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/compat.h>
  37 #include <linux/bit_spinlock.h>
  38 #include <linux/security.h>
  39 #include <linux/xattr.h>
  40 #include <linux/vmalloc.h>
  41 #include <linux/slab.h>
  42 #include <linux/blkdev.h>
  43 #include <linux/uuid.h>
  44 #include <linux/btrfs.h>
  45 #include <linux/uaccess.h>
  46 #include "ctree.h"
  47 #include "disk-io.h"
  48 #include "transaction.h"
  49 #include "btrfs_inode.h"
  50 #include "print-tree.h"
  51 #include "volumes.h"
  52 #include "locking.h"
  53 #include "inode-map.h"
  54 #include "backref.h"
  55 #include "rcu-string.h"
  56 #include "send.h"
  57 #include "dev-replace.h"
  58 #include "props.h"
  59 #include "sysfs.h"
  60 #include "qgroup.h"
  61 #include "tree-log.h"
  62 #include "compression.h"
  63
  64 #ifdef CONFIG_64BIT
  65 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  66  * structures are incorrect, as the timespec structure from userspace
  67  * is 4 bytes too small. We define these alternatives here to teach
  68  * the kernel about the 32-bit struct packing.
  69  */
  70 struct btrfs_ioctl_timespec_32 {
  71         __u64 sec;
  72         __u32 nsec;
  73 } __attribute__ ((__packed__));
  74
  75 struct btrfs_ioctl_received_subvol_args_32 {
  76         char    uuid[BTRFS_UUID_SIZE];  /* in */
  77         __u64   stransid;               /* in */
  78         __u64   rtransid;               /* out */
  79         struct btrfs_ioctl_timespec_32 stime; /* in */
  80         struct btrfs_ioctl_timespec_32 rtime; /* out */
  81         __u64   flags;                  /* in */
  82         __u64   reserved[16];           /* in */
  83 } __attribute__ ((__packed__));
  84
  85 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  86                                 struct btrfs_ioctl_received_subvol_args_32)
  87 #endif
  88
  89
  90 static int btrfs_clone(struct inode *src, struct inode *inode,
  91                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  92                        int no_time_update);
  93
  94 /* Mask out flags that are inappropriate for the given type of inode. */
  95 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  96 {
  97         if (S_ISDIR(mode))
  98                 return flags;
  99         else if (S_ISREG(mode))
 100                 return flags & ~FS_DIRSYNC_FL;
 101         else
 102                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 103 }
 104
 105 /*
 106  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
 107  */
 108 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
 109 {
 110         unsigned int iflags = 0;
 111
 112         if (flags & BTRFS_INODE_SYNC)
 113                 iflags |= FS_SYNC_FL;
 114         if (flags & BTRFS_INODE_IMMUTABLE)
 115                 iflags |= FS_IMMUTABLE_FL;
 116         if (flags & BTRFS_INODE_APPEND)
 117                 iflags |= FS_APPEND_FL;
 118         if (flags & BTRFS_INODE_NODUMP)
 119                 iflags |= FS_NODUMP_FL;
 120         if (flags & BTRFS_INODE_NOATIME)
 121                 iflags |= FS_NOATIME_FL;
 122         if (flags & BTRFS_INODE_DIRSYNC)
 123                 iflags |= FS_DIRSYNC_FL;
 124         if (flags & BTRFS_INODE_NODATACOW)
 125                 iflags |= FS_NOCOW_FL;
 126
 127         if (flags & BTRFS_INODE_NOCOMPRESS)
 128                 iflags |= FS_NOCOMP_FL;
 129         else if (flags & BTRFS_INODE_COMPRESS)
 130                 iflags |= FS_COMPR_FL;
 131
 132         return iflags;
 133 }
 134
 135 /*
 136  * Update inode->i_flags based on the btrfs internal flags.
 137  */
 138 void btrfs_update_iflags(struct inode *inode)
 139 {
 140         struct btrfs_inode *ip = BTRFS_I(inode);
 141         unsigned int new_fl = 0;
 142
 143         if (ip->flags & BTRFS_INODE_SYNC)
 144                 new_fl |= S_SYNC;
 145         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 146                 new_fl |= S_IMMUTABLE;
 147         if (ip->flags & BTRFS_INODE_APPEND)
 148                 new_fl |= S_APPEND;
 149         if (ip->flags & BTRFS_INODE_NOATIME)
 150                 new_fl |= S_NOATIME;
 151         if (ip->flags & BTRFS_INODE_DIRSYNC)
 152                 new_fl |= S_DIRSYNC;
 153
 154         set_mask_bits(&inode->i_flags,
 155                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 156                       new_fl);
 157 }
 158
 159 /*
 160  * Inherit flags from the parent inode.
 161  *
 162  * Currently only the compression flags and the cow flags are inherited.
 163  */
 164 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 165 {
 166         unsigned int flags;
 167
 168         if (!dir)
 169                 return;
 170
 171         flags = BTRFS_I(dir)->flags;
 172
 173         if (flags & BTRFS_INODE_NOCOMPRESS) {
 174                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 175                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 176         } else if (flags & BTRFS_INODE_COMPRESS) {
 177                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 178                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 179         }
 180
 181         if (flags & BTRFS_INODE_NODATACOW) {
 182                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 183                 if (S_ISREG(inode->i_mode))
 184                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
 185         }
 186
 187         btrfs_update_iflags(inode);
 188 }
 189
 190 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 191 {
 192         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 193         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 194
 195         if (copy_to_user(arg, &flags, sizeof(flags)))
 196                 return -EFAULT;
 197         return 0;
 198 }
 199
 200 static int check_flags(unsigned int flags)
 201 {
 202         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 203                       FS_NOATIME_FL | FS_NODUMP_FL | \
 204                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 205                       FS_NOCOMP_FL | FS_COMPR_FL |
 206                       FS_NOCOW_FL))
 207                 return -EOPNOTSUPP;
 208
 209         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 210                 return -EINVAL;
 211
 212         return 0;
 213 }
 214
 215 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 216 {
 217         struct inode *inode = file_inode(file);
 218         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 219         struct btrfs_inode *ip = BTRFS_I(inode);
 220         struct btrfs_root *root = ip->root;
 221         struct btrfs_trans_handle *trans;
 222         unsigned int flags, oldflags;
 223         int ret;
 224         u64 ip_oldflags;
 225         unsigned int i_oldflags;
 226         umode_t mode;
 227
 228         if (!inode_owner_or_capable(inode))
 229                 return -EPERM;
 230
 231         if (btrfs_root_readonly(root))
 232                 return -EROFS;
 233
 234         if (copy_from_user(&flags, arg, sizeof(flags)))
 235                 return -EFAULT;
 236
 237         ret = check_flags(flags);
 238         if (ret)
 239                 return ret;
 240
 241         ret = mnt_want_write_file(file);
 242         if (ret)
 243                 return ret;
 244
 245         inode_lock(inode);
 246
 247         ip_oldflags = ip->flags;
 248         i_oldflags = inode->i_flags;
 249         mode = inode->i_mode;
 250
 251         flags = btrfs_mask_flags(inode->i_mode, flags);
 252         oldflags = btrfs_flags_to_ioctl(ip->flags);
 253         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 254                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 255                         ret = -EPERM;
 256                         goto out_unlock;
 257                 }
 258         }
 259
 260         if (flags & FS_SYNC_FL)
 261                 ip->flags |= BTRFS_INODE_SYNC;
 262         else
 263                 ip->flags &= ~BTRFS_INODE_SYNC;
 264         if (flags & FS_IMMUTABLE_FL)
 265                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 266         else
 267                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 268         if (flags & FS_APPEND_FL)
 269                 ip->flags |= BTRFS_INODE_APPEND;
 270         else
 271                 ip->flags &= ~BTRFS_INODE_APPEND;
 272         if (flags & FS_NODUMP_FL)
 273                 ip->flags |= BTRFS_INODE_NODUMP;
 274         else
 275                 ip->flags &= ~BTRFS_INODE_NODUMP;
 276         if (flags & FS_NOATIME_FL)
 277                 ip->flags |= BTRFS_INODE_NOATIME;
 278         else
 279                 ip->flags &= ~BTRFS_INODE_NOATIME;
 280         if (flags & FS_DIRSYNC_FL)
 281                 ip->flags |= BTRFS_INODE_DIRSYNC;
 282         else
 283                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 284         if (flags & FS_NOCOW_FL) {
 285                 if (S_ISREG(mode)) {
 286                         /*
 287                          * It's safe to turn csums off here, no extents exist.
 288                          * Otherwise we want the flag to reflect the real COW
 289                          * status of the file and will not set it.
 290                          */
 291                         if (inode->i_size == 0)
 292                                 ip->flags |= BTRFS_INODE_NODATACOW
 293                                            | BTRFS_INODE_NODATASUM;
 294                 } else {
 295                         ip->flags |= BTRFS_INODE_NODATACOW;
 296                 }
 297         } else {
 298                 /*
 299                  * Revert back under same assumptions as above
 300                  */
 301                 if (S_ISREG(mode)) {
 302                         if (inode->i_size == 0)
 303                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 304                                              | BTRFS_INODE_NODATASUM);
 305                 } else {
 306                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 307                 }
 308         }
 309
 310         /*
 311          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 312          * flag may be changed automatically if compression code won't make
 313          * things smaller.
 314          */
 315         if (flags & FS_NOCOMP_FL) {
 316                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 317                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 318
 319                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 320                 if (ret && ret != -ENODATA)
 321                         goto out_drop;
 322         } else if (flags & FS_COMPR_FL) {
 323                 const char *comp;
 324
 325                 ip->flags |= BTRFS_INODE_COMPRESS;
 326                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 327
 328                 if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
 329                         comp = "lzo";
 330                 else
 331                         comp = "zlib";
 332                 ret = btrfs_set_prop(inode, "btrfs.compression",
 333                                      comp, strlen(comp), 0);
 334                 if (ret)
 335                         goto out_drop;
 336
 337         } else {
 338                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 339                 if (ret && ret != -ENODATA)
 340                         goto out_drop;
 341                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 342         }
 343
 344         trans = btrfs_start_transaction(root, 1);
 345         if (IS_ERR(trans)) {
 346                 ret = PTR_ERR(trans);
 347                 goto out_drop;
 348         }
 349
 350         btrfs_update_iflags(inode);
 351         inode_inc_iversion(inode);
 352         inode->i_ctime = current_time(inode);
 353         ret = btrfs_update_inode(trans, root, inode);
 354
 355         btrfs_end_transaction(trans);
 356  out_drop:
 357         if (ret) {
 358                 ip->flags = ip_oldflags;
 359                 inode->i_flags = i_oldflags;
 360         }
 361
 362  out_unlock:
 363         inode_unlock(inode);
 364         mnt_drop_write_file(file);
 365         return ret;
 366 }
 367
 368 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 369 {
 370         struct inode *inode = file_inode(file);
 371
 372         return put_user(inode->i_generation, arg);
 373 }
 374
 375 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 376 {
 377         struct inode *inode = file_inode(file);
 378         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 379         struct btrfs_device *device;
 380         struct request_queue *q;
 381         struct fstrim_range range;
 382         u64 minlen = ULLONG_MAX;
 383         u64 num_devices = 0;
 384         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 385         int ret;
 386
 387         if (!capable(CAP_SYS_ADMIN))
 388                 return -EPERM;
 389
 390         rcu_read_lock();
 391         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 392                                 dev_list) {
 393                 if (!device->bdev)
 394                         continue;
 395                 q = bdev_get_queue(device->bdev);
 396                 if (blk_queue_discard(q)) {
 397                         num_devices++;
 398                         minlen = min_t(u64, q->limits.discard_granularity,
 399                                      minlen);
 400                 }
 401         }
 402         rcu_read_unlock();
 403
 404         if (!num_devices)
 405                 return -EOPNOTSUPP;
 406         if (copy_from_user(&range, arg, sizeof(range)))
 407                 return -EFAULT;
 408         if (range.start > total_bytes ||
 409             range.len < fs_info->sb->s_blocksize)
 410                 return -EINVAL;
 411
 412         range.len = min(range.len, total_bytes - range.start);
 413         range.minlen = max(range.minlen, minlen);
 414         ret = btrfs_trim_fs(fs_info, &range);
 415         if (ret < 0)
 416                 return ret;
 417
 418         if (copy_to_user(arg, &range, sizeof(range)))
 419                 return -EFAULT;
 420
 421         return 0;
 422 }
 423
 424 int btrfs_is_empty_uuid(u8 *uuid)
 425 {
 426         int i;
 427
 428         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 429                 if (uuid[i])
 430                         return 0;
 431         }
 432         return 1;
 433 }
 434
 435 static noinline int create_subvol(struct inode *dir,
 436                                   struct dentry *dentry,
 437                                   const char *name, int namelen,
 438                                   u64 *async_transid,
 439                                   struct btrfs_qgroup_inherit *inherit)
 440 {
 441         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 442         struct btrfs_trans_handle *trans;
 443         struct btrfs_key key;
 444         struct btrfs_root_item *root_item;
 445         struct btrfs_inode_item *inode_item;
 446         struct extent_buffer *leaf;
 447         struct btrfs_root *root = BTRFS_I(dir)->root;
 448         struct btrfs_root *new_root;
 449         struct btrfs_block_rsv block_rsv;
 450         struct timespec cur_time = current_time(dir);
 451         struct inode *inode;
 452         int ret;
 453         int err;
 454         u64 objectid;
 455         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 456         u64 index = 0;
 457         u64 qgroup_reserved;
 458         uuid_le new_uuid;
 459
 460         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 461         if (!root_item)
 462                 return -ENOMEM;
 463
 464         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 465         if (ret)
 466                 goto fail_free;
 467
 468         /*
 469          * Don't create subvolume whose level is not zero. Or qgroup will be
 470          * screwed up since it assumes subvolume qgroup's level to be 0.
 471          */
 472         if (btrfs_qgroup_level(objectid)) {
 473                 ret = -ENOSPC;
 474                 goto fail_free;
 475         }
 476
 477         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 478         /*
 479          * The same as the snapshot creation, please see the comment
 480          * of create_snapshot().
 481          */
 482         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 483                                                8, &qgroup_reserved, false);
 484         if (ret)
 485                 goto fail_free;
 486
 487         trans = btrfs_start_transaction(root, 0);
 488         if (IS_ERR(trans)) {
 489                 ret = PTR_ERR(trans);
 490                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 491                 goto fail_free;
 492         }
 493         trans->block_rsv = &block_rsv;
 494         trans->bytes_reserved = block_rsv.size;
 495
 496         ret = btrfs_qgroup_inherit(trans, fs_info, 0, objectid, inherit);
 497         if (ret)
 498                 goto fail;
 499
 500         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 501         if (IS_ERR(leaf)) {
 502                 ret = PTR_ERR(leaf);
 503                 goto fail;
 504         }
 505
 506         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
 507         btrfs_set_header_bytenr(leaf, leaf->start);
 508         btrfs_set_header_generation(leaf, trans->transid);
 509         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 510         btrfs_set_header_owner(leaf, objectid);
 511
 512         write_extent_buffer_fsid(leaf, fs_info->fsid);
 513         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
 514         btrfs_mark_buffer_dirty(leaf);
 515
 516         inode_item = &root_item->inode;
 517         btrfs_set_stack_inode_generation(inode_item, 1);
 518         btrfs_set_stack_inode_size(inode_item, 3);
 519         btrfs_set_stack_inode_nlink(inode_item, 1);
 520         btrfs_set_stack_inode_nbytes(inode_item,
 521                                      fs_info->nodesize);
 522         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 523
 524         btrfs_set_root_flags(root_item, 0);
 525         btrfs_set_root_limit(root_item, 0);
 526         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 527
 528         btrfs_set_root_bytenr(root_item, leaf->start);
 529         btrfs_set_root_generation(root_item, trans->transid);
 530         btrfs_set_root_level(root_item, 0);
 531         btrfs_set_root_refs(root_item, 1);
 532         btrfs_set_root_used(root_item, leaf->len);
 533         btrfs_set_root_last_snapshot(root_item, 0);
 534
 535         btrfs_set_root_generation_v2(root_item,
 536                         btrfs_root_generation(root_item));
 537         uuid_le_gen(&new_uuid);
 538         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 539         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 540         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 541         root_item->ctime = root_item->otime;
 542         btrfs_set_root_ctransid(root_item, trans->transid);
 543         btrfs_set_root_otransid(root_item, trans->transid);
 544
 545         btrfs_tree_unlock(leaf);
 546         free_extent_buffer(leaf);
 547         leaf = NULL;
 548
 549         btrfs_set_root_dirid(root_item, new_dirid);
 550
 551         key.objectid = objectid;
 552         key.offset = 0;
 553         key.type = BTRFS_ROOT_ITEM_KEY;
 554         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 555                                 root_item);
 556         if (ret)
 557                 goto fail;
 558
 559         key.offset = (u64)-1;
 560         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 561         if (IS_ERR(new_root)) {
 562                 ret = PTR_ERR(new_root);
 563                 btrfs_abort_transaction(trans, ret);
 564                 goto fail;
 565         }
 566
 567         btrfs_record_root_in_trans(trans, new_root);
 568
 569         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 570         if (ret) {
 571                 /* We potentially lose an unused inode item here */
 572                 btrfs_abort_transaction(trans, ret);
 573                 goto fail;
 574         }
 575
 576         mutex_lock(&new_root->objectid_mutex);
 577         new_root->highest_objectid = new_dirid;
 578         mutex_unlock(&new_root->objectid_mutex);
 579
 580         /*
 581          * insert the directory item
 582          */
 583         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 584         if (ret) {
 585                 btrfs_abort_transaction(trans, ret);
 586                 goto fail;
 587         }
 588
 589         ret = btrfs_insert_dir_item(trans, root,
 590                                     name, namelen, BTRFS_I(dir), &key,
 591                                     BTRFS_FT_DIR, index);
 592         if (ret) {
 593                 btrfs_abort_transaction(trans, ret);
 594                 goto fail;
 595         }
 596
 597         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 598         ret = btrfs_update_inode(trans, root, dir);
 599         BUG_ON(ret);
 600
 601         ret = btrfs_add_root_ref(trans, fs_info,
 602                                  objectid, root->root_key.objectid,
 603                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 604         BUG_ON(ret);
 605
 606         ret = btrfs_uuid_tree_add(trans, fs_info, root_item->uuid,
 607                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 608         if (ret)
 609                 btrfs_abort_transaction(trans, ret);
 610
 611 fail:
 612         kfree(root_item);
 613         trans->block_rsv = NULL;
 614         trans->bytes_reserved = 0;
 615         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 616
 617         if (async_transid) {
 618                 *async_transid = trans->transid;
 619                 err = btrfs_commit_transaction_async(trans, 1);
 620                 if (err)
 621                         err = btrfs_commit_transaction(trans);
 622         } else {
 623                 err = btrfs_commit_transaction(trans);
 624         }
 625         if (err && !ret)
 626                 ret = err;
 627
 628         if (!ret) {
 629                 inode = btrfs_lookup_dentry(dir, dentry);
 630                 if (IS_ERR(inode))
 631                         return PTR_ERR(inode);
 632                 d_instantiate(dentry, inode);
 633         }
 634         return ret;
 635
 636 fail_free:
 637         kfree(root_item);
 638         return ret;
 639 }
 640
 641 static void btrfs_wait_for_no_snapshoting_writes(struct btrfs_root *root)
 642 {
 643         s64 writers;
 644         DEFINE_WAIT(wait);
 645
 646         do {
 647                 prepare_to_wait(&root->subv_writers->wait, &wait,
 648                                 TASK_UNINTERRUPTIBLE);
 649
 650                 writers = percpu_counter_sum(&root->subv_writers->counter);
 651                 if (writers)
 652                         schedule();
 653
 654                 finish_wait(&root->subv_writers->wait, &wait);
 655         } while (writers);
 656 }
 657
 658 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 659                            struct dentry *dentry,
 660                            u64 *async_transid, bool readonly,
 661                            struct btrfs_qgroup_inherit *inherit)
 662 {
 663         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 664         struct inode *inode;
 665         struct btrfs_pending_snapshot *pending_snapshot;
 666         struct btrfs_trans_handle *trans;
 667         int ret;
 668
 669         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 670                 return -EINVAL;
 671
 672         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 673         if (!pending_snapshot)
 674                 return -ENOMEM;
 675
 676         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 677                         GFP_KERNEL);
 678         pending_snapshot->path = btrfs_alloc_path();
 679         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 680                 ret = -ENOMEM;
 681                 goto free_pending;
 682         }
 683
 684         atomic_inc(&root->will_be_snapshoted);
 685         smp_mb__after_atomic();
 686         btrfs_wait_for_no_snapshoting_writes(root);
 687
 688         ret = btrfs_start_delalloc_inodes(root, 0);
 689         if (ret)
 690                 goto dec_and_free;
 691
 692         btrfs_wait_ordered_extents(root, -1, 0, (u64)-1);
 693
 694         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 695                              BTRFS_BLOCK_RSV_TEMP);
 696         /*
 697          * 1 - parent dir inode
 698          * 2 - dir entries
 699          * 1 - root item
 700          * 2 - root ref/backref
 701          * 1 - root of snapshot
 702          * 1 - UUID item
 703          */
 704         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 705                                         &pending_snapshot->block_rsv, 8,
 706                                         &pending_snapshot->qgroup_reserved,
 707                                         false);
 708         if (ret)
 709                 goto dec_and_free;
 710
 711         pending_snapshot->dentry = dentry;
 712         pending_snapshot->root = root;
 713         pending_snapshot->readonly = readonly;
 714         pending_snapshot->dir = dir;
 715         pending_snapshot->inherit = inherit;
 716
 717         trans = btrfs_start_transaction(root, 0);
 718         if (IS_ERR(trans)) {
 719                 ret = PTR_ERR(trans);
 720                 goto fail;
 721         }
 722
 723         spin_lock(&fs_info->trans_lock);
 724         list_add(&pending_snapshot->list,
 725                  &trans->transaction->pending_snapshots);
 726         spin_unlock(&fs_info->trans_lock);
 727         if (async_transid) {
 728                 *async_transid = trans->transid;
 729                 ret = btrfs_commit_transaction_async(trans, 1);
 730                 if (ret)
 731                         ret = btrfs_commit_transaction(trans);
 732         } else {
 733                 ret = btrfs_commit_transaction(trans);
 734         }
 735         if (ret)
 736                 goto fail;
 737
 738         ret = pending_snapshot->error;
 739         if (ret)
 740                 goto fail;
 741
 742         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 743         if (ret)
 744                 goto fail;
 745
 746         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 747         if (IS_ERR(inode)) {
 748                 ret = PTR_ERR(inode);
 749                 goto fail;
 750         }
 751
 752         d_instantiate(dentry, inode);
 753         ret = 0;
 754 fail:
 755         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 756 dec_and_free:
 757         if (atomic_dec_and_test(&root->will_be_snapshoted))
 758                 wake_up_atomic_t(&root->will_be_snapshoted);
 759 free_pending:
 760         kfree(pending_snapshot->root_item);
 761         btrfs_free_path(pending_snapshot->path);
 762         kfree(pending_snapshot);
 763
 764         return ret;
 765 }
 766
 767 /*  copy of may_delete in fs/namei.c()
 768  *      Check whether we can remove a link victim from directory dir, check
 769  *  whether the type of victim is right.
 770  *  1. We can't do it if dir is read-only (done in permission())
 771  *  2. We should have write and exec permissions on dir
 772  *  3. We can't remove anything from append-only dir
 773  *  4. We can't do anything with immutable dir (done in permission())
 774  *  5. If the sticky bit on dir is set we should either
 775  *      a. be owner of dir, or
 776  *      b. be owner of victim, or
 777  *      c. have CAP_FOWNER capability
 778  *  6. If the victim is append-only or immutable we can't do anything with
 779  *     links pointing to it.
 780  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 781  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 782  *  9. We can't remove a root or mountpoint.
 783  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 784  *     nfs_async_unlink().
 785  */
 786
 787 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 788 {
 789         int error;
 790
 791         if (d_really_is_negative(victim))
 792                 return -ENOENT;
 793
 794         BUG_ON(d_inode(victim->d_parent) != dir);
 795         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 796
 797         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 798         if (error)
 799                 return error;
 800         if (IS_APPEND(dir))
 801                 return -EPERM;
 802         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 803             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 804                 return -EPERM;
 805         if (isdir) {
 806                 if (!d_is_dir(victim))
 807                         return -ENOTDIR;
 808                 if (IS_ROOT(victim))
 809                         return -EBUSY;
 810         } else if (d_is_dir(victim))
 811                 return -EISDIR;
 812         if (IS_DEADDIR(dir))
 813                 return -ENOENT;
 814         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 815                 return -EBUSY;
 816         return 0;
 817 }
 818
 819 /* copy of may_create in fs/namei.c() */
 820 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 821 {
 822         if (d_really_is_positive(child))
 823                 return -EEXIST;
 824         if (IS_DEADDIR(dir))
 825                 return -ENOENT;
 826         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 827 }
 828
 829 /*
 830  * Create a new subvolume below @parent.  This is largely modeled after
 831  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 832  * inside this filesystem so it's quite a bit simpler.
 833  */
 834 static noinline int btrfs_mksubvol(const struct path *parent,
 835                                    const char *name, int namelen,
 836                                    struct btrfs_root *snap_src,
 837                                    u64 *async_transid, bool readonly,
 838                                    struct btrfs_qgroup_inherit *inherit)
 839 {
 840         struct inode *dir = d_inode(parent->dentry);
 841         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 842         struct dentry *dentry;
 843         int error;
 844
 845         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 846         if (error == -EINTR)
 847                 return error;
 848
 849         dentry = lookup_one_len(name, parent->dentry, namelen);
 850         error = PTR_ERR(dentry);
 851         if (IS_ERR(dentry))
 852                 goto out_unlock;
 853
 854         error = btrfs_may_create(dir, dentry);
 855         if (error)
 856                 goto out_dput;
 857
 858         /*
 859          * even if this name doesn't exist, we may get hash collisions.
 860          * check for them now when we can safely fail
 861          */
 862         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 863                                                dir->i_ino, name,
 864                                                namelen);
 865         if (error)
 866                 goto out_dput;
 867
 868         down_read(&fs_info->subvol_sem);
 869
 870         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 871                 goto out_up_read;
 872
 873         if (snap_src) {
 874                 error = create_snapshot(snap_src, dir, dentry,
 875                                         async_transid, readonly, inherit);
 876         } else {
 877                 error = create_subvol(dir, dentry, name, namelen,
 878                                       async_transid, inherit);
 879         }
 880         if (!error)
 881                 fsnotify_mkdir(dir, dentry);
 882 out_up_read:
 883         up_read(&fs_info->subvol_sem);
 884 out_dput:
 885         dput(dentry);
 886 out_unlock:
 887         inode_unlock(dir);
 888         return error;
 889 }
 890
 891 /*
 892  * When we're defragging a range, we don't want to kick it off again
 893  * if it is really just waiting for delalloc to send it down.
 894  * If we find a nice big extent or delalloc range for the bytes in the
 895  * file you want to defrag, we return 0 to let you know to skip this
 896  * part of the file
 897  */
 898 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 899 {
 900         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 901         struct extent_map *em = NULL;
 902         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 903         u64 end;
 904
 905         read_lock(&em_tree->lock);
 906         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 907         read_unlock(&em_tree->lock);
 908
 909         if (em) {
 910                 end = extent_map_end(em);
 911                 free_extent_map(em);
 912                 if (end - offset > thresh)
 913                         return 0;
 914         }
 915         /* if we already have a nice delalloc here, just stop */
 916         thresh /= 2;
 917         end = count_range_bits(io_tree, &offset, offset + thresh,
 918                                thresh, EXTENT_DELALLOC, 1);
 919         if (end >= thresh)
 920                 return 0;
 921         return 1;
 922 }
 923
 924 /*
 925  * helper function to walk through a file and find extents
 926  * newer than a specific transid, and smaller than thresh.
 927  *
 928  * This is used by the defragging code to find new and small
 929  * extents
 930  */
 931 static int find_new_extents(struct btrfs_root *root,
 932                             struct inode *inode, u64 newer_than,
 933                             u64 *off, u32 thresh)
 934 {
 935         struct btrfs_path *path;
 936         struct btrfs_key min_key;
 937         struct extent_buffer *leaf;
 938         struct btrfs_file_extent_item *extent;
 939         int type;
 940         int ret;
 941         u64 ino = btrfs_ino(BTRFS_I(inode));
 942
 943         path = btrfs_alloc_path();
 944         if (!path)
 945                 return -ENOMEM;
 946
 947         min_key.objectid = ino;
 948         min_key.type = BTRFS_EXTENT_DATA_KEY;
 949         min_key.offset = *off;
 950
 951         while (1) {
 952                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
 953                 if (ret != 0)
 954                         goto none;
 955 process_slot:
 956                 if (min_key.objectid != ino)
 957                         goto none;
 958                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 959                         goto none;
 960
 961                 leaf = path->nodes[0];
 962                 extent = btrfs_item_ptr(leaf, path->slots[0],
 963                                         struct btrfs_file_extent_item);
 964
 965                 type = btrfs_file_extent_type(leaf, extent);
 966                 if (type == BTRFS_FILE_EXTENT_REG &&
 967                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 968                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 969                         *off = min_key.offset;
 970                         btrfs_free_path(path);
 971                         return 0;
 972                 }
 973
 974                 path->slots[0]++;
 975                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
 976                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 977                         goto process_slot;
 978                 }
 979
 980                 if (min_key.offset == (u64)-1)
 981                         goto none;
 982
 983                 min_key.offset++;
 984                 btrfs_release_path(path);
 985         }
 986 none:
 987         btrfs_free_path(path);
 988         return -ENOENT;
 989 }
 990
 991 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 992 {
 993         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 994         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 995         struct extent_map *em;
 996         u64 len = PAGE_SIZE;
 997
 998         /*
 999          * hopefully we have this extent in the tree already, try without
1000          * the full extent lock
1001          */
1002         read_lock(&em_tree->lock);
1003         em = lookup_extent_mapping(em_tree, start, len);
1004         read_unlock(&em_tree->lock);
1005
1006         if (!em) {
1007                 struct extent_state *cached = NULL;
1008                 u64 end = start + len - 1;
1009
1010                 /* get the big lock and read metadata off disk */
1011                 lock_extent_bits(io_tree, start, end, &cached);
1012                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1013                 unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS);
1014
1015                 if (IS_ERR(em))
1016                         return NULL;
1017         }
1018
1019         return em;
1020 }
1021
1022 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1023 {
1024         struct extent_map *next;
1025         bool ret = true;
1026
1027         /* this is the last extent */
1028         if (em->start + em->len >= i_size_read(inode))
1029                 return false;
1030
1031         next = defrag_lookup_extent(inode, em->start + em->len);
1032         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1033                 ret = false;
1034         else if ((em->block_start + em->block_len == next->block_start) &&
1035                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1036                 ret = false;
1037
1038         free_extent_map(next);
1039         return ret;
1040 }
1041
1042 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1043                                u64 *last_len, u64 *skip, u64 *defrag_end,
1044                                int compress)
1045 {
1046         struct extent_map *em;
1047         int ret = 1;
1048         bool next_mergeable = true;
1049         bool prev_mergeable = true;
1050
1051         /*
1052          * make sure that once we start defragging an extent, we keep on
1053          * defragging it
1054          */
1055         if (start < *defrag_end)
1056                 return 1;
1057
1058         *skip = 0;
1059
1060         em = defrag_lookup_extent(inode, start);
1061         if (!em)
1062                 return 0;
1063
1064         /* this will cover holes, and inline extents */
1065         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1066                 ret = 0;
1067                 goto out;
1068         }
1069
1070         if (!*defrag_end)
1071                 prev_mergeable = false;
1072
1073         next_mergeable = defrag_check_next_extent(inode, em);
1074         /*
1075          * we hit a real extent, if it is big or the next extent is not a
1076          * real extent, don't bother defragging it
1077          */
1078         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1079             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1080                 ret = 0;
1081 out:
1082         /*
1083          * last_len ends up being a counter of how many bytes we've defragged.
1084          * every time we choose not to defrag an extent, we reset *last_len
1085          * so that the next tiny extent will force a defrag.
1086          *
1087          * The end result of this is that tiny extents before a single big
1088          * extent will force at least part of that big extent to be defragged.
1089          */
1090         if (ret) {
1091                 *defrag_end = extent_map_end(em);
1092         } else {
1093                 *last_len = 0;
1094                 *skip = extent_map_end(em);
1095                 *defrag_end = 0;
1096         }
1097
1098         free_extent_map(em);
1099         return ret;
1100 }
1101
1102 /*
1103  * it doesn't do much good to defrag one or two pages
1104  * at a time.  This pulls in a nice chunk of pages
1105  * to COW and defrag.
1106  *
1107  * It also makes sure the delalloc code has enough
1108  * dirty data to avoid making new small extents as part
1109  * of the defrag
1110  *
1111  * It's a good idea to start RA on this range
1112  * before calling this.
1113  */
1114 static int cluster_pages_for_defrag(struct inode *inode,
1115                                     struct page **pages,
1116                                     unsigned long start_index,
1117                                     unsigned long num_pages)
1118 {
1119         unsigned long file_end;
1120         u64 isize = i_size_read(inode);
1121         u64 page_start;
1122         u64 page_end;
1123         u64 page_cnt;
1124         int ret;
1125         int i;
1126         int i_done;
1127         struct btrfs_ordered_extent *ordered;
1128         struct extent_state *cached_state = NULL;
1129         struct extent_io_tree *tree;
1130         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1131
1132         file_end = (isize - 1) >> PAGE_SHIFT;
1133         if (!isize || start_index > file_end)
1134                 return 0;
1135
1136         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1137
1138         ret = btrfs_delalloc_reserve_space(inode,
1139                         start_index << PAGE_SHIFT,
1140                         page_cnt << PAGE_SHIFT);
1141         if (ret)
1142                 return ret;
1143         i_done = 0;
1144         tree = &BTRFS_I(inode)->io_tree;
1145
1146         /* step one, lock all the pages */
1147         for (i = 0; i < page_cnt; i++) {
1148                 struct page *page;
1149 again:
1150                 page = find_or_create_page(inode->i_mapping,
1151                                            start_index + i, mask);
1152                 if (!page)
1153                         break;
1154
1155                 page_start = page_offset(page);
1156                 page_end = page_start + PAGE_SIZE - 1;
1157                 while (1) {
1158                         lock_extent_bits(tree, page_start, page_end,
1159                                          &cached_state);
1160                         ordered = btrfs_lookup_ordered_extent(inode,
1161                                                               page_start);
1162                         unlock_extent_cached(tree, page_start, page_end,
1163                                              &cached_state, GFP_NOFS);
1164                         if (!ordered)
1165                                 break;
1166
1167                         unlock_page(page);
1168                         btrfs_start_ordered_extent(inode, ordered, 1);
1169                         btrfs_put_ordered_extent(ordered);
1170                         lock_page(page);
1171                         /*
1172                          * we unlocked the page above, so we need check if
1173                          * it was released or not.
1174                          */
1175                         if (page->mapping != inode->i_mapping) {
1176                                 unlock_page(page);
1177                                 put_page(page);
1178                                 goto again;
1179                         }
1180                 }
1181
1182                 if (!PageUptodate(page)) {
1183                         btrfs_readpage(NULL, page);
1184                         lock_page(page);
1185                         if (!PageUptodate(page)) {
1186                                 unlock_page(page);
1187                                 put_page(page);
1188                                 ret = -EIO;
1189                                 break;
1190                         }
1191                 }
1192
1193                 if (page->mapping != inode->i_mapping) {
1194                         unlock_page(page);
1195                         put_page(page);
1196                         goto again;
1197                 }
1198
1199                 pages[i] = page;
1200                 i_done++;
1201         }
1202         if (!i_done || ret)
1203                 goto out;
1204
1205         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1206                 goto out;
1207
1208         /*
1209          * so now we have a nice long stream of locked
1210          * and up to date pages, lets wait on them
1211          */
1212         for (i = 0; i < i_done; i++)
1213                 wait_on_page_writeback(pages[i]);
1214
1215         page_start = page_offset(pages[0]);
1216         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1217
1218         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1219                          page_start, page_end - 1, &cached_state);
1220         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1221                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1222                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1223                           &cached_state, GFP_NOFS);
1224
1225         if (i_done != page_cnt) {
1226                 spin_lock(&BTRFS_I(inode)->lock);
1227                 BTRFS_I(inode)->outstanding_extents++;
1228                 spin_unlock(&BTRFS_I(inode)->lock);
1229                 btrfs_delalloc_release_space(inode,
1230                                 start_index << PAGE_SHIFT,
1231                                 (page_cnt - i_done) << PAGE_SHIFT);
1232         }
1233
1234
1235         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1236                           &cached_state);
1237
1238         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1239                              page_start, page_end - 1, &cached_state,
1240                              GFP_NOFS);
1241
1242         for (i = 0; i < i_done; i++) {
1243                 clear_page_dirty_for_io(pages[i]);
1244                 ClearPageChecked(pages[i]);
1245                 set_page_extent_mapped(pages[i]);
1246                 set_page_dirty(pages[i]);
1247                 unlock_page(pages[i]);
1248                 put_page(pages[i]);
1249         }
1250         return i_done;
1251 out:
1252         for (i = 0; i < i_done; i++) {
1253                 unlock_page(pages[i]);
1254                 put_page(pages[i]);
1255         }
1256         btrfs_delalloc_release_space(inode,
1257                         start_index << PAGE_SHIFT,
1258                         page_cnt << PAGE_SHIFT);
1259         return ret;
1260
1261 }
1262
1263 int btrfs_defrag_file(struct inode *inode, struct file *file,
1264                       struct btrfs_ioctl_defrag_range_args *range,
1265                       u64 newer_than, unsigned long max_to_defrag)
1266 {
1267         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1268         struct btrfs_root *root = BTRFS_I(inode)->root;
1269         struct file_ra_state *ra = NULL;
1270         unsigned long last_index;
1271         u64 isize = i_size_read(inode);
1272         u64 last_len = 0;
1273         u64 skip = 0;
1274         u64 defrag_end = 0;
1275         u64 newer_off = range->start;
1276         unsigned long i;
1277         unsigned long ra_index = 0;
1278         int ret;
1279         int defrag_count = 0;
1280         int compress_type = BTRFS_COMPRESS_ZLIB;
1281         u32 extent_thresh = range->extent_thresh;
1282         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1283         unsigned long cluster = max_cluster;
1284         u64 new_align = ~((u64)SZ_128K - 1);
1285         struct page **pages = NULL;
1286
1287         if (isize == 0)
1288                 return 0;
1289
1290         if (range->start >= isize)
1291                 return -EINVAL;
1292
1293         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1294                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1295                         return -EINVAL;
1296                 if (range->compress_type)
1297                         compress_type = range->compress_type;
1298         }
1299
1300         if (extent_thresh == 0)
1301                 extent_thresh = SZ_256K;
1302
1303         /*
1304          * if we were not given a file, allocate a readahead
1305          * context
1306          */
1307         if (!file) {
1308                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1309                 if (!ra)
1310                         return -ENOMEM;
1311                 file_ra_state_init(ra, inode->i_mapping);
1312         } else {
1313                 ra = &file->f_ra;
1314         }
1315
1316         pages = kmalloc_array(max_cluster, sizeof(struct page *),
1317                         GFP_NOFS);
1318         if (!pages) {
1319                 ret = -ENOMEM;
1320                 goto out_ra;
1321         }
1322
1323         /* find the last page to defrag */
1324         if (range->start + range->len > range->start) {
1325                 last_index = min_t(u64, isize - 1,
1326                          range->start + range->len - 1) >> PAGE_SHIFT;
1327         } else {
1328                 last_index = (isize - 1) >> PAGE_SHIFT;
1329         }
1330
1331         if (newer_than) {
1332                 ret = find_new_extents(root, inode, newer_than,
1333                                        &newer_off, SZ_64K);
1334                 if (!ret) {
1335                         range->start = newer_off;
1336                         /*
1337                          * we always align our defrag to help keep
1338                          * the extents in the file evenly spaced
1339                          */
1340                         i = (newer_off & new_align) >> PAGE_SHIFT;
1341                 } else
1342                         goto out_ra;
1343         } else {
1344                 i = range->start >> PAGE_SHIFT;
1345         }
1346         if (!max_to_defrag)
1347                 max_to_defrag = last_index - i + 1;
1348
1349         /*
1350          * make writeback starts from i, so the defrag range can be
1351          * written sequentially.
1352          */
1353         if (i < inode->i_mapping->writeback_index)
1354                 inode->i_mapping->writeback_index = i;
1355
1356         while (i <= last_index && defrag_count < max_to_defrag &&
1357                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1358                 /*
1359                  * make sure we stop running if someone unmounts
1360                  * the FS
1361                  */
1362                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1363                         break;
1364
1365                 if (btrfs_defrag_cancelled(fs_info)) {
1366                         btrfs_debug(fs_info, "defrag_file cancelled");
1367                         ret = -EAGAIN;
1368                         break;
1369                 }
1370
1371                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1372                                          extent_thresh, &last_len, &skip,
1373                                          &defrag_end, range->flags &
1374                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1375                         unsigned long next;
1376                         /*
1377                          * the should_defrag function tells us how much to skip
1378                          * bump our counter by the suggested amount
1379                          */
1380                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1381                         i = max(i + 1, next);
1382                         continue;
1383                 }
1384
1385                 if (!newer_than) {
1386                         cluster = (PAGE_ALIGN(defrag_end) >>
1387                                    PAGE_SHIFT) - i;
1388                         cluster = min(cluster, max_cluster);
1389                 } else {
1390                         cluster = max_cluster;
1391                 }
1392
1393                 if (i + cluster > ra_index) {
1394                         ra_index = max(i, ra_index);
1395                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1396                                        cluster);
1397                         ra_index += cluster;
1398                 }
1399
1400                 inode_lock(inode);
1401                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1402                         BTRFS_I(inode)->force_compress = compress_type;
1403                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1404                 if (ret < 0) {
1405                         inode_unlock(inode);
1406                         goto out_ra;
1407                 }
1408
1409                 defrag_count += ret;
1410                 balance_dirty_pages_ratelimited(inode->i_mapping);
1411                 inode_unlock(inode);
1412
1413                 if (newer_than) {
1414                         if (newer_off == (u64)-1)
1415                                 break;
1416
1417                         if (ret > 0)
1418                                 i += ret;
1419
1420                         newer_off = max(newer_off + 1,
1421                                         (u64)i << PAGE_SHIFT);
1422
1423                         ret = find_new_extents(root, inode, newer_than,
1424                                                &newer_off, SZ_64K);
1425                         if (!ret) {
1426                                 range->start = newer_off;
1427                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1428                         } else {
1429                                 break;
1430                         }
1431                 } else {
1432                         if (ret > 0) {
1433                                 i += ret;
1434                                 last_len += ret << PAGE_SHIFT;
1435                         } else {
1436                                 i++;
1437                                 last_len = 0;
1438                         }
1439                 }
1440         }
1441
1442         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1443                 filemap_flush(inode->i_mapping);
1444                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1445                              &BTRFS_I(inode)->runtime_flags))
1446                         filemap_flush(inode->i_mapping);
1447         }
1448
1449         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1450                 /* the filemap_flush will queue IO into the worker threads, but
1451                  * we have to make sure the IO is actually started and that
1452                  * ordered extents get created before we return
1453                  */
1454                 atomic_inc(&fs_info->async_submit_draining);
1455                 while (atomic_read(&fs_info->nr_async_submits) ||
1456                        atomic_read(&fs_info->async_delalloc_pages)) {
1457                         wait_event(fs_info->async_submit_wait,
1458                                    (atomic_read(&fs_info->nr_async_submits) == 0 &&
1459                                     atomic_read(&fs_info->async_delalloc_pages) == 0));
1460                 }
1461                 atomic_dec(&fs_info->async_submit_draining);
1462         }
1463
1464         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1465                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1466         }
1467
1468         ret = defrag_count;
1469
1470 out_ra:
1471         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1472                 inode_lock(inode);
1473                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1474                 inode_unlock(inode);
1475         }
1476         if (!file)
1477                 kfree(ra);
1478         kfree(pages);
1479         return ret;
1480 }
1481
1482 static noinline int btrfs_ioctl_resize(struct file *file,
1483                                         void __user *arg)
1484 {
1485         struct inode *inode = file_inode(file);
1486         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1487         u64 new_size;
1488         u64 old_size;
1489         u64 devid = 1;
1490         struct btrfs_root *root = BTRFS_I(inode)->root;
1491         struct btrfs_ioctl_vol_args *vol_args;
1492         struct btrfs_trans_handle *trans;
1493         struct btrfs_device *device = NULL;
1494         char *sizestr;
1495         char *retptr;
1496         char *devstr = NULL;
1497         int ret = 0;
1498         int mod = 0;
1499
1500         if (!capable(CAP_SYS_ADMIN))
1501                 return -EPERM;
1502
1503         ret = mnt_want_write_file(file);
1504         if (ret)
1505                 return ret;
1506
1507         if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
1508                 mnt_drop_write_file(file);
1509                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1510         }
1511
1512         mutex_lock(&fs_info->volume_mutex);
1513         vol_args = memdup_user(arg, sizeof(*vol_args));
1514         if (IS_ERR(vol_args)) {
1515                 ret = PTR_ERR(vol_args);
1516                 goto out;
1517         }
1518
1519         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1520
1521         sizestr = vol_args->name;
1522         devstr = strchr(sizestr, ':');
1523         if (devstr) {
1524                 sizestr = devstr + 1;
1525                 *devstr = '\0';
1526                 devstr = vol_args->name;
1527                 ret = kstrtoull(devstr, 10, &devid);
1528                 if (ret)
1529                         goto out_free;
1530                 if (!devid) {
1531                         ret = -EINVAL;
1532                         goto out_free;
1533                 }
1534                 btrfs_info(fs_info, "resizing devid %llu", devid);
1535         }
1536
1537         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1538         if (!device) {
1539                 btrfs_info(fs_info, "resizer unable to find device %llu",
1540                            devid);
1541                 ret = -ENODEV;
1542                 goto out_free;
1543         }
1544
1545         if (!device->writeable) {
1546                 btrfs_info(fs_info,
1547                            "resizer unable to apply on readonly device %llu",
1548                        devid);
1549                 ret = -EPERM;
1550                 goto out_free;
1551         }
1552
1553         if (!strcmp(sizestr, "max"))
1554                 new_size = device->bdev->bd_inode->i_size;
1555         else {
1556                 if (sizestr[0] == '-') {
1557                         mod = -1;
1558                         sizestr++;
1559                 } else if (sizestr[0] == '+') {
1560                         mod = 1;
1561                         sizestr++;
1562                 }
1563                 new_size = memparse(sizestr, &retptr);
1564                 if (*retptr != '\0' || new_size == 0) {
1565                         ret = -EINVAL;
1566                         goto out_free;
1567                 }
1568         }
1569
1570         if (device->is_tgtdev_for_dev_replace) {
1571                 ret = -EPERM;
1572                 goto out_free;
1573         }
1574
1575         old_size = btrfs_device_get_total_bytes(device);
1576
1577         if (mod < 0) {
1578                 if (new_size > old_size) {
1579                         ret = -EINVAL;
1580                         goto out_free;
1581                 }
1582                 new_size = old_size - new_size;
1583         } else if (mod > 0) {
1584                 if (new_size > ULLONG_MAX - old_size) {
1585                         ret = -ERANGE;
1586                         goto out_free;
1587                 }
1588                 new_size = old_size + new_size;
1589         }
1590
1591         if (new_size < SZ_256M) {
1592                 ret = -EINVAL;
1593                 goto out_free;
1594         }
1595         if (new_size > device->bdev->bd_inode->i_size) {
1596                 ret = -EFBIG;
1597                 goto out_free;
1598         }
1599
1600         new_size = div_u64(new_size, fs_info->sectorsize);
1601         new_size *= fs_info->sectorsize;
1602
1603         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1604                           rcu_str_deref(device->name), new_size);
1605
1606         if (new_size > old_size) {
1607                 trans = btrfs_start_transaction(root, 0);
1608                 if (IS_ERR(trans)) {
1609                         ret = PTR_ERR(trans);
1610                         goto out_free;
1611                 }
1612                 ret = btrfs_grow_device(trans, device, new_size);
1613                 btrfs_commit_transaction(trans);
1614         } else if (new_size < old_size) {
1615                 ret = btrfs_shrink_device(device, new_size);
1616         } /* equal, nothing need to do */
1617
1618 out_free:
1619         kfree(vol_args);
1620 out:
1621         mutex_unlock(&fs_info->volume_mutex);
1622         atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
1623         mnt_drop_write_file(file);
1624         return ret;
1625 }
1626
1627 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1628                                 const char *name, unsigned long fd, int subvol,
1629                                 u64 *transid, bool readonly,
1630                                 struct btrfs_qgroup_inherit *inherit)
1631 {
1632         int namelen;
1633         int ret = 0;
1634
1635         if (!S_ISDIR(file_inode(file)->i_mode))
1636                 return -ENOTDIR;
1637
1638         ret = mnt_want_write_file(file);
1639         if (ret)
1640                 goto out;
1641
1642         namelen = strlen(name);
1643         if (strchr(name, '/')) {
1644                 ret = -EINVAL;
1645                 goto out_drop_write;
1646         }
1647
1648         if (name[0] == '.' &&
1649            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1650                 ret = -EEXIST;
1651                 goto out_drop_write;
1652         }
1653
1654         if (subvol) {
1655                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1656                                      NULL, transid, readonly, inherit);
1657         } else {
1658                 struct fd src = fdget(fd);
1659                 struct inode *src_inode;
1660                 if (!src.file) {
1661                         ret = -EINVAL;
1662                         goto out_drop_write;
1663                 }
1664
1665                 src_inode = file_inode(src.file);
1666                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1667                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1668                                    "Snapshot src from another FS");
1669                         ret = -EXDEV;
1670                 } else if (!inode_owner_or_capable(src_inode)) {
1671                         /*
1672                          * Subvolume creation is not restricted, but snapshots
1673                          * are limited to own subvolumes only
1674                          */
1675                         ret = -EPERM;
1676                 } else {
1677                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1678                                              BTRFS_I(src_inode)->root,
1679                                              transid, readonly, inherit);
1680                 }
1681                 fdput(src);
1682         }
1683 out_drop_write:
1684         mnt_drop_write_file(file);
1685 out:
1686         return ret;
1687 }
1688
1689 static noinline int btrfs_ioctl_snap_create(struct file *file,
1690                                             void __user *arg, int subvol)
1691 {
1692         struct btrfs_ioctl_vol_args *vol_args;
1693         int ret;
1694
1695         if (!S_ISDIR(file_inode(file)->i_mode))
1696                 return -ENOTDIR;
1697
1698         vol_args = memdup_user(arg, sizeof(*vol_args));
1699         if (IS_ERR(vol_args))
1700                 return PTR_ERR(vol_args);
1701         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1702
1703         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1704                                               vol_args->fd, subvol,
1705                                               NULL, false, NULL);
1706
1707         kfree(vol_args);
1708         return ret;
1709 }
1710
1711 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1712                                                void __user *arg, int subvol)
1713 {
1714         struct btrfs_ioctl_vol_args_v2 *vol_args;
1715         int ret;
1716         u64 transid = 0;
1717         u64 *ptr = NULL;
1718         bool readonly = false;
1719         struct btrfs_qgroup_inherit *inherit = NULL;
1720
1721         if (!S_ISDIR(file_inode(file)->i_mode))
1722                 return -ENOTDIR;
1723
1724         vol_args = memdup_user(arg, sizeof(*vol_args));
1725         if (IS_ERR(vol_args))
1726                 return PTR_ERR(vol_args);
1727         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1728
1729         if (vol_args->flags &
1730             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1731               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1732                 ret = -EOPNOTSUPP;
1733                 goto free_args;
1734         }
1735
1736         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1737                 ptr = &transid;
1738         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1739                 readonly = true;
1740         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1741                 if (vol_args->size > PAGE_SIZE) {
1742                         ret = -EINVAL;
1743                         goto free_args;
1744                 }
1745                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1746                 if (IS_ERR(inherit)) {
1747                         ret = PTR_ERR(inherit);
1748                         goto free_args;
1749                 }
1750         }
1751
1752         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1753                                               vol_args->fd, subvol, ptr,
1754                                               readonly, inherit);
1755         if (ret)
1756                 goto free_inherit;
1757
1758         if (ptr && copy_to_user(arg +
1759                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1760                                         transid),
1761                                 ptr, sizeof(*ptr)))
1762                 ret = -EFAULT;
1763
1764 free_inherit:
1765         kfree(inherit);
1766 free_args:
1767         kfree(vol_args);
1768         return ret;
1769 }
1770
1771 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1772                                                 void __user *arg)
1773 {
1774         struct inode *inode = file_inode(file);
1775         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1776         struct btrfs_root *root = BTRFS_I(inode)->root;
1777         int ret = 0;
1778         u64 flags = 0;
1779
1780         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1781                 return -EINVAL;
1782
1783         down_read(&fs_info->subvol_sem);
1784         if (btrfs_root_readonly(root))
1785                 flags |= BTRFS_SUBVOL_RDONLY;
1786         up_read(&fs_info->subvol_sem);
1787
1788         if (copy_to_user(arg, &flags, sizeof(flags)))
1789                 ret = -EFAULT;
1790
1791         return ret;
1792 }
1793
1794 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1795                                               void __user *arg)
1796 {
1797         struct inode *inode = file_inode(file);
1798         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1799         struct btrfs_root *root = BTRFS_I(inode)->root;
1800         struct btrfs_trans_handle *trans;
1801         u64 root_flags;
1802         u64 flags;
1803         int ret = 0;
1804
1805         if (!inode_owner_or_capable(inode))
1806                 return -EPERM;
1807
1808         ret = mnt_want_write_file(file);
1809         if (ret)
1810                 goto out;
1811
1812         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1813                 ret = -EINVAL;
1814                 goto out_drop_write;
1815         }
1816
1817         if (copy_from_user(&flags, arg, sizeof(flags))) {
1818                 ret = -EFAULT;
1819                 goto out_drop_write;
1820         }
1821
1822         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1823                 ret = -EINVAL;
1824                 goto out_drop_write;
1825         }
1826
1827         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1828                 ret = -EOPNOTSUPP;
1829                 goto out_drop_write;
1830         }
1831
1832         down_write(&fs_info->subvol_sem);
1833
1834         /* nothing to do */
1835         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1836                 goto out_drop_sem;
1837
1838         root_flags = btrfs_root_flags(&root->root_item);
1839         if (flags & BTRFS_SUBVOL_RDONLY) {
1840                 btrfs_set_root_flags(&root->root_item,
1841                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1842         } else {
1843                 /*
1844                  * Block RO -> RW transition if this subvolume is involved in
1845                  * send
1846                  */
1847                 spin_lock(&root->root_item_lock);
1848                 if (root->send_in_progress == 0) {
1849                         btrfs_set_root_flags(&root->root_item,
1850                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1851                         spin_unlock(&root->root_item_lock);
1852                 } else {
1853                         spin_unlock(&root->root_item_lock);
1854                         btrfs_warn(fs_info,
1855                                    "Attempt to set subvolume %llu read-write during send",
1856                                    root->root_key.objectid);
1857                         ret = -EPERM;
1858                         goto out_drop_sem;
1859                 }
1860         }
1861
1862         trans = btrfs_start_transaction(root, 1);
1863         if (IS_ERR(trans)) {
1864                 ret = PTR_ERR(trans);
1865                 goto out_reset;
1866         }
1867
1868         ret = btrfs_update_root(trans, fs_info->tree_root,
1869                                 &root->root_key, &root->root_item);
1870
1871         btrfs_commit_transaction(trans);
1872 out_reset:
1873         if (ret)
1874                 btrfs_set_root_flags(&root->root_item, root_flags);
1875 out_drop_sem:
1876         up_write(&fs_info->subvol_sem);
1877 out_drop_write:
1878         mnt_drop_write_file(file);
1879 out:
1880         return ret;
1881 }
1882
1883 /*
1884  * helper to check if the subvolume references other subvolumes
1885  */
1886 static noinline int may_destroy_subvol(struct btrfs_root *root)
1887 {
1888         struct btrfs_fs_info *fs_info = root->fs_info;
1889         struct btrfs_path *path;
1890         struct btrfs_dir_item *di;
1891         struct btrfs_key key;
1892         u64 dir_id;
1893         int ret;
1894
1895         path = btrfs_alloc_path();
1896         if (!path)
1897                 return -ENOMEM;
1898
1899         /* Make sure this root isn't set as the default subvol */
1900         dir_id = btrfs_super_root_dir(fs_info->super_copy);
1901         di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
1902                                    dir_id, "default", 7, 0);
1903         if (di && !IS_ERR(di)) {
1904                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1905                 if (key.objectid == root->root_key.objectid) {
1906                         ret = -EPERM;
1907                         btrfs_err(fs_info,
1908                                   "deleting default subvolume %llu is not allowed",
1909                                   key.objectid);
1910                         goto out;
1911                 }
1912                 btrfs_release_path(path);
1913         }
1914
1915         key.objectid = root->root_key.objectid;
1916         key.type = BTRFS_ROOT_REF_KEY;
1917         key.offset = (u64)-1;
1918
1919         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1920         if (ret < 0)
1921                 goto out;
1922         BUG_ON(ret == 0);
1923
1924         ret = 0;
1925         if (path->slots[0] > 0) {
1926                 path->slots[0]--;
1927                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1928                 if (key.objectid == root->root_key.objectid &&
1929                     key.type == BTRFS_ROOT_REF_KEY)
1930                         ret = -ENOTEMPTY;
1931         }
1932 out:
1933         btrfs_free_path(path);
1934         return ret;
1935 }
1936
1937 static noinline int key_in_sk(struct btrfs_key *key,
1938                               struct btrfs_ioctl_search_key *sk)
1939 {
1940         struct btrfs_key test;
1941         int ret;
1942
1943         test.objectid = sk->min_objectid;
1944         test.type = sk->min_type;
1945         test.offset = sk->min_offset;
1946
1947         ret = btrfs_comp_cpu_keys(key, &test);
1948         if (ret < 0)
1949                 return 0;
1950
1951         test.objectid = sk->max_objectid;
1952         test.type = sk->max_type;
1953         test.offset = sk->max_offset;
1954
1955         ret = btrfs_comp_cpu_keys(key, &test);
1956         if (ret > 0)
1957                 return 0;
1958         return 1;
1959 }
1960
1961 static noinline int copy_to_sk(struct btrfs_path *path,
1962                                struct btrfs_key *key,
1963                                struct btrfs_ioctl_search_key *sk,
1964                                size_t *buf_size,
1965                                char __user *ubuf,
1966                                unsigned long *sk_offset,
1967                                int *num_found)
1968 {
1969         u64 found_transid;
1970         struct extent_buffer *leaf;
1971         struct btrfs_ioctl_search_header sh;
1972         struct btrfs_key test;
1973         unsigned long item_off;
1974         unsigned long item_len;
1975         int nritems;
1976         int i;
1977         int slot;
1978         int ret = 0;
1979
1980         leaf = path->nodes[0];
1981         slot = path->slots[0];
1982         nritems = btrfs_header_nritems(leaf);
1983
1984         if (btrfs_header_generation(leaf) > sk->max_transid) {
1985                 i = nritems;
1986                 goto advance_key;
1987         }
1988         found_transid = btrfs_header_generation(leaf);
1989
1990         for (i = slot; i < nritems; i++) {
1991                 item_off = btrfs_item_ptr_offset(leaf, i);
1992                 item_len = btrfs_item_size_nr(leaf, i);
1993
1994                 btrfs_item_key_to_cpu(leaf, key, i);
1995                 if (!key_in_sk(key, sk))
1996                         continue;
1997
1998                 if (sizeof(sh) + item_len > *buf_size) {
1999                         if (*num_found) {
2000                                 ret = 1;
2001                                 goto out;
2002                         }
2003
2004                         /*
2005                          * return one empty item back for v1, which does not
2006                          * handle -EOVERFLOW
2007                          */
2008
2009                         *buf_size = sizeof(sh) + item_len;
2010                         item_len = 0;
2011                         ret = -EOVERFLOW;
2012                 }
2013
2014                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2015                         ret = 1;
2016                         goto out;
2017                 }
2018
2019                 sh.objectid = key->objectid;
2020                 sh.offset = key->offset;
2021                 sh.type = key->type;
2022                 sh.len = item_len;
2023                 sh.transid = found_transid;
2024
2025                 /* copy search result header */
2026                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2027                         ret = -EFAULT;
2028                         goto out;
2029                 }
2030
2031                 *sk_offset += sizeof(sh);
2032
2033                 if (item_len) {
2034                         char __user *up = ubuf + *sk_offset;
2035                         /* copy the item */
2036                         if (read_extent_buffer_to_user(leaf, up,
2037                                                        item_off, item_len)) {
2038                                 ret = -EFAULT;
2039                                 goto out;
2040                         }
2041
2042                         *sk_offset += item_len;
2043                 }
2044                 (*num_found)++;
2045
2046                 if (ret) /* -EOVERFLOW from above */
2047                         goto out;
2048
2049                 if (*num_found >= sk->nr_items) {
2050                         ret = 1;
2051                         goto out;
2052                 }
2053         }
2054 advance_key:
2055         ret = 0;
2056         test.objectid = sk->max_objectid;
2057         test.type = sk->max_type;
2058         test.offset = sk->max_offset;
2059         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2060                 ret = 1;
2061         else if (key->offset < (u64)-1)
2062                 key->offset++;
2063         else if (key->type < (u8)-1) {
2064                 key->offset = 0;
2065                 key->type++;
2066         } else if (key->objectid < (u64)-1) {
2067                 key->offset = 0;
2068                 key->type = 0;
2069                 key->objectid++;
2070         } else
2071                 ret = 1;
2072 out:
2073         /*
2074          *  0: all items from this leaf copied, continue with next
2075          *  1: * more items can be copied, but unused buffer is too small
2076          *     * all items were found
2077          *     Either way, it will stops the loop which iterates to the next
2078          *     leaf
2079          *  -EOVERFLOW: item was to large for buffer
2080          *  -EFAULT: could not copy extent buffer back to userspace
2081          */
2082         return ret;
2083 }
2084
2085 static noinline int search_ioctl(struct inode *inode,
2086                                  struct btrfs_ioctl_search_key *sk,
2087                                  size_t *buf_size,
2088                                  char __user *ubuf)
2089 {
2090         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2091         struct btrfs_root *root;
2092         struct btrfs_key key;
2093         struct btrfs_path *path;
2094         int ret;
2095         int num_found = 0;
2096         unsigned long sk_offset = 0;
2097
2098         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2099                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2100                 return -EOVERFLOW;
2101         }
2102
2103         path = btrfs_alloc_path();
2104         if (!path)
2105                 return -ENOMEM;
2106
2107         if (sk->tree_id == 0) {
2108                 /* search the root of the inode that was passed */
2109                 root = BTRFS_I(inode)->root;
2110         } else {
2111                 key.objectid = sk->tree_id;
2112                 key.type = BTRFS_ROOT_ITEM_KEY;
2113                 key.offset = (u64)-1;
2114                 root = btrfs_read_fs_root_no_name(info, &key);
2115                 if (IS_ERR(root)) {
2116                         btrfs_free_path(path);
2117                         return -ENOENT;
2118                 }
2119         }
2120
2121         key.objectid = sk->min_objectid;
2122         key.type = sk->min_type;
2123         key.offset = sk->min_offset;
2124
2125         while (1) {
2126                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2127                 if (ret != 0) {
2128                         if (ret > 0)
2129                                 ret = 0;
2130                         goto err;
2131                 }
2132                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2133                                  &sk_offset, &num_found);
2134                 btrfs_release_path(path);
2135                 if (ret)
2136                         break;
2137
2138         }
2139         if (ret > 0)
2140                 ret = 0;
2141 err:
2142         sk->nr_items = num_found;
2143         btrfs_free_path(path);
2144         return ret;
2145 }
2146
2147 static noinline int btrfs_ioctl_tree_search(struct file *file,
2148                                            void __user *argp)
2149 {
2150         struct btrfs_ioctl_search_args __user *uargs;
2151         struct btrfs_ioctl_search_key sk;
2152         struct inode *inode;
2153         int ret;
2154         size_t buf_size;
2155
2156         if (!capable(CAP_SYS_ADMIN))
2157                 return -EPERM;
2158
2159         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2160
2161         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2162                 return -EFAULT;
2163
2164         buf_size = sizeof(uargs->buf);
2165
2166         inode = file_inode(file);
2167         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2168
2169         /*
2170          * In the origin implementation an overflow is handled by returning a
2171          * search header with a len of zero, so reset ret.
2172          */
2173         if (ret == -EOVERFLOW)
2174                 ret = 0;
2175
2176         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2177                 ret = -EFAULT;
2178         return ret;
2179 }
2180
2181 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2182                                                void __user *argp)
2183 {
2184         struct btrfs_ioctl_search_args_v2 __user *uarg;
2185         struct btrfs_ioctl_search_args_v2 args;
2186         struct inode *inode;
2187         int ret;
2188         size_t buf_size;
2189         const size_t buf_limit = SZ_16M;
2190
2191         if (!capable(CAP_SYS_ADMIN))
2192                 return -EPERM;
2193
2194         /* copy search header and buffer size */
2195         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2196         if (copy_from_user(&args, uarg, sizeof(args)))
2197                 return -EFAULT;
2198
2199         buf_size = args.buf_size;
2200
2201         if (buf_size < sizeof(struct btrfs_ioctl_search_header))
2202                 return -EOVERFLOW;
2203
2204         /* limit result size to 16MB */
2205         if (buf_size > buf_limit)
2206                 buf_size = buf_limit;
2207
2208         inode = file_inode(file);
2209         ret = search_ioctl(inode, &args.key, &buf_size,
2210                            (char *)(&uarg->buf[0]));
2211         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2212                 ret = -EFAULT;
2213         else if (ret == -EOVERFLOW &&
2214                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2215                 ret = -EFAULT;
2216
2217         return ret;
2218 }
2219
2220 /*
2221  * Search INODE_REFs to identify path name of 'dirid' directory
2222  * in a 'tree_id' tree. and sets path name to 'name'.
2223  */
2224 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2225                                 u64 tree_id, u64 dirid, char *name)
2226 {
2227         struct btrfs_root *root;
2228         struct btrfs_key key;
2229         char *ptr;
2230         int ret = -1;
2231         int slot;
2232         int len;
2233         int total_len = 0;
2234         struct btrfs_inode_ref *iref;
2235         struct extent_buffer *l;
2236         struct btrfs_path *path;
2237
2238         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2239                 name[0]='\0';
2240                 return 0;
2241         }
2242
2243         path = btrfs_alloc_path();
2244         if (!path)
2245                 return -ENOMEM;
2246
2247         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
2248
2249         key.objectid = tree_id;
2250         key.type = BTRFS_ROOT_ITEM_KEY;
2251         key.offset = (u64)-1;
2252         root = btrfs_read_fs_root_no_name(info, &key);
2253         if (IS_ERR(root)) {
2254                 btrfs_err(info, "could not find root %llu", tree_id);
2255                 ret = -ENOENT;
2256                 goto out;
2257         }
2258
2259         key.objectid = dirid;
2260         key.type = BTRFS_INODE_REF_KEY;
2261         key.offset = (u64)-1;
2262
2263         while (1) {
2264                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2265                 if (ret < 0)
2266                         goto out;
2267                 else if (ret > 0) {
2268                         ret = btrfs_previous_item(root, path, dirid,
2269                                                   BTRFS_INODE_REF_KEY);
2270                         if (ret < 0)
2271                                 goto out;
2272                         else if (ret > 0) {
2273                                 ret = -ENOENT;
2274                                 goto out;
2275                         }
2276                 }
2277
2278                 l = path->nodes[0];
2279                 slot = path->slots[0];
2280                 btrfs_item_key_to_cpu(l, &key, slot);
2281
2282                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2283                 len = btrfs_inode_ref_name_len(l, iref);
2284                 ptr -= len + 1;
2285                 total_len += len + 1;
2286                 if (ptr < name) {
2287                         ret = -ENAMETOOLONG;
2288                         goto out;
2289                 }
2290
2291                 *(ptr + len) = '/';
2292                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2293
2294                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2295                         break;
2296
2297                 btrfs_release_path(path);
2298                 key.objectid = key.offset;
2299                 key.offset = (u64)-1;
2300                 dirid = key.objectid;
2301         }
2302         memmove(name, ptr, total_len);
2303         name[total_len] = '\0';
2304         ret = 0;
2305 out:
2306         btrfs_free_path(path);
2307         return ret;
2308 }
2309
2310 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2311                                            void __user *argp)
2312 {
2313          struct btrfs_ioctl_ino_lookup_args *args;
2314          struct inode *inode;
2315         int ret = 0;
2316
2317         args = memdup_user(argp, sizeof(*args));
2318         if (IS_ERR(args))
2319                 return PTR_ERR(args);
2320
2321         inode = file_inode(file);
2322
2323         /*
2324          * Unprivileged query to obtain the containing subvolume root id. The
2325          * path is reset so it's consistent with btrfs_search_path_in_tree.
2326          */
2327         if (args->treeid == 0)
2328                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2329
2330         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2331                 args->name[0] = 0;
2332                 goto out;
2333         }
2334
2335         if (!capable(CAP_SYS_ADMIN)) {
2336                 ret = -EPERM;
2337                 goto out;
2338         }
2339
2340         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2341                                         args->treeid, args->objectid,
2342                                         args->name);
2343
2344 out:
2345         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2346                 ret = -EFAULT;
2347
2348         kfree(args);
2349         return ret;
2350 }
2351
2352 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2353                                              void __user *arg)
2354 {
2355         struct dentry *parent = file->f_path.dentry;
2356         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2357         struct dentry *dentry;
2358         struct inode *dir = d_inode(parent);
2359         struct inode *inode;
2360         struct btrfs_root *root = BTRFS_I(dir)->root;
2361         struct btrfs_root *dest = NULL;
2362         struct btrfs_ioctl_vol_args *vol_args;
2363         struct btrfs_trans_handle *trans;
2364         struct btrfs_block_rsv block_rsv;
2365         u64 root_flags;
2366         u64 qgroup_reserved;
2367         int namelen;
2368         int ret;
2369         int err = 0;
2370
2371         if (!S_ISDIR(dir->i_mode))
2372                 return -ENOTDIR;
2373
2374         vol_args = memdup_user(arg, sizeof(*vol_args));
2375         if (IS_ERR(vol_args))
2376                 return PTR_ERR(vol_args);
2377
2378         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2379         namelen = strlen(vol_args->name);
2380         if (strchr(vol_args->name, '/') ||
2381             strncmp(vol_args->name, "..", namelen) == 0) {
2382                 err = -EINVAL;
2383                 goto out;
2384         }
2385
2386         err = mnt_want_write_file(file);
2387         if (err)
2388                 goto out;
2389
2390
2391         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2392         if (err == -EINTR)
2393                 goto out_drop_write;
2394         dentry = lookup_one_len(vol_args->name, parent, namelen);
2395         if (IS_ERR(dentry)) {
2396                 err = PTR_ERR(dentry);
2397                 goto out_unlock_dir;
2398         }
2399
2400         if (d_really_is_negative(dentry)) {
2401                 err = -ENOENT;
2402                 goto out_dput;
2403         }
2404
2405         inode = d_inode(dentry);
2406         dest = BTRFS_I(inode)->root;
2407         if (!capable(CAP_SYS_ADMIN)) {
2408                 /*
2409                  * Regular user.  Only allow this with a special mount
2410                  * option, when the user has write+exec access to the
2411                  * subvol root, and when rmdir(2) would have been
2412                  * allowed.
2413                  *
2414                  * Note that this is _not_ check that the subvol is
2415                  * empty or doesn't contain data that we wouldn't
2416                  * otherwise be able to delete.
2417                  *
2418                  * Users who want to delete empty subvols should try
2419                  * rmdir(2).
2420                  */
2421                 err = -EPERM;
2422                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2423                         goto out_dput;
2424
2425                 /*
2426                  * Do not allow deletion if the parent dir is the same
2427                  * as the dir to be deleted.  That means the ioctl
2428                  * must be called on the dentry referencing the root
2429                  * of the subvol, not a random directory contained
2430                  * within it.
2431                  */
2432                 err = -EINVAL;
2433                 if (root == dest)
2434                         goto out_dput;
2435
2436                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2437                 if (err)
2438                         goto out_dput;
2439         }
2440
2441         /* check if subvolume may be deleted by a user */
2442         err = btrfs_may_delete(dir, dentry, 1);
2443         if (err)
2444                 goto out_dput;
2445
2446         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2447                 err = -EINVAL;
2448                 goto out_dput;
2449         }
2450
2451         inode_lock(inode);
2452
2453         /*
2454          * Don't allow to delete a subvolume with send in progress. This is
2455          * inside the i_mutex so the error handling that has to drop the bit
2456          * again is not run concurrently.
2457          */
2458         spin_lock(&dest->root_item_lock);
2459         root_flags = btrfs_root_flags(&dest->root_item);
2460         if (dest->send_in_progress == 0) {
2461                 btrfs_set_root_flags(&dest->root_item,
2462                                 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2463                 spin_unlock(&dest->root_item_lock);
2464         } else {
2465                 spin_unlock(&dest->root_item_lock);
2466                 btrfs_warn(fs_info,
2467                            "Attempt to delete subvolume %llu during send",
2468                            dest->root_key.objectid);
2469                 err = -EPERM;
2470                 goto out_unlock_inode;
2471         }
2472
2473         down_write(&fs_info->subvol_sem);
2474
2475         err = may_destroy_subvol(dest);
2476         if (err)
2477                 goto out_up_write;
2478
2479         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2480         /*
2481          * One for dir inode, two for dir entries, two for root
2482          * ref/backref.
2483          */
2484         err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2485                                                5, &qgroup_reserved, true);
2486         if (err)
2487                 goto out_up_write;
2488
2489         trans = btrfs_start_transaction(root, 0);
2490         if (IS_ERR(trans)) {
2491                 err = PTR_ERR(trans);
2492                 goto out_release;
2493         }
2494         trans->block_rsv = &block_rsv;
2495         trans->bytes_reserved = block_rsv.size;
2496
2497         btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
2498
2499         ret = btrfs_unlink_subvol(trans, root, dir,
2500                                 dest->root_key.objectid,
2501                                 dentry->d_name.name,
2502                                 dentry->d_name.len);
2503         if (ret) {
2504                 err = ret;
2505                 btrfs_abort_transaction(trans, ret);
2506                 goto out_end_trans;
2507         }
2508
2509         btrfs_record_root_in_trans(trans, dest);
2510
2511         memset(&dest->root_item.drop_progress, 0,
2512                 sizeof(dest->root_item.drop_progress));
2513         dest->root_item.drop_level = 0;
2514         btrfs_set_root_refs(&dest->root_item, 0);
2515
2516         if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2517                 ret = btrfs_insert_orphan_item(trans,
2518                                         fs_info->tree_root,
2519                                         dest->root_key.objectid);
2520                 if (ret) {
2521                         btrfs_abort_transaction(trans, ret);
2522                         err = ret;
2523                         goto out_end_trans;
2524                 }
2525         }
2526
2527         ret = btrfs_uuid_tree_rem(trans, fs_info, dest->root_item.uuid,
2528                                   BTRFS_UUID_KEY_SUBVOL,
2529                                   dest->root_key.objectid);
2530         if (ret && ret != -ENOENT) {
2531                 btrfs_abort_transaction(trans, ret);
2532                 err = ret;
2533                 goto out_end_trans;
2534         }
2535         if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2536                 ret = btrfs_uuid_tree_rem(trans, fs_info,
2537                                           dest->root_item.received_uuid,
2538                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2539                                           dest->root_key.objectid);
2540                 if (ret && ret != -ENOENT) {
2541                         btrfs_abort_transaction(trans, ret);
2542                         err = ret;
2543                         goto out_end_trans;
2544                 }
2545         }
2546
2547 out_end_trans:
2548         trans->block_rsv = NULL;
2549         trans->bytes_reserved = 0;
2550         ret = btrfs_end_transaction(trans);
2551         if (ret && !err)
2552                 err = ret;
2553         inode->i_flags |= S_DEAD;
2554 out_release:
2555         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
2556 out_up_write:
2557         up_write(&fs_info->subvol_sem);
2558         if (err) {
2559                 spin_lock(&dest->root_item_lock);
2560                 root_flags = btrfs_root_flags(&dest->root_item);
2561                 btrfs_set_root_flags(&dest->root_item,
2562                                 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2563                 spin_unlock(&dest->root_item_lock);
2564         }
2565 out_unlock_inode:
2566         inode_unlock(inode);
2567         if (!err) {
2568                 d_invalidate(dentry);
2569                 btrfs_invalidate_inodes(dest);
2570                 d_delete(dentry);
2571                 ASSERT(dest->send_in_progress == 0);
2572
2573                 /* the last ref */
2574                 if (dest->ino_cache_inode) {
2575                         iput(dest->ino_cache_inode);
2576                         dest->ino_cache_inode = NULL;
2577                 }
2578         }
2579 out_dput:
2580         dput(dentry);
2581 out_unlock_dir:
2582         inode_unlock(dir);
2583 out_drop_write:
2584         mnt_drop_write_file(file);
2585 out:
2586         kfree(vol_args);
2587         return err;
2588 }
2589
2590 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2591 {
2592         struct inode *inode = file_inode(file);
2593         struct btrfs_root *root = BTRFS_I(inode)->root;
2594         struct btrfs_ioctl_defrag_range_args *range;
2595         int ret;
2596
2597         ret = mnt_want_write_file(file);
2598         if (ret)
2599                 return ret;
2600
2601         if (btrfs_root_readonly(root)) {
2602                 ret = -EROFS;
2603                 goto out;
2604         }
2605
2606         switch (inode->i_mode & S_IFMT) {
2607         case S_IFDIR:
2608                 if (!capable(CAP_SYS_ADMIN)) {
2609                         ret = -EPERM;
2610                         goto out;
2611                 }
2612                 ret = btrfs_defrag_root(root);
2613                 break;
2614         case S_IFREG:
2615                 if (!(file->f_mode & FMODE_WRITE)) {
2616                         ret = -EINVAL;
2617                         goto out;
2618                 }
2619
2620                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2621                 if (!range) {
2622                         ret = -ENOMEM;
2623                         goto out;
2624                 }
2625
2626                 if (argp) {
2627                         if (copy_from_user(range, argp,
2628                                            sizeof(*range))) {
2629                                 ret = -EFAULT;
2630                                 kfree(range);
2631                                 goto out;
2632                         }
2633                         /* compression requires us to start the IO */
2634                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2635                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2636                                 range->extent_thresh = (u32)-1;
2637                         }
2638                 } else {
2639                         /* the rest are all set to zero by kzalloc */
2640                         range->len = (u64)-1;
2641                 }
2642                 ret = btrfs_defrag_file(file_inode(file), file,
2643                                         range, 0, 0);
2644                 if (ret > 0)
2645                         ret = 0;
2646                 kfree(range);
2647                 break;
2648         default:
2649                 ret = -EINVAL;
2650         }
2651 out:
2652         mnt_drop_write_file(file);
2653         return ret;
2654 }
2655
2656 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2657 {
2658         struct btrfs_ioctl_vol_args *vol_args;
2659         int ret;
2660
2661         if (!capable(CAP_SYS_ADMIN))
2662                 return -EPERM;
2663
2664         if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1))
2665                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2666
2667         mutex_lock(&fs_info->volume_mutex);
2668         vol_args = memdup_user(arg, sizeof(*vol_args));
2669         if (IS_ERR(vol_args)) {
2670                 ret = PTR_ERR(vol_args);
2671                 goto out;
2672         }
2673
2674         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2675         ret = btrfs_init_new_device(fs_info, vol_args->name);
2676
2677         if (!ret)
2678                 btrfs_info(fs_info, "disk added %s", vol_args->name);
2679
2680         kfree(vol_args);
2681 out:
2682         mutex_unlock(&fs_info->volume_mutex);
2683         atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
2684         return ret;
2685 }
2686
2687 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2688 {
2689         struct inode *inode = file_inode(file);
2690         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2691         struct btrfs_ioctl_vol_args_v2 *vol_args;
2692         int ret;
2693
2694         if (!capable(CAP_SYS_ADMIN))
2695                 return -EPERM;
2696
2697         ret = mnt_want_write_file(file);
2698         if (ret)
2699                 return ret;
2700
2701         vol_args = memdup_user(arg, sizeof(*vol_args));
2702         if (IS_ERR(vol_args)) {
2703                 ret = PTR_ERR(vol_args);
2704                 goto err_drop;
2705         }
2706
2707         /* Check for compatibility reject unknown flags */
2708         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED)
2709                 return -EOPNOTSUPP;
2710
2711         if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
2712                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2713                 goto out;
2714         }
2715
2716         mutex_lock(&fs_info->volume_mutex);
2717         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2718                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
2719         } else {
2720                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
2721                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2722         }
2723         mutex_unlock(&fs_info->volume_mutex);
2724         atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
2725
2726         if (!ret) {
2727                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2728                         btrfs_info(fs_info, "device deleted: id %llu",
2729                                         vol_args->devid);
2730                 else
2731                         btrfs_info(fs_info, "device deleted: %s",
2732                                         vol_args->name);
2733         }
2734 out:
2735         kfree(vol_args);
2736 err_drop:
2737         mnt_drop_write_file(file);
2738         return ret;
2739 }
2740
2741 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2742 {
2743         struct inode *inode = file_inode(file);
2744         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2745         struct btrfs_ioctl_vol_args *vol_args;
2746         int ret;
2747
2748         if (!capable(CAP_SYS_ADMIN))
2749                 return -EPERM;
2750
2751         ret = mnt_want_write_file(file);
2752         if (ret)
2753                 return ret;
2754
2755         if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
2756                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2757                 goto out_drop_write;
2758         }
2759
2760         vol_args = memdup_user(arg, sizeof(*vol_args));
2761         if (IS_ERR(vol_args)) {
2762                 ret = PTR_ERR(vol_args);
2763                 goto out;
2764         }
2765
2766         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2767         mutex_lock(&fs_info->volume_mutex);
2768         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2769         mutex_unlock(&fs_info->volume_mutex);
2770
2771         if (!ret)
2772                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
2773         kfree(vol_args);
2774 out:
2775         atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
2776 out_drop_write:
2777         mnt_drop_write_file(file);
2778
2779         return ret;
2780 }
2781
2782 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
2783                                 void __user *arg)
2784 {
2785         struct btrfs_ioctl_fs_info_args *fi_args;
2786         struct btrfs_device *device;
2787         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2788         int ret = 0;
2789
2790         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2791         if (!fi_args)
2792                 return -ENOMEM;
2793
2794         mutex_lock(&fs_devices->device_list_mutex);
2795         fi_args->num_devices = fs_devices->num_devices;
2796         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
2797
2798         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2799                 if (device->devid > fi_args->max_id)
2800                         fi_args->max_id = device->devid;
2801         }
2802         mutex_unlock(&fs_devices->device_list_mutex);
2803
2804         fi_args->nodesize = fs_info->super_copy->nodesize;
2805         fi_args->sectorsize = fs_info->super_copy->sectorsize;
2806         fi_args->clone_alignment = fs_info->super_copy->sectorsize;
2807
2808         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2809                 ret = -EFAULT;
2810
2811         kfree(fi_args);
2812         return ret;
2813 }
2814
2815 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
2816                                  void __user *arg)
2817 {
2818         struct btrfs_ioctl_dev_info_args *di_args;
2819         struct btrfs_device *dev;
2820         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2821         int ret = 0;
2822         char *s_uuid = NULL;
2823
2824         di_args = memdup_user(arg, sizeof(*di_args));
2825         if (IS_ERR(di_args))
2826                 return PTR_ERR(di_args);
2827
2828         if (!btrfs_is_empty_uuid(di_args->uuid))
2829                 s_uuid = di_args->uuid;
2830
2831         mutex_lock(&fs_devices->device_list_mutex);
2832         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
2833
2834         if (!dev) {
2835                 ret = -ENODEV;
2836                 goto out;
2837         }
2838
2839         di_args->devid = dev->devid;
2840         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2841         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2842         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2843         if (dev->name) {
2844                 struct rcu_string *name;
2845
2846                 rcu_read_lock();
2847                 name = rcu_dereference(dev->name);
2848                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2849                 rcu_read_unlock();
2850                 di_args->path[sizeof(di_args->path) - 1] = 0;
2851         } else {
2852                 di_args->path[0] = '\0';
2853         }
2854
2855 out:
2856         mutex_unlock(&fs_devices->device_list_mutex);
2857         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2858                 ret = -EFAULT;
2859
2860         kfree(di_args);
2861         return ret;
2862 }
2863
2864 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
2865 {
2866         struct page *page;
2867
2868         page = grab_cache_page(inode->i_mapping, index);
2869         if (!page)
2870                 return ERR_PTR(-ENOMEM);
2871
2872         if (!PageUptodate(page)) {
2873                 int ret;
2874
2875                 ret = btrfs_readpage(NULL, page);
2876                 if (ret)
2877                         return ERR_PTR(ret);
2878                 lock_page(page);
2879                 if (!PageUptodate(page)) {
2880                         unlock_page(page);
2881                         put_page(page);
2882                         return ERR_PTR(-EIO);
2883                 }
2884                 if (page->mapping != inode->i_mapping) {
2885                         unlock_page(page);
2886                         put_page(page);
2887                         return ERR_PTR(-EAGAIN);
2888                 }
2889         }
2890
2891         return page;
2892 }
2893
2894 static int gather_extent_pages(struct inode *inode, struct page **pages,
2895                                int num_pages, u64 off)
2896 {
2897         int i;
2898         pgoff_t index = off >> PAGE_SHIFT;
2899
2900         for (i = 0; i < num_pages; i++) {
2901 again:
2902                 pages[i] = extent_same_get_page(inode, index + i);
2903                 if (IS_ERR(pages[i])) {
2904                         int err = PTR_ERR(pages[i]);
2905
2906                         if (err == -EAGAIN)
2907                                 goto again;
2908                         pages[i] = NULL;
2909                         return err;
2910                 }
2911         }
2912         return 0;
2913 }
2914
2915 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
2916                              bool retry_range_locking)
2917 {
2918         /*
2919          * Do any pending delalloc/csum calculations on inode, one way or
2920          * another, and lock file content.
2921          * The locking order is:
2922          *
2923          *   1) pages
2924          *   2) range in the inode's io tree
2925          */
2926         while (1) {
2927                 struct btrfs_ordered_extent *ordered;
2928                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2929                 ordered = btrfs_lookup_first_ordered_extent(inode,
2930                                                             off + len - 1);
2931                 if ((!ordered ||
2932                      ordered->file_offset + ordered->len <= off ||
2933                      ordered->file_offset >= off + len) &&
2934                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2935                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2936                         if (ordered)
2937                                 btrfs_put_ordered_extent(ordered);
2938                         break;
2939                 }
2940                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2941                 if (ordered)
2942                         btrfs_put_ordered_extent(ordered);
2943                 if (!retry_range_locking)
2944                         return -EAGAIN;
2945                 btrfs_wait_ordered_range(inode, off, len);
2946         }
2947         return 0;
2948 }
2949
2950 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2951 {
2952         inode_unlock(inode1);
2953         inode_unlock(inode2);
2954 }
2955
2956 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2957 {
2958         if (inode1 < inode2)
2959                 swap(inode1, inode2);
2960
2961         inode_lock_nested(inode1, I_MUTEX_PARENT);
2962         inode_lock_nested(inode2, I_MUTEX_CHILD);
2963 }
2964
2965 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2966                                       struct inode *inode2, u64 loff2, u64 len)
2967 {
2968         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2969         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2970 }
2971
2972 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2973                                     struct inode *inode2, u64 loff2, u64 len,
2974                                     bool retry_range_locking)
2975 {
2976         int ret;
2977
2978         if (inode1 < inode2) {
2979                 swap(inode1, inode2);
2980                 swap(loff1, loff2);
2981         }
2982         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
2983         if (ret)
2984                 return ret;
2985         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
2986         if (ret)
2987                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
2988                               loff1 + len - 1);
2989         return ret;
2990 }
2991
2992 struct cmp_pages {
2993         int             num_pages;
2994         struct page     **src_pages;
2995         struct page     **dst_pages;
2996 };
2997
2998 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
2999 {
3000         int i;
3001         struct page *pg;
3002
3003         for (i = 0; i < cmp->num_pages; i++) {
3004                 pg = cmp->src_pages[i];
3005                 if (pg) {
3006                         unlock_page(pg);
3007                         put_page(pg);
3008                 }
3009                 pg = cmp->dst_pages[i];
3010                 if (pg) {
3011                         unlock_page(pg);
3012                         put_page(pg);
3013                 }
3014         }
3015         kfree(cmp->src_pages);
3016         kfree(cmp->dst_pages);
3017 }
3018
3019 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
3020                                   struct inode *dst, u64 dst_loff,
3021                                   u64 len, struct cmp_pages *cmp)
3022 {
3023         int ret;
3024         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
3025         struct page **src_pgarr, **dst_pgarr;
3026
3027         /*
3028          * We must gather up all the pages before we initiate our
3029          * extent locking. We use an array for the page pointers. Size
3030          * of the array is bounded by len, which is in turn bounded by
3031          * BTRFS_MAX_DEDUPE_LEN.
3032          */
3033         src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3034         dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3035         if (!src_pgarr || !dst_pgarr) {
3036                 kfree(src_pgarr);
3037                 kfree(dst_pgarr);
3038                 return -ENOMEM;
3039         }
3040         cmp->num_pages = num_pages;
3041         cmp->src_pages = src_pgarr;
3042         cmp->dst_pages = dst_pgarr;
3043
3044         /*
3045          * If deduping ranges in the same inode, locking rules make it mandatory
3046          * to always lock pages in ascending order to avoid deadlocks with
3047          * concurrent tasks (such as starting writeback/delalloc).
3048          */
3049         if (src == dst && dst_loff < loff) {
3050                 swap(src_pgarr, dst_pgarr);
3051                 swap(loff, dst_loff);
3052         }
3053
3054         ret = gather_extent_pages(src, src_pgarr, cmp->num_pages, loff);
3055         if (ret)
3056                 goto out;
3057
3058         ret = gather_extent_pages(dst, dst_pgarr, cmp->num_pages, dst_loff);
3059
3060 out:
3061         if (ret)
3062                 btrfs_cmp_data_free(cmp);
3063         return 0;
3064 }
3065
3066 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3067 {
3068         int ret = 0;
3069         int i;
3070         struct page *src_page, *dst_page;
3071         unsigned int cmp_len = PAGE_SIZE;
3072         void *addr, *dst_addr;
3073
3074         i = 0;
3075         while (len) {
3076                 if (len < PAGE_SIZE)
3077                         cmp_len = len;
3078
3079                 BUG_ON(i >= cmp->num_pages);
3080
3081                 src_page = cmp->src_pages[i];
3082                 dst_page = cmp->dst_pages[i];
3083                 ASSERT(PageLocked(src_page));
3084                 ASSERT(PageLocked(dst_page));
3085
3086                 addr = kmap_atomic(src_page);
3087                 dst_addr = kmap_atomic(dst_page);
3088
3089                 flush_dcache_page(src_page);
3090                 flush_dcache_page(dst_page);
3091
3092                 if (memcmp(addr, dst_addr, cmp_len))
3093                         ret = -EBADE;
3094
3095                 kunmap_atomic(addr);
3096                 kunmap_atomic(dst_addr);
3097
3098                 if (ret)
3099                         break;
3100
3101                 len -= cmp_len;
3102                 i++;
3103         }
3104
3105         return ret;
3106 }
3107
3108 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3109                                      u64 olen)
3110 {
3111         u64 len = *plen;
3112         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3113
3114         if (off + olen > inode->i_size || off + olen < off)
3115                 return -EINVAL;
3116
3117         /* if we extend to eof, continue to block boundary */
3118         if (off + len == inode->i_size)
3119                 *plen = len = ALIGN(inode->i_size, bs) - off;
3120
3121         /* Check that we are block aligned - btrfs_clone() requires this */
3122         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3123                 return -EINVAL;
3124
3125         return 0;
3126 }
3127
3128 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3129                              struct inode *dst, u64 dst_loff)
3130 {
3131         int ret;
3132         u64 len = olen;
3133         struct cmp_pages cmp;
3134         bool same_inode = (src == dst);
3135         u64 same_lock_start = 0;
3136         u64 same_lock_len = 0;
3137
3138         if (len == 0)
3139                 return 0;
3140
3141         if (same_inode)
3142                 inode_lock(src);
3143         else
3144                 btrfs_double_inode_lock(src, dst);
3145
3146         ret = extent_same_check_offsets(src, loff, &len, olen);
3147         if (ret)
3148                 goto out_unlock;
3149
3150         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3151         if (ret)
3152                 goto out_unlock;
3153
3154         if (same_inode) {
3155                 /*
3156                  * Single inode case wants the same checks, except we
3157                  * don't want our length pushed out past i_size as
3158                  * comparing that data range makes no sense.
3159                  *
3160                  * extent_same_check_offsets() will do this for an
3161                  * unaligned length at i_size, so catch it here and
3162                  * reject the request.
3163                  *
3164                  * This effectively means we require aligned extents
3165                  * for the single-inode case, whereas the other cases
3166                  * allow an unaligned length so long as it ends at
3167                  * i_size.
3168                  */
3169                 if (len != olen) {
3170                         ret = -EINVAL;
3171                         goto out_unlock;
3172                 }
3173
3174                 /* Check for overlapping ranges */
3175                 if (dst_loff + len > loff && dst_loff < loff + len) {
3176                         ret = -EINVAL;
3177                         goto out_unlock;
3178                 }
3179
3180                 same_lock_start = min_t(u64, loff, dst_loff);
3181                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3182         }
3183
3184         /* don't make the dst file partly checksummed */
3185         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3186             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3187                 ret = -EINVAL;
3188                 goto out_unlock;
3189         }
3190
3191 again:
3192         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
3193         if (ret)
3194                 goto out_unlock;
3195
3196         if (same_inode)
3197                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3198                                         false);
3199         else
3200                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3201                                                false);
3202         /*
3203          * If one of the inodes has dirty pages in the respective range or
3204          * ordered extents, we need to flush dellaloc and wait for all ordered
3205          * extents in the range. We must unlock the pages and the ranges in the
3206          * io trees to avoid deadlocks when flushing delalloc (requires locking
3207          * pages) and when waiting for ordered extents to complete (they require
3208          * range locking).
3209          */
3210         if (ret == -EAGAIN) {
3211                 /*
3212                  * Ranges in the io trees already unlocked. Now unlock all
3213                  * pages before waiting for all IO to complete.
3214                  */
3215                 btrfs_cmp_data_free(&cmp);
3216                 if (same_inode) {
3217                         btrfs_wait_ordered_range(src, same_lock_start,
3218                                                  same_lock_len);
3219                 } else {
3220                         btrfs_wait_ordered_range(src, loff, len);
3221                         btrfs_wait_ordered_range(dst, dst_loff, len);
3222                 }
3223                 goto again;
3224         }
3225         ASSERT(ret == 0);
3226         if (WARN_ON(ret)) {
3227                 /* ranges in the io trees already unlocked */
3228                 btrfs_cmp_data_free(&cmp);
3229                 return ret;
3230         }
3231
3232         /* pass original length for comparison so we stay within i_size */
3233         ret = btrfs_cmp_data(olen, &cmp);
3234         if (ret == 0)
3235                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3236
3237         if (same_inode)
3238                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3239                               same_lock_start + same_lock_len - 1);
3240         else
3241                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3242
3243         btrfs_cmp_data_free(&cmp);
3244 out_unlock:
3245         if (same_inode)
3246                 inode_unlock(src);
3247         else
3248                 btrfs_double_inode_unlock(src, dst);
3249
3250         return ret;
3251 }
3252
3253 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3254
3255 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3256                                 struct file *dst_file, u64 dst_loff)
3257 {
3258         struct inode *src = file_inode(src_file);
3259         struct inode *dst = file_inode(dst_file);
3260         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3261         ssize_t res;
3262
3263         if (olen > BTRFS_MAX_DEDUPE_LEN)
3264                 olen = BTRFS_MAX_DEDUPE_LEN;
3265
3266         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3267                 /*
3268                  * Btrfs does not support blocksize < page_size. As a
3269                  * result, btrfs_cmp_data() won't correctly handle
3270                  * this situation without an update.
3271                  */
3272                 return -EINVAL;
3273         }
3274
3275         res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3276         if (res)
3277                 return res;
3278         return olen;
3279 }
3280
3281 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3282                                      struct inode *inode,
3283                                      u64 endoff,
3284                                      const u64 destoff,
3285                                      const u64 olen,
3286                                      int no_time_update)
3287 {
3288         struct btrfs_root *root = BTRFS_I(inode)->root;
3289         int ret;
3290
3291         inode_inc_iversion(inode);
3292         if (!no_time_update)
3293                 inode->i_mtime = inode->i_ctime = current_time(inode);
3294         /*
3295          * We round up to the block size at eof when determining which
3296          * extents to clone above, but shouldn't round up the file size.
3297          */
3298         if (endoff > destoff + olen)
3299                 endoff = destoff + olen;
3300         if (endoff > inode->i_size)
3301                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3302
3303         ret = btrfs_update_inode(trans, root, inode);
3304         if (ret) {
3305                 btrfs_abort_transaction(trans, ret);
3306                 btrfs_end_transaction(trans);
3307                 goto out;
3308         }
3309         ret = btrfs_end_transaction(trans);
3310 out:
3311         return ret;
3312 }
3313
3314 static void clone_update_extent_map(struct btrfs_inode *inode,
3315                                     const struct btrfs_trans_handle *trans,
3316                                     const struct btrfs_path *path,
3317                                     const u64 hole_offset,
3318                                     const u64 hole_len)
3319 {
3320         struct extent_map_tree *em_tree = &inode->extent_tree;
3321         struct extent_map *em;
3322         int ret;
3323
3324         em = alloc_extent_map();
3325         if (!em) {
3326                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3327                 return;
3328         }
3329
3330         if (path) {
3331                 struct btrfs_file_extent_item *fi;
3332
3333                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3334                                     struct btrfs_file_extent_item);
3335                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3336                 em->generation = -1;
3337                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3338                     BTRFS_FILE_EXTENT_INLINE)
3339                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3340                                         &inode->runtime_flags);
3341         } else {
3342                 em->start = hole_offset;
3343                 em->len = hole_len;
3344                 em->ram_bytes = em->len;
3345                 em->orig_start = hole_offset;
3346                 em->block_start = EXTENT_MAP_HOLE;
3347                 em->block_len = 0;
3348                 em->orig_block_len = 0;
3349                 em->compress_type = BTRFS_COMPRESS_NONE;
3350                 em->generation = trans->transid;
3351         }
3352
3353         while (1) {
3354                 write_lock(&em_tree->lock);
3355                 ret = add_extent_mapping(em_tree, em, 1);
3356                 write_unlock(&em_tree->lock);
3357                 if (ret != -EEXIST) {
3358                         free_extent_map(em);
3359                         break;
3360                 }
3361                 btrfs_drop_extent_cache(inode, em->start,
3362                                         em->start + em->len - 1, 0);
3363         }
3364
3365         if (ret)
3366                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3367 }
3368
3369 /*
3370  * Make sure we do not end up inserting an inline extent into a file that has
3371  * already other (non-inline) extents. If a file has an inline extent it can
3372  * not have any other extents and the (single) inline extent must start at the
3373  * file offset 0. Failing to respect these rules will lead to file corruption,
3374  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3375  *
3376  * We can have extents that have been already written to disk or we can have
3377  * dirty ranges still in delalloc, in which case the extent maps and items are
3378  * created only when we run delalloc, and the delalloc ranges might fall outside
3379  * the range we are currently locking in the inode's io tree. So we check the
3380  * inode's i_size because of that (i_size updates are done while holding the
3381  * i_mutex, which we are holding here).
3382  * We also check to see if the inode has a size not greater than "datal" but has
3383  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3384  * protected against such concurrent fallocate calls by the i_mutex).
3385  *
3386  * If the file has no extents but a size greater than datal, do not allow the
3387  * copy because we would need turn the inline extent into a non-inline one (even
3388  * with NO_HOLES enabled). If we find our destination inode only has one inline
3389  * extent, just overwrite it with the source inline extent if its size is less
3390  * than the source extent's size, or we could copy the source inline extent's
3391  * data into the destination inode's inline extent if the later is greater then
3392  * the former.
3393  */
3394 static int clone_copy_inline_extent(struct inode *dst,
3395                                     struct btrfs_trans_handle *trans,
3396                                     struct btrfs_path *path,
3397                                     struct btrfs_key *new_key,
3398                                     const u64 drop_start,
3399                                     const u64 datal,
3400                                     const u64 skip,
3401                                     const u64 size,
3402                                     char *inline_data)
3403 {
3404         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3405         struct btrfs_root *root = BTRFS_I(dst)->root;
3406         const u64 aligned_end = ALIGN(new_key->offset + datal,
3407                                       fs_info->sectorsize);
3408         int ret;
3409         struct btrfs_key key;
3410
3411         if (new_key->offset > 0)
3412                 return -EOPNOTSUPP;
3413
3414         key.objectid = btrfs_ino(BTRFS_I(dst));
3415         key.type = BTRFS_EXTENT_DATA_KEY;
3416         key.offset = 0;
3417         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3418         if (ret < 0) {
3419                 return ret;
3420         } else if (ret > 0) {
3421                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3422                         ret = btrfs_next_leaf(root, path);
3423                         if (ret < 0)
3424                                 return ret;
3425                         else if (ret > 0)
3426                                 goto copy_inline_extent;
3427                 }
3428                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3429                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3430                     key.type == BTRFS_EXTENT_DATA_KEY) {
3431                         ASSERT(key.offset > 0);
3432                         return -EOPNOTSUPP;
3433                 }
3434         } else if (i_size_read(dst) <= datal) {
3435                 struct btrfs_file_extent_item *ei;
3436                 u64 ext_len;
3437
3438                 /*
3439                  * If the file size is <= datal, make sure there are no other
3440                  * extents following (can happen do to an fallocate call with
3441                  * the flag FALLOC_FL_KEEP_SIZE).
3442                  */
3443                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3444                                     struct btrfs_file_extent_item);
3445                 /*
3446                  * If it's an inline extent, it can not have other extents
3447                  * following it.
3448                  */
3449                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3450                     BTRFS_FILE_EXTENT_INLINE)
3451                         goto copy_inline_extent;
3452
3453                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3454                 if (ext_len > aligned_end)
3455                         return -EOPNOTSUPP;
3456
3457                 ret = btrfs_next_item(root, path);
3458                 if (ret < 0) {
3459                         return ret;
3460                 } else if (ret == 0) {
3461                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3462                                               path->slots[0]);
3463                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3464                             key.type == BTRFS_EXTENT_DATA_KEY)
3465                                 return -EOPNOTSUPP;
3466                 }
3467         }
3468
3469 copy_inline_extent:
3470         /*
3471          * We have no extent items, or we have an extent at offset 0 which may
3472          * or may not be inlined. All these cases are dealt the same way.
3473          */
3474         if (i_size_read(dst) > datal) {
3475                 /*
3476                  * If the destination inode has an inline extent...
3477                  * This would require copying the data from the source inline
3478                  * extent into the beginning of the destination's inline extent.
3479                  * But this is really complex, both extents can be compressed
3480                  * or just one of them, which would require decompressing and
3481                  * re-compressing data (which could increase the new compressed
3482                  * size, not allowing the compressed data to fit anymore in an
3483                  * inline extent).
3484                  * So just don't support this case for now (it should be rare,
3485                  * we are not really saving space when cloning inline extents).
3486                  */
3487                 return -EOPNOTSUPP;
3488         }
3489
3490         btrfs_release_path(path);
3491         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3492         if (ret)
3493                 return ret;
3494         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3495         if (ret)
3496                 return ret;
3497
3498         if (skip) {
3499                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3500
3501                 memmove(inline_data + start, inline_data + start + skip, datal);
3502         }
3503
3504         write_extent_buffer(path->nodes[0], inline_data,
3505                             btrfs_item_ptr_offset(path->nodes[0],
3506                                                   path->slots[0]),
3507                             size);
3508         inode_add_bytes(dst, datal);
3509
3510         return 0;
3511 }
3512
3513 /**
3514  * btrfs_clone() - clone a range from inode file to another
3515  *
3516  * @src: Inode to clone from
3517  * @inode: Inode to clone to
3518  * @off: Offset within source to start clone from
3519  * @olen: Original length, passed by user, of range to clone
3520  * @olen_aligned: Block-aligned value of olen
3521  * @destoff: Offset within @inode to start clone
3522  * @no_time_update: Whether to update mtime/ctime on the target inode
3523  */
3524 static int btrfs_clone(struct inode *src, struct inode *inode,
3525                        const u64 off, const u64 olen, const u64 olen_aligned,
3526                        const u64 destoff, int no_time_update)
3527 {
3528         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3529         struct btrfs_root *root = BTRFS_I(inode)->root;
3530         struct btrfs_path *path = NULL;
3531         struct extent_buffer *leaf;
3532         struct btrfs_trans_handle *trans;
3533         char *buf = NULL;
3534         struct btrfs_key key;
3535         u32 nritems;
3536         int slot;
3537         int ret;
3538         const u64 len = olen_aligned;
3539         u64 last_dest_end = destoff;
3540
3541         ret = -ENOMEM;
3542         buf = kmalloc(fs_info->nodesize, GFP_KERNEL | __GFP_NOWARN);
3543         if (!buf) {
3544                 buf = vmalloc(fs_info->nodesize);
3545                 if (!buf)
3546                         return ret;
3547         }
3548
3549         path = btrfs_alloc_path();
3550         if (!path) {
3551                 kvfree(buf);
3552                 return ret;
3553         }
3554
3555         path->reada = READA_FORWARD;
3556         /* clone data */
3557         key.objectid = btrfs_ino(BTRFS_I(src));
3558         key.type = BTRFS_EXTENT_DATA_KEY;
3559         key.offset = off;
3560
3561         while (1) {
3562                 u64 next_key_min_offset = key.offset + 1;
3563
3564                 /*
3565                  * note the key will change type as we walk through the
3566                  * tree.
3567                  */
3568                 path->leave_spinning = 1;
3569                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3570                                 0, 0);
3571                 if (ret < 0)
3572                         goto out;
3573                 /*
3574                  * First search, if no extent item that starts at offset off was
3575                  * found but the previous item is an extent item, it's possible
3576                  * it might overlap our target range, therefore process it.
3577                  */
3578                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3579                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3580                                               path->slots[0] - 1);
3581                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3582                                 path->slots[0]--;
3583                 }
3584
3585                 nritems = btrfs_header_nritems(path->nodes[0]);
3586 process_slot:
3587                 if (path->slots[0] >= nritems) {
3588                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3589                         if (ret < 0)
3590                                 goto out;
3591                         if (ret > 0)
3592                                 break;
3593                         nritems = btrfs_header_nritems(path->nodes[0]);
3594                 }
3595                 leaf = path->nodes[0];
3596                 slot = path->slots[0];
3597
3598                 btrfs_item_key_to_cpu(leaf, &key, slot);
3599                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3600                     key.objectid != btrfs_ino(BTRFS_I(src)))
3601                         break;
3602
3603                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3604                         struct btrfs_file_extent_item *extent;
3605                         int type;
3606                         u32 size;
3607                         struct btrfs_key new_key;
3608                         u64 disko = 0, diskl = 0;
3609                         u64 datao = 0, datal = 0;
3610                         u8 comp;
3611                         u64 drop_start;
3612
3613                         extent = btrfs_item_ptr(leaf, slot,
3614                                                 struct btrfs_file_extent_item);
3615                         comp = btrfs_file_extent_compression(leaf, extent);
3616                         type = btrfs_file_extent_type(leaf, extent);
3617                         if (type == BTRFS_FILE_EXTENT_REG ||
3618                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3619                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3620                                                                       extent);
3621                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3622                                                                  extent);
3623                                 datao = btrfs_file_extent_offset(leaf, extent);
3624                                 datal = btrfs_file_extent_num_bytes(leaf,
3625                                                                     extent);
3626                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3627                                 /* take upper bound, may be compressed */
3628                                 datal = btrfs_file_extent_ram_bytes(leaf,
3629                                                                     extent);
3630                         }
3631
3632                         /*
3633                          * The first search might have left us at an extent
3634                          * item that ends before our target range's start, can
3635                          * happen if we have holes and NO_HOLES feature enabled.
3636                          */
3637                         if (key.offset + datal <= off) {
3638                                 path->slots[0]++;
3639                                 goto process_slot;
3640                         } else if (key.offset >= off + len) {
3641                                 break;
3642                         }
3643                         next_key_min_offset = key.offset + datal;
3644                         size = btrfs_item_size_nr(leaf, slot);
3645                         read_extent_buffer(leaf, buf,
3646                                            btrfs_item_ptr_offset(leaf, slot),
3647                                            size);
3648
3649                         btrfs_release_path(path);
3650                         path->leave_spinning = 0;
3651
3652                         memcpy(&new_key, &key, sizeof(new_key));
3653                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
3654                         if (off <= key.offset)
3655                                 new_key.offset = key.offset + destoff - off;
3656                         else
3657                                 new_key.offset = destoff;
3658
3659                         /*
3660                          * Deal with a hole that doesn't have an extent item
3661                          * that represents it (NO_HOLES feature enabled).
3662                          * This hole is either in the middle of the cloning
3663                          * range or at the beginning (fully overlaps it or
3664                          * partially overlaps it).
3665                          */
3666                         if (new_key.offset != last_dest_end)
3667                                 drop_start = last_dest_end;
3668                         else
3669                                 drop_start = new_key.offset;
3670
3671                         /*
3672                          * 1 - adjusting old extent (we may have to split it)
3673                          * 1 - add new extent
3674                          * 1 - inode update
3675                          */
3676                         trans = btrfs_start_transaction(root, 3);
3677                         if (IS_ERR(trans)) {
3678                                 ret = PTR_ERR(trans);
3679                                 goto out;
3680                         }
3681
3682                         if (type == BTRFS_FILE_EXTENT_REG ||
3683                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3684                                 /*
3685                                  *    a  | --- range to clone ---|  b
3686                                  * | ------------- extent ------------- |
3687                                  */
3688
3689                                 /* subtract range b */
3690                                 if (key.offset + datal > off + len)
3691                                         datal = off + len - key.offset;
3692
3693                                 /* subtract range a */
3694                                 if (off > key.offset) {
3695                                         datao += off - key.offset;
3696                                         datal -= off - key.offset;
3697                                 }
3698
3699                                 ret = btrfs_drop_extents(trans, root, inode,
3700                                                          drop_start,
3701                                                          new_key.offset + datal,
3702                                                          1);
3703                                 if (ret) {
3704                                         if (ret != -EOPNOTSUPP)
3705                                                 btrfs_abort_transaction(trans,
3706                                                                         ret);
3707                                         btrfs_end_transaction(trans);
3708                                         goto out;
3709                                 }
3710
3711                                 ret = btrfs_insert_empty_item(trans, root, path,
3712                                                               &new_key, size);
3713                                 if (ret) {
3714                                         btrfs_abort_transaction(trans, ret);
3715                                         btrfs_end_transaction(trans);
3716                                         goto out;
3717                                 }
3718
3719                                 leaf = path->nodes[0];
3720                                 slot = path->slots[0];
3721                                 write_extent_buffer(leaf, buf,
3722                                             btrfs_item_ptr_offset(leaf, slot),
3723                                             size);
3724
3725                                 extent = btrfs_item_ptr(leaf, slot,
3726                                                 struct btrfs_file_extent_item);
3727
3728                                 /* disko == 0 means it's a hole */
3729                                 if (!disko)
3730                                         datao = 0;
3731
3732                                 btrfs_set_file_extent_offset(leaf, extent,
3733                                                              datao);
3734                                 btrfs_set_file_extent_num_bytes(leaf, extent,
3735                                                                 datal);
3736
3737                                 if (disko) {
3738                                         inode_add_bytes(inode, datal);
3739                                         ret = btrfs_inc_extent_ref(trans,
3740                                                         fs_info,
3741                                                         disko, diskl, 0,
3742                                                         root->root_key.objectid,
3743                                                         btrfs_ino(BTRFS_I(inode)),
3744                                                         new_key.offset - datao);
3745                                         if (ret) {
3746                                                 btrfs_abort_transaction(trans,
3747                                                                         ret);
3748                                                 btrfs_end_transaction(trans);
3749                                                 goto out;
3750
3751                                         }
3752                                 }
3753                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3754                                 u64 skip = 0;
3755                                 u64 trim = 0;
3756
3757                                 if (off > key.offset) {
3758                                         skip = off - key.offset;
3759                                         new_key.offset += skip;
3760                                 }
3761
3762                                 if (key.offset + datal > off + len)
3763                                         trim = key.offset + datal - (off + len);
3764
3765                                 if (comp && (skip || trim)) {
3766                                         ret = -EINVAL;
3767                                         btrfs_end_transaction(trans);
3768                                         goto out;
3769                                 }
3770                                 size -= skip + trim;
3771                                 datal -= skip + trim;
3772
3773                                 ret = clone_copy_inline_extent(inode,
3774                                                                trans, path,
3775                                                                &new_key,
3776                                                                drop_start,
3777                                                                datal,
3778                                                                skip, size, buf);
3779                                 if (ret) {
3780                                         if (ret != -EOPNOTSUPP)
3781                                                 btrfs_abort_transaction(trans,
3782                                                                         ret);
3783                                         btrfs_end_transaction(trans);
3784                                         goto out;
3785                                 }
3786                                 leaf = path->nodes[0];
3787                                 slot = path->slots[0];
3788                         }
3789
3790                         /* If we have an implicit hole (NO_HOLES feature). */
3791                         if (drop_start < new_key.offset)
3792                                 clone_update_extent_map(BTRFS_I(inode), trans,
3793                                                 NULL, drop_start,
3794                                                 new_key.offset - drop_start);
3795
3796                         clone_update_extent_map(BTRFS_I(inode), trans,
3797                                         path, 0, 0);
3798
3799                         btrfs_mark_buffer_dirty(leaf);
3800                         btrfs_release_path(path);
3801
3802                         last_dest_end = ALIGN(new_key.offset + datal,
3803                                               fs_info->sectorsize);
3804                         ret = clone_finish_inode_update(trans, inode,
3805                                                         last_dest_end,
3806                                                         destoff, olen,
3807                                                         no_time_update);
3808                         if (ret)
3809                                 goto out;
3810                         if (new_key.offset + datal >= destoff + len)
3811                                 break;
3812                 }
3813                 btrfs_release_path(path);
3814                 key.offset = next_key_min_offset;
3815
3816                 if (fatal_signal_pending(current)) {
3817                         ret = -EINTR;
3818                         goto out;
3819                 }
3820         }
3821         ret = 0;
3822
3823         if (last_dest_end < destoff + len) {
3824                 /*
3825                  * We have an implicit hole (NO_HOLES feature is enabled) that
3826                  * fully or partially overlaps our cloning range at its end.
3827                  */
3828                 btrfs_release_path(path);
3829
3830                 /*
3831                  * 1 - remove extent(s)
3832                  * 1 - inode update
3833                  */
3834                 trans = btrfs_start_transaction(root, 2);
3835                 if (IS_ERR(trans)) {
3836                         ret = PTR_ERR(trans);
3837                         goto out;
3838                 }
3839                 ret = btrfs_drop_extents(trans, root, inode,
3840                                          last_dest_end, destoff + len, 1);
3841                 if (ret) {
3842                         if (ret != -EOPNOTSUPP)
3843                                 btrfs_abort_transaction(trans, ret);
3844                         btrfs_end_transaction(trans);
3845                         goto out;
3846                 }
3847                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
3848                                 last_dest_end,
3849                                 destoff + len - last_dest_end);
3850                 ret = clone_finish_inode_update(trans, inode, destoff + len,
3851                                                 destoff, olen, no_time_update);
3852         }
3853
3854 out:
3855         btrfs_free_path(path);
3856         kvfree(buf);
3857         return ret;
3858 }
3859
3860 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3861                                         u64 off, u64 olen, u64 destoff)
3862 {
3863         struct inode *inode = file_inode(file);
3864         struct inode *src = file_inode(file_src);
3865         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3866         struct btrfs_root *root = BTRFS_I(inode)->root;
3867         int ret;
3868         u64 len = olen;
3869         u64 bs = fs_info->sb->s_blocksize;
3870         int same_inode = src == inode;
3871
3872         /*
3873          * TODO:
3874          * - split compressed inline extents.  annoying: we need to
3875          *   decompress into destination's address_space (the file offset
3876          *   may change, so source mapping won't do), then recompress (or
3877          *   otherwise reinsert) a subrange.
3878          *
3879          * - split destination inode's inline extents.  The inline extents can
3880          *   be either compressed or non-compressed.
3881          */
3882
3883         if (btrfs_root_readonly(root))
3884                 return -EROFS;
3885
3886         if (file_src->f_path.mnt != file->f_path.mnt ||
3887             src->i_sb != inode->i_sb)
3888                 return -EXDEV;
3889
3890         /* don't make the dst file partly checksummed */
3891         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3892             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3893                 return -EINVAL;
3894
3895         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3896                 return -EISDIR;
3897
3898         if (!same_inode) {
3899                 btrfs_double_inode_lock(src, inode);
3900         } else {
3901                 inode_lock(src);
3902         }
3903
3904         /* determine range to clone */
3905         ret = -EINVAL;
3906         if (off + len > src->i_size || off + len < off)
3907                 goto out_unlock;
3908         if (len == 0)
3909                 olen = len = src->i_size - off;
3910         /* if we extend to eof, continue to block boundary */
3911         if (off + len == src->i_size)
3912                 len = ALIGN(src->i_size, bs) - off;
3913
3914         if (len == 0) {
3915                 ret = 0;
3916                 goto out_unlock;
3917         }
3918
3919         /* verify the end result is block aligned */
3920         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3921             !IS_ALIGNED(destoff, bs))
3922                 goto out_unlock;
3923
3924         /* verify if ranges are overlapped within the same file */
3925         if (same_inode) {
3926                 if (destoff + len > off && destoff < off + len)
3927                         goto out_unlock;
3928         }
3929
3930         if (destoff > inode->i_size) {
3931                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3932                 if (ret)
3933                         goto out_unlock;
3934         }
3935
3936         /*
3937          * Lock the target range too. Right after we replace the file extent
3938          * items in the fs tree (which now point to the cloned data), we might
3939          * have a worker replace them with extent items relative to a write
3940          * operation that was issued before this clone operation (i.e. confront
3941          * with inode.c:btrfs_finish_ordered_io).
3942          */
3943         if (same_inode) {
3944                 u64 lock_start = min_t(u64, off, destoff);
3945                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3946
3947                 ret = lock_extent_range(src, lock_start, lock_len, true);
3948         } else {
3949                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
3950                                                true);
3951         }
3952         ASSERT(ret == 0);
3953         if (WARN_ON(ret)) {
3954                 /* ranges in the io trees already unlocked */
3955                 goto out_unlock;
3956         }
3957
3958         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3959
3960         if (same_inode) {
3961                 u64 lock_start = min_t(u64, off, destoff);
3962                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
3963
3964                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3965         } else {
3966                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
3967         }
3968         /*
3969          * Truncate page cache pages so that future reads will see the cloned
3970          * data immediately and not the previous data.
3971          */
3972         truncate_inode_pages_range(&inode->i_data,
3973                                 round_down(destoff, PAGE_SIZE),
3974                                 round_up(destoff + len, PAGE_SIZE) - 1);
3975 out_unlock:
3976         if (!same_inode)
3977                 btrfs_double_inode_unlock(src, inode);
3978         else
3979                 inode_unlock(src);
3980         return ret;
3981 }
3982
3983 int btrfs_clone_file_range(struct file *src_file, loff_t off,
3984                 struct file *dst_file, loff_t destoff, u64 len)
3985 {
3986         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
3987 }
3988
3989 /*
3990  * there are many ways the trans_start and trans_end ioctls can lead
3991  * to deadlocks.  They should only be used by applications that
3992  * basically own the machine, and have a very in depth understanding
3993  * of all the possible deadlocks and enospc problems.
3994  */
3995 static long btrfs_ioctl_trans_start(struct file *file)
3996 {
3997         struct inode *inode = file_inode(file);
3998         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3999         struct btrfs_root *root = BTRFS_I(inode)->root;
4000         struct btrfs_trans_handle *trans;
4001         int ret;
4002
4003         ret = -EPERM;
4004         if (!capable(CAP_SYS_ADMIN))
4005                 goto out;
4006
4007         ret = -EINPROGRESS;
4008         if (file->private_data)
4009                 goto out;
4010
4011         ret = -EROFS;
4012         if (btrfs_root_readonly(root))
4013                 goto out;
4014
4015         ret = mnt_want_write_file(file);
4016         if (ret)
4017                 goto out;
4018
4019         atomic_inc(&fs_info->open_ioctl_trans);
4020
4021         ret = -ENOMEM;
4022         trans = btrfs_start_ioctl_transaction(root);
4023         if (IS_ERR(trans))
4024                 goto out_drop;
4025
4026         file->private_data = trans;
4027         return 0;
4028
4029 out_drop:
4030         atomic_dec(&fs_info->open_ioctl_trans);
4031         mnt_drop_write_file(file);
4032 out:
4033         return ret;
4034 }
4035
4036 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4037 {
4038         struct inode *inode = file_inode(file);
4039         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4040         struct btrfs_root *root = BTRFS_I(inode)->root;
4041         struct btrfs_root *new_root;
4042         struct btrfs_dir_item *di;
4043         struct btrfs_trans_handle *trans;
4044         struct btrfs_path *path;
4045         struct btrfs_key location;
4046         struct btrfs_disk_key disk_key;
4047         u64 objectid = 0;
4048         u64 dir_id;
4049         int ret;
4050
4051         if (!capable(CAP_SYS_ADMIN))
4052                 return -EPERM;
4053
4054         ret = mnt_want_write_file(file);
4055         if (ret)
4056                 return ret;
4057
4058         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4059                 ret = -EFAULT;
4060                 goto out;
4061         }
4062
4063         if (!objectid)
4064                 objectid = BTRFS_FS_TREE_OBJECTID;
4065
4066         location.objectid = objectid;
4067         location.type = BTRFS_ROOT_ITEM_KEY;
4068         location.offset = (u64)-1;
4069
4070         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4071         if (IS_ERR(new_root)) {
4072                 ret = PTR_ERR(new_root);
4073                 goto out;
4074         }
4075
4076         path = btrfs_alloc_path();
4077         if (!path) {
4078                 ret = -ENOMEM;
4079                 goto out;
4080         }
4081         path->leave_spinning = 1;
4082
4083         trans = btrfs_start_transaction(root, 1);
4084         if (IS_ERR(trans)) {
4085                 btrfs_free_path(path);
4086                 ret = PTR_ERR(trans);
4087                 goto out;
4088         }
4089
4090         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4091         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4092                                    dir_id, "default", 7, 1);
4093         if (IS_ERR_OR_NULL(di)) {
4094                 btrfs_free_path(path);
4095                 btrfs_end_transaction(trans);
4096                 btrfs_err(fs_info,
4097                           "Umm, you don't have the default diritem, this isn't going to work");
4098                 ret = -ENOENT;
4099                 goto out;
4100         }
4101
4102         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4103         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4104         btrfs_mark_buffer_dirty(path->nodes[0]);
4105         btrfs_free_path(path);
4106
4107         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4108         btrfs_end_transaction(trans);
4109 out:
4110         mnt_drop_write_file(file);
4111         return ret;
4112 }
4113
4114 void btrfs_get_block_group_info(struct list_head *groups_list,
4115                                 struct btrfs_ioctl_space_info *space)
4116 {
4117         struct btrfs_block_group_cache *block_group;
4118
4119         space->total_bytes = 0;
4120         space->used_bytes = 0;
4121         space->flags = 0;
4122         list_for_each_entry(block_group, groups_list, list) {
4123                 space->flags = block_group->flags;
4124                 space->total_bytes += block_group->key.offset;
4125                 space->used_bytes +=
4126                         btrfs_block_group_used(&block_group->item);
4127         }
4128 }
4129
4130 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4131                                    void __user *arg)
4132 {
4133         struct btrfs_ioctl_space_args space_args;
4134         struct btrfs_ioctl_space_info space;
4135         struct btrfs_ioctl_space_info *dest;
4136         struct btrfs_ioctl_space_info *dest_orig;
4137         struct btrfs_ioctl_space_info __user *user_dest;
4138         struct btrfs_space_info *info;
4139         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
4140                        BTRFS_BLOCK_GROUP_SYSTEM,
4141                        BTRFS_BLOCK_GROUP_METADATA,
4142                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
4143         int num_types = 4;
4144         int alloc_size;
4145         int ret = 0;
4146         u64 slot_count = 0;
4147         int i, c;
4148
4149         if (copy_from_user(&space_args,
4150                            (struct btrfs_ioctl_space_args __user *)arg,
4151                            sizeof(space_args)))
4152                 return -EFAULT;
4153
4154         for (i = 0; i < num_types; i++) {
4155                 struct btrfs_space_info *tmp;
4156
4157                 info = NULL;
4158                 rcu_read_lock();
4159                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4160                                         list) {
4161                         if (tmp->flags == types[i]) {
4162                                 info = tmp;
4163                                 break;
4164                         }
4165                 }
4166                 rcu_read_unlock();
4167
4168                 if (!info)
4169                         continue;
4170
4171                 down_read(&info->groups_sem);
4172                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4173                         if (!list_empty(&info->block_groups[c]))
4174                                 slot_count++;
4175                 }
4176                 up_read(&info->groups_sem);
4177         }
4178
4179         /*
4180          * Global block reserve, exported as a space_info
4181          */
4182         slot_count++;
4183
4184         /* space_slots == 0 means they are asking for a count */
4185         if (space_args.space_slots == 0) {
4186                 space_args.total_spaces = slot_count;
4187                 goto out;
4188         }
4189
4190         slot_count = min_t(u64, space_args.space_slots, slot_count);
4191
4192         alloc_size = sizeof(*dest) * slot_count;
4193
4194         /* we generally have at most 6 or so space infos, one for each raid
4195          * level.  So, a whole page should be more than enough for everyone
4196          */
4197         if (alloc_size > PAGE_SIZE)
4198                 return -ENOMEM;
4199
4200         space_args.total_spaces = 0;
4201         dest = kmalloc(alloc_size, GFP_KERNEL);
4202         if (!dest)
4203                 return -ENOMEM;
4204         dest_orig = dest;
4205
4206         /* now we have a buffer to copy into */
4207         for (i = 0; i < num_types; i++) {
4208                 struct btrfs_space_info *tmp;
4209
4210                 if (!slot_count)
4211                         break;
4212
4213                 info = NULL;
4214                 rcu_read_lock();
4215                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4216                                         list) {
4217                         if (tmp->flags == types[i]) {
4218                                 info = tmp;
4219                                 break;
4220                         }
4221                 }
4222                 rcu_read_unlock();
4223
4224                 if (!info)
4225                         continue;
4226                 down_read(&info->groups_sem);
4227                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4228                         if (!list_empty(&info->block_groups[c])) {
4229                                 btrfs_get_block_group_info(
4230                                         &info->block_groups[c], &space);
4231                                 memcpy(dest, &space, sizeof(space));
4232                                 dest++;
4233                                 space_args.total_spaces++;
4234                                 slot_count--;
4235                         }
4236                         if (!slot_count)
4237                                 break;
4238                 }
4239                 up_read(&info->groups_sem);
4240         }
4241
4242         /*
4243          * Add global block reserve
4244          */
4245         if (slot_count) {
4246                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4247
4248                 spin_lock(&block_rsv->lock);
4249                 space.total_bytes = block_rsv->size;
4250                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4251                 spin_unlock(&block_rsv->lock);
4252                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4253                 memcpy(dest, &space, sizeof(space));
4254                 space_args.total_spaces++;
4255         }
4256
4257         user_dest = (struct btrfs_ioctl_space_info __user *)
4258                 (arg + sizeof(struct btrfs_ioctl_space_args));
4259
4260         if (copy_to_user(user_dest, dest_orig, alloc_size))
4261                 ret = -EFAULT;
4262
4263         kfree(dest_orig);
4264 out:
4265         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4266                 ret = -EFAULT;
4267
4268         return ret;
4269 }
4270
4271 /*
4272  * there are many ways the trans_start and trans_end ioctls can lead
4273  * to deadlocks.  They should only be used by applications that
4274  * basically own the machine, and have a very in depth understanding
4275  * of all the possible deadlocks and enospc problems.
4276  */
4277 long btrfs_ioctl_trans_end(struct file *file)
4278 {
4279         struct inode *inode = file_inode(file);
4280         struct btrfs_root *root = BTRFS_I(inode)->root;
4281         struct btrfs_trans_handle *trans;
4282
4283         trans = file->private_data;
4284         if (!trans)
4285                 return -EINVAL;
4286         file->private_data = NULL;
4287
4288         btrfs_end_transaction(trans);
4289
4290         atomic_dec(&root->fs_info->open_ioctl_trans);
4291
4292         mnt_drop_write_file(file);
4293         return 0;
4294 }
4295
4296 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4297                                             void __user *argp)
4298 {
4299         struct btrfs_trans_handle *trans;
4300         u64 transid;
4301         int ret;
4302
4303         trans = btrfs_attach_transaction_barrier(root);
4304         if (IS_ERR(trans)) {
4305                 if (PTR_ERR(trans) != -ENOENT)
4306                         return PTR_ERR(trans);
4307
4308                 /* No running transaction, don't bother */
4309                 transid = root->fs_info->last_trans_committed;
4310                 goto out;
4311         }
4312         transid = trans->transid;
4313         ret = btrfs_commit_transaction_async(trans, 0);
4314         if (ret) {
4315                 btrfs_end_transaction(trans);
4316                 return ret;
4317         }
4318 out:
4319         if (argp)
4320                 if (copy_to_user(argp, &transid, sizeof(transid)))
4321                         return -EFAULT;
4322         return 0;
4323 }
4324
4325 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4326                                            void __user *argp)
4327 {
4328         u64 transid;
4329
4330         if (argp) {
4331                 if (copy_from_user(&transid, argp, sizeof(transid)))
4332                         return -EFAULT;
4333         } else {
4334                 transid = 0;  /* current trans */
4335         }
4336         return btrfs_wait_for_commit(fs_info, transid);
4337 }
4338
4339 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4340 {
4341         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4342         struct btrfs_ioctl_scrub_args *sa;
4343         int ret;
4344
4345         if (!capable(CAP_SYS_ADMIN))
4346                 return -EPERM;
4347
4348         sa = memdup_user(arg, sizeof(*sa));
4349         if (IS_ERR(sa))
4350                 return PTR_ERR(sa);
4351
4352         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4353                 ret = mnt_want_write_file(file);
4354                 if (ret)
4355                         goto out;
4356         }
4357
4358         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4359                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4360                               0);
4361
4362         if (copy_to_user(arg, sa, sizeof(*sa)))
4363                 ret = -EFAULT;
4364
4365         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4366                 mnt_drop_write_file(file);
4367 out:
4368         kfree(sa);
4369         return ret;
4370 }
4371
4372 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4373 {
4374         if (!capable(CAP_SYS_ADMIN))
4375                 return -EPERM;
4376
4377         return btrfs_scrub_cancel(fs_info);
4378 }
4379
4380 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4381                                        void __user *arg)
4382 {
4383         struct btrfs_ioctl_scrub_args *sa;
4384         int ret;
4385
4386         if (!capable(CAP_SYS_ADMIN))
4387                 return -EPERM;
4388
4389         sa = memdup_user(arg, sizeof(*sa));
4390         if (IS_ERR(sa))
4391                 return PTR_ERR(sa);
4392
4393         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4394
4395         if (copy_to_user(arg, sa, sizeof(*sa)))
4396                 ret = -EFAULT;
4397
4398         kfree(sa);
4399         return ret;
4400 }
4401
4402 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4403                                       void __user *arg)
4404 {
4405         struct btrfs_ioctl_get_dev_stats *sa;
4406         int ret;
4407
4408         sa = memdup_user(arg, sizeof(*sa));
4409         if (IS_ERR(sa))
4410                 return PTR_ERR(sa);
4411
4412         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4413                 kfree(sa);
4414                 return -EPERM;
4415         }
4416
4417         ret = btrfs_get_dev_stats(fs_info, sa);
4418
4419         if (copy_to_user(arg, sa, sizeof(*sa)))
4420                 ret = -EFAULT;
4421
4422         kfree(sa);
4423         return ret;
4424 }
4425
4426 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4427                                     void __user *arg)
4428 {
4429         struct btrfs_ioctl_dev_replace_args *p;
4430         int ret;
4431
4432         if (!capable(CAP_SYS_ADMIN))
4433                 return -EPERM;
4434
4435         p = memdup_user(arg, sizeof(*p));
4436         if (IS_ERR(p))
4437                 return PTR_ERR(p);
4438
4439         switch (p->cmd) {
4440         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4441                 if (fs_info->sb->s_flags & MS_RDONLY) {
4442                         ret = -EROFS;
4443                         goto out;
4444                 }
4445                 if (atomic_xchg(
4446                         &fs_info->mutually_exclusive_operation_running, 1)) {
4447                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4448                 } else {
4449                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4450                         atomic_set(
4451                          &fs_info->mutually_exclusive_operation_running, 0);
4452                 }
4453                 break;
4454         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4455                 btrfs_dev_replace_status(fs_info, p);
4456                 ret = 0;
4457                 break;
4458         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4459                 ret = btrfs_dev_replace_cancel(fs_info, p);
4460                 break;
4461         default:
4462                 ret = -EINVAL;
4463                 break;
4464         }
4465
4466         if (copy_to_user(arg, p, sizeof(*p)))
4467                 ret = -EFAULT;
4468 out:
4469         kfree(p);
4470         return ret;
4471 }
4472
4473 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4474 {
4475         int ret = 0;
4476         int i;
4477         u64 rel_ptr;
4478         int size;
4479         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4480         struct inode_fs_paths *ipath = NULL;
4481         struct btrfs_path *path;
4482
4483         if (!capable(CAP_DAC_READ_SEARCH))
4484                 return -EPERM;
4485
4486         path = btrfs_alloc_path();
4487         if (!path) {
4488                 ret = -ENOMEM;
4489                 goto out;
4490         }
4491
4492         ipa = memdup_user(arg, sizeof(*ipa));
4493         if (IS_ERR(ipa)) {
4494                 ret = PTR_ERR(ipa);
4495                 ipa = NULL;
4496                 goto out;
4497         }
4498
4499         size = min_t(u32, ipa->size, 4096);
4500         ipath = init_ipath(size, root, path);
4501         if (IS_ERR(ipath)) {
4502                 ret = PTR_ERR(ipath);
4503                 ipath = NULL;
4504                 goto out;
4505         }
4506
4507         ret = paths_from_inode(ipa->inum, ipath);
4508         if (ret < 0)
4509                 goto out;
4510
4511         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4512                 rel_ptr = ipath->fspath->val[i] -
4513                           (u64)(unsigned long)ipath->fspath->val;
4514                 ipath->fspath->val[i] = rel_ptr;
4515         }
4516
4517         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
4518                            (void *)(unsigned long)ipath->fspath, size);
4519         if (ret) {
4520                 ret = -EFAULT;
4521                 goto out;
4522         }
4523
4524 out:
4525         btrfs_free_path(path);
4526         free_ipath(ipath);
4527         kfree(ipa);
4528
4529         return ret;
4530 }
4531
4532 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4533 {
4534         struct btrfs_data_container *inodes = ctx;
4535         const size_t c = 3 * sizeof(u64);
4536
4537         if (inodes->bytes_left >= c) {
4538                 inodes->bytes_left -= c;
4539                 inodes->val[inodes->elem_cnt] = inum;
4540                 inodes->val[inodes->elem_cnt + 1] = offset;
4541                 inodes->val[inodes->elem_cnt + 2] = root;
4542                 inodes->elem_cnt += 3;
4543         } else {
4544                 inodes->bytes_missing += c - inodes->bytes_left;
4545                 inodes->bytes_left = 0;
4546                 inodes->elem_missed += 3;
4547         }
4548
4549         return 0;
4550 }
4551
4552 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4553                                         void __user *arg)
4554 {
4555         int ret = 0;
4556         int size;
4557         struct btrfs_ioctl_logical_ino_args *loi;
4558         struct btrfs_data_container *inodes = NULL;
4559         struct btrfs_path *path = NULL;
4560
4561         if (!capable(CAP_SYS_ADMIN))
4562                 return -EPERM;
4563
4564         loi = memdup_user(arg, sizeof(*loi));
4565         if (IS_ERR(loi))
4566                 return PTR_ERR(loi);
4567
4568         path = btrfs_alloc_path();
4569         if (!path) {
4570                 ret = -ENOMEM;
4571                 goto out;
4572         }
4573
4574         size = min_t(u32, loi->size, SZ_64K);
4575         inodes = init_data_container(size);
4576         if (IS_ERR(inodes)) {
4577                 ret = PTR_ERR(inodes);
4578                 inodes = NULL;
4579                 goto out;
4580         }
4581
4582         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4583                                           build_ino_list, inodes);
4584         if (ret == -EINVAL)
4585                 ret = -ENOENT;
4586         if (ret < 0)
4587                 goto out;
4588
4589         ret = copy_to_user((void *)(unsigned long)loi->inodes,
4590                            (void *)(unsigned long)inodes, size);
4591         if (ret)
4592                 ret = -EFAULT;
4593
4594 out:
4595         btrfs_free_path(path);
4596         vfree(inodes);
4597         kfree(loi);
4598
4599         return ret;
4600 }
4601
4602 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4603                                struct btrfs_ioctl_balance_args *bargs)
4604 {
4605         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4606
4607         bargs->flags = bctl->flags;
4608
4609         if (atomic_read(&fs_info->balance_running))
4610                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4611         if (atomic_read(&fs_info->balance_pause_req))
4612                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4613         if (atomic_read(&fs_info->balance_cancel_req))
4614                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4615
4616         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4617         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4618         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4619
4620         if (lock) {
4621                 spin_lock(&fs_info->balance_lock);
4622                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4623                 spin_unlock(&fs_info->balance_lock);
4624         } else {
4625                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4626         }
4627 }
4628
4629 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4630 {
4631         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4632         struct btrfs_fs_info *fs_info = root->fs_info;
4633         struct btrfs_ioctl_balance_args *bargs;
4634         struct btrfs_balance_control *bctl;
4635         bool need_unlock; /* for mut. excl. ops lock */
4636         int ret;
4637
4638         if (!capable(CAP_SYS_ADMIN))
4639                 return -EPERM;
4640
4641         ret = mnt_want_write_file(file);
4642         if (ret)
4643                 return ret;
4644
4645 again:
4646         if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
4647                 mutex_lock(&fs_info->volume_mutex);
4648                 mutex_lock(&fs_info->balance_mutex);
4649                 need_unlock = true;
4650                 goto locked;
4651         }
4652
4653         /*
4654          * mut. excl. ops lock is locked.  Three possibilities:
4655          *   (1) some other op is running
4656          *   (2) balance is running
4657          *   (3) balance is paused -- special case (think resume)
4658          */
4659         mutex_lock(&fs_info->balance_mutex);
4660         if (fs_info->balance_ctl) {
4661                 /* this is either (2) or (3) */
4662                 if (!atomic_read(&fs_info->balance_running)) {
4663                         mutex_unlock(&fs_info->balance_mutex);
4664                         if (!mutex_trylock(&fs_info->volume_mutex))
4665                                 goto again;
4666                         mutex_lock(&fs_info->balance_mutex);
4667
4668                         if (fs_info->balance_ctl &&
4669                             !atomic_read(&fs_info->balance_running)) {
4670                                 /* this is (3) */
4671                                 need_unlock = false;
4672                                 goto locked;
4673                         }
4674
4675                         mutex_unlock(&fs_info->balance_mutex);
4676                         mutex_unlock(&fs_info->volume_mutex);
4677                         goto again;
4678                 } else {
4679                         /* this is (2) */
4680                         mutex_unlock(&fs_info->balance_mutex);
4681                         ret = -EINPROGRESS;
4682                         goto out;
4683                 }
4684         } else {
4685                 /* this is (1) */
4686                 mutex_unlock(&fs_info->balance_mutex);
4687                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4688                 goto out;
4689         }
4690
4691 locked:
4692         BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
4693
4694         if (arg) {
4695                 bargs = memdup_user(arg, sizeof(*bargs));
4696                 if (IS_ERR(bargs)) {
4697                         ret = PTR_ERR(bargs);
4698                         goto out_unlock;
4699                 }
4700
4701                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4702                         if (!fs_info->balance_ctl) {
4703                                 ret = -ENOTCONN;
4704                                 goto out_bargs;
4705                         }
4706
4707                         bctl = fs_info->balance_ctl;
4708                         spin_lock(&fs_info->balance_lock);
4709                         bctl->flags |= BTRFS_BALANCE_RESUME;
4710                         spin_unlock(&fs_info->balance_lock);
4711
4712                         goto do_balance;
4713                 }
4714         } else {
4715                 bargs = NULL;
4716         }
4717
4718         if (fs_info->balance_ctl) {
4719                 ret = -EINPROGRESS;
4720                 goto out_bargs;
4721         }
4722
4723         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4724         if (!bctl) {
4725                 ret = -ENOMEM;
4726                 goto out_bargs;
4727         }
4728
4729         bctl->fs_info = fs_info;
4730         if (arg) {
4731                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4732                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4733                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4734
4735                 bctl->flags = bargs->flags;
4736         } else {
4737                 /* balance everything - no filters */
4738                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4739         }
4740
4741         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4742                 ret = -EINVAL;
4743                 goto out_bctl;
4744         }
4745
4746 do_balance:
4747         /*
4748          * Ownership of bctl and mutually_exclusive_operation_running
4749          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
4750          * or, if restriper was paused all the way until unmount, in
4751          * free_fs_info.  mutually_exclusive_operation_running is
4752          * cleared in __cancel_balance.
4753          */
4754         need_unlock = false;
4755
4756         ret = btrfs_balance(bctl, bargs);
4757         bctl = NULL;
4758
4759         if (arg) {
4760                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4761                         ret = -EFAULT;
4762         }
4763
4764 out_bctl:
4765         kfree(bctl);
4766 out_bargs:
4767         kfree(bargs);
4768 out_unlock:
4769         mutex_unlock(&fs_info->balance_mutex);
4770         mutex_unlock(&fs_info->volume_mutex);
4771         if (need_unlock)
4772                 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
4773 out:
4774         mnt_drop_write_file(file);
4775         return ret;
4776 }
4777
4778 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4779 {
4780         if (!capable(CAP_SYS_ADMIN))
4781                 return -EPERM;
4782
4783         switch (cmd) {
4784         case BTRFS_BALANCE_CTL_PAUSE:
4785                 return btrfs_pause_balance(fs_info);
4786         case BTRFS_BALANCE_CTL_CANCEL:
4787                 return btrfs_cancel_balance(fs_info);
4788         }
4789
4790         return -EINVAL;
4791 }
4792
4793 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4794                                          void __user *arg)
4795 {
4796         struct btrfs_ioctl_balance_args *bargs;
4797         int ret = 0;
4798
4799         if (!capable(CAP_SYS_ADMIN))
4800                 return -EPERM;
4801
4802         mutex_lock(&fs_info->balance_mutex);
4803         if (!fs_info->balance_ctl) {
4804                 ret = -ENOTCONN;
4805                 goto out;
4806         }
4807
4808         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4809         if (!bargs) {
4810                 ret = -ENOMEM;
4811                 goto out;
4812         }
4813
4814         update_ioctl_balance_args(fs_info, 1, bargs);
4815
4816         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4817                 ret = -EFAULT;
4818
4819         kfree(bargs);
4820 out:
4821         mutex_unlock(&fs_info->balance_mutex);
4822         return ret;
4823 }
4824
4825 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4826 {
4827         struct inode *inode = file_inode(file);
4828         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4829         struct btrfs_ioctl_quota_ctl_args *sa;
4830         struct btrfs_trans_handle *trans = NULL;
4831         int ret;
4832         int err;
4833
4834         if (!capable(CAP_SYS_ADMIN))
4835                 return -EPERM;
4836
4837         ret = mnt_want_write_file(file);
4838         if (ret)
4839                 return ret;
4840
4841         sa = memdup_user(arg, sizeof(*sa));
4842         if (IS_ERR(sa)) {
4843                 ret = PTR_ERR(sa);
4844                 goto drop_write;
4845         }
4846
4847         down_write(&fs_info->subvol_sem);
4848         trans = btrfs_start_transaction(fs_info->tree_root, 2);
4849         if (IS_ERR(trans)) {
4850                 ret = PTR_ERR(trans);
4851                 goto out;
4852         }
4853
4854         switch (sa->cmd) {
4855         case BTRFS_QUOTA_CTL_ENABLE:
4856                 ret = btrfs_quota_enable(trans, fs_info);
4857                 break;
4858         case BTRFS_QUOTA_CTL_DISABLE:
4859                 ret = btrfs_quota_disable(trans, fs_info);
4860                 break;
4861         default:
4862                 ret = -EINVAL;
4863                 break;
4864         }
4865
4866         err = btrfs_commit_transaction(trans);
4867         if (err && !ret)
4868                 ret = err;
4869 out:
4870         kfree(sa);
4871         up_write(&fs_info->subvol_sem);
4872 drop_write:
4873         mnt_drop_write_file(file);
4874         return ret;
4875 }
4876
4877 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4878 {
4879         struct inode *inode = file_inode(file);
4880         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4881         struct btrfs_root *root = BTRFS_I(inode)->root;
4882         struct btrfs_ioctl_qgroup_assign_args *sa;
4883         struct btrfs_trans_handle *trans;
4884         int ret;
4885         int err;
4886
4887         if (!capable(CAP_SYS_ADMIN))
4888                 return -EPERM;
4889
4890         ret = mnt_want_write_file(file);
4891         if (ret)
4892                 return ret;
4893
4894         sa = memdup_user(arg, sizeof(*sa));
4895         if (IS_ERR(sa)) {
4896                 ret = PTR_ERR(sa);
4897                 goto drop_write;
4898         }
4899
4900         trans = btrfs_join_transaction(root);
4901         if (IS_ERR(trans)) {
4902                 ret = PTR_ERR(trans);
4903                 goto out;
4904         }
4905
4906         /* FIXME: check if the IDs really exist */
4907         if (sa->assign) {
4908                 ret = btrfs_add_qgroup_relation(trans, fs_info,
4909                                                 sa->src, sa->dst);
4910         } else {
4911                 ret = btrfs_del_qgroup_relation(trans, fs_info,
4912                                                 sa->src, sa->dst);
4913         }
4914
4915         /* update qgroup status and info */
4916         err = btrfs_run_qgroups(trans, fs_info);
4917         if (err < 0)
4918                 btrfs_handle_fs_error(fs_info, err,
4919                                       "failed to update qgroup status and info");
4920         err = btrfs_end_transaction(trans);
4921         if (err && !ret)
4922                 ret = err;
4923
4924 out:
4925         kfree(sa);
4926 drop_write:
4927         mnt_drop_write_file(file);
4928         return ret;
4929 }
4930
4931 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4932 {
4933         struct inode *inode = file_inode(file);
4934         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4935         struct btrfs_root *root = BTRFS_I(inode)->root;
4936         struct btrfs_ioctl_qgroup_create_args *sa;
4937         struct btrfs_trans_handle *trans;
4938         int ret;
4939         int err;
4940
4941         if (!capable(CAP_SYS_ADMIN))
4942                 return -EPERM;
4943
4944         ret = mnt_want_write_file(file);
4945         if (ret)
4946                 return ret;
4947
4948         sa = memdup_user(arg, sizeof(*sa));
4949         if (IS_ERR(sa)) {
4950                 ret = PTR_ERR(sa);
4951                 goto drop_write;
4952         }
4953
4954         if (!sa->qgroupid) {
4955                 ret = -EINVAL;
4956                 goto out;
4957         }
4958
4959         trans = btrfs_join_transaction(root);
4960         if (IS_ERR(trans)) {
4961                 ret = PTR_ERR(trans);
4962                 goto out;
4963         }
4964
4965         /* FIXME: check if the IDs really exist */
4966         if (sa->create) {
4967                 ret = btrfs_create_qgroup(trans, fs_info, sa->qgroupid);
4968         } else {
4969                 ret = btrfs_remove_qgroup(trans, fs_info, sa->qgroupid);
4970         }
4971
4972         err = btrfs_end_transaction(trans);
4973         if (err && !ret)
4974                 ret = err;
4975
4976 out:
4977         kfree(sa);
4978 drop_write:
4979         mnt_drop_write_file(file);
4980         return ret;
4981 }
4982
4983 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4984 {
4985         struct inode *inode = file_inode(file);
4986         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4987         struct btrfs_root *root = BTRFS_I(inode)->root;
4988         struct btrfs_ioctl_qgroup_limit_args *sa;
4989         struct btrfs_trans_handle *trans;
4990         int ret;
4991         int err;
4992         u64 qgroupid;
4993
4994         if (!capable(CAP_SYS_ADMIN))
4995                 return -EPERM;
4996
4997         ret = mnt_want_write_file(file);
4998         if (ret)
4999                 return ret;
5000
5001         sa = memdup_user(arg, sizeof(*sa));
5002         if (IS_ERR(sa)) {
5003                 ret = PTR_ERR(sa);
5004                 goto drop_write;
5005         }
5006
5007         trans = btrfs_join_transaction(root);
5008         if (IS_ERR(trans)) {
5009                 ret = PTR_ERR(trans);
5010                 goto out;
5011         }
5012
5013         qgroupid = sa->qgroupid;
5014         if (!qgroupid) {
5015                 /* take the current subvol as qgroup */
5016                 qgroupid = root->root_key.objectid;
5017         }
5018
5019         /* FIXME: check if the IDs really exist */
5020         ret = btrfs_limit_qgroup(trans, fs_info, qgroupid, &sa->lim);
5021
5022         err = btrfs_end_transaction(trans);
5023         if (err && !ret)
5024                 ret = err;
5025
5026 out:
5027         kfree(sa);
5028 drop_write:
5029         mnt_drop_write_file(file);
5030         return ret;
5031 }
5032
5033 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5034 {
5035         struct inode *inode = file_inode(file);
5036         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5037         struct btrfs_ioctl_quota_rescan_args *qsa;
5038         int ret;
5039
5040         if (!capable(CAP_SYS_ADMIN))
5041                 return -EPERM;
5042
5043         ret = mnt_want_write_file(file);
5044         if (ret)
5045                 return ret;
5046
5047         qsa = memdup_user(arg, sizeof(*qsa));
5048         if (IS_ERR(qsa)) {
5049                 ret = PTR_ERR(qsa);
5050                 goto drop_write;
5051         }
5052
5053         if (qsa->flags) {
5054                 ret = -EINVAL;
5055                 goto out;
5056         }
5057
5058         ret = btrfs_qgroup_rescan(fs_info);
5059
5060 out:
5061         kfree(qsa);
5062 drop_write:
5063         mnt_drop_write_file(file);
5064         return ret;
5065 }
5066
5067 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5068 {
5069         struct inode *inode = file_inode(file);
5070         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5071         struct btrfs_ioctl_quota_rescan_args *qsa;
5072         int ret = 0;
5073
5074         if (!capable(CAP_SYS_ADMIN))
5075                 return -EPERM;
5076
5077         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5078         if (!qsa)
5079                 return -ENOMEM;
5080
5081         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5082                 qsa->flags = 1;
5083                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5084         }
5085
5086         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5087                 ret = -EFAULT;
5088
5089         kfree(qsa);
5090         return ret;
5091 }
5092
5093 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5094 {
5095         struct inode *inode = file_inode(file);
5096         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5097
5098         if (!capable(CAP_SYS_ADMIN))
5099                 return -EPERM;
5100
5101         return btrfs_qgroup_wait_for_completion(fs_info, true);
5102 }
5103
5104 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5105                                             struct btrfs_ioctl_received_subvol_args *sa)
5106 {
5107         struct inode *inode = file_inode(file);
5108         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5109         struct btrfs_root *root = BTRFS_I(inode)->root;
5110         struct btrfs_root_item *root_item = &root->root_item;
5111         struct btrfs_trans_handle *trans;
5112         struct timespec ct = current_time(inode);
5113         int ret = 0;
5114         int received_uuid_changed;
5115
5116         if (!inode_owner_or_capable(inode))
5117                 return -EPERM;
5118
5119         ret = mnt_want_write_file(file);
5120         if (ret < 0)
5121                 return ret;
5122
5123         down_write(&fs_info->subvol_sem);
5124
5125         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5126                 ret = -EINVAL;
5127                 goto out;
5128         }
5129
5130         if (btrfs_root_readonly(root)) {
5131                 ret = -EROFS;
5132                 goto out;
5133         }
5134
5135         /*
5136          * 1 - root item
5137          * 2 - uuid items (received uuid + subvol uuid)
5138          */
5139         trans = btrfs_start_transaction(root, 3);
5140         if (IS_ERR(trans)) {
5141                 ret = PTR_ERR(trans);
5142                 trans = NULL;
5143                 goto out;
5144         }
5145
5146         sa->rtransid = trans->transid;
5147         sa->rtime.sec = ct.tv_sec;
5148         sa->rtime.nsec = ct.tv_nsec;
5149
5150         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5151                                        BTRFS_UUID_SIZE);
5152         if (received_uuid_changed &&
5153             !btrfs_is_empty_uuid(root_item->received_uuid))
5154                 btrfs_uuid_tree_rem(trans, fs_info, root_item->received_uuid,
5155                                     BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5156                                     root->root_key.objectid);
5157         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5158         btrfs_set_root_stransid(root_item, sa->stransid);
5159         btrfs_set_root_rtransid(root_item, sa->rtransid);
5160         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5161         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5162         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5163         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5164
5165         ret = btrfs_update_root(trans, fs_info->tree_root,
5166                                 &root->root_key, &root->root_item);
5167         if (ret < 0) {
5168                 btrfs_end_transaction(trans);
5169                 goto out;
5170         }
5171         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5172                 ret = btrfs_uuid_tree_add(trans, fs_info, sa->uuid,
5173                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5174                                           root->root_key.objectid);
5175                 if (ret < 0 && ret != -EEXIST) {
5176                         btrfs_abort_transaction(trans, ret);
5177                         goto out;
5178                 }
5179         }
5180         ret = btrfs_commit_transaction(trans);
5181         if (ret < 0) {
5182                 btrfs_abort_transaction(trans, ret);
5183                 goto out;
5184         }
5185
5186 out:
5187         up_write(&fs_info->subvol_sem);
5188         mnt_drop_write_file(file);
5189         return ret;
5190 }
5191
5192 #ifdef CONFIG_64BIT
5193 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5194                                                 void __user *arg)
5195 {
5196         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5197         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5198         int ret = 0;
5199
5200         args32 = memdup_user(arg, sizeof(*args32));
5201         if (IS_ERR(args32))
5202                 return PTR_ERR(args32);
5203
5204         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5205         if (!args64) {
5206                 ret = -ENOMEM;
5207                 goto out;
5208         }
5209
5210         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5211         args64->stransid = args32->stransid;
5212         args64->rtransid = args32->rtransid;
5213         args64->stime.sec = args32->stime.sec;
5214         args64->stime.nsec = args32->stime.nsec;
5215         args64->rtime.sec = args32->rtime.sec;
5216         args64->rtime.nsec = args32->rtime.nsec;
5217         args64->flags = args32->flags;
5218
5219         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5220         if (ret)
5221                 goto out;
5222
5223         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5224         args32->stransid = args64->stransid;
5225         args32->rtransid = args64->rtransid;
5226         args32->stime.sec = args64->stime.sec;
5227         args32->stime.nsec = args64->stime.nsec;
5228         args32->rtime.sec = args64->rtime.sec;
5229         args32->rtime.nsec = args64->rtime.nsec;
5230         args32->flags = args64->flags;
5231
5232         ret = copy_to_user(arg, args32, sizeof(*args32));
5233         if (ret)
5234                 ret = -EFAULT;
5235
5236 out:
5237         kfree(args32);
5238         kfree(args64);
5239         return ret;
5240 }
5241 #endif
5242
5243 static long btrfs_ioctl_set_received_subvol(struct file *file,
5244                                             void __user *arg)
5245 {
5246         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5247         int ret = 0;
5248
5249         sa = memdup_user(arg, sizeof(*sa));
5250         if (IS_ERR(sa))
5251                 return PTR_ERR(sa);
5252
5253         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5254
5255         if (ret)
5256                 goto out;
5257
5258         ret = copy_to_user(arg, sa, sizeof(*sa));
5259         if (ret)
5260                 ret = -EFAULT;
5261
5262 out:
5263         kfree(sa);
5264         return ret;
5265 }
5266
5267 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5268 {
5269         struct inode *inode = file_inode(file);
5270         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5271         size_t len;
5272         int ret;
5273         char label[BTRFS_LABEL_SIZE];
5274
5275         spin_lock(&fs_info->super_lock);
5276         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5277         spin_unlock(&fs_info->super_lock);
5278
5279         len = strnlen(label, BTRFS_LABEL_SIZE);
5280
5281         if (len == BTRFS_LABEL_SIZE) {
5282                 btrfs_warn(fs_info,
5283                            "label is too long, return the first %zu bytes",
5284                            --len);
5285         }
5286
5287         ret = copy_to_user(arg, label, len);
5288
5289         return ret ? -EFAULT : 0;
5290 }
5291
5292 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5293 {
5294         struct inode *inode = file_inode(file);
5295         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5296         struct btrfs_root *root = BTRFS_I(inode)->root;
5297         struct btrfs_super_block *super_block = fs_info->super_copy;
5298         struct btrfs_trans_handle *trans;
5299         char label[BTRFS_LABEL_SIZE];
5300         int ret;
5301
5302         if (!capable(CAP_SYS_ADMIN))
5303                 return -EPERM;
5304
5305         if (copy_from_user(label, arg, sizeof(label)))
5306                 return -EFAULT;
5307
5308         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5309                 btrfs_err(fs_info,
5310                           "unable to set label with more than %d bytes",
5311                           BTRFS_LABEL_SIZE - 1);
5312                 return -EINVAL;
5313         }
5314
5315         ret = mnt_want_write_file(file);
5316         if (ret)
5317                 return ret;
5318
5319         trans = btrfs_start_transaction(root, 0);
5320         if (IS_ERR(trans)) {
5321                 ret = PTR_ERR(trans);
5322                 goto out_unlock;
5323         }
5324
5325         spin_lock(&fs_info->super_lock);
5326         strcpy(super_block->label, label);
5327         spin_unlock(&fs_info->super_lock);
5328         ret = btrfs_commit_transaction(trans);
5329
5330 out_unlock:
5331         mnt_drop_write_file(file);
5332         return ret;
5333 }
5334
5335 #define INIT_FEATURE_FLAGS(suffix) \
5336         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5337           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5338           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5339
5340 int btrfs_ioctl_get_supported_features(void __user *arg)
5341 {
5342         static const struct btrfs_ioctl_feature_flags features[3] = {
5343                 INIT_FEATURE_FLAGS(SUPP),
5344                 INIT_FEATURE_FLAGS(SAFE_SET),
5345                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5346         };
5347
5348         if (copy_to_user(arg, &features, sizeof(features)))
5349                 return -EFAULT;
5350
5351         return 0;
5352 }
5353
5354 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5355 {
5356         struct inode *inode = file_inode(file);
5357         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5358         struct btrfs_super_block *super_block = fs_info->super_copy;
5359         struct btrfs_ioctl_feature_flags features;
5360
5361         features.compat_flags = btrfs_super_compat_flags(super_block);
5362         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5363         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5364
5365         if (copy_to_user(arg, &features, sizeof(features)))
5366                 return -EFAULT;
5367
5368         return 0;
5369 }
5370
5371 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5372                               enum btrfs_feature_set set,
5373                               u64 change_mask, u64 flags, u64 supported_flags,
5374                               u64 safe_set, u64 safe_clear)
5375 {
5376         const char *type = btrfs_feature_set_names[set];
5377         char *names;
5378         u64 disallowed, unsupported;
5379         u64 set_mask = flags & change_mask;
5380         u64 clear_mask = ~flags & change_mask;
5381
5382         unsupported = set_mask & ~supported_flags;
5383         if (unsupported) {
5384                 names = btrfs_printable_features(set, unsupported);
5385                 if (names) {
5386                         btrfs_warn(fs_info,
5387                                    "this kernel does not support the %s feature bit%s",
5388                                    names, strchr(names, ',') ? "s" : "");
5389                         kfree(names);
5390                 } else
5391                         btrfs_warn(fs_info,
5392                                    "this kernel does not support %s bits 0x%llx",
5393                                    type, unsupported);
5394                 return -EOPNOTSUPP;
5395         }
5396
5397         disallowed = set_mask & ~safe_set;
5398         if (disallowed) {
5399                 names = btrfs_printable_features(set, disallowed);
5400                 if (names) {
5401                         btrfs_warn(fs_info,
5402                                    "can't set the %s feature bit%s while mounted",
5403                                    names, strchr(names, ',') ? "s" : "");
5404                         kfree(names);
5405                 } else
5406                         btrfs_warn(fs_info,
5407                                    "can't set %s bits 0x%llx while mounted",
5408                                    type, disallowed);
5409                 return -EPERM;
5410         }
5411
5412         disallowed = clear_mask & ~safe_clear;
5413         if (disallowed) {
5414                 names = btrfs_printable_features(set, disallowed);
5415                 if (names) {
5416                         btrfs_warn(fs_info,
5417                                    "can't clear the %s feature bit%s while mounted",
5418                                    names, strchr(names, ',') ? "s" : "");
5419                         kfree(names);
5420                 } else
5421                         btrfs_warn(fs_info,
5422                                    "can't clear %s bits 0x%llx while mounted",
5423                                    type, disallowed);
5424                 return -EPERM;
5425         }
5426
5427         return 0;
5428 }
5429
5430 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5431 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5432                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5433                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5434                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5435
5436 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5437 {
5438         struct inode *inode = file_inode(file);
5439         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5440         struct btrfs_root *root = BTRFS_I(inode)->root;
5441         struct btrfs_super_block *super_block = fs_info->super_copy;
5442         struct btrfs_ioctl_feature_flags flags[2];
5443         struct btrfs_trans_handle *trans;
5444         u64 newflags;
5445         int ret;
5446
5447         if (!capable(CAP_SYS_ADMIN))
5448                 return -EPERM;
5449
5450         if (copy_from_user(flags, arg, sizeof(flags)))
5451                 return -EFAULT;
5452
5453         /* Nothing to do */
5454         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5455             !flags[0].incompat_flags)
5456                 return 0;
5457
5458         ret = check_feature(fs_info, flags[0].compat_flags,
5459                             flags[1].compat_flags, COMPAT);
5460         if (ret)
5461                 return ret;
5462
5463         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5464                             flags[1].compat_ro_flags, COMPAT_RO);
5465         if (ret)
5466                 return ret;
5467
5468         ret = check_feature(fs_info, flags[0].incompat_flags,
5469                             flags[1].incompat_flags, INCOMPAT);
5470         if (ret)
5471                 return ret;
5472
5473         ret = mnt_want_write_file(file);
5474         if (ret)
5475                 return ret;
5476
5477         trans = btrfs_start_transaction(root, 0);
5478         if (IS_ERR(trans)) {
5479                 ret = PTR_ERR(trans);
5480                 goto out_drop_write;
5481         }
5482
5483         spin_lock(&fs_info->super_lock);
5484         newflags = btrfs_super_compat_flags(super_block);
5485         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5486         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5487         btrfs_set_super_compat_flags(super_block, newflags);
5488
5489         newflags = btrfs_super_compat_ro_flags(super_block);
5490         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5491         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5492         btrfs_set_super_compat_ro_flags(super_block, newflags);
5493
5494         newflags = btrfs_super_incompat_flags(super_block);
5495         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5496         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5497         btrfs_set_super_incompat_flags(super_block, newflags);
5498         spin_unlock(&fs_info->super_lock);
5499
5500         ret = btrfs_commit_transaction(trans);
5501 out_drop_write:
5502         mnt_drop_write_file(file);
5503
5504         return ret;
5505 }
5506
5507 long btrfs_ioctl(struct file *file, unsigned int
5508                 cmd, unsigned long arg)
5509 {
5510         struct inode *inode = file_inode(file);
5511         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5512         struct btrfs_root *root = BTRFS_I(inode)->root;
5513         void __user *argp = (void __user *)arg;
5514
5515         switch (cmd) {
5516         case FS_IOC_GETFLAGS:
5517                 return btrfs_ioctl_getflags(file, argp);
5518         case FS_IOC_SETFLAGS:
5519                 return btrfs_ioctl_setflags(file, argp);
5520         case FS_IOC_GETVERSION:
5521                 return btrfs_ioctl_getversion(file, argp);
5522         case FITRIM:
5523                 return btrfs_ioctl_fitrim(file, argp);
5524         case BTRFS_IOC_SNAP_CREATE:
5525                 return btrfs_ioctl_snap_create(file, argp, 0);
5526         case BTRFS_IOC_SNAP_CREATE_V2:
5527                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5528         case BTRFS_IOC_SUBVOL_CREATE:
5529                 return btrfs_ioctl_snap_create(file, argp, 1);
5530         case BTRFS_IOC_SUBVOL_CREATE_V2:
5531                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5532         case BTRFS_IOC_SNAP_DESTROY:
5533                 return btrfs_ioctl_snap_destroy(file, argp);
5534         case BTRFS_IOC_SUBVOL_GETFLAGS:
5535                 return btrfs_ioctl_subvol_getflags(file, argp);
5536         case BTRFS_IOC_SUBVOL_SETFLAGS:
5537                 return btrfs_ioctl_subvol_setflags(file, argp);
5538         case BTRFS_IOC_DEFAULT_SUBVOL:
5539                 return btrfs_ioctl_default_subvol(file, argp);
5540         case BTRFS_IOC_DEFRAG:
5541                 return btrfs_ioctl_defrag(file, NULL);
5542         case BTRFS_IOC_DEFRAG_RANGE:
5543                 return btrfs_ioctl_defrag(file, argp);
5544         case BTRFS_IOC_RESIZE:
5545                 return btrfs_ioctl_resize(file, argp);
5546         case BTRFS_IOC_ADD_DEV:
5547                 return btrfs_ioctl_add_dev(fs_info, argp);
5548         case BTRFS_IOC_RM_DEV:
5549                 return btrfs_ioctl_rm_dev(file, argp);
5550         case BTRFS_IOC_RM_DEV_V2:
5551                 return btrfs_ioctl_rm_dev_v2(file, argp);
5552         case BTRFS_IOC_FS_INFO:
5553                 return btrfs_ioctl_fs_info(fs_info, argp);
5554         case BTRFS_IOC_DEV_INFO:
5555                 return btrfs_ioctl_dev_info(fs_info, argp);
5556         case BTRFS_IOC_BALANCE:
5557                 return btrfs_ioctl_balance(file, NULL);
5558         case BTRFS_IOC_TRANS_START:
5559                 return btrfs_ioctl_trans_start(file);
5560         case BTRFS_IOC_TRANS_END:
5561                 return btrfs_ioctl_trans_end(file);
5562         case BTRFS_IOC_TREE_SEARCH:
5563                 return btrfs_ioctl_tree_search(file, argp);
5564         case BTRFS_IOC_TREE_SEARCH_V2:
5565                 return btrfs_ioctl_tree_search_v2(file, argp);
5566         case BTRFS_IOC_INO_LOOKUP:
5567                 return btrfs_ioctl_ino_lookup(file, argp);
5568         case BTRFS_IOC_INO_PATHS:
5569                 return btrfs_ioctl_ino_to_path(root, argp);
5570         case BTRFS_IOC_LOGICAL_INO:
5571                 return btrfs_ioctl_logical_to_ino(fs_info, argp);
5572         case BTRFS_IOC_SPACE_INFO:
5573                 return btrfs_ioctl_space_info(fs_info, argp);
5574         case BTRFS_IOC_SYNC: {
5575                 int ret;
5576
5577                 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
5578                 if (ret)
5579                         return ret;
5580                 ret = btrfs_sync_fs(inode->i_sb, 1);
5581                 /*
5582                  * The transaction thread may want to do more work,
5583                  * namely it pokes the cleaner kthread that will start
5584                  * processing uncleaned subvols.
5585                  */
5586                 wake_up_process(fs_info->transaction_kthread);
5587                 return ret;
5588         }
5589         case BTRFS_IOC_START_SYNC:
5590                 return btrfs_ioctl_start_sync(root, argp);
5591         case BTRFS_IOC_WAIT_SYNC:
5592                 return btrfs_ioctl_wait_sync(fs_info, argp);
5593         case BTRFS_IOC_SCRUB:
5594                 return btrfs_ioctl_scrub(file, argp);
5595         case BTRFS_IOC_SCRUB_CANCEL:
5596                 return btrfs_ioctl_scrub_cancel(fs_info);
5597         case BTRFS_IOC_SCRUB_PROGRESS:
5598                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5599         case BTRFS_IOC_BALANCE_V2:
5600                 return btrfs_ioctl_balance(file, argp);
5601         case BTRFS_IOC_BALANCE_CTL:
5602                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5603         case BTRFS_IOC_BALANCE_PROGRESS:
5604                 return btrfs_ioctl_balance_progress(fs_info, argp);
5605         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5606                 return btrfs_ioctl_set_received_subvol(file, argp);
5607 #ifdef CONFIG_64BIT
5608         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5609                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5610 #endif
5611         case BTRFS_IOC_SEND:
5612                 return btrfs_ioctl_send(file, argp);
5613         case BTRFS_IOC_GET_DEV_STATS:
5614                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5615         case BTRFS_IOC_QUOTA_CTL:
5616                 return btrfs_ioctl_quota_ctl(file, argp);
5617         case BTRFS_IOC_QGROUP_ASSIGN:
5618                 return btrfs_ioctl_qgroup_assign(file, argp);
5619         case BTRFS_IOC_QGROUP_CREATE:
5620                 return btrfs_ioctl_qgroup_create(file, argp);
5621         case BTRFS_IOC_QGROUP_LIMIT:
5622                 return btrfs_ioctl_qgroup_limit(file, argp);
5623         case BTRFS_IOC_QUOTA_RESCAN:
5624                 return btrfs_ioctl_quota_rescan(file, argp);
5625         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5626                 return btrfs_ioctl_quota_rescan_status(file, argp);
5627         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5628                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5629         case BTRFS_IOC_DEV_REPLACE:
5630                 return btrfs_ioctl_dev_replace(fs_info, argp);
5631         case BTRFS_IOC_GET_FSLABEL:
5632                 return btrfs_ioctl_get_fslabel(file, argp);
5633         case BTRFS_IOC_SET_FSLABEL:
5634                 return btrfs_ioctl_set_fslabel(file, argp);
5635         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5636                 return btrfs_ioctl_get_supported_features(argp);
5637         case BTRFS_IOC_GET_FEATURES:
5638                 return btrfs_ioctl_get_features(file, argp);
5639         case BTRFS_IOC_SET_FEATURES:
5640                 return btrfs_ioctl_set_features(file, argp);
5641         }
5642
5643         return -ENOTTY;
5644 }
5645
5646 #ifdef CONFIG_COMPAT
5647 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5648 {
5649         /*
5650          * These all access 32-bit values anyway so no further
5651          * handling is necessary.
5652          */
5653         switch (cmd) {
5654         case FS_IOC32_GETFLAGS:
5655                 cmd = FS_IOC_GETFLAGS;
5656                 break;
5657         case FS_IOC32_SETFLAGS:
5658                 cmd = FS_IOC_SETFLAGS;
5659                 break;
5660         case FS_IOC32_GETVERSION:
5661                 cmd = FS_IOC_GETVERSION;
5662                 break;
5663         }
5664
5665         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5666 }
5667 #endif