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/file.h>
   9 #include <linux/fs.h>
  10 #include <linux/fsnotify.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/highmem.h>
  13 #include <linux/time.h>
  14 #include <linux/string.h>
  15 #include <linux/backing-dev.h>
  16 #include <linux/mount.h>
  17 #include <linux/namei.h>
  18 #include <linux/writeback.h>
  19 #include <linux/compat.h>
  20 #include <linux/security.h>
  21 #include <linux/xattr.h>
  22 #include <linux/mm.h>
  23 #include <linux/slab.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/uuid.h>
  26 #include <linux/btrfs.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/iversion.h>
  29 #include "ctree.h"
  30 #include "disk-io.h"
  31 #include "transaction.h"
  32 #include "btrfs_inode.h"
  33 #include "print-tree.h"
  34 #include "volumes.h"
  35 #include "locking.h"
  36 #include "inode-map.h"
  37 #include "backref.h"
  38 #include "rcu-string.h"
  39 #include "send.h"
  40 #include "dev-replace.h"
  41 #include "props.h"
  42 #include "sysfs.h"
  43 #include "qgroup.h"
  44 #include "tree-log.h"
  45 #include "compression.h"
  46
  47 #ifdef CONFIG_64BIT
  48 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  49  * structures are incorrect, as the timespec structure from userspace
  50  * is 4 bytes too small. We define these alternatives here to teach
  51  * the kernel about the 32-bit struct packing.
  52  */
  53 struct btrfs_ioctl_timespec_32 {
  54         __u64 sec;
  55         __u32 nsec;
  56 } __attribute__ ((__packed__));
  57
  58 struct btrfs_ioctl_received_subvol_args_32 {
  59         char    uuid[BTRFS_UUID_SIZE];  /* in */
  60         __u64   stransid;               /* in */
  61         __u64   rtransid;               /* out */
  62         struct btrfs_ioctl_timespec_32 stime; /* in */
  63         struct btrfs_ioctl_timespec_32 rtime; /* out */
  64         __u64   flags;                  /* in */
  65         __u64   reserved[16];           /* in */
  66 } __attribute__ ((__packed__));
  67
  68 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  69                                 struct btrfs_ioctl_received_subvol_args_32)
  70 #endif
  71
  72 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  73 struct btrfs_ioctl_send_args_32 {
  74         __s64 send_fd;                  /* in */
  75         __u64 clone_sources_count;      /* in */
  76         compat_uptr_t clone_sources;    /* in */
  77         __u64 parent_root;              /* in */
  78         __u64 flags;                    /* in */
  79         __u64 reserved[4];              /* in */
  80 } __attribute__ ((__packed__));
  81
  82 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  83                                struct btrfs_ioctl_send_args_32)
  84 #endif
  85
  86 static int btrfs_clone(struct inode *src, struct inode *inode,
  87                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  88                        int no_time_update);
  89
  90 /* Mask out flags that are inappropriate for the given type of inode. */
  91 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
  92                 unsigned int flags)
  93 {
  94         if (S_ISDIR(inode->i_mode))
  95                 return flags;
  96         else if (S_ISREG(inode->i_mode))
  97                 return flags & ~FS_DIRSYNC_FL;
  98         else
  99                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 100 }
 101
 102 /*
 103  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 104  * ioctl.
 105  */
 106 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
 107 {
 108         unsigned int iflags = 0;
 109
 110         if (flags & BTRFS_INODE_SYNC)
 111                 iflags |= FS_SYNC_FL;
 112         if (flags & BTRFS_INODE_IMMUTABLE)
 113                 iflags |= FS_IMMUTABLE_FL;
 114         if (flags & BTRFS_INODE_APPEND)
 115                 iflags |= FS_APPEND_FL;
 116         if (flags & BTRFS_INODE_NODUMP)
 117                 iflags |= FS_NODUMP_FL;
 118         if (flags & BTRFS_INODE_NOATIME)
 119                 iflags |= FS_NOATIME_FL;
 120         if (flags & BTRFS_INODE_DIRSYNC)
 121                 iflags |= FS_DIRSYNC_FL;
 122         if (flags & BTRFS_INODE_NODATACOW)
 123                 iflags |= FS_NOCOW_FL;
 124
 125         if (flags & BTRFS_INODE_NOCOMPRESS)
 126                 iflags |= FS_NOCOMP_FL;
 127         else if (flags & BTRFS_INODE_COMPRESS)
 128                 iflags |= FS_COMPR_FL;
 129
 130         return iflags;
 131 }
 132
 133 /*
 134  * Update inode->i_flags based on the btrfs internal flags.
 135  */
 136 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 137 {
 138         struct btrfs_inode *binode = BTRFS_I(inode);
 139         unsigned int new_fl = 0;
 140
 141         if (binode->flags & BTRFS_INODE_SYNC)
 142                 new_fl |= S_SYNC;
 143         if (binode->flags & BTRFS_INODE_IMMUTABLE)
 144                 new_fl |= S_IMMUTABLE;
 145         if (binode->flags & BTRFS_INODE_APPEND)
 146                 new_fl |= S_APPEND;
 147         if (binode->flags & BTRFS_INODE_NOATIME)
 148                 new_fl |= S_NOATIME;
 149         if (binode->flags & BTRFS_INODE_DIRSYNC)
 150                 new_fl |= S_DIRSYNC;
 151
 152         set_mask_bits(&inode->i_flags,
 153                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 154                       new_fl);
 155 }
 156
 157 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 158 {
 159         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 160         unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
 161
 162         if (copy_to_user(arg, &flags, sizeof(flags)))
 163                 return -EFAULT;
 164         return 0;
 165 }
 166
 167 /* Check if @flags are a supported and valid set of FS_*_FL flags */
 168 static int check_fsflags(unsigned int flags)
 169 {
 170         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 171                       FS_NOATIME_FL | FS_NODUMP_FL | \
 172                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 173                       FS_NOCOMP_FL | FS_COMPR_FL |
 174                       FS_NOCOW_FL))
 175                 return -EOPNOTSUPP;
 176
 177         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 178                 return -EINVAL;
 179
 180         return 0;
 181 }
 182
 183 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 184 {
 185         struct inode *inode = file_inode(file);
 186         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 187         struct btrfs_inode *binode = BTRFS_I(inode);
 188         struct btrfs_root *root = binode->root;
 189         struct btrfs_trans_handle *trans;
 190         unsigned int fsflags, old_fsflags;
 191         int ret;
 192         u64 old_flags;
 193         unsigned int old_i_flags;
 194         umode_t mode;
 195
 196         if (!inode_owner_or_capable(inode))
 197                 return -EPERM;
 198
 199         if (btrfs_root_readonly(root))
 200                 return -EROFS;
 201
 202         if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
 203                 return -EFAULT;
 204
 205         ret = check_fsflags(fsflags);
 206         if (ret)
 207                 return ret;
 208
 209         ret = mnt_want_write_file(file);
 210         if (ret)
 211                 return ret;
 212
 213         inode_lock(inode);
 214
 215         old_flags = binode->flags;
 216         old_i_flags = inode->i_flags;
 217         mode = inode->i_mode;
 218
 219         fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
 220         old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
 221         if ((fsflags ^ old_fsflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 222                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 223                         ret = -EPERM;
 224                         goto out_unlock;
 225                 }
 226         }
 227
 228         if (fsflags & FS_SYNC_FL)
 229                 binode->flags |= BTRFS_INODE_SYNC;
 230         else
 231                 binode->flags &= ~BTRFS_INODE_SYNC;
 232         if (fsflags & FS_IMMUTABLE_FL)
 233                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 234         else
 235                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 236         if (fsflags & FS_APPEND_FL)
 237                 binode->flags |= BTRFS_INODE_APPEND;
 238         else
 239                 binode->flags &= ~BTRFS_INODE_APPEND;
 240         if (fsflags & FS_NODUMP_FL)
 241                 binode->flags |= BTRFS_INODE_NODUMP;
 242         else
 243                 binode->flags &= ~BTRFS_INODE_NODUMP;
 244         if (fsflags & FS_NOATIME_FL)
 245                 binode->flags |= BTRFS_INODE_NOATIME;
 246         else
 247                 binode->flags &= ~BTRFS_INODE_NOATIME;
 248         if (fsflags & FS_DIRSYNC_FL)
 249                 binode->flags |= BTRFS_INODE_DIRSYNC;
 250         else
 251                 binode->flags &= ~BTRFS_INODE_DIRSYNC;
 252         if (fsflags & FS_NOCOW_FL) {
 253                 if (S_ISREG(mode)) {
 254                         /*
 255                          * It's safe to turn csums off here, no extents exist.
 256                          * Otherwise we want the flag to reflect the real COW
 257                          * status of the file and will not set it.
 258                          */
 259                         if (inode->i_size == 0)
 260                                 binode->flags |= BTRFS_INODE_NODATACOW
 261                                               | BTRFS_INODE_NODATASUM;
 262                 } else {
 263                         binode->flags |= BTRFS_INODE_NODATACOW;
 264                 }
 265         } else {
 266                 /*
 267                  * Revert back under same assumptions as above
 268                  */
 269                 if (S_ISREG(mode)) {
 270                         if (inode->i_size == 0)
 271                                 binode->flags &= ~(BTRFS_INODE_NODATACOW
 272                                              | BTRFS_INODE_NODATASUM);
 273                 } else {
 274                         binode->flags &= ~BTRFS_INODE_NODATACOW;
 275                 }
 276         }
 277
 278         /*
 279          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 280          * flag may be changed automatically if compression code won't make
 281          * things smaller.
 282          */
 283         if (fsflags & FS_NOCOMP_FL) {
 284                 binode->flags &= ~BTRFS_INODE_COMPRESS;
 285                 binode->flags |= BTRFS_INODE_NOCOMPRESS;
 286
 287                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 288                 if (ret && ret != -ENODATA)
 289                         goto out_drop;
 290         } else if (fsflags & FS_COMPR_FL) {
 291                 const char *comp;
 292
 293                 if (IS_SWAPFILE(inode)) {
 294                         ret = -ETXTBSY;
 295                         goto out_unlock;
 296                 }
 297
 298                 binode->flags |= BTRFS_INODE_COMPRESS;
 299                 binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
 300
 301                 comp = btrfs_compress_type2str(fs_info->compress_type);
 302                 if (!comp || comp[0] == 0)
 303                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 304
 305                 ret = btrfs_set_prop(inode, "btrfs.compression",
 306                                      comp, strlen(comp), 0);
 307                 if (ret)
 308                         goto out_drop;
 309
 310         } else {
 311                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 312                 if (ret && ret != -ENODATA)
 313                         goto out_drop;
 314                 binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 315         }
 316
 317         trans = btrfs_start_transaction(root, 1);
 318         if (IS_ERR(trans)) {
 319                 ret = PTR_ERR(trans);
 320                 goto out_drop;
 321         }
 322
 323         btrfs_sync_inode_flags_to_i_flags(inode);
 324         inode_inc_iversion(inode);
 325         inode->i_ctime = current_time(inode);
 326         ret = btrfs_update_inode(trans, root, inode);
 327
 328         btrfs_end_transaction(trans);
 329  out_drop:
 330         if (ret) {
 331                 binode->flags = old_flags;
 332                 inode->i_flags = old_i_flags;
 333         }
 334
 335  out_unlock:
 336         inode_unlock(inode);
 337         mnt_drop_write_file(file);
 338         return ret;
 339 }
 340
 341 /*
 342  * Translate btrfs internal inode flags to xflags as expected by the
 343  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
 344  * silently dropped.
 345  */
 346 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
 347 {
 348         unsigned int xflags = 0;
 349
 350         if (flags & BTRFS_INODE_APPEND)
 351                 xflags |= FS_XFLAG_APPEND;
 352         if (flags & BTRFS_INODE_IMMUTABLE)
 353                 xflags |= FS_XFLAG_IMMUTABLE;
 354         if (flags & BTRFS_INODE_NOATIME)
 355                 xflags |= FS_XFLAG_NOATIME;
 356         if (flags & BTRFS_INODE_NODUMP)
 357                 xflags |= FS_XFLAG_NODUMP;
 358         if (flags & BTRFS_INODE_SYNC)
 359                 xflags |= FS_XFLAG_SYNC;
 360
 361         return xflags;
 362 }
 363
 364 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
 365 static int check_xflags(unsigned int flags)
 366 {
 367         if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
 368                       FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
 369                 return -EOPNOTSUPP;
 370         return 0;
 371 }
 372
 373 /*
 374  * Set the xflags from the internal inode flags. The remaining items of fsxattr
 375  * are zeroed.
 376  */
 377 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
 378 {
 379         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 380         struct fsxattr fa;
 381
 382         memset(&fa, 0, sizeof(fa));
 383         fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags);
 384
 385         if (copy_to_user(arg, &fa, sizeof(fa)))
 386                 return -EFAULT;
 387
 388         return 0;
 389 }
 390
 391 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
 392 {
 393         struct inode *inode = file_inode(file);
 394         struct btrfs_inode *binode = BTRFS_I(inode);
 395         struct btrfs_root *root = binode->root;
 396         struct btrfs_trans_handle *trans;
 397         struct fsxattr fa;
 398         unsigned old_flags;
 399         unsigned old_i_flags;
 400         int ret = 0;
 401
 402         if (!inode_owner_or_capable(inode))
 403                 return -EPERM;
 404
 405         if (btrfs_root_readonly(root))
 406                 return -EROFS;
 407
 408         memset(&fa, 0, sizeof(fa));
 409         if (copy_from_user(&fa, arg, sizeof(fa)))
 410                 return -EFAULT;
 411
 412         ret = check_xflags(fa.fsx_xflags);
 413         if (ret)
 414                 return ret;
 415
 416         if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
 417                 return -EOPNOTSUPP;
 418
 419         ret = mnt_want_write_file(file);
 420         if (ret)
 421                 return ret;
 422
 423         inode_lock(inode);
 424
 425         old_flags = binode->flags;
 426         old_i_flags = inode->i_flags;
 427
 428         /* We need the capabilities to change append-only or immutable inode */
 429         if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
 430              (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
 431             !capable(CAP_LINUX_IMMUTABLE)) {
 432                 ret = -EPERM;
 433                 goto out_unlock;
 434         }
 435
 436         if (fa.fsx_xflags & FS_XFLAG_SYNC)
 437                 binode->flags |= BTRFS_INODE_SYNC;
 438         else
 439                 binode->flags &= ~BTRFS_INODE_SYNC;
 440         if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
 441                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 442         else
 443                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 444         if (fa.fsx_xflags & FS_XFLAG_APPEND)
 445                 binode->flags |= BTRFS_INODE_APPEND;
 446         else
 447                 binode->flags &= ~BTRFS_INODE_APPEND;
 448         if (fa.fsx_xflags & FS_XFLAG_NODUMP)
 449                 binode->flags |= BTRFS_INODE_NODUMP;
 450         else
 451                 binode->flags &= ~BTRFS_INODE_NODUMP;
 452         if (fa.fsx_xflags & FS_XFLAG_NOATIME)
 453                 binode->flags |= BTRFS_INODE_NOATIME;
 454         else
 455                 binode->flags &= ~BTRFS_INODE_NOATIME;
 456
 457         /* 1 item for the inode */
 458         trans = btrfs_start_transaction(root, 1);
 459         if (IS_ERR(trans)) {
 460                 ret = PTR_ERR(trans);
 461                 goto out_unlock;
 462         }
 463
 464         btrfs_sync_inode_flags_to_i_flags(inode);
 465         inode_inc_iversion(inode);
 466         inode->i_ctime = current_time(inode);
 467         ret = btrfs_update_inode(trans, root, inode);
 468
 469         btrfs_end_transaction(trans);
 470
 471 out_unlock:
 472         if (ret) {
 473                 binode->flags = old_flags;
 474                 inode->i_flags = old_i_flags;
 475         }
 476
 477         inode_unlock(inode);
 478         mnt_drop_write_file(file);
 479
 480         return ret;
 481 }
 482
 483 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 484 {
 485         struct inode *inode = file_inode(file);
 486
 487         return put_user(inode->i_generation, arg);
 488 }
 489
 490 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 491 {
 492         struct inode *inode = file_inode(file);
 493         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 494         struct btrfs_device *device;
 495         struct request_queue *q;
 496         struct fstrim_range range;
 497         u64 minlen = ULLONG_MAX;
 498         u64 num_devices = 0;
 499         int ret;
 500
 501         if (!capable(CAP_SYS_ADMIN))
 502                 return -EPERM;
 503
 504         rcu_read_lock();
 505         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 506                                 dev_list) {
 507                 if (!device->bdev)
 508                         continue;
 509                 q = bdev_get_queue(device->bdev);
 510                 if (blk_queue_discard(q)) {
 511                         num_devices++;
 512                         minlen = min_t(u64, q->limits.discard_granularity,
 513                                      minlen);
 514                 }
 515         }
 516         rcu_read_unlock();
 517
 518         if (!num_devices)
 519                 return -EOPNOTSUPP;
 520         if (copy_from_user(&range, arg, sizeof(range)))
 521                 return -EFAULT;
 522
 523         /*
 524          * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
 525          * block group is in the logical address space, which can be any
 526          * sectorsize aligned bytenr in  the range [0, U64_MAX].
 527          */
 528         if (range.len < fs_info->sb->s_blocksize)
 529                 return -EINVAL;
 530
 531         range.minlen = max(range.minlen, minlen);
 532         ret = btrfs_trim_fs(fs_info, &range);
 533         if (ret < 0)
 534                 return ret;
 535
 536         if (copy_to_user(arg, &range, sizeof(range)))
 537                 return -EFAULT;
 538
 539         return 0;
 540 }
 541
 542 int btrfs_is_empty_uuid(u8 *uuid)
 543 {
 544         int i;
 545
 546         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 547                 if (uuid[i])
 548                         return 0;
 549         }
 550         return 1;
 551 }
 552
 553 static noinline int create_subvol(struct inode *dir,
 554                                   struct dentry *dentry,
 555                                   const char *name, int namelen,
 556                                   u64 *async_transid,
 557                                   struct btrfs_qgroup_inherit *inherit)
 558 {
 559         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 560         struct btrfs_trans_handle *trans;
 561         struct btrfs_key key;
 562         struct btrfs_root_item *root_item;
 563         struct btrfs_inode_item *inode_item;
 564         struct extent_buffer *leaf;
 565         struct btrfs_root *root = BTRFS_I(dir)->root;
 566         struct btrfs_root *new_root;
 567         struct btrfs_block_rsv block_rsv;
 568         struct timespec64 cur_time = current_time(dir);
 569         struct inode *inode;
 570         int ret;
 571         int err;
 572         u64 objectid;
 573         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 574         u64 index = 0;
 575         uuid_le new_uuid;
 576
 577         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 578         if (!root_item)
 579                 return -ENOMEM;
 580
 581         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 582         if (ret)
 583                 goto fail_free;
 584
 585         /*
 586          * Don't create subvolume whose level is not zero. Or qgroup will be
 587          * screwed up since it assumes subvolume qgroup's level to be 0.
 588          */
 589         if (btrfs_qgroup_level(objectid)) {
 590                 ret = -ENOSPC;
 591                 goto fail_free;
 592         }
 593
 594         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 595         /*
 596          * The same as the snapshot creation, please see the comment
 597          * of create_snapshot().
 598          */
 599         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
 600         if (ret)
 601                 goto fail_free;
 602
 603         trans = btrfs_start_transaction(root, 0);
 604         if (IS_ERR(trans)) {
 605                 ret = PTR_ERR(trans);
 606                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 607                 goto fail_free;
 608         }
 609         trans->block_rsv = &block_rsv;
 610         trans->bytes_reserved = block_rsv.size;
 611
 612         ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
 613         if (ret)
 614                 goto fail;
 615
 616         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 617         if (IS_ERR(leaf)) {
 618                 ret = PTR_ERR(leaf);
 619                 goto fail;
 620         }
 621
 622         btrfs_mark_buffer_dirty(leaf);
 623
 624         inode_item = &root_item->inode;
 625         btrfs_set_stack_inode_generation(inode_item, 1);
 626         btrfs_set_stack_inode_size(inode_item, 3);
 627         btrfs_set_stack_inode_nlink(inode_item, 1);
 628         btrfs_set_stack_inode_nbytes(inode_item,
 629                                      fs_info->nodesize);
 630         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 631
 632         btrfs_set_root_flags(root_item, 0);
 633         btrfs_set_root_limit(root_item, 0);
 634         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 635
 636         btrfs_set_root_bytenr(root_item, leaf->start);
 637         btrfs_set_root_generation(root_item, trans->transid);
 638         btrfs_set_root_level(root_item, 0);
 639         btrfs_set_root_refs(root_item, 1);
 640         btrfs_set_root_used(root_item, leaf->len);
 641         btrfs_set_root_last_snapshot(root_item, 0);
 642
 643         btrfs_set_root_generation_v2(root_item,
 644                         btrfs_root_generation(root_item));
 645         uuid_le_gen(&new_uuid);
 646         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 647         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 648         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 649         root_item->ctime = root_item->otime;
 650         btrfs_set_root_ctransid(root_item, trans->transid);
 651         btrfs_set_root_otransid(root_item, trans->transid);
 652
 653         btrfs_tree_unlock(leaf);
 654         free_extent_buffer(leaf);
 655         leaf = NULL;
 656
 657         btrfs_set_root_dirid(root_item, new_dirid);
 658
 659         key.objectid = objectid;
 660         key.offset = 0;
 661         key.type = BTRFS_ROOT_ITEM_KEY;
 662         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 663                                 root_item);
 664         if (ret)
 665                 goto fail;
 666
 667         key.offset = (u64)-1;
 668         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 669         if (IS_ERR(new_root)) {
 670                 ret = PTR_ERR(new_root);
 671                 btrfs_abort_transaction(trans, ret);
 672                 goto fail;
 673         }
 674
 675         btrfs_record_root_in_trans(trans, new_root);
 676
 677         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 678         if (ret) {
 679                 /* We potentially lose an unused inode item here */
 680                 btrfs_abort_transaction(trans, ret);
 681                 goto fail;
 682         }
 683
 684         mutex_lock(&new_root->objectid_mutex);
 685         new_root->highest_objectid = new_dirid;
 686         mutex_unlock(&new_root->objectid_mutex);
 687
 688         /*
 689          * insert the directory item
 690          */
 691         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 692         if (ret) {
 693                 btrfs_abort_transaction(trans, ret);
 694                 goto fail;
 695         }
 696
 697         ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
 698                                     BTRFS_FT_DIR, index);
 699         if (ret) {
 700                 btrfs_abort_transaction(trans, ret);
 701                 goto fail;
 702         }
 703
 704         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 705         ret = btrfs_update_inode(trans, root, dir);
 706         BUG_ON(ret);
 707
 708         ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
 709                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 710         BUG_ON(ret);
 711
 712         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 713                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 714         if (ret)
 715                 btrfs_abort_transaction(trans, ret);
 716
 717 fail:
 718         kfree(root_item);
 719         trans->block_rsv = NULL;
 720         trans->bytes_reserved = 0;
 721         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 722
 723         if (async_transid) {
 724                 *async_transid = trans->transid;
 725                 err = btrfs_commit_transaction_async(trans, 1);
 726                 if (err)
 727                         err = btrfs_commit_transaction(trans);
 728         } else {
 729                 err = btrfs_commit_transaction(trans);
 730         }
 731         if (err && !ret)
 732                 ret = err;
 733
 734         if (!ret) {
 735                 inode = btrfs_lookup_dentry(dir, dentry);
 736                 if (IS_ERR(inode))
 737                         return PTR_ERR(inode);
 738                 d_instantiate(dentry, inode);
 739         }
 740         return ret;
 741
 742 fail_free:
 743         kfree(root_item);
 744         return ret;
 745 }
 746
 747 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 748                            struct dentry *dentry,
 749                            u64 *async_transid, bool readonly,
 750                            struct btrfs_qgroup_inherit *inherit)
 751 {
 752         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 753         struct inode *inode;
 754         struct btrfs_pending_snapshot *pending_snapshot;
 755         struct btrfs_trans_handle *trans;
 756         int ret;
 757         bool snapshot_force_cow = false;
 758
 759         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 760                 return -EINVAL;
 761
 762         if (atomic_read(&root->nr_swapfiles)) {
 763                 btrfs_warn(fs_info,
 764                            "cannot snapshot subvolume with active swapfile");
 765                 return -ETXTBSY;
 766         }
 767
 768         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 769         if (!pending_snapshot)
 770                 return -ENOMEM;
 771
 772         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 773                         GFP_KERNEL);
 774         pending_snapshot->path = btrfs_alloc_path();
 775         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 776                 ret = -ENOMEM;
 777                 goto free_pending;
 778         }
 779
 780         /*
 781          * Force new buffered writes to reserve space even when NOCOW is
 782          * possible. This is to avoid later writeback (running dealloc) to
 783          * fallback to COW mode and unexpectedly fail with ENOSPC.
 784          */
 785         atomic_inc(&root->will_be_snapshotted);
 786         smp_mb__after_atomic();
 787         /* wait for no snapshot writes */
 788         wait_event(root->subv_writers->wait,
 789                    percpu_counter_sum(&root->subv_writers->counter) == 0);
 790
 791         ret = btrfs_start_delalloc_snapshot(root);
 792         if (ret)
 793                 goto dec_and_free;
 794
 795         /*
 796          * All previous writes have started writeback in NOCOW mode, so now
 797          * we force future writes to fallback to COW mode during snapshot
 798          * creation.
 799          */
 800         atomic_inc(&root->snapshot_force_cow);
 801         snapshot_force_cow = true;
 802
 803         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 804
 805         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 806                              BTRFS_BLOCK_RSV_TEMP);
 807         /*
 808          * 1 - parent dir inode
 809          * 2 - dir entries
 810          * 1 - root item
 811          * 2 - root ref/backref
 812          * 1 - root of snapshot
 813          * 1 - UUID item
 814          */
 815         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 816                                         &pending_snapshot->block_rsv, 8,
 817                                         false);
 818         if (ret)
 819                 goto dec_and_free;
 820
 821         pending_snapshot->dentry = dentry;
 822         pending_snapshot->root = root;
 823         pending_snapshot->readonly = readonly;
 824         pending_snapshot->dir = dir;
 825         pending_snapshot->inherit = inherit;
 826
 827         trans = btrfs_start_transaction(root, 0);
 828         if (IS_ERR(trans)) {
 829                 ret = PTR_ERR(trans);
 830                 goto fail;
 831         }
 832
 833         spin_lock(&fs_info->trans_lock);
 834         list_add(&pending_snapshot->list,
 835                  &trans->transaction->pending_snapshots);
 836         spin_unlock(&fs_info->trans_lock);
 837         if (async_transid) {
 838                 *async_transid = trans->transid;
 839                 ret = btrfs_commit_transaction_async(trans, 1);
 840                 if (ret)
 841                         ret = btrfs_commit_transaction(trans);
 842         } else {
 843                 ret = btrfs_commit_transaction(trans);
 844         }
 845         if (ret)
 846                 goto fail;
 847
 848         ret = pending_snapshot->error;
 849         if (ret)
 850                 goto fail;
 851
 852         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 853         if (ret)
 854                 goto fail;
 855
 856         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 857         if (IS_ERR(inode)) {
 858                 ret = PTR_ERR(inode);
 859                 goto fail;
 860         }
 861
 862         d_instantiate(dentry, inode);
 863         ret = 0;
 864 fail:
 865         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 866 dec_and_free:
 867         if (snapshot_force_cow)
 868                 atomic_dec(&root->snapshot_force_cow);
 869         if (atomic_dec_and_test(&root->will_be_snapshotted))
 870                 wake_up_var(&root->will_be_snapshotted);
 871 free_pending:
 872         kfree(pending_snapshot->root_item);
 873         btrfs_free_path(pending_snapshot->path);
 874         kfree(pending_snapshot);
 875
 876         return ret;
 877 }
 878
 879 /*  copy of may_delete in fs/namei.c()
 880  *      Check whether we can remove a link victim from directory dir, check
 881  *  whether the type of victim is right.
 882  *  1. We can't do it if dir is read-only (done in permission())
 883  *  2. We should have write and exec permissions on dir
 884  *  3. We can't remove anything from append-only dir
 885  *  4. We can't do anything with immutable dir (done in permission())
 886  *  5. If the sticky bit on dir is set we should either
 887  *      a. be owner of dir, or
 888  *      b. be owner of victim, or
 889  *      c. have CAP_FOWNER capability
 890  *  6. If the victim is append-only or immutable we can't do anything with
 891  *     links pointing to it.
 892  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 893  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 894  *  9. We can't remove a root or mountpoint.
 895  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 896  *     nfs_async_unlink().
 897  */
 898
 899 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 900 {
 901         int error;
 902
 903         if (d_really_is_negative(victim))
 904                 return -ENOENT;
 905
 906         BUG_ON(d_inode(victim->d_parent) != dir);
 907         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 908
 909         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 910         if (error)
 911                 return error;
 912         if (IS_APPEND(dir))
 913                 return -EPERM;
 914         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 915             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 916                 return -EPERM;
 917         if (isdir) {
 918                 if (!d_is_dir(victim))
 919                         return -ENOTDIR;
 920                 if (IS_ROOT(victim))
 921                         return -EBUSY;
 922         } else if (d_is_dir(victim))
 923                 return -EISDIR;
 924         if (IS_DEADDIR(dir))
 925                 return -ENOENT;
 926         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 927                 return -EBUSY;
 928         return 0;
 929 }
 930
 931 /* copy of may_create in fs/namei.c() */
 932 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 933 {
 934         if (d_really_is_positive(child))
 935                 return -EEXIST;
 936         if (IS_DEADDIR(dir))
 937                 return -ENOENT;
 938         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 939 }
 940
 941 /*
 942  * Create a new subvolume below @parent.  This is largely modeled after
 943  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 944  * inside this filesystem so it's quite a bit simpler.
 945  */
 946 static noinline int btrfs_mksubvol(const struct path *parent,
 947                                    const char *name, int namelen,
 948                                    struct btrfs_root *snap_src,
 949                                    u64 *async_transid, bool readonly,
 950                                    struct btrfs_qgroup_inherit *inherit)
 951 {
 952         struct inode *dir = d_inode(parent->dentry);
 953         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 954         struct dentry *dentry;
 955         int error;
 956
 957         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 958         if (error == -EINTR)
 959                 return error;
 960
 961         dentry = lookup_one_len(name, parent->dentry, namelen);
 962         error = PTR_ERR(dentry);
 963         if (IS_ERR(dentry))
 964                 goto out_unlock;
 965
 966         error = btrfs_may_create(dir, dentry);
 967         if (error)
 968                 goto out_dput;
 969
 970         /*
 971          * even if this name doesn't exist, we may get hash collisions.
 972          * check for them now when we can safely fail
 973          */
 974         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 975                                                dir->i_ino, name,
 976                                                namelen);
 977         if (error)
 978                 goto out_dput;
 979
 980         down_read(&fs_info->subvol_sem);
 981
 982         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 983                 goto out_up_read;
 984
 985         if (snap_src) {
 986                 error = create_snapshot(snap_src, dir, dentry,
 987                                         async_transid, readonly, inherit);
 988         } else {
 989                 error = create_subvol(dir, dentry, name, namelen,
 990                                       async_transid, inherit);
 991         }
 992         if (!error)
 993                 fsnotify_mkdir(dir, dentry);
 994 out_up_read:
 995         up_read(&fs_info->subvol_sem);
 996 out_dput:
 997         dput(dentry);
 998 out_unlock:
 999         inode_unlock(dir);
1000         return error;
1001 }
1002
1003 /*
1004  * When we're defragging a range, we don't want to kick it off again
1005  * if it is really just waiting for delalloc to send it down.
1006  * If we find a nice big extent or delalloc range for the bytes in the
1007  * file you want to defrag, we return 0 to let you know to skip this
1008  * part of the file
1009  */
1010 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
1011 {
1012         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1013         struct extent_map *em = NULL;
1014         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1015         u64 end;
1016
1017         read_lock(&em_tree->lock);
1018         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1019         read_unlock(&em_tree->lock);
1020
1021         if (em) {
1022                 end = extent_map_end(em);
1023                 free_extent_map(em);
1024                 if (end - offset > thresh)
1025                         return 0;
1026         }
1027         /* if we already have a nice delalloc here, just stop */
1028         thresh /= 2;
1029         end = count_range_bits(io_tree, &offset, offset + thresh,
1030                                thresh, EXTENT_DELALLOC, 1);
1031         if (end >= thresh)
1032                 return 0;
1033         return 1;
1034 }
1035
1036 /*
1037  * helper function to walk through a file and find extents
1038  * newer than a specific transid, and smaller than thresh.
1039  *
1040  * This is used by the defragging code to find new and small
1041  * extents
1042  */
1043 static int find_new_extents(struct btrfs_root *root,
1044                             struct inode *inode, u64 newer_than,
1045                             u64 *off, u32 thresh)
1046 {
1047         struct btrfs_path *path;
1048         struct btrfs_key min_key;
1049         struct extent_buffer *leaf;
1050         struct btrfs_file_extent_item *extent;
1051         int type;
1052         int ret;
1053         u64 ino = btrfs_ino(BTRFS_I(inode));
1054
1055         path = btrfs_alloc_path();
1056         if (!path)
1057                 return -ENOMEM;
1058
1059         min_key.objectid = ino;
1060         min_key.type = BTRFS_EXTENT_DATA_KEY;
1061         min_key.offset = *off;
1062
1063         while (1) {
1064                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
1065                 if (ret != 0)
1066                         goto none;
1067 process_slot:
1068                 if (min_key.objectid != ino)
1069                         goto none;
1070                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1071                         goto none;
1072
1073                 leaf = path->nodes[0];
1074                 extent = btrfs_item_ptr(leaf, path->slots[0],
1075                                         struct btrfs_file_extent_item);
1076
1077                 type = btrfs_file_extent_type(leaf, extent);
1078                 if (type == BTRFS_FILE_EXTENT_REG &&
1079                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1080                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
1081                         *off = min_key.offset;
1082                         btrfs_free_path(path);
1083                         return 0;
1084                 }
1085
1086                 path->slots[0]++;
1087                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
1088                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1089                         goto process_slot;
1090                 }
1091
1092                 if (min_key.offset == (u64)-1)
1093                         goto none;
1094
1095                 min_key.offset++;
1096                 btrfs_release_path(path);
1097         }
1098 none:
1099         btrfs_free_path(path);
1100         return -ENOENT;
1101 }
1102
1103 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1104 {
1105         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1106         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1107         struct extent_map *em;
1108         u64 len = PAGE_SIZE;
1109
1110         /*
1111          * hopefully we have this extent in the tree already, try without
1112          * the full extent lock
1113          */
1114         read_lock(&em_tree->lock);
1115         em = lookup_extent_mapping(em_tree, start, len);
1116         read_unlock(&em_tree->lock);
1117
1118         if (!em) {
1119                 struct extent_state *cached = NULL;
1120                 u64 end = start + len - 1;
1121
1122                 /* get the big lock and read metadata off disk */
1123                 lock_extent_bits(io_tree, start, end, &cached);
1124                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1125                 unlock_extent_cached(io_tree, start, end, &cached);
1126
1127                 if (IS_ERR(em))
1128                         return NULL;
1129         }
1130
1131         return em;
1132 }
1133
1134 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1135 {
1136         struct extent_map *next;
1137         bool ret = true;
1138
1139         /* this is the last extent */
1140         if (em->start + em->len >= i_size_read(inode))
1141                 return false;
1142
1143         next = defrag_lookup_extent(inode, em->start + em->len);
1144         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1145                 ret = false;
1146         else if ((em->block_start + em->block_len == next->block_start) &&
1147                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1148                 ret = false;
1149
1150         free_extent_map(next);
1151         return ret;
1152 }
1153
1154 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1155                                u64 *last_len, u64 *skip, u64 *defrag_end,
1156                                int compress)
1157 {
1158         struct extent_map *em;
1159         int ret = 1;
1160         bool next_mergeable = true;
1161         bool prev_mergeable = true;
1162
1163         /*
1164          * make sure that once we start defragging an extent, we keep on
1165          * defragging it
1166          */
1167         if (start < *defrag_end)
1168                 return 1;
1169
1170         *skip = 0;
1171
1172         em = defrag_lookup_extent(inode, start);
1173         if (!em)
1174                 return 0;
1175
1176         /* this will cover holes, and inline extents */
1177         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1178                 ret = 0;
1179                 goto out;
1180         }
1181
1182         if (!*defrag_end)
1183                 prev_mergeable = false;
1184
1185         next_mergeable = defrag_check_next_extent(inode, em);
1186         /*
1187          * we hit a real extent, if it is big or the next extent is not a
1188          * real extent, don't bother defragging it
1189          */
1190         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1191             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1192                 ret = 0;
1193 out:
1194         /*
1195          * last_len ends up being a counter of how many bytes we've defragged.
1196          * every time we choose not to defrag an extent, we reset *last_len
1197          * so that the next tiny extent will force a defrag.
1198          *
1199          * The end result of this is that tiny extents before a single big
1200          * extent will force at least part of that big extent to be defragged.
1201          */
1202         if (ret) {
1203                 *defrag_end = extent_map_end(em);
1204         } else {
1205                 *last_len = 0;
1206                 *skip = extent_map_end(em);
1207                 *defrag_end = 0;
1208         }
1209
1210         free_extent_map(em);
1211         return ret;
1212 }
1213
1214 /*
1215  * it doesn't do much good to defrag one or two pages
1216  * at a time.  This pulls in a nice chunk of pages
1217  * to COW and defrag.
1218  *
1219  * It also makes sure the delalloc code has enough
1220  * dirty data to avoid making new small extents as part
1221  * of the defrag
1222  *
1223  * It's a good idea to start RA on this range
1224  * before calling this.
1225  */
1226 static int cluster_pages_for_defrag(struct inode *inode,
1227                                     struct page **pages,
1228                                     unsigned long start_index,
1229                                     unsigned long num_pages)
1230 {
1231         unsigned long file_end;
1232         u64 isize = i_size_read(inode);
1233         u64 page_start;
1234         u64 page_end;
1235         u64 page_cnt;
1236         int ret;
1237         int i;
1238         int i_done;
1239         struct btrfs_ordered_extent *ordered;
1240         struct extent_state *cached_state = NULL;
1241         struct extent_io_tree *tree;
1242         struct extent_changeset *data_reserved = NULL;
1243         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1244
1245         file_end = (isize - 1) >> PAGE_SHIFT;
1246         if (!isize || start_index > file_end)
1247                 return 0;
1248
1249         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1250
1251         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1252                         start_index << PAGE_SHIFT,
1253                         page_cnt << PAGE_SHIFT);
1254         if (ret)
1255                 return ret;
1256         i_done = 0;
1257         tree = &BTRFS_I(inode)->io_tree;
1258
1259         /* step one, lock all the pages */
1260         for (i = 0; i < page_cnt; i++) {
1261                 struct page *page;
1262 again:
1263                 page = find_or_create_page(inode->i_mapping,
1264                                            start_index + i, mask);
1265                 if (!page)
1266                         break;
1267
1268                 page_start = page_offset(page);
1269                 page_end = page_start + PAGE_SIZE - 1;
1270                 while (1) {
1271                         lock_extent_bits(tree, page_start, page_end,
1272                                          &cached_state);
1273                         ordered = btrfs_lookup_ordered_extent(inode,
1274                                                               page_start);
1275                         unlock_extent_cached(tree, page_start, page_end,
1276                                              &cached_state);
1277                         if (!ordered)
1278                                 break;
1279
1280                         unlock_page(page);
1281                         btrfs_start_ordered_extent(inode, ordered, 1);
1282                         btrfs_put_ordered_extent(ordered);
1283                         lock_page(page);
1284                         /*
1285                          * we unlocked the page above, so we need check if
1286                          * it was released or not.
1287                          */
1288                         if (page->mapping != inode->i_mapping) {
1289                                 unlock_page(page);
1290                                 put_page(page);
1291                                 goto again;
1292                         }
1293                 }
1294
1295                 if (!PageUptodate(page)) {
1296                         btrfs_readpage(NULL, page);
1297                         lock_page(page);
1298                         if (!PageUptodate(page)) {
1299                                 unlock_page(page);
1300                                 put_page(page);
1301                                 ret = -EIO;
1302                                 break;
1303                         }
1304                 }
1305
1306                 if (page->mapping != inode->i_mapping) {
1307                         unlock_page(page);
1308                         put_page(page);
1309                         goto again;
1310                 }
1311
1312                 pages[i] = page;
1313                 i_done++;
1314         }
1315         if (!i_done || ret)
1316                 goto out;
1317
1318         if (!(inode->i_sb->s_flags & SB_ACTIVE))
1319                 goto out;
1320
1321         /*
1322          * so now we have a nice long stream of locked
1323          * and up to date pages, lets wait on them
1324          */
1325         for (i = 0; i < i_done; i++)
1326                 wait_on_page_writeback(pages[i]);
1327
1328         page_start = page_offset(pages[0]);
1329         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1330
1331         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1332                          page_start, page_end - 1, &cached_state);
1333         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1334                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1335                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1336                           &cached_state);
1337
1338         if (i_done != page_cnt) {
1339                 spin_lock(&BTRFS_I(inode)->lock);
1340                 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1341                 spin_unlock(&BTRFS_I(inode)->lock);
1342                 btrfs_delalloc_release_space(inode, data_reserved,
1343                                 start_index << PAGE_SHIFT,
1344                                 (page_cnt - i_done) << PAGE_SHIFT, true);
1345         }
1346
1347
1348         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1349                           &cached_state);
1350
1351         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1352                              page_start, page_end - 1, &cached_state);
1353
1354         for (i = 0; i < i_done; i++) {
1355                 clear_page_dirty_for_io(pages[i]);
1356                 ClearPageChecked(pages[i]);
1357                 set_page_extent_mapped(pages[i]);
1358                 set_page_dirty(pages[i]);
1359                 unlock_page(pages[i]);
1360                 put_page(pages[i]);
1361         }
1362         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1363                                        false);
1364         extent_changeset_free(data_reserved);
1365         return i_done;
1366 out:
1367         for (i = 0; i < i_done; i++) {
1368                 unlock_page(pages[i]);
1369                 put_page(pages[i]);
1370         }
1371         btrfs_delalloc_release_space(inode, data_reserved,
1372                         start_index << PAGE_SHIFT,
1373                         page_cnt << PAGE_SHIFT, true);
1374         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1375                                        true);
1376         extent_changeset_free(data_reserved);
1377         return ret;
1378
1379 }
1380
1381 int btrfs_defrag_file(struct inode *inode, struct file *file,
1382                       struct btrfs_ioctl_defrag_range_args *range,
1383                       u64 newer_than, unsigned long max_to_defrag)
1384 {
1385         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1386         struct btrfs_root *root = BTRFS_I(inode)->root;
1387         struct file_ra_state *ra = NULL;
1388         unsigned long last_index;
1389         u64 isize = i_size_read(inode);
1390         u64 last_len = 0;
1391         u64 skip = 0;
1392         u64 defrag_end = 0;
1393         u64 newer_off = range->start;
1394         unsigned long i;
1395         unsigned long ra_index = 0;
1396         int ret;
1397         int defrag_count = 0;
1398         int compress_type = BTRFS_COMPRESS_ZLIB;
1399         u32 extent_thresh = range->extent_thresh;
1400         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1401         unsigned long cluster = max_cluster;
1402         u64 new_align = ~((u64)SZ_128K - 1);
1403         struct page **pages = NULL;
1404         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1405
1406         if (isize == 0)
1407                 return 0;
1408
1409         if (range->start >= isize)
1410                 return -EINVAL;
1411
1412         if (do_compress) {
1413                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1414                         return -EINVAL;
1415                 if (range->compress_type)
1416                         compress_type = range->compress_type;
1417         }
1418
1419         if (extent_thresh == 0)
1420                 extent_thresh = SZ_256K;
1421
1422         /*
1423          * If we were not given a file, allocate a readahead context. As
1424          * readahead is just an optimization, defrag will work without it so
1425          * we don't error out.
1426          */
1427         if (!file) {
1428                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1429                 if (ra)
1430                         file_ra_state_init(ra, inode->i_mapping);
1431         } else {
1432                 ra = &file->f_ra;
1433         }
1434
1435         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1436         if (!pages) {
1437                 ret = -ENOMEM;
1438                 goto out_ra;
1439         }
1440
1441         /* find the last page to defrag */
1442         if (range->start + range->len > range->start) {
1443                 last_index = min_t(u64, isize - 1,
1444                          range->start + range->len - 1) >> PAGE_SHIFT;
1445         } else {
1446                 last_index = (isize - 1) >> PAGE_SHIFT;
1447         }
1448
1449         if (newer_than) {
1450                 ret = find_new_extents(root, inode, newer_than,
1451                                        &newer_off, SZ_64K);
1452                 if (!ret) {
1453                         range->start = newer_off;
1454                         /*
1455                          * we always align our defrag to help keep
1456                          * the extents in the file evenly spaced
1457                          */
1458                         i = (newer_off & new_align) >> PAGE_SHIFT;
1459                 } else
1460                         goto out_ra;
1461         } else {
1462                 i = range->start >> PAGE_SHIFT;
1463         }
1464         if (!max_to_defrag)
1465                 max_to_defrag = last_index - i + 1;
1466
1467         /*
1468          * make writeback starts from i, so the defrag range can be
1469          * written sequentially.
1470          */
1471         if (i < inode->i_mapping->writeback_index)
1472                 inode->i_mapping->writeback_index = i;
1473
1474         while (i <= last_index && defrag_count < max_to_defrag &&
1475                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1476                 /*
1477                  * make sure we stop running if someone unmounts
1478                  * the FS
1479                  */
1480                 if (!(inode->i_sb->s_flags & SB_ACTIVE))
1481                         break;
1482
1483                 if (btrfs_defrag_cancelled(fs_info)) {
1484                         btrfs_debug(fs_info, "defrag_file cancelled");
1485                         ret = -EAGAIN;
1486                         break;
1487                 }
1488
1489                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1490                                          extent_thresh, &last_len, &skip,
1491                                          &defrag_end, do_compress)){
1492                         unsigned long next;
1493                         /*
1494                          * the should_defrag function tells us how much to skip
1495                          * bump our counter by the suggested amount
1496                          */
1497                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1498                         i = max(i + 1, next);
1499                         continue;
1500                 }
1501
1502                 if (!newer_than) {
1503                         cluster = (PAGE_ALIGN(defrag_end) >>
1504                                    PAGE_SHIFT) - i;
1505                         cluster = min(cluster, max_cluster);
1506                 } else {
1507                         cluster = max_cluster;
1508                 }
1509
1510                 if (i + cluster > ra_index) {
1511                         ra_index = max(i, ra_index);
1512                         if (ra)
1513                                 page_cache_sync_readahead(inode->i_mapping, ra,
1514                                                 file, ra_index, cluster);
1515                         ra_index += cluster;
1516                 }
1517
1518                 inode_lock(inode);
1519                 if (IS_SWAPFILE(inode)) {
1520                         ret = -ETXTBSY;
1521                 } else {
1522                         if (do_compress)
1523                                 BTRFS_I(inode)->defrag_compress = compress_type;
1524                         ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1525                 }
1526                 if (ret < 0) {
1527                         inode_unlock(inode);
1528                         goto out_ra;
1529                 }
1530
1531                 defrag_count += ret;
1532                 balance_dirty_pages_ratelimited(inode->i_mapping);
1533                 inode_unlock(inode);
1534
1535                 if (newer_than) {
1536                         if (newer_off == (u64)-1)
1537                                 break;
1538
1539                         if (ret > 0)
1540                                 i += ret;
1541
1542                         newer_off = max(newer_off + 1,
1543                                         (u64)i << PAGE_SHIFT);
1544
1545                         ret = find_new_extents(root, inode, newer_than,
1546                                                &newer_off, SZ_64K);
1547                         if (!ret) {
1548                                 range->start = newer_off;
1549                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1550                         } else {
1551                                 break;
1552                         }
1553                 } else {
1554                         if (ret > 0) {
1555                                 i += ret;
1556                                 last_len += ret << PAGE_SHIFT;
1557                         } else {
1558                                 i++;
1559                                 last_len = 0;
1560                         }
1561                 }
1562         }
1563
1564         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1565                 filemap_flush(inode->i_mapping);
1566                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1567                              &BTRFS_I(inode)->runtime_flags))
1568                         filemap_flush(inode->i_mapping);
1569         }
1570
1571         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1572                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1573         } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1574                 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1575         }
1576
1577         ret = defrag_count;
1578
1579 out_ra:
1580         if (do_compress) {
1581                 inode_lock(inode);
1582                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1583                 inode_unlock(inode);
1584         }
1585         if (!file)
1586                 kfree(ra);
1587         kfree(pages);
1588         return ret;
1589 }
1590
1591 static noinline int btrfs_ioctl_resize(struct file *file,
1592                                         void __user *arg)
1593 {
1594         struct inode *inode = file_inode(file);
1595         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1596         u64 new_size;
1597         u64 old_size;
1598         u64 devid = 1;
1599         struct btrfs_root *root = BTRFS_I(inode)->root;
1600         struct btrfs_ioctl_vol_args *vol_args;
1601         struct btrfs_trans_handle *trans;
1602         struct btrfs_device *device = NULL;
1603         char *sizestr;
1604         char *retptr;
1605         char *devstr = NULL;
1606         int ret = 0;
1607         int mod = 0;
1608
1609         if (!capable(CAP_SYS_ADMIN))
1610                 return -EPERM;
1611
1612         ret = mnt_want_write_file(file);
1613         if (ret)
1614                 return ret;
1615
1616         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1617                 mnt_drop_write_file(file);
1618                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1619         }
1620
1621         vol_args = memdup_user(arg, sizeof(*vol_args));
1622         if (IS_ERR(vol_args)) {
1623                 ret = PTR_ERR(vol_args);
1624                 goto out;
1625         }
1626
1627         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1628
1629         sizestr = vol_args->name;
1630         devstr = strchr(sizestr, ':');
1631         if (devstr) {
1632                 sizestr = devstr + 1;
1633                 *devstr = '\0';
1634                 devstr = vol_args->name;
1635                 ret = kstrtoull(devstr, 10, &devid);
1636                 if (ret)
1637                         goto out_free;
1638                 if (!devid) {
1639                         ret = -EINVAL;
1640                         goto out_free;
1641                 }
1642                 btrfs_info(fs_info, "resizing devid %llu", devid);
1643         }
1644
1645         device = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
1646         if (!device) {
1647                 btrfs_info(fs_info, "resizer unable to find device %llu",
1648                            devid);
1649                 ret = -ENODEV;
1650                 goto out_free;
1651         }
1652
1653         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1654                 btrfs_info(fs_info,
1655                            "resizer unable to apply on readonly device %llu",
1656                        devid);
1657                 ret = -EPERM;
1658                 goto out_free;
1659         }
1660
1661         if (!strcmp(sizestr, "max"))
1662                 new_size = device->bdev->bd_inode->i_size;
1663         else {
1664                 if (sizestr[0] == '-') {
1665                         mod = -1;
1666                         sizestr++;
1667                 } else if (sizestr[0] == '+') {
1668                         mod = 1;
1669                         sizestr++;
1670                 }
1671                 new_size = memparse(sizestr, &retptr);
1672                 if (*retptr != '\0' || new_size == 0) {
1673                         ret = -EINVAL;
1674                         goto out_free;
1675                 }
1676         }
1677
1678         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1679                 ret = -EPERM;
1680                 goto out_free;
1681         }
1682
1683         old_size = btrfs_device_get_total_bytes(device);
1684
1685         if (mod < 0) {
1686                 if (new_size > old_size) {
1687                         ret = -EINVAL;
1688                         goto out_free;
1689                 }
1690                 new_size = old_size - new_size;
1691         } else if (mod > 0) {
1692                 if (new_size > ULLONG_MAX - old_size) {
1693                         ret = -ERANGE;
1694                         goto out_free;
1695                 }
1696                 new_size = old_size + new_size;
1697         }
1698
1699         if (new_size < SZ_256M) {
1700                 ret = -EINVAL;
1701                 goto out_free;
1702         }
1703         if (new_size > device->bdev->bd_inode->i_size) {
1704                 ret = -EFBIG;
1705                 goto out_free;
1706         }
1707
1708         new_size = round_down(new_size, fs_info->sectorsize);
1709
1710         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1711                           rcu_str_deref(device->name), new_size);
1712
1713         if (new_size > old_size) {
1714                 trans = btrfs_start_transaction(root, 0);
1715                 if (IS_ERR(trans)) {
1716                         ret = PTR_ERR(trans);
1717                         goto out_free;
1718                 }
1719                 ret = btrfs_grow_device(trans, device, new_size);
1720                 btrfs_commit_transaction(trans);
1721         } else if (new_size < old_size) {
1722                 ret = btrfs_shrink_device(device, new_size);
1723         } /* equal, nothing need to do */
1724
1725 out_free:
1726         kfree(vol_args);
1727 out:
1728         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1729         mnt_drop_write_file(file);
1730         return ret;
1731 }
1732
1733 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1734                                 const char *name, unsigned long fd, int subvol,
1735                                 u64 *transid, bool readonly,
1736                                 struct btrfs_qgroup_inherit *inherit)
1737 {
1738         int namelen;
1739         int ret = 0;
1740
1741         if (!S_ISDIR(file_inode(file)->i_mode))
1742                 return -ENOTDIR;
1743
1744         ret = mnt_want_write_file(file);
1745         if (ret)
1746                 goto out;
1747
1748         namelen = strlen(name);
1749         if (strchr(name, '/')) {
1750                 ret = -EINVAL;
1751                 goto out_drop_write;
1752         }
1753
1754         if (name[0] == '.' &&
1755            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1756                 ret = -EEXIST;
1757                 goto out_drop_write;
1758         }
1759
1760         if (subvol) {
1761                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1762                                      NULL, transid, readonly, inherit);
1763         } else {
1764                 struct fd src = fdget(fd);
1765                 struct inode *src_inode;
1766                 if (!src.file) {
1767                         ret = -EINVAL;
1768                         goto out_drop_write;
1769                 }
1770
1771                 src_inode = file_inode(src.file);
1772                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1773                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1774                                    "Snapshot src from another FS");
1775                         ret = -EXDEV;
1776                 } else if (!inode_owner_or_capable(src_inode)) {
1777                         /*
1778                          * Subvolume creation is not restricted, but snapshots
1779                          * are limited to own subvolumes only
1780                          */
1781                         ret = -EPERM;
1782                 } else {
1783                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1784                                              BTRFS_I(src_inode)->root,
1785                                              transid, readonly, inherit);
1786                 }
1787                 fdput(src);
1788         }
1789 out_drop_write:
1790         mnt_drop_write_file(file);
1791 out:
1792         return ret;
1793 }
1794
1795 static noinline int btrfs_ioctl_snap_create(struct file *file,
1796                                             void __user *arg, int subvol)
1797 {
1798         struct btrfs_ioctl_vol_args *vol_args;
1799         int ret;
1800
1801         if (!S_ISDIR(file_inode(file)->i_mode))
1802                 return -ENOTDIR;
1803
1804         vol_args = memdup_user(arg, sizeof(*vol_args));
1805         if (IS_ERR(vol_args))
1806                 return PTR_ERR(vol_args);
1807         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1808
1809         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1810                                               vol_args->fd, subvol,
1811                                               NULL, false, NULL);
1812
1813         kfree(vol_args);
1814         return ret;
1815 }
1816
1817 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1818                                                void __user *arg, int subvol)
1819 {
1820         struct btrfs_ioctl_vol_args_v2 *vol_args;
1821         int ret;
1822         u64 transid = 0;
1823         u64 *ptr = NULL;
1824         bool readonly = false;
1825         struct btrfs_qgroup_inherit *inherit = NULL;
1826
1827         if (!S_ISDIR(file_inode(file)->i_mode))
1828                 return -ENOTDIR;
1829
1830         vol_args = memdup_user(arg, sizeof(*vol_args));
1831         if (IS_ERR(vol_args))
1832                 return PTR_ERR(vol_args);
1833         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1834
1835         if (vol_args->flags &
1836             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1837               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1838                 ret = -EOPNOTSUPP;
1839                 goto free_args;
1840         }
1841
1842         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1843                 ptr = &transid;
1844         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1845                 readonly = true;
1846         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1847                 if (vol_args->size > PAGE_SIZE) {
1848                         ret = -EINVAL;
1849                         goto free_args;
1850                 }
1851                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1852                 if (IS_ERR(inherit)) {
1853                         ret = PTR_ERR(inherit);
1854                         goto free_args;
1855                 }
1856         }
1857
1858         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1859                                               vol_args->fd, subvol, ptr,
1860                                               readonly, inherit);
1861         if (ret)
1862                 goto free_inherit;
1863
1864         if (ptr && copy_to_user(arg +
1865                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1866                                         transid),
1867                                 ptr, sizeof(*ptr)))
1868                 ret = -EFAULT;
1869
1870 free_inherit:
1871         kfree(inherit);
1872 free_args:
1873         kfree(vol_args);
1874         return ret;
1875 }
1876
1877 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1878                                                 void __user *arg)
1879 {
1880         struct inode *inode = file_inode(file);
1881         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1882         struct btrfs_root *root = BTRFS_I(inode)->root;
1883         int ret = 0;
1884         u64 flags = 0;
1885
1886         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1887                 return -EINVAL;
1888
1889         down_read(&fs_info->subvol_sem);
1890         if (btrfs_root_readonly(root))
1891                 flags |= BTRFS_SUBVOL_RDONLY;
1892         up_read(&fs_info->subvol_sem);
1893
1894         if (copy_to_user(arg, &flags, sizeof(flags)))
1895                 ret = -EFAULT;
1896
1897         return ret;
1898 }
1899
1900 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1901                                               void __user *arg)
1902 {
1903         struct inode *inode = file_inode(file);
1904         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1905         struct btrfs_root *root = BTRFS_I(inode)->root;
1906         struct btrfs_trans_handle *trans;
1907         u64 root_flags;
1908         u64 flags;
1909         int ret = 0;
1910
1911         if (!inode_owner_or_capable(inode))
1912                 return -EPERM;
1913
1914         ret = mnt_want_write_file(file);
1915         if (ret)
1916                 goto out;
1917
1918         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1919                 ret = -EINVAL;
1920                 goto out_drop_write;
1921         }
1922
1923         if (copy_from_user(&flags, arg, sizeof(flags))) {
1924                 ret = -EFAULT;
1925                 goto out_drop_write;
1926         }
1927
1928         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1929                 ret = -EINVAL;
1930                 goto out_drop_write;
1931         }
1932
1933         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1934                 ret = -EOPNOTSUPP;
1935                 goto out_drop_write;
1936         }
1937
1938         down_write(&fs_info->subvol_sem);
1939
1940         /* nothing to do */
1941         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1942                 goto out_drop_sem;
1943
1944         root_flags = btrfs_root_flags(&root->root_item);
1945         if (flags & BTRFS_SUBVOL_RDONLY) {
1946                 btrfs_set_root_flags(&root->root_item,
1947                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1948         } else {
1949                 /*
1950                  * Block RO -> RW transition if this subvolume is involved in
1951                  * send
1952                  */
1953                 spin_lock(&root->root_item_lock);
1954                 if (root->send_in_progress == 0) {
1955                         btrfs_set_root_flags(&root->root_item,
1956                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1957                         spin_unlock(&root->root_item_lock);
1958                 } else {
1959                         spin_unlock(&root->root_item_lock);
1960                         btrfs_warn(fs_info,
1961                                    "Attempt to set subvolume %llu read-write during send",
1962                                    root->root_key.objectid);
1963                         ret = -EPERM;
1964                         goto out_drop_sem;
1965                 }
1966         }
1967
1968         trans = btrfs_start_transaction(root, 1);
1969         if (IS_ERR(trans)) {
1970                 ret = PTR_ERR(trans);
1971                 goto out_reset;
1972         }
1973
1974         ret = btrfs_update_root(trans, fs_info->tree_root,
1975                                 &root->root_key, &root->root_item);
1976         if (ret < 0) {
1977                 btrfs_end_transaction(trans);
1978                 goto out_reset;
1979         }
1980
1981         ret = btrfs_commit_transaction(trans);
1982
1983 out_reset:
1984         if (ret)
1985                 btrfs_set_root_flags(&root->root_item, root_flags);
1986 out_drop_sem:
1987         up_write(&fs_info->subvol_sem);
1988 out_drop_write:
1989         mnt_drop_write_file(file);
1990 out:
1991         return ret;
1992 }
1993
1994 static noinline int key_in_sk(struct btrfs_key *key,
1995                               struct btrfs_ioctl_search_key *sk)
1996 {
1997         struct btrfs_key test;
1998         int ret;
1999
2000         test.objectid = sk->min_objectid;
2001         test.type = sk->min_type;
2002         test.offset = sk->min_offset;
2003
2004         ret = btrfs_comp_cpu_keys(key, &test);
2005         if (ret < 0)
2006                 return 0;
2007
2008         test.objectid = sk->max_objectid;
2009         test.type = sk->max_type;
2010         test.offset = sk->max_offset;
2011
2012         ret = btrfs_comp_cpu_keys(key, &test);
2013         if (ret > 0)
2014                 return 0;
2015         return 1;
2016 }
2017
2018 static noinline int copy_to_sk(struct btrfs_path *path,
2019                                struct btrfs_key *key,
2020                                struct btrfs_ioctl_search_key *sk,
2021                                size_t *buf_size,
2022                                char __user *ubuf,
2023                                unsigned long *sk_offset,
2024                                int *num_found)
2025 {
2026         u64 found_transid;
2027         struct extent_buffer *leaf;
2028         struct btrfs_ioctl_search_header sh;
2029         struct btrfs_key test;
2030         unsigned long item_off;
2031         unsigned long item_len;
2032         int nritems;
2033         int i;
2034         int slot;
2035         int ret = 0;
2036
2037         leaf = path->nodes[0];
2038         slot = path->slots[0];
2039         nritems = btrfs_header_nritems(leaf);
2040
2041         if (btrfs_header_generation(leaf) > sk->max_transid) {
2042                 i = nritems;
2043                 goto advance_key;
2044         }
2045         found_transid = btrfs_header_generation(leaf);
2046
2047         for (i = slot; i < nritems; i++) {
2048                 item_off = btrfs_item_ptr_offset(leaf, i);
2049                 item_len = btrfs_item_size_nr(leaf, i);
2050
2051                 btrfs_item_key_to_cpu(leaf, key, i);
2052                 if (!key_in_sk(key, sk))
2053                         continue;
2054
2055                 if (sizeof(sh) + item_len > *buf_size) {
2056                         if (*num_found) {
2057                                 ret = 1;
2058                                 goto out;
2059                         }
2060
2061                         /*
2062                          * return one empty item back for v1, which does not
2063                          * handle -EOVERFLOW
2064                          */
2065
2066                         *buf_size = sizeof(sh) + item_len;
2067                         item_len = 0;
2068                         ret = -EOVERFLOW;
2069                 }
2070
2071                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2072                         ret = 1;
2073                         goto out;
2074                 }
2075
2076                 sh.objectid = key->objectid;
2077                 sh.offset = key->offset;
2078                 sh.type = key->type;
2079                 sh.len = item_len;
2080                 sh.transid = found_transid;
2081
2082                 /* copy search result header */
2083                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2084                         ret = -EFAULT;
2085                         goto out;
2086                 }
2087
2088                 *sk_offset += sizeof(sh);
2089
2090                 if (item_len) {
2091                         char __user *up = ubuf + *sk_offset;
2092                         /* copy the item */
2093                         if (read_extent_buffer_to_user(leaf, up,
2094                                                        item_off, item_len)) {
2095                                 ret = -EFAULT;
2096                                 goto out;
2097                         }
2098
2099                         *sk_offset += item_len;
2100                 }
2101                 (*num_found)++;
2102
2103                 if (ret) /* -EOVERFLOW from above */
2104                         goto out;
2105
2106                 if (*num_found >= sk->nr_items) {
2107                         ret = 1;
2108                         goto out;
2109                 }
2110         }
2111 advance_key:
2112         ret = 0;
2113         test.objectid = sk->max_objectid;
2114         test.type = sk->max_type;
2115         test.offset = sk->max_offset;
2116         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2117                 ret = 1;
2118         else if (key->offset < (u64)-1)
2119                 key->offset++;
2120         else if (key->type < (u8)-1) {
2121                 key->offset = 0;
2122                 key->type++;
2123         } else if (key->objectid < (u64)-1) {
2124                 key->offset = 0;
2125                 key->type = 0;
2126                 key->objectid++;
2127         } else
2128                 ret = 1;
2129 out:
2130         /*
2131          *  0: all items from this leaf copied, continue with next
2132          *  1: * more items can be copied, but unused buffer is too small
2133          *     * all items were found
2134          *     Either way, it will stops the loop which iterates to the next
2135          *     leaf
2136          *  -EOVERFLOW: item was to large for buffer
2137          *  -EFAULT: could not copy extent buffer back to userspace
2138          */
2139         return ret;
2140 }
2141
2142 static noinline int search_ioctl(struct inode *inode,
2143                                  struct btrfs_ioctl_search_key *sk,
2144                                  size_t *buf_size,
2145                                  char __user *ubuf)
2146 {
2147         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2148         struct btrfs_root *root;
2149         struct btrfs_key key;
2150         struct btrfs_path *path;
2151         int ret;
2152         int num_found = 0;
2153         unsigned long sk_offset = 0;
2154
2155         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2156                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2157                 return -EOVERFLOW;
2158         }
2159
2160         path = btrfs_alloc_path();
2161         if (!path)
2162                 return -ENOMEM;
2163
2164         if (sk->tree_id == 0) {
2165                 /* search the root of the inode that was passed */
2166                 root = BTRFS_I(inode)->root;
2167         } else {
2168                 key.objectid = sk->tree_id;
2169                 key.type = BTRFS_ROOT_ITEM_KEY;
2170                 key.offset = (u64)-1;
2171                 root = btrfs_read_fs_root_no_name(info, &key);
2172                 if (IS_ERR(root)) {
2173                         btrfs_free_path(path);
2174                         return PTR_ERR(root);
2175                 }
2176         }
2177
2178         key.objectid = sk->min_objectid;
2179         key.type = sk->min_type;
2180         key.offset = sk->min_offset;
2181
2182         while (1) {
2183                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2184                 if (ret != 0) {
2185                         if (ret > 0)
2186                                 ret = 0;
2187                         goto err;
2188                 }
2189                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2190                                  &sk_offset, &num_found);
2191                 btrfs_release_path(path);
2192                 if (ret)
2193                         break;
2194
2195         }
2196         if (ret > 0)
2197                 ret = 0;
2198 err:
2199         sk->nr_items = num_found;
2200         btrfs_free_path(path);
2201         return ret;
2202 }
2203
2204 static noinline int btrfs_ioctl_tree_search(struct file *file,
2205                                            void __user *argp)
2206 {
2207         struct btrfs_ioctl_search_args __user *uargs;
2208         struct btrfs_ioctl_search_key sk;
2209         struct inode *inode;
2210         int ret;
2211         size_t buf_size;
2212
2213         if (!capable(CAP_SYS_ADMIN))
2214                 return -EPERM;
2215
2216         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2217
2218         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2219                 return -EFAULT;
2220
2221         buf_size = sizeof(uargs->buf);
2222
2223         inode = file_inode(file);
2224         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2225
2226         /*
2227          * In the origin implementation an overflow is handled by returning a
2228          * search header with a len of zero, so reset ret.
2229          */
2230         if (ret == -EOVERFLOW)
2231                 ret = 0;
2232
2233         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2234                 ret = -EFAULT;
2235         return ret;
2236 }
2237
2238 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2239                                                void __user *argp)
2240 {
2241         struct btrfs_ioctl_search_args_v2 __user *uarg;
2242         struct btrfs_ioctl_search_args_v2 args;
2243         struct inode *inode;
2244         int ret;
2245         size_t buf_size;
2246         const size_t buf_limit = SZ_16M;
2247
2248         if (!capable(CAP_SYS_ADMIN))
2249                 return -EPERM;
2250
2251         /* copy search header and buffer size */
2252         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2253         if (copy_from_user(&args, uarg, sizeof(args)))
2254                 return -EFAULT;
2255
2256         buf_size = args.buf_size;
2257
2258         /* limit result size to 16MB */
2259         if (buf_size > buf_limit)
2260                 buf_size = buf_limit;
2261
2262         inode = file_inode(file);
2263         ret = search_ioctl(inode, &args.key, &buf_size,
2264                            (char __user *)(&uarg->buf[0]));
2265         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2266                 ret = -EFAULT;
2267         else if (ret == -EOVERFLOW &&
2268                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2269                 ret = -EFAULT;
2270
2271         return ret;
2272 }
2273
2274 /*
2275  * Search INODE_REFs to identify path name of 'dirid' directory
2276  * in a 'tree_id' tree. and sets path name to 'name'.
2277  */
2278 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2279                                 u64 tree_id, u64 dirid, char *name)
2280 {
2281         struct btrfs_root *root;
2282         struct btrfs_key key;
2283         char *ptr;
2284         int ret = -1;
2285         int slot;
2286         int len;
2287         int total_len = 0;
2288         struct btrfs_inode_ref *iref;
2289         struct extent_buffer *l;
2290         struct btrfs_path *path;
2291
2292         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2293                 name[0]='\0';
2294                 return 0;
2295         }
2296
2297         path = btrfs_alloc_path();
2298         if (!path)
2299                 return -ENOMEM;
2300
2301         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2302
2303         key.objectid = tree_id;
2304         key.type = BTRFS_ROOT_ITEM_KEY;
2305         key.offset = (u64)-1;
2306         root = btrfs_read_fs_root_no_name(info, &key);
2307         if (IS_ERR(root)) {
2308                 ret = PTR_ERR(root);
2309                 goto out;
2310         }
2311
2312         key.objectid = dirid;
2313         key.type = BTRFS_INODE_REF_KEY;
2314         key.offset = (u64)-1;
2315
2316         while (1) {
2317                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2318                 if (ret < 0)
2319                         goto out;
2320                 else if (ret > 0) {
2321                         ret = btrfs_previous_item(root, path, dirid,
2322                                                   BTRFS_INODE_REF_KEY);
2323                         if (ret < 0)
2324                                 goto out;
2325                         else if (ret > 0) {
2326                                 ret = -ENOENT;
2327                                 goto out;
2328                         }
2329                 }
2330
2331                 l = path->nodes[0];
2332                 slot = path->slots[0];
2333                 btrfs_item_key_to_cpu(l, &key, slot);
2334
2335                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2336                 len = btrfs_inode_ref_name_len(l, iref);
2337                 ptr -= len + 1;
2338                 total_len += len + 1;
2339                 if (ptr < name) {
2340                         ret = -ENAMETOOLONG;
2341                         goto out;
2342                 }
2343
2344                 *(ptr + len) = '/';
2345                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2346
2347                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2348                         break;
2349
2350                 btrfs_release_path(path);
2351                 key.objectid = key.offset;
2352                 key.offset = (u64)-1;
2353                 dirid = key.objectid;
2354         }
2355         memmove(name, ptr, total_len);
2356         name[total_len] = '\0';
2357         ret = 0;
2358 out:
2359         btrfs_free_path(path);
2360         return ret;
2361 }
2362
2363 static int btrfs_search_path_in_tree_user(struct inode *inode,
2364                                 struct btrfs_ioctl_ino_lookup_user_args *args)
2365 {
2366         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2367         struct super_block *sb = inode->i_sb;
2368         struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2369         u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2370         u64 dirid = args->dirid;
2371         unsigned long item_off;
2372         unsigned long item_len;
2373         struct btrfs_inode_ref *iref;
2374         struct btrfs_root_ref *rref;
2375         struct btrfs_root *root;
2376         struct btrfs_path *path;
2377         struct btrfs_key key, key2;
2378         struct extent_buffer *leaf;
2379         struct inode *temp_inode;
2380         char *ptr;
2381         int slot;
2382         int len;
2383         int total_len = 0;
2384         int ret;
2385
2386         path = btrfs_alloc_path();
2387         if (!path)
2388                 return -ENOMEM;
2389
2390         /*
2391          * If the bottom subvolume does not exist directly under upper_limit,
2392          * construct the path in from the bottom up.
2393          */
2394         if (dirid != upper_limit.objectid) {
2395                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2396
2397                 key.objectid = treeid;
2398                 key.type = BTRFS_ROOT_ITEM_KEY;
2399                 key.offset = (u64)-1;
2400                 root = btrfs_read_fs_root_no_name(fs_info, &key);
2401                 if (IS_ERR(root)) {
2402                         ret = PTR_ERR(root);
2403                         goto out;
2404                 }
2405
2406                 key.objectid = dirid;
2407                 key.type = BTRFS_INODE_REF_KEY;
2408                 key.offset = (u64)-1;
2409                 while (1) {
2410                         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2411                         if (ret < 0) {
2412                                 goto out;
2413                         } else if (ret > 0) {
2414                                 ret = btrfs_previous_item(root, path, dirid,
2415                                                           BTRFS_INODE_REF_KEY);
2416                                 if (ret < 0) {
2417                                         goto out;
2418                                 } else if (ret > 0) {
2419                                         ret = -ENOENT;
2420                                         goto out;
2421                                 }
2422                         }
2423
2424                         leaf = path->nodes[0];
2425                         slot = path->slots[0];
2426                         btrfs_item_key_to_cpu(leaf, &key, slot);
2427
2428                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2429                         len = btrfs_inode_ref_name_len(leaf, iref);
2430                         ptr -= len + 1;
2431                         total_len += len + 1;
2432                         if (ptr < args->path) {
2433                                 ret = -ENAMETOOLONG;
2434                                 goto out;
2435                         }
2436
2437                         *(ptr + len) = '/';
2438                         read_extent_buffer(leaf, ptr,
2439                                         (unsigned long)(iref + 1), len);
2440
2441                         /* Check the read+exec permission of this directory */
2442                         ret = btrfs_previous_item(root, path, dirid,
2443                                                   BTRFS_INODE_ITEM_KEY);
2444                         if (ret < 0) {
2445                                 goto out;
2446                         } else if (ret > 0) {
2447                                 ret = -ENOENT;
2448                                 goto out;
2449                         }
2450
2451                         leaf = path->nodes[0];
2452                         slot = path->slots[0];
2453                         btrfs_item_key_to_cpu(leaf, &key2, slot);
2454                         if (key2.objectid != dirid) {
2455                                 ret = -ENOENT;
2456                                 goto out;
2457                         }
2458
2459                         temp_inode = btrfs_iget(sb, &key2, root, NULL);
2460                         if (IS_ERR(temp_inode)) {
2461                                 ret = PTR_ERR(temp_inode);
2462                                 goto out;
2463                         }
2464                         ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2465                         iput(temp_inode);
2466                         if (ret) {
2467                                 ret = -EACCES;
2468                                 goto out;
2469                         }
2470
2471                         if (key.offset == upper_limit.objectid)
2472                                 break;
2473                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2474                                 ret = -EACCES;
2475                                 goto out;
2476                         }
2477
2478                         btrfs_release_path(path);
2479                         key.objectid = key.offset;
2480                         key.offset = (u64)-1;
2481                         dirid = key.objectid;
2482                 }
2483
2484                 memmove(args->path, ptr, total_len);
2485                 args->path[total_len] = '\0';
2486                 btrfs_release_path(path);
2487         }
2488
2489         /* Get the bottom subvolume's name from ROOT_REF */
2490         root = fs_info->tree_root;
2491         key.objectid = treeid;
2492         key.type = BTRFS_ROOT_REF_KEY;
2493         key.offset = args->treeid;
2494         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2495         if (ret < 0) {
2496                 goto out;
2497         } else if (ret > 0) {
2498                 ret = -ENOENT;
2499                 goto out;
2500         }
2501
2502         leaf = path->nodes[0];
2503         slot = path->slots[0];
2504         btrfs_item_key_to_cpu(leaf, &key, slot);
2505
2506         item_off = btrfs_item_ptr_offset(leaf, slot);
2507         item_len = btrfs_item_size_nr(leaf, slot);
2508         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2509         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2510         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2511                 ret = -EINVAL;
2512                 goto out;
2513         }
2514
2515         /* Copy subvolume's name */
2516         item_off += sizeof(struct btrfs_root_ref);
2517         item_len -= sizeof(struct btrfs_root_ref);
2518         read_extent_buffer(leaf, args->name, item_off, item_len);
2519         args->name[item_len] = 0;
2520
2521 out:
2522         btrfs_free_path(path);
2523         return ret;
2524 }
2525
2526 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2527                                            void __user *argp)
2528 {
2529         struct btrfs_ioctl_ino_lookup_args *args;
2530         struct inode *inode;
2531         int ret = 0;
2532
2533         args = memdup_user(argp, sizeof(*args));
2534         if (IS_ERR(args))
2535                 return PTR_ERR(args);
2536
2537         inode = file_inode(file);
2538
2539         /*
2540          * Unprivileged query to obtain the containing subvolume root id. The
2541          * path is reset so it's consistent with btrfs_search_path_in_tree.
2542          */
2543         if (args->treeid == 0)
2544                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2545
2546         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2547                 args->name[0] = 0;
2548                 goto out;
2549         }
2550
2551         if (!capable(CAP_SYS_ADMIN)) {
2552                 ret = -EPERM;
2553                 goto out;
2554         }
2555
2556         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2557                                         args->treeid, args->objectid,
2558                                         args->name);
2559
2560 out:
2561         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2562                 ret = -EFAULT;
2563
2564         kfree(args);
2565         return ret;
2566 }
2567
2568 /*
2569  * Version of ino_lookup ioctl (unprivileged)
2570  *
2571  * The main differences from ino_lookup ioctl are:
2572  *
2573  *   1. Read + Exec permission will be checked using inode_permission() during
2574  *      path construction. -EACCES will be returned in case of failure.
2575  *   2. Path construction will be stopped at the inode number which corresponds
2576  *      to the fd with which this ioctl is called. If constructed path does not
2577  *      exist under fd's inode, -EACCES will be returned.
2578  *   3. The name of bottom subvolume is also searched and filled.
2579  */
2580 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2581 {
2582         struct btrfs_ioctl_ino_lookup_user_args *args;
2583         struct inode *inode;
2584         int ret;
2585
2586         args = memdup_user(argp, sizeof(*args));
2587         if (IS_ERR(args))
2588                 return PTR_ERR(args);
2589
2590         inode = file_inode(file);
2591
2592         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2593             BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2594                 /*
2595                  * The subvolume does not exist under fd with which this is
2596                  * called
2597                  */
2598                 kfree(args);
2599                 return -EACCES;
2600         }
2601
2602         ret = btrfs_search_path_in_tree_user(inode, args);
2603
2604         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2605                 ret = -EFAULT;
2606
2607         kfree(args);
2608         return ret;
2609 }
2610
2611 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2612 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2613 {
2614         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2615         struct btrfs_fs_info *fs_info;
2616         struct btrfs_root *root;
2617         struct btrfs_path *path;
2618         struct btrfs_key key;
2619         struct btrfs_root_item *root_item;
2620         struct btrfs_root_ref *rref;
2621         struct extent_buffer *leaf;
2622         unsigned long item_off;
2623         unsigned long item_len;
2624         struct inode *inode;
2625         int slot;
2626         int ret = 0;
2627
2628         path = btrfs_alloc_path();
2629         if (!path)
2630                 return -ENOMEM;
2631
2632         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2633         if (!subvol_info) {
2634                 btrfs_free_path(path);
2635                 return -ENOMEM;
2636         }
2637
2638         inode = file_inode(file);
2639         fs_info = BTRFS_I(inode)->root->fs_info;
2640
2641         /* Get root_item of inode's subvolume */
2642         key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2643         key.type = BTRFS_ROOT_ITEM_KEY;
2644         key.offset = (u64)-1;
2645         root = btrfs_read_fs_root_no_name(fs_info, &key);
2646         if (IS_ERR(root)) {
2647                 ret = PTR_ERR(root);
2648                 goto out;
2649         }
2650         root_item = &root->root_item;
2651
2652         subvol_info->treeid = key.objectid;
2653
2654         subvol_info->generation = btrfs_root_generation(root_item);
2655         subvol_info->flags = btrfs_root_flags(root_item);
2656
2657         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2658         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2659                                                     BTRFS_UUID_SIZE);
2660         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2661                                                     BTRFS_UUID_SIZE);
2662
2663         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2664         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2665         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2666
2667         subvol_info->otransid = btrfs_root_otransid(root_item);
2668         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2669         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2670
2671         subvol_info->stransid = btrfs_root_stransid(root_item);
2672         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2673         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2674
2675         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2676         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2677         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2678
2679         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2680                 /* Search root tree for ROOT_BACKREF of this subvolume */
2681                 root = fs_info->tree_root;
2682
2683                 key.type = BTRFS_ROOT_BACKREF_KEY;
2684                 key.offset = 0;
2685                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2686                 if (ret < 0) {
2687                         goto out;
2688                 } else if (path->slots[0] >=
2689                            btrfs_header_nritems(path->nodes[0])) {
2690                         ret = btrfs_next_leaf(root, path);
2691                         if (ret < 0) {
2692                                 goto out;
2693                         } else if (ret > 0) {
2694                                 ret = -EUCLEAN;
2695                                 goto out;
2696                         }
2697                 }
2698
2699                 leaf = path->nodes[0];
2700                 slot = path->slots[0];
2701                 btrfs_item_key_to_cpu(leaf, &key, slot);
2702                 if (key.objectid == subvol_info->treeid &&
2703                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2704                         subvol_info->parent_id = key.offset;
2705
2706                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2707                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2708
2709                         item_off = btrfs_item_ptr_offset(leaf, slot)
2710                                         + sizeof(struct btrfs_root_ref);
2711                         item_len = btrfs_item_size_nr(leaf, slot)
2712                                         - sizeof(struct btrfs_root_ref);
2713                         read_extent_buffer(leaf, subvol_info->name,
2714                                            item_off, item_len);
2715                 } else {
2716                         ret = -ENOENT;
2717                         goto out;
2718                 }
2719         }
2720
2721         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2722                 ret = -EFAULT;
2723
2724 out:
2725         btrfs_free_path(path);
2726         kzfree(subvol_info);
2727         return ret;
2728 }
2729
2730 /*
2731  * Return ROOT_REF information of the subvolume containing this inode
2732  * except the subvolume name.
2733  */
2734 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2735 {
2736         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2737         struct btrfs_root_ref *rref;
2738         struct btrfs_root *root;
2739         struct btrfs_path *path;
2740         struct btrfs_key key;
2741         struct extent_buffer *leaf;
2742         struct inode *inode;
2743         u64 objectid;
2744         int slot;
2745         int ret;
2746         u8 found;
2747
2748         path = btrfs_alloc_path();
2749         if (!path)
2750                 return -ENOMEM;
2751
2752         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2753         if (IS_ERR(rootrefs)) {
2754                 btrfs_free_path(path);
2755                 return PTR_ERR(rootrefs);
2756         }
2757
2758         inode = file_inode(file);
2759         root = BTRFS_I(inode)->root->fs_info->tree_root;
2760         objectid = BTRFS_I(inode)->root->root_key.objectid;
2761
2762         key.objectid = objectid;
2763         key.type = BTRFS_ROOT_REF_KEY;
2764         key.offset = rootrefs->min_treeid;
2765         found = 0;
2766
2767         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2768         if (ret < 0) {
2769                 goto out;
2770         } else if (path->slots[0] >=
2771                    btrfs_header_nritems(path->nodes[0])) {
2772                 ret = btrfs_next_leaf(root, path);
2773                 if (ret < 0) {
2774                         goto out;
2775                 } else if (ret > 0) {
2776                         ret = -EUCLEAN;
2777                         goto out;
2778                 }
2779         }
2780         while (1) {
2781                 leaf = path->nodes[0];
2782                 slot = path->slots[0];
2783
2784                 btrfs_item_key_to_cpu(leaf, &key, slot);
2785                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2786                         ret = 0;
2787                         goto out;
2788                 }
2789
2790                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2791                         ret = -EOVERFLOW;
2792                         goto out;
2793                 }
2794
2795                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2796                 rootrefs->rootref[found].treeid = key.offset;
2797                 rootrefs->rootref[found].dirid =
2798                                   btrfs_root_ref_dirid(leaf, rref);
2799                 found++;
2800
2801                 ret = btrfs_next_item(root, path);
2802                 if (ret < 0) {
2803                         goto out;
2804                 } else if (ret > 0) {
2805                         ret = -EUCLEAN;
2806                         goto out;
2807                 }
2808         }
2809
2810 out:
2811         if (!ret || ret == -EOVERFLOW) {
2812                 rootrefs->num_items = found;
2813                 /* update min_treeid for next search */
2814                 if (found)
2815                         rootrefs->min_treeid =
2816                                 rootrefs->rootref[found - 1].treeid + 1;
2817                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2818                         ret = -EFAULT;
2819         }
2820
2821         kfree(rootrefs);
2822         btrfs_free_path(path);
2823
2824         return ret;
2825 }
2826
2827 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2828                                              void __user *arg)
2829 {
2830         struct dentry *parent = file->f_path.dentry;
2831         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2832         struct dentry *dentry;
2833         struct inode *dir = d_inode(parent);
2834         struct inode *inode;
2835         struct btrfs_root *root = BTRFS_I(dir)->root;
2836         struct btrfs_root *dest = NULL;
2837         struct btrfs_ioctl_vol_args *vol_args;
2838         int namelen;
2839         int err = 0;
2840
2841         if (!S_ISDIR(dir->i_mode))
2842                 return -ENOTDIR;
2843
2844         vol_args = memdup_user(arg, sizeof(*vol_args));
2845         if (IS_ERR(vol_args))
2846                 return PTR_ERR(vol_args);
2847
2848         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2849         namelen = strlen(vol_args->name);
2850         if (strchr(vol_args->name, '/') ||
2851             strncmp(vol_args->name, "..", namelen) == 0) {
2852                 err = -EINVAL;
2853                 goto out;
2854         }
2855
2856         err = mnt_want_write_file(file);
2857         if (err)
2858                 goto out;
2859
2860
2861         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2862         if (err == -EINTR)
2863                 goto out_drop_write;
2864         dentry = lookup_one_len(vol_args->name, parent, namelen);
2865         if (IS_ERR(dentry)) {
2866                 err = PTR_ERR(dentry);
2867                 goto out_unlock_dir;
2868         }
2869
2870         if (d_really_is_negative(dentry)) {
2871                 err = -ENOENT;
2872                 goto out_dput;
2873         }
2874
2875         inode = d_inode(dentry);
2876         dest = BTRFS_I(inode)->root;
2877         if (!capable(CAP_SYS_ADMIN)) {
2878                 /*
2879                  * Regular user.  Only allow this with a special mount
2880                  * option, when the user has write+exec access to the
2881                  * subvol root, and when rmdir(2) would have been
2882                  * allowed.
2883                  *
2884                  * Note that this is _not_ check that the subvol is
2885                  * empty or doesn't contain data that we wouldn't
2886                  * otherwise be able to delete.
2887                  *
2888                  * Users who want to delete empty subvols should try
2889                  * rmdir(2).
2890                  */
2891                 err = -EPERM;
2892                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2893                         goto out_dput;
2894
2895                 /*
2896                  * Do not allow deletion if the parent dir is the same
2897                  * as the dir to be deleted.  That means the ioctl
2898                  * must be called on the dentry referencing the root
2899                  * of the subvol, not a random directory contained
2900                  * within it.
2901                  */
2902                 err = -EINVAL;
2903                 if (root == dest)
2904                         goto out_dput;
2905
2906                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2907                 if (err)
2908                         goto out_dput;
2909         }
2910
2911         /* check if subvolume may be deleted by a user */
2912         err = btrfs_may_delete(dir, dentry, 1);
2913         if (err)
2914                 goto out_dput;
2915
2916         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2917                 err = -EINVAL;
2918                 goto out_dput;
2919         }
2920
2921         inode_lock(inode);
2922         err = btrfs_delete_subvolume(dir, dentry);
2923         inode_unlock(inode);
2924         if (!err)
2925                 d_delete(dentry);
2926
2927 out_dput:
2928         dput(dentry);
2929 out_unlock_dir:
2930         inode_unlock(dir);
2931 out_drop_write:
2932         mnt_drop_write_file(file);
2933 out:
2934         kfree(vol_args);
2935         return err;
2936 }
2937
2938 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2939 {
2940         struct inode *inode = file_inode(file);
2941         struct btrfs_root *root = BTRFS_I(inode)->root;
2942         struct btrfs_ioctl_defrag_range_args *range;
2943         int ret;
2944
2945         ret = mnt_want_write_file(file);
2946         if (ret)
2947                 return ret;
2948
2949         if (btrfs_root_readonly(root)) {
2950                 ret = -EROFS;
2951                 goto out;
2952         }
2953
2954         switch (inode->i_mode & S_IFMT) {
2955         case S_IFDIR:
2956                 if (!capable(CAP_SYS_ADMIN)) {
2957                         ret = -EPERM;
2958                         goto out;
2959                 }
2960                 ret = btrfs_defrag_root(root);
2961                 break;
2962         case S_IFREG:
2963                 /*
2964                  * Note that this does not check the file descriptor for write
2965                  * access. This prevents defragmenting executables that are
2966                  * running and allows defrag on files open in read-only mode.
2967                  */
2968                 if (!capable(CAP_SYS_ADMIN) &&
2969                     inode_permission(inode, MAY_WRITE)) {
2970                         ret = -EPERM;
2971                         goto out;
2972                 }
2973
2974                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2975                 if (!range) {
2976                         ret = -ENOMEM;
2977                         goto out;
2978                 }
2979
2980                 if (argp) {
2981                         if (copy_from_user(range, argp,
2982                                            sizeof(*range))) {
2983                                 ret = -EFAULT;
2984                                 kfree(range);
2985                                 goto out;
2986                         }
2987                         /* compression requires us to start the IO */
2988                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2989                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2990                                 range->extent_thresh = (u32)-1;
2991                         }
2992                 } else {
2993                         /* the rest are all set to zero by kzalloc */
2994                         range->len = (u64)-1;
2995                 }
2996                 ret = btrfs_defrag_file(file_inode(file), file,
2997                                         range, BTRFS_OLDEST_GENERATION, 0);
2998                 if (ret > 0)
2999                         ret = 0;
3000                 kfree(range);
3001                 break;
3002         default:
3003                 ret = -EINVAL;
3004         }
3005 out:
3006         mnt_drop_write_file(file);
3007         return ret;
3008 }
3009
3010 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
3011 {
3012         struct btrfs_ioctl_vol_args *vol_args;
3013         int ret;
3014
3015         if (!capable(CAP_SYS_ADMIN))
3016                 return -EPERM;
3017
3018         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
3019                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3020
3021         vol_args = memdup_user(arg, sizeof(*vol_args));
3022         if (IS_ERR(vol_args)) {
3023                 ret = PTR_ERR(vol_args);
3024                 goto out;
3025         }
3026
3027         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3028         ret = btrfs_init_new_device(fs_info, vol_args->name);
3029
3030         if (!ret)
3031                 btrfs_info(fs_info, "disk added %s", vol_args->name);
3032
3033         kfree(vol_args);
3034 out:
3035         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3036         return ret;
3037 }
3038
3039 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3040 {
3041         struct inode *inode = file_inode(file);
3042         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3043         struct btrfs_ioctl_vol_args_v2 *vol_args;
3044         int ret;
3045
3046         if (!capable(CAP_SYS_ADMIN))
3047                 return -EPERM;
3048
3049         ret = mnt_want_write_file(file);
3050         if (ret)
3051                 return ret;
3052
3053         vol_args = memdup_user(arg, sizeof(*vol_args));
3054         if (IS_ERR(vol_args)) {
3055                 ret = PTR_ERR(vol_args);
3056                 goto err_drop;
3057         }
3058
3059         /* Check for compatibility reject unknown flags */
3060         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) {
3061                 ret = -EOPNOTSUPP;
3062                 goto out;
3063         }
3064
3065         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3066                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3067                 goto out;
3068         }
3069
3070         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3071                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3072         } else {
3073                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3074                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3075         }
3076         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3077
3078         if (!ret) {
3079                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3080                         btrfs_info(fs_info, "device deleted: id %llu",
3081                                         vol_args->devid);
3082                 else
3083                         btrfs_info(fs_info, "device deleted: %s",
3084                                         vol_args->name);
3085         }
3086 out:
3087         kfree(vol_args);
3088 err_drop:
3089         mnt_drop_write_file(file);
3090         return ret;
3091 }
3092
3093 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3094 {
3095         struct inode *inode = file_inode(file);
3096         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3097         struct btrfs_ioctl_vol_args *vol_args;
3098         int ret;
3099
3100         if (!capable(CAP_SYS_ADMIN))
3101                 return -EPERM;
3102
3103         ret = mnt_want_write_file(file);
3104         if (ret)
3105                 return ret;
3106
3107         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3108                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3109                 goto out_drop_write;
3110         }
3111
3112         vol_args = memdup_user(arg, sizeof(*vol_args));
3113         if (IS_ERR(vol_args)) {
3114                 ret = PTR_ERR(vol_args);
3115                 goto out;
3116         }
3117
3118         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3119         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3120
3121         if (!ret)
3122                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3123         kfree(vol_args);
3124 out:
3125         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3126 out_drop_write:
3127         mnt_drop_write_file(file);
3128
3129         return ret;
3130 }
3131
3132 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3133                                 void __user *arg)
3134 {
3135         struct btrfs_ioctl_fs_info_args *fi_args;
3136         struct btrfs_device *device;
3137         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3138         int ret = 0;
3139
3140         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3141         if (!fi_args)
3142                 return -ENOMEM;
3143
3144         rcu_read_lock();
3145         fi_args->num_devices = fs_devices->num_devices;
3146
3147         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3148                 if (device->devid > fi_args->max_id)
3149                         fi_args->max_id = device->devid;
3150         }
3151         rcu_read_unlock();
3152
3153         memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
3154         fi_args->nodesize = fs_info->nodesize;
3155         fi_args->sectorsize = fs_info->sectorsize;
3156         fi_args->clone_alignment = fs_info->sectorsize;
3157
3158         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3159                 ret = -EFAULT;
3160
3161         kfree(fi_args);
3162         return ret;
3163 }
3164
3165 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3166                                  void __user *arg)
3167 {
3168         struct btrfs_ioctl_dev_info_args *di_args;
3169         struct btrfs_device *dev;
3170         int ret = 0;
3171         char *s_uuid = NULL;
3172
3173         di_args = memdup_user(arg, sizeof(*di_args));
3174         if (IS_ERR(di_args))
3175                 return PTR_ERR(di_args);
3176
3177         if (!btrfs_is_empty_uuid(di_args->uuid))
3178                 s_uuid = di_args->uuid;
3179
3180         rcu_read_lock();
3181         dev = btrfs_find_device(fs_info->fs_devices, di_args->devid, s_uuid,
3182                                 NULL, true);
3183
3184         if (!dev) {
3185                 ret = -ENODEV;
3186                 goto out;
3187         }
3188
3189         di_args->devid = dev->devid;
3190         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3191         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3192         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3193         if (dev->name) {
3194                 strncpy(di_args->path, rcu_str_deref(dev->name),
3195                                 sizeof(di_args->path) - 1);
3196                 di_args->path[sizeof(di_args->path) - 1] = 0;
3197         } else {
3198                 di_args->path[0] = '\0';
3199         }
3200
3201 out:
3202         rcu_read_unlock();
3203         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3204                 ret = -EFAULT;
3205
3206         kfree(di_args);
3207         return ret;
3208 }
3209
3210 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
3211                                        struct inode *inode2, u64 loff2, u64 len)
3212 {
3213         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3214         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3215 }
3216
3217 static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
3218                                      struct inode *inode2, u64 loff2, u64 len)
3219 {
3220         if (inode1 < inode2) {
3221                 swap(inode1, inode2);
3222                 swap(loff1, loff2);
3223         } else if (inode1 == inode2 && loff2 < loff1) {
3224                 swap(loff1, loff2);
3225         }
3226         lock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3227         lock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3228 }
3229
3230 static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len,
3231                                    struct inode *dst, u64 dst_loff)
3232 {
3233         int ret;
3234
3235         /*
3236          * Lock destination range to serialize with concurrent readpages() and
3237          * source range to serialize with relocation.
3238          */
3239         btrfs_double_extent_lock(src, loff, dst, dst_loff, len);
3240         ret = btrfs_clone(src, dst, loff, len, len, dst_loff, 1);
3241         btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3242
3243         return ret;
3244 }
3245
3246 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3247
3248 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3249                              struct inode *dst, u64 dst_loff)
3250 {
3251         int ret;
3252         u64 i, tail_len, chunk_count;
3253
3254         tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
3255         chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
3256
3257         for (i = 0; i < chunk_count; i++) {
3258                 ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
3259                                               dst, dst_loff);
3260                 if (ret)
3261                         return ret;
3262
3263                 loff += BTRFS_MAX_DEDUPE_LEN;
3264                 dst_loff += BTRFS_MAX_DEDUPE_LEN;
3265         }
3266
3267         if (tail_len > 0)
3268                 ret = btrfs_extent_same_range(src, loff, tail_len, dst,
3269                                               dst_loff);
3270
3271         return ret;
3272 }
3273
3274 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3275                                      struct inode *inode,
3276                                      u64 endoff,
3277                                      const u64 destoff,
3278                                      const u64 olen,
3279                                      int no_time_update)
3280 {
3281         struct btrfs_root *root = BTRFS_I(inode)->root;
3282         int ret;
3283
3284         inode_inc_iversion(inode);
3285         if (!no_time_update)
3286                 inode->i_mtime = inode->i_ctime = current_time(inode);
3287         /*
3288          * We round up to the block size at eof when determining which
3289          * extents to clone above, but shouldn't round up the file size.
3290          */
3291         if (endoff > destoff + olen)
3292                 endoff = destoff + olen;
3293         if (endoff > inode->i_size)
3294                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3295
3296         ret = btrfs_update_inode(trans, root, inode);
3297         if (ret) {
3298                 btrfs_abort_transaction(trans, ret);
3299                 btrfs_end_transaction(trans);
3300                 goto out;
3301         }
3302         ret = btrfs_end_transaction(trans);
3303 out:
3304         return ret;
3305 }
3306
3307 static void clone_update_extent_map(struct btrfs_inode *inode,
3308                                     const struct btrfs_trans_handle *trans,
3309                                     const struct btrfs_path *path,
3310                                     const u64 hole_offset,
3311                                     const u64 hole_len)
3312 {
3313         struct extent_map_tree *em_tree = &inode->extent_tree;
3314         struct extent_map *em;
3315         int ret;
3316
3317         em = alloc_extent_map();
3318         if (!em) {
3319                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3320                 return;
3321         }
3322
3323         if (path) {
3324                 struct btrfs_file_extent_item *fi;
3325
3326                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3327                                     struct btrfs_file_extent_item);
3328                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3329                 em->generation = -1;
3330                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3331                     BTRFS_FILE_EXTENT_INLINE)
3332                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3333                                         &inode->runtime_flags);
3334         } else {
3335                 em->start = hole_offset;
3336                 em->len = hole_len;
3337                 em->ram_bytes = em->len;
3338                 em->orig_start = hole_offset;
3339                 em->block_start = EXTENT_MAP_HOLE;
3340                 em->block_len = 0;
3341                 em->orig_block_len = 0;
3342                 em->compress_type = BTRFS_COMPRESS_NONE;
3343                 em->generation = trans->transid;
3344         }
3345
3346         while (1) {
3347                 write_lock(&em_tree->lock);
3348                 ret = add_extent_mapping(em_tree, em, 1);
3349                 write_unlock(&em_tree->lock);
3350                 if (ret != -EEXIST) {
3351                         free_extent_map(em);
3352                         break;
3353                 }
3354                 btrfs_drop_extent_cache(inode, em->start,
3355                                         em->start + em->len - 1, 0);
3356         }
3357
3358         if (ret)
3359                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3360 }
3361
3362 /*
3363  * Make sure we do not end up inserting an inline extent into a file that has
3364  * already other (non-inline) extents. If a file has an inline extent it can
3365  * not have any other extents and the (single) inline extent must start at the
3366  * file offset 0. Failing to respect these rules will lead to file corruption,
3367  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3368  *
3369  * We can have extents that have been already written to disk or we can have
3370  * dirty ranges still in delalloc, in which case the extent maps and items are
3371  * created only when we run delalloc, and the delalloc ranges might fall outside
3372  * the range we are currently locking in the inode's io tree. So we check the
3373  * inode's i_size because of that (i_size updates are done while holding the
3374  * i_mutex, which we are holding here).
3375  * We also check to see if the inode has a size not greater than "datal" but has
3376  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3377  * protected against such concurrent fallocate calls by the i_mutex).
3378  *
3379  * If the file has no extents but a size greater than datal, do not allow the
3380  * copy because we would need turn the inline extent into a non-inline one (even
3381  * with NO_HOLES enabled). If we find our destination inode only has one inline
3382  * extent, just overwrite it with the source inline extent if its size is less
3383  * than the source extent's size, or we could copy the source inline extent's
3384  * data into the destination inode's inline extent if the later is greater then
3385  * the former.
3386  */
3387 static int clone_copy_inline_extent(struct inode *dst,
3388                                     struct btrfs_trans_handle *trans,
3389                                     struct btrfs_path *path,
3390                                     struct btrfs_key *new_key,
3391                                     const u64 drop_start,
3392                                     const u64 datal,
3393                                     const u64 skip,
3394                                     const u64 size,
3395                                     char *inline_data)
3396 {
3397         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3398         struct btrfs_root *root = BTRFS_I(dst)->root;
3399         const u64 aligned_end = ALIGN(new_key->offset + datal,
3400                                       fs_info->sectorsize);
3401         int ret;
3402         struct btrfs_key key;
3403
3404         if (new_key->offset > 0)
3405                 return -EOPNOTSUPP;
3406
3407         key.objectid = btrfs_ino(BTRFS_I(dst));
3408         key.type = BTRFS_EXTENT_DATA_KEY;
3409         key.offset = 0;
3410         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3411         if (ret < 0) {
3412                 return ret;
3413         } else if (ret > 0) {
3414                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3415                         ret = btrfs_next_leaf(root, path);
3416                         if (ret < 0)
3417                                 return ret;
3418                         else if (ret > 0)
3419                                 goto copy_inline_extent;
3420                 }
3421                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3422                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3423                     key.type == BTRFS_EXTENT_DATA_KEY) {
3424                         ASSERT(key.offset > 0);
3425                         return -EOPNOTSUPP;
3426                 }
3427         } else if (i_size_read(dst) <= datal) {
3428                 struct btrfs_file_extent_item *ei;
3429                 u64 ext_len;
3430
3431                 /*
3432                  * If the file size is <= datal, make sure there are no other
3433                  * extents following (can happen do to an fallocate call with
3434                  * the flag FALLOC_FL_KEEP_SIZE).
3435                  */
3436                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3437                                     struct btrfs_file_extent_item);
3438                 /*
3439                  * If it's an inline extent, it can not have other extents
3440                  * following it.
3441                  */
3442                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3443                     BTRFS_FILE_EXTENT_INLINE)
3444                         goto copy_inline_extent;
3445
3446                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3447                 if (ext_len > aligned_end)
3448                         return -EOPNOTSUPP;
3449
3450                 ret = btrfs_next_item(root, path);
3451                 if (ret < 0) {
3452                         return ret;
3453                 } else if (ret == 0) {
3454                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3455                                               path->slots[0]);
3456                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3457                             key.type == BTRFS_EXTENT_DATA_KEY)
3458                                 return -EOPNOTSUPP;
3459                 }
3460         }
3461
3462 copy_inline_extent:
3463         /*
3464          * We have no extent items, or we have an extent at offset 0 which may
3465          * or may not be inlined. All these cases are dealt the same way.
3466          */
3467         if (i_size_read(dst) > datal) {
3468                 /*
3469                  * If the destination inode has an inline extent...
3470                  * This would require copying the data from the source inline
3471                  * extent into the beginning of the destination's inline extent.
3472                  * But this is really complex, both extents can be compressed
3473                  * or just one of them, which would require decompressing and
3474                  * re-compressing data (which could increase the new compressed
3475                  * size, not allowing the compressed data to fit anymore in an
3476                  * inline extent).
3477                  * So just don't support this case for now (it should be rare,
3478                  * we are not really saving space when cloning inline extents).
3479                  */
3480                 return -EOPNOTSUPP;
3481         }
3482
3483         btrfs_release_path(path);
3484         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3485         if (ret)
3486                 return ret;
3487         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3488         if (ret)
3489                 return ret;
3490
3491         if (skip) {
3492                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3493
3494                 memmove(inline_data + start, inline_data + start + skip, datal);
3495         }
3496
3497         write_extent_buffer(path->nodes[0], inline_data,
3498                             btrfs_item_ptr_offset(path->nodes[0],
3499                                                   path->slots[0]),
3500                             size);
3501         inode_add_bytes(dst, datal);
3502
3503         return 0;
3504 }
3505
3506 /**
3507  * btrfs_clone() - clone a range from inode file to another
3508  *
3509  * @src: Inode to clone from
3510  * @inode: Inode to clone to
3511  * @off: Offset within source to start clone from
3512  * @olen: Original length, passed by user, of range to clone
3513  * @olen_aligned: Block-aligned value of olen
3514  * @destoff: Offset within @inode to start clone
3515  * @no_time_update: Whether to update mtime/ctime on the target inode
3516  */
3517 static int btrfs_clone(struct inode *src, struct inode *inode,
3518                        const u64 off, const u64 olen, const u64 olen_aligned,
3519                        const u64 destoff, int no_time_update)
3520 {
3521         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3522         struct btrfs_root *root = BTRFS_I(inode)->root;
3523         struct btrfs_path *path = NULL;
3524         struct extent_buffer *leaf;
3525         struct btrfs_trans_handle *trans;
3526         char *buf = NULL;
3527         struct btrfs_key key;
3528         u32 nritems;
3529         int slot;
3530         int ret;
3531         const u64 len = olen_aligned;
3532         u64 last_dest_end = destoff;
3533
3534         ret = -ENOMEM;
3535         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3536         if (!buf)
3537                 return ret;
3538
3539         path = btrfs_alloc_path();
3540         if (!path) {
3541                 kvfree(buf);
3542                 return ret;
3543         }
3544
3545         path->reada = READA_FORWARD;
3546         /* clone data */
3547         key.objectid = btrfs_ino(BTRFS_I(src));
3548         key.type = BTRFS_EXTENT_DATA_KEY;
3549         key.offset = off;
3550
3551         while (1) {
3552                 u64 next_key_min_offset = key.offset + 1;
3553
3554                 /*
3555                  * note the key will change type as we walk through the
3556                  * tree.
3557                  */
3558                 path->leave_spinning = 1;
3559                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3560                                 0, 0);
3561                 if (ret < 0)
3562                         goto out;
3563                 /*
3564                  * First search, if no extent item that starts at offset off was
3565                  * found but the previous item is an extent item, it's possible
3566                  * it might overlap our target range, therefore process it.
3567                  */
3568                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3569                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3570                                               path->slots[0] - 1);
3571                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3572                                 path->slots[0]--;
3573                 }
3574
3575                 nritems = btrfs_header_nritems(path->nodes[0]);
3576 process_slot:
3577                 if (path->slots[0] >= nritems) {
3578                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3579                         if (ret < 0)
3580                                 goto out;
3581                         if (ret > 0)
3582                                 break;
3583                         nritems = btrfs_header_nritems(path->nodes[0]);
3584                 }
3585                 leaf = path->nodes[0];
3586                 slot = path->slots[0];
3587
3588                 btrfs_item_key_to_cpu(leaf, &key, slot);
3589                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3590                     key.objectid != btrfs_ino(BTRFS_I(src)))
3591                         break;
3592
3593                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3594                         struct btrfs_file_extent_item *extent;
3595                         int type;
3596                         u32 size;
3597                         struct btrfs_key new_key;
3598                         u64 disko = 0, diskl = 0;
3599                         u64 datao = 0, datal = 0;
3600                         u8 comp;
3601                         u64 drop_start;
3602
3603                         extent = btrfs_item_ptr(leaf, slot,
3604                                                 struct btrfs_file_extent_item);
3605                         comp = btrfs_file_extent_compression(leaf, extent);
3606                         type = btrfs_file_extent_type(leaf, extent);
3607                         if (type == BTRFS_FILE_EXTENT_REG ||
3608                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3609                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3610                                                                       extent);
3611                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3612                                                                  extent);
3613                                 datao = btrfs_file_extent_offset(leaf, extent);
3614                                 datal = btrfs_file_extent_num_bytes(leaf,
3615                                                                     extent);
3616                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3617                                 /* take upper bound, may be compressed */
3618                                 datal = btrfs_file_extent_ram_bytes(leaf,
3619                                                                     extent);
3620                         }
3621
3622                         /*
3623                          * The first search might have left us at an extent
3624                          * item that ends before our target range's start, can
3625                          * happen if we have holes and NO_HOLES feature enabled.
3626                          */
3627                         if (key.offset + datal <= off) {
3628                                 path->slots[0]++;
3629                                 goto process_slot;
3630                         } else if (key.offset >= off + len) {
3631                                 break;
3632                         }
3633                         next_key_min_offset = key.offset + datal;
3634                         size = btrfs_item_size_nr(leaf, slot);
3635                         read_extent_buffer(leaf, buf,
3636                                            btrfs_item_ptr_offset(leaf, slot),
3637                                            size);
3638
3639                         btrfs_release_path(path);
3640                         path->leave_spinning = 0;
3641
3642                         memcpy(&new_key, &key, sizeof(new_key));
3643                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
3644                         if (off <= key.offset)
3645                                 new_key.offset = key.offset + destoff - off;
3646                         else
3647                                 new_key.offset = destoff;
3648
3649                         /*
3650                          * Deal with a hole that doesn't have an extent item
3651                          * that represents it (NO_HOLES feature enabled).
3652                          * This hole is either in the middle of the cloning
3653                          * range or at the beginning (fully overlaps it or
3654                          * partially overlaps it).
3655                          */
3656                         if (new_key.offset != last_dest_end)
3657                                 drop_start = last_dest_end;
3658                         else
3659                                 drop_start = new_key.offset;
3660
3661                         /*
3662                          * 1 - adjusting old extent (we may have to split it)
3663                          * 1 - add new extent
3664                          * 1 - inode update
3665                          */
3666                         trans = btrfs_start_transaction(root, 3);
3667                         if (IS_ERR(trans)) {
3668                                 ret = PTR_ERR(trans);
3669                                 goto out;
3670                         }
3671
3672                         if (type == BTRFS_FILE_EXTENT_REG ||
3673                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3674                                 /*
3675                                  *    a  | --- range to clone ---|  b
3676                                  * | ------------- extent ------------- |
3677                                  */
3678
3679                                 /* subtract range b */
3680                                 if (key.offset + datal > off + len)
3681                                         datal = off + len - key.offset;
3682
3683                                 /* subtract range a */
3684                                 if (off > key.offset) {
3685                                         datao += off - key.offset;
3686                                         datal -= off - key.offset;
3687                                 }
3688
3689                                 ret = btrfs_drop_extents(trans, root, inode,
3690                                                          drop_start,
3691                                                          new_key.offset + datal,
3692                                                          1);
3693                                 if (ret) {
3694                                         if (ret != -EOPNOTSUPP)
3695                                                 btrfs_abort_transaction(trans,
3696                                                                         ret);
3697                                         btrfs_end_transaction(trans);
3698                                         goto out;
3699                                 }
3700
3701                                 ret = btrfs_insert_empty_item(trans, root, path,
3702                                                               &new_key, size);
3703                                 if (ret) {
3704                                         btrfs_abort_transaction(trans, ret);
3705                                         btrfs_end_transaction(trans);
3706                                         goto out;
3707                                 }
3708
3709                                 leaf = path->nodes[0];
3710                                 slot = path->slots[0];
3711                                 write_extent_buffer(leaf, buf,
3712                                             btrfs_item_ptr_offset(leaf, slot),
3713                                             size);
3714
3715                                 extent = btrfs_item_ptr(leaf, slot,
3716                                                 struct btrfs_file_extent_item);
3717
3718                                 /* disko == 0 means it's a hole */
3719                                 if (!disko)
3720                                         datao = 0;
3721
3722                                 btrfs_set_file_extent_offset(leaf, extent,
3723                                                              datao);
3724                                 btrfs_set_file_extent_num_bytes(leaf, extent,
3725                                                                 datal);
3726
3727                                 if (disko) {
3728                                         inode_add_bytes(inode, datal);
3729                                         ret = btrfs_inc_extent_ref(trans,
3730                                                         root,
3731                                                         disko, diskl, 0,
3732                                                         root->root_key.objectid,
3733                                                         btrfs_ino(BTRFS_I(inode)),
3734                                                         new_key.offset - datao);
3735                                         if (ret) {
3736                                                 btrfs_abort_transaction(trans,
3737                                                                         ret);
3738                                                 btrfs_end_transaction(trans);
3739                                                 goto out;
3740
3741                                         }
3742                                 }
3743                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3744                                 u64 skip = 0;
3745                                 u64 trim = 0;
3746
3747                                 if (off > key.offset) {
3748                                         skip = off - key.offset;
3749                                         new_key.offset += skip;
3750                                 }
3751
3752                                 if (key.offset + datal > off + len)
3753                                         trim = key.offset + datal - (off + len);
3754
3755                                 if (comp && (skip || trim)) {
3756                                         ret = -EINVAL;
3757                                         btrfs_end_transaction(trans);
3758                                         goto out;
3759                                 }
3760                                 size -= skip + trim;
3761                                 datal -= skip + trim;
3762
3763                                 ret = clone_copy_inline_extent(inode,
3764                                                                trans, path,
3765                                                                &new_key,
3766                                                                drop_start,
3767                                                                datal,
3768                                                                skip, size, buf);
3769                                 if (ret) {
3770                                         if (ret != -EOPNOTSUPP)
3771                                                 btrfs_abort_transaction(trans,
3772                                                                         ret);
3773                                         btrfs_end_transaction(trans);
3774                                         goto out;
3775                                 }
3776                                 leaf = path->nodes[0];
3777                                 slot = path->slots[0];
3778                         }
3779
3780                         /* If we have an implicit hole (NO_HOLES feature). */
3781                         if (drop_start < new_key.offset)
3782                                 clone_update_extent_map(BTRFS_I(inode), trans,
3783                                                 NULL, drop_start,
3784                                                 new_key.offset - drop_start);
3785
3786                         clone_update_extent_map(BTRFS_I(inode), trans,
3787                                         path, 0, 0);
3788
3789                         btrfs_mark_buffer_dirty(leaf);
3790                         btrfs_release_path(path);
3791
3792                         last_dest_end = ALIGN(new_key.offset + datal,
3793                                               fs_info->sectorsize);
3794                         ret = clone_finish_inode_update(trans, inode,
3795                                                         last_dest_end,
3796                                                         destoff, olen,
3797                                                         no_time_update);
3798                         if (ret)
3799                                 goto out;
3800                         if (new_key.offset + datal >= destoff + len)
3801                                 break;
3802                 }
3803                 btrfs_release_path(path);
3804                 key.offset = next_key_min_offset;
3805
3806                 if (fatal_signal_pending(current)) {
3807                         ret = -EINTR;
3808                         goto out;
3809                 }
3810         }
3811         ret = 0;
3812
3813         if (last_dest_end < destoff + len) {
3814                 /*
3815                  * We have an implicit hole (NO_HOLES feature is enabled) that
3816                  * fully or partially overlaps our cloning range at its end.
3817                  */
3818                 btrfs_release_path(path);
3819
3820                 /*
3821                  * 1 - remove extent(s)
3822                  * 1 - inode update
3823                  */
3824                 trans = btrfs_start_transaction(root, 2);
3825                 if (IS_ERR(trans)) {
3826                         ret = PTR_ERR(trans);
3827                         goto out;
3828                 }
3829                 ret = btrfs_drop_extents(trans, root, inode,
3830                                          last_dest_end, destoff + len, 1);
3831                 if (ret) {
3832                         if (ret != -EOPNOTSUPP)
3833                                 btrfs_abort_transaction(trans, ret);
3834                         btrfs_end_transaction(trans);
3835                         goto out;
3836                 }
3837                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
3838                                 last_dest_end,
3839                                 destoff + len - last_dest_end);
3840                 ret = clone_finish_inode_update(trans, inode, destoff + len,
3841                                                 destoff, olen, no_time_update);
3842         }
3843
3844 out:
3845         btrfs_free_path(path);
3846         kvfree(buf);
3847         return ret;
3848 }
3849
3850 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3851                                         u64 off, u64 olen, u64 destoff)
3852 {
3853         struct inode *inode = file_inode(file);
3854         struct inode *src = file_inode(file_src);
3855         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3856         int ret;
3857         u64 len = olen;
3858         u64 bs = fs_info->sb->s_blocksize;
3859
3860         /*
3861          * TODO:
3862          * - split compressed inline extents.  annoying: we need to
3863          *   decompress into destination's address_space (the file offset
3864          *   may change, so source mapping won't do), then recompress (or
3865          *   otherwise reinsert) a subrange.
3866          *
3867          * - split destination inode's inline extents.  The inline extents can
3868          *   be either compressed or non-compressed.
3869          */
3870
3871         /*
3872          * VFS's generic_remap_file_range_prep() protects us from cloning the
3873          * eof block into the middle of a file, which would result in corruption
3874          * if the file size is not blocksize aligned. So we don't need to check
3875          * for that case here.
3876          */
3877         if (off + len == src->i_size)
3878                 len = ALIGN(src->i_size, bs) - off;
3879
3880         if (destoff > inode->i_size) {
3881                 const u64 wb_start = ALIGN_DOWN(inode->i_size, bs);
3882
3883                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3884                 if (ret)
3885                         return ret;
3886                 /*
3887                  * We may have truncated the last block if the inode's size is
3888                  * not sector size aligned, so we need to wait for writeback to
3889                  * complete before proceeding further, otherwise we can race
3890                  * with cloning and attempt to increment a reference to an
3891                  * extent that no longer exists (writeback completed right after
3892                  * we found the previous extent covering eof and before we
3893                  * attempted to increment its reference count).
3894                  */
3895                 ret = btrfs_wait_ordered_range(inode, wb_start,
3896                                                destoff - wb_start);
3897                 if (ret)
3898                         return ret;
3899         }
3900
3901         /*
3902          * Lock destination range to serialize with concurrent readpages() and
3903          * source range to serialize with relocation.
3904          */
3905         btrfs_double_extent_lock(src, off, inode, destoff, len);
3906         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3907         btrfs_double_extent_unlock(src, off, inode, destoff, len);
3908         /*
3909          * Truncate page cache pages so that future reads will see the cloned
3910          * data immediately and not the previous data.
3911          */
3912         truncate_inode_pages_range(&inode->i_data,
3913                                 round_down(destoff, PAGE_SIZE),
3914                                 round_up(destoff + len, PAGE_SIZE) - 1);
3915
3916         return ret;
3917 }
3918
3919 static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
3920                                        struct file *file_out, loff_t pos_out,
3921                                        loff_t *len, unsigned int remap_flags)
3922 {
3923         struct inode *inode_in = file_inode(file_in);
3924         struct inode *inode_out = file_inode(file_out);
3925         u64 bs = BTRFS_I(inode_out)->root->fs_info->sb->s_blocksize;
3926         bool same_inode = inode_out == inode_in;
3927         u64 wb_len;
3928         int ret;
3929
3930         if (!(remap_flags & REMAP_FILE_DEDUP)) {
3931                 struct btrfs_root *root_out = BTRFS_I(inode_out)->root;
3932
3933                 if (btrfs_root_readonly(root_out))
3934                         return -EROFS;
3935
3936                 if (file_in->f_path.mnt != file_out->f_path.mnt ||
3937                     inode_in->i_sb != inode_out->i_sb)
3938                         return -EXDEV;
3939         }
3940
3941         if (same_inode)
3942                 inode_lock(inode_in);
3943         else
3944                 lock_two_nondirectories(inode_in, inode_out);
3945
3946         /* don't make the dst file partly checksummed */
3947         if ((BTRFS_I(inode_in)->flags & BTRFS_INODE_NODATASUM) !=
3948             (BTRFS_I(inode_out)->flags & BTRFS_INODE_NODATASUM)) {
3949                 ret = -EINVAL;
3950                 goto out_unlock;
3951         }
3952
3953         /*
3954          * Now that the inodes are locked, we need to start writeback ourselves
3955          * and can not rely on the writeback from the VFS's generic helper
3956          * generic_remap_file_range_prep() because:
3957          *
3958          * 1) For compression we must call filemap_fdatawrite_range() range
3959          *    twice (btrfs_fdatawrite_range() does it for us), and the generic
3960          *    helper only calls it once;
3961          *
3962          * 2) filemap_fdatawrite_range(), called by the generic helper only
3963          *    waits for the writeback to complete, i.e. for IO to be done, and
3964          *    not for the ordered extents to complete. We need to wait for them
3965          *    to complete so that new file extent items are in the fs tree.
3966          */
3967         if (*len == 0 && !(remap_flags & REMAP_FILE_DEDUP))
3968                 wb_len = ALIGN(inode_in->i_size, bs) - ALIGN_DOWN(pos_in, bs);
3969         else
3970                 wb_len = ALIGN(*len, bs);
3971
3972         /*
3973          * Since we don't lock ranges, wait for ongoing lockless dio writes (as
3974          * any in progress could create its ordered extents after we wait for
3975          * existing ordered extents below).
3976          */
3977         inode_dio_wait(inode_in);
3978         if (!same_inode)
3979                 inode_dio_wait(inode_out);
3980
3981         ret = btrfs_wait_ordered_range(inode_in, ALIGN_DOWN(pos_in, bs),
3982                                        wb_len);
3983         if (ret < 0)
3984                 goto out_unlock;
3985         ret = btrfs_wait_ordered_range(inode_out, ALIGN_DOWN(pos_out, bs),
3986                                        wb_len);
3987         if (ret < 0)
3988                 goto out_unlock;
3989
3990         ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
3991                                             len, remap_flags);
3992         if (ret < 0 || *len == 0)
3993                 goto out_unlock;
3994
3995         return 0;
3996
3997  out_unlock:
3998         if (same_inode)
3999                 inode_unlock(inode_in);
4000         else
4001                 unlock_two_nondirectories(inode_in, inode_out);
4002
4003         return ret;
4004 }
4005
4006 loff_t btrfs_remap_file_range(struct file *src_file, loff_t off,
4007                 struct file *dst_file, loff_t destoff, loff_t len,
4008                 unsigned int remap_flags)
4009 {
4010         struct inode *src_inode = file_inode(src_file);
4011         struct inode *dst_inode = file_inode(dst_file);
4012         bool same_inode = dst_inode == src_inode;
4013         int ret;
4014
4015         if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
4016                 return -EINVAL;
4017
4018         ret = btrfs_remap_file_range_prep(src_file, off, dst_file, destoff,
4019                                           &len, remap_flags);
4020         if (ret < 0 || len == 0)
4021                 return ret;
4022
4023         if (remap_flags & REMAP_FILE_DEDUP)
4024                 ret = btrfs_extent_same(src_inode, off, len, dst_inode, destoff);
4025         else
4026                 ret = btrfs_clone_files(dst_file, src_file, off, len, destoff);
4027
4028         if (same_inode)
4029                 inode_unlock(src_inode);
4030         else
4031                 unlock_two_nondirectories(src_inode, dst_inode);
4032
4033         return ret < 0 ? ret : len;
4034 }
4035
4036 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4037 {
4038         struct inode *inode = file_inode(file);
4039         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4040         struct btrfs_root *root = BTRFS_I(inode)->root;
4041         struct btrfs_root *new_root;
4042         struct btrfs_dir_item *di;
4043         struct btrfs_trans_handle *trans;
4044         struct btrfs_path *path;
4045         struct btrfs_key location;
4046         struct btrfs_disk_key disk_key;
4047         u64 objectid = 0;
4048         u64 dir_id;
4049         int ret;
4050
4051         if (!capable(CAP_SYS_ADMIN))
4052                 return -EPERM;
4053
4054         ret = mnt_want_write_file(file);
4055         if (ret)
4056                 return ret;
4057
4058         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4059                 ret = -EFAULT;
4060                 goto out;
4061         }
4062
4063         if (!objectid)
4064                 objectid = BTRFS_FS_TREE_OBJECTID;
4065
4066         location.objectid = objectid;
4067         location.type = BTRFS_ROOT_ITEM_KEY;
4068         location.offset = (u64)-1;
4069
4070         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4071         if (IS_ERR(new_root)) {
4072                 ret = PTR_ERR(new_root);
4073                 goto out;
4074         }
4075         if (!is_fstree(new_root->root_key.objectid)) {
4076                 ret = -ENOENT;
4077                 goto out;
4078         }
4079
4080         path = btrfs_alloc_path();
4081         if (!path) {
4082                 ret = -ENOMEM;
4083                 goto out;
4084         }
4085         path->leave_spinning = 1;
4086
4087         trans = btrfs_start_transaction(root, 1);
4088         if (IS_ERR(trans)) {
4089                 btrfs_free_path(path);
4090                 ret = PTR_ERR(trans);
4091                 goto out;
4092         }
4093
4094         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4095         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4096                                    dir_id, "default", 7, 1);
4097         if (IS_ERR_OR_NULL(di)) {
4098                 btrfs_free_path(path);
4099                 btrfs_end_transaction(trans);
4100                 btrfs_err(fs_info,
4101                           "Umm, you don't have the default diritem, this isn't going to work");
4102                 ret = -ENOENT;
4103                 goto out;
4104         }
4105
4106         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4107         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4108         btrfs_mark_buffer_dirty(path->nodes[0]);
4109         btrfs_free_path(path);
4110
4111         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4112         btrfs_end_transaction(trans);
4113 out:
4114         mnt_drop_write_file(file);
4115         return ret;
4116 }
4117
4118 static void get_block_group_info(struct list_head *groups_list,
4119                                  struct btrfs_ioctl_space_info *space)
4120 {
4121         struct btrfs_block_group_cache *block_group;
4122
4123         space->total_bytes = 0;
4124         space->used_bytes = 0;
4125         space->flags = 0;
4126         list_for_each_entry(block_group, groups_list, list) {
4127                 space->flags = block_group->flags;
4128                 space->total_bytes += block_group->key.offset;
4129                 space->used_bytes +=
4130                         btrfs_block_group_used(&block_group->item);
4131         }
4132 }
4133
4134 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4135                                    void __user *arg)
4136 {
4137         struct btrfs_ioctl_space_args space_args;
4138         struct btrfs_ioctl_space_info space;
4139         struct btrfs_ioctl_space_info *dest;
4140         struct btrfs_ioctl_space_info *dest_orig;
4141         struct btrfs_ioctl_space_info __user *user_dest;
4142         struct btrfs_space_info *info;
4143         static const u64 types[] = {
4144                 BTRFS_BLOCK_GROUP_DATA,
4145                 BTRFS_BLOCK_GROUP_SYSTEM,
4146                 BTRFS_BLOCK_GROUP_METADATA,
4147                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4148         };
4149         int num_types = 4;
4150         int alloc_size;
4151         int ret = 0;
4152         u64 slot_count = 0;
4153         int i, c;
4154
4155         if (copy_from_user(&space_args,
4156                            (struct btrfs_ioctl_space_args __user *)arg,
4157                            sizeof(space_args)))
4158                 return -EFAULT;
4159
4160         for (i = 0; i < num_types; i++) {
4161                 struct btrfs_space_info *tmp;
4162
4163                 info = NULL;
4164                 rcu_read_lock();
4165                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4166                                         list) {
4167                         if (tmp->flags == types[i]) {
4168                                 info = tmp;
4169                                 break;
4170                         }
4171                 }
4172                 rcu_read_unlock();
4173
4174                 if (!info)
4175                         continue;
4176
4177                 down_read(&info->groups_sem);
4178                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4179                         if (!list_empty(&info->block_groups[c]))
4180                                 slot_count++;
4181                 }
4182                 up_read(&info->groups_sem);
4183         }
4184
4185         /*
4186          * Global block reserve, exported as a space_info
4187          */
4188         slot_count++;
4189
4190         /* space_slots == 0 means they are asking for a count */
4191         if (space_args.space_slots == 0) {
4192                 space_args.total_spaces = slot_count;
4193                 goto out;
4194         }
4195
4196         slot_count = min_t(u64, space_args.space_slots, slot_count);
4197
4198         alloc_size = sizeof(*dest) * slot_count;
4199
4200         /* we generally have at most 6 or so space infos, one for each raid
4201          * level.  So, a whole page should be more than enough for everyone
4202          */
4203         if (alloc_size > PAGE_SIZE)
4204                 return -ENOMEM;
4205
4206         space_args.total_spaces = 0;
4207         dest = kmalloc(alloc_size, GFP_KERNEL);
4208         if (!dest)
4209                 return -ENOMEM;
4210         dest_orig = dest;
4211
4212         /* now we have a buffer to copy into */
4213         for (i = 0; i < num_types; i++) {
4214                 struct btrfs_space_info *tmp;
4215
4216                 if (!slot_count)
4217                         break;
4218
4219                 info = NULL;
4220                 rcu_read_lock();
4221                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4222                                         list) {
4223                         if (tmp->flags == types[i]) {
4224                                 info = tmp;
4225                                 break;
4226                         }
4227                 }
4228                 rcu_read_unlock();
4229
4230                 if (!info)
4231                         continue;
4232                 down_read(&info->groups_sem);
4233                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4234                         if (!list_empty(&info->block_groups[c])) {
4235                                 get_block_group_info(&info->block_groups[c],
4236                                                      &space);
4237                                 memcpy(dest, &space, sizeof(space));
4238                                 dest++;
4239                                 space_args.total_spaces++;
4240                                 slot_count--;
4241                         }
4242                         if (!slot_count)
4243                                 break;
4244                 }
4245                 up_read(&info->groups_sem);
4246         }
4247
4248         /*
4249          * Add global block reserve
4250          */
4251         if (slot_count) {
4252                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4253
4254                 spin_lock(&block_rsv->lock);
4255                 space.total_bytes = block_rsv->size;
4256                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4257                 spin_unlock(&block_rsv->lock);
4258                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4259                 memcpy(dest, &space, sizeof(space));
4260                 space_args.total_spaces++;
4261         }
4262
4263         user_dest = (struct btrfs_ioctl_space_info __user *)
4264                 (arg + sizeof(struct btrfs_ioctl_space_args));
4265
4266         if (copy_to_user(user_dest, dest_orig, alloc_size))
4267                 ret = -EFAULT;
4268
4269         kfree(dest_orig);
4270 out:
4271         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4272                 ret = -EFAULT;
4273
4274         return ret;
4275 }
4276
4277 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4278                                             void __user *argp)
4279 {
4280         struct btrfs_trans_handle *trans;
4281         u64 transid;
4282         int ret;
4283
4284         trans = btrfs_attach_transaction_barrier(root);
4285         if (IS_ERR(trans)) {
4286                 if (PTR_ERR(trans) != -ENOENT)
4287                         return PTR_ERR(trans);
4288
4289                 /* No running transaction, don't bother */
4290                 transid = root->fs_info->last_trans_committed;
4291                 goto out;
4292         }
4293         transid = trans->transid;
4294         ret = btrfs_commit_transaction_async(trans, 0);
4295         if (ret) {
4296                 btrfs_end_transaction(trans);
4297                 return ret;
4298         }
4299 out:
4300         if (argp)
4301                 if (copy_to_user(argp, &transid, sizeof(transid)))
4302                         return -EFAULT;
4303         return 0;
4304 }
4305
4306 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4307                                            void __user *argp)
4308 {
4309         u64 transid;
4310
4311         if (argp) {
4312                 if (copy_from_user(&transid, argp, sizeof(transid)))
4313                         return -EFAULT;
4314         } else {
4315                 transid = 0;  /* current trans */
4316         }
4317         return btrfs_wait_for_commit(fs_info, transid);
4318 }
4319
4320 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4321 {
4322         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4323         struct btrfs_ioctl_scrub_args *sa;
4324         int ret;
4325
4326         if (!capable(CAP_SYS_ADMIN))
4327                 return -EPERM;
4328
4329         sa = memdup_user(arg, sizeof(*sa));
4330         if (IS_ERR(sa))
4331                 return PTR_ERR(sa);
4332
4333         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4334                 ret = mnt_want_write_file(file);
4335                 if (ret)
4336                         goto out;
4337         }
4338
4339         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4340                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4341                               0);
4342
4343         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
4344                 ret = -EFAULT;
4345
4346         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4347                 mnt_drop_write_file(file);
4348 out:
4349         kfree(sa);
4350         return ret;
4351 }
4352
4353 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4354 {
4355         if (!capable(CAP_SYS_ADMIN))
4356                 return -EPERM;
4357
4358         return btrfs_scrub_cancel(fs_info);
4359 }
4360
4361 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4362                                        void __user *arg)
4363 {
4364         struct btrfs_ioctl_scrub_args *sa;
4365         int ret;
4366
4367         if (!capable(CAP_SYS_ADMIN))
4368                 return -EPERM;
4369
4370         sa = memdup_user(arg, sizeof(*sa));
4371         if (IS_ERR(sa))
4372                 return PTR_ERR(sa);
4373
4374         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4375
4376         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
4377                 ret = -EFAULT;
4378
4379         kfree(sa);
4380         return ret;
4381 }
4382
4383 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4384                                       void __user *arg)
4385 {
4386         struct btrfs_ioctl_get_dev_stats *sa;
4387         int ret;
4388
4389         sa = memdup_user(arg, sizeof(*sa));
4390         if (IS_ERR(sa))
4391                 return PTR_ERR(sa);
4392
4393         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4394                 kfree(sa);
4395                 return -EPERM;
4396         }
4397
4398         ret = btrfs_get_dev_stats(fs_info, sa);
4399
4400         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
4401                 ret = -EFAULT;
4402
4403         kfree(sa);
4404         return ret;
4405 }
4406
4407 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4408                                     void __user *arg)
4409 {
4410         struct btrfs_ioctl_dev_replace_args *p;
4411         int ret;
4412
4413         if (!capable(CAP_SYS_ADMIN))
4414                 return -EPERM;
4415
4416         p = memdup_user(arg, sizeof(*p));
4417         if (IS_ERR(p))
4418                 return PTR_ERR(p);
4419
4420         switch (p->cmd) {
4421         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4422                 if (sb_rdonly(fs_info->sb)) {
4423                         ret = -EROFS;
4424                         goto out;
4425                 }
4426                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4427                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4428                 } else {
4429                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4430                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4431                 }
4432                 break;
4433         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4434                 btrfs_dev_replace_status(fs_info, p);
4435                 ret = 0;
4436                 break;
4437         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4438                 p->result = btrfs_dev_replace_cancel(fs_info);
4439                 ret = 0;
4440                 break;
4441         default:
4442                 ret = -EINVAL;
4443                 break;
4444         }
4445
4446         if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
4447                 ret = -EFAULT;
4448 out:
4449         kfree(p);
4450         return ret;
4451 }
4452
4453 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4454 {
4455         int ret = 0;
4456         int i;
4457         u64 rel_ptr;
4458         int size;
4459         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4460         struct inode_fs_paths *ipath = NULL;
4461         struct btrfs_path *path;
4462
4463         if (!capable(CAP_DAC_READ_SEARCH))
4464                 return -EPERM;
4465
4466         path = btrfs_alloc_path();
4467         if (!path) {
4468                 ret = -ENOMEM;
4469                 goto out;
4470         }
4471
4472         ipa = memdup_user(arg, sizeof(*ipa));
4473         if (IS_ERR(ipa)) {
4474                 ret = PTR_ERR(ipa);
4475                 ipa = NULL;
4476                 goto out;
4477         }
4478
4479         size = min_t(u32, ipa->size, 4096);
4480         ipath = init_ipath(size, root, path);
4481         if (IS_ERR(ipath)) {
4482                 ret = PTR_ERR(ipath);
4483                 ipath = NULL;
4484                 goto out;
4485         }
4486
4487         ret = paths_from_inode(ipa->inum, ipath);
4488         if (ret < 0)
4489                 goto out;
4490
4491         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4492                 rel_ptr = ipath->fspath->val[i] -
4493                           (u64)(unsigned long)ipath->fspath->val;
4494                 ipath->fspath->val[i] = rel_ptr;
4495         }
4496
4497         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4498                            ipath->fspath, size);
4499         if (ret) {
4500                 ret = -EFAULT;
4501                 goto out;
4502         }
4503
4504 out:
4505         btrfs_free_path(path);
4506         free_ipath(ipath);
4507         kfree(ipa);
4508
4509         return ret;
4510 }
4511
4512 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4513 {
4514         struct btrfs_data_container *inodes = ctx;
4515         const size_t c = 3 * sizeof(u64);
4516
4517         if (inodes->bytes_left >= c) {
4518                 inodes->bytes_left -= c;
4519                 inodes->val[inodes->elem_cnt] = inum;
4520                 inodes->val[inodes->elem_cnt + 1] = offset;
4521                 inodes->val[inodes->elem_cnt + 2] = root;
4522                 inodes->elem_cnt += 3;
4523         } else {
4524                 inodes->bytes_missing += c - inodes->bytes_left;
4525                 inodes->bytes_left = 0;
4526                 inodes->elem_missed += 3;
4527         }
4528
4529         return 0;
4530 }
4531
4532 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4533                                         void __user *arg, int version)
4534 {
4535         int ret = 0;
4536         int size;
4537         struct btrfs_ioctl_logical_ino_args *loi;
4538         struct btrfs_data_container *inodes = NULL;
4539         struct btrfs_path *path = NULL;
4540         bool ignore_offset;
4541
4542         if (!capable(CAP_SYS_ADMIN))
4543                 return -EPERM;
4544
4545         loi = memdup_user(arg, sizeof(*loi));
4546         if (IS_ERR(loi))
4547                 return PTR_ERR(loi);
4548
4549         if (version == 1) {
4550                 ignore_offset = false;
4551                 size = min_t(u32, loi->size, SZ_64K);
4552         } else {
4553                 /* All reserved bits must be 0 for now */
4554                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4555                         ret = -EINVAL;
4556                         goto out_loi;
4557                 }
4558                 /* Only accept flags we have defined so far */
4559                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4560                         ret = -EINVAL;
4561                         goto out_loi;
4562                 }
4563                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4564                 size = min_t(u32, loi->size, SZ_16M);
4565         }
4566
4567         path = btrfs_alloc_path();
4568         if (!path) {
4569                 ret = -ENOMEM;
4570                 goto out;
4571         }
4572
4573         inodes = init_data_container(size);
4574         if (IS_ERR(inodes)) {
4575                 ret = PTR_ERR(inodes);
4576                 inodes = NULL;
4577                 goto out;
4578         }
4579
4580         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4581                                           build_ino_list, inodes, ignore_offset);
4582         if (ret == -EINVAL)
4583                 ret = -ENOENT;
4584         if (ret < 0)
4585                 goto out;
4586
4587         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4588                            size);
4589         if (ret)
4590                 ret = -EFAULT;
4591
4592 out:
4593         btrfs_free_path(path);
4594         kvfree(inodes);
4595 out_loi:
4596         kfree(loi);
4597
4598         return ret;
4599 }
4600
4601 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4602                                struct btrfs_ioctl_balance_args *bargs)
4603 {
4604         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4605
4606         bargs->flags = bctl->flags;
4607
4608         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4609                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4610         if (atomic_read(&fs_info->balance_pause_req))
4611                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4612         if (atomic_read(&fs_info->balance_cancel_req))
4613                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4614
4615         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4616         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4617         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4618
4619         spin_lock(&fs_info->balance_lock);
4620         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4621         spin_unlock(&fs_info->balance_lock);
4622 }
4623
4624 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4625 {
4626         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4627         struct btrfs_fs_info *fs_info = root->fs_info;
4628         struct btrfs_ioctl_balance_args *bargs;
4629         struct btrfs_balance_control *bctl;
4630         bool need_unlock; /* for mut. excl. ops lock */
4631         int ret;
4632
4633         if (!capable(CAP_SYS_ADMIN))
4634                 return -EPERM;
4635
4636         ret = mnt_want_write_file(file);
4637         if (ret)
4638                 return ret;
4639
4640 again:
4641         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4642                 mutex_lock(&fs_info->balance_mutex);
4643                 need_unlock = true;
4644                 goto locked;
4645         }
4646
4647         /*
4648          * mut. excl. ops lock is locked.  Three possibilities:
4649          *   (1) some other op is running
4650          *   (2) balance is running
4651          *   (3) balance is paused -- special case (think resume)
4652          */
4653         mutex_lock(&fs_info->balance_mutex);
4654         if (fs_info->balance_ctl) {
4655                 /* this is either (2) or (3) */
4656                 if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4657                         mutex_unlock(&fs_info->balance_mutex);
4658                         /*
4659                          * Lock released to allow other waiters to continue,
4660                          * we'll reexamine the status again.
4661                          */
4662                         mutex_lock(&fs_info->balance_mutex);
4663
4664                         if (fs_info->balance_ctl &&
4665                             !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4666                                 /* this is (3) */
4667                                 need_unlock = false;
4668                                 goto locked;
4669                         }
4670
4671                         mutex_unlock(&fs_info->balance_mutex);
4672                         goto again;
4673                 } else {
4674                         /* this is (2) */
4675                         mutex_unlock(&fs_info->balance_mutex);
4676                         ret = -EINPROGRESS;
4677                         goto out;
4678                 }
4679         } else {
4680                 /* this is (1) */
4681                 mutex_unlock(&fs_info->balance_mutex);
4682                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4683                 goto out;
4684         }
4685
4686 locked:
4687         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4688
4689         if (arg) {
4690                 bargs = memdup_user(arg, sizeof(*bargs));
4691                 if (IS_ERR(bargs)) {
4692                         ret = PTR_ERR(bargs);
4693                         goto out_unlock;
4694                 }
4695
4696                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4697                         if (!fs_info->balance_ctl) {
4698                                 ret = -ENOTCONN;
4699                                 goto out_bargs;
4700                         }
4701
4702                         bctl = fs_info->balance_ctl;
4703                         spin_lock(&fs_info->balance_lock);
4704                         bctl->flags |= BTRFS_BALANCE_RESUME;
4705                         spin_unlock(&fs_info->balance_lock);
4706
4707                         goto do_balance;
4708                 }
4709         } else {
4710                 bargs = NULL;
4711         }
4712
4713         if (fs_info->balance_ctl) {
4714                 ret = -EINPROGRESS;
4715                 goto out_bargs;
4716         }
4717
4718         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4719         if (!bctl) {
4720                 ret = -ENOMEM;
4721                 goto out_bargs;
4722         }
4723
4724         if (arg) {
4725                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4726                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4727                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4728
4729                 bctl->flags = bargs->flags;
4730         } else {
4731                 /* balance everything - no filters */
4732                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4733         }
4734
4735         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4736                 ret = -EINVAL;
4737                 goto out_bctl;
4738         }
4739
4740 do_balance:
4741         /*
4742          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
4743          * btrfs_balance.  bctl is freed in reset_balance_state, or, if
4744          * restriper was paused all the way until unmount, in free_fs_info.
4745          * The flag should be cleared after reset_balance_state.
4746          */
4747         need_unlock = false;
4748
4749         ret = btrfs_balance(fs_info, bctl, bargs);
4750         bctl = NULL;
4751
4752         if ((ret == 0 || ret == -ECANCELED) && arg) {
4753                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4754                         ret = -EFAULT;
4755         }
4756
4757 out_bctl:
4758         kfree(bctl);
4759 out_bargs:
4760         kfree(bargs);
4761 out_unlock:
4762         mutex_unlock(&fs_info->balance_mutex);
4763         if (need_unlock)
4764                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4765 out:
4766         mnt_drop_write_file(file);
4767         return ret;
4768 }
4769
4770 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4771 {
4772         if (!capable(CAP_SYS_ADMIN))
4773                 return -EPERM;
4774
4775         switch (cmd) {
4776         case BTRFS_BALANCE_CTL_PAUSE:
4777                 return btrfs_pause_balance(fs_info);
4778         case BTRFS_BALANCE_CTL_CANCEL:
4779                 return btrfs_cancel_balance(fs_info);
4780         }
4781
4782         return -EINVAL;
4783 }
4784
4785 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4786                                          void __user *arg)
4787 {
4788         struct btrfs_ioctl_balance_args *bargs;
4789         int ret = 0;
4790
4791         if (!capable(CAP_SYS_ADMIN))
4792                 return -EPERM;
4793
4794         mutex_lock(&fs_info->balance_mutex);
4795         if (!fs_info->balance_ctl) {
4796                 ret = -ENOTCONN;
4797                 goto out;
4798         }
4799
4800         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4801         if (!bargs) {
4802                 ret = -ENOMEM;
4803                 goto out;
4804         }
4805
4806         btrfs_update_ioctl_balance_args(fs_info, bargs);
4807
4808         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4809                 ret = -EFAULT;
4810
4811         kfree(bargs);
4812 out:
4813         mutex_unlock(&fs_info->balance_mutex);
4814         return ret;
4815 }
4816
4817 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4818 {
4819         struct inode *inode = file_inode(file);
4820         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4821         struct btrfs_ioctl_quota_ctl_args *sa;
4822         int ret;
4823
4824         if (!capable(CAP_SYS_ADMIN))
4825                 return -EPERM;
4826
4827         ret = mnt_want_write_file(file);
4828         if (ret)
4829                 return ret;
4830
4831         sa = memdup_user(arg, sizeof(*sa));
4832         if (IS_ERR(sa)) {
4833                 ret = PTR_ERR(sa);
4834                 goto drop_write;
4835         }
4836
4837         down_write(&fs_info->subvol_sem);
4838
4839         switch (sa->cmd) {
4840         case BTRFS_QUOTA_CTL_ENABLE:
4841                 ret = btrfs_quota_enable(fs_info);
4842                 break;
4843         case BTRFS_QUOTA_CTL_DISABLE:
4844                 ret = btrfs_quota_disable(fs_info);
4845                 break;
4846         default:
4847                 ret = -EINVAL;
4848                 break;
4849         }
4850
4851         kfree(sa);
4852         up_write(&fs_info->subvol_sem);
4853 drop_write:
4854         mnt_drop_write_file(file);
4855         return ret;
4856 }
4857
4858 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4859 {
4860         struct inode *inode = file_inode(file);
4861         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4862         struct btrfs_root *root = BTRFS_I(inode)->root;
4863         struct btrfs_ioctl_qgroup_assign_args *sa;
4864         struct btrfs_trans_handle *trans;
4865         int ret;
4866         int err;
4867
4868         if (!capable(CAP_SYS_ADMIN))
4869                 return -EPERM;
4870
4871         ret = mnt_want_write_file(file);
4872         if (ret)
4873                 return ret;
4874
4875         sa = memdup_user(arg, sizeof(*sa));
4876         if (IS_ERR(sa)) {
4877                 ret = PTR_ERR(sa);
4878                 goto drop_write;
4879         }
4880
4881         trans = btrfs_join_transaction(root);
4882         if (IS_ERR(trans)) {
4883                 ret = PTR_ERR(trans);
4884                 goto out;
4885         }
4886
4887         if (sa->assign) {
4888                 ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
4889         } else {
4890                 ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
4891         }
4892
4893         /* update qgroup status and info */
4894         err = btrfs_run_qgroups(trans);
4895         if (err < 0)
4896                 btrfs_handle_fs_error(fs_info, err,
4897                                       "failed to update qgroup status and info");
4898         err = btrfs_end_transaction(trans);
4899         if (err && !ret)
4900                 ret = err;
4901
4902 out:
4903         kfree(sa);
4904 drop_write:
4905         mnt_drop_write_file(file);
4906         return ret;
4907 }
4908
4909 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4910 {
4911         struct inode *inode = file_inode(file);
4912         struct btrfs_root *root = BTRFS_I(inode)->root;
4913         struct btrfs_ioctl_qgroup_create_args *sa;
4914         struct btrfs_trans_handle *trans;
4915         int ret;
4916         int err;
4917
4918         if (!capable(CAP_SYS_ADMIN))
4919                 return -EPERM;
4920
4921         ret = mnt_want_write_file(file);
4922         if (ret)
4923                 return ret;
4924
4925         sa = memdup_user(arg, sizeof(*sa));
4926         if (IS_ERR(sa)) {
4927                 ret = PTR_ERR(sa);
4928                 goto drop_write;
4929         }
4930
4931         if (!sa->qgroupid) {
4932                 ret = -EINVAL;
4933                 goto out;
4934         }
4935
4936         trans = btrfs_join_transaction(root);
4937         if (IS_ERR(trans)) {
4938                 ret = PTR_ERR(trans);
4939                 goto out;
4940         }
4941
4942         if (sa->create) {
4943                 ret = btrfs_create_qgroup(trans, sa->qgroupid);
4944         } else {
4945                 ret = btrfs_remove_qgroup(trans, sa->qgroupid);
4946         }
4947
4948         err = btrfs_end_transaction(trans);
4949         if (err && !ret)
4950                 ret = err;
4951
4952 out:
4953         kfree(sa);
4954 drop_write:
4955         mnt_drop_write_file(file);
4956         return ret;
4957 }
4958
4959 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4960 {
4961         struct inode *inode = file_inode(file);
4962         struct btrfs_root *root = BTRFS_I(inode)->root;
4963         struct btrfs_ioctl_qgroup_limit_args *sa;
4964         struct btrfs_trans_handle *trans;
4965         int ret;
4966         int err;
4967         u64 qgroupid;
4968
4969         if (!capable(CAP_SYS_ADMIN))
4970                 return -EPERM;
4971
4972         ret = mnt_want_write_file(file);
4973         if (ret)
4974                 return ret;
4975
4976         sa = memdup_user(arg, sizeof(*sa));
4977         if (IS_ERR(sa)) {
4978                 ret = PTR_ERR(sa);
4979                 goto drop_write;
4980         }
4981
4982         trans = btrfs_join_transaction(root);
4983         if (IS_ERR(trans)) {
4984                 ret = PTR_ERR(trans);
4985                 goto out;
4986         }
4987
4988         qgroupid = sa->qgroupid;
4989         if (!qgroupid) {
4990                 /* take the current subvol as qgroup */
4991                 qgroupid = root->root_key.objectid;
4992         }
4993
4994         ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
4995
4996         err = btrfs_end_transaction(trans);
4997         if (err && !ret)
4998                 ret = err;
4999
5000 out:
5001         kfree(sa);
5002 drop_write:
5003         mnt_drop_write_file(file);
5004         return ret;
5005 }
5006
5007 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5008 {
5009         struct inode *inode = file_inode(file);
5010         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5011         struct btrfs_ioctl_quota_rescan_args *qsa;
5012         int ret;
5013
5014         if (!capable(CAP_SYS_ADMIN))
5015                 return -EPERM;
5016
5017         ret = mnt_want_write_file(file);
5018         if (ret)
5019                 return ret;
5020
5021         qsa = memdup_user(arg, sizeof(*qsa));
5022         if (IS_ERR(qsa)) {
5023                 ret = PTR_ERR(qsa);
5024                 goto drop_write;
5025         }
5026
5027         if (qsa->flags) {
5028                 ret = -EINVAL;
5029                 goto out;
5030         }
5031
5032         ret = btrfs_qgroup_rescan(fs_info);
5033
5034 out:
5035         kfree(qsa);
5036 drop_write:
5037         mnt_drop_write_file(file);
5038         return ret;
5039 }
5040
5041 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5042 {
5043         struct inode *inode = file_inode(file);
5044         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5045         struct btrfs_ioctl_quota_rescan_args *qsa;
5046         int ret = 0;
5047
5048         if (!capable(CAP_SYS_ADMIN))
5049                 return -EPERM;
5050
5051         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5052         if (!qsa)
5053                 return -ENOMEM;
5054
5055         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5056                 qsa->flags = 1;
5057                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5058         }
5059
5060         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5061                 ret = -EFAULT;
5062
5063         kfree(qsa);
5064         return ret;
5065 }
5066
5067 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5068 {
5069         struct inode *inode = file_inode(file);
5070         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5071
5072         if (!capable(CAP_SYS_ADMIN))
5073                 return -EPERM;
5074
5075         return btrfs_qgroup_wait_for_completion(fs_info, true);
5076 }
5077
5078 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5079                                             struct btrfs_ioctl_received_subvol_args *sa)
5080 {
5081         struct inode *inode = file_inode(file);
5082         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5083         struct btrfs_root *root = BTRFS_I(inode)->root;
5084         struct btrfs_root_item *root_item = &root->root_item;
5085         struct btrfs_trans_handle *trans;
5086         struct timespec64 ct = current_time(inode);
5087         int ret = 0;
5088         int received_uuid_changed;
5089
5090         if (!inode_owner_or_capable(inode))
5091                 return -EPERM;
5092
5093         ret = mnt_want_write_file(file);
5094         if (ret < 0)
5095                 return ret;
5096
5097         down_write(&fs_info->subvol_sem);
5098
5099         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5100                 ret = -EINVAL;
5101                 goto out;
5102         }
5103
5104         if (btrfs_root_readonly(root)) {
5105                 ret = -EROFS;
5106                 goto out;
5107         }
5108
5109         /*
5110          * 1 - root item
5111          * 2 - uuid items (received uuid + subvol uuid)
5112          */
5113         trans = btrfs_start_transaction(root, 3);
5114         if (IS_ERR(trans)) {
5115                 ret = PTR_ERR(trans);
5116                 trans = NULL;
5117                 goto out;
5118         }
5119
5120         sa->rtransid = trans->transid;
5121         sa->rtime.sec = ct.tv_sec;
5122         sa->rtime.nsec = ct.tv_nsec;
5123
5124         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5125                                        BTRFS_UUID_SIZE);
5126         if (received_uuid_changed &&
5127             !btrfs_is_empty_uuid(root_item->received_uuid)) {
5128                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
5129                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5130                                           root->root_key.objectid);
5131                 if (ret && ret != -ENOENT) {
5132                         btrfs_abort_transaction(trans, ret);
5133                         btrfs_end_transaction(trans);
5134                         goto out;
5135                 }
5136         }
5137         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5138         btrfs_set_root_stransid(root_item, sa->stransid);
5139         btrfs_set_root_rtransid(root_item, sa->rtransid);
5140         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5141         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5142         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5143         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5144
5145         ret = btrfs_update_root(trans, fs_info->tree_root,
5146                                 &root->root_key, &root->root_item);
5147         if (ret < 0) {
5148                 btrfs_end_transaction(trans);
5149                 goto out;
5150         }
5151         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5152                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
5153                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5154                                           root->root_key.objectid);
5155                 if (ret < 0 && ret != -EEXIST) {
5156                         btrfs_abort_transaction(trans, ret);
5157                         btrfs_end_transaction(trans);
5158                         goto out;
5159                 }
5160         }
5161         ret = btrfs_commit_transaction(trans);
5162 out:
5163         up_write(&fs_info->subvol_sem);
5164         mnt_drop_write_file(file);
5165         return ret;
5166 }
5167
5168 #ifdef CONFIG_64BIT
5169 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5170                                                 void __user *arg)
5171 {
5172         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5173         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5174         int ret = 0;
5175
5176         args32 = memdup_user(arg, sizeof(*args32));
5177         if (IS_ERR(args32))
5178                 return PTR_ERR(args32);
5179
5180         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5181         if (!args64) {
5182                 ret = -ENOMEM;
5183                 goto out;
5184         }
5185
5186         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5187         args64->stransid = args32->stransid;
5188         args64->rtransid = args32->rtransid;
5189         args64->stime.sec = args32->stime.sec;
5190         args64->stime.nsec = args32->stime.nsec;
5191         args64->rtime.sec = args32->rtime.sec;
5192         args64->rtime.nsec = args32->rtime.nsec;
5193         args64->flags = args32->flags;
5194
5195         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5196         if (ret)
5197                 goto out;
5198
5199         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5200         args32->stransid = args64->stransid;
5201         args32->rtransid = args64->rtransid;
5202         args32->stime.sec = args64->stime.sec;
5203         args32->stime.nsec = args64->stime.nsec;
5204         args32->rtime.sec = args64->rtime.sec;
5205         args32->rtime.nsec = args64->rtime.nsec;
5206         args32->flags = args64->flags;
5207
5208         ret = copy_to_user(arg, args32, sizeof(*args32));
5209         if (ret)
5210                 ret = -EFAULT;
5211
5212 out:
5213         kfree(args32);
5214         kfree(args64);
5215         return ret;
5216 }
5217 #endif
5218
5219 static long btrfs_ioctl_set_received_subvol(struct file *file,
5220                                             void __user *arg)
5221 {
5222         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5223         int ret = 0;
5224
5225         sa = memdup_user(arg, sizeof(*sa));
5226         if (IS_ERR(sa))
5227                 return PTR_ERR(sa);
5228
5229         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5230
5231         if (ret)
5232                 goto out;
5233
5234         ret = copy_to_user(arg, sa, sizeof(*sa));
5235         if (ret)
5236                 ret = -EFAULT;
5237
5238 out:
5239         kfree(sa);
5240         return ret;
5241 }
5242
5243 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5244 {
5245         struct inode *inode = file_inode(file);
5246         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5247         size_t len;
5248         int ret;
5249         char label[BTRFS_LABEL_SIZE];
5250
5251         spin_lock(&fs_info->super_lock);
5252         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5253         spin_unlock(&fs_info->super_lock);
5254
5255         len = strnlen(label, BTRFS_LABEL_SIZE);
5256
5257         if (len == BTRFS_LABEL_SIZE) {
5258                 btrfs_warn(fs_info,
5259                            "label is too long, return the first %zu bytes",
5260                            --len);
5261         }
5262
5263         ret = copy_to_user(arg, label, len);
5264
5265         return ret ? -EFAULT : 0;
5266 }
5267
5268 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5269 {
5270         struct inode *inode = file_inode(file);
5271         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5272         struct btrfs_root *root = BTRFS_I(inode)->root;
5273         struct btrfs_super_block *super_block = fs_info->super_copy;
5274         struct btrfs_trans_handle *trans;
5275         char label[BTRFS_LABEL_SIZE];
5276         int ret;
5277
5278         if (!capable(CAP_SYS_ADMIN))
5279                 return -EPERM;
5280
5281         if (copy_from_user(label, arg, sizeof(label)))
5282                 return -EFAULT;
5283
5284         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5285                 btrfs_err(fs_info,
5286                           "unable to set label with more than %d bytes",
5287                           BTRFS_LABEL_SIZE - 1);
5288                 return -EINVAL;
5289         }
5290
5291         ret = mnt_want_write_file(file);
5292         if (ret)
5293                 return ret;
5294
5295         trans = btrfs_start_transaction(root, 0);
5296         if (IS_ERR(trans)) {
5297                 ret = PTR_ERR(trans);
5298                 goto out_unlock;
5299         }
5300
5301         spin_lock(&fs_info->super_lock);
5302         strcpy(super_block->label, label);
5303         spin_unlock(&fs_info->super_lock);
5304         ret = btrfs_commit_transaction(trans);
5305
5306 out_unlock:
5307         mnt_drop_write_file(file);
5308         return ret;
5309 }
5310
5311 #define INIT_FEATURE_FLAGS(suffix) \
5312         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5313           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5314           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5315
5316 int btrfs_ioctl_get_supported_features(void __user *arg)
5317 {
5318         static const struct btrfs_ioctl_feature_flags features[3] = {
5319                 INIT_FEATURE_FLAGS(SUPP),
5320                 INIT_FEATURE_FLAGS(SAFE_SET),
5321                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5322         };
5323
5324         if (copy_to_user(arg, &features, sizeof(features)))
5325                 return -EFAULT;
5326
5327         return 0;
5328 }
5329
5330 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5331 {
5332         struct inode *inode = file_inode(file);
5333         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5334         struct btrfs_super_block *super_block = fs_info->super_copy;
5335         struct btrfs_ioctl_feature_flags features;
5336
5337         features.compat_flags = btrfs_super_compat_flags(super_block);
5338         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5339         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5340
5341         if (copy_to_user(arg, &features, sizeof(features)))
5342                 return -EFAULT;
5343
5344         return 0;
5345 }
5346
5347 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5348                               enum btrfs_feature_set set,
5349                               u64 change_mask, u64 flags, u64 supported_flags,
5350                               u64 safe_set, u64 safe_clear)
5351 {
5352         const char *type = btrfs_feature_set_names[set];
5353         char *names;
5354         u64 disallowed, unsupported;
5355         u64 set_mask = flags & change_mask;
5356         u64 clear_mask = ~flags & change_mask;
5357
5358         unsupported = set_mask & ~supported_flags;
5359         if (unsupported) {
5360                 names = btrfs_printable_features(set, unsupported);
5361                 if (names) {
5362                         btrfs_warn(fs_info,
5363                                    "this kernel does not support the %s feature bit%s",
5364                                    names, strchr(names, ',') ? "s" : "");
5365                         kfree(names);
5366                 } else
5367                         btrfs_warn(fs_info,
5368                                    "this kernel does not support %s bits 0x%llx",
5369                                    type, unsupported);
5370                 return -EOPNOTSUPP;
5371         }
5372
5373         disallowed = set_mask & ~safe_set;
5374         if (disallowed) {
5375                 names = btrfs_printable_features(set, disallowed);
5376                 if (names) {
5377                         btrfs_warn(fs_info,
5378                                    "can't set the %s feature bit%s while mounted",
5379                                    names, strchr(names, ',') ? "s" : "");
5380                         kfree(names);
5381                 } else
5382                         btrfs_warn(fs_info,
5383                                    "can't set %s bits 0x%llx while mounted",
5384                                    type, disallowed);
5385                 return -EPERM;
5386         }
5387
5388         disallowed = clear_mask & ~safe_clear;
5389         if (disallowed) {
5390                 names = btrfs_printable_features(set, disallowed);
5391                 if (names) {
5392                         btrfs_warn(fs_info,
5393                                    "can't clear the %s feature bit%s while mounted",
5394                                    names, strchr(names, ',') ? "s" : "");
5395                         kfree(names);
5396                 } else
5397                         btrfs_warn(fs_info,
5398                                    "can't clear %s bits 0x%llx while mounted",
5399                                    type, disallowed);
5400                 return -EPERM;
5401         }
5402
5403         return 0;
5404 }
5405
5406 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5407 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5408                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5409                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5410                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5411
5412 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5413 {
5414         struct inode *inode = file_inode(file);
5415         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5416         struct btrfs_root *root = BTRFS_I(inode)->root;
5417         struct btrfs_super_block *super_block = fs_info->super_copy;
5418         struct btrfs_ioctl_feature_flags flags[2];
5419         struct btrfs_trans_handle *trans;
5420         u64 newflags;
5421         int ret;
5422
5423         if (!capable(CAP_SYS_ADMIN))
5424                 return -EPERM;
5425
5426         if (copy_from_user(flags, arg, sizeof(flags)))
5427                 return -EFAULT;
5428
5429         /* Nothing to do */
5430         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5431             !flags[0].incompat_flags)
5432                 return 0;
5433
5434         ret = check_feature(fs_info, flags[0].compat_flags,
5435                             flags[1].compat_flags, COMPAT);
5436         if (ret)
5437                 return ret;
5438
5439         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5440                             flags[1].compat_ro_flags, COMPAT_RO);
5441         if (ret)
5442                 return ret;
5443
5444         ret = check_feature(fs_info, flags[0].incompat_flags,
5445                             flags[1].incompat_flags, INCOMPAT);
5446         if (ret)
5447                 return ret;
5448
5449         ret = mnt_want_write_file(file);
5450         if (ret)
5451                 return ret;
5452
5453         trans = btrfs_start_transaction(root, 0);
5454         if (IS_ERR(trans)) {
5455                 ret = PTR_ERR(trans);
5456                 goto out_drop_write;
5457         }
5458
5459         spin_lock(&fs_info->super_lock);
5460         newflags = btrfs_super_compat_flags(super_block);
5461         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5462         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5463         btrfs_set_super_compat_flags(super_block, newflags);
5464
5465         newflags = btrfs_super_compat_ro_flags(super_block);
5466         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5467         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5468         btrfs_set_super_compat_ro_flags(super_block, newflags);
5469
5470         newflags = btrfs_super_incompat_flags(super_block);
5471         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5472         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5473         btrfs_set_super_incompat_flags(super_block, newflags);
5474         spin_unlock(&fs_info->super_lock);
5475
5476         ret = btrfs_commit_transaction(trans);
5477 out_drop_write:
5478         mnt_drop_write_file(file);
5479
5480         return ret;
5481 }
5482
5483 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5484 {
5485         struct btrfs_ioctl_send_args *arg;
5486         int ret;
5487
5488         if (compat) {
5489 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5490                 struct btrfs_ioctl_send_args_32 args32;
5491
5492                 ret = copy_from_user(&args32, argp, sizeof(args32));
5493                 if (ret)
5494                         return -EFAULT;
5495                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5496                 if (!arg)
5497                         return -ENOMEM;
5498                 arg->send_fd = args32.send_fd;
5499                 arg->clone_sources_count = args32.clone_sources_count;
5500                 arg->clone_sources = compat_ptr(args32.clone_sources);
5501                 arg->parent_root = args32.parent_root;
5502                 arg->flags = args32.flags;
5503                 memcpy(arg->reserved, args32.reserved,
5504                        sizeof(args32.reserved));
5505 #else
5506                 return -ENOTTY;
5507 #endif
5508         } else {
5509                 arg = memdup_user(argp, sizeof(*arg));
5510                 if (IS_ERR(arg))
5511                         return PTR_ERR(arg);
5512         }
5513         ret = btrfs_ioctl_send(file, arg);
5514         kfree(arg);
5515         return ret;
5516 }
5517
5518 long btrfs_ioctl(struct file *file, unsigned int
5519                 cmd, unsigned long arg)
5520 {
5521         struct inode *inode = file_inode(file);
5522         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5523         struct btrfs_root *root = BTRFS_I(inode)->root;
5524         void __user *argp = (void __user *)arg;
5525
5526         switch (cmd) {
5527         case FS_IOC_GETFLAGS:
5528                 return btrfs_ioctl_getflags(file, argp);
5529         case FS_IOC_SETFLAGS:
5530                 return btrfs_ioctl_setflags(file, argp);
5531         case FS_IOC_GETVERSION:
5532                 return btrfs_ioctl_getversion(file, argp);
5533         case FITRIM:
5534                 return btrfs_ioctl_fitrim(file, argp);
5535         case BTRFS_IOC_SNAP_CREATE:
5536                 return btrfs_ioctl_snap_create(file, argp, 0);
5537         case BTRFS_IOC_SNAP_CREATE_V2:
5538                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5539         case BTRFS_IOC_SUBVOL_CREATE:
5540                 return btrfs_ioctl_snap_create(file, argp, 1);
5541         case BTRFS_IOC_SUBVOL_CREATE_V2:
5542                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5543         case BTRFS_IOC_SNAP_DESTROY:
5544                 return btrfs_ioctl_snap_destroy(file, argp);
5545         case BTRFS_IOC_SUBVOL_GETFLAGS:
5546                 return btrfs_ioctl_subvol_getflags(file, argp);
5547         case BTRFS_IOC_SUBVOL_SETFLAGS:
5548                 return btrfs_ioctl_subvol_setflags(file, argp);
5549         case BTRFS_IOC_DEFAULT_SUBVOL:
5550                 return btrfs_ioctl_default_subvol(file, argp);
5551         case BTRFS_IOC_DEFRAG:
5552                 return btrfs_ioctl_defrag(file, NULL);
5553         case BTRFS_IOC_DEFRAG_RANGE:
5554                 return btrfs_ioctl_defrag(file, argp);
5555         case BTRFS_IOC_RESIZE:
5556                 return btrfs_ioctl_resize(file, argp);
5557         case BTRFS_IOC_ADD_DEV:
5558                 return btrfs_ioctl_add_dev(fs_info, argp);
5559         case BTRFS_IOC_RM_DEV:
5560                 return btrfs_ioctl_rm_dev(file, argp);
5561         case BTRFS_IOC_RM_DEV_V2:
5562                 return btrfs_ioctl_rm_dev_v2(file, argp);
5563         case BTRFS_IOC_FS_INFO:
5564                 return btrfs_ioctl_fs_info(fs_info, argp);
5565         case BTRFS_IOC_DEV_INFO:
5566                 return btrfs_ioctl_dev_info(fs_info, argp);
5567         case BTRFS_IOC_BALANCE:
5568                 return btrfs_ioctl_balance(file, NULL);
5569         case BTRFS_IOC_TREE_SEARCH:
5570                 return btrfs_ioctl_tree_search(file, argp);
5571         case BTRFS_IOC_TREE_SEARCH_V2:
5572                 return btrfs_ioctl_tree_search_v2(file, argp);
5573         case BTRFS_IOC_INO_LOOKUP:
5574                 return btrfs_ioctl_ino_lookup(file, argp);
5575         case BTRFS_IOC_INO_PATHS:
5576                 return btrfs_ioctl_ino_to_path(root, argp);
5577         case BTRFS_IOC_LOGICAL_INO:
5578                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5579         case BTRFS_IOC_LOGICAL_INO_V2:
5580                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5581         case BTRFS_IOC_SPACE_INFO:
5582                 return btrfs_ioctl_space_info(fs_info, argp);
5583         case BTRFS_IOC_SYNC: {
5584                 int ret;
5585
5586                 ret = btrfs_start_delalloc_roots(fs_info, -1);
5587                 if (ret)
5588                         return ret;
5589                 ret = btrfs_sync_fs(inode->i_sb, 1);
5590                 /*
5591                  * The transaction thread may want to do more work,
5592                  * namely it pokes the cleaner kthread that will start
5593                  * processing uncleaned subvols.
5594                  */
5595                 wake_up_process(fs_info->transaction_kthread);
5596                 return ret;
5597         }
5598         case BTRFS_IOC_START_SYNC:
5599                 return btrfs_ioctl_start_sync(root, argp);
5600         case BTRFS_IOC_WAIT_SYNC:
5601                 return btrfs_ioctl_wait_sync(fs_info, argp);
5602         case BTRFS_IOC_SCRUB:
5603                 return btrfs_ioctl_scrub(file, argp);
5604         case BTRFS_IOC_SCRUB_CANCEL:
5605                 return btrfs_ioctl_scrub_cancel(fs_info);
5606         case BTRFS_IOC_SCRUB_PROGRESS:
5607                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5608         case BTRFS_IOC_BALANCE_V2:
5609                 return btrfs_ioctl_balance(file, argp);
5610         case BTRFS_IOC_BALANCE_CTL:
5611                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5612         case BTRFS_IOC_BALANCE_PROGRESS:
5613                 return btrfs_ioctl_balance_progress(fs_info, argp);
5614         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5615                 return btrfs_ioctl_set_received_subvol(file, argp);
5616 #ifdef CONFIG_64BIT
5617         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5618                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5619 #endif
5620         case BTRFS_IOC_SEND:
5621                 return _btrfs_ioctl_send(file, argp, false);
5622 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5623         case BTRFS_IOC_SEND_32:
5624                 return _btrfs_ioctl_send(file, argp, true);
5625 #endif
5626         case BTRFS_IOC_GET_DEV_STATS:
5627                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5628         case BTRFS_IOC_QUOTA_CTL:
5629                 return btrfs_ioctl_quota_ctl(file, argp);
5630         case BTRFS_IOC_QGROUP_ASSIGN:
5631                 return btrfs_ioctl_qgroup_assign(file, argp);
5632         case BTRFS_IOC_QGROUP_CREATE:
5633                 return btrfs_ioctl_qgroup_create(file, argp);
5634         case BTRFS_IOC_QGROUP_LIMIT:
5635                 return btrfs_ioctl_qgroup_limit(file, argp);
5636         case BTRFS_IOC_QUOTA_RESCAN:
5637                 return btrfs_ioctl_quota_rescan(file, argp);
5638         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5639                 return btrfs_ioctl_quota_rescan_status(file, argp);
5640         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5641                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5642         case BTRFS_IOC_DEV_REPLACE:
5643                 return btrfs_ioctl_dev_replace(fs_info, argp);
5644         case BTRFS_IOC_GET_FSLABEL:
5645                 return btrfs_ioctl_get_fslabel(file, argp);
5646         case BTRFS_IOC_SET_FSLABEL:
5647                 return btrfs_ioctl_set_fslabel(file, argp);
5648         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5649                 return btrfs_ioctl_get_supported_features(argp);
5650         case BTRFS_IOC_GET_FEATURES:
5651                 return btrfs_ioctl_get_features(file, argp);
5652         case BTRFS_IOC_SET_FEATURES:
5653                 return btrfs_ioctl_set_features(file, argp);
5654         case FS_IOC_FSGETXATTR:
5655                 return btrfs_ioctl_fsgetxattr(file, argp);
5656         case FS_IOC_FSSETXATTR:
5657                 return btrfs_ioctl_fssetxattr(file, argp);
5658         case BTRFS_IOC_GET_SUBVOL_INFO:
5659                 return btrfs_ioctl_get_subvol_info(file, argp);
5660         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5661                 return btrfs_ioctl_get_subvol_rootref(file, argp);
5662         case BTRFS_IOC_INO_LOOKUP_USER:
5663                 return btrfs_ioctl_ino_lookup_user(file, argp);
5664         }
5665
5666         return -ENOTTY;
5667 }
5668
5669 #ifdef CONFIG_COMPAT
5670 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5671 {
5672         /*
5673          * These all access 32-bit values anyway so no further
5674          * handling is necessary.
5675          */
5676         switch (cmd) {
5677         case FS_IOC32_GETFLAGS:
5678                 cmd = FS_IOC_GETFLAGS;
5679                 break;
5680         case FS_IOC32_SETFLAGS:
5681                 cmd = FS_IOC_SETFLAGS;
5682                 break;
5683         case FS_IOC32_GETVERSION:
5684                 cmd = FS_IOC_GETVERSION;
5685                 break;
5686         }
5687
5688         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5689 }
5690 #endif