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
  60 static int btrfs_clone(struct inode *src, struct inode *inode,
  61                        u64 off, u64 olen, u64 olen_aligned, u64 destoff);
  62
  63 /* Mask out flags that are inappropriate for the given type of inode. */
  64 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  65 {
  66         if (S_ISDIR(mode))
  67                 return flags;
  68         else if (S_ISREG(mode))
  69                 return flags & ~FS_DIRSYNC_FL;
  70         else
  71                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  72 }
  73
  74 /*
  75  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  76  */
  77 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  78 {
  79         unsigned int iflags = 0;
  80
  81         if (flags & BTRFS_INODE_SYNC)
  82                 iflags |= FS_SYNC_FL;
  83         if (flags & BTRFS_INODE_IMMUTABLE)
  84                 iflags |= FS_IMMUTABLE_FL;
  85         if (flags & BTRFS_INODE_APPEND)
  86                 iflags |= FS_APPEND_FL;
  87         if (flags & BTRFS_INODE_NODUMP)
  88                 iflags |= FS_NODUMP_FL;
  89         if (flags & BTRFS_INODE_NOATIME)
  90                 iflags |= FS_NOATIME_FL;
  91         if (flags & BTRFS_INODE_DIRSYNC)
  92                 iflags |= FS_DIRSYNC_FL;
  93         if (flags & BTRFS_INODE_NODATACOW)
  94                 iflags |= FS_NOCOW_FL;
  95
  96         if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
  97                 iflags |= FS_COMPR_FL;
  98         else if (flags & BTRFS_INODE_NOCOMPRESS)
  99                 iflags |= FS_NOCOMP_FL;
 100
 101         return iflags;
 102 }
 103
 104 /*
 105  * Update inode->i_flags based on the btrfs internal flags.
 106  */
 107 void btrfs_update_iflags(struct inode *inode)
 108 {
 109         struct btrfs_inode *ip = BTRFS_I(inode);
 110
 111         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
 112
 113         if (ip->flags & BTRFS_INODE_SYNC)
 114                 inode->i_flags |= S_SYNC;
 115         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 116                 inode->i_flags |= S_IMMUTABLE;
 117         if (ip->flags & BTRFS_INODE_APPEND)
 118                 inode->i_flags |= S_APPEND;
 119         if (ip->flags & BTRFS_INODE_NOATIME)
 120                 inode->i_flags |= S_NOATIME;
 121         if (ip->flags & BTRFS_INODE_DIRSYNC)
 122                 inode->i_flags |= S_DIRSYNC;
 123 }
 124
 125 /*
 126  * Inherit flags from the parent inode.
 127  *
 128  * Currently only the compression flags and the cow flags are inherited.
 129  */
 130 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 131 {
 132         unsigned int flags;
 133
 134         if (!dir)
 135                 return;
 136
 137         flags = BTRFS_I(dir)->flags;
 138
 139         if (flags & BTRFS_INODE_NOCOMPRESS) {
 140                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 141                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 142         } else if (flags & BTRFS_INODE_COMPRESS) {
 143                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 144                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 145         }
 146
 147         if (flags & BTRFS_INODE_NODATACOW) {
 148                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 149                 if (S_ISREG(inode->i_mode))
 150                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
 151         }
 152
 153         btrfs_update_iflags(inode);
 154 }
 155
 156 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 157 {
 158         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 159         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 160
 161         if (copy_to_user(arg, &flags, sizeof(flags)))
 162                 return -EFAULT;
 163         return 0;
 164 }
 165
 166 static int check_flags(unsigned int flags)
 167 {
 168         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 169                       FS_NOATIME_FL | FS_NODUMP_FL | \
 170                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 171                       FS_NOCOMP_FL | FS_COMPR_FL |
 172                       FS_NOCOW_FL))
 173                 return -EOPNOTSUPP;
 174
 175         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 176                 return -EINVAL;
 177
 178         return 0;
 179 }
 180
 181 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 182 {
 183         struct inode *inode = file_inode(file);
 184         struct btrfs_inode *ip = BTRFS_I(inode);
 185         struct btrfs_root *root = ip->root;
 186         struct btrfs_trans_handle *trans;
 187         unsigned int flags, oldflags;
 188         int ret;
 189         u64 ip_oldflags;
 190         unsigned int i_oldflags;
 191         umode_t mode;
 192
 193         if (btrfs_root_readonly(root))
 194                 return -EROFS;
 195
 196         if (copy_from_user(&flags, arg, sizeof(flags)))
 197                 return -EFAULT;
 198
 199         ret = check_flags(flags);
 200         if (ret)
 201                 return ret;
 202
 203         if (!inode_owner_or_capable(inode))
 204                 return -EACCES;
 205
 206         ret = mnt_want_write_file(file);
 207         if (ret)
 208                 return ret;
 209
 210         mutex_lock(&inode->i_mutex);
 211
 212         ip_oldflags = ip->flags;
 213         i_oldflags = inode->i_flags;
 214         mode = inode->i_mode;
 215
 216         flags = btrfs_mask_flags(inode->i_mode, flags);
 217         oldflags = btrfs_flags_to_ioctl(ip->flags);
 218         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 219                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 220                         ret = -EPERM;
 221                         goto out_unlock;
 222                 }
 223         }
 224
 225         if (flags & FS_SYNC_FL)
 226                 ip->flags |= BTRFS_INODE_SYNC;
 227         else
 228                 ip->flags &= ~BTRFS_INODE_SYNC;
 229         if (flags & FS_IMMUTABLE_FL)
 230                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 231         else
 232                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 233         if (flags & FS_APPEND_FL)
 234                 ip->flags |= BTRFS_INODE_APPEND;
 235         else
 236                 ip->flags &= ~BTRFS_INODE_APPEND;
 237         if (flags & FS_NODUMP_FL)
 238                 ip->flags |= BTRFS_INODE_NODUMP;
 239         else
 240                 ip->flags &= ~BTRFS_INODE_NODUMP;
 241         if (flags & FS_NOATIME_FL)
 242                 ip->flags |= BTRFS_INODE_NOATIME;
 243         else
 244                 ip->flags &= ~BTRFS_INODE_NOATIME;
 245         if (flags & FS_DIRSYNC_FL)
 246                 ip->flags |= BTRFS_INODE_DIRSYNC;
 247         else
 248                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 249         if (flags & FS_NOCOW_FL) {
 250                 if (S_ISREG(mode)) {
 251                         /*
 252                          * It's safe to turn csums off here, no extents exist.
 253                          * Otherwise we want the flag to reflect the real COW
 254                          * status of the file and will not set it.
 255                          */
 256                         if (inode->i_size == 0)
 257                                 ip->flags |= BTRFS_INODE_NODATACOW
 258                                            | BTRFS_INODE_NODATASUM;
 259                 } else {
 260                         ip->flags |= BTRFS_INODE_NODATACOW;
 261                 }
 262         } else {
 263                 /*
 264                  * Revert back under same assuptions as above
 265                  */
 266                 if (S_ISREG(mode)) {
 267                         if (inode->i_size == 0)
 268                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 269                                              | BTRFS_INODE_NODATASUM);
 270                 } else {
 271                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 272                 }
 273         }
 274
 275         /*
 276          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 277          * flag may be changed automatically if compression code won't make
 278          * things smaller.
 279          */
 280         if (flags & FS_NOCOMP_FL) {
 281                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 282                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 283         } else if (flags & FS_COMPR_FL) {
 284                 ip->flags |= BTRFS_INODE_COMPRESS;
 285                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 286         } else {
 287                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 288         }
 289
 290         trans = btrfs_start_transaction(root, 1);
 291         if (IS_ERR(trans)) {
 292                 ret = PTR_ERR(trans);
 293                 goto out_drop;
 294         }
 295
 296         btrfs_update_iflags(inode);
 297         inode_inc_iversion(inode);
 298         inode->i_ctime = CURRENT_TIME;
 299         ret = btrfs_update_inode(trans, root, inode);
 300
 301         btrfs_end_transaction(trans, root);
 302  out_drop:
 303         if (ret) {
 304                 ip->flags = ip_oldflags;
 305                 inode->i_flags = i_oldflags;
 306         }
 307
 308  out_unlock:
 309         mutex_unlock(&inode->i_mutex);
 310         mnt_drop_write_file(file);
 311         return ret;
 312 }
 313
 314 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 315 {
 316         struct inode *inode = file_inode(file);
 317
 318         return put_user(inode->i_generation, arg);
 319 }
 320
 321 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 322 {
 323         struct btrfs_fs_info *fs_info = btrfs_sb(fdentry(file)->d_sb);
 324         struct btrfs_device *device;
 325         struct request_queue *q;
 326         struct fstrim_range range;
 327         u64 minlen = ULLONG_MAX;
 328         u64 num_devices = 0;
 329         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 330         int ret;
 331
 332         if (!capable(CAP_SYS_ADMIN))
 333                 return -EPERM;
 334
 335         rcu_read_lock();
 336         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 337                                 dev_list) {
 338                 if (!device->bdev)
 339                         continue;
 340                 q = bdev_get_queue(device->bdev);
 341                 if (blk_queue_discard(q)) {
 342                         num_devices++;
 343                         minlen = min((u64)q->limits.discard_granularity,
 344                                      minlen);
 345                 }
 346         }
 347         rcu_read_unlock();
 348
 349         if (!num_devices)
 350                 return -EOPNOTSUPP;
 351         if (copy_from_user(&range, arg, sizeof(range)))
 352                 return -EFAULT;
 353         if (range.start > total_bytes ||
 354             range.len < fs_info->sb->s_blocksize)
 355                 return -EINVAL;
 356
 357         range.len = min(range.len, total_bytes - range.start);
 358         range.minlen = max(range.minlen, minlen);
 359         ret = btrfs_trim_fs(fs_info->tree_root, &range);
 360         if (ret < 0)
 361                 return ret;
 362
 363         if (copy_to_user(arg, &range, sizeof(range)))
 364                 return -EFAULT;
 365
 366         return 0;
 367 }
 368
 369 int btrfs_is_empty_uuid(u8 *uuid)
 370 {
 371         int i;
 372
 373         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 374                 if (uuid[i])
 375                         return 0;
 376         }
 377         return 1;
 378 }
 379
 380 static noinline int create_subvol(struct inode *dir,
 381                                   struct dentry *dentry,
 382                                   char *name, int namelen,
 383                                   u64 *async_transid,
 384                                   struct btrfs_qgroup_inherit *inherit)
 385 {
 386         struct btrfs_trans_handle *trans;
 387         struct btrfs_key key;
 388         struct btrfs_root_item root_item;
 389         struct btrfs_inode_item *inode_item;
 390         struct extent_buffer *leaf;
 391         struct btrfs_root *root = BTRFS_I(dir)->root;
 392         struct btrfs_root *new_root;
 393         struct btrfs_block_rsv block_rsv;
 394         struct timespec cur_time = CURRENT_TIME;
 395         int ret;
 396         int err;
 397         u64 objectid;
 398         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 399         u64 index = 0;
 400         u64 qgroup_reserved;
 401         uuid_le new_uuid;
 402
 403         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 404         if (ret)
 405                 return ret;
 406
 407         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 408         /*
 409          * The same as the snapshot creation, please see the comment
 410          * of create_snapshot().
 411          */
 412         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 413                                                8, &qgroup_reserved, false);
 414         if (ret)
 415                 return ret;
 416
 417         trans = btrfs_start_transaction(root, 0);
 418         if (IS_ERR(trans)) {
 419                 ret = PTR_ERR(trans);
 420                 goto out;
 421         }
 422         trans->block_rsv = &block_rsv;
 423         trans->bytes_reserved = block_rsv.size;
 424
 425         ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);
 426         if (ret)
 427                 goto fail;
 428
 429         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 430                                       0, objectid, NULL, 0, 0, 0);
 431         if (IS_ERR(leaf)) {
 432                 ret = PTR_ERR(leaf);
 433                 goto fail;
 434         }
 435
 436         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 437         btrfs_set_header_bytenr(leaf, leaf->start);
 438         btrfs_set_header_generation(leaf, trans->transid);
 439         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 440         btrfs_set_header_owner(leaf, objectid);
 441
 442         write_extent_buffer(leaf, root->fs_info->fsid, btrfs_header_fsid(),
 443                             BTRFS_FSID_SIZE);
 444         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 445                             btrfs_header_chunk_tree_uuid(leaf),
 446                             BTRFS_UUID_SIZE);
 447         btrfs_mark_buffer_dirty(leaf);
 448
 449         memset(&root_item, 0, sizeof(root_item));
 450
 451         inode_item = &root_item.inode;
 452         btrfs_set_stack_inode_generation(inode_item, 1);
 453         btrfs_set_stack_inode_size(inode_item, 3);
 454         btrfs_set_stack_inode_nlink(inode_item, 1);
 455         btrfs_set_stack_inode_nbytes(inode_item, root->leafsize);
 456         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 457
 458         btrfs_set_root_flags(&root_item, 0);
 459         btrfs_set_root_limit(&root_item, 0);
 460         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 461
 462         btrfs_set_root_bytenr(&root_item, leaf->start);
 463         btrfs_set_root_generation(&root_item, trans->transid);
 464         btrfs_set_root_level(&root_item, 0);
 465         btrfs_set_root_refs(&root_item, 1);
 466         btrfs_set_root_used(&root_item, leaf->len);
 467         btrfs_set_root_last_snapshot(&root_item, 0);
 468
 469         btrfs_set_root_generation_v2(&root_item,
 470                         btrfs_root_generation(&root_item));
 471         uuid_le_gen(&new_uuid);
 472         memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
 473         btrfs_set_stack_timespec_sec(&root_item.otime, cur_time.tv_sec);
 474         btrfs_set_stack_timespec_nsec(&root_item.otime, cur_time.tv_nsec);
 475         root_item.ctime = root_item.otime;
 476         btrfs_set_root_ctransid(&root_item, trans->transid);
 477         btrfs_set_root_otransid(&root_item, trans->transid);
 478
 479         btrfs_tree_unlock(leaf);
 480         free_extent_buffer(leaf);
 481         leaf = NULL;
 482
 483         btrfs_set_root_dirid(&root_item, new_dirid);
 484
 485         key.objectid = objectid;
 486         key.offset = 0;
 487         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 488         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 489                                 &root_item);
 490         if (ret)
 491                 goto fail;
 492
 493         key.offset = (u64)-1;
 494         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 495         if (IS_ERR(new_root)) {
 496                 btrfs_abort_transaction(trans, root, PTR_ERR(new_root));
 497                 ret = PTR_ERR(new_root);
 498                 goto fail;
 499         }
 500
 501         btrfs_record_root_in_trans(trans, new_root);
 502
 503         ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
 504         if (ret) {
 505                 /* We potentially lose an unused inode item here */
 506                 btrfs_abort_transaction(trans, root, ret);
 507                 goto fail;
 508         }
 509
 510         /*
 511          * insert the directory item
 512          */
 513         ret = btrfs_set_inode_index(dir, &index);
 514         if (ret) {
 515                 btrfs_abort_transaction(trans, root, ret);
 516                 goto fail;
 517         }
 518
 519         ret = btrfs_insert_dir_item(trans, root,
 520                                     name, namelen, dir, &key,
 521                                     BTRFS_FT_DIR, index);
 522         if (ret) {
 523                 btrfs_abort_transaction(trans, root, ret);
 524                 goto fail;
 525         }
 526
 527         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 528         ret = btrfs_update_inode(trans, root, dir);
 529         BUG_ON(ret);
 530
 531         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 532                                  objectid, root->root_key.objectid,
 533                                  btrfs_ino(dir), index, name, namelen);
 534         BUG_ON(ret);
 535
 536         ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
 537                                   root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
 538                                   objectid);
 539         if (ret)
 540                 btrfs_abort_transaction(trans, root, ret);
 541
 542 fail:
 543         trans->block_rsv = NULL;
 544         trans->bytes_reserved = 0;
 545         if (async_transid) {
 546                 *async_transid = trans->transid;
 547                 err = btrfs_commit_transaction_async(trans, root, 1);
 548                 if (err)
 549                         err = btrfs_commit_transaction(trans, root);
 550         } else {
 551                 err = btrfs_commit_transaction(trans, root);
 552         }
 553         if (err && !ret)
 554                 ret = err;
 555
 556         if (!ret)
 557                 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 558 out:
 559         btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
 560         return ret;
 561 }
 562
 563 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 564                            struct dentry *dentry, char *name, int namelen,
 565                            u64 *async_transid, bool readonly,
 566                            struct btrfs_qgroup_inherit *inherit)
 567 {
 568         struct inode *inode;
 569         struct btrfs_pending_snapshot *pending_snapshot;
 570         struct btrfs_trans_handle *trans;
 571         int ret;
 572
 573         if (!root->ref_cows)
 574                 return -EINVAL;
 575
 576         ret = btrfs_start_delalloc_inodes(root, 0);
 577         if (ret)
 578                 return ret;
 579
 580         btrfs_wait_ordered_extents(root, -1);
 581
 582         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 583         if (!pending_snapshot)
 584                 return -ENOMEM;
 585
 586         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 587                              BTRFS_BLOCK_RSV_TEMP);
 588         /*
 589          * 1 - parent dir inode
 590          * 2 - dir entries
 591          * 1 - root item
 592          * 2 - root ref/backref
 593          * 1 - root of snapshot
 594          * 1 - UUID item
 595          */
 596         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 597                                         &pending_snapshot->block_rsv, 8,
 598                                         &pending_snapshot->qgroup_reserved,
 599                                         false);
 600         if (ret)
 601                 goto out;
 602
 603         pending_snapshot->dentry = dentry;
 604         pending_snapshot->root = root;
 605         pending_snapshot->readonly = readonly;
 606         pending_snapshot->dir = dir;
 607         pending_snapshot->inherit = inherit;
 608
 609         trans = btrfs_start_transaction(root, 0);
 610         if (IS_ERR(trans)) {
 611                 ret = PTR_ERR(trans);
 612                 goto fail;
 613         }
 614
 615         spin_lock(&root->fs_info->trans_lock);
 616         list_add(&pending_snapshot->list,
 617                  &trans->transaction->pending_snapshots);
 618         spin_unlock(&root->fs_info->trans_lock);
 619         if (async_transid) {
 620                 *async_transid = trans->transid;
 621                 ret = btrfs_commit_transaction_async(trans,
 622                                      root->fs_info->extent_root, 1);
 623                 if (ret)
 624                         ret = btrfs_commit_transaction(trans, root);
 625         } else {
 626                 ret = btrfs_commit_transaction(trans,
 627                                                root->fs_info->extent_root);
 628         }
 629         if (ret)
 630                 goto fail;
 631
 632         ret = pending_snapshot->error;
 633         if (ret)
 634                 goto fail;
 635
 636         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 637         if (ret)
 638                 goto fail;
 639
 640         inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 641         if (IS_ERR(inode)) {
 642                 ret = PTR_ERR(inode);
 643                 goto fail;
 644         }
 645         BUG_ON(!inode);
 646         d_instantiate(dentry, inode);
 647         ret = 0;
 648 fail:
 649         btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,
 650                                          &pending_snapshot->block_rsv,
 651                                          pending_snapshot->qgroup_reserved);
 652 out:
 653         kfree(pending_snapshot);
 654         return ret;
 655 }
 656
 657 /*  copy of check_sticky in fs/namei.c()
 658 * It's inline, so penalty for filesystems that don't use sticky bit is
 659 * minimal.
 660 */
 661 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
 662 {
 663         kuid_t fsuid = current_fsuid();
 664
 665         if (!(dir->i_mode & S_ISVTX))
 666                 return 0;
 667         if (uid_eq(inode->i_uid, fsuid))
 668                 return 0;
 669         if (uid_eq(dir->i_uid, fsuid))
 670                 return 0;
 671         return !capable(CAP_FOWNER);
 672 }
 673
 674 /*  copy of may_delete in fs/namei.c()
 675  *      Check whether we can remove a link victim from directory dir, check
 676  *  whether the type of victim is right.
 677  *  1. We can't do it if dir is read-only (done in permission())
 678  *  2. We should have write and exec permissions on dir
 679  *  3. We can't remove anything from append-only dir
 680  *  4. We can't do anything with immutable dir (done in permission())
 681  *  5. If the sticky bit on dir is set we should either
 682  *      a. be owner of dir, or
 683  *      b. be owner of victim, or
 684  *      c. have CAP_FOWNER capability
 685  *  6. If the victim is append-only or immutable we can't do antyhing with
 686  *     links pointing to it.
 687  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 688  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 689  *  9. We can't remove a root or mountpoint.
 690  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 691  *     nfs_async_unlink().
 692  */
 693
 694 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 695 {
 696         int error;
 697
 698         if (!victim->d_inode)
 699                 return -ENOENT;
 700
 701         BUG_ON(victim->d_parent->d_inode != dir);
 702         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 703
 704         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 705         if (error)
 706                 return error;
 707         if (IS_APPEND(dir))
 708                 return -EPERM;
 709         if (btrfs_check_sticky(dir, victim->d_inode)||
 710                 IS_APPEND(victim->d_inode)||
 711             IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
 712                 return -EPERM;
 713         if (isdir) {
 714                 if (!S_ISDIR(victim->d_inode->i_mode))
 715                         return -ENOTDIR;
 716                 if (IS_ROOT(victim))
 717                         return -EBUSY;
 718         } else if (S_ISDIR(victim->d_inode->i_mode))
 719                 return -EISDIR;
 720         if (IS_DEADDIR(dir))
 721                 return -ENOENT;
 722         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 723                 return -EBUSY;
 724         return 0;
 725 }
 726
 727 /* copy of may_create in fs/namei.c() */
 728 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 729 {
 730         if (child->d_inode)
 731                 return -EEXIST;
 732         if (IS_DEADDIR(dir))
 733                 return -ENOENT;
 734         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 735 }
 736
 737 /*
 738  * Create a new subvolume below @parent.  This is largely modeled after
 739  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 740  * inside this filesystem so it's quite a bit simpler.
 741  */
 742 static noinline int btrfs_mksubvol(struct path *parent,
 743                                    char *name, int namelen,
 744                                    struct btrfs_root *snap_src,
 745                                    u64 *async_transid, bool readonly,
 746                                    struct btrfs_qgroup_inherit *inherit)
 747 {
 748         struct inode *dir  = parent->dentry->d_inode;
 749         struct dentry *dentry;
 750         int error;
 751
 752         error = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
 753         if (error == -EINTR)
 754                 return error;
 755
 756         dentry = lookup_one_len(name, parent->dentry, namelen);
 757         error = PTR_ERR(dentry);
 758         if (IS_ERR(dentry))
 759                 goto out_unlock;
 760
 761         error = -EEXIST;
 762         if (dentry->d_inode)
 763                 goto out_dput;
 764
 765         error = btrfs_may_create(dir, dentry);
 766         if (error)
 767                 goto out_dput;
 768
 769         /*
 770          * even if this name doesn't exist, we may get hash collisions.
 771          * check for them now when we can safely fail
 772          */
 773         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 774                                                dir->i_ino, name,
 775                                                namelen);
 776         if (error)
 777                 goto out_dput;
 778
 779         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 780
 781         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 782                 goto out_up_read;
 783
 784         if (snap_src) {
 785                 error = create_snapshot(snap_src, dir, dentry, name, namelen,
 786                                         async_transid, readonly, inherit);
 787         } else {
 788                 error = create_subvol(dir, dentry, name, namelen,
 789                                       async_transid, inherit);
 790         }
 791         if (!error)
 792                 fsnotify_mkdir(dir, dentry);
 793 out_up_read:
 794         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 795 out_dput:
 796         dput(dentry);
 797 out_unlock:
 798         mutex_unlock(&dir->i_mutex);
 799         return error;
 800 }
 801
 802 /*
 803  * When we're defragging a range, we don't want to kick it off again
 804  * if it is really just waiting for delalloc to send it down.
 805  * If we find a nice big extent or delalloc range for the bytes in the
 806  * file you want to defrag, we return 0 to let you know to skip this
 807  * part of the file
 808  */
 809 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
 810 {
 811         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 812         struct extent_map *em = NULL;
 813         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 814         u64 end;
 815
 816         read_lock(&em_tree->lock);
 817         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 818         read_unlock(&em_tree->lock);
 819
 820         if (em) {
 821                 end = extent_map_end(em);
 822                 free_extent_map(em);
 823                 if (end - offset > thresh)
 824                         return 0;
 825         }
 826         /* if we already have a nice delalloc here, just stop */
 827         thresh /= 2;
 828         end = count_range_bits(io_tree, &offset, offset + thresh,
 829                                thresh, EXTENT_DELALLOC, 1);
 830         if (end >= thresh)
 831                 return 0;
 832         return 1;
 833 }
 834
 835 /*
 836  * helper function to walk through a file and find extents
 837  * newer than a specific transid, and smaller than thresh.
 838  *
 839  * This is used by the defragging code to find new and small
 840  * extents
 841  */
 842 static int find_new_extents(struct btrfs_root *root,
 843                             struct inode *inode, u64 newer_than,
 844                             u64 *off, int thresh)
 845 {
 846         struct btrfs_path *path;
 847         struct btrfs_key min_key;
 848         struct extent_buffer *leaf;
 849         struct btrfs_file_extent_item *extent;
 850         int type;
 851         int ret;
 852         u64 ino = btrfs_ino(inode);
 853
 854         path = btrfs_alloc_path();
 855         if (!path)
 856                 return -ENOMEM;
 857
 858         min_key.objectid = ino;
 859         min_key.type = BTRFS_EXTENT_DATA_KEY;
 860         min_key.offset = *off;
 861
 862         path->keep_locks = 1;
 863
 864         while (1) {
 865                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
 866                 if (ret != 0)
 867                         goto none;
 868                 if (min_key.objectid != ino)
 869                         goto none;
 870                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 871                         goto none;
 872
 873                 leaf = path->nodes[0];
 874                 extent = btrfs_item_ptr(leaf, path->slots[0],
 875                                         struct btrfs_file_extent_item);
 876
 877                 type = btrfs_file_extent_type(leaf, extent);
 878                 if (type == BTRFS_FILE_EXTENT_REG &&
 879                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 880                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 881                         *off = min_key.offset;
 882                         btrfs_free_path(path);
 883                         return 0;
 884                 }
 885
 886                 if (min_key.offset == (u64)-1)
 887                         goto none;
 888
 889                 min_key.offset++;
 890                 btrfs_release_path(path);
 891         }
 892 none:
 893         btrfs_free_path(path);
 894         return -ENOENT;
 895 }
 896
 897 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 898 {
 899         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 900         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 901         struct extent_map *em;
 902         u64 len = PAGE_CACHE_SIZE;
 903
 904         /*
 905          * hopefully we have this extent in the tree already, try without
 906          * the full extent lock
 907          */
 908         read_lock(&em_tree->lock);
 909         em = lookup_extent_mapping(em_tree, start, len);
 910         read_unlock(&em_tree->lock);
 911
 912         if (!em) {
 913                 /* get the big lock and read metadata off disk */
 914                 lock_extent(io_tree, start, start + len - 1);
 915                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 916                 unlock_extent(io_tree, start, start + len - 1);
 917
 918                 if (IS_ERR(em))
 919                         return NULL;
 920         }
 921
 922         return em;
 923 }
 924
 925 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
 926 {
 927         struct extent_map *next;
 928         bool ret = true;
 929
 930         /* this is the last extent */
 931         if (em->start + em->len >= i_size_read(inode))
 932                 return false;
 933
 934         next = defrag_lookup_extent(inode, em->start + em->len);
 935         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
 936                 ret = false;
 937
 938         free_extent_map(next);
 939         return ret;
 940 }
 941
 942 static int should_defrag_range(struct inode *inode, u64 start, int thresh,
 943                                u64 *last_len, u64 *skip, u64 *defrag_end,
 944                                int compress)
 945 {
 946         struct extent_map *em;
 947         int ret = 1;
 948         bool next_mergeable = true;
 949
 950         /*
 951          * make sure that once we start defragging an extent, we keep on
 952          * defragging it
 953          */
 954         if (start < *defrag_end)
 955                 return 1;
 956
 957         *skip = 0;
 958
 959         em = defrag_lookup_extent(inode, start);
 960         if (!em)
 961                 return 0;
 962
 963         /* this will cover holes, and inline extents */
 964         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
 965                 ret = 0;
 966                 goto out;
 967         }
 968
 969         next_mergeable = defrag_check_next_extent(inode, em);
 970
 971         /*
 972          * we hit a real extent, if it is big or the next extent is not a
 973          * real extent, don't bother defragging it
 974          */
 975         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
 976             (em->len >= thresh || !next_mergeable))
 977                 ret = 0;
 978 out:
 979         /*
 980          * last_len ends up being a counter of how many bytes we've defragged.
 981          * every time we choose not to defrag an extent, we reset *last_len
 982          * so that the next tiny extent will force a defrag.
 983          *
 984          * The end result of this is that tiny extents before a single big
 985          * extent will force at least part of that big extent to be defragged.
 986          */
 987         if (ret) {
 988                 *defrag_end = extent_map_end(em);
 989         } else {
 990                 *last_len = 0;
 991                 *skip = extent_map_end(em);
 992                 *defrag_end = 0;
 993         }
 994
 995         free_extent_map(em);
 996         return ret;
 997 }
 998
 999 /*
1000  * it doesn't do much good to defrag one or two pages
1001  * at a time.  This pulls in a nice chunk of pages
1002  * to COW and defrag.
1003  *
1004  * It also makes sure the delalloc code has enough
1005  * dirty data to avoid making new small extents as part
1006  * of the defrag
1007  *
1008  * It's a good idea to start RA on this range
1009  * before calling this.
1010  */
1011 static int cluster_pages_for_defrag(struct inode *inode,
1012                                     struct page **pages,
1013                                     unsigned long start_index,
1014                                     int num_pages)
1015 {
1016         unsigned long file_end;
1017         u64 isize = i_size_read(inode);
1018         u64 page_start;
1019         u64 page_end;
1020         u64 page_cnt;
1021         int ret;
1022         int i;
1023         int i_done;
1024         struct btrfs_ordered_extent *ordered;
1025         struct extent_state *cached_state = NULL;
1026         struct extent_io_tree *tree;
1027         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1028
1029         file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
1030         if (!isize || start_index > file_end)
1031                 return 0;
1032
1033         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1034
1035         ret = btrfs_delalloc_reserve_space(inode,
1036                                            page_cnt << PAGE_CACHE_SHIFT);
1037         if (ret)
1038                 return ret;
1039         i_done = 0;
1040         tree = &BTRFS_I(inode)->io_tree;
1041
1042         /* step one, lock all the pages */
1043         for (i = 0; i < page_cnt; i++) {
1044                 struct page *page;
1045 again:
1046                 page = find_or_create_page(inode->i_mapping,
1047                                            start_index + i, mask);
1048                 if (!page)
1049                         break;
1050
1051                 page_start = page_offset(page);
1052                 page_end = page_start + PAGE_CACHE_SIZE - 1;
1053                 while (1) {
1054                         lock_extent(tree, page_start, page_end);
1055                         ordered = btrfs_lookup_ordered_extent(inode,
1056                                                               page_start);
1057                         unlock_extent(tree, page_start, page_end);
1058                         if (!ordered)
1059                                 break;
1060
1061                         unlock_page(page);
1062                         btrfs_start_ordered_extent(inode, ordered, 1);
1063                         btrfs_put_ordered_extent(ordered);
1064                         lock_page(page);
1065                         /*
1066                          * we unlocked the page above, so we need check if
1067                          * it was released or not.
1068                          */
1069                         if (page->mapping != inode->i_mapping) {
1070                                 unlock_page(page);
1071                                 page_cache_release(page);
1072                                 goto again;
1073                         }
1074                 }
1075
1076                 if (!PageUptodate(page)) {
1077                         btrfs_readpage(NULL, page);
1078                         lock_page(page);
1079                         if (!PageUptodate(page)) {
1080                                 unlock_page(page);
1081                                 page_cache_release(page);
1082                                 ret = -EIO;
1083                                 break;
1084                         }
1085                 }
1086
1087                 if (page->mapping != inode->i_mapping) {
1088                         unlock_page(page);
1089                         page_cache_release(page);
1090                         goto again;
1091                 }
1092
1093                 pages[i] = page;
1094                 i_done++;
1095         }
1096         if (!i_done || ret)
1097                 goto out;
1098
1099         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1100                 goto out;
1101
1102         /*
1103          * so now we have a nice long stream of locked
1104          * and up to date pages, lets wait on them
1105          */
1106         for (i = 0; i < i_done; i++)
1107                 wait_on_page_writeback(pages[i]);
1108
1109         page_start = page_offset(pages[0]);
1110         page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1111
1112         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1113                          page_start, page_end - 1, 0, &cached_state);
1114         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1115                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1116                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1117                           &cached_state, GFP_NOFS);
1118
1119         if (i_done != page_cnt) {
1120                 spin_lock(&BTRFS_I(inode)->lock);
1121                 BTRFS_I(inode)->outstanding_extents++;
1122                 spin_unlock(&BTRFS_I(inode)->lock);
1123                 btrfs_delalloc_release_space(inode,
1124                                      (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1125         }
1126
1127
1128         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1129                           &cached_state, GFP_NOFS);
1130
1131         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1132                              page_start, page_end - 1, &cached_state,
1133                              GFP_NOFS);
1134
1135         for (i = 0; i < i_done; i++) {
1136                 clear_page_dirty_for_io(pages[i]);
1137                 ClearPageChecked(pages[i]);
1138                 set_page_extent_mapped(pages[i]);
1139                 set_page_dirty(pages[i]);
1140                 unlock_page(pages[i]);
1141                 page_cache_release(pages[i]);
1142         }
1143         return i_done;
1144 out:
1145         for (i = 0; i < i_done; i++) {
1146                 unlock_page(pages[i]);
1147                 page_cache_release(pages[i]);
1148         }
1149         btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1150         return ret;
1151
1152 }
1153
1154 int btrfs_defrag_file(struct inode *inode, struct file *file,
1155                       struct btrfs_ioctl_defrag_range_args *range,
1156                       u64 newer_than, unsigned long max_to_defrag)
1157 {
1158         struct btrfs_root *root = BTRFS_I(inode)->root;
1159         struct file_ra_state *ra = NULL;
1160         unsigned long last_index;
1161         u64 isize = i_size_read(inode);
1162         u64 last_len = 0;
1163         u64 skip = 0;
1164         u64 defrag_end = 0;
1165         u64 newer_off = range->start;
1166         unsigned long i;
1167         unsigned long ra_index = 0;
1168         int ret;
1169         int defrag_count = 0;
1170         int compress_type = BTRFS_COMPRESS_ZLIB;
1171         int extent_thresh = range->extent_thresh;
1172         int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1173         int cluster = max_cluster;
1174         u64 new_align = ~((u64)128 * 1024 - 1);
1175         struct page **pages = NULL;
1176
1177         if (isize == 0)
1178                 return 0;
1179
1180         if (range->start >= isize)
1181                 return -EINVAL;
1182
1183         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1184                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1185                         return -EINVAL;
1186                 if (range->compress_type)
1187                         compress_type = range->compress_type;
1188         }
1189
1190         if (extent_thresh == 0)
1191                 extent_thresh = 256 * 1024;
1192
1193         /*
1194          * if we were not given a file, allocate a readahead
1195          * context
1196          */
1197         if (!file) {
1198                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1199                 if (!ra)
1200                         return -ENOMEM;
1201                 file_ra_state_init(ra, inode->i_mapping);
1202         } else {
1203                 ra = &file->f_ra;
1204         }
1205
1206         pages = kmalloc_array(max_cluster, sizeof(struct page *),
1207                         GFP_NOFS);
1208         if (!pages) {
1209                 ret = -ENOMEM;
1210                 goto out_ra;
1211         }
1212
1213         /* find the last page to defrag */
1214         if (range->start + range->len > range->start) {
1215                 last_index = min_t(u64, isize - 1,
1216                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1217         } else {
1218                 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1219         }
1220
1221         if (newer_than) {
1222                 ret = find_new_extents(root, inode, newer_than,
1223                                        &newer_off, 64 * 1024);
1224                 if (!ret) {
1225                         range->start = newer_off;
1226                         /*
1227                          * we always align our defrag to help keep
1228                          * the extents in the file evenly spaced
1229                          */
1230                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1231                 } else
1232                         goto out_ra;
1233         } else {
1234                 i = range->start >> PAGE_CACHE_SHIFT;
1235         }
1236         if (!max_to_defrag)
1237                 max_to_defrag = last_index + 1;
1238
1239         /*
1240          * make writeback starts from i, so the defrag range can be
1241          * written sequentially.
1242          */
1243         if (i < inode->i_mapping->writeback_index)
1244                 inode->i_mapping->writeback_index = i;
1245
1246         while (i <= last_index && defrag_count < max_to_defrag &&
1247                (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1248                 PAGE_CACHE_SHIFT)) {
1249                 /*
1250                  * make sure we stop running if someone unmounts
1251                  * the FS
1252                  */
1253                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1254                         break;
1255
1256                 if (btrfs_defrag_cancelled(root->fs_info)) {
1257                         printk(KERN_DEBUG "btrfs: defrag_file cancelled\n");
1258                         ret = -EAGAIN;
1259                         break;
1260                 }
1261
1262                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1263                                          extent_thresh, &last_len, &skip,
1264                                          &defrag_end, range->flags &
1265                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1266                         unsigned long next;
1267                         /*
1268                          * the should_defrag function tells us how much to skip
1269                          * bump our counter by the suggested amount
1270                          */
1271                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1272                         i = max(i + 1, next);
1273                         continue;
1274                 }
1275
1276                 if (!newer_than) {
1277                         cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1278                                    PAGE_CACHE_SHIFT) - i;
1279                         cluster = min(cluster, max_cluster);
1280                 } else {
1281                         cluster = max_cluster;
1282                 }
1283
1284                 if (i + cluster > ra_index) {
1285                         ra_index = max(i, ra_index);
1286                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1287                                        cluster);
1288                         ra_index += max_cluster;
1289                 }
1290
1291                 mutex_lock(&inode->i_mutex);
1292                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1293                         BTRFS_I(inode)->force_compress = compress_type;
1294                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1295                 if (ret < 0) {
1296                         mutex_unlock(&inode->i_mutex);
1297                         goto out_ra;
1298                 }
1299
1300                 defrag_count += ret;
1301                 balance_dirty_pages_ratelimited(inode->i_mapping);
1302                 mutex_unlock(&inode->i_mutex);
1303
1304                 if (newer_than) {
1305                         if (newer_off == (u64)-1)
1306                                 break;
1307
1308                         if (ret > 0)
1309                                 i += ret;
1310
1311                         newer_off = max(newer_off + 1,
1312                                         (u64)i << PAGE_CACHE_SHIFT);
1313
1314                         ret = find_new_extents(root, inode,
1315                                                newer_than, &newer_off,
1316                                                64 * 1024);
1317                         if (!ret) {
1318                                 range->start = newer_off;
1319                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1320                         } else {
1321                                 break;
1322                         }
1323                 } else {
1324                         if (ret > 0) {
1325                                 i += ret;
1326                                 last_len += ret << PAGE_CACHE_SHIFT;
1327                         } else {
1328                                 i++;
1329                                 last_len = 0;
1330                         }
1331                 }
1332         }
1333
1334         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1335                 filemap_flush(inode->i_mapping);
1336
1337         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1338                 /* the filemap_flush will queue IO into the worker threads, but
1339                  * we have to make sure the IO is actually started and that
1340                  * ordered extents get created before we return
1341                  */
1342                 atomic_inc(&root->fs_info->async_submit_draining);
1343                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1344                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1345                         wait_event(root->fs_info->async_submit_wait,
1346                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1347                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1348                 }
1349                 atomic_dec(&root->fs_info->async_submit_draining);
1350         }
1351
1352         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1353                 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1354         }
1355
1356         ret = defrag_count;
1357
1358 out_ra:
1359         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1360                 mutex_lock(&inode->i_mutex);
1361                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1362                 mutex_unlock(&inode->i_mutex);
1363         }
1364         if (!file)
1365                 kfree(ra);
1366         kfree(pages);
1367         return ret;
1368 }
1369
1370 static noinline int btrfs_ioctl_resize(struct file *file,
1371                                         void __user *arg)
1372 {
1373         u64 new_size;
1374         u64 old_size;
1375         u64 devid = 1;
1376         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
1377         struct btrfs_ioctl_vol_args *vol_args;
1378         struct btrfs_trans_handle *trans;
1379         struct btrfs_device *device = NULL;
1380         char *sizestr;
1381         char *devstr = NULL;
1382         int ret = 0;
1383         int mod = 0;
1384
1385         if (!capable(CAP_SYS_ADMIN))
1386                 return -EPERM;
1387
1388         ret = mnt_want_write_file(file);
1389         if (ret)
1390                 return ret;
1391
1392         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1393                         1)) {
1394                 mnt_drop_write_file(file);
1395                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1396         }
1397
1398         mutex_lock(&root->fs_info->volume_mutex);
1399         vol_args = memdup_user(arg, sizeof(*vol_args));
1400         if (IS_ERR(vol_args)) {
1401                 ret = PTR_ERR(vol_args);
1402                 goto out;
1403         }
1404
1405         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1406
1407         sizestr = vol_args->name;
1408         devstr = strchr(sizestr, ':');
1409         if (devstr) {
1410                 char *end;
1411                 sizestr = devstr + 1;
1412                 *devstr = '\0';
1413                 devstr = vol_args->name;
1414                 devid = simple_strtoull(devstr, &end, 10);
1415                 if (!devid) {
1416                         ret = -EINVAL;
1417                         goto out_free;
1418                 }
1419                 printk(KERN_INFO "btrfs: resizing devid %llu\n", devid);
1420         }
1421
1422         device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
1423         if (!device) {
1424                 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1425                        devid);
1426                 ret = -ENODEV;
1427                 goto out_free;
1428         }
1429
1430         if (!device->writeable) {
1431                 printk(KERN_INFO "btrfs: resizer unable to apply on "
1432                        "readonly device %llu\n",
1433                        devid);
1434                 ret = -EPERM;
1435                 goto out_free;
1436         }
1437
1438         if (!strcmp(sizestr, "max"))
1439                 new_size = device->bdev->bd_inode->i_size;
1440         else {
1441                 if (sizestr[0] == '-') {
1442                         mod = -1;
1443                         sizestr++;
1444                 } else if (sizestr[0] == '+') {
1445                         mod = 1;
1446                         sizestr++;
1447                 }
1448                 new_size = memparse(sizestr, NULL);
1449                 if (new_size == 0) {
1450                         ret = -EINVAL;
1451                         goto out_free;
1452                 }
1453         }
1454
1455         if (device->is_tgtdev_for_dev_replace) {
1456                 ret = -EPERM;
1457                 goto out_free;
1458         }
1459
1460         old_size = device->total_bytes;
1461
1462         if (mod < 0) {
1463                 if (new_size > old_size) {
1464                         ret = -EINVAL;
1465                         goto out_free;
1466                 }
1467                 new_size = old_size - new_size;
1468         } else if (mod > 0) {
1469                 new_size = old_size + new_size;
1470         }
1471
1472         if (new_size < 256 * 1024 * 1024) {
1473                 ret = -EINVAL;
1474                 goto out_free;
1475         }
1476         if (new_size > device->bdev->bd_inode->i_size) {
1477                 ret = -EFBIG;
1478                 goto out_free;
1479         }
1480
1481         do_div(new_size, root->sectorsize);
1482         new_size *= root->sectorsize;
1483
1484         printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
1485                       rcu_str_deref(device->name), new_size);
1486
1487         if (new_size > old_size) {
1488                 trans = btrfs_start_transaction(root, 0);
1489                 if (IS_ERR(trans)) {
1490                         ret = PTR_ERR(trans);
1491                         goto out_free;
1492                 }
1493                 ret = btrfs_grow_device(trans, device, new_size);
1494                 btrfs_commit_transaction(trans, root);
1495         } else if (new_size < old_size) {
1496                 ret = btrfs_shrink_device(device, new_size);
1497         } /* equal, nothing need to do */
1498
1499 out_free:
1500         kfree(vol_args);
1501 out:
1502         mutex_unlock(&root->fs_info->volume_mutex);
1503         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
1504         mnt_drop_write_file(file);
1505         return ret;
1506 }
1507
1508 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1509                                 char *name, unsigned long fd, int subvol,
1510                                 u64 *transid, bool readonly,
1511                                 struct btrfs_qgroup_inherit *inherit)
1512 {
1513         int namelen;
1514         int ret = 0;
1515
1516         ret = mnt_want_write_file(file);
1517         if (ret)
1518                 goto out;
1519
1520         namelen = strlen(name);
1521         if (strchr(name, '/')) {
1522                 ret = -EINVAL;
1523                 goto out_drop_write;
1524         }
1525
1526         if (name[0] == '.' &&
1527            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1528                 ret = -EEXIST;
1529                 goto out_drop_write;
1530         }
1531
1532         if (subvol) {
1533                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1534                                      NULL, transid, readonly, inherit);
1535         } else {
1536                 struct fd src = fdget(fd);
1537                 struct inode *src_inode;
1538                 if (!src.file) {
1539                         ret = -EINVAL;
1540                         goto out_drop_write;
1541                 }
1542
1543                 src_inode = file_inode(src.file);
1544                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1545                         printk(KERN_INFO "btrfs: Snapshot src from "
1546                                "another FS\n");
1547                         ret = -EINVAL;
1548                 } else {
1549                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1550                                              BTRFS_I(src_inode)->root,
1551                                              transid, readonly, inherit);
1552                 }
1553                 fdput(src);
1554         }
1555 out_drop_write:
1556         mnt_drop_write_file(file);
1557 out:
1558         return ret;
1559 }
1560
1561 static noinline int btrfs_ioctl_snap_create(struct file *file,
1562                                             void __user *arg, int subvol)
1563 {
1564         struct btrfs_ioctl_vol_args *vol_args;
1565         int ret;
1566
1567         vol_args = memdup_user(arg, sizeof(*vol_args));
1568         if (IS_ERR(vol_args))
1569                 return PTR_ERR(vol_args);
1570         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1571
1572         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1573                                               vol_args->fd, subvol,
1574                                               NULL, false, NULL);
1575
1576         kfree(vol_args);
1577         return ret;
1578 }
1579
1580 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1581                                                void __user *arg, int subvol)
1582 {
1583         struct btrfs_ioctl_vol_args_v2 *vol_args;
1584         int ret;
1585         u64 transid = 0;
1586         u64 *ptr = NULL;
1587         bool readonly = false;
1588         struct btrfs_qgroup_inherit *inherit = NULL;
1589
1590         vol_args = memdup_user(arg, sizeof(*vol_args));
1591         if (IS_ERR(vol_args))
1592                 return PTR_ERR(vol_args);
1593         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1594
1595         if (vol_args->flags &
1596             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1597               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1598                 ret = -EOPNOTSUPP;
1599                 goto out;
1600         }
1601
1602         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1603                 ptr = &transid;
1604         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1605                 readonly = true;
1606         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1607                 if (vol_args->size > PAGE_CACHE_SIZE) {
1608                         ret = -EINVAL;
1609                         goto out;
1610                 }
1611                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1612                 if (IS_ERR(inherit)) {
1613                         ret = PTR_ERR(inherit);
1614                         goto out;
1615                 }
1616         }
1617
1618         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1619                                               vol_args->fd, subvol, ptr,
1620                                               readonly, inherit);
1621
1622         if (ret == 0 && ptr &&
1623             copy_to_user(arg +
1624                          offsetof(struct btrfs_ioctl_vol_args_v2,
1625                                   transid), ptr, sizeof(*ptr)))
1626                 ret = -EFAULT;
1627 out:
1628         kfree(vol_args);
1629         kfree(inherit);
1630         return ret;
1631 }
1632
1633 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1634                                                 void __user *arg)
1635 {
1636         struct inode *inode = file_inode(file);
1637         struct btrfs_root *root = BTRFS_I(inode)->root;
1638         int ret = 0;
1639         u64 flags = 0;
1640
1641         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1642                 return -EINVAL;
1643
1644         down_read(&root->fs_info->subvol_sem);
1645         if (btrfs_root_readonly(root))
1646                 flags |= BTRFS_SUBVOL_RDONLY;
1647         up_read(&root->fs_info->subvol_sem);
1648
1649         if (copy_to_user(arg, &flags, sizeof(flags)))
1650                 ret = -EFAULT;
1651
1652         return ret;
1653 }
1654
1655 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1656                                               void __user *arg)
1657 {
1658         struct inode *inode = file_inode(file);
1659         struct btrfs_root *root = BTRFS_I(inode)->root;
1660         struct btrfs_trans_handle *trans;
1661         u64 root_flags;
1662         u64 flags;
1663         int ret = 0;
1664
1665         ret = mnt_want_write_file(file);
1666         if (ret)
1667                 goto out;
1668
1669         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1670                 ret = -EINVAL;
1671                 goto out_drop_write;
1672         }
1673
1674         if (copy_from_user(&flags, arg, sizeof(flags))) {
1675                 ret = -EFAULT;
1676                 goto out_drop_write;
1677         }
1678
1679         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1680                 ret = -EINVAL;
1681                 goto out_drop_write;
1682         }
1683
1684         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1685                 ret = -EOPNOTSUPP;
1686                 goto out_drop_write;
1687         }
1688
1689         if (!inode_owner_or_capable(inode)) {
1690                 ret = -EACCES;
1691                 goto out_drop_write;
1692         }
1693
1694         down_write(&root->fs_info->subvol_sem);
1695
1696         /* nothing to do */
1697         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1698                 goto out_drop_sem;
1699
1700         root_flags = btrfs_root_flags(&root->root_item);
1701         if (flags & BTRFS_SUBVOL_RDONLY)
1702                 btrfs_set_root_flags(&root->root_item,
1703                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1704         else
1705                 btrfs_set_root_flags(&root->root_item,
1706                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1707
1708         trans = btrfs_start_transaction(root, 1);
1709         if (IS_ERR(trans)) {
1710                 ret = PTR_ERR(trans);
1711                 goto out_reset;
1712         }
1713
1714         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1715                                 &root->root_key, &root->root_item);
1716
1717         btrfs_commit_transaction(trans, root);
1718 out_reset:
1719         if (ret)
1720                 btrfs_set_root_flags(&root->root_item, root_flags);
1721 out_drop_sem:
1722         up_write(&root->fs_info->subvol_sem);
1723 out_drop_write:
1724         mnt_drop_write_file(file);
1725 out:
1726         return ret;
1727 }
1728
1729 /*
1730  * helper to check if the subvolume references other subvolumes
1731  */
1732 static noinline int may_destroy_subvol(struct btrfs_root *root)
1733 {
1734         struct btrfs_path *path;
1735         struct btrfs_dir_item *di;
1736         struct btrfs_key key;
1737         u64 dir_id;
1738         int ret;
1739
1740         path = btrfs_alloc_path();
1741         if (!path)
1742                 return -ENOMEM;
1743
1744         /* Make sure this root isn't set as the default subvol */
1745         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
1746         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, path,
1747                                    dir_id, "default", 7, 0);
1748         if (di && !IS_ERR(di)) {
1749                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1750                 if (key.objectid == root->root_key.objectid) {
1751                         ret = -ENOTEMPTY;
1752                         goto out;
1753                 }
1754                 btrfs_release_path(path);
1755         }
1756
1757         key.objectid = root->root_key.objectid;
1758         key.type = BTRFS_ROOT_REF_KEY;
1759         key.offset = (u64)-1;
1760
1761         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1762                                 &key, path, 0, 0);
1763         if (ret < 0)
1764                 goto out;
1765         BUG_ON(ret == 0);
1766
1767         ret = 0;
1768         if (path->slots[0] > 0) {
1769                 path->slots[0]--;
1770                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1771                 if (key.objectid == root->root_key.objectid &&
1772                     key.type == BTRFS_ROOT_REF_KEY)
1773                         ret = -ENOTEMPTY;
1774         }
1775 out:
1776         btrfs_free_path(path);
1777         return ret;
1778 }
1779
1780 static noinline int key_in_sk(struct btrfs_key *key,
1781                               struct btrfs_ioctl_search_key *sk)
1782 {
1783         struct btrfs_key test;
1784         int ret;
1785
1786         test.objectid = sk->min_objectid;
1787         test.type = sk->min_type;
1788         test.offset = sk->min_offset;
1789
1790         ret = btrfs_comp_cpu_keys(key, &test);
1791         if (ret < 0)
1792                 return 0;
1793
1794         test.objectid = sk->max_objectid;
1795         test.type = sk->max_type;
1796         test.offset = sk->max_offset;
1797
1798         ret = btrfs_comp_cpu_keys(key, &test);
1799         if (ret > 0)
1800                 return 0;
1801         return 1;
1802 }
1803
1804 static noinline int copy_to_sk(struct btrfs_root *root,
1805                                struct btrfs_path *path,
1806                                struct btrfs_key *key,
1807                                struct btrfs_ioctl_search_key *sk,
1808                                char *buf,
1809                                unsigned long *sk_offset,
1810                                int *num_found)
1811 {
1812         u64 found_transid;
1813         struct extent_buffer *leaf;
1814         struct btrfs_ioctl_search_header sh;
1815         unsigned long item_off;
1816         unsigned long item_len;
1817         int nritems;
1818         int i;
1819         int slot;
1820         int ret = 0;
1821
1822         leaf = path->nodes[0];
1823         slot = path->slots[0];
1824         nritems = btrfs_header_nritems(leaf);
1825
1826         if (btrfs_header_generation(leaf) > sk->max_transid) {
1827                 i = nritems;
1828                 goto advance_key;
1829         }
1830         found_transid = btrfs_header_generation(leaf);
1831
1832         for (i = slot; i < nritems; i++) {
1833                 item_off = btrfs_item_ptr_offset(leaf, i);
1834                 item_len = btrfs_item_size_nr(leaf, i);
1835
1836                 btrfs_item_key_to_cpu(leaf, key, i);
1837                 if (!key_in_sk(key, sk))
1838                         continue;
1839
1840                 if (sizeof(sh) + item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1841                         item_len = 0;
1842
1843                 if (sizeof(sh) + item_len + *sk_offset >
1844                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1845                         ret = 1;
1846                         goto overflow;
1847                 }
1848
1849                 sh.objectid = key->objectid;
1850                 sh.offset = key->offset;
1851                 sh.type = key->type;
1852                 sh.len = item_len;
1853                 sh.transid = found_transid;
1854
1855                 /* copy search result header */
1856                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1857                 *sk_offset += sizeof(sh);
1858
1859                 if (item_len) {
1860                         char *p = buf + *sk_offset;
1861                         /* copy the item */
1862                         read_extent_buffer(leaf, p,
1863                                            item_off, item_len);
1864                         *sk_offset += item_len;
1865                 }
1866                 (*num_found)++;
1867
1868                 if (*num_found >= sk->nr_items)
1869                         break;
1870         }
1871 advance_key:
1872         ret = 0;
1873         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1874                 key->offset++;
1875         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1876                 key->offset = 0;
1877                 key->type++;
1878         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1879                 key->offset = 0;
1880                 key->type = 0;
1881                 key->objectid++;
1882         } else
1883                 ret = 1;
1884 overflow:
1885         return ret;
1886 }
1887
1888 static noinline int search_ioctl(struct inode *inode,
1889                                  struct btrfs_ioctl_search_args *args)
1890 {
1891         struct btrfs_root *root;
1892         struct btrfs_key key;
1893         struct btrfs_path *path;
1894         struct btrfs_ioctl_search_key *sk = &args->key;
1895         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1896         int ret;
1897         int num_found = 0;
1898         unsigned long sk_offset = 0;
1899
1900         path = btrfs_alloc_path();
1901         if (!path)
1902                 return -ENOMEM;
1903
1904         if (sk->tree_id == 0) {
1905                 /* search the root of the inode that was passed */
1906                 root = BTRFS_I(inode)->root;
1907         } else {
1908                 key.objectid = sk->tree_id;
1909                 key.type = BTRFS_ROOT_ITEM_KEY;
1910                 key.offset = (u64)-1;
1911                 root = btrfs_read_fs_root_no_name(info, &key);
1912                 if (IS_ERR(root)) {
1913                         printk(KERN_ERR "could not find root %llu\n",
1914                                sk->tree_id);
1915                         btrfs_free_path(path);
1916                         return -ENOENT;
1917                 }
1918         }
1919
1920         key.objectid = sk->min_objectid;
1921         key.type = sk->min_type;
1922         key.offset = sk->min_offset;
1923
1924         path->keep_locks = 1;
1925
1926         while (1) {
1927                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
1928                 if (ret != 0) {
1929                         if (ret > 0)
1930                                 ret = 0;
1931                         goto err;
1932                 }
1933                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1934                                  &sk_offset, &num_found);
1935                 btrfs_release_path(path);
1936                 if (ret || num_found >= sk->nr_items)
1937                         break;
1938
1939         }
1940         ret = 0;
1941 err:
1942         sk->nr_items = num_found;
1943         btrfs_free_path(path);
1944         return ret;
1945 }
1946
1947 static noinline int btrfs_ioctl_tree_search(struct file *file,
1948                                            void __user *argp)
1949 {
1950          struct btrfs_ioctl_search_args *args;
1951          struct inode *inode;
1952          int ret;
1953
1954         if (!capable(CAP_SYS_ADMIN))
1955                 return -EPERM;
1956
1957         args = memdup_user(argp, sizeof(*args));
1958         if (IS_ERR(args))
1959                 return PTR_ERR(args);
1960
1961         inode = file_inode(file);
1962         ret = search_ioctl(inode, args);
1963         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1964                 ret = -EFAULT;
1965         kfree(args);
1966         return ret;
1967 }
1968
1969 /*
1970  * Search INODE_REFs to identify path name of 'dirid' directory
1971  * in a 'tree_id' tree. and sets path name to 'name'.
1972  */
1973 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1974                                 u64 tree_id, u64 dirid, char *name)
1975 {
1976         struct btrfs_root *root;
1977         struct btrfs_key key;
1978         char *ptr;
1979         int ret = -1;
1980         int slot;
1981         int len;
1982         int total_len = 0;
1983         struct btrfs_inode_ref *iref;
1984         struct extent_buffer *l;
1985         struct btrfs_path *path;
1986
1987         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1988                 name[0]='\0';
1989                 return 0;
1990         }
1991
1992         path = btrfs_alloc_path();
1993         if (!path)
1994                 return -ENOMEM;
1995
1996         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1997
1998         key.objectid = tree_id;
1999         key.type = BTRFS_ROOT_ITEM_KEY;
2000         key.offset = (u64)-1;
2001         root = btrfs_read_fs_root_no_name(info, &key);
2002         if (IS_ERR(root)) {
2003                 printk(KERN_ERR "could not find root %llu\n", tree_id);
2004                 ret = -ENOENT;
2005                 goto out;
2006         }
2007
2008         key.objectid = dirid;
2009         key.type = BTRFS_INODE_REF_KEY;
2010         key.offset = (u64)-1;
2011
2012         while (1) {
2013                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2014                 if (ret < 0)
2015                         goto out;
2016                 else if (ret > 0) {
2017                         ret = btrfs_previous_item(root, path, dirid,
2018                                                   BTRFS_INODE_REF_KEY);
2019                         if (ret < 0)
2020                                 goto out;
2021                         else if (ret > 0) {
2022                                 ret = -ENOENT;
2023                                 goto out;
2024                         }
2025                 }
2026
2027                 l = path->nodes[0];
2028                 slot = path->slots[0];
2029                 btrfs_item_key_to_cpu(l, &key, slot);
2030
2031                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2032                 len = btrfs_inode_ref_name_len(l, iref);
2033                 ptr -= len + 1;
2034                 total_len += len + 1;
2035                 if (ptr < name) {
2036                         ret = -ENAMETOOLONG;
2037                         goto out;
2038                 }
2039
2040                 *(ptr + len) = '/';
2041                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2042
2043                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2044                         break;
2045
2046                 btrfs_release_path(path);
2047                 key.objectid = key.offset;
2048                 key.offset = (u64)-1;
2049                 dirid = key.objectid;
2050         }
2051         memmove(name, ptr, total_len);
2052         name[total_len] = '\0';
2053         ret = 0;
2054 out:
2055         btrfs_free_path(path);
2056         return ret;
2057 }
2058
2059 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2060                                            void __user *argp)
2061 {
2062          struct btrfs_ioctl_ino_lookup_args *args;
2063          struct inode *inode;
2064          int ret;
2065
2066         if (!capable(CAP_SYS_ADMIN))
2067                 return -EPERM;
2068
2069         args = memdup_user(argp, sizeof(*args));
2070         if (IS_ERR(args))
2071                 return PTR_ERR(args);
2072
2073         inode = file_inode(file);
2074
2075         if (args->treeid == 0)
2076                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2077
2078         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2079                                         args->treeid, args->objectid,
2080                                         args->name);
2081
2082         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2083                 ret = -EFAULT;
2084
2085         kfree(args);
2086         return ret;
2087 }
2088
2089 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2090                                              void __user *arg)
2091 {
2092         struct dentry *parent = fdentry(file);
2093         struct dentry *dentry;
2094         struct inode *dir = parent->d_inode;
2095         struct inode *inode;
2096         struct btrfs_root *root = BTRFS_I(dir)->root;
2097         struct btrfs_root *dest = NULL;
2098         struct btrfs_ioctl_vol_args *vol_args;
2099         struct btrfs_trans_handle *trans;
2100         struct btrfs_block_rsv block_rsv;
2101         u64 qgroup_reserved;
2102         int namelen;
2103         int ret;
2104         int err = 0;
2105
2106         vol_args = memdup_user(arg, sizeof(*vol_args));
2107         if (IS_ERR(vol_args))
2108                 return PTR_ERR(vol_args);
2109
2110         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2111         namelen = strlen(vol_args->name);
2112         if (strchr(vol_args->name, '/') ||
2113             strncmp(vol_args->name, "..", namelen) == 0) {
2114                 err = -EINVAL;
2115                 goto out;
2116         }
2117
2118         err = mnt_want_write_file(file);
2119         if (err)
2120                 goto out;
2121
2122         err = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT);
2123         if (err == -EINTR)
2124                 goto out;
2125         dentry = lookup_one_len(vol_args->name, parent, namelen);
2126         if (IS_ERR(dentry)) {
2127                 err = PTR_ERR(dentry);
2128                 goto out_unlock_dir;
2129         }
2130
2131         if (!dentry->d_inode) {
2132                 err = -ENOENT;
2133                 goto out_dput;
2134         }
2135
2136         inode = dentry->d_inode;
2137         dest = BTRFS_I(inode)->root;
2138         if (!capable(CAP_SYS_ADMIN)) {
2139                 /*
2140                  * Regular user.  Only allow this with a special mount
2141                  * option, when the user has write+exec access to the
2142                  * subvol root, and when rmdir(2) would have been
2143                  * allowed.
2144                  *
2145                  * Note that this is _not_ check that the subvol is
2146                  * empty or doesn't contain data that we wouldn't
2147                  * otherwise be able to delete.
2148                  *
2149                  * Users who want to delete empty subvols should try
2150                  * rmdir(2).
2151                  */
2152                 err = -EPERM;
2153                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2154                         goto out_dput;
2155
2156                 /*
2157                  * Do not allow deletion if the parent dir is the same
2158                  * as the dir to be deleted.  That means the ioctl
2159                  * must be called on the dentry referencing the root
2160                  * of the subvol, not a random directory contained
2161                  * within it.
2162                  */
2163                 err = -EINVAL;
2164                 if (root == dest)
2165                         goto out_dput;
2166
2167                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2168                 if (err)
2169                         goto out_dput;
2170         }
2171
2172         /* check if subvolume may be deleted by a user */
2173         err = btrfs_may_delete(dir, dentry, 1);
2174         if (err)
2175                 goto out_dput;
2176
2177         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2178                 err = -EINVAL;
2179                 goto out_dput;
2180         }
2181
2182         mutex_lock(&inode->i_mutex);
2183         err = d_invalidate(dentry);
2184         if (err)
2185                 goto out_unlock;
2186
2187         down_write(&root->fs_info->subvol_sem);
2188
2189         err = may_destroy_subvol(dest);
2190         if (err)
2191                 goto out_up_write;
2192
2193         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2194         /*
2195          * One for dir inode, two for dir entries, two for root
2196          * ref/backref.
2197          */
2198         err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2199                                                5, &qgroup_reserved, true);
2200         if (err)
2201                 goto out_up_write;
2202
2203         trans = btrfs_start_transaction(root, 0);
2204         if (IS_ERR(trans)) {
2205                 err = PTR_ERR(trans);
2206                 goto out_release;
2207         }
2208         trans->block_rsv = &block_rsv;
2209         trans->bytes_reserved = block_rsv.size;
2210
2211         ret = btrfs_unlink_subvol(trans, root, dir,
2212                                 dest->root_key.objectid,
2213                                 dentry->d_name.name,
2214                                 dentry->d_name.len);
2215         if (ret) {
2216                 err = ret;
2217                 btrfs_abort_transaction(trans, root, ret);
2218                 goto out_end_trans;
2219         }
2220
2221         btrfs_record_root_in_trans(trans, dest);
2222
2223         memset(&dest->root_item.drop_progress, 0,
2224                 sizeof(dest->root_item.drop_progress));
2225         dest->root_item.drop_level = 0;
2226         btrfs_set_root_refs(&dest->root_item, 0);
2227
2228         if (!xchg(&dest->orphan_item_inserted, 1)) {
2229                 ret = btrfs_insert_orphan_item(trans,
2230                                         root->fs_info->tree_root,
2231                                         dest->root_key.objectid);
2232                 if (ret) {
2233                         btrfs_abort_transaction(trans, root, ret);
2234                         err = ret;
2235                         goto out_end_trans;
2236                 }
2237         }
2238
2239         ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2240                                   dest->root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
2241                                   dest->root_key.objectid);
2242         if (ret && ret != -ENOENT) {
2243                 btrfs_abort_transaction(trans, root, ret);
2244                 err = ret;
2245                 goto out_end_trans;
2246         }
2247         if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2248                 ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2249                                           dest->root_item.received_uuid,
2250                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2251                                           dest->root_key.objectid);
2252                 if (ret && ret != -ENOENT) {
2253                         btrfs_abort_transaction(trans, root, ret);
2254                         err = ret;
2255                         goto out_end_trans;
2256                 }
2257         }
2258
2259 out_end_trans:
2260         trans->block_rsv = NULL;
2261         trans->bytes_reserved = 0;
2262         ret = btrfs_end_transaction(trans, root);
2263         if (ret && !err)
2264                 err = ret;
2265         inode->i_flags |= S_DEAD;
2266 out_release:
2267         btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
2268 out_up_write:
2269         up_write(&root->fs_info->subvol_sem);
2270 out_unlock:
2271         mutex_unlock(&inode->i_mutex);
2272         if (!err) {
2273                 shrink_dcache_sb(root->fs_info->sb);
2274                 btrfs_invalidate_inodes(dest);
2275                 d_delete(dentry);
2276
2277                 /* the last ref */
2278                 if (dest->cache_inode) {
2279                         iput(dest->cache_inode);
2280                         dest->cache_inode = NULL;
2281                 }
2282         }
2283 out_dput:
2284         dput(dentry);
2285 out_unlock_dir:
2286         mutex_unlock(&dir->i_mutex);
2287         mnt_drop_write_file(file);
2288 out:
2289         kfree(vol_args);
2290         return err;
2291 }
2292
2293 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2294 {
2295         struct inode *inode = file_inode(file);
2296         struct btrfs_root *root = BTRFS_I(inode)->root;
2297         struct btrfs_ioctl_defrag_range_args *range;
2298         int ret;
2299
2300         ret = mnt_want_write_file(file);
2301         if (ret)
2302                 return ret;
2303
2304         if (btrfs_root_readonly(root)) {
2305                 ret = -EROFS;
2306                 goto out;
2307         }
2308
2309         switch (inode->i_mode & S_IFMT) {
2310         case S_IFDIR:
2311                 if (!capable(CAP_SYS_ADMIN)) {
2312                         ret = -EPERM;
2313                         goto out;
2314                 }
2315                 ret = btrfs_defrag_root(root);
2316                 if (ret)
2317                         goto out;
2318                 ret = btrfs_defrag_root(root->fs_info->extent_root);
2319                 break;
2320         case S_IFREG:
2321                 if (!(file->f_mode & FMODE_WRITE)) {
2322                         ret = -EINVAL;
2323                         goto out;
2324                 }
2325
2326                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2327                 if (!range) {
2328                         ret = -ENOMEM;
2329                         goto out;
2330                 }
2331
2332                 if (argp) {
2333                         if (copy_from_user(range, argp,
2334                                            sizeof(*range))) {
2335                                 ret = -EFAULT;
2336                                 kfree(range);
2337                                 goto out;
2338                         }
2339                         /* compression requires us to start the IO */
2340                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2341                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2342                                 range->extent_thresh = (u32)-1;
2343                         }
2344                 } else {
2345                         /* the rest are all set to zero by kzalloc */
2346                         range->len = (u64)-1;
2347                 }
2348                 ret = btrfs_defrag_file(file_inode(file), file,
2349                                         range, 0, 0);
2350                 if (ret > 0)
2351                         ret = 0;
2352                 kfree(range);
2353                 break;
2354         default:
2355                 ret = -EINVAL;
2356         }
2357 out:
2358         mnt_drop_write_file(file);
2359         return ret;
2360 }
2361
2362 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2363 {
2364         struct btrfs_ioctl_vol_args *vol_args;
2365         int ret;
2366
2367         if (!capable(CAP_SYS_ADMIN))
2368                 return -EPERM;
2369
2370         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2371                         1)) {
2372                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2373         }
2374
2375         mutex_lock(&root->fs_info->volume_mutex);
2376         vol_args = memdup_user(arg, sizeof(*vol_args));
2377         if (IS_ERR(vol_args)) {
2378                 ret = PTR_ERR(vol_args);
2379                 goto out;
2380         }
2381
2382         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2383         ret = btrfs_init_new_device(root, vol_args->name);
2384
2385         kfree(vol_args);
2386 out:
2387         mutex_unlock(&root->fs_info->volume_mutex);
2388         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2389         return ret;
2390 }
2391
2392 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2393 {
2394         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
2395         struct btrfs_ioctl_vol_args *vol_args;
2396         int ret;
2397
2398         if (!capable(CAP_SYS_ADMIN))
2399                 return -EPERM;
2400
2401         ret = mnt_want_write_file(file);
2402         if (ret)
2403                 return ret;
2404
2405         vol_args = memdup_user(arg, sizeof(*vol_args));
2406         if (IS_ERR(vol_args)) {
2407                 ret = PTR_ERR(vol_args);
2408                 goto out;
2409         }
2410
2411         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2412
2413         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2414                         1)) {
2415                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2416                 goto out;
2417         }
2418
2419         mutex_lock(&root->fs_info->volume_mutex);
2420         ret = btrfs_rm_device(root, vol_args->name);
2421         mutex_unlock(&root->fs_info->volume_mutex);
2422         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2423
2424 out:
2425         kfree(vol_args);
2426         mnt_drop_write_file(file);
2427         return ret;
2428 }
2429
2430 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2431 {
2432         struct btrfs_ioctl_fs_info_args *fi_args;
2433         struct btrfs_device *device;
2434         struct btrfs_device *next;
2435         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2436         int ret = 0;
2437
2438         if (!capable(CAP_SYS_ADMIN))
2439                 return -EPERM;
2440
2441         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2442         if (!fi_args)
2443                 return -ENOMEM;
2444
2445         mutex_lock(&fs_devices->device_list_mutex);
2446         fi_args->num_devices = fs_devices->num_devices;
2447         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2448
2449         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2450                 if (device->devid > fi_args->max_id)
2451                         fi_args->max_id = device->devid;
2452         }
2453         mutex_unlock(&fs_devices->device_list_mutex);
2454
2455         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2456                 ret = -EFAULT;
2457
2458         kfree(fi_args);
2459         return ret;
2460 }
2461
2462 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2463 {
2464         struct btrfs_ioctl_dev_info_args *di_args;
2465         struct btrfs_device *dev;
2466         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2467         int ret = 0;
2468         char *s_uuid = NULL;
2469
2470         if (!capable(CAP_SYS_ADMIN))
2471                 return -EPERM;
2472
2473         di_args = memdup_user(arg, sizeof(*di_args));
2474         if (IS_ERR(di_args))
2475                 return PTR_ERR(di_args);
2476
2477         if (!btrfs_is_empty_uuid(di_args->uuid))
2478                 s_uuid = di_args->uuid;
2479
2480         mutex_lock(&fs_devices->device_list_mutex);
2481         dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
2482
2483         if (!dev) {
2484                 ret = -ENODEV;
2485                 goto out;
2486         }
2487
2488         di_args->devid = dev->devid;
2489         di_args->bytes_used = dev->bytes_used;
2490         di_args->total_bytes = dev->total_bytes;
2491         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2492         if (dev->name) {
2493                 struct rcu_string *name;
2494
2495                 rcu_read_lock();
2496                 name = rcu_dereference(dev->name);
2497                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2498                 rcu_read_unlock();
2499                 di_args->path[sizeof(di_args->path) - 1] = 0;
2500         } else {
2501                 di_args->path[0] = '\0';
2502         }
2503
2504 out:
2505         mutex_unlock(&fs_devices->device_list_mutex);
2506         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2507                 ret = -EFAULT;
2508
2509         kfree(di_args);
2510         return ret;
2511 }
2512
2513 static struct page *extent_same_get_page(struct inode *inode, u64 off)
2514 {
2515         struct page *page;
2516         pgoff_t index;
2517         struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
2518
2519         index = off >> PAGE_CACHE_SHIFT;
2520
2521         page = grab_cache_page(inode->i_mapping, index);
2522         if (!page)
2523                 return NULL;
2524
2525         if (!PageUptodate(page)) {
2526                 if (extent_read_full_page_nolock(tree, page, btrfs_get_extent,
2527                                                  0))
2528                         return NULL;
2529                 lock_page(page);
2530                 if (!PageUptodate(page)) {
2531                         unlock_page(page);
2532                         page_cache_release(page);
2533                         return NULL;
2534                 }
2535         }
2536         unlock_page(page);
2537
2538         return page;
2539 }
2540
2541 static inline void lock_extent_range(struct inode *inode, u64 off, u64 len)
2542 {
2543         /* do any pending delalloc/csum calc on src, one way or
2544            another, and lock file content */
2545         while (1) {
2546                 struct btrfs_ordered_extent *ordered;
2547                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2548                 ordered = btrfs_lookup_first_ordered_extent(inode,
2549                                                             off + len - 1);
2550                 if (!ordered &&
2551                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2552                                     off + len - 1, EXTENT_DELALLOC, 0, NULL))
2553                         break;
2554                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2555                 if (ordered)
2556                         btrfs_put_ordered_extent(ordered);
2557                 btrfs_wait_ordered_range(inode, off, len);
2558         }
2559 }
2560
2561 static void btrfs_double_unlock(struct inode *inode1, u64 loff1,
2562                                 struct inode *inode2, u64 loff2, u64 len)
2563 {
2564         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2565         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2566
2567         mutex_unlock(&inode1->i_mutex);
2568         mutex_unlock(&inode2->i_mutex);
2569 }
2570
2571 static void btrfs_double_lock(struct inode *inode1, u64 loff1,
2572                               struct inode *inode2, u64 loff2, u64 len)
2573 {
2574         if (inode1 < inode2) {
2575                 swap(inode1, inode2);
2576                 swap(loff1, loff2);
2577         }
2578
2579         mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
2580         lock_extent_range(inode1, loff1, len);
2581         if (inode1 != inode2) {
2582                 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD);
2583                 lock_extent_range(inode2, loff2, len);
2584         }
2585 }
2586
2587 static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
2588                           u64 dst_loff, u64 len)
2589 {
2590         int ret = 0;
2591         struct page *src_page, *dst_page;
2592         unsigned int cmp_len = PAGE_CACHE_SIZE;
2593         void *addr, *dst_addr;
2594
2595         while (len) {
2596                 if (len < PAGE_CACHE_SIZE)
2597                         cmp_len = len;
2598
2599                 src_page = extent_same_get_page(src, loff);
2600                 if (!src_page)
2601                         return -EINVAL;
2602                 dst_page = extent_same_get_page(dst, dst_loff);
2603                 if (!dst_page) {
2604                         page_cache_release(src_page);
2605                         return -EINVAL;
2606                 }
2607                 addr = kmap_atomic(src_page);
2608                 dst_addr = kmap_atomic(dst_page);
2609
2610                 flush_dcache_page(src_page);
2611                 flush_dcache_page(dst_page);
2612
2613                 if (memcmp(addr, dst_addr, cmp_len))
2614                         ret = BTRFS_SAME_DATA_DIFFERS;
2615
2616                 kunmap_atomic(addr);
2617                 kunmap_atomic(dst_addr);
2618                 page_cache_release(src_page);
2619                 page_cache_release(dst_page);
2620
2621                 if (ret)
2622                         break;
2623
2624                 loff += cmp_len;
2625                 dst_loff += cmp_len;
2626                 len -= cmp_len;
2627         }
2628
2629         return ret;
2630 }
2631
2632 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 len)
2633 {
2634         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
2635
2636         if (off + len > inode->i_size || off + len < off)
2637                 return -EINVAL;
2638         /* Check that we are block aligned - btrfs_clone() requires this */
2639         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
2640                 return -EINVAL;
2641
2642         return 0;
2643 }
2644
2645 static int btrfs_extent_same(struct inode *src, u64 loff, u64 len,
2646                              struct inode *dst, u64 dst_loff)
2647 {
2648         int ret;
2649
2650         /*
2651          * btrfs_clone() can't handle extents in the same file
2652          * yet. Once that works, we can drop this check and replace it
2653          * with a check for the same inode, but overlapping extents.
2654          */
2655         if (src == dst)
2656                 return -EINVAL;
2657
2658         btrfs_double_lock(src, loff, dst, dst_loff, len);
2659
2660         ret = extent_same_check_offsets(src, loff, len);
2661         if (ret)
2662                 goto out_unlock;
2663
2664         ret = extent_same_check_offsets(dst, dst_loff, len);
2665         if (ret)
2666                 goto out_unlock;
2667
2668         /* don't make the dst file partly checksummed */
2669         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2670             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
2671                 ret = -EINVAL;
2672                 goto out_unlock;
2673         }
2674
2675         ret = btrfs_cmp_data(src, loff, dst, dst_loff, len);
2676         if (ret == 0)
2677                 ret = btrfs_clone(src, dst, loff, len, len, dst_loff);
2678
2679 out_unlock:
2680         btrfs_double_unlock(src, loff, dst, dst_loff, len);
2681
2682         return ret;
2683 }
2684
2685 #define BTRFS_MAX_DEDUPE_LEN    (16 * 1024 * 1024)
2686
2687 static long btrfs_ioctl_file_extent_same(struct file *file,
2688                                          void __user *argp)
2689 {
2690         struct btrfs_ioctl_same_args tmp;
2691         struct btrfs_ioctl_same_args *same;
2692         struct btrfs_ioctl_same_extent_info *info;
2693         struct inode *src = file->f_dentry->d_inode;
2694         struct file *dst_file = NULL;
2695         struct inode *dst;
2696         u64 off;
2697         u64 len;
2698         int i;
2699         int ret;
2700         unsigned long size;
2701         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
2702         bool is_admin = capable(CAP_SYS_ADMIN);
2703
2704         if (!(file->f_mode & FMODE_READ))
2705                 return -EINVAL;
2706
2707         ret = mnt_want_write_file(file);
2708         if (ret)
2709                 return ret;
2710
2711         if (copy_from_user(&tmp,
2712                            (struct btrfs_ioctl_same_args __user *)argp,
2713                            sizeof(tmp))) {
2714                 ret = -EFAULT;
2715                 goto out;
2716         }
2717
2718         size = sizeof(tmp) +
2719                 tmp.dest_count * sizeof(struct btrfs_ioctl_same_extent_info);
2720
2721         same = memdup_user((struct btrfs_ioctl_same_args __user *)argp, size);
2722
2723         if (IS_ERR(same)) {
2724                 ret = PTR_ERR(same);
2725                 goto out;
2726         }
2727
2728         off = same->logical_offset;
2729         len = same->length;
2730
2731         /*
2732          * Limit the total length we will dedupe for each operation.
2733          * This is intended to bound the total time spent in this
2734          * ioctl to something sane.
2735          */
2736         if (len > BTRFS_MAX_DEDUPE_LEN)
2737                 len = BTRFS_MAX_DEDUPE_LEN;
2738
2739         if (WARN_ON_ONCE(bs < PAGE_CACHE_SIZE)) {
2740                 /*
2741                  * Btrfs does not support blocksize < page_size. As a
2742                  * result, btrfs_cmp_data() won't correctly handle
2743                  * this situation without an update.
2744                  */
2745                 ret = -EINVAL;
2746                 goto out;
2747         }
2748
2749         ret = -EISDIR;
2750         if (S_ISDIR(src->i_mode))
2751                 goto out;
2752
2753         ret = -EACCES;
2754         if (!S_ISREG(src->i_mode))
2755                 goto out;
2756
2757         /* pre-format output fields to sane values */
2758         for (i = 0; i < same->dest_count; i++) {
2759                 same->info[i].bytes_deduped = 0ULL;
2760                 same->info[i].status = 0;
2761         }
2762
2763         ret = 0;
2764         for (i = 0; i < same->dest_count; i++) {
2765                 info = &same->info[i];
2766
2767                 dst_file = fget(info->fd);
2768                 if (!dst_file) {
2769                         info->status = -EBADF;
2770                         goto next;
2771                 }
2772
2773                 if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) {
2774                         info->status = -EINVAL;
2775                         goto next;
2776                 }
2777
2778                 info->status = -EXDEV;
2779                 if (file->f_path.mnt != dst_file->f_path.mnt)
2780                         goto next;
2781
2782                 dst = dst_file->f_dentry->d_inode;
2783                 if (src->i_sb != dst->i_sb)
2784                         goto next;
2785
2786                 if (S_ISDIR(dst->i_mode)) {
2787                         info->status = -EISDIR;
2788                         goto next;
2789                 }
2790
2791                 if (!S_ISREG(dst->i_mode)) {
2792                         info->status = -EACCES;
2793                         goto next;
2794                 }
2795
2796                 info->status = btrfs_extent_same(src, off, len, dst,
2797                                                 info->logical_offset);
2798                 if (info->status == 0)
2799                         info->bytes_deduped += len;
2800
2801 next:
2802                 if (dst_file)
2803                         fput(dst_file);
2804         }
2805
2806         ret = copy_to_user(argp, same, size);
2807         if (ret)
2808                 ret = -EFAULT;
2809
2810 out:
2811         mnt_drop_write_file(file);
2812         return ret;
2813 }
2814
2815 /**
2816  * btrfs_clone() - clone a range from inode file to another
2817  *
2818  * @src: Inode to clone from
2819  * @inode: Inode to clone to
2820  * @off: Offset within source to start clone from
2821  * @olen: Original length, passed by user, of range to clone
2822  * @olen_aligned: Block-aligned value of olen, extent_same uses
2823  *               identical values here
2824  * @destoff: Offset within @inode to start clone
2825  */
2826 static int btrfs_clone(struct inode *src, struct inode *inode,
2827                        u64 off, u64 olen, u64 olen_aligned, u64 destoff)
2828 {
2829         struct btrfs_root *root = BTRFS_I(inode)->root;
2830         struct btrfs_path *path = NULL;
2831         struct extent_buffer *leaf;
2832         struct btrfs_trans_handle *trans;
2833         char *buf = NULL;
2834         struct btrfs_key key;
2835         u32 nritems;
2836         int slot;
2837         int ret;
2838         u64 len = olen_aligned;
2839
2840         ret = -ENOMEM;
2841         buf = vmalloc(btrfs_level_size(root, 0));
2842         if (!buf)
2843                 return ret;
2844
2845         path = btrfs_alloc_path();
2846         if (!path) {
2847                 vfree(buf);
2848                 return ret;
2849         }
2850
2851         path->reada = 2;
2852         /* clone data */
2853         key.objectid = btrfs_ino(src);
2854         key.type = BTRFS_EXTENT_DATA_KEY;
2855         key.offset = 0;
2856
2857         while (1) {
2858                 /*
2859                  * note the key will change type as we walk through the
2860                  * tree.
2861                  */
2862                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
2863                                 0, 0);
2864                 if (ret < 0)
2865                         goto out;
2866
2867                 nritems = btrfs_header_nritems(path->nodes[0]);
2868                 if (path->slots[0] >= nritems) {
2869                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
2870                         if (ret < 0)
2871                                 goto out;
2872                         if (ret > 0)
2873                                 break;
2874                         nritems = btrfs_header_nritems(path->nodes[0]);
2875                 }
2876                 leaf = path->nodes[0];
2877                 slot = path->slots[0];
2878
2879                 btrfs_item_key_to_cpu(leaf, &key, slot);
2880                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2881                     key.objectid != btrfs_ino(src))
2882                         break;
2883
2884                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2885                         struct btrfs_file_extent_item *extent;
2886                         int type;
2887                         u32 size;
2888                         struct btrfs_key new_key;
2889                         u64 disko = 0, diskl = 0;
2890                         u64 datao = 0, datal = 0;
2891                         u8 comp;
2892                         u64 endoff;
2893
2894                         size = btrfs_item_size_nr(leaf, slot);
2895                         read_extent_buffer(leaf, buf,
2896                                            btrfs_item_ptr_offset(leaf, slot),
2897                                            size);
2898
2899                         extent = btrfs_item_ptr(leaf, slot,
2900                                                 struct btrfs_file_extent_item);
2901                         comp = btrfs_file_extent_compression(leaf, extent);
2902                         type = btrfs_file_extent_type(leaf, extent);
2903                         if (type == BTRFS_FILE_EXTENT_REG ||
2904                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2905                                 disko = btrfs_file_extent_disk_bytenr(leaf,
2906                                                                       extent);
2907                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2908                                                                  extent);
2909                                 datao = btrfs_file_extent_offset(leaf, extent);
2910                                 datal = btrfs_file_extent_num_bytes(leaf,
2911                                                                     extent);
2912                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2913                                 /* take upper bound, may be compressed */
2914                                 datal = btrfs_file_extent_ram_bytes(leaf,
2915                                                                     extent);
2916                         }
2917                         btrfs_release_path(path);
2918
2919                         if (key.offset + datal <= off ||
2920                             key.offset >= off + len - 1)
2921                                 goto next;
2922
2923                         memcpy(&new_key, &key, sizeof(new_key));
2924                         new_key.objectid = btrfs_ino(inode);
2925                         if (off <= key.offset)
2926                                 new_key.offset = key.offset + destoff - off;
2927                         else
2928                                 new_key.offset = destoff;
2929
2930                         /*
2931                          * 1 - adjusting old extent (we may have to split it)
2932                          * 1 - add new extent
2933                          * 1 - inode update
2934                          */
2935                         trans = btrfs_start_transaction(root, 3);
2936                         if (IS_ERR(trans)) {
2937                                 ret = PTR_ERR(trans);
2938                                 goto out;
2939                         }
2940
2941                         if (type == BTRFS_FILE_EXTENT_REG ||
2942                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2943                                 /*
2944                                  *    a  | --- range to clone ---|  b
2945                                  * | ------------- extent ------------- |
2946                                  */
2947
2948                                 /* substract range b */
2949                                 if (key.offset + datal > off + len)
2950                                         datal = off + len - key.offset;
2951
2952                                 /* substract range a */
2953                                 if (off > key.offset) {
2954                                         datao += off - key.offset;
2955                                         datal -= off - key.offset;
2956                                 }
2957
2958                                 ret = btrfs_drop_extents(trans, root, inode,
2959                                                          new_key.offset,
2960                                                          new_key.offset + datal,
2961                                                          1);
2962                                 if (ret) {
2963                                         btrfs_abort_transaction(trans, root,
2964                                                                 ret);
2965                                         btrfs_end_transaction(trans, root);
2966                                         goto out;
2967                                 }
2968
2969                                 ret = btrfs_insert_empty_item(trans, root, path,
2970                                                               &new_key, size);
2971                                 if (ret) {
2972                                         btrfs_abort_transaction(trans, root,
2973                                                                 ret);
2974                                         btrfs_end_transaction(trans, root);
2975                                         goto out;
2976                                 }
2977
2978                                 leaf = path->nodes[0];
2979                                 slot = path->slots[0];
2980                                 write_extent_buffer(leaf, buf,
2981                                             btrfs_item_ptr_offset(leaf, slot),
2982                                             size);
2983
2984                                 extent = btrfs_item_ptr(leaf, slot,
2985                                                 struct btrfs_file_extent_item);
2986
2987                                 /* disko == 0 means it's a hole */
2988                                 if (!disko)
2989                                         datao = 0;
2990
2991                                 btrfs_set_file_extent_offset(leaf, extent,
2992                                                              datao);
2993                                 btrfs_set_file_extent_num_bytes(leaf, extent,
2994                                                                 datal);
2995                                 if (disko) {
2996                                         inode_add_bytes(inode, datal);
2997                                         ret = btrfs_inc_extent_ref(trans, root,
2998                                                         disko, diskl, 0,
2999                                                         root->root_key.objectid,
3000                                                         btrfs_ino(inode),
3001                                                         new_key.offset - datao,
3002                                                         0);
3003                                         if (ret) {
3004                                                 btrfs_abort_transaction(trans,
3005                                                                         root,
3006                                                                         ret);
3007                                                 btrfs_end_transaction(trans,
3008                                                                       root);
3009                                                 goto out;
3010
3011                                         }
3012                                 }
3013                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3014                                 u64 skip = 0;
3015                                 u64 trim = 0;
3016                                 if (off > key.offset) {
3017                                         skip = off - key.offset;
3018                                         new_key.offset += skip;
3019                                 }
3020
3021                                 if (key.offset + datal > off + len)
3022                                         trim = key.offset + datal - (off + len);
3023
3024                                 if (comp && (skip || trim)) {
3025                                         ret = -EINVAL;
3026                                         btrfs_end_transaction(trans, root);
3027                                         goto out;
3028                                 }
3029                                 size -= skip + trim;
3030                                 datal -= skip + trim;
3031
3032                                 ret = btrfs_drop_extents(trans, root, inode,
3033                                                          new_key.offset,
3034                                                          new_key.offset + datal,
3035                                                          1);
3036                                 if (ret) {
3037                                         btrfs_abort_transaction(trans, root,
3038                                                                 ret);
3039                                         btrfs_end_transaction(trans, root);
3040                                         goto out;
3041                                 }
3042
3043                                 ret = btrfs_insert_empty_item(trans, root, path,
3044                                                               &new_key, size);
3045                                 if (ret) {
3046                                         btrfs_abort_transaction(trans, root,
3047                                                                 ret);
3048                                         btrfs_end_transaction(trans, root);
3049                                         goto out;
3050                                 }
3051
3052                                 if (skip) {
3053                                         u32 start =
3054                                           btrfs_file_extent_calc_inline_size(0);
3055                                         memmove(buf+start, buf+start+skip,
3056                                                 datal);
3057                                 }
3058
3059                                 leaf = path->nodes[0];
3060                                 slot = path->slots[0];
3061                                 write_extent_buffer(leaf, buf,
3062                                             btrfs_item_ptr_offset(leaf, slot),
3063                                             size);
3064                                 inode_add_bytes(inode, datal);
3065                         }
3066
3067                         btrfs_mark_buffer_dirty(leaf);
3068                         btrfs_release_path(path);
3069
3070                         inode_inc_iversion(inode);
3071                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
3072
3073                         /*
3074                          * we round up to the block size at eof when
3075                          * determining which extents to clone above,
3076                          * but shouldn't round up the file size
3077                          */
3078                         endoff = new_key.offset + datal;
3079                         if (endoff > destoff+olen)
3080                                 endoff = destoff+olen;
3081                         if (endoff > inode->i_size)
3082                                 btrfs_i_size_write(inode, endoff);
3083
3084                         ret = btrfs_update_inode(trans, root, inode);
3085                         if (ret) {
3086                                 btrfs_abort_transaction(trans, root, ret);
3087                                 btrfs_end_transaction(trans, root);
3088                                 goto out;
3089                         }
3090                         ret = btrfs_end_transaction(trans, root);
3091                 }
3092 next:
3093                 btrfs_release_path(path);
3094                 key.offset++;
3095         }
3096         ret = 0;
3097
3098 out:
3099         btrfs_release_path(path);
3100         btrfs_free_path(path);
3101         vfree(buf);
3102         return ret;
3103 }
3104
3105 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
3106                                        u64 off, u64 olen, u64 destoff)
3107 {
3108         struct inode *inode = fdentry(file)->d_inode;
3109         struct btrfs_root *root = BTRFS_I(inode)->root;
3110         struct fd src_file;
3111         struct inode *src;
3112         int ret;
3113         u64 len = olen;
3114         u64 bs = root->fs_info->sb->s_blocksize;
3115         int same_inode = 0;
3116
3117         /*
3118          * TODO:
3119          * - split compressed inline extents.  annoying: we need to
3120          *   decompress into destination's address_space (the file offset
3121          *   may change, so source mapping won't do), then recompress (or
3122          *   otherwise reinsert) a subrange.
3123          * - allow ranges within the same file to be cloned (provided
3124          *   they don't overlap)?
3125          */
3126
3127         /* the destination must be opened for writing */
3128         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
3129                 return -EINVAL;
3130
3131         if (btrfs_root_readonly(root))
3132                 return -EROFS;
3133
3134         ret = mnt_want_write_file(file);
3135         if (ret)
3136                 return ret;
3137
3138         src_file = fdget(srcfd);
3139         if (!src_file.file) {
3140                 ret = -EBADF;
3141                 goto out_drop_write;
3142         }
3143
3144         ret = -EXDEV;
3145         if (src_file.file->f_path.mnt != file->f_path.mnt)
3146                 goto out_fput;
3147
3148         src = file_inode(src_file.file);
3149
3150         ret = -EINVAL;
3151         if (src == inode)
3152                 same_inode = 1;
3153
3154         /* the src must be open for reading */
3155         if (!(src_file.file->f_mode & FMODE_READ))
3156                 goto out_fput;
3157
3158         /* don't make the dst file partly checksummed */
3159         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3160             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3161                 goto out_fput;
3162
3163         ret = -EISDIR;
3164         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3165                 goto out_fput;
3166
3167         ret = -EXDEV;
3168         if (src->i_sb != inode->i_sb)
3169                 goto out_fput;
3170
3171         if (!same_inode) {
3172                 if (inode < src) {
3173                         mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
3174                         mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
3175                 } else {
3176                         mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
3177                         mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
3178                 }
3179         } else {
3180                 mutex_lock(&src->i_mutex);
3181         }
3182
3183         /* determine range to clone */
3184         ret = -EINVAL;
3185         if (off + len > src->i_size || off + len < off)
3186                 goto out_unlock;
3187         if (len == 0)
3188                 olen = len = src->i_size - off;
3189         /* if we extend to eof, continue to block boundary */
3190         if (off + len == src->i_size)
3191                 len = ALIGN(src->i_size, bs) - off;
3192
3193         /* verify the end result is block aligned */
3194         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3195             !IS_ALIGNED(destoff, bs))
3196                 goto out_unlock;
3197
3198         /* verify if ranges are overlapped within the same file */
3199         if (same_inode) {
3200                 if (destoff + len > off && destoff < off + len)
3201                         goto out_unlock;
3202         }
3203
3204         if (destoff > inode->i_size) {
3205                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3206                 if (ret)
3207                         goto out_unlock;
3208         }
3209
3210         /* truncate page cache pages from target inode range */
3211         truncate_inode_pages_range(&inode->i_data, destoff,
3212                                    PAGE_CACHE_ALIGN(destoff + len) - 1);
3213
3214         lock_extent_range(src, off, len);
3215
3216         ret = btrfs_clone(src, inode, off, olen, len, destoff);
3217
3218         unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
3219 out_unlock:
3220         mutex_unlock(&src->i_mutex);
3221         if (!same_inode)
3222                 mutex_unlock(&inode->i_mutex);
3223 out_fput:
3224         fdput(src_file);
3225 out_drop_write:
3226         mnt_drop_write_file(file);
3227         return ret;
3228 }
3229
3230 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
3231 {
3232         struct btrfs_ioctl_clone_range_args args;
3233
3234         if (copy_from_user(&args, argp, sizeof(args)))
3235                 return -EFAULT;
3236         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
3237                                  args.src_length, args.dest_offset);
3238 }
3239
3240 /*
3241  * there are many ways the trans_start and trans_end ioctls can lead
3242  * to deadlocks.  They should only be used by applications that
3243  * basically own the machine, and have a very in depth understanding
3244  * of all the possible deadlocks and enospc problems.
3245  */
3246 static long btrfs_ioctl_trans_start(struct file *file)
3247 {
3248         struct inode *inode = file_inode(file);
3249         struct btrfs_root *root = BTRFS_I(inode)->root;
3250         struct btrfs_trans_handle *trans;
3251         int ret;
3252
3253         ret = -EPERM;
3254         if (!capable(CAP_SYS_ADMIN))
3255                 goto out;
3256
3257         ret = -EINPROGRESS;
3258         if (file->private_data)
3259                 goto out;
3260
3261         ret = -EROFS;
3262         if (btrfs_root_readonly(root))
3263                 goto out;
3264
3265         ret = mnt_want_write_file(file);
3266         if (ret)
3267                 goto out;
3268
3269         atomic_inc(&root->fs_info->open_ioctl_trans);
3270
3271         ret = -ENOMEM;
3272         trans = btrfs_start_ioctl_transaction(root);
3273         if (IS_ERR(trans))
3274                 goto out_drop;
3275
3276         file->private_data = trans;
3277         return 0;
3278
3279 out_drop:
3280         atomic_dec(&root->fs_info->open_ioctl_trans);
3281         mnt_drop_write_file(file);
3282 out:
3283         return ret;
3284 }
3285
3286 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3287 {
3288         struct inode *inode = file_inode(file);
3289         struct btrfs_root *root = BTRFS_I(inode)->root;
3290         struct btrfs_root *new_root;
3291         struct btrfs_dir_item *di;
3292         struct btrfs_trans_handle *trans;
3293         struct btrfs_path *path;
3294         struct btrfs_key location;
3295         struct btrfs_disk_key disk_key;
3296         u64 objectid = 0;
3297         u64 dir_id;
3298         int ret;
3299
3300         if (!capable(CAP_SYS_ADMIN))
3301                 return -EPERM;
3302
3303         ret = mnt_want_write_file(file);
3304         if (ret)
3305                 return ret;
3306
3307         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3308                 ret = -EFAULT;
3309                 goto out;
3310         }
3311
3312         if (!objectid)
3313                 objectid = BTRFS_FS_TREE_OBJECTID;
3314
3315         location.objectid = objectid;
3316         location.type = BTRFS_ROOT_ITEM_KEY;
3317         location.offset = (u64)-1;
3318
3319         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
3320         if (IS_ERR(new_root)) {
3321                 ret = PTR_ERR(new_root);
3322                 goto out;
3323         }
3324
3325         path = btrfs_alloc_path();
3326         if (!path) {
3327                 ret = -ENOMEM;
3328                 goto out;
3329         }
3330         path->leave_spinning = 1;
3331
3332         trans = btrfs_start_transaction(root, 1);
3333         if (IS_ERR(trans)) {
3334                 btrfs_free_path(path);
3335                 ret = PTR_ERR(trans);
3336                 goto out;
3337         }
3338
3339         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
3340         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
3341                                    dir_id, "default", 7, 1);
3342         if (IS_ERR_OR_NULL(di)) {
3343                 btrfs_free_path(path);
3344                 btrfs_end_transaction(trans, root);
3345                 printk(KERN_ERR "Umm, you don't have the default dir item, "
3346                        "this isn't going to work\n");
3347                 ret = -ENOENT;
3348                 goto out;
3349         }
3350
3351         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3352         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
3353         btrfs_mark_buffer_dirty(path->nodes[0]);
3354         btrfs_free_path(path);
3355
3356         btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
3357         btrfs_end_transaction(trans, root);
3358 out:
3359         mnt_drop_write_file(file);
3360         return ret;
3361 }
3362
3363 void btrfs_get_block_group_info(struct list_head *groups_list,
3364                                 struct btrfs_ioctl_space_info *space)
3365 {
3366         struct btrfs_block_group_cache *block_group;
3367
3368         space->total_bytes = 0;
3369         space->used_bytes = 0;
3370         space->flags = 0;
3371         list_for_each_entry(block_group, groups_list, list) {
3372                 space->flags = block_group->flags;
3373                 space->total_bytes += block_group->key.offset;
3374                 space->used_bytes +=
3375                         btrfs_block_group_used(&block_group->item);
3376         }
3377 }
3378
3379 static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
3380 {
3381         struct btrfs_ioctl_space_args space_args;
3382         struct btrfs_ioctl_space_info space;
3383         struct btrfs_ioctl_space_info *dest;
3384         struct btrfs_ioctl_space_info *dest_orig;
3385         struct btrfs_ioctl_space_info __user *user_dest;
3386         struct btrfs_space_info *info;
3387         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
3388                        BTRFS_BLOCK_GROUP_SYSTEM,
3389                        BTRFS_BLOCK_GROUP_METADATA,
3390                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
3391         int num_types = 4;
3392         int alloc_size;
3393         int ret = 0;
3394         u64 slot_count = 0;
3395         int i, c;
3396
3397         if (copy_from_user(&space_args,
3398                            (struct btrfs_ioctl_space_args __user *)arg,
3399                            sizeof(space_args)))
3400                 return -EFAULT;
3401
3402         for (i = 0; i < num_types; i++) {
3403                 struct btrfs_space_info *tmp;
3404
3405                 info = NULL;
3406                 rcu_read_lock();
3407                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
3408                                         list) {
3409                         if (tmp->flags == types[i]) {
3410                                 info = tmp;
3411                                 break;
3412                         }
3413                 }
3414                 rcu_read_unlock();
3415
3416                 if (!info)
3417                         continue;
3418
3419                 down_read(&info->groups_sem);
3420                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3421                         if (!list_empty(&info->block_groups[c]))
3422                                 slot_count++;
3423                 }
3424                 up_read(&info->groups_sem);
3425         }
3426
3427         /* space_slots == 0 means they are asking for a count */
3428         if (space_args.space_slots == 0) {
3429                 space_args.total_spaces = slot_count;
3430                 goto out;
3431         }
3432
3433         slot_count = min_t(u64, space_args.space_slots, slot_count);
3434
3435         alloc_size = sizeof(*dest) * slot_count;
3436
3437         /* we generally have at most 6 or so space infos, one for each raid
3438          * level.  So, a whole page should be more than enough for everyone
3439          */
3440         if (alloc_size > PAGE_CACHE_SIZE)
3441                 return -ENOMEM;
3442
3443         space_args.total_spaces = 0;
3444         dest = kmalloc(alloc_size, GFP_NOFS);
3445         if (!dest)
3446                 return -ENOMEM;
3447         dest_orig = dest;
3448
3449         /* now we have a buffer to copy into */
3450         for (i = 0; i < num_types; i++) {
3451                 struct btrfs_space_info *tmp;
3452
3453                 if (!slot_count)
3454                         break;
3455
3456                 info = NULL;
3457                 rcu_read_lock();
3458                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
3459                                         list) {
3460                         if (tmp->flags == types[i]) {
3461                                 info = tmp;
3462                                 break;
3463                         }
3464                 }
3465                 rcu_read_unlock();
3466
3467                 if (!info)
3468                         continue;
3469                 down_read(&info->groups_sem);
3470                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3471                         if (!list_empty(&info->block_groups[c])) {
3472                                 btrfs_get_block_group_info(
3473                                         &info->block_groups[c], &space);
3474                                 memcpy(dest, &space, sizeof(space));
3475                                 dest++;
3476                                 space_args.total_spaces++;
3477                                 slot_count--;
3478                         }
3479                         if (!slot_count)
3480                                 break;
3481                 }
3482                 up_read(&info->groups_sem);
3483         }
3484
3485         user_dest = (struct btrfs_ioctl_space_info __user *)
3486                 (arg + sizeof(struct btrfs_ioctl_space_args));
3487
3488         if (copy_to_user(user_dest, dest_orig, alloc_size))
3489                 ret = -EFAULT;
3490
3491         kfree(dest_orig);
3492 out:
3493         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3494                 ret = -EFAULT;
3495
3496         return ret;
3497 }
3498
3499 /*
3500  * there are many ways the trans_start and trans_end ioctls can lead
3501  * to deadlocks.  They should only be used by applications that
3502  * basically own the machine, and have a very in depth understanding
3503  * of all the possible deadlocks and enospc problems.
3504  */
3505 long btrfs_ioctl_trans_end(struct file *file)
3506 {
3507         struct inode *inode = file_inode(file);
3508         struct btrfs_root *root = BTRFS_I(inode)->root;
3509         struct btrfs_trans_handle *trans;
3510
3511         trans = file->private_data;
3512         if (!trans)
3513                 return -EINVAL;
3514         file->private_data = NULL;
3515
3516         btrfs_end_transaction(trans, root);
3517
3518         atomic_dec(&root->fs_info->open_ioctl_trans);
3519
3520         mnt_drop_write_file(file);
3521         return 0;
3522 }
3523
3524 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3525                                             void __user *argp)
3526 {
3527         struct btrfs_trans_handle *trans;
3528         u64 transid;
3529         int ret;
3530
3531         trans = btrfs_attach_transaction_barrier(root);
3532         if (IS_ERR(trans)) {
3533                 if (PTR_ERR(trans) != -ENOENT)
3534                         return PTR_ERR(trans);
3535
3536                 /* No running transaction, don't bother */
3537                 transid = root->fs_info->last_trans_committed;
3538                 goto out;
3539         }
3540         transid = trans->transid;
3541         ret = btrfs_commit_transaction_async(trans, root, 0);
3542         if (ret) {
3543                 btrfs_end_transaction(trans, root);
3544                 return ret;
3545         }
3546 out:
3547         if (argp)
3548                 if (copy_to_user(argp, &transid, sizeof(transid)))
3549                         return -EFAULT;
3550         return 0;
3551 }
3552
3553 static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
3554                                            void __user *argp)
3555 {
3556         u64 transid;
3557
3558         if (argp) {
3559                 if (copy_from_user(&transid, argp, sizeof(transid)))
3560                         return -EFAULT;
3561         } else {
3562                 transid = 0;  /* current trans */
3563         }
3564         return btrfs_wait_for_commit(root, transid);
3565 }
3566
3567 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3568 {
3569         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3570         struct btrfs_ioctl_scrub_args *sa;
3571         int ret;
3572
3573         if (!capable(CAP_SYS_ADMIN))
3574                 return -EPERM;
3575
3576         sa = memdup_user(arg, sizeof(*sa));
3577         if (IS_ERR(sa))
3578                 return PTR_ERR(sa);
3579
3580         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3581                 ret = mnt_want_write_file(file);
3582                 if (ret)
3583                         goto out;
3584         }
3585
3586         ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
3587                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3588                               0);
3589
3590         if (copy_to_user(arg, sa, sizeof(*sa)))
3591                 ret = -EFAULT;
3592
3593         if (!(sa->flags & BTRFS_SCRUB_READONLY))
3594                 mnt_drop_write_file(file);
3595 out:
3596         kfree(sa);
3597         return ret;
3598 }
3599
3600 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
3601 {
3602         if (!capable(CAP_SYS_ADMIN))
3603                 return -EPERM;
3604
3605         return btrfs_scrub_cancel(root->fs_info);
3606 }
3607
3608 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
3609                                        void __user *arg)
3610 {
3611         struct btrfs_ioctl_scrub_args *sa;
3612         int ret;
3613
3614         if (!capable(CAP_SYS_ADMIN))
3615                 return -EPERM;
3616
3617         sa = memdup_user(arg, sizeof(*sa));
3618         if (IS_ERR(sa))
3619                 return PTR_ERR(sa);
3620
3621         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
3622
3623         if (copy_to_user(arg, sa, sizeof(*sa)))
3624                 ret = -EFAULT;
3625
3626         kfree(sa);
3627         return ret;
3628 }
3629
3630 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
3631                                       void __user *arg)
3632 {
3633         struct btrfs_ioctl_get_dev_stats *sa;
3634         int ret;
3635
3636         sa = memdup_user(arg, sizeof(*sa));
3637         if (IS_ERR(sa))
3638                 return PTR_ERR(sa);
3639
3640         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3641                 kfree(sa);
3642                 return -EPERM;
3643         }
3644
3645         ret = btrfs_get_dev_stats(root, sa);
3646
3647         if (copy_to_user(arg, sa, sizeof(*sa)))
3648                 ret = -EFAULT;
3649
3650         kfree(sa);
3651         return ret;
3652 }
3653
3654 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
3655 {
3656         struct btrfs_ioctl_dev_replace_args *p;
3657         int ret;
3658
3659         if (!capable(CAP_SYS_ADMIN))
3660                 return -EPERM;
3661
3662         p = memdup_user(arg, sizeof(*p));
3663         if (IS_ERR(p))
3664                 return PTR_ERR(p);
3665
3666         switch (p->cmd) {
3667         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3668                 if (root->fs_info->sb->s_flags & MS_RDONLY) {
3669                         ret = -EROFS;
3670                         goto out;
3671                 }
3672                 if (atomic_xchg(
3673                         &root->fs_info->mutually_exclusive_operation_running,
3674                         1)) {
3675                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3676                 } else {
3677                         ret = btrfs_dev_replace_start(root, p);
3678                         atomic_set(
3679                          &root->fs_info->mutually_exclusive_operation_running,
3680                          0);
3681                 }
3682                 break;
3683         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3684                 btrfs_dev_replace_status(root->fs_info, p);
3685                 ret = 0;
3686                 break;
3687         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3688                 ret = btrfs_dev_replace_cancel(root->fs_info, p);
3689                 break;
3690         default:
3691                 ret = -EINVAL;
3692                 break;
3693         }
3694
3695         if (copy_to_user(arg, p, sizeof(*p)))
3696                 ret = -EFAULT;
3697 out:
3698         kfree(p);
3699         return ret;
3700 }
3701
3702 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3703 {
3704         int ret = 0;
3705         int i;
3706         u64 rel_ptr;
3707         int size;
3708         struct btrfs_ioctl_ino_path_args *ipa = NULL;
3709         struct inode_fs_paths *ipath = NULL;
3710         struct btrfs_path *path;
3711
3712         if (!capable(CAP_DAC_READ_SEARCH))
3713                 return -EPERM;
3714
3715         path = btrfs_alloc_path();
3716         if (!path) {
3717                 ret = -ENOMEM;
3718                 goto out;
3719         }
3720
3721         ipa = memdup_user(arg, sizeof(*ipa));
3722         if (IS_ERR(ipa)) {
3723                 ret = PTR_ERR(ipa);
3724                 ipa = NULL;
3725                 goto out;
3726         }
3727
3728         size = min_t(u32, ipa->size, 4096);
3729         ipath = init_ipath(size, root, path);
3730         if (IS_ERR(ipath)) {
3731                 ret = PTR_ERR(ipath);
3732                 ipath = NULL;
3733                 goto out;
3734         }
3735
3736         ret = paths_from_inode(ipa->inum, ipath);
3737         if (ret < 0)
3738                 goto out;
3739
3740         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3741                 rel_ptr = ipath->fspath->val[i] -
3742                           (u64)(unsigned long)ipath->fspath->val;
3743                 ipath->fspath->val[i] = rel_ptr;
3744         }
3745
3746         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
3747                            (void *)(unsigned long)ipath->fspath, size);
3748         if (ret) {
3749                 ret = -EFAULT;
3750                 goto out;
3751         }
3752
3753 out:
3754         btrfs_free_path(path);
3755         free_ipath(ipath);
3756         kfree(ipa);
3757
3758         return ret;
3759 }
3760
3761 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3762 {
3763         struct btrfs_data_container *inodes = ctx;
3764         const size_t c = 3 * sizeof(u64);
3765
3766         if (inodes->bytes_left >= c) {
3767                 inodes->bytes_left -= c;
3768                 inodes->val[inodes->elem_cnt] = inum;
3769                 inodes->val[inodes->elem_cnt + 1] = offset;
3770                 inodes->val[inodes->elem_cnt + 2] = root;
3771                 inodes->elem_cnt += 3;
3772         } else {
3773                 inodes->bytes_missing += c - inodes->bytes_left;
3774                 inodes->bytes_left = 0;
3775                 inodes->elem_missed += 3;
3776         }
3777
3778         return 0;
3779 }
3780
3781 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
3782                                         void __user *arg)
3783 {
3784         int ret = 0;
3785         int size;
3786         struct btrfs_ioctl_logical_ino_args *loi;
3787         struct btrfs_data_container *inodes = NULL;
3788         struct btrfs_path *path = NULL;
3789
3790         if (!capable(CAP_SYS_ADMIN))
3791                 return -EPERM;
3792
3793         loi = memdup_user(arg, sizeof(*loi));
3794         if (IS_ERR(loi)) {
3795                 ret = PTR_ERR(loi);
3796                 loi = NULL;
3797                 goto out;
3798         }
3799
3800         path = btrfs_alloc_path();
3801         if (!path) {
3802                 ret = -ENOMEM;
3803                 goto out;
3804         }
3805
3806         size = min_t(u32, loi->size, 64 * 1024);
3807         inodes = init_data_container(size);
3808         if (IS_ERR(inodes)) {
3809                 ret = PTR_ERR(inodes);
3810                 inodes = NULL;
3811                 goto out;
3812         }
3813
3814         ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
3815                                           build_ino_list, inodes);
3816         if (ret == -EINVAL)
3817                 ret = -ENOENT;
3818         if (ret < 0)
3819                 goto out;
3820
3821         ret = copy_to_user((void *)(unsigned long)loi->inodes,
3822                            (void *)(unsigned long)inodes, size);
3823         if (ret)
3824                 ret = -EFAULT;
3825
3826 out:
3827         btrfs_free_path(path);
3828         vfree(inodes);
3829         kfree(loi);
3830
3831         return ret;
3832 }
3833
3834 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3835                                struct btrfs_ioctl_balance_args *bargs)
3836 {
3837         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3838
3839         bargs->flags = bctl->flags;
3840
3841         if (atomic_read(&fs_info->balance_running))
3842                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3843         if (atomic_read(&fs_info->balance_pause_req))
3844                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3845         if (atomic_read(&fs_info->balance_cancel_req))
3846                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3847
3848         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3849         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3850         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3851
3852         if (lock) {
3853                 spin_lock(&fs_info->balance_lock);
3854                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3855                 spin_unlock(&fs_info->balance_lock);
3856         } else {
3857                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3858         }
3859 }
3860
3861 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3862 {
3863         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3864         struct btrfs_fs_info *fs_info = root->fs_info;
3865         struct btrfs_ioctl_balance_args *bargs;
3866         struct btrfs_balance_control *bctl;
3867         bool need_unlock; /* for mut. excl. ops lock */
3868         int ret;
3869
3870         if (!capable(CAP_SYS_ADMIN))
3871                 return -EPERM;
3872
3873         ret = mnt_want_write_file(file);
3874         if (ret)
3875                 return ret;
3876
3877 again:
3878         if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
3879                 mutex_lock(&fs_info->volume_mutex);
3880                 mutex_lock(&fs_info->balance_mutex);
3881                 need_unlock = true;
3882                 goto locked;
3883         }
3884
3885         /*
3886          * mut. excl. ops lock is locked.  Three possibilites:
3887          *   (1) some other op is running
3888          *   (2) balance is running
3889          *   (3) balance is paused -- special case (think resume)
3890          */
3891         mutex_lock(&fs_info->balance_mutex);
3892         if (fs_info->balance_ctl) {
3893                 /* this is either (2) or (3) */
3894                 if (!atomic_read(&fs_info->balance_running)) {
3895                         mutex_unlock(&fs_info->balance_mutex);
3896                         if (!mutex_trylock(&fs_info->volume_mutex))
3897                                 goto again;
3898                         mutex_lock(&fs_info->balance_mutex);
3899
3900                         if (fs_info->balance_ctl &&
3901                             !atomic_read(&fs_info->balance_running)) {
3902                                 /* this is (3) */
3903                                 need_unlock = false;
3904                                 goto locked;
3905                         }
3906
3907                         mutex_unlock(&fs_info->balance_mutex);
3908                         mutex_unlock(&fs_info->volume_mutex);
3909                         goto again;
3910                 } else {
3911                         /* this is (2) */
3912                         mutex_unlock(&fs_info->balance_mutex);
3913                         ret = -EINPROGRESS;
3914                         goto out;
3915                 }
3916         } else {
3917                 /* this is (1) */
3918                 mutex_unlock(&fs_info->balance_mutex);
3919                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3920                 goto out;
3921         }
3922
3923 locked:
3924         BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
3925
3926         if (arg) {
3927                 bargs = memdup_user(arg, sizeof(*bargs));
3928                 if (IS_ERR(bargs)) {
3929                         ret = PTR_ERR(bargs);
3930                         goto out_unlock;
3931                 }
3932
3933                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
3934                         if (!fs_info->balance_ctl) {
3935                                 ret = -ENOTCONN;
3936                                 goto out_bargs;
3937                         }
3938
3939                         bctl = fs_info->balance_ctl;
3940                         spin_lock(&fs_info->balance_lock);
3941                         bctl->flags |= BTRFS_BALANCE_RESUME;
3942                         spin_unlock(&fs_info->balance_lock);
3943
3944                         goto do_balance;
3945                 }
3946         } else {
3947                 bargs = NULL;
3948         }
3949
3950         if (fs_info->balance_ctl) {
3951                 ret = -EINPROGRESS;
3952                 goto out_bargs;
3953         }
3954
3955         bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3956         if (!bctl) {
3957                 ret = -ENOMEM;
3958                 goto out_bargs;
3959         }
3960
3961         bctl->fs_info = fs_info;
3962         if (arg) {
3963                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3964                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3965                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3966
3967                 bctl->flags = bargs->flags;
3968         } else {
3969                 /* balance everything - no filters */
3970                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3971         }
3972
3973 do_balance:
3974         /*
3975          * Ownership of bctl and mutually_exclusive_operation_running
3976          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
3977          * or, if restriper was paused all the way until unmount, in
3978          * free_fs_info.  mutually_exclusive_operation_running is
3979          * cleared in __cancel_balance.
3980          */
3981         need_unlock = false;
3982
3983         ret = btrfs_balance(bctl, bargs);
3984
3985         if (arg) {
3986                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3987                         ret = -EFAULT;
3988         }
3989
3990 out_bargs:
3991         kfree(bargs);
3992 out_unlock:
3993         mutex_unlock(&fs_info->balance_mutex);
3994         mutex_unlock(&fs_info->volume_mutex);
3995         if (need_unlock)
3996                 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3997 out:
3998         mnt_drop_write_file(file);
3999         return ret;
4000 }
4001
4002 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
4003 {
4004         if (!capable(CAP_SYS_ADMIN))
4005                 return -EPERM;
4006
4007         switch (cmd) {
4008         case BTRFS_BALANCE_CTL_PAUSE:
4009                 return btrfs_pause_balance(root->fs_info);
4010         case BTRFS_BALANCE_CTL_CANCEL:
4011                 return btrfs_cancel_balance(root->fs_info);
4012         }
4013
4014         return -EINVAL;
4015 }
4016
4017 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
4018                                          void __user *arg)
4019 {
4020         struct btrfs_fs_info *fs_info = root->fs_info;
4021         struct btrfs_ioctl_balance_args *bargs;
4022         int ret = 0;
4023
4024         if (!capable(CAP_SYS_ADMIN))
4025                 return -EPERM;
4026
4027         mutex_lock(&fs_info->balance_mutex);
4028         if (!fs_info->balance_ctl) {
4029                 ret = -ENOTCONN;
4030                 goto out;
4031         }
4032
4033         bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
4034         if (!bargs) {
4035                 ret = -ENOMEM;
4036                 goto out;
4037         }
4038
4039         update_ioctl_balance_args(fs_info, 1, bargs);
4040
4041         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4042                 ret = -EFAULT;
4043
4044         kfree(bargs);
4045 out:
4046         mutex_unlock(&fs_info->balance_mutex);
4047         return ret;
4048 }
4049
4050 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4051 {
4052         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4053         struct btrfs_ioctl_quota_ctl_args *sa;
4054         struct btrfs_trans_handle *trans = NULL;
4055         int ret;
4056         int err;
4057
4058         if (!capable(CAP_SYS_ADMIN))
4059                 return -EPERM;
4060
4061         ret = mnt_want_write_file(file);
4062         if (ret)
4063                 return ret;
4064
4065         sa = memdup_user(arg, sizeof(*sa));
4066         if (IS_ERR(sa)) {
4067                 ret = PTR_ERR(sa);
4068                 goto drop_write;
4069         }
4070
4071         down_write(&root->fs_info->subvol_sem);
4072         trans = btrfs_start_transaction(root->fs_info->tree_root, 2);
4073         if (IS_ERR(trans)) {
4074                 ret = PTR_ERR(trans);
4075                 goto out;
4076         }
4077
4078         switch (sa->cmd) {
4079         case BTRFS_QUOTA_CTL_ENABLE:
4080                 ret = btrfs_quota_enable(trans, root->fs_info);
4081                 break;
4082         case BTRFS_QUOTA_CTL_DISABLE:
4083                 ret = btrfs_quota_disable(trans, root->fs_info);
4084                 break;
4085         default:
4086                 ret = -EINVAL;
4087                 break;
4088         }
4089
4090         err = btrfs_commit_transaction(trans, root->fs_info->tree_root);
4091         if (err && !ret)
4092                 ret = err;
4093 out:
4094         kfree(sa);
4095         up_write(&root->fs_info->subvol_sem);
4096 drop_write:
4097         mnt_drop_write_file(file);
4098         return ret;
4099 }
4100
4101 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4102 {
4103         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4104         struct btrfs_ioctl_qgroup_assign_args *sa;
4105         struct btrfs_trans_handle *trans;
4106         int ret;
4107         int err;
4108
4109         if (!capable(CAP_SYS_ADMIN))
4110                 return -EPERM;
4111
4112         ret = mnt_want_write_file(file);
4113         if (ret)
4114                 return ret;
4115
4116         sa = memdup_user(arg, sizeof(*sa));
4117         if (IS_ERR(sa)) {
4118                 ret = PTR_ERR(sa);
4119                 goto drop_write;
4120         }
4121
4122         trans = btrfs_join_transaction(root);
4123         if (IS_ERR(trans)) {
4124                 ret = PTR_ERR(trans);
4125                 goto out;
4126         }
4127
4128         /* FIXME: check if the IDs really exist */
4129         if (sa->assign) {
4130                 ret = btrfs_add_qgroup_relation(trans, root->fs_info,
4131                                                 sa->src, sa->dst);
4132         } else {
4133                 ret = btrfs_del_qgroup_relation(trans, root->fs_info,
4134                                                 sa->src, sa->dst);
4135         }
4136
4137         err = btrfs_end_transaction(trans, root);
4138         if (err && !ret)
4139                 ret = err;
4140
4141 out:
4142         kfree(sa);
4143 drop_write:
4144         mnt_drop_write_file(file);
4145         return ret;
4146 }
4147
4148 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4149 {
4150         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4151         struct btrfs_ioctl_qgroup_create_args *sa;
4152         struct btrfs_trans_handle *trans;
4153         int ret;
4154         int err;
4155
4156         if (!capable(CAP_SYS_ADMIN))
4157                 return -EPERM;
4158
4159         ret = mnt_want_write_file(file);
4160         if (ret)
4161                 return ret;
4162
4163         sa = memdup_user(arg, sizeof(*sa));
4164         if (IS_ERR(sa)) {
4165                 ret = PTR_ERR(sa);
4166                 goto drop_write;
4167         }
4168
4169         if (!sa->qgroupid) {
4170                 ret = -EINVAL;
4171                 goto out;
4172         }
4173
4174         trans = btrfs_join_transaction(root);
4175         if (IS_ERR(trans)) {
4176                 ret = PTR_ERR(trans);
4177                 goto out;
4178         }
4179
4180         /* FIXME: check if the IDs really exist */
4181         if (sa->create) {
4182                 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid,
4183                                           NULL);
4184         } else {
4185                 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
4186         }
4187
4188         err = btrfs_end_transaction(trans, root);
4189         if (err && !ret)
4190                 ret = err;
4191
4192 out:
4193         kfree(sa);
4194 drop_write:
4195         mnt_drop_write_file(file);
4196         return ret;
4197 }
4198
4199 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4200 {
4201         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4202         struct btrfs_ioctl_qgroup_limit_args *sa;
4203         struct btrfs_trans_handle *trans;
4204         int ret;
4205         int err;
4206         u64 qgroupid;
4207
4208         if (!capable(CAP_SYS_ADMIN))
4209                 return -EPERM;
4210
4211         ret = mnt_want_write_file(file);
4212         if (ret)
4213                 return ret;
4214
4215         sa = memdup_user(arg, sizeof(*sa));
4216         if (IS_ERR(sa)) {
4217                 ret = PTR_ERR(sa);
4218                 goto drop_write;
4219         }
4220
4221         trans = btrfs_join_transaction(root);
4222         if (IS_ERR(trans)) {
4223                 ret = PTR_ERR(trans);
4224                 goto out;
4225         }
4226
4227         qgroupid = sa->qgroupid;
4228         if (!qgroupid) {
4229                 /* take the current subvol as qgroup */
4230                 qgroupid = root->root_key.objectid;
4231         }
4232
4233         /* FIXME: check if the IDs really exist */
4234         ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
4235
4236         err = btrfs_end_transaction(trans, root);
4237         if (err && !ret)
4238                 ret = err;
4239
4240 out:
4241         kfree(sa);
4242 drop_write:
4243         mnt_drop_write_file(file);
4244         return ret;
4245 }
4246
4247 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4248 {
4249         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4250         struct btrfs_ioctl_quota_rescan_args *qsa;
4251         int ret;
4252
4253         if (!capable(CAP_SYS_ADMIN))
4254                 return -EPERM;
4255
4256         ret = mnt_want_write_file(file);
4257         if (ret)
4258                 return ret;
4259
4260         qsa = memdup_user(arg, sizeof(*qsa));
4261         if (IS_ERR(qsa)) {
4262                 ret = PTR_ERR(qsa);
4263                 goto drop_write;
4264         }
4265
4266         if (qsa->flags) {
4267                 ret = -EINVAL;
4268                 goto out;
4269         }
4270
4271         ret = btrfs_qgroup_rescan(root->fs_info);
4272
4273 out:
4274         kfree(qsa);
4275 drop_write:
4276         mnt_drop_write_file(file);
4277         return ret;
4278 }
4279
4280 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
4281 {
4282         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4283         struct btrfs_ioctl_quota_rescan_args *qsa;
4284         int ret = 0;
4285
4286         if (!capable(CAP_SYS_ADMIN))
4287                 return -EPERM;
4288
4289         qsa = kzalloc(sizeof(*qsa), GFP_NOFS);
4290         if (!qsa)
4291                 return -ENOMEM;
4292
4293         if (root->fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4294                 qsa->flags = 1;
4295                 qsa->progress = root->fs_info->qgroup_rescan_progress.objectid;
4296         }
4297
4298         if (copy_to_user(arg, qsa, sizeof(*qsa)))
4299                 ret = -EFAULT;
4300
4301         kfree(qsa);
4302         return ret;
4303 }
4304
4305 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
4306 {
4307         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
4308
4309         if (!capable(CAP_SYS_ADMIN))
4310                 return -EPERM;
4311
4312         return btrfs_qgroup_wait_for_completion(root->fs_info);
4313 }
4314
4315 static long btrfs_ioctl_set_received_subvol(struct file *file,
4316                                             void __user *arg)
4317 {
4318         struct btrfs_ioctl_received_subvol_args *sa = NULL;
4319         struct inode *inode = file_inode(file);
4320         struct btrfs_root *root = BTRFS_I(inode)->root;
4321         struct btrfs_root_item *root_item = &root->root_item;
4322         struct btrfs_trans_handle *trans;
4323         struct timespec ct = CURRENT_TIME;
4324         int ret = 0;
4325         int received_uuid_changed;
4326
4327         ret = mnt_want_write_file(file);
4328         if (ret < 0)
4329                 return ret;
4330
4331         down_write(&root->fs_info->subvol_sem);
4332
4333         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
4334                 ret = -EINVAL;
4335                 goto out;
4336         }
4337
4338         if (btrfs_root_readonly(root)) {
4339                 ret = -EROFS;
4340                 goto out;
4341         }
4342
4343         if (!inode_owner_or_capable(inode)) {
4344                 ret = -EACCES;
4345                 goto out;
4346         }
4347
4348         sa = memdup_user(arg, sizeof(*sa));
4349         if (IS_ERR(sa)) {
4350                 ret = PTR_ERR(sa);
4351                 sa = NULL;
4352                 goto out;
4353         }
4354
4355         /*
4356          * 1 - root item
4357          * 2 - uuid items (received uuid + subvol uuid)
4358          */
4359         trans = btrfs_start_transaction(root, 3);
4360         if (IS_ERR(trans)) {
4361                 ret = PTR_ERR(trans);
4362                 trans = NULL;
4363                 goto out;
4364         }
4365
4366         sa->rtransid = trans->transid;
4367         sa->rtime.sec = ct.tv_sec;
4368         sa->rtime.nsec = ct.tv_nsec;
4369
4370         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
4371                                        BTRFS_UUID_SIZE);
4372         if (received_uuid_changed &&
4373             !btrfs_is_empty_uuid(root_item->received_uuid))
4374                 btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
4375                                     root_item->received_uuid,
4376                                     BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4377                                     root->root_key.objectid);
4378         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
4379         btrfs_set_root_stransid(root_item, sa->stransid);
4380         btrfs_set_root_rtransid(root_item, sa->rtransid);
4381         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
4382         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
4383         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
4384         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
4385
4386         ret = btrfs_update_root(trans, root->fs_info->tree_root,
4387                                 &root->root_key, &root->root_item);
4388         if (ret < 0) {
4389                 btrfs_end_transaction(trans, root);
4390                 goto out;
4391         }
4392         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
4393                 ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
4394                                           sa->uuid,
4395                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4396                                           root->root_key.objectid);
4397                 if (ret < 0 && ret != -EEXIST) {
4398                         btrfs_abort_transaction(trans, root, ret);
4399                         goto out;
4400                 }
4401         }
4402         ret = btrfs_commit_transaction(trans, root);
4403         if (ret < 0) {
4404                 btrfs_abort_transaction(trans, root, ret);
4405                 goto out;
4406         }
4407
4408         ret = copy_to_user(arg, sa, sizeof(*sa));
4409         if (ret)
4410                 ret = -EFAULT;
4411
4412 out:
4413         kfree(sa);
4414         up_write(&root->fs_info->subvol_sem);
4415         mnt_drop_write_file(file);
4416         return ret;
4417 }
4418
4419 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
4420 {
4421         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4422         size_t len;
4423         int ret;
4424         char label[BTRFS_LABEL_SIZE];
4425
4426         spin_lock(&root->fs_info->super_lock);
4427         memcpy(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4428         spin_unlock(&root->fs_info->super_lock);
4429
4430         len = strnlen(label, BTRFS_LABEL_SIZE);
4431
4432         if (len == BTRFS_LABEL_SIZE) {
4433                 pr_warn("btrfs: label is too long, return the first %zu bytes\n",
4434                         --len);
4435         }
4436
4437         ret = copy_to_user(arg, label, len);
4438
4439         return ret ? -EFAULT : 0;
4440 }
4441
4442 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4443 {
4444         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4445         struct btrfs_super_block *super_block = root->fs_info->super_copy;
4446         struct btrfs_trans_handle *trans;
4447         char label[BTRFS_LABEL_SIZE];
4448         int ret;
4449
4450         if (!capable(CAP_SYS_ADMIN))
4451                 return -EPERM;
4452
4453         if (copy_from_user(label, arg, sizeof(label)))
4454                 return -EFAULT;
4455
4456         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4457                 pr_err("btrfs: unable to set label with more than %d bytes\n",
4458                        BTRFS_LABEL_SIZE - 1);
4459                 return -EINVAL;
4460         }
4461
4462         ret = mnt_want_write_file(file);
4463         if (ret)
4464                 return ret;
4465
4466         trans = btrfs_start_transaction(root, 0);
4467         if (IS_ERR(trans)) {
4468                 ret = PTR_ERR(trans);
4469                 goto out_unlock;
4470         }
4471
4472         spin_lock(&root->fs_info->super_lock);
4473         strcpy(super_block->label, label);
4474         spin_unlock(&root->fs_info->super_lock);
4475         ret = btrfs_end_transaction(trans, root);
4476
4477 out_unlock:
4478         mnt_drop_write_file(file);
4479         return ret;
4480 }
4481
4482 long btrfs_ioctl(struct file *file, unsigned int
4483                 cmd, unsigned long arg)
4484 {
4485         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4486         void __user *argp = (void __user *)arg;
4487
4488         switch (cmd) {
4489         case FS_IOC_GETFLAGS:
4490                 return btrfs_ioctl_getflags(file, argp);
4491         case FS_IOC_SETFLAGS:
4492                 return btrfs_ioctl_setflags(file, argp);
4493         case FS_IOC_GETVERSION:
4494                 return btrfs_ioctl_getversion(file, argp);
4495         case FITRIM:
4496                 return btrfs_ioctl_fitrim(file, argp);
4497         case BTRFS_IOC_SNAP_CREATE:
4498                 return btrfs_ioctl_snap_create(file, argp, 0);
4499         case BTRFS_IOC_SNAP_CREATE_V2:
4500                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
4501         case BTRFS_IOC_SUBVOL_CREATE:
4502                 return btrfs_ioctl_snap_create(file, argp, 1);
4503         case BTRFS_IOC_SUBVOL_CREATE_V2:
4504                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
4505         case BTRFS_IOC_SNAP_DESTROY:
4506                 return btrfs_ioctl_snap_destroy(file, argp);
4507         case BTRFS_IOC_SUBVOL_GETFLAGS:
4508                 return btrfs_ioctl_subvol_getflags(file, argp);
4509         case BTRFS_IOC_SUBVOL_SETFLAGS:
4510                 return btrfs_ioctl_subvol_setflags(file, argp);
4511         case BTRFS_IOC_DEFAULT_SUBVOL:
4512                 return btrfs_ioctl_default_subvol(file, argp);
4513         case BTRFS_IOC_DEFRAG:
4514                 return btrfs_ioctl_defrag(file, NULL);
4515         case BTRFS_IOC_DEFRAG_RANGE:
4516                 return btrfs_ioctl_defrag(file, argp);
4517         case BTRFS_IOC_RESIZE:
4518                 return btrfs_ioctl_resize(file, argp);
4519         case BTRFS_IOC_ADD_DEV:
4520                 return btrfs_ioctl_add_dev(root, argp);
4521         case BTRFS_IOC_RM_DEV:
4522                 return btrfs_ioctl_rm_dev(file, argp);
4523         case BTRFS_IOC_FS_INFO:
4524                 return btrfs_ioctl_fs_info(root, argp);
4525         case BTRFS_IOC_DEV_INFO:
4526                 return btrfs_ioctl_dev_info(root, argp);
4527         case BTRFS_IOC_BALANCE:
4528                 return btrfs_ioctl_balance(file, NULL);
4529         case BTRFS_IOC_CLONE:
4530                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
4531         case BTRFS_IOC_CLONE_RANGE:
4532                 return btrfs_ioctl_clone_range(file, argp);
4533         case BTRFS_IOC_TRANS_START:
4534                 return btrfs_ioctl_trans_start(file);
4535         case BTRFS_IOC_TRANS_END:
4536                 return btrfs_ioctl_trans_end(file);
4537         case BTRFS_IOC_TREE_SEARCH:
4538                 return btrfs_ioctl_tree_search(file, argp);
4539         case BTRFS_IOC_INO_LOOKUP:
4540                 return btrfs_ioctl_ino_lookup(file, argp);
4541         case BTRFS_IOC_INO_PATHS:
4542                 return btrfs_ioctl_ino_to_path(root, argp);
4543         case BTRFS_IOC_LOGICAL_INO:
4544                 return btrfs_ioctl_logical_to_ino(root, argp);
4545         case BTRFS_IOC_SPACE_INFO:
4546                 return btrfs_ioctl_space_info(root, argp);
4547         case BTRFS_IOC_SYNC: {
4548                 int ret;
4549
4550                 ret = btrfs_start_delalloc_roots(root->fs_info, 0);
4551                 if (ret)
4552                         return ret;
4553                 ret = btrfs_sync_fs(file->f_dentry->d_sb, 1);
4554                 return ret;
4555         }
4556         case BTRFS_IOC_START_SYNC:
4557                 return btrfs_ioctl_start_sync(root, argp);
4558         case BTRFS_IOC_WAIT_SYNC:
4559                 return btrfs_ioctl_wait_sync(root, argp);
4560         case BTRFS_IOC_SCRUB:
4561                 return btrfs_ioctl_scrub(file, argp);
4562         case BTRFS_IOC_SCRUB_CANCEL:
4563                 return btrfs_ioctl_scrub_cancel(root, argp);
4564         case BTRFS_IOC_SCRUB_PROGRESS:
4565                 return btrfs_ioctl_scrub_progress(root, argp);
4566         case BTRFS_IOC_BALANCE_V2:
4567                 return btrfs_ioctl_balance(file, argp);
4568         case BTRFS_IOC_BALANCE_CTL:
4569                 return btrfs_ioctl_balance_ctl(root, arg);
4570         case BTRFS_IOC_BALANCE_PROGRESS:
4571                 return btrfs_ioctl_balance_progress(root, argp);
4572         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
4573                 return btrfs_ioctl_set_received_subvol(file, argp);
4574         case BTRFS_IOC_SEND:
4575                 return btrfs_ioctl_send(file, argp);
4576         case BTRFS_IOC_GET_DEV_STATS:
4577                 return btrfs_ioctl_get_dev_stats(root, argp);
4578         case BTRFS_IOC_QUOTA_CTL:
4579                 return btrfs_ioctl_quota_ctl(file, argp);
4580         case BTRFS_IOC_QGROUP_ASSIGN:
4581                 return btrfs_ioctl_qgroup_assign(file, argp);
4582         case BTRFS_IOC_QGROUP_CREATE:
4583                 return btrfs_ioctl_qgroup_create(file, argp);
4584         case BTRFS_IOC_QGROUP_LIMIT:
4585                 return btrfs_ioctl_qgroup_limit(file, argp);
4586         case BTRFS_IOC_QUOTA_RESCAN:
4587                 return btrfs_ioctl_quota_rescan(file, argp);
4588         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
4589                 return btrfs_ioctl_quota_rescan_status(file, argp);
4590         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
4591                 return btrfs_ioctl_quota_rescan_wait(file, argp);
4592         case BTRFS_IOC_DEV_REPLACE:
4593                 return btrfs_ioctl_dev_replace(root, argp);
4594         case BTRFS_IOC_GET_FSLABEL:
4595                 return btrfs_ioctl_get_fslabel(file, argp);
4596         case BTRFS_IOC_SET_FSLABEL:
4597                 return btrfs_ioctl_set_fslabel(file, argp);
4598         case BTRFS_IOC_FILE_EXTENT_SAME:
4599                 return btrfs_ioctl_file_extent_same(file, argp);
4600         }
4601
4602         return -ENOTTY;
4603 }