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 = grab_cache_page(inode->i_mapping,
 863                                             start_index + i);
 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                 atomic_inc(&BTRFS_I(inode)->outstanding_extents);
 934                 btrfs_delalloc_release_space(inode,
 935                                      (num_pages - i_done) << PAGE_CACHE_SHIFT);
 936         }
 937
 938
 939         btrfs_set_extent_delalloc(inode, page_start, page_end - 1,
 940                                   &cached_state);
 941
 942         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
 943                              page_start, page_end - 1, &cached_state,
 944                              GFP_NOFS);
 945
 946         for (i = 0; i < i_done; i++) {
 947                 clear_page_dirty_for_io(pages[i]);
 948                 ClearPageChecked(pages[i]);
 949                 set_page_extent_mapped(pages[i]);
 950                 set_page_dirty(pages[i]);
 951                 unlock_page(pages[i]);
 952                 page_cache_release(pages[i]);
 953         }
 954         return i_done;
 955 out:
 956         for (i = 0; i < i_done; i++) {
 957                 unlock_page(pages[i]);
 958                 page_cache_release(pages[i]);
 959         }
 960         btrfs_delalloc_release_space(inode, num_pages << PAGE_CACHE_SHIFT);
 961         return ret;
 962
 963 }
 964
 965 int btrfs_defrag_file(struct inode *inode, struct file *file,
 966                       struct btrfs_ioctl_defrag_range_args *range,
 967                       u64 newer_than, unsigned long max_to_defrag)
 968 {
 969         struct btrfs_root *root = BTRFS_I(inode)->root;
 970         struct btrfs_super_block *disk_super;
 971         struct file_ra_state *ra = NULL;
 972         unsigned long last_index;
 973         u64 features;
 974         u64 last_len = 0;
 975         u64 skip = 0;
 976         u64 defrag_end = 0;
 977         u64 newer_off = range->start;
 978         int newer_left = 0;
 979         unsigned long i;
 980         int ret;
 981         int defrag_count = 0;
 982         int compress_type = BTRFS_COMPRESS_ZLIB;
 983         int extent_thresh = range->extent_thresh;
 984         int newer_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
 985         u64 new_align = ~((u64)128 * 1024 - 1);
 986         struct page **pages = NULL;
 987
 988         if (extent_thresh == 0)
 989                 extent_thresh = 256 * 1024;
 990
 991         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
 992                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
 993                         return -EINVAL;
 994                 if (range->compress_type)
 995                         compress_type = range->compress_type;
 996         }
 997
 998         if (inode->i_size == 0)
 999                 return 0;
1000
1001         /*
1002          * if we were not given a file, allocate a readahead
1003          * context
1004          */
1005         if (!file) {
1006                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1007                 if (!ra)
1008                         return -ENOMEM;
1009                 file_ra_state_init(ra, inode->i_mapping);
1010         } else {
1011                 ra = &file->f_ra;
1012         }
1013
1014         pages = kmalloc(sizeof(struct page *) * newer_cluster,
1015                         GFP_NOFS);
1016         if (!pages) {
1017                 ret = -ENOMEM;
1018                 goto out_ra;
1019         }
1020
1021         /* find the last page to defrag */
1022         if (range->start + range->len > range->start) {
1023                 last_index = min_t(u64, inode->i_size - 1,
1024                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1025         } else {
1026                 last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
1027         }
1028
1029         if (newer_than) {
1030                 ret = find_new_extents(root, inode, newer_than,
1031                                        &newer_off, 64 * 1024);
1032                 if (!ret) {
1033                         range->start = newer_off;
1034                         /*
1035                          * we always align our defrag to help keep
1036                          * the extents in the file evenly spaced
1037                          */
1038                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1039                         newer_left = newer_cluster;
1040                 } else
1041                         goto out_ra;
1042         } else {
1043                 i = range->start >> PAGE_CACHE_SHIFT;
1044         }
1045         if (!max_to_defrag)
1046                 max_to_defrag = last_index - 1;
1047
1048         while (i <= last_index && defrag_count < max_to_defrag) {
1049                 /*
1050                  * make sure we stop running if someone unmounts
1051                  * the FS
1052                  */
1053                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1054                         break;
1055
1056                 if (!newer_than &&
1057                     !should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1058                                         PAGE_CACHE_SIZE,
1059                                         extent_thresh,
1060                                         &last_len, &skip,
1061                                         &defrag_end)) {
1062                         unsigned long next;
1063                         /*
1064                          * the should_defrag function tells us how much to skip
1065                          * bump our counter by the suggested amount
1066                          */
1067                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1068                         i = max(i + 1, next);
1069                         continue;
1070                 }
1071                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1072                         BTRFS_I(inode)->force_compress = compress_type;
1073
1074                 btrfs_force_ra(inode->i_mapping, ra, file, i, newer_cluster);
1075
1076                 ret = cluster_pages_for_defrag(inode, pages, i, newer_cluster);
1077                 if (ret < 0)
1078                         goto out_ra;
1079
1080                 defrag_count += ret;
1081                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret);
1082                 i += ret;
1083
1084                 if (newer_than) {
1085                         if (newer_off == (u64)-1)
1086                                 break;
1087
1088                         newer_off = max(newer_off + 1,
1089                                         (u64)i << PAGE_CACHE_SHIFT);
1090
1091                         ret = find_new_extents(root, inode,
1092                                                newer_than, &newer_off,
1093                                                64 * 1024);
1094                         if (!ret) {
1095                                 range->start = newer_off;
1096                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1097                                 newer_left = newer_cluster;
1098                         } else {
1099                                 break;
1100                         }
1101                 } else {
1102                         i++;
1103                 }
1104         }
1105
1106         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1107                 filemap_flush(inode->i_mapping);
1108
1109         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1110                 /* the filemap_flush will queue IO into the worker threads, but
1111                  * we have to make sure the IO is actually started and that
1112                  * ordered extents get created before we return
1113                  */
1114                 atomic_inc(&root->fs_info->async_submit_draining);
1115                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1116                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1117                         wait_event(root->fs_info->async_submit_wait,
1118                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1119                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1120                 }
1121                 atomic_dec(&root->fs_info->async_submit_draining);
1122
1123                 mutex_lock(&inode->i_mutex);
1124                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1125                 mutex_unlock(&inode->i_mutex);
1126         }
1127
1128         disk_super = &root->fs_info->super_copy;
1129         features = btrfs_super_incompat_flags(disk_super);
1130         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1131                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
1132                 btrfs_set_super_incompat_flags(disk_super, features);
1133         }
1134
1135         if (!file)
1136                 kfree(ra);
1137         return defrag_count;
1138
1139 out_ra:
1140         if (!file)
1141                 kfree(ra);
1142         kfree(pages);
1143         return ret;
1144 }
1145
1146 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
1147                                         void __user *arg)
1148 {
1149         u64 new_size;
1150         u64 old_size;
1151         u64 devid = 1;
1152         struct btrfs_ioctl_vol_args *vol_args;
1153         struct btrfs_trans_handle *trans;
1154         struct btrfs_device *device = NULL;
1155         char *sizestr;
1156         char *devstr = NULL;
1157         int ret = 0;
1158         int mod = 0;
1159
1160         if (root->fs_info->sb->s_flags & MS_RDONLY)
1161                 return -EROFS;
1162
1163         if (!capable(CAP_SYS_ADMIN))
1164                 return -EPERM;
1165
1166         vol_args = memdup_user(arg, sizeof(*vol_args));
1167         if (IS_ERR(vol_args))
1168                 return PTR_ERR(vol_args);
1169
1170         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1171
1172         mutex_lock(&root->fs_info->volume_mutex);
1173         sizestr = vol_args->name;
1174         devstr = strchr(sizestr, ':');
1175         if (devstr) {
1176                 char *end;
1177                 sizestr = devstr + 1;
1178                 *devstr = '\0';
1179                 devstr = vol_args->name;
1180                 devid = simple_strtoull(devstr, &end, 10);
1181                 printk(KERN_INFO "resizing devid %llu\n",
1182                        (unsigned long long)devid);
1183         }
1184         device = btrfs_find_device(root, devid, NULL, NULL);
1185         if (!device) {
1186                 printk(KERN_INFO "resizer unable to find device %llu\n",
1187                        (unsigned long long)devid);
1188                 ret = -EINVAL;
1189                 goto out_unlock;
1190         }
1191         if (!strcmp(sizestr, "max"))
1192                 new_size = device->bdev->bd_inode->i_size;
1193         else {
1194                 if (sizestr[0] == '-') {
1195                         mod = -1;
1196                         sizestr++;
1197                 } else if (sizestr[0] == '+') {
1198                         mod = 1;
1199                         sizestr++;
1200                 }
1201                 new_size = memparse(sizestr, NULL);
1202                 if (new_size == 0) {
1203                         ret = -EINVAL;
1204                         goto out_unlock;
1205                 }
1206         }
1207
1208         old_size = device->total_bytes;
1209
1210         if (mod < 0) {
1211                 if (new_size > old_size) {
1212                         ret = -EINVAL;
1213                         goto out_unlock;
1214                 }
1215                 new_size = old_size - new_size;
1216         } else if (mod > 0) {
1217                 new_size = old_size + new_size;
1218         }
1219
1220         if (new_size < 256 * 1024 * 1024) {
1221                 ret = -EINVAL;
1222                 goto out_unlock;
1223         }
1224         if (new_size > device->bdev->bd_inode->i_size) {
1225                 ret = -EFBIG;
1226                 goto out_unlock;
1227         }
1228
1229         do_div(new_size, root->sectorsize);
1230         new_size *= root->sectorsize;
1231
1232         printk(KERN_INFO "new size for %s is %llu\n",
1233                 device->name, (unsigned long long)new_size);
1234
1235         if (new_size > old_size) {
1236                 trans = btrfs_start_transaction(root, 0);
1237                 if (IS_ERR(trans)) {
1238                         ret = PTR_ERR(trans);
1239                         goto out_unlock;
1240                 }
1241                 ret = btrfs_grow_device(trans, device, new_size);
1242                 btrfs_commit_transaction(trans, root);
1243         } else {
1244                 ret = btrfs_shrink_device(device, new_size);
1245         }
1246
1247 out_unlock:
1248         mutex_unlock(&root->fs_info->volume_mutex);
1249         kfree(vol_args);
1250         return ret;
1251 }
1252
1253 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1254                                                     char *name,
1255                                                     unsigned long fd,
1256                                                     int subvol,
1257                                                     u64 *transid,
1258                                                     bool readonly)
1259 {
1260         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1261         struct file *src_file;
1262         int namelen;
1263         int ret = 0;
1264
1265         if (root->fs_info->sb->s_flags & MS_RDONLY)
1266                 return -EROFS;
1267
1268         namelen = strlen(name);
1269         if (strchr(name, '/')) {
1270                 ret = -EINVAL;
1271                 goto out;
1272         }
1273
1274         if (subvol) {
1275                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1276                                      NULL, transid, readonly);
1277         } else {
1278                 struct inode *src_inode;
1279                 src_file = fget(fd);
1280                 if (!src_file) {
1281                         ret = -EINVAL;
1282                         goto out;
1283                 }
1284
1285                 src_inode = src_file->f_path.dentry->d_inode;
1286                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1287                         printk(KERN_INFO "btrfs: Snapshot src from "
1288                                "another FS\n");
1289                         ret = -EINVAL;
1290                         fput(src_file);
1291                         goto out;
1292                 }
1293                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1294                                      BTRFS_I(src_inode)->root,
1295                                      transid, readonly);
1296                 fput(src_file);
1297         }
1298 out:
1299         return ret;
1300 }
1301
1302 static noinline int btrfs_ioctl_snap_create(struct file *file,
1303                                             void __user *arg, int subvol)
1304 {
1305         struct btrfs_ioctl_vol_args *vol_args;
1306         int ret;
1307
1308         vol_args = memdup_user(arg, sizeof(*vol_args));
1309         if (IS_ERR(vol_args))
1310                 return PTR_ERR(vol_args);
1311         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1312
1313         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1314                                               vol_args->fd, subvol,
1315                                               NULL, false);
1316
1317         kfree(vol_args);
1318         return ret;
1319 }
1320
1321 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1322                                                void __user *arg, int subvol)
1323 {
1324         struct btrfs_ioctl_vol_args_v2 *vol_args;
1325         int ret;
1326         u64 transid = 0;
1327         u64 *ptr = NULL;
1328         bool readonly = false;
1329
1330         vol_args = memdup_user(arg, sizeof(*vol_args));
1331         if (IS_ERR(vol_args))
1332                 return PTR_ERR(vol_args);
1333         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1334
1335         if (vol_args->flags &
1336             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1337                 ret = -EOPNOTSUPP;
1338                 goto out;
1339         }
1340
1341         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1342                 ptr = &transid;
1343         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1344                 readonly = true;
1345
1346         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1347                                               vol_args->fd, subvol,
1348                                               ptr, readonly);
1349
1350         if (ret == 0 && ptr &&
1351             copy_to_user(arg +
1352                          offsetof(struct btrfs_ioctl_vol_args_v2,
1353                                   transid), ptr, sizeof(*ptr)))
1354                 ret = -EFAULT;
1355 out:
1356         kfree(vol_args);
1357         return ret;
1358 }
1359
1360 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1361                                                 void __user *arg)
1362 {
1363         struct inode *inode = fdentry(file)->d_inode;
1364         struct btrfs_root *root = BTRFS_I(inode)->root;
1365         int ret = 0;
1366         u64 flags = 0;
1367
1368         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1369                 return -EINVAL;
1370
1371         down_read(&root->fs_info->subvol_sem);
1372         if (btrfs_root_readonly(root))
1373                 flags |= BTRFS_SUBVOL_RDONLY;
1374         up_read(&root->fs_info->subvol_sem);
1375
1376         if (copy_to_user(arg, &flags, sizeof(flags)))
1377                 ret = -EFAULT;
1378
1379         return ret;
1380 }
1381
1382 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1383                                               void __user *arg)
1384 {
1385         struct inode *inode = fdentry(file)->d_inode;
1386         struct btrfs_root *root = BTRFS_I(inode)->root;
1387         struct btrfs_trans_handle *trans;
1388         u64 root_flags;
1389         u64 flags;
1390         int ret = 0;
1391
1392         if (root->fs_info->sb->s_flags & MS_RDONLY)
1393                 return -EROFS;
1394
1395         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1396                 return -EINVAL;
1397
1398         if (copy_from_user(&flags, arg, sizeof(flags)))
1399                 return -EFAULT;
1400
1401         if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
1402                 return -EINVAL;
1403
1404         if (flags & ~BTRFS_SUBVOL_RDONLY)
1405                 return -EOPNOTSUPP;
1406
1407         if (!inode_owner_or_capable(inode))
1408                 return -EACCES;
1409
1410         down_write(&root->fs_info->subvol_sem);
1411
1412         /* nothing to do */
1413         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1414                 goto out;
1415
1416         root_flags = btrfs_root_flags(&root->root_item);
1417         if (flags & BTRFS_SUBVOL_RDONLY)
1418                 btrfs_set_root_flags(&root->root_item,
1419                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1420         else
1421                 btrfs_set_root_flags(&root->root_item,
1422                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1423
1424         trans = btrfs_start_transaction(root, 1);
1425         if (IS_ERR(trans)) {
1426                 ret = PTR_ERR(trans);
1427                 goto out_reset;
1428         }
1429
1430         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1431                                 &root->root_key, &root->root_item);
1432
1433         btrfs_commit_transaction(trans, root);
1434 out_reset:
1435         if (ret)
1436                 btrfs_set_root_flags(&root->root_item, root_flags);
1437 out:
1438         up_write(&root->fs_info->subvol_sem);
1439         return ret;
1440 }
1441
1442 /*
1443  * helper to check if the subvolume references other subvolumes
1444  */
1445 static noinline int may_destroy_subvol(struct btrfs_root *root)
1446 {
1447         struct btrfs_path *path;
1448         struct btrfs_key key;
1449         int ret;
1450
1451         path = btrfs_alloc_path();
1452         if (!path)
1453                 return -ENOMEM;
1454
1455         key.objectid = root->root_key.objectid;
1456         key.type = BTRFS_ROOT_REF_KEY;
1457         key.offset = (u64)-1;
1458
1459         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1460                                 &key, path, 0, 0);
1461         if (ret < 0)
1462                 goto out;
1463         BUG_ON(ret == 0);
1464
1465         ret = 0;
1466         if (path->slots[0] > 0) {
1467                 path->slots[0]--;
1468                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1469                 if (key.objectid == root->root_key.objectid &&
1470                     key.type == BTRFS_ROOT_REF_KEY)
1471                         ret = -ENOTEMPTY;
1472         }
1473 out:
1474         btrfs_free_path(path);
1475         return ret;
1476 }
1477
1478 static noinline int key_in_sk(struct btrfs_key *key,
1479                               struct btrfs_ioctl_search_key *sk)
1480 {
1481         struct btrfs_key test;
1482         int ret;
1483
1484         test.objectid = sk->min_objectid;
1485         test.type = sk->min_type;
1486         test.offset = sk->min_offset;
1487
1488         ret = btrfs_comp_cpu_keys(key, &test);
1489         if (ret < 0)
1490                 return 0;
1491
1492         test.objectid = sk->max_objectid;
1493         test.type = sk->max_type;
1494         test.offset = sk->max_offset;
1495
1496         ret = btrfs_comp_cpu_keys(key, &test);
1497         if (ret > 0)
1498                 return 0;
1499         return 1;
1500 }
1501
1502 static noinline int copy_to_sk(struct btrfs_root *root,
1503                                struct btrfs_path *path,
1504                                struct btrfs_key *key,
1505                                struct btrfs_ioctl_search_key *sk,
1506                                char *buf,
1507                                unsigned long *sk_offset,
1508                                int *num_found)
1509 {
1510         u64 found_transid;
1511         struct extent_buffer *leaf;
1512         struct btrfs_ioctl_search_header sh;
1513         unsigned long item_off;
1514         unsigned long item_len;
1515         int nritems;
1516         int i;
1517         int slot;
1518         int ret = 0;
1519
1520         leaf = path->nodes[0];
1521         slot = path->slots[0];
1522         nritems = btrfs_header_nritems(leaf);
1523
1524         if (btrfs_header_generation(leaf) > sk->max_transid) {
1525                 i = nritems;
1526                 goto advance_key;
1527         }
1528         found_transid = btrfs_header_generation(leaf);
1529
1530         for (i = slot; i < nritems; i++) {
1531                 item_off = btrfs_item_ptr_offset(leaf, i);
1532                 item_len = btrfs_item_size_nr(leaf, i);
1533
1534                 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1535                         item_len = 0;
1536
1537                 if (sizeof(sh) + item_len + *sk_offset >
1538                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1539                         ret = 1;
1540                         goto overflow;
1541                 }
1542
1543                 btrfs_item_key_to_cpu(leaf, key, i);
1544                 if (!key_in_sk(key, sk))
1545                         continue;
1546
1547                 sh.objectid = key->objectid;
1548                 sh.offset = key->offset;
1549                 sh.type = key->type;
1550                 sh.len = item_len;
1551                 sh.transid = found_transid;
1552
1553                 /* copy search result header */
1554                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1555                 *sk_offset += sizeof(sh);
1556
1557                 if (item_len) {
1558                         char *p = buf + *sk_offset;
1559                         /* copy the item */
1560                         read_extent_buffer(leaf, p,
1561                                            item_off, item_len);
1562                         *sk_offset += item_len;
1563                 }
1564                 (*num_found)++;
1565
1566                 if (*num_found >= sk->nr_items)
1567                         break;
1568         }
1569 advance_key:
1570         ret = 0;
1571         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1572                 key->offset++;
1573         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1574                 key->offset = 0;
1575                 key->type++;
1576         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1577                 key->offset = 0;
1578                 key->type = 0;
1579                 key->objectid++;
1580         } else
1581                 ret = 1;
1582 overflow:
1583         return ret;
1584 }
1585
1586 static noinline int search_ioctl(struct inode *inode,
1587                                  struct btrfs_ioctl_search_args *args)
1588 {
1589         struct btrfs_root *root;
1590         struct btrfs_key key;
1591         struct btrfs_key max_key;
1592         struct btrfs_path *path;
1593         struct btrfs_ioctl_search_key *sk = &args->key;
1594         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1595         int ret;
1596         int num_found = 0;
1597         unsigned long sk_offset = 0;
1598
1599         path = btrfs_alloc_path();
1600         if (!path)
1601                 return -ENOMEM;
1602
1603         if (sk->tree_id == 0) {
1604                 /* search the root of the inode that was passed */
1605                 root = BTRFS_I(inode)->root;
1606         } else {
1607                 key.objectid = sk->tree_id;
1608                 key.type = BTRFS_ROOT_ITEM_KEY;
1609                 key.offset = (u64)-1;
1610                 root = btrfs_read_fs_root_no_name(info, &key);
1611                 if (IS_ERR(root)) {
1612                         printk(KERN_ERR "could not find root %llu\n",
1613                                sk->tree_id);
1614                         btrfs_free_path(path);
1615                         return -ENOENT;
1616                 }
1617         }
1618
1619         key.objectid = sk->min_objectid;
1620         key.type = sk->min_type;
1621         key.offset = sk->min_offset;
1622
1623         max_key.objectid = sk->max_objectid;
1624         max_key.type = sk->max_type;
1625         max_key.offset = sk->max_offset;
1626
1627         path->keep_locks = 1;
1628
1629         while(1) {
1630                 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1631                                            sk->min_transid);
1632                 if (ret != 0) {
1633                         if (ret > 0)
1634                                 ret = 0;
1635                         goto err;
1636                 }
1637                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1638                                  &sk_offset, &num_found);
1639                 btrfs_release_path(path);
1640                 if (ret || num_found >= sk->nr_items)
1641                         break;
1642
1643         }
1644         ret = 0;
1645 err:
1646         sk->nr_items = num_found;
1647         btrfs_free_path(path);
1648         return ret;
1649 }
1650
1651 static noinline int btrfs_ioctl_tree_search(struct file *file,
1652                                            void __user *argp)
1653 {
1654          struct btrfs_ioctl_search_args *args;
1655          struct inode *inode;
1656          int ret;
1657
1658         if (!capable(CAP_SYS_ADMIN))
1659                 return -EPERM;
1660
1661         args = memdup_user(argp, sizeof(*args));
1662         if (IS_ERR(args))
1663                 return PTR_ERR(args);
1664
1665         inode = fdentry(file)->d_inode;
1666         ret = search_ioctl(inode, args);
1667         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1668                 ret = -EFAULT;
1669         kfree(args);
1670         return ret;
1671 }
1672
1673 /*
1674  * Search INODE_REFs to identify path name of 'dirid' directory
1675  * in a 'tree_id' tree. and sets path name to 'name'.
1676  */
1677 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1678                                 u64 tree_id, u64 dirid, char *name)
1679 {
1680         struct btrfs_root *root;
1681         struct btrfs_key key;
1682         char *ptr;
1683         int ret = -1;
1684         int slot;
1685         int len;
1686         int total_len = 0;
1687         struct btrfs_inode_ref *iref;
1688         struct extent_buffer *l;
1689         struct btrfs_path *path;
1690
1691         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1692                 name[0]='\0';
1693                 return 0;
1694         }
1695
1696         path = btrfs_alloc_path();
1697         if (!path)
1698                 return -ENOMEM;
1699
1700         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1701
1702         key.objectid = tree_id;
1703         key.type = BTRFS_ROOT_ITEM_KEY;
1704         key.offset = (u64)-1;
1705         root = btrfs_read_fs_root_no_name(info, &key);
1706         if (IS_ERR(root)) {
1707                 printk(KERN_ERR "could not find root %llu\n", tree_id);
1708                 ret = -ENOENT;
1709                 goto out;
1710         }
1711
1712         key.objectid = dirid;
1713         key.type = BTRFS_INODE_REF_KEY;
1714         key.offset = (u64)-1;
1715
1716         while(1) {
1717                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1718                 if (ret < 0)
1719                         goto out;
1720
1721                 l = path->nodes[0];
1722                 slot = path->slots[0];
1723                 if (ret > 0 && slot > 0)
1724                         slot--;
1725                 btrfs_item_key_to_cpu(l, &key, slot);
1726
1727                 if (ret > 0 && (key.objectid != dirid ||
1728                                 key.type != BTRFS_INODE_REF_KEY)) {
1729                         ret = -ENOENT;
1730                         goto out;
1731                 }
1732
1733                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1734                 len = btrfs_inode_ref_name_len(l, iref);
1735                 ptr -= len + 1;
1736                 total_len += len + 1;
1737                 if (ptr < name)
1738                         goto out;
1739
1740                 *(ptr + len) = '/';
1741                 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1742
1743                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1744                         break;
1745
1746                 btrfs_release_path(path);
1747                 key.objectid = key.offset;
1748                 key.offset = (u64)-1;
1749                 dirid = key.objectid;
1750
1751         }
1752         if (ptr < name)
1753                 goto out;
1754         memcpy(name, ptr, total_len);
1755         name[total_len]='\0';
1756         ret = 0;
1757 out:
1758         btrfs_free_path(path);
1759         return ret;
1760 }
1761
1762 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1763                                            void __user *argp)
1764 {
1765          struct btrfs_ioctl_ino_lookup_args *args;
1766          struct inode *inode;
1767          int ret;
1768
1769         if (!capable(CAP_SYS_ADMIN))
1770                 return -EPERM;
1771
1772         args = memdup_user(argp, sizeof(*args));
1773         if (IS_ERR(args))
1774                 return PTR_ERR(args);
1775
1776         inode = fdentry(file)->d_inode;
1777
1778         if (args->treeid == 0)
1779                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1780
1781         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1782                                         args->treeid, args->objectid,
1783                                         args->name);
1784
1785         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1786                 ret = -EFAULT;
1787
1788         kfree(args);
1789         return ret;
1790 }
1791
1792 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1793                                              void __user *arg)
1794 {
1795         struct dentry *parent = fdentry(file);
1796         struct dentry *dentry;
1797         struct inode *dir = parent->d_inode;
1798         struct inode *inode;
1799         struct btrfs_root *root = BTRFS_I(dir)->root;
1800         struct btrfs_root *dest = NULL;
1801         struct btrfs_ioctl_vol_args *vol_args;
1802         struct btrfs_trans_handle *trans;
1803         int namelen;
1804         int ret;
1805         int err = 0;
1806
1807         vol_args = memdup_user(arg, sizeof(*vol_args));
1808         if (IS_ERR(vol_args))
1809                 return PTR_ERR(vol_args);
1810
1811         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1812         namelen = strlen(vol_args->name);
1813         if (strchr(vol_args->name, '/') ||
1814             strncmp(vol_args->name, "..", namelen) == 0) {
1815                 err = -EINVAL;
1816                 goto out;
1817         }
1818
1819         err = mnt_want_write(file->f_path.mnt);
1820         if (err)
1821                 goto out;
1822
1823         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1824         dentry = lookup_one_len(vol_args->name, parent, namelen);
1825         if (IS_ERR(dentry)) {
1826                 err = PTR_ERR(dentry);
1827                 goto out_unlock_dir;
1828         }
1829
1830         if (!dentry->d_inode) {
1831                 err = -ENOENT;
1832                 goto out_dput;
1833         }
1834
1835         inode = dentry->d_inode;
1836         dest = BTRFS_I(inode)->root;
1837         if (!capable(CAP_SYS_ADMIN)){
1838                 /*
1839                  * Regular user.  Only allow this with a special mount
1840                  * option, when the user has write+exec access to the
1841                  * subvol root, and when rmdir(2) would have been
1842                  * allowed.
1843                  *
1844                  * Note that this is _not_ check that the subvol is
1845                  * empty or doesn't contain data that we wouldn't
1846                  * otherwise be able to delete.
1847                  *
1848                  * Users who want to delete empty subvols should try
1849                  * rmdir(2).
1850                  */
1851                 err = -EPERM;
1852                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1853                         goto out_dput;
1854
1855                 /*
1856                  * Do not allow deletion if the parent dir is the same
1857                  * as the dir to be deleted.  That means the ioctl
1858                  * must be called on the dentry referencing the root
1859                  * of the subvol, not a random directory contained
1860                  * within it.
1861                  */
1862                 err = -EINVAL;
1863                 if (root == dest)
1864                         goto out_dput;
1865
1866                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1867                 if (err)
1868                         goto out_dput;
1869
1870                 /* check if subvolume may be deleted by a non-root user */
1871                 err = btrfs_may_delete(dir, dentry, 1);
1872                 if (err)
1873                         goto out_dput;
1874         }
1875
1876         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1877                 err = -EINVAL;
1878                 goto out_dput;
1879         }
1880
1881         mutex_lock(&inode->i_mutex);
1882         err = d_invalidate(dentry);
1883         if (err)
1884                 goto out_unlock;
1885
1886         down_write(&root->fs_info->subvol_sem);
1887
1888         err = may_destroy_subvol(dest);
1889         if (err)
1890                 goto out_up_write;
1891
1892         trans = btrfs_start_transaction(root, 0);
1893         if (IS_ERR(trans)) {
1894                 err = PTR_ERR(trans);
1895                 goto out_up_write;
1896         }
1897         trans->block_rsv = &root->fs_info->global_block_rsv;
1898
1899         ret = btrfs_unlink_subvol(trans, root, dir,
1900                                 dest->root_key.objectid,
1901                                 dentry->d_name.name,
1902                                 dentry->d_name.len);
1903         BUG_ON(ret);
1904
1905         btrfs_record_root_in_trans(trans, dest);
1906
1907         memset(&dest->root_item.drop_progress, 0,
1908                 sizeof(dest->root_item.drop_progress));
1909         dest->root_item.drop_level = 0;
1910         btrfs_set_root_refs(&dest->root_item, 0);
1911
1912         if (!xchg(&dest->orphan_item_inserted, 1)) {
1913                 ret = btrfs_insert_orphan_item(trans,
1914                                         root->fs_info->tree_root,
1915                                         dest->root_key.objectid);
1916                 BUG_ON(ret);
1917         }
1918
1919         ret = btrfs_end_transaction(trans, root);
1920         BUG_ON(ret);
1921         inode->i_flags |= S_DEAD;
1922 out_up_write:
1923         up_write(&root->fs_info->subvol_sem);
1924 out_unlock:
1925         mutex_unlock(&inode->i_mutex);
1926         if (!err) {
1927                 shrink_dcache_sb(root->fs_info->sb);
1928                 btrfs_invalidate_inodes(dest);
1929                 d_delete(dentry);
1930         }
1931 out_dput:
1932         dput(dentry);
1933 out_unlock_dir:
1934         mutex_unlock(&dir->i_mutex);
1935         mnt_drop_write(file->f_path.mnt);
1936 out:
1937         kfree(vol_args);
1938         return err;
1939 }
1940
1941 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1942 {
1943         struct inode *inode = fdentry(file)->d_inode;
1944         struct btrfs_root *root = BTRFS_I(inode)->root;
1945         struct btrfs_ioctl_defrag_range_args *range;
1946         int ret;
1947
1948         if (btrfs_root_readonly(root))
1949                 return -EROFS;
1950
1951         ret = mnt_want_write(file->f_path.mnt);
1952         if (ret)
1953                 return ret;
1954
1955         switch (inode->i_mode & S_IFMT) {
1956         case S_IFDIR:
1957                 if (!capable(CAP_SYS_ADMIN)) {
1958                         ret = -EPERM;
1959                         goto out;
1960                 }
1961                 ret = btrfs_defrag_root(root, 0);
1962                 if (ret)
1963                         goto out;
1964                 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
1965                 break;
1966         case S_IFREG:
1967                 if (!(file->f_mode & FMODE_WRITE)) {
1968                         ret = -EINVAL;
1969                         goto out;
1970                 }
1971
1972                 range = kzalloc(sizeof(*range), GFP_KERNEL);
1973                 if (!range) {
1974                         ret = -ENOMEM;
1975                         goto out;
1976                 }
1977
1978                 if (argp) {
1979                         if (copy_from_user(range, argp,
1980                                            sizeof(*range))) {
1981                                 ret = -EFAULT;
1982                                 kfree(range);
1983                                 goto out;
1984                         }
1985                         /* compression requires us to start the IO */
1986                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1987                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
1988                                 range->extent_thresh = (u32)-1;
1989                         }
1990                 } else {
1991                         /* the rest are all set to zero by kzalloc */
1992                         range->len = (u64)-1;
1993                 }
1994                 ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
1995                                         range, 0, 0);
1996                 if (ret > 0)
1997                         ret = 0;
1998                 kfree(range);
1999                 break;
2000         default:
2001                 ret = -EINVAL;
2002         }
2003 out:
2004         mnt_drop_write(file->f_path.mnt);
2005         return ret;
2006 }
2007
2008 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2009 {
2010         struct btrfs_ioctl_vol_args *vol_args;
2011         int ret;
2012
2013         if (!capable(CAP_SYS_ADMIN))
2014                 return -EPERM;
2015
2016         vol_args = memdup_user(arg, sizeof(*vol_args));
2017         if (IS_ERR(vol_args))
2018                 return PTR_ERR(vol_args);
2019
2020         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2021         ret = btrfs_init_new_device(root, vol_args->name);
2022
2023         kfree(vol_args);
2024         return ret;
2025 }
2026
2027 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
2028 {
2029         struct btrfs_ioctl_vol_args *vol_args;
2030         int ret;
2031
2032         if (!capable(CAP_SYS_ADMIN))
2033                 return -EPERM;
2034
2035         if (root->fs_info->sb->s_flags & MS_RDONLY)
2036                 return -EROFS;
2037
2038         vol_args = memdup_user(arg, sizeof(*vol_args));
2039         if (IS_ERR(vol_args))
2040                 return PTR_ERR(vol_args);
2041
2042         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2043         ret = btrfs_rm_device(root, vol_args->name);
2044
2045         kfree(vol_args);
2046         return ret;
2047 }
2048
2049 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2050 {
2051         struct btrfs_ioctl_fs_info_args *fi_args;
2052         struct btrfs_device *device;
2053         struct btrfs_device *next;
2054         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2055         int ret = 0;
2056
2057         if (!capable(CAP_SYS_ADMIN))
2058                 return -EPERM;
2059
2060         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2061         if (!fi_args)
2062                 return -ENOMEM;
2063
2064         fi_args->num_devices = fs_devices->num_devices;
2065         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2066
2067         mutex_lock(&fs_devices->device_list_mutex);
2068         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2069                 if (device->devid > fi_args->max_id)
2070                         fi_args->max_id = device->devid;
2071         }
2072         mutex_unlock(&fs_devices->device_list_mutex);
2073
2074         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2075                 ret = -EFAULT;
2076
2077         kfree(fi_args);
2078         return ret;
2079 }
2080
2081 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2082 {
2083         struct btrfs_ioctl_dev_info_args *di_args;
2084         struct btrfs_device *dev;
2085         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2086         int ret = 0;
2087         char *s_uuid = NULL;
2088         char empty_uuid[BTRFS_UUID_SIZE] = {0};
2089
2090         if (!capable(CAP_SYS_ADMIN))
2091                 return -EPERM;
2092
2093         di_args = memdup_user(arg, sizeof(*di_args));
2094         if (IS_ERR(di_args))
2095                 return PTR_ERR(di_args);
2096
2097         if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2098                 s_uuid = di_args->uuid;
2099
2100         mutex_lock(&fs_devices->device_list_mutex);
2101         dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL);
2102         mutex_unlock(&fs_devices->device_list_mutex);
2103
2104         if (!dev) {
2105                 ret = -ENODEV;
2106                 goto out;
2107         }
2108
2109         di_args->devid = dev->devid;
2110         di_args->bytes_used = dev->bytes_used;
2111         di_args->total_bytes = dev->total_bytes;
2112         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2113         strncpy(di_args->path, dev->name, sizeof(di_args->path));
2114
2115 out:
2116         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2117                 ret = -EFAULT;
2118
2119         kfree(di_args);
2120         return ret;
2121 }
2122
2123 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2124                                        u64 off, u64 olen, u64 destoff)
2125 {
2126         struct inode *inode = fdentry(file)->d_inode;
2127         struct btrfs_root *root = BTRFS_I(inode)->root;
2128         struct file *src_file;
2129         struct inode *src;
2130         struct btrfs_trans_handle *trans;
2131         struct btrfs_path *path;
2132         struct extent_buffer *leaf;
2133         char *buf;
2134         struct btrfs_key key;
2135         u32 nritems;
2136         int slot;
2137         int ret;
2138         u64 len = olen;
2139         u64 bs = root->fs_info->sb->s_blocksize;
2140         u64 hint_byte;
2141
2142         /*
2143          * TODO:
2144          * - split compressed inline extents.  annoying: we need to
2145          *   decompress into destination's address_space (the file offset
2146          *   may change, so source mapping won't do), then recompress (or
2147          *   otherwise reinsert) a subrange.
2148          * - allow ranges within the same file to be cloned (provided
2149          *   they don't overlap)?
2150          */
2151
2152         /* the destination must be opened for writing */
2153         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2154                 return -EINVAL;
2155
2156         if (btrfs_root_readonly(root))
2157                 return -EROFS;
2158
2159         ret = mnt_want_write(file->f_path.mnt);
2160         if (ret)
2161                 return ret;
2162
2163         src_file = fget(srcfd);
2164         if (!src_file) {
2165                 ret = -EBADF;
2166                 goto out_drop_write;
2167         }
2168
2169         src = src_file->f_dentry->d_inode;
2170
2171         ret = -EINVAL;
2172         if (src == inode)
2173                 goto out_fput;
2174
2175         /* the src must be open for reading */
2176         if (!(src_file->f_mode & FMODE_READ))
2177                 goto out_fput;
2178
2179         ret = -EISDIR;
2180         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2181                 goto out_fput;
2182
2183         ret = -EXDEV;
2184         if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
2185                 goto out_fput;
2186
2187         ret = -ENOMEM;
2188         buf = vmalloc(btrfs_level_size(root, 0));
2189         if (!buf)
2190                 goto out_fput;
2191
2192         path = btrfs_alloc_path();
2193         if (!path) {
2194                 vfree(buf);
2195                 goto out_fput;
2196         }
2197         path->reada = 2;
2198
2199         if (inode < src) {
2200                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2201                 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2202         } else {
2203                 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2204                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2205         }
2206
2207         /* determine range to clone */
2208         ret = -EINVAL;
2209         if (off + len > src->i_size || off + len < off)
2210                 goto out_unlock;
2211         if (len == 0)
2212                 olen = len = src->i_size - off;
2213         /* if we extend to eof, continue to block boundary */
2214         if (off + len == src->i_size)
2215                 len = ALIGN(src->i_size, bs) - off;
2216
2217         /* verify the end result is block aligned */
2218         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2219             !IS_ALIGNED(destoff, bs))
2220                 goto out_unlock;
2221
2222         /* do any pending delalloc/csum calc on src, one way or
2223            another, and lock file content */
2224         while (1) {
2225                 struct btrfs_ordered_extent *ordered;
2226                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2227                 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
2228                 if (!ordered &&
2229                     !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
2230                                    EXTENT_DELALLOC, 0, NULL))
2231                         break;
2232                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2233                 if (ordered)
2234                         btrfs_put_ordered_extent(ordered);
2235                 btrfs_wait_ordered_range(src, off, len);
2236         }
2237
2238         /* clone data */
2239         key.objectid = btrfs_ino(src);
2240         key.type = BTRFS_EXTENT_DATA_KEY;
2241         key.offset = 0;
2242
2243         while (1) {
2244                 /*
2245                  * note the key will change type as we walk through the
2246                  * tree.
2247                  */
2248                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2249                 if (ret < 0)
2250                         goto out;
2251
2252                 nritems = btrfs_header_nritems(path->nodes[0]);
2253                 if (path->slots[0] >= nritems) {
2254                         ret = btrfs_next_leaf(root, path);
2255                         if (ret < 0)
2256                                 goto out;
2257                         if (ret > 0)
2258                                 break;
2259                         nritems = btrfs_header_nritems(path->nodes[0]);
2260                 }
2261                 leaf = path->nodes[0];
2262                 slot = path->slots[0];
2263
2264                 btrfs_item_key_to_cpu(leaf, &key, slot);
2265                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2266                     key.objectid != btrfs_ino(src))
2267                         break;
2268
2269                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2270                         struct btrfs_file_extent_item *extent;
2271                         int type;
2272                         u32 size;
2273                         struct btrfs_key new_key;
2274                         u64 disko = 0, diskl = 0;
2275                         u64 datao = 0, datal = 0;
2276                         u8 comp;
2277                         u64 endoff;
2278
2279                         size = btrfs_item_size_nr(leaf, slot);
2280                         read_extent_buffer(leaf, buf,
2281                                            btrfs_item_ptr_offset(leaf, slot),
2282                                            size);
2283
2284                         extent = btrfs_item_ptr(leaf, slot,
2285                                                 struct btrfs_file_extent_item);
2286                         comp = btrfs_file_extent_compression(leaf, extent);
2287                         type = btrfs_file_extent_type(leaf, extent);
2288                         if (type == BTRFS_FILE_EXTENT_REG ||
2289                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2290                                 disko = btrfs_file_extent_disk_bytenr(leaf,
2291                                                                       extent);
2292                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2293                                                                  extent);
2294                                 datao = btrfs_file_extent_offset(leaf, extent);
2295                                 datal = btrfs_file_extent_num_bytes(leaf,
2296                                                                     extent);
2297                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2298                                 /* take upper bound, may be compressed */
2299                                 datal = btrfs_file_extent_ram_bytes(leaf,
2300                                                                     extent);
2301                         }
2302                         btrfs_release_path(path);
2303
2304                         if (key.offset + datal <= off ||
2305                             key.offset >= off+len)
2306                                 goto next;
2307
2308                         memcpy(&new_key, &key, sizeof(new_key));
2309                         new_key.objectid = btrfs_ino(inode);
2310                         if (off <= key.offset)
2311                                 new_key.offset = key.offset + destoff - off;
2312                         else
2313                                 new_key.offset = destoff;
2314
2315                         trans = btrfs_start_transaction(root, 1);
2316                         if (IS_ERR(trans)) {
2317                                 ret = PTR_ERR(trans);
2318                                 goto out;
2319                         }
2320
2321                         if (type == BTRFS_FILE_EXTENT_REG ||
2322                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2323                                 if (off > key.offset) {
2324                                         datao += off - key.offset;
2325                                         datal -= off - key.offset;
2326                                 }
2327
2328                                 if (key.offset + datal > off + len)
2329                                         datal = off + len - key.offset;
2330
2331                                 ret = btrfs_drop_extents(trans, inode,
2332                                                          new_key.offset,
2333                                                          new_key.offset + datal,
2334                                                          &hint_byte, 1);
2335                                 BUG_ON(ret);
2336
2337                                 ret = btrfs_insert_empty_item(trans, root, path,
2338                                                               &new_key, size);
2339                                 BUG_ON(ret);
2340
2341                                 leaf = path->nodes[0];
2342                                 slot = path->slots[0];
2343                                 write_extent_buffer(leaf, buf,
2344                                             btrfs_item_ptr_offset(leaf, slot),
2345                                             size);
2346
2347                                 extent = btrfs_item_ptr(leaf, slot,
2348                                                 struct btrfs_file_extent_item);
2349
2350                                 /* disko == 0 means it's a hole */
2351                                 if (!disko)
2352                                         datao = 0;
2353
2354                                 btrfs_set_file_extent_offset(leaf, extent,
2355                                                              datao);
2356                                 btrfs_set_file_extent_num_bytes(leaf, extent,
2357                                                                 datal);
2358                                 if (disko) {
2359                                         inode_add_bytes(inode, datal);
2360                                         ret = btrfs_inc_extent_ref(trans, root,
2361                                                         disko, diskl, 0,
2362                                                         root->root_key.objectid,
2363                                                         btrfs_ino(inode),
2364                                                         new_key.offset - datao);
2365                                         BUG_ON(ret);
2366                                 }
2367                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2368                                 u64 skip = 0;
2369                                 u64 trim = 0;
2370                                 if (off > key.offset) {
2371                                         skip = off - key.offset;
2372                                         new_key.offset += skip;
2373                                 }
2374
2375                                 if (key.offset + datal > off+len)
2376                                         trim = key.offset + datal - (off+len);
2377
2378                                 if (comp && (skip || trim)) {
2379                                         ret = -EINVAL;
2380                                         btrfs_end_transaction(trans, root);
2381                                         goto out;
2382                                 }
2383                                 size -= skip + trim;
2384                                 datal -= skip + trim;
2385
2386                                 ret = btrfs_drop_extents(trans, inode,
2387                                                          new_key.offset,
2388                                                          new_key.offset + datal,
2389                                                          &hint_byte, 1);
2390                                 BUG_ON(ret);
2391
2392                                 ret = btrfs_insert_empty_item(trans, root, path,
2393                                                               &new_key, size);
2394                                 BUG_ON(ret);
2395
2396                                 if (skip) {
2397                                         u32 start =
2398                                           btrfs_file_extent_calc_inline_size(0);
2399                                         memmove(buf+start, buf+start+skip,
2400                                                 datal);
2401                                 }
2402
2403                                 leaf = path->nodes[0];
2404                                 slot = path->slots[0];
2405                                 write_extent_buffer(leaf, buf,
2406                                             btrfs_item_ptr_offset(leaf, slot),
2407                                             size);
2408                                 inode_add_bytes(inode, datal);
2409                         }
2410
2411                         btrfs_mark_buffer_dirty(leaf);
2412                         btrfs_release_path(path);
2413
2414                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2415
2416                         /*
2417                          * we round up to the block size at eof when
2418                          * determining which extents to clone above,
2419                          * but shouldn't round up the file size
2420                          */
2421                         endoff = new_key.offset + datal;
2422                         if (endoff > destoff+olen)
2423                                 endoff = destoff+olen;
2424                         if (endoff > inode->i_size)
2425                                 btrfs_i_size_write(inode, endoff);
2426
2427                         BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
2428                         ret = btrfs_update_inode(trans, root, inode);
2429                         BUG_ON(ret);
2430                         btrfs_end_transaction(trans, root);
2431                 }
2432 next:
2433                 btrfs_release_path(path);
2434                 key.offset++;
2435         }
2436         ret = 0;
2437 out:
2438         btrfs_release_path(path);
2439         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2440 out_unlock:
2441         mutex_unlock(&src->i_mutex);
2442         mutex_unlock(&inode->i_mutex);
2443         vfree(buf);
2444         btrfs_free_path(path);
2445 out_fput:
2446         fput(src_file);
2447 out_drop_write:
2448         mnt_drop_write(file->f_path.mnt);
2449         return ret;
2450 }
2451
2452 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2453 {
2454         struct btrfs_ioctl_clone_range_args args;
2455
2456         if (copy_from_user(&args, argp, sizeof(args)))
2457                 return -EFAULT;
2458         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2459                                  args.src_length, args.dest_offset);
2460 }
2461
2462 /*
2463  * there are many ways the trans_start and trans_end ioctls can lead
2464  * to deadlocks.  They should only be used by applications that
2465  * basically own the machine, and have a very in depth understanding
2466  * of all the possible deadlocks and enospc problems.
2467  */
2468 static long btrfs_ioctl_trans_start(struct file *file)
2469 {
2470         struct inode *inode = fdentry(file)->d_inode;
2471         struct btrfs_root *root = BTRFS_I(inode)->root;
2472         struct btrfs_trans_handle *trans;
2473         int ret;
2474
2475         ret = -EPERM;
2476         if (!capable(CAP_SYS_ADMIN))
2477                 goto out;
2478
2479         ret = -EINPROGRESS;
2480         if (file->private_data)
2481                 goto out;
2482
2483         ret = -EROFS;
2484         if (btrfs_root_readonly(root))
2485                 goto out;
2486
2487         ret = mnt_want_write(file->f_path.mnt);
2488         if (ret)
2489                 goto out;
2490
2491         atomic_inc(&root->fs_info->open_ioctl_trans);
2492
2493         ret = -ENOMEM;
2494         trans = btrfs_start_ioctl_transaction(root);
2495         if (IS_ERR(trans))
2496                 goto out_drop;
2497
2498         file->private_data = trans;
2499         return 0;
2500
2501 out_drop:
2502         atomic_dec(&root->fs_info->open_ioctl_trans);
2503         mnt_drop_write(file->f_path.mnt);
2504 out:
2505         return ret;
2506 }
2507
2508 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2509 {
2510         struct inode *inode = fdentry(file)->d_inode;
2511         struct btrfs_root *root = BTRFS_I(inode)->root;
2512         struct btrfs_root *new_root;
2513         struct btrfs_dir_item *di;
2514         struct btrfs_trans_handle *trans;
2515         struct btrfs_path *path;
2516         struct btrfs_key location;
2517         struct btrfs_disk_key disk_key;
2518         struct btrfs_super_block *disk_super;
2519         u64 features;
2520         u64 objectid = 0;
2521         u64 dir_id;
2522
2523         if (!capable(CAP_SYS_ADMIN))
2524                 return -EPERM;
2525
2526         if (copy_from_user(&objectid, argp, sizeof(objectid)))
2527                 return -EFAULT;
2528
2529         if (!objectid)
2530                 objectid = root->root_key.objectid;
2531
2532         location.objectid = objectid;
2533         location.type = BTRFS_ROOT_ITEM_KEY;
2534         location.offset = (u64)-1;
2535
2536         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2537         if (IS_ERR(new_root))
2538                 return PTR_ERR(new_root);
2539
2540         if (btrfs_root_refs(&new_root->root_item) == 0)
2541                 return -ENOENT;
2542
2543         path = btrfs_alloc_path();
2544         if (!path)
2545                 return -ENOMEM;
2546         path->leave_spinning = 1;
2547
2548         trans = btrfs_start_transaction(root, 1);
2549         if (IS_ERR(trans)) {
2550                 btrfs_free_path(path);
2551                 return PTR_ERR(trans);
2552         }
2553
2554         dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
2555         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2556                                    dir_id, "default", 7, 1);
2557         if (IS_ERR_OR_NULL(di)) {
2558                 btrfs_free_path(path);
2559                 btrfs_end_transaction(trans, root);
2560                 printk(KERN_ERR "Umm, you don't have the default dir item, "
2561                        "this isn't going to work\n");
2562                 return -ENOENT;
2563         }
2564
2565         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2566         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2567         btrfs_mark_buffer_dirty(path->nodes[0]);
2568         btrfs_free_path(path);
2569
2570         disk_super = &root->fs_info->super_copy;
2571         features = btrfs_super_incompat_flags(disk_super);
2572         if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2573                 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2574                 btrfs_set_super_incompat_flags(disk_super, features);
2575         }
2576         btrfs_end_transaction(trans, root);
2577
2578         return 0;
2579 }
2580
2581 static void get_block_group_info(struct list_head *groups_list,
2582                                  struct btrfs_ioctl_space_info *space)
2583 {
2584         struct btrfs_block_group_cache *block_group;
2585
2586         space->total_bytes = 0;
2587         space->used_bytes = 0;
2588         space->flags = 0;
2589         list_for_each_entry(block_group, groups_list, list) {
2590                 space->flags = block_group->flags;
2591                 space->total_bytes += block_group->key.offset;
2592                 space->used_bytes +=
2593                         btrfs_block_group_used(&block_group->item);
2594         }
2595 }
2596
2597 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2598 {
2599         struct btrfs_ioctl_space_args space_args;
2600         struct btrfs_ioctl_space_info space;
2601         struct btrfs_ioctl_space_info *dest;
2602         struct btrfs_ioctl_space_info *dest_orig;
2603         struct btrfs_ioctl_space_info __user *user_dest;
2604         struct btrfs_space_info *info;
2605         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2606                        BTRFS_BLOCK_GROUP_SYSTEM,
2607                        BTRFS_BLOCK_GROUP_METADATA,
2608                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2609         int num_types = 4;
2610         int alloc_size;
2611         int ret = 0;
2612         u64 slot_count = 0;
2613         int i, c;
2614
2615         if (copy_from_user(&space_args,
2616                            (struct btrfs_ioctl_space_args __user *)arg,
2617                            sizeof(space_args)))
2618                 return -EFAULT;
2619
2620         for (i = 0; i < num_types; i++) {
2621                 struct btrfs_space_info *tmp;
2622
2623                 info = NULL;
2624                 rcu_read_lock();
2625                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2626                                         list) {
2627                         if (tmp->flags == types[i]) {
2628                                 info = tmp;
2629                                 break;
2630                         }
2631                 }
2632                 rcu_read_unlock();
2633
2634                 if (!info)
2635                         continue;
2636
2637                 down_read(&info->groups_sem);
2638                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2639                         if (!list_empty(&info->block_groups[c]))
2640                                 slot_count++;
2641                 }
2642                 up_read(&info->groups_sem);
2643         }
2644
2645         /* space_slots == 0 means they are asking for a count */
2646         if (space_args.space_slots == 0) {
2647                 space_args.total_spaces = slot_count;
2648                 goto out;
2649         }
2650
2651         slot_count = min_t(u64, space_args.space_slots, slot_count);
2652
2653         alloc_size = sizeof(*dest) * slot_count;
2654
2655         /* we generally have at most 6 or so space infos, one for each raid
2656          * level.  So, a whole page should be more than enough for everyone
2657          */
2658         if (alloc_size > PAGE_CACHE_SIZE)
2659                 return -ENOMEM;
2660
2661         space_args.total_spaces = 0;
2662         dest = kmalloc(alloc_size, GFP_NOFS);
2663         if (!dest)
2664                 return -ENOMEM;
2665         dest_orig = dest;
2666
2667         /* now we have a buffer to copy into */
2668         for (i = 0; i < num_types; i++) {
2669                 struct btrfs_space_info *tmp;
2670
2671                 if (!slot_count)
2672                         break;
2673
2674                 info = NULL;
2675                 rcu_read_lock();
2676                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2677                                         list) {
2678                         if (tmp->flags == types[i]) {
2679                                 info = tmp;
2680                                 break;
2681                         }
2682                 }
2683                 rcu_read_unlock();
2684
2685                 if (!info)
2686                         continue;
2687                 down_read(&info->groups_sem);
2688                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2689                         if (!list_empty(&info->block_groups[c])) {
2690                                 get_block_group_info(&info->block_groups[c],
2691                                                      &space);
2692                                 memcpy(dest, &space, sizeof(space));
2693                                 dest++;
2694                                 space_args.total_spaces++;
2695                                 slot_count--;
2696                         }
2697                         if (!slot_count)
2698                                 break;
2699                 }
2700                 up_read(&info->groups_sem);
2701         }
2702
2703         user_dest = (struct btrfs_ioctl_space_info *)
2704                 (arg + sizeof(struct btrfs_ioctl_space_args));
2705
2706         if (copy_to_user(user_dest, dest_orig, alloc_size))
2707                 ret = -EFAULT;
2708
2709         kfree(dest_orig);
2710 out:
2711         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2712                 ret = -EFAULT;
2713
2714         return ret;
2715 }
2716
2717 /*
2718  * there are many ways the trans_start and trans_end ioctls can lead
2719  * to deadlocks.  They should only be used by applications that
2720  * basically own the machine, and have a very in depth understanding
2721  * of all the possible deadlocks and enospc problems.
2722  */
2723 long btrfs_ioctl_trans_end(struct file *file)
2724 {
2725         struct inode *inode = fdentry(file)->d_inode;
2726         struct btrfs_root *root = BTRFS_I(inode)->root;
2727         struct btrfs_trans_handle *trans;
2728
2729         trans = file->private_data;
2730         if (!trans)
2731                 return -EINVAL;
2732         file->private_data = NULL;
2733
2734         btrfs_end_transaction(trans, root);
2735
2736         atomic_dec(&root->fs_info->open_ioctl_trans);
2737
2738         mnt_drop_write(file->f_path.mnt);
2739         return 0;
2740 }
2741
2742 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2743 {
2744         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2745         struct btrfs_trans_handle *trans;
2746         u64 transid;
2747         int ret;
2748
2749         trans = btrfs_start_transaction(root, 0);
2750         if (IS_ERR(trans))
2751                 return PTR_ERR(trans);
2752         transid = trans->transid;
2753         ret = btrfs_commit_transaction_async(trans, root, 0);
2754         if (ret) {
2755                 btrfs_end_transaction(trans, root);
2756                 return ret;
2757         }
2758
2759         if (argp)
2760                 if (copy_to_user(argp, &transid, sizeof(transid)))
2761                         return -EFAULT;
2762         return 0;
2763 }
2764
2765 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2766 {
2767         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2768         u64 transid;
2769
2770         if (argp) {
2771                 if (copy_from_user(&transid, argp, sizeof(transid)))
2772                         return -EFAULT;
2773         } else {
2774                 transid = 0;  /* current trans */
2775         }
2776         return btrfs_wait_for_commit(root, transid);
2777 }
2778
2779 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg)
2780 {
2781         int ret;
2782         struct btrfs_ioctl_scrub_args *sa;
2783
2784         if (!capable(CAP_SYS_ADMIN))
2785                 return -EPERM;
2786
2787         sa = memdup_user(arg, sizeof(*sa));
2788         if (IS_ERR(sa))
2789                 return PTR_ERR(sa);
2790
2791         ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
2792                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
2793
2794         if (copy_to_user(arg, sa, sizeof(*sa)))
2795                 ret = -EFAULT;
2796
2797         kfree(sa);
2798         return ret;
2799 }
2800
2801 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
2802 {
2803         if (!capable(CAP_SYS_ADMIN))
2804                 return -EPERM;
2805
2806         return btrfs_scrub_cancel(root);
2807 }
2808
2809 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
2810                                        void __user *arg)
2811 {
2812         struct btrfs_ioctl_scrub_args *sa;
2813         int ret;
2814
2815         if (!capable(CAP_SYS_ADMIN))
2816                 return -EPERM;
2817
2818         sa = memdup_user(arg, sizeof(*sa));
2819         if (IS_ERR(sa))
2820                 return PTR_ERR(sa);
2821
2822         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
2823
2824         if (copy_to_user(arg, sa, sizeof(*sa)))
2825                 ret = -EFAULT;
2826
2827         kfree(sa);
2828         return ret;
2829 }
2830
2831 long btrfs_ioctl(struct file *file, unsigned int
2832                 cmd, unsigned long arg)
2833 {
2834         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2835         void __user *argp = (void __user *)arg;
2836
2837         switch (cmd) {
2838         case FS_IOC_GETFLAGS:
2839                 return btrfs_ioctl_getflags(file, argp);
2840         case FS_IOC_SETFLAGS:
2841                 return btrfs_ioctl_setflags(file, argp);
2842         case FS_IOC_GETVERSION:
2843                 return btrfs_ioctl_getversion(file, argp);
2844         case FITRIM:
2845                 return btrfs_ioctl_fitrim(file, argp);
2846         case BTRFS_IOC_SNAP_CREATE:
2847                 return btrfs_ioctl_snap_create(file, argp, 0);
2848         case BTRFS_IOC_SNAP_CREATE_V2:
2849                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
2850         case BTRFS_IOC_SUBVOL_CREATE:
2851                 return btrfs_ioctl_snap_create(file, argp, 1);
2852         case BTRFS_IOC_SNAP_DESTROY:
2853                 return btrfs_ioctl_snap_destroy(file, argp);
2854         case BTRFS_IOC_SUBVOL_GETFLAGS:
2855                 return btrfs_ioctl_subvol_getflags(file, argp);
2856         case BTRFS_IOC_SUBVOL_SETFLAGS:
2857                 return btrfs_ioctl_subvol_setflags(file, argp);
2858         case BTRFS_IOC_DEFAULT_SUBVOL:
2859                 return btrfs_ioctl_default_subvol(file, argp);
2860         case BTRFS_IOC_DEFRAG:
2861                 return btrfs_ioctl_defrag(file, NULL);
2862         case BTRFS_IOC_DEFRAG_RANGE:
2863                 return btrfs_ioctl_defrag(file, argp);
2864         case BTRFS_IOC_RESIZE:
2865                 return btrfs_ioctl_resize(root, argp);
2866         case BTRFS_IOC_ADD_DEV:
2867                 return btrfs_ioctl_add_dev(root, argp);
2868         case BTRFS_IOC_RM_DEV:
2869                 return btrfs_ioctl_rm_dev(root, argp);
2870         case BTRFS_IOC_FS_INFO:
2871                 return btrfs_ioctl_fs_info(root, argp);
2872         case BTRFS_IOC_DEV_INFO:
2873                 return btrfs_ioctl_dev_info(root, argp);
2874         case BTRFS_IOC_BALANCE:
2875                 return btrfs_balance(root->fs_info->dev_root);
2876         case BTRFS_IOC_CLONE:
2877                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
2878         case BTRFS_IOC_CLONE_RANGE:
2879                 return btrfs_ioctl_clone_range(file, argp);
2880         case BTRFS_IOC_TRANS_START:
2881                 return btrfs_ioctl_trans_start(file);
2882         case BTRFS_IOC_TRANS_END:
2883                 return btrfs_ioctl_trans_end(file);
2884         case BTRFS_IOC_TREE_SEARCH:
2885                 return btrfs_ioctl_tree_search(file, argp);
2886         case BTRFS_IOC_INO_LOOKUP:
2887                 return btrfs_ioctl_ino_lookup(file, argp);
2888         case BTRFS_IOC_SPACE_INFO:
2889                 return btrfs_ioctl_space_info(root, argp);
2890         case BTRFS_IOC_SYNC:
2891                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
2892                 return 0;
2893         case BTRFS_IOC_START_SYNC:
2894                 return btrfs_ioctl_start_sync(file, argp);
2895         case BTRFS_IOC_WAIT_SYNC:
2896                 return btrfs_ioctl_wait_sync(file, argp);
2897         case BTRFS_IOC_SCRUB:
2898                 return btrfs_ioctl_scrub(root, argp);
2899         case BTRFS_IOC_SCRUB_CANCEL:
2900                 return btrfs_ioctl_scrub_cancel(root, argp);
2901         case BTRFS_IOC_SCRUB_PROGRESS:
2902                 return btrfs_ioctl_scrub_progress(root, argp);
2903         }
2904
2905         return -ENOTTY;
2906 }