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 */
  70struct btrfs_ioctl_timespec_32 {
  71	__u64 sec;
  72	__u32 nsec;
  73} __attribute__ ((__packed__));
  74
  75struct 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
  90static 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. */
  95static 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 */
 108static 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 */
 138void 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 */
 164void 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
 190static 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
 200static 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
 215static 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
 368static 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
 375static 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
 424int 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
 435static 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
 612fail:
 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
 637fail_free:
 638	kfree(root_item);
 639	return ret;
 640}
 641
 642static 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
 659static 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;
 755fail:
 756	btrfs_subvolume_release_metadata(fs_info,
 757					 &pending_snapshot->block_rsv,
 758					 pending_snapshot->qgroup_reserved);
 759dec_and_free:
 760	if (atomic_dec_and_test(&root->will_be_snapshoted))
 761		wake_up_atomic_t(&root->will_be_snapshoted);
 762free_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
 790static 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() */
 823static 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 */
 837static 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);
 885out_up_read:
 886	up_read(&fs_info->subvol_sem);
 887out_dput:
 888	dput(dentry);
 889out_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 */
 901static 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 */
 934static 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;
 958process_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	}
 989none:
 990	btrfs_free_path(path);
 991	return -ENOENT;
 992}
 993
 994static 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
1025static 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
1045static 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;
1084out:
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 */
1117static 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;
1152again:
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;
1254out:
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
1266int 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
1473out_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
1485static 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
1621out_free:
1622	kfree(vol_args);
1623out:
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
1630static 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	}
1686out_drop_write:
1687	mnt_drop_write_file(file);
1688out:
1689	return ret;
1690}
1691
1692static 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
1714static 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
1767free_inherit:
1768	kfree(inherit);
1769free_args:
1770	kfree(vol_args);
1771	return ret;
1772}
1773
1774static 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
1797static 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);
1875out_reset:
1876	if (ret)
1877		btrfs_set_root_flags(&root->root_item, root_flags);
1878out_drop_sem:
1879	up_write(&fs_info->subvol_sem);
1880out_drop_write:
1881	mnt_drop_write_file(file);
1882out:
1883	return ret;
1884}
1885
1886/*
1887 * helper to check if the subvolume references other subvolumes
1888 */
1889static 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	}
1935out:
1936	btrfs_free_path(path);
1937	return ret;
1938}
1939
1940static 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
1964static 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	}
2057advance_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;
2075out:
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
2088static 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;
2144err:
2145	sk->nr_items = num_found;
2146	btrfs_free_path(path);
2147	return ret;
2148}
2149
2150static 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
2184static 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 */
2227static 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;
2308out:
2309	btrfs_free_path(path);
2310	return ret;
2311}
2312
2313static 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
2347out:
2348	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2349		ret = -EFAULT;
2350
2351	kfree(args);
2352	return ret;
2353}
2354
2355static 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
2550out_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;
2557out_release:
2558	btrfs_subvolume_release_metadata(fs_info, &block_rsv, qgroup_reserved);
2559out_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	}
2568out_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	}
2582out_dput:
2583	dput(dentry);
2584out_unlock_dir:
2585	inode_unlock(dir);
2586out_drop_write:
2587	mnt_drop_write_file(file);
2588out:
2589	kfree(vol_args);
2590	return err;
2591}
2592
2593static 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	}
2657out:
2658	mnt_drop_write_file(file);
2659	return ret;
2660}
2661
2662static 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);
2687out:
2688	mutex_unlock(&fs_info->volume_mutex);
2689	atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
2690	return ret;
2691}
2692
2693static 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	}
2740out:
2741	kfree(vol_args);
2742err_drop:
2743	mnt_drop_write_file(file);
2744	return ret;
2745}
2746
2747static 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);
2780out:
2781	atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
2782out_drop_write:
2783	mnt_drop_write_file(file);
2784
2785	return ret;
2786}
2787
2788static 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
2821static 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
2861out:
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
2870static 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
2900static 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++) {
2907again:
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
2921static 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
2956static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2957{
2958	inode_unlock(inode1);
2959	inode_unlock(inode2);
2960}
2961
2962static 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
2971static 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
2978static 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
2998struct cmp_pages {
2999	int		num_pages;
3000	struct page	**src_pages;
3001	struct page	**dst_pages;
3002};
3003
3004static 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
3025static 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
3056out:
3057	if (ret)
3058		btrfs_cmp_data_free(cmp);
3059	return 0;
3060}
3061
3062static 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
3105static 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
3125static 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
3197again:
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);
3250out_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
3261ssize_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
3287static 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);
3316out:
3317	return ret;
3318}
3319
3320static 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 */
3402static 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
3478copy_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 */
3533static 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]);
3595process_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
3861out:
3862	btrfs_free_path(path);
3863	kvfree(buf);
3864	return ret;
3865}
3866
3867static 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);
3982out_unlock:
3983	if (!same_inode)
3984		btrfs_double_inode_unlock(src, inode);
3985	else
3986		inode_unlock(src);
3987	return ret;
3988}
3989
 
 
 
 
 
 
 
 
 
 
 
 
3990int 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 */
4002static 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
4036out_drop:
4037	atomic_dec(&fs_info->open_ioctl_trans);
4038	mnt_drop_write_file(file);
4039out:
4040	return ret;
4041}
4042
4043static 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);
4116out:
4117	mnt_drop_write_file(file);
4118	return ret;
4119}
4120
4121void 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
4137static 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);
4271out:
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 */
4284long 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
4303static 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	}
4325out:
4326	if (argp)
4327		if (copy_to_user(argp, &transid, sizeof(transid)))
4328			return -EFAULT;
4329	return 0;
4330}
4331
4332static 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
4346static 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);
4374out:
4375	kfree(sa);
4376	return ret;
4377}
4378
4379static 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
4387static 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
4409static 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
4433static 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;
4475out:
4476	kfree(p);
4477	return ret;
4478}
4479
4480static 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
4531out:
4532	btrfs_free_path(path);
4533	free_ipath(ipath);
4534	kfree(ipa);
4535
4536	return ret;
4537}
4538
4539static 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
4559static 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
4601out:
4602	btrfs_free_path(path);
4603	vfree(inodes);
4604	kfree(loi);
4605
4606	return ret;
4607}
4608
4609void 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
4636static 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
4652again:
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
4698locked:
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
4753do_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
4771out_bctl:
4772	kfree(bctl);
4773out_bargs:
4774	kfree(bargs);
4775out_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);
4780out:
4781	mnt_drop_write_file(file);
4782	return ret;
4783}
4784
4785static 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
4800static 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);
4827out:
4828	mutex_unlock(&fs_info->balance_mutex);
4829	return ret;
4830}
4831
4832static 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;
4876out:
4877	kfree(sa);
4878	up_write(&fs_info->subvol_sem);
4879drop_write:
4880	mnt_drop_write_file(file);
4881	return ret;
4882}
4883
4884static 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
4931out:
4932	kfree(sa);
4933drop_write:
4934	mnt_drop_write_file(file);
4935	return ret;
4936}
4937
4938static 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
4983out:
4984	kfree(sa);
4985drop_write:
4986	mnt_drop_write_file(file);
4987	return ret;
4988}
4989
4990static 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
5033out:
5034	kfree(sa);
5035drop_write:
5036	mnt_drop_write_file(file);
5037	return ret;
5038}
5039
5040static 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
5067out:
5068	kfree(qsa);
5069drop_write:
5070	mnt_drop_write_file(file);
5071	return ret;
5072}
5073
5074static 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
5100static 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
5111static 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
5193out:
5194	up_write(&fs_info->subvol_sem);
5195	mnt_drop_write_file(file);
5196	return ret;
5197}
5198
5199#ifdef CONFIG_64BIT
5200static 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
5243out:
5244	kfree(args32);
5245	kfree(args64);
5246	return ret;
5247}
5248#endif
5249
5250static 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
5269out:
5270	kfree(sa);
5271	return ret;
5272}
5273
5274static 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
5299static 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
5337out_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
5347int 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
5361static 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
5378static 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)	\
5438check_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
5443static 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);
5508out_drop_write:
5509	mnt_drop_write_file(file);
5510
5511	return ret;
5512}
5513
5514long 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
5654long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5655{
5656	/*
5657	 * These all access 32-bit values anyway so no further
5658	 * handling is necessary.
5659	 */
5660	switch (cmd) {
5661	case FS_IOC32_GETFLAGS:
5662		cmd = FS_IOC_GETFLAGS;
5663		break;
5664	case FS_IOC32_SETFLAGS:
5665		cmd = FS_IOC_SETFLAGS;
5666		break;
5667	case FS_IOC32_GETVERSION:
5668		cmd = FS_IOC_GETVERSION;
5669		break;
5670	}
5671
5672	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5673}
5674#endif