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
  54 /* Mask out flags that are inappropriate for the given type of inode. */
  55 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  56 {
  57         if (S_ISDIR(mode))
  58                 return flags;
  59         else if (S_ISREG(mode))
  60                 return flags & ~FS_DIRSYNC_FL;
  61         else
  62                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  63 }
  64
  65 /*
  66  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  67  */
  68 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  69 {
  70         unsigned int iflags = 0;
  71
  72         if (flags & BTRFS_INODE_SYNC)
  73                 iflags |= FS_SYNC_FL;
  74         if (flags & BTRFS_INODE_IMMUTABLE)
  75                 iflags |= FS_IMMUTABLE_FL;
  76         if (flags & BTRFS_INODE_APPEND)
  77                 iflags |= FS_APPEND_FL;
  78         if (flags & BTRFS_INODE_NODUMP)
  79                 iflags |= FS_NODUMP_FL;
  80         if (flags & BTRFS_INODE_NOATIME)
  81                 iflags |= FS_NOATIME_FL;
  82         if (flags & BTRFS_INODE_DIRSYNC)
  83                 iflags |= FS_DIRSYNC_FL;
  84
  85         return iflags;
  86 }
  87
  88 /*
  89  * Update inode->i_flags based on the btrfs internal flags.
  90  */
  91 void btrfs_update_iflags(struct inode *inode)
  92 {
  93         struct btrfs_inode *ip = BTRFS_I(inode);
  94
  95         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
  96
  97         if (ip->flags & BTRFS_INODE_SYNC)
  98                 inode->i_flags |= S_SYNC;
  99         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 100                 inode->i_flags |= S_IMMUTABLE;
 101         if (ip->flags & BTRFS_INODE_APPEND)
 102                 inode->i_flags |= S_APPEND;
 103         if (ip->flags & BTRFS_INODE_NOATIME)
 104                 inode->i_flags |= S_NOATIME;
 105         if (ip->flags & BTRFS_INODE_DIRSYNC)
 106                 inode->i_flags |= S_DIRSYNC;
 107 }
 108
 109 /*
 110  * Inherit flags from the parent inode.
 111  *
 112  * Unlike extN we don't have any flags we don't want to inherit currently.
 113  */
 114 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 115 {
 116         unsigned int flags;
 117
 118         if (!dir)
 119                 return;
 120
 121         flags = BTRFS_I(dir)->flags;
 122
 123         if (S_ISREG(inode->i_mode))
 124                 flags &= ~BTRFS_INODE_DIRSYNC;
 125         else if (!S_ISDIR(inode->i_mode))
 126                 flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME);
 127
 128         BTRFS_I(inode)->flags = flags;
 129         btrfs_update_iflags(inode);
 130 }
 131
 132 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 133 {
 134         struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
 135         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 136
 137         if (copy_to_user(arg, &flags, sizeof(flags)))
 138                 return -EFAULT;
 139         return 0;
 140 }
 141
 142 static int check_flags(unsigned int flags)
 143 {
 144         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 145                       FS_NOATIME_FL | FS_NODUMP_FL | \
 146                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 147                       FS_NOCOMP_FL | FS_COMPR_FL | \
 148                       FS_NOCOW_FL | FS_COW_FL))
 149                 return -EOPNOTSUPP;
 150
 151         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 152                 return -EINVAL;
 153
 154         if ((flags & FS_NOCOW_FL) && (flags & FS_COW_FL))
 155                 return -EINVAL;
 156
 157         return 0;
 158 }
 159
 160 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 161 {
 162         struct inode *inode = file->f_path.dentry->d_inode;
 163         struct btrfs_inode *ip = BTRFS_I(inode);
 164         struct btrfs_root *root = ip->root;
 165         struct btrfs_trans_handle *trans;
 166         unsigned int flags, oldflags;
 167         int ret;
 168
 169         if (btrfs_root_readonly(root))
 170                 return -EROFS;
 171
 172         if (copy_from_user(&flags, arg, sizeof(flags)))
 173                 return -EFAULT;
 174
 175         ret = check_flags(flags);
 176         if (ret)
 177                 return ret;
 178
 179         if (!inode_owner_or_capable(inode))
 180                 return -EACCES;
 181
 182         mutex_lock(&inode->i_mutex);
 183
 184         flags = btrfs_mask_flags(inode->i_mode, flags);
 185         oldflags = btrfs_flags_to_ioctl(ip->flags);
 186         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 187                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 188                         ret = -EPERM;
 189                         goto out_unlock;
 190                 }
 191         }
 192
 193         ret = mnt_want_write(file->f_path.mnt);
 194         if (ret)
 195                 goto out_unlock;
 196
 197         if (flags & FS_SYNC_FL)
 198                 ip->flags |= BTRFS_INODE_SYNC;
 199         else
 200                 ip->flags &= ~BTRFS_INODE_SYNC;
 201         if (flags & FS_IMMUTABLE_FL)
 202                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 203         else
 204                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 205         if (flags & FS_APPEND_FL)
 206                 ip->flags |= BTRFS_INODE_APPEND;
 207         else
 208                 ip->flags &= ~BTRFS_INODE_APPEND;
 209         if (flags & FS_NODUMP_FL)
 210                 ip->flags |= BTRFS_INODE_NODUMP;
 211         else
 212                 ip->flags &= ~BTRFS_INODE_NODUMP;
 213         if (flags & FS_NOATIME_FL)
 214                 ip->flags |= BTRFS_INODE_NOATIME;
 215         else
 216                 ip->flags &= ~BTRFS_INODE_NOATIME;
 217         if (flags & FS_DIRSYNC_FL)
 218                 ip->flags |= BTRFS_INODE_DIRSYNC;
 219         else
 220                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 221
 222         /*
 223          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 224          * flag may be changed automatically if compression code won't make
 225          * things smaller.
 226          */
 227         if (flags & FS_NOCOMP_FL) {
 228                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 229                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 230         } else if (flags & FS_COMPR_FL) {
 231                 ip->flags |= BTRFS_INODE_COMPRESS;
 232                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 233         }
 234         if (flags & FS_NOCOW_FL)
 235                 ip->flags |= BTRFS_INODE_NODATACOW;
 236         else if (flags & FS_COW_FL)
 237                 ip->flags &= ~BTRFS_INODE_NODATACOW;
 238
 239         trans = btrfs_join_transaction(root, 1);
 240         BUG_ON(IS_ERR(trans));
 241
 242         ret = btrfs_update_inode(trans, root, inode);
 243         BUG_ON(ret);
 244
 245         btrfs_update_iflags(inode);
 246         inode->i_ctime = CURRENT_TIME;
 247         btrfs_end_transaction(trans, root);
 248
 249         mnt_drop_write(file->f_path.mnt);
 250
 251         ret = 0;
 252  out_unlock:
 253         mutex_unlock(&inode->i_mutex);
 254         return ret;
 255 }
 256
 257 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 258 {
 259         struct inode *inode = file->f_path.dentry->d_inode;
 260
 261         return put_user(inode->i_generation, arg);
 262 }
 263
 264 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 265 {
 266         struct btrfs_root *root = fdentry(file)->d_sb->s_fs_info;
 267         struct btrfs_fs_info *fs_info = root->fs_info;
 268         struct btrfs_device *device;
 269         struct request_queue *q;
 270         struct fstrim_range range;
 271         u64 minlen = ULLONG_MAX;
 272         u64 num_devices = 0;
 273         int ret;
 274
 275         if (!capable(CAP_SYS_ADMIN))
 276                 return -EPERM;
 277
 278         mutex_lock(&fs_info->fs_devices->device_list_mutex);
 279         list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
 280                 if (!device->bdev)
 281                         continue;
 282                 q = bdev_get_queue(device->bdev);
 283                 if (blk_queue_discard(q)) {
 284                         num_devices++;
 285                         minlen = min((u64)q->limits.discard_granularity,
 286                                      minlen);
 287                 }
 288         }
 289         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
 290         if (!num_devices)
 291                 return -EOPNOTSUPP;
 292
 293         if (copy_from_user(&range, arg, sizeof(range)))
 294                 return -EFAULT;
 295
 296         range.minlen = max(range.minlen, minlen);
 297         ret = btrfs_trim_fs(root, &range);
 298         if (ret < 0)
 299                 return ret;
 300
 301         if (copy_to_user(arg, &range, sizeof(range)))
 302                 return -EFAULT;
 303
 304         return 0;
 305 }
 306
 307 static noinline int create_subvol(struct btrfs_root *root,
 308                                   struct dentry *dentry,
 309                                   char *name, int namelen,
 310                                   u64 *async_transid)
 311 {
 312         struct btrfs_trans_handle *trans;
 313         struct btrfs_key key;
 314         struct btrfs_root_item root_item;
 315         struct btrfs_inode_item *inode_item;
 316         struct extent_buffer *leaf;
 317         struct btrfs_root *new_root;
 318         struct dentry *parent = dget_parent(dentry);
 319         struct inode *dir;
 320         int ret;
 321         int err;
 322         u64 objectid;
 323         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 324         u64 index = 0;
 325
 326         ret = btrfs_find_free_objectid(NULL, root->fs_info->tree_root,
 327                                        0, &objectid);
 328         if (ret) {
 329                 dput(parent);
 330                 return ret;
 331         }
 332
 333         dir = parent->d_inode;
 334
 335         /*
 336          * 1 - inode item
 337          * 2 - refs
 338          * 1 - root item
 339          * 2 - dir items
 340          */
 341         trans = btrfs_start_transaction(root, 6);
 342         if (IS_ERR(trans)) {
 343                 dput(parent);
 344                 return PTR_ERR(trans);
 345         }
 346
 347         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 348                                       0, objectid, NULL, 0, 0, 0);
 349         if (IS_ERR(leaf)) {
 350                 ret = PTR_ERR(leaf);
 351                 goto fail;
 352         }
 353
 354         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 355         btrfs_set_header_bytenr(leaf, leaf->start);
 356         btrfs_set_header_generation(leaf, trans->transid);
 357         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 358         btrfs_set_header_owner(leaf, objectid);
 359
 360         write_extent_buffer(leaf, root->fs_info->fsid,
 361                             (unsigned long)btrfs_header_fsid(leaf),
 362                             BTRFS_FSID_SIZE);
 363         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 364                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 365                             BTRFS_UUID_SIZE);
 366         btrfs_mark_buffer_dirty(leaf);
 367
 368         inode_item = &root_item.inode;
 369         memset(inode_item, 0, sizeof(*inode_item));
 370         inode_item->generation = cpu_to_le64(1);
 371         inode_item->size = cpu_to_le64(3);
 372         inode_item->nlink = cpu_to_le32(1);
 373         inode_item->nbytes = cpu_to_le64(root->leafsize);
 374         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 375
 376         root_item.flags = 0;
 377         root_item.byte_limit = 0;
 378         inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
 379
 380         btrfs_set_root_bytenr(&root_item, leaf->start);
 381         btrfs_set_root_generation(&root_item, trans->transid);
 382         btrfs_set_root_level(&root_item, 0);
 383         btrfs_set_root_refs(&root_item, 1);
 384         btrfs_set_root_used(&root_item, leaf->len);
 385         btrfs_set_root_last_snapshot(&root_item, 0);
 386
 387         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
 388         root_item.drop_level = 0;
 389
 390         btrfs_tree_unlock(leaf);
 391         free_extent_buffer(leaf);
 392         leaf = NULL;
 393
 394         btrfs_set_root_dirid(&root_item, new_dirid);
 395
 396         key.objectid = objectid;
 397         key.offset = 0;
 398         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 399         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 400                                 &root_item);
 401         if (ret)
 402                 goto fail;
 403
 404         key.offset = (u64)-1;
 405         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 406         BUG_ON(IS_ERR(new_root));
 407
 408         btrfs_record_root_in_trans(trans, new_root);
 409
 410         ret = btrfs_create_subvol_root(trans, new_root, new_dirid,
 411                                        BTRFS_I(dir)->block_group);
 412         /*
 413          * insert the directory item
 414          */
 415         ret = btrfs_set_inode_index(dir, &index);
 416         BUG_ON(ret);
 417
 418         ret = btrfs_insert_dir_item(trans, root,
 419                                     name, namelen, dir->i_ino, &key,
 420                                     BTRFS_FT_DIR, index);
 421         if (ret)
 422                 goto fail;
 423
 424         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 425         ret = btrfs_update_inode(trans, root, dir);
 426         BUG_ON(ret);
 427
 428         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 429                                  objectid, root->root_key.objectid,
 430                                  dir->i_ino, index, name, namelen);
 431
 432         BUG_ON(ret);
 433
 434         d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 435 fail:
 436         dput(parent);
 437         if (async_transid) {
 438                 *async_transid = trans->transid;
 439                 err = btrfs_commit_transaction_async(trans, root, 1);
 440         } else {
 441                 err = btrfs_commit_transaction(trans, root);
 442         }
 443         if (err && !ret)
 444                 ret = err;
 445         return ret;
 446 }
 447
 448 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 449                            char *name, int namelen, u64 *async_transid,
 450                            bool readonly)
 451 {
 452         struct inode *inode;
 453         struct dentry *parent;
 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         list_add(&pending_snapshot->list,
 480                  &trans->transaction->pending_snapshots);
 481         if (async_transid) {
 482                 *async_transid = trans->transid;
 483                 ret = btrfs_commit_transaction_async(trans,
 484                                      root->fs_info->extent_root, 1);
 485         } else {
 486                 ret = btrfs_commit_transaction(trans,
 487                                                root->fs_info->extent_root);
 488         }
 489         BUG_ON(ret);
 490
 491         ret = pending_snapshot->error;
 492         if (ret)
 493                 goto fail;
 494
 495         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 496         if (ret)
 497                 goto fail;
 498
 499         parent = dget_parent(dentry);
 500         inode = btrfs_lookup_dentry(parent->d_inode, dentry);
 501         dput(parent);
 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 static int should_defrag_range(struct inode *inode, u64 start, u64 len,
 653                                int thresh, u64 *last_len, u64 *skip,
 654                                u64 *defrag_end)
 655 {
 656         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 657         struct extent_map *em = NULL;
 658         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 659         int ret = 1;
 660
 661
 662         if (thresh == 0)
 663                 thresh = 256 * 1024;
 664
 665         /*
 666          * make sure that once we start defragging and extent, we keep on
 667          * defragging it
 668          */
 669         if (start < *defrag_end)
 670                 return 1;
 671
 672         *skip = 0;
 673
 674         /*
 675          * hopefully we have this extent in the tree already, try without
 676          * the full extent lock
 677          */
 678         read_lock(&em_tree->lock);
 679         em = lookup_extent_mapping(em_tree, start, len);
 680         read_unlock(&em_tree->lock);
 681
 682         if (!em) {
 683                 /* get the big lock and read metadata off disk */
 684                 lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
 685                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 686                 unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
 687
 688                 if (IS_ERR(em))
 689                         return 0;
 690         }
 691
 692         /* this will cover holes, and inline extents */
 693         if (em->block_start >= EXTENT_MAP_LAST_BYTE)
 694                 ret = 0;
 695
 696         /*
 697          * we hit a real extent, if it is big don't bother defragging it again
 698          */
 699         if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
 700                 ret = 0;
 701
 702         /*
 703          * last_len ends up being a counter of how many bytes we've defragged.
 704          * every time we choose not to defrag an extent, we reset *last_len
 705          * so that the next tiny extent will force a defrag.
 706          *
 707          * The end result of this is that tiny extents before a single big
 708          * extent will force at least part of that big extent to be defragged.
 709          */
 710         if (ret) {
 711                 *last_len += len;
 712                 *defrag_end = extent_map_end(em);
 713         } else {
 714                 *last_len = 0;
 715                 *skip = extent_map_end(em);
 716                 *defrag_end = 0;
 717         }
 718
 719         free_extent_map(em);
 720         return ret;
 721 }
 722
 723 static int btrfs_defrag_file(struct file *file,
 724                              struct btrfs_ioctl_defrag_range_args *range)
 725 {
 726         struct inode *inode = fdentry(file)->d_inode;
 727         struct btrfs_root *root = BTRFS_I(inode)->root;
 728         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 729         struct btrfs_ordered_extent *ordered;
 730         struct page *page;
 731         struct btrfs_super_block *disk_super;
 732         unsigned long last_index;
 733         unsigned long ra_pages = root->fs_info->bdi.ra_pages;
 734         unsigned long total_read = 0;
 735         u64 features;
 736         u64 page_start;
 737         u64 page_end;
 738         u64 last_len = 0;
 739         u64 skip = 0;
 740         u64 defrag_end = 0;
 741         unsigned long i;
 742         int ret;
 743         int compress_type = BTRFS_COMPRESS_ZLIB;
 744
 745         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
 746                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
 747                         return -EINVAL;
 748                 if (range->compress_type)
 749                         compress_type = range->compress_type;
 750         }
 751
 752         if (inode->i_size == 0)
 753                 return 0;
 754
 755         if (range->start + range->len > range->start) {
 756                 last_index = min_t(u64, inode->i_size - 1,
 757                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
 758         } else {
 759                 last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
 760         }
 761
 762         i = range->start >> PAGE_CACHE_SHIFT;
 763         while (i <= last_index) {
 764                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
 765                                         PAGE_CACHE_SIZE,
 766                                         range->extent_thresh,
 767                                         &last_len, &skip,
 768                                         &defrag_end)) {
 769                         unsigned long next;
 770                         /*
 771                          * the should_defrag function tells us how much to skip
 772                          * bump our counter by the suggested amount
 773                          */
 774                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 775                         i = max(i + 1, next);
 776                         continue;
 777                 }
 778
 779                 if (total_read % ra_pages == 0) {
 780                         btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
 781                                        min(last_index, i + ra_pages - 1));
 782                 }
 783                 total_read++;
 784                 mutex_lock(&inode->i_mutex);
 785                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
 786                         BTRFS_I(inode)->force_compress = compress_type;
 787
 788                 ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
 789                 if (ret)
 790                         goto err_unlock;
 791 again:
 792                 if (inode->i_size == 0 ||
 793                     i > ((inode->i_size - 1) >> PAGE_CACHE_SHIFT)) {
 794                         ret = 0;
 795                         goto err_reservations;
 796                 }
 797
 798                 page = grab_cache_page(inode->i_mapping, i);
 799                 if (!page) {
 800                         ret = -ENOMEM;
 801                         goto err_reservations;
 802                 }
 803
 804                 if (!PageUptodate(page)) {
 805                         btrfs_readpage(NULL, page);
 806                         lock_page(page);
 807                         if (!PageUptodate(page)) {
 808                                 unlock_page(page);
 809                                 page_cache_release(page);
 810                                 ret = -EIO;
 811                                 goto err_reservations;
 812                         }
 813                 }
 814
 815                 if (page->mapping != inode->i_mapping) {
 816                         unlock_page(page);
 817                         page_cache_release(page);
 818                         goto again;
 819                 }
 820
 821                 wait_on_page_writeback(page);
 822
 823                 if (PageDirty(page)) {
 824                         btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
 825                         goto loop_unlock;
 826                 }
 827
 828                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 829                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 830                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
 831
 832                 ordered = btrfs_lookup_ordered_extent(inode, page_start);
 833                 if (ordered) {
 834                         unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 835                         unlock_page(page);
 836                         page_cache_release(page);
 837                         btrfs_start_ordered_extent(inode, ordered, 1);
 838                         btrfs_put_ordered_extent(ordered);
 839                         goto again;
 840                 }
 841                 set_page_extent_mapped(page);
 842
 843                 /*
 844                  * this makes sure page_mkwrite is called on the
 845                  * page if it is dirtied again later
 846                  */
 847                 clear_page_dirty_for_io(page);
 848                 clear_extent_bits(&BTRFS_I(inode)->io_tree, page_start,
 849                                   page_end, EXTENT_DIRTY | EXTENT_DELALLOC |
 850                                   EXTENT_DO_ACCOUNTING, GFP_NOFS);
 851
 852                 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
 853                 ClearPageChecked(page);
 854                 set_page_dirty(page);
 855                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 856
 857 loop_unlock:
 858                 unlock_page(page);
 859                 page_cache_release(page);
 860                 mutex_unlock(&inode->i_mutex);
 861
 862                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
 863                 i++;
 864         }
 865
 866         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
 867                 filemap_flush(inode->i_mapping);
 868
 869         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
 870                 /* the filemap_flush will queue IO into the worker threads, but
 871                  * we have to make sure the IO is actually started and that
 872                  * ordered extents get created before we return
 873                  */
 874                 atomic_inc(&root->fs_info->async_submit_draining);
 875                 while (atomic_read(&root->fs_info->nr_async_submits) ||
 876                       atomic_read(&root->fs_info->async_delalloc_pages)) {
 877                         wait_event(root->fs_info->async_submit_wait,
 878                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
 879                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
 880                 }
 881                 atomic_dec(&root->fs_info->async_submit_draining);
 882
 883                 mutex_lock(&inode->i_mutex);
 884                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
 885                 mutex_unlock(&inode->i_mutex);
 886         }
 887
 888         disk_super = &root->fs_info->super_copy;
 889         features = btrfs_super_incompat_flags(disk_super);
 890         if (range->compress_type == BTRFS_COMPRESS_LZO) {
 891                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
 892                 btrfs_set_super_incompat_flags(disk_super, features);
 893         }
 894
 895         return 0;
 896
 897 err_reservations:
 898         btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
 899 err_unlock:
 900         mutex_unlock(&inode->i_mutex);
 901         return ret;
 902 }
 903
 904 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 905                                         void __user *arg)
 906 {
 907         u64 new_size;
 908         u64 old_size;
 909         u64 devid = 1;
 910         struct btrfs_ioctl_vol_args *vol_args;
 911         struct btrfs_trans_handle *trans;
 912         struct btrfs_device *device = NULL;
 913         char *sizestr;
 914         char *devstr = NULL;
 915         int ret = 0;
 916         int mod = 0;
 917
 918         if (root->fs_info->sb->s_flags & MS_RDONLY)
 919                 return -EROFS;
 920
 921         if (!capable(CAP_SYS_ADMIN))
 922                 return -EPERM;
 923
 924         vol_args = memdup_user(arg, sizeof(*vol_args));
 925         if (IS_ERR(vol_args))
 926                 return PTR_ERR(vol_args);
 927
 928         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 929
 930         mutex_lock(&root->fs_info->volume_mutex);
 931         sizestr = vol_args->name;
 932         devstr = strchr(sizestr, ':');
 933         if (devstr) {
 934                 char *end;
 935                 sizestr = devstr + 1;
 936                 *devstr = '\0';
 937                 devstr = vol_args->name;
 938                 devid = simple_strtoull(devstr, &end, 10);
 939                 printk(KERN_INFO "resizing devid %llu\n",
 940                        (unsigned long long)devid);
 941         }
 942         device = btrfs_find_device(root, devid, NULL, NULL);
 943         if (!device) {
 944                 printk(KERN_INFO "resizer unable to find device %llu\n",
 945                        (unsigned long long)devid);
 946                 ret = -EINVAL;
 947                 goto out_unlock;
 948         }
 949         if (!strcmp(sizestr, "max"))
 950                 new_size = device->bdev->bd_inode->i_size;
 951         else {
 952                 if (sizestr[0] == '-') {
 953                         mod = -1;
 954                         sizestr++;
 955                 } else if (sizestr[0] == '+') {
 956                         mod = 1;
 957                         sizestr++;
 958                 }
 959                 new_size = memparse(sizestr, NULL);
 960                 if (new_size == 0) {
 961                         ret = -EINVAL;
 962                         goto out_unlock;
 963                 }
 964         }
 965
 966         old_size = device->total_bytes;
 967
 968         if (mod < 0) {
 969                 if (new_size > old_size) {
 970                         ret = -EINVAL;
 971                         goto out_unlock;
 972                 }
 973                 new_size = old_size - new_size;
 974         } else if (mod > 0) {
 975                 new_size = old_size + new_size;
 976         }
 977
 978         if (new_size < 256 * 1024 * 1024) {
 979                 ret = -EINVAL;
 980                 goto out_unlock;
 981         }
 982         if (new_size > device->bdev->bd_inode->i_size) {
 983                 ret = -EFBIG;
 984                 goto out_unlock;
 985         }
 986
 987         do_div(new_size, root->sectorsize);
 988         new_size *= root->sectorsize;
 989
 990         printk(KERN_INFO "new size for %s is %llu\n",
 991                 device->name, (unsigned long long)new_size);
 992
 993         if (new_size > old_size) {
 994                 trans = btrfs_start_transaction(root, 0);
 995                 if (IS_ERR(trans)) {
 996                         ret = PTR_ERR(trans);
 997                         goto out_unlock;
 998                 }
 999                 ret = btrfs_grow_device(trans, device, new_size);
1000                 btrfs_commit_transaction(trans, root);
1001         } else {
1002                 ret = btrfs_shrink_device(device, new_size);
1003         }
1004
1005 out_unlock:
1006         mutex_unlock(&root->fs_info->volume_mutex);
1007         kfree(vol_args);
1008         return ret;
1009 }
1010
1011 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1012                                                     char *name,
1013                                                     unsigned long fd,
1014                                                     int subvol,
1015                                                     u64 *transid,
1016                                                     bool readonly)
1017 {
1018         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1019         struct file *src_file;
1020         int namelen;
1021         int ret = 0;
1022
1023         if (root->fs_info->sb->s_flags & MS_RDONLY)
1024                 return -EROFS;
1025
1026         namelen = strlen(name);
1027         if (strchr(name, '/')) {
1028                 ret = -EINVAL;
1029                 goto out;
1030         }
1031
1032         if (subvol) {
1033                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1034                                      NULL, transid, readonly);
1035         } else {
1036                 struct inode *src_inode;
1037                 src_file = fget(fd);
1038                 if (!src_file) {
1039                         ret = -EINVAL;
1040                         goto out;
1041                 }
1042
1043                 src_inode = src_file->f_path.dentry->d_inode;
1044                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1045                         printk(KERN_INFO "btrfs: Snapshot src from "
1046                                "another FS\n");
1047                         ret = -EINVAL;
1048                         fput(src_file);
1049                         goto out;
1050                 }
1051                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1052                                      BTRFS_I(src_inode)->root,
1053                                      transid, readonly);
1054                 fput(src_file);
1055         }
1056 out:
1057         return ret;
1058 }
1059
1060 static noinline int btrfs_ioctl_snap_create(struct file *file,
1061                                             void __user *arg, int subvol)
1062 {
1063         struct btrfs_ioctl_vol_args *vol_args;
1064         int ret;
1065
1066         vol_args = memdup_user(arg, sizeof(*vol_args));
1067         if (IS_ERR(vol_args))
1068                 return PTR_ERR(vol_args);
1069         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1070
1071         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1072                                               vol_args->fd, subvol,
1073                                               NULL, false);
1074
1075         kfree(vol_args);
1076         return ret;
1077 }
1078
1079 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1080                                                void __user *arg, int subvol)
1081 {
1082         struct btrfs_ioctl_vol_args_v2 *vol_args;
1083         int ret;
1084         u64 transid = 0;
1085         u64 *ptr = NULL;
1086         bool readonly = false;
1087
1088         vol_args = memdup_user(arg, sizeof(*vol_args));
1089         if (IS_ERR(vol_args))
1090                 return PTR_ERR(vol_args);
1091         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1092
1093         if (vol_args->flags &
1094             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
1095                 ret = -EOPNOTSUPP;
1096                 goto out;
1097         }
1098
1099         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1100                 ptr = &transid;
1101         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1102                 readonly = true;
1103
1104         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1105                                               vol_args->fd, subvol,
1106                                               ptr, readonly);
1107
1108         if (ret == 0 && ptr &&
1109             copy_to_user(arg +
1110                          offsetof(struct btrfs_ioctl_vol_args_v2,
1111                                   transid), ptr, sizeof(*ptr)))
1112                 ret = -EFAULT;
1113 out:
1114         kfree(vol_args);
1115         return ret;
1116 }
1117
1118 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1119                                                 void __user *arg)
1120 {
1121         struct inode *inode = fdentry(file)->d_inode;
1122         struct btrfs_root *root = BTRFS_I(inode)->root;
1123         int ret = 0;
1124         u64 flags = 0;
1125
1126         if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
1127                 return -EINVAL;
1128
1129         down_read(&root->fs_info->subvol_sem);
1130         if (btrfs_root_readonly(root))
1131                 flags |= BTRFS_SUBVOL_RDONLY;
1132         up_read(&root->fs_info->subvol_sem);
1133
1134         if (copy_to_user(arg, &flags, sizeof(flags)))
1135                 ret = -EFAULT;
1136
1137         return ret;
1138 }
1139
1140 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1141                                               void __user *arg)
1142 {
1143         struct inode *inode = fdentry(file)->d_inode;
1144         struct btrfs_root *root = BTRFS_I(inode)->root;
1145         struct btrfs_trans_handle *trans;
1146         u64 root_flags;
1147         u64 flags;
1148         int ret = 0;
1149
1150         if (root->fs_info->sb->s_flags & MS_RDONLY)
1151                 return -EROFS;
1152
1153         if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
1154                 return -EINVAL;
1155
1156         if (copy_from_user(&flags, arg, sizeof(flags)))
1157                 return -EFAULT;
1158
1159         if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
1160                 return -EINVAL;
1161
1162         if (flags & ~BTRFS_SUBVOL_RDONLY)
1163                 return -EOPNOTSUPP;
1164
1165         if (!inode_owner_or_capable(inode))
1166                 return -EACCES;
1167
1168         down_write(&root->fs_info->subvol_sem);
1169
1170         /* nothing to do */
1171         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1172                 goto out;
1173
1174         root_flags = btrfs_root_flags(&root->root_item);
1175         if (flags & BTRFS_SUBVOL_RDONLY)
1176                 btrfs_set_root_flags(&root->root_item,
1177                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1178         else
1179                 btrfs_set_root_flags(&root->root_item,
1180                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1181
1182         trans = btrfs_start_transaction(root, 1);
1183         if (IS_ERR(trans)) {
1184                 ret = PTR_ERR(trans);
1185                 goto out_reset;
1186         }
1187
1188         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1189                                 &root->root_key, &root->root_item);
1190
1191         btrfs_commit_transaction(trans, root);
1192 out_reset:
1193         if (ret)
1194                 btrfs_set_root_flags(&root->root_item, root_flags);
1195 out:
1196         up_write(&root->fs_info->subvol_sem);
1197         return ret;
1198 }
1199
1200 /*
1201  * helper to check if the subvolume references other subvolumes
1202  */
1203 static noinline int may_destroy_subvol(struct btrfs_root *root)
1204 {
1205         struct btrfs_path *path;
1206         struct btrfs_key key;
1207         int ret;
1208
1209         path = btrfs_alloc_path();
1210         if (!path)
1211                 return -ENOMEM;
1212
1213         key.objectid = root->root_key.objectid;
1214         key.type = BTRFS_ROOT_REF_KEY;
1215         key.offset = (u64)-1;
1216
1217         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1218                                 &key, path, 0, 0);
1219         if (ret < 0)
1220                 goto out;
1221         BUG_ON(ret == 0);
1222
1223         ret = 0;
1224         if (path->slots[0] > 0) {
1225                 path->slots[0]--;
1226                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1227                 if (key.objectid == root->root_key.objectid &&
1228                     key.type == BTRFS_ROOT_REF_KEY)
1229                         ret = -ENOTEMPTY;
1230         }
1231 out:
1232         btrfs_free_path(path);
1233         return ret;
1234 }
1235
1236 static noinline int key_in_sk(struct btrfs_key *key,
1237                               struct btrfs_ioctl_search_key *sk)
1238 {
1239         struct btrfs_key test;
1240         int ret;
1241
1242         test.objectid = sk->min_objectid;
1243         test.type = sk->min_type;
1244         test.offset = sk->min_offset;
1245
1246         ret = btrfs_comp_cpu_keys(key, &test);
1247         if (ret < 0)
1248                 return 0;
1249
1250         test.objectid = sk->max_objectid;
1251         test.type = sk->max_type;
1252         test.offset = sk->max_offset;
1253
1254         ret = btrfs_comp_cpu_keys(key, &test);
1255         if (ret > 0)
1256                 return 0;
1257         return 1;
1258 }
1259
1260 static noinline int copy_to_sk(struct btrfs_root *root,
1261                                struct btrfs_path *path,
1262                                struct btrfs_key *key,
1263                                struct btrfs_ioctl_search_key *sk,
1264                                char *buf,
1265                                unsigned long *sk_offset,
1266                                int *num_found)
1267 {
1268         u64 found_transid;
1269         struct extent_buffer *leaf;
1270         struct btrfs_ioctl_search_header sh;
1271         unsigned long item_off;
1272         unsigned long item_len;
1273         int nritems;
1274         int i;
1275         int slot;
1276         int found = 0;
1277         int ret = 0;
1278
1279         leaf = path->nodes[0];
1280         slot = path->slots[0];
1281         nritems = btrfs_header_nritems(leaf);
1282
1283         if (btrfs_header_generation(leaf) > sk->max_transid) {
1284                 i = nritems;
1285                 goto advance_key;
1286         }
1287         found_transid = btrfs_header_generation(leaf);
1288
1289         for (i = slot; i < nritems; i++) {
1290                 item_off = btrfs_item_ptr_offset(leaf, i);
1291                 item_len = btrfs_item_size_nr(leaf, i);
1292
1293                 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1294                         item_len = 0;
1295
1296                 if (sizeof(sh) + item_len + *sk_offset >
1297                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1298                         ret = 1;
1299                         goto overflow;
1300                 }
1301
1302                 btrfs_item_key_to_cpu(leaf, key, i);
1303                 if (!key_in_sk(key, sk))
1304                         continue;
1305
1306                 sh.objectid = key->objectid;
1307                 sh.offset = key->offset;
1308                 sh.type = key->type;
1309                 sh.len = item_len;
1310                 sh.transid = found_transid;
1311
1312                 /* copy search result header */
1313                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1314                 *sk_offset += sizeof(sh);
1315
1316                 if (item_len) {
1317                         char *p = buf + *sk_offset;
1318                         /* copy the item */
1319                         read_extent_buffer(leaf, p,
1320                                            item_off, item_len);
1321                         *sk_offset += item_len;
1322                 }
1323                 found++;
1324
1325                 if (*num_found >= sk->nr_items)
1326                         break;
1327         }
1328 advance_key:
1329         ret = 0;
1330         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1331                 key->offset++;
1332         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1333                 key->offset = 0;
1334                 key->type++;
1335         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1336                 key->offset = 0;
1337                 key->type = 0;
1338                 key->objectid++;
1339         } else
1340                 ret = 1;
1341 overflow:
1342         *num_found += found;
1343         return ret;
1344 }
1345
1346 static noinline int search_ioctl(struct inode *inode,
1347                                  struct btrfs_ioctl_search_args *args)
1348 {
1349         struct btrfs_root *root;
1350         struct btrfs_key key;
1351         struct btrfs_key max_key;
1352         struct btrfs_path *path;
1353         struct btrfs_ioctl_search_key *sk = &args->key;
1354         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1355         int ret;
1356         int num_found = 0;
1357         unsigned long sk_offset = 0;
1358
1359         path = btrfs_alloc_path();
1360         if (!path)
1361                 return -ENOMEM;
1362
1363         if (sk->tree_id == 0) {
1364                 /* search the root of the inode that was passed */
1365                 root = BTRFS_I(inode)->root;
1366         } else {
1367                 key.objectid = sk->tree_id;
1368                 key.type = BTRFS_ROOT_ITEM_KEY;
1369                 key.offset = (u64)-1;
1370                 root = btrfs_read_fs_root_no_name(info, &key);
1371                 if (IS_ERR(root)) {
1372                         printk(KERN_ERR "could not find root %llu\n",
1373                                sk->tree_id);
1374                         btrfs_free_path(path);
1375                         return -ENOENT;
1376                 }
1377         }
1378
1379         key.objectid = sk->min_objectid;
1380         key.type = sk->min_type;
1381         key.offset = sk->min_offset;
1382
1383         max_key.objectid = sk->max_objectid;
1384         max_key.type = sk->max_type;
1385         max_key.offset = sk->max_offset;
1386
1387         path->keep_locks = 1;
1388
1389         while(1) {
1390                 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1391                                            sk->min_transid);
1392                 if (ret != 0) {
1393                         if (ret > 0)
1394                                 ret = 0;
1395                         goto err;
1396                 }
1397                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1398                                  &sk_offset, &num_found);
1399                 btrfs_release_path(root, path);
1400                 if (ret || num_found >= sk->nr_items)
1401                         break;
1402
1403         }
1404         ret = 0;
1405 err:
1406         sk->nr_items = num_found;
1407         btrfs_free_path(path);
1408         return ret;
1409 }
1410
1411 static noinline int btrfs_ioctl_tree_search(struct file *file,
1412                                            void __user *argp)
1413 {
1414          struct btrfs_ioctl_search_args *args;
1415          struct inode *inode;
1416          int ret;
1417
1418         if (!capable(CAP_SYS_ADMIN))
1419                 return -EPERM;
1420
1421         args = memdup_user(argp, sizeof(*args));
1422         if (IS_ERR(args))
1423                 return PTR_ERR(args);
1424
1425         inode = fdentry(file)->d_inode;
1426         ret = search_ioctl(inode, args);
1427         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1428                 ret = -EFAULT;
1429         kfree(args);
1430         return ret;
1431 }
1432
1433 /*
1434  * Search INODE_REFs to identify path name of 'dirid' directory
1435  * in a 'tree_id' tree. and sets path name to 'name'.
1436  */
1437 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1438                                 u64 tree_id, u64 dirid, char *name)
1439 {
1440         struct btrfs_root *root;
1441         struct btrfs_key key;
1442         char *ptr;
1443         int ret = -1;
1444         int slot;
1445         int len;
1446         int total_len = 0;
1447         struct btrfs_inode_ref *iref;
1448         struct extent_buffer *l;
1449         struct btrfs_path *path;
1450
1451         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1452                 name[0]='\0';
1453                 return 0;
1454         }
1455
1456         path = btrfs_alloc_path();
1457         if (!path)
1458                 return -ENOMEM;
1459
1460         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1461
1462         key.objectid = tree_id;
1463         key.type = BTRFS_ROOT_ITEM_KEY;
1464         key.offset = (u64)-1;
1465         root = btrfs_read_fs_root_no_name(info, &key);
1466         if (IS_ERR(root)) {
1467                 printk(KERN_ERR "could not find root %llu\n", tree_id);
1468                 ret = -ENOENT;
1469                 goto out;
1470         }
1471
1472         key.objectid = dirid;
1473         key.type = BTRFS_INODE_REF_KEY;
1474         key.offset = (u64)-1;
1475
1476         while(1) {
1477                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1478                 if (ret < 0)
1479                         goto out;
1480
1481                 l = path->nodes[0];
1482                 slot = path->slots[0];
1483                 if (ret > 0 && slot > 0)
1484                         slot--;
1485                 btrfs_item_key_to_cpu(l, &key, slot);
1486
1487                 if (ret > 0 && (key.objectid != dirid ||
1488                                 key.type != BTRFS_INODE_REF_KEY)) {
1489                         ret = -ENOENT;
1490                         goto out;
1491                 }
1492
1493                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1494                 len = btrfs_inode_ref_name_len(l, iref);
1495                 ptr -= len + 1;
1496                 total_len += len + 1;
1497                 if (ptr < name)
1498                         goto out;
1499
1500                 *(ptr + len) = '/';
1501                 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1502
1503                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1504                         break;
1505
1506                 btrfs_release_path(root, path);
1507                 key.objectid = key.offset;
1508                 key.offset = (u64)-1;
1509                 dirid = key.objectid;
1510
1511         }
1512         if (ptr < name)
1513                 goto out;
1514         memcpy(name, ptr, total_len);
1515         name[total_len]='\0';
1516         ret = 0;
1517 out:
1518         btrfs_free_path(path);
1519         return ret;
1520 }
1521
1522 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1523                                            void __user *argp)
1524 {
1525          struct btrfs_ioctl_ino_lookup_args *args;
1526          struct inode *inode;
1527          int ret;
1528
1529         if (!capable(CAP_SYS_ADMIN))
1530                 return -EPERM;
1531
1532         args = memdup_user(argp, sizeof(*args));
1533         if (IS_ERR(args))
1534                 return PTR_ERR(args);
1535
1536         inode = fdentry(file)->d_inode;
1537
1538         if (args->treeid == 0)
1539                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
1540
1541         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
1542                                         args->treeid, args->objectid,
1543                                         args->name);
1544
1545         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1546                 ret = -EFAULT;
1547
1548         kfree(args);
1549         return ret;
1550 }
1551
1552 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
1553                                              void __user *arg)
1554 {
1555         struct dentry *parent = fdentry(file);
1556         struct dentry *dentry;
1557         struct inode *dir = parent->d_inode;
1558         struct inode *inode;
1559         struct btrfs_root *root = BTRFS_I(dir)->root;
1560         struct btrfs_root *dest = NULL;
1561         struct btrfs_ioctl_vol_args *vol_args;
1562         struct btrfs_trans_handle *trans;
1563         int namelen;
1564         int ret;
1565         int err = 0;
1566
1567         vol_args = memdup_user(arg, sizeof(*vol_args));
1568         if (IS_ERR(vol_args))
1569                 return PTR_ERR(vol_args);
1570
1571         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1572         namelen = strlen(vol_args->name);
1573         if (strchr(vol_args->name, '/') ||
1574             strncmp(vol_args->name, "..", namelen) == 0) {
1575                 err = -EINVAL;
1576                 goto out;
1577         }
1578
1579         err = mnt_want_write(file->f_path.mnt);
1580         if (err)
1581                 goto out;
1582
1583         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
1584         dentry = lookup_one_len(vol_args->name, parent, namelen);
1585         if (IS_ERR(dentry)) {
1586                 err = PTR_ERR(dentry);
1587                 goto out_unlock_dir;
1588         }
1589
1590         if (!dentry->d_inode) {
1591                 err = -ENOENT;
1592                 goto out_dput;
1593         }
1594
1595         inode = dentry->d_inode;
1596         dest = BTRFS_I(inode)->root;
1597         if (!capable(CAP_SYS_ADMIN)){
1598                 /*
1599                  * Regular user.  Only allow this with a special mount
1600                  * option, when the user has write+exec access to the
1601                  * subvol root, and when rmdir(2) would have been
1602                  * allowed.
1603                  *
1604                  * Note that this is _not_ check that the subvol is
1605                  * empty or doesn't contain data that we wouldn't
1606                  * otherwise be able to delete.
1607                  *
1608                  * Users who want to delete empty subvols should try
1609                  * rmdir(2).
1610                  */
1611                 err = -EPERM;
1612                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1613                         goto out_dput;
1614
1615                 /*
1616                  * Do not allow deletion if the parent dir is the same
1617                  * as the dir to be deleted.  That means the ioctl
1618                  * must be called on the dentry referencing the root
1619                  * of the subvol, not a random directory contained
1620                  * within it.
1621                  */
1622                 err = -EINVAL;
1623                 if (root == dest)
1624                         goto out_dput;
1625
1626                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
1627                 if (err)
1628                         goto out_dput;
1629
1630                 /* check if subvolume may be deleted by a non-root user */
1631                 err = btrfs_may_delete(dir, dentry, 1);
1632                 if (err)
1633                         goto out_dput;
1634         }
1635
1636         if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
1637                 err = -EINVAL;
1638                 goto out_dput;
1639         }
1640
1641         mutex_lock(&inode->i_mutex);
1642         err = d_invalidate(dentry);
1643         if (err)
1644                 goto out_unlock;
1645
1646         down_write(&root->fs_info->subvol_sem);
1647
1648         err = may_destroy_subvol(dest);
1649         if (err)
1650                 goto out_up_write;
1651
1652         trans = btrfs_start_transaction(root, 0);
1653         if (IS_ERR(trans)) {
1654                 err = PTR_ERR(trans);
1655                 goto out_up_write;
1656         }
1657         trans->block_rsv = &root->fs_info->global_block_rsv;
1658
1659         ret = btrfs_unlink_subvol(trans, root, dir,
1660                                 dest->root_key.objectid,
1661                                 dentry->d_name.name,
1662                                 dentry->d_name.len);
1663         BUG_ON(ret);
1664
1665         btrfs_record_root_in_trans(trans, dest);
1666
1667         memset(&dest->root_item.drop_progress, 0,
1668                 sizeof(dest->root_item.drop_progress));
1669         dest->root_item.drop_level = 0;
1670         btrfs_set_root_refs(&dest->root_item, 0);
1671
1672         if (!xchg(&dest->orphan_item_inserted, 1)) {
1673                 ret = btrfs_insert_orphan_item(trans,
1674                                         root->fs_info->tree_root,
1675                                         dest->root_key.objectid);
1676                 BUG_ON(ret);
1677         }
1678
1679         ret = btrfs_end_transaction(trans, root);
1680         BUG_ON(ret);
1681         inode->i_flags |= S_DEAD;
1682 out_up_write:
1683         up_write(&root->fs_info->subvol_sem);
1684 out_unlock:
1685         mutex_unlock(&inode->i_mutex);
1686         if (!err) {
1687                 shrink_dcache_sb(root->fs_info->sb);
1688                 btrfs_invalidate_inodes(dest);
1689                 d_delete(dentry);
1690         }
1691 out_dput:
1692         dput(dentry);
1693 out_unlock_dir:
1694         mutex_unlock(&dir->i_mutex);
1695         mnt_drop_write(file->f_path.mnt);
1696 out:
1697         kfree(vol_args);
1698         return err;
1699 }
1700
1701 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
1702 {
1703         struct inode *inode = fdentry(file)->d_inode;
1704         struct btrfs_root *root = BTRFS_I(inode)->root;
1705         struct btrfs_ioctl_defrag_range_args *range;
1706         int ret;
1707
1708         if (btrfs_root_readonly(root))
1709                 return -EROFS;
1710
1711         ret = mnt_want_write(file->f_path.mnt);
1712         if (ret)
1713                 return ret;
1714
1715         switch (inode->i_mode & S_IFMT) {
1716         case S_IFDIR:
1717                 if (!capable(CAP_SYS_ADMIN)) {
1718                         ret = -EPERM;
1719                         goto out;
1720                 }
1721                 ret = btrfs_defrag_root(root, 0);
1722                 if (ret)
1723                         goto out;
1724                 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
1725                 break;
1726         case S_IFREG:
1727                 if (!(file->f_mode & FMODE_WRITE)) {
1728                         ret = -EINVAL;
1729                         goto out;
1730                 }
1731
1732                 range = kzalloc(sizeof(*range), GFP_KERNEL);
1733                 if (!range) {
1734                         ret = -ENOMEM;
1735                         goto out;
1736                 }
1737
1738                 if (argp) {
1739                         if (copy_from_user(range, argp,
1740                                            sizeof(*range))) {
1741                                 ret = -EFAULT;
1742                                 kfree(range);
1743                                 goto out;
1744                         }
1745                         /* compression requires us to start the IO */
1746                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1747                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
1748                                 range->extent_thresh = (u32)-1;
1749                         }
1750                 } else {
1751                         /* the rest are all set to zero by kzalloc */
1752                         range->len = (u64)-1;
1753                 }
1754                 ret = btrfs_defrag_file(file, range);
1755                 kfree(range);
1756                 break;
1757         default:
1758                 ret = -EINVAL;
1759         }
1760 out:
1761         mnt_drop_write(file->f_path.mnt);
1762         return ret;
1763 }
1764
1765 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
1766 {
1767         struct btrfs_ioctl_vol_args *vol_args;
1768         int ret;
1769
1770         if (!capable(CAP_SYS_ADMIN))
1771                 return -EPERM;
1772
1773         vol_args = memdup_user(arg, sizeof(*vol_args));
1774         if (IS_ERR(vol_args))
1775                 return PTR_ERR(vol_args);
1776
1777         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1778         ret = btrfs_init_new_device(root, vol_args->name);
1779
1780         kfree(vol_args);
1781         return ret;
1782 }
1783
1784 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
1785 {
1786         struct btrfs_ioctl_vol_args *vol_args;
1787         int ret;
1788
1789         if (!capable(CAP_SYS_ADMIN))
1790                 return -EPERM;
1791
1792         if (root->fs_info->sb->s_flags & MS_RDONLY)
1793                 return -EROFS;
1794
1795         vol_args = memdup_user(arg, sizeof(*vol_args));
1796         if (IS_ERR(vol_args))
1797                 return PTR_ERR(vol_args);
1798
1799         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1800         ret = btrfs_rm_device(root, vol_args->name);
1801
1802         kfree(vol_args);
1803         return ret;
1804 }
1805
1806 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
1807                                        u64 off, u64 olen, u64 destoff)
1808 {
1809         struct inode *inode = fdentry(file)->d_inode;
1810         struct btrfs_root *root = BTRFS_I(inode)->root;
1811         struct file *src_file;
1812         struct inode *src;
1813         struct btrfs_trans_handle *trans;
1814         struct btrfs_path *path;
1815         struct extent_buffer *leaf;
1816         char *buf;
1817         struct btrfs_key key;
1818         u32 nritems;
1819         int slot;
1820         int ret;
1821         u64 len = olen;
1822         u64 bs = root->fs_info->sb->s_blocksize;
1823         u64 hint_byte;
1824
1825         /*
1826          * TODO:
1827          * - split compressed inline extents.  annoying: we need to
1828          *   decompress into destination's address_space (the file offset
1829          *   may change, so source mapping won't do), then recompress (or
1830          *   otherwise reinsert) a subrange.
1831          * - allow ranges within the same file to be cloned (provided
1832          *   they don't overlap)?
1833          */
1834
1835         /* the destination must be opened for writing */
1836         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
1837                 return -EINVAL;
1838
1839         if (btrfs_root_readonly(root))
1840                 return -EROFS;
1841
1842         ret = mnt_want_write(file->f_path.mnt);
1843         if (ret)
1844                 return ret;
1845
1846         src_file = fget(srcfd);
1847         if (!src_file) {
1848                 ret = -EBADF;
1849                 goto out_drop_write;
1850         }
1851
1852         src = src_file->f_dentry->d_inode;
1853
1854         ret = -EINVAL;
1855         if (src == inode)
1856                 goto out_fput;
1857
1858         /* the src must be open for reading */
1859         if (!(src_file->f_mode & FMODE_READ))
1860                 goto out_fput;
1861
1862         ret = -EISDIR;
1863         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
1864                 goto out_fput;
1865
1866         ret = -EXDEV;
1867         if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
1868                 goto out_fput;
1869
1870         ret = -ENOMEM;
1871         buf = vmalloc(btrfs_level_size(root, 0));
1872         if (!buf)
1873                 goto out_fput;
1874
1875         path = btrfs_alloc_path();
1876         if (!path) {
1877                 vfree(buf);
1878                 goto out_fput;
1879         }
1880         path->reada = 2;
1881
1882         if (inode < src) {
1883                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
1884                 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
1885         } else {
1886                 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
1887                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
1888         }
1889
1890         /* determine range to clone */
1891         ret = -EINVAL;
1892         if (off + len > src->i_size || off + len < off)
1893                 goto out_unlock;
1894         if (len == 0)
1895                 olen = len = src->i_size - off;
1896         /* if we extend to eof, continue to block boundary */
1897         if (off + len == src->i_size)
1898                 len = ALIGN(src->i_size, bs) - off;
1899
1900         /* verify the end result is block aligned */
1901         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
1902             !IS_ALIGNED(destoff, bs))
1903                 goto out_unlock;
1904
1905         /* do any pending delalloc/csum calc on src, one way or
1906            another, and lock file content */
1907         while (1) {
1908                 struct btrfs_ordered_extent *ordered;
1909                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1910                 ordered = btrfs_lookup_first_ordered_extent(src, off+len);
1911                 if (!ordered &&
1912                     !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
1913                                    EXTENT_DELALLOC, 0, NULL))
1914                         break;
1915                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1916                 if (ordered)
1917                         btrfs_put_ordered_extent(ordered);
1918                 btrfs_wait_ordered_range(src, off, len);
1919         }
1920
1921         /* clone data */
1922         key.objectid = src->i_ino;
1923         key.type = BTRFS_EXTENT_DATA_KEY;
1924         key.offset = 0;
1925
1926         while (1) {
1927                 /*
1928                  * note the key will change type as we walk through the
1929                  * tree.
1930                  */
1931                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1932                 if (ret < 0)
1933                         goto out;
1934
1935                 nritems = btrfs_header_nritems(path->nodes[0]);
1936                 if (path->slots[0] >= nritems) {
1937                         ret = btrfs_next_leaf(root, path);
1938                         if (ret < 0)
1939                                 goto out;
1940                         if (ret > 0)
1941                                 break;
1942                         nritems = btrfs_header_nritems(path->nodes[0]);
1943                 }
1944                 leaf = path->nodes[0];
1945                 slot = path->slots[0];
1946
1947                 btrfs_item_key_to_cpu(leaf, &key, slot);
1948                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
1949                     key.objectid != src->i_ino)
1950                         break;
1951
1952                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
1953                         struct btrfs_file_extent_item *extent;
1954                         int type;
1955                         u32 size;
1956                         struct btrfs_key new_key;
1957                         u64 disko = 0, diskl = 0;
1958                         u64 datao = 0, datal = 0;
1959                         u8 comp;
1960                         u64 endoff;
1961
1962                         size = btrfs_item_size_nr(leaf, slot);
1963                         read_extent_buffer(leaf, buf,
1964                                            btrfs_item_ptr_offset(leaf, slot),
1965                                            size);
1966
1967                         extent = btrfs_item_ptr(leaf, slot,
1968                                                 struct btrfs_file_extent_item);
1969                         comp = btrfs_file_extent_compression(leaf, extent);
1970                         type = btrfs_file_extent_type(leaf, extent);
1971                         if (type == BTRFS_FILE_EXTENT_REG ||
1972                             type == BTRFS_FILE_EXTENT_PREALLOC) {
1973                                 disko = btrfs_file_extent_disk_bytenr(leaf,
1974                                                                       extent);
1975                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
1976                                                                  extent);
1977                                 datao = btrfs_file_extent_offset(leaf, extent);
1978                                 datal = btrfs_file_extent_num_bytes(leaf,
1979                                                                     extent);
1980                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1981                                 /* take upper bound, may be compressed */
1982                                 datal = btrfs_file_extent_ram_bytes(leaf,
1983                                                                     extent);
1984                         }
1985                         btrfs_release_path(root, path);
1986
1987                         if (key.offset + datal <= off ||
1988                             key.offset >= off+len)
1989                                 goto next;
1990
1991                         memcpy(&new_key, &key, sizeof(new_key));
1992                         new_key.objectid = inode->i_ino;
1993                         if (off <= key.offset)
1994                                 new_key.offset = key.offset + destoff - off;
1995                         else
1996                                 new_key.offset = destoff;
1997
1998                         trans = btrfs_start_transaction(root, 1);
1999                         if (IS_ERR(trans)) {
2000                                 ret = PTR_ERR(trans);
2001                                 goto out;
2002                         }
2003
2004                         if (type == BTRFS_FILE_EXTENT_REG ||
2005                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2006                                 if (off > key.offset) {
2007                                         datao += off - key.offset;
2008                                         datal -= off - key.offset;
2009                                 }
2010
2011                                 if (key.offset + datal > off + len)
2012                                         datal = off + len - key.offset;
2013
2014                                 ret = btrfs_drop_extents(trans, inode,
2015                                                          new_key.offset,
2016                                                          new_key.offset + datal,
2017                                                          &hint_byte, 1);
2018                                 BUG_ON(ret);
2019
2020                                 ret = btrfs_insert_empty_item(trans, root, path,
2021                                                               &new_key, size);
2022                                 BUG_ON(ret);
2023
2024                                 leaf = path->nodes[0];
2025                                 slot = path->slots[0];
2026                                 write_extent_buffer(leaf, buf,
2027                                             btrfs_item_ptr_offset(leaf, slot),
2028                                             size);
2029
2030                                 extent = btrfs_item_ptr(leaf, slot,
2031                                                 struct btrfs_file_extent_item);
2032
2033                                 /* disko == 0 means it's a hole */
2034                                 if (!disko)
2035                                         datao = 0;
2036
2037                                 btrfs_set_file_extent_offset(leaf, extent,
2038                                                              datao);
2039                                 btrfs_set_file_extent_num_bytes(leaf, extent,
2040                                                                 datal);
2041                                 if (disko) {
2042                                         inode_add_bytes(inode, datal);
2043                                         ret = btrfs_inc_extent_ref(trans, root,
2044                                                         disko, diskl, 0,
2045                                                         root->root_key.objectid,
2046                                                         inode->i_ino,
2047                                                         new_key.offset - datao);
2048                                         BUG_ON(ret);
2049                                 }
2050                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2051                                 u64 skip = 0;
2052                                 u64 trim = 0;
2053                                 if (off > key.offset) {
2054                                         skip = off - key.offset;
2055                                         new_key.offset += skip;
2056                                 }
2057
2058                                 if (key.offset + datal > off+len)
2059                                         trim = key.offset + datal - (off+len);
2060
2061                                 if (comp && (skip || trim)) {
2062                                         ret = -EINVAL;
2063                                         btrfs_end_transaction(trans, root);
2064                                         goto out;
2065                                 }
2066                                 size -= skip + trim;
2067                                 datal -= skip + trim;
2068
2069                                 ret = btrfs_drop_extents(trans, inode,
2070                                                          new_key.offset,
2071                                                          new_key.offset + datal,
2072                                                          &hint_byte, 1);
2073                                 BUG_ON(ret);
2074
2075                                 ret = btrfs_insert_empty_item(trans, root, path,
2076                                                               &new_key, size);
2077                                 BUG_ON(ret);
2078
2079                                 if (skip) {
2080                                         u32 start =
2081                                           btrfs_file_extent_calc_inline_size(0);
2082                                         memmove(buf+start, buf+start+skip,
2083                                                 datal);
2084                                 }
2085
2086                                 leaf = path->nodes[0];
2087                                 slot = path->slots[0];
2088                                 write_extent_buffer(leaf, buf,
2089                                             btrfs_item_ptr_offset(leaf, slot),
2090                                             size);
2091                                 inode_add_bytes(inode, datal);
2092                         }
2093
2094                         btrfs_mark_buffer_dirty(leaf);
2095                         btrfs_release_path(root, path);
2096
2097                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2098
2099                         /*
2100                          * we round up to the block size at eof when
2101                          * determining which extents to clone above,
2102                          * but shouldn't round up the file size
2103                          */
2104                         endoff = new_key.offset + datal;
2105                         if (endoff > destoff+olen)
2106                                 endoff = destoff+olen;
2107                         if (endoff > inode->i_size)
2108                                 btrfs_i_size_write(inode, endoff);
2109
2110                         BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
2111                         ret = btrfs_update_inode(trans, root, inode);
2112                         BUG_ON(ret);
2113                         btrfs_end_transaction(trans, root);
2114                 }
2115 next:
2116                 btrfs_release_path(root, path);
2117                 key.offset++;
2118         }
2119         ret = 0;
2120 out:
2121         btrfs_release_path(root, path);
2122         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
2123 out_unlock:
2124         mutex_unlock(&src->i_mutex);
2125         mutex_unlock(&inode->i_mutex);
2126         vfree(buf);
2127         btrfs_free_path(path);
2128 out_fput:
2129         fput(src_file);
2130 out_drop_write:
2131         mnt_drop_write(file->f_path.mnt);
2132         return ret;
2133 }
2134
2135 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2136 {
2137         struct btrfs_ioctl_clone_range_args args;
2138
2139         if (copy_from_user(&args, argp, sizeof(args)))
2140                 return -EFAULT;
2141         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2142                                  args.src_length, args.dest_offset);
2143 }
2144
2145 /*
2146  * there are many ways the trans_start and trans_end ioctls can lead
2147  * to deadlocks.  They should only be used by applications that
2148  * basically own the machine, and have a very in depth understanding
2149  * of all the possible deadlocks and enospc problems.
2150  */
2151 static long btrfs_ioctl_trans_start(struct file *file)
2152 {
2153         struct inode *inode = fdentry(file)->d_inode;
2154         struct btrfs_root *root = BTRFS_I(inode)->root;
2155         struct btrfs_trans_handle *trans;
2156         int ret;
2157
2158         ret = -EPERM;
2159         if (!capable(CAP_SYS_ADMIN))
2160                 goto out;
2161
2162         ret = -EINPROGRESS;
2163         if (file->private_data)
2164                 goto out;
2165
2166         ret = -EROFS;
2167         if (btrfs_root_readonly(root))
2168                 goto out;
2169
2170         ret = mnt_want_write(file->f_path.mnt);
2171         if (ret)
2172                 goto out;
2173
2174         mutex_lock(&root->fs_info->trans_mutex);
2175         root->fs_info->open_ioctl_trans++;
2176         mutex_unlock(&root->fs_info->trans_mutex);
2177
2178         ret = -ENOMEM;
2179         trans = btrfs_start_ioctl_transaction(root, 0);
2180         if (IS_ERR(trans))
2181                 goto out_drop;
2182
2183         file->private_data = trans;
2184         return 0;
2185
2186 out_drop:
2187         mutex_lock(&root->fs_info->trans_mutex);
2188         root->fs_info->open_ioctl_trans--;
2189         mutex_unlock(&root->fs_info->trans_mutex);
2190         mnt_drop_write(file->f_path.mnt);
2191 out:
2192         return ret;
2193 }
2194
2195 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2196 {
2197         struct inode *inode = fdentry(file)->d_inode;
2198         struct btrfs_root *root = BTRFS_I(inode)->root;
2199         struct btrfs_root *new_root;
2200         struct btrfs_dir_item *di;
2201         struct btrfs_trans_handle *trans;
2202         struct btrfs_path *path;
2203         struct btrfs_key location;
2204         struct btrfs_disk_key disk_key;
2205         struct btrfs_super_block *disk_super;
2206         u64 features;
2207         u64 objectid = 0;
2208         u64 dir_id;
2209
2210         if (!capable(CAP_SYS_ADMIN))
2211                 return -EPERM;
2212
2213         if (copy_from_user(&objectid, argp, sizeof(objectid)))
2214                 return -EFAULT;
2215
2216         if (!objectid)
2217                 objectid = root->root_key.objectid;
2218
2219         location.objectid = objectid;
2220         location.type = BTRFS_ROOT_ITEM_KEY;
2221         location.offset = (u64)-1;
2222
2223         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2224         if (IS_ERR(new_root))
2225                 return PTR_ERR(new_root);
2226
2227         if (btrfs_root_refs(&new_root->root_item) == 0)
2228                 return -ENOENT;
2229
2230         path = btrfs_alloc_path();
2231         if (!path)
2232                 return -ENOMEM;
2233         path->leave_spinning = 1;
2234
2235         trans = btrfs_start_transaction(root, 1);
2236         if (IS_ERR(trans)) {
2237                 btrfs_free_path(path);
2238                 return PTR_ERR(trans);
2239         }
2240
2241         dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
2242         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2243                                    dir_id, "default", 7, 1);
2244         if (IS_ERR_OR_NULL(di)) {
2245                 btrfs_free_path(path);
2246                 btrfs_end_transaction(trans, root);
2247                 printk(KERN_ERR "Umm, you don't have the default dir item, "
2248                        "this isn't going to work\n");
2249                 return -ENOENT;
2250         }
2251
2252         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2253         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2254         btrfs_mark_buffer_dirty(path->nodes[0]);
2255         btrfs_free_path(path);
2256
2257         disk_super = &root->fs_info->super_copy;
2258         features = btrfs_super_incompat_flags(disk_super);
2259         if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
2260                 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
2261                 btrfs_set_super_incompat_flags(disk_super, features);
2262         }
2263         btrfs_end_transaction(trans, root);
2264
2265         return 0;
2266 }
2267
2268 static void get_block_group_info(struct list_head *groups_list,
2269                                  struct btrfs_ioctl_space_info *space)
2270 {
2271         struct btrfs_block_group_cache *block_group;
2272
2273         space->total_bytes = 0;
2274         space->used_bytes = 0;
2275         space->flags = 0;
2276         list_for_each_entry(block_group, groups_list, list) {
2277                 space->flags = block_group->flags;
2278                 space->total_bytes += block_group->key.offset;
2279                 space->used_bytes +=
2280                         btrfs_block_group_used(&block_group->item);
2281         }
2282 }
2283
2284 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2285 {
2286         struct btrfs_ioctl_space_args space_args;
2287         struct btrfs_ioctl_space_info space;
2288         struct btrfs_ioctl_space_info *dest;
2289         struct btrfs_ioctl_space_info *dest_orig;
2290         struct btrfs_ioctl_space_info *user_dest;
2291         struct btrfs_space_info *info;
2292         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2293                        BTRFS_BLOCK_GROUP_SYSTEM,
2294                        BTRFS_BLOCK_GROUP_METADATA,
2295                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2296         int num_types = 4;
2297         int alloc_size;
2298         int ret = 0;
2299         u64 slot_count = 0;
2300         int i, c;
2301
2302         if (copy_from_user(&space_args,
2303                            (struct btrfs_ioctl_space_args __user *)arg,
2304                            sizeof(space_args)))
2305                 return -EFAULT;
2306
2307         for (i = 0; i < num_types; i++) {
2308                 struct btrfs_space_info *tmp;
2309
2310                 info = NULL;
2311                 rcu_read_lock();
2312                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2313                                         list) {
2314                         if (tmp->flags == types[i]) {
2315                                 info = tmp;
2316                                 break;
2317                         }
2318                 }
2319                 rcu_read_unlock();
2320
2321                 if (!info)
2322                         continue;
2323
2324                 down_read(&info->groups_sem);
2325                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2326                         if (!list_empty(&info->block_groups[c]))
2327                                 slot_count++;
2328                 }
2329                 up_read(&info->groups_sem);
2330         }
2331
2332         /* space_slots == 0 means they are asking for a count */
2333         if (space_args.space_slots == 0) {
2334                 space_args.total_spaces = slot_count;
2335                 goto out;
2336         }
2337
2338         slot_count = min_t(u64, space_args.space_slots, slot_count);
2339
2340         alloc_size = sizeof(*dest) * slot_count;
2341
2342         /* we generally have at most 6 or so space infos, one for each raid
2343          * level.  So, a whole page should be more than enough for everyone
2344          */
2345         if (alloc_size > PAGE_CACHE_SIZE)
2346                 return -ENOMEM;
2347
2348         space_args.total_spaces = 0;
2349         dest = kmalloc(alloc_size, GFP_NOFS);
2350         if (!dest)
2351                 return -ENOMEM;
2352         dest_orig = dest;
2353
2354         /* now we have a buffer to copy into */
2355         for (i = 0; i < num_types; i++) {
2356                 struct btrfs_space_info *tmp;
2357
2358                 if (!slot_count)
2359                         break;
2360
2361                 info = NULL;
2362                 rcu_read_lock();
2363                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2364                                         list) {
2365                         if (tmp->flags == types[i]) {
2366                                 info = tmp;
2367                                 break;
2368                         }
2369                 }
2370                 rcu_read_unlock();
2371
2372                 if (!info)
2373                         continue;
2374                 down_read(&info->groups_sem);
2375                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2376                         if (!list_empty(&info->block_groups[c])) {
2377                                 get_block_group_info(&info->block_groups[c],
2378                                                      &space);
2379                                 memcpy(dest, &space, sizeof(space));
2380                                 dest++;
2381                                 space_args.total_spaces++;
2382                                 slot_count--;
2383                         }
2384                         if (!slot_count)
2385                                 break;
2386                 }
2387                 up_read(&info->groups_sem);
2388         }
2389
2390         user_dest = (struct btrfs_ioctl_space_info *)
2391                 (arg + sizeof(struct btrfs_ioctl_space_args));
2392
2393         if (copy_to_user(user_dest, dest_orig, alloc_size))
2394                 ret = -EFAULT;
2395
2396         kfree(dest_orig);
2397 out:
2398         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
2399                 ret = -EFAULT;
2400
2401         return ret;
2402 }
2403
2404 /*
2405  * there are many ways the trans_start and trans_end ioctls can lead
2406  * to deadlocks.  They should only be used by applications that
2407  * basically own the machine, and have a very in depth understanding
2408  * of all the possible deadlocks and enospc problems.
2409  */
2410 long btrfs_ioctl_trans_end(struct file *file)
2411 {
2412         struct inode *inode = fdentry(file)->d_inode;
2413         struct btrfs_root *root = BTRFS_I(inode)->root;
2414         struct btrfs_trans_handle *trans;
2415
2416         trans = file->private_data;
2417         if (!trans)
2418                 return -EINVAL;
2419         file->private_data = NULL;
2420
2421         btrfs_end_transaction(trans, root);
2422
2423         mutex_lock(&root->fs_info->trans_mutex);
2424         root->fs_info->open_ioctl_trans--;
2425         mutex_unlock(&root->fs_info->trans_mutex);
2426
2427         mnt_drop_write(file->f_path.mnt);
2428         return 0;
2429 }
2430
2431 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
2432 {
2433         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2434         struct btrfs_trans_handle *trans;
2435         u64 transid;
2436         int ret;
2437
2438         trans = btrfs_start_transaction(root, 0);
2439         if (IS_ERR(trans))
2440                 return PTR_ERR(trans);
2441         transid = trans->transid;
2442         ret = btrfs_commit_transaction_async(trans, root, 0);
2443         if (ret) {
2444                 btrfs_end_transaction(trans, root);
2445                 return ret;
2446         }
2447
2448         if (argp)
2449                 if (copy_to_user(argp, &transid, sizeof(transid)))
2450                         return -EFAULT;
2451         return 0;
2452 }
2453
2454 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
2455 {
2456         struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
2457         u64 transid;
2458
2459         if (argp) {
2460                 if (copy_from_user(&transid, argp, sizeof(transid)))
2461                         return -EFAULT;
2462         } else {
2463                 transid = 0;  /* current trans */
2464         }
2465         return btrfs_wait_for_commit(root, transid);
2466 }
2467
2468 long btrfs_ioctl(struct file *file, unsigned int
2469                 cmd, unsigned long arg)
2470 {
2471         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2472         void __user *argp = (void __user *)arg;
2473
2474         switch (cmd) {
2475         case FS_IOC_GETFLAGS:
2476                 return btrfs_ioctl_getflags(file, argp);
2477         case FS_IOC_SETFLAGS:
2478                 return btrfs_ioctl_setflags(file, argp);
2479         case FS_IOC_GETVERSION:
2480                 return btrfs_ioctl_getversion(file, argp);
2481         case FITRIM:
2482                 return btrfs_ioctl_fitrim(file, argp);
2483         case BTRFS_IOC_SNAP_CREATE:
2484                 return btrfs_ioctl_snap_create(file, argp, 0);
2485         case BTRFS_IOC_SNAP_CREATE_V2:
2486                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
2487         case BTRFS_IOC_SUBVOL_CREATE:
2488                 return btrfs_ioctl_snap_create(file, argp, 1);
2489         case BTRFS_IOC_SNAP_DESTROY:
2490                 return btrfs_ioctl_snap_destroy(file, argp);
2491         case BTRFS_IOC_SUBVOL_GETFLAGS:
2492                 return btrfs_ioctl_subvol_getflags(file, argp);
2493         case BTRFS_IOC_SUBVOL_SETFLAGS:
2494                 return btrfs_ioctl_subvol_setflags(file, argp);
2495         case BTRFS_IOC_DEFAULT_SUBVOL:
2496                 return btrfs_ioctl_default_subvol(file, argp);
2497         case BTRFS_IOC_DEFRAG:
2498                 return btrfs_ioctl_defrag(file, NULL);
2499         case BTRFS_IOC_DEFRAG_RANGE:
2500                 return btrfs_ioctl_defrag(file, argp);
2501         case BTRFS_IOC_RESIZE:
2502                 return btrfs_ioctl_resize(root, argp);
2503         case BTRFS_IOC_ADD_DEV:
2504                 return btrfs_ioctl_add_dev(root, argp);
2505         case BTRFS_IOC_RM_DEV:
2506                 return btrfs_ioctl_rm_dev(root, argp);
2507         case BTRFS_IOC_BALANCE:
2508                 return btrfs_balance(root->fs_info->dev_root);
2509         case BTRFS_IOC_CLONE:
2510                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
2511         case BTRFS_IOC_CLONE_RANGE:
2512                 return btrfs_ioctl_clone_range(file, argp);
2513         case BTRFS_IOC_TRANS_START:
2514                 return btrfs_ioctl_trans_start(file);
2515         case BTRFS_IOC_TRANS_END:
2516                 return btrfs_ioctl_trans_end(file);
2517         case BTRFS_IOC_TREE_SEARCH:
2518                 return btrfs_ioctl_tree_search(file, argp);
2519         case BTRFS_IOC_INO_LOOKUP:
2520                 return btrfs_ioctl_ino_lookup(file, argp);
2521         case BTRFS_IOC_SPACE_INFO:
2522                 return btrfs_ioctl_space_info(root, argp);
2523         case BTRFS_IOC_SYNC:
2524                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
2525                 return 0;
2526         case BTRFS_IOC_START_SYNC:
2527                 return btrfs_ioctl_start_sync(file, argp);
2528         case BTRFS_IOC_WAIT_SYNC:
2529                 return btrfs_ioctl_wait_sync(file, argp);
2530         }
2531
2532         return -ENOTTY;
2533 }