fs/btrfs/ioctl.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/bio.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/file.h>
  23 #include <linux/fs.h>
  24 #include <linux/fsnotify.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/highmem.h>
  27 #include <linux/time.h>
  28 #include <linux/init.h>
  29 #include <linux/string.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/mount.h>
  32 #include <linux/mpage.h>
  33 #include <linux/namei.h>
  34 #include <linux/swap.h>
  35 #include <linux/writeback.h>
  36 #include <linux/statfs.h>
  37 #include <linux/compat.h>
  38 #include <linux/bit_spinlock.h>
  39 #include <linux/security.h>
  40 #include <linux/xattr.h>
  41 #include <linux/vmalloc.h>
  42 #include <linux/slab.h>
  43 #include <linux/blkdev.h>
  44 #include <linux/uuid.h>
  45 #include <linux/btrfs.h>
  46 #include <linux/uaccess.h>
  47 #include "ctree.h"
  48 #include "disk-io.h"
  49 #include "transaction.h"
  50 #include "btrfs_inode.h"
  51 #include "print-tree.h"
  52 #include "volumes.h"
  53 #include "locking.h"
  54 #include "inode-map.h"
  55 #include "backref.h"
  56 #include "rcu-string.h"
  57 #include "send.h"
  58 #include "dev-replace.h"
  59 #include "props.h"
  60 #include "sysfs.h"
  61 #include "qgroup.h"
  62
  63 #ifdef CONFIG_64BIT
  64 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  65  * structures are incorrect, as the timespec structure from userspace
  66  * is 4 bytes too small. We define these alternatives here to teach
  67  * the kernel about the 32-bit struct packing.
  68  */
  69 struct btrfs_ioctl_timespec_32 {
  70         __u64 sec;
  71         __u32 nsec;
  72 } __attribute__ ((__packed__));
  73
  74 struct btrfs_ioctl_received_subvol_args_32 {
  75         char    uuid[BTRFS_UUID_SIZE];  /* in */
  76         __u64   stransid;               /* in */
  77         __u64   rtransid;               /* out */
  78         struct btrfs_ioctl_timespec_32 stime; /* in */
  79         struct btrfs_ioctl_timespec_32 rtime; /* out */
  80         __u64   flags;                  /* in */
  81         __u64   reserved[16];           /* in */
  82 } __attribute__ ((__packed__));
  83
  84 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  85                                 struct btrfs_ioctl_received_subvol_args_32)
  86 #endif
  87
  88
  89 static int btrfs_clone(struct inode *src, struct inode *inode,
  90                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  91                        int no_time_update);
  92
  93 /* Mask out flags that are inappropriate for the given type of inode. */
  94 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  95 {
  96         if (S_ISDIR(mode))
  97                 return flags;
  98         else if (S_ISREG(mode))
  99                 return flags & ~FS_DIRSYNC_FL;
 100         else
 101                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 102 }
 103
 104 /*
 105  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
 106  */
 107 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
 108 {
 109         unsigned int iflags = 0;
 110
 111         if (flags & BTRFS_INODE_SYNC)
 112                 iflags |= FS_SYNC_FL;
 113         if (flags & BTRFS_INODE_IMMUTABLE)
 114                 iflags |= FS_IMMUTABLE_FL;
 115         if (flags & BTRFS_INODE_APPEND)
 116                 iflags |= FS_APPEND_FL;
 117         if (flags & BTRFS_INODE_NODUMP)
 118                 iflags |= FS_NODUMP_FL;
 119         if (flags & BTRFS_INODE_NOATIME)
 120                 iflags |= FS_NOATIME_FL;
 121         if (flags & BTRFS_INODE_DIRSYNC)
 122                 iflags |= FS_DIRSYNC_FL;
 123         if (flags & BTRFS_INODE_NODATACOW)
 124                 iflags |= FS_NOCOW_FL;
 125
 126         if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
 127                 iflags |= FS_COMPR_FL;
 128         else if (flags & BTRFS_INODE_NOCOMPRESS)
 129                 iflags |= FS_NOCOMP_FL;
 130
 131         return iflags;
 132 }
 133
 134 /*
 135  * Update inode->i_flags based on the btrfs internal flags.
 136  */
 137 void btrfs_update_iflags(struct inode *inode)
 138 {
 139         struct btrfs_inode *ip = BTRFS_I(inode);
 140         unsigned int new_fl = 0;
 141
 142         if (ip->flags & BTRFS_INODE_SYNC)
 143                 new_fl |= S_SYNC;
 144         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 145                 new_fl |= S_IMMUTABLE;
 146         if (ip->flags & BTRFS_INODE_APPEND)
 147                 new_fl |= S_APPEND;
 148         if (ip->flags & BTRFS_INODE_NOATIME)
 149                 new_fl |= S_NOATIME;
 150         if (ip->flags & BTRFS_INODE_DIRSYNC)
 151                 new_fl |= S_DIRSYNC;
 152
 153         set_mask_bits(&inode->i_flags,
 154                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 155                       new_fl);
 156 }
 157
 158 /*
 159  * Inherit flags from the parent inode.
 160  *
 161  * Currently only the compression flags and the cow flags are inherited.
 162  */
 163 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 164 {
 165         unsigned int flags;
 166
 167         if (!dir)
 168                 return;
 169
 170         flags = BTRFS_I(dir)->flags;
 171
 172         if (flags & BTRFS_INODE_NOCOMPRESS) {
 173                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 174                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 175         } else if (flags & BTRFS_INODE_COMPRESS) {
 176                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 177                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 178         }
 179
 180         if (flags & BTRFS_INODE_NODATACOW) {
 181                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 182                 if (S_ISREG(inode->i_mode))
 183                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
 184         }
 185
 186         btrfs_update_iflags(inode);
 187 }
 188
 189 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 190 {
 191         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 192         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 193
 194         if (copy_to_user(arg, &flags, sizeof(flags)))
 195                 return -EFAULT;
 196         return 0;
 197 }
 198
 199 static int check_flags(unsigned int flags)
 200 {
 201         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 202                       FS_NOATIME_FL | FS_NODUMP_FL | \
 203                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 204                       FS_NOCOMP_FL | FS_COMPR_FL |
 205                       FS_NOCOW_FL))
 206                 return -EOPNOTSUPP;
 207
 208         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 209                 return -EINVAL;
 210
 211         return 0;
 212 }
 213
 214 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 215 {
 216         struct inode *inode = file_inode(file);
 217         struct btrfs_inode *ip = BTRFS_I(inode);
 218         struct btrfs_root *root = ip->root;
 219         struct btrfs_trans_handle *trans;
 220         unsigned int flags, oldflags;
 221         int ret;
 222         u64 ip_oldflags;
 223         unsigned int i_oldflags;
 224         umode_t mode;
 225
 226         if (!inode_owner_or_capable(inode))
 227                 return -EPERM;
 228
 229         if (btrfs_root_readonly(root))
 230                 return -EROFS;
 231
 232         if (copy_from_user(&flags, arg, sizeof(flags)))
 233                 return -EFAULT;
 234
 235         ret = check_flags(flags);
 236         if (ret)
 237                 return ret;
 238
 239         ret = mnt_want_write_file(file);
 240         if (ret)
 241                 return ret;
 242
 243         inode_lock(inode);
 244
 245         ip_oldflags = ip->flags;
 246         i_oldflags = inode->i_flags;
 247         mode = inode->i_mode;
 248
 249         flags = btrfs_mask_flags(inode->i_mode, flags);
 250         oldflags = btrfs_flags_to_ioctl(ip->flags);
 251         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 252                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 253                         ret = -EPERM;
 254                         goto out_unlock;
 255                 }
 256         }
 257
 258         if (flags & FS_SYNC_FL)
 259                 ip->flags |= BTRFS_INODE_SYNC;
 260         else
 261                 ip->flags &= ~BTRFS_INODE_SYNC;
 262         if (flags & FS_IMMUTABLE_FL)
 263                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 264         else
 265                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 266         if (flags & FS_APPEND_FL)
 267                 ip->flags |= BTRFS_INODE_APPEND;
 268         else
 269                 ip->flags &= ~BTRFS_INODE_APPEND;
 270         if (flags & FS_NODUMP_FL)
 271                 ip->flags |= BTRFS_INODE_NODUMP;
 272         else
 273                 ip->flags &= ~BTRFS_INODE_NODUMP;
 274         if (flags & FS_NOATIME_FL)
 275                 ip->flags |= BTRFS_INODE_NOATIME;
 276         else
 277                 ip->flags &= ~BTRFS_INODE_NOATIME;
 278         if (flags & FS_DIRSYNC_FL)
 279                 ip->flags |= BTRFS_INODE_DIRSYNC;
 280         else
 281                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 282         if (flags & FS_NOCOW_FL) {
 283                 if (S_ISREG(mode)) {
 284                         /*
 285                          * It's safe to turn csums off here, no extents exist.
 286                          * Otherwise we want the flag to reflect the real COW
 287                          * status of the file and will not set it.
 288                          */
 289                         if (inode->i_size == 0)
 290                                 ip->flags |= BTRFS_INODE_NODATACOW
 291                                            | BTRFS_INODE_NODATASUM;
 292                 } else {
 293                         ip->flags |= BTRFS_INODE_NODATACOW;
 294                 }
 295         } else {
 296                 /*
 297                  * Revert back under same assuptions as above
 298                  */
 299                 if (S_ISREG(mode)) {
 300                         if (inode->i_size == 0)
 301                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 302                                              | BTRFS_INODE_NODATASUM);
 303                 } else {
 304                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 305                 }
 306         }
 307
 308         /*
 309          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 310          * flag may be changed automatically if compression code won't make
 311          * things smaller.
 312          */
 313         if (flags & FS_NOCOMP_FL) {
 314                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 315                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 316
 317                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 318                 if (ret && ret != -ENODATA)
 319                         goto out_drop;
 320         } else if (flags & FS_COMPR_FL) {
 321                 const char *comp;
 322
 323                 ip->flags |= BTRFS_INODE_COMPRESS;
 324                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 325
 326                 if (root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
 327                         comp = "lzo";
 328                 else
 329                         comp = "zlib";
 330                 ret = btrfs_set_prop(inode, "btrfs.compression",
 331                                      comp, strlen(comp), 0);
 332                 if (ret)
 333                         goto out_drop;
 334
 335         } else {
 336                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 337                 if (ret && ret != -ENODATA)
 338                         goto out_drop;
 339                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 340         }
 341
 342         trans = btrfs_start_transaction(root, 1);
 343         if (IS_ERR(trans)) {
 344                 ret = PTR_ERR(trans);
 345                 goto out_drop;
 346         }
 347
 348         btrfs_update_iflags(inode);
 349         inode_inc_iversion(inode);
 350         inode->i_ctime = CURRENT_TIME;
 351         ret = btrfs_update_inode(trans, root, inode);
 352
 353         btrfs_end_transaction(trans, root);
 354  out_drop:
 355         if (ret) {
 356                 ip->flags = ip_oldflags;
 357                 inode->i_flags = i_oldflags;
 358         }
 359
 360  out_unlock:
 361         inode_unlock(inode);
 362         mnt_drop_write_file(file);
 363         return ret;
 364 }
 365
 366 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 367 {
 368         struct inode *inode = file_inode(file);
 369
 370         return put_user(inode->i_generation, arg);
 371 }
 372
 373 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 374 {
 375         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
 376         struct btrfs_device *device;
 377         struct request_queue *q;
 378         struct fstrim_range range;
 379         u64 minlen = ULLONG_MAX;
 380         u64 num_devices = 0;
 381         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 382         int ret;
 383
 384         if (!capable(CAP_SYS_ADMIN))
 385                 return -EPERM;
 386
 387         rcu_read_lock();
 388         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 389                                 dev_list) {
 390                 if (!device->bdev)
 391                         continue;
 392                 q = bdev_get_queue(device->bdev);
 393                 if (blk_queue_discard(q)) {
 394                         num_devices++;
 395                         minlen = min((u64)q->limits.discard_granularity,
 396                                      minlen);
 397                 }
 398         }
 399         rcu_read_unlock();
 400
 401         if (!num_devices)
 402                 return -EOPNOTSUPP;
 403         if (copy_from_user(&range, arg, sizeof(range)))
 404                 return -EFAULT;
 405         if (range.start > total_bytes ||
 406             range.len < fs_info->sb->s_blocksize)
 407                 return -EINVAL;
 408
 409         range.len = min(range.len, total_bytes - range.start);
 410         range.minlen = max(range.minlen, minlen);
 411         ret = btrfs_trim_fs(fs_info->tree_root, &range);
 412         if (ret < 0)
 413                 return ret;
 414
 415         if (copy_to_user(arg, &range, sizeof(range)))
 416                 return -EFAULT;
 417
 418         return 0;
 419 }
 420
 421 int btrfs_is_empty_uuid(u8 *uuid)
 422 {
 423         int i;
 424
 425         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 426                 if (uuid[i])
 427                         return 0;
 428         }
 429         return 1;
 430 }
 431
 432 static noinline int create_subvol(struct inode *dir,
 433                                   struct dentry *dentry,
 434                                   char *name, int namelen,
 435                                   u64 *async_transid,
 436                                   struct btrfs_qgroup_inherit *inherit)
 437 {
 438         struct btrfs_trans_handle *trans;
 439         struct btrfs_key key;
 440         struct btrfs_root_item root_item;
 441         struct btrfs_inode_item *inode_item;
 442         struct extent_buffer *leaf;
 443         struct btrfs_root *root = BTRFS_I(dir)->root;
 444         struct btrfs_root *new_root;
 445         struct btrfs_block_rsv block_rsv;
 446         struct timespec cur_time = CURRENT_TIME;
 447         struct inode *inode;
 448         int ret;
 449         int err;
 450         u64 objectid;
 451         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 452         u64 index = 0;
 453         u64 qgroup_reserved;
 454         uuid_le new_uuid;
 455
 456         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 457         if (ret)
 458                 return ret;
 459
 460         /*
 461          * Don't create subvolume whose level is not zero. Or qgroup will be
 462          * screwed up since it assume subvolme qgroup's level to be 0.
 463          */
 464         if (btrfs_qgroup_level(objectid))
 465                 return -ENOSPC;
 466
 467         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 468         /*
 469          * The same as the snapshot creation, please see the comment
 470          * of create_snapshot().
 471          */
 472         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 473                                                8, &qgroup_reserved, false);
 474         if (ret)
 475                 return ret;
 476
 477         trans = btrfs_start_transaction(root, 0);
 478         if (IS_ERR(trans)) {
 479                 ret = PTR_ERR(trans);
 480                 btrfs_subvolume_release_metadata(root, &block_rsv,
 481                                                  qgroup_reserved);
 482                 return ret;
 483         }
 484         trans->block_rsv = &block_rsv;
 485         trans->bytes_reserved = block_rsv.size;
 486
 487         ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);
 488         if (ret)
 489                 goto fail;
 490
 491         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 492         if (IS_ERR(leaf)) {
 493                 ret = PTR_ERR(leaf);
 494                 goto fail;
 495         }
 496
 497         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 498         btrfs_set_header_bytenr(leaf, leaf->start);
 499         btrfs_set_header_generation(leaf, trans->transid);
 500         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 501         btrfs_set_header_owner(leaf, objectid);
 502
 503         write_extent_buffer(leaf, root->fs_info->fsid, btrfs_header_fsid(),
 504                             BTRFS_FSID_SIZE);
 505         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 506                             btrfs_header_chunk_tree_uuid(leaf),
 507                             BTRFS_UUID_SIZE);
 508         btrfs_mark_buffer_dirty(leaf);
 509
 510         memset(&root_item, 0, sizeof(root_item));
 511
 512         inode_item = &root_item.inode;
 513         btrfs_set_stack_inode_generation(inode_item, 1);
 514         btrfs_set_stack_inode_size(inode_item, 3);
 515         btrfs_set_stack_inode_nlink(inode_item, 1);
 516         btrfs_set_stack_inode_nbytes(inode_item, root->nodesize);
 517         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 518
 519         btrfs_set_root_flags(&root_item, 0);
 520         btrfs_set_root_limit(&root_item, 0);
 521         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 522
 523         btrfs_set_root_bytenr(&root_item, leaf->start);
 524         btrfs_set_root_generation(&root_item, trans->transid);
 525         btrfs_set_root_level(&root_item, 0);
 526         btrfs_set_root_refs(&root_item, 1);
 527         btrfs_set_root_used(&root_item, leaf->len);
 528         btrfs_set_root_last_snapshot(&root_item, 0);
 529
 530         btrfs_set_root_generation_v2(&root_item,
 531                         btrfs_root_generation(&root_item));
 532         uuid_le_gen(&new_uuid);
 533         memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
 534         btrfs_set_stack_timespec_sec(&root_item.otime, cur_time.tv_sec);
 535         btrfs_set_stack_timespec_nsec(&root_item.otime, cur_time.tv_nsec);
 536         root_item.ctime = root_item.otime;
 537         btrfs_set_root_ctransid(&root_item, trans->transid);
 538         btrfs_set_root_otransid(&root_item, trans->transid);
 539
 540         btrfs_tree_unlock(leaf);
 541         free_extent_buffer(leaf);
 542         leaf = NULL;
 543
 544         btrfs_set_root_dirid(&root_item, new_dirid);
 545
 546         key.objectid = objectid;
 547         key.offset = 0;
 548         key.type = BTRFS_ROOT_ITEM_KEY;
 549         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 550                                 &root_item);
 551         if (ret)
 552                 goto fail;
 553
 554         key.offset = (u64)-1;
 555         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 556         if (IS_ERR(new_root)) {
 557                 ret = PTR_ERR(new_root);
 558                 btrfs_abort_transaction(trans, root, ret);
 559                 goto fail;
 560         }
 561
 562         btrfs_record_root_in_trans(trans, new_root);
 563
 564         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 565         if (ret) {
 566                 /* We potentially lose an unused inode item here */
 567                 btrfs_abort_transaction(trans, root, ret);
 568                 goto fail;
 569         }
 570
 571         mutex_lock(&new_root->objectid_mutex);
 572         new_root->highest_objectid = new_dirid;
 573         mutex_unlock(&new_root->objectid_mutex);
 574
 575         /*
 576          * insert the directory item
 577          */
 578         ret = btrfs_set_inode_index(dir, &index);
 579         if (ret) {
 580                 btrfs_abort_transaction(trans, root, ret);
 581                 goto fail;
 582         }
 583
 584         ret = btrfs_insert_dir_item(trans, root,
 585                                     name, namelen, dir, &key,
 586                                     BTRFS_FT_DIR, index);
 587         if (ret) {
 588                 btrfs_abort_transaction(trans, root, ret);
 589                 goto fail;
 590         }
 591
 592         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 593         ret = btrfs_update_inode(trans, root, dir);
 594         BUG_ON(ret);
 595
 596         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 597                                  objectid, root->root_key.objectid,
 598                                  btrfs_ino(dir), index, name, namelen);
 599         BUG_ON(ret);
 600
 601         ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
 602                                   root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
 603                                   objectid);
 604         if (ret)
 605                 btrfs_abort_transaction(trans, root, ret);
 606
 607 fail:
 608         trans->block_rsv = NULL;
 609         trans->bytes_reserved = 0;
 610         btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
 611
 612         if (async_transid) {
 613                 *async_transid = trans->transid;
 614                 err = btrfs_commit_transaction_async(trans, root, 1);
 615                 if (err)
 616                         err = btrfs_commit_transaction(trans, root);
 617         } else {
 618                 err = btrfs_commit_transaction(trans, root);
 619         }
 620         if (err && !ret)
 621                 ret = err;
 622
 623         if (!ret) {
 624                 inode = btrfs_lookup_dentry(dir, dentry);
 625                 if (IS_ERR(inode))
 626                         return PTR_ERR(inode);
 627                 d_instantiate(dentry, inode);
 628         }
 629         return ret;
 630 }
 631
 632 static void btrfs_wait_for_no_snapshoting_writes(struct btrfs_root *root)
 633 {
 634         s64 writers;
 635         DEFINE_WAIT(wait);
 636
 637         do {
 638                 prepare_to_wait(&root->subv_writers->wait, &wait,
 639                                 TASK_UNINTERRUPTIBLE);
 640
 641                 writers = percpu_counter_sum(&root->subv_writers->counter);
 642                 if (writers)
 643                         schedule();
 644
 645                 finish_wait(&root->subv_writers->wait, &wait);
 646         } while (writers);
 647 }
 648
 649 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 650                            struct dentry *dentry, char *name, int namelen,
 651                            u64 *async_transid, bool readonly,
 652                            struct btrfs_qgroup_inherit *inherit)
 653 {
 654         struct inode *inode;
 655         struct btrfs_pending_snapshot *pending_snapshot;
 656         struct btrfs_trans_handle *trans;
 657         int ret;
 658
 659         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 660                 return -EINVAL;
 661
 662         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 663         if (!pending_snapshot)
 664                 return -ENOMEM;
 665
 666         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 667                         GFP_NOFS);
 668         pending_snapshot->path = btrfs_alloc_path();
 669         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 670                 ret = -ENOMEM;
 671                 goto free_pending;
 672         }
 673
 674         atomic_inc(&root->will_be_snapshoted);
 675         smp_mb__after_atomic();
 676         btrfs_wait_for_no_snapshoting_writes(root);
 677
 678         ret = btrfs_start_delalloc_inodes(root, 0);
 679         if (ret)
 680                 goto dec_and_free;
 681
 682         btrfs_wait_ordered_extents(root, -1);
 683
 684         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 685                              BTRFS_BLOCK_RSV_TEMP);
 686         /*
 687          * 1 - parent dir inode
 688          * 2 - dir entries
 689          * 1 - root item
 690          * 2 - root ref/backref
 691          * 1 - root of snapshot
 692          * 1 - UUID item
 693          */
 694         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 695                                         &pending_snapshot->block_rsv, 8,
 696                                         &pending_snapshot->qgroup_reserved,
 697                                         false);
 698         if (ret)
 699                 goto dec_and_free;
 700
 701         pending_snapshot->dentry = dentry;
 702         pending_snapshot->root = root;
 703         pending_snapshot->readonly = readonly;
 704         pending_snapshot->dir = dir;
 705         pending_snapshot->inherit = inherit;
 706
 707         trans = btrfs_start_transaction(root, 0);
 708         if (IS_ERR(trans)) {
 709                 ret = PTR_ERR(trans);
 710                 goto fail;
 711         }
 712
 713         spin_lock(&root->fs_info->trans_lock);
 714         list_add(&pending_snapshot->list,
 715                  &trans->transaction->pending_snapshots);
 716         spin_unlock(&root->fs_info->trans_lock);
 717         if (async_transid) {
 718                 *async_transid = trans->transid;
 719                 ret = btrfs_commit_transaction_async(trans,
 720                                      root->fs_info->extent_root, 1);
 721                 if (ret)
 722                         ret = btrfs_commit_transaction(trans, root);
 723         } else {
 724                 ret = btrfs_commit_transaction(trans,
 725                                                root->fs_info->extent_root);
 726         }
 727         if (ret)
 728                 goto fail;
 729
 730         ret = pending_snapshot->error;
 731         if (ret)
 732                 goto fail;
 733
 734         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 735         if (ret)
 736                 goto fail;
 737
 738         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 739         if (IS_ERR(inode)) {
 740                 ret = PTR_ERR(inode);
 741                 goto fail;
 742         }
 743
 744         d_instantiate(dentry, inode);
 745         ret = 0;
 746 fail:
 747         btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,
 748                                          &pending_snapshot->block_rsv,
 749                                          pending_snapshot->qgroup_reserved);
 750 dec_and_free:
 751         if (atomic_dec_and_test(&root->will_be_snapshoted))
 752                 wake_up_atomic_t(&root->will_be_snapshoted);
 753 free_pending:
 754         kfree(pending_snapshot->root_item);
 755         btrfs_free_path(pending_snapshot->path);
 756         kfree(pending_snapshot);
 757
 758         return ret;
 759 }
 760
 761 /*  copy of may_delete in fs/namei.c()
 762  *      Check whether we can remove a link victim from directory dir, check
 763  *  whether the type of victim is right.
 764  *  1. We can't do it if dir is read-only (done in permission())
 765  *  2. We should have write and exec permissions on dir
 766  *  3. We can't remove anything from append-only dir
 767  *  4. We can't do anything with immutable dir (done in permission())
 768  *  5. If the sticky bit on dir is set we should either
 769  *      a. be owner of dir, or
 770  *      b. be owner of victim, or
 771  *      c. have CAP_FOWNER capability
 772  *  6. If the victim is append-only or immutable we can't do antyhing with
 773  *     links pointing to it.
 774  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 775  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 776  *  9. We can't remove a root or mountpoint.
 777  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 778  *     nfs_async_unlink().
 779  */
 780
 781 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 782 {
 783         int error;
 784
 785         if (d_really_is_negative(victim))
 786                 return -ENOENT;
 787
 788         BUG_ON(d_inode(victim->d_parent) != dir);
 789         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 790
 791         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 792         if (error)
 793                 return error;
 794         if (IS_APPEND(dir))
 795                 return -EPERM;
 796         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 797             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 798                 return -EPERM;
 799         if (isdir) {
 800                 if (!d_is_dir(victim))
 801                         return -ENOTDIR;
 802                 if (IS_ROOT(victim))
 803                         return -EBUSY;
 804         } else if (d_is_dir(victim))
 805                 return -EISDIR;
 806         if (IS_DEADDIR(dir))
 807                 return -ENOENT;
 808         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 809                 return -EBUSY;
 810         return 0;
 811 }
 812
 813 /* copy of may_create in fs/namei.c() */
 814 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 815 {
 816         if (d_really_is_positive(child))
 817                 return -EEXIST;
 818         if (IS_DEADDIR(dir))
 819                 return -ENOENT;
 820         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 821 }
 822
 823 /*
 824  * Create a new subvolume below @parent.  This is largely modeled after
 825  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 826  * inside this filesystem so it's quite a bit simpler.
 827  */
 828 static noinline int btrfs_mksubvol(struct path *parent,
 829                                    char *name, int namelen,
 830                                    struct btrfs_root *snap_src,
 831                                    u64 *async_transid, bool readonly,
 832                                    struct btrfs_qgroup_inherit *inherit)
 833 {
 834         struct inode *dir  = d_inode(parent->dentry);
 835         struct dentry *dentry;
 836         int error;
 837
 838         error = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
 839         if (error == -EINTR)
 840                 return error;
 841
 842         dentry = lookup_one_len(name, parent->dentry, namelen);
 843         error = PTR_ERR(dentry);
 844         if (IS_ERR(dentry))
 845                 goto out_unlock;
 846
 847         error = -EEXIST;
 848         if (d_really_is_positive(dentry))
 849                 goto out_dput;
 850
 851         error = btrfs_may_create(dir, dentry);
 852         if (error)
 853                 goto out_dput;
 854
 855         /*
 856          * even if this name doesn't exist, we may get hash collisions.
 857          * check for them now when we can safely fail
 858          */
 859         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 860                                                dir->i_ino, name,
 861                                                namelen);
 862         if (error)
 863                 goto out_dput;
 864
 865         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 866
 867         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 868                 goto out_up_read;
 869
 870         if (snap_src) {
 871                 error = create_snapshot(snap_src, dir, dentry, name, namelen,
 872                                         async_transid, readonly, inherit);
 873         } else {
 874                 error = create_subvol(dir, dentry, name, namelen,
 875                                       async_transid, inherit);
 876         }
 877         if (!error)
 878                 fsnotify_mkdir(dir, dentry);
 879 out_up_read:
 880         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 881 out_dput:
 882         dput(dentry);
 883 out_unlock:
 884         inode_unlock(dir);
 885         return error;
 886 }
 887
 888 /*
 889  * When we're defragging a range, we don't want to kick it off again
 890  * if it is really just waiting for delalloc to send it down.
 891  * If we find a nice big extent or delalloc range for the bytes in the
 892  * file you want to defrag, we return 0 to let you know to skip this
 893  * part of the file
 894  */
 895 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 896 {
 897         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 898         struct extent_map *em = NULL;
 899         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 900         u64 end;
 901
 902         read_lock(&em_tree->lock);
 903         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 904         read_unlock(&em_tree->lock);
 905
 906         if (em) {
 907                 end = extent_map_end(em);
 908                 free_extent_map(em);
 909                 if (end - offset > thresh)
 910                         return 0;
 911         }
 912         /* if we already have a nice delalloc here, just stop */
 913         thresh /= 2;
 914         end = count_range_bits(io_tree, &offset, offset + thresh,
 915                                thresh, EXTENT_DELALLOC, 1);
 916         if (end >= thresh)
 917                 return 0;
 918         return 1;
 919 }
 920
 921 /*
 922  * helper function to walk through a file and find extents
 923  * newer than a specific transid, and smaller than thresh.
 924  *
 925  * This is used by the defragging code to find new and small
 926  * extents
 927  */
 928 static int find_new_extents(struct btrfs_root *root,
 929                             struct inode *inode, u64 newer_than,
 930                             u64 *off, u32 thresh)
 931 {
 932         struct btrfs_path *path;
 933         struct btrfs_key min_key;
 934         struct extent_buffer *leaf;
 935         struct btrfs_file_extent_item *extent;
 936         int type;
 937         int ret;
 938         u64 ino = btrfs_ino(inode);
 939
 940         path = btrfs_alloc_path();
 941         if (!path)
 942                 return -ENOMEM;
 943
 944         min_key.objectid = ino;
 945         min_key.type = BTRFS_EXTENT_DATA_KEY;
 946         min_key.offset = *off;
 947
 948         while (1) {
 949                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
 950                 if (ret != 0)
 951                         goto none;
 952 process_slot:
 953                 if (min_key.objectid != ino)
 954                         goto none;
 955                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 956                         goto none;
 957
 958                 leaf = path->nodes[0];
 959                 extent = btrfs_item_ptr(leaf, path->slots[0],
 960                                         struct btrfs_file_extent_item);
 961
 962                 type = btrfs_file_extent_type(leaf, extent);
 963                 if (type == BTRFS_FILE_EXTENT_REG &&
 964                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 965                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 966                         *off = min_key.offset;
 967                         btrfs_free_path(path);
 968                         return 0;
 969                 }
 970
 971                 path->slots[0]++;
 972                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
 973                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 974                         goto process_slot;
 975                 }
 976
 977                 if (min_key.offset == (u64)-1)
 978                         goto none;
 979
 980                 min_key.offset++;
 981                 btrfs_release_path(path);
 982         }
 983 none:
 984         btrfs_free_path(path);
 985         return -ENOENT;
 986 }
 987
 988 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 989 {
 990         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 991         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 992         struct extent_map *em;
 993         u64 len = PAGE_CACHE_SIZE;
 994
 995         /*
 996          * hopefully we have this extent in the tree already, try without
 997          * the full extent lock
 998          */
 999         read_lock(&em_tree->lock);
1000         em = lookup_extent_mapping(em_tree, start, len);
1001         read_unlock(&em_tree->lock);
1002
1003         if (!em) {
1004                 struct extent_state *cached = NULL;
1005                 u64 end = start + len - 1;
1006
1007                 /* get the big lock and read metadata off disk */
1008                 lock_extent_bits(io_tree, start, end, &cached);
1009                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
1010                 unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS);
1011
1012                 if (IS_ERR(em))
1013                         return NULL;
1014         }
1015
1016         return em;
1017 }
1018
1019 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1020 {
1021         struct extent_map *next;
1022         bool ret = true;
1023
1024         /* this is the last extent */
1025         if (em->start + em->len >= i_size_read(inode))
1026                 return false;
1027
1028         next = defrag_lookup_extent(inode, em->start + em->len);
1029         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1030                 ret = false;
1031         else if ((em->block_start + em->block_len == next->block_start) &&
1032                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1033                 ret = false;
1034
1035         free_extent_map(next);
1036         return ret;
1037 }
1038
1039 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1040                                u64 *last_len, u64 *skip, u64 *defrag_end,
1041                                int compress)
1042 {
1043         struct extent_map *em;
1044         int ret = 1;
1045         bool next_mergeable = true;
1046         bool prev_mergeable = true;
1047
1048         /*
1049          * make sure that once we start defragging an extent, we keep on
1050          * defragging it
1051          */
1052         if (start < *defrag_end)
1053                 return 1;
1054
1055         *skip = 0;
1056
1057         em = defrag_lookup_extent(inode, start);
1058         if (!em)
1059                 return 0;
1060
1061         /* this will cover holes, and inline extents */
1062         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1063                 ret = 0;
1064                 goto out;
1065         }
1066
1067         if (!*defrag_end)
1068                 prev_mergeable = false;
1069
1070         next_mergeable = defrag_check_next_extent(inode, em);
1071         /*
1072          * we hit a real extent, if it is big or the next extent is not a
1073          * real extent, don't bother defragging it
1074          */
1075         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1076             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1077                 ret = 0;
1078 out:
1079         /*
1080          * last_len ends up being a counter of how many bytes we've defragged.
1081          * every time we choose not to defrag an extent, we reset *last_len
1082          * so that the next tiny extent will force a defrag.
1083          *
1084          * The end result of this is that tiny extents before a single big
1085          * extent will force at least part of that big extent to be defragged.
1086          */
1087         if (ret) {
1088                 *defrag_end = extent_map_end(em);
1089         } else {
1090                 *last_len = 0;
1091                 *skip = extent_map_end(em);
1092                 *defrag_end = 0;
1093         }
1094
1095         free_extent_map(em);
1096         return ret;
1097 }
1098
1099 /*
1100  * it doesn't do much good to defrag one or two pages
1101  * at a time.  This pulls in a nice chunk of pages
1102  * to COW and defrag.
1103  *
1104  * It also makes sure the delalloc code has enough
1105  * dirty data to avoid making new small extents as part
1106  * of the defrag
1107  *
1108  * It's a good idea to start RA on this range
1109  * before calling this.
1110  */
1111 static int cluster_pages_for_defrag(struct inode *inode,
1112                                     struct page **pages,
1113                                     unsigned long start_index,
1114                                     unsigned long num_pages)
1115 {
1116         unsigned long file_end;
1117         u64 isize = i_size_read(inode);
1118         u64 page_start;
1119         u64 page_end;
1120         u64 page_cnt;
1121         int ret;
1122         int i;
1123         int i_done;
1124         struct btrfs_ordered_extent *ordered;
1125         struct extent_state *cached_state = NULL;
1126         struct extent_io_tree *tree;
1127         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1128
1129         file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
1130         if (!isize || start_index > file_end)
1131                 return 0;
1132
1133         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1134
1135         ret = btrfs_delalloc_reserve_space(inode,
1136                         start_index << PAGE_CACHE_SHIFT,
1137                         page_cnt << PAGE_CACHE_SHIFT);
1138         if (ret)
1139                 return ret;
1140         i_done = 0;
1141         tree = &BTRFS_I(inode)->io_tree;
1142
1143         /* step one, lock all the pages */
1144         for (i = 0; i < page_cnt; i++) {
1145                 struct page *page;
1146 again:
1147                 page = find_or_create_page(inode->i_mapping,
1148                                            start_index + i, mask);
1149                 if (!page)
1150                         break;
1151
1152                 page_start = page_offset(page);
1153                 page_end = page_start + PAGE_CACHE_SIZE - 1;
1154                 while (1) {
1155                         lock_extent_bits(tree, page_start, page_end,
1156                                          &cached_state);
1157                         ordered = btrfs_lookup_ordered_extent(inode,
1158                                                               page_start);
1159                         unlock_extent_cached(tree, page_start, page_end,
1160                                              &cached_state, GFP_NOFS);
1161                         if (!ordered)
1162                                 break;
1163
1164                         unlock_page(page);
1165                         btrfs_start_ordered_extent(inode, ordered, 1);
1166                         btrfs_put_ordered_extent(ordered);
1167                         lock_page(page);
1168                         /*
1169                          * we unlocked the page above, so we need check if
1170                          * it was released or not.
1171                          */
1172                         if (page->mapping != inode->i_mapping) {
1173                                 unlock_page(page);
1174                                 page_cache_release(page);
1175                                 goto again;
1176                         }
1177                 }
1178
1179                 if (!PageUptodate(page)) {
1180                         btrfs_readpage(NULL, page);
1181                         lock_page(page);
1182                         if (!PageUptodate(page)) {
1183                                 unlock_page(page);
1184                                 page_cache_release(page);
1185                                 ret = -EIO;
1186                                 break;
1187                         }
1188                 }
1189
1190                 if (page->mapping != inode->i_mapping) {
1191                         unlock_page(page);
1192                         page_cache_release(page);
1193                         goto again;
1194                 }
1195
1196                 pages[i] = page;
1197                 i_done++;
1198         }
1199         if (!i_done || ret)
1200                 goto out;
1201
1202         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1203                 goto out;
1204
1205         /*
1206          * so now we have a nice long stream of locked
1207          * and up to date pages, lets wait on them
1208          */
1209         for (i = 0; i < i_done; i++)
1210                 wait_on_page_writeback(pages[i]);
1211
1212         page_start = page_offset(pages[0]);
1213         page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1214
1215         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1216                          page_start, page_end - 1, &cached_state);
1217         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1218                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1219                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1220                           &cached_state, GFP_NOFS);
1221
1222         if (i_done != page_cnt) {
1223                 spin_lock(&BTRFS_I(inode)->lock);
1224                 BTRFS_I(inode)->outstanding_extents++;
1225                 spin_unlock(&BTRFS_I(inode)->lock);
1226                 btrfs_delalloc_release_space(inode,
1227                                 start_index << PAGE_CACHE_SHIFT,
1228                                 (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1229         }
1230
1231
1232         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1233                           &cached_state, GFP_NOFS);
1234
1235         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1236                              page_start, page_end - 1, &cached_state,
1237                              GFP_NOFS);
1238
1239         for (i = 0; i < i_done; i++) {
1240                 clear_page_dirty_for_io(pages[i]);
1241                 ClearPageChecked(pages[i]);
1242                 set_page_extent_mapped(pages[i]);
1243                 set_page_dirty(pages[i]);
1244                 unlock_page(pages[i]);
1245                 page_cache_release(pages[i]);
1246         }
1247         return i_done;
1248 out:
1249         for (i = 0; i < i_done; i++) {
1250                 unlock_page(pages[i]);
1251                 page_cache_release(pages[i]);
1252         }
1253         btrfs_delalloc_release_space(inode,
1254                         start_index << PAGE_CACHE_SHIFT,
1255                         page_cnt << PAGE_CACHE_SHIFT);
1256         return ret;
1257
1258 }
1259
1260 int btrfs_defrag_file(struct inode *inode, struct file *file,
1261                       struct btrfs_ioctl_defrag_range_args *range,
1262                       u64 newer_than, unsigned long max_to_defrag)
1263 {
1264         struct btrfs_root *root = BTRFS_I(inode)->root;
1265         struct file_ra_state *ra = NULL;
1266         unsigned long last_index;
1267         u64 isize = i_size_read(inode);
1268         u64 last_len = 0;
1269         u64 skip = 0;
1270         u64 defrag_end = 0;
1271         u64 newer_off = range->start;
1272         unsigned long i;
1273         unsigned long ra_index = 0;
1274         int ret;
1275         int defrag_count = 0;
1276         int compress_type = BTRFS_COMPRESS_ZLIB;
1277         u32 extent_thresh = range->extent_thresh;
1278         unsigned long max_cluster = SZ_256K >> PAGE_CACHE_SHIFT;
1279         unsigned long cluster = max_cluster;
1280         u64 new_align = ~((u64)SZ_128K - 1);
1281         struct page **pages = NULL;
1282
1283         if (isize == 0)
1284                 return 0;
1285
1286         if (range->start >= isize)
1287                 return -EINVAL;
1288
1289         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1290                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1291                         return -EINVAL;
1292                 if (range->compress_type)
1293                         compress_type = range->compress_type;
1294         }
1295
1296         if (extent_thresh == 0)
1297                 extent_thresh = SZ_256K;
1298
1299         /*
1300          * if we were not given a file, allocate a readahead
1301          * context
1302          */
1303         if (!file) {
1304                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1305                 if (!ra)
1306                         return -ENOMEM;
1307                 file_ra_state_init(ra, inode->i_mapping);
1308         } else {
1309                 ra = &file->f_ra;
1310         }
1311
1312         pages = kmalloc_array(max_cluster, sizeof(struct page *),
1313                         GFP_NOFS);
1314         if (!pages) {
1315                 ret = -ENOMEM;
1316                 goto out_ra;
1317         }
1318
1319         /* find the last page to defrag */
1320         if (range->start + range->len > range->start) {
1321                 last_index = min_t(u64, isize - 1,
1322                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1323         } else {
1324                 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1325         }
1326
1327         if (newer_than) {
1328                 ret = find_new_extents(root, inode, newer_than,
1329                                        &newer_off, SZ_64K);
1330                 if (!ret) {
1331                         range->start = newer_off;
1332                         /*
1333                          * we always align our defrag to help keep
1334                          * the extents in the file evenly spaced
1335                          */
1336                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1337                 } else
1338                         goto out_ra;
1339         } else {
1340                 i = range->start >> PAGE_CACHE_SHIFT;
1341         }
1342         if (!max_to_defrag)
1343                 max_to_defrag = last_index - i + 1;
1344
1345         /*
1346          * make writeback starts from i, so the defrag range can be
1347          * written sequentially.
1348          */
1349         if (i < inode->i_mapping->writeback_index)
1350                 inode->i_mapping->writeback_index = i;
1351
1352         while (i <= last_index && defrag_count < max_to_defrag &&
1353                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE))) {
1354                 /*
1355                  * make sure we stop running if someone unmounts
1356                  * the FS
1357                  */
1358                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1359                         break;
1360
1361                 if (btrfs_defrag_cancelled(root->fs_info)) {
1362                         btrfs_debug(root->fs_info, "defrag_file cancelled");
1363                         ret = -EAGAIN;
1364                         break;
1365                 }
1366
1367                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1368                                          extent_thresh, &last_len, &skip,
1369                                          &defrag_end, range->flags &
1370                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1371                         unsigned long next;
1372                         /*
1373                          * the should_defrag function tells us how much to skip
1374                          * bump our counter by the suggested amount
1375                          */
1376                         next = DIV_ROUND_UP(skip, PAGE_CACHE_SIZE);
1377                         i = max(i + 1, next);
1378                         continue;
1379                 }
1380
1381                 if (!newer_than) {
1382                         cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1383                                    PAGE_CACHE_SHIFT) - i;
1384                         cluster = min(cluster, max_cluster);
1385                 } else {
1386                         cluster = max_cluster;
1387                 }
1388
1389                 if (i + cluster > ra_index) {
1390                         ra_index = max(i, ra_index);
1391                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1392                                        cluster);
1393                         ra_index += cluster;
1394                 }
1395
1396                 inode_lock(inode);
1397                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1398                         BTRFS_I(inode)->force_compress = compress_type;
1399                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1400                 if (ret < 0) {
1401                         inode_unlock(inode);
1402                         goto out_ra;
1403                 }
1404
1405                 defrag_count += ret;
1406                 balance_dirty_pages_ratelimited(inode->i_mapping);
1407                 inode_unlock(inode);
1408
1409                 if (newer_than) {
1410                         if (newer_off == (u64)-1)
1411                                 break;
1412
1413                         if (ret > 0)
1414                                 i += ret;
1415
1416                         newer_off = max(newer_off + 1,
1417                                         (u64)i << PAGE_CACHE_SHIFT);
1418
1419                         ret = find_new_extents(root, inode, newer_than,
1420                                                &newer_off, SZ_64K);
1421                         if (!ret) {
1422                                 range->start = newer_off;
1423                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1424                         } else {
1425                                 break;
1426                         }
1427                 } else {
1428                         if (ret > 0) {
1429                                 i += ret;
1430                                 last_len += ret << PAGE_CACHE_SHIFT;
1431                         } else {
1432                                 i++;
1433                                 last_len = 0;
1434                         }
1435                 }
1436         }
1437
1438         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1439                 filemap_flush(inode->i_mapping);
1440                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1441                              &BTRFS_I(inode)->runtime_flags))
1442                         filemap_flush(inode->i_mapping);
1443         }
1444
1445         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1446                 /* the filemap_flush will queue IO into the worker threads, but
1447                  * we have to make sure the IO is actually started and that
1448                  * ordered extents get created before we return
1449                  */
1450                 atomic_inc(&root->fs_info->async_submit_draining);
1451                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1452                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1453                         wait_event(root->fs_info->async_submit_wait,
1454                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1455                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1456                 }
1457                 atomic_dec(&root->fs_info->async_submit_draining);
1458         }
1459
1460         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1461                 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1462         }
1463
1464         ret = defrag_count;
1465
1466 out_ra:
1467         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1468                 inode_lock(inode);
1469                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1470                 inode_unlock(inode);
1471         }
1472         if (!file)
1473                 kfree(ra);
1474         kfree(pages);
1475         return ret;
1476 }
1477
1478 static noinline int btrfs_ioctl_resize(struct file *file,
1479                                         void __user *arg)
1480 {
1481         u64 new_size;
1482         u64 old_size;
1483         u64 devid = 1;
1484         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
1485         struct btrfs_ioctl_vol_args *vol_args;
1486         struct btrfs_trans_handle *trans;
1487         struct btrfs_device *device = NULL;
1488         char *sizestr;
1489         char *retptr;
1490         char *devstr = NULL;
1491         int ret = 0;
1492         int mod = 0;
1493
1494         if (!capable(CAP_SYS_ADMIN))
1495                 return -EPERM;
1496
1497         ret = mnt_want_write_file(file);
1498         if (ret)
1499                 return ret;
1500
1501         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1502                         1)) {
1503                 mnt_drop_write_file(file);
1504                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1505         }
1506
1507         mutex_lock(&root->fs_info->volume_mutex);
1508         vol_args = memdup_user(arg, sizeof(*vol_args));
1509         if (IS_ERR(vol_args)) {
1510                 ret = PTR_ERR(vol_args);
1511                 goto out;
1512         }
1513
1514         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1515
1516         sizestr = vol_args->name;
1517         devstr = strchr(sizestr, ':');
1518         if (devstr) {
1519                 sizestr = devstr + 1;
1520                 *devstr = '\0';
1521                 devstr = vol_args->name;
1522                 ret = kstrtoull(devstr, 10, &devid);
1523                 if (ret)
1524                         goto out_free;
1525                 if (!devid) {
1526                         ret = -EINVAL;
1527                         goto out_free;
1528                 }
1529                 btrfs_info(root->fs_info, "resizing devid %llu", devid);
1530         }
1531
1532         device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
1533         if (!device) {
1534                 btrfs_info(root->fs_info, "resizer unable to find device %llu",
1535                        devid);
1536                 ret = -ENODEV;
1537                 goto out_free;
1538         }
1539
1540         if (!device->writeable) {
1541                 btrfs_info(root->fs_info,
1542                            "resizer unable to apply on readonly device %llu",
1543                        devid);
1544                 ret = -EPERM;
1545                 goto out_free;
1546         }
1547
1548         if (!strcmp(sizestr, "max"))
1549                 new_size = device->bdev->bd_inode->i_size;
1550         else {
1551                 if (sizestr[0] == '-') {
1552                         mod = -1;
1553                         sizestr++;
1554                 } else if (sizestr[0] == '+') {
1555                         mod = 1;
1556                         sizestr++;
1557                 }
1558                 new_size = memparse(sizestr, &retptr);
1559                 if (*retptr != '\0' || new_size == 0) {
1560                         ret = -EINVAL;
1561                         goto out_free;
1562                 }
1563         }
1564
1565         if (device->is_tgtdev_for_dev_replace) {
1566                 ret = -EPERM;
1567                 goto out_free;
1568         }
1569
1570         old_size = btrfs_device_get_total_bytes(device);
1571
1572         if (mod < 0) {
1573                 if (new_size > old_size) {
1574                         ret = -EINVAL;
1575                         goto out_free;
1576                 }
1577                 new_size = old_size - new_size;
1578         } else if (mod > 0) {
1579                 if (new_size > ULLONG_MAX - old_size) {
1580                         ret = -ERANGE;
1581                         goto out_free;
1582                 }
1583                 new_size = old_size + new_size;
1584         }
1585
1586         if (new_size < SZ_256M) {
1587                 ret = -EINVAL;
1588                 goto out_free;
1589         }
1590         if (new_size > device->bdev->bd_inode->i_size) {
1591                 ret = -EFBIG;
1592                 goto out_free;
1593         }
1594
1595         new_size = div_u64(new_size, root->sectorsize);
1596         new_size *= root->sectorsize;
1597
1598         btrfs_info_in_rcu(root->fs_info, "new size for %s is %llu",
1599                       rcu_str_deref(device->name), new_size);
1600
1601         if (new_size > old_size) {
1602                 trans = btrfs_start_transaction(root, 0);
1603                 if (IS_ERR(trans)) {
1604                         ret = PTR_ERR(trans);
1605                         goto out_free;
1606                 }
1607                 ret = btrfs_grow_device(trans, device, new_size);
1608                 btrfs_commit_transaction(trans, root);
1609         } else if (new_size < old_size) {
1610                 ret = btrfs_shrink_device(device, new_size);
1611         } /* equal, nothing need to do */
1612
1613 out_free:
1614         kfree(vol_args);
1615 out:
1616         mutex_unlock(&root->fs_info->volume_mutex);
1617         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
1618         mnt_drop_write_file(file);
1619         return ret;
1620 }
1621
1622 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1623                                 char *name, unsigned long fd, int subvol,
1624                                 u64 *transid, bool readonly,
1625                                 struct btrfs_qgroup_inherit *inherit)
1626 {
1627         int namelen;
1628         int ret = 0;
1629
1630         ret = mnt_want_write_file(file);
1631         if (ret)
1632                 goto out;
1633
1634         namelen = strlen(name);
1635         if (strchr(name, '/')) {
1636                 ret = -EINVAL;
1637                 goto out_drop_write;
1638         }
1639
1640         if (name[0] == '.' &&
1641            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1642                 ret = -EEXIST;
1643                 goto out_drop_write;
1644         }
1645
1646         if (subvol) {
1647                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1648                                      NULL, transid, readonly, inherit);
1649         } else {
1650                 struct fd src = fdget(fd);
1651                 struct inode *src_inode;
1652                 if (!src.file) {
1653                         ret = -EINVAL;
1654                         goto out_drop_write;
1655                 }
1656
1657                 src_inode = file_inode(src.file);
1658                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1659                         btrfs_info(BTRFS_I(src_inode)->root->fs_info,
1660                                    "Snapshot src from another FS");
1661                         ret = -EXDEV;
1662                 } else if (!inode_owner_or_capable(src_inode)) {
1663                         /*
1664                          * Subvolume creation is not restricted, but snapshots
1665                          * are limited to own subvolumes only
1666                          */
1667                         ret = -EPERM;
1668                 } else {
1669                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1670                                              BTRFS_I(src_inode)->root,
1671                                              transid, readonly, inherit);
1672                 }
1673                 fdput(src);
1674         }
1675 out_drop_write:
1676         mnt_drop_write_file(file);
1677 out:
1678         return ret;
1679 }
1680
1681 static noinline int btrfs_ioctl_snap_create(struct file *file,
1682                                             void __user *arg, int subvol)
1683 {
1684         struct btrfs_ioctl_vol_args *vol_args;
1685         int ret;
1686
1687         vol_args = memdup_user(arg, sizeof(*vol_args));
1688         if (IS_ERR(vol_args))
1689                 return PTR_ERR(vol_args);
1690         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1691
1692         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1693                                               vol_args->fd, subvol,
1694                                               NULL, false, NULL);
1695
1696         kfree(vol_args);
1697         return ret;
1698 }
1699
1700 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1701                                                void __user *arg, int subvol)
1702 {
1703         struct btrfs_ioctl_vol_args_v2 *vol_args;
1704         int ret;
1705         u64 transid = 0;
1706         u64 *ptr = NULL;
1707         bool readonly = false;
1708         struct btrfs_qgroup_inherit *inherit = NULL;
1709
1710         vol_args = memdup_user(arg, sizeof(*vol_args));
1711         if (IS_ERR(vol_args))
1712                 return PTR_ERR(vol_args);
1713         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1714
1715         if (vol_args->flags &
1716             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1717               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1718                 ret = -EOPNOTSUPP;
1719                 goto free_args;
1720         }
1721
1722         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1723                 ptr = &transid;
1724         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1725                 readonly = true;
1726         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1727                 if (vol_args->size > PAGE_CACHE_SIZE) {
1728                         ret = -EINVAL;
1729                         goto free_args;
1730                 }
1731                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1732                 if (IS_ERR(inherit)) {
1733                         ret = PTR_ERR(inherit);
1734                         goto free_args;
1735                 }
1736         }
1737
1738         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1739                                               vol_args->fd, subvol, ptr,
1740                                               readonly, inherit);
1741         if (ret)
1742                 goto free_inherit;
1743
1744         if (ptr && copy_to_user(arg +
1745                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1746                                         transid),
1747                                 ptr, sizeof(*ptr)))
1748                 ret = -EFAULT;
1749
1750 free_inherit:
1751         kfree(inherit);
1752 free_args:
1753         kfree(vol_args);
1754         return ret;
1755 }
1756
1757 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1758                                                 void __user *arg)
1759 {
1760         struct inode *inode = file_inode(file);
1761         struct btrfs_root *root = BTRFS_I(inode)->root;
1762         int ret = 0;
1763         u64 flags = 0;
1764
1765         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1766                 return -EINVAL;
1767
1768         down_read(&root->fs_info->subvol_sem);
1769         if (btrfs_root_readonly(root))
1770                 flags |= BTRFS_SUBVOL_RDONLY;
1771         up_read(&root->fs_info->subvol_sem);
1772
1773         if (copy_to_user(arg, &flags, sizeof(flags)))
1774                 ret = -EFAULT;
1775
1776         return ret;
1777 }
1778
1779 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1780                                               void __user *arg)
1781 {
1782         struct inode *inode = file_inode(file);
1783         struct btrfs_root *root = BTRFS_I(inode)->root;
1784         struct btrfs_trans_handle *trans;
1785         u64 root_flags;
1786         u64 flags;
1787         int ret = 0;
1788
1789         if (!inode_owner_or_capable(inode))
1790                 return -EPERM;
1791
1792         ret = mnt_want_write_file(file);
1793         if (ret)
1794                 goto out;
1795
1796         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1797                 ret = -EINVAL;
1798                 goto out_drop_write;
1799         }
1800
1801         if (copy_from_user(&flags, arg, sizeof(flags))) {
1802                 ret = -EFAULT;
1803                 goto out_drop_write;
1804         }
1805
1806         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1807                 ret = -EINVAL;
1808                 goto out_drop_write;
1809         }
1810
1811         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1812                 ret = -EOPNOTSUPP;
1813                 goto out_drop_write;
1814         }
1815
1816         down_write(&root->fs_info->subvol_sem);
1817
1818         /* nothing to do */
1819         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1820                 goto out_drop_sem;
1821
1822         root_flags = btrfs_root_flags(&root->root_item);
1823         if (flags & BTRFS_SUBVOL_RDONLY) {
1824                 btrfs_set_root_flags(&root->root_item,
1825                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1826         } else {
1827                 /*
1828                  * Block RO -> RW transition if this subvolume is involved in
1829                  * send
1830                  */
1831                 spin_lock(&root->root_item_lock);
1832                 if (root->send_in_progress == 0) {
1833                         btrfs_set_root_flags(&root->root_item,
1834                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1835                         spin_unlock(&root->root_item_lock);
1836                 } else {
1837                         spin_unlock(&root->root_item_lock);
1838                         btrfs_warn(root->fs_info,
1839                         "Attempt to set subvolume %llu read-write during send",
1840                                         root->root_key.objectid);
1841                         ret = -EPERM;
1842                         goto out_drop_sem;
1843                 }
1844         }
1845
1846         trans = btrfs_start_transaction(root, 1);
1847         if (IS_ERR(trans)) {
1848                 ret = PTR_ERR(trans);
1849                 goto out_reset;
1850         }
1851
1852         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1853                                 &root->root_key, &root->root_item);
1854
1855         btrfs_commit_transaction(trans, root);
1856 out_reset:
1857         if (ret)
1858                 btrfs_set_root_flags(&root->root_item, root_flags);
1859 out_drop_sem:
1860         up_write(&root->fs_info->subvol_sem);
1861 out_drop_write:
1862         mnt_drop_write_file(file);
1863 out:
1864         return ret;
1865 }
1866
1867 /*
1868  * helper to check if the subvolume references other subvolumes
1869  */
1870 static noinline int may_destroy_subvol(struct btrfs_root *root)
1871 {
1872         struct btrfs_path *path;
1873         struct btrfs_dir_item *di;
1874         struct btrfs_key key;
1875         u64 dir_id;
1876         int ret;
1877
1878         path = btrfs_alloc_path();
1879         if (!path)
1880                 return -ENOMEM;
1881
1882         /* Make sure this root isn't set as the default subvol */
1883         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
1884         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, path,
1885                                    dir_id, "default", 7, 0);
1886         if (di && !IS_ERR(di)) {
1887                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1888                 if (key.objectid == root->root_key.objectid) {
1889                         ret = -EPERM;
1890                         btrfs_err(root->fs_info, "deleting default subvolume "
1891                                   "%llu is not allowed", key.objectid);
1892                         goto out;
1893                 }
1894                 btrfs_release_path(path);
1895         }
1896
1897         key.objectid = root->root_key.objectid;
1898         key.type = BTRFS_ROOT_REF_KEY;
1899         key.offset = (u64)-1;
1900
1901         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1902                                 &key, path, 0, 0);
1903         if (ret < 0)
1904                 goto out;
1905         BUG_ON(ret == 0);
1906
1907         ret = 0;
1908         if (path->slots[0] > 0) {
1909                 path->slots[0]--;
1910                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1911                 if (key.objectid == root->root_key.objectid &&
1912                     key.type == BTRFS_ROOT_REF_KEY)
1913                         ret = -ENOTEMPTY;
1914         }
1915 out:
1916         btrfs_free_path(path);
1917         return ret;
1918 }
1919
1920 static noinline int key_in_sk(struct btrfs_key *key,
1921                               struct btrfs_ioctl_search_key *sk)
1922 {
1923         struct btrfs_key test;
1924         int ret;
1925
1926         test.objectid = sk->min_objectid;
1927         test.type = sk->min_type;
1928         test.offset = sk->min_offset;
1929
1930         ret = btrfs_comp_cpu_keys(key, &test);
1931         if (ret < 0)
1932                 return 0;
1933
1934         test.objectid = sk->max_objectid;
1935         test.type = sk->max_type;
1936         test.offset = sk->max_offset;
1937
1938         ret = btrfs_comp_cpu_keys(key, &test);
1939         if (ret > 0)
1940                 return 0;
1941         return 1;
1942 }
1943
1944 static noinline int copy_to_sk(struct btrfs_root *root,
1945                                struct btrfs_path *path,
1946                                struct btrfs_key *key,
1947                                struct btrfs_ioctl_search_key *sk,
1948                                size_t *buf_size,
1949                                char __user *ubuf,
1950                                unsigned long *sk_offset,
1951                                int *num_found)
1952 {
1953         u64 found_transid;
1954         struct extent_buffer *leaf;
1955         struct btrfs_ioctl_search_header sh;
1956         struct btrfs_key test;
1957         unsigned long item_off;
1958         unsigned long item_len;
1959         int nritems;
1960         int i;
1961         int slot;
1962         int ret = 0;
1963
1964         leaf = path->nodes[0];
1965         slot = path->slots[0];
1966         nritems = btrfs_header_nritems(leaf);
1967
1968         if (btrfs_header_generation(leaf) > sk->max_transid) {
1969                 i = nritems;
1970                 goto advance_key;
1971         }
1972         found_transid = btrfs_header_generation(leaf);
1973
1974         for (i = slot; i < nritems; i++) {
1975                 item_off = btrfs_item_ptr_offset(leaf, i);
1976                 item_len = btrfs_item_size_nr(leaf, i);
1977
1978                 btrfs_item_key_to_cpu(leaf, key, i);
1979                 if (!key_in_sk(key, sk))
1980                         continue;
1981
1982                 if (sizeof(sh) + item_len > *buf_size) {
1983                         if (*num_found) {
1984                                 ret = 1;
1985                                 goto out;
1986                         }
1987
1988                         /*
1989                          * return one empty item back for v1, which does not
1990                          * handle -EOVERFLOW
1991                          */
1992
1993                         *buf_size = sizeof(sh) + item_len;
1994                         item_len = 0;
1995                         ret = -EOVERFLOW;
1996                 }
1997
1998                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
1999                         ret = 1;
2000                         goto out;
2001                 }
2002
2003                 sh.objectid = key->objectid;
2004                 sh.offset = key->offset;
2005                 sh.type = key->type;
2006                 sh.len = item_len;
2007                 sh.transid = found_transid;
2008
2009                 /* copy search result header */
2010                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2011                         ret = -EFAULT;
2012                         goto out;
2013                 }
2014
2015                 *sk_offset += sizeof(sh);
2016
2017                 if (item_len) {
2018                         char __user *up = ubuf + *sk_offset;
2019                         /* copy the item */
2020                         if (read_extent_buffer_to_user(leaf, up,
2021                                                        item_off, item_len)) {
2022                                 ret = -EFAULT;
2023                                 goto out;
2024                         }
2025
2026                         *sk_offset += item_len;
2027                 }
2028                 (*num_found)++;
2029
2030                 if (ret) /* -EOVERFLOW from above */
2031                         goto out;
2032
2033                 if (*num_found >= sk->nr_items) {
2034                         ret = 1;
2035                         goto out;
2036                 }
2037         }
2038 advance_key:
2039         ret = 0;
2040         test.objectid = sk->max_objectid;
2041         test.type = sk->max_type;
2042         test.offset = sk->max_offset;
2043         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2044                 ret = 1;
2045         else if (key->offset < (u64)-1)
2046                 key->offset++;
2047         else if (key->type < (u8)-1) {
2048                 key->offset = 0;
2049                 key->type++;
2050         } else if (key->objectid < (u64)-1) {
2051                 key->offset = 0;
2052                 key->type = 0;
2053                 key->objectid++;
2054         } else
2055                 ret = 1;
2056 out:
2057         /*
2058          *  0: all items from this leaf copied, continue with next
2059          *  1: * more items can be copied, but unused buffer is too small
2060          *     * all items were found
2061          *     Either way, it will stops the loop which iterates to the next
2062          *     leaf
2063          *  -EOVERFLOW: item was to large for buffer
2064          *  -EFAULT: could not copy extent buffer back to userspace
2065          */
2066         return ret;
2067 }
2068
2069 static noinline int search_ioctl(struct inode *inode,
2070                                  struct btrfs_ioctl_search_key *sk,
2071                                  size_t *buf_size,
2072                                  char __user *ubuf)
2073 {
2074         struct btrfs_root *root;
2075         struct btrfs_key key;
2076         struct btrfs_path *path;
2077         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
2078         int ret;
2079         int num_found = 0;
2080         unsigned long sk_offset = 0;
2081
2082         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2083                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2084                 return -EOVERFLOW;
2085         }
2086
2087         path = btrfs_alloc_path();
2088         if (!path)
2089                 return -ENOMEM;
2090
2091         if (sk->tree_id == 0) {
2092                 /* search the root of the inode that was passed */
2093                 root = BTRFS_I(inode)->root;
2094         } else {
2095                 key.objectid = sk->tree_id;
2096                 key.type = BTRFS_ROOT_ITEM_KEY;
2097                 key.offset = (u64)-1;
2098                 root = btrfs_read_fs_root_no_name(info, &key);
2099                 if (IS_ERR(root)) {
2100                         btrfs_err(info, "could not find root %llu",
2101                                sk->tree_id);
2102                         btrfs_free_path(path);
2103                         return -ENOENT;
2104                 }
2105         }
2106
2107         key.objectid = sk->min_objectid;
2108         key.type = sk->min_type;
2109         key.offset = sk->min_offset;
2110
2111         while (1) {
2112                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2113                 if (ret != 0) {
2114                         if (ret > 0)
2115                                 ret = 0;
2116                         goto err;
2117                 }
2118                 ret = copy_to_sk(root, path, &key, sk, buf_size, ubuf,
2119                                  &sk_offset, &num_found);
2120                 btrfs_release_path(path);
2121                 if (ret)
2122                         break;
2123
2124         }
2125         if (ret > 0)
2126                 ret = 0;
2127 err:
2128         sk->nr_items = num_found;
2129         btrfs_free_path(path);
2130         return ret;
2131 }
2132
2133 static noinline int btrfs_ioctl_tree_search(struct file *file,
2134                                            void __user *argp)
2135 {
2136         struct btrfs_ioctl_search_args __user *uargs;
2137         struct btrfs_ioctl_search_key sk;
2138         struct inode *inode;
2139         int ret;
2140         size_t buf_size;
2141
2142         if (!capable(CAP_SYS_ADMIN))
2143                 return -EPERM;
2144
2145         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2146
2147         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2148                 return -EFAULT;
2149
2150         buf_size = sizeof(uargs->buf);
2151
2152         inode = file_inode(file);
2153         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2154
2155         /*
2156          * In the origin implementation an overflow is handled by returning a
2157          * search header with a len of zero, so reset ret.
2158          */
2159         if (ret == -EOVERFLOW)
2160                 ret = 0;
2161
2162         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2163                 ret = -EFAULT;
2164         return ret;
2165 }
2166
2167 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2168                                                void __user *argp)
2169 {
2170         struct btrfs_ioctl_search_args_v2 __user *uarg;
2171         struct btrfs_ioctl_search_args_v2 args;
2172         struct inode *inode;
2173         int ret;
2174         size_t buf_size;
2175         const size_t buf_limit = SZ_16M;
2176
2177         if (!capable(CAP_SYS_ADMIN))
2178                 return -EPERM;
2179
2180         /* copy search header and buffer size */
2181         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2182         if (copy_from_user(&args, uarg, sizeof(args)))
2183                 return -EFAULT;
2184
2185         buf_size = args.buf_size;
2186
2187         if (buf_size < sizeof(struct btrfs_ioctl_search_header))
2188                 return -EOVERFLOW;
2189
2190         /* limit result size to 16MB */
2191         if (buf_size > buf_limit)
2192                 buf_size = buf_limit;
2193
2194         inode = file_inode(file);
2195         ret = search_ioctl(inode, &args.key, &buf_size,
2196                            (char *)(&uarg->buf[0]));
2197         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2198                 ret = -EFAULT;
2199         else if (ret == -EOVERFLOW &&
2200                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2201                 ret = -EFAULT;
2202
2203         return ret;
2204 }
2205
2206 /*
2207  * Search INODE_REFs to identify path name of 'dirid' directory
2208  * in a 'tree_id' tree. and sets path name to 'name'.
2209  */
2210 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2211                                 u64 tree_id, u64 dirid, char *name)
2212 {
2213         struct btrfs_root *root;
2214         struct btrfs_key key;
2215         char *ptr;
2216         int ret = -1;
2217         int slot;
2218         int len;
2219         int total_len = 0;
2220         struct btrfs_inode_ref *iref;
2221         struct extent_buffer *l;
2222         struct btrfs_path *path;
2223
2224         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2225                 name[0]='\0';
2226                 return 0;
2227         }
2228
2229         path = btrfs_alloc_path();
2230         if (!path)
2231                 return -ENOMEM;
2232
2233         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
2234
2235         key.objectid = tree_id;
2236         key.type = BTRFS_ROOT_ITEM_KEY;
2237         key.offset = (u64)-1;
2238         root = btrfs_read_fs_root_no_name(info, &key);
2239         if (IS_ERR(root)) {
2240                 btrfs_err(info, "could not find root %llu", tree_id);
2241                 ret = -ENOENT;
2242                 goto out;
2243         }
2244
2245         key.objectid = dirid;
2246         key.type = BTRFS_INODE_REF_KEY;
2247         key.offset = (u64)-1;
2248
2249         while (1) {
2250                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2251                 if (ret < 0)
2252                         goto out;
2253                 else if (ret > 0) {
2254                         ret = btrfs_previous_item(root, path, dirid,
2255                                                   BTRFS_INODE_REF_KEY);
2256                         if (ret < 0)
2257                                 goto out;
2258                         else if (ret > 0) {
2259                                 ret = -ENOENT;
2260                                 goto out;
2261                         }
2262                 }
2263
2264                 l = path->nodes[0];
2265                 slot = path->slots[0];
2266                 btrfs_item_key_to_cpu(l, &key, slot);
2267
2268                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2269                 len = btrfs_inode_ref_name_len(l, iref);
2270                 ptr -= len + 1;
2271                 total_len += len + 1;
2272                 if (ptr < name) {
2273                         ret = -ENAMETOOLONG;
2274                         goto out;
2275                 }
2276
2277                 *(ptr + len) = '/';
2278                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2279
2280                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2281                         break;
2282
2283                 btrfs_release_path(path);
2284                 key.objectid = key.offset;
2285                 key.offset = (u64)-1;
2286                 dirid = key.objectid;
2287         }
2288         memmove(name, ptr, total_len);
2289         name[total_len] = '\0';
2290         ret = 0;
2291 out:
2292         btrfs_free_path(path);
2293         return ret;
2294 }
2295
2296 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2297                                            void __user *argp)
2298 {
2299          struct btrfs_ioctl_ino_lookup_args *args;
2300          struct inode *inode;
2301         int ret = 0;
2302
2303         args = memdup_user(argp, sizeof(*args));
2304         if (IS_ERR(args))
2305                 return PTR_ERR(args);
2306
2307         inode = file_inode(file);
2308
2309         /*
2310          * Unprivileged query to obtain the containing subvolume root id. The
2311          * path is reset so it's consistent with btrfs_search_path_in_tree.
2312          */
2313         if (args->treeid == 0)
2314                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2315
2316         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2317                 args->name[0] = 0;
2318                 goto out;
2319         }
2320
2321         if (!capable(CAP_SYS_ADMIN)) {
2322                 ret = -EPERM;
2323                 goto out;
2324         }
2325
2326         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2327                                         args->treeid, args->objectid,
2328                                         args->name);
2329
2330 out:
2331         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2332                 ret = -EFAULT;
2333
2334         kfree(args);
2335         return ret;
2336 }
2337
2338 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2339                                              void __user *arg)
2340 {
2341         struct dentry *parent = file->f_path.dentry;
2342         struct dentry *dentry;
2343         struct inode *dir = d_inode(parent);
2344         struct inode *inode;
2345         struct btrfs_root *root = BTRFS_I(dir)->root;
2346         struct btrfs_root *dest = NULL;
2347         struct btrfs_ioctl_vol_args *vol_args;
2348         struct btrfs_trans_handle *trans;
2349         struct btrfs_block_rsv block_rsv;
2350         u64 root_flags;
2351         u64 qgroup_reserved;
2352         int namelen;
2353         int ret;
2354         int err = 0;
2355
2356         vol_args = memdup_user(arg, sizeof(*vol_args));
2357         if (IS_ERR(vol_args))
2358                 return PTR_ERR(vol_args);
2359
2360         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2361         namelen = strlen(vol_args->name);
2362         if (strchr(vol_args->name, '/') ||
2363             strncmp(vol_args->name, "..", namelen) == 0) {
2364                 err = -EINVAL;
2365                 goto out;
2366         }
2367
2368         err = mnt_want_write_file(file);
2369         if (err)
2370                 goto out;
2371
2372
2373         err = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
2374         if (err == -EINTR)
2375                 goto out_drop_write;
2376         dentry = lookup_one_len(vol_args->name, parent, namelen);
2377         if (IS_ERR(dentry)) {
2378                 err = PTR_ERR(dentry);
2379                 goto out_unlock_dir;
2380         }
2381
2382         if (d_really_is_negative(dentry)) {
2383                 err = -ENOENT;
2384                 goto out_dput;
2385         }
2386
2387         inode = d_inode(dentry);
2388         dest = BTRFS_I(inode)->root;
2389         if (!capable(CAP_SYS_ADMIN)) {
2390                 /*
2391                  * Regular user.  Only allow this with a special mount
2392                  * option, when the user has write+exec access to the
2393                  * subvol root, and when rmdir(2) would have been
2394                  * allowed.
2395                  *
2396                  * Note that this is _not_ check that the subvol is
2397                  * empty or doesn't contain data that we wouldn't
2398                  * otherwise be able to delete.
2399                  *
2400                  * Users who want to delete empty subvols should try
2401                  * rmdir(2).
2402                  */
2403                 err = -EPERM;
2404                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2405                         goto out_dput;
2406
2407                 /*
2408                  * Do not allow deletion if the parent dir is the same
2409                  * as the dir to be deleted.  That means the ioctl
2410                  * must be called on the dentry referencing the root
2411                  * of the subvol, not a random directory contained
2412                  * within it.
2413                  */
2414                 err = -EINVAL;
2415                 if (root == dest)
2416                         goto out_dput;
2417
2418                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2419                 if (err)
2420                         goto out_dput;
2421         }
2422
2423         /* check if subvolume may be deleted by a user */
2424         err = btrfs_may_delete(dir, dentry, 1);
2425         if (err)
2426                 goto out_dput;
2427
2428         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2429                 err = -EINVAL;
2430                 goto out_dput;
2431         }
2432
2433         inode_lock(inode);
2434
2435         /*
2436          * Don't allow to delete a subvolume with send in progress. This is
2437          * inside the i_mutex so the error handling that has to drop the bit
2438          * again is not run concurrently.
2439          */
2440         spin_lock(&dest->root_item_lock);
2441         root_flags = btrfs_root_flags(&dest->root_item);
2442         if (dest->send_in_progress == 0) {
2443                 btrfs_set_root_flags(&dest->root_item,
2444                                 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2445                 spin_unlock(&dest->root_item_lock);
2446         } else {
2447                 spin_unlock(&dest->root_item_lock);
2448                 btrfs_warn(root->fs_info,
2449                         "Attempt to delete subvolume %llu during send",
2450                         dest->root_key.objectid);
2451                 err = -EPERM;
2452                 goto out_unlock_inode;
2453         }
2454
2455         down_write(&root->fs_info->subvol_sem);
2456
2457         err = may_destroy_subvol(dest);
2458         if (err)
2459                 goto out_up_write;
2460
2461         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2462         /*
2463          * One for dir inode, two for dir entries, two for root
2464          * ref/backref.
2465          */
2466         err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2467                                                5, &qgroup_reserved, true);
2468         if (err)
2469                 goto out_up_write;
2470
2471         trans = btrfs_start_transaction(root, 0);
2472         if (IS_ERR(trans)) {
2473                 err = PTR_ERR(trans);
2474                 goto out_release;
2475         }
2476         trans->block_rsv = &block_rsv;
2477         trans->bytes_reserved = block_rsv.size;
2478
2479         ret = btrfs_unlink_subvol(trans, root, dir,
2480                                 dest->root_key.objectid,
2481                                 dentry->d_name.name,
2482                                 dentry->d_name.len);
2483         if (ret) {
2484                 err = ret;
2485                 btrfs_abort_transaction(trans, root, ret);
2486                 goto out_end_trans;
2487         }
2488
2489         btrfs_record_root_in_trans(trans, dest);
2490
2491         memset(&dest->root_item.drop_progress, 0,
2492                 sizeof(dest->root_item.drop_progress));
2493         dest->root_item.drop_level = 0;
2494         btrfs_set_root_refs(&dest->root_item, 0);
2495
2496         if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2497                 ret = btrfs_insert_orphan_item(trans,
2498                                         root->fs_info->tree_root,
2499                                         dest->root_key.objectid);
2500                 if (ret) {
2501                         btrfs_abort_transaction(trans, root, ret);
2502                         err = ret;
2503                         goto out_end_trans;
2504                 }
2505         }
2506
2507         ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2508                                   dest->root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
2509                                   dest->root_key.objectid);
2510         if (ret && ret != -ENOENT) {
2511                 btrfs_abort_transaction(trans, root, ret);
2512                 err = ret;
2513                 goto out_end_trans;
2514         }
2515         if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2516                 ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2517                                           dest->root_item.received_uuid,
2518                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2519                                           dest->root_key.objectid);
2520                 if (ret && ret != -ENOENT) {
2521                         btrfs_abort_transaction(trans, root, ret);
2522                         err = ret;
2523                         goto out_end_trans;
2524                 }
2525         }
2526
2527 out_end_trans:
2528         trans->block_rsv = NULL;
2529         trans->bytes_reserved = 0;
2530         ret = btrfs_end_transaction(trans, root);
2531         if (ret && !err)
2532                 err = ret;
2533         inode->i_flags |= S_DEAD;
2534 out_release:
2535         btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
2536 out_up_write:
2537         up_write(&root->fs_info->subvol_sem);
2538         if (err) {
2539                 spin_lock(&dest->root_item_lock);
2540                 root_flags = btrfs_root_flags(&dest->root_item);
2541                 btrfs_set_root_flags(&dest->root_item,
2542                                 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2543                 spin_unlock(&dest->root_item_lock);
2544         }
2545 out_unlock_inode:
2546         inode_unlock(inode);
2547         if (!err) {
2548                 d_invalidate(dentry);
2549                 btrfs_invalidate_inodes(dest);
2550                 d_delete(dentry);
2551                 ASSERT(dest->send_in_progress == 0);
2552
2553                 /* the last ref */
2554                 if (dest->ino_cache_inode) {
2555                         iput(dest->ino_cache_inode);
2556                         dest->ino_cache_inode = NULL;
2557                 }
2558         }
2559 out_dput:
2560         dput(dentry);
2561 out_unlock_dir:
2562         inode_unlock(dir);
2563 out_drop_write:
2564         mnt_drop_write_file(file);
2565 out:
2566         kfree(vol_args);
2567         return err;
2568 }
2569
2570 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2571 {
2572         struct inode *inode = file_inode(file);
2573         struct btrfs_root *root = BTRFS_I(inode)->root;
2574         struct btrfs_ioctl_defrag_range_args *range;
2575         int ret;
2576
2577         ret = mnt_want_write_file(file);
2578         if (ret)
2579                 return ret;
2580
2581         if (btrfs_root_readonly(root)) {
2582                 ret = -EROFS;
2583                 goto out;
2584         }
2585
2586         switch (inode->i_mode & S_IFMT) {
2587         case S_IFDIR:
2588                 if (!capable(CAP_SYS_ADMIN)) {
2589                         ret = -EPERM;
2590                         goto out;
2591                 }
2592                 ret = btrfs_defrag_root(root);
2593                 if (ret)
2594                         goto out;
2595                 ret = btrfs_defrag_root(root->fs_info->extent_root);
2596                 break;
2597         case S_IFREG:
2598                 if (!(file->f_mode & FMODE_WRITE)) {
2599                         ret = -EINVAL;
2600                         goto out;
2601                 }
2602
2603                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2604                 if (!range) {
2605                         ret = -ENOMEM;
2606                         goto out;
2607                 }
2608
2609                 if (argp) {
2610                         if (copy_from_user(range, argp,
2611                                            sizeof(*range))) {
2612                                 ret = -EFAULT;
2613                                 kfree(range);
2614                                 goto out;
2615                         }
2616                         /* compression requires us to start the IO */
2617                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2618                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2619                                 range->extent_thresh = (u32)-1;
2620                         }
2621                 } else {
2622                         /* the rest are all set to zero by kzalloc */
2623                         range->len = (u64)-1;
2624                 }
2625                 ret = btrfs_defrag_file(file_inode(file), file,
2626                                         range, 0, 0);
2627                 if (ret > 0)
2628                         ret = 0;
2629                 kfree(range);
2630                 break;
2631         default:
2632                 ret = -EINVAL;
2633         }
2634 out:
2635         mnt_drop_write_file(file);
2636         return ret;
2637 }
2638
2639 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2640 {
2641         struct btrfs_ioctl_vol_args *vol_args;
2642         int ret;
2643
2644         if (!capable(CAP_SYS_ADMIN))
2645                 return -EPERM;
2646
2647         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2648                         1)) {
2649                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2650         }
2651
2652         mutex_lock(&root->fs_info->volume_mutex);
2653         vol_args = memdup_user(arg, sizeof(*vol_args));
2654         if (IS_ERR(vol_args)) {
2655                 ret = PTR_ERR(vol_args);
2656                 goto out;
2657         }
2658
2659         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2660         ret = btrfs_init_new_device(root, vol_args->name);
2661
2662         if (!ret)
2663                 btrfs_info(root->fs_info, "disk added %s",vol_args->name);
2664
2665         kfree(vol_args);
2666 out:
2667         mutex_unlock(&root->fs_info->volume_mutex);
2668         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2669         return ret;
2670 }
2671
2672 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2673 {
2674         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
2675         struct btrfs_ioctl_vol_args *vol_args;
2676         int ret;
2677
2678         if (!capable(CAP_SYS_ADMIN))
2679                 return -EPERM;
2680
2681         ret = mnt_want_write_file(file);
2682         if (ret)
2683                 return ret;
2684
2685         vol_args = memdup_user(arg, sizeof(*vol_args));
2686         if (IS_ERR(vol_args)) {
2687                 ret = PTR_ERR(vol_args);
2688                 goto err_drop;
2689         }
2690
2691         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2692
2693         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2694                         1)) {
2695                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2696                 goto out;
2697         }
2698
2699         mutex_lock(&root->fs_info->volume_mutex);
2700         ret = btrfs_rm_device(root, vol_args->name);
2701         mutex_unlock(&root->fs_info->volume_mutex);
2702         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2703
2704         if (!ret)
2705                 btrfs_info(root->fs_info, "disk deleted %s",vol_args->name);
2706
2707 out:
2708         kfree(vol_args);
2709 err_drop:
2710         mnt_drop_write_file(file);
2711         return ret;
2712 }
2713
2714 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2715 {
2716         struct btrfs_ioctl_fs_info_args *fi_args;
2717         struct btrfs_device *device;
2718         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2719         int ret = 0;
2720
2721         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2722         if (!fi_args)
2723                 return -ENOMEM;
2724
2725         mutex_lock(&fs_devices->device_list_mutex);
2726         fi_args->num_devices = fs_devices->num_devices;
2727         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2728
2729         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2730                 if (device->devid > fi_args->max_id)
2731                         fi_args->max_id = device->devid;
2732         }
2733         mutex_unlock(&fs_devices->device_list_mutex);
2734
2735         fi_args->nodesize = root->fs_info->super_copy->nodesize;
2736         fi_args->sectorsize = root->fs_info->super_copy->sectorsize;
2737         fi_args->clone_alignment = root->fs_info->super_copy->sectorsize;
2738
2739         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2740                 ret = -EFAULT;
2741
2742         kfree(fi_args);
2743         return ret;
2744 }
2745
2746 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2747 {
2748         struct btrfs_ioctl_dev_info_args *di_args;
2749         struct btrfs_device *dev;
2750         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2751         int ret = 0;
2752         char *s_uuid = NULL;
2753
2754         di_args = memdup_user(arg, sizeof(*di_args));
2755         if (IS_ERR(di_args))
2756                 return PTR_ERR(di_args);
2757
2758         if (!btrfs_is_empty_uuid(di_args->uuid))
2759                 s_uuid = di_args->uuid;
2760
2761         mutex_lock(&fs_devices->device_list_mutex);
2762         dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
2763
2764         if (!dev) {
2765                 ret = -ENODEV;
2766                 goto out;
2767         }
2768
2769         di_args->devid = dev->devid;
2770         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2771         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2772         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2773         if (dev->name) {
2774                 struct rcu_string *name;
2775
2776                 rcu_read_lock();
2777                 name = rcu_dereference(dev->name);
2778                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2779                 rcu_read_unlock();
2780                 di_args->path[sizeof(di_args->path) - 1] = 0;
2781         } else {
2782                 di_args->path[0] = '\0';
2783         }
2784
2785 out:
2786         mutex_unlock(&fs_devices->device_list_mutex);
2787         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2788                 ret = -EFAULT;
2789
2790         kfree(di_args);
2791         return ret;
2792 }
2793
2794 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
2795 {
2796         struct page *page;
2797
2798         page = grab_cache_page(inode->i_mapping, index);
2799         if (!page)
2800                 return ERR_PTR(-ENOMEM);
2801
2802         if (!PageUptodate(page)) {
2803                 int ret;
2804
2805                 ret = btrfs_readpage(NULL, page);
2806                 if (ret)
2807                         return ERR_PTR(ret);
2808                 lock_page(page);
2809                 if (!PageUptodate(page)) {
2810                         unlock_page(page);
2811                         page_cache_release(page);
2812                         return ERR_PTR(-EIO);
2813                 }
2814                 if (page->mapping != inode->i_mapping) {
2815                         unlock_page(page);
2816                         page_cache_release(page);
2817                         return ERR_PTR(-EAGAIN);
2818                 }
2819         }
2820
2821         return page;
2822 }
2823
2824 static int gather_extent_pages(struct inode *inode, struct page **pages,
2825                                int num_pages, u64 off)
2826 {
2827         int i;
2828         pgoff_t index = off >> PAGE_CACHE_SHIFT;
2829
2830         for (i = 0; i < num_pages; i++) {
2831 again:
2832                 pages[i] = extent_same_get_page(inode, index + i);
2833                 if (IS_ERR(pages[i])) {
2834                         int err = PTR_ERR(pages[i]);
2835
2836                         if (err == -EAGAIN)
2837                                 goto again;
2838                         pages[i] = NULL;
2839                         return err;
2840                 }
2841         }
2842         return 0;
2843 }
2844
2845 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
2846                              bool retry_range_locking)
2847 {
2848         /*
2849          * Do any pending delalloc/csum calculations on inode, one way or
2850          * another, and lock file content.
2851          * The locking order is:
2852          *
2853          *   1) pages
2854          *   2) range in the inode's io tree
2855          */
2856         while (1) {
2857                 struct btrfs_ordered_extent *ordered;
2858                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2859                 ordered = btrfs_lookup_first_ordered_extent(inode,
2860                                                             off + len - 1);
2861                 if ((!ordered ||
2862                      ordered->file_offset + ordered->len <= off ||
2863                      ordered->file_offset >= off + len) &&
2864                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2865                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2866                         if (ordered)
2867                                 btrfs_put_ordered_extent(ordered);
2868                         break;
2869                 }
2870                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2871                 if (ordered)
2872                         btrfs_put_ordered_extent(ordered);
2873                 if (!retry_range_locking)
2874                         return -EAGAIN;
2875                 btrfs_wait_ordered_range(inode, off, len);
2876         }
2877         return 0;
2878 }
2879
2880 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2881 {
2882         inode_unlock(inode1);
2883         inode_unlock(inode2);
2884 }
2885
2886 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2887 {
2888         if (inode1 < inode2)
2889                 swap(inode1, inode2);
2890
2891         inode_lock_nested(inode1, I_MUTEX_PARENT);
2892         inode_lock_nested(inode2, I_MUTEX_CHILD);
2893 }
2894
2895 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2896                                       struct inode *inode2, u64 loff2, u64 len)
2897 {
2898         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2899         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2900 }
2901
2902 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2903                                     struct inode *inode2, u64 loff2, u64 len,
2904                                     bool retry_range_locking)
2905 {
2906         int ret;
2907
2908         if (inode1 < inode2) {
2909                 swap(inode1, inode2);
2910                 swap(loff1, loff2);
2911         }
2912         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
2913         if (ret)
2914                 return ret;
2915         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
2916         if (ret)
2917                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
2918                               loff1 + len - 1);
2919         return ret;
2920 }
2921
2922 struct cmp_pages {
2923         int             num_pages;
2924         struct page     **src_pages;
2925         struct page     **dst_pages;
2926 };
2927
2928 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
2929 {
2930         int i;
2931         struct page *pg;
2932
2933         for (i = 0; i < cmp->num_pages; i++) {
2934                 pg = cmp->src_pages[i];
2935                 if (pg) {
2936                         unlock_page(pg);
2937                         page_cache_release(pg);
2938                 }
2939                 pg = cmp->dst_pages[i];
2940                 if (pg) {
2941                         unlock_page(pg);
2942                         page_cache_release(pg);
2943                 }
2944         }
2945         kfree(cmp->src_pages);
2946         kfree(cmp->dst_pages);
2947 }
2948
2949 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
2950                                   struct inode *dst, u64 dst_loff,
2951                                   u64 len, struct cmp_pages *cmp)
2952 {
2953         int ret;
2954         int num_pages = PAGE_CACHE_ALIGN(len) >> PAGE_CACHE_SHIFT;
2955         struct page **src_pgarr, **dst_pgarr;
2956
2957         /*
2958          * We must gather up all the pages before we initiate our
2959          * extent locking. We use an array for the page pointers. Size
2960          * of the array is bounded by len, which is in turn bounded by
2961          * BTRFS_MAX_DEDUPE_LEN.
2962          */
2963         src_pgarr = kzalloc(num_pages * sizeof(struct page *), GFP_NOFS);
2964         dst_pgarr = kzalloc(num_pages * sizeof(struct page *), GFP_NOFS);
2965         if (!src_pgarr || !dst_pgarr) {
2966                 kfree(src_pgarr);
2967                 kfree(dst_pgarr);
2968                 return -ENOMEM;
2969         }
2970         cmp->num_pages = num_pages;
2971         cmp->src_pages = src_pgarr;
2972         cmp->dst_pages = dst_pgarr;
2973
2974         ret = gather_extent_pages(src, cmp->src_pages, cmp->num_pages, loff);
2975         if (ret)
2976                 goto out;
2977
2978         ret = gather_extent_pages(dst, cmp->dst_pages, cmp->num_pages, dst_loff);
2979
2980 out:
2981         if (ret)
2982                 btrfs_cmp_data_free(cmp);
2983         return 0;
2984 }
2985
2986 static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
2987                           u64 dst_loff, u64 len, struct cmp_pages *cmp)
2988 {
2989         int ret = 0;
2990         int i;
2991         struct page *src_page, *dst_page;
2992         unsigned int cmp_len = PAGE_CACHE_SIZE;
2993         void *addr, *dst_addr;
2994
2995         i = 0;
2996         while (len) {
2997                 if (len < PAGE_CACHE_SIZE)
2998                         cmp_len = len;
2999
3000                 BUG_ON(i >= cmp->num_pages);
3001
3002                 src_page = cmp->src_pages[i];
3003                 dst_page = cmp->dst_pages[i];
3004                 ASSERT(PageLocked(src_page));
3005                 ASSERT(PageLocked(dst_page));
3006
3007                 addr = kmap_atomic(src_page);
3008                 dst_addr = kmap_atomic(dst_page);
3009
3010                 flush_dcache_page(src_page);
3011                 flush_dcache_page(dst_page);
3012
3013                 if (memcmp(addr, dst_addr, cmp_len))
3014                         ret = -EBADE;
3015
3016                 kunmap_atomic(addr);
3017                 kunmap_atomic(dst_addr);
3018
3019                 if (ret)
3020                         break;
3021
3022                 len -= cmp_len;
3023                 i++;
3024         }
3025
3026         return ret;
3027 }
3028
3029 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3030                                      u64 olen)
3031 {
3032         u64 len = *plen;
3033         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3034
3035         if (off + olen > inode->i_size || off + olen < off)
3036                 return -EINVAL;
3037
3038         /* if we extend to eof, continue to block boundary */
3039         if (off + len == inode->i_size)
3040                 *plen = len = ALIGN(inode->i_size, bs) - off;
3041
3042         /* Check that we are block aligned - btrfs_clone() requires this */
3043         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3044                 return -EINVAL;
3045
3046         return 0;
3047 }
3048
3049 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3050                              struct inode *dst, u64 dst_loff)
3051 {
3052         int ret;
3053         u64 len = olen;
3054         struct cmp_pages cmp;
3055         int same_inode = 0;
3056         u64 same_lock_start = 0;
3057         u64 same_lock_len = 0;
3058
3059         if (src == dst)
3060                 same_inode = 1;
3061
3062         if (len == 0)
3063                 return 0;
3064
3065         if (same_inode) {
3066                 inode_lock(src);
3067
3068                 ret = extent_same_check_offsets(src, loff, &len, olen);
3069                 if (ret)
3070                         goto out_unlock;
3071
3072                 /*
3073                  * Single inode case wants the same checks, except we
3074                  * don't want our length pushed out past i_size as
3075                  * comparing that data range makes no sense.
3076                  *
3077                  * extent_same_check_offsets() will do this for an
3078                  * unaligned length at i_size, so catch it here and
3079                  * reject the request.
3080                  *
3081                  * This effectively means we require aligned extents
3082                  * for the single-inode case, whereas the other cases
3083                  * allow an unaligned length so long as it ends at
3084                  * i_size.
3085                  */
3086                 if (len != olen) {
3087                         ret = -EINVAL;
3088                         goto out_unlock;
3089                 }
3090
3091                 /* Check for overlapping ranges */
3092                 if (dst_loff + len > loff && dst_loff < loff + len) {
3093                         ret = -EINVAL;
3094                         goto out_unlock;
3095                 }
3096
3097                 same_lock_start = min_t(u64, loff, dst_loff);
3098                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3099         } else {
3100                 btrfs_double_inode_lock(src, dst);
3101
3102                 ret = extent_same_check_offsets(src, loff, &len, olen);
3103                 if (ret)
3104                         goto out_unlock;
3105
3106                 ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3107                 if (ret)
3108                         goto out_unlock;
3109         }
3110
3111         /* don't make the dst file partly checksummed */
3112         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3113             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3114                 ret = -EINVAL;
3115                 goto out_unlock;
3116         }
3117
3118 again:
3119         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
3120         if (ret)
3121                 goto out_unlock;
3122
3123         if (same_inode)
3124                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3125                                         false);
3126         else
3127                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3128                                                false);
3129         /*
3130          * If one of the inodes has dirty pages in the respective range or
3131          * ordered extents, we need to flush dellaloc and wait for all ordered
3132          * extents in the range. We must unlock the pages and the ranges in the
3133          * io trees to avoid deadlocks when flushing delalloc (requires locking
3134          * pages) and when waiting for ordered extents to complete (they require
3135          * range locking).
3136          */
3137         if (ret == -EAGAIN) {
3138                 /*
3139                  * Ranges in the io trees already unlocked. Now unlock all
3140                  * pages before waiting for all IO to complete.
3141                  */
3142                 btrfs_cmp_data_free(&cmp);
3143                 if (same_inode) {
3144                         btrfs_wait_ordered_range(src, same_lock_start,
3145                                                  same_lock_len);
3146                 } else {
3147                         btrfs_wait_ordered_range(src, loff, len);
3148                         btrfs_wait_ordered_range(dst, dst_loff, len);
3149                 }
3150                 goto again;
3151         }
3152         ASSERT(ret == 0);
3153         if (WARN_ON(ret)) {
3154                 /* ranges in the io trees already unlocked */
3155                 btrfs_cmp_data_free(&cmp);
3156                 return ret;
3157         }
3158
3159         /* pass original length for comparison so we stay within i_size */
3160         ret = btrfs_cmp_data(src, loff, dst, dst_loff, olen, &cmp);
3161         if (ret == 0)
3162                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3163
3164         if (same_inode)
3165                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3166                               same_lock_start + same_lock_len - 1);
3167         else
3168                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3169
3170         btrfs_cmp_data_free(&cmp);
3171 out_unlock:
3172         if (same_inode)
3173                 inode_unlock(src);
3174         else
3175                 btrfs_double_inode_unlock(src, dst);
3176
3177         return ret;
3178 }
3179
3180 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3181
3182 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3183                                 struct file *dst_file, u64 dst_loff)
3184 {
3185         struct inode *src = file_inode(src_file);
3186         struct inode *dst = file_inode(dst_file);
3187         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3188         ssize_t res;
3189
3190         if (olen > BTRFS_MAX_DEDUPE_LEN)
3191                 olen = BTRFS_MAX_DEDUPE_LEN;
3192
3193         if (WARN_ON_ONCE(bs < PAGE_CACHE_SIZE)) {
3194                 /*
3195                  * Btrfs does not support blocksize < page_size. As a
3196                  * result, btrfs_cmp_data() won't correctly handle
3197                  * this situation without an update.
3198                  */
3199                 return -EINVAL;
3200         }
3201
3202         res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3203         if (res)
3204                 return res;
3205         return olen;
3206 }
3207
3208 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3209                                      struct inode *inode,
3210                                      u64 endoff,
3211                                      const u64 destoff,
3212                                      const u64 olen,
3213                                      int no_time_update)
3214 {
3215         struct btrfs_root *root = BTRFS_I(inode)->root;
3216         int ret;
3217
3218         inode_inc_iversion(inode);
3219         if (!no_time_update)
3220                 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3221         /*
3222          * We round up to the block size at eof when determining which
3223          * extents to clone above, but shouldn't round up the file size.
3224          */
3225         if (endoff > destoff + olen)
3226                 endoff = destoff + olen;
3227         if (endoff > inode->i_size)
3228                 btrfs_i_size_write(inode, endoff);
3229
3230         ret = btrfs_update_inode(trans, root, inode);
3231         if (ret) {
3232                 btrfs_abort_transaction(trans, root, ret);
3233                 btrfs_end_transaction(trans, root);
3234                 goto out;
3235         }
3236         ret = btrfs_end_transaction(trans, root);
3237 out:
3238         return ret;
3239 }
3240
3241 static void clone_update_extent_map(struct inode *inode,
3242                                     const struct btrfs_trans_handle *trans,
3243                                     const struct btrfs_path *path,
3244                                     const u64 hole_offset,
3245                                     const u64 hole_len)
3246 {
3247         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3248         struct extent_map *em;
3249         int ret;
3250
3251         em = alloc_extent_map();
3252         if (!em) {
3253                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3254                         &BTRFS_I(inode)->runtime_flags);
3255                 return;
3256         }
3257
3258         if (path) {
3259                 struct btrfs_file_extent_item *fi;
3260
3261                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3262                                     struct btrfs_file_extent_item);
3263                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3264                 em->generation = -1;
3265                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3266                     BTRFS_FILE_EXTENT_INLINE)
3267                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3268                                 &BTRFS_I(inode)->runtime_flags);
3269         } else {
3270                 em->start = hole_offset;
3271                 em->len = hole_len;
3272                 em->ram_bytes = em->len;
3273                 em->orig_start = hole_offset;
3274                 em->block_start = EXTENT_MAP_HOLE;
3275                 em->block_len = 0;
3276                 em->orig_block_len = 0;
3277                 em->compress_type = BTRFS_COMPRESS_NONE;
3278                 em->generation = trans->transid;
3279         }
3280
3281         while (1) {
3282                 write_lock(&em_tree->lock);
3283                 ret = add_extent_mapping(em_tree, em, 1);
3284                 write_unlock(&em_tree->lock);
3285                 if (ret != -EEXIST) {
3286                         free_extent_map(em);
3287                         break;
3288                 }
3289                 btrfs_drop_extent_cache(inode, em->start,
3290                                         em->start + em->len - 1, 0);
3291         }
3292
3293         if (ret)
3294                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3295                         &BTRFS_I(inode)->runtime_flags);
3296 }
3297
3298 /*
3299  * Make sure we do not end up inserting an inline extent into a file that has
3300  * already other (non-inline) extents. If a file has an inline extent it can
3301  * not have any other extents and the (single) inline extent must start at the
3302  * file offset 0. Failing to respect these rules will lead to file corruption,
3303  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3304  *
3305  * We can have extents that have been already written to disk or we can have
3306  * dirty ranges still in delalloc, in which case the extent maps and items are
3307  * created only when we run delalloc, and the delalloc ranges might fall outside
3308  * the range we are currently locking in the inode's io tree. So we check the
3309  * inode's i_size because of that (i_size updates are done while holding the
3310  * i_mutex, which we are holding here).
3311  * We also check to see if the inode has a size not greater than "datal" but has
3312  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3313  * protected against such concurrent fallocate calls by the i_mutex).
3314  *
3315  * If the file has no extents but a size greater than datal, do not allow the
3316  * copy because we would need turn the inline extent into a non-inline one (even
3317  * with NO_HOLES enabled). If we find our destination inode only has one inline
3318  * extent, just overwrite it with the source inline extent if its size is less
3319  * than the source extent's size, or we could copy the source inline extent's
3320  * data into the destination inode's inline extent if the later is greater then
3321  * the former.
3322  */
3323 static int clone_copy_inline_extent(struct inode *src,
3324                                     struct inode *dst,
3325                                     struct btrfs_trans_handle *trans,
3326                                     struct btrfs_path *path,
3327                                     struct btrfs_key *new_key,
3328                                     const u64 drop_start,
3329                                     const u64 datal,
3330                                     const u64 skip,
3331                                     const u64 size,
3332                                     char *inline_data)
3333 {
3334         struct btrfs_root *root = BTRFS_I(dst)->root;
3335         const u64 aligned_end = ALIGN(new_key->offset + datal,
3336                                       root->sectorsize);
3337         int ret;
3338         struct btrfs_key key;
3339
3340         if (new_key->offset > 0)
3341                 return -EOPNOTSUPP;
3342
3343         key.objectid = btrfs_ino(dst);
3344         key.type = BTRFS_EXTENT_DATA_KEY;
3345         key.offset = 0;
3346         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3347         if (ret < 0) {
3348                 return ret;
3349         } else if (ret > 0) {
3350                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3351                         ret = btrfs_next_leaf(root, path);
3352                         if (ret < 0)
3353                                 return ret;
3354                         else if (ret > 0)
3355                                 goto copy_inline_extent;
3356                 }
3357                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3358                 if (key.objectid == btrfs_ino(dst) &&
3359                     key.type == BTRFS_EXTENT_DATA_KEY) {
3360                         ASSERT(key.offset > 0);
3361                         return -EOPNOTSUPP;
3362                 }
3363         } else if (i_size_read(dst) <= datal) {
3364                 struct btrfs_file_extent_item *ei;
3365                 u64 ext_len;
3366
3367                 /*
3368                  * If the file size is <= datal, make sure there are no other
3369                  * extents following (can happen do to an fallocate call with
3370                  * the flag FALLOC_FL_KEEP_SIZE).
3371                  */
3372                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3373                                     struct btrfs_file_extent_item);
3374                 /*
3375                  * If it's an inline extent, it can not have other extents
3376                  * following it.
3377                  */
3378                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3379                     BTRFS_FILE_EXTENT_INLINE)
3380                         goto copy_inline_extent;
3381
3382                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3383                 if (ext_len > aligned_end)
3384                         return -EOPNOTSUPP;
3385
3386                 ret = btrfs_next_item(root, path);
3387                 if (ret < 0) {
3388                         return ret;
3389                 } else if (ret == 0) {
3390                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3391                                               path->slots[0]);
3392                         if (key.objectid == btrfs_ino(dst) &&
3393                             key.type == BTRFS_EXTENT_DATA_KEY)
3394                                 return -EOPNOTSUPP;
3395                 }
3396         }
3397
3398 copy_inline_extent:
3399         /*
3400          * We have no extent items, or we have an extent at offset 0 which may
3401          * or may not be inlined. All these cases are dealt the same way.
3402          */
3403         if (i_size_read(dst) > datal) {
3404                 /*
3405                  * If the destination inode has an inline extent...
3406                  * This would require copying the data from the source inline
3407                  * extent into the beginning of the destination's inline extent.
3408                  * But this is really complex, both extents can be compressed
3409                  * or just one of them, which would require decompressing and
3410                  * re-compressing data (which could increase the new compressed
3411                  * size, not allowing the compressed data to fit anymore in an
3412                  * inline extent).
3413                  * So just don't support this case for now (it should be rare,
3414                  * we are not really saving space when cloning inline extents).
3415                  */
3416                 return -EOPNOTSUPP;
3417         }
3418
3419         btrfs_release_path(path);
3420         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3421         if (ret)
3422                 return ret;
3423         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3424         if (ret)
3425                 return ret;
3426
3427         if (skip) {
3428                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3429
3430                 memmove(inline_data + start, inline_data + start + skip, datal);
3431         }
3432
3433         write_extent_buffer(path->nodes[0], inline_data,
3434                             btrfs_item_ptr_offset(path->nodes[0],
3435                                                   path->slots[0]),
3436                             size);
3437         inode_add_bytes(dst, datal);
3438
3439         return 0;
3440 }
3441
3442 /**
3443  * btrfs_clone() - clone a range from inode file to another
3444  *
3445  * @src: Inode to clone from
3446  * @inode: Inode to clone to
3447  * @off: Offset within source to start clone from
3448  * @olen: Original length, passed by user, of range to clone
3449  * @olen_aligned: Block-aligned value of olen
3450  * @destoff: Offset within @inode to start clone
3451  * @no_time_update: Whether to update mtime/ctime on the target inode
3452  */
3453 static int btrfs_clone(struct inode *src, struct inode *inode,
3454                        const u64 off, const u64 olen, const u64 olen_aligned,
3455                        const u64 destoff, int no_time_update)
3456 {
3457         struct btrfs_root *root = BTRFS_I(inode)->root;
3458         struct btrfs_path *path = NULL;
3459         struct extent_buffer *leaf;
3460         struct btrfs_trans_handle *trans;
3461         char *buf = NULL;
3462         struct btrfs_key key;
3463         u32 nritems;
3464         int slot;
3465         int ret;
3466         const u64 len = olen_aligned;
3467         u64 last_dest_end = destoff;
3468
3469         ret = -ENOMEM;
3470         buf = vmalloc(root->nodesize);
3471         if (!buf)
3472                 return ret;
3473
3474         path = btrfs_alloc_path();
3475         if (!path) {
3476                 vfree(buf);
3477                 return ret;
3478         }
3479
3480         path->reada = READA_FORWARD;
3481         /* clone data */
3482         key.objectid = btrfs_ino(src);
3483         key.type = BTRFS_EXTENT_DATA_KEY;
3484         key.offset = off;
3485
3486         while (1) {
3487                 u64 next_key_min_offset = key.offset + 1;
3488
3489                 /*
3490                  * note the key will change type as we walk through the
3491                  * tree.
3492                  */
3493                 path->leave_spinning = 1;
3494                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3495                                 0, 0);
3496                 if (ret < 0)
3497                         goto out;
3498                 /*
3499                  * First search, if no extent item that starts at offset off was
3500                  * found but the previous item is an extent item, it's possible
3501                  * it might overlap our target range, therefore process it.
3502                  */
3503                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3504                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3505                                               path->slots[0] - 1);
3506                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3507                                 path->slots[0]--;
3508                 }
3509
3510                 nritems = btrfs_header_nritems(path->nodes[0]);
3511 process_slot:
3512                 if (path->slots[0] >= nritems) {
3513                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3514                         if (ret < 0)
3515                                 goto out;
3516                         if (ret > 0)
3517                                 break;
3518                         nritems = btrfs_header_nritems(path->nodes[0]);
3519                 }
3520                 leaf = path->nodes[0];
3521                 slot = path->slots[0];
3522
3523                 btrfs_item_key_to_cpu(leaf, &key, slot);
3524                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3525                     key.objectid != btrfs_ino(src))
3526                         break;
3527
3528                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3529                         struct btrfs_file_extent_item *extent;
3530                         int type;
3531                         u32 size;
3532                         struct btrfs_key new_key;
3533                         u64 disko = 0, diskl = 0;
3534                         u64 datao = 0, datal = 0;
3535                         u8 comp;
3536                         u64 drop_start;
3537
3538                         extent = btrfs_item_ptr(leaf, slot,
3539                                                 struct btrfs_file_extent_item);
3540                         comp = btrfs_file_extent_compression(leaf, extent);
3541                         type = btrfs_file_extent_type(leaf, extent);
3542                         if (type == BTRFS_FILE_EXTENT_REG ||
3543                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3544                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3545                                                                       extent);
3546                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3547                                                                  extent);
3548                                 datao = btrfs_file_extent_offset(leaf, extent);
3549                                 datal = btrfs_file_extent_num_bytes(leaf,
3550                                                                     extent);
3551                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3552                                 /* take upper bound, may be compressed */
3553                                 datal = btrfs_file_extent_ram_bytes(leaf,
3554                                                                     extent);
3555                         }
3556
3557                         /*
3558                          * The first search might have left us at an extent
3559                          * item that ends before our target range's start, can
3560                          * happen if we have holes and NO_HOLES feature enabled.
3561                          */
3562                         if (key.offset + datal <= off) {
3563                                 path->slots[0]++;
3564                                 goto process_slot;
3565                         } else if (key.offset >= off + len) {
3566                                 break;
3567                         }
3568                         next_key_min_offset = key.offset + datal;
3569                         size = btrfs_item_size_nr(leaf, slot);
3570                         read_extent_buffer(leaf, buf,
3571                                            btrfs_item_ptr_offset(leaf, slot),
3572                                            size);
3573
3574                         btrfs_release_path(path);
3575                         path->leave_spinning = 0;
3576
3577                         memcpy(&new_key, &key, sizeof(new_key));
3578                         new_key.objectid = btrfs_ino(inode);
3579                         if (off <= key.offset)
3580                                 new_key.offset = key.offset + destoff - off;
3581                         else
3582                                 new_key.offset = destoff;
3583
3584                         /*
3585                          * Deal with a hole that doesn't have an extent item
3586                          * that represents it (NO_HOLES feature enabled).
3587                          * This hole is either in the middle of the cloning
3588                          * range or at the beginning (fully overlaps it or
3589                          * partially overlaps it).
3590                          */
3591                         if (new_key.offset != last_dest_end)
3592                                 drop_start = last_dest_end;
3593                         else
3594                                 drop_start = new_key.offset;
3595
3596                         /*
3597                          * 1 - adjusting old extent (we may have to split it)
3598                          * 1 - add new extent
3599                          * 1 - inode update
3600                          */
3601                         trans = btrfs_start_transaction(root, 3);
3602                         if (IS_ERR(trans)) {
3603                                 ret = PTR_ERR(trans);
3604                                 goto out;
3605                         }
3606
3607                         if (type == BTRFS_FILE_EXTENT_REG ||
3608                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3609                                 /*
3610                                  *    a  | --- range to clone ---|  b
3611                                  * | ------------- extent ------------- |
3612                                  */
3613
3614                                 /* subtract range b */
3615                                 if (key.offset + datal > off + len)
3616                                         datal = off + len - key.offset;
3617
3618                                 /* subtract range a */
3619                                 if (off > key.offset) {
3620                                         datao += off - key.offset;
3621                                         datal -= off - key.offset;
3622                                 }
3623
3624                                 ret = btrfs_drop_extents(trans, root, inode,
3625                                                          drop_start,
3626                                                          new_key.offset + datal,
3627                                                          1);
3628                                 if (ret) {
3629                                         if (ret != -EOPNOTSUPP)
3630                                                 btrfs_abort_transaction(trans,
3631                                                                 root, ret);
3632                                         btrfs_end_transaction(trans, root);
3633                                         goto out;
3634                                 }
3635
3636                                 ret = btrfs_insert_empty_item(trans, root, path,
3637                                                               &new_key, size);
3638                                 if (ret) {
3639                                         btrfs_abort_transaction(trans, root,
3640                                                                 ret);
3641                                         btrfs_end_transaction(trans, root);
3642                                         goto out;
3643                                 }
3644
3645                                 leaf = path->nodes[0];
3646                                 slot = path->slots[0];
3647                                 write_extent_buffer(leaf, buf,
3648                                             btrfs_item_ptr_offset(leaf, slot),
3649                                             size);
3650
3651                                 extent = btrfs_item_ptr(leaf, slot,
3652                                                 struct btrfs_file_extent_item);
3653
3654                                 /* disko == 0 means it's a hole */
3655                                 if (!disko)
3656                                         datao = 0;
3657
3658                                 btrfs_set_file_extent_offset(leaf, extent,
3659                                                              datao);
3660                                 btrfs_set_file_extent_num_bytes(leaf, extent,
3661                                                                 datal);
3662
3663                                 if (disko) {
3664                                         inode_add_bytes(inode, datal);
3665                                         ret = btrfs_inc_extent_ref(trans, root,
3666                                                         disko, diskl, 0,
3667                                                         root->root_key.objectid,
3668                                                         btrfs_ino(inode),
3669                                                         new_key.offset - datao);
3670                                         if (ret) {
3671                                                 btrfs_abort_transaction(trans,
3672                                                                         root,
3673                                                                         ret);
3674                                                 btrfs_end_transaction(trans,
3675                                                                       root);
3676                                                 goto out;
3677
3678                                         }
3679                                 }
3680                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3681                                 u64 skip = 0;
3682                                 u64 trim = 0;
3683
3684                                 if (off > key.offset) {
3685                                         skip = off - key.offset;
3686                                         new_key.offset += skip;
3687                                 }
3688
3689                                 if (key.offset + datal > off + len)
3690                                         trim = key.offset + datal - (off + len);
3691
3692                                 if (comp && (skip || trim)) {
3693                                         ret = -EINVAL;
3694                                         btrfs_end_transaction(trans, root);
3695                                         goto out;
3696                                 }
3697                                 size -= skip + trim;
3698                                 datal -= skip + trim;
3699
3700                                 ret = clone_copy_inline_extent(src, inode,
3701                                                                trans, path,
3702                                                                &new_key,
3703                                                                drop_start,
3704                                                                datal,
3705                                                                skip, size, buf);
3706                                 if (ret) {
3707                                         if (ret != -EOPNOTSUPP)
3708                                                 btrfs_abort_transaction(trans,
3709                                                                         root,
3710                                                                         ret);
3711                                         btrfs_end_transaction(trans, root);
3712                                         goto out;
3713                                 }
3714                                 leaf = path->nodes[0];
3715                                 slot = path->slots[0];
3716                         }
3717
3718                         /* If we have an implicit hole (NO_HOLES feature). */
3719                         if (drop_start < new_key.offset)
3720                                 clone_update_extent_map(inode, trans,
3721                                                 NULL, drop_start,
3722                                                 new_key.offset - drop_start);
3723
3724                         clone_update_extent_map(inode, trans, path, 0, 0);
3725
3726                         btrfs_mark_buffer_dirty(leaf);
3727                         btrfs_release_path(path);
3728
3729                         last_dest_end = ALIGN(new_key.offset + datal,
3730                                               root->sectorsize);
3731                         ret = clone_finish_inode_update(trans, inode,
3732                                                         last_dest_end,
3733                                                         destoff, olen,
3734                                                         no_time_update);
3735                         if (ret)
3736                                 goto out;
3737                         if (new_key.offset + datal >= destoff + len)
3738                                 break;
3739                 }
3740                 btrfs_release_path(path);
3741                 key.offset = next_key_min_offset;
3742         }
3743         ret = 0;
3744
3745         if (last_dest_end < destoff + len) {
3746                 /*
3747                  * We have an implicit hole (NO_HOLES feature is enabled) that
3748                  * fully or partially overlaps our cloning range at its end.
3749                  */
3750                 btrfs_release_path(path);
3751
3752                 /*
3753                  * 1 - remove extent(s)
3754                  * 1 - inode update
3755                  */
3756                 trans = btrfs_start_transaction(root, 2);
3757                 if (IS_ERR(trans)) {
3758                         ret = PTR_ERR(trans);
3759                         goto out;
3760                 }
3761                 ret = btrfs_drop_extents(trans, root, inode,
3762                                          last_dest_end, destoff + len, 1);
3763                 if (ret) {
3764                         if (ret != -EOPNOTSUPP)
3765                                 btrfs_abort_transaction(trans, root, ret);
3766                         btrfs_end_transaction(trans, root);
3767                         goto out;
3768                 }
3769                 clone_update_extent_map(inode, trans, NULL, last_dest_end,
3770                                         destoff + len - last_dest_end);
3771                 ret = clone_finish_inode_update(trans, inode, destoff + len,
3772                                                 destoff, olen, no_time_update);
3773         }
3774
3775 out:
3776         btrfs_free_path(path);
3777         vfree(buf);
3778         return ret;
3779 }
3780
3781 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3782                                         u64 off, u64 olen, u64 destoff)
3783 {
3784         struct inode *inode = file_inode(file);
3785         struct inode *src = file_inode(file_src);
3786         struct btrfs_root *root = BTRFS_I(inode)->root;
3787         int ret;
3788         u64 len = olen;
3789         u64 bs = root->fs_info->sb->s_blocksize;
3790         int same_inode = src == inode;
3791
3792         /*
3793          * TODO:
3794          * - split compressed inline extents.  annoying: we need to
3795          *   decompress into destination's address_space (the file offset
3796          *   may change, so source mapping won't do), then recompress (or
3797          *   otherwise reinsert) a subrange.
3798          *
3799          * - split destination inode's inline extents.  The inline extents can
3800          *   be either compressed or non-compressed.
3801          */
3802
3803         if (btrfs_root_readonly(root))
3804                 return -EROFS;
3805
3806         if (file_src->f_path.mnt != file->f_path.mnt ||
3807             src->i_sb != inode->i_sb)
3808                 return -EXDEV;
3809
3810         /* don't make the dst file partly checksummed */
3811         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3812             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3813                 return -EINVAL;
3814
3815         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3816                 return -EISDIR;
3817
3818         if (!same_inode) {
3819                 btrfs_double_inode_lock(src, inode);
3820         } else {
3821                 inode_lock(src);
3822         }
3823
3824         /* determine range to clone */
3825         ret = -EINVAL;
3826         if (off + len > src->i_size || off + len < off)
3827                 goto out_unlock;
3828         if (len == 0)
3829                 olen = len = src->i_size - off;
3830         /* if we extend to eof, continue to block boundary */
3831         if (off + len == src->i_size)
3832                 len = ALIGN(src->i_size, bs) - off;
3833
3834         if (len == 0) {
3835                 ret = 0;
3836                 goto out_unlock;
3837         }
3838
3839         /* verify the end result is block aligned */
3840         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3841             !IS_ALIGNED(destoff, bs))
3842                 goto out_unlock;
3843
3844         /* verify if ranges are overlapped within the same file */
3845         if (same_inode) {
3846                 if (destoff + len > off && destoff < off + len)
3847                         goto out_unlock;
3848         }
3849
3850         if (destoff > inode->i_size) {
3851                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3852                 if (ret)
3853                         goto out_unlock;
3854         }
3855
3856         /*
3857          * Lock the target range too. Right after we replace the file extent
3858          * items in the fs tree (which now point to the cloned data), we might
3859          * have a worker replace them with extent items relative to a write
3860          * operation that was issued before this clone operation (i.e. confront
3861          * with inode.c:btrfs_finish_ordered_io).
3862          */
3863         if (same_inode) {
3864                 u64 lock_start = min_t(u64, off, destoff);
3865                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3866
3867                 ret = lock_extent_range(src, lock_start, lock_len, true);
3868         } else {
3869                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
3870                                                true);
3871         }
3872         ASSERT(ret == 0);
3873         if (WARN_ON(ret)) {
3874                 /* ranges in the io trees already unlocked */
3875                 goto out_unlock;
3876         }
3877
3878         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3879
3880         if (same_inode) {
3881                 u64 lock_start = min_t(u64, off, destoff);
3882                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
3883
3884                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3885         } else {
3886                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
3887         }
3888         /*
3889          * Truncate page cache pages so that future reads will see the cloned
3890          * data immediately and not the previous data.
3891          */
3892         truncate_inode_pages_range(&inode->i_data, destoff,
3893                                    PAGE_CACHE_ALIGN(destoff + len) - 1);
3894 out_unlock:
3895         if (!same_inode)
3896                 btrfs_double_inode_unlock(src, inode);
3897         else
3898                 inode_unlock(src);
3899         return ret;
3900 }
3901
3902 ssize_t btrfs_copy_file_range(struct file *file_in, loff_t pos_in,
3903                               struct file *file_out, loff_t pos_out,
3904                               size_t len, unsigned int flags)
3905 {
3906         ssize_t ret;
3907
3908         ret = btrfs_clone_files(file_out, file_in, pos_in, len, pos_out);
3909         if (ret == 0)
3910                 ret = len;
3911         return ret;
3912 }
3913
3914 int btrfs_clone_file_range(struct file *src_file, loff_t off,
3915                 struct file *dst_file, loff_t destoff, u64 len)
3916 {
3917         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
3918 }
3919
3920 /*
3921  * there are many ways the trans_start and trans_end ioctls can lead
3922  * to deadlocks.  They should only be used by applications that
3923  * basically own the machine, and have a very in depth understanding
3924  * of all the possible deadlocks and enospc problems.
3925  */
3926 static long btrfs_ioctl_trans_start(struct file *file)
3927 {
3928         struct inode *inode = file_inode(file);
3929         struct btrfs_root *root = BTRFS_I(inode)->root;
3930         struct btrfs_trans_handle *trans;
3931         int ret;
3932
3933         ret = -EPERM;
3934         if (!capable(CAP_SYS_ADMIN))
3935                 goto out;
3936
3937         ret = -EINPROGRESS;
3938         if (file->private_data)
3939                 goto out;
3940
3941         ret = -EROFS;
3942         if (btrfs_root_readonly(root))
3943                 goto out;
3944
3945         ret = mnt_want_write_file(file);
3946         if (ret)
3947                 goto out;
3948
3949         atomic_inc(&root->fs_info->open_ioctl_trans);
3950
3951         ret = -ENOMEM;
3952         trans = btrfs_start_ioctl_transaction(root);
3953         if (IS_ERR(trans))
3954                 goto out_drop;
3955
3956         file->private_data = trans;
3957         return 0;
3958
3959 out_drop:
3960         atomic_dec(&root->fs_info->open_ioctl_trans);
3961         mnt_drop_write_file(file);
3962 out:
3963         return ret;
3964 }
3965
3966 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3967 {
3968         struct inode *inode = file_inode(file);
3969         struct btrfs_root *root = BTRFS_I(inode)->root;
3970         struct btrfs_root *new_root;
3971         struct btrfs_dir_item *di;
3972         struct btrfs_trans_handle *trans;
3973         struct btrfs_path *path;
3974         struct btrfs_key location;
3975         struct btrfs_disk_key disk_key;
3976         u64 objectid = 0;
3977         u64 dir_id;
3978         int ret;
3979
3980         if (!capable(CAP_SYS_ADMIN))
3981                 return -EPERM;
3982
3983         ret = mnt_want_write_file(file);
3984         if (ret)
3985                 return ret;
3986
3987         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3988                 ret = -EFAULT;
3989                 goto out;
3990         }
3991
3992         if (!objectid)
3993                 objectid = BTRFS_FS_TREE_OBJECTID;
3994
3995         location.objectid = objectid;
3996         location.type = BTRFS_ROOT_ITEM_KEY;
3997         location.offset = (u64)-1;
3998
3999         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
4000         if (IS_ERR(new_root)) {
4001                 ret = PTR_ERR(new_root);
4002                 goto out;
4003         }
4004
4005         path = btrfs_alloc_path();
4006         if (!path) {
4007                 ret = -ENOMEM;
4008                 goto out;
4009         }
4010         path->leave_spinning = 1;
4011
4012         trans = btrfs_start_transaction(root, 1);
4013         if (IS_ERR(trans)) {
4014                 btrfs_free_path(path);
4015                 ret = PTR_ERR(trans);
4016                 goto out;
4017         }
4018
4019         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
4020         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
4021                                    dir_id, "default", 7, 1);
4022         if (IS_ERR_OR_NULL(di)) {
4023                 btrfs_free_path(path);
4024                 btrfs_end_transaction(trans, root);
4025                 btrfs_err(new_root->fs_info, "Umm, you don't have the default dir"
4026                            "item, this isn't going to work");
4027                 ret = -ENOENT;
4028                 goto out;
4029         }
4030
4031         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4032         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4033         btrfs_mark_buffer_dirty(path->nodes[0]);
4034         btrfs_free_path(path);
4035
4036         btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
4037         btrfs_end_transaction(trans, root);
4038 out:
4039         mnt_drop_write_file(file);
4040         return ret;
4041 }
4042
4043 void btrfs_get_block_group_info(struct list_head *groups_list,
4044                                 struct btrfs_ioctl_space_info *space)
4045 {
4046         struct btrfs_block_group_cache *block_group;
4047
4048         space->total_bytes = 0;
4049         space->used_bytes = 0;
4050         space->flags = 0;
4051         list_for_each_entry(block_group, groups_list, list) {
4052                 space->flags = block_group->flags;
4053                 space->total_bytes += block_group->key.offset;
4054                 space->used_bytes +=
4055                         btrfs_block_group_used(&block_group->item);
4056         }
4057 }
4058
4059 static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
4060 {
4061         struct btrfs_ioctl_space_args space_args;
4062         struct btrfs_ioctl_space_info space;
4063         struct btrfs_ioctl_space_info *dest;
4064         struct btrfs_ioctl_space_info *dest_orig;
4065         struct btrfs_ioctl_space_info __user *user_dest;
4066         struct btrfs_space_info *info;
4067         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
4068                        BTRFS_BLOCK_GROUP_SYSTEM,
4069                        BTRFS_BLOCK_GROUP_METADATA,
4070                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
4071         int num_types = 4;
4072         int alloc_size;
4073         int ret = 0;
4074         u64 slot_count = 0;
4075         int i, c;
4076
4077         if (copy_from_user(&space_args,
4078                            (struct btrfs_ioctl_space_args __user *)arg,
4079                            sizeof(space_args)))
4080                 return -EFAULT;
4081
4082         for (i = 0; i < num_types; i++) {
4083                 struct btrfs_space_info *tmp;
4084
4085                 info = NULL;
4086                 rcu_read_lock();
4087                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
4088                                         list) {
4089                         if (tmp->flags == types[i]) {
4090                                 info = tmp;
4091                                 break;
4092                         }
4093                 }
4094                 rcu_read_unlock();
4095
4096                 if (!info)
4097                         continue;
4098
4099                 down_read(&info->groups_sem);
4100                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4101                         if (!list_empty(&info->block_groups[c]))
4102                                 slot_count++;
4103                 }
4104                 up_read(&info->groups_sem);
4105         }
4106
4107         /*
4108          * Global block reserve, exported as a space_info
4109          */
4110         slot_count++;
4111
4112         /* space_slots == 0 means they are asking for a count */
4113         if (space_args.space_slots == 0) {
4114                 space_args.total_spaces = slot_count;
4115                 goto out;
4116         }
4117
4118         slot_count = min_t(u64, space_args.space_slots, slot_count);
4119
4120         alloc_size = sizeof(*dest) * slot_count;
4121
4122         /* we generally have at most 6 or so space infos, one for each raid
4123          * level.  So, a whole page should be more than enough for everyone
4124          */
4125         if (alloc_size > PAGE_CACHE_SIZE)
4126                 return -ENOMEM;
4127
4128         space_args.total_spaces = 0;
4129         dest = kmalloc(alloc_size, GFP_KERNEL);
4130         if (!dest)
4131                 return -ENOMEM;
4132         dest_orig = dest;
4133
4134         /* now we have a buffer to copy into */
4135         for (i = 0; i < num_types; i++) {
4136                 struct btrfs_space_info *tmp;
4137
4138                 if (!slot_count)
4139                         break;
4140
4141                 info = NULL;
4142                 rcu_read_lock();
4143                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
4144                                         list) {
4145                         if (tmp->flags == types[i]) {
4146                                 info = tmp;
4147                                 break;
4148                         }
4149                 }
4150                 rcu_read_unlock();
4151
4152                 if (!info)
4153                         continue;
4154                 down_read(&info->groups_sem);
4155                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4156                         if (!list_empty(&info->block_groups[c])) {
4157                                 btrfs_get_block_group_info(
4158                                         &info->block_groups[c], &space);
4159                                 memcpy(dest, &space, sizeof(space));
4160                                 dest++;
4161                                 space_args.total_spaces++;
4162                                 slot_count--;
4163                         }
4164                         if (!slot_count)
4165                                 break;
4166                 }
4167                 up_read(&info->groups_sem);
4168         }
4169
4170         /*
4171          * Add global block reserve
4172          */
4173         if (slot_count) {
4174                 struct btrfs_block_rsv *block_rsv = &root->fs_info->global_block_rsv;
4175
4176                 spin_lock(&block_rsv->lock);
4177                 space.total_bytes = block_rsv->size;
4178                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4179                 spin_unlock(&block_rsv->lock);
4180                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4181                 memcpy(dest, &space, sizeof(space));
4182                 space_args.total_spaces++;
4183         }
4184
4185         user_dest = (struct btrfs_ioctl_space_info __user *)
4186                 (arg + sizeof(struct btrfs_ioctl_space_args));
4187
4188         if (copy_to_user(user_dest, dest_orig, alloc_size))
4189                 ret = -EFAULT;
4190
4191         kfree(dest_orig);
4192 out:
4193         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4194                 ret = -EFAULT;
4195
4196         return ret;
4197 }
4198
4199 /*
4200  * there are many ways the trans_start and trans_end ioctls can lead
4201  * to deadlocks.  They should only be used by applications that
4202  * basically own the machine, and have a very in depth understanding
4203  * of all the possible deadlocks and enospc problems.
4204  */
4205 long btrfs_ioctl_trans_end(struct file *file)
4206 {
4207         struct inode *inode = file_inode(file);
4208         struct btrfs_root *root = BTRFS_I(inode)->root;
4209         struct btrfs_trans_handle *trans;
4210
4211         trans = file->private_data;
4212         if (!trans)
4213                 return -EINVAL;
4214         file->private_data = NULL;
4215
4216         btrfs_end_transaction(trans, root);
4217
4218         atomic_dec(&root->fs_info->open_ioctl_trans);
4219
4220         mnt_drop_write_file(file);
4221         return 0;
4222 }
4223
4224 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4225                                             void __user *argp)
4226 {
4227         struct btrfs_trans_handle *trans;
4228         u64 transid;
4229         int ret;
4230
4231         trans = btrfs_attach_transaction_barrier(root);
4232         if (IS_ERR(trans)) {
4233                 if (PTR_ERR(trans) != -ENOENT)
4234                         return PTR_ERR(trans);
4235
4236                 /* No running transaction, don't bother */
4237                 transid = root->fs_info->last_trans_committed;
4238                 goto out;
4239         }
4240         transid = trans->transid;
4241         ret = btrfs_commit_transaction_async(trans, root, 0);
4242         if (ret) {
4243                 btrfs_end_transaction(trans, root);
4244                 return ret;
4245         }
4246 out:
4247         if (argp)
4248                 if (copy_to_user(argp, &transid, sizeof(transid)))
4249                         return -EFAULT;
4250         return 0;
4251 }
4252
4253 static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
4254                                            void __user *argp)
4255 {
4256         u64 transid;
4257
4258         if (argp) {
4259                 if (copy_from_user(&transid, argp, sizeof(transid)))
4260                         return -EFAULT;
4261         } else {
4262                 transid = 0;  /* current trans */
4263         }
4264         return btrfs_wait_for_commit(root, transid);
4265 }
4266
4267 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4268 {
4269         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4270         struct btrfs_ioctl_scrub_args *sa;
4271         int ret;
4272
4273         if (!capable(CAP_SYS_ADMIN))
4274                 return -EPERM;
4275
4276         sa = memdup_user(arg, sizeof(*sa));
4277         if (IS_ERR(sa))
4278                 return PTR_ERR(sa);
4279
4280         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4281                 ret = mnt_want_write_file(file);
4282                 if (ret)
4283                         goto out;
4284         }
4285
4286         ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
4287                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4288                               0);
4289
4290         if (copy_to_user(arg, sa, sizeof(*sa)))
4291                 ret = -EFAULT;
4292
4293         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4294                 mnt_drop_write_file(file);
4295 out:
4296         kfree(sa);
4297         return ret;
4298 }
4299
4300 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
4301 {
4302         if (!capable(CAP_SYS_ADMIN))
4303                 return -EPERM;
4304
4305         return btrfs_scrub_cancel(root->fs_info);
4306 }
4307
4308 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
4309                                        void __user *arg)
4310 {
4311         struct btrfs_ioctl_scrub_args *sa;
4312         int ret;
4313
4314         if (!capable(CAP_SYS_ADMIN))
4315                 return -EPERM;
4316
4317         sa = memdup_user(arg, sizeof(*sa));
4318         if (IS_ERR(sa))
4319                 return PTR_ERR(sa);
4320
4321         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
4322
4323         if (copy_to_user(arg, sa, sizeof(*sa)))
4324                 ret = -EFAULT;
4325
4326         kfree(sa);
4327         return ret;
4328 }
4329
4330 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
4331                                       void __user *arg)
4332 {
4333         struct btrfs_ioctl_get_dev_stats *sa;
4334         int ret;
4335
4336         sa = memdup_user(arg, sizeof(*sa));
4337         if (IS_ERR(sa))
4338                 return PTR_ERR(sa);
4339
4340         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4341                 kfree(sa);
4342                 return -EPERM;
4343         }
4344
4345         ret = btrfs_get_dev_stats(root, sa);
4346
4347         if (copy_to_user(arg, sa, sizeof(*sa)))
4348                 ret = -EFAULT;
4349
4350         kfree(sa);
4351         return ret;
4352 }
4353
4354 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
4355 {
4356         struct btrfs_ioctl_dev_replace_args *p;
4357         int ret;
4358
4359         if (!capable(CAP_SYS_ADMIN))
4360                 return -EPERM;
4361
4362         p = memdup_user(arg, sizeof(*p));
4363         if (IS_ERR(p))
4364                 return PTR_ERR(p);
4365
4366         switch (p->cmd) {
4367         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4368                 if (root->fs_info->sb->s_flags & MS_RDONLY) {
4369                         ret = -EROFS;
4370                         goto out;
4371                 }
4372                 if (atomic_xchg(
4373                         &root->fs_info->mutually_exclusive_operation_running,
4374                         1)) {
4375                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4376                 } else {
4377                         ret = btrfs_dev_replace_start(root, p);
4378                         atomic_set(
4379                          &root->fs_info->mutually_exclusive_operation_running,
4380                          0);
4381                 }
4382                 break;
4383         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4384                 btrfs_dev_replace_status(root->fs_info, p);
4385                 ret = 0;
4386                 break;
4387         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4388                 ret = btrfs_dev_replace_cancel(root->fs_info, p);
4389                 break;
4390         default:
4391                 ret = -EINVAL;
4392                 break;
4393         }
4394
4395         if (copy_to_user(arg, p, sizeof(*p)))
4396                 ret = -EFAULT;
4397 out:
4398         kfree(p);
4399         return ret;
4400 }
4401
4402 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4403 {
4404         int ret = 0;
4405         int i;
4406         u64 rel_ptr;
4407         int size;
4408         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4409         struct inode_fs_paths *ipath = NULL;
4410         struct btrfs_path *path;
4411
4412         if (!capable(CAP_DAC_READ_SEARCH))
4413                 return -EPERM;
4414
4415         path = btrfs_alloc_path();
4416         if (!path) {
4417                 ret = -ENOMEM;
4418                 goto out;
4419         }
4420
4421         ipa = memdup_user(arg, sizeof(*ipa));
4422         if (IS_ERR(ipa)) {
4423                 ret = PTR_ERR(ipa);
4424                 ipa = NULL;
4425                 goto out;
4426         }
4427
4428         size = min_t(u32, ipa->size, 4096);
4429         ipath = init_ipath(size, root, path);
4430         if (IS_ERR(ipath)) {
4431                 ret = PTR_ERR(ipath);
4432                 ipath = NULL;
4433                 goto out;
4434         }
4435
4436         ret = paths_from_inode(ipa->inum, ipath);
4437         if (ret < 0)
4438                 goto out;
4439
4440         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4441                 rel_ptr = ipath->fspath->val[i] -
4442                           (u64)(unsigned long)ipath->fspath->val;
4443                 ipath->fspath->val[i] = rel_ptr;
4444         }
4445
4446         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
4447                            (void *)(unsigned long)ipath->fspath, size);
4448         if (ret) {
4449                 ret = -EFAULT;
4450                 goto out;
4451         }
4452
4453 out:
4454         btrfs_free_path(path);
4455         free_ipath(ipath);
4456         kfree(ipa);
4457
4458         return ret;
4459 }
4460
4461 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4462 {
4463         struct btrfs_data_container *inodes = ctx;
4464         const size_t c = 3 * sizeof(u64);
4465
4466         if (inodes->bytes_left >= c) {
4467                 inodes->bytes_left -= c;
4468                 inodes->val[inodes->elem_cnt] = inum;
4469                 inodes->val[inodes->elem_cnt + 1] = offset;
4470                 inodes->val[inodes->elem_cnt + 2] = root;
4471                 inodes->elem_cnt += 3;
4472         } else {
4473                 inodes->bytes_missing += c - inodes->bytes_left;
4474                 inodes->bytes_left = 0;
4475                 inodes->elem_missed += 3;
4476         }
4477
4478         return 0;
4479 }
4480
4481 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
4482                                         void __user *arg)
4483 {
4484         int ret = 0;
4485         int size;
4486         struct btrfs_ioctl_logical_ino_args *loi;
4487         struct btrfs_data_container *inodes = NULL;
4488         struct btrfs_path *path = NULL;
4489
4490         if (!capable(CAP_SYS_ADMIN))
4491                 return -EPERM;
4492
4493         loi = memdup_user(arg, sizeof(*loi));
4494         if (IS_ERR(loi)) {
4495                 ret = PTR_ERR(loi);
4496                 loi = NULL;
4497                 goto out;
4498         }
4499
4500         path = btrfs_alloc_path();
4501         if (!path) {
4502                 ret = -ENOMEM;
4503                 goto out;
4504         }
4505
4506         size = min_t(u32, loi->size, SZ_64K);
4507         inodes = init_data_container(size);
4508         if (IS_ERR(inodes)) {
4509                 ret = PTR_ERR(inodes);
4510                 inodes = NULL;
4511                 goto out;
4512         }
4513
4514         ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
4515                                           build_ino_list, inodes);
4516         if (ret == -EINVAL)
4517                 ret = -ENOENT;
4518         if (ret < 0)
4519                 goto out;
4520
4521         ret = copy_to_user((void *)(unsigned long)loi->inodes,
4522                            (void *)(unsigned long)inodes, size);
4523         if (ret)
4524                 ret = -EFAULT;
4525
4526 out:
4527         btrfs_free_path(path);
4528         vfree(inodes);
4529         kfree(loi);
4530
4531         return ret;
4532 }
4533
4534 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4535                                struct btrfs_ioctl_balance_args *bargs)
4536 {
4537         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4538
4539         bargs->flags = bctl->flags;
4540
4541         if (atomic_read(&fs_info->balance_running))
4542                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4543         if (atomic_read(&fs_info->balance_pause_req))
4544                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4545         if (atomic_read(&fs_info->balance_cancel_req))
4546                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4547
4548         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4549         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4550         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4551
4552         if (lock) {
4553                 spin_lock(&fs_info->balance_lock);
4554                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4555                 spin_unlock(&fs_info->balance_lock);
4556         } else {
4557                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4558         }
4559 }
4560
4561 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4562 {
4563         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4564         struct btrfs_fs_info *fs_info = root->fs_info;
4565         struct btrfs_ioctl_balance_args *bargs;
4566         struct btrfs_balance_control *bctl;
4567         bool need_unlock; /* for mut. excl. ops lock */
4568         int ret;
4569
4570         if (!capable(CAP_SYS_ADMIN))
4571                 return -EPERM;
4572
4573         ret = mnt_want_write_file(file);
4574         if (ret)
4575                 return ret;
4576
4577 again:
4578         if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
4579                 mutex_lock(&fs_info->volume_mutex);
4580                 mutex_lock(&fs_info->balance_mutex);
4581                 need_unlock = true;
4582                 goto locked;
4583         }
4584
4585         /*
4586          * mut. excl. ops lock is locked.  Three possibilites:
4587          *   (1) some other op is running
4588          *   (2) balance is running
4589          *   (3) balance is paused -- special case (think resume)
4590          */
4591         mutex_lock(&fs_info->balance_mutex);
4592         if (fs_info->balance_ctl) {
4593                 /* this is either (2) or (3) */
4594                 if (!atomic_read(&fs_info->balance_running)) {
4595                         mutex_unlock(&fs_info->balance_mutex);
4596                         if (!mutex_trylock(&fs_info->volume_mutex))
4597                                 goto again;
4598                         mutex_lock(&fs_info->balance_mutex);
4599
4600                         if (fs_info->balance_ctl &&
4601                             !atomic_read(&fs_info->balance_running)) {
4602                                 /* this is (3) */
4603                                 need_unlock = false;
4604                                 goto locked;
4605                         }
4606
4607                         mutex_unlock(&fs_info->balance_mutex);
4608                         mutex_unlock(&fs_info->volume_mutex);
4609                         goto again;
4610                 } else {
4611                         /* this is (2) */
4612                         mutex_unlock(&fs_info->balance_mutex);
4613                         ret = -EINPROGRESS;
4614                         goto out;
4615                 }
4616         } else {
4617                 /* this is (1) */
4618                 mutex_unlock(&fs_info->balance_mutex);
4619                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4620                 goto out;
4621         }
4622
4623 locked:
4624         BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
4625
4626         if (arg) {
4627                 bargs = memdup_user(arg, sizeof(*bargs));
4628                 if (IS_ERR(bargs)) {
4629                         ret = PTR_ERR(bargs);
4630                         goto out_unlock;
4631                 }
4632
4633                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4634                         if (!fs_info->balance_ctl) {
4635                                 ret = -ENOTCONN;
4636                                 goto out_bargs;
4637                         }
4638
4639                         bctl = fs_info->balance_ctl;
4640                         spin_lock(&fs_info->balance_lock);
4641                         bctl->flags |= BTRFS_BALANCE_RESUME;
4642                         spin_unlock(&fs_info->balance_lock);
4643
4644                         goto do_balance;
4645                 }
4646         } else {
4647                 bargs = NULL;
4648         }
4649
4650         if (fs_info->balance_ctl) {
4651                 ret = -EINPROGRESS;
4652                 goto out_bargs;
4653         }
4654
4655         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4656         if (!bctl) {
4657                 ret = -ENOMEM;
4658                 goto out_bargs;
4659         }
4660
4661         bctl->fs_info = fs_info;
4662         if (arg) {
4663                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4664                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4665                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4666
4667                 bctl->flags = bargs->flags;
4668         } else {
4669                 /* balance everything - no filters */
4670                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4671         }
4672
4673         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4674                 ret = -EINVAL;
4675                 goto out_bctl;
4676         }
4677
4678 do_balance:
4679         /*
4680          * Ownership of bctl and mutually_exclusive_operation_running
4681          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
4682          * or, if restriper was paused all the way until unmount, in
4683          * free_fs_info.  mutually_exclusive_operation_running is
4684          * cleared in __cancel_balance.
4685          */
4686         need_unlock = false;
4687
4688         ret = btrfs_balance(bctl, bargs);
4689         bctl = NULL;
4690
4691         if (arg) {
4692                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4693                         ret = -EFAULT;
4694         }
4695
4696 out_bctl:
4697         kfree(bctl);
4698 out_bargs:
4699         kfree(bargs);
4700 out_unlock:
4701         mutex_unlock(&fs_info->balance_mutex);
4702         mutex_unlock(&fs_info->volume_mutex);
4703         if (need_unlock)
4704                 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
4705 out:
4706         mnt_drop_write_file(file);
4707         return ret;
4708 }
4709
4710 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
4711 {
4712         if (!capable(CAP_SYS_ADMIN))
4713                 return -EPERM;
4714
4715         switch (cmd) {
4716         case BTRFS_BALANCE_CTL_PAUSE:
4717                 return btrfs_pause_balance(root->fs_info);
4718         case BTRFS_BALANCE_CTL_CANCEL:
4719                 return btrfs_cancel_balance(root->fs_info);
4720         }
4721
4722         return -EINVAL;
4723 }
4724
4725 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
4726                                          void __user *arg)
4727 {
4728         struct btrfs_fs_info *fs_info = root->fs_info;
4729         struct btrfs_ioctl_balance_args *bargs;
4730         int ret = 0;
4731
4732         if (!capable(CAP_SYS_ADMIN))
4733                 return -EPERM;
4734
4735         mutex_lock(&fs_info->balance_mutex);
4736         if (!fs_info->balance_ctl) {
4737                 ret = -ENOTCONN;
4738                 goto out;
4739         }
4740
4741         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4742         if (!bargs) {
4743                 ret = -ENOMEM;
4744                 goto out;
4745         }
4746
4747         update_ioctl_balance_args(fs_info, 1, bargs);
4748
4749         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4750                 ret = -EFAULT;
4751
4752         kfree(bargs);
4753 out:
4754         mutex_unlock(&fs_info->balance_mutex);
4755         return ret;
4756 }
4757
4758 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4759 {
4760         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4761         struct btrfs_ioctl_quota_ctl_args *sa;
4762         struct btrfs_trans_handle *trans = NULL;
4763         int ret;
4764         int err;
4765
4766         if (!capable(CAP_SYS_ADMIN))
4767                 return -EPERM;
4768
4769         ret = mnt_want_write_file(file);
4770         if (ret)
4771                 return ret;
4772
4773         sa = memdup_user(arg, sizeof(*sa));
4774         if (IS_ERR(sa)) {
4775                 ret = PTR_ERR(sa);
4776                 goto drop_write;
4777         }
4778
4779         down_write(&root->fs_info->subvol_sem);
4780         trans = btrfs_start_transaction(root->fs_info->tree_root, 2);
4781         if (IS_ERR(trans)) {
4782                 ret = PTR_ERR(trans);
4783                 goto out;
4784         }
4785
4786         switch (sa->cmd) {
4787         case BTRFS_QUOTA_CTL_ENABLE:
4788                 ret = btrfs_quota_enable(trans, root->fs_info);
4789                 break;
4790         case BTRFS_QUOTA_CTL_DISABLE:
4791                 ret = btrfs_quota_disable(trans, root->fs_info);
4792                 break;
4793         default:
4794                 ret = -EINVAL;
4795                 break;
4796         }
4797
4798         err = btrfs_commit_transaction(trans, root->fs_info->tree_root);
4799         if (err && !ret)
4800                 ret = err;
4801 out:
4802         kfree(sa);
4803         up_write(&root->fs_info->subvol_sem);
4804 drop_write:
4805         mnt_drop_write_file(file);
4806         return ret;
4807 }
4808
4809 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4810 {
4811         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4812         struct btrfs_ioctl_qgroup_assign_args *sa;
4813         struct btrfs_trans_handle *trans;
4814         int ret;
4815         int err;
4816
4817         if (!capable(CAP_SYS_ADMIN))
4818                 return -EPERM;
4819
4820         ret = mnt_want_write_file(file);
4821         if (ret)
4822                 return ret;
4823
4824         sa = memdup_user(arg, sizeof(*sa));
4825         if (IS_ERR(sa)) {
4826                 ret = PTR_ERR(sa);
4827                 goto drop_write;
4828         }
4829
4830         trans = btrfs_join_transaction(root);
4831         if (IS_ERR(trans)) {
4832                 ret = PTR_ERR(trans);
4833                 goto out;
4834         }
4835
4836         /* FIXME: check if the IDs really exist */
4837         if (sa->assign) {
4838                 ret = btrfs_add_qgroup_relation(trans, root->fs_info,
4839                                                 sa->src, sa->dst);
4840         } else {
4841                 ret = btrfs_del_qgroup_relation(trans, root->fs_info,
4842                                                 sa->src, sa->dst);
4843         }
4844
4845         /* update qgroup status and info */
4846         err = btrfs_run_qgroups(trans, root->fs_info);
4847         if (err < 0)
4848                 btrfs_std_error(root->fs_info, ret,
4849                             "failed to update qgroup status and info\n");
4850         err = btrfs_end_transaction(trans, root);
4851         if (err && !ret)
4852                 ret = err;
4853
4854 out:
4855         kfree(sa);
4856 drop_write:
4857         mnt_drop_write_file(file);
4858         return ret;
4859 }
4860
4861 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4862 {
4863         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4864         struct btrfs_ioctl_qgroup_create_args *sa;
4865         struct btrfs_trans_handle *trans;
4866         int ret;
4867         int err;
4868
4869         if (!capable(CAP_SYS_ADMIN))
4870                 return -EPERM;
4871
4872         ret = mnt_want_write_file(file);
4873         if (ret)
4874                 return ret;
4875
4876         sa = memdup_user(arg, sizeof(*sa));
4877         if (IS_ERR(sa)) {
4878                 ret = PTR_ERR(sa);
4879                 goto drop_write;
4880         }
4881
4882         if (!sa->qgroupid) {
4883                 ret = -EINVAL;
4884                 goto out;
4885         }
4886
4887         trans = btrfs_join_transaction(root);
4888         if (IS_ERR(trans)) {
4889                 ret = PTR_ERR(trans);
4890                 goto out;
4891         }
4892
4893         /* FIXME: check if the IDs really exist */
4894         if (sa->create) {
4895                 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid);
4896         } else {
4897                 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
4898         }
4899
4900         err = btrfs_end_transaction(trans, root);
4901         if (err && !ret)
4902                 ret = err;
4903
4904 out:
4905         kfree(sa);
4906 drop_write:
4907         mnt_drop_write_file(file);
4908         return ret;
4909 }
4910
4911 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4912 {
4913         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4914         struct btrfs_ioctl_qgroup_limit_args *sa;
4915         struct btrfs_trans_handle *trans;
4916         int ret;
4917         int err;
4918         u64 qgroupid;
4919
4920         if (!capable(CAP_SYS_ADMIN))
4921                 return -EPERM;
4922
4923         ret = mnt_want_write_file(file);
4924         if (ret)
4925                 return ret;
4926
4927         sa = memdup_user(arg, sizeof(*sa));
4928         if (IS_ERR(sa)) {
4929                 ret = PTR_ERR(sa);
4930                 goto drop_write;
4931         }
4932
4933         trans = btrfs_join_transaction(root);
4934         if (IS_ERR(trans)) {
4935                 ret = PTR_ERR(trans);
4936                 goto out;
4937         }
4938
4939         qgroupid = sa->qgroupid;
4940         if (!qgroupid) {
4941                 /* take the current subvol as qgroup */
4942                 qgroupid = root->root_key.objectid;
4943         }
4944
4945         /* FIXME: check if the IDs really exist */
4946         ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
4947
4948         err = btrfs_end_transaction(trans, root);
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_quota_rescan(struct file *file, void __user *arg)
4960 {
4961         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4962         struct btrfs_ioctl_quota_rescan_args *qsa;
4963         int ret;
4964
4965         if (!capable(CAP_SYS_ADMIN))
4966                 return -EPERM;
4967
4968         ret = mnt_want_write_file(file);
4969         if (ret)
4970                 return ret;
4971
4972         qsa = memdup_user(arg, sizeof(*qsa));
4973         if (IS_ERR(qsa)) {
4974                 ret = PTR_ERR(qsa);
4975                 goto drop_write;
4976         }
4977
4978         if (qsa->flags) {
4979                 ret = -EINVAL;
4980                 goto out;
4981         }
4982
4983         ret = btrfs_qgroup_rescan(root->fs_info);
4984
4985 out:
4986         kfree(qsa);
4987 drop_write:
4988         mnt_drop_write_file(file);
4989         return ret;
4990 }
4991
4992 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
4993 {
4994         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4995         struct btrfs_ioctl_quota_rescan_args *qsa;
4996         int ret = 0;
4997
4998         if (!capable(CAP_SYS_ADMIN))
4999                 return -EPERM;
5000
5001         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5002         if (!qsa)
5003                 return -ENOMEM;
5004
5005         if (root->fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5006                 qsa->flags = 1;
5007                 qsa->progress = root->fs_info->qgroup_rescan_progress.objectid;
5008         }
5009
5010         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5011                 ret = -EFAULT;
5012
5013         kfree(qsa);
5014         return ret;
5015 }
5016
5017 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5018 {
5019         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5020
5021         if (!capable(CAP_SYS_ADMIN))
5022                 return -EPERM;
5023
5024         return btrfs_qgroup_wait_for_completion(root->fs_info);
5025 }
5026
5027 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5028                                             struct btrfs_ioctl_received_subvol_args *sa)
5029 {
5030         struct inode *inode = file_inode(file);
5031         struct btrfs_root *root = BTRFS_I(inode)->root;
5032         struct btrfs_root_item *root_item = &root->root_item;
5033         struct btrfs_trans_handle *trans;
5034         struct timespec ct = CURRENT_TIME;
5035         int ret = 0;
5036         int received_uuid_changed;
5037
5038         if (!inode_owner_or_capable(inode))
5039                 return -EPERM;
5040
5041         ret = mnt_want_write_file(file);
5042         if (ret < 0)
5043                 return ret;
5044
5045         down_write(&root->fs_info->subvol_sem);
5046
5047         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
5048                 ret = -EINVAL;
5049                 goto out;
5050         }
5051
5052         if (btrfs_root_readonly(root)) {
5053                 ret = -EROFS;
5054                 goto out;
5055         }
5056
5057         /*
5058          * 1 - root item
5059          * 2 - uuid items (received uuid + subvol uuid)
5060          */
5061         trans = btrfs_start_transaction(root, 3);
5062         if (IS_ERR(trans)) {
5063                 ret = PTR_ERR(trans);
5064                 trans = NULL;
5065                 goto out;
5066         }
5067
5068         sa->rtransid = trans->transid;
5069         sa->rtime.sec = ct.tv_sec;
5070         sa->rtime.nsec = ct.tv_nsec;
5071
5072         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5073                                        BTRFS_UUID_SIZE);
5074         if (received_uuid_changed &&
5075             !btrfs_is_empty_uuid(root_item->received_uuid))
5076                 btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
5077                                     root_item->received_uuid,
5078                                     BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5079                                     root->root_key.objectid);
5080         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5081         btrfs_set_root_stransid(root_item, sa->stransid);
5082         btrfs_set_root_rtransid(root_item, sa->rtransid);
5083         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5084         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5085         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5086         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5087
5088         ret = btrfs_update_root(trans, root->fs_info->tree_root,
5089                                 &root->root_key, &root->root_item);
5090         if (ret < 0) {
5091                 btrfs_end_transaction(trans, root);
5092                 goto out;
5093         }
5094         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5095                 ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
5096                                           sa->uuid,
5097                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5098                                           root->root_key.objectid);
5099                 if (ret < 0 && ret != -EEXIST) {
5100                         btrfs_abort_transaction(trans, root, ret);
5101                         goto out;
5102                 }
5103         }
5104         ret = btrfs_commit_transaction(trans, root);
5105         if (ret < 0) {
5106                 btrfs_abort_transaction(trans, root, ret);
5107                 goto out;
5108         }
5109
5110 out:
5111         up_write(&root->fs_info->subvol_sem);
5112         mnt_drop_write_file(file);
5113         return ret;
5114 }
5115
5116 #ifdef CONFIG_64BIT
5117 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5118                                                 void __user *arg)
5119 {
5120         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5121         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5122         int ret = 0;
5123
5124         args32 = memdup_user(arg, sizeof(*args32));
5125         if (IS_ERR(args32)) {
5126                 ret = PTR_ERR(args32);
5127                 args32 = NULL;
5128                 goto out;
5129         }
5130
5131         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5132         if (!args64) {
5133                 ret = -ENOMEM;
5134                 goto out;
5135         }
5136
5137         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5138         args64->stransid = args32->stransid;
5139         args64->rtransid = args32->rtransid;
5140         args64->stime.sec = args32->stime.sec;
5141         args64->stime.nsec = args32->stime.nsec;
5142         args64->rtime.sec = args32->rtime.sec;
5143         args64->rtime.nsec = args32->rtime.nsec;
5144         args64->flags = args32->flags;
5145
5146         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5147         if (ret)
5148                 goto out;
5149
5150         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5151         args32->stransid = args64->stransid;
5152         args32->rtransid = args64->rtransid;
5153         args32->stime.sec = args64->stime.sec;
5154         args32->stime.nsec = args64->stime.nsec;
5155         args32->rtime.sec = args64->rtime.sec;
5156         args32->rtime.nsec = args64->rtime.nsec;
5157         args32->flags = args64->flags;
5158
5159         ret = copy_to_user(arg, args32, sizeof(*args32));
5160         if (ret)
5161                 ret = -EFAULT;
5162
5163 out:
5164         kfree(args32);
5165         kfree(args64);
5166         return ret;
5167 }
5168 #endif
5169
5170 static long btrfs_ioctl_set_received_subvol(struct file *file,
5171                                             void __user *arg)
5172 {
5173         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5174         int ret = 0;
5175
5176         sa = memdup_user(arg, sizeof(*sa));
5177         if (IS_ERR(sa)) {
5178                 ret = PTR_ERR(sa);
5179                 sa = NULL;
5180                 goto out;
5181         }
5182
5183         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5184
5185         if (ret)
5186                 goto out;
5187
5188         ret = copy_to_user(arg, sa, sizeof(*sa));
5189         if (ret)
5190                 ret = -EFAULT;
5191
5192 out:
5193         kfree(sa);
5194         return ret;
5195 }
5196
5197 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5198 {
5199         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5200         size_t len;
5201         int ret;
5202         char label[BTRFS_LABEL_SIZE];
5203
5204         spin_lock(&root->fs_info->super_lock);
5205         memcpy(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5206         spin_unlock(&root->fs_info->super_lock);
5207
5208         len = strnlen(label, BTRFS_LABEL_SIZE);
5209
5210         if (len == BTRFS_LABEL_SIZE) {
5211                 btrfs_warn(root->fs_info,
5212                         "label is too long, return the first %zu bytes", --len);
5213         }
5214
5215         ret = copy_to_user(arg, label, len);
5216
5217         return ret ? -EFAULT : 0;
5218 }
5219
5220 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5221 {
5222         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5223         struct btrfs_super_block *super_block = root->fs_info->super_copy;
5224         struct btrfs_trans_handle *trans;
5225         char label[BTRFS_LABEL_SIZE];
5226         int ret;
5227
5228         if (!capable(CAP_SYS_ADMIN))
5229                 return -EPERM;
5230
5231         if (copy_from_user(label, arg, sizeof(label)))
5232                 return -EFAULT;
5233
5234         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5235                 btrfs_err(root->fs_info, "unable to set label with more than %d bytes",
5236                        BTRFS_LABEL_SIZE - 1);
5237                 return -EINVAL;
5238         }
5239
5240         ret = mnt_want_write_file(file);
5241         if (ret)
5242                 return ret;
5243
5244         trans = btrfs_start_transaction(root, 0);
5245         if (IS_ERR(trans)) {
5246                 ret = PTR_ERR(trans);
5247                 goto out_unlock;
5248         }
5249
5250         spin_lock(&root->fs_info->super_lock);
5251         strcpy(super_block->label, label);
5252         spin_unlock(&root->fs_info->super_lock);
5253         ret = btrfs_commit_transaction(trans, root);
5254
5255 out_unlock:
5256         mnt_drop_write_file(file);
5257         return ret;
5258 }
5259
5260 #define INIT_FEATURE_FLAGS(suffix) \
5261         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5262           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5263           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5264
5265 static int btrfs_ioctl_get_supported_features(struct file *file,
5266                                               void __user *arg)
5267 {
5268         static const struct btrfs_ioctl_feature_flags features[3] = {
5269                 INIT_FEATURE_FLAGS(SUPP),
5270                 INIT_FEATURE_FLAGS(SAFE_SET),
5271                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5272         };
5273
5274         if (copy_to_user(arg, &features, sizeof(features)))
5275                 return -EFAULT;
5276
5277         return 0;
5278 }
5279
5280 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5281 {
5282         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5283         struct btrfs_super_block *super_block = root->fs_info->super_copy;
5284         struct btrfs_ioctl_feature_flags features;
5285
5286         features.compat_flags = btrfs_super_compat_flags(super_block);
5287         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5288         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5289
5290         if (copy_to_user(arg, &features, sizeof(features)))
5291                 return -EFAULT;
5292
5293         return 0;
5294 }
5295
5296 static int check_feature_bits(struct btrfs_root *root,
5297                               enum btrfs_feature_set set,
5298                               u64 change_mask, u64 flags, u64 supported_flags,
5299                               u64 safe_set, u64 safe_clear)
5300 {
5301         const char *type = btrfs_feature_set_names[set];
5302         char *names;
5303         u64 disallowed, unsupported;
5304         u64 set_mask = flags & change_mask;
5305         u64 clear_mask = ~flags & change_mask;
5306
5307         unsupported = set_mask & ~supported_flags;
5308         if (unsupported) {
5309                 names = btrfs_printable_features(set, unsupported);
5310                 if (names) {
5311                         btrfs_warn(root->fs_info,
5312                            "this kernel does not support the %s feature bit%s",
5313                            names, strchr(names, ',') ? "s" : "");
5314                         kfree(names);
5315                 } else
5316                         btrfs_warn(root->fs_info,
5317                            "this kernel does not support %s bits 0x%llx",
5318                            type, unsupported);
5319                 return -EOPNOTSUPP;
5320         }
5321
5322         disallowed = set_mask & ~safe_set;
5323         if (disallowed) {
5324                 names = btrfs_printable_features(set, disallowed);
5325                 if (names) {
5326                         btrfs_warn(root->fs_info,
5327                            "can't set the %s feature bit%s while mounted",
5328                            names, strchr(names, ',') ? "s" : "");
5329                         kfree(names);
5330                 } else
5331                         btrfs_warn(root->fs_info,
5332                            "can't set %s bits 0x%llx while mounted",
5333                            type, disallowed);
5334                 return -EPERM;
5335         }
5336
5337         disallowed = clear_mask & ~safe_clear;
5338         if (disallowed) {
5339                 names = btrfs_printable_features(set, disallowed);
5340                 if (names) {
5341                         btrfs_warn(root->fs_info,
5342                            "can't clear the %s feature bit%s while mounted",
5343                            names, strchr(names, ',') ? "s" : "");
5344                         kfree(names);
5345                 } else
5346                         btrfs_warn(root->fs_info,
5347                            "can't clear %s bits 0x%llx while mounted",
5348                            type, disallowed);
5349                 return -EPERM;
5350         }
5351
5352         return 0;
5353 }
5354
5355 #define check_feature(root, change_mask, flags, mask_base)      \
5356 check_feature_bits(root, FEAT_##mask_base, change_mask, flags,  \
5357                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5358                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5359                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5360
5361 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5362 {
5363         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5364         struct btrfs_super_block *super_block = root->fs_info->super_copy;
5365         struct btrfs_ioctl_feature_flags flags[2];
5366         struct btrfs_trans_handle *trans;
5367         u64 newflags;
5368         int ret;
5369
5370         if (!capable(CAP_SYS_ADMIN))
5371                 return -EPERM;
5372
5373         if (copy_from_user(flags, arg, sizeof(flags)))
5374                 return -EFAULT;
5375
5376         /* Nothing to do */
5377         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5378             !flags[0].incompat_flags)
5379                 return 0;
5380
5381         ret = check_feature(root, flags[0].compat_flags,
5382                             flags[1].compat_flags, COMPAT);
5383         if (ret)
5384                 return ret;
5385
5386         ret = check_feature(root, flags[0].compat_ro_flags,
5387                             flags[1].compat_ro_flags, COMPAT_RO);
5388         if (ret)
5389                 return ret;
5390
5391         ret = check_feature(root, flags[0].incompat_flags,
5392                             flags[1].incompat_flags, INCOMPAT);
5393         if (ret)
5394                 return ret;
5395
5396         trans = btrfs_start_transaction(root, 0);
5397         if (IS_ERR(trans))
5398                 return PTR_ERR(trans);
5399
5400         spin_lock(&root->fs_info->super_lock);
5401         newflags = btrfs_super_compat_flags(super_block);
5402         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5403         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5404         btrfs_set_super_compat_flags(super_block, newflags);
5405
5406         newflags = btrfs_super_compat_ro_flags(super_block);
5407         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5408         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5409         btrfs_set_super_compat_ro_flags(super_block, newflags);
5410
5411         newflags = btrfs_super_incompat_flags(super_block);
5412         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5413         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5414         btrfs_set_super_incompat_flags(super_block, newflags);
5415         spin_unlock(&root->fs_info->super_lock);
5416
5417         return btrfs_commit_transaction(trans, root);
5418 }
5419
5420 long btrfs_ioctl(struct file *file, unsigned int
5421                 cmd, unsigned long arg)
5422 {
5423         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5424         void __user *argp = (void __user *)arg;
5425
5426         switch (cmd) {
5427         case FS_IOC_GETFLAGS:
5428                 return btrfs_ioctl_getflags(file, argp);
5429         case FS_IOC_SETFLAGS:
5430                 return btrfs_ioctl_setflags(file, argp);
5431         case FS_IOC_GETVERSION:
5432                 return btrfs_ioctl_getversion(file, argp);
5433         case FITRIM:
5434                 return btrfs_ioctl_fitrim(file, argp);
5435         case BTRFS_IOC_SNAP_CREATE:
5436                 return btrfs_ioctl_snap_create(file, argp, 0);
5437         case BTRFS_IOC_SNAP_CREATE_V2:
5438                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5439         case BTRFS_IOC_SUBVOL_CREATE:
5440                 return btrfs_ioctl_snap_create(file, argp, 1);
5441         case BTRFS_IOC_SUBVOL_CREATE_V2:
5442                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5443         case BTRFS_IOC_SNAP_DESTROY:
5444                 return btrfs_ioctl_snap_destroy(file, argp);
5445         case BTRFS_IOC_SUBVOL_GETFLAGS:
5446                 return btrfs_ioctl_subvol_getflags(file, argp);
5447         case BTRFS_IOC_SUBVOL_SETFLAGS:
5448                 return btrfs_ioctl_subvol_setflags(file, argp);
5449         case BTRFS_IOC_DEFAULT_SUBVOL:
5450                 return btrfs_ioctl_default_subvol(file, argp);
5451         case BTRFS_IOC_DEFRAG:
5452                 return btrfs_ioctl_defrag(file, NULL);
5453         case BTRFS_IOC_DEFRAG_RANGE:
5454                 return btrfs_ioctl_defrag(file, argp);
5455         case BTRFS_IOC_RESIZE:
5456                 return btrfs_ioctl_resize(file, argp);
5457         case BTRFS_IOC_ADD_DEV:
5458                 return btrfs_ioctl_add_dev(root, argp);
5459         case BTRFS_IOC_RM_DEV:
5460                 return btrfs_ioctl_rm_dev(file, argp);
5461         case BTRFS_IOC_FS_INFO:
5462                 return btrfs_ioctl_fs_info(root, argp);
5463         case BTRFS_IOC_DEV_INFO:
5464                 return btrfs_ioctl_dev_info(root, argp);
5465         case BTRFS_IOC_BALANCE:
5466                 return btrfs_ioctl_balance(file, NULL);
5467         case BTRFS_IOC_TRANS_START:
5468                 return btrfs_ioctl_trans_start(file);
5469         case BTRFS_IOC_TRANS_END:
5470                 return btrfs_ioctl_trans_end(file);
5471         case BTRFS_IOC_TREE_SEARCH:
5472                 return btrfs_ioctl_tree_search(file, argp);
5473         case BTRFS_IOC_TREE_SEARCH_V2:
5474                 return btrfs_ioctl_tree_search_v2(file, argp);
5475         case BTRFS_IOC_INO_LOOKUP:
5476                 return btrfs_ioctl_ino_lookup(file, argp);
5477         case BTRFS_IOC_INO_PATHS:
5478                 return btrfs_ioctl_ino_to_path(root, argp);
5479         case BTRFS_IOC_LOGICAL_INO:
5480                 return btrfs_ioctl_logical_to_ino(root, argp);
5481         case BTRFS_IOC_SPACE_INFO:
5482                 return btrfs_ioctl_space_info(root, argp);
5483         case BTRFS_IOC_SYNC: {
5484                 int ret;
5485
5486                 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1);
5487                 if (ret)
5488                         return ret;
5489                 ret = btrfs_sync_fs(file_inode(file)->i_sb, 1);
5490                 /*
5491                  * The transaction thread may want to do more work,
5492                  * namely it pokes the cleaner ktread that will start
5493                  * processing uncleaned subvols.
5494                  */
5495                 wake_up_process(root->fs_info->transaction_kthread);
5496                 return ret;
5497         }
5498         case BTRFS_IOC_START_SYNC:
5499                 return btrfs_ioctl_start_sync(root, argp);
5500         case BTRFS_IOC_WAIT_SYNC:
5501                 return btrfs_ioctl_wait_sync(root, argp);
5502         case BTRFS_IOC_SCRUB:
5503                 return btrfs_ioctl_scrub(file, argp);
5504         case BTRFS_IOC_SCRUB_CANCEL:
5505                 return btrfs_ioctl_scrub_cancel(root, argp);
5506         case BTRFS_IOC_SCRUB_PROGRESS:
5507                 return btrfs_ioctl_scrub_progress(root, argp);
5508         case BTRFS_IOC_BALANCE_V2:
5509                 return btrfs_ioctl_balance(file, argp);
5510         case BTRFS_IOC_BALANCE_CTL:
5511                 return btrfs_ioctl_balance_ctl(root, arg);
5512         case BTRFS_IOC_BALANCE_PROGRESS:
5513                 return btrfs_ioctl_balance_progress(root, argp);
5514         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5515                 return btrfs_ioctl_set_received_subvol(file, argp);
5516 #ifdef CONFIG_64BIT
5517         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5518                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5519 #endif
5520         case BTRFS_IOC_SEND:
5521                 return btrfs_ioctl_send(file, argp);
5522         case BTRFS_IOC_GET_DEV_STATS:
5523                 return btrfs_ioctl_get_dev_stats(root, argp);
5524         case BTRFS_IOC_QUOTA_CTL:
5525                 return btrfs_ioctl_quota_ctl(file, argp);
5526         case BTRFS_IOC_QGROUP_ASSIGN:
5527                 return btrfs_ioctl_qgroup_assign(file, argp);
5528         case BTRFS_IOC_QGROUP_CREATE:
5529                 return btrfs_ioctl_qgroup_create(file, argp);
5530         case BTRFS_IOC_QGROUP_LIMIT:
5531                 return btrfs_ioctl_qgroup_limit(file, argp);
5532         case BTRFS_IOC_QUOTA_RESCAN:
5533                 return btrfs_ioctl_quota_rescan(file, argp);
5534         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5535                 return btrfs_ioctl_quota_rescan_status(file, argp);
5536         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5537                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5538         case BTRFS_IOC_DEV_REPLACE:
5539                 return btrfs_ioctl_dev_replace(root, argp);
5540         case BTRFS_IOC_GET_FSLABEL:
5541                 return btrfs_ioctl_get_fslabel(file, argp);
5542         case BTRFS_IOC_SET_FSLABEL:
5543                 return btrfs_ioctl_set_fslabel(file, argp);
5544         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5545                 return btrfs_ioctl_get_supported_features(file, argp);
5546         case BTRFS_IOC_GET_FEATURES:
5547                 return btrfs_ioctl_get_features(file, argp);
5548         case BTRFS_IOC_SET_FEATURES:
5549                 return btrfs_ioctl_set_features(file, argp);
5550         }
5551
5552         return -ENOTTY;
5553 }