fs/btrfs/ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/bio.h>
   8 #include <linux/buffer_head.h>
   9 #include <linux/file.h>
  10 #include <linux/fs.h>
  11 #include <linux/fsnotify.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/highmem.h>
  14 #include <linux/time.h>
  15 #include <linux/init.h>
  16 #include <linux/string.h>
  17 #include <linux/backing-dev.h>
  18 #include <linux/mount.h>
  19 #include <linux/mpage.h>
  20 #include <linux/namei.h>
  21 #include <linux/swap.h>
  22 #include <linux/writeback.h>
  23 #include <linux/compat.h>
  24 #include <linux/bit_spinlock.h>
  25 #include <linux/security.h>
  26 #include <linux/xattr.h>
  27 #include <linux/mm.h>
  28 #include <linux/slab.h>
  29 #include <linux/blkdev.h>
  30 #include <linux/uuid.h>
  31 #include <linux/btrfs.h>
  32 #include <linux/uaccess.h>
  33 #include <linux/iversion.h>
  34 #include "ctree.h"
  35 #include "disk-io.h"
  36 #include "transaction.h"
  37 #include "btrfs_inode.h"
  38 #include "print-tree.h"
  39 #include "volumes.h"
  40 #include "locking.h"
  41 #include "inode-map.h"
  42 #include "backref.h"
  43 #include "rcu-string.h"
  44 #include "send.h"
  45 #include "dev-replace.h"
  46 #include "props.h"
  47 #include "sysfs.h"
  48 #include "qgroup.h"
  49 #include "tree-log.h"
  50 #include "compression.h"
  51
  52 #ifdef CONFIG_64BIT
  53 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  54  * structures are incorrect, as the timespec structure from userspace
  55  * is 4 bytes too small. We define these alternatives here to teach
  56  * the kernel about the 32-bit struct packing.
  57  */
  58 struct btrfs_ioctl_timespec_32 {
  59         __u64 sec;
  60         __u32 nsec;
  61 } __attribute__ ((__packed__));
  62
  63 struct btrfs_ioctl_received_subvol_args_32 {
  64         char    uuid[BTRFS_UUID_SIZE];  /* in */
  65         __u64   stransid;               /* in */
  66         __u64   rtransid;               /* out */
  67         struct btrfs_ioctl_timespec_32 stime; /* in */
  68         struct btrfs_ioctl_timespec_32 rtime; /* out */
  69         __u64   flags;                  /* in */
  70         __u64   reserved[16];           /* in */
  71 } __attribute__ ((__packed__));
  72
  73 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  74                                 struct btrfs_ioctl_received_subvol_args_32)
  75 #endif
  76
  77 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  78 struct btrfs_ioctl_send_args_32 {
  79         __s64 send_fd;                  /* in */
  80         __u64 clone_sources_count;      /* in */
  81         compat_uptr_t clone_sources;    /* in */
  82         __u64 parent_root;              /* in */
  83         __u64 flags;                    /* in */
  84         __u64 reserved[4];              /* in */
  85 } __attribute__ ((__packed__));
  86
  87 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  88                                struct btrfs_ioctl_send_args_32)
  89 #endif
  90
  91 static int btrfs_clone(struct inode *src, struct inode *inode,
  92                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  93                        int no_time_update);
  94
  95 /* Mask out flags that are inappropriate for the given type of inode. */
  96 static unsigned int btrfs_mask_flags(umode_t mode, unsigned int flags)
  97 {
  98         if (S_ISDIR(mode))
  99                 return flags;
 100         else if (S_ISREG(mode))
 101                 return flags & ~FS_DIRSYNC_FL;
 102         else
 103                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 104 }
 105
 106 /*
 107  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
 108  */
 109 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
 110 {
 111         unsigned int iflags = 0;
 112
 113         if (flags & BTRFS_INODE_SYNC)
 114                 iflags |= FS_SYNC_FL;
 115         if (flags & BTRFS_INODE_IMMUTABLE)
 116                 iflags |= FS_IMMUTABLE_FL;
 117         if (flags & BTRFS_INODE_APPEND)
 118                 iflags |= FS_APPEND_FL;
 119         if (flags & BTRFS_INODE_NODUMP)
 120                 iflags |= FS_NODUMP_FL;
 121         if (flags & BTRFS_INODE_NOATIME)
 122                 iflags |= FS_NOATIME_FL;
 123         if (flags & BTRFS_INODE_DIRSYNC)
 124                 iflags |= FS_DIRSYNC_FL;
 125         if (flags & BTRFS_INODE_NODATACOW)
 126                 iflags |= FS_NOCOW_FL;
 127
 128         if (flags & BTRFS_INODE_NOCOMPRESS)
 129                 iflags |= FS_NOCOMP_FL;
 130         else if (flags & BTRFS_INODE_COMPRESS)
 131                 iflags |= FS_COMPR_FL;
 132
 133         return iflags;
 134 }
 135
 136 /*
 137  * Update inode->i_flags based on the btrfs internal flags.
 138  */
 139 void btrfs_update_iflags(struct inode *inode)
 140 {
 141         struct btrfs_inode *ip = BTRFS_I(inode);
 142         unsigned int new_fl = 0;
 143
 144         if (ip->flags & BTRFS_INODE_SYNC)
 145                 new_fl |= S_SYNC;
 146         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 147                 new_fl |= S_IMMUTABLE;
 148         if (ip->flags & BTRFS_INODE_APPEND)
 149                 new_fl |= S_APPEND;
 150         if (ip->flags & BTRFS_INODE_NOATIME)
 151                 new_fl |= S_NOATIME;
 152         if (ip->flags & BTRFS_INODE_DIRSYNC)
 153                 new_fl |= S_DIRSYNC;
 154
 155         set_mask_bits(&inode->i_flags,
 156                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 157                       new_fl);
 158 }
 159
 160 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 161 {
 162         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 163         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 164
 165         if (copy_to_user(arg, &flags, sizeof(flags)))
 166                 return -EFAULT;
 167         return 0;
 168 }
 169
 170 static int check_flags(unsigned int flags)
 171 {
 172         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 173                       FS_NOATIME_FL | FS_NODUMP_FL | \
 174                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 175                       FS_NOCOMP_FL | FS_COMPR_FL |
 176                       FS_NOCOW_FL))
 177                 return -EOPNOTSUPP;
 178
 179         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 180                 return -EINVAL;
 181
 182         return 0;
 183 }
 184
 185 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 186 {
 187         struct inode *inode = file_inode(file);
 188         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 189         struct btrfs_inode *ip = BTRFS_I(inode);
 190         struct btrfs_root *root = ip->root;
 191         struct btrfs_trans_handle *trans;
 192         unsigned int flags, oldflags;
 193         int ret;
 194         u64 ip_oldflags;
 195         unsigned int i_oldflags;
 196         umode_t mode;
 197
 198         if (!inode_owner_or_capable(inode))
 199                 return -EPERM;
 200
 201         if (btrfs_root_readonly(root))
 202                 return -EROFS;
 203
 204         if (copy_from_user(&flags, arg, sizeof(flags)))
 205                 return -EFAULT;
 206
 207         ret = check_flags(flags);
 208         if (ret)
 209                 return ret;
 210
 211         ret = mnt_want_write_file(file);
 212         if (ret)
 213                 return ret;
 214
 215         inode_lock(inode);
 216
 217         ip_oldflags = ip->flags;
 218         i_oldflags = inode->i_flags;
 219         mode = inode->i_mode;
 220
 221         flags = btrfs_mask_flags(inode->i_mode, flags);
 222         oldflags = btrfs_flags_to_ioctl(ip->flags);
 223         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 224                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 225                         ret = -EPERM;
 226                         goto out_unlock;
 227                 }
 228         }
 229
 230         if (flags & FS_SYNC_FL)
 231                 ip->flags |= BTRFS_INODE_SYNC;
 232         else
 233                 ip->flags &= ~BTRFS_INODE_SYNC;
 234         if (flags & FS_IMMUTABLE_FL)
 235                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 236         else
 237                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 238         if (flags & FS_APPEND_FL)
 239                 ip->flags |= BTRFS_INODE_APPEND;
 240         else
 241                 ip->flags &= ~BTRFS_INODE_APPEND;
 242         if (flags & FS_NODUMP_FL)
 243                 ip->flags |= BTRFS_INODE_NODUMP;
 244         else
 245                 ip->flags &= ~BTRFS_INODE_NODUMP;
 246         if (flags & FS_NOATIME_FL)
 247                 ip->flags |= BTRFS_INODE_NOATIME;
 248         else
 249                 ip->flags &= ~BTRFS_INODE_NOATIME;
 250         if (flags & FS_DIRSYNC_FL)
 251                 ip->flags |= BTRFS_INODE_DIRSYNC;
 252         else
 253                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 254         if (flags & FS_NOCOW_FL) {
 255                 if (S_ISREG(mode)) {
 256                         /*
 257                          * It's safe to turn csums off here, no extents exist.
 258                          * Otherwise we want the flag to reflect the real COW
 259                          * status of the file and will not set it.
 260                          */
 261                         if (inode->i_size == 0)
 262                                 ip->flags |= BTRFS_INODE_NODATACOW
 263                                            | BTRFS_INODE_NODATASUM;
 264                 } else {
 265                         ip->flags |= BTRFS_INODE_NODATACOW;
 266                 }
 267         } else {
 268                 /*
 269                  * Revert back under same assumptions as above
 270                  */
 271                 if (S_ISREG(mode)) {
 272                         if (inode->i_size == 0)
 273                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 274                                              | BTRFS_INODE_NODATASUM);
 275                 } else {
 276                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 277                 }
 278         }
 279
 280         /*
 281          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 282          * flag may be changed automatically if compression code won't make
 283          * things smaller.
 284          */
 285         if (flags & FS_NOCOMP_FL) {
 286                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 287                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 288
 289                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 290                 if (ret && ret != -ENODATA)
 291                         goto out_drop;
 292         } else if (flags & FS_COMPR_FL) {
 293                 const char *comp;
 294
 295                 ip->flags |= BTRFS_INODE_COMPRESS;
 296                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 297
 298                 comp = btrfs_compress_type2str(fs_info->compress_type);
 299                 if (!comp || comp[0] == 0)
 300                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 301
 302                 ret = btrfs_set_prop(inode, "btrfs.compression",
 303                                      comp, strlen(comp), 0);
 304                 if (ret)
 305                         goto out_drop;
 306
 307         } else {
 308                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 309                 if (ret && ret != -ENODATA)
 310                         goto out_drop;
 311                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 312         }
 313
 314         trans = btrfs_start_transaction(root, 1);
 315         if (IS_ERR(trans)) {
 316                 ret = PTR_ERR(trans);
 317                 goto out_drop;
 318         }
 319
 320         btrfs_update_iflags(inode);
 321         inode_inc_iversion(inode);
 322         inode->i_ctime = current_time(inode);
 323         ret = btrfs_update_inode(trans, root, inode);
 324
 325         btrfs_end_transaction(trans);
 326  out_drop:
 327         if (ret) {
 328                 ip->flags = ip_oldflags;
 329                 inode->i_flags = i_oldflags;
 330         }
 331
 332  out_unlock:
 333         inode_unlock(inode);
 334         mnt_drop_write_file(file);
 335         return ret;
 336 }
 337
 338 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 339 {
 340         struct inode *inode = file_inode(file);
 341
 342         return put_user(inode->i_generation, arg);
 343 }
 344
 345 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 346 {
 347         struct inode *inode = file_inode(file);
 348         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 349         struct btrfs_device *device;
 350         struct request_queue *q;
 351         struct fstrim_range range;
 352         u64 minlen = ULLONG_MAX;
 353         u64 num_devices = 0;
 354         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 355         int ret;
 356
 357         if (!capable(CAP_SYS_ADMIN))
 358                 return -EPERM;
 359
 360         rcu_read_lock();
 361         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 362                                 dev_list) {
 363                 if (!device->bdev)
 364                         continue;
 365                 q = bdev_get_queue(device->bdev);
 366                 if (blk_queue_discard(q)) {
 367                         num_devices++;
 368                         minlen = min_t(u64, q->limits.discard_granularity,
 369                                      minlen);
 370                 }
 371         }
 372         rcu_read_unlock();
 373
 374         if (!num_devices)
 375                 return -EOPNOTSUPP;
 376         if (copy_from_user(&range, arg, sizeof(range)))
 377                 return -EFAULT;
 378         if (range.start > total_bytes ||
 379             range.len < fs_info->sb->s_blocksize)
 380                 return -EINVAL;
 381
 382         range.len = min(range.len, total_bytes - range.start);
 383         range.minlen = max(range.minlen, minlen);
 384         ret = btrfs_trim_fs(fs_info, &range);
 385         if (ret < 0)
 386                 return ret;
 387
 388         if (copy_to_user(arg, &range, sizeof(range)))
 389                 return -EFAULT;
 390
 391         return 0;
 392 }
 393
 394 int btrfs_is_empty_uuid(u8 *uuid)
 395 {
 396         int i;
 397
 398         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 399                 if (uuid[i])
 400                         return 0;
 401         }
 402         return 1;
 403 }
 404
 405 static noinline int create_subvol(struct inode *dir,
 406                                   struct dentry *dentry,
 407                                   const char *name, int namelen,
 408                                   u64 *async_transid,
 409                                   struct btrfs_qgroup_inherit *inherit)
 410 {
 411         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 412         struct btrfs_trans_handle *trans;
 413         struct btrfs_key key;
 414         struct btrfs_root_item *root_item;
 415         struct btrfs_inode_item *inode_item;
 416         struct extent_buffer *leaf;
 417         struct btrfs_root *root = BTRFS_I(dir)->root;
 418         struct btrfs_root *new_root;
 419         struct btrfs_block_rsv block_rsv;
 420         struct timespec cur_time = current_time(dir);
 421         struct inode *inode;
 422         int ret;
 423         int err;
 424         u64 objectid;
 425         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 426         u64 index = 0;
 427         u64 qgroup_reserved;
 428         uuid_le new_uuid;
 429
 430         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 431         if (!root_item)
 432                 return -ENOMEM;
 433
 434         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 435         if (ret)
 436                 goto fail_free;
 437
 438         /*
 439          * Don't create subvolume whose level is not zero. Or qgroup will be
 440          * screwed up since it assumes subvolume qgroup's level to be 0.
 441          */
 442         if (btrfs_qgroup_level(objectid)) {
 443                 ret = -ENOSPC;
 444                 goto fail_free;
 445         }
 446
 447         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 448         /*
 449          * The same as the snapshot creation, please see the comment
 450          * of create_snapshot().
 451          */
 452         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 453                                                8, &qgroup_reserved, false);
 454         if (ret)
 455                 goto fail_free;
 456
 457         trans = btrfs_start_transaction(root, 0);
 458         if (IS_ERR(trans)) {
 459                 ret = PTR_ERR(trans);
 460                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 461                 goto fail_free;
 462         }
 463         trans->block_rsv = &block_rsv;
 464         trans->bytes_reserved = block_rsv.size;
 465
 466         ret = btrfs_qgroup_inherit(trans, fs_info, 0, objectid, inherit);
 467         if (ret)
 468                 goto fail;
 469
 470         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 471         if (IS_ERR(leaf)) {
 472                 ret = PTR_ERR(leaf);
 473                 goto fail;
 474         }
 475
 476         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
 477         btrfs_set_header_bytenr(leaf, leaf->start);
 478         btrfs_set_header_generation(leaf, trans->transid);
 479         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 480         btrfs_set_header_owner(leaf, objectid);
 481
 482         write_extent_buffer_fsid(leaf, fs_info->fsid);
 483         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
 484         btrfs_mark_buffer_dirty(leaf);
 485
 486         inode_item = &root_item->inode;
 487         btrfs_set_stack_inode_generation(inode_item, 1);
 488         btrfs_set_stack_inode_size(inode_item, 3);
 489         btrfs_set_stack_inode_nlink(inode_item, 1);
 490         btrfs_set_stack_inode_nbytes(inode_item,
 491                                      fs_info->nodesize);
 492         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 493
 494         btrfs_set_root_flags(root_item, 0);
 495         btrfs_set_root_limit(root_item, 0);
 496         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 497
 498         btrfs_set_root_bytenr(root_item, leaf->start);
 499         btrfs_set_root_generation(root_item, trans->transid);
 500         btrfs_set_root_level(root_item, 0);
 501         btrfs_set_root_refs(root_item, 1);
 502         btrfs_set_root_used(root_item, leaf->len);
 503         btrfs_set_root_last_snapshot(root_item, 0);
 504
 505         btrfs_set_root_generation_v2(root_item,
 506                         btrfs_root_generation(root_item));
 507         uuid_le_gen(&new_uuid);
 508         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 509         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 510         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 511         root_item->ctime = root_item->otime;
 512         btrfs_set_root_ctransid(root_item, trans->transid);
 513         btrfs_set_root_otransid(root_item, trans->transid);
 514
 515         btrfs_tree_unlock(leaf);
 516         free_extent_buffer(leaf);
 517         leaf = NULL;
 518
 519         btrfs_set_root_dirid(root_item, new_dirid);
 520
 521         key.objectid = objectid;
 522         key.offset = 0;
 523         key.type = BTRFS_ROOT_ITEM_KEY;
 524         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 525                                 root_item);
 526         if (ret)
 527                 goto fail;
 528
 529         key.offset = (u64)-1;
 530         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 531         if (IS_ERR(new_root)) {
 532                 ret = PTR_ERR(new_root);
 533                 btrfs_abort_transaction(trans, ret);
 534                 goto fail;
 535         }
 536
 537         btrfs_record_root_in_trans(trans, new_root);
 538
 539         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 540         if (ret) {
 541                 /* We potentially lose an unused inode item here */
 542                 btrfs_abort_transaction(trans, ret);
 543                 goto fail;
 544         }
 545
 546         mutex_lock(&new_root->objectid_mutex);
 547         new_root->highest_objectid = new_dirid;
 548         mutex_unlock(&new_root->objectid_mutex);
 549
 550         /*
 551          * insert the directory item
 552          */
 553         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 554         if (ret) {
 555                 btrfs_abort_transaction(trans, ret);
 556                 goto fail;
 557         }
 558
 559         ret = btrfs_insert_dir_item(trans, root,
 560                                     name, namelen, BTRFS_I(dir), &key,
 561                                     BTRFS_FT_DIR, index);
 562         if (ret) {
 563                 btrfs_abort_transaction(trans, ret);
 564                 goto fail;
 565         }
 566
 567         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 568         ret = btrfs_update_inode(trans, root, dir);
 569         BUG_ON(ret);
 570
 571         ret = btrfs_add_root_ref(trans, fs_info,
 572                                  objectid, root->root_key.objectid,
 573                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 574         BUG_ON(ret);
 575
 576         ret = btrfs_uuid_tree_add(trans, fs_info, root_item->uuid,
 577                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 578         if (ret)
 579                 btrfs_abort_transaction(trans, ret);
 580
 581 fail:
 582         kfree(root_item);
 583         trans->block_rsv = NULL;
 584         trans->bytes_reserved = 0;
 585         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 586
 587         if (async_transid) {
 588                 *async_transid = trans->transid;
 589                 err = btrfs_commit_transaction_async(trans, 1);
 590                 if (err)
 591                         err = btrfs_commit_transaction(trans);
 592         } else {
 593                 err = btrfs_commit_transaction(trans);
 594         }
 595         if (err && !ret)
 596                 ret = err;
 597
 598         if (!ret) {
 599                 inode = btrfs_lookup_dentry(dir, dentry);
 600                 if (IS_ERR(inode))
 601                         return PTR_ERR(inode);
 602                 d_instantiate(dentry, inode);
 603         }
 604         return ret;
 605
 606 fail_free:
 607         kfree(root_item);
 608         return ret;
 609 }
 610
 611 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 612                            struct dentry *dentry,
 613                            u64 *async_transid, bool readonly,
 614                            struct btrfs_qgroup_inherit *inherit)
 615 {
 616         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 617         struct inode *inode;
 618         struct btrfs_pending_snapshot *pending_snapshot;
 619         struct btrfs_trans_handle *trans;
 620         int ret;
 621
 622         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 623                 return -EINVAL;
 624
 625         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 626         if (!pending_snapshot)
 627                 return -ENOMEM;
 628
 629         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 630                         GFP_KERNEL);
 631         pending_snapshot->path = btrfs_alloc_path();
 632         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 633                 ret = -ENOMEM;
 634                 goto free_pending;
 635         }
 636
 637         atomic_inc(&root->will_be_snapshotted);
 638         smp_mb__after_atomic();
 639         /* wait for no snapshot writes */
 640         wait_event(root->subv_writers->wait,
 641                    percpu_counter_sum(&root->subv_writers->counter) == 0);
 642
 643         ret = btrfs_start_delalloc_inodes(root);
 644         if (ret)
 645                 goto dec_and_free;
 646
 647         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 648
 649         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 650                              BTRFS_BLOCK_RSV_TEMP);
 651         /*
 652          * 1 - parent dir inode
 653          * 2 - dir entries
 654          * 1 - root item
 655          * 2 - root ref/backref
 656          * 1 - root of snapshot
 657          * 1 - UUID item
 658          */
 659         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 660                                         &pending_snapshot->block_rsv, 8,
 661                                         &pending_snapshot->qgroup_reserved,
 662                                         false);
 663         if (ret)
 664                 goto dec_and_free;
 665
 666         pending_snapshot->dentry = dentry;
 667         pending_snapshot->root = root;
 668         pending_snapshot->readonly = readonly;
 669         pending_snapshot->dir = dir;
 670         pending_snapshot->inherit = inherit;
 671
 672         trans = btrfs_start_transaction(root, 0);
 673         if (IS_ERR(trans)) {
 674                 ret = PTR_ERR(trans);
 675                 goto fail;
 676         }
 677
 678         spin_lock(&fs_info->trans_lock);
 679         list_add(&pending_snapshot->list,
 680                  &trans->transaction->pending_snapshots);
 681         spin_unlock(&fs_info->trans_lock);
 682         if (async_transid) {
 683                 *async_transid = trans->transid;
 684                 ret = btrfs_commit_transaction_async(trans, 1);
 685                 if (ret)
 686                         ret = btrfs_commit_transaction(trans);
 687         } else {
 688                 ret = btrfs_commit_transaction(trans);
 689         }
 690         if (ret)
 691                 goto fail;
 692
 693         ret = pending_snapshot->error;
 694         if (ret)
 695                 goto fail;
 696
 697         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 698         if (ret)
 699                 goto fail;
 700
 701         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 702         if (IS_ERR(inode)) {
 703                 ret = PTR_ERR(inode);
 704                 goto fail;
 705         }
 706
 707         d_instantiate(dentry, inode);
 708         ret = 0;
 709 fail:
 710         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 711 dec_and_free:
 712         if (atomic_dec_and_test(&root->will_be_snapshotted))
 713                 wake_up_var(&root->will_be_snapshotted);
 714 free_pending:
 715         kfree(pending_snapshot->root_item);
 716         btrfs_free_path(pending_snapshot->path);
 717         kfree(pending_snapshot);
 718
 719         return ret;
 720 }
 721
 722 /*  copy of may_delete in fs/namei.c()
 723  *      Check whether we can remove a link victim from directory dir, check
 724  *  whether the type of victim is right.
 725  *  1. We can't do it if dir is read-only (done in permission())
 726  *  2. We should have write and exec permissions on dir
 727  *  3. We can't remove anything from append-only dir
 728  *  4. We can't do anything with immutable dir (done in permission())
 729  *  5. If the sticky bit on dir is set we should either
 730  *      a. be owner of dir, or
 731  *      b. be owner of victim, or
 732  *      c. have CAP_FOWNER capability
 733  *  6. If the victim is append-only or immutable we can't do anything with
 734  *     links pointing to it.
 735  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 736  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 737  *  9. We can't remove a root or mountpoint.
 738  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 739  *     nfs_async_unlink().
 740  */
 741
 742 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 743 {
 744         int error;
 745
 746         if (d_really_is_negative(victim))
 747                 return -ENOENT;
 748
 749         BUG_ON(d_inode(victim->d_parent) != dir);
 750         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 751
 752         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 753         if (error)
 754                 return error;
 755         if (IS_APPEND(dir))
 756                 return -EPERM;
 757         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 758             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 759                 return -EPERM;
 760         if (isdir) {
 761                 if (!d_is_dir(victim))
 762                         return -ENOTDIR;
 763                 if (IS_ROOT(victim))
 764                         return -EBUSY;
 765         } else if (d_is_dir(victim))
 766                 return -EISDIR;
 767         if (IS_DEADDIR(dir))
 768                 return -ENOENT;
 769         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 770                 return -EBUSY;
 771         return 0;
 772 }
 773
 774 /* copy of may_create in fs/namei.c() */
 775 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 776 {
 777         if (d_really_is_positive(child))
 778                 return -EEXIST;
 779         if (IS_DEADDIR(dir))
 780                 return -ENOENT;
 781         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 782 }
 783
 784 /*
 785  * Create a new subvolume below @parent.  This is largely modeled after
 786  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 787  * inside this filesystem so it's quite a bit simpler.
 788  */
 789 static noinline int btrfs_mksubvol(const struct path *parent,
 790                                    const char *name, int namelen,
 791                                    struct btrfs_root *snap_src,
 792                                    u64 *async_transid, bool readonly,
 793                                    struct btrfs_qgroup_inherit *inherit)
 794 {
 795         struct inode *dir = d_inode(parent->dentry);
 796         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 797         struct dentry *dentry;
 798         int error;
 799
 800         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 801         if (error == -EINTR)
 802                 return error;
 803
 804         dentry = lookup_one_len(name, parent->dentry, namelen);
 805         error = PTR_ERR(dentry);
 806         if (IS_ERR(dentry))
 807                 goto out_unlock;
 808
 809         error = btrfs_may_create(dir, dentry);
 810         if (error)
 811                 goto out_dput;
 812
 813         /*
 814          * even if this name doesn't exist, we may get hash collisions.
 815          * check for them now when we can safely fail
 816          */
 817         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 818                                                dir->i_ino, name,
 819                                                namelen);
 820         if (error)
 821                 goto out_dput;
 822
 823         down_read(&fs_info->subvol_sem);
 824
 825         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 826                 goto out_up_read;
 827
 828         if (snap_src) {
 829                 error = create_snapshot(snap_src, dir, dentry,
 830                                         async_transid, readonly, inherit);
 831         } else {
 832                 error = create_subvol(dir, dentry, name, namelen,
 833                                       async_transid, inherit);
 834         }
 835         if (!error)
 836                 fsnotify_mkdir(dir, dentry);
 837 out_up_read:
 838         up_read(&fs_info->subvol_sem);
 839 out_dput:
 840         dput(dentry);
 841 out_unlock:
 842         inode_unlock(dir);
 843         return error;
 844 }
 845
 846 /*
 847  * When we're defragging a range, we don't want to kick it off again
 848  * if it is really just waiting for delalloc to send it down.
 849  * If we find a nice big extent or delalloc range for the bytes in the
 850  * file you want to defrag, we return 0 to let you know to skip this
 851  * part of the file
 852  */
 853 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 854 {
 855         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 856         struct extent_map *em = NULL;
 857         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 858         u64 end;
 859
 860         read_lock(&em_tree->lock);
 861         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 862         read_unlock(&em_tree->lock);
 863
 864         if (em) {
 865                 end = extent_map_end(em);
 866                 free_extent_map(em);
 867                 if (end - offset > thresh)
 868                         return 0;
 869         }
 870         /* if we already have a nice delalloc here, just stop */
 871         thresh /= 2;
 872         end = count_range_bits(io_tree, &offset, offset + thresh,
 873                                thresh, EXTENT_DELALLOC, 1);
 874         if (end >= thresh)
 875                 return 0;
 876         return 1;
 877 }
 878
 879 /*
 880  * helper function to walk through a file and find extents
 881  * newer than a specific transid, and smaller than thresh.
 882  *
 883  * This is used by the defragging code to find new and small
 884  * extents
 885  */
 886 static int find_new_extents(struct btrfs_root *root,
 887                             struct inode *inode, u64 newer_than,
 888                             u64 *off, u32 thresh)
 889 {
 890         struct btrfs_path *path;
 891         struct btrfs_key min_key;
 892         struct extent_buffer *leaf;
 893         struct btrfs_file_extent_item *extent;
 894         int type;
 895         int ret;
 896         u64 ino = btrfs_ino(BTRFS_I(inode));
 897
 898         path = btrfs_alloc_path();
 899         if (!path)
 900                 return -ENOMEM;
 901
 902         min_key.objectid = ino;
 903         min_key.type = BTRFS_EXTENT_DATA_KEY;
 904         min_key.offset = *off;
 905
 906         while (1) {
 907                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
 908                 if (ret != 0)
 909                         goto none;
 910 process_slot:
 911                 if (min_key.objectid != ino)
 912                         goto none;
 913                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 914                         goto none;
 915
 916                 leaf = path->nodes[0];
 917                 extent = btrfs_item_ptr(leaf, path->slots[0],
 918                                         struct btrfs_file_extent_item);
 919
 920                 type = btrfs_file_extent_type(leaf, extent);
 921                 if (type == BTRFS_FILE_EXTENT_REG &&
 922                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 923                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 924                         *off = min_key.offset;
 925                         btrfs_free_path(path);
 926                         return 0;
 927                 }
 928
 929                 path->slots[0]++;
 930                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
 931                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 932                         goto process_slot;
 933                 }
 934
 935                 if (min_key.offset == (u64)-1)
 936                         goto none;
 937
 938                 min_key.offset++;
 939                 btrfs_release_path(path);
 940         }
 941 none:
 942         btrfs_free_path(path);
 943         return -ENOENT;
 944 }
 945
 946 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 947 {
 948         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 949         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 950         struct extent_map *em;
 951         u64 len = PAGE_SIZE;
 952
 953         /*
 954          * hopefully we have this extent in the tree already, try without
 955          * the full extent lock
 956          */
 957         read_lock(&em_tree->lock);
 958         em = lookup_extent_mapping(em_tree, start, len);
 959         read_unlock(&em_tree->lock);
 960
 961         if (!em) {
 962                 struct extent_state *cached = NULL;
 963                 u64 end = start + len - 1;
 964
 965                 /* get the big lock and read metadata off disk */
 966                 lock_extent_bits(io_tree, start, end, &cached);
 967                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
 968                 unlock_extent_cached(io_tree, start, end, &cached);
 969
 970                 if (IS_ERR(em))
 971                         return NULL;
 972         }
 973
 974         return em;
 975 }
 976
 977 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
 978 {
 979         struct extent_map *next;
 980         bool ret = true;
 981
 982         /* this is the last extent */
 983         if (em->start + em->len >= i_size_read(inode))
 984                 return false;
 985
 986         next = defrag_lookup_extent(inode, em->start + em->len);
 987         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
 988                 ret = false;
 989         else if ((em->block_start + em->block_len == next->block_start) &&
 990                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
 991                 ret = false;
 992
 993         free_extent_map(next);
 994         return ret;
 995 }
 996
 997 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
 998                                u64 *last_len, u64 *skip, u64 *defrag_end,
 999                                int compress)
1000 {
1001         struct extent_map *em;
1002         int ret = 1;
1003         bool next_mergeable = true;
1004         bool prev_mergeable = true;
1005
1006         /*
1007          * make sure that once we start defragging an extent, we keep on
1008          * defragging it
1009          */
1010         if (start < *defrag_end)
1011                 return 1;
1012
1013         *skip = 0;
1014
1015         em = defrag_lookup_extent(inode, start);
1016         if (!em)
1017                 return 0;
1018
1019         /* this will cover holes, and inline extents */
1020         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1021                 ret = 0;
1022                 goto out;
1023         }
1024
1025         if (!*defrag_end)
1026                 prev_mergeable = false;
1027
1028         next_mergeable = defrag_check_next_extent(inode, em);
1029         /*
1030          * we hit a real extent, if it is big or the next extent is not a
1031          * real extent, don't bother defragging it
1032          */
1033         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1034             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1035                 ret = 0;
1036 out:
1037         /*
1038          * last_len ends up being a counter of how many bytes we've defragged.
1039          * every time we choose not to defrag an extent, we reset *last_len
1040          * so that the next tiny extent will force a defrag.
1041          *
1042          * The end result of this is that tiny extents before a single big
1043          * extent will force at least part of that big extent to be defragged.
1044          */
1045         if (ret) {
1046                 *defrag_end = extent_map_end(em);
1047         } else {
1048                 *last_len = 0;
1049                 *skip = extent_map_end(em);
1050                 *defrag_end = 0;
1051         }
1052
1053         free_extent_map(em);
1054         return ret;
1055 }
1056
1057 /*
1058  * it doesn't do much good to defrag one or two pages
1059  * at a time.  This pulls in a nice chunk of pages
1060  * to COW and defrag.
1061  *
1062  * It also makes sure the delalloc code has enough
1063  * dirty data to avoid making new small extents as part
1064  * of the defrag
1065  *
1066  * It's a good idea to start RA on this range
1067  * before calling this.
1068  */
1069 static int cluster_pages_for_defrag(struct inode *inode,
1070                                     struct page **pages,
1071                                     unsigned long start_index,
1072                                     unsigned long num_pages)
1073 {
1074         unsigned long file_end;
1075         u64 isize = i_size_read(inode);
1076         u64 page_start;
1077         u64 page_end;
1078         u64 page_cnt;
1079         int ret;
1080         int i;
1081         int i_done;
1082         struct btrfs_ordered_extent *ordered;
1083         struct extent_state *cached_state = NULL;
1084         struct extent_io_tree *tree;
1085         struct extent_changeset *data_reserved = NULL;
1086         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1087
1088         file_end = (isize - 1) >> PAGE_SHIFT;
1089         if (!isize || start_index > file_end)
1090                 return 0;
1091
1092         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1093
1094         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1095                         start_index << PAGE_SHIFT,
1096                         page_cnt << PAGE_SHIFT);
1097         if (ret)
1098                 return ret;
1099         i_done = 0;
1100         tree = &BTRFS_I(inode)->io_tree;
1101
1102         /* step one, lock all the pages */
1103         for (i = 0; i < page_cnt; i++) {
1104                 struct page *page;
1105 again:
1106                 page = find_or_create_page(inode->i_mapping,
1107                                            start_index + i, mask);
1108                 if (!page)
1109                         break;
1110
1111                 page_start = page_offset(page);
1112                 page_end = page_start + PAGE_SIZE - 1;
1113                 while (1) {
1114                         lock_extent_bits(tree, page_start, page_end,
1115                                          &cached_state);
1116                         ordered = btrfs_lookup_ordered_extent(inode,
1117                                                               page_start);
1118                         unlock_extent_cached(tree, page_start, page_end,
1119                                              &cached_state);
1120                         if (!ordered)
1121                                 break;
1122
1123                         unlock_page(page);
1124                         btrfs_start_ordered_extent(inode, ordered, 1);
1125                         btrfs_put_ordered_extent(ordered);
1126                         lock_page(page);
1127                         /*
1128                          * we unlocked the page above, so we need check if
1129                          * it was released or not.
1130                          */
1131                         if (page->mapping != inode->i_mapping) {
1132                                 unlock_page(page);
1133                                 put_page(page);
1134                                 goto again;
1135                         }
1136                 }
1137
1138                 if (!PageUptodate(page)) {
1139                         btrfs_readpage(NULL, page);
1140                         lock_page(page);
1141                         if (!PageUptodate(page)) {
1142                                 unlock_page(page);
1143                                 put_page(page);
1144                                 ret = -EIO;
1145                                 break;
1146                         }
1147                 }
1148
1149                 if (page->mapping != inode->i_mapping) {
1150                         unlock_page(page);
1151                         put_page(page);
1152                         goto again;
1153                 }
1154
1155                 pages[i] = page;
1156                 i_done++;
1157         }
1158         if (!i_done || ret)
1159                 goto out;
1160
1161         if (!(inode->i_sb->s_flags & SB_ACTIVE))
1162                 goto out;
1163
1164         /*
1165          * so now we have a nice long stream of locked
1166          * and up to date pages, lets wait on them
1167          */
1168         for (i = 0; i < i_done; i++)
1169                 wait_on_page_writeback(pages[i]);
1170
1171         page_start = page_offset(pages[0]);
1172         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1173
1174         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1175                          page_start, page_end - 1, &cached_state);
1176         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1177                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1178                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1179                           &cached_state);
1180
1181         if (i_done != page_cnt) {
1182                 spin_lock(&BTRFS_I(inode)->lock);
1183                 BTRFS_I(inode)->outstanding_extents++;
1184                 spin_unlock(&BTRFS_I(inode)->lock);
1185                 btrfs_delalloc_release_space(inode, data_reserved,
1186                                 start_index << PAGE_SHIFT,
1187                                 (page_cnt - i_done) << PAGE_SHIFT, true);
1188         }
1189
1190
1191         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1192                           &cached_state);
1193
1194         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1195                              page_start, page_end - 1, &cached_state);
1196
1197         for (i = 0; i < i_done; i++) {
1198                 clear_page_dirty_for_io(pages[i]);
1199                 ClearPageChecked(pages[i]);
1200                 set_page_extent_mapped(pages[i]);
1201                 set_page_dirty(pages[i]);
1202                 unlock_page(pages[i]);
1203                 put_page(pages[i]);
1204         }
1205         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1206                                        false);
1207         extent_changeset_free(data_reserved);
1208         return i_done;
1209 out:
1210         for (i = 0; i < i_done; i++) {
1211                 unlock_page(pages[i]);
1212                 put_page(pages[i]);
1213         }
1214         btrfs_delalloc_release_space(inode, data_reserved,
1215                         start_index << PAGE_SHIFT,
1216                         page_cnt << PAGE_SHIFT, true);
1217         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1218                                        true);
1219         extent_changeset_free(data_reserved);
1220         return ret;
1221
1222 }
1223
1224 int btrfs_defrag_file(struct inode *inode, struct file *file,
1225                       struct btrfs_ioctl_defrag_range_args *range,
1226                       u64 newer_than, unsigned long max_to_defrag)
1227 {
1228         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1229         struct btrfs_root *root = BTRFS_I(inode)->root;
1230         struct file_ra_state *ra = NULL;
1231         unsigned long last_index;
1232         u64 isize = i_size_read(inode);
1233         u64 last_len = 0;
1234         u64 skip = 0;
1235         u64 defrag_end = 0;
1236         u64 newer_off = range->start;
1237         unsigned long i;
1238         unsigned long ra_index = 0;
1239         int ret;
1240         int defrag_count = 0;
1241         int compress_type = BTRFS_COMPRESS_ZLIB;
1242         u32 extent_thresh = range->extent_thresh;
1243         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1244         unsigned long cluster = max_cluster;
1245         u64 new_align = ~((u64)SZ_128K - 1);
1246         struct page **pages = NULL;
1247         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1248
1249         if (isize == 0)
1250                 return 0;
1251
1252         if (range->start >= isize)
1253                 return -EINVAL;
1254
1255         if (do_compress) {
1256                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1257                         return -EINVAL;
1258                 if (range->compress_type)
1259                         compress_type = range->compress_type;
1260         }
1261
1262         if (extent_thresh == 0)
1263                 extent_thresh = SZ_256K;
1264
1265         /*
1266          * If we were not given a file, allocate a readahead context. As
1267          * readahead is just an optimization, defrag will work without it so
1268          * we don't error out.
1269          */
1270         if (!file) {
1271                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1272                 if (ra)
1273                         file_ra_state_init(ra, inode->i_mapping);
1274         } else {
1275                 ra = &file->f_ra;
1276         }
1277
1278         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1279         if (!pages) {
1280                 ret = -ENOMEM;
1281                 goto out_ra;
1282         }
1283
1284         /* find the last page to defrag */
1285         if (range->start + range->len > range->start) {
1286                 last_index = min_t(u64, isize - 1,
1287                          range->start + range->len - 1) >> PAGE_SHIFT;
1288         } else {
1289                 last_index = (isize - 1) >> PAGE_SHIFT;
1290         }
1291
1292         if (newer_than) {
1293                 ret = find_new_extents(root, inode, newer_than,
1294                                        &newer_off, SZ_64K);
1295                 if (!ret) {
1296                         range->start = newer_off;
1297                         /*
1298                          * we always align our defrag to help keep
1299                          * the extents in the file evenly spaced
1300                          */
1301                         i = (newer_off & new_align) >> PAGE_SHIFT;
1302                 } else
1303                         goto out_ra;
1304         } else {
1305                 i = range->start >> PAGE_SHIFT;
1306         }
1307         if (!max_to_defrag)
1308                 max_to_defrag = last_index - i + 1;
1309
1310         /*
1311          * make writeback starts from i, so the defrag range can be
1312          * written sequentially.
1313          */
1314         if (i < inode->i_mapping->writeback_index)
1315                 inode->i_mapping->writeback_index = i;
1316
1317         while (i <= last_index && defrag_count < max_to_defrag &&
1318                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1319                 /*
1320                  * make sure we stop running if someone unmounts
1321                  * the FS
1322                  */
1323                 if (!(inode->i_sb->s_flags & SB_ACTIVE))
1324                         break;
1325
1326                 if (btrfs_defrag_cancelled(fs_info)) {
1327                         btrfs_debug(fs_info, "defrag_file cancelled");
1328                         ret = -EAGAIN;
1329                         break;
1330                 }
1331
1332                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1333                                          extent_thresh, &last_len, &skip,
1334                                          &defrag_end, do_compress)){
1335                         unsigned long next;
1336                         /*
1337                          * the should_defrag function tells us how much to skip
1338                          * bump our counter by the suggested amount
1339                          */
1340                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1341                         i = max(i + 1, next);
1342                         continue;
1343                 }
1344
1345                 if (!newer_than) {
1346                         cluster = (PAGE_ALIGN(defrag_end) >>
1347                                    PAGE_SHIFT) - i;
1348                         cluster = min(cluster, max_cluster);
1349                 } else {
1350                         cluster = max_cluster;
1351                 }
1352
1353                 if (i + cluster > ra_index) {
1354                         ra_index = max(i, ra_index);
1355                         if (ra)
1356                                 page_cache_sync_readahead(inode->i_mapping, ra,
1357                                                 file, ra_index, cluster);
1358                         ra_index += cluster;
1359                 }
1360
1361                 inode_lock(inode);
1362                 if (do_compress)
1363                         BTRFS_I(inode)->defrag_compress = compress_type;
1364                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1365                 if (ret < 0) {
1366                         inode_unlock(inode);
1367                         goto out_ra;
1368                 }
1369
1370                 defrag_count += ret;
1371                 balance_dirty_pages_ratelimited(inode->i_mapping);
1372                 inode_unlock(inode);
1373
1374                 if (newer_than) {
1375                         if (newer_off == (u64)-1)
1376                                 break;
1377
1378                         if (ret > 0)
1379                                 i += ret;
1380
1381                         newer_off = max(newer_off + 1,
1382                                         (u64)i << PAGE_SHIFT);
1383
1384                         ret = find_new_extents(root, inode, newer_than,
1385                                                &newer_off, SZ_64K);
1386                         if (!ret) {
1387                                 range->start = newer_off;
1388                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1389                         } else {
1390                                 break;
1391                         }
1392                 } else {
1393                         if (ret > 0) {
1394                                 i += ret;
1395                                 last_len += ret << PAGE_SHIFT;
1396                         } else {
1397                                 i++;
1398                                 last_len = 0;
1399                         }
1400                 }
1401         }
1402
1403         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1404                 filemap_flush(inode->i_mapping);
1405                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1406                              &BTRFS_I(inode)->runtime_flags))
1407                         filemap_flush(inode->i_mapping);
1408         }
1409
1410         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1411                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1412         } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1413                 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1414         }
1415
1416         ret = defrag_count;
1417
1418 out_ra:
1419         if (do_compress) {
1420                 inode_lock(inode);
1421                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1422                 inode_unlock(inode);
1423         }
1424         if (!file)
1425                 kfree(ra);
1426         kfree(pages);
1427         return ret;
1428 }
1429
1430 static noinline int btrfs_ioctl_resize(struct file *file,
1431                                         void __user *arg)
1432 {
1433         struct inode *inode = file_inode(file);
1434         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1435         u64 new_size;
1436         u64 old_size;
1437         u64 devid = 1;
1438         struct btrfs_root *root = BTRFS_I(inode)->root;
1439         struct btrfs_ioctl_vol_args *vol_args;
1440         struct btrfs_trans_handle *trans;
1441         struct btrfs_device *device = NULL;
1442         char *sizestr;
1443         char *retptr;
1444         char *devstr = NULL;
1445         int ret = 0;
1446         int mod = 0;
1447
1448         if (!capable(CAP_SYS_ADMIN))
1449                 return -EPERM;
1450
1451         ret = mnt_want_write_file(file);
1452         if (ret)
1453                 return ret;
1454
1455         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1456                 mnt_drop_write_file(file);
1457                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1458         }
1459
1460         vol_args = memdup_user(arg, sizeof(*vol_args));
1461         if (IS_ERR(vol_args)) {
1462                 ret = PTR_ERR(vol_args);
1463                 goto out;
1464         }
1465
1466         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1467
1468         sizestr = vol_args->name;
1469         devstr = strchr(sizestr, ':');
1470         if (devstr) {
1471                 sizestr = devstr + 1;
1472                 *devstr = '\0';
1473                 devstr = vol_args->name;
1474                 ret = kstrtoull(devstr, 10, &devid);
1475                 if (ret)
1476                         goto out_free;
1477                 if (!devid) {
1478                         ret = -EINVAL;
1479                         goto out_free;
1480                 }
1481                 btrfs_info(fs_info, "resizing devid %llu", devid);
1482         }
1483
1484         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1485         if (!device) {
1486                 btrfs_info(fs_info, "resizer unable to find device %llu",
1487                            devid);
1488                 ret = -ENODEV;
1489                 goto out_free;
1490         }
1491
1492         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1493                 btrfs_info(fs_info,
1494                            "resizer unable to apply on readonly device %llu",
1495                        devid);
1496                 ret = -EPERM;
1497                 goto out_free;
1498         }
1499
1500         if (!strcmp(sizestr, "max"))
1501                 new_size = device->bdev->bd_inode->i_size;
1502         else {
1503                 if (sizestr[0] == '-') {
1504                         mod = -1;
1505                         sizestr++;
1506                 } else if (sizestr[0] == '+') {
1507                         mod = 1;
1508                         sizestr++;
1509                 }
1510                 new_size = memparse(sizestr, &retptr);
1511                 if (*retptr != '\0' || new_size == 0) {
1512                         ret = -EINVAL;
1513                         goto out_free;
1514                 }
1515         }
1516
1517         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1518                 ret = -EPERM;
1519                 goto out_free;
1520         }
1521
1522         old_size = btrfs_device_get_total_bytes(device);
1523
1524         if (mod < 0) {
1525                 if (new_size > old_size) {
1526                         ret = -EINVAL;
1527                         goto out_free;
1528                 }
1529                 new_size = old_size - new_size;
1530         } else if (mod > 0) {
1531                 if (new_size > ULLONG_MAX - old_size) {
1532                         ret = -ERANGE;
1533                         goto out_free;
1534                 }
1535                 new_size = old_size + new_size;
1536         }
1537
1538         if (new_size < SZ_256M) {
1539                 ret = -EINVAL;
1540                 goto out_free;
1541         }
1542         if (new_size > device->bdev->bd_inode->i_size) {
1543                 ret = -EFBIG;
1544                 goto out_free;
1545         }
1546
1547         new_size = round_down(new_size, fs_info->sectorsize);
1548
1549         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1550                           rcu_str_deref(device->name), new_size);
1551
1552         if (new_size > old_size) {
1553                 trans = btrfs_start_transaction(root, 0);
1554                 if (IS_ERR(trans)) {
1555                         ret = PTR_ERR(trans);
1556                         goto out_free;
1557                 }
1558                 ret = btrfs_grow_device(trans, device, new_size);
1559                 btrfs_commit_transaction(trans);
1560         } else if (new_size < old_size) {
1561                 ret = btrfs_shrink_device(device, new_size);
1562         } /* equal, nothing need to do */
1563
1564 out_free:
1565         kfree(vol_args);
1566 out:
1567         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1568         mnt_drop_write_file(file);
1569         return ret;
1570 }
1571
1572 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1573                                 const char *name, unsigned long fd, int subvol,
1574                                 u64 *transid, bool readonly,
1575                                 struct btrfs_qgroup_inherit *inherit)
1576 {
1577         int namelen;
1578         int ret = 0;
1579
1580         if (!S_ISDIR(file_inode(file)->i_mode))
1581                 return -ENOTDIR;
1582
1583         ret = mnt_want_write_file(file);
1584         if (ret)
1585                 goto out;
1586
1587         namelen = strlen(name);
1588         if (strchr(name, '/')) {
1589                 ret = -EINVAL;
1590                 goto out_drop_write;
1591         }
1592
1593         if (name[0] == '.' &&
1594            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1595                 ret = -EEXIST;
1596                 goto out_drop_write;
1597         }
1598
1599         if (subvol) {
1600                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1601                                      NULL, transid, readonly, inherit);
1602         } else {
1603                 struct fd src = fdget(fd);
1604                 struct inode *src_inode;
1605                 if (!src.file) {
1606                         ret = -EINVAL;
1607                         goto out_drop_write;
1608                 }
1609
1610                 src_inode = file_inode(src.file);
1611                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1612                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1613                                    "Snapshot src from another FS");
1614                         ret = -EXDEV;
1615                 } else if (!inode_owner_or_capable(src_inode)) {
1616                         /*
1617                          * Subvolume creation is not restricted, but snapshots
1618                          * are limited to own subvolumes only
1619                          */
1620                         ret = -EPERM;
1621                 } else {
1622                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1623                                              BTRFS_I(src_inode)->root,
1624                                              transid, readonly, inherit);
1625                 }
1626                 fdput(src);
1627         }
1628 out_drop_write:
1629         mnt_drop_write_file(file);
1630 out:
1631         return ret;
1632 }
1633
1634 static noinline int btrfs_ioctl_snap_create(struct file *file,
1635                                             void __user *arg, int subvol)
1636 {
1637         struct btrfs_ioctl_vol_args *vol_args;
1638         int ret;
1639
1640         if (!S_ISDIR(file_inode(file)->i_mode))
1641                 return -ENOTDIR;
1642
1643         vol_args = memdup_user(arg, sizeof(*vol_args));
1644         if (IS_ERR(vol_args))
1645                 return PTR_ERR(vol_args);
1646         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1647
1648         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1649                                               vol_args->fd, subvol,
1650                                               NULL, false, NULL);
1651
1652         kfree(vol_args);
1653         return ret;
1654 }
1655
1656 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1657                                                void __user *arg, int subvol)
1658 {
1659         struct btrfs_ioctl_vol_args_v2 *vol_args;
1660         int ret;
1661         u64 transid = 0;
1662         u64 *ptr = NULL;
1663         bool readonly = false;
1664         struct btrfs_qgroup_inherit *inherit = NULL;
1665
1666         if (!S_ISDIR(file_inode(file)->i_mode))
1667                 return -ENOTDIR;
1668
1669         vol_args = memdup_user(arg, sizeof(*vol_args));
1670         if (IS_ERR(vol_args))
1671                 return PTR_ERR(vol_args);
1672         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1673
1674         if (vol_args->flags &
1675             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1676               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1677                 ret = -EOPNOTSUPP;
1678                 goto free_args;
1679         }
1680
1681         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1682                 ptr = &transid;
1683         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1684                 readonly = true;
1685         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1686                 if (vol_args->size > PAGE_SIZE) {
1687                         ret = -EINVAL;
1688                         goto free_args;
1689                 }
1690                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1691                 if (IS_ERR(inherit)) {
1692                         ret = PTR_ERR(inherit);
1693                         goto free_args;
1694                 }
1695         }
1696
1697         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1698                                               vol_args->fd, subvol, ptr,
1699                                               readonly, inherit);
1700         if (ret)
1701                 goto free_inherit;
1702
1703         if (ptr && copy_to_user(arg +
1704                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1705                                         transid),
1706                                 ptr, sizeof(*ptr)))
1707                 ret = -EFAULT;
1708
1709 free_inherit:
1710         kfree(inherit);
1711 free_args:
1712         kfree(vol_args);
1713         return ret;
1714 }
1715
1716 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1717                                                 void __user *arg)
1718 {
1719         struct inode *inode = file_inode(file);
1720         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1721         struct btrfs_root *root = BTRFS_I(inode)->root;
1722         int ret = 0;
1723         u64 flags = 0;
1724
1725         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1726                 return -EINVAL;
1727
1728         down_read(&fs_info->subvol_sem);
1729         if (btrfs_root_readonly(root))
1730                 flags |= BTRFS_SUBVOL_RDONLY;
1731         up_read(&fs_info->subvol_sem);
1732
1733         if (copy_to_user(arg, &flags, sizeof(flags)))
1734                 ret = -EFAULT;
1735
1736         return ret;
1737 }
1738
1739 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1740                                               void __user *arg)
1741 {
1742         struct inode *inode = file_inode(file);
1743         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1744         struct btrfs_root *root = BTRFS_I(inode)->root;
1745         struct btrfs_trans_handle *trans;
1746         u64 root_flags;
1747         u64 flags;
1748         int ret = 0;
1749
1750         if (!inode_owner_or_capable(inode))
1751                 return -EPERM;
1752
1753         ret = mnt_want_write_file(file);
1754         if (ret)
1755                 goto out;
1756
1757         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1758                 ret = -EINVAL;
1759                 goto out_drop_write;
1760         }
1761
1762         if (copy_from_user(&flags, arg, sizeof(flags))) {
1763                 ret = -EFAULT;
1764                 goto out_drop_write;
1765         }
1766
1767         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1768                 ret = -EINVAL;
1769                 goto out_drop_write;
1770         }
1771
1772         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1773                 ret = -EOPNOTSUPP;
1774                 goto out_drop_write;
1775         }
1776
1777         down_write(&fs_info->subvol_sem);
1778
1779         /* nothing to do */
1780         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1781                 goto out_drop_sem;
1782
1783         root_flags = btrfs_root_flags(&root->root_item);
1784         if (flags & BTRFS_SUBVOL_RDONLY) {
1785                 btrfs_set_root_flags(&root->root_item,
1786                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1787         } else {
1788                 /*
1789                  * Block RO -> RW transition if this subvolume is involved in
1790                  * send
1791                  */
1792                 spin_lock(&root->root_item_lock);
1793                 if (root->send_in_progress == 0) {
1794                         btrfs_set_root_flags(&root->root_item,
1795                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1796                         spin_unlock(&root->root_item_lock);
1797                 } else {
1798                         spin_unlock(&root->root_item_lock);
1799                         btrfs_warn(fs_info,
1800                                    "Attempt to set subvolume %llu read-write during send",
1801                                    root->root_key.objectid);
1802                         ret = -EPERM;
1803                         goto out_drop_sem;
1804                 }
1805         }
1806
1807         trans = btrfs_start_transaction(root, 1);
1808         if (IS_ERR(trans)) {
1809                 ret = PTR_ERR(trans);
1810                 goto out_reset;
1811         }
1812
1813         ret = btrfs_update_root(trans, fs_info->tree_root,
1814                                 &root->root_key, &root->root_item);
1815         if (ret < 0) {
1816                 btrfs_end_transaction(trans);
1817                 goto out_reset;
1818         }
1819
1820         ret = btrfs_commit_transaction(trans);
1821
1822 out_reset:
1823         if (ret)
1824                 btrfs_set_root_flags(&root->root_item, root_flags);
1825 out_drop_sem:
1826         up_write(&fs_info->subvol_sem);
1827 out_drop_write:
1828         mnt_drop_write_file(file);
1829 out:
1830         return ret;
1831 }
1832
1833 static noinline int key_in_sk(struct btrfs_key *key,
1834                               struct btrfs_ioctl_search_key *sk)
1835 {
1836         struct btrfs_key test;
1837         int ret;
1838
1839         test.objectid = sk->min_objectid;
1840         test.type = sk->min_type;
1841         test.offset = sk->min_offset;
1842
1843         ret = btrfs_comp_cpu_keys(key, &test);
1844         if (ret < 0)
1845                 return 0;
1846
1847         test.objectid = sk->max_objectid;
1848         test.type = sk->max_type;
1849         test.offset = sk->max_offset;
1850
1851         ret = btrfs_comp_cpu_keys(key, &test);
1852         if (ret > 0)
1853                 return 0;
1854         return 1;
1855 }
1856
1857 static noinline int copy_to_sk(struct btrfs_path *path,
1858                                struct btrfs_key *key,
1859                                struct btrfs_ioctl_search_key *sk,
1860                                size_t *buf_size,
1861                                char __user *ubuf,
1862                                unsigned long *sk_offset,
1863                                int *num_found)
1864 {
1865         u64 found_transid;
1866         struct extent_buffer *leaf;
1867         struct btrfs_ioctl_search_header sh;
1868         struct btrfs_key test;
1869         unsigned long item_off;
1870         unsigned long item_len;
1871         int nritems;
1872         int i;
1873         int slot;
1874         int ret = 0;
1875
1876         leaf = path->nodes[0];
1877         slot = path->slots[0];
1878         nritems = btrfs_header_nritems(leaf);
1879
1880         if (btrfs_header_generation(leaf) > sk->max_transid) {
1881                 i = nritems;
1882                 goto advance_key;
1883         }
1884         found_transid = btrfs_header_generation(leaf);
1885
1886         for (i = slot; i < nritems; i++) {
1887                 item_off = btrfs_item_ptr_offset(leaf, i);
1888                 item_len = btrfs_item_size_nr(leaf, i);
1889
1890                 btrfs_item_key_to_cpu(leaf, key, i);
1891                 if (!key_in_sk(key, sk))
1892                         continue;
1893
1894                 if (sizeof(sh) + item_len > *buf_size) {
1895                         if (*num_found) {
1896                                 ret = 1;
1897                                 goto out;
1898                         }
1899
1900                         /*
1901                          * return one empty item back for v1, which does not
1902                          * handle -EOVERFLOW
1903                          */
1904
1905                         *buf_size = sizeof(sh) + item_len;
1906                         item_len = 0;
1907                         ret = -EOVERFLOW;
1908                 }
1909
1910                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
1911                         ret = 1;
1912                         goto out;
1913                 }
1914
1915                 sh.objectid = key->objectid;
1916                 sh.offset = key->offset;
1917                 sh.type = key->type;
1918                 sh.len = item_len;
1919                 sh.transid = found_transid;
1920
1921                 /* copy search result header */
1922                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
1923                         ret = -EFAULT;
1924                         goto out;
1925                 }
1926
1927                 *sk_offset += sizeof(sh);
1928
1929                 if (item_len) {
1930                         char __user *up = ubuf + *sk_offset;
1931                         /* copy the item */
1932                         if (read_extent_buffer_to_user(leaf, up,
1933                                                        item_off, item_len)) {
1934                                 ret = -EFAULT;
1935                                 goto out;
1936                         }
1937
1938                         *sk_offset += item_len;
1939                 }
1940                 (*num_found)++;
1941
1942                 if (ret) /* -EOVERFLOW from above */
1943                         goto out;
1944
1945                 if (*num_found >= sk->nr_items) {
1946                         ret = 1;
1947                         goto out;
1948                 }
1949         }
1950 advance_key:
1951         ret = 0;
1952         test.objectid = sk->max_objectid;
1953         test.type = sk->max_type;
1954         test.offset = sk->max_offset;
1955         if (btrfs_comp_cpu_keys(key, &test) >= 0)
1956                 ret = 1;
1957         else if (key->offset < (u64)-1)
1958                 key->offset++;
1959         else if (key->type < (u8)-1) {
1960                 key->offset = 0;
1961                 key->type++;
1962         } else if (key->objectid < (u64)-1) {
1963                 key->offset = 0;
1964                 key->type = 0;
1965                 key->objectid++;
1966         } else
1967                 ret = 1;
1968 out:
1969         /*
1970          *  0: all items from this leaf copied, continue with next
1971          *  1: * more items can be copied, but unused buffer is too small
1972          *     * all items were found
1973          *     Either way, it will stops the loop which iterates to the next
1974          *     leaf
1975          *  -EOVERFLOW: item was to large for buffer
1976          *  -EFAULT: could not copy extent buffer back to userspace
1977          */
1978         return ret;
1979 }
1980
1981 static noinline int search_ioctl(struct inode *inode,
1982                                  struct btrfs_ioctl_search_key *sk,
1983                                  size_t *buf_size,
1984                                  char __user *ubuf)
1985 {
1986         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
1987         struct btrfs_root *root;
1988         struct btrfs_key key;
1989         struct btrfs_path *path;
1990         int ret;
1991         int num_found = 0;
1992         unsigned long sk_offset = 0;
1993
1994         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
1995                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
1996                 return -EOVERFLOW;
1997         }
1998
1999         path = btrfs_alloc_path();
2000         if (!path)
2001                 return -ENOMEM;
2002
2003         if (sk->tree_id == 0) {
2004                 /* search the root of the inode that was passed */
2005                 root = BTRFS_I(inode)->root;
2006         } else {
2007                 key.objectid = sk->tree_id;
2008                 key.type = BTRFS_ROOT_ITEM_KEY;
2009                 key.offset = (u64)-1;
2010                 root = btrfs_read_fs_root_no_name(info, &key);
2011                 if (IS_ERR(root)) {
2012                         btrfs_free_path(path);
2013                         return -ENOENT;
2014                 }
2015         }
2016
2017         key.objectid = sk->min_objectid;
2018         key.type = sk->min_type;
2019         key.offset = sk->min_offset;
2020
2021         while (1) {
2022                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2023                 if (ret != 0) {
2024                         if (ret > 0)
2025                                 ret = 0;
2026                         goto err;
2027                 }
2028                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2029                                  &sk_offset, &num_found);
2030                 btrfs_release_path(path);
2031                 if (ret)
2032                         break;
2033
2034         }
2035         if (ret > 0)
2036                 ret = 0;
2037 err:
2038         sk->nr_items = num_found;
2039         btrfs_free_path(path);
2040         return ret;
2041 }
2042
2043 static noinline int btrfs_ioctl_tree_search(struct file *file,
2044                                            void __user *argp)
2045 {
2046         struct btrfs_ioctl_search_args __user *uargs;
2047         struct btrfs_ioctl_search_key sk;
2048         struct inode *inode;
2049         int ret;
2050         size_t buf_size;
2051
2052         if (!capable(CAP_SYS_ADMIN))
2053                 return -EPERM;
2054
2055         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2056
2057         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2058                 return -EFAULT;
2059
2060         buf_size = sizeof(uargs->buf);
2061
2062         inode = file_inode(file);
2063         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2064
2065         /*
2066          * In the origin implementation an overflow is handled by returning a
2067          * search header with a len of zero, so reset ret.
2068          */
2069         if (ret == -EOVERFLOW)
2070                 ret = 0;
2071
2072         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2073                 ret = -EFAULT;
2074         return ret;
2075 }
2076
2077 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2078                                                void __user *argp)
2079 {
2080         struct btrfs_ioctl_search_args_v2 __user *uarg;
2081         struct btrfs_ioctl_search_args_v2 args;
2082         struct inode *inode;
2083         int ret;
2084         size_t buf_size;
2085         const size_t buf_limit = SZ_16M;
2086
2087         if (!capable(CAP_SYS_ADMIN))
2088                 return -EPERM;
2089
2090         /* copy search header and buffer size */
2091         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2092         if (copy_from_user(&args, uarg, sizeof(args)))
2093                 return -EFAULT;
2094
2095         buf_size = args.buf_size;
2096
2097         /* limit result size to 16MB */
2098         if (buf_size > buf_limit)
2099                 buf_size = buf_limit;
2100
2101         inode = file_inode(file);
2102         ret = search_ioctl(inode, &args.key, &buf_size,
2103                            (char __user *)(&uarg->buf[0]));
2104         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2105                 ret = -EFAULT;
2106         else if (ret == -EOVERFLOW &&
2107                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2108                 ret = -EFAULT;
2109
2110         return ret;
2111 }
2112
2113 /*
2114  * Search INODE_REFs to identify path name of 'dirid' directory
2115  * in a 'tree_id' tree. and sets path name to 'name'.
2116  */
2117 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2118                                 u64 tree_id, u64 dirid, char *name)
2119 {
2120         struct btrfs_root *root;
2121         struct btrfs_key key;
2122         char *ptr;
2123         int ret = -1;
2124         int slot;
2125         int len;
2126         int total_len = 0;
2127         struct btrfs_inode_ref *iref;
2128         struct extent_buffer *l;
2129         struct btrfs_path *path;
2130
2131         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2132                 name[0]='\0';
2133                 return 0;
2134         }
2135
2136         path = btrfs_alloc_path();
2137         if (!path)
2138                 return -ENOMEM;
2139
2140         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2141
2142         key.objectid = tree_id;
2143         key.type = BTRFS_ROOT_ITEM_KEY;
2144         key.offset = (u64)-1;
2145         root = btrfs_read_fs_root_no_name(info, &key);
2146         if (IS_ERR(root)) {
2147                 btrfs_err(info, "could not find root %llu", tree_id);
2148                 ret = -ENOENT;
2149                 goto out;
2150         }
2151
2152         key.objectid = dirid;
2153         key.type = BTRFS_INODE_REF_KEY;
2154         key.offset = (u64)-1;
2155
2156         while (1) {
2157                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2158                 if (ret < 0)
2159                         goto out;
2160                 else if (ret > 0) {
2161                         ret = btrfs_previous_item(root, path, dirid,
2162                                                   BTRFS_INODE_REF_KEY);
2163                         if (ret < 0)
2164                                 goto out;
2165                         else if (ret > 0) {
2166                                 ret = -ENOENT;
2167                                 goto out;
2168                         }
2169                 }
2170
2171                 l = path->nodes[0];
2172                 slot = path->slots[0];
2173                 btrfs_item_key_to_cpu(l, &key, slot);
2174
2175                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2176                 len = btrfs_inode_ref_name_len(l, iref);
2177                 ptr -= len + 1;
2178                 total_len += len + 1;
2179                 if (ptr < name) {
2180                         ret = -ENAMETOOLONG;
2181                         goto out;
2182                 }
2183
2184                 *(ptr + len) = '/';
2185                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2186
2187                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2188                         break;
2189
2190                 btrfs_release_path(path);
2191                 key.objectid = key.offset;
2192                 key.offset = (u64)-1;
2193                 dirid = key.objectid;
2194         }
2195         memmove(name, ptr, total_len);
2196         name[total_len] = '\0';
2197         ret = 0;
2198 out:
2199         btrfs_free_path(path);
2200         return ret;
2201 }
2202
2203 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2204                                            void __user *argp)
2205 {
2206          struct btrfs_ioctl_ino_lookup_args *args;
2207          struct inode *inode;
2208         int ret = 0;
2209
2210         args = memdup_user(argp, sizeof(*args));
2211         if (IS_ERR(args))
2212                 return PTR_ERR(args);
2213
2214         inode = file_inode(file);
2215
2216         /*
2217          * Unprivileged query to obtain the containing subvolume root id. The
2218          * path is reset so it's consistent with btrfs_search_path_in_tree.
2219          */
2220         if (args->treeid == 0)
2221                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2222
2223         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2224                 args->name[0] = 0;
2225                 goto out;
2226         }
2227
2228         if (!capable(CAP_SYS_ADMIN)) {
2229                 ret = -EPERM;
2230                 goto out;
2231         }
2232
2233         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2234                                         args->treeid, args->objectid,
2235                                         args->name);
2236
2237 out:
2238         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2239                 ret = -EFAULT;
2240
2241         kfree(args);
2242         return ret;
2243 }
2244
2245 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2246                                              void __user *arg)
2247 {
2248         struct dentry *parent = file->f_path.dentry;
2249         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2250         struct dentry *dentry;
2251         struct inode *dir = d_inode(parent);
2252         struct inode *inode;
2253         struct btrfs_root *root = BTRFS_I(dir)->root;
2254         struct btrfs_root *dest = NULL;
2255         struct btrfs_ioctl_vol_args *vol_args;
2256         int namelen;
2257         int err = 0;
2258
2259         if (!S_ISDIR(dir->i_mode))
2260                 return -ENOTDIR;
2261
2262         vol_args = memdup_user(arg, sizeof(*vol_args));
2263         if (IS_ERR(vol_args))
2264                 return PTR_ERR(vol_args);
2265
2266         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2267         namelen = strlen(vol_args->name);
2268         if (strchr(vol_args->name, '/') ||
2269             strncmp(vol_args->name, "..", namelen) == 0) {
2270                 err = -EINVAL;
2271                 goto out;
2272         }
2273
2274         err = mnt_want_write_file(file);
2275         if (err)
2276                 goto out;
2277
2278
2279         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2280         if (err == -EINTR)
2281                 goto out_drop_write;
2282         dentry = lookup_one_len(vol_args->name, parent, namelen);
2283         if (IS_ERR(dentry)) {
2284                 err = PTR_ERR(dentry);
2285                 goto out_unlock_dir;
2286         }
2287
2288         if (d_really_is_negative(dentry)) {
2289                 err = -ENOENT;
2290                 goto out_dput;
2291         }
2292
2293         inode = d_inode(dentry);
2294         dest = BTRFS_I(inode)->root;
2295         if (!capable(CAP_SYS_ADMIN)) {
2296                 /*
2297                  * Regular user.  Only allow this with a special mount
2298                  * option, when the user has write+exec access to the
2299                  * subvol root, and when rmdir(2) would have been
2300                  * allowed.
2301                  *
2302                  * Note that this is _not_ check that the subvol is
2303                  * empty or doesn't contain data that we wouldn't
2304                  * otherwise be able to delete.
2305                  *
2306                  * Users who want to delete empty subvols should try
2307                  * rmdir(2).
2308                  */
2309                 err = -EPERM;
2310                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2311                         goto out_dput;
2312
2313                 /*
2314                  * Do not allow deletion if the parent dir is the same
2315                  * as the dir to be deleted.  That means the ioctl
2316                  * must be called on the dentry referencing the root
2317                  * of the subvol, not a random directory contained
2318                  * within it.
2319                  */
2320                 err = -EINVAL;
2321                 if (root == dest)
2322                         goto out_dput;
2323
2324                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2325                 if (err)
2326                         goto out_dput;
2327         }
2328
2329         /* check if subvolume may be deleted by a user */
2330         err = btrfs_may_delete(dir, dentry, 1);
2331         if (err)
2332                 goto out_dput;
2333
2334         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2335                 err = -EINVAL;
2336                 goto out_dput;
2337         }
2338
2339         inode_lock(inode);
2340         err = btrfs_delete_subvolume(dir, dentry);
2341         inode_unlock(inode);
2342         if (!err)
2343                 d_delete(dentry);
2344
2345 out_dput:
2346         dput(dentry);
2347 out_unlock_dir:
2348         inode_unlock(dir);
2349 out_drop_write:
2350         mnt_drop_write_file(file);
2351 out:
2352         kfree(vol_args);
2353         return err;
2354 }
2355
2356 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2357 {
2358         struct inode *inode = file_inode(file);
2359         struct btrfs_root *root = BTRFS_I(inode)->root;
2360         struct btrfs_ioctl_defrag_range_args *range;
2361         int ret;
2362
2363         ret = mnt_want_write_file(file);
2364         if (ret)
2365                 return ret;
2366
2367         if (btrfs_root_readonly(root)) {
2368                 ret = -EROFS;
2369                 goto out;
2370         }
2371
2372         switch (inode->i_mode & S_IFMT) {
2373         case S_IFDIR:
2374                 if (!capable(CAP_SYS_ADMIN)) {
2375                         ret = -EPERM;
2376                         goto out;
2377                 }
2378                 ret = btrfs_defrag_root(root);
2379                 break;
2380         case S_IFREG:
2381                 if (!(file->f_mode & FMODE_WRITE)) {
2382                         ret = -EINVAL;
2383                         goto out;
2384                 }
2385
2386                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2387                 if (!range) {
2388                         ret = -ENOMEM;
2389                         goto out;
2390                 }
2391
2392                 if (argp) {
2393                         if (copy_from_user(range, argp,
2394                                            sizeof(*range))) {
2395                                 ret = -EFAULT;
2396                                 kfree(range);
2397                                 goto out;
2398                         }
2399                         /* compression requires us to start the IO */
2400                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2401                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2402                                 range->extent_thresh = (u32)-1;
2403                         }
2404                 } else {
2405                         /* the rest are all set to zero by kzalloc */
2406                         range->len = (u64)-1;
2407                 }
2408                 ret = btrfs_defrag_file(file_inode(file), file,
2409                                         range, BTRFS_OLDEST_GENERATION, 0);
2410                 if (ret > 0)
2411                         ret = 0;
2412                 kfree(range);
2413                 break;
2414         default:
2415                 ret = -EINVAL;
2416         }
2417 out:
2418         mnt_drop_write_file(file);
2419         return ret;
2420 }
2421
2422 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2423 {
2424         struct btrfs_ioctl_vol_args *vol_args;
2425         int ret;
2426
2427         if (!capable(CAP_SYS_ADMIN))
2428                 return -EPERM;
2429
2430         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
2431                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2432
2433         vol_args = memdup_user(arg, sizeof(*vol_args));
2434         if (IS_ERR(vol_args)) {
2435                 ret = PTR_ERR(vol_args);
2436                 goto out;
2437         }
2438
2439         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2440         ret = btrfs_init_new_device(fs_info, vol_args->name);
2441
2442         if (!ret)
2443                 btrfs_info(fs_info, "disk added %s", vol_args->name);
2444
2445         kfree(vol_args);
2446 out:
2447         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2448         return ret;
2449 }
2450
2451 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2452 {
2453         struct inode *inode = file_inode(file);
2454         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2455         struct btrfs_ioctl_vol_args_v2 *vol_args;
2456         int ret;
2457
2458         if (!capable(CAP_SYS_ADMIN))
2459                 return -EPERM;
2460
2461         ret = mnt_want_write_file(file);
2462         if (ret)
2463                 return ret;
2464
2465         vol_args = memdup_user(arg, sizeof(*vol_args));
2466         if (IS_ERR(vol_args)) {
2467                 ret = PTR_ERR(vol_args);
2468                 goto err_drop;
2469         }
2470
2471         /* Check for compatibility reject unknown flags */
2472         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED)
2473                 return -EOPNOTSUPP;
2474
2475         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
2476                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2477                 goto out;
2478         }
2479
2480         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2481                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
2482         } else {
2483                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
2484                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2485         }
2486         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2487
2488         if (!ret) {
2489                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2490                         btrfs_info(fs_info, "device deleted: id %llu",
2491                                         vol_args->devid);
2492                 else
2493                         btrfs_info(fs_info, "device deleted: %s",
2494                                         vol_args->name);
2495         }
2496 out:
2497         kfree(vol_args);
2498 err_drop:
2499         mnt_drop_write_file(file);
2500         return ret;
2501 }
2502
2503 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2504 {
2505         struct inode *inode = file_inode(file);
2506         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2507         struct btrfs_ioctl_vol_args *vol_args;
2508         int ret;
2509
2510         if (!capable(CAP_SYS_ADMIN))
2511                 return -EPERM;
2512
2513         ret = mnt_want_write_file(file);
2514         if (ret)
2515                 return ret;
2516
2517         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
2518                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2519                 goto out_drop_write;
2520         }
2521
2522         vol_args = memdup_user(arg, sizeof(*vol_args));
2523         if (IS_ERR(vol_args)) {
2524                 ret = PTR_ERR(vol_args);
2525                 goto out;
2526         }
2527
2528         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2529         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2530
2531         if (!ret)
2532                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
2533         kfree(vol_args);
2534 out:
2535         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2536 out_drop_write:
2537         mnt_drop_write_file(file);
2538
2539         return ret;
2540 }
2541
2542 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
2543                                 void __user *arg)
2544 {
2545         struct btrfs_ioctl_fs_info_args *fi_args;
2546         struct btrfs_device *device;
2547         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2548         int ret = 0;
2549
2550         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2551         if (!fi_args)
2552                 return -ENOMEM;
2553
2554         rcu_read_lock();
2555         fi_args->num_devices = fs_devices->num_devices;
2556
2557         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
2558                 if (device->devid > fi_args->max_id)
2559                         fi_args->max_id = device->devid;
2560         }
2561         rcu_read_unlock();
2562
2563         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
2564         fi_args->nodesize = fs_info->nodesize;
2565         fi_args->sectorsize = fs_info->sectorsize;
2566         fi_args->clone_alignment = fs_info->sectorsize;
2567
2568         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2569                 ret = -EFAULT;
2570
2571         kfree(fi_args);
2572         return ret;
2573 }
2574
2575 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
2576                                  void __user *arg)
2577 {
2578         struct btrfs_ioctl_dev_info_args *di_args;
2579         struct btrfs_device *dev;
2580         int ret = 0;
2581         char *s_uuid = NULL;
2582
2583         di_args = memdup_user(arg, sizeof(*di_args));
2584         if (IS_ERR(di_args))
2585                 return PTR_ERR(di_args);
2586
2587         if (!btrfs_is_empty_uuid(di_args->uuid))
2588                 s_uuid = di_args->uuid;
2589
2590         rcu_read_lock();
2591         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
2592
2593         if (!dev) {
2594                 ret = -ENODEV;
2595                 goto out;
2596         }
2597
2598         di_args->devid = dev->devid;
2599         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2600         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2601         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2602         if (dev->name) {
2603                 struct rcu_string *name;
2604
2605                 name = rcu_dereference(dev->name);
2606                 strncpy(di_args->path, name->str, sizeof(di_args->path) - 1);
2607                 di_args->path[sizeof(di_args->path) - 1] = 0;
2608         } else {
2609                 di_args->path[0] = '\0';
2610         }
2611
2612 out:
2613         rcu_read_unlock();
2614         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2615                 ret = -EFAULT;
2616
2617         kfree(di_args);
2618         return ret;
2619 }
2620
2621 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
2622 {
2623         struct page *page;
2624
2625         page = grab_cache_page(inode->i_mapping, index);
2626         if (!page)
2627                 return ERR_PTR(-ENOMEM);
2628
2629         if (!PageUptodate(page)) {
2630                 int ret;
2631
2632                 ret = btrfs_readpage(NULL, page);
2633                 if (ret)
2634                         return ERR_PTR(ret);
2635                 lock_page(page);
2636                 if (!PageUptodate(page)) {
2637                         unlock_page(page);
2638                         put_page(page);
2639                         return ERR_PTR(-EIO);
2640                 }
2641                 if (page->mapping != inode->i_mapping) {
2642                         unlock_page(page);
2643                         put_page(page);
2644                         return ERR_PTR(-EAGAIN);
2645                 }
2646         }
2647
2648         return page;
2649 }
2650
2651 static int gather_extent_pages(struct inode *inode, struct page **pages,
2652                                int num_pages, u64 off)
2653 {
2654         int i;
2655         pgoff_t index = off >> PAGE_SHIFT;
2656
2657         for (i = 0; i < num_pages; i++) {
2658 again:
2659                 pages[i] = extent_same_get_page(inode, index + i);
2660                 if (IS_ERR(pages[i])) {
2661                         int err = PTR_ERR(pages[i]);
2662
2663                         if (err == -EAGAIN)
2664                                 goto again;
2665                         pages[i] = NULL;
2666                         return err;
2667                 }
2668         }
2669         return 0;
2670 }
2671
2672 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
2673                              bool retry_range_locking)
2674 {
2675         /*
2676          * Do any pending delalloc/csum calculations on inode, one way or
2677          * another, and lock file content.
2678          * The locking order is:
2679          *
2680          *   1) pages
2681          *   2) range in the inode's io tree
2682          */
2683         while (1) {
2684                 struct btrfs_ordered_extent *ordered;
2685                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2686                 ordered = btrfs_lookup_first_ordered_extent(inode,
2687                                                             off + len - 1);
2688                 if ((!ordered ||
2689                      ordered->file_offset + ordered->len <= off ||
2690                      ordered->file_offset >= off + len) &&
2691                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2692                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2693                         if (ordered)
2694                                 btrfs_put_ordered_extent(ordered);
2695                         break;
2696                 }
2697                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2698                 if (ordered)
2699                         btrfs_put_ordered_extent(ordered);
2700                 if (!retry_range_locking)
2701                         return -EAGAIN;
2702                 btrfs_wait_ordered_range(inode, off, len);
2703         }
2704         return 0;
2705 }
2706
2707 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2708 {
2709         inode_unlock(inode1);
2710         inode_unlock(inode2);
2711 }
2712
2713 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2714 {
2715         if (inode1 < inode2)
2716                 swap(inode1, inode2);
2717
2718         inode_lock_nested(inode1, I_MUTEX_PARENT);
2719         inode_lock_nested(inode2, I_MUTEX_CHILD);
2720 }
2721
2722 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2723                                       struct inode *inode2, u64 loff2, u64 len)
2724 {
2725         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2726         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2727 }
2728
2729 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2730                                     struct inode *inode2, u64 loff2, u64 len,
2731                                     bool retry_range_locking)
2732 {
2733         int ret;
2734
2735         if (inode1 < inode2) {
2736                 swap(inode1, inode2);
2737                 swap(loff1, loff2);
2738         }
2739         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
2740         if (ret)
2741                 return ret;
2742         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
2743         if (ret)
2744                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
2745                               loff1 + len - 1);
2746         return ret;
2747 }
2748
2749 struct cmp_pages {
2750         int             num_pages;
2751         struct page     **src_pages;
2752         struct page     **dst_pages;
2753 };
2754
2755 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
2756 {
2757         int i;
2758         struct page *pg;
2759
2760         for (i = 0; i < cmp->num_pages; i++) {
2761                 pg = cmp->src_pages[i];
2762                 if (pg) {
2763                         unlock_page(pg);
2764                         put_page(pg);
2765                 }
2766                 pg = cmp->dst_pages[i];
2767                 if (pg) {
2768                         unlock_page(pg);
2769                         put_page(pg);
2770                 }
2771         }
2772         kfree(cmp->src_pages);
2773         kfree(cmp->dst_pages);
2774 }
2775
2776 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
2777                                   struct inode *dst, u64 dst_loff,
2778                                   u64 len, struct cmp_pages *cmp)
2779 {
2780         int ret;
2781         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
2782         struct page **src_pgarr, **dst_pgarr;
2783
2784         /*
2785          * We must gather up all the pages before we initiate our
2786          * extent locking. We use an array for the page pointers. Size
2787          * of the array is bounded by len, which is in turn bounded by
2788          * BTRFS_MAX_DEDUPE_LEN.
2789          */
2790         src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
2791         dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
2792         if (!src_pgarr || !dst_pgarr) {
2793                 kfree(src_pgarr);
2794                 kfree(dst_pgarr);
2795                 return -ENOMEM;
2796         }
2797         cmp->num_pages = num_pages;
2798         cmp->src_pages = src_pgarr;
2799         cmp->dst_pages = dst_pgarr;
2800
2801         /*
2802          * If deduping ranges in the same inode, locking rules make it mandatory
2803          * to always lock pages in ascending order to avoid deadlocks with
2804          * concurrent tasks (such as starting writeback/delalloc).
2805          */
2806         if (src == dst && dst_loff < loff) {
2807                 swap(src_pgarr, dst_pgarr);
2808                 swap(loff, dst_loff);
2809         }
2810
2811         ret = gather_extent_pages(src, src_pgarr, cmp->num_pages, loff);
2812         if (ret)
2813                 goto out;
2814
2815         ret = gather_extent_pages(dst, dst_pgarr, cmp->num_pages, dst_loff);
2816
2817 out:
2818         if (ret)
2819                 btrfs_cmp_data_free(cmp);
2820         return ret;
2821 }
2822
2823 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
2824 {
2825         int ret = 0;
2826         int i;
2827         struct page *src_page, *dst_page;
2828         unsigned int cmp_len = PAGE_SIZE;
2829         void *addr, *dst_addr;
2830
2831         i = 0;
2832         while (len) {
2833                 if (len < PAGE_SIZE)
2834                         cmp_len = len;
2835
2836                 BUG_ON(i >= cmp->num_pages);
2837
2838                 src_page = cmp->src_pages[i];
2839                 dst_page = cmp->dst_pages[i];
2840                 ASSERT(PageLocked(src_page));
2841                 ASSERT(PageLocked(dst_page));
2842
2843                 addr = kmap_atomic(src_page);
2844                 dst_addr = kmap_atomic(dst_page);
2845
2846                 flush_dcache_page(src_page);
2847                 flush_dcache_page(dst_page);
2848
2849                 if (memcmp(addr, dst_addr, cmp_len))
2850                         ret = -EBADE;
2851
2852                 kunmap_atomic(addr);
2853                 kunmap_atomic(dst_addr);
2854
2855                 if (ret)
2856                         break;
2857
2858                 len -= cmp_len;
2859                 i++;
2860         }
2861
2862         return ret;
2863 }
2864
2865 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
2866                                      u64 olen)
2867 {
2868         u64 len = *plen;
2869         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
2870
2871         if (off + olen > inode->i_size || off + olen < off)
2872                 return -EINVAL;
2873
2874         /* if we extend to eof, continue to block boundary */
2875         if (off + len == inode->i_size)
2876                 *plen = len = ALIGN(inode->i_size, bs) - off;
2877
2878         /* Check that we are block aligned - btrfs_clone() requires this */
2879         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
2880                 return -EINVAL;
2881
2882         return 0;
2883 }
2884
2885 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
2886                              struct inode *dst, u64 dst_loff)
2887 {
2888         int ret;
2889         u64 len = olen;
2890         struct cmp_pages cmp;
2891         bool same_inode = (src == dst);
2892         u64 same_lock_start = 0;
2893         u64 same_lock_len = 0;
2894
2895         if (len == 0)
2896                 return 0;
2897
2898         if (same_inode)
2899                 inode_lock(src);
2900         else
2901                 btrfs_double_inode_lock(src, dst);
2902
2903         ret = extent_same_check_offsets(src, loff, &len, olen);
2904         if (ret)
2905                 goto out_unlock;
2906
2907         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
2908         if (ret)
2909                 goto out_unlock;
2910
2911         if (same_inode) {
2912                 /*
2913                  * Single inode case wants the same checks, except we
2914                  * don't want our length pushed out past i_size as
2915                  * comparing that data range makes no sense.
2916                  *
2917                  * extent_same_check_offsets() will do this for an
2918                  * unaligned length at i_size, so catch it here and
2919                  * reject the request.
2920                  *
2921                  * This effectively means we require aligned extents
2922                  * for the single-inode case, whereas the other cases
2923                  * allow an unaligned length so long as it ends at
2924                  * i_size.
2925                  */
2926                 if (len != olen) {
2927                         ret = -EINVAL;
2928                         goto out_unlock;
2929                 }
2930
2931                 /* Check for overlapping ranges */
2932                 if (dst_loff + len > loff && dst_loff < loff + len) {
2933                         ret = -EINVAL;
2934                         goto out_unlock;
2935                 }
2936
2937                 same_lock_start = min_t(u64, loff, dst_loff);
2938                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
2939         }
2940
2941         /* don't make the dst file partly checksummed */
2942         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2943             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
2944                 ret = -EINVAL;
2945                 goto out_unlock;
2946         }
2947
2948 again:
2949         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
2950         if (ret)
2951                 goto out_unlock;
2952
2953         if (same_inode)
2954                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
2955                                         false);
2956         else
2957                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
2958                                                false);
2959         /*
2960          * If one of the inodes has dirty pages in the respective range or
2961          * ordered extents, we need to flush dellaloc and wait for all ordered
2962          * extents in the range. We must unlock the pages and the ranges in the
2963          * io trees to avoid deadlocks when flushing delalloc (requires locking
2964          * pages) and when waiting for ordered extents to complete (they require
2965          * range locking).
2966          */
2967         if (ret == -EAGAIN) {
2968                 /*
2969                  * Ranges in the io trees already unlocked. Now unlock all
2970                  * pages before waiting for all IO to complete.
2971                  */
2972                 btrfs_cmp_data_free(&cmp);
2973                 if (same_inode) {
2974                         btrfs_wait_ordered_range(src, same_lock_start,
2975                                                  same_lock_len);
2976                 } else {
2977                         btrfs_wait_ordered_range(src, loff, len);
2978                         btrfs_wait_ordered_range(dst, dst_loff, len);
2979                 }
2980                 goto again;
2981         }
2982         ASSERT(ret == 0);
2983         if (WARN_ON(ret)) {
2984                 /* ranges in the io trees already unlocked */
2985                 btrfs_cmp_data_free(&cmp);
2986                 return ret;
2987         }
2988
2989         /* pass original length for comparison so we stay within i_size */
2990         ret = btrfs_cmp_data(olen, &cmp);
2991         if (ret == 0)
2992                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
2993
2994         if (same_inode)
2995                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
2996                               same_lock_start + same_lock_len - 1);
2997         else
2998                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
2999
3000         btrfs_cmp_data_free(&cmp);
3001 out_unlock:
3002         if (same_inode)
3003                 inode_unlock(src);
3004         else
3005                 btrfs_double_inode_unlock(src, dst);
3006
3007         return ret;
3008 }
3009
3010 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3011
3012 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3013                                 struct file *dst_file, u64 dst_loff)
3014 {
3015         struct inode *src = file_inode(src_file);
3016         struct inode *dst = file_inode(dst_file);
3017         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3018         ssize_t res;
3019
3020         if (olen > BTRFS_MAX_DEDUPE_LEN)
3021                 olen = BTRFS_MAX_DEDUPE_LEN;
3022
3023         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3024                 /*
3025                  * Btrfs does not support blocksize < page_size. As a
3026                  * result, btrfs_cmp_data() won't correctly handle
3027                  * this situation without an update.
3028                  */
3029                 return -EINVAL;
3030         }
3031
3032         res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3033         if (res)
3034                 return res;
3035         return olen;
3036 }
3037
3038 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3039                                      struct inode *inode,
3040                                      u64 endoff,
3041                                      const u64 destoff,
3042                                      const u64 olen,
3043                                      int no_time_update)
3044 {
3045         struct btrfs_root *root = BTRFS_I(inode)->root;
3046         int ret;
3047
3048         inode_inc_iversion(inode);
3049         if (!no_time_update)
3050                 inode->i_mtime = inode->i_ctime = current_time(inode);
3051         /*
3052          * We round up to the block size at eof when determining which
3053          * extents to clone above, but shouldn't round up the file size.
3054          */
3055         if (endoff > destoff + olen)
3056                 endoff = destoff + olen;
3057         if (endoff > inode->i_size)
3058                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3059
3060         ret = btrfs_update_inode(trans, root, inode);
3061         if (ret) {
3062                 btrfs_abort_transaction(trans, ret);
3063                 btrfs_end_transaction(trans);
3064                 goto out;
3065         }
3066         ret = btrfs_end_transaction(trans);
3067 out:
3068         return ret;
3069 }
3070
3071 static void clone_update_extent_map(struct btrfs_inode *inode,
3072                                     const struct btrfs_trans_handle *trans,
3073                                     const struct btrfs_path *path,
3074                                     const u64 hole_offset,
3075                                     const u64 hole_len)
3076 {
3077         struct extent_map_tree *em_tree = &inode->extent_tree;
3078         struct extent_map *em;
3079         int ret;
3080
3081         em = alloc_extent_map();
3082         if (!em) {
3083                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3084                 return;
3085         }
3086
3087         if (path) {
3088                 struct btrfs_file_extent_item *fi;
3089
3090                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3091                                     struct btrfs_file_extent_item);
3092                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3093                 em->generation = -1;
3094                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3095                     BTRFS_FILE_EXTENT_INLINE)
3096                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3097                                         &inode->runtime_flags);
3098         } else {
3099                 em->start = hole_offset;
3100                 em->len = hole_len;
3101                 em->ram_bytes = em->len;
3102                 em->orig_start = hole_offset;
3103                 em->block_start = EXTENT_MAP_HOLE;
3104                 em->block_len = 0;
3105                 em->orig_block_len = 0;
3106                 em->compress_type = BTRFS_COMPRESS_NONE;
3107                 em->generation = trans->transid;
3108         }
3109
3110         while (1) {
3111                 write_lock(&em_tree->lock);
3112                 ret = add_extent_mapping(em_tree, em, 1);
3113                 write_unlock(&em_tree->lock);
3114                 if (ret != -EEXIST) {
3115                         free_extent_map(em);
3116                         break;
3117                 }
3118                 btrfs_drop_extent_cache(inode, em->start,
3119                                         em->start + em->len - 1, 0);
3120         }
3121
3122         if (ret)
3123                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3124 }
3125
3126 /*
3127  * Make sure we do not end up inserting an inline extent into a file that has
3128  * already other (non-inline) extents. If a file has an inline extent it can
3129  * not have any other extents and the (single) inline extent must start at the
3130  * file offset 0. Failing to respect these rules will lead to file corruption,
3131  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3132  *
3133  * We can have extents that have been already written to disk or we can have
3134  * dirty ranges still in delalloc, in which case the extent maps and items are
3135  * created only when we run delalloc, and the delalloc ranges might fall outside
3136  * the range we are currently locking in the inode's io tree. So we check the
3137  * inode's i_size because of that (i_size updates are done while holding the
3138  * i_mutex, which we are holding here).
3139  * We also check to see if the inode has a size not greater than "datal" but has
3140  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3141  * protected against such concurrent fallocate calls by the i_mutex).
3142  *
3143  * If the file has no extents but a size greater than datal, do not allow the
3144  * copy because we would need turn the inline extent into a non-inline one (even
3145  * with NO_HOLES enabled). If we find our destination inode only has one inline
3146  * extent, just overwrite it with the source inline extent if its size is less
3147  * than the source extent's size, or we could copy the source inline extent's
3148  * data into the destination inode's inline extent if the later is greater then
3149  * the former.
3150  */
3151 static int clone_copy_inline_extent(struct inode *dst,
3152                                     struct btrfs_trans_handle *trans,
3153                                     struct btrfs_path *path,
3154                                     struct btrfs_key *new_key,
3155                                     const u64 drop_start,
3156                                     const u64 datal,
3157                                     const u64 skip,
3158                                     const u64 size,
3159                                     char *inline_data)
3160 {
3161         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3162         struct btrfs_root *root = BTRFS_I(dst)->root;
3163         const u64 aligned_end = ALIGN(new_key->offset + datal,
3164                                       fs_info->sectorsize);
3165         int ret;
3166         struct btrfs_key key;
3167
3168         if (new_key->offset > 0)
3169                 return -EOPNOTSUPP;
3170
3171         key.objectid = btrfs_ino(BTRFS_I(dst));
3172         key.type = BTRFS_EXTENT_DATA_KEY;
3173         key.offset = 0;
3174         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3175         if (ret < 0) {
3176                 return ret;
3177         } else if (ret > 0) {
3178                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3179                         ret = btrfs_next_leaf(root, path);
3180                         if (ret < 0)
3181                                 return ret;
3182                         else if (ret > 0)
3183                                 goto copy_inline_extent;
3184                 }
3185                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3186                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3187                     key.type == BTRFS_EXTENT_DATA_KEY) {
3188                         ASSERT(key.offset > 0);
3189                         return -EOPNOTSUPP;
3190                 }
3191         } else if (i_size_read(dst) <= datal) {
3192                 struct btrfs_file_extent_item *ei;
3193                 u64 ext_len;
3194
3195                 /*
3196                  * If the file size is <= datal, make sure there are no other
3197                  * extents following (can happen do to an fallocate call with
3198                  * the flag FALLOC_FL_KEEP_SIZE).
3199                  */
3200                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3201                                     struct btrfs_file_extent_item);
3202                 /*
3203                  * If it's an inline extent, it can not have other extents
3204                  * following it.
3205                  */
3206                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3207                     BTRFS_FILE_EXTENT_INLINE)
3208                         goto copy_inline_extent;
3209
3210                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3211                 if (ext_len > aligned_end)
3212                         return -EOPNOTSUPP;
3213
3214                 ret = btrfs_next_item(root, path);
3215                 if (ret < 0) {
3216                         return ret;
3217                 } else if (ret == 0) {
3218                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3219                                               path->slots[0]);
3220                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3221                             key.type == BTRFS_EXTENT_DATA_KEY)
3222                                 return -EOPNOTSUPP;
3223                 }
3224         }
3225
3226 copy_inline_extent:
3227         /*
3228          * We have no extent items, or we have an extent at offset 0 which may
3229          * or may not be inlined. All these cases are dealt the same way.
3230          */
3231         if (i_size_read(dst) > datal) {
3232                 /*
3233                  * If the destination inode has an inline extent...
3234                  * This would require copying the data from the source inline
3235                  * extent into the beginning of the destination's inline extent.
3236                  * But this is really complex, both extents can be compressed
3237                  * or just one of them, which would require decompressing and
3238                  * re-compressing data (which could increase the new compressed
3239                  * size, not allowing the compressed data to fit anymore in an
3240                  * inline extent).
3241                  * So just don't support this case for now (it should be rare,
3242                  * we are not really saving space when cloning inline extents).
3243                  */
3244                 return -EOPNOTSUPP;
3245         }
3246
3247         btrfs_release_path(path);
3248         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3249         if (ret)
3250                 return ret;
3251         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3252         if (ret)
3253                 return ret;
3254
3255         if (skip) {
3256                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3257
3258                 memmove(inline_data + start, inline_data + start + skip, datal);
3259         }
3260
3261         write_extent_buffer(path->nodes[0], inline_data,
3262                             btrfs_item_ptr_offset(path->nodes[0],
3263                                                   path->slots[0]),
3264                             size);
3265         inode_add_bytes(dst, datal);
3266
3267         return 0;
3268 }
3269
3270 /**
3271  * btrfs_clone() - clone a range from inode file to another
3272  *
3273  * @src: Inode to clone from
3274  * @inode: Inode to clone to
3275  * @off: Offset within source to start clone from
3276  * @olen: Original length, passed by user, of range to clone
3277  * @olen_aligned: Block-aligned value of olen
3278  * @destoff: Offset within @inode to start clone
3279  * @no_time_update: Whether to update mtime/ctime on the target inode
3280  */
3281 static int btrfs_clone(struct inode *src, struct inode *inode,
3282                        const u64 off, const u64 olen, const u64 olen_aligned,
3283                        const u64 destoff, int no_time_update)
3284 {
3285         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3286         struct btrfs_root *root = BTRFS_I(inode)->root;
3287         struct btrfs_path *path = NULL;
3288         struct extent_buffer *leaf;
3289         struct btrfs_trans_handle *trans;
3290         char *buf = NULL;
3291         struct btrfs_key key;
3292         u32 nritems;
3293         int slot;
3294         int ret;
3295         const u64 len = olen_aligned;
3296         u64 last_dest_end = destoff;
3297
3298         ret = -ENOMEM;
3299         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3300         if (!buf)
3301                 return ret;
3302
3303         path = btrfs_alloc_path();
3304         if (!path) {
3305                 kvfree(buf);
3306                 return ret;
3307         }
3308
3309         path->reada = READA_FORWARD;
3310         /* clone data */
3311         key.objectid = btrfs_ino(BTRFS_I(src));
3312         key.type = BTRFS_EXTENT_DATA_KEY;
3313         key.offset = off;
3314
3315         while (1) {
3316                 u64 next_key_min_offset = key.offset + 1;
3317
3318                 /*
3319                  * note the key will change type as we walk through the
3320                  * tree.
3321                  */
3322                 path->leave_spinning = 1;
3323                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3324                                 0, 0);
3325                 if (ret < 0)
3326                         goto out;
3327                 /*
3328                  * First search, if no extent item that starts at offset off was
3329                  * found but the previous item is an extent item, it's possible
3330                  * it might overlap our target range, therefore process it.
3331                  */
3332                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3333                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3334                                               path->slots[0] - 1);
3335                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3336                                 path->slots[0]--;
3337                 }
3338
3339                 nritems = btrfs_header_nritems(path->nodes[0]);
3340 process_slot:
3341                 if (path->slots[0] >= nritems) {
3342                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3343                         if (ret < 0)
3344                                 goto out;
3345                         if (ret > 0)
3346                                 break;
3347                         nritems = btrfs_header_nritems(path->nodes[0]);
3348                 }
3349                 leaf = path->nodes[0];
3350                 slot = path->slots[0];
3351
3352                 btrfs_item_key_to_cpu(leaf, &key, slot);
3353                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3354                     key.objectid != btrfs_ino(BTRFS_I(src)))
3355                         break;
3356
3357                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3358                         struct btrfs_file_extent_item *extent;
3359                         int type;
3360                         u32 size;
3361                         struct btrfs_key new_key;
3362                         u64 disko = 0, diskl = 0;
3363                         u64 datao = 0, datal = 0;
3364                         u8 comp;
3365                         u64 drop_start;
3366
3367                         extent = btrfs_item_ptr(leaf, slot,
3368                                                 struct btrfs_file_extent_item);
3369                         comp = btrfs_file_extent_compression(leaf, extent);
3370                         type = btrfs_file_extent_type(leaf, extent);
3371                         if (type == BTRFS_FILE_EXTENT_REG ||
3372                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3373                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3374                                                                       extent);
3375                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3376                                                                  extent);
3377                                 datao = btrfs_file_extent_offset(leaf, extent);
3378                                 datal = btrfs_file_extent_num_bytes(leaf,
3379                                                                     extent);
3380                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3381                                 /* take upper bound, may be compressed */
3382                                 datal = btrfs_file_extent_ram_bytes(leaf,
3383                                                                     extent);
3384                         }
3385
3386                         /*
3387                          * The first search might have left us at an extent
3388                          * item that ends before our target range's start, can
3389                          * happen if we have holes and NO_HOLES feature enabled.
3390                          */
3391                         if (key.offset + datal <= off) {
3392                                 path->slots[0]++;
3393                                 goto process_slot;
3394                         } else if (key.offset >= off + len) {
3395                                 break;
3396                         }
3397                         next_key_min_offset = key.offset + datal;
3398                         size = btrfs_item_size_nr(leaf, slot);
3399                         read_extent_buffer(leaf, buf,
3400                                            btrfs_item_ptr_offset(leaf, slot),
3401                                            size);
3402
3403                         btrfs_release_path(path);
3404                         path->leave_spinning = 0;
3405
3406                         memcpy(&new_key, &key, sizeof(new_key));
3407                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
3408                         if (off <= key.offset)
3409                                 new_key.offset = key.offset + destoff - off;
3410                         else
3411                                 new_key.offset = destoff;
3412
3413                         /*
3414                          * Deal with a hole that doesn't have an extent item
3415                          * that represents it (NO_HOLES feature enabled).
3416                          * This hole is either in the middle of the cloning
3417                          * range or at the beginning (fully overlaps it or
3418                          * partially overlaps it).
3419                          */
3420                         if (new_key.offset != last_dest_end)
3421                                 drop_start = last_dest_end;
3422                         else
3423                                 drop_start = new_key.offset;
3424
3425                         /*
3426                          * 1 - adjusting old extent (we may have to split it)
3427                          * 1 - add new extent
3428                          * 1 - inode update
3429                          */
3430                         trans = btrfs_start_transaction(root, 3);
3431                         if (IS_ERR(trans)) {
3432                                 ret = PTR_ERR(trans);
3433                                 goto out;
3434                         }
3435
3436                         if (type == BTRFS_FILE_EXTENT_REG ||
3437                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3438                                 /*
3439                                  *    a  | --- range to clone ---|  b
3440                                  * | ------------- extent ------------- |
3441                                  */
3442
3443                                 /* subtract range b */
3444                                 if (key.offset + datal > off + len)
3445                                         datal = off + len - key.offset;
3446
3447                                 /* subtract range a */
3448                                 if (off > key.offset) {
3449                                         datao += off - key.offset;
3450                                         datal -= off - key.offset;
3451                                 }
3452
3453                                 ret = btrfs_drop_extents(trans, root, inode,
3454                                                          drop_start,
3455                                                          new_key.offset + datal,
3456                                                          1);
3457                                 if (ret) {
3458                                         if (ret != -EOPNOTSUPP)
3459                                                 btrfs_abort_transaction(trans,
3460                                                                         ret);
3461                                         btrfs_end_transaction(trans);
3462                                         goto out;
3463                                 }
3464
3465                                 ret = btrfs_insert_empty_item(trans, root, path,
3466                                                               &new_key, size);
3467                                 if (ret) {
3468                                         btrfs_abort_transaction(trans, ret);
3469                                         btrfs_end_transaction(trans);
3470                                         goto out;
3471                                 }
3472
3473                                 leaf = path->nodes[0];
3474                                 slot = path->slots[0];
3475                                 write_extent_buffer(leaf, buf,
3476                                             btrfs_item_ptr_offset(leaf, slot),
3477                                             size);
3478
3479                                 extent = btrfs_item_ptr(leaf, slot,
3480                                                 struct btrfs_file_extent_item);
3481
3482                                 /* disko == 0 means it's a hole */
3483                                 if (!disko)
3484                                         datao = 0;
3485
3486                                 btrfs_set_file_extent_offset(leaf, extent,
3487                                                              datao);
3488                                 btrfs_set_file_extent_num_bytes(leaf, extent,
3489                                                                 datal);
3490
3491                                 if (disko) {
3492                                         inode_add_bytes(inode, datal);
3493                                         ret = btrfs_inc_extent_ref(trans,
3494                                                         root,
3495                                                         disko, diskl, 0,
3496                                                         root->root_key.objectid,
3497                                                         btrfs_ino(BTRFS_I(inode)),
3498                                                         new_key.offset - datao);
3499                                         if (ret) {
3500                                                 btrfs_abort_transaction(trans,
3501                                                                         ret);
3502                                                 btrfs_end_transaction(trans);
3503                                                 goto out;
3504
3505                                         }
3506                                 }
3507                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3508                                 u64 skip = 0;
3509                                 u64 trim = 0;
3510
3511                                 if (off > key.offset) {
3512                                         skip = off - key.offset;
3513                                         new_key.offset += skip;
3514                                 }
3515
3516                                 if (key.offset + datal > off + len)
3517                                         trim = key.offset + datal - (off + len);
3518
3519                                 if (comp && (skip || trim)) {
3520                                         ret = -EINVAL;
3521                                         btrfs_end_transaction(trans);
3522                                         goto out;
3523                                 }
3524                                 size -= skip + trim;
3525                                 datal -= skip + trim;
3526
3527                                 ret = clone_copy_inline_extent(inode,
3528                                                                trans, path,
3529                                                                &new_key,
3530                                                                drop_start,
3531                                                                datal,
3532                                                                skip, size, buf);
3533                                 if (ret) {
3534                                         if (ret != -EOPNOTSUPP)
3535                                                 btrfs_abort_transaction(trans,
3536                                                                         ret);
3537                                         btrfs_end_transaction(trans);
3538                                         goto out;
3539                                 }
3540                                 leaf = path->nodes[0];
3541                                 slot = path->slots[0];
3542                         }
3543
3544                         /* If we have an implicit hole (NO_HOLES feature). */
3545                         if (drop_start < new_key.offset)
3546                                 clone_update_extent_map(BTRFS_I(inode), trans,
3547                                                 NULL, drop_start,
3548                                                 new_key.offset - drop_start);
3549
3550                         clone_update_extent_map(BTRFS_I(inode), trans,
3551                                         path, 0, 0);
3552
3553                         btrfs_mark_buffer_dirty(leaf);
3554                         btrfs_release_path(path);
3555
3556                         last_dest_end = ALIGN(new_key.offset + datal,
3557                                               fs_info->sectorsize);
3558                         ret = clone_finish_inode_update(trans, inode,
3559                                                         last_dest_end,
3560                                                         destoff, olen,
3561                                                         no_time_update);
3562                         if (ret)
3563                                 goto out;
3564                         if (new_key.offset + datal >= destoff + len)
3565                                 break;
3566                 }
3567                 btrfs_release_path(path);
3568                 key.offset = next_key_min_offset;
3569
3570                 if (fatal_signal_pending(current)) {
3571                         ret = -EINTR;
3572                         goto out;
3573                 }
3574         }
3575         ret = 0;
3576
3577         if (last_dest_end < destoff + len) {
3578                 /*
3579                  * We have an implicit hole (NO_HOLES feature is enabled) that
3580                  * fully or partially overlaps our cloning range at its end.
3581                  */
3582                 btrfs_release_path(path);
3583
3584                 /*
3585                  * 1 - remove extent(s)
3586                  * 1 - inode update
3587                  */
3588                 trans = btrfs_start_transaction(root, 2);
3589                 if (IS_ERR(trans)) {
3590                         ret = PTR_ERR(trans);
3591                         goto out;
3592                 }
3593                 ret = btrfs_drop_extents(trans, root, inode,
3594                                          last_dest_end, destoff + len, 1);
3595                 if (ret) {
3596                         if (ret != -EOPNOTSUPP)
3597                                 btrfs_abort_transaction(trans, ret);
3598                         btrfs_end_transaction(trans);
3599                         goto out;
3600                 }
3601                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
3602                                 last_dest_end,
3603                                 destoff + len - last_dest_end);
3604                 ret = clone_finish_inode_update(trans, inode, destoff + len,
3605                                                 destoff, olen, no_time_update);
3606         }
3607
3608 out:
3609         btrfs_free_path(path);
3610         kvfree(buf);
3611         return ret;
3612 }
3613
3614 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3615                                         u64 off, u64 olen, u64 destoff)
3616 {
3617         struct inode *inode = file_inode(file);
3618         struct inode *src = file_inode(file_src);
3619         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3620         struct btrfs_root *root = BTRFS_I(inode)->root;
3621         int ret;
3622         u64 len = olen;
3623         u64 bs = fs_info->sb->s_blocksize;
3624         int same_inode = src == inode;
3625
3626         /*
3627          * TODO:
3628          * - split compressed inline extents.  annoying: we need to
3629          *   decompress into destination's address_space (the file offset
3630          *   may change, so source mapping won't do), then recompress (or
3631          *   otherwise reinsert) a subrange.
3632          *
3633          * - split destination inode's inline extents.  The inline extents can
3634          *   be either compressed or non-compressed.
3635          */
3636
3637         if (btrfs_root_readonly(root))
3638                 return -EROFS;
3639
3640         if (file_src->f_path.mnt != file->f_path.mnt ||
3641             src->i_sb != inode->i_sb)
3642                 return -EXDEV;
3643
3644         /* don't make the dst file partly checksummed */
3645         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3646             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3647                 return -EINVAL;
3648
3649         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3650                 return -EISDIR;
3651
3652         if (!same_inode) {
3653                 btrfs_double_inode_lock(src, inode);
3654         } else {
3655                 inode_lock(src);
3656         }
3657
3658         /* determine range to clone */
3659         ret = -EINVAL;
3660         if (off + len > src->i_size || off + len < off)
3661                 goto out_unlock;
3662         if (len == 0)
3663                 olen = len = src->i_size - off;
3664         /* if we extend to eof, continue to block boundary */
3665         if (off + len == src->i_size)
3666                 len = ALIGN(src->i_size, bs) - off;
3667
3668         if (len == 0) {
3669                 ret = 0;
3670                 goto out_unlock;
3671         }
3672
3673         /* verify the end result is block aligned */
3674         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3675             !IS_ALIGNED(destoff, bs))
3676                 goto out_unlock;
3677
3678         /* verify if ranges are overlapped within the same file */
3679         if (same_inode) {
3680                 if (destoff + len > off && destoff < off + len)
3681                         goto out_unlock;
3682         }
3683
3684         if (destoff > inode->i_size) {
3685                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3686                 if (ret)
3687                         goto out_unlock;
3688         }
3689
3690         /*
3691          * Lock the target range too. Right after we replace the file extent
3692          * items in the fs tree (which now point to the cloned data), we might
3693          * have a worker replace them with extent items relative to a write
3694          * operation that was issued before this clone operation (i.e. confront
3695          * with inode.c:btrfs_finish_ordered_io).
3696          */
3697         if (same_inode) {
3698                 u64 lock_start = min_t(u64, off, destoff);
3699                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3700
3701                 ret = lock_extent_range(src, lock_start, lock_len, true);
3702         } else {
3703                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
3704                                                true);
3705         }
3706         ASSERT(ret == 0);
3707         if (WARN_ON(ret)) {
3708                 /* ranges in the io trees already unlocked */
3709                 goto out_unlock;
3710         }
3711
3712         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3713
3714         if (same_inode) {
3715                 u64 lock_start = min_t(u64, off, destoff);
3716                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
3717
3718                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3719         } else {
3720                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
3721         }
3722         /*
3723          * Truncate page cache pages so that future reads will see the cloned
3724          * data immediately and not the previous data.
3725          */
3726         truncate_inode_pages_range(&inode->i_data,
3727                                 round_down(destoff, PAGE_SIZE),
3728                                 round_up(destoff + len, PAGE_SIZE) - 1);
3729 out_unlock:
3730         if (!same_inode)
3731                 btrfs_double_inode_unlock(src, inode);
3732         else
3733                 inode_unlock(src);
3734         return ret;
3735 }
3736
3737 int btrfs_clone_file_range(struct file *src_file, loff_t off,
3738                 struct file *dst_file, loff_t destoff, u64 len)
3739 {
3740         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
3741 }
3742
3743 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3744 {
3745         struct inode *inode = file_inode(file);
3746         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3747         struct btrfs_root *root = BTRFS_I(inode)->root;
3748         struct btrfs_root *new_root;
3749         struct btrfs_dir_item *di;
3750         struct btrfs_trans_handle *trans;
3751         struct btrfs_path *path;
3752         struct btrfs_key location;
3753         struct btrfs_disk_key disk_key;
3754         u64 objectid = 0;
3755         u64 dir_id;
3756         int ret;
3757
3758         if (!capable(CAP_SYS_ADMIN))
3759                 return -EPERM;
3760
3761         ret = mnt_want_write_file(file);
3762         if (ret)
3763                 return ret;
3764
3765         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3766                 ret = -EFAULT;
3767                 goto out;
3768         }
3769
3770         if (!objectid)
3771                 objectid = BTRFS_FS_TREE_OBJECTID;
3772
3773         location.objectid = objectid;
3774         location.type = BTRFS_ROOT_ITEM_KEY;
3775         location.offset = (u64)-1;
3776
3777         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
3778         if (IS_ERR(new_root)) {
3779                 ret = PTR_ERR(new_root);
3780                 goto out;
3781         }
3782         if (!is_fstree(new_root->objectid)) {
3783                 ret = -ENOENT;
3784                 goto out;
3785         }
3786
3787         path = btrfs_alloc_path();
3788         if (!path) {
3789                 ret = -ENOMEM;
3790                 goto out;
3791         }
3792         path->leave_spinning = 1;
3793
3794         trans = btrfs_start_transaction(root, 1);
3795         if (IS_ERR(trans)) {
3796                 btrfs_free_path(path);
3797                 ret = PTR_ERR(trans);
3798                 goto out;
3799         }
3800
3801         dir_id = btrfs_super_root_dir(fs_info->super_copy);
3802         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
3803                                    dir_id, "default", 7, 1);
3804         if (IS_ERR_OR_NULL(di)) {
3805                 btrfs_free_path(path);
3806                 btrfs_end_transaction(trans);
3807                 btrfs_err(fs_info,
3808                           "Umm, you don't have the default diritem, this isn't going to work");
3809                 ret = -ENOENT;
3810                 goto out;
3811         }
3812
3813         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3814         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
3815         btrfs_mark_buffer_dirty(path->nodes[0]);
3816         btrfs_free_path(path);
3817
3818         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
3819         btrfs_end_transaction(trans);
3820 out:
3821         mnt_drop_write_file(file);
3822         return ret;
3823 }
3824
3825 static void get_block_group_info(struct list_head *groups_list,
3826                                  struct btrfs_ioctl_space_info *space)
3827 {
3828         struct btrfs_block_group_cache *block_group;
3829
3830         space->total_bytes = 0;
3831         space->used_bytes = 0;
3832         space->flags = 0;
3833         list_for_each_entry(block_group, groups_list, list) {
3834                 space->flags = block_group->flags;
3835                 space->total_bytes += block_group->key.offset;
3836                 space->used_bytes +=
3837                         btrfs_block_group_used(&block_group->item);
3838         }
3839 }
3840
3841 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
3842                                    void __user *arg)
3843 {
3844         struct btrfs_ioctl_space_args space_args;
3845         struct btrfs_ioctl_space_info space;
3846         struct btrfs_ioctl_space_info *dest;
3847         struct btrfs_ioctl_space_info *dest_orig;
3848         struct btrfs_ioctl_space_info __user *user_dest;
3849         struct btrfs_space_info *info;
3850         static const u64 types[] = {
3851                 BTRFS_BLOCK_GROUP_DATA,
3852                 BTRFS_BLOCK_GROUP_SYSTEM,
3853                 BTRFS_BLOCK_GROUP_METADATA,
3854                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
3855         };
3856         int num_types = 4;
3857         int alloc_size;
3858         int ret = 0;
3859         u64 slot_count = 0;
3860         int i, c;
3861
3862         if (copy_from_user(&space_args,
3863                            (struct btrfs_ioctl_space_args __user *)arg,
3864                            sizeof(space_args)))
3865                 return -EFAULT;
3866
3867         for (i = 0; i < num_types; i++) {
3868                 struct btrfs_space_info *tmp;
3869
3870                 info = NULL;
3871                 rcu_read_lock();
3872                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
3873                                         list) {
3874                         if (tmp->flags == types[i]) {
3875                                 info = tmp;
3876                                 break;
3877                         }
3878                 }
3879                 rcu_read_unlock();
3880
3881                 if (!info)
3882                         continue;
3883
3884                 down_read(&info->groups_sem);
3885                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3886                         if (!list_empty(&info->block_groups[c]))
3887                                 slot_count++;
3888                 }
3889                 up_read(&info->groups_sem);
3890         }
3891
3892         /*
3893          * Global block reserve, exported as a space_info
3894          */
3895         slot_count++;
3896
3897         /* space_slots == 0 means they are asking for a count */
3898         if (space_args.space_slots == 0) {
3899                 space_args.total_spaces = slot_count;
3900                 goto out;
3901         }
3902
3903         slot_count = min_t(u64, space_args.space_slots, slot_count);
3904
3905         alloc_size = sizeof(*dest) * slot_count;
3906
3907         /* we generally have at most 6 or so space infos, one for each raid
3908          * level.  So, a whole page should be more than enough for everyone
3909          */
3910         if (alloc_size > PAGE_SIZE)
3911                 return -ENOMEM;
3912
3913         space_args.total_spaces = 0;
3914         dest = kmalloc(alloc_size, GFP_KERNEL);
3915         if (!dest)
3916                 return -ENOMEM;
3917         dest_orig = dest;
3918
3919         /* now we have a buffer to copy into */
3920         for (i = 0; i < num_types; i++) {
3921                 struct btrfs_space_info *tmp;
3922
3923                 if (!slot_count)
3924                         break;
3925
3926                 info = NULL;
3927                 rcu_read_lock();
3928                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
3929                                         list) {
3930                         if (tmp->flags == types[i]) {
3931                                 info = tmp;
3932                                 break;
3933                         }
3934                 }
3935                 rcu_read_unlock();
3936
3937                 if (!info)
3938                         continue;
3939                 down_read(&info->groups_sem);
3940                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3941                         if (!list_empty(&info->block_groups[c])) {
3942                                 get_block_group_info(&info->block_groups[c],
3943                                                      &space);
3944                                 memcpy(dest, &space, sizeof(space));
3945                                 dest++;
3946                                 space_args.total_spaces++;
3947                                 slot_count--;
3948                         }
3949                         if (!slot_count)
3950                                 break;
3951                 }
3952                 up_read(&info->groups_sem);
3953         }
3954
3955         /*
3956          * Add global block reserve
3957          */
3958         if (slot_count) {
3959                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3960
3961                 spin_lock(&block_rsv->lock);
3962                 space.total_bytes = block_rsv->size;
3963                 space.used_bytes = block_rsv->size - block_rsv->reserved;
3964                 spin_unlock(&block_rsv->lock);
3965                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
3966                 memcpy(dest, &space, sizeof(space));
3967                 space_args.total_spaces++;
3968         }
3969
3970         user_dest = (struct btrfs_ioctl_space_info __user *)
3971                 (arg + sizeof(struct btrfs_ioctl_space_args));
3972
3973         if (copy_to_user(user_dest, dest_orig, alloc_size))
3974                 ret = -EFAULT;
3975
3976         kfree(dest_orig);
3977 out:
3978         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3979                 ret = -EFAULT;
3980
3981         return ret;
3982 }
3983
3984 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3985                                             void __user *argp)
3986 {
3987         struct btrfs_trans_handle *trans;
3988         u64 transid;
3989         int ret;
3990
3991         trans = btrfs_attach_transaction_barrier(root);
3992         if (IS_ERR(trans)) {
3993                 if (PTR_ERR(trans) != -ENOENT)
3994                         return PTR_ERR(trans);
3995
3996                 /* No running transaction, don't bother */
3997                 transid = root->fs_info->last_trans_committed;
3998                 goto out;
3999         }
4000         transid = trans->transid;
4001         ret = btrfs_commit_transaction_async(trans, 0);
4002         if (ret) {
4003                 btrfs_end_transaction(trans);
4004                 return ret;
4005         }
4006 out:
4007         if (argp)
4008                 if (copy_to_user(argp, &transid, sizeof(transid)))
4009                         return -EFAULT;
4010         return 0;
4011 }
4012
4013 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4014                                            void __user *argp)
4015 {
4016         u64 transid;
4017
4018         if (argp) {
4019                 if (copy_from_user(&transid, argp, sizeof(transid)))
4020                         return -EFAULT;
4021         } else {
4022                 transid = 0;  /* current trans */
4023         }
4024         return btrfs_wait_for_commit(fs_info, transid);
4025 }
4026
4027 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4028 {
4029         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4030         struct btrfs_ioctl_scrub_args *sa;
4031         int ret;
4032
4033         if (!capable(CAP_SYS_ADMIN))
4034                 return -EPERM;
4035
4036         sa = memdup_user(arg, sizeof(*sa));
4037         if (IS_ERR(sa))
4038                 return PTR_ERR(sa);
4039
4040         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4041                 ret = mnt_want_write_file(file);
4042                 if (ret)
4043                         goto out;
4044         }
4045
4046         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4047                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4048                               0);
4049
4050         if (copy_to_user(arg, sa, sizeof(*sa)))
4051                 ret = -EFAULT;
4052
4053         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4054                 mnt_drop_write_file(file);
4055 out:
4056         kfree(sa);
4057         return ret;
4058 }
4059
4060 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4061 {
4062         if (!capable(CAP_SYS_ADMIN))
4063                 return -EPERM;
4064
4065         return btrfs_scrub_cancel(fs_info);
4066 }
4067
4068 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4069                                        void __user *arg)
4070 {
4071         struct btrfs_ioctl_scrub_args *sa;
4072         int ret;
4073
4074         if (!capable(CAP_SYS_ADMIN))
4075                 return -EPERM;
4076
4077         sa = memdup_user(arg, sizeof(*sa));
4078         if (IS_ERR(sa))
4079                 return PTR_ERR(sa);
4080
4081         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4082
4083         if (copy_to_user(arg, sa, sizeof(*sa)))
4084                 ret = -EFAULT;
4085
4086         kfree(sa);
4087         return ret;
4088 }
4089
4090 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4091                                       void __user *arg)
4092 {
4093         struct btrfs_ioctl_get_dev_stats *sa;
4094         int ret;
4095
4096         sa = memdup_user(arg, sizeof(*sa));
4097         if (IS_ERR(sa))
4098                 return PTR_ERR(sa);
4099
4100         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4101                 kfree(sa);
4102                 return -EPERM;
4103         }
4104
4105         ret = btrfs_get_dev_stats(fs_info, sa);
4106
4107         if (copy_to_user(arg, sa, sizeof(*sa)))
4108                 ret = -EFAULT;
4109
4110         kfree(sa);
4111         return ret;
4112 }
4113
4114 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4115                                     void __user *arg)
4116 {
4117         struct btrfs_ioctl_dev_replace_args *p;
4118         int ret;
4119
4120         if (!capable(CAP_SYS_ADMIN))
4121                 return -EPERM;
4122
4123         p = memdup_user(arg, sizeof(*p));
4124         if (IS_ERR(p))
4125                 return PTR_ERR(p);
4126
4127         switch (p->cmd) {
4128         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4129                 if (sb_rdonly(fs_info->sb)) {
4130                         ret = -EROFS;
4131                         goto out;
4132                 }
4133                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4134                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4135                 } else {
4136                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4137                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4138                 }
4139                 break;
4140         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4141                 btrfs_dev_replace_status(fs_info, p);
4142                 ret = 0;
4143                 break;
4144         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4145                 p->result = btrfs_dev_replace_cancel(fs_info);
4146                 ret = 0;
4147                 break;
4148         default:
4149                 ret = -EINVAL;
4150                 break;
4151         }
4152
4153         if (copy_to_user(arg, p, sizeof(*p)))
4154                 ret = -EFAULT;
4155 out:
4156         kfree(p);
4157         return ret;
4158 }
4159
4160 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4161 {
4162         int ret = 0;
4163         int i;
4164         u64 rel_ptr;
4165         int size;
4166         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4167         struct inode_fs_paths *ipath = NULL;
4168         struct btrfs_path *path;
4169
4170         if (!capable(CAP_DAC_READ_SEARCH))
4171                 return -EPERM;
4172
4173         path = btrfs_alloc_path();
4174         if (!path) {
4175                 ret = -ENOMEM;
4176                 goto out;
4177         }
4178
4179         ipa = memdup_user(arg, sizeof(*ipa));
4180         if (IS_ERR(ipa)) {
4181                 ret = PTR_ERR(ipa);
4182                 ipa = NULL;
4183                 goto out;
4184         }
4185
4186         size = min_t(u32, ipa->size, 4096);
4187         ipath = init_ipath(size, root, path);
4188         if (IS_ERR(ipath)) {
4189                 ret = PTR_ERR(ipath);
4190                 ipath = NULL;
4191                 goto out;
4192         }
4193
4194         ret = paths_from_inode(ipa->inum, ipath);
4195         if (ret < 0)
4196                 goto out;
4197
4198         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4199                 rel_ptr = ipath->fspath->val[i] -
4200                           (u64)(unsigned long)ipath->fspath->val;
4201                 ipath->fspath->val[i] = rel_ptr;
4202         }
4203
4204         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4205                            ipath->fspath, size);
4206         if (ret) {
4207                 ret = -EFAULT;
4208                 goto out;
4209         }
4210
4211 out:
4212         btrfs_free_path(path);
4213         free_ipath(ipath);
4214         kfree(ipa);
4215
4216         return ret;
4217 }
4218
4219 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4220 {
4221         struct btrfs_data_container *inodes = ctx;
4222         const size_t c = 3 * sizeof(u64);
4223
4224         if (inodes->bytes_left >= c) {
4225                 inodes->bytes_left -= c;
4226                 inodes->val[inodes->elem_cnt] = inum;
4227                 inodes->val[inodes->elem_cnt + 1] = offset;
4228                 inodes->val[inodes->elem_cnt + 2] = root;
4229                 inodes->elem_cnt += 3;
4230         } else {
4231                 inodes->bytes_missing += c - inodes->bytes_left;
4232                 inodes->bytes_left = 0;
4233                 inodes->elem_missed += 3;
4234         }
4235
4236         return 0;
4237 }
4238
4239 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4240                                         void __user *arg, int version)
4241 {
4242         int ret = 0;
4243         int size;
4244         struct btrfs_ioctl_logical_ino_args *loi;
4245         struct btrfs_data_container *inodes = NULL;
4246         struct btrfs_path *path = NULL;
4247         bool ignore_offset;
4248
4249         if (!capable(CAP_SYS_ADMIN))
4250                 return -EPERM;
4251
4252         loi = memdup_user(arg, sizeof(*loi));
4253         if (IS_ERR(loi))
4254                 return PTR_ERR(loi);
4255
4256         if (version == 1) {
4257                 ignore_offset = false;
4258                 size = min_t(u32, loi->size, SZ_64K);
4259         } else {
4260                 /* All reserved bits must be 0 for now */
4261                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4262                         ret = -EINVAL;
4263                         goto out_loi;
4264                 }
4265                 /* Only accept flags we have defined so far */
4266                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4267                         ret = -EINVAL;
4268                         goto out_loi;
4269                 }
4270                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4271                 size = min_t(u32, loi->size, SZ_16M);
4272         }
4273
4274         path = btrfs_alloc_path();
4275         if (!path) {
4276                 ret = -ENOMEM;
4277                 goto out;
4278         }
4279
4280         inodes = init_data_container(size);
4281         if (IS_ERR(inodes)) {
4282                 ret = PTR_ERR(inodes);
4283                 inodes = NULL;
4284                 goto out;
4285         }
4286
4287         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4288                                           build_ino_list, inodes, ignore_offset);
4289         if (ret == -EINVAL)
4290                 ret = -ENOENT;
4291         if (ret < 0)
4292                 goto out;
4293
4294         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4295                            size);
4296         if (ret)
4297                 ret = -EFAULT;
4298
4299 out:
4300         btrfs_free_path(path);
4301         kvfree(inodes);
4302 out_loi:
4303         kfree(loi);
4304
4305         return ret;
4306 }
4307
4308 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4309                                struct btrfs_ioctl_balance_args *bargs)
4310 {
4311         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4312
4313         bargs->flags = bctl->flags;
4314
4315         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4316                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4317         if (atomic_read(&fs_info->balance_pause_req))
4318                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4319         if (atomic_read(&fs_info->balance_cancel_req))
4320                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4321
4322         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4323         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4324         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4325
4326         spin_lock(&fs_info->balance_lock);
4327         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4328         spin_unlock(&fs_info->balance_lock);
4329 }
4330
4331 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4332 {
4333         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4334         struct btrfs_fs_info *fs_info = root->fs_info;
4335         struct btrfs_ioctl_balance_args *bargs;
4336         struct btrfs_balance_control *bctl;
4337         bool need_unlock; /* for mut. excl. ops lock */
4338         int ret;
4339
4340         if (!capable(CAP_SYS_ADMIN))
4341                 return -EPERM;
4342
4343         ret = mnt_want_write_file(file);
4344         if (ret)
4345                 return ret;
4346
4347 again:
4348         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4349                 mutex_lock(&fs_info->balance_mutex);
4350                 need_unlock = true;
4351                 goto locked;
4352         }
4353
4354         /*
4355          * mut. excl. ops lock is locked.  Three possibilities:
4356          *   (1) some other op is running
4357          *   (2) balance is running
4358          *   (3) balance is paused -- special case (think resume)
4359          */
4360         mutex_lock(&fs_info->balance_mutex);
4361         if (fs_info->balance_ctl) {
4362                 /* this is either (2) or (3) */
4363                 if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4364                         mutex_unlock(&fs_info->balance_mutex);
4365                         /*
4366                          * Lock released to allow other waiters to continue,
4367                          * we'll reexamine the status again.
4368                          */
4369                         mutex_lock(&fs_info->balance_mutex);
4370
4371                         if (fs_info->balance_ctl &&
4372                             !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4373                                 /* this is (3) */
4374                                 need_unlock = false;
4375                                 goto locked;
4376                         }
4377
4378                         mutex_unlock(&fs_info->balance_mutex);
4379                         goto again;
4380                 } else {
4381                         /* this is (2) */
4382                         mutex_unlock(&fs_info->balance_mutex);
4383                         ret = -EINPROGRESS;
4384                         goto out;
4385                 }
4386         } else {
4387                 /* this is (1) */
4388                 mutex_unlock(&fs_info->balance_mutex);
4389                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4390                 goto out;
4391         }
4392
4393 locked:
4394         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4395
4396         if (arg) {
4397                 bargs = memdup_user(arg, sizeof(*bargs));
4398                 if (IS_ERR(bargs)) {
4399                         ret = PTR_ERR(bargs);
4400                         goto out_unlock;
4401                 }
4402
4403                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4404                         if (!fs_info->balance_ctl) {
4405                                 ret = -ENOTCONN;
4406                                 goto out_bargs;
4407                         }
4408
4409                         bctl = fs_info->balance_ctl;
4410                         spin_lock(&fs_info->balance_lock);
4411                         bctl->flags |= BTRFS_BALANCE_RESUME;
4412                         spin_unlock(&fs_info->balance_lock);
4413
4414                         goto do_balance;
4415                 }
4416         } else {
4417                 bargs = NULL;
4418         }
4419
4420         if (fs_info->balance_ctl) {
4421                 ret = -EINPROGRESS;
4422                 goto out_bargs;
4423         }
4424
4425         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4426         if (!bctl) {
4427                 ret = -ENOMEM;
4428                 goto out_bargs;
4429         }
4430
4431         if (arg) {
4432                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4433                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4434                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4435
4436                 bctl->flags = bargs->flags;
4437         } else {
4438                 /* balance everything - no filters */
4439                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4440         }
4441
4442         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4443                 ret = -EINVAL;
4444                 goto out_bctl;
4445         }
4446
4447 do_balance:
4448         /*
4449          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
4450          * btrfs_balance.  bctl is freed in reset_balance_state, or, if
4451          * restriper was paused all the way until unmount, in free_fs_info.
4452          * The flag should be cleared after reset_balance_state.
4453          */
4454         need_unlock = false;
4455
4456         ret = btrfs_balance(fs_info, bctl, bargs);
4457         bctl = NULL;
4458
4459         if (arg) {
4460                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4461                         ret = -EFAULT;
4462         }
4463
4464 out_bctl:
4465         kfree(bctl);
4466 out_bargs:
4467         kfree(bargs);
4468 out_unlock:
4469         mutex_unlock(&fs_info->balance_mutex);
4470         if (need_unlock)
4471                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4472 out:
4473         mnt_drop_write_file(file);
4474         return ret;
4475 }
4476
4477 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4478 {
4479         if (!capable(CAP_SYS_ADMIN))
4480                 return -EPERM;
4481
4482         switch (cmd) {
4483         case BTRFS_BALANCE_CTL_PAUSE:
4484                 return btrfs_pause_balance(fs_info);
4485         case BTRFS_BALANCE_CTL_CANCEL:
4486                 return btrfs_cancel_balance(fs_info);
4487         }
4488
4489         return -EINVAL;
4490 }
4491
4492 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4493                                          void __user *arg)
4494 {
4495         struct btrfs_ioctl_balance_args *bargs;
4496         int ret = 0;
4497
4498         if (!capable(CAP_SYS_ADMIN))
4499                 return -EPERM;
4500
4501         mutex_lock(&fs_info->balance_mutex);
4502         if (!fs_info->balance_ctl) {
4503                 ret = -ENOTCONN;
4504                 goto out;
4505         }
4506
4507         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4508         if (!bargs) {
4509                 ret = -ENOMEM;
4510                 goto out;
4511         }
4512
4513         btrfs_update_ioctl_balance_args(fs_info, bargs);
4514
4515         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4516                 ret = -EFAULT;
4517
4518         kfree(bargs);
4519 out:
4520         mutex_unlock(&fs_info->balance_mutex);
4521         return ret;
4522 }
4523
4524 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4525 {
4526         struct inode *inode = file_inode(file);
4527         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4528         struct btrfs_ioctl_quota_ctl_args *sa;
4529         struct btrfs_trans_handle *trans = NULL;
4530         int ret;
4531         int err;
4532
4533         if (!capable(CAP_SYS_ADMIN))
4534                 return -EPERM;
4535
4536         ret = mnt_want_write_file(file);
4537         if (ret)
4538                 return ret;
4539
4540         sa = memdup_user(arg, sizeof(*sa));
4541         if (IS_ERR(sa)) {
4542                 ret = PTR_ERR(sa);
4543                 goto drop_write;
4544         }
4545
4546         down_write(&fs_info->subvol_sem);
4547         trans = btrfs_start_transaction(fs_info->tree_root, 2);
4548         if (IS_ERR(trans)) {
4549                 ret = PTR_ERR(trans);
4550                 goto out;
4551         }
4552
4553         switch (sa->cmd) {
4554         case BTRFS_QUOTA_CTL_ENABLE:
4555                 ret = btrfs_quota_enable(trans, fs_info);
4556                 break;
4557         case BTRFS_QUOTA_CTL_DISABLE:
4558                 ret = btrfs_quota_disable(trans, fs_info);
4559                 break;
4560         default:
4561                 ret = -EINVAL;
4562                 break;
4563         }
4564
4565         err = btrfs_commit_transaction(trans);
4566         if (err && !ret)
4567                 ret = err;
4568 out:
4569         kfree(sa);
4570         up_write(&fs_info->subvol_sem);
4571 drop_write:
4572         mnt_drop_write_file(file);
4573         return ret;
4574 }
4575
4576 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4577 {
4578         struct inode *inode = file_inode(file);
4579         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4580         struct btrfs_root *root = BTRFS_I(inode)->root;
4581         struct btrfs_ioctl_qgroup_assign_args *sa;
4582         struct btrfs_trans_handle *trans;
4583         int ret;
4584         int err;
4585
4586         if (!capable(CAP_SYS_ADMIN))
4587                 return -EPERM;
4588
4589         ret = mnt_want_write_file(file);
4590         if (ret)
4591                 return ret;
4592
4593         sa = memdup_user(arg, sizeof(*sa));
4594         if (IS_ERR(sa)) {
4595                 ret = PTR_ERR(sa);
4596                 goto drop_write;
4597         }
4598
4599         trans = btrfs_join_transaction(root);
4600         if (IS_ERR(trans)) {
4601                 ret = PTR_ERR(trans);
4602                 goto out;
4603         }
4604
4605         if (sa->assign) {
4606                 ret = btrfs_add_qgroup_relation(trans, fs_info,
4607                                                 sa->src, sa->dst);
4608         } else {
4609                 ret = btrfs_del_qgroup_relation(trans, fs_info,
4610                                                 sa->src, sa->dst);
4611         }
4612
4613         /* update qgroup status and info */
4614         err = btrfs_run_qgroups(trans, fs_info);
4615         if (err < 0)
4616                 btrfs_handle_fs_error(fs_info, err,
4617                                       "failed to update qgroup status and info");
4618         err = btrfs_end_transaction(trans);
4619         if (err && !ret)
4620                 ret = err;
4621
4622 out:
4623         kfree(sa);
4624 drop_write:
4625         mnt_drop_write_file(file);
4626         return ret;
4627 }
4628
4629 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4630 {
4631         struct inode *inode = file_inode(file);
4632         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4633         struct btrfs_root *root = BTRFS_I(inode)->root;
4634         struct btrfs_ioctl_qgroup_create_args *sa;
4635         struct btrfs_trans_handle *trans;
4636         int ret;
4637         int err;
4638
4639         if (!capable(CAP_SYS_ADMIN))
4640                 return -EPERM;
4641
4642         ret = mnt_want_write_file(file);
4643         if (ret)
4644                 return ret;
4645
4646         sa = memdup_user(arg, sizeof(*sa));
4647         if (IS_ERR(sa)) {
4648                 ret = PTR_ERR(sa);
4649                 goto drop_write;
4650         }
4651
4652         if (!sa->qgroupid) {
4653                 ret = -EINVAL;
4654                 goto out;
4655         }
4656
4657         trans = btrfs_join_transaction(root);
4658         if (IS_ERR(trans)) {
4659                 ret = PTR_ERR(trans);
4660                 goto out;
4661         }
4662
4663         if (sa->create) {
4664                 ret = btrfs_create_qgroup(trans, fs_info, sa->qgroupid);
4665         } else {
4666                 ret = btrfs_remove_qgroup(trans, fs_info, sa->qgroupid);
4667         }
4668
4669         err = btrfs_end_transaction(trans);
4670         if (err && !ret)
4671                 ret = err;
4672
4673 out:
4674         kfree(sa);
4675 drop_write:
4676         mnt_drop_write_file(file);
4677         return ret;
4678 }
4679
4680 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4681 {
4682         struct inode *inode = file_inode(file);
4683         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4684         struct btrfs_root *root = BTRFS_I(inode)->root;
4685         struct btrfs_ioctl_qgroup_limit_args *sa;
4686         struct btrfs_trans_handle *trans;
4687         int ret;
4688         int err;
4689         u64 qgroupid;
4690
4691         if (!capable(CAP_SYS_ADMIN))
4692                 return -EPERM;
4693
4694         ret = mnt_want_write_file(file);
4695         if (ret)
4696                 return ret;
4697
4698         sa = memdup_user(arg, sizeof(*sa));
4699         if (IS_ERR(sa)) {
4700                 ret = PTR_ERR(sa);
4701                 goto drop_write;
4702         }
4703
4704         trans = btrfs_join_transaction(root);
4705         if (IS_ERR(trans)) {
4706                 ret = PTR_ERR(trans);
4707                 goto out;
4708         }
4709
4710         qgroupid = sa->qgroupid;
4711         if (!qgroupid) {
4712                 /* take the current subvol as qgroup */
4713                 qgroupid = root->root_key.objectid;
4714         }
4715
4716         ret = btrfs_limit_qgroup(trans, fs_info, qgroupid, &sa->lim);
4717
4718         err = btrfs_end_transaction(trans);
4719         if (err && !ret)
4720                 ret = err;
4721
4722 out:
4723         kfree(sa);
4724 drop_write:
4725         mnt_drop_write_file(file);
4726         return ret;
4727 }
4728
4729 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4730 {
4731         struct inode *inode = file_inode(file);
4732         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4733         struct btrfs_ioctl_quota_rescan_args *qsa;
4734         int ret;
4735
4736         if (!capable(CAP_SYS_ADMIN))
4737                 return -EPERM;
4738
4739         ret = mnt_want_write_file(file);
4740         if (ret)
4741                 return ret;
4742
4743         qsa = memdup_user(arg, sizeof(*qsa));
4744         if (IS_ERR(qsa)) {
4745                 ret = PTR_ERR(qsa);
4746                 goto drop_write;
4747         }
4748
4749         if (qsa->flags) {
4750                 ret = -EINVAL;
4751                 goto out;
4752         }
4753
4754         ret = btrfs_qgroup_rescan(fs_info);
4755
4756 out:
4757         kfree(qsa);
4758 drop_write:
4759         mnt_drop_write_file(file);
4760         return ret;
4761 }
4762
4763 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
4764 {
4765         struct inode *inode = file_inode(file);
4766         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4767         struct btrfs_ioctl_quota_rescan_args *qsa;
4768         int ret = 0;
4769
4770         if (!capable(CAP_SYS_ADMIN))
4771                 return -EPERM;
4772
4773         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
4774         if (!qsa)
4775                 return -ENOMEM;
4776
4777         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4778                 qsa->flags = 1;
4779                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
4780         }
4781
4782         if (copy_to_user(arg, qsa, sizeof(*qsa)))
4783                 ret = -EFAULT;
4784
4785         kfree(qsa);
4786         return ret;
4787 }
4788
4789 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
4790 {
4791         struct inode *inode = file_inode(file);
4792         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4793
4794         if (!capable(CAP_SYS_ADMIN))
4795                 return -EPERM;
4796
4797         return btrfs_qgroup_wait_for_completion(fs_info, true);
4798 }
4799
4800 static long _btrfs_ioctl_set_received_subvol(struct file *file,
4801                                             struct btrfs_ioctl_received_subvol_args *sa)
4802 {
4803         struct inode *inode = file_inode(file);
4804         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4805         struct btrfs_root *root = BTRFS_I(inode)->root;
4806         struct btrfs_root_item *root_item = &root->root_item;
4807         struct btrfs_trans_handle *trans;
4808         struct timespec ct = current_time(inode);
4809         int ret = 0;
4810         int received_uuid_changed;
4811
4812         if (!inode_owner_or_capable(inode))
4813                 return -EPERM;
4814
4815         ret = mnt_want_write_file(file);
4816         if (ret < 0)
4817                 return ret;
4818
4819         down_write(&fs_info->subvol_sem);
4820
4821         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
4822                 ret = -EINVAL;
4823                 goto out;
4824         }
4825
4826         if (btrfs_root_readonly(root)) {
4827                 ret = -EROFS;
4828                 goto out;
4829         }
4830
4831         /*
4832          * 1 - root item
4833          * 2 - uuid items (received uuid + subvol uuid)
4834          */
4835         trans = btrfs_start_transaction(root, 3);
4836         if (IS_ERR(trans)) {
4837                 ret = PTR_ERR(trans);
4838                 trans = NULL;
4839                 goto out;
4840         }
4841
4842         sa->rtransid = trans->transid;
4843         sa->rtime.sec = ct.tv_sec;
4844         sa->rtime.nsec = ct.tv_nsec;
4845
4846         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
4847                                        BTRFS_UUID_SIZE);
4848         if (received_uuid_changed &&
4849             !btrfs_is_empty_uuid(root_item->received_uuid)) {
4850                 ret = btrfs_uuid_tree_rem(trans, fs_info,
4851                                           root_item->received_uuid,
4852                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4853                                           root->root_key.objectid);
4854                 if (ret && ret != -ENOENT) {
4855                         btrfs_abort_transaction(trans, ret);
4856                         btrfs_end_transaction(trans);
4857                         goto out;
4858                 }
4859         }
4860         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
4861         btrfs_set_root_stransid(root_item, sa->stransid);
4862         btrfs_set_root_rtransid(root_item, sa->rtransid);
4863         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
4864         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
4865         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
4866         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
4867
4868         ret = btrfs_update_root(trans, fs_info->tree_root,
4869                                 &root->root_key, &root->root_item);
4870         if (ret < 0) {
4871                 btrfs_end_transaction(trans);
4872                 goto out;
4873         }
4874         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
4875                 ret = btrfs_uuid_tree_add(trans, fs_info, sa->uuid,
4876                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4877                                           root->root_key.objectid);
4878                 if (ret < 0 && ret != -EEXIST) {
4879                         btrfs_abort_transaction(trans, ret);
4880                         btrfs_end_transaction(trans);
4881                         goto out;
4882                 }
4883         }
4884         ret = btrfs_commit_transaction(trans);
4885 out:
4886         up_write(&fs_info->subvol_sem);
4887         mnt_drop_write_file(file);
4888         return ret;
4889 }
4890
4891 #ifdef CONFIG_64BIT
4892 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
4893                                                 void __user *arg)
4894 {
4895         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
4896         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
4897         int ret = 0;
4898
4899         args32 = memdup_user(arg, sizeof(*args32));
4900         if (IS_ERR(args32))
4901                 return PTR_ERR(args32);
4902
4903         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
4904         if (!args64) {
4905                 ret = -ENOMEM;
4906                 goto out;
4907         }
4908
4909         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
4910         args64->stransid = args32->stransid;
4911         args64->rtransid = args32->rtransid;
4912         args64->stime.sec = args32->stime.sec;
4913         args64->stime.nsec = args32->stime.nsec;
4914         args64->rtime.sec = args32->rtime.sec;
4915         args64->rtime.nsec = args32->rtime.nsec;
4916         args64->flags = args32->flags;
4917
4918         ret = _btrfs_ioctl_set_received_subvol(file, args64);
4919         if (ret)
4920                 goto out;
4921
4922         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
4923         args32->stransid = args64->stransid;
4924         args32->rtransid = args64->rtransid;
4925         args32->stime.sec = args64->stime.sec;
4926         args32->stime.nsec = args64->stime.nsec;
4927         args32->rtime.sec = args64->rtime.sec;
4928         args32->rtime.nsec = args64->rtime.nsec;
4929         args32->flags = args64->flags;
4930
4931         ret = copy_to_user(arg, args32, sizeof(*args32));
4932         if (ret)
4933                 ret = -EFAULT;
4934
4935 out:
4936         kfree(args32);
4937         kfree(args64);
4938         return ret;
4939 }
4940 #endif
4941
4942 static long btrfs_ioctl_set_received_subvol(struct file *file,
4943                                             void __user *arg)
4944 {
4945         struct btrfs_ioctl_received_subvol_args *sa = NULL;
4946         int ret = 0;
4947
4948         sa = memdup_user(arg, sizeof(*sa));
4949         if (IS_ERR(sa))
4950                 return PTR_ERR(sa);
4951
4952         ret = _btrfs_ioctl_set_received_subvol(file, sa);
4953
4954         if (ret)
4955                 goto out;
4956
4957         ret = copy_to_user(arg, sa, sizeof(*sa));
4958         if (ret)
4959                 ret = -EFAULT;
4960
4961 out:
4962         kfree(sa);
4963         return ret;
4964 }
4965
4966 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
4967 {
4968         struct inode *inode = file_inode(file);
4969         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4970         size_t len;
4971         int ret;
4972         char label[BTRFS_LABEL_SIZE];
4973
4974         spin_lock(&fs_info->super_lock);
4975         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4976         spin_unlock(&fs_info->super_lock);
4977
4978         len = strnlen(label, BTRFS_LABEL_SIZE);
4979
4980         if (len == BTRFS_LABEL_SIZE) {
4981                 btrfs_warn(fs_info,
4982                            "label is too long, return the first %zu bytes",
4983                            --len);
4984         }
4985
4986         ret = copy_to_user(arg, label, len);
4987
4988         return ret ? -EFAULT : 0;
4989 }
4990
4991 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4992 {
4993         struct inode *inode = file_inode(file);
4994         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4995         struct btrfs_root *root = BTRFS_I(inode)->root;
4996         struct btrfs_super_block *super_block = fs_info->super_copy;
4997         struct btrfs_trans_handle *trans;
4998         char label[BTRFS_LABEL_SIZE];
4999         int ret;
5000
5001         if (!capable(CAP_SYS_ADMIN))
5002                 return -EPERM;
5003
5004         if (copy_from_user(label, arg, sizeof(label)))
5005                 return -EFAULT;
5006
5007         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5008                 btrfs_err(fs_info,
5009                           "unable to set label with more than %d bytes",
5010                           BTRFS_LABEL_SIZE - 1);
5011                 return -EINVAL;
5012         }
5013
5014         ret = mnt_want_write_file(file);
5015         if (ret)
5016                 return ret;
5017
5018         trans = btrfs_start_transaction(root, 0);
5019         if (IS_ERR(trans)) {
5020                 ret = PTR_ERR(trans);
5021                 goto out_unlock;
5022         }
5023
5024         spin_lock(&fs_info->super_lock);
5025         strcpy(super_block->label, label);
5026         spin_unlock(&fs_info->super_lock);
5027         ret = btrfs_commit_transaction(trans);
5028
5029 out_unlock:
5030         mnt_drop_write_file(file);
5031         return ret;
5032 }
5033
5034 #define INIT_FEATURE_FLAGS(suffix) \
5035         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5036           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5037           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5038
5039 int btrfs_ioctl_get_supported_features(void __user *arg)
5040 {
5041         static const struct btrfs_ioctl_feature_flags features[3] = {
5042                 INIT_FEATURE_FLAGS(SUPP),
5043                 INIT_FEATURE_FLAGS(SAFE_SET),
5044                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5045         };
5046
5047         if (copy_to_user(arg, &features, sizeof(features)))
5048                 return -EFAULT;
5049
5050         return 0;
5051 }
5052
5053 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5054 {
5055         struct inode *inode = file_inode(file);
5056         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5057         struct btrfs_super_block *super_block = fs_info->super_copy;
5058         struct btrfs_ioctl_feature_flags features;
5059
5060         features.compat_flags = btrfs_super_compat_flags(super_block);
5061         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5062         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5063
5064         if (copy_to_user(arg, &features, sizeof(features)))
5065                 return -EFAULT;
5066
5067         return 0;
5068 }
5069
5070 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5071                               enum btrfs_feature_set set,
5072                               u64 change_mask, u64 flags, u64 supported_flags,
5073                               u64 safe_set, u64 safe_clear)
5074 {
5075         const char *type = btrfs_feature_set_names[set];
5076         char *names;
5077         u64 disallowed, unsupported;
5078         u64 set_mask = flags & change_mask;
5079         u64 clear_mask = ~flags & change_mask;
5080
5081         unsupported = set_mask & ~supported_flags;
5082         if (unsupported) {
5083                 names = btrfs_printable_features(set, unsupported);
5084                 if (names) {
5085                         btrfs_warn(fs_info,
5086                                    "this kernel does not support the %s feature bit%s",
5087                                    names, strchr(names, ',') ? "s" : "");
5088                         kfree(names);
5089                 } else
5090                         btrfs_warn(fs_info,
5091                                    "this kernel does not support %s bits 0x%llx",
5092                                    type, unsupported);
5093                 return -EOPNOTSUPP;
5094         }
5095
5096         disallowed = set_mask & ~safe_set;
5097         if (disallowed) {
5098                 names = btrfs_printable_features(set, disallowed);
5099                 if (names) {
5100                         btrfs_warn(fs_info,
5101                                    "can't set the %s feature bit%s while mounted",
5102                                    names, strchr(names, ',') ? "s" : "");
5103                         kfree(names);
5104                 } else
5105                         btrfs_warn(fs_info,
5106                                    "can't set %s bits 0x%llx while mounted",
5107                                    type, disallowed);
5108                 return -EPERM;
5109         }
5110
5111         disallowed = clear_mask & ~safe_clear;
5112         if (disallowed) {
5113                 names = btrfs_printable_features(set, disallowed);
5114                 if (names) {
5115                         btrfs_warn(fs_info,
5116                                    "can't clear the %s feature bit%s while mounted",
5117                                    names, strchr(names, ',') ? "s" : "");
5118                         kfree(names);
5119                 } else
5120                         btrfs_warn(fs_info,
5121                                    "can't clear %s bits 0x%llx while mounted",
5122                                    type, disallowed);
5123                 return -EPERM;
5124         }
5125
5126         return 0;
5127 }
5128
5129 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5130 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5131                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5132                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5133                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5134
5135 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5136 {
5137         struct inode *inode = file_inode(file);
5138         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5139         struct btrfs_root *root = BTRFS_I(inode)->root;
5140         struct btrfs_super_block *super_block = fs_info->super_copy;
5141         struct btrfs_ioctl_feature_flags flags[2];
5142         struct btrfs_trans_handle *trans;
5143         u64 newflags;
5144         int ret;
5145
5146         if (!capable(CAP_SYS_ADMIN))
5147                 return -EPERM;
5148
5149         if (copy_from_user(flags, arg, sizeof(flags)))
5150                 return -EFAULT;
5151
5152         /* Nothing to do */
5153         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5154             !flags[0].incompat_flags)
5155                 return 0;
5156
5157         ret = check_feature(fs_info, flags[0].compat_flags,
5158                             flags[1].compat_flags, COMPAT);
5159         if (ret)
5160                 return ret;
5161
5162         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5163                             flags[1].compat_ro_flags, COMPAT_RO);
5164         if (ret)
5165                 return ret;
5166
5167         ret = check_feature(fs_info, flags[0].incompat_flags,
5168                             flags[1].incompat_flags, INCOMPAT);
5169         if (ret)
5170                 return ret;
5171
5172         ret = mnt_want_write_file(file);
5173         if (ret)
5174                 return ret;
5175
5176         trans = btrfs_start_transaction(root, 0);
5177         if (IS_ERR(trans)) {
5178                 ret = PTR_ERR(trans);
5179                 goto out_drop_write;
5180         }
5181
5182         spin_lock(&fs_info->super_lock);
5183         newflags = btrfs_super_compat_flags(super_block);
5184         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5185         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5186         btrfs_set_super_compat_flags(super_block, newflags);
5187
5188         newflags = btrfs_super_compat_ro_flags(super_block);
5189         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5190         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5191         btrfs_set_super_compat_ro_flags(super_block, newflags);
5192
5193         newflags = btrfs_super_incompat_flags(super_block);
5194         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5195         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5196         btrfs_set_super_incompat_flags(super_block, newflags);
5197         spin_unlock(&fs_info->super_lock);
5198
5199         ret = btrfs_commit_transaction(trans);
5200 out_drop_write:
5201         mnt_drop_write_file(file);
5202
5203         return ret;
5204 }
5205
5206 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5207 {
5208         struct btrfs_ioctl_send_args *arg;
5209         int ret;
5210
5211         if (compat) {
5212 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5213                 struct btrfs_ioctl_send_args_32 args32;
5214
5215                 ret = copy_from_user(&args32, argp, sizeof(args32));
5216                 if (ret)
5217                         return -EFAULT;
5218                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5219                 if (!arg)
5220                         return -ENOMEM;
5221                 arg->send_fd = args32.send_fd;
5222                 arg->clone_sources_count = args32.clone_sources_count;
5223                 arg->clone_sources = compat_ptr(args32.clone_sources);
5224                 arg->parent_root = args32.parent_root;
5225                 arg->flags = args32.flags;
5226                 memcpy(arg->reserved, args32.reserved,
5227                        sizeof(args32.reserved));
5228 #else
5229                 return -ENOTTY;
5230 #endif
5231         } else {
5232                 arg = memdup_user(argp, sizeof(*arg));
5233                 if (IS_ERR(arg))
5234                         return PTR_ERR(arg);
5235         }
5236         ret = btrfs_ioctl_send(file, arg);
5237         kfree(arg);
5238         return ret;
5239 }
5240
5241 long btrfs_ioctl(struct file *file, unsigned int
5242                 cmd, unsigned long arg)
5243 {
5244         struct inode *inode = file_inode(file);
5245         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5246         struct btrfs_root *root = BTRFS_I(inode)->root;
5247         void __user *argp = (void __user *)arg;
5248
5249         switch (cmd) {
5250         case FS_IOC_GETFLAGS:
5251                 return btrfs_ioctl_getflags(file, argp);
5252         case FS_IOC_SETFLAGS:
5253                 return btrfs_ioctl_setflags(file, argp);
5254         case FS_IOC_GETVERSION:
5255                 return btrfs_ioctl_getversion(file, argp);
5256         case FITRIM:
5257                 return btrfs_ioctl_fitrim(file, argp);
5258         case BTRFS_IOC_SNAP_CREATE:
5259                 return btrfs_ioctl_snap_create(file, argp, 0);
5260         case BTRFS_IOC_SNAP_CREATE_V2:
5261                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5262         case BTRFS_IOC_SUBVOL_CREATE:
5263                 return btrfs_ioctl_snap_create(file, argp, 1);
5264         case BTRFS_IOC_SUBVOL_CREATE_V2:
5265                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5266         case BTRFS_IOC_SNAP_DESTROY:
5267                 return btrfs_ioctl_snap_destroy(file, argp);
5268         case BTRFS_IOC_SUBVOL_GETFLAGS:
5269                 return btrfs_ioctl_subvol_getflags(file, argp);
5270         case BTRFS_IOC_SUBVOL_SETFLAGS:
5271                 return btrfs_ioctl_subvol_setflags(file, argp);
5272         case BTRFS_IOC_DEFAULT_SUBVOL:
5273                 return btrfs_ioctl_default_subvol(file, argp);
5274         case BTRFS_IOC_DEFRAG:
5275                 return btrfs_ioctl_defrag(file, NULL);
5276         case BTRFS_IOC_DEFRAG_RANGE:
5277                 return btrfs_ioctl_defrag(file, argp);
5278         case BTRFS_IOC_RESIZE:
5279                 return btrfs_ioctl_resize(file, argp);
5280         case BTRFS_IOC_ADD_DEV:
5281                 return btrfs_ioctl_add_dev(fs_info, argp);
5282         case BTRFS_IOC_RM_DEV:
5283                 return btrfs_ioctl_rm_dev(file, argp);
5284         case BTRFS_IOC_RM_DEV_V2:
5285                 return btrfs_ioctl_rm_dev_v2(file, argp);
5286         case BTRFS_IOC_FS_INFO:
5287                 return btrfs_ioctl_fs_info(fs_info, argp);
5288         case BTRFS_IOC_DEV_INFO:
5289                 return btrfs_ioctl_dev_info(fs_info, argp);
5290         case BTRFS_IOC_BALANCE:
5291                 return btrfs_ioctl_balance(file, NULL);
5292         case BTRFS_IOC_TREE_SEARCH:
5293                 return btrfs_ioctl_tree_search(file, argp);
5294         case BTRFS_IOC_TREE_SEARCH_V2:
5295                 return btrfs_ioctl_tree_search_v2(file, argp);
5296         case BTRFS_IOC_INO_LOOKUP:
5297                 return btrfs_ioctl_ino_lookup(file, argp);
5298         case BTRFS_IOC_INO_PATHS:
5299                 return btrfs_ioctl_ino_to_path(root, argp);
5300         case BTRFS_IOC_LOGICAL_INO:
5301                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5302         case BTRFS_IOC_LOGICAL_INO_V2:
5303                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5304         case BTRFS_IOC_SPACE_INFO:
5305                 return btrfs_ioctl_space_info(fs_info, argp);
5306         case BTRFS_IOC_SYNC: {
5307                 int ret;
5308
5309                 ret = btrfs_start_delalloc_roots(fs_info, -1);
5310                 if (ret)
5311                         return ret;
5312                 ret = btrfs_sync_fs(inode->i_sb, 1);
5313                 /*
5314                  * The transaction thread may want to do more work,
5315                  * namely it pokes the cleaner kthread that will start
5316                  * processing uncleaned subvols.
5317                  */
5318                 wake_up_process(fs_info->transaction_kthread);
5319                 return ret;
5320         }
5321         case BTRFS_IOC_START_SYNC:
5322                 return btrfs_ioctl_start_sync(root, argp);
5323         case BTRFS_IOC_WAIT_SYNC:
5324                 return btrfs_ioctl_wait_sync(fs_info, argp);
5325         case BTRFS_IOC_SCRUB:
5326                 return btrfs_ioctl_scrub(file, argp);
5327         case BTRFS_IOC_SCRUB_CANCEL:
5328                 return btrfs_ioctl_scrub_cancel(fs_info);
5329         case BTRFS_IOC_SCRUB_PROGRESS:
5330                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5331         case BTRFS_IOC_BALANCE_V2:
5332                 return btrfs_ioctl_balance(file, argp);
5333         case BTRFS_IOC_BALANCE_CTL:
5334                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5335         case BTRFS_IOC_BALANCE_PROGRESS:
5336                 return btrfs_ioctl_balance_progress(fs_info, argp);
5337         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5338                 return btrfs_ioctl_set_received_subvol(file, argp);
5339 #ifdef CONFIG_64BIT
5340         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5341                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5342 #endif
5343         case BTRFS_IOC_SEND:
5344                 return _btrfs_ioctl_send(file, argp, false);
5345 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5346         case BTRFS_IOC_SEND_32:
5347                 return _btrfs_ioctl_send(file, argp, true);
5348 #endif
5349         case BTRFS_IOC_GET_DEV_STATS:
5350                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5351         case BTRFS_IOC_QUOTA_CTL:
5352                 return btrfs_ioctl_quota_ctl(file, argp);
5353         case BTRFS_IOC_QGROUP_ASSIGN:
5354                 return btrfs_ioctl_qgroup_assign(file, argp);
5355         case BTRFS_IOC_QGROUP_CREATE:
5356                 return btrfs_ioctl_qgroup_create(file, argp);
5357         case BTRFS_IOC_QGROUP_LIMIT:
5358                 return btrfs_ioctl_qgroup_limit(file, argp);
5359         case BTRFS_IOC_QUOTA_RESCAN:
5360                 return btrfs_ioctl_quota_rescan(file, argp);
5361         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5362                 return btrfs_ioctl_quota_rescan_status(file, argp);
5363         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5364                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5365         case BTRFS_IOC_DEV_REPLACE:
5366                 return btrfs_ioctl_dev_replace(fs_info, argp);
5367         case BTRFS_IOC_GET_FSLABEL:
5368                 return btrfs_ioctl_get_fslabel(file, argp);
5369         case BTRFS_IOC_SET_FSLABEL:
5370                 return btrfs_ioctl_set_fslabel(file, argp);
5371         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5372                 return btrfs_ioctl_get_supported_features(argp);
5373         case BTRFS_IOC_GET_FEATURES:
5374                 return btrfs_ioctl_get_features(file, argp);
5375         case BTRFS_IOC_SET_FEATURES:
5376                 return btrfs_ioctl_set_features(file, argp);
5377         }
5378
5379         return -ENOTTY;
5380 }
5381
5382 #ifdef CONFIG_COMPAT
5383 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5384 {
5385         /*
5386          * These all access 32-bit values anyway so no further
5387          * handling is necessary.
5388          */
5389         switch (cmd) {
5390         case FS_IOC32_GETFLAGS:
5391                 cmd = FS_IOC_GETFLAGS;
5392                 break;
5393         case FS_IOC32_SETFLAGS:
5394                 cmd = FS_IOC_SETFLAGS;
5395                 break;
5396         case FS_IOC32_GETVERSION:
5397                 cmd = FS_IOC_GETVERSION;
5398                 break;
5399         }
5400
5401         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5402 }
5403 #endif