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((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                                   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                                                  qgroup_reserved);
 492                 goto fail_free;
 493         }
 494         trans->block_rsv = &block_rsv;
 495         trans->bytes_reserved = block_rsv.size;
 496
 497         ret = btrfs_qgroup_inherit(trans, fs_info, 0, objectid, inherit);
 498         if (ret)
 499                 goto fail;
 500
 501         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 502         if (IS_ERR(leaf)) {
 503                 ret = PTR_ERR(leaf);
 504                 goto fail;
 505         }
 506
 507         memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
 508         btrfs_set_header_bytenr(leaf, leaf->start);
 509         btrfs_set_header_generation(leaf, trans->transid);
 510         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 511         btrfs_set_header_owner(leaf, objectid);
 512
 513         write_extent_buffer_fsid(leaf, fs_info->fsid);
 514         write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
 515         btrfs_mark_buffer_dirty(leaf);
 516
 517         inode_item = &root_item->inode;
 518         btrfs_set_stack_inode_generation(inode_item, 1);
 519         btrfs_set_stack_inode_size(inode_item, 3);
 520         btrfs_set_stack_inode_nlink(inode_item, 1);
 521         btrfs_set_stack_inode_nbytes(inode_item,
 522                                      fs_info->nodesize);
 523         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 524
 525         btrfs_set_root_flags(root_item, 0);
 526         btrfs_set_root_limit(root_item, 0);
 527         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 528
 529         btrfs_set_root_bytenr(root_item, leaf->start);
 530         btrfs_set_root_generation(root_item, trans->transid);
 531         btrfs_set_root_level(root_item, 0);
 532         btrfs_set_root_refs(root_item, 1);
 533         btrfs_set_root_used(root_item, leaf->len);
 534         btrfs_set_root_last_snapshot(root_item, 0);
 535
 536         btrfs_set_root_generation_v2(root_item,
 537                         btrfs_root_generation(root_item));
 538         uuid_le_gen(&new_uuid);
 539         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 540         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 541         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 542         root_item->ctime = root_item->otime;
 543         btrfs_set_root_ctransid(root_item, trans->transid);
 544         btrfs_set_root_otransid(root_item, trans->transid);
 545
 546         btrfs_tree_unlock(leaf);
 547         free_extent_buffer(leaf);
 548         leaf = NULL;
 549
 550         btrfs_set_root_dirid(root_item, new_dirid);
 551
 552         key.objectid = objectid;
 553         key.offset = 0;
 554         key.type = BTRFS_ROOT_ITEM_KEY;
 555         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 556                                 root_item);
 557         if (ret)
 558                 goto fail;
 559
 560         key.offset = (u64)-1;
 561         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 562         if (IS_ERR(new_root)) {
 563                 ret = PTR_ERR(new_root);
 564                 btrfs_abort_transaction(trans, ret);
 565                 goto fail;
 566         }
 567
 568         btrfs_record_root_in_trans(trans, new_root);
 569
 570         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 571         if (ret) {
 572                 /* We potentially lose an unused inode item here */
 573                 btrfs_abort_transaction(trans, ret);
 574                 goto fail;
 575         }
 576
 577         mutex_lock(&new_root->objectid_mutex);
 578         new_root->highest_objectid = new_dirid;
 579         mutex_unlock(&new_root->objectid_mutex);
 580
 581         /*
 582          * insert the directory item
 583          */
 584         ret = btrfs_set_inode_index(dir, &index);
 585         if (ret) {
 586                 btrfs_abort_transaction(trans, ret);
 587                 goto fail;
 588         }
 589
 590         ret = btrfs_insert_dir_item(trans, root,
 591                                     name, namelen, dir, &key,
 592                                     BTRFS_FT_DIR, index);
 593         if (ret) {
 594                 btrfs_abort_transaction(trans, ret);
 595                 goto fail;
 596         }
 597
 598         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 599         ret = btrfs_update_inode(trans, root, dir);
 600         BUG_ON(ret);
 601
 602         ret = btrfs_add_root_ref(trans, fs_info,
 603                                  objectid, root->root_key.objectid,
 604                                  btrfs_ino(dir), index, name, namelen);
 605         BUG_ON(ret);
 606
 607         ret = btrfs_uuid_tree_add(trans, fs_info, root_item->uuid,
 608                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 609         if (ret)
 610                 btrfs_abort_transaction(trans, ret);
 611
 612 fail:
 613         kfree(root_item);
 614         trans->block_rsv = NULL;
 615         trans->bytes_reserved = 0;
 616         btrfs_subvolume_release_metadata(fs_info, &block_rsv, qgroup_reserved);
 617
 618         if (async_transid) {
 619                 *async_transid = trans->transid;
 620                 err = btrfs_commit_transaction_async(trans, 1);
 621                 if (err)
 622                         err = btrfs_commit_transaction(trans);
 623         } else {
 624                 err = btrfs_commit_transaction(trans);
 625         }
 626         if (err && !ret)
 627                 ret = err;
 628
 629         if (!ret) {
 630                 inode = btrfs_lookup_dentry(dir, dentry);
 631                 if (IS_ERR(inode))
 632                         return PTR_ERR(inode);
 633                 d_instantiate(dentry, inode);
 634         }
 635         return ret;
 636
 637 fail_free:
 638         kfree(root_item);
 639         return ret;
 640 }
 641
 642 static void btrfs_wait_for_no_snapshoting_writes(struct btrfs_root *root)
 643 {
 644         s64 writers;
 645         DEFINE_WAIT(wait);
 646
 647         do {
 648                 prepare_to_wait(&root->subv_writers->wait, &wait,
 649                                 TASK_UNINTERRUPTIBLE);
 650
 651                 writers = percpu_counter_sum(&root->subv_writers->counter);
 652                 if (writers)
 653                         schedule();
 654
 655                 finish_wait(&root->subv_writers->wait, &wait);
 656         } while (writers);
 657 }
 658
 659 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 660                            struct dentry *dentry, char *name, int namelen,
 661                            u64 *async_transid, bool readonly,
 662                            struct btrfs_qgroup_inherit *inherit)
 663 {
 664         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 665         struct inode *inode;
 666         struct btrfs_pending_snapshot *pending_snapshot;
 667         struct btrfs_trans_handle *trans;
 668         int ret;
 669
 670         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 671                 return -EINVAL;
 672
 673         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 674         if (!pending_snapshot)
 675                 return -ENOMEM;
 676
 677         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 678                         GFP_NOFS);
 679         pending_snapshot->path = btrfs_alloc_path();
 680         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 681                 ret = -ENOMEM;
 682                 goto free_pending;
 683         }
 684
 685         atomic_inc(&root->will_be_snapshoted);
 686         smp_mb__after_atomic();
 687         btrfs_wait_for_no_snapshoting_writes(root);
 688
 689         ret = btrfs_start_delalloc_inodes(root, 0);
 690         if (ret)
 691                 goto dec_and_free;
 692
 693         btrfs_wait_ordered_extents(root, -1, 0, (u64)-1);
 694
 695         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 696                              BTRFS_BLOCK_RSV_TEMP);
 697         /*
 698          * 1 - parent dir inode
 699          * 2 - dir entries
 700          * 1 - root item
 701          * 2 - root ref/backref
 702          * 1 - root of snapshot
 703          * 1 - UUID item
 704          */
 705         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 706                                         &pending_snapshot->block_rsv, 8,
 707                                         &pending_snapshot->qgroup_reserved,
 708                                         false);
 709         if (ret)
 710                 goto dec_and_free;
 711
 712         pending_snapshot->dentry = dentry;
 713         pending_snapshot->root = root;
 714         pending_snapshot->readonly = readonly;
 715         pending_snapshot->dir = dir;
 716         pending_snapshot->inherit = inherit;
 717
 718         trans = btrfs_start_transaction(root, 0);
 719         if (IS_ERR(trans)) {
 720                 ret = PTR_ERR(trans);
 721                 goto fail;
 722         }
 723
 724         spin_lock(&fs_info->trans_lock);
 725         list_add(&pending_snapshot->list,
 726                  &trans->transaction->pending_snapshots);
 727         spin_unlock(&fs_info->trans_lock);
 728         if (async_transid) {
 729                 *async_transid = trans->transid;
 730                 ret = btrfs_commit_transaction_async(trans, 1);
 731                 if (ret)
 732                         ret = btrfs_commit_transaction(trans);
 733         } else {
 734                 ret = btrfs_commit_transaction(trans);
 735         }
 736         if (ret)
 737                 goto fail;
 738
 739         ret = pending_snapshot->error;
 740         if (ret)
 741                 goto fail;
 742
 743         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 744         if (ret)
 745                 goto fail;
 746
 747         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 748         if (IS_ERR(inode)) {
 749                 ret = PTR_ERR(inode);
 750                 goto fail;
 751         }
 752
 753         d_instantiate(dentry, inode);
 754         ret = 0;
 755 fail:
 756         btrfs_subvolume_release_metadata(fs_info,
 757                                          &pending_snapshot->block_rsv,
 758                                          pending_snapshot->qgroup_reserved);
 759 dec_and_free:
 760         if (atomic_dec_and_test(&root->will_be_snapshoted))
 761                 wake_up_atomic_t(&root->will_be_snapshoted);
 762 free_pending:
 763         kfree(pending_snapshot->root_item);
 764         btrfs_free_path(pending_snapshot->path);
 765         kfree(pending_snapshot);
 766
 767         return ret;
 768 }
 769
 770 /*  copy of may_delete in fs/namei.c()
 771  *      Check whether we can remove a link victim from directory dir, check
 772  *  whether the type of victim is right.
 773  *  1. We can't do it if dir is read-only (done in permission())
 774  *  2. We should have write and exec permissions on dir
 775  *  3. We can't remove anything from append-only dir
 776  *  4. We can't do anything with immutable dir (done in permission())
 777  *  5. If the sticky bit on dir is set we should either
 778  *      a. be owner of dir, or
 779  *      b. be owner of victim, or
 780  *      c. have CAP_FOWNER capability
 781  *  6. If the victim is append-only or immutable we can't do anything with
 782  *     links pointing to it.
 783  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 784  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 785  *  9. We can't remove a root or mountpoint.
 786  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 787  *     nfs_async_unlink().
 788  */
 789
 790 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 791 {
 792         int error;
 793
 794         if (d_really_is_negative(victim))
 795                 return -ENOENT;
 796
 797         BUG_ON(d_inode(victim->d_parent) != dir);
 798         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 799
 800         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 801         if (error)
 802                 return error;
 803         if (IS_APPEND(dir))
 804                 return -EPERM;
 805         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 806             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 807                 return -EPERM;
 808         if (isdir) {
 809                 if (!d_is_dir(victim))
 810                         return -ENOTDIR;
 811                 if (IS_ROOT(victim))
 812                         return -EBUSY;
 813         } else if (d_is_dir(victim))
 814                 return -EISDIR;
 815         if (IS_DEADDIR(dir))
 816                 return -ENOENT;
 817         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 818                 return -EBUSY;
 819         return 0;
 820 }
 821
 822 /* copy of may_create in fs/namei.c() */
 823 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 824 {
 825         if (d_really_is_positive(child))
 826                 return -EEXIST;
 827         if (IS_DEADDIR(dir))
 828                 return -ENOENT;
 829         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 830 }
 831
 832 /*
 833  * Create a new subvolume below @parent.  This is largely modeled after
 834  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 835  * inside this filesystem so it's quite a bit simpler.
 836  */
 837 static noinline int btrfs_mksubvol(const struct path *parent,
 838                                    char *name, int namelen,
 839                                    struct btrfs_root *snap_src,
 840                                    u64 *async_transid, bool readonly,
 841                                    struct btrfs_qgroup_inherit *inherit)
 842 {
 843         struct inode *dir = d_inode(parent->dentry);
 844         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 845         struct dentry *dentry;
 846         int error;
 847
 848         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 849         if (error == -EINTR)
 850                 return error;
 851
 852         dentry = lookup_one_len(name, parent->dentry, namelen);
 853         error = PTR_ERR(dentry);
 854         if (IS_ERR(dentry))
 855                 goto out_unlock;
 856
 857         error = btrfs_may_create(dir, dentry);
 858         if (error)
 859                 goto out_dput;
 860
 861         /*
 862          * even if this name doesn't exist, we may get hash collisions.
 863          * check for them now when we can safely fail
 864          */
 865         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 866                                                dir->i_ino, name,
 867                                                namelen);
 868         if (error)
 869                 goto out_dput;
 870
 871         down_read(&fs_info->subvol_sem);
 872
 873         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 874                 goto out_up_read;
 875
 876         if (snap_src) {
 877                 error = create_snapshot(snap_src, dir, dentry, name, namelen,
 878                                         async_transid, readonly, inherit);
 879         } else {
 880                 error = create_subvol(dir, dentry, name, namelen,
 881                                       async_transid, inherit);
 882         }
 883         if (!error)
 884                 fsnotify_mkdir(dir, dentry);
 885 out_up_read:
 886         up_read(&fs_info->subvol_sem);
 887 out_dput:
 888         dput(dentry);
 889 out_unlock:
 890         inode_unlock(dir);
 891         return error;
 892 }
 893
 894 /*
 895  * When we're defragging a range, we don't want to kick it off again
 896  * if it is really just waiting for delalloc to send it down.
 897  * If we find a nice big extent or delalloc range for the bytes in the
 898  * file you want to defrag, we return 0 to let you know to skip this
 899  * part of the file
 900  */
 901 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 902 {
 903         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 904         struct extent_map *em = NULL;
 905         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 906         u64 end;
 907
 908         read_lock(&em_tree->lock);
 909         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 910         read_unlock(&em_tree->lock);
 911
 912         if (em) {
 913                 end = extent_map_end(em);
 914                 free_extent_map(em);
 915                 if (end - offset > thresh)
 916                         return 0;
 917         }
 918         /* if we already have a nice delalloc here, just stop */
 919         thresh /= 2;
 920         end = count_range_bits(io_tree, &offset, offset + thresh,
 921                                thresh, EXTENT_DELALLOC, 1);
 922         if (end >= thresh)
 923                 return 0;
 924         return 1;
 925 }
 926
 927 /*
 928  * helper function to walk through a file and find extents
 929  * newer than a specific transid, and smaller than thresh.
 930  *
 931  * This is used by the defragging code to find new and small
 932  * extents
 933  */
 934 static int find_new_extents(struct btrfs_root *root,
 935                             struct inode *inode, u64 newer_than,
 936                             u64 *off, u32 thresh)
 937 {
 938         struct btrfs_path *path;
 939         struct btrfs_key min_key;
 940         struct extent_buffer *leaf;
 941         struct btrfs_file_extent_item *extent;
 942         int type;
 943         int ret;
 944         u64 ino = btrfs_ino(inode);
 945
 946         path = btrfs_alloc_path();
 947         if (!path)
 948                 return -ENOMEM;
 949
 950         min_key.objectid = ino;
 951         min_key.type = BTRFS_EXTENT_DATA_KEY;
 952         min_key.offset = *off;
 953
 954         while (1) {
 955                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
 956                 if (ret != 0)
 957                         goto none;
 958 process_slot:
 959                 if (min_key.objectid != ino)
 960                         goto none;
 961                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 962                         goto none;
 963
 964                 leaf = path->nodes[0];
 965                 extent = btrfs_item_ptr(leaf, path->slots[0],
 966                                         struct btrfs_file_extent_item);
 967
 968                 type = btrfs_file_extent_type(leaf, extent);
 969                 if (type == BTRFS_FILE_EXTENT_REG &&
 970                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 971                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 972                         *off = min_key.offset;
 973                         btrfs_free_path(path);
 974                         return 0;
 975                 }
 976
 977                 path->slots[0]++;
 978                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
 979                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 980                         goto process_slot;
 981                 }
 982
 983                 if (min_key.offset == (u64)-1)
 984                         goto none;
 985
 986                 min_key.offset++;
 987                 btrfs_release_path(path);
 988         }
 989 none:
 990         btrfs_free_path(path);
 991         return -ENOENT;
 992 }
 993
 994 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 995 {
 996         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 997         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 998         struct extent_map *em;
 999         u64 len = PAGE_SIZE;
1000
1001         /*
1002          * hopefully we have this extent in the tree already, try without
1003          * the full extent lock
1004          */
1005         read_lock(&em_tree->lock);
1006         em = lookup_extent_mapping(em_tree, start, len);
1007         read_unlock(&em_tree->lock);
1008
1009         if (!em) {
1010                 struct extent_state *cached = NULL;
1011                 u64 end = start + len - 1;
1012
1013                 /* get the big lock and read metadata off disk */
1014                 lock_extent_bits(io_tree, start, end, &cached);
1015                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
1016                 unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS);
1017
1018                 if (IS_ERR(em))
1019                         return NULL;
1020         }
1021
1022         return em;
1023 }
1024
1025 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1026 {
1027         struct extent_map *next;
1028         bool ret = true;
1029
1030         /* this is the last extent */
1031         if (em->start + em->len >= i_size_read(inode))
1032                 return false;
1033
1034         next = defrag_lookup_extent(inode, em->start + em->len);
1035         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1036                 ret = false;
1037         else if ((em->block_start + em->block_len == next->block_start) &&
1038                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1039                 ret = false;
1040
1041         free_extent_map(next);
1042         return ret;
1043 }
1044
1045 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1046                                u64 *last_len, u64 *skip, u64 *defrag_end,
1047                                int compress)
1048 {
1049         struct extent_map *em;
1050         int ret = 1;
1051         bool next_mergeable = true;
1052         bool prev_mergeable = true;
1053
1054         /*
1055          * make sure that once we start defragging an extent, we keep on
1056          * defragging it
1057          */
1058         if (start < *defrag_end)
1059                 return 1;
1060
1061         *skip = 0;
1062
1063         em = defrag_lookup_extent(inode, start);
1064         if (!em)
1065                 return 0;
1066
1067         /* this will cover holes, and inline extents */
1068         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1069                 ret = 0;
1070                 goto out;
1071         }
1072
1073         if (!*defrag_end)
1074                 prev_mergeable = false;
1075
1076         next_mergeable = defrag_check_next_extent(inode, em);
1077         /*
1078          * we hit a real extent, if it is big or the next extent is not a
1079          * real extent, don't bother defragging it
1080          */
1081         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1082             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1083                 ret = 0;
1084 out:
1085         /*
1086          * last_len ends up being a counter of how many bytes we've defragged.
1087          * every time we choose not to defrag an extent, we reset *last_len
1088          * so that the next tiny extent will force a defrag.
1089          *
1090          * The end result of this is that tiny extents before a single big
1091          * extent will force at least part of that big extent to be defragged.
1092          */
1093         if (ret) {
1094                 *defrag_end = extent_map_end(em);
1095         } else {
1096                 *last_len = 0;
1097                 *skip = extent_map_end(em);
1098                 *defrag_end = 0;
1099         }
1100
1101         free_extent_map(em);
1102         return ret;
1103 }
1104
1105 /*
1106  * it doesn't do much good to defrag one or two pages
1107  * at a time.  This pulls in a nice chunk of pages
1108  * to COW and defrag.
1109  *
1110  * It also makes sure the delalloc code has enough
1111  * dirty data to avoid making new small extents as part
1112  * of the defrag
1113  *
1114  * It's a good idea to start RA on this range
1115  * before calling this.
1116  */
1117 static int cluster_pages_for_defrag(struct inode *inode,
1118                                     struct page **pages,
1119                                     unsigned long start_index,
1120                                     unsigned long num_pages)
1121 {
1122         unsigned long file_end;
1123         u64 isize = i_size_read(inode);
1124         u64 page_start;
1125         u64 page_end;
1126         u64 page_cnt;
1127         int ret;
1128         int i;
1129         int i_done;
1130         struct btrfs_ordered_extent *ordered;
1131         struct extent_state *cached_state = NULL;
1132         struct extent_io_tree *tree;
1133         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1134
1135         file_end = (isize - 1) >> PAGE_SHIFT;
1136         if (!isize || start_index > file_end)
1137                 return 0;
1138
1139         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1140
1141         ret = btrfs_delalloc_reserve_space(inode,
1142                         start_index << PAGE_SHIFT,
1143                         page_cnt << PAGE_SHIFT);
1144         if (ret)
1145                 return ret;
1146         i_done = 0;
1147         tree = &BTRFS_I(inode)->io_tree;
1148
1149         /* step one, lock all the pages */
1150         for (i = 0; i < page_cnt; i++) {
1151                 struct page *page;
1152 again:
1153                 page = find_or_create_page(inode->i_mapping,
1154                                            start_index + i, mask);
1155                 if (!page)
1156                         break;
1157
1158                 page_start = page_offset(page);
1159                 page_end = page_start + PAGE_SIZE - 1;
1160                 while (1) {
1161                         lock_extent_bits(tree, page_start, page_end,
1162                                          &cached_state);
1163                         ordered = btrfs_lookup_ordered_extent(inode,
1164                                                               page_start);
1165                         unlock_extent_cached(tree, page_start, page_end,
1166                                              &cached_state, GFP_NOFS);
1167                         if (!ordered)
1168                                 break;
1169
1170                         unlock_page(page);
1171                         btrfs_start_ordered_extent(inode, ordered, 1);
1172                         btrfs_put_ordered_extent(ordered);
1173                         lock_page(page);
1174                         /*
1175                          * we unlocked the page above, so we need check if
1176                          * it was released or not.
1177                          */
1178                         if (page->mapping != inode->i_mapping) {
1179                                 unlock_page(page);
1180                                 put_page(page);
1181                                 goto again;
1182                         }
1183                 }
1184
1185                 if (!PageUptodate(page)) {
1186                         btrfs_readpage(NULL, page);
1187                         lock_page(page);
1188                         if (!PageUptodate(page)) {
1189                                 unlock_page(page);
1190                                 put_page(page);
1191                                 ret = -EIO;
1192                                 break;
1193                         }
1194                 }
1195
1196                 if (page->mapping != inode->i_mapping) {
1197                         unlock_page(page);
1198                         put_page(page);
1199                         goto again;
1200                 }
1201
1202                 pages[i] = page;
1203                 i_done++;
1204         }
1205         if (!i_done || ret)
1206                 goto out;
1207
1208         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1209                 goto out;
1210
1211         /*
1212          * so now we have a nice long stream of locked
1213          * and up to date pages, lets wait on them
1214          */
1215         for (i = 0; i < i_done; i++)
1216                 wait_on_page_writeback(pages[i]);
1217
1218         page_start = page_offset(pages[0]);
1219         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1220
1221         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1222                          page_start, page_end - 1, &cached_state);
1223         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1224                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1225                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1226                           &cached_state, GFP_NOFS);
1227
1228         if (i_done != page_cnt) {
1229                 spin_lock(&BTRFS_I(inode)->lock);
1230                 BTRFS_I(inode)->outstanding_extents++;
1231                 spin_unlock(&BTRFS_I(inode)->lock);
1232                 btrfs_delalloc_release_space(inode,
1233                                 start_index << PAGE_SHIFT,
1234                                 (page_cnt - i_done) << PAGE_SHIFT);
1235         }
1236
1237
1238         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1239                           &cached_state);
1240
1241         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1242                              page_start, page_end - 1, &cached_state,
1243                              GFP_NOFS);
1244
1245         for (i = 0; i < i_done; i++) {
1246                 clear_page_dirty_for_io(pages[i]);
1247                 ClearPageChecked(pages[i]);
1248                 set_page_extent_mapped(pages[i]);
1249                 set_page_dirty(pages[i]);
1250                 unlock_page(pages[i]);
1251                 put_page(pages[i]);
1252         }
1253         return i_done;
1254 out:
1255         for (i = 0; i < i_done; i++) {
1256                 unlock_page(pages[i]);
1257                 put_page(pages[i]);
1258         }
1259         btrfs_delalloc_release_space(inode,
1260                         start_index << PAGE_SHIFT,
1261                         page_cnt << PAGE_SHIFT);
1262         return ret;
1263
1264 }
1265
1266 int btrfs_defrag_file(struct inode *inode, struct file *file,
1267                       struct btrfs_ioctl_defrag_range_args *range,
1268                       u64 newer_than, unsigned long max_to_defrag)
1269 {
1270         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1271         struct btrfs_root *root = BTRFS_I(inode)->root;
1272         struct file_ra_state *ra = NULL;
1273         unsigned long last_index;
1274         u64 isize = i_size_read(inode);
1275         u64 last_len = 0;
1276         u64 skip = 0;
1277         u64 defrag_end = 0;
1278         u64 newer_off = range->start;
1279         unsigned long i;
1280         unsigned long ra_index = 0;
1281         int ret;
1282         int defrag_count = 0;
1283         int compress_type = BTRFS_COMPRESS_ZLIB;
1284         u32 extent_thresh = range->extent_thresh;
1285         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1286         unsigned long cluster = max_cluster;
1287         u64 new_align = ~((u64)SZ_128K - 1);
1288         struct page **pages = NULL;
1289
1290         if (isize == 0)
1291                 return 0;
1292
1293         if (range->start >= isize)
1294                 return -EINVAL;
1295
1296         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1297                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1298                         return -EINVAL;
1299                 if (range->compress_type)
1300                         compress_type = range->compress_type;
1301         }
1302
1303         if (extent_thresh == 0)
1304                 extent_thresh = SZ_256K;
1305
1306         /*
1307          * if we were not given a file, allocate a readahead
1308          * context
1309          */
1310         if (!file) {
1311                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1312                 if (!ra)
1313                         return -ENOMEM;
1314                 file_ra_state_init(ra, inode->i_mapping);
1315         } else {
1316                 ra = &file->f_ra;
1317         }
1318
1319         pages = kmalloc_array(max_cluster, sizeof(struct page *),
1320                         GFP_NOFS);
1321         if (!pages) {
1322                 ret = -ENOMEM;
1323                 goto out_ra;
1324         }
1325
1326         /* find the last page to defrag */
1327         if (range->start + range->len > range->start) {
1328                 last_index = min_t(u64, isize - 1,
1329                          range->start + range->len - 1) >> PAGE_SHIFT;
1330         } else {
1331                 last_index = (isize - 1) >> PAGE_SHIFT;
1332         }
1333
1334         if (newer_than) {
1335                 ret = find_new_extents(root, inode, newer_than,
1336                                        &newer_off, SZ_64K);
1337                 if (!ret) {
1338                         range->start = newer_off;
1339                         /*
1340                          * we always align our defrag to help keep
1341                          * the extents in the file evenly spaced
1342                          */
1343                         i = (newer_off & new_align) >> PAGE_SHIFT;
1344                 } else
1345                         goto out_ra;
1346         } else {
1347                 i = range->start >> PAGE_SHIFT;
1348         }
1349         if (!max_to_defrag)
1350                 max_to_defrag = last_index - i + 1;
1351
1352         /*
1353          * make writeback starts from i, so the defrag range can be
1354          * written sequentially.
1355          */
1356         if (i < inode->i_mapping->writeback_index)
1357                 inode->i_mapping->writeback_index = i;
1358
1359         while (i <= last_index && defrag_count < max_to_defrag &&
1360                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1361                 /*
1362                  * make sure we stop running if someone unmounts
1363                  * the FS
1364                  */
1365                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1366                         break;
1367
1368                 if (btrfs_defrag_cancelled(fs_info)) {
1369                         btrfs_debug(fs_info, "defrag_file cancelled");
1370                         ret = -EAGAIN;
1371                         break;
1372                 }
1373
1374                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1375                                          extent_thresh, &last_len, &skip,
1376                                          &defrag_end, range->flags &
1377                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1378                         unsigned long next;
1379                         /*
1380                          * the should_defrag function tells us how much to skip
1381                          * bump our counter by the suggested amount
1382                          */
1383                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1384                         i = max(i + 1, next);
1385                         continue;
1386                 }
1387
1388                 if (!newer_than) {
1389                         cluster = (PAGE_ALIGN(defrag_end) >>
1390                                    PAGE_SHIFT) - i;
1391                         cluster = min(cluster, max_cluster);
1392                 } else {
1393                         cluster = max_cluster;
1394                 }
1395
1396                 if (i + cluster > ra_index) {
1397                         ra_index = max(i, ra_index);
1398                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1399                                        cluster);
1400                         ra_index += cluster;
1401                 }
1402
1403                 inode_lock(inode);
1404                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1405                         BTRFS_I(inode)->force_compress = compress_type;
1406                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1407                 if (ret < 0) {
1408                         inode_unlock(inode);
1409                         goto out_ra;
1410                 }
1411
1412                 defrag_count += ret;
1413                 balance_dirty_pages_ratelimited(inode->i_mapping);
1414                 inode_unlock(inode);
1415
1416                 if (newer_than) {
1417                         if (newer_off == (u64)-1)
1418                                 break;
1419
1420                         if (ret > 0)
1421                                 i += ret;
1422
1423                         newer_off = max(newer_off + 1,
1424                                         (u64)i << PAGE_SHIFT);
1425
1426                         ret = find_new_extents(root, inode, newer_than,
1427                                                &newer_off, SZ_64K);
1428                         if (!ret) {
1429                                 range->start = newer_off;
1430                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1431                         } else {
1432                                 break;
1433                         }
1434                 } else {
1435                         if (ret > 0) {
1436                                 i += ret;
1437                                 last_len += ret << PAGE_SHIFT;
1438                         } else {
1439                                 i++;
1440                                 last_len = 0;
1441                         }
1442                 }
1443         }
1444
1445         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1446                 filemap_flush(inode->i_mapping);
1447                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1448                              &BTRFS_I(inode)->runtime_flags))
1449                         filemap_flush(inode->i_mapping);
1450         }
1451
1452         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1453                 /* the filemap_flush will queue IO into the worker threads, but
1454                  * we have to make sure the IO is actually started and that
1455                  * ordered extents get created before we return
1456                  */
1457                 atomic_inc(&fs_info->async_submit_draining);
1458                 while (atomic_read(&fs_info->nr_async_submits) ||
1459                        atomic_read(&fs_info->async_delalloc_pages)) {
1460                         wait_event(fs_info->async_submit_wait,
1461                                    (atomic_read(&fs_info->nr_async_submits) == 0 &&
1462                                     atomic_read(&fs_info->async_delalloc_pages) == 0));
1463                 }
1464                 atomic_dec(&fs_info->async_submit_draining);
1465         }
1466
1467         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1468                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1469         }
1470
1471         ret = defrag_count;
1472
1473 out_ra:
1474         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1475                 inode_lock(inode);
1476                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1477                 inode_unlock(inode);
1478         }
1479         if (!file)
1480                 kfree(ra);
1481         kfree(pages);
1482         return ret;
1483 }
1484
1485 static noinline int btrfs_ioctl_resize(struct file *file,
1486                                         void __user *arg)
1487 {
1488         struct inode *inode = file_inode(file);
1489         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1490         u64 new_size;
1491         u64 old_size;
1492         u64 devid = 1;
1493         struct btrfs_root *root = BTRFS_I(inode)->root;
1494         struct btrfs_ioctl_vol_args *vol_args;
1495         struct btrfs_trans_handle *trans;
1496         struct btrfs_device *device = NULL;
1497         char *sizestr;
1498         char *retptr;
1499         char *devstr = NULL;
1500         int ret = 0;
1501         int mod = 0;
1502
1503         if (!capable(CAP_SYS_ADMIN))
1504                 return -EPERM;
1505
1506         ret = mnt_want_write_file(file);
1507         if (ret)
1508                 return ret;
1509
1510         if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
1511                 mnt_drop_write_file(file);
1512                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1513         }
1514
1515         mutex_lock(&fs_info->volume_mutex);
1516         vol_args = memdup_user(arg, sizeof(*vol_args));
1517         if (IS_ERR(vol_args)) {
1518                 ret = PTR_ERR(vol_args);
1519                 goto out;
1520         }
1521
1522         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1523
1524         sizestr = vol_args->name;
1525         devstr = strchr(sizestr, ':');
1526         if (devstr) {
1527                 sizestr = devstr + 1;
1528                 *devstr = '\0';
1529                 devstr = vol_args->name;
1530                 ret = kstrtoull(devstr, 10, &devid);
1531                 if (ret)
1532                         goto out_free;
1533                 if (!devid) {
1534                         ret = -EINVAL;
1535                         goto out_free;
1536                 }
1537                 btrfs_info(fs_info, "resizing devid %llu", devid);
1538         }
1539
1540         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1541         if (!device) {
1542                 btrfs_info(fs_info, "resizer unable to find device %llu",
1543                            devid);
1544                 ret = -ENODEV;
1545                 goto out_free;
1546         }
1547
1548         if (!device->writeable) {
1549                 btrfs_info(fs_info,
1550                            "resizer unable to apply on readonly device %llu",
1551                        devid);
1552                 ret = -EPERM;
1553                 goto out_free;
1554         }
1555
1556         if (!strcmp(sizestr, "max"))
1557                 new_size = device->bdev->bd_inode->i_size;
1558         else {
1559                 if (sizestr[0] == '-') {
1560                         mod = -1;
1561                         sizestr++;
1562                 } else if (sizestr[0] == '+') {
1563                         mod = 1;
1564                         sizestr++;
1565                 }
1566                 new_size = memparse(sizestr, &retptr);
1567                 if (*retptr != '\0' || new_size == 0) {
1568                         ret = -EINVAL;
1569                         goto out_free;
1570                 }
1571         }
1572
1573         if (device->is_tgtdev_for_dev_replace) {
1574                 ret = -EPERM;
1575                 goto out_free;
1576         }
1577
1578         old_size = btrfs_device_get_total_bytes(device);
1579
1580         if (mod < 0) {
1581                 if (new_size > old_size) {
1582                         ret = -EINVAL;
1583                         goto out_free;
1584                 }
1585                 new_size = old_size - new_size;
1586         } else if (mod > 0) {
1587                 if (new_size > ULLONG_MAX - old_size) {
1588                         ret = -ERANGE;
1589                         goto out_free;
1590                 }
1591                 new_size = old_size + new_size;
1592         }
1593
1594         if (new_size < SZ_256M) {
1595                 ret = -EINVAL;
1596                 goto out_free;
1597         }
1598         if (new_size > device->bdev->bd_inode->i_size) {
1599                 ret = -EFBIG;
1600                 goto out_free;
1601         }
1602
1603         new_size = div_u64(new_size, fs_info->sectorsize);
1604         new_size *= fs_info->sectorsize;
1605
1606         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1607                           rcu_str_deref(device->name), new_size);
1608
1609         if (new_size > old_size) {
1610                 trans = btrfs_start_transaction(root, 0);
1611                 if (IS_ERR(trans)) {
1612                         ret = PTR_ERR(trans);
1613                         goto out_free;
1614                 }
1615                 ret = btrfs_grow_device(trans, device, new_size);
1616                 btrfs_commit_transaction(trans);
1617         } else if (new_size < old_size) {
1618                 ret = btrfs_shrink_device(device, new_size);
1619         } /* equal, nothing need to do */
1620
1621 out_free:
1622         kfree(vol_args);
1623 out:
1624         mutex_unlock(&fs_info->volume_mutex);
1625         atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
1626         mnt_drop_write_file(file);
1627         return ret;
1628 }
1629
1630 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1631                                 char *name, unsigned long fd, int subvol,
1632                                 u64 *transid, bool readonly,
1633                                 struct btrfs_qgroup_inherit *inherit)
1634 {
1635         int namelen;
1636         int ret = 0;
1637
1638         if (!S_ISDIR(file_inode(file)->i_mode))
1639                 return -ENOTDIR;
1640
1641         ret = mnt_want_write_file(file);
1642         if (ret)
1643                 goto out;
1644
1645         namelen = strlen(name);
1646         if (strchr(name, '/')) {
1647                 ret = -EINVAL;
1648                 goto out_drop_write;
1649         }
1650
1651         if (name[0] == '.' &&
1652            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1653                 ret = -EEXIST;
1654                 goto out_drop_write;
1655         }
1656
1657         if (subvol) {
1658                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1659                                      NULL, transid, readonly, inherit);
1660         } else {
1661                 struct fd src = fdget(fd);
1662                 struct inode *src_inode;
1663                 if (!src.file) {
1664                         ret = -EINVAL;
1665                         goto out_drop_write;
1666                 }
1667
1668                 src_inode = file_inode(src.file);
1669                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1670                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1671                                    "Snapshot src from another FS");
1672                         ret = -EXDEV;
1673                 } else if (!inode_owner_or_capable(src_inode)) {
1674                         /*
1675                          * Subvolume creation is not restricted, but snapshots
1676                          * are limited to own subvolumes only
1677                          */
1678                         ret = -EPERM;
1679                 } else {
1680                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1681                                              BTRFS_I(src_inode)->root,
1682                                              transid, readonly, inherit);
1683                 }
1684                 fdput(src);
1685         }
1686 out_drop_write:
1687         mnt_drop_write_file(file);
1688 out:
1689         return ret;
1690 }
1691
1692 static noinline int btrfs_ioctl_snap_create(struct file *file,
1693                                             void __user *arg, int subvol)
1694 {
1695         struct btrfs_ioctl_vol_args *vol_args;
1696         int ret;
1697
1698         if (!S_ISDIR(file_inode(file)->i_mode))
1699                 return -ENOTDIR;
1700
1701         vol_args = memdup_user(arg, sizeof(*vol_args));
1702         if (IS_ERR(vol_args))
1703                 return PTR_ERR(vol_args);
1704         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1705
1706         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1707                                               vol_args->fd, subvol,
1708                                               NULL, false, NULL);
1709
1710         kfree(vol_args);
1711         return ret;
1712 }
1713
1714 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1715                                                void __user *arg, int subvol)
1716 {
1717         struct btrfs_ioctl_vol_args_v2 *vol_args;
1718         int ret;
1719         u64 transid = 0;
1720         u64 *ptr = NULL;
1721         bool readonly = false;
1722         struct btrfs_qgroup_inherit *inherit = NULL;
1723
1724         if (!S_ISDIR(file_inode(file)->i_mode))
1725                 return -ENOTDIR;
1726
1727         vol_args = memdup_user(arg, sizeof(*vol_args));
1728         if (IS_ERR(vol_args))
1729                 return PTR_ERR(vol_args);
1730         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1731
1732         if (vol_args->flags &
1733             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1734               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1735                 ret = -EOPNOTSUPP;
1736                 goto free_args;
1737         }
1738
1739         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1740                 ptr = &transid;
1741         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1742                 readonly = true;
1743         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1744                 if (vol_args->size > PAGE_SIZE) {
1745                         ret = -EINVAL;
1746                         goto free_args;
1747                 }
1748                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1749                 if (IS_ERR(inherit)) {
1750                         ret = PTR_ERR(inherit);
1751                         goto free_args;
1752                 }
1753         }
1754
1755         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1756                                               vol_args->fd, subvol, ptr,
1757                                               readonly, inherit);
1758         if (ret)
1759                 goto free_inherit;
1760
1761         if (ptr && copy_to_user(arg +
1762                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1763                                         transid),
1764                                 ptr, sizeof(*ptr)))
1765                 ret = -EFAULT;
1766
1767 free_inherit:
1768         kfree(inherit);
1769 free_args:
1770         kfree(vol_args);
1771         return ret;
1772 }
1773
1774 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1775                                                 void __user *arg)
1776 {
1777         struct inode *inode = file_inode(file);
1778         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1779         struct btrfs_root *root = BTRFS_I(inode)->root;
1780         int ret = 0;
1781         u64 flags = 0;
1782
1783         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1784                 return -EINVAL;
1785
1786         down_read(&fs_info->subvol_sem);
1787         if (btrfs_root_readonly(root))
1788                 flags |= BTRFS_SUBVOL_RDONLY;
1789         up_read(&fs_info->subvol_sem);
1790
1791         if (copy_to_user(arg, &flags, sizeof(flags)))
1792                 ret = -EFAULT;
1793
1794         return ret;
1795 }
1796
1797 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1798                                               void __user *arg)
1799 {
1800         struct inode *inode = file_inode(file);
1801         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1802         struct btrfs_root *root = BTRFS_I(inode)->root;
1803         struct btrfs_trans_handle *trans;
1804         u64 root_flags;
1805         u64 flags;
1806         int ret = 0;
1807
1808         if (!inode_owner_or_capable(inode))
1809                 return -EPERM;
1810
1811         ret = mnt_want_write_file(file);
1812         if (ret)
1813                 goto out;
1814
1815         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1816                 ret = -EINVAL;
1817                 goto out_drop_write;
1818         }
1819
1820         if (copy_from_user(&flags, arg, sizeof(flags))) {
1821                 ret = -EFAULT;
1822                 goto out_drop_write;
1823         }
1824
1825         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1826                 ret = -EINVAL;
1827                 goto out_drop_write;
1828         }
1829
1830         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1831                 ret = -EOPNOTSUPP;
1832                 goto out_drop_write;
1833         }
1834
1835         down_write(&fs_info->subvol_sem);
1836
1837         /* nothing to do */
1838         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1839                 goto out_drop_sem;
1840
1841         root_flags = btrfs_root_flags(&root->root_item);
1842         if (flags & BTRFS_SUBVOL_RDONLY) {
1843                 btrfs_set_root_flags(&root->root_item,
1844                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1845         } else {
1846                 /*
1847                  * Block RO -> RW transition if this subvolume is involved in
1848                  * send
1849                  */
1850                 spin_lock(&root->root_item_lock);
1851                 if (root->send_in_progress == 0) {
1852                         btrfs_set_root_flags(&root->root_item,
1853                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1854                         spin_unlock(&root->root_item_lock);
1855                 } else {
1856                         spin_unlock(&root->root_item_lock);
1857                         btrfs_warn(fs_info,
1858                                    "Attempt to set subvolume %llu read-write during send",
1859                                    root->root_key.objectid);
1860                         ret = -EPERM;
1861                         goto out_drop_sem;
1862                 }
1863         }
1864
1865         trans = btrfs_start_transaction(root, 1);
1866         if (IS_ERR(trans)) {
1867                 ret = PTR_ERR(trans);
1868                 goto out_reset;
1869         }
1870
1871         ret = btrfs_update_root(trans, fs_info->tree_root,
1872                                 &root->root_key, &root->root_item);
1873
1874         btrfs_commit_transaction(trans);
1875 out_reset:
1876         if (ret)
1877                 btrfs_set_root_flags(&root->root_item, root_flags);
1878 out_drop_sem:
1879         up_write(&fs_info->subvol_sem);
1880 out_drop_write:
1881         mnt_drop_write_file(file);
1882 out:
1883         return ret;
1884 }
1885
1886 /*
1887  * helper to check if the subvolume references other subvolumes
1888  */
1889 static noinline int may_destroy_subvol(struct btrfs_root *root)
1890 {
1891         struct btrfs_fs_info *fs_info = root->fs_info;
1892         struct btrfs_path *path;
1893         struct btrfs_dir_item *di;
1894         struct btrfs_key key;
1895         u64 dir_id;
1896         int ret;
1897
1898         path = btrfs_alloc_path();
1899         if (!path)
1900                 return -ENOMEM;
1901
1902         /* Make sure this root isn't set as the default subvol */
1903         dir_id = btrfs_super_root_dir(fs_info->super_copy);
1904         di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
1905                                    dir_id, "default", 7, 0);
1906         if (di && !IS_ERR(di)) {
1907                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1908                 if (key.objectid == root->root_key.objectid) {
1909                         ret = -EPERM;
1910                         btrfs_err(fs_info,
1911                                   "deleting default subvolume %llu is not allowed",
1912                                   key.objectid);
1913                         goto out;
1914                 }
1915                 btrfs_release_path(path);
1916         }
1917
1918         key.objectid = root->root_key.objectid;
1919         key.type = BTRFS_ROOT_REF_KEY;
1920         key.offset = (u64)-1;
1921
1922         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1923         if (ret < 0)
1924                 goto out;
1925         BUG_ON(ret == 0);
1926
1927         ret = 0;
1928         if (path->slots[0] > 0) {
1929                 path->slots[0]--;
1930                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1931                 if (key.objectid == root->root_key.objectid &&
1932                     key.type == BTRFS_ROOT_REF_KEY)
1933                         ret = -ENOTEMPTY;
1934         }
1935 out:
1936         btrfs_free_path(path);
1937         return ret;
1938 }
1939
1940 static noinline int key_in_sk(struct btrfs_key *key,
1941                               struct btrfs_ioctl_search_key *sk)
1942 {
1943         struct btrfs_key test;
1944         int ret;
1945
1946         test.objectid = sk->min_objectid;
1947         test.type = sk->min_type;
1948         test.offset = sk->min_offset;
1949
1950         ret = btrfs_comp_cpu_keys(key, &test);
1951         if (ret < 0)
1952                 return 0;
1953
1954         test.objectid = sk->max_objectid;
1955         test.type = sk->max_type;
1956         test.offset = sk->max_offset;
1957
1958         ret = btrfs_comp_cpu_keys(key, &test);
1959         if (ret > 0)
1960                 return 0;
1961         return 1;
1962 }
1963
1964 static noinline int copy_to_sk(struct btrfs_path *path,
1965                                struct btrfs_key *key,
1966                                struct btrfs_ioctl_search_key *sk,
1967                                size_t *buf_size,
1968                                char __user *ubuf,
1969                                unsigned long *sk_offset,
1970                                int *num_found)
1971 {
1972         u64 found_transid;
1973         struct extent_buffer *leaf;
1974         struct btrfs_ioctl_search_header sh;
1975         struct btrfs_key test;
1976         unsigned long item_off;
1977         unsigned long item_len;
1978         int nritems;
1979         int i;
1980         int slot;
1981         int ret = 0;
1982
1983         leaf = path->nodes[0];
1984         slot = path->slots[0];
1985         nritems = btrfs_header_nritems(leaf);
1986
1987         if (btrfs_header_generation(leaf) > sk->max_transid) {
1988                 i = nritems;
1989                 goto advance_key;
1990         }
1991         found_transid = btrfs_header_generation(leaf);
1992
1993         for (i = slot; i < nritems; i++) {
1994                 item_off = btrfs_item_ptr_offset(leaf, i);
1995                 item_len = btrfs_item_size_nr(leaf, i);
1996
1997                 btrfs_item_key_to_cpu(leaf, key, i);
1998                 if (!key_in_sk(key, sk))
1999                         continue;
2000
2001                 if (sizeof(sh) + item_len > *buf_size) {
2002                         if (*num_found) {
2003                                 ret = 1;
2004                                 goto out;
2005                         }
2006
2007                         /*
2008                          * return one empty item back for v1, which does not
2009                          * handle -EOVERFLOW
2010                          */
2011
2012                         *buf_size = sizeof(sh) + item_len;
2013                         item_len = 0;
2014                         ret = -EOVERFLOW;
2015                 }
2016
2017                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2018                         ret = 1;
2019                         goto out;
2020                 }
2021
2022                 sh.objectid = key->objectid;
2023                 sh.offset = key->offset;
2024                 sh.type = key->type;
2025                 sh.len = item_len;
2026                 sh.transid = found_transid;
2027
2028                 /* copy search result header */
2029                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2030                         ret = -EFAULT;
2031                         goto out;
2032                 }
2033
2034                 *sk_offset += sizeof(sh);
2035
2036                 if (item_len) {
2037                         char __user *up = ubuf + *sk_offset;
2038                         /* copy the item */
2039                         if (read_extent_buffer_to_user(leaf, up,
2040                                                        item_off, item_len)) {
2041                                 ret = -EFAULT;
2042                                 goto out;
2043                         }
2044
2045                         *sk_offset += item_len;
2046                 }
2047                 (*num_found)++;
2048
2049                 if (ret) /* -EOVERFLOW from above */
2050                         goto out;
2051
2052                 if (*num_found >= sk->nr_items) {
2053                         ret = 1;
2054                         goto out;
2055                 }
2056         }
2057 advance_key:
2058         ret = 0;
2059         test.objectid = sk->max_objectid;
2060         test.type = sk->max_type;
2061         test.offset = sk->max_offset;
2062         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2063                 ret = 1;
2064         else if (key->offset < (u64)-1)
2065                 key->offset++;
2066         else if (key->type < (u8)-1) {
2067                 key->offset = 0;
2068                 key->type++;
2069         } else if (key->objectid < (u64)-1) {
2070                 key->offset = 0;
2071                 key->type = 0;
2072                 key->objectid++;
2073         } else
2074                 ret = 1;
2075 out:
2076         /*
2077          *  0: all items from this leaf copied, continue with next
2078          *  1: * more items can be copied, but unused buffer is too small
2079          *     * all items were found
2080          *     Either way, it will stops the loop which iterates to the next
2081          *     leaf
2082          *  -EOVERFLOW: item was to large for buffer
2083          *  -EFAULT: could not copy extent buffer back to userspace
2084          */
2085         return ret;
2086 }
2087
2088 static noinline int search_ioctl(struct inode *inode,
2089                                  struct btrfs_ioctl_search_key *sk,
2090                                  size_t *buf_size,
2091                                  char __user *ubuf)
2092 {
2093         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2094         struct btrfs_root *root;
2095         struct btrfs_key key;
2096         struct btrfs_path *path;
2097         int ret;
2098         int num_found = 0;
2099         unsigned long sk_offset = 0;
2100
2101         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2102                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2103                 return -EOVERFLOW;
2104         }
2105
2106         path = btrfs_alloc_path();
2107         if (!path)
2108                 return -ENOMEM;
2109
2110         if (sk->tree_id == 0) {
2111                 /* search the root of the inode that was passed */
2112                 root = BTRFS_I(inode)->root;
2113         } else {
2114                 key.objectid = sk->tree_id;
2115                 key.type = BTRFS_ROOT_ITEM_KEY;
2116                 key.offset = (u64)-1;
2117                 root = btrfs_read_fs_root_no_name(info, &key);
2118                 if (IS_ERR(root)) {
2119                         btrfs_free_path(path);
2120                         return -ENOENT;
2121                 }
2122         }
2123
2124         key.objectid = sk->min_objectid;
2125         key.type = sk->min_type;
2126         key.offset = sk->min_offset;
2127
2128         while (1) {
2129                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2130                 if (ret != 0) {
2131                         if (ret > 0)
2132                                 ret = 0;
2133                         goto err;
2134                 }
2135                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2136                                  &sk_offset, &num_found);
2137                 btrfs_release_path(path);
2138                 if (ret)
2139                         break;
2140
2141         }
2142         if (ret > 0)
2143                 ret = 0;
2144 err:
2145         sk->nr_items = num_found;
2146         btrfs_free_path(path);
2147         return ret;
2148 }
2149
2150 static noinline int btrfs_ioctl_tree_search(struct file *file,
2151                                            void __user *argp)
2152 {
2153         struct btrfs_ioctl_search_args __user *uargs;
2154         struct btrfs_ioctl_search_key sk;
2155         struct inode *inode;
2156         int ret;
2157         size_t buf_size;
2158
2159         if (!capable(CAP_SYS_ADMIN))
2160                 return -EPERM;
2161
2162         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2163
2164         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2165                 return -EFAULT;
2166
2167         buf_size = sizeof(uargs->buf);
2168
2169         inode = file_inode(file);
2170         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2171
2172         /*
2173          * In the origin implementation an overflow is handled by returning a
2174          * search header with a len of zero, so reset ret.
2175          */
2176         if (ret == -EOVERFLOW)
2177                 ret = 0;
2178
2179         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2180                 ret = -EFAULT;
2181         return ret;
2182 }
2183
2184 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2185                                                void __user *argp)
2186 {
2187         struct btrfs_ioctl_search_args_v2 __user *uarg;
2188         struct btrfs_ioctl_search_args_v2 args;
2189         struct inode *inode;
2190         int ret;
2191         size_t buf_size;
2192         const size_t buf_limit = SZ_16M;
2193
2194         if (!capable(CAP_SYS_ADMIN))
2195                 return -EPERM;
2196
2197         /* copy search header and buffer size */
2198         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2199         if (copy_from_user(&args, uarg, sizeof(args)))
2200                 return -EFAULT;
2201
2202         buf_size = args.buf_size;
2203
2204         if (buf_size < sizeof(struct btrfs_ioctl_search_header))
2205                 return -EOVERFLOW;
2206
2207         /* limit result size to 16MB */
2208         if (buf_size > buf_limit)
2209                 buf_size = buf_limit;
2210
2211         inode = file_inode(file);
2212         ret = search_ioctl(inode, &args.key, &buf_size,
2213                            (char *)(&uarg->buf[0]));
2214         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2215                 ret = -EFAULT;
2216         else if (ret == -EOVERFLOW &&
2217                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2218                 ret = -EFAULT;
2219
2220         return ret;
2221 }
2222
2223 /*
2224  * Search INODE_REFs to identify path name of 'dirid' directory
2225  * in a 'tree_id' tree. and sets path name to 'name'.
2226  */
2227 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2228                                 u64 tree_id, u64 dirid, char *name)
2229 {
2230         struct btrfs_root *root;
2231         struct btrfs_key key;
2232         char *ptr;
2233         int ret = -1;
2234         int slot;
2235         int len;
2236         int total_len = 0;
2237         struct btrfs_inode_ref *iref;
2238         struct extent_buffer *l;
2239         struct btrfs_path *path;
2240
2241         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2242                 name[0]='\0';
2243                 return 0;
2244         }
2245
2246         path = btrfs_alloc_path();
2247         if (!path)
2248                 return -ENOMEM;
2249
2250         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
2251
2252         key.objectid = tree_id;
2253         key.type = BTRFS_ROOT_ITEM_KEY;
2254         key.offset = (u64)-1;
2255         root = btrfs_read_fs_root_no_name(info, &key);
2256         if (IS_ERR(root)) {
2257                 btrfs_err(info, "could not find root %llu", tree_id);
2258                 ret = -ENOENT;
2259                 goto out;
2260         }
2261
2262         key.objectid = dirid;
2263         key.type = BTRFS_INODE_REF_KEY;
2264         key.offset = (u64)-1;
2265
2266         while (1) {
2267                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2268                 if (ret < 0)
2269                         goto out;
2270                 else if (ret > 0) {
2271                         ret = btrfs_previous_item(root, path, dirid,
2272                                                   BTRFS_INODE_REF_KEY);
2273                         if (ret < 0)
2274                                 goto out;
2275                         else if (ret > 0) {
2276                                 ret = -ENOENT;
2277                                 goto out;
2278                         }
2279                 }
2280
2281                 l = path->nodes[0];
2282                 slot = path->slots[0];
2283                 btrfs_item_key_to_cpu(l, &key, slot);
2284
2285                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2286                 len = btrfs_inode_ref_name_len(l, iref);
2287                 ptr -= len + 1;
2288                 total_len += len + 1;
2289                 if (ptr < name) {
2290                         ret = -ENAMETOOLONG;
2291                         goto out;
2292                 }
2293
2294                 *(ptr + len) = '/';
2295                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2296
2297                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2298                         break;
2299
2300                 btrfs_release_path(path);
2301                 key.objectid = key.offset;
2302                 key.offset = (u64)-1;
2303                 dirid = key.objectid;
2304         }
2305         memmove(name, ptr, total_len);
2306         name[total_len] = '\0';
2307         ret = 0;
2308 out:
2309         btrfs_free_path(path);
2310         return ret;
2311 }
2312
2313 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2314                                            void __user *argp)
2315 {
2316          struct btrfs_ioctl_ino_lookup_args *args;
2317          struct inode *inode;
2318         int ret = 0;
2319
2320         args = memdup_user(argp, sizeof(*args));
2321         if (IS_ERR(args))
2322                 return PTR_ERR(args);
2323
2324         inode = file_inode(file);
2325
2326         /*
2327          * Unprivileged query to obtain the containing subvolume root id. The
2328          * path is reset so it's consistent with btrfs_search_path_in_tree.
2329          */
2330         if (args->treeid == 0)
2331                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2332
2333         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2334                 args->name[0] = 0;
2335                 goto out;
2336         }
2337
2338         if (!capable(CAP_SYS_ADMIN)) {
2339                 ret = -EPERM;
2340                 goto out;
2341         }
2342
2343         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2344                                         args->treeid, args->objectid,
2345                                         args->name);
2346
2347 out:
2348         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2349                 ret = -EFAULT;
2350
2351         kfree(args);
2352         return ret;
2353 }
2354
2355 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2356                                              void __user *arg)
2357 {
2358         struct dentry *parent = file->f_path.dentry;
2359         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2360         struct dentry *dentry;
2361         struct inode *dir = d_inode(parent);
2362         struct inode *inode;
2363         struct btrfs_root *root = BTRFS_I(dir)->root;
2364         struct btrfs_root *dest = NULL;
2365         struct btrfs_ioctl_vol_args *vol_args;
2366         struct btrfs_trans_handle *trans;
2367         struct btrfs_block_rsv block_rsv;
2368         u64 root_flags;
2369         u64 qgroup_reserved;
2370         int namelen;
2371         int ret;
2372         int err = 0;
2373
2374         if (!S_ISDIR(dir->i_mode))
2375                 return -ENOTDIR;
2376
2377         vol_args = memdup_user(arg, sizeof(*vol_args));
2378         if (IS_ERR(vol_args))
2379                 return PTR_ERR(vol_args);
2380
2381         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2382         namelen = strlen(vol_args->name);
2383         if (strchr(vol_args->name, '/') ||
2384             strncmp(vol_args->name, "..", namelen) == 0) {
2385                 err = -EINVAL;
2386                 goto out;
2387         }
2388
2389         err = mnt_want_write_file(file);
2390         if (err)
2391                 goto out;
2392
2393
2394         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2395         if (err == -EINTR)
2396                 goto out_drop_write;
2397         dentry = lookup_one_len(vol_args->name, parent, namelen);
2398         if (IS_ERR(dentry)) {
2399                 err = PTR_ERR(dentry);
2400                 goto out_unlock_dir;
2401         }
2402
2403         if (d_really_is_negative(dentry)) {
2404                 err = -ENOENT;
2405                 goto out_dput;
2406         }
2407
2408         inode = d_inode(dentry);
2409         dest = BTRFS_I(inode)->root;
2410         if (!capable(CAP_SYS_ADMIN)) {
2411                 /*
2412                  * Regular user.  Only allow this with a special mount
2413                  * option, when the user has write+exec access to the
2414                  * subvol root, and when rmdir(2) would have been
2415                  * allowed.
2416                  *
2417                  * Note that this is _not_ check that the subvol is
2418                  * empty or doesn't contain data that we wouldn't
2419                  * otherwise be able to delete.
2420                  *
2421                  * Users who want to delete empty subvols should try
2422                  * rmdir(2).
2423                  */
2424                 err = -EPERM;
2425                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2426                         goto out_dput;
2427
2428                 /*
2429                  * Do not allow deletion if the parent dir is the same
2430                  * as the dir to be deleted.  That means the ioctl
2431                  * must be called on the dentry referencing the root
2432                  * of the subvol, not a random directory contained
2433                  * within it.
2434                  */
2435                 err = -EINVAL;
2436                 if (root == dest)
2437                         goto out_dput;
2438
2439                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2440                 if (err)
2441                         goto out_dput;
2442         }
2443
2444         /* check if subvolume may be deleted by a user */
2445         err = btrfs_may_delete(dir, dentry, 1);
2446         if (err)
2447                 goto out_dput;
2448
2449         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2450                 err = -EINVAL;
2451                 goto out_dput;
2452         }
2453
2454         inode_lock(inode);
2455
2456         /*
2457          * Don't allow to delete a subvolume with send in progress. This is
2458          * inside the i_mutex so the error handling that has to drop the bit
2459          * again is not run concurrently.
2460          */
2461         spin_lock(&dest->root_item_lock);
2462         root_flags = btrfs_root_flags(&dest->root_item);
2463         if (dest->send_in_progress == 0) {
2464                 btrfs_set_root_flags(&dest->root_item,
2465                                 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2466                 spin_unlock(&dest->root_item_lock);
2467         } else {
2468                 spin_unlock(&dest->root_item_lock);
2469                 btrfs_warn(fs_info,
2470                            "Attempt to delete subvolume %llu during send",
2471                            dest->root_key.objectid);
2472                 err = -EPERM;
2473                 goto out_unlock_inode;
2474         }
2475
2476         down_write(&fs_info->subvol_sem);
2477
2478         err = may_destroy_subvol(dest);
2479         if (err)
2480                 goto out_up_write;
2481
2482         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2483         /*
2484          * One for dir inode, two for dir entries, two for root
2485          * ref/backref.
2486          */
2487         err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2488                                                5, &qgroup_reserved, true);
2489         if (err)
2490                 goto out_up_write;
2491
2492         trans = btrfs_start_transaction(root, 0);
2493         if (IS_ERR(trans)) {
2494                 err = PTR_ERR(trans);
2495                 goto out_release;
2496         }
2497         trans->block_rsv = &block_rsv;
2498         trans->bytes_reserved = block_rsv.size;
2499
2500         btrfs_record_snapshot_destroy(trans, dir);
2501
2502         ret = btrfs_unlink_subvol(trans, root, dir,
2503                                 dest->root_key.objectid,
2504                                 dentry->d_name.name,
2505                                 dentry->d_name.len);
2506         if (ret) {
2507                 err = ret;
2508                 btrfs_abort_transaction(trans, ret);
2509                 goto out_end_trans;
2510         }
2511
2512         btrfs_record_root_in_trans(trans, dest);
2513
2514         memset(&dest->root_item.drop_progress, 0,
2515                 sizeof(dest->root_item.drop_progress));
2516         dest->root_item.drop_level = 0;
2517         btrfs_set_root_refs(&dest->root_item, 0);
2518
2519         if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2520                 ret = btrfs_insert_orphan_item(trans,
2521                                         fs_info->tree_root,
2522                                         dest->root_key.objectid);
2523                 if (ret) {
2524                         btrfs_abort_transaction(trans, ret);
2525                         err = ret;
2526                         goto out_end_trans;
2527                 }
2528         }
2529
2530         ret = btrfs_uuid_tree_rem(trans, fs_info, dest->root_item.uuid,
2531                                   BTRFS_UUID_KEY_SUBVOL,
2532                                   dest->root_key.objectid);
2533         if (ret && ret != -ENOENT) {
2534                 btrfs_abort_transaction(trans, ret);
2535                 err = ret;
2536                 goto out_end_trans;
2537         }
2538         if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2539                 ret = btrfs_uuid_tree_rem(trans, fs_info,
2540                                           dest->root_item.received_uuid,
2541                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2542                                           dest->root_key.objectid);
2543                 if (ret && ret != -ENOENT) {
2544                         btrfs_abort_transaction(trans, ret);
2545                         err = ret;
2546                         goto out_end_trans;
2547                 }
2548         }
2549
2550 out_end_trans:
2551         trans->block_rsv = NULL;
2552         trans->bytes_reserved = 0;
2553         ret = btrfs_end_transaction(trans);
2554         if (ret && !err)
2555                 err = ret;
2556         inode->i_flags |= S_DEAD;
2557 out_release:
2558         btrfs_subvolume_release_metadata(fs_info, &block_rsv, qgroup_reserved);
2559 out_up_write:
2560         up_write(&fs_info->subvol_sem);
2561         if (err) {
2562                 spin_lock(&dest->root_item_lock);
2563                 root_flags = btrfs_root_flags(&dest->root_item);
2564                 btrfs_set_root_flags(&dest->root_item,
2565                                 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2566                 spin_unlock(&dest->root_item_lock);
2567         }
2568 out_unlock_inode:
2569         inode_unlock(inode);
2570         if (!err) {
2571                 d_invalidate(dentry);
2572                 btrfs_invalidate_inodes(dest);
2573                 d_delete(dentry);
2574                 ASSERT(dest->send_in_progress == 0);
2575
2576                 /* the last ref */
2577                 if (dest->ino_cache_inode) {
2578                         iput(dest->ino_cache_inode);
2579                         dest->ino_cache_inode = NULL;
2580                 }
2581         }
2582 out_dput:
2583         dput(dentry);
2584 out_unlock_dir:
2585         inode_unlock(dir);
2586 out_drop_write:
2587         mnt_drop_write_file(file);
2588 out:
2589         kfree(vol_args);
2590         return err;
2591 }
2592
2593 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2594 {
2595         struct inode *inode = file_inode(file);
2596         struct btrfs_root *root = BTRFS_I(inode)->root;
2597         struct btrfs_ioctl_defrag_range_args *range;
2598         int ret;
2599
2600         ret = mnt_want_write_file(file);
2601         if (ret)
2602                 return ret;
2603
2604         if (btrfs_root_readonly(root)) {
2605                 ret = -EROFS;
2606                 goto out;
2607         }
2608
2609         switch (inode->i_mode & S_IFMT) {
2610         case S_IFDIR:
2611                 if (!capable(CAP_SYS_ADMIN)) {
2612                         ret = -EPERM;
2613                         goto out;
2614                 }
2615                 ret = btrfs_defrag_root(root);
2616                 if (ret)
2617                         goto out;
2618                 ret = btrfs_defrag_root(root->fs_info->extent_root);
2619                 break;
2620         case S_IFREG:
2621                 if (!(file->f_mode & FMODE_WRITE)) {
2622                         ret = -EINVAL;
2623                         goto out;
2624                 }
2625
2626                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2627                 if (!range) {
2628                         ret = -ENOMEM;
2629                         goto out;
2630                 }
2631
2632                 if (argp) {
2633                         if (copy_from_user(range, argp,
2634                                            sizeof(*range))) {
2635                                 ret = -EFAULT;
2636                                 kfree(range);
2637                                 goto out;
2638                         }
2639                         /* compression requires us to start the IO */
2640                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2641                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2642                                 range->extent_thresh = (u32)-1;
2643                         }
2644                 } else {
2645                         /* the rest are all set to zero by kzalloc */
2646                         range->len = (u64)-1;
2647                 }
2648                 ret = btrfs_defrag_file(file_inode(file), file,
2649                                         range, 0, 0);
2650                 if (ret > 0)
2651                         ret = 0;
2652                 kfree(range);
2653                 break;
2654         default:
2655                 ret = -EINVAL;
2656         }
2657 out:
2658         mnt_drop_write_file(file);
2659         return ret;
2660 }
2661
2662 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2663 {
2664         struct btrfs_ioctl_vol_args *vol_args;
2665         int ret;
2666
2667         if (!capable(CAP_SYS_ADMIN))
2668                 return -EPERM;
2669
2670         if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1))
2671                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2672
2673         mutex_lock(&fs_info->volume_mutex);
2674         vol_args = memdup_user(arg, sizeof(*vol_args));
2675         if (IS_ERR(vol_args)) {
2676                 ret = PTR_ERR(vol_args);
2677                 goto out;
2678         }
2679
2680         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2681         ret = btrfs_init_new_device(fs_info, vol_args->name);
2682
2683         if (!ret)
2684                 btrfs_info(fs_info, "disk added %s", vol_args->name);
2685
2686         kfree(vol_args);
2687 out:
2688         mutex_unlock(&fs_info->volume_mutex);
2689         atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
2690         return ret;
2691 }
2692
2693 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2694 {
2695         struct inode *inode = file_inode(file);
2696         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2697         struct btrfs_ioctl_vol_args_v2 *vol_args;
2698         int ret;
2699
2700         if (!capable(CAP_SYS_ADMIN))
2701                 return -EPERM;
2702
2703         ret = mnt_want_write_file(file);
2704         if (ret)
2705                 return ret;
2706
2707         vol_args = memdup_user(arg, sizeof(*vol_args));
2708         if (IS_ERR(vol_args)) {
2709                 ret = PTR_ERR(vol_args);
2710                 goto err_drop;
2711         }
2712
2713         /* Check for compatibility reject unknown flags */
2714         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED)
2715                 return -EOPNOTSUPP;
2716
2717         if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
2718                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2719                 goto out;
2720         }
2721
2722         mutex_lock(&fs_info->volume_mutex);
2723         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2724                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
2725         } else {
2726                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
2727                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2728         }
2729         mutex_unlock(&fs_info->volume_mutex);
2730         atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
2731
2732         if (!ret) {
2733                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2734                         btrfs_info(fs_info, "device deleted: id %llu",
2735                                         vol_args->devid);
2736                 else
2737                         btrfs_info(fs_info, "device deleted: %s",
2738                                         vol_args->name);
2739         }
2740 out:
2741         kfree(vol_args);
2742 err_drop:
2743         mnt_drop_write_file(file);
2744         return ret;
2745 }
2746
2747 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2748 {
2749         struct inode *inode = file_inode(file);
2750         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2751         struct btrfs_ioctl_vol_args *vol_args;
2752         int ret;
2753
2754         if (!capable(CAP_SYS_ADMIN))
2755                 return -EPERM;
2756
2757         ret = mnt_want_write_file(file);
2758         if (ret)
2759                 return ret;
2760
2761         if (atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
2762                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2763                 goto out_drop_write;
2764         }
2765
2766         vol_args = memdup_user(arg, sizeof(*vol_args));
2767         if (IS_ERR(vol_args)) {
2768                 ret = PTR_ERR(vol_args);
2769                 goto out;
2770         }
2771
2772         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2773         mutex_lock(&fs_info->volume_mutex);
2774         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2775         mutex_unlock(&fs_info->volume_mutex);
2776
2777         if (!ret)
2778                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
2779         kfree(vol_args);
2780 out:
2781         atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
2782 out_drop_write:
2783         mnt_drop_write_file(file);
2784
2785         return ret;
2786 }
2787
2788 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
2789                                 void __user *arg)
2790 {
2791         struct btrfs_ioctl_fs_info_args *fi_args;
2792         struct btrfs_device *device;
2793         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2794         int ret = 0;
2795
2796         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2797         if (!fi_args)
2798                 return -ENOMEM;
2799
2800         mutex_lock(&fs_devices->device_list_mutex);
2801         fi_args->num_devices = fs_devices->num_devices;
2802         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
2803
2804         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2805                 if (device->devid > fi_args->max_id)
2806                         fi_args->max_id = device->devid;
2807         }
2808         mutex_unlock(&fs_devices->device_list_mutex);
2809
2810         fi_args->nodesize = fs_info->super_copy->nodesize;
2811         fi_args->sectorsize = fs_info->super_copy->sectorsize;
2812         fi_args->clone_alignment = fs_info->super_copy->sectorsize;
2813
2814         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2815                 ret = -EFAULT;
2816
2817         kfree(fi_args);
2818         return ret;
2819 }
2820
2821 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
2822                                  void __user *arg)
2823 {
2824         struct btrfs_ioctl_dev_info_args *di_args;
2825         struct btrfs_device *dev;
2826         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2827         int ret = 0;
2828         char *s_uuid = NULL;
2829
2830         di_args = memdup_user(arg, sizeof(*di_args));
2831         if (IS_ERR(di_args))
2832                 return PTR_ERR(di_args);
2833
2834         if (!btrfs_is_empty_uuid(di_args->uuid))
2835                 s_uuid = di_args->uuid;
2836
2837         mutex_lock(&fs_devices->device_list_mutex);
2838         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
2839
2840         if (!dev) {
2841                 ret = -ENODEV;
2842                 goto out;
2843         }
2844
2845         di_args->devid = dev->devid;
2846         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2847         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2848         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2849         if (dev->name) {
2850                 struct rcu_string *name;
2851
2852                 rcu_read_lock();
2853                 name = rcu_dereference(dev->name);
2854                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2855                 rcu_read_unlock();
2856                 di_args->path[sizeof(di_args->path) - 1] = 0;
2857         } else {
2858                 di_args->path[0] = '\0';
2859         }
2860
2861 out:
2862         mutex_unlock(&fs_devices->device_list_mutex);
2863         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2864                 ret = -EFAULT;
2865
2866         kfree(di_args);
2867         return ret;
2868 }
2869
2870 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
2871 {
2872         struct page *page;
2873
2874         page = grab_cache_page(inode->i_mapping, index);
2875         if (!page)
2876                 return ERR_PTR(-ENOMEM);
2877
2878         if (!PageUptodate(page)) {
2879                 int ret;
2880
2881                 ret = btrfs_readpage(NULL, page);
2882                 if (ret)
2883                         return ERR_PTR(ret);
2884                 lock_page(page);
2885                 if (!PageUptodate(page)) {
2886                         unlock_page(page);
2887                         put_page(page);
2888                         return ERR_PTR(-EIO);
2889                 }
2890                 if (page->mapping != inode->i_mapping) {
2891                         unlock_page(page);
2892                         put_page(page);
2893                         return ERR_PTR(-EAGAIN);
2894                 }
2895         }
2896
2897         return page;
2898 }
2899
2900 static int gather_extent_pages(struct inode *inode, struct page **pages,
2901                                int num_pages, u64 off)
2902 {
2903         int i;
2904         pgoff_t index = off >> PAGE_SHIFT;
2905
2906         for (i = 0; i < num_pages; i++) {
2907 again:
2908                 pages[i] = extent_same_get_page(inode, index + i);
2909                 if (IS_ERR(pages[i])) {
2910                         int err = PTR_ERR(pages[i]);
2911
2912                         if (err == -EAGAIN)
2913                                 goto again;
2914                         pages[i] = NULL;
2915                         return err;
2916                 }
2917         }
2918         return 0;
2919 }
2920
2921 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
2922                              bool retry_range_locking)
2923 {
2924         /*
2925          * Do any pending delalloc/csum calculations on inode, one way or
2926          * another, and lock file content.
2927          * The locking order is:
2928          *
2929          *   1) pages
2930          *   2) range in the inode's io tree
2931          */
2932         while (1) {
2933                 struct btrfs_ordered_extent *ordered;
2934                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2935                 ordered = btrfs_lookup_first_ordered_extent(inode,
2936                                                             off + len - 1);
2937                 if ((!ordered ||
2938                      ordered->file_offset + ordered->len <= off ||
2939                      ordered->file_offset >= off + len) &&
2940                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2941                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2942                         if (ordered)
2943                                 btrfs_put_ordered_extent(ordered);
2944                         break;
2945                 }
2946                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2947                 if (ordered)
2948                         btrfs_put_ordered_extent(ordered);
2949                 if (!retry_range_locking)
2950                         return -EAGAIN;
2951                 btrfs_wait_ordered_range(inode, off, len);
2952         }
2953         return 0;
2954 }
2955
2956 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2957 {
2958         inode_unlock(inode1);
2959         inode_unlock(inode2);
2960 }
2961
2962 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2963 {
2964         if (inode1 < inode2)
2965                 swap(inode1, inode2);
2966
2967         inode_lock_nested(inode1, I_MUTEX_PARENT);
2968         inode_lock_nested(inode2, I_MUTEX_CHILD);
2969 }
2970
2971 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2972                                       struct inode *inode2, u64 loff2, u64 len)
2973 {
2974         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2975         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2976 }
2977
2978 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2979                                     struct inode *inode2, u64 loff2, u64 len,
2980                                     bool retry_range_locking)
2981 {
2982         int ret;
2983
2984         if (inode1 < inode2) {
2985                 swap(inode1, inode2);
2986                 swap(loff1, loff2);
2987         }
2988         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
2989         if (ret)
2990                 return ret;
2991         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
2992         if (ret)
2993                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
2994                               loff1 + len - 1);
2995         return ret;
2996 }
2997
2998 struct cmp_pages {
2999         int             num_pages;
3000         struct page     **src_pages;
3001         struct page     **dst_pages;
3002 };
3003
3004 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
3005 {
3006         int i;
3007         struct page *pg;
3008
3009         for (i = 0; i < cmp->num_pages; i++) {
3010                 pg = cmp->src_pages[i];
3011                 if (pg) {
3012                         unlock_page(pg);
3013                         put_page(pg);
3014                 }
3015                 pg = cmp->dst_pages[i];
3016                 if (pg) {
3017                         unlock_page(pg);
3018                         put_page(pg);
3019                 }
3020         }
3021         kfree(cmp->src_pages);
3022         kfree(cmp->dst_pages);
3023 }
3024
3025 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
3026                                   struct inode *dst, u64 dst_loff,
3027                                   u64 len, struct cmp_pages *cmp)
3028 {
3029         int ret;
3030         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
3031         struct page **src_pgarr, **dst_pgarr;
3032
3033         /*
3034          * We must gather up all the pages before we initiate our
3035          * extent locking. We use an array for the page pointers. Size
3036          * of the array is bounded by len, which is in turn bounded by
3037          * BTRFS_MAX_DEDUPE_LEN.
3038          */
3039         src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3040         dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3041         if (!src_pgarr || !dst_pgarr) {
3042                 kfree(src_pgarr);
3043                 kfree(dst_pgarr);
3044                 return -ENOMEM;
3045         }
3046         cmp->num_pages = num_pages;
3047         cmp->src_pages = src_pgarr;
3048         cmp->dst_pages = dst_pgarr;
3049
3050         ret = gather_extent_pages(src, cmp->src_pages, cmp->num_pages, loff);
3051         if (ret)
3052                 goto out;
3053
3054         ret = gather_extent_pages(dst, cmp->dst_pages, cmp->num_pages, dst_loff);
3055
3056 out:
3057         if (ret)
3058                 btrfs_cmp_data_free(cmp);
3059         return 0;
3060 }
3061
3062 static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
3063                           u64 dst_loff, u64 len, struct cmp_pages *cmp)
3064 {
3065         int ret = 0;
3066         int i;
3067         struct page *src_page, *dst_page;
3068         unsigned int cmp_len = PAGE_SIZE;
3069         void *addr, *dst_addr;
3070
3071         i = 0;
3072         while (len) {
3073                 if (len < PAGE_SIZE)
3074                         cmp_len = len;
3075
3076                 BUG_ON(i >= cmp->num_pages);
3077
3078                 src_page = cmp->src_pages[i];
3079                 dst_page = cmp->dst_pages[i];
3080                 ASSERT(PageLocked(src_page));
3081                 ASSERT(PageLocked(dst_page));
3082
3083                 addr = kmap_atomic(src_page);
3084                 dst_addr = kmap_atomic(dst_page);
3085
3086                 flush_dcache_page(src_page);
3087                 flush_dcache_page(dst_page);
3088
3089                 if (memcmp(addr, dst_addr, cmp_len))
3090                         ret = -EBADE;
3091
3092                 kunmap_atomic(addr);
3093                 kunmap_atomic(dst_addr);
3094
3095                 if (ret)
3096                         break;
3097
3098                 len -= cmp_len;
3099                 i++;
3100         }
3101
3102         return ret;
3103 }
3104
3105 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3106                                      u64 olen)
3107 {
3108         u64 len = *plen;
3109         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3110
3111         if (off + olen > inode->i_size || off + olen < off)
3112                 return -EINVAL;
3113
3114         /* if we extend to eof, continue to block boundary */
3115         if (off + len == inode->i_size)
3116                 *plen = len = ALIGN(inode->i_size, bs) - off;
3117
3118         /* Check that we are block aligned - btrfs_clone() requires this */
3119         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3120                 return -EINVAL;
3121
3122         return 0;
3123 }
3124
3125 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3126                              struct inode *dst, u64 dst_loff)
3127 {
3128         int ret;
3129         u64 len = olen;
3130         struct cmp_pages cmp;
3131         int same_inode = 0;
3132         u64 same_lock_start = 0;
3133         u64 same_lock_len = 0;
3134
3135         if (src == dst)
3136                 same_inode = 1;
3137
3138         if (len == 0)
3139                 return 0;
3140
3141         if (same_inode) {
3142                 inode_lock(src);
3143
3144                 ret = extent_same_check_offsets(src, loff, &len, olen);
3145                 if (ret)
3146                         goto out_unlock;
3147                 ret = extent_same_check_offsets(src, dst_loff, &len, olen);
3148                 if (ret)
3149                         goto out_unlock;
3150
3151                 /*
3152                  * Single inode case wants the same checks, except we
3153                  * don't want our length pushed out past i_size as
3154                  * comparing that data range makes no sense.
3155                  *
3156                  * extent_same_check_offsets() will do this for an
3157                  * unaligned length at i_size, so catch it here and
3158                  * reject the request.
3159                  *
3160                  * This effectively means we require aligned extents
3161                  * for the single-inode case, whereas the other cases
3162                  * allow an unaligned length so long as it ends at
3163                  * i_size.
3164                  */
3165                 if (len != olen) {
3166                         ret = -EINVAL;
3167                         goto out_unlock;
3168                 }
3169
3170                 /* Check for overlapping ranges */
3171                 if (dst_loff + len > loff && dst_loff < loff + len) {
3172                         ret = -EINVAL;
3173                         goto out_unlock;
3174                 }
3175
3176                 same_lock_start = min_t(u64, loff, dst_loff);
3177                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3178         } else {
3179                 btrfs_double_inode_lock(src, dst);
3180
3181                 ret = extent_same_check_offsets(src, loff, &len, olen);
3182                 if (ret)
3183                         goto out_unlock;
3184
3185                 ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3186                 if (ret)
3187                         goto out_unlock;
3188         }
3189
3190         /* don't make the dst file partly checksummed */
3191         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3192             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3193                 ret = -EINVAL;
3194                 goto out_unlock;
3195         }
3196
3197 again:
3198         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
3199         if (ret)
3200                 goto out_unlock;
3201
3202         if (same_inode)
3203                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3204                                         false);
3205         else
3206                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3207                                                false);
3208         /*
3209          * If one of the inodes has dirty pages in the respective range or
3210          * ordered extents, we need to flush dellaloc and wait for all ordered
3211          * extents in the range. We must unlock the pages and the ranges in the
3212          * io trees to avoid deadlocks when flushing delalloc (requires locking
3213          * pages) and when waiting for ordered extents to complete (they require
3214          * range locking).
3215          */
3216         if (ret == -EAGAIN) {
3217                 /*
3218                  * Ranges in the io trees already unlocked. Now unlock all
3219                  * pages before waiting for all IO to complete.
3220                  */
3221                 btrfs_cmp_data_free(&cmp);
3222                 if (same_inode) {
3223                         btrfs_wait_ordered_range(src, same_lock_start,
3224                                                  same_lock_len);
3225                 } else {
3226                         btrfs_wait_ordered_range(src, loff, len);
3227                         btrfs_wait_ordered_range(dst, dst_loff, len);
3228                 }
3229                 goto again;
3230         }
3231         ASSERT(ret == 0);
3232         if (WARN_ON(ret)) {
3233                 /* ranges in the io trees already unlocked */
3234                 btrfs_cmp_data_free(&cmp);
3235                 return ret;
3236         }
3237
3238         /* pass original length for comparison so we stay within i_size */
3239         ret = btrfs_cmp_data(src, loff, dst, dst_loff, olen, &cmp);
3240         if (ret == 0)
3241                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3242
3243         if (same_inode)
3244                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3245                               same_lock_start + same_lock_len - 1);
3246         else
3247                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3248
3249         btrfs_cmp_data_free(&cmp);
3250 out_unlock:
3251         if (same_inode)
3252                 inode_unlock(src);
3253         else
3254                 btrfs_double_inode_unlock(src, dst);
3255
3256         return ret;
3257 }
3258
3259 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3260
3261 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3262                                 struct file *dst_file, u64 dst_loff)
3263 {
3264         struct inode *src = file_inode(src_file);
3265         struct inode *dst = file_inode(dst_file);
3266         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3267         ssize_t res;
3268
3269         if (olen > BTRFS_MAX_DEDUPE_LEN)
3270                 olen = BTRFS_MAX_DEDUPE_LEN;
3271
3272         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3273                 /*
3274                  * Btrfs does not support blocksize < page_size. As a
3275                  * result, btrfs_cmp_data() won't correctly handle
3276                  * this situation without an update.
3277                  */
3278                 return -EINVAL;
3279         }
3280
3281         res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3282         if (res)
3283                 return res;
3284         return olen;
3285 }
3286
3287 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3288                                      struct inode *inode,
3289                                      u64 endoff,
3290                                      const u64 destoff,
3291                                      const u64 olen,
3292                                      int no_time_update)
3293 {
3294         struct btrfs_root *root = BTRFS_I(inode)->root;
3295         int ret;
3296
3297         inode_inc_iversion(inode);
3298         if (!no_time_update)
3299                 inode->i_mtime = inode->i_ctime = current_time(inode);
3300         /*
3301          * We round up to the block size at eof when determining which
3302          * extents to clone above, but shouldn't round up the file size.
3303          */
3304         if (endoff > destoff + olen)
3305                 endoff = destoff + olen;
3306         if (endoff > inode->i_size)
3307                 btrfs_i_size_write(inode, endoff);
3308
3309         ret = btrfs_update_inode(trans, root, inode);
3310         if (ret) {
3311                 btrfs_abort_transaction(trans, ret);
3312                 btrfs_end_transaction(trans);
3313                 goto out;
3314         }
3315         ret = btrfs_end_transaction(trans);
3316 out:
3317         return ret;
3318 }
3319
3320 static void clone_update_extent_map(struct inode *inode,
3321                                     const struct btrfs_trans_handle *trans,
3322                                     const struct btrfs_path *path,
3323                                     const u64 hole_offset,
3324                                     const u64 hole_len)
3325 {
3326         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3327         struct extent_map *em;
3328         int ret;
3329
3330         em = alloc_extent_map();
3331         if (!em) {
3332                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3333                         &BTRFS_I(inode)->runtime_flags);
3334                 return;
3335         }
3336
3337         if (path) {
3338                 struct btrfs_file_extent_item *fi;
3339
3340                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3341                                     struct btrfs_file_extent_item);
3342                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3343                 em->generation = -1;
3344                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3345                     BTRFS_FILE_EXTENT_INLINE)
3346                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3347                                 &BTRFS_I(inode)->runtime_flags);
3348         } else {
3349                 em->start = hole_offset;
3350                 em->len = hole_len;
3351                 em->ram_bytes = em->len;
3352                 em->orig_start = hole_offset;
3353                 em->block_start = EXTENT_MAP_HOLE;
3354                 em->block_len = 0;
3355                 em->orig_block_len = 0;
3356                 em->compress_type = BTRFS_COMPRESS_NONE;
3357                 em->generation = trans->transid;
3358         }
3359
3360         while (1) {
3361                 write_lock(&em_tree->lock);
3362                 ret = add_extent_mapping(em_tree, em, 1);
3363                 write_unlock(&em_tree->lock);
3364                 if (ret != -EEXIST) {
3365                         free_extent_map(em);
3366                         break;
3367                 }
3368                 btrfs_drop_extent_cache(inode, em->start,
3369                                         em->start + em->len - 1, 0);
3370         }
3371
3372         if (ret)
3373                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3374                         &BTRFS_I(inode)->runtime_flags);
3375 }
3376
3377 /*
3378  * Make sure we do not end up inserting an inline extent into a file that has
3379  * already other (non-inline) extents. If a file has an inline extent it can
3380  * not have any other extents and the (single) inline extent must start at the
3381  * file offset 0. Failing to respect these rules will lead to file corruption,
3382  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3383  *
3384  * We can have extents that have been already written to disk or we can have
3385  * dirty ranges still in delalloc, in which case the extent maps and items are
3386  * created only when we run delalloc, and the delalloc ranges might fall outside
3387  * the range we are currently locking in the inode's io tree. So we check the
3388  * inode's i_size because of that (i_size updates are done while holding the
3389  * i_mutex, which we are holding here).
3390  * We also check to see if the inode has a size not greater than "datal" but has
3391  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3392  * protected against such concurrent fallocate calls by the i_mutex).
3393  *
3394  * If the file has no extents but a size greater than datal, do not allow the
3395  * copy because we would need turn the inline extent into a non-inline one (even
3396  * with NO_HOLES enabled). If we find our destination inode only has one inline
3397  * extent, just overwrite it with the source inline extent if its size is less
3398  * than the source extent's size, or we could copy the source inline extent's
3399  * data into the destination inode's inline extent if the later is greater then
3400  * the former.
3401  */
3402 static int clone_copy_inline_extent(struct inode *src,
3403                                     struct inode *dst,
3404                                     struct btrfs_trans_handle *trans,
3405                                     struct btrfs_path *path,
3406                                     struct btrfs_key *new_key,
3407                                     const u64 drop_start,
3408                                     const u64 datal,
3409                                     const u64 skip,
3410                                     const u64 size,
3411                                     char *inline_data)
3412 {
3413         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3414         struct btrfs_root *root = BTRFS_I(dst)->root;
3415         const u64 aligned_end = ALIGN(new_key->offset + datal,
3416                                       fs_info->sectorsize);
3417         int ret;
3418         struct btrfs_key key;
3419
3420         if (new_key->offset > 0)
3421                 return -EOPNOTSUPP;
3422
3423         key.objectid = btrfs_ino(dst);
3424         key.type = BTRFS_EXTENT_DATA_KEY;
3425         key.offset = 0;
3426         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3427         if (ret < 0) {
3428                 return ret;
3429         } else if (ret > 0) {
3430                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3431                         ret = btrfs_next_leaf(root, path);
3432                         if (ret < 0)
3433                                 return ret;
3434                         else if (ret > 0)
3435                                 goto copy_inline_extent;
3436                 }
3437                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3438                 if (key.objectid == btrfs_ino(dst) &&
3439                     key.type == BTRFS_EXTENT_DATA_KEY) {
3440                         ASSERT(key.offset > 0);
3441                         return -EOPNOTSUPP;
3442                 }
3443         } else if (i_size_read(dst) <= datal) {
3444                 struct btrfs_file_extent_item *ei;
3445                 u64 ext_len;
3446
3447                 /*
3448                  * If the file size is <= datal, make sure there are no other
3449                  * extents following (can happen do to an fallocate call with
3450                  * the flag FALLOC_FL_KEEP_SIZE).
3451                  */
3452                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3453                                     struct btrfs_file_extent_item);
3454                 /*
3455                  * If it's an inline extent, it can not have other extents
3456                  * following it.
3457                  */
3458                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3459                     BTRFS_FILE_EXTENT_INLINE)
3460                         goto copy_inline_extent;
3461
3462                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3463                 if (ext_len > aligned_end)
3464                         return -EOPNOTSUPP;
3465
3466                 ret = btrfs_next_item(root, path);
3467                 if (ret < 0) {
3468                         return ret;
3469                 } else if (ret == 0) {
3470                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3471                                               path->slots[0]);
3472                         if (key.objectid == btrfs_ino(dst) &&
3473                             key.type == BTRFS_EXTENT_DATA_KEY)
3474                                 return -EOPNOTSUPP;
3475                 }
3476         }
3477
3478 copy_inline_extent:
3479         /*
3480          * We have no extent items, or we have an extent at offset 0 which may
3481          * or may not be inlined. All these cases are dealt the same way.
3482          */
3483         if (i_size_read(dst) > datal) {
3484                 /*
3485                  * If the destination inode has an inline extent...
3486                  * This would require copying the data from the source inline
3487                  * extent into the beginning of the destination's inline extent.
3488                  * But this is really complex, both extents can be compressed
3489                  * or just one of them, which would require decompressing and
3490                  * re-compressing data (which could increase the new compressed
3491                  * size, not allowing the compressed data to fit anymore in an
3492                  * inline extent).
3493                  * So just don't support this case for now (it should be rare,
3494                  * we are not really saving space when cloning inline extents).
3495                  */
3496                 return -EOPNOTSUPP;
3497         }
3498
3499         btrfs_release_path(path);
3500         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3501         if (ret)
3502                 return ret;
3503         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3504         if (ret)
3505                 return ret;
3506
3507         if (skip) {
3508                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3509
3510                 memmove(inline_data + start, inline_data + start + skip, datal);
3511         }
3512
3513         write_extent_buffer(path->nodes[0], inline_data,
3514                             btrfs_item_ptr_offset(path->nodes[0],
3515                                                   path->slots[0]),
3516                             size);
3517         inode_add_bytes(dst, datal);
3518
3519         return 0;
3520 }
3521
3522 /**
3523  * btrfs_clone() - clone a range from inode file to another
3524  *
3525  * @src: Inode to clone from
3526  * @inode: Inode to clone to
3527  * @off: Offset within source to start clone from
3528  * @olen: Original length, passed by user, of range to clone
3529  * @olen_aligned: Block-aligned value of olen
3530  * @destoff: Offset within @inode to start clone
3531  * @no_time_update: Whether to update mtime/ctime on the target inode
3532  */
3533 static int btrfs_clone(struct inode *src, struct inode *inode,
3534                        const u64 off, const u64 olen, const u64 olen_aligned,
3535                        const u64 destoff, int no_time_update)
3536 {
3537         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3538         struct btrfs_root *root = BTRFS_I(inode)->root;
3539         struct btrfs_path *path = NULL;
3540         struct extent_buffer *leaf;
3541         struct btrfs_trans_handle *trans;
3542         char *buf = NULL;
3543         struct btrfs_key key;
3544         u32 nritems;
3545         int slot;
3546         int ret;
3547         const u64 len = olen_aligned;
3548         u64 last_dest_end = destoff;
3549
3550         ret = -ENOMEM;
3551         buf = kmalloc(fs_info->nodesize, GFP_KERNEL | __GFP_NOWARN);
3552         if (!buf) {
3553                 buf = vmalloc(fs_info->nodesize);
3554                 if (!buf)
3555                         return ret;
3556         }
3557
3558         path = btrfs_alloc_path();
3559         if (!path) {
3560                 kvfree(buf);
3561                 return ret;
3562         }
3563
3564         path->reada = READA_FORWARD;
3565         /* clone data */
3566         key.objectid = btrfs_ino(src);
3567         key.type = BTRFS_EXTENT_DATA_KEY;
3568         key.offset = off;
3569
3570         while (1) {
3571                 u64 next_key_min_offset = key.offset + 1;
3572
3573                 /*
3574                  * note the key will change type as we walk through the
3575                  * tree.
3576                  */
3577                 path->leave_spinning = 1;
3578                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3579                                 0, 0);
3580                 if (ret < 0)
3581                         goto out;
3582                 /*
3583                  * First search, if no extent item that starts at offset off was
3584                  * found but the previous item is an extent item, it's possible
3585                  * it might overlap our target range, therefore process it.
3586                  */
3587                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3588                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3589                                               path->slots[0] - 1);
3590                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3591                                 path->slots[0]--;
3592                 }
3593
3594                 nritems = btrfs_header_nritems(path->nodes[0]);
3595 process_slot:
3596                 if (path->slots[0] >= nritems) {
3597                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3598                         if (ret < 0)
3599                                 goto out;
3600                         if (ret > 0)
3601                                 break;
3602                         nritems = btrfs_header_nritems(path->nodes[0]);
3603                 }
3604                 leaf = path->nodes[0];
3605                 slot = path->slots[0];
3606
3607                 btrfs_item_key_to_cpu(leaf, &key, slot);
3608                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3609                     key.objectid != btrfs_ino(src))
3610                         break;
3611
3612                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3613                         struct btrfs_file_extent_item *extent;
3614                         int type;
3615                         u32 size;
3616                         struct btrfs_key new_key;
3617                         u64 disko = 0, diskl = 0;
3618                         u64 datao = 0, datal = 0;
3619                         u8 comp;
3620                         u64 drop_start;
3621
3622                         extent = btrfs_item_ptr(leaf, slot,
3623                                                 struct btrfs_file_extent_item);
3624                         comp = btrfs_file_extent_compression(leaf, extent);
3625                         type = btrfs_file_extent_type(leaf, extent);
3626                         if (type == BTRFS_FILE_EXTENT_REG ||
3627                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3628                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3629                                                                       extent);
3630                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3631                                                                  extent);
3632                                 datao = btrfs_file_extent_offset(leaf, extent);
3633                                 datal = btrfs_file_extent_num_bytes(leaf,
3634                                                                     extent);
3635                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3636                                 /* take upper bound, may be compressed */
3637                                 datal = btrfs_file_extent_ram_bytes(leaf,
3638                                                                     extent);
3639                         }
3640
3641                         /*
3642                          * The first search might have left us at an extent
3643                          * item that ends before our target range's start, can
3644                          * happen if we have holes and NO_HOLES feature enabled.
3645                          */
3646                         if (key.offset + datal <= off) {
3647                                 path->slots[0]++;
3648                                 goto process_slot;
3649                         } else if (key.offset >= off + len) {
3650                                 break;
3651                         }
3652                         next_key_min_offset = key.offset + datal;
3653                         size = btrfs_item_size_nr(leaf, slot);
3654                         read_extent_buffer(leaf, buf,
3655                                            btrfs_item_ptr_offset(leaf, slot),
3656                                            size);
3657
3658                         btrfs_release_path(path);
3659                         path->leave_spinning = 0;
3660
3661                         memcpy(&new_key, &key, sizeof(new_key));
3662                         new_key.objectid = btrfs_ino(inode);
3663                         if (off <= key.offset)
3664                                 new_key.offset = key.offset + destoff - off;
3665                         else
3666                                 new_key.offset = destoff;
3667
3668                         /*
3669                          * Deal with a hole that doesn't have an extent item
3670                          * that represents it (NO_HOLES feature enabled).
3671                          * This hole is either in the middle of the cloning
3672                          * range or at the beginning (fully overlaps it or
3673                          * partially overlaps it).
3674                          */
3675                         if (new_key.offset != last_dest_end)
3676                                 drop_start = last_dest_end;
3677                         else
3678                                 drop_start = new_key.offset;
3679
3680                         /*
3681                          * 1 - adjusting old extent (we may have to split it)
3682                          * 1 - add new extent
3683                          * 1 - inode update
3684                          */
3685                         trans = btrfs_start_transaction(root, 3);
3686                         if (IS_ERR(trans)) {
3687                                 ret = PTR_ERR(trans);
3688                                 goto out;
3689                         }
3690
3691                         if (type == BTRFS_FILE_EXTENT_REG ||
3692                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3693                                 /*
3694                                  *    a  | --- range to clone ---|  b
3695                                  * | ------------- extent ------------- |
3696                                  */
3697
3698                                 /* subtract range b */
3699                                 if (key.offset + datal > off + len)
3700                                         datal = off + len - key.offset;
3701
3702                                 /* subtract range a */
3703                                 if (off > key.offset) {
3704                                         datao += off - key.offset;
3705                                         datal -= off - key.offset;
3706                                 }
3707
3708                                 ret = btrfs_drop_extents(trans, root, inode,
3709                                                          drop_start,
3710                                                          new_key.offset + datal,
3711                                                          1);
3712                                 if (ret) {
3713                                         if (ret != -EOPNOTSUPP)
3714                                                 btrfs_abort_transaction(trans,
3715                                                                         ret);
3716                                         btrfs_end_transaction(trans);
3717                                         goto out;
3718                                 }
3719
3720                                 ret = btrfs_insert_empty_item(trans, root, path,
3721                                                               &new_key, size);
3722                                 if (ret) {
3723                                         btrfs_abort_transaction(trans, ret);
3724                                         btrfs_end_transaction(trans);
3725                                         goto out;
3726                                 }
3727
3728                                 leaf = path->nodes[0];
3729                                 slot = path->slots[0];
3730                                 write_extent_buffer(leaf, buf,
3731                                             btrfs_item_ptr_offset(leaf, slot),
3732                                             size);
3733
3734                                 extent = btrfs_item_ptr(leaf, slot,
3735                                                 struct btrfs_file_extent_item);
3736
3737                                 /* disko == 0 means it's a hole */
3738                                 if (!disko)
3739                                         datao = 0;
3740
3741                                 btrfs_set_file_extent_offset(leaf, extent,
3742                                                              datao);
3743                                 btrfs_set_file_extent_num_bytes(leaf, extent,
3744                                                                 datal);
3745
3746                                 if (disko) {
3747                                         inode_add_bytes(inode, datal);
3748                                         ret = btrfs_inc_extent_ref(trans,
3749                                                         fs_info,
3750                                                         disko, diskl, 0,
3751                                                         root->root_key.objectid,
3752                                                         btrfs_ino(inode),
3753                                                         new_key.offset - datao);
3754                                         if (ret) {
3755                                                 btrfs_abort_transaction(trans,
3756                                                                         ret);
3757                                                 btrfs_end_transaction(trans);
3758                                                 goto out;
3759
3760                                         }
3761                                 }
3762                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3763                                 u64 skip = 0;
3764                                 u64 trim = 0;
3765
3766                                 if (off > key.offset) {
3767                                         skip = off - key.offset;
3768                                         new_key.offset += skip;
3769                                 }
3770
3771                                 if (key.offset + datal > off + len)
3772                                         trim = key.offset + datal - (off + len);
3773
3774                                 if (comp && (skip || trim)) {
3775                                         ret = -EINVAL;
3776                                         btrfs_end_transaction(trans);
3777                                         goto out;
3778                                 }
3779                                 size -= skip + trim;
3780                                 datal -= skip + trim;
3781
3782                                 ret = clone_copy_inline_extent(src, inode,
3783                                                                trans, path,
3784                                                                &new_key,
3785                                                                drop_start,
3786                                                                datal,
3787                                                                skip, size, buf);
3788                                 if (ret) {
3789                                         if (ret != -EOPNOTSUPP)
3790                                                 btrfs_abort_transaction(trans,
3791                                                                         ret);
3792                                         btrfs_end_transaction(trans);
3793                                         goto out;
3794                                 }
3795                                 leaf = path->nodes[0];
3796                                 slot = path->slots[0];
3797                         }
3798
3799                         /* If we have an implicit hole (NO_HOLES feature). */
3800                         if (drop_start < new_key.offset)
3801                                 clone_update_extent_map(inode, trans,
3802                                                 NULL, drop_start,
3803                                                 new_key.offset - drop_start);
3804
3805                         clone_update_extent_map(inode, trans, path, 0, 0);
3806
3807                         btrfs_mark_buffer_dirty(leaf);
3808                         btrfs_release_path(path);
3809
3810                         last_dest_end = ALIGN(new_key.offset + datal,
3811                                               fs_info->sectorsize);
3812                         ret = clone_finish_inode_update(trans, inode,
3813                                                         last_dest_end,
3814                                                         destoff, olen,
3815                                                         no_time_update);
3816                         if (ret)
3817                                 goto out;
3818                         if (new_key.offset + datal >= destoff + len)
3819                                 break;
3820                 }
3821                 btrfs_release_path(path);
3822                 key.offset = next_key_min_offset;
3823
3824                 if (fatal_signal_pending(current)) {
3825                         ret = -EINTR;
3826                         goto out;
3827                 }
3828         }
3829         ret = 0;
3830
3831         if (last_dest_end < destoff + len) {
3832                 /*
3833                  * We have an implicit hole (NO_HOLES feature is enabled) that
3834                  * fully or partially overlaps our cloning range at its end.
3835                  */
3836                 btrfs_release_path(path);
3837
3838                 /*
3839                  * 1 - remove extent(s)
3840                  * 1 - inode update
3841                  */
3842                 trans = btrfs_start_transaction(root, 2);
3843                 if (IS_ERR(trans)) {
3844                         ret = PTR_ERR(trans);
3845                         goto out;
3846                 }
3847                 ret = btrfs_drop_extents(trans, root, inode,
3848                                          last_dest_end, destoff + len, 1);
3849                 if (ret) {
3850                         if (ret != -EOPNOTSUPP)
3851                                 btrfs_abort_transaction(trans, ret);
3852                         btrfs_end_transaction(trans);
3853                         goto out;
3854                 }
3855                 clone_update_extent_map(inode, trans, NULL, last_dest_end,
3856                                         destoff + len - last_dest_end);
3857                 ret = clone_finish_inode_update(trans, inode, destoff + len,
3858                                                 destoff, olen, no_time_update);
3859         }
3860
3861 out:
3862         btrfs_free_path(path);
3863         kvfree(buf);
3864         return ret;
3865 }
3866
3867 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3868                                         u64 off, u64 olen, u64 destoff)
3869 {
3870         struct inode *inode = file_inode(file);
3871         struct inode *src = file_inode(file_src);
3872         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3873         struct btrfs_root *root = BTRFS_I(inode)->root;
3874         int ret;
3875         u64 len = olen;
3876         u64 bs = fs_info->sb->s_blocksize;
3877         int same_inode = src == inode;
3878
3879         /*
3880          * TODO:
3881          * - split compressed inline extents.  annoying: we need to
3882          *   decompress into destination's address_space (the file offset
3883          *   may change, so source mapping won't do), then recompress (or
3884          *   otherwise reinsert) a subrange.
3885          *
3886          * - split destination inode's inline extents.  The inline extents can
3887          *   be either compressed or non-compressed.
3888          */
3889
3890         if (btrfs_root_readonly(root))
3891                 return -EROFS;
3892
3893         if (file_src->f_path.mnt != file->f_path.mnt ||
3894             src->i_sb != inode->i_sb)
3895                 return -EXDEV;
3896
3897         /* don't make the dst file partly checksummed */
3898         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3899             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3900                 return -EINVAL;
3901
3902         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3903                 return -EISDIR;
3904
3905         if (!same_inode) {
3906                 btrfs_double_inode_lock(src, inode);
3907         } else {
3908                 inode_lock(src);
3909         }
3910
3911         /* determine range to clone */
3912         ret = -EINVAL;
3913         if (off + len > src->i_size || off + len < off)
3914                 goto out_unlock;
3915         if (len == 0)
3916                 olen = len = src->i_size - off;
3917         /* if we extend to eof, continue to block boundary */
3918         if (off + len == src->i_size)
3919                 len = ALIGN(src->i_size, bs) - off;
3920
3921         if (len == 0) {
3922                 ret = 0;
3923                 goto out_unlock;
3924         }
3925
3926         /* verify the end result is block aligned */
3927         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3928             !IS_ALIGNED(destoff, bs))
3929                 goto out_unlock;
3930
3931         /* verify if ranges are overlapped within the same file */
3932         if (same_inode) {
3933                 if (destoff + len > off && destoff < off + len)
3934                         goto out_unlock;
3935         }
3936
3937         if (destoff > inode->i_size) {
3938                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3939                 if (ret)
3940                         goto out_unlock;
3941         }
3942
3943         /*
3944          * Lock the target range too. Right after we replace the file extent
3945          * items in the fs tree (which now point to the cloned data), we might
3946          * have a worker replace them with extent items relative to a write
3947          * operation that was issued before this clone operation (i.e. confront
3948          * with inode.c:btrfs_finish_ordered_io).
3949          */
3950         if (same_inode) {
3951                 u64 lock_start = min_t(u64, off, destoff);
3952                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3953
3954                 ret = lock_extent_range(src, lock_start, lock_len, true);
3955         } else {
3956                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
3957                                                true);
3958         }
3959         ASSERT(ret == 0);
3960         if (WARN_ON(ret)) {
3961                 /* ranges in the io trees already unlocked */
3962                 goto out_unlock;
3963         }
3964
3965         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3966
3967         if (same_inode) {
3968                 u64 lock_start = min_t(u64, off, destoff);
3969                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
3970
3971                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3972         } else {
3973                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
3974         }
3975         /*
3976          * Truncate page cache pages so that future reads will see the cloned
3977          * data immediately and not the previous data.
3978          */
3979         truncate_inode_pages_range(&inode->i_data,
3980                                 round_down(destoff, PAGE_SIZE),
3981                                 round_up(destoff + len, PAGE_SIZE) - 1);
3982 out_unlock:
3983         if (!same_inode)
3984                 btrfs_double_inode_unlock(src, inode);
3985         else
3986                 inode_unlock(src);
3987         return ret;
3988 }
3989
3990 int btrfs_clone_file_range(struct file *src_file, loff_t off,
3991                 struct file *dst_file, loff_t destoff, u64 len)
3992 {
3993         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
3994 }
3995
3996 /*
3997  * there are many ways the trans_start and trans_end ioctls can lead
3998  * to deadlocks.  They should only be used by applications that
3999  * basically own the machine, and have a very in depth understanding
4000  * of all the possible deadlocks and enospc problems.
4001  */
4002 static long btrfs_ioctl_trans_start(struct file *file)
4003 {
4004         struct inode *inode = file_inode(file);
4005         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4006         struct btrfs_root *root = BTRFS_I(inode)->root;
4007         struct btrfs_trans_handle *trans;
4008         int ret;
4009
4010         ret = -EPERM;
4011         if (!capable(CAP_SYS_ADMIN))
4012                 goto out;
4013
4014         ret = -EINPROGRESS;
4015         if (file->private_data)
4016                 goto out;
4017
4018         ret = -EROFS;
4019         if (btrfs_root_readonly(root))
4020                 goto out;
4021
4022         ret = mnt_want_write_file(file);
4023         if (ret)
4024                 goto out;
4025
4026         atomic_inc(&fs_info->open_ioctl_trans);
4027
4028         ret = -ENOMEM;
4029         trans = btrfs_start_ioctl_transaction(root);
4030         if (IS_ERR(trans))
4031                 goto out_drop;
4032
4033         file->private_data = trans;
4034         return 0;
4035
4036 out_drop:
4037         atomic_dec(&fs_info->open_ioctl_trans);
4038         mnt_drop_write_file(file);
4039 out:
4040         return ret;
4041 }
4042
4043 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4044 {
4045         struct inode *inode = file_inode(file);
4046         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4047         struct btrfs_root *root = BTRFS_I(inode)->root;
4048         struct btrfs_root *new_root;
4049         struct btrfs_dir_item *di;
4050         struct btrfs_trans_handle *trans;
4051         struct btrfs_path *path;
4052         struct btrfs_key location;
4053         struct btrfs_disk_key disk_key;
4054         u64 objectid = 0;
4055         u64 dir_id;
4056         int ret;
4057
4058         if (!capable(CAP_SYS_ADMIN))
4059                 return -EPERM;
4060
4061         ret = mnt_want_write_file(file);
4062         if (ret)
4063                 return ret;
4064
4065         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4066                 ret = -EFAULT;
4067                 goto out;
4068         }
4069
4070         if (!objectid)
4071                 objectid = BTRFS_FS_TREE_OBJECTID;
4072
4073         location.objectid = objectid;
4074         location.type = BTRFS_ROOT_ITEM_KEY;
4075         location.offset = (u64)-1;
4076
4077         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4078         if (IS_ERR(new_root)) {
4079                 ret = PTR_ERR(new_root);
4080                 goto out;
4081         }
4082
4083         path = btrfs_alloc_path();
4084         if (!path) {
4085                 ret = -ENOMEM;
4086                 goto out;
4087         }
4088         path->leave_spinning = 1;
4089
4090         trans = btrfs_start_transaction(root, 1);
4091         if (IS_ERR(trans)) {
4092                 btrfs_free_path(path);
4093                 ret = PTR_ERR(trans);
4094                 goto out;
4095         }
4096
4097         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4098         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4099                                    dir_id, "default", 7, 1);
4100         if (IS_ERR_OR_NULL(di)) {
4101                 btrfs_free_path(path);
4102                 btrfs_end_transaction(trans);
4103                 btrfs_err(fs_info,
4104                           "Umm, you don't have the default diritem, this isn't going to work");
4105                 ret = -ENOENT;
4106                 goto out;
4107         }
4108
4109         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4110         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4111         btrfs_mark_buffer_dirty(path->nodes[0]);
4112         btrfs_free_path(path);
4113
4114         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4115         btrfs_end_transaction(trans);
4116 out:
4117         mnt_drop_write_file(file);
4118         return ret;
4119 }
4120
4121 void btrfs_get_block_group_info(struct list_head *groups_list,
4122                                 struct btrfs_ioctl_space_info *space)
4123 {
4124         struct btrfs_block_group_cache *block_group;
4125
4126         space->total_bytes = 0;
4127         space->used_bytes = 0;
4128         space->flags = 0;
4129         list_for_each_entry(block_group, groups_list, list) {
4130                 space->flags = block_group->flags;
4131                 space->total_bytes += block_group->key.offset;
4132                 space->used_bytes +=
4133                         btrfs_block_group_used(&block_group->item);
4134         }
4135 }
4136
4137 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4138                                    void __user *arg)
4139 {
4140         struct btrfs_ioctl_space_args space_args;
4141         struct btrfs_ioctl_space_info space;
4142         struct btrfs_ioctl_space_info *dest;
4143         struct btrfs_ioctl_space_info *dest_orig;
4144         struct btrfs_ioctl_space_info __user *user_dest;
4145         struct btrfs_space_info *info;
4146         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
4147                        BTRFS_BLOCK_GROUP_SYSTEM,
4148                        BTRFS_BLOCK_GROUP_METADATA,
4149                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
4150         int num_types = 4;
4151         int alloc_size;
4152         int ret = 0;
4153         u64 slot_count = 0;
4154         int i, c;
4155
4156         if (copy_from_user(&space_args,
4157                            (struct btrfs_ioctl_space_args __user *)arg,
4158                            sizeof(space_args)))
4159                 return -EFAULT;
4160
4161         for (i = 0; i < num_types; i++) {
4162                 struct btrfs_space_info *tmp;
4163
4164                 info = NULL;
4165                 rcu_read_lock();
4166                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4167                                         list) {
4168                         if (tmp->flags == types[i]) {
4169                                 info = tmp;
4170                                 break;
4171                         }
4172                 }
4173                 rcu_read_unlock();
4174
4175                 if (!info)
4176                         continue;
4177
4178                 down_read(&info->groups_sem);
4179                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4180                         if (!list_empty(&info->block_groups[c]))
4181                                 slot_count++;
4182                 }
4183                 up_read(&info->groups_sem);
4184         }
4185
4186         /*
4187          * Global block reserve, exported as a space_info
4188          */
4189         slot_count++;
4190
4191         /* space_slots == 0 means they are asking for a count */
4192         if (space_args.space_slots == 0) {
4193                 space_args.total_spaces = slot_count;
4194                 goto out;
4195         }
4196
4197         slot_count = min_t(u64, space_args.space_slots, slot_count);
4198
4199         alloc_size = sizeof(*dest) * slot_count;
4200
4201         /* we generally have at most 6 or so space infos, one for each raid
4202          * level.  So, a whole page should be more than enough for everyone
4203          */
4204         if (alloc_size > PAGE_SIZE)
4205                 return -ENOMEM;
4206
4207         space_args.total_spaces = 0;
4208         dest = kmalloc(alloc_size, GFP_KERNEL);
4209         if (!dest)
4210                 return -ENOMEM;
4211         dest_orig = dest;
4212
4213         /* now we have a buffer to copy into */
4214         for (i = 0; i < num_types; i++) {
4215                 struct btrfs_space_info *tmp;
4216
4217                 if (!slot_count)
4218                         break;
4219
4220                 info = NULL;
4221                 rcu_read_lock();
4222                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4223                                         list) {
4224                         if (tmp->flags == types[i]) {
4225                                 info = tmp;
4226                                 break;
4227                         }
4228                 }
4229                 rcu_read_unlock();
4230
4231                 if (!info)
4232                         continue;
4233                 down_read(&info->groups_sem);
4234                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4235                         if (!list_empty(&info->block_groups[c])) {
4236                                 btrfs_get_block_group_info(
4237                                         &info->block_groups[c], &space);
4238                                 memcpy(dest, &space, sizeof(space));
4239                                 dest++;
4240                                 space_args.total_spaces++;
4241                                 slot_count--;
4242                         }
4243                         if (!slot_count)
4244                                 break;
4245                 }
4246                 up_read(&info->groups_sem);
4247         }
4248
4249         /*
4250          * Add global block reserve
4251          */
4252         if (slot_count) {
4253                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4254
4255                 spin_lock(&block_rsv->lock);
4256                 space.total_bytes = block_rsv->size;
4257                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4258                 spin_unlock(&block_rsv->lock);
4259                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4260                 memcpy(dest, &space, sizeof(space));
4261                 space_args.total_spaces++;
4262         }
4263
4264         user_dest = (struct btrfs_ioctl_space_info __user *)
4265                 (arg + sizeof(struct btrfs_ioctl_space_args));
4266
4267         if (copy_to_user(user_dest, dest_orig, alloc_size))
4268                 ret = -EFAULT;
4269
4270         kfree(dest_orig);
4271 out:
4272         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4273                 ret = -EFAULT;
4274
4275         return ret;
4276 }
4277
4278 /*
4279  * there are many ways the trans_start and trans_end ioctls can lead
4280  * to deadlocks.  They should only be used by applications that
4281  * basically own the machine, and have a very in depth understanding
4282  * of all the possible deadlocks and enospc problems.
4283  */
4284 long btrfs_ioctl_trans_end(struct file *file)
4285 {
4286         struct inode *inode = file_inode(file);
4287         struct btrfs_root *root = BTRFS_I(inode)->root;
4288         struct btrfs_trans_handle *trans;
4289
4290         trans = file->private_data;
4291         if (!trans)
4292                 return -EINVAL;
4293         file->private_data = NULL;
4294
4295         btrfs_end_transaction(trans);
4296
4297         atomic_dec(&root->fs_info->open_ioctl_trans);
4298
4299         mnt_drop_write_file(file);
4300         return 0;
4301 }
4302
4303 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4304                                             void __user *argp)
4305 {
4306         struct btrfs_trans_handle *trans;
4307         u64 transid;
4308         int ret;
4309
4310         trans = btrfs_attach_transaction_barrier(root);
4311         if (IS_ERR(trans)) {
4312                 if (PTR_ERR(trans) != -ENOENT)
4313                         return PTR_ERR(trans);
4314
4315                 /* No running transaction, don't bother */
4316                 transid = root->fs_info->last_trans_committed;
4317                 goto out;
4318         }
4319         transid = trans->transid;
4320         ret = btrfs_commit_transaction_async(trans, 0);
4321         if (ret) {
4322                 btrfs_end_transaction(trans);
4323                 return ret;
4324         }
4325 out:
4326         if (argp)
4327                 if (copy_to_user(argp, &transid, sizeof(transid)))
4328                         return -EFAULT;
4329         return 0;
4330 }
4331
4332 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4333                                            void __user *argp)
4334 {
4335         u64 transid;
4336
4337         if (argp) {
4338                 if (copy_from_user(&transid, argp, sizeof(transid)))
4339                         return -EFAULT;
4340         } else {
4341                 transid = 0;  /* current trans */
4342         }
4343         return btrfs_wait_for_commit(fs_info, transid);
4344 }
4345
4346 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4347 {
4348         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4349         struct btrfs_ioctl_scrub_args *sa;
4350         int ret;
4351
4352         if (!capable(CAP_SYS_ADMIN))
4353                 return -EPERM;
4354
4355         sa = memdup_user(arg, sizeof(*sa));
4356         if (IS_ERR(sa))
4357                 return PTR_ERR(sa);
4358
4359         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4360                 ret = mnt_want_write_file(file);
4361                 if (ret)
4362                         goto out;
4363         }
4364
4365         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4366                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4367                               0);
4368
4369         if (copy_to_user(arg, sa, sizeof(*sa)))
4370                 ret = -EFAULT;
4371
4372         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4373                 mnt_drop_write_file(file);
4374 out:
4375         kfree(sa);
4376         return ret;
4377 }
4378
4379 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4380 {
4381         if (!capable(CAP_SYS_ADMIN))
4382                 return -EPERM;
4383
4384         return btrfs_scrub_cancel(fs_info);
4385 }
4386
4387 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4388                                        void __user *arg)
4389 {
4390         struct btrfs_ioctl_scrub_args *sa;
4391         int ret;
4392
4393         if (!capable(CAP_SYS_ADMIN))
4394                 return -EPERM;
4395
4396         sa = memdup_user(arg, sizeof(*sa));
4397         if (IS_ERR(sa))
4398                 return PTR_ERR(sa);
4399
4400         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4401
4402         if (copy_to_user(arg, sa, sizeof(*sa)))
4403                 ret = -EFAULT;
4404
4405         kfree(sa);
4406         return ret;
4407 }
4408
4409 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4410                                       void __user *arg)
4411 {
4412         struct btrfs_ioctl_get_dev_stats *sa;
4413         int ret;
4414
4415         sa = memdup_user(arg, sizeof(*sa));
4416         if (IS_ERR(sa))
4417                 return PTR_ERR(sa);
4418
4419         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4420                 kfree(sa);
4421                 return -EPERM;
4422         }
4423
4424         ret = btrfs_get_dev_stats(fs_info, sa);
4425
4426         if (copy_to_user(arg, sa, sizeof(*sa)))
4427                 ret = -EFAULT;
4428
4429         kfree(sa);
4430         return ret;
4431 }
4432
4433 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4434                                     void __user *arg)
4435 {
4436         struct btrfs_ioctl_dev_replace_args *p;
4437         int ret;
4438
4439         if (!capable(CAP_SYS_ADMIN))
4440                 return -EPERM;
4441
4442         p = memdup_user(arg, sizeof(*p));
4443         if (IS_ERR(p))
4444                 return PTR_ERR(p);
4445
4446         switch (p->cmd) {
4447         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4448                 if (fs_info->sb->s_flags & MS_RDONLY) {
4449                         ret = -EROFS;
4450                         goto out;
4451                 }
4452                 if (atomic_xchg(
4453                         &fs_info->mutually_exclusive_operation_running, 1)) {
4454                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4455                 } else {
4456                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4457                         atomic_set(
4458                          &fs_info->mutually_exclusive_operation_running, 0);
4459                 }
4460                 break;
4461         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4462                 btrfs_dev_replace_status(fs_info, p);
4463                 ret = 0;
4464                 break;
4465         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4466                 ret = btrfs_dev_replace_cancel(fs_info, p);
4467                 break;
4468         default:
4469                 ret = -EINVAL;
4470                 break;
4471         }
4472
4473         if (copy_to_user(arg, p, sizeof(*p)))
4474                 ret = -EFAULT;
4475 out:
4476         kfree(p);
4477         return ret;
4478 }
4479
4480 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4481 {
4482         int ret = 0;
4483         int i;
4484         u64 rel_ptr;
4485         int size;
4486         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4487         struct inode_fs_paths *ipath = NULL;
4488         struct btrfs_path *path;
4489
4490         if (!capable(CAP_DAC_READ_SEARCH))
4491                 return -EPERM;
4492
4493         path = btrfs_alloc_path();
4494         if (!path) {
4495                 ret = -ENOMEM;
4496                 goto out;
4497         }
4498
4499         ipa = memdup_user(arg, sizeof(*ipa));
4500         if (IS_ERR(ipa)) {
4501                 ret = PTR_ERR(ipa);
4502                 ipa = NULL;
4503                 goto out;
4504         }
4505
4506         size = min_t(u32, ipa->size, 4096);
4507         ipath = init_ipath(size, root, path);
4508         if (IS_ERR(ipath)) {
4509                 ret = PTR_ERR(ipath);
4510                 ipath = NULL;
4511                 goto out;
4512         }
4513
4514         ret = paths_from_inode(ipa->inum, ipath);
4515         if (ret < 0)
4516                 goto out;
4517
4518         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4519                 rel_ptr = ipath->fspath->val[i] -
4520                           (u64)(unsigned long)ipath->fspath->val;
4521                 ipath->fspath->val[i] = rel_ptr;
4522         }
4523
4524         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
4525                            (void *)(unsigned long)ipath->fspath, size);
4526         if (ret) {
4527                 ret = -EFAULT;
4528                 goto out;
4529         }
4530
4531 out:
4532         btrfs_free_path(path);
4533         free_ipath(ipath);
4534         kfree(ipa);
4535
4536         return ret;
4537 }
4538
4539 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4540 {
4541         struct btrfs_data_container *inodes = ctx;
4542         const size_t c = 3 * sizeof(u64);
4543
4544         if (inodes->bytes_left >= c) {
4545                 inodes->bytes_left -= c;
4546                 inodes->val[inodes->elem_cnt] = inum;
4547                 inodes->val[inodes->elem_cnt + 1] = offset;
4548                 inodes->val[inodes->elem_cnt + 2] = root;
4549                 inodes->elem_cnt += 3;
4550         } else {
4551                 inodes->bytes_missing += c - inodes->bytes_left;
4552                 inodes->bytes_left = 0;
4553                 inodes->elem_missed += 3;
4554         }
4555
4556         return 0;
4557 }
4558
4559 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4560                                         void __user *arg)
4561 {
4562         int ret = 0;
4563         int size;
4564         struct btrfs_ioctl_logical_ino_args *loi;
4565         struct btrfs_data_container *inodes = NULL;
4566         struct btrfs_path *path = NULL;
4567
4568         if (!capable(CAP_SYS_ADMIN))
4569                 return -EPERM;
4570
4571         loi = memdup_user(arg, sizeof(*loi));
4572         if (IS_ERR(loi))
4573                 return PTR_ERR(loi);
4574
4575         path = btrfs_alloc_path();
4576         if (!path) {
4577                 ret = -ENOMEM;
4578                 goto out;
4579         }
4580
4581         size = min_t(u32, loi->size, SZ_64K);
4582         inodes = init_data_container(size);
4583         if (IS_ERR(inodes)) {
4584                 ret = PTR_ERR(inodes);
4585                 inodes = NULL;
4586                 goto out;
4587         }
4588
4589         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4590                                           build_ino_list, inodes);
4591         if (ret == -EINVAL)
4592                 ret = -ENOENT;
4593         if (ret < 0)
4594                 goto out;
4595
4596         ret = copy_to_user((void *)(unsigned long)loi->inodes,
4597                            (void *)(unsigned long)inodes, size);
4598         if (ret)
4599                 ret = -EFAULT;
4600
4601 out:
4602         btrfs_free_path(path);
4603         vfree(inodes);
4604         kfree(loi);
4605
4606         return ret;
4607 }
4608
4609 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4610                                struct btrfs_ioctl_balance_args *bargs)
4611 {
4612         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4613
4614         bargs->flags = bctl->flags;
4615
4616         if (atomic_read(&fs_info->balance_running))
4617                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4618         if (atomic_read(&fs_info->balance_pause_req))
4619                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4620         if (atomic_read(&fs_info->balance_cancel_req))
4621                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4622
4623         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4624         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4625         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4626
4627         if (lock) {
4628                 spin_lock(&fs_info->balance_lock);
4629                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4630                 spin_unlock(&fs_info->balance_lock);
4631         } else {
4632                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4633         }
4634 }
4635
4636 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4637 {
4638         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4639         struct btrfs_fs_info *fs_info = root->fs_info;
4640         struct btrfs_ioctl_balance_args *bargs;
4641         struct btrfs_balance_control *bctl;
4642         bool need_unlock; /* for mut. excl. ops lock */
4643         int ret;
4644
4645         if (!capable(CAP_SYS_ADMIN))
4646                 return -EPERM;
4647
4648         ret = mnt_want_write_file(file);
4649         if (ret)
4650                 return ret;
4651
4652 again:
4653         if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
4654                 mutex_lock(&fs_info->volume_mutex);
4655                 mutex_lock(&fs_info->balance_mutex);
4656                 need_unlock = true;
4657                 goto locked;
4658         }
4659
4660         /*
4661          * mut. excl. ops lock is locked.  Three possibilities:
4662          *   (1) some other op is running
4663          *   (2) balance is running
4664          *   (3) balance is paused -- special case (think resume)
4665          */
4666         mutex_lock(&fs_info->balance_mutex);
4667         if (fs_info->balance_ctl) {
4668                 /* this is either (2) or (3) */
4669                 if (!atomic_read(&fs_info->balance_running)) {
4670                         mutex_unlock(&fs_info->balance_mutex);
4671                         if (!mutex_trylock(&fs_info->volume_mutex))
4672                                 goto again;
4673                         mutex_lock(&fs_info->balance_mutex);
4674
4675                         if (fs_info->balance_ctl &&
4676                             !atomic_read(&fs_info->balance_running)) {
4677                                 /* this is (3) */
4678                                 need_unlock = false;
4679                                 goto locked;
4680                         }
4681
4682                         mutex_unlock(&fs_info->balance_mutex);
4683                         mutex_unlock(&fs_info->volume_mutex);
4684                         goto again;
4685                 } else {
4686                         /* this is (2) */
4687                         mutex_unlock(&fs_info->balance_mutex);
4688                         ret = -EINPROGRESS;
4689                         goto out;
4690                 }
4691         } else {
4692                 /* this is (1) */
4693                 mutex_unlock(&fs_info->balance_mutex);
4694                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4695                 goto out;
4696         }
4697
4698 locked:
4699         BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
4700
4701         if (arg) {
4702                 bargs = memdup_user(arg, sizeof(*bargs));
4703                 if (IS_ERR(bargs)) {
4704                         ret = PTR_ERR(bargs);
4705                         goto out_unlock;
4706                 }
4707
4708                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4709                         if (!fs_info->balance_ctl) {
4710                                 ret = -ENOTCONN;
4711                                 goto out_bargs;
4712                         }
4713
4714                         bctl = fs_info->balance_ctl;
4715                         spin_lock(&fs_info->balance_lock);
4716                         bctl->flags |= BTRFS_BALANCE_RESUME;
4717                         spin_unlock(&fs_info->balance_lock);
4718
4719                         goto do_balance;
4720                 }
4721         } else {
4722                 bargs = NULL;
4723         }
4724
4725         if (fs_info->balance_ctl) {
4726                 ret = -EINPROGRESS;
4727                 goto out_bargs;
4728         }
4729
4730         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4731         if (!bctl) {
4732                 ret = -ENOMEM;
4733                 goto out_bargs;
4734         }
4735
4736         bctl->fs_info = fs_info;
4737         if (arg) {
4738                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4739                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4740                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4741
4742                 bctl->flags = bargs->flags;
4743         } else {
4744                 /* balance everything - no filters */
4745                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4746         }
4747
4748         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4749                 ret = -EINVAL;
4750                 goto out_bctl;
4751         }
4752
4753 do_balance:
4754         /*
4755          * Ownership of bctl and mutually_exclusive_operation_running
4756          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
4757          * or, if restriper was paused all the way until unmount, in
4758          * free_fs_info.  mutually_exclusive_operation_running is
4759          * cleared in __cancel_balance.
4760          */
4761         need_unlock = false;
4762
4763         ret = btrfs_balance(bctl, bargs);
4764         bctl = NULL;
4765
4766         if (arg) {
4767                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4768                         ret = -EFAULT;
4769         }
4770
4771 out_bctl:
4772         kfree(bctl);
4773 out_bargs:
4774         kfree(bargs);
4775 out_unlock:
4776         mutex_unlock(&fs_info->balance_mutex);
4777         mutex_unlock(&fs_info->volume_mutex);
4778         if (need_unlock)
4779                 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
4780 out:
4781         mnt_drop_write_file(file);
4782         return ret;
4783 }
4784
4785 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4786 {
4787         if (!capable(CAP_SYS_ADMIN))
4788                 return -EPERM;
4789
4790         switch (cmd) {
4791         case BTRFS_BALANCE_CTL_PAUSE:
4792                 return btrfs_pause_balance(fs_info);
4793         case BTRFS_BALANCE_CTL_CANCEL:
4794                 return btrfs_cancel_balance(fs_info);
4795         }
4796
4797         return -EINVAL;
4798 }
4799
4800 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4801                                          void __user *arg)
4802 {
4803         struct btrfs_ioctl_balance_args *bargs;
4804         int ret = 0;
4805
4806         if (!capable(CAP_SYS_ADMIN))
4807                 return -EPERM;
4808
4809         mutex_lock(&fs_info->balance_mutex);
4810         if (!fs_info->balance_ctl) {
4811                 ret = -ENOTCONN;
4812                 goto out;
4813         }
4814
4815         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4816         if (!bargs) {
4817                 ret = -ENOMEM;
4818                 goto out;
4819         }
4820
4821         update_ioctl_balance_args(fs_info, 1, bargs);
4822
4823         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4824                 ret = -EFAULT;
4825
4826         kfree(bargs);
4827 out:
4828         mutex_unlock(&fs_info->balance_mutex);
4829         return ret;
4830 }
4831
4832 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4833 {
4834         struct inode *inode = file_inode(file);
4835         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4836         struct btrfs_ioctl_quota_ctl_args *sa;
4837         struct btrfs_trans_handle *trans = NULL;
4838         int ret;
4839         int err;
4840
4841         if (!capable(CAP_SYS_ADMIN))
4842                 return -EPERM;
4843
4844         ret = mnt_want_write_file(file);
4845         if (ret)
4846                 return ret;
4847
4848         sa = memdup_user(arg, sizeof(*sa));
4849         if (IS_ERR(sa)) {
4850                 ret = PTR_ERR(sa);
4851                 goto drop_write;
4852         }
4853
4854         down_write(&fs_info->subvol_sem);
4855         trans = btrfs_start_transaction(fs_info->tree_root, 2);
4856         if (IS_ERR(trans)) {
4857                 ret = PTR_ERR(trans);
4858                 goto out;
4859         }
4860
4861         switch (sa->cmd) {
4862         case BTRFS_QUOTA_CTL_ENABLE:
4863                 ret = btrfs_quota_enable(trans, fs_info);
4864                 break;
4865         case BTRFS_QUOTA_CTL_DISABLE:
4866                 ret = btrfs_quota_disable(trans, fs_info);
4867                 break;
4868         default:
4869                 ret = -EINVAL;
4870                 break;
4871         }
4872
4873         err = btrfs_commit_transaction(trans);
4874         if (err && !ret)
4875                 ret = err;
4876 out:
4877         kfree(sa);
4878         up_write(&fs_info->subvol_sem);
4879 drop_write:
4880         mnt_drop_write_file(file);
4881         return ret;
4882 }
4883
4884 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4885 {
4886         struct inode *inode = file_inode(file);
4887         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4888         struct btrfs_root *root = BTRFS_I(inode)->root;
4889         struct btrfs_ioctl_qgroup_assign_args *sa;
4890         struct btrfs_trans_handle *trans;
4891         int ret;
4892         int err;
4893
4894         if (!capable(CAP_SYS_ADMIN))
4895                 return -EPERM;
4896
4897         ret = mnt_want_write_file(file);
4898         if (ret)
4899                 return ret;
4900
4901         sa = memdup_user(arg, sizeof(*sa));
4902         if (IS_ERR(sa)) {
4903                 ret = PTR_ERR(sa);
4904                 goto drop_write;
4905         }
4906
4907         trans = btrfs_join_transaction(root);
4908         if (IS_ERR(trans)) {
4909                 ret = PTR_ERR(trans);
4910                 goto out;
4911         }
4912
4913         /* FIXME: check if the IDs really exist */
4914         if (sa->assign) {
4915                 ret = btrfs_add_qgroup_relation(trans, fs_info,
4916                                                 sa->src, sa->dst);
4917         } else {
4918                 ret = btrfs_del_qgroup_relation(trans, fs_info,
4919                                                 sa->src, sa->dst);
4920         }
4921
4922         /* update qgroup status and info */
4923         err = btrfs_run_qgroups(trans, fs_info);
4924         if (err < 0)
4925                 btrfs_handle_fs_error(fs_info, err,
4926                                       "failed to update qgroup status and info");
4927         err = btrfs_end_transaction(trans);
4928         if (err && !ret)
4929                 ret = err;
4930
4931 out:
4932         kfree(sa);
4933 drop_write:
4934         mnt_drop_write_file(file);
4935         return ret;
4936 }
4937
4938 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4939 {
4940         struct inode *inode = file_inode(file);
4941         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4942         struct btrfs_root *root = BTRFS_I(inode)->root;
4943         struct btrfs_ioctl_qgroup_create_args *sa;
4944         struct btrfs_trans_handle *trans;
4945         int ret;
4946         int err;
4947
4948         if (!capable(CAP_SYS_ADMIN))
4949                 return -EPERM;
4950
4951         ret = mnt_want_write_file(file);
4952         if (ret)
4953                 return ret;
4954
4955         sa = memdup_user(arg, sizeof(*sa));
4956         if (IS_ERR(sa)) {
4957                 ret = PTR_ERR(sa);
4958                 goto drop_write;
4959         }
4960
4961         if (!sa->qgroupid) {
4962                 ret = -EINVAL;
4963                 goto out;
4964         }
4965
4966         trans = btrfs_join_transaction(root);
4967         if (IS_ERR(trans)) {
4968                 ret = PTR_ERR(trans);
4969                 goto out;
4970         }
4971
4972         /* FIXME: check if the IDs really exist */
4973         if (sa->create) {
4974                 ret = btrfs_create_qgroup(trans, fs_info, sa->qgroupid);
4975         } else {
4976                 ret = btrfs_remove_qgroup(trans, fs_info, sa->qgroupid);
4977         }
4978
4979         err = btrfs_end_transaction(trans);
4980         if (err && !ret)
4981                 ret = err;
4982
4983 out:
4984         kfree(sa);
4985 drop_write:
4986         mnt_drop_write_file(file);
4987         return ret;
4988 }
4989
4990 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4991 {
4992         struct inode *inode = file_inode(file);
4993         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4994         struct btrfs_root *root = BTRFS_I(inode)->root;
4995         struct btrfs_ioctl_qgroup_limit_args *sa;
4996         struct btrfs_trans_handle *trans;
4997         int ret;
4998         int err;
4999         u64 qgroupid;
5000
5001         if (!capable(CAP_SYS_ADMIN))
5002                 return -EPERM;
5003
5004         ret = mnt_want_write_file(file);
5005         if (ret)
5006                 return ret;
5007
5008         sa = memdup_user(arg, sizeof(*sa));
5009         if (IS_ERR(sa)) {
5010                 ret = PTR_ERR(sa);
5011                 goto drop_write;
5012         }
5013
5014         trans = btrfs_join_transaction(root);
5015         if (IS_ERR(trans)) {
5016                 ret = PTR_ERR(trans);
5017                 goto out;
5018         }
5019
5020         qgroupid = sa->qgroupid;
5021         if (!qgroupid) {
5022                 /* take the current subvol as qgroup */
5023                 qgroupid = root->root_key.objectid;
5024         }
5025
5026         /* FIXME: check if the IDs really exist */
5027         ret = btrfs_limit_qgroup(trans, fs_info, qgroupid, &sa->lim);
5028
5029         err = btrfs_end_transaction(trans);
5030         if (err && !ret)
5031                 ret = err;
5032
5033 out:
5034         kfree(sa);
5035 drop_write:
5036         mnt_drop_write_file(file);
5037         return ret;
5038 }
5039
5040 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5041 {
5042         struct inode *inode = file_inode(file);
5043         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5044         struct btrfs_ioctl_quota_rescan_args *qsa;
5045         int ret;
5046
5047         if (!capable(CAP_SYS_ADMIN))
5048                 return -EPERM;
5049
5050         ret = mnt_want_write_file(file);
5051         if (ret)
5052                 return ret;
5053
5054         qsa = memdup_user(arg, sizeof(*qsa));
5055         if (IS_ERR(qsa)) {
5056                 ret = PTR_ERR(qsa);
5057                 goto drop_write;
5058         }
5059
5060         if (qsa->flags) {
5061                 ret = -EINVAL;
5062                 goto out;
5063         }
5064
5065         ret = btrfs_qgroup_rescan(fs_info);
5066
5067 out:
5068         kfree(qsa);
5069 drop_write:
5070         mnt_drop_write_file(file);
5071         return ret;
5072 }
5073
5074 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5075 {
5076         struct inode *inode = file_inode(file);
5077         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5078         struct btrfs_ioctl_quota_rescan_args *qsa;
5079         int ret = 0;
5080
5081         if (!capable(CAP_SYS_ADMIN))
5082                 return -EPERM;
5083
5084         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5085         if (!qsa)
5086                 return -ENOMEM;
5087
5088         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5089                 qsa->flags = 1;
5090                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5091         }
5092
5093         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5094                 ret = -EFAULT;
5095
5096         kfree(qsa);
5097         return ret;
5098 }
5099
5100 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5101 {
5102         struct inode *inode = file_inode(file);
5103         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5104
5105         if (!capable(CAP_SYS_ADMIN))
5106                 return -EPERM;
5107
5108         return btrfs_qgroup_wait_for_completion(fs_info, true);
5109 }
5110
5111 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5112                                             struct btrfs_ioctl_received_subvol_args *sa)
5113 {
5114         struct inode *inode = file_inode(file);
5115         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5116         struct btrfs_root *root = BTRFS_I(inode)->root;
5117         struct btrfs_root_item *root_item = &root->root_item;
5118         struct btrfs_trans_handle *trans;
5119         struct timespec ct = current_time(inode);
5120         int ret = 0;
5121         int received_uuid_changed;
5122
5123         if (!inode_owner_or_capable(inode))
5124                 return -EPERM;
5125
5126         ret = mnt_want_write_file(file);
5127         if (ret < 0)
5128                 return ret;
5129
5130         down_write(&fs_info->subvol_sem);
5131
5132         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
5133                 ret = -EINVAL;
5134                 goto out;
5135         }
5136
5137         if (btrfs_root_readonly(root)) {
5138                 ret = -EROFS;
5139                 goto out;
5140         }
5141
5142         /*
5143          * 1 - root item
5144          * 2 - uuid items (received uuid + subvol uuid)
5145          */
5146         trans = btrfs_start_transaction(root, 3);
5147         if (IS_ERR(trans)) {
5148                 ret = PTR_ERR(trans);
5149                 trans = NULL;
5150                 goto out;
5151         }
5152
5153         sa->rtransid = trans->transid;
5154         sa->rtime.sec = ct.tv_sec;
5155         sa->rtime.nsec = ct.tv_nsec;
5156
5157         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5158                                        BTRFS_UUID_SIZE);
5159         if (received_uuid_changed &&
5160             !btrfs_is_empty_uuid(root_item->received_uuid))
5161                 btrfs_uuid_tree_rem(trans, fs_info, root_item->received_uuid,
5162                                     BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5163                                     root->root_key.objectid);
5164         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5165         btrfs_set_root_stransid(root_item, sa->stransid);
5166         btrfs_set_root_rtransid(root_item, sa->rtransid);
5167         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5168         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5169         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5170         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5171
5172         ret = btrfs_update_root(trans, fs_info->tree_root,
5173                                 &root->root_key, &root->root_item);
5174         if (ret < 0) {
5175                 btrfs_end_transaction(trans);
5176                 goto out;
5177         }
5178         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5179                 ret = btrfs_uuid_tree_add(trans, fs_info, sa->uuid,
5180                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5181                                           root->root_key.objectid);
5182                 if (ret < 0 && ret != -EEXIST) {
5183                         btrfs_abort_transaction(trans, ret);
5184                         goto out;
5185                 }
5186         }
5187         ret = btrfs_commit_transaction(trans);
5188         if (ret < 0) {
5189                 btrfs_abort_transaction(trans, ret);
5190                 goto out;
5191         }
5192
5193 out:
5194         up_write(&fs_info->subvol_sem);
5195         mnt_drop_write_file(file);
5196         return ret;
5197 }
5198
5199 #ifdef CONFIG_64BIT
5200 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5201                                                 void __user *arg)
5202 {
5203         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5204         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5205         int ret = 0;
5206
5207         args32 = memdup_user(arg, sizeof(*args32));
5208         if (IS_ERR(args32))
5209                 return PTR_ERR(args32);
5210
5211         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5212         if (!args64) {
5213                 ret = -ENOMEM;
5214                 goto out;
5215         }
5216
5217         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5218         args64->stransid = args32->stransid;
5219         args64->rtransid = args32->rtransid;
5220         args64->stime.sec = args32->stime.sec;
5221         args64->stime.nsec = args32->stime.nsec;
5222         args64->rtime.sec = args32->rtime.sec;
5223         args64->rtime.nsec = args32->rtime.nsec;
5224         args64->flags = args32->flags;
5225
5226         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5227         if (ret)
5228                 goto out;
5229
5230         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5231         args32->stransid = args64->stransid;
5232         args32->rtransid = args64->rtransid;
5233         args32->stime.sec = args64->stime.sec;
5234         args32->stime.nsec = args64->stime.nsec;
5235         args32->rtime.sec = args64->rtime.sec;
5236         args32->rtime.nsec = args64->rtime.nsec;
5237         args32->flags = args64->flags;
5238
5239         ret = copy_to_user(arg, args32, sizeof(*args32));
5240         if (ret)
5241                 ret = -EFAULT;
5242
5243 out:
5244         kfree(args32);
5245         kfree(args64);
5246         return ret;
5247 }
5248 #endif
5249
5250 static long btrfs_ioctl_set_received_subvol(struct file *file,
5251                                             void __user *arg)
5252 {
5253         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5254         int ret = 0;
5255
5256         sa = memdup_user(arg, sizeof(*sa));
5257         if (IS_ERR(sa))
5258                 return PTR_ERR(sa);
5259
5260         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5261
5262         if (ret)
5263                 goto out;
5264
5265         ret = copy_to_user(arg, sa, sizeof(*sa));
5266         if (ret)
5267                 ret = -EFAULT;
5268
5269 out:
5270         kfree(sa);
5271         return ret;
5272 }
5273
5274 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5275 {
5276         struct inode *inode = file_inode(file);
5277         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5278         size_t len;
5279         int ret;
5280         char label[BTRFS_LABEL_SIZE];
5281
5282         spin_lock(&fs_info->super_lock);
5283         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5284         spin_unlock(&fs_info->super_lock);
5285
5286         len = strnlen(label, BTRFS_LABEL_SIZE);
5287
5288         if (len == BTRFS_LABEL_SIZE) {
5289                 btrfs_warn(fs_info,
5290                            "label is too long, return the first %zu bytes",
5291                            --len);
5292         }
5293
5294         ret = copy_to_user(arg, label, len);
5295
5296         return ret ? -EFAULT : 0;
5297 }
5298
5299 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5300 {
5301         struct inode *inode = file_inode(file);
5302         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5303         struct btrfs_root *root = BTRFS_I(inode)->root;
5304         struct btrfs_super_block *super_block = fs_info->super_copy;
5305         struct btrfs_trans_handle *trans;
5306         char label[BTRFS_LABEL_SIZE];
5307         int ret;
5308
5309         if (!capable(CAP_SYS_ADMIN))
5310                 return -EPERM;
5311
5312         if (copy_from_user(label, arg, sizeof(label)))
5313                 return -EFAULT;
5314
5315         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5316                 btrfs_err(fs_info,
5317                           "unable to set label with more than %d bytes",
5318                           BTRFS_LABEL_SIZE - 1);
5319                 return -EINVAL;
5320         }
5321
5322         ret = mnt_want_write_file(file);
5323         if (ret)
5324                 return ret;
5325
5326         trans = btrfs_start_transaction(root, 0);
5327         if (IS_ERR(trans)) {
5328                 ret = PTR_ERR(trans);
5329                 goto out_unlock;
5330         }
5331
5332         spin_lock(&fs_info->super_lock);
5333         strcpy(super_block->label, label);
5334         spin_unlock(&fs_info->super_lock);
5335         ret = btrfs_commit_transaction(trans);
5336
5337 out_unlock:
5338         mnt_drop_write_file(file);
5339         return ret;
5340 }
5341
5342 #define INIT_FEATURE_FLAGS(suffix) \
5343         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5344           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5345           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5346
5347 int btrfs_ioctl_get_supported_features(void __user *arg)
5348 {
5349         static const struct btrfs_ioctl_feature_flags features[3] = {
5350                 INIT_FEATURE_FLAGS(SUPP),
5351                 INIT_FEATURE_FLAGS(SAFE_SET),
5352                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5353         };
5354
5355         if (copy_to_user(arg, &features, sizeof(features)))
5356                 return -EFAULT;
5357
5358         return 0;
5359 }
5360
5361 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5362 {
5363         struct inode *inode = file_inode(file);
5364         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5365         struct btrfs_super_block *super_block = fs_info->super_copy;
5366         struct btrfs_ioctl_feature_flags features;
5367
5368         features.compat_flags = btrfs_super_compat_flags(super_block);
5369         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5370         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5371
5372         if (copy_to_user(arg, &features, sizeof(features)))
5373                 return -EFAULT;
5374
5375         return 0;
5376 }
5377
5378 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5379                               enum btrfs_feature_set set,
5380                               u64 change_mask, u64 flags, u64 supported_flags,
5381                               u64 safe_set, u64 safe_clear)
5382 {
5383         const char *type = btrfs_feature_set_names[set];
5384         char *names;
5385         u64 disallowed, unsupported;
5386         u64 set_mask = flags & change_mask;
5387         u64 clear_mask = ~flags & change_mask;
5388
5389         unsupported = set_mask & ~supported_flags;
5390         if (unsupported) {
5391                 names = btrfs_printable_features(set, unsupported);
5392                 if (names) {
5393                         btrfs_warn(fs_info,
5394                                    "this kernel does not support the %s feature bit%s",
5395                                    names, strchr(names, ',') ? "s" : "");
5396                         kfree(names);
5397                 } else
5398                         btrfs_warn(fs_info,
5399                                    "this kernel does not support %s bits 0x%llx",
5400                                    type, unsupported);
5401                 return -EOPNOTSUPP;
5402         }
5403
5404         disallowed = set_mask & ~safe_set;
5405         if (disallowed) {
5406                 names = btrfs_printable_features(set, disallowed);
5407                 if (names) {
5408                         btrfs_warn(fs_info,
5409                                    "can't set the %s feature bit%s while mounted",
5410                                    names, strchr(names, ',') ? "s" : "");
5411                         kfree(names);
5412                 } else
5413                         btrfs_warn(fs_info,
5414                                    "can't set %s bits 0x%llx while mounted",
5415                                    type, disallowed);
5416                 return -EPERM;
5417         }
5418
5419         disallowed = clear_mask & ~safe_clear;
5420         if (disallowed) {
5421                 names = btrfs_printable_features(set, disallowed);
5422                 if (names) {
5423                         btrfs_warn(fs_info,
5424                                    "can't clear the %s feature bit%s while mounted",
5425                                    names, strchr(names, ',') ? "s" : "");
5426                         kfree(names);
5427                 } else
5428                         btrfs_warn(fs_info,
5429                                    "can't clear %s bits 0x%llx while mounted",
5430                                    type, disallowed);
5431                 return -EPERM;
5432         }
5433
5434         return 0;
5435 }
5436
5437 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5438 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5439                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5440                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5441                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5442
5443 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5444 {
5445         struct inode *inode = file_inode(file);
5446         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5447         struct btrfs_root *root = BTRFS_I(inode)->root;
5448         struct btrfs_super_block *super_block = fs_info->super_copy;
5449         struct btrfs_ioctl_feature_flags flags[2];
5450         struct btrfs_trans_handle *trans;
5451         u64 newflags;
5452         int ret;
5453
5454         if (!capable(CAP_SYS_ADMIN))
5455                 return -EPERM;
5456
5457         if (copy_from_user(flags, arg, sizeof(flags)))
5458                 return -EFAULT;
5459
5460         /* Nothing to do */
5461         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5462             !flags[0].incompat_flags)
5463                 return 0;
5464
5465         ret = check_feature(fs_info, flags[0].compat_flags,
5466                             flags[1].compat_flags, COMPAT);
5467         if (ret)
5468                 return ret;
5469
5470         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5471                             flags[1].compat_ro_flags, COMPAT_RO);
5472         if (ret)
5473                 return ret;
5474
5475         ret = check_feature(fs_info, flags[0].incompat_flags,
5476                             flags[1].incompat_flags, INCOMPAT);
5477         if (ret)
5478                 return ret;
5479
5480         ret = mnt_want_write_file(file);
5481         if (ret)
5482                 return ret;
5483
5484         trans = btrfs_start_transaction(root, 0);
5485         if (IS_ERR(trans)) {
5486                 ret = PTR_ERR(trans);
5487                 goto out_drop_write;
5488         }
5489
5490         spin_lock(&fs_info->super_lock);
5491         newflags = btrfs_super_compat_flags(super_block);
5492         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5493         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5494         btrfs_set_super_compat_flags(super_block, newflags);
5495
5496         newflags = btrfs_super_compat_ro_flags(super_block);
5497         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5498         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5499         btrfs_set_super_compat_ro_flags(super_block, newflags);
5500
5501         newflags = btrfs_super_incompat_flags(super_block);
5502         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5503         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5504         btrfs_set_super_incompat_flags(super_block, newflags);
5505         spin_unlock(&fs_info->super_lock);
5506
5507         ret = btrfs_commit_transaction(trans);
5508 out_drop_write:
5509         mnt_drop_write_file(file);
5510
5511         return ret;
5512 }
5513
5514 long btrfs_ioctl(struct file *file, unsigned int
5515                 cmd, unsigned long arg)
5516 {
5517         struct inode *inode = file_inode(file);
5518         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5519         struct btrfs_root *root = BTRFS_I(inode)->root;
5520         void __user *argp = (void __user *)arg;
5521
5522         switch (cmd) {
5523         case FS_IOC_GETFLAGS:
5524                 return btrfs_ioctl_getflags(file, argp);
5525         case FS_IOC_SETFLAGS:
5526                 return btrfs_ioctl_setflags(file, argp);
5527         case FS_IOC_GETVERSION:
5528                 return btrfs_ioctl_getversion(file, argp);
5529         case FITRIM:
5530                 return btrfs_ioctl_fitrim(file, argp);
5531         case BTRFS_IOC_SNAP_CREATE:
5532                 return btrfs_ioctl_snap_create(file, argp, 0);
5533         case BTRFS_IOC_SNAP_CREATE_V2:
5534                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5535         case BTRFS_IOC_SUBVOL_CREATE:
5536                 return btrfs_ioctl_snap_create(file, argp, 1);
5537         case BTRFS_IOC_SUBVOL_CREATE_V2:
5538                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5539         case BTRFS_IOC_SNAP_DESTROY:
5540                 return btrfs_ioctl_snap_destroy(file, argp);
5541         case BTRFS_IOC_SUBVOL_GETFLAGS:
5542                 return btrfs_ioctl_subvol_getflags(file, argp);
5543         case BTRFS_IOC_SUBVOL_SETFLAGS:
5544                 return btrfs_ioctl_subvol_setflags(file, argp);
5545         case BTRFS_IOC_DEFAULT_SUBVOL:
5546                 return btrfs_ioctl_default_subvol(file, argp);
5547         case BTRFS_IOC_DEFRAG:
5548                 return btrfs_ioctl_defrag(file, NULL);
5549         case BTRFS_IOC_DEFRAG_RANGE:
5550                 return btrfs_ioctl_defrag(file, argp);
5551         case BTRFS_IOC_RESIZE:
5552                 return btrfs_ioctl_resize(file, argp);
5553         case BTRFS_IOC_ADD_DEV:
5554                 return btrfs_ioctl_add_dev(fs_info, argp);
5555         case BTRFS_IOC_RM_DEV:
5556                 return btrfs_ioctl_rm_dev(file, argp);
5557         case BTRFS_IOC_RM_DEV_V2:
5558                 return btrfs_ioctl_rm_dev_v2(file, argp);
5559         case BTRFS_IOC_FS_INFO:
5560                 return btrfs_ioctl_fs_info(fs_info, argp);
5561         case BTRFS_IOC_DEV_INFO:
5562                 return btrfs_ioctl_dev_info(fs_info, argp);
5563         case BTRFS_IOC_BALANCE:
5564                 return btrfs_ioctl_balance(file, NULL);
5565         case BTRFS_IOC_TRANS_START:
5566                 return btrfs_ioctl_trans_start(file);
5567         case BTRFS_IOC_TRANS_END:
5568                 return btrfs_ioctl_trans_end(file);
5569         case BTRFS_IOC_TREE_SEARCH:
5570                 return btrfs_ioctl_tree_search(file, argp);
5571         case BTRFS_IOC_TREE_SEARCH_V2:
5572                 return btrfs_ioctl_tree_search_v2(file, argp);
5573         case BTRFS_IOC_INO_LOOKUP:
5574                 return btrfs_ioctl_ino_lookup(file, argp);
5575         case BTRFS_IOC_INO_PATHS:
5576                 return btrfs_ioctl_ino_to_path(root, argp);
5577         case BTRFS_IOC_LOGICAL_INO:
5578                 return btrfs_ioctl_logical_to_ino(fs_info, argp);
5579         case BTRFS_IOC_SPACE_INFO:
5580                 return btrfs_ioctl_space_info(fs_info, argp);
5581         case BTRFS_IOC_SYNC: {
5582                 int ret;
5583
5584                 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
5585                 if (ret)
5586                         return ret;
5587                 ret = btrfs_sync_fs(inode->i_sb, 1);
5588                 /*
5589                  * The transaction thread may want to do more work,
5590                  * namely it pokes the cleaner kthread that will start
5591                  * processing uncleaned subvols.
5592                  */
5593                 wake_up_process(fs_info->transaction_kthread);
5594                 return ret;
5595         }
5596         case BTRFS_IOC_START_SYNC:
5597                 return btrfs_ioctl_start_sync(root, argp);
5598         case BTRFS_IOC_WAIT_SYNC:
5599                 return btrfs_ioctl_wait_sync(fs_info, argp);
5600         case BTRFS_IOC_SCRUB:
5601                 return btrfs_ioctl_scrub(file, argp);
5602         case BTRFS_IOC_SCRUB_CANCEL:
5603                 return btrfs_ioctl_scrub_cancel(fs_info);
5604         case BTRFS_IOC_SCRUB_PROGRESS:
5605                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5606         case BTRFS_IOC_BALANCE_V2:
5607                 return btrfs_ioctl_balance(file, argp);
5608         case BTRFS_IOC_BALANCE_CTL:
5609                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5610         case BTRFS_IOC_BALANCE_PROGRESS:
5611                 return btrfs_ioctl_balance_progress(fs_info, argp);
5612         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5613                 return btrfs_ioctl_set_received_subvol(file, argp);
5614 #ifdef CONFIG_64BIT
5615         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5616                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5617 #endif
5618         case BTRFS_IOC_SEND:
5619                 return btrfs_ioctl_send(file, argp);
5620         case BTRFS_IOC_GET_DEV_STATS:
5621                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5622         case BTRFS_IOC_QUOTA_CTL:
5623                 return btrfs_ioctl_quota_ctl(file, argp);
5624         case BTRFS_IOC_QGROUP_ASSIGN:
5625                 return btrfs_ioctl_qgroup_assign(file, argp);
5626         case BTRFS_IOC_QGROUP_CREATE:
5627                 return btrfs_ioctl_qgroup_create(file, argp);
5628         case BTRFS_IOC_QGROUP_LIMIT:
5629                 return btrfs_ioctl_qgroup_limit(file, argp);
5630         case BTRFS_IOC_QUOTA_RESCAN:
5631                 return btrfs_ioctl_quota_rescan(file, argp);
5632         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5633                 return btrfs_ioctl_quota_rescan_status(file, argp);
5634         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5635                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5636         case BTRFS_IOC_DEV_REPLACE:
5637                 return btrfs_ioctl_dev_replace(fs_info, argp);
5638         case BTRFS_IOC_GET_FSLABEL:
5639                 return btrfs_ioctl_get_fslabel(file, argp);
5640         case BTRFS_IOC_SET_FSLABEL:
5641                 return btrfs_ioctl_set_fslabel(file, argp);
5642         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5643                 return btrfs_ioctl_get_supported_features(argp);
5644         case BTRFS_IOC_GET_FEATURES:
5645                 return btrfs_ioctl_get_features(file, argp);
5646         case BTRFS_IOC_SET_FEATURES:
5647                 return btrfs_ioctl_set_features(file, argp);
5648         }
5649
5650         return -ENOTTY;
5651 }
5652
5653 #ifdef CONFIG_COMPAT
5654 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5655 {
5656         switch (cmd) {
5657         case FS_IOC32_GETFLAGS:
5658                 cmd = FS_IOC_GETFLAGS;
5659                 break;
5660         case FS_IOC32_SETFLAGS:
5661                 cmd = FS_IOC_SETFLAGS;
5662                 break;
5663         case FS_IOC32_GETVERSION:
5664                 cmd = FS_IOC_GETVERSION;
5665                 break;
5666         default:
5667                 return -ENOIOCTLCMD;
5668         }
5669
5670         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5671 }
5672 #endif