtoul(skip_spaces(buf), 0, &t);
 138         if (ret < 0)
 139                 return ret;
 140         *ui = t;
 141         return count;
 142 }
 143
 144 static ssize_t f2fs_attr_show(struct kobject *kobj,
 145                                 struct attribute *attr, char *buf)
 146 {
 147         struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
 148                                                                 s_kobj);
 149         struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
 150
 151         return a->show ? a->show(a, sbi, buf) : 0;
 152 }
 153
 154 static ssize_t f2fs_attr_store(struct kobject *kobj, struct attribute *attr,
 155                                                 const char *buf, size_t len)
 156 {
 157         struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
 158                                                                         s_kobj);
 159         struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
 160
 161         return a->store ? a->store(a, sbi, buf, len) : 0;
 162 }
 163
 164 static void f2fs_sb_release(struct kobject *kobj)
 165 {
 166         struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
 167                                                                 s_kobj);
 168         complete(&sbi->s_kobj_unregister);
 169 }
 170
 171 #define F2FS_ATTR_OFFSET(_struct_type, _name, _mode, _show, _store, _offset) \
 172 static struct f2fs_attr f2fs_attr_##_name = {                   \
 173         .attr = {.name = __stringify(_name), .mode = _mode },   \
 174         .show   = _show,                                        \
 175         .store  = _store,                                       \
 176         .struct_type = _struct_type,                            \
 177         .offset = _offset                                       \
 178 }
 179
 180 #define F2FS_RW_ATTR(struct_type, struct_name, name, elname)    \
 181         F2FS_ATTR_OFFSET(struct_type, name, 0644,               \
 182                 f2fs_sbi_show, f2fs_sbi_store,                  \
 183                 offsetof(struct struct_name, elname))
 184
 185 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_min_sleep_time, min_sleep_time);
 186 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time);
 187 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
 188 F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
 189 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
 190 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, max_small_discards, max_discards);
 191 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
 192 F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
 193 F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
 194 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
 195 F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
 196
 197 #define ATTR_LIST(name) (&f2fs_attr_##name.attr)
 198 static struct attribute *f2fs_attrs[] = {
 199         ATTR_LIST(gc_min_sleep_time),
 200         ATTR_LIST(gc_max_sleep_time),
 201         ATTR_LIST(gc_no_gc_sleep_time),
 202         ATTR_LIST(gc_idle),
 203         ATTR_LIST(reclaim_segments),
 204         ATTR_LIST(max_small_discards),
 205         ATTR_LIST(ipu_policy),
 206         ATTR_LIST(min_ipu_util),
 207         ATTR_LIST(max_victim_search),
 208         ATTR_LIST(dir_level),
 209         ATTR_LIST(ram_thresh),
 210         NULL,
 211 };
 212
 213 static const struct sysfs_ops f2fs_attr_ops = {
 214         .show   = f2fs_attr_show,
 215         .store  = f2fs_attr_store,
 216 };
 217
 218 static struct kobj_type f2fs_ktype = {
 219         .default_attrs  = f2fs_attrs,
 220         .sysfs_ops      = &f2fs_attr_ops,
 221         .release        = f2fs_sb_release,
 222 };
 223
 224 void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...)
 225 {
 226         struct va_format vaf;
 227         va_list args;
 228
 229         va_start(args, fmt);
 230         vaf.fmt = fmt;
 231         vaf.va = &args;
 232         printk("%sF2FS-fs (%s): %pV\n", level, sb->s_id, &vaf);
 233         va_end(args);
 234 }
 235
 236 static void init_once(void *foo)
 237 {
 238         struct f2fs_inode_info *fi = (struct f2fs_inode_info *) foo;
 239
 240         inode_init_once(&fi->vfs_inode);
 241 }
 242
 243 static int parse_options(struct super_block *sb, char *options)
 244 {
 245         struct f2fs_sb_info *sbi = F2FS_SB(sb);
 246         substring_t args[MAX_OPT_ARGS];
 247         char *p, *name;
 248         int arg = 0;
 249
 250         if (!options)
 251                 return 0;
 252
 253         while ((p = strsep(&options, ",")) != NULL) {
 254                 int token;
 255                 if (!*p)
 256                         continue;
 257                 /*
 258                  * Initialize args struct so we know whether arg was
 259                  * found; some options take optional arguments.
 260                  */
 261                 args[0].to = args[0].from = NULL;
 262                 token = match_token(p, f2fs_tokens, args);
 263
 264                 switch (token) {
 265                 case Opt_gc_background:
 266                         name = match_strdup(&args[0]);
 267
 268                         if (!name)
 269                                 return -ENOMEM;
 270                         if (strlen(name) == 2 && !strncmp(name, "on", 2))
 271                                 set_opt(sbi, BG_GC);
 272                         else if (strlen(name) == 3 && !strncmp(name, "off", 3))
 273                                 clear_opt(sbi, BG_GC);
 274                         else {
 275                                 kfree(name);
 276                                 return -EINVAL;
 277                         }
 278                         kfree(name);
 279                         break;
 280                 case Opt_disable_roll_forward:
 281                         set_opt(sbi, DISABLE_ROLL_FORWARD);
 282                         break;
 283                 case Opt_discard:
 284                         set_opt(sbi, DISCARD);
 285                         break;
 286                 case Opt_noheap:
 287                         set_opt(sbi, NOHEAP);
 288                         break;
 289 #ifdef CONFIG_F2FS_FS_XATTR
 290                 case Opt_user_xattr:
 291                         set_opt(sbi, XATTR_USER);
 292                         break;
 293                 case Opt_nouser_xattr:
 294                         clear_opt(sbi, XATTR_USER);
 295                         break;
 296                 case Opt_inline_xattr:
 297                         set_opt(sbi, INLINE_XATTR);
 298                         break;
 299 #else
 300                 case Opt_user_xattr:
 301                         f2fs_msg(sb, KERN_INFO,
 302                                 "user_xattr options not supported");
 303                         break;
 304                 case Opt_nouser_xattr:
 305                         f2fs_msg(sb, KERN_INFO,
 306                                 "nouser_xattr options not supported");
 307                         break;
 308                 case Opt_inline_xattr:
 309                         f2fs_msg(sb, KERN_INFO,
 310                                 "inline_xattr options not supported");
 311                         break;
 312 #endif
 313 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 314                 case Opt_acl:
 315                         set_opt(sbi, POSIX_ACL);
 316                         break;
 317                 case Opt_noacl:
 318                         clear_opt(sbi, POSIX_ACL);
 319                         break;
 320 #else
 321                 case Opt_acl:
 322                         f2fs_msg(sb, KERN_INFO, "acl options not supported");
 323                         break;
 324                 case Opt_noacl:
 325                         f2fs_msg(sb, KERN_INFO, "noacl options not supported");
 326                         break;
 327 #endif
 328                 case Opt_active_logs:
 329                         if (args->from && match_int(args, &arg))
 330                                 return -EINVAL;
 331                         if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
 332                                 return -EINVAL;
 333                         sbi->active_logs = arg;
 334                         break;
 335                 case Opt_disable_ext_identify:
 336                         set_opt(sbi, DISABLE_EXT_IDENTIFY);
 337                         break;
 338                 case Opt_inline_data:
 339                         set_opt(sbi, INLINE_DATA);
 340                         break;
 341                 case Opt_flush_merge:
 342                         set_opt(sbi, FLUSH_MERGE);
 343                         break;
 344                 case Opt_nobarrier:
 345                         set_opt(sbi, NOBARRIER);
 346                         break;
 347                 default:
 348                         f2fs_msg(sb, KERN_ERR,
 349                                 "Unrecognized mount option \"%s\" or missing value",
 350                                 p);
 351                         return -EINVAL;
 352                 }
 353         }
 354         return 0;
 355 }
 356
 357 static struct inode *f2fs_alloc_inode(struct super_block *sb)
 358 {
 359         struct f2fs_inode_info *fi;
 360
 361         fi = kmem_cache_alloc(f2fs_inode_cachep, GFP_F2FS_ZERO);
 362         if (!fi)
 363                 return NULL;
 364
 365         init_once((void *) fi);
 366
 367         /* Initialize f2fs-specific inode info */
 368         fi->vfs_inode.i_version = 1;
 369         atomic_set(&fi->dirty_dents, 0);
 370         fi->i_current_depth = 1;
 371         fi->i_advise = 0;
 372         rwlock_init(&fi->ext.ext_lock);
 373         init_rwsem(&fi->i_sem);
 374
 375         set_inode_flag(fi, FI_NEW_INODE);
 376
 377         if (test_opt(F2FS_SB(sb), INLINE_XATTR))
 378                 set_inode_flag(fi, FI_INLINE_XATTR);
 379
 380         /* Will be used by directory only */
 381         fi->i_dir_level = F2FS_SB(sb)->dir_level;
 382
 383         return &fi->vfs_inode;
 384 }
 385
 386 static int f2fs_drop_inode(struct inode *inode)
 387 {
 388         /*
 389          * This is to avoid a deadlock condition like below.
 390          * writeback_single_inode(inode)
 391          *  - f2fs_write_data_page
 392          *    - f2fs_gc -> iput -> evict
 393          *       - inode_wait_for_writeback(inode)
 394          */
 395         if (!inode_unhashed(inode) && inode->i_state & I_SYNC)
 396                 return 0;
 397         return generic_drop_inode(inode);
 398 }
 399
 400 /*
 401  * f2fs_dirty_inode() is called from __mark_inode_dirty()
 402  *
 403  * We should call set_dirty_inode to write the dirty inode through write_inode.
 404  */
 405 static void f2fs_dirty_inode(struct inode *inode, int flags)
 406 {
 407         set_inode_flag(F2FS_I(inode), FI_DIRTY_INODE);
 408 }
 409
 410 static void f2fs_i_callback(struct rcu_head *head)
 411 {
 412         struct inode *inode = container_of(head, struct inode, i_rcu);
 413         kmem_cache_free(f2fs_inode_cachep, F2FS_I(inode));
 414 }
 415
 416 static void f2fs_destroy_inode(struct inode *inode)
 417 {
 418         call_rcu(&inode->i_rcu, f2fs_i_callback);
 419 }
 420
 421 static void f2fs_put_super(struct super_block *sb)
 422 {
 423         struct f2fs_sb_info *sbi = F2FS_SB(sb);
 424
 425         if (sbi->s_proc) {
 426                 remove_proc_entry("segment_info", sbi->s_proc);
 427                 remove_proc_entry(sb->s_id, f2fs_proc_root);
 428         }
 429         kobject_del(&sbi->s_kobj);
 430
 431         f2fs_destroy_stats(sbi);
 432         stop_gc_thread(sbi);
 433
 434         /* We don't need to do checkpoint when it's clean */
 435         if (sbi->s_dirty)
 436                 write_checkpoint(sbi, true);
 437
 438         /*
 439          * normally superblock is clean, so we need to release this.
 440          * In addition, EIO will skip do checkpoint, we need this as well.
 441          */
 442         release_dirty_inode(sbi);
 443
 444         iput(sbi->node_inode);
 445         iput(sbi->meta_inode);
 446
 447         /* destroy f2fs internal modules */
 448         destroy_node_manager(sbi);
 449         destroy_segment_manager(sbi);
 450
 451         kfree(sbi->ckpt);
 452         kobject_put(&sbi->s_kobj);
 453         wait_for_completion(&sbi->s_kobj_unregister);
 454
 455         sb->s_fs_info = NULL;
 456         brelse(sbi->raw_super_buf);
 457         kfree(sbi);
 458 }
 459
 460 int f2fs_sync_fs(struct super_block *sb, int sync)
 461 {
 462         struct f2fs_sb_info *sbi = F2FS_SB(sb);
 463
 464         trace_f2fs_sync_fs(sb, sync);
 465
 466         if (sync) {
 467                 mutex_lock(&sbi->gc_mutex);
 468                 write_checkpoint(sbi, false);
 469                 mutex_unlock(&sbi->gc_mutex);
 470         } else {
 471                 f2fs_balance_fs(sbi);
 472         }
 473
 474         return 0;
 475 }
 476
 477 static int f2fs_freeze(struct super_block *sb)
 478 {
 479         int err;
 480
 481         if (f2fs_readonly(sb))
 482                 return 0;
 483
 484         err = f2fs_sync_fs(sb, 1);
 485         return err;
 486 }
 487
 488 static int f2fs_unfreeze(struct super_block *sb)
 489 {
 490         return 0;
 491 }
 492
 493 static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 494 {
 495         struct super_block *sb = dentry->d_sb;
 496         struct f2fs_sb_info *sbi = F2FS_SB(sb);
 497         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 498         block_t total_count, user_block_count, start_count, ovp_count;
 499
 500         total_count = le64_to_cpu(sbi->raw_super->block_count);
 501         user_block_count = sbi->user_block_count;
 502         start_count = le32_to_cpu(sbi->raw_super->segment0_blkaddr);
 503         ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
 504         buf->f_type = F2FS_SUPER_MAGIC;
 505         buf->f_bsize = sbi->blocksize;
 506
 507         buf->f_blocks = total_count - start_count;
 508         buf->f_bfree = buf->f_blocks - valid_user_blocks(sbi) - ovp_count;
 509         buf->f_bavail = user_block_count - valid_user_blocks(sbi);
 510
 511         buf->f_files = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;
 512         buf->f_ffree = buf->f_files - valid_inode_count(sbi);
 513
 514         buf->f_namelen = F2FS_NAME_LEN;
 515         buf->f_fsid.val[0] = (u32)id;
 516         buf->f_fsid.val[1] = (u32)(id >> 32);
 517
 518         return 0;
 519 }
 520
 521 static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 522 {
 523         struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
 524
 525         if (!f2fs_readonly(sbi->sb) && test_opt(sbi, BG_GC))
 526                 seq_printf(seq, ",background_gc=%s", "on");
 527         else
 528                 seq_printf(seq, ",background_gc=%s", "off");
 529         if (test_opt(sbi, DISABLE_ROLL_FORWARD))
 530                 seq_puts(seq, ",disable_roll_forward");
 531         if (test_opt(sbi, DISCARD))
 532                 seq_puts(seq, ",discard");
 533         if (test_opt(sbi, NOHEAP))
 534                 seq_puts(seq, ",no_heap_alloc");
 535 #ifdef CONFIG_F2FS_FS_XATTR
 536         if (test_opt(sbi, XATTR_USER))
 537                 seq_puts(seq, ",user_xattr");
 538         else
 539                 seq_puts(seq, ",nouser_xattr");
 540         if (test_opt(sbi, INLINE_XATTR))
 541                 seq_puts(seq, ",inline_xattr");
 542 #endif
 543 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 544         if (test_opt(sbi, POSIX_ACL))
 545                 seq_puts(seq, ",acl");
 546         else
 547                 seq_puts(seq, ",noacl");
 548 #endif
 549         if (test_opt(sbi, DISABLE_EXT_IDENTIFY))
 550                 seq_puts(seq, ",disable_ext_identify");
 551         if (test_opt(sbi, INLINE_DATA))
 552                 seq_puts(seq, ",inline_data");
 553         if (!f2fs_readonly(sbi->sb) && test_opt(sbi, FLUSH_MERGE))
 554                 seq_puts(seq, ",flush_merge");
 555         if (test_opt(sbi, NOBARRIER))
 556                 seq_puts(seq, ",nobarrier");
 557         seq_printf(seq, ",active_logs=%u", sbi->active_logs);
 558
 559         return 0;
 560 }
 561
 562 static int segment_info_seq_show(struct seq_file *seq, void *offset)
 563 {
 564         struct super_block *sb = seq->private;
 565         struct f2fs_sb_info *sbi = F2FS_SB(sb);
 566         unsigned int total_segs =
 567                         le32_to_cpu(sbi->raw_super->segment_count_main);
 568         int i;
 569
 570         seq_puts(seq, "format: segment_type|valid_blocks\n"
 571                 "segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)\n");
 572
 573         for (i = 0; i < total_segs; i++) {
 574                 struct seg_entry *se = get_seg_entry(sbi, i);
 575
 576                 if ((i % 10) == 0)
 577                         seq_printf(seq, "%-5d", i);
 578                 seq_printf(seq, "%d|%-3u", se->type,
 579                                         get_valid_blocks(sbi, i, 1));
 580                 if ((i % 10) == 9 || i == (total_segs - 1))
 581                         seq_putc(seq, '\n');
 582                 else
 583                         seq_putc(seq, ' ');
 584         }
 585
 586         return 0;
 587 }
 588
 589 static int segment_info_open_fs(struct inode *inode, struct file *file)
 590 {
 591         return single_open(file, segment_info_seq_show, PDE_DATA(inode));
 592 }
 593
 594 static const struct file_operations f2fs_seq_segment_info_fops = {
 595         .owner = THIS_MODULE,
 596         .open = segment_info_open_fs,
 597         .read = seq_read,
 598         .llseek = seq_lseek,
 599         .release = single_release,
 600 };
 601
 602 static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 603 {
 604         struct f2fs_sb_info *sbi = F2FS_SB(sb);
 605         struct f2fs_mount_info org_mount_opt;
 606         int err, active_logs;
 607         bool need_restart_gc = false;
 608         bool need_stop_gc = false;
 609
 610         sync_filesystem(sb);
 611
 612         /*
 613          * Save the old mount options in case we
 614          * need to restore them.
 615          */
 616         org_mount_opt = sbi->mount_opt;
 617         active_logs = sbi->active_logs;
 618
 619         /* parse mount options */
 620         err = parse_options(sb, data);
 621         if (err)
 622                 goto restore_opts;
 623
 624         /*
 625          * Previous and new state of filesystem is RO,
 626          * so skip checking GC and FLUSH_MERGE conditions.
 627          */
 628         if (f2fs_readonly(sb) && (*flags & MS_RDONLY))
 629                 goto skip;
 630
 631         /*
 632          * We stop the GC thread if FS is mounted as RO
 633          * or if background_gc = off is passed in mount
 634          * option. Also sync the filesystem.
 635          */
 636         if ((*flags & MS_RDONLY) || !test_opt(sbi, BG_GC)) {
 637                 if (sbi->gc_thread) {
 638                         stop_gc_thread(sbi);
 639                         f2fs_sync_fs(sb, 1);
 640                         need_restart_gc = true;
 641                 }
 642         } else if (test_opt(sbi, BG_GC) && !sbi->gc_thread) {
 643                 err = start_gc_thread(sbi);
 644                 if (err)
 645                         goto restore_opts;
 646                 need_stop_gc = true;
 647         }
 648
 649         /*
 650          * We stop issue flush thread if FS is mounted as RO
 651          * or if flush_merge is not passed in mount option.
 652          */
 653         if ((*flags & MS_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
 654                 destroy_flush_cmd_control(sbi);
 655         } else if (test_opt(sbi, FLUSH_MERGE) && !SM_I(sbi)->cmd_control_info) {
 656                 err = create_flush_cmd_control(sbi);
 657                 if (err)
 658                         goto restore_gc;
 659         }
 660 skip:
 661         /* Update the POSIXACL Flag */
 662          sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 663                 (test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
 664         return 0;
 665 restore_gc:
 666         if (need_restart_gc) {
 667                 if (start_gc_thread(sbi))
 668                         f2fs_msg(sbi->sb, KERN_WARNING,
 669                                 "background gc thread has stopped");
 670         } else if (need_stop_gc) {
 671                 stop_gc_thread(sbi);
 672         }
 673 restore_opts:
 674         sbi->mount_opt = org_mount_opt;
 675         sbi->active_logs = active_logs;
 676         return err;
 677 }
 678
 679 static struct super_operations f2fs_sops = {
 680         .alloc_inode    = f2fs_alloc_inode,
 681         .drop_inode     = f2fs_drop_inode,
 682         .destroy_inode  = f2fs_destroy_inode,
 683         .write_inode    = f2fs_write_inode,
 684         .dirty_inode    = f2fs_dirty_inode,
 685         .show_options   = f2fs_show_options,
 686         .evict_inode    = f2fs_evict_inode,
 687         .put_super      = f2fs_put_super,
 688         .sync_fs        = f2fs_sync_fs,
 689         .freeze_fs      = f2fs_freeze,
 690         .unfreeze_fs    = f2fs_unfreeze,
 691         .statfs         = f2fs_statfs,
 692         .remount_fs     = f2fs_remount,
 693 };
 694
 695 static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
 696                 u64 ino, u32 generation)
 697 {
 698         struct f2fs_sb_info *sbi = F2FS_SB(sb);
 699         struct inode *inode;
 700
 701         if (check_nid_range(sbi, ino))
 702                 return ERR_PTR(-ESTALE);
 703
 704         /*
 705          * f2fs_iget isn't quite right if the inode is currently unallocated!
 706          * However f2fs_iget currently does appropriate checks to handle stale
 707          * inodes so everything is OK.
 708          */
 709         inode = f2fs_iget(sb, ino);
 710         if (IS_ERR(inode))
 711                 return ERR_CAST(inode);
 712         if (unlikely(generation && inode->i_generation != generation)) {
 713                 /* we didn't find the right inode.. */
 714                 iput(inode);
 715                 return ERR_PTR(-ESTALE);
 716         }
 717         return inode;
 718 }
 719
 720 static struct dentry *f2fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
 721                 int fh_len, int fh_type)
 722 {
 723         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 724                                     f2fs_nfs_get_inode);
 725 }
 726
 727 static struct dentry *f2fs_fh_to_parent(struct super_block *sb, struct fid *fid,
 728                 int fh_len, int fh_type)
 729 {
 730         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 731                                     f2fs_nfs_get_inode);
 732 }
 733
 734 static const struct export_operations f2fs_export_ops = {
 735         .fh_to_dentry = f2fs_fh_to_dentry,
 736         .fh_to_parent = f2fs_fh_to_parent,
 737         .get_parent = f2fs_get_parent,
 738 };
 739
 740 static loff_t max_file_size(unsigned bits)
 741 {
 742         loff_t result = (DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS);
 743         loff_t leaf_count = ADDRS_PER_BLOCK;
 744
 745         /* two direct node blocks */
 746         result += (leaf_count * 2);
 747
 748         /* two indirect node blocks */
 749         leaf_count *= NIDS_PER_BLOCK;
 750         result += (leaf_count * 2);
 751
 752         /* one double indirect node block */
 753         leaf_count *= NIDS_PER_BLOCK;
 754         result += leaf_count;
 755
 756         result <<= bits;
 757         return result;
 758 }
 759
 760 static int sanity_check_raw_super(struct super_block *sb,
 761                         struct f2fs_super_block *raw_super)
 762 {
 763         unsigned int blocksize;
 764
 765         if (F2FS_SUPER_MAGIC != le32_to_cpu(raw_super->magic)) {
 766                 f2fs_msg(sb, KERN_INFO,
 767                         "Magic Mismatch, valid(0x%x) - read(0x%x)",
 768                         F2FS_SUPER_MAGIC, le32_to_cpu(raw_super->magic));
 769                 return 1;
 770         }
 771
 772         /* Currently, support only 4KB page cache size */
 773         if (F2FS_BLKSIZE != PAGE_CACHE_SIZE) {
 774                 f2fs_msg(sb, KERN_INFO,
 775                         "Invalid page_cache_size (%lu), supports only 4KB\n",
 776                         PAGE_CACHE_SIZE);
 777                 return 1;
 778         }
 779
 780         /* Currently, support only 4KB block size */
 781         blocksize = 1 << le32_to_cpu(raw_super->log_blocksize);
 782         if (blocksize != F2FS_BLKSIZE) {
 783                 f2fs_msg(sb, KERN_INFO,
 784                         "Invalid blocksize (%u), supports only 4KB\n",
 785                         blocksize);
 786                 return 1;
 787         }
 788
 789         if (le32_to_cpu(raw_super->log_sectorsize) !=
 790                                         F2FS_LOG_SECTOR_SIZE) {
 791                 f2fs_msg(sb, KERN_INFO, "Invalid log sectorsize");
 792                 return 1;
 793         }
 794         if (le32_to_cpu(raw_super->log_sectors_per_block) !=
 795                                         F2FS_LOG_SECTORS_PER_BLOCK) {
 796                 f2fs_msg(sb, KERN_INFO, "Invalid log sectors per block");
 797                 return 1;
 798         }
 799         return 0;
 800 }
 801
 802 static int sanity_check_ckpt(struct f2fs_sb_info *sbi)
 803 {
 804         unsigned int total, fsmeta;
 805         struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
 806         struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
 807
 808         total = le32_to_cpu(raw_super->segment_count);
 809         fsmeta = le32_to_cpu(raw_super->segment_count_ckpt);
 810         fsmeta += le32_to_cpu(raw_super->segment_count_sit);
 811         fsmeta += le32_to_cpu(raw_super->segment_count_nat);
 812         fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
 813         fsmeta += le32_to_cpu(raw_super->segment_count_ssa);
 814
 815         if (unlikely(fsmeta >= total))
 816                 return 1;
 817
 818         if (unlikely(f2fs_cp_error(sbi))) {
 819                 f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
 820                 return 1;
 821         }
 822         return 0;
 823 }
 824
 825 static void init_sb_info(struct f2fs_sb_info *sbi)
 826 {
 827         struct f2fs_super_block *raw_super = sbi->raw_super;
 828         int i;
 829
 830         sbi->log_sectors_per_block =
 831                 le32_to_cpu(raw_super->log_sectors_per_block);
 832         sbi->log_blocksize = le32_to_cpu(raw_super->log_blocksize);
 833         sbi->blocksize = 1 << sbi->log_blocksize;
 834         sbi->log_blocks_per_seg = le32_to_cpu(raw_super->log_blocks_per_seg);
 835         sbi->blocks_per_seg = 1 << sbi->log_blocks_per_seg;
 836         sbi->segs_per_sec = le32_to_cpu(raw_super->segs_per_sec);
 837         sbi->secs_per_zone = le32_to_cpu(raw_super->secs_per_zone);
 838         sbi->total_sections = le32_to_cpu(raw_super->section_count);
 839         sbi->total_node_count =
 840                 (le32_to_cpu(raw_super->segment_count_nat) / 2)
 841                         * sbi->blocks_per_seg * NAT_ENTRY_PER_BLOCK;
 842         sbi->root_ino_num = le32_to_cpu(raw_super->root_ino);
 843         sbi->node_ino_num = le32_to_cpu(raw_super->node_ino);
 844         sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino);
 845         sbi->cur_victim_sec = NULL_SECNO;
 846         sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH;
 847
 848         for (i = 0; i < NR_COUNT_TYPE; i++)
 849                 atomic_set(&sbi->nr_pages[i], 0);
 850
 851         sbi->dir_level = DEF_DIR_LEVEL;
 852 }
 853
 854 /*
 855  * Read f2fs raw super block.
 856  * Because we have two copies of super block, so read the first one at first,
 857  * if the first one is invalid, move to read the second one.
 858  */
 859 static int read_raw_super_block(struct super_block *sb,
 860                         struct f2fs_super_block **raw_super,
 861                         struct buffer_head **raw_super_buf)
 862 {
 863         int block = 0;
 864
 865 retry:
 866         *raw_super_buf = sb_bread(sb, block);
 867         if (!*raw_super_buf) {
 868                 f2fs_msg(sb, KERN_ERR, "Unable to read %dth superblock",
 869                                 block + 1);
 870                 if (block == 0) {
 871                         block++;
 872                         goto retry;
 873                 } else {
 874                         return -EIO;
 875                 }
 876         }
 877
 878         *raw_super = (struct f2fs_super_block *)
 879                 ((char *)(*raw_super_buf)->b_data + F2FS_SUPER_OFFSET);
 880
 881         /* sanity checking of raw super */
 882         if (sanity_check_raw_super(sb, *raw_super)) {
 883                 brelse(*raw_super_buf);
 884                 f2fs_msg(sb, KERN_ERR,
 885                         "Can't find valid F2FS filesystem in %dth superblock",
 886                                                                 block + 1);
 887                 if (block == 0) {
 888                         block++;
 889                         goto retry;
 890                 } else {
 891                         return -EINVAL;
 892                 }
 893         }
 894
 895         return 0;
 896 }
 897
 898 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 899 {
 900         struct f2fs_sb_info *sbi;
 901         struct f2fs_super_block *raw_super;
 902         struct buffer_head *raw_super_buf;
 903         struct inode *root;
 904         long err = -EINVAL;
 905         bool retry = true;
 906         int i;
 907
 908 try_onemore:
 909         /* allocate memory for f2fs-specific super block info */
 910         sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
 911         if (!sbi)
 912                 return -ENOMEM;
 913
 914         /* set a block size */
 915         if (unlikely(!sb_set_blocksize(sb, F2FS_BLKSIZE))) {
 916                 f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
 917                 goto free_sbi;
 918         }
 919
 920         err = read_raw_super_block(sb, &raw_super, &raw_super_buf);
 921         if (err)
 922                 goto free_sbi;
 923
 924         sb->s_fs_info = sbi;
 925         /* init some FS parameters */
 926         sbi->active_logs = NR_CURSEG_TYPE;
 927
 928         set_opt(sbi, BG_GC);
 929
 930 #ifdef CONFIG_F2FS_FS_XATTR
 931         set_opt(sbi, XATTR_USER);
 932 #endif
 933 #ifdef CONFIG_F2FS_FS_POSIX_ACL
 934         set_opt(sbi, POSIX_ACL);
 935 #endif
 936         /* parse mount options */
 937         err = parse_options(sb, (char *)data);
 938         if (err)
 939                 goto free_sb_buf;
 940
 941         sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
 942         sb->s_max_links = F2FS_LINK_MAX;
 943         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 944
 945         sb->s_op = &f2fs_sops;
 946         sb->s_xattr = f2fs_xattr_handlers;
 947         sb->s_export_op = &f2fs_export_ops;
 948         sb->s_magic = F2FS_SUPER_MAGIC;
 949         sb->s_time_gran = 1;
 950         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 951                 (test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
 952         memcpy(sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
 953
 954         /* init f2fs-specific super block info */
 955         sbi->sb = sb;
 956         sbi->raw_super = raw_super;
 957         sbi->raw_super_buf = raw_super_buf;
 958         mutex_init(&sbi->gc_mutex);
 959         mutex_init(&sbi->writepages);
 960         mutex_init(&sbi->cp_mutex);
 961         init_rwsem(&sbi->node_write);
 962         sbi->por_doing = false;
 963         spin_lock_init(&sbi->stat_lock);
 964
 965         init_rwsem(&sbi->read_io.io_rwsem);
 966         sbi->read_io.sbi = sbi;
 967         sbi->read_io.bio = NULL;
 968         for (i = 0; i < NR_PAGE_TYPE; i++) {
 969                 init_rwsem(&sbi->write_io[i].io_rwsem);
 970                 sbi->write_io[i].sbi = sbi;
 971                 sbi->write_io[i].bio = NULL;
 972         }
 973
 974         init_rwsem(&sbi->cp_rwsem);
 975         init_waitqueue_head(&sbi->cp_wait);
 976         init_sb_info(sbi);
 977
 978         /* get an inode for meta space */
 979         sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
 980         if (IS_ERR(sbi->meta_inode)) {
 981                 f2fs_msg(sb, KERN_ERR, "Failed to read F2FS meta data inode");
 982                 err = PTR_ERR(sbi->meta_inode);
 983                 goto free_sb_buf;
 984         }
 985
 986         err = get_valid_checkpoint(sbi);
 987         if (err) {
 988                 f2fs_msg(sb, KERN_ERR, "Failed to get valid F2FS checkpoint");
 989                 goto free_meta_inode;
 990         }
 991
 992         /* sanity checking of checkpoint */
 993         err = -EINVAL;
 994         if (sanity_check_ckpt(sbi)) {
 995                 f2fs_msg(sb, KERN_ERR, "Invalid F2FS checkpoint");
 996                 goto free_cp;
 997         }
 998
 999         sbi->total_valid_node_count =
1000                                 le32_to_cpu(sbi->ckpt->valid_node_count);
1001         sbi->total_valid_inode_count =
1002                                 le32_to_cpu(sbi->ckpt->valid_inode_count);
1003         sbi->user_block_count = le64_to_cpu(sbi->ckpt->user_block_count);
1004         sbi->total_valid_block_count =
1005                                 le64_to_cpu(sbi->ckpt->valid_block_count);
1006         sbi->last_valid_block_count = sbi->total_valid_block_count;
1007         sbi->alloc_valid_block_count = 0;
1008         INIT_LIST_HEAD(&sbi->dir_inode_list);
1009         spin_lock_init(&sbi->dir_inode_lock);
1010
1011         init_ino_entry_info(sbi);
1012
1013         /* setup f2fs internal modules */
1014         err = build_segment_manager(sbi);
1015         if (err) {
1016                 f2fs_msg(sb, KERN_ERR,
1017                         "Failed to initialize F2FS segment manager");
1018                 goto free_sm;
1019         }
1020         err = build_node_manager(sbi);
1021         if (err) {
1022                 f2fs_msg(sb, KERN_ERR,
1023                         "Failed to initialize F2FS node manager");
1024                 goto free_nm;
1025         }
1026
1027         build_gc_manager(sbi);
1028
1029         /* get an inode for node space */
1030         sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
1031         if (IS_ERR(sbi->node_inode)) {
1032                 f2fs_msg(sb, KERN_ERR, "Failed to read node inode");
1033                 err = PTR_ERR(sbi->node_inode);
1034                 goto free_nm;
1035         }
1036
1037         /* if there are nt orphan nodes free them */
1038         recover_orphan_inodes(sbi);
1039
1040         /* read root inode and dentry */
1041         root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
1042         if (IS_ERR(root)) {
1043                 f2fs_msg(sb, KERN_ERR, "Failed to read root inode");
1044                 err = PTR_ERR(root);
1045                 goto free_node_inode;
1046         }
1047         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
1048                 iput(root);
1049                 err = -EINVAL;
1050                 goto free_node_inode;
1051         }
1052
1053         sb->s_root = d_make_root(root); /* allocate root dentry */
1054         if (!sb->s_root) {
1055                 err = -ENOMEM;
1056                 goto free_root_inode;
1057         }
1058
1059         err = f2fs_build_stats(sbi);
1060         if (err)
1061                 goto free_root_inode;
1062
1063         if (f2fs_proc_root)
1064                 sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
1065
1066         if (sbi->s_proc)
1067                 proc_create_data("segment_info", S_IRUGO, sbi->s_proc,
1068                                  &f2fs_seq_segment_info_fops, sb);
1069
1070         if (test_opt(sbi, DISCARD)) {
1071                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1072                 if (!blk_queue_discard(q))
1073                         f2fs_msg(sb, KERN_WARNING,
1074                                         "mounting with \"discard\" option, but "
1075                                         "the device does not support discard");
1076         }
1077
1078         sbi->s_kobj.kset = f2fs_kset;
1079         init_completion(&sbi->s_kobj_unregister);
1080         err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL,
1081                                                         "%s", sb->s_id);
1082         if (err)
1083                 goto free_proc;
1084
1085         /* recover fsynced data */
1086         if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
1087                 err = recover_fsync_data(sbi);
1088                 if (err) {
1089                         f2fs_msg(sb, KERN_ERR,
1090                                 "Cannot recover all fsync data errno=%ld", err);
1091                         goto free_kobj;
1092                 }
1093         }
1094
1095         /*
1096          * If filesystem is not mounted as read-only then
1097          * do start the gc_thread.
1098          */
1099         if (!f2fs_readonly(sb)) {
1100                 /* After POR, we can run background GC thread.*/
1101                 err = start_gc_thread(sbi);
1102                 if (err)
1103                         goto free_kobj;
1104         }
1105         return 0;
1106
1107 free_kobj:
1108         kobject_del(&sbi->s_kobj);
1109 free_proc:
1110         if (sbi->s_proc) {
1111                 remove_proc_entry("segment_info", sbi->s_proc);
1112                 remove_proc_entry(sb->s_id, f2fs_proc_root);
1113         }
1114         f2fs_destroy_stats(sbi);
1115 free_root_inode:
1116         dput(sb->s_root);
1117         sb->s_root = NULL;
1118 free_node_inode:
1119         iput(sbi->node_inode);
1120 free_nm:
1121         destroy_node_manager(sbi);
1122 free_sm:
1123         destroy_segment_manager(sbi);
1124 free_cp:
1125         kfree(sbi->ckpt);
1126 free_meta_inode:
1127         make_bad_inode(sbi->meta_inode);
1128         iput(sbi->meta_inode);
1129 free_sb_buf:
1130         brelse(raw_super_buf);
1131 free_sbi:
1132         kfree(sbi);
1133
1134         /* give only one another chance */
1135         if (retry) {
1136                 retry = 0;
1137                 shrink_dcache_sb(sb);
1138                 goto try_onemore;
1139         }
1140         return err;
1141 }
1142
1143 static struct dentry *f2fs_mount(struct file_system_type *fs_type, int flags,
1144                         const char *dev_name, void *data)
1145 {
1146         return mount_bdev(fs_type, flags, dev_name, data, f2fs_fill_super);
1147 }
1148
1149 static struct file_system_type f2fs_fs_type = {
1150         .owner          = THIS_MODULE,
1151         .name           = "f2fs",
1152         .mount          = f2fs_mount,
1153         .kill_sb        = kill_block_super,
1154         .fs_flags       = FS_REQUIRES_DEV,
1155 };
1156 MODULE_ALIAS_FS("f2fs");
1157
1158 static int __init init_inodecache(void)
1159 {
1160         f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
1161                         sizeof(struct f2fs_inode_info));
1162         if (!f2fs_inode_cachep)
1163                 return -ENOMEM;
1164         return 0;
1165 }
1166
1167 static void destroy_inodecache(void)
1168 {
1169         /*
1170          * Make sure all delayed rcu free inodes are flushed before we
1171          * destroy cache.
1172          */
1173         rcu_barrier();
1174         kmem_cache_destroy(f2fs_inode_cachep);
1175 }
1176
1177 static int __init init_f2fs_fs(void)
1178 {
1179         int err;
1180
1181         err = init_inodecache();
1182         if (err)
1183                 goto fail;
1184         err = create_node_manager_caches();
1185         if (err)
1186                 goto free_inodecache;
1187         err = create_segment_manager_caches();
1188         if (err)
1189                 goto free_node_manager_caches;
1190         err = create_gc_caches();
1191         if (err)
1192                 goto free_segment_manager_caches;
1193         err = create_checkpoint_caches();
1194         if (err)
1195                 goto free_gc_caches;
1196         f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj);
1197         if (!f2fs_kset) {
1198                 err = -ENOMEM;
1199                 goto free_checkpoint_caches;
1200         }
1201         err = register_filesystem(&f2fs_fs_type);
1202         if (err)
1203                 goto free_kset;
1204         f2fs_create_root_stats();
1205         f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
1206         return 0;
1207
1208 free_kset:
1209         kset_unregister(f2fs_kset);
1210 free_checkpoint_caches:
1211         destroy_checkpoint_caches();
1212 free_gc_caches:
1213         destroy_gc_caches();
1214 free_segment_manager_caches:
1215         destroy_segment_manager_caches();
1216 free_node_manager_caches:
1217         destroy_node_manager_caches();
1218 free_inodecache:
1219         destroy_inodecache();
1220 fail:
1221         return err;
1222 }
1223
1224 static void __exit exit_f2fs_fs(void)
1225 {
1226         remove_proc_entry("fs/f2fs", NULL);
1227         f2fs_destroy_root_stats();
1228         unregister_filesystem(&f2fs_fs_type);
1229         destroy_checkpoint_caches();
1230         destroy_gc_caches();
1231         destroy_segment_manager_caches();
1232         destroy_node_manager_caches();
1233         destroy_inodecache();
1234         kset_unregister(f2fs_kset);
1235 }
1236
1237 module_init(init_f2fs_fs)
1238 module_exit(exit_f2fs_fs)
1239
1240 MODULE_AUTHOR("Samsung Electronics's Praesto Team");
1241 MODULE_DESCRIPTION("Flash Friendly File System");
1242 MODULE_LICENSE("GPL");