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 "compat.h"
  45 #include "ctree.h"
  46 #include "disk-io.h"
  47 #include "transaction.h"
  48 #include "btrfs_inode.h"
  49 #include "ioctl.h"
  50 #include "print-tree.h"
  51 #include "volumes.h"
  52 #include "locking.h"
  53 #include "inode-map.h"
  54
  55 /* Mask out flags that are inappropriate for the given type of inode. */
  56 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  57 {
  58         if (S_ISDIR(mode))
  59                 return flags;
  60         else if (S_ISREG(mode))
  61                 return flags & ~FS_DIRSYNC_FL;
  62         else
  63                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  64 }
  65
  66 /*
  67  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  68  */
  69 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  70 {
  71         unsigned int iflags = 0;
  72
  73         if (flags & BTRFS_INODE_SYNC)
  74                 iflags |= FS_SYNC_FL;
  75         if (flags & BTRFS_INODE_IMMUTABLE)
  76                 iflags |= FS_IMMUTABLE_FL;
  77         if (flags & BTRFS_INODE_APPEND)
  78                 iflags |= FS_APPEND_FL;
  79         if (flags & BTRFS_INODE_NODUMP)
  80                 iflags |= FS_NODUMP_FL;
  81         if (flags & BTRFS_INODE_NOATIME)
  82                 iflags |= FS_NOATIME_FL;
  83         if (flags & BTRFS_INODE_DIRSYNC)
  84                 iflags |= FS_DIRSYNC_FL;
  85         if (flags & BTRFS_INODE_NODATACOW)
  86                 iflags |= FS_NOCOW_FL;
  87
  88         if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
  89                 iflags |= FS_COMPR_FL;
  90         else if (flags & BTRFS_INODE_NOCOMPRESS)
  91                 iflags |= FS_NOCOMP_FL;
  92
  93         return iflags;
  94 }
  95
  96 /*
  97  * Update inode->i_flags based on the btrfs internal flags.
  98  */
  99 void btrfs_update_iflags(struct inode *inode)
 100 {
 101         struct btrfs_inode *ip = BTRFS_I(inode);
 102
 103         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
 104
 105         if (ip->flags & BTRFS_INODE_SYNC)
 106                 inode->i_flags |= S_SYNC;
 107         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 108                 inode->i_flags |= S_IMMUTABLE;
 109         if (ip->flags & BTRFS_INODE_APPEND)
 110                 inode->i_flags |= S_APPEND;
 111         if (ip->flags & BTRFS_INODE_NOATIME)
 112                 inode->i_flags |= S_NOATIME;
 113         if (ip->flags & BTRFS_INODE_DIRSYNC)
 114                 inode->i_flags |= S_DIRSYNC;
 115 }
 116
 117 /*
 118  * Inherit flags from the parent inode.
 119  *
 120  * Unlike extN we don't have any flags we don't want to inherit currently.
 121  */
 122 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 123 {
 124         unsigned int flags;
 125
 126         if (!dir)
 127                 return;
 128
 129         flags = BTRFS_I(dir)->flags;
 130
 131         if (S_ISREG(inode->i_mode))
 132                 flags &= ~BTRFS_INODE_DIRSYNC;
 133         else if (!S_ISDIR(inode->i_mode))
 134                 flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME);
 135
 136         BTRFS_I(inode)->flags = flags;
 137         btrfs_update_iflags(inode);
 138 }
 139
 140 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 141 {
 142         struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
 143         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 144
 145         if (copy_to_user(arg, &flags, sizeof(flags)))
 146                 return -EFAULT;
 147         return 0;
 148 }
 149
 150 static int check_flags(unsigned int flags)
 151 {
 152         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 153                       FS_NOATIME_FL | FS_NODUMP_FL | \
 154                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 155                       FS_NOCOMP_FL | FS_COMPR_FL |
 156                       FS_NOCOW_FL))
 157                 return -EOPNOTSUPP;
 158
 159         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 160                 return -EINVAL;
 161
 162         return 0;
 163 }
 164
 165 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 166 {
 167         struct inode *inode = file->f_path.dentry->d_inode;
 168         struct btrfs_inode *ip = BTRFS_I(inode);
 169         struct btrfs_root *root = ip->root;
 170         struct btrfs_trans_handle *trans;
 171         unsigned int flags, oldflags;
 172         int ret;
 173
 174         if (btrfs_root_readonly(root))
 175                 return -EROFS;
 176
 177         if (copy_from_user(&flags, arg, sizeof(flags)))
 178                 return -EFAULT;
 179
 180         ret = check_flags(flags);
 181         if (ret)
 182                 return ret;
 183
 184         if (!inode_owner_or_capable(inode))
 185                 return -EACCES;
 186
 187         mutex_lock(&inode->i_mutex);
 188
 189         flags = btrfs_mask_flags(inode->i_mode, flags);
 190         oldflags = btrfs_flags_to_ioctl(ip->flags);
 191         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 192                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 193                         ret = -EPERM;
 194                         goto out_unlock;
 195                 }
 196         }
 197
 198         ret = mnt_want_write(file->f_path.mnt);
 199         if (ret)
 200                 goto out_unlock;
 201
 202         if (flags & FS_SYNC_FL)
 203                 ip->flags |= BTRFS_INODE_SYNC;
 204         else
 205                 ip->flags &= ~BTRFS_INODE_SYNC;
 206         if (flags & FS_IMMUTABLE_FL)
 207                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 208         else
 209                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 210         if (flags & FS_APPEND_FL)
 211                 ip->flags |= BTRFS_INODE_APPEND;
 212         else
 213                 ip->flags &= ~BTRFS_INODE_APPEND;
 214         if (flags & FS_NODUMP_FL)
 215                 ip->flags |= BTRFS_INODE_NODUMP;
 216         else
 217                 ip->flags &= ~BTRFS_INODE_NODUMP;
 218         if (flags & FS_NOATIME_FL)
 219                 ip->flags |= BTRFS_INODE_NOATIME;
 220         else
 221                 ip->flags &= ~BTRFS_INODE_NOATIME;
 222         if (flags & FS_DIRSYNC_FL)
 223                 ip->flags |= BTRFS_INODE_DIRSYNC;
 224         else
 225                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 226         if (flags & FS_NOCOW_FL)
 227                 ip->flags |= BTRFS_INODE_NODATACOW;
 228         else
 229                 ip->flags &= ~BTRFS_INODE_NODATACOW;
 230
 231         /*
 232          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 233          * flag may be changed automatically if compression code won't make
 234          * things smaller.
 235          */
 236         if (flags & FS_NOCOMP_FL) {
 237                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 238                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 239         } else if (flags & FS_COMPR_FL) {
 240                 ip->flags |= BTRFS_INODE_COMPRESS;
 241                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 242         } else {
 243                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 244         }
 245
 246         trans = btrfs_join_transaction(root);
 247         BUG_ON(IS_ERR(trans));
 248
 249         ret = btrfs_update_inode(trans, root, inode);
 250         BUG_ON(ret);
 251
 252         btrfs_update_iflags(inode);
 253         inode->i_ctime = CURRENT_TIME;
 254         btrfs_end_transaction(trans, root);
 255
 256         mnt_drop_write(file->f_path.mnt);
 257
 258         ret = 0;
 259  out_unlock:
 260         mutex_unlock(&inode->i_mutex);
 261         return ret;
 262 }
 263
 264 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 265 {
 266         struct inode *inode = file->f_path.dentry->d_inode;
 267
 268         return put_user(inode->i_generation, arg);
 269 }
 270
 271 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 272 {
 273         struct btrfs_root *root = fdentry(file)->d_sb->s_fs_info;
 274         struct btrfs_fs_info *fs_info = root->fs_info;
 275         struct btrfs_device *device;
 276         struct request_queue *q;
 277         struct fstrim_range range;
 278         u64 minlen = ULLONG_MAX;
 279         u64 num_devices = 0;
 280         int ret;
 281
 282         if (!capable(CAP_SYS_ADMIN))
 283                 return -EPERM;
 284
 285         rcu_read_lock();
 286         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 287                                 dev_list) {
 288                 if (!device->bdev)
 289                         continue;
 290                 q = bdev_get_queue(device->bdev);
 291                 if (blk_queue_discard(q)) {
 292                         num_devices++;
 293                         minlen = min((u64)q->limits.discard_granularity,
 294                                      minlen);
 295                 }
 296         }
 297         rcu_read_unlock();
 298         if (!num_devices)
 299                 return -EOPNOTSUPP;
 300
 301         if (copy_from_user(&range, arg, sizeof(range)))
 302                 return -EFAULT;
 303
 304         range.minlen = max(range.minlen, minlen);
 305         ret = btrfs_trim_fs(root, &range);
 306         if (ret < 0)
 307                 return ret;
 308
 309         if (copy_to_user(arg, &range, sizeof(range)))
 310                 return -EFAULT;
 311
 312         return 0;
 313 }
 314
 315 static noinline int create_subvol(struct btrfs_root *root,
 316                                   struct dentry *dentry,
 317                                   char *name, int namelen,
 318                                   u64 *async_transid)
 319 {
 320         struct btrfs_trans_handle *trans;
 321         struct btrfs_key key;
 322         struct btrfs_root_item root_item;
 323         struct btrfs_inode_item *inode_item;
 324         struct extent_buffer *leaf;
 325         struct btrfs_root *new_root;
 326         struct dentry *parent = dentry->d_parent;
 327         struct inode *dir;
 328         int ret;
 329         int err;
 330         u64 objectid;
 331         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 332         u64 index = 0;
 333
 334         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 335         if (ret)
 336                 return ret;
 337
 338         dir = parent->d_inode;
 339
 340         /*
 341          * 1 - inode item
 342          * 2 - refs
 343          * 1 - root item
 344          * 2 - dir items
 345          */
 346         trans = btrfs_start_transaction(root, 6);
 347         if (IS_ERR(trans))
 348                 return PTR_ERR(trans);
 349
 350         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 351                                       0, objectid, NULL, 0, 0, 0);
 352         if (IS_ERR(leaf)) {
 353                 ret = PTR_ERR(leaf);
 354                 goto fail;
 355         }
 356
 357         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 358         btrfs_set_header_bytenr(leaf, leaf->start);
 359         btrfs_set_header_generation(leaf, trans->transid);
 360         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 361         btrfs_set_header_owner(leaf, objectid);
 362
 363         write_extent_buffer(leaf, root->fs_info->fsid,
 364                             (unsigned long)btrfs_header_fsid(leaf),
 365                             BTRFS_FSID_SIZE);
 366         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 367                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 368                             BTRFS_UUID_SIZE);
 369         btrfs_mark_buffer_dirty(leaf);
 370
 371         inode_item = &root_item.inode;
 372         memset(inode_item, 0, sizeof(*inode_item));
 373         inode_item->generation = cpu_to_le64(1);
 374         inode_item->size = cpu_to_le64(3);
 375         inode_item->nlink = cpu_to_le32(1);
 376         inode_item->nbytes = cpu_to_le64(root->leafsize);
 377         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 378
 379         root_item.flags = 0;
 380         root_item.byte_limit = 0;
 381         inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
 382
 383         btrfs_set_root_bytenr(&root_item, leaf->start);
 384         btrfs_set_root_generation(&root_item, trans->transid);
 385         btrfs_set_root_level(&root_item, 0);
 386         btrfs_set_root_refs(&root_item, 1);
 387         btrfs_set_root_used(&root_item, leaf->len);
 388         btrfs_set_root_last_snapshot(&root_item, 0);
 389
 390         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
 391         root_item.drop_level = 0;
 392
 393         btrfs_tree_unlock(leaf);
 394         free_extent_buffer(leaf);
 395         leaf = NULL;
 396
 397         btrfs_set_root_dirid(&root_item, new_dirid);
 398
 399         key.objectid = objectid;
 400         key.offset = 0;
 401         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 402         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 403                                 &root_item);
 404         if (ret)
 405                 goto fail;
 406
 407         key.offset = (u64)-1;
 408         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 409         BUG_ON(IS_ERR(new_root));
 410
 411         btrfs_record_root_in_trans(trans, new_root);
 412
 413         ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
 414         /*
 415          * insert the directory item
 416          */
 417         ret = btrfs_set_inode_index(dir, &index);
 418         BUG_ON(ret);
 419
 420         ret = btrfs_insert_dir_item(trans, root,
 421                                     name, namelen, dir, &key,
 422                                     BTRFS_FT_DIR, index);
 423         if (ret)
 424                 goto fail;
 425
 426         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 427         ret = btrfs_update_inode(trans, root, dir);
 428         BUG_ON(ret);
 429
 430         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 431                                  objectid, root->root_key.objectid,
 432                                  btrfs_ino(dir), index, name, namelen);
 433
 434         BUG_ON(ret);
 435
 436         d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 437 fail:
 438         if (async_transid) {
 439                 *async_transid = trans->transid;
 440                 err = btrfs_commit_transaction_async(trans, root, 1);
 441         } else {
 442                 err = btrfs_commit_transaction(trans, root);
 443         }
 444         if (err && !ret)
 445                 ret = err;
 446         return ret;
 447 }
 448
 449 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 450                            char *name, int namelen, u64 *async_transid,
 451                            bool readonly)
 452 {
 453         struct inode *inode;
 454         struct btrfs_pending_snapshot *pending_snapshot;
 455         struct btrfs_trans_handle *trans;
 456         int ret;
 457
 458         if (!root->ref_cows)
 459                 return -EINVAL;
 460
 461         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 462         if (!pending_snapshot)
 463                 return -ENOMEM;
 464
 465         btrfs_init_block_rsv(&pending_snapshot->block_rsv);
 466         pending_snapshot->dentry = dentry;
 467         pending_snapshot->root = root;
 468         pending_snapshot->readonly = readonly;
 469
 470         trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
 471         if (IS_ERR(trans)) {
 472                 ret = PTR_ERR(trans);
 473                 goto fail;
 474         }
 475
 476         ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
 477         BUG_ON(ret);
 478
 479         spin_lock(&root->fs_info->trans_lock);
 480         list_add(&pending_snapshot->list,
 481                  &trans->transaction->pending_snapshots);
 482         spin_unlock(&root->fs_info->trans_lock);
 483         if (async_transid) {
 484                 *async_transid = trans->transid;
 485                 ret = btrfs_commit_transaction_async(trans,
 486                                      root->fs_info->extent_root, 1);
 487         } else {
 488                 ret = btrfs_commit_transaction(trans,
 489                                                root->fs_info->extent_root);
 490         }
 491         BUG_ON(ret);
 492
 493         ret = pending_snapshot->error;
 494         if (ret)
 495                 goto fail;
 496
 497         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 498         if (ret)
 499                 goto fail;
 500
 501         inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 502         if (IS_ERR(inode)) {
 503                 ret = PTR_ERR(inode);
 504                 goto fail;
 505         }
 506         BUG_ON(!inode);
 507         d_instantiate(dentry, inode);
 508         ret = 0;
 509 fail:
 510         kfree(pending_snapshot);
 511         return ret;
 512 }
 513
 514 /*  copy of check_sticky in fs/namei.c()
 515 * It's inline, so penalty for filesystems that don't use sticky bit is
 516 * minimal.
 517 */
 518 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
 519 {
 520         uid_t fsuid = current_fsuid();
 521
 522         if (!(dir->i_mode & S_ISVTX))
 523                 return 0;
 524         if (inode->i_uid == fsuid)
 525                 return 0;
 526         if (dir->i_uid == fsuid)
 527                 return 0;
 528         return !capable(CAP_FOWNER);
 529 }
 530
 531 /*  copy of may_delete in fs/namei.c()
 532  *      Check whether we can remove a link victim from directory dir, check
 533  *  whether the type of victim is right.
 534  *  1. We can't do it if dir is read-only (done in permission())
 535  *  2. We should have write and exec permissions on dir
 536  *  3. We can't remove anything from append-only dir
 537  *  4. We can't do anything with immutable dir (done in permission())
 538  *  5. If the sticky bit on dir is set we should either
 539  *      a. be owner of dir, or
 540  *      b. be owner of victim, or
 541  *      c. have CAP_FOWNER capability
 542  *  6. If the victim is append-only or immutable we can't do antyhing with
 543  *     links pointing to it.
 544  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 545  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 546  *  9. We can't remove a root or mountpoint.
 547  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 548  *     nfs_async_unlink().
 549  */
 550
 551 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
 552 {
 553         int error;
 554
 555         if (!victim->d_inode)
 556                 return -ENOENT;
 557
 558         BUG_ON(victim->d_parent->d_inode != dir);
 559         audit_inode_child(victim, dir);
 560
 561         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 562         if (error)
 563                 return error;
 564         if (IS_APPEND(dir))
 565                 return -EPERM;
 566         if (btrfs_check_sticky(dir, victim->d_inode)||
 567                 IS_APPEND(victim->d_inode)||
 568             IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
 569                 return -EPERM;
 570         if (isdir) {
 571                 if (!S_ISDIR(victim->d_inode->i_mode))
 572                         return -ENOTDIR;
 573                 if (IS_ROOT(victim))
 574                         return -EBUSY;
 575         } else if (S_ISDIR(victim->d_inode->i_mode))
 576                 return -EISDIR;
 577         if (IS_DEADDIR(dir))
 578                 return -ENOENT;
 579         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 580                 return -EBUSY;
 581         return 0;
 582 }
 583
 584 /* copy of may_create in fs/namei.c() */
 585 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 586 {
 587         if (child->d_inode)
 588                 return -EEXIST;
 589         if (IS_DEADDIR(dir))
 590                 return -ENOENT;
 591         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 592 }
 593
 594 /*
 595  * Create a new subvolume below @parent.  This is largely modeled after
 596  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 597  * inside this filesystem so it's quite a bit simpler.
 598  */
 599 static noinline int btrfs_mksubvol(struct path *parent,
 600                                    char *name, int namelen,
 601                                    struct btrfs_root *snap_src,
 602                                    u64 *async_transid, bool readonly)
 603 {
 604         struct inode *dir  = parent->dentry->d_inode;
 605         struct dentry *dentry;
 606         int error;
 607
 608         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 609
 610         dentry = lookup_one_len(name, parent->dentry, namelen);
 611         error = PTR_ERR(dentry);
 612         if (IS_ERR(dentry))
 613                 goto out_unlock;
 614
 615         error = -EEXIST;
 616         if (dentry->d_inode)
 617                 goto out_dput;
 618
 619         error = mnt_want_write(parent->mnt);
 620         if (error)
 621                 goto out_dput;
 622
 623         error = btrfs_may_create(dir, dentry);
 624         if (error)
 625                 goto out_drop_write;
 626
 627         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 628
 629         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 630                 goto out_up_read;
 631
 632         if (snap_src) {
 633                 error = create_snapshot(snap_src, dentry,
 634                                         name, namelen, async_transid, readonly);
 635         } else {
 636                 error = create_subvol(BTRFS_I(dir)->root, dentry,
 637                                       name, namelen, async_transid);
 638         }
 639         if (!error)
 640                 fsnotify_mkdir(dir, dentry);
 641 out_up_read:
 642         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 643 out_drop_write:
 644         mnt_drop_write(parent->mnt);
 645 out_dput:
 646         dput(dentry);
 647 out_unlock:
 648         mutex_unlock(&dir->i_mutex);
 649         return error;
 650 }
 651
 652 /*
 653  * When we're defragging a range, we don't want to kick it off again
 654  * if it is really just waiting for delalloc to send it down.
 655  * If we find a nice big extent or delalloc range for the bytes in the
 656  * file you want to defrag, we return 0 to let you know to skip this
 657  * part of the file
 658  */
 659 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
 660 {
 661         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 662         struct extent_map *em = NULL;
 663         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 664         u64 end;
 665
 666         read_lock(&em_tree->lock);
 667         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 668         read_unlock(&em_tree->lock);
 669
 670         if (em) {
 671                 end = extent_map_end(em);
 672                 free_extent_map(em);
 673                 if (end - offset > thresh)
 674                         return 0;
 675         }
 676         /* if we already have a nice delalloc here, just stop */
 677         thresh /= 2;
 678         end = count_range_bits(io_tree, &offset, offset + thresh,
 679                                thresh, EXTENT_DELALLOC, 1);
 680         if (end >= thresh)
 681                 return 0;
 682         return 1;
 683 }
 684
 685 /*
 686  * helper function to walk through a file and find extents
 687  * newer than a specific transid, and smaller than thresh.
 688  *
 689  * This is used by the defragging code to find new and small
 690  * extents
 691  */
 692 static int find_new_extents(struct btrfs_root *root,
 693                             struct inode *inode, u64 newer_than,
 694                             u64 *off, int thresh)
 695 {
 696         struct btrfs_path *path;
 697         struct btrfs_key min_key;
 698         struct btrfs_key max_key;
 699         struct extent_buffer *leaf;
 700         struct btrfs_file_extent_item *extent;
 701         int type;
 702         int ret;
 703         u64 ino = btrfs_ino(inode);
 704
 705         path = btrfs_alloc_path();
 706         if (!path)
 707                 return -ENOMEM;
 708
 709         min_key.objectid = ino;
 710         min_key.type = BTRFS_EXTENT_DATA_KEY;
 711         min_key.offset = *off;
 712
 713         max_key.objectid = ino;
 714         max_key.type = (u8)-1;
 715         max_key.offset = (u64)-1;
 716
 717         path->keep_locks = 1;
 718
 719         while(1) {
 720                 ret = btrfs_search_forward(root, &min_key, &max_key,
 721                                            path, 0, newer_than);
 722                 if (ret != 0)
 723                         goto none;
 724                 if (min_key.objectid != ino)
 725                         goto none;
 726                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 727                         goto none;
 728
 729                 leaf = path->nodes[0];
 730                 extent = btrfs_item_ptr(leaf, path->slots[0],
 731                                         struct btrfs_file_extent_item);
 732
 733                 type = btrfs_file_extent_type(leaf, extent);
 734                 if (type == BTRFS_FILE_EXTENT_REG &&
 735                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 736                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 737                         *off = min_key.offset;
 738                         btrfs_free_path(path);
 739                         return 0;
 740                 }
 741
 742                 if (min_key.offset == (u64)-1)
 743                         goto none;
 744
 745                 min_key.offset++;
 746                 btrfs_release_path(path);
 747         }
 748 none:
 749         btrfs_free_path(path);
 750         return -ENOENT;
 751 }
 752
 753 static int should_defrag_range(struct inode *inode, u64 start, u64 len,
 754                                int thresh, u64 *last_len, u64 *skip,
 755                                u64 *defrag_end)
 756 {
 757         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 758         struct extent_map *em = NULL;
 759         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 760         int ret = 1;
 761
 762         /*
 763          * make sure that once we start defragging and extent, we keep on
 764          * defragging it
 765          */
 766         if (start < *defrag_end)
 767                 return 1;
 768
 769         *skip = 0;
 770
 771         /*
 772          * hopefully we have this extent in the tree already, try without
 773          * the full extent lock
 774          */
 775         read_lock(&em_tree->lock);
 776         em = lookup_extent_mapping(em_tree, start, len);
 777         read_unlock(&em_tree->lock);
 778
 779         if (!em) {
 780                 /* get the big lock and read metadata off disk */
 781                 lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
 782                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 783                 unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
 784
 785                 if (IS_ERR(em))
 786                         return 0;
 787         }
 788
 789         /* this will cover holes, and inline extents */
 790         if (em->block_start >= EXTENT_MAP_LAST_BYTE)
 791                 ret = 0;
 792
 793         /*
 794          * we hit a real extent, if it is big don't bother defragging it again
 795          */
 796         if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
 797                 ret = 0;
 798
 799         /*
 800          * last_len ends up being a counter of how many bytes we've defragged.
 801          * every time we choose not to defrag an extent, we reset *last_len
 802          * so that the next tiny extent will force a defrag.
 803          *
 804          * The end result of this is that tiny extents before a single big
 805          * extent will force at least part of that big extent to be defragged.
 806          */
 807         if (ret) {
 808                 *last_len += len;
 809                 *defrag_end = extent_map_end(em);
 810         } else {
 811                 *last_len = 0;
 812                 *skip = extent_map_end(em);
 813                 *defrag_end = 0;
 814         }
 815
 816         free_extent_map(em);
 817         return ret;
 818 }
 819
 820 /*
 821  * it doesn't do much good to defrag one or two pages
 822  * at a time.  This pulls in a nice chunk of pages
 823  * to COW and defrag.
 824  *
 825  * It also makes sure the delalloc code has enough
 826  * dirty data to avoid making new small extents as part
 827  * of the defrag
 828  *
 829  * It's a good idea to start RA on this range
 830  * before calling this.
 831  */
 832 static int cluster_pages_for_defrag(struct inode *inode,
 833                                     struct page **pages,
 834                                     unsigned long start_index,
 835                                     int num_pages)
 836 {
 837         unsigned long file_end;
 838         u64 isize = i_size_read(inode);
 839         u64 page_start;
 840         u64 page_end;
 841         int ret;
 842         int i;
 843         int i_done;
 844         struct btrfs_ordered_extent *ordered;
 845         struct extent_state *cached_state = NULL;
 846
 847         if (isize == 0)
 848                 return 0;
 849         file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
 850
 851         ret = btrfs_delalloc_reserve_space(inode,
 852                                            num_pages << PAGE_CACHE_SHIFT);
 853         if (ret)
 854                 return ret;
 855 again:
 856         ret = 0;
 857         i_done = 0;
 858
 859         /* step one, lock all the pages */
 860         for (i = 0; i < num_pages; i++) {
 861                 struct page *page;
 862                 page = find_or_create_page(inode->i_mapping,
 863                                             start_index + i, GFP_NOFS);
 864                 if (!page)
 865                         break;
 866
 867                 if (!PageUptodate(page)) {
 868                         btrfs_readpage(NULL, page);
 869                         lock_page(page);
 870                         if (!PageUptodate(page)) {
 871                                 unlock_page(page);
 872                                 page_cache_release(page);
 873                                 ret = -EIO;
 874                                 break;
 875                         }
 876                 }
 877                 isize = i_size_read(inode);
 878                 file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
 879                 if (!isize || page->index > file_end ||
 880                     page->mapping != inode->i_mapping) {
 881                         /* whoops, we blew past eof, skip this page */
 882                         unlock_page(page);
 883                         page_cache_release(page);
 884                         break;
 885                 }
 886                 pages[i] = page;
 887                 i_done++;
 888         }
 889         if (!i_done || ret)
 890                 goto out;
 891
 892         if (!(inode->i_sb->s_flags & MS_ACTIVE))
 893                 goto out;
 894
 895         /*
 896          * so now we have a nice long stream of locked
 897          * and up to date pages, lets wait on them
 898          */
 899         for (i = 0; i < i_done; i++)
 900                 wait_on_page_writeback(pages[i]);
 901
 902         page_start = page_offset(pages[0]);
 903         page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
 904
 905         lock_extent_bits(&BTRFS_I(inode)->io_tree,
 906                          page_start, page_end - 1, 0, &cached_state,
 907                          GFP_NOFS);
 908         ordered = btrfs_lookup_first_ordered_extent(inode, page_end - 1);
 909         if (ordered &&
 910             ordered->file_offset + ordered->len > page_start &&
 911             ordered->file_offset < page_end) {
 912                 btrfs_put_ordered_extent(ordered);
 913                 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
 914                                      page_start, page_end - 1,
 915                                      &cached_state, GFP_NOFS);
 916                 for (i = 0; i < i_done; i++) {
 917                         unlock_page(pages[i]);
 918                         page_cache_release(pages[i]);
 919                 }
 920                 btrfs_wait_ordered_range(inode, page_start,
 921                                          page_end - page_start);
 922                 goto again;
 923         }
 924         if (ordered)
 925                 btrfs_put_ordered_extent(ordered);
 926
 927         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
 928                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
 929                           EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
 930                           GFP_NOFS);
 931
 932         if (i_done != num_pages) {
 933                 spin_lock(&BTRFS_I(inode)->lock);
 934                 BTRFS_I(inode)->outstanding_extents++;
 935                 spin_unlock(&BTRFS_I(inode)->lock);
 936                 btrfs_delalloc_release_space(inode,
 937                                      (num_pages - i_done) << PAGE_CACHE_SHIFT);
 938         }
 939
 940
 941         btrfs_set_extent_delalloc(inode, page_start, page_end - 1,
 942                                   &cached_state);
 943
 944         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
 945                              page_start, page_end - 1, &cached_state,
 946                              GFP_NOFS);
 947
 948         for (i = 0; i < i_done; i++) {
 949                 clear_page_dirty_for_io(pages[i]);
 950                 ClearPageChecked(pages[i]);
 951                 set_page_extent_mapped(pages[i]);
 952                 set_page_dirty(pages[i]);
 953                 unlock_page(pages[i]);
 954                 page_cache_release(pages[i]);
 955         }
 956         return i_done;
 957 out:
 958         for (i = 0; i < i_done; i++) {
 959                 unlock_page(pages[i]);
 960                 page_cache_release(pages[i]);
 961         }
 962         btrfs_delalloc_release_space(inode, num_pages << PAGE_CACHE_SHIFT);
 963         return ret;
 964
 965 }
 966
 967 int btrfs_defrag_file(struct inode *inode, struct file *file,
 968                       struct btrfs_ioctl_defrag_range_args *range,
 969                       u64 newer_than, unsigned long max_to_defrag)
 970 {
 971         struct btrfs_root *root = BTRFS_I(inode)->root;
 972         struct btrfs_super_block *disk_super;
 973         struct file_ra_state *ra = NULL;
 974         unsigned long last_index;
 975         u64 features;
 976         u64 last_len = 0;
 977         u64 skip = 0;
 978         u64 defrag_end = 0;
 979         u64 newer_off = range->start;
 980         int newer_left = 0;
 981         unsigned long i;
 982         int ret;
 983         int defrag_count = 0;
 984         int compress_type = BTRFS_COMPRESS_ZLIB;
 985         int extent_thresh = range->extent_thresh;
 986         int newer_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
 987         u64 new_align = ~((u64)128 * 1024 - 1);
 988         struct page **pages = NULL;
 989
 990         if (extent_thresh == 0)
 991                 extent_thresh = 256 * 1024;
 992
 993         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
 994                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
 995                         return -EINVAL;
 996                 if (range->compress_type)
 997                         compress_type = range->compress_type;
 998         }
 999
1000         if (inode->i_size == 0)
1001                 return 0;
1002
1003         /*
1004          * if we were not given a file, allocate a readahead
1005          * context
1006          */
1007         if (!file) {
1008                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1009                 if (!ra)
1010                         return -ENOMEM;
1011                 file_ra_state_init(ra, inode->i_mapping);
1012         } else {
1013                 ra = &file->f_ra;
1014         }
1015
1016         pages = kmalloc(sizeof(struct page *) * newer_cluster,
1017                         GFP_NOFS);
1018         if (!pages) {
1019                 ret = -ENOMEM;
1020                 goto out_ra;
1021         }
1022
1023         /* find the last page to defrag */
1024         if (range->start + range->len > range->start) {
1025                 last_index = min_t(u64, inode->i_size - 1,
1026                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1027         } else {
1028                 last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
1029         }
1030
1031         if (newer_than) {
1032                 ret = find_new_extents(root, inode, newer_than,
1033                                        &newer_off, 64 * 1024);
1034                 if (!ret) {
1035                         range->start = newer_off;
1036                         /*
1037                          * we always align our defrag to help keep
1038                          * the extents in the file evenly spaced
1039                          */
1040                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1041                         newer_left = newer_cluster;
1042                 } else
1043                         goto out_ra;
1044         } else {
1045                 i = range->start >> PAGE_CACHE_SHIFT;
1046         }
1047         if (!max_to_defrag)
1048                 max_to_defrag = last_index - 1;
1049
1050         /*
1051          * make writeback starts from i, so the defrag range can be
1052          * written sequentially.
1053          */
1054         if (i < inode->i_mapping->writeback_index)
1055                 inode->i_mapping->writeback_index = i;
1056
1057         while (i <= last_index && defrag_count < max_to_defrag &&
1058                (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1059                 PAGE_CACHE_SHIFT)) {
1060                 /*
1061                  * make sure we stop running if someone unmounts
1062                  * the FS
1063                  */
1064                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1065                         break;
1066
1067                 if (!newer_than &&
1068                     !should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1069                                         PAGE_CACHE_SIZE,
1070                                         extent_thresh,
1071                                         &last_len, &skip,
1072                                         &defrag_end)) {
1073                         unsigned long next;
1074                         /*
1075                          * the should_defrag function tells us how much to skip
1076                          * bump our counter by the suggested amount
1077                          */
1078                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1079                         i = max(i + 1, next);
1080                         continue;
1081                 }
1082                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1083                         BTRFS_I(inode)->force_compress = compress_type;
1084
1085                 btrfs_force_ra(inode->i_mapping, ra, file, i, newer_cluster);
1086
1087                 ret = cluster_pages_for_defrag(inode, pages, i, newer_cluster);
1088                 if (ret < 0)
1089                         goto out_ra;
1090
1091                 defrag_count += ret;
1092                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
1093                 i += ret;
1094
1095                 if (newer_than) {
1096                         if (newer_off == (u64)-1)
1097                                 break;
1098
1099                         newer_off = max(newer_off + 1,
1100                                         (u64)i << PAGE_CACHE_SHIFT);
1101
1102                         ret = find_new_extents(root, inode,
1103                                                newer_than, &newer_off,
1104                                                64 * 1024);
1105                         if (!ret) {
1106                                 range->start = newer_off;
1107                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1108                                 newer_left = newer_cluster;
1109                         } else {
1110                                 break;
1111                         }
1112                 } else {
1113                         i++;
1114                 }
1115         }
1116
1117         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1118                 filemap_flush(inode->i_mapping);
1119
1120         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1121                 /* the filemap_flush will queue IO into the worker threads, but
1122                  * we have to make sure the IO is actually started and that
1123                  * ordered extents get created before we return
1124                  */
1125                 atomic_inc(&root->fs_info->async_submit_draining);
1126                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1127                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1128                         wait_event(root->fs_info->async_submit_wait,
1129                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1130                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1131                 }
1132                 atomic_dec(&root->fs_info->async_submit_draining);
1133
1134                 mutex_lock(&inode->i_mutex);
1135                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1136                 mutex_unlock(&inode->i_mutex);
1137         }
1138
1139         disk_super = &root->fs_info->super_copy;
1140         features = btrfs_super_incompat_flags(disk_super);
1141         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1142                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1143                 btrfs_set_super_incompat_flags(disk_super, features);
1144         }
1145
1146         if (!file)
1147                 kfree(ra);
1148         return defrag_count;
1149
1150 out_ra:
1151         if (!file)
1152                 kfree(ra);
1153         kfree(pages);
1154         return ret;
1155 }
1156
1157 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
1158                                         void __user *arg)
1159 {
1160         u64 new_size;
1161         u64 old_size;
1162         u64 devid = 1;
1163         struct btrfs_ioctl_vol_args *vol_args;
1164         struct btrfs_trans_handle *trans;
1165         struct btrfs_device *device = NULL;
1166         char *sizestr;
1167         char *devstr = NULL;
1168         int ret = 0;
1169         int mod = 0;
1170
1171         if (root->fs_info->sb->s_flags & MS_RDONLY)
1172                 return -EROFS;
1173
1174         if (!capable(CAP_SYS_ADMIN))
1175                 return -EPERM;
1176
1177         vol_args = memdup_user(arg, sizeof(*vol_args));
1178         if (IS_ERR(vol_args))
1179                 return PTR_ERR(vol_args);
1180
1181         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1182
1183         mutex_lock(&root->fs_info->volume_mutex);
1184         sizestr = vol_args->name;
1185         devstr = strchr(sizestr, ':');
1186         if (devstr) {
1187                 char *end;
1188                 sizestr = devstr + 1;
1189                 *devstr = '\0';
1190                 devstr = vol_args->name;
1191                 devid = simple_strtoull(devstr, &end, 10);
1192                 printk(KERN_INFO "resizing devid %llu\n",
1193                        (unsigned long long)devid);
1194         }
1195         device = btrfs_find_device(root, devid, NULL, NULL);
1196         if (!device) {
1197                 printk(KERN_INFO "resizer unable to find device %llu\n",
1198                        (unsigned long long)devid);
1199                 ret = -EINVAL;
1200                 goto out_unlock;
1201         }
1202         if (!strcmp(sizestr, "max"))
1203                 new_size = device->bdev->bd_inode->i_size;
1204         else {
1205                 if (sizestr[0] == '-') {
1206                         mod = -1;
1207                         sizestr++;
1208                 } else if (sizestr[0] == '+') {
1209                         mod = 1;
1210                         sizestr++;
1211                 }
1212                 new_size = memparse(sizestr, NULL);
1213                 if (new_size == 0) {
1214                         ret = -EINVAL;
1215                         goto out_unlock;
1216                 }
1217         }
1218
1219         old_size = device->total_bytes;
1220
1221         if (mod < 0) {
1222                 if (new_size > old_size) {
1223                         ret = -EINVAL;
1224                         goto out_unlock;
1225                 }
1226                 new_size = old_size - new_size;
1227         } else if (mod > 0) {
1228                 new_size = old_size + new_size;
1229         }
1230
1231         if (new_size < 256 * 1024 * 1024) {
1232                 ret = -EINVAL;
1233                 goto out_unlock;
1234         }
1235         if (new_size > device->bdev->bd_inode->i_size) {
1236                 ret = -EFBIG;
1237                 goto out_unlock;
1238         }
1239
1240         do_div(new_size, root->sectorsize);
1241         new_size *= root->sectorsize;
1242
1243         printk(KERN_INFO "new size for %s is %llu\n",
1244                 device->name, (unsigned long long)new_size);
1245
1246         if (new_size > old_size) {
1247                 trans = btrfs_start_transaction(root, 0);
1248                 if (IS_ERR(trans)) {
1249                         ret = PTR_ERR(trans);
1250                         goto out_unlock;
1251                 }
1252                 ret = btrfs_grow_device(trans, device, new_size);
1253                 btrfs_commit_transaction(trans, root);
1254         } else {
1255                 ret = btrfs_shrink_device(device, new_size);
1256         }
1257
1258 out_unlock:
1259         mutex_unlock(&root->fs_info->volume_mutex);
1260         kfree(vol_args);
1261         return ret;
1262 }
1263
1264 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1265                                                     char *name,
1266                                                     unsigned long fd,
1267                                                     int subvol,
1268                                                     u64 *transid,
1269                                                     bool readonly)
1270 {
1271         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1272         struct file *src_file;
1273         int namelen;
1274         int ret = 0;
1275
1276         if (root->fs_info->sb->s_flags & MS_RDONLY)
1277                 return -EROFS;
1278
1279         namelen = strlen(name);
1280         if (strchr(name, '/')) {
1281                 ret = -EINVAL;
1282                 goto out;
1283         }
1284
1285         if (subvol) {
1286                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1287                                      NULL, transid, readonly);
1288         } else {
1289                 struct inode *src_inode;
1290                 src_file = fget(fd);
1291                 if (!src_file) {
1292                         ret = -EINVAL;
1293                         goto out;
1294                 }
1295
1296                 src_inode = src_file->f_path.dentry->d_inode;
1297                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1298                         printk(KERN_INFO "btrfs: Snapshot src from "
1299                                "another FS\n");
1300                         ret = -EINVAL;
1301                         fput(src_file);
1302                         goto out;
1303                 }
1304                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1305                                      BTRFS_I(src_inode)->root,
1306                                      transid, readonly);
1307                 fput(src_file);
1308         }
1309 out:
1310         return ret;
1311 }
1312
1313 static noinline int btrfs_ioctl_snap_create(struct file *file,
1314                                             void __user *arg, int subvol)
1315 {
1316         struct btrfs_ioctl_vol_args *vol_args;
1317         int ret;
1318
1319         vol_args = memdup_user(arg, sizeof(*vol_args));
1320         if (IS_ERR(vol_args))
1321                 return PTR_ERR(vol_args);
1322         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1323
1324         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1325                                               vol_args->fd, subvol,
1326                                               NULL, false);
1327
1328         kfree(vol_args);
1329         return ret;
1330 }
1331
1332 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1333                                                void __user *arg, int subvol)
1334 {
1335         struct btrfs_ioctl_vol_args_v2 *vol_args;
1336         int ret;
1337         u64 transid = 0;
1338         u64 *ptr = NULL;
1339         bool readonly = false;
1340
1341         vol_args = memdup_user(arg, sizeof(*vol_args));
1342         if (IS_ERR(vol_args))
1343                 return PTR_ERR(vol_args);
1344         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1345
1346         if (vol_args->flags &
1347             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1348                 ret = -EOPNOTSUPP;
1349                 goto out;
1350         }
1351
1352         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1353                 ptr = &transid;
1354         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1355                 readonly = true;
1356
1357         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1358                                               vol_args->fd, subvol,
1359                                               ptr, readonly);
1360
1361         if (ret == 0 && ptr &&
1362             copy_to_user(arg +
1363                          offsetof(struct btrfs_ioctl_vol_args_v2,
1364                                   transid), ptr, sizeof(*ptr)))
1365                 ret = -EFAULT;
1366 out:
1367         kfree(vol_args);
1368         return ret;
1369 }
1370
1371 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1372                                                 void __user *arg)
1373 {
1374         struct inode *inode = fdentry(file)->d_inode;
1375         struct btrfs_root *root = BTRFS_I(inode)->root;
1376         int ret = 0;
1377         u64 flags = 0;
1378
1379         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1380                 return -EINVAL;
1381
1382         down_read(&root->fs_info->subvol_sem);
1383         if (btrfs_root_readonly(root))
1384                 flags |= BTRFS_SUBVOL_RDONLY;
1385         up_read(&root->fs_info->subvol_sem);
1386
1387         if (copy_to_user(arg, &flags, sizeof(flags)))
1388                 ret = -EFAULT;
1389
1390         return ret;
1391 }
1392
1393 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1394                                               void __user *arg)
1395 {
1396         struct inode *inode = fdentry(file)->d_inode;
1397         struct btrfs_root *root = BTRFS_I(inode)->root;
1398         struct btrfs_trans_handle *trans;
1399         u64 root_flags;
1400         u64 flags;
1401         int ret = 0;
1402
1403         if (root->fs_info->sb->s_flags & MS_RDONLY)
1404                 return -EROFS;
1405
1406         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1407                 return -EINVAL;
1408
1409         if (copy_from_user(&flags, arg, sizeof(flags)))
1410                 return -EFAULT;
1411
1412         if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
1413                 return -EINVAL;
1414
1415         if (flags & ~BTRFS_SUBVOL_RDONLY)
1416                 return -EOPNOTSUPP;
1417
1418         if (!inode_owner_or_capable(inode))
1419                 return -EACCES;
1420
1421         down_write(&root->fs_info->subvol_sem);
1422
1423         /* nothing to do */
1424         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1425                 goto out;
1426
1427         root_flags = btrfs_root_flags(&root->root_item);
1428         if (flags & BTRFS_SUBVOL_RDONLY)
1429                 btrfs_set_root_flags(&root->root_item,
1430                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1431         else
1432                 btrfs_set_root_flags(&root->root_item,
1433                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1434
1435         trans = btrfs_start_transaction(root, 1);
1436         if (IS_ERR(trans)) {
1437                 ret = PTR_ERR(trans);
1438                 goto out_reset;
1439         }
1440
1441         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1442                                 &root->root_key, &root->root_item);
1443
1444         btrfs_commit_transaction(trans, root);
1445 out_reset:
1446         if (ret)
1447                 btrfs_set_root_flags(&root->root_item, root_flags);
1448 out:
1449         up_write(&root->fs_info->subvol_sem);
1450         return ret;
1451 }
1452
1453 /*
1454  * helper to check if the subvolume references other subvolumes
1455  */
1456 static noinline int may_destroy_subvol(struct btrfs_root *root)
1457 {
1458         struct btrfs_path *path;
1459         struct btrfs_key key;
1460         int ret;
1461
1462         path = btrfs_alloc_path();
1463         if (!path)
1464                 return -ENOMEM;
1465
1466         key.objectid = root->root_key.objectid;
1467         key.type = BTRFS_ROOT_REF_KEY;
1468         key.offset = (u64)-1;
1469
1470         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1471                                 &key, path, 0, 0);
1472         if (ret < 0)
1473                 goto out;
1474         BUG_ON(ret == 0);
1475
1476         ret = 0;
1477         if (path->slots[0] > 0) {
1478                 path->slots[0]--;
1479                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1480                 if (key.objectid == root->root_key.objectid &&
1481                     key.type == BTRFS_ROOT_REF_KEY)
1482                         ret = -ENOTEMPTY;
1483         }
1484 out:
1485         btrfs_free_path(path);
1486         return ret;
1487 }
1488
1489 static noinline int key_in_sk(struct btrfs_key *key,
1490                               struct btrfs_ioctl_search_key *sk)
1491 {
1492         struct btrfs_key test;
1493         int ret;
1494
1495         test.objectid = sk->min_objectid;
1496         test.type = sk->min_type;
1497         test.offset = sk->min_offset;
1498
1499         ret = btrfs_comp_cpu_keys(key, &test);
1500         if (ret < 0)
1501                 return 0;
1502
1503         test.objectid = sk->max_objectid;
1504         test.type = sk->max_type;
1505         test.offset = sk->max_offset;
1506
1507         ret = btrfs_comp_cpu_keys(key, &test);
1508         if (ret > 0)
1509                 return 0;
1510         return 1;
1511 }
1512
1513 static noinline int copy_to_sk(struct btrfs_root *root,
1514                                struct btrfs_path *path,
1515                                struct btrfs_key *key,
1516                                struct btrfs_ioctl_search_key *sk,
1517                                char *buf,
1518                                unsigned long *sk_offset,
1519                                int *num_found)
1520 {
1521         u64 found_transid;
1522         struct extent_buffer *leaf;
1523         struct btrfs_ioctl_search_header sh;
1524         unsigned long item_off;
1525         unsigned long item_len;
1526         int nritems;
1527         int i;
1528         int slot;
1529         int ret = 0;
1530
1531         leaf = path->nodes[0];
1532         slot = path->slots[0];
1533         nritems = btrfs_header_nritems(leaf);
1534
1535         if (btrfs_header_generation(leaf) > sk->max_transid) {
1536                 i = nritems;
1537                 goto advance_key;
1538         }
1539         found_transid = btrfs_header_generation(leaf);
1540
1541         for (i = slot; i < nritems; i++) {
1542                 item_off = btrfs_item_ptr_offset(leaf, i);
1543                 item_len = btrfs_item_size_nr(leaf, i);
1544
1545                 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1546                         item_len = 0;
1547
1548                 if (sizeof(sh) + item_len + *sk_offset >
1549                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1550                         ret = 1;
1551                         goto overflow;
1552                 }
1553
1554                 btrfs_item_key_to_cpu(leaf, key, i);
1555                 if (!key_in_sk(key, sk))
1556                         continue;
1557
1558                 sh.objectid = key->objectid;
1559                 sh.offset = key->offset;
1560                 sh.type = key->type;
1561                 sh.len = item_len;
1562                 sh.transid = found_transid;
1563
1564                 /* copy search result header */
1565                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1566                 *sk_offset += sizeof(sh);
1567
1568                 if (item_len) {
1569                         char *p = buf + *sk_offset;
1570                         /* copy the item */
1571                         read_extent_buffer(leaf, p,
1572                                            item_off, item_len);
1573                         *sk_offset += item_len;
1574                 }
1575                 (*num_found)++;
1576
1577                 if (*num_found >= sk->nr_items)
1578                         break;
1579         }
1580 advance_key:
1581         ret = 0;
1582         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1583                 key->offset++;
1584         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1585                 key->offset = 0;
1586                 key->type++;
1587         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1588                 key->offset = 0;
1589                 key->type = 0;
1590                 key->objectid++;
1591         } else
1592                 ret = 1;
1593 overflow:
1594         return ret;
1595 }
1596
1597 static noinline int search_ioctl(struct inode *inode,
1598                                  struct btrfs_ioctl_search_args *args)
1599 {
1600         struct btrfs_root *root;
1601         struct btrfs_key key;
1602         struct btrfs_key max_key;
1603         struct btrfs_path *path;
1604         struct btrfs_ioctl_search_key *sk = &args->key;
1605         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1606         int ret;
1607         int num_found = 0;
1608         unsigned long sk_offset = 0;
1609
1610         path = btrfs_alloc_path();
1611         if (!path)
1612                 return -ENOMEM;
1613
1614         if (sk->tree_id == 0) {
1615                 /* search the root of the inode that was passed */
1616                 root = BTRFS_I(inode)->root;
1617         } else {
1618                 key.objectid = sk->tree_id;
1619                 key.type = BTRFS_ROOT_ITEM_KEY;
1620                 key.offset = (u64)-1;
1621                 root = btrfs_read_fs_root_no_name(info, &key);
1622                 if (IS_ERR(root)) {
1623                         printk(KERN_ERR "could not find root %llu\n",
1624                                sk->tree_id);
1625                         btrfs_free_path(path);
1626                         return -ENOENT;
1627                 }
1628         }
1629
1630         key.objectid = sk->min_objectid;
1631         key.type = sk->min_type;
1632         key.offset = sk->min_offset;
1633
1634         max_key.objectid = sk->max_objectid;
1635         max_key.type = sk->max_type;
1636         max_key.offset = sk->max_offset;
1637
1638         path->keep_locks = 1;
1639
1640         while(1) {
1641                 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1642                                            sk->min_transid);
1643                 if (ret != 0) {
1644                         if (ret > 0)
1645                                 ret = 0;
1646                         goto err;
1647                 }
1648                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1649                                  &sk_offset, &num_found);
1650                 btrfs_release_path(path);
1651                 if (ret || num_found >= sk->nr_items)
1652                         break;
1653
1654         }
1655         ret = 0;
1656 err:
1657         sk->nr_items = num_found;
1658         btrfs_free_path(path);
1659         return ret;
1660 }
1661
1662 static noinline int btrfs_ioctl_tree_search(struct file *file,
1663                                            void __user *argp)
1664 {
1665          struct btrfs_ioctl_search_args *args;
1666          struct inode *inode;
1667          int ret;
1668
1669         if (!capable(CAP_SYS_ADMIN))
1670                 return -EPERM;
1671
1672         args = memdup_user(argp, sizeof(*args));
1673         if (IS_ERR(args))
1674                 return PTR_ERR(args);
1675
1676         inode = fdentry(file)->d_inode;
1677         ret = search_ioctl(inode, args);
1678         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1679                 ret = -EFAULT;
1680         kfree(args);
1681         return ret;
1682 }
1683
1684 /*
1685  * Search INODE_REFs to identify path name of 'dirid' directory
1686  * in a 'tree_id' tree. and sets path name to 'name'.
1687  */
1688 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1689                                 u64 tree_id, u64 dirid, char *name)
1690 {
1691         struct btrfs_root *root;
1692         struct btrfs_key key;
1693         char *ptr;
1694         int ret = -1;
1695         int slot;
1696         int len;
1697         int total_len = 0;
1698         struct btrfs_inode_ref *iref;
1699         struct extent_buffer *l;
1700         struct btrfs_path *path;
1701
1702         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1703                 name[0]='\0';
1704                 return 0;
1705         }
1706
1707         path = btrfs_alloc_path();
1708         if (!path)
1709                 return -ENOMEM;
1710
1711         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1712
1713         key.objectid = tree_id;
1714         key.type = BTRFS_ROOT_ITEM_KEY;
1715         key.offset = (u64)-1;
1716         root = btrfs_read_fs_root_no_name(info, &key);
1717         if (IS_ERR(root)) {
1718                 printk(KERN_ERR "could not find root %llu\n", tree_id);
1719                 ret = -ENOENT;
1720                 goto out;
1721         }
1722
1723         key.objectid = dirid;
1724         key.type = BTRFS_INODE_REF_KEY;
1725         key.offset = (u64)-1;
1726
1727         while(1) {
1728                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1729                 if (ret < 0)
1730                         goto out;
1731
1732                 l = path->nodes[0];
1733                 slot = path->slots[0];
1734                 if (ret > 0 && slot > 0)
1735                         slot--;
1736                 btrfs_item_key_to_cpu(l, &key, slot);
1737
1738                 if (ret > 0 && (key.objectid != dirid ||
1739                                 key.type != BTRFS_INODE_REF_KEY)) {
1740                         ret = -ENOENT;
1741                         goto out;
1742                 }
1743
1744                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1745                 len = btrfs_inode_ref_name_len(l, iref);
1746                 ptr -= len + 1;
1747                 total_len += len + 1;
1748                 if (ptr < name)
1749                         goto out;
1750
1751                 *(ptr + len) = '/';
1752                 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1753
1754                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1755                         break;
1756
1757                 btrfs_release_path(path);
1758                 key.objectid = key.offset;
1759                 key.offset = (u64)-1;
1760                 dirid = key.objectid;
1761         }
1762         if (ptr < name)
1763                 goto out;
1764         memmove(name, ptr, total_len);
1765         name[total_len]='\0';
1766         ret = 0;
1767 out:
1768         btrfs_free_path(path);
1769         return ret;
1770 }
1771
1772 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1773                                            void __user *argp)
1774 {
1775          struct btrfs_ioctl_ino_lookup_args *args;
1776          struct inode *inode;
1777          int ret;
1778
1779         if (!capable(CAP_SYS_ADMIN))
1780                 return -EPERM;
1781
1782         args = memdup_user(argp, sizeof(*args));
1783         if (IS_ERR(args))
1784                 return PTR_ERR(args);
1785
1786         inode = fdentry(file)->d_inode;
1787
1788         if (args->treeid == 0)
1789                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1790
1791         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1792                                         args->treeid, args->objectid,
1793                                         args->name);
1794
1795         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1796                 ret = -EFAULT;
1797
1798         kfree(args);
1799         return ret;
1800 }
1801
1802 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1803                                              void __user *arg)
1804 {
1805         struct dentry *parent = fdentry(file);
1806         struct dentry *dentry;
1807         struct inode *dir = parent->d_inode;
1808         struct inode *inode;
1809         struct btrfs_root *root = BTRFS_I(dir)->root;
1810         struct btrfs_root *dest = NULL;
1811         struct btrfs_ioctl_vol_args *vol_args;
1812         struct btrfs_trans_handle *trans;
1813         int namelen;
1814         int ret;
1815         int err = 0;
1816
1817         vol_args = memdup_user(arg, sizeof(*vol_args));
1818         if (IS_ERR(vol_args))
1819                 return PTR_ERR(vol_args);
1820
1821         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1822         namelen = strlen(vol_args->name);
1823         if (strchr(vol_args->name, '/') ||
1824             strncmp(vol_args->name, "..", namelen) == 0) {
1825                 err = -EINVAL;
1826                 goto out;
1827         }
1828
1829         err = mnt_want_write(file->f_path.mnt);
1830         if (err)
1831                 goto out;
1832
1833         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1834         dentry = lookup_one_len(vol_args->name, parent, namelen);
1835         if (IS_ERR(dentry)) {
1836                 err = PTR_ERR(dentry);
1837                 goto out_unlock_dir;
1838         }
1839
1840         if (!dentry->d_inode) {
1841                 err = -ENOENT;
1842                 goto out_dput;
1843         }
1844
1845         inode = dentry->d_inode;
1846         dest = BTRFS_I(inode)->root;
1847         if (!capable(CAP_SYS_ADMIN)){
1848                 /*
1849                  * Regular user.  Only allow this with a special mount
1850                  * option, when the user has write+exec access to the
1851                  * subvol root, and when rmdir(2) would have been
1852                  * allowed.
1853                  *
1854                  * Note that this is _not_ check that the subvol is
1855                  * empty or doesn't contain data that we wouldn't
1856                  * otherwise be able to delete.
1857                  *
1858                  * Users who want to delete empty subvols should try
1859                  * rmdir(2).
1860                  */
1861                 err = -EPERM;
1862                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1863                         goto out_dput;
1864
1865                 /*
1866                  * Do not allow deletion if the parent dir is the same
1867                  * as the dir to be deleted.  That means the ioctl
1868                  * must be called on the dentry referencing the root
1869                  * of the subvol, not a random directory contained
1870                  * within it.
1871                  */
1872                 err = -EINVAL;
1873                 if (root == dest)
1874                         goto out_dput;
1875
1876                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1877                 if (err)
1878                         goto out_dput;
1879
1880                 /* check if subvolume may be deleted by a non-root user */
1881                 err = btrfs_may_delete(dir, dentry, 1);
1882                 if (err)
1883                         goto out_dput;
1884         }
1885
1886         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1887                 err = -EINVAL;
1888                 goto out_dput;
1889         }
1890
1891         mutex_lock(&inode->i_mutex);
1892         err = d_invalidate(dentry);
1893         if (err)
1894                 goto out_unlock;
1895
1896         down_write(&root->fs_info->subvol_sem);
1897
1898         err = may_destroy_subvol(dest);
1899         if (err)
1900                 goto out_up_write;
1901
1902         trans = btrfs_start_transaction(root, 0);
1903         if (IS_ERR(trans)) {
1904                 err = PTR_ERR(trans);
1905                 goto out_up_write;
1906         }
1907         trans->block_rsv = &root->fs_info->global_block_rsv;
1908
1909         ret = btrfs_unlink_subvol(trans, root, dir,
1910                                 dest->root_key.objectid,
1911                                 dentry->d_name.name,
1912                                 dentry->d_name.len);
1913         BUG_ON(ret);
1914
1915         btrfs_record_root_in_trans(trans, dest);
1916
1917         memset(&dest->root_item.drop_progress, 0,
1918                 sizeof(dest->root_item.drop_progress));
1919         dest->root_item.drop_level = 0;
1920         btrfs_set_root_refs(&dest->root_item, 0);
1921
1922         if (!xchg(&dest->orphan_item_inserted, 1)) {
1923                 ret = btrfs_insert_orphan_item(trans,
1924                                         root->fs_info->tree_root,
1925                                         dest->root_key.objectid);
1926                 BUG_ON(ret);
1927         }
1928
1929         ret = btrfs_end_transaction(trans, root);
1930         BUG_ON(ret);
1931         inode->i_flags |= S_DEAD;
1932 out_up_write:
1933         up_write(&root->fs_info->subvol_sem);
1934 out_unlock:
1935         mutex_unlock(&inode->i_mutex);
1936         if (!err) {
1937                 shrink_dcache_sb(root->fs_info->sb);
1938                 btrfs_invalidate_inodes(dest);
1939                 d_delete(dentry);
1940         }
1941 out_dput:
1942         dput(dentry);
1943 out_unlock_dir:
1944         mutex_unlock(&dir->i_mutex);
1945         mnt_drop_write(file->f_path.mnt);
1946 out:
1947         kfree(vol_args);
1948         return err;
1949 }
1950
1951 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1952 {
1953         struct inode *inode = fdentry(file)->d_inode;
1954         struct btrfs_root *root = BTRFS_I(inode)->root;
1955         struct btrfs_ioctl_defrag_range_args *range;
1956         int ret;
1957
1958         if (btrfs_root_readonly(root))
1959                 return -EROFS;
1960
1961         ret = mnt_want_write(file->f_path.mnt);
1962         if (ret)
1963                 return ret;
1964
1965         switch (inode->i_mode & S_IFMT) {
1966         case S_IFDIR:
1967                 if (!capable(CAP_SYS_ADMIN)) {
1968                         ret = -EPERM;
1969                         goto out;
1970                 }
1971                 ret = btrfs_defrag_root(root, 0);
1972                 if (ret)
1973                         goto out;
1974                 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
1975                 break;
1976         case S_IFREG:
1977                 if (!(file->f_mode & FMODE_WRITE)) {
1978                         ret = -EINVAL;
1979                         goto out;
1980                 }
1981
1982                 range = kzalloc(sizeof(*range), GFP_KERNEL);
1983                 if (!range) {
1984                         ret = -ENOMEM;
1985                         goto out;
1986                 }
1987
1988                 if (argp) {
1989                         if (copy_from_user(range, argp,
1990                                            sizeof(*range))) {
1991                                 ret = -EFAULT;
1992                                 kfree(range);
1993                                 goto out;
1994                         }
1995                         /* compression requires us to start the IO */
1996                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1997                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
1998                                 range->extent_thresh = (u32)-1;
1999                         }
2000                 } else {
2001                         /* the rest are all set to zero by kzalloc */
2002                         range->len = (u64)-1;
2003                 }
2004                 ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2005                                         range, 0, 0);
2006                 if (ret > 0)
2007                         ret = 0;
2008                 kfree(range);
2009                 break;
2010         default:
2011                 ret = -EINVAL;
2012         }
2013 out:
2014         mnt_drop_write(file->f_path.mnt);
2015         return ret;
2016 }
2017
2018 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2019 {
2020         struct btrfs_ioctl_vol_args *vol_args;
2021         int ret;
2022
2023         if (!capable(CAP_SYS_ADMIN))
2024                 return -EPERM;
2025
2026         vol_args = memdup_user(arg, sizeof(*vol_args));
2027         if (IS_ERR(vol_args))
2028                 return PTR_ERR(vol_args);
2029
2030         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2031         ret = btrfs_init_new_device(root, vol_args->name);
2032
2033         kfree(vol_args);
2034         return ret;
2035 }
2036
2037 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
2038 {
2039         struct btrfs_ioctl_vol_args *vol_args;
2040         int ret;
2041
2042         if (!capable(CAP_SYS_ADMIN))
2043                 return -EPERM;
2044
2045         if (root->fs_info->sb->s_flags & MS_RDONLY)
2046                 return -EROFS;
2047
2048         vol_args = memdup_user(arg, sizeof(*vol_args));
2049         if (IS_ERR(vol_args))
2050                 return PTR_ERR(vol_args);
2051
2052         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2053         ret = btrfs_rm_device(root, vol_args->name);
2054
2055         kfree(vol_args);
2056         return ret;
2057 }
2058
2059 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2060 {
2061         struct btrfs_ioctl_fs_info_args *fi_args;
2062         struct btrfs_device *device;
2063         struct btrfs_device *next;
2064         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2065         int ret = 0;
2066
2067         if (!capable(CAP_SYS_ADMIN))
2068                 return -EPERM;
2069
2070         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2071         if (!fi_args)
2072                 return -ENOMEM;
2073
2074         fi_args->num_devices = fs_devices->num_devices;
2075         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2076
2077         mutex_lock(&fs_devices->device_list_mutex);
2078         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2079                 if (device->devid > fi_args->max_id)
2080                         fi_args->max_id = device->devid;
2081         }
2082         mutex_unlock(&fs_devices->device_list_mutex);
2083
2084         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2085                 ret = -EFAULT;
2086
2087         kfree(fi_args);
2088         return ret;
2089 }
2090
2091 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2092 {
2093         struct btrfs_ioctl_dev_info_args *di_args;
2094         struct btrfs_device *dev;
2095         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2096         int ret = 0;
2097         char *s_uuid = NULL;
2098         char empty_uuid[BTRFS_UUID_SIZE] = {0};
2099
2100         if (!capable(CAP_SYS_ADMIN))
2101                 return -EPERM;
2102
2103         di_args = memdup_user(arg, sizeof(*di_args));
2104         if (IS_ERR(di_args))
2105                 return PTR_ERR(di_args);
2106
2107         if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2108                 s_uuid = di_args->uuid;
2109
2110         mutex_lock(&fs_devices->device_list_mutex);
2111         dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL);
2112         mutex_unlock(&fs_devices->device_list_mutex);
2113
2114         if (!dev) {
2115                 ret = -ENODEV;
2116                 goto out;
2117         }
2118
2119         di_args->devid = dev->devid;
2120         di_args->bytes_used = dev->bytes_used;
2121         di_args->total_bytes = dev->total_bytes;
2122         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2123         strncpy(di_args->path, dev->name, sizeof(di_args->path));
2124
2125 out:
2126         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2127                 ret = -EFAULT;
2128
2129         kfree(di_args);
2130         return ret;
2131 }
2132
2133 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2134                                        u64 off, u64 olen, u64 destoff)
2135 {
2136         struct inode *inode = fdentry(file)->d_inode;
2137         struct btrfs_root *root = BTRFS_I(inode)->root;
2138         struct file *src_file;
2139         struct inode *src;
2140         struct btrfs_trans_handle *trans;
2141         struct btrfs_path *path;
2142         struct extent_buffer *leaf;
2143         char *buf;
2144         struct btrfs_key key;
2145         u32 nritems;
2146         int slot;
2147         int ret;
2148         u64 len = olen;
2149         u64 bs = root->fs_info->sb->s_blocksize;
2150         u64 hint_byte;
2151
2152         /*
2153          * TODO:
2154          * - split compressed inline extents.  annoying: we need to
2155          *   decompress into destination's address_space (the file offset
2156          *   may change, so source mapping won't do), then recompress (or
2157          *   otherwise reinsert) a subrange.
2158          * - allow ranges within the same file to be cloned (provided
2159          *   they don't overlap)?
2160          */
2161
2162         /* the destination must be opened for writing */
2163         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2164                 return -EINVAL;
2165
2166         if (btrfs_root_readonly(root))
2167                 return -EROFS;
2168
2169         ret = mnt_want_write(file->f_path.mnt);
2170         if (ret)
2171                 return ret;
2172
2173         src_file = fget(srcfd);
2174         if (!src_file) {
2175                 ret = -EBADF;
2176                 goto out_drop_write;
2177         }
2178
2179         src = src_file->f_dentry->d_inode;
2180
2181         ret = -EINVAL;
2182         if (src == inode)
2183                 goto out_fput;
2184
2185         /* the src must be open for reading */
2186         if (!(src_file->f_mode & FMODE_READ))
2187                 goto out_fput;
2188
2189         /* don't make the dst file partly checksummed */
2190         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2191             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2192                 goto out_fput;
2193
2194         ret = -EISDIR;
2195         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2196                 goto out_fput;
2197
2198         ret = -EXDEV;
2199         if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
2200                 goto out_fput;
2201
2202         ret = -ENOMEM;
2203         buf = vmalloc(btrfs_level_size(root, 0));
2204         if (!buf)
2205                 goto out_fput;
2206
2207         path = btrfs_alloc_path();
2208         if (!path) {
2209                 vfree(buf);
2210                 goto out_fput;
2211         }
2212         path->reada = 2;
2213
2214         if (inode < src) {
2215                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2216                 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2217         } else {
2218                 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2219                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2220         }
2221
2222         /* determine range to clone */
2223         ret = -EINVAL;
2224         if (off + len > src->i_size || off + len < off)
2225                 goto out_unlock;
2226         if (len == 0)
2227                 olen = len = src->i_size - off;
2228         /* if we extend to eof, continue to block boundary */
2229         if (off + len == src->i_size)
2230                 len = ALIGN(src->i_size, bs) - off;
2231
2232         /* verify the end result is block aligned */
2233         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2234             !IS_ALIGNED(destoff, bs))
2235                 goto out_unlock;
2236
2237         if (destoff > inode->i_size) {
2238                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2239                 if (ret)
2240                         goto out_unlock;
2241         }
2242
2243         /* truncate page cache pages from target inode range */
2244         truncate_inode_pages_range(&inode->i_data, destoff,
2245                                    PAGE_CACHE_ALIGN(destoff + len) - 1);
2246
2247         /* do any pending delalloc/csum calc on src, one way or
2248            another, and lock file content */
2249         while (1) {
2250                 struct btrfs_ordered_extent *ordered;
2251                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2252                 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
2253                 if (!ordered &&
2254                     !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
2255                                    EXTENT_DELALLOC, 0, NULL))
2256                         break;
2257                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2258                 if (ordered)
2259                         btrfs_put_ordered_extent(ordered);
2260                 btrfs_wait_ordered_range(src, off, len);
2261         }
2262
2263         /* clone data */
2264         key.objectid = btrfs_ino(src);
2265         key.type = BTRFS_EXTENT_DATA_KEY;
2266         key.offset = 0;
2267
2268         while (1) {
2269                 /*
2270                  * note the key will change type as we walk through the
2271                  * tree.
2272                  */
2273                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2274                 if (ret < 0)
2275                         goto out;
2276
2277                 nritems = btrfs_header_nritems(path->nodes[0]);
2278                 if (path->slots[0] >= nritems) {
2279                         ret = btrfs_next_leaf(root, path);
2280                         if (ret < 0)
2281                                 goto out;
2282                         if (ret > 0)
2283                                 break;
2284                         nritems = btrfs_header_nritems(path->nodes[0]);
2285                 }
2286                 leaf = path->nodes[0];
2287                 slot = path->slots[0];
2288
2289                 btrfs_item_key_to_cpu(leaf, &key, slot);
2290                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2291                     key.objectid != btrfs_ino(src))
2292                         break;
2293
2294                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2295                         struct btrfs_file_extent_item *extent;
2296                         int type;
2297                         u32 size;
2298                         struct btrfs_key new_key;
2299                         u64 disko = 0, diskl = 0;
2300                         u64 datao = 0, datal = 0;
2301                         u8 comp;
2302                         u64 endoff;
2303
2304                         size = btrfs_item_size_nr(leaf, slot);
2305                         read_extent_buffer(leaf, buf,
2306                                            btrfs_item_ptr_offset(leaf, slot),
2307                                            size);
2308
2309                         extent = btrfs_item_ptr(leaf, slot,
2310                                                 struct btrfs_file_extent_item);
2311                         comp = btrfs_file_extent_compression(leaf, extent);
2312                         type = btrfs_file_extent_type(leaf, extent);
2313                         if (type == BTRFS_FILE_EXTENT_REG ||
2314                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2315                                 disko = btrfs_file_extent_disk_bytenr(leaf,
2316                                                                       extent);
2317                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2318                                                                  extent);
2319                                 datao = btrfs_file_extent_offset(leaf, extent);
2320                                 datal = btrfs_file_extent_num_bytes(leaf,
2321                                                                     extent);
2322                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2323                                 /* take upper bound, may be compressed */
2324                                 datal = btrfs_file_extent_ram_bytes(leaf,
2325                                                                     extent);
2326                         }
2327                         btrfs_release_path(path);
2328
2329                         if (key.offset + datal <= off ||
2330                             key.offset >= off+len)
2331                                 goto next;
2332
2333                         memcpy(&new_key, &key, sizeof(new_key));
2334                         new_key.objectid = btrfs_ino(inode);
2335                         if (off <= key.offset)
2336                                 new_key.offset = key.offset + destoff - off;
2337                         else
2338                                 new_key.offset = destoff;
2339
2340                         /*
2341                          * 1 - adjusting old extent (we may have to split it)
2342                          * 1 - add new extent
2343                          * 1 - inode update
2344                          */
2345                         trans = btrfs_start_transaction(root, 3);
2346                         if (IS_ERR(trans)) {
2347                                 ret = PTR_ERR(trans);
2348                                 goto out;
2349                         }
2350
2351                         if (type == BTRFS_FILE_EXTENT_REG ||
2352                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2353                                 /*
2354                                  *    a  | --- range to clone ---|  b
2355                                  * | ------------- extent ------------- |
2356                                  */
2357
2358                                 /* substract range b */
2359                                 if (key.offset + datal > off + len)
2360                                         datal = off + len - key.offset;
2361
2362                                 /* substract range a */
2363                                 if (off > key.offset) {
2364                                         datao += off - key.offset;
2365                                         datal -= off - key.offset;
2366                                 }
2367
2368                                 ret = btrfs_drop_extents(trans, inode,
2369                                                          new_key.offset,
2370                                                          new_key.offset + datal,
2371                                                          &hint_byte, 1);
2372                                 BUG_ON(ret);
2373
2374                                 ret = btrfs_insert_empty_item(trans, root, path,
2375                                                               &new_key, size);
2376                                 BUG_ON(ret);
2377
2378                                 leaf = path->nodes[0];
2379                                 slot = path->slots[0];
2380                                 write_extent_buffer(leaf, buf,
2381                                             btrfs_item_ptr_offset(leaf, slot),
2382                                             size);
2383
2384                                 extent = btrfs_item_ptr(leaf, slot,
2385                                                 struct btrfs_file_extent_item);
2386
2387                                 /* disko == 0 means it's a hole */
2388                                 if (!disko)
2389                                         datao = 0;
2390
2391                                 btrfs_set_file_extent_offset(leaf, extent,
2392                                                              datao);
2393                                 btrfs_set_file_extent_num_bytes(leaf, extent,
2394                                                                 datal);
2395                                 if (disko) {
2396                                         inode_add_bytes(inode, datal);
2397                                         ret = btrfs_inc_extent_ref(trans, root,
2398                                                         disko, diskl, 0,
2399                                                         root->root_key.objectid,
2400                                                         btrfs_ino(inode),
2401                                                         new_key.offset - datao);
2402                                         BUG_ON(ret);
2403                                 }
2404                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2405                                 u64 skip = 0;
2406                                 u64 trim = 0;
2407                                 if (off > key.offset) {
2408                                         skip = off - key.offset;
2409                                         new_key.offset += skip;
2410                                 }
2411
2412                                 if (key.offset + datal > off+len)
2413                                         trim = key.offset + datal - (off+len);
2414
2415                                 if (comp && (skip || trim)) {
2416                                         ret = -EINVAL;
2417                                         btrfs_end_transaction(trans, root);
2418                                         goto out;
2419                                 }
2420                                 size -= skip + trim;
2421                                 datal -= skip + trim;
2422
2423                                 ret = btrfs_drop_extents(trans, inode,
2424                                                          new_key.offset,
2425                                                          new_key.offset + datal,
2426                                                          &hint_byte, 1);
2427                                 BUG_ON(ret);
2428
2429                                 ret = btrfs_insert_empty_item(trans, root, path,
2430                                                               &new_key, size);
2431                                 BUG_ON(ret);
2432
2433                                 if (skip) {
2434                                         u32 start =
2435                                           btrfs_file_extent_calc_inline_size(0);
2436                                         memmove(buf+start, buf+start+skip,
2437                                                 datal);
2438                                 }
2439
2440                                 leaf = path->nodes[0];
2441                                 slot = path->slots[0];
2442                                 write_extent_buffer(leaf, buf,
2443                                             btrfs_item_ptr_offset(leaf, slot),
2444                                             size);
2445                                 inode_add_bytes(inode, datal);
2446                         }
2447
2448                         btrfs_mark_buffer_dirty(leaf);
2449                         btrfs_release_path(path);
2450
2451                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2452
2453                         /*
2454                          * we round up to the block size at eof when
2455                          * determining which extents to clone above,
2456                          * but shouldn't round up the file size
2457                          */
2458                         endoff = new_key.offset + datal;
2459                         if (endoff > destoff+olen)
2460                                 endoff = destoff+olen;
2461                         if (endoff > inode->i_size)
2462                                 btrfs_i_size_write(inode, endoff);
2463
2464                         ret = btrfs_update_inode(trans, root, inode);
2465                         BUG_ON(ret);
2466                         btrfs_end_transaction(trans, root);
2467                 }
2468 next:
2469                 btrfs_release_path(path);
2470                 key.offset++;
2471         }
2472         ret = 0;
2473 out:
2474         btrfs_release_path(path);
2475         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2476 out_unlock:
2477         mutex_unlock(&src->i_mutex);
2478         mutex_unlock(&inode->i_mutex);
2479         vfree(buf);
2480         btrfs_free_path(path);
2481 out_fput:
2482         fput(src_file);
2483 out_drop_write:
2484         mnt_drop_write(file->f_path.mnt);
2485         return ret;
2486 }
2487
2488 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2489 {
2490         struct btrfs_ioctl_clone_range_args args;
2491
2492         if (copy_from_user(&args, argp, sizeof(args)))
2493                 return -EFAULT;
2494         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2495                                  args.src_length, args.dest_offset);
2496 }
2497
2498 /*
2499  * there are many ways the trans_start and trans_end ioctls can lead
2500  * to deadlocks.  They should only be used by applications that
2501  * basically own the machine, and have a very in depth understanding
2502  * of all the possible deadlocks and enospc problems.
2503  */
2504 static long btrfs_ioctl_trans_start(struct file *file)
2505 {
2506         struct inode *inode = fdentry(file)->d_inode;
2507         struct btrfs_root *root = BTRFS_I(inode)->root;
2508         struct btrfs_trans_handle *trans;
2509         int ret;
2510
2511         ret = -EPERM;
2512         if (!capable(CAP_SYS_ADMIN))
2513                 goto out;
2514
2515         ret = -EINPROGRESS;
2516         if (file->private_data)
2517                 goto out;
2518
2519         ret = -EROFS;
2520         if (btrfs_root_readonly(root))
2521                 goto out;
2522
2523         ret = mnt_want_write(file->f_path.mnt);
2524         if (ret)
2525                 goto out;
2526
2527         atomic_inc(&root->fs_info->open_ioctl_trans);
2528
2529         ret = -ENOMEM;
2530         trans = btrfs_start_ioctl_transaction(root);
2531         if (IS_ERR(trans))
2532                 goto out_drop;
2533
2534         file->private_data = trans;
2535         return 0;
2536
2537 out_drop:
2538         atomic_dec(&root->fs_info->open_ioctl_trans);
2539         mnt_drop_write(file->f_path.mnt);
2540 out:
2541         return ret;
2542 }
2543
2544 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2545 {
2546         struct inode *inode = fdentry(file)->d_inode;
2547         struct btrfs_root *root = BTRFS_I(inode)->root;
2548         struct btrfs_root *new_root;
2549         struct btrfs_dir_item *di;
2550         struct btrfs_trans_handle *trans;
2551         struct btrfs_path *path;
2552         struct btrfs_key location;
2553         struct btrfs_disk_key disk_key;
2554         struct btrfs_super_block *disk_super;
2555         u64 features;
2556         u64 objectid = 0;
2557         u64 dir_id;
2558
2559         if (!capable(CAP_SYS_ADMIN))
2560                 return -EPERM;
2561
2562         if (copy_from_user(&objectid, argp, sizeof(objectid)))
2563                 return -EFAULT;
2564
2565         if (!objectid)
2566                 objectid = root->root_key.objectid;
2567
2568         location.objectid = objectid;
2569         location.type = BTRFS_ROOT_ITEM_KEY;
2570         location.offset = (u64)-1;
2571
2572         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2573         if (IS_ERR(new_root))
2574                 return PTR_ERR(new_root);
2575
2576         if (btrfs_root_refs(&new_root->root_item) == 0)
2577                 return -ENOENT;
2578
2579         path = btrfs_alloc_path();
2580         if (!path)
2581                 return -ENOMEM;
2582         path->leave_spinning = 1;
2583
2584         trans = btrfs_start_transaction(root, 1);
2585         if (IS_ERR(trans)) {
2586                 btrfs_free_path(path);
2587                 return PTR_ERR(trans);
2588         }
2589
2590         dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
2591         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2592                                    dir_id, "default", 7, 1);
2593         if (IS_ERR_OR_NULL(di)) {
2594                 btrfs_free_path(path);
2595                 btrfs_end_transaction(trans, root);
2596                 printk(KERN_ERR "Umm, you don't have the default dir item, "
2597                        "this isn't going to work\n");
2598                 return -ENOENT;
2599         }
2600
2601         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2602         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2603         btrfs_mark_buffer_dirty(path->nodes[0]);
2604         btrfs_free_path(path);
2605
2606         disk_super = &root->fs_info->super_copy;
2607         features = btrfs_super_incompat_flags(disk_super);
2608         if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2609                 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2610                 btrfs_set_super_incompat_flags(disk_super, features);
2611         }
2612         btrfs_end_transaction(trans, root);
2613
2614         return 0;
2615 }
2616
2617 static void get_block_group_info(struct list_head *groups_list,
2618                                  struct btrfs_ioctl_space_info *space)
2619 {
2620         struct btrfs_block_group_cache *block_group;
2621
2622         space->total_bytes = 0;
2623         space->used_bytes = 0;
2624         space->flags = 0;
2625         list_for_each_entry(block_group, groups_list, list) {
2626                 space->flags = block_group->flags;
2627                 space->total_bytes += block_group->key.offset;
2628                 space->used_bytes +=
2629                         btrfs_block_group_used(&block_group->item);
2630         }
2631 }
2632
2633 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2634 {
2635         struct btrfs_ioctl_space_args space_args;
2636         struct btrfs_ioctl_space_info space;
2637         struct btrfs_ioctl_space_info *dest;
2638         struct btrfs_ioctl_space_info *dest_orig;
2639         struct btrfs_ioctl_space_info __user *user_dest;
2640         struct btrfs_space_info *info;
2641         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2642                        BTRFS_BLOCK_GROUP_SYSTEM,
2643                        BTRFS_BLOCK_GROUP_METADATA,
2644                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2645         int num_types = 4;
2646         int alloc_size;
2647         int ret = 0;
2648         u64 slot_count = 0;
2649         int i, c;
2650
2651         if (copy_from_user(&space_args,
2652                            (struct btrfs_ioctl_space_args __user *)arg,
2653                            sizeof(space_args)))
2654                 return -EFAULT;
2655
2656         for (i = 0; i < num_types; i++) {
2657                 struct btrfs_space_info *tmp;
2658
2659                 info = NULL;
2660                 rcu_read_lock();
2661                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2662                                         list) {
2663                         if (tmp->flags == types[i]) {
2664                                 info = tmp;
2665                                 break;
2666                         }
2667                 }
2668                 rcu_read_unlock();
2669
2670                 if (!info)
2671                         continue;
2672
2673                 down_read(&info->groups_sem);
2674                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2675                         if (!list_empty(&info->block_groups[c]))
2676                                 slot_count++;
2677                 }
2678                 up_read(&info->groups_sem);
2679         }
2680
2681         /* space_slots == 0 means they are asking for a count */
2682         if (space_args.space_slots == 0) {
2683                 space_args.total_spaces = slot_count;
2684                 goto out;
2685         }
2686
2687         slot_count = min_t(u64, space_args.space_slots, slot_count);
2688
2689         alloc_size = sizeof(*dest) * slot_count;
2690
2691         /* we generally have at most 6 or so space infos, one for each raid
2692          * level.  So, a whole page should be more than enough for everyone
2693          */
2694         if (alloc_size > PAGE_CACHE_SIZE)
2695                 return -ENOMEM;
2696
2697         space_args.total_spaces = 0;
2698         dest = kmalloc(alloc_size, GFP_NOFS);
2699         if (!dest)
2700                 return -ENOMEM;
2701         dest_orig = dest;
2702
2703         /* now we have a buffer to copy into */
2704         for (i = 0; i < num_types; i++) {
2705                 struct btrfs_space_info *tmp;
2706
2707                 if (!slot_count)
2708                         break;
2709
2710                 info = NULL;
2711                 rcu_read_lock();
2712                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2713                                         list) {
2714                         if (tmp->flags == types[i]) {
2715                                 info = tmp;
2716                                 break;
2717                         }
2718                 }
2719                 rcu_read_unlock();
2720
2721                 if (!info)
2722                         continue;
2723                 down_read(&info->groups_sem);
2724                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2725                         if (!list_empty(&info->block_groups[c])) {
2726                                 get_block_group_info(&info->block_groups[c],
2727                                                      &space);
2728                                 memcpy(dest, &space, sizeof(space));
2729                                 dest++;
2730                                 space_args.total_spaces++;
2731                                 slot_count--;
2732                         }
2733                         if (!slot_count)
2734                                 break;
2735                 }
2736                 up_read(&info->groups_sem);
2737         }
2738
2739         user_dest = (struct btrfs_ioctl_space_info *)
2740                 (arg + sizeof(struct btrfs_ioctl_space_args));
2741
2742         if (copy_to_user(user_dest, dest_orig, alloc_size))
2743                 ret = -EFAULT;
2744
2745         kfree(dest_orig);
2746 out:
2747         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2748                 ret = -EFAULT;
2749
2750         return ret;
2751 }
2752
2753 /*
2754  * there are many ways the trans_start and trans_end ioctls can lead
2755  * to deadlocks.  They should only be used by applications that
2756  * basically own the machine, and have a very in depth understanding
2757  * of all the possible deadlocks and enospc problems.
2758  */
2759 long btrfs_ioctl_trans_end(struct file *file)
2760 {
2761         struct inode *inode = fdentry(file)->d_inode;
2762         struct btrfs_root *root = BTRFS_I(inode)->root;
2763         struct btrfs_trans_handle *trans;
2764
2765         trans = file->private_data;
2766         if (!trans)
2767                 return -EINVAL;
2768         file->private_data = NULL;
2769
2770         btrfs_end_transaction(trans, root);
2771
2772         atomic_dec(&root->fs_info->open_ioctl_trans);
2773
2774         mnt_drop_write(file->f_path.mnt);
2775         return 0;
2776 }
2777
2778 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2779 {
2780         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2781         struct btrfs_trans_handle *trans;
2782         u64 transid;
2783         int ret;
2784
2785         trans = btrfs_start_transaction(root, 0);
2786         if (IS_ERR(trans))
2787                 return PTR_ERR(trans);
2788         transid = trans->transid;
2789         ret = btrfs_commit_transaction_async(trans, root, 0);
2790         if (ret) {
2791                 btrfs_end_transaction(trans, root);
2792                 return ret;
2793         }
2794
2795         if (argp)
2796                 if (copy_to_user(argp, &transid, sizeof(transid)))
2797                         return -EFAULT;
2798         return 0;
2799 }
2800
2801 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2802 {
2803         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2804         u64 transid;
2805
2806         if (argp) {
2807                 if (copy_from_user(&transid, argp, sizeof(transid)))
2808                         return -EFAULT;
2809         } else {
2810                 transid = 0;  /* current trans */
2811         }
2812         return btrfs_wait_for_commit(root, transid);
2813 }
2814
2815 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg)
2816 {
2817         int ret;
2818         struct btrfs_ioctl_scrub_args *sa;
2819
2820         if (!capable(CAP_SYS_ADMIN))
2821                 return -EPERM;
2822
2823         sa = memdup_user(arg, sizeof(*sa));
2824         if (IS_ERR(sa))
2825                 return PTR_ERR(sa);
2826
2827         ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
2828                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
2829
2830         if (copy_to_user(arg, sa, sizeof(*sa)))
2831                 ret = -EFAULT;
2832
2833         kfree(sa);
2834         return ret;
2835 }
2836
2837 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
2838 {
2839         if (!capable(CAP_SYS_ADMIN))
2840                 return -EPERM;
2841
2842         return btrfs_scrub_cancel(root);
2843 }
2844
2845 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
2846                                        void __user *arg)
2847 {
2848         struct btrfs_ioctl_scrub_args *sa;
2849         int ret;
2850
2851         if (!capable(CAP_SYS_ADMIN))
2852                 return -EPERM;
2853
2854         sa = memdup_user(arg, sizeof(*sa));
2855         if (IS_ERR(sa))
2856                 return PTR_ERR(sa);
2857
2858         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
2859
2860         if (copy_to_user(arg, sa, sizeof(*sa)))
2861                 ret = -EFAULT;
2862
2863         kfree(sa);
2864         return ret;
2865 }
2866
2867 long btrfs_ioctl(struct file *file, unsigned int
2868                 cmd, unsigned long arg)
2869 {
2870         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2871         void __user *argp = (void __user *)arg;
2872
2873         switch (cmd) {
2874         case FS_IOC_GETFLAGS:
2875                 return btrfs_ioctl_getflags(file, argp);
2876         case FS_IOC_SETFLAGS:
2877                 return btrfs_ioctl_setflags(file, argp);
2878         case FS_IOC_GETVERSION:
2879                 return btrfs_ioctl_getversion(file, argp);
2880         case FITRIM:
2881                 return btrfs_ioctl_fitrim(file, argp);
2882         case BTRFS_IOC_SNAP_CREATE:
2883                 return btrfs_ioctl_snap_create(file, argp, 0);
2884         case BTRFS_IOC_SNAP_CREATE_V2:
2885                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
2886         case BTRFS_IOC_SUBVOL_CREATE:
2887                 return btrfs_ioctl_snap_create(file, argp, 1);
2888         case BTRFS_IOC_SNAP_DESTROY:
2889                 return btrfs_ioctl_snap_destroy(file, argp);
2890         case BTRFS_IOC_SUBVOL_GETFLAGS:
2891                 return btrfs_ioctl_subvol_getflags(file, argp);
2892         case BTRFS_IOC_SUBVOL_SETFLAGS:
2893                 return btrfs_ioctl_subvol_setflags(file, argp);
2894         case BTRFS_IOC_DEFAULT_SUBVOL:
2895                 return btrfs_ioctl_default_subvol(file, argp);
2896         case BTRFS_IOC_DEFRAG:
2897                 return btrfs_ioctl_defrag(file, NULL);
2898         case BTRFS_IOC_DEFRAG_RANGE:
2899                 return btrfs_ioctl_defrag(file, argp);
2900         case BTRFS_IOC_RESIZE:
2901                 return btrfs_ioctl_resize(root, argp);
2902         case BTRFS_IOC_ADD_DEV:
2903                 return btrfs_ioctl_add_dev(root, argp);
2904         case BTRFS_IOC_RM_DEV:
2905                 return btrfs_ioctl_rm_dev(root, argp);
2906         case BTRFS_IOC_FS_INFO:
2907                 return btrfs_ioctl_fs_info(root, argp);
2908         case BTRFS_IOC_DEV_INFO:
2909                 return btrfs_ioctl_dev_info(root, argp);
2910         case BTRFS_IOC_BALANCE:
2911                 return btrfs_balance(root->fs_info->dev_root);
2912         case BTRFS_IOC_CLONE:
2913                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
2914         case BTRFS_IOC_CLONE_RANGE:
2915                 return btrfs_ioctl_clone_range(file, argp);
2916         case BTRFS_IOC_TRANS_START:
2917                 return btrfs_ioctl_trans_start(file);
2918         case BTRFS_IOC_TRANS_END:
2919                 return btrfs_ioctl_trans_end(file);
2920         case BTRFS_IOC_TREE_SEARCH:
2921                 return btrfs_ioctl_tree_search(file, argp);
2922         case BTRFS_IOC_INO_LOOKUP:
2923                 return btrfs_ioctl_ino_lookup(file, argp);
2924         case BTRFS_IOC_SPACE_INFO:
2925                 return btrfs_ioctl_space_info(root, argp);
2926         case BTRFS_IOC_SYNC:
2927                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
2928                 return 0;
2929         case BTRFS_IOC_START_SYNC:
2930                 return btrfs_ioctl_start_sync(file, argp);
2931         case BTRFS_IOC_WAIT_SYNC:
2932                 return btrfs_ioctl_wait_sync(file, argp);
2933         case BTRFS_IOC_SCRUB:
2934                 return btrfs_ioctl_scrub(root, argp);
2935         case BTRFS_IOC_SCRUB_CANCEL:
2936                 return btrfs_ioctl_scrub_cancel(root, argp);
2937         case BTRFS_IOC_SCRUB_PROGRESS:
2938                 return btrfs_ioctl_scrub_progress(root, argp);
2939         }
2940
2941         return -ENOTTY;
2942 }