1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2007 Oracle.  All rights reserved.
   4 */
   5
   6#include <linux/kernel.h>
   7#include <linux/bio.h>
   8#include <linux/buffer_head.h>
   9#include <linux/file.h>
  10#include <linux/fs.h>
  11#include <linux/fsnotify.h>
  12#include <linux/pagemap.h>
  13#include <linux/highmem.h>
  14#include <linux/time.h>
  15#include <linux/init.h>
  16#include <linux/string.h>
  17#include <linux/backing-dev.h>
  18#include <linux/mount.h>
  19#include <linux/mpage.h>
  20#include <linux/namei.h>
  21#include <linux/swap.h>
  22#include <linux/writeback.h>
  23#include <linux/compat.h>
  24#include <linux/bit_spinlock.h>
  25#include <linux/security.h>
  26#include <linux/xattr.h>
  27#include <linux/mm.h>
  28#include <linux/slab.h>
  29#include <linux/blkdev.h>
  30#include <linux/uuid.h>
  31#include <linux/btrfs.h>
  32#include <linux/uaccess.h>
  33#include <linux/iversion.h>
 
  34#include "ctree.h"
  35#include "disk-io.h"
 
  36#include "transaction.h"
  37#include "btrfs_inode.h"
  38#include "print-tree.h"
  39#include "volumes.h"
  40#include "locking.h"
  41#include "inode-map.h"
  42#include "backref.h"
  43#include "rcu-string.h"
  44#include "send.h"
  45#include "dev-replace.h"
  46#include "props.h"
  47#include "sysfs.h"
  48#include "qgroup.h"
  49#include "tree-log.h"
  50#include "compression.h"
 
 
 
  51
  52#ifdef CONFIG_64BIT
  53/* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  54 * structures are incorrect, as the timespec structure from userspace
  55 * is 4 bytes too small. We define these alternatives here to teach
  56 * the kernel about the 32-bit struct packing.
  57 */
  58struct btrfs_ioctl_timespec_32 {
  59	__u64 sec;
  60	__u32 nsec;
  61} __attribute__ ((__packed__));
  62
  63struct btrfs_ioctl_received_subvol_args_32 {
  64	char	uuid[BTRFS_UUID_SIZE];	/* in */
  65	__u64	stransid;		/* in */
  66	__u64	rtransid;		/* out */
  67	struct btrfs_ioctl_timespec_32 stime; /* in */
  68	struct btrfs_ioctl_timespec_32 rtime; /* out */
  69	__u64	flags;			/* in */
  70	__u64	reserved[16];		/* in */
  71} __attribute__ ((__packed__));
  72
  73#define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  74				struct btrfs_ioctl_received_subvol_args_32)
  75#endif
  76
  77#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  78struct btrfs_ioctl_send_args_32 {
  79	__s64 send_fd;			/* in */
  80	__u64 clone_sources_count;	/* in */
  81	compat_uptr_t clone_sources;	/* in */
  82	__u64 parent_root;		/* in */
  83	__u64 flags;			/* in */
  84	__u64 reserved[4];		/* in */
  85} __attribute__ ((__packed__));
  86
  87#define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  88			       struct btrfs_ioctl_send_args_32)
  89#endif
  90
  91static int btrfs_clone(struct inode *src, struct inode *inode,
  92		       u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  93		       int no_time_update);
  94
  95/* Mask out flags that are inappropriate for the given type of inode. */
  96static unsigned int btrfs_mask_flags(umode_t mode, unsigned int flags)
 
  97{
  98	if (S_ISDIR(mode))
  99		return flags;
 100	else if (S_ISREG(mode))
 101		return flags & ~FS_DIRSYNC_FL;
 102	else
 103		return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 104}
 105
 106/*
 107 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
 
 108 */
 109static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
 110{
 111	unsigned int iflags = 0;
 112
 113	if (flags & BTRFS_INODE_SYNC)
 114		iflags |= FS_SYNC_FL;
 115	if (flags & BTRFS_INODE_IMMUTABLE)
 116		iflags |= FS_IMMUTABLE_FL;
 117	if (flags & BTRFS_INODE_APPEND)
 118		iflags |= FS_APPEND_FL;
 119	if (flags & BTRFS_INODE_NODUMP)
 120		iflags |= FS_NODUMP_FL;
 121	if (flags & BTRFS_INODE_NOATIME)
 122		iflags |= FS_NOATIME_FL;
 123	if (flags & BTRFS_INODE_DIRSYNC)
 124		iflags |= FS_DIRSYNC_FL;
 125	if (flags & BTRFS_INODE_NODATACOW)
 126		iflags |= FS_NOCOW_FL;
 127
 128	if (flags & BTRFS_INODE_NOCOMPRESS)
 129		iflags |= FS_NOCOMP_FL;
 130	else if (flags & BTRFS_INODE_COMPRESS)
 131		iflags |= FS_COMPR_FL;
 132
 133	return iflags;
 134}
 135
 136/*
 137 * Update inode->i_flags based on the btrfs internal flags.
 138 */
 139void btrfs_update_iflags(struct inode *inode)
 140{
 141	struct btrfs_inode *ip = BTRFS_I(inode);
 142	unsigned int new_fl = 0;
 143
 144	if (ip->flags & BTRFS_INODE_SYNC)
 145		new_fl |= S_SYNC;
 146	if (ip->flags & BTRFS_INODE_IMMUTABLE)
 147		new_fl |= S_IMMUTABLE;
 148	if (ip->flags & BTRFS_INODE_APPEND)
 149		new_fl |= S_APPEND;
 150	if (ip->flags & BTRFS_INODE_NOATIME)
 151		new_fl |= S_NOATIME;
 152	if (ip->flags & BTRFS_INODE_DIRSYNC)
 153		new_fl |= S_DIRSYNC;
 154
 155	set_mask_bits(&inode->i_flags,
 156		      S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 157		      new_fl);
 158}
 159
 160static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 161{
 162	struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 163	unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 164
 165	if (copy_to_user(arg, &flags, sizeof(flags)))
 166		return -EFAULT;
 167	return 0;
 168}
 169
 170static int check_flags(unsigned int flags)
 171{
 172	if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 173		      FS_NOATIME_FL | FS_NODUMP_FL | \
 174		      FS_SYNC_FL | FS_DIRSYNC_FL | \
 175		      FS_NOCOMP_FL | FS_COMPR_FL |
 176		      FS_NOCOW_FL))
 177		return -EOPNOTSUPP;
 178
 
 179	if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 180		return -EINVAL;
 181
 
 
 
 
 
 
 
 
 
 182	return 0;
 183}
 184
 185static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 
 186{
 187	struct inode *inode = file_inode(file);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 188	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 189	struct btrfs_inode *ip = BTRFS_I(inode);
 190	struct btrfs_root *root = ip->root;
 191	struct btrfs_trans_handle *trans;
 192	unsigned int flags, oldflags;
 193	int ret;
 194	u64 ip_oldflags;
 195	unsigned int i_oldflags;
 196	umode_t mode;
 197
 198	if (!inode_owner_or_capable(inode))
 199		return -EPERM;
 200
 201	if (btrfs_root_readonly(root))
 202		return -EROFS;
 203
 204	if (copy_from_user(&flags, arg, sizeof(flags)))
 205		return -EFAULT;
 206
 207	ret = check_flags(flags);
 
 
 208	if (ret)
 209		return ret;
 210
 211	ret = mnt_want_write_file(file);
 212	if (ret)
 213		return ret;
 214
 215	inode_lock(inode);
 216
 217	ip_oldflags = ip->flags;
 218	i_oldflags = inode->i_flags;
 219	mode = inode->i_mode;
 220
 221	flags = btrfs_mask_flags(inode->i_mode, flags);
 222	oldflags = btrfs_flags_to_ioctl(ip->flags);
 223	if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 224		if (!capable(CAP_LINUX_IMMUTABLE)) {
 225			ret = -EPERM;
 226			goto out_unlock;
 227		}
 228	}
 229
 230	if (flags & FS_SYNC_FL)
 231		ip->flags |= BTRFS_INODE_SYNC;
 232	else
 233		ip->flags &= ~BTRFS_INODE_SYNC;
 234	if (flags & FS_IMMUTABLE_FL)
 235		ip->flags |= BTRFS_INODE_IMMUTABLE;
 236	else
 237		ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 238	if (flags & FS_APPEND_FL)
 239		ip->flags |= BTRFS_INODE_APPEND;
 240	else
 241		ip->flags &= ~BTRFS_INODE_APPEND;
 242	if (flags & FS_NODUMP_FL)
 243		ip->flags |= BTRFS_INODE_NODUMP;
 244	else
 245		ip->flags &= ~BTRFS_INODE_NODUMP;
 246	if (flags & FS_NOATIME_FL)
 247		ip->flags |= BTRFS_INODE_NOATIME;
 248	else
 249		ip->flags &= ~BTRFS_INODE_NOATIME;
 250	if (flags & FS_DIRSYNC_FL)
 251		ip->flags |= BTRFS_INODE_DIRSYNC;
 
 
 
 
 
 
 
 
 
 
 252	else
 253		ip->flags &= ~BTRFS_INODE_DIRSYNC;
 254	if (flags & FS_NOCOW_FL) {
 255		if (S_ISREG(mode)) {
 256			/*
 257			 * It's safe to turn csums off here, no extents exist.
 258			 * Otherwise we want the flag to reflect the real COW
 259			 * status of the file and will not set it.
 260			 */
 261			if (inode->i_size == 0)
 262				ip->flags |= BTRFS_INODE_NODATACOW
 263					   | BTRFS_INODE_NODATASUM;
 264		} else {
 265			ip->flags |= BTRFS_INODE_NODATACOW;
 266		}
 267	} else {
 268		/*
 269		 * Revert back under same assumptions as above
 270		 */
 271		if (S_ISREG(mode)) {
 272			if (inode->i_size == 0)
 273				ip->flags &= ~(BTRFS_INODE_NODATACOW
 274				             | BTRFS_INODE_NODATASUM);
 275		} else {
 276			ip->flags &= ~BTRFS_INODE_NODATACOW;
 277		}
 278	}
 279
 280	/*
 281	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 282	 * flag may be changed automatically if compression code won't make
 283	 * things smaller.
 284	 */
 285	if (flags & FS_NOCOMP_FL) {
 286		ip->flags &= ~BTRFS_INODE_COMPRESS;
 287		ip->flags |= BTRFS_INODE_NOCOMPRESS;
 288
 289		ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 290		if (ret && ret != -ENODATA)
 291			goto out_drop;
 292	} else if (flags & FS_COMPR_FL) {
 293		const char *comp;
 294
 295		ip->flags |= BTRFS_INODE_COMPRESS;
 296		ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 297
 298		comp = btrfs_compress_type2str(fs_info->compress_type);
 299		if (!comp || comp[0] == 0)
 300			comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 301
 302		ret = btrfs_set_prop(inode, "btrfs.compression",
 303				     comp, strlen(comp), 0);
 304		if (ret)
 305			goto out_drop;
 306
 307	} else {
 308		ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 309		if (ret && ret != -ENODATA)
 310			goto out_drop;
 311		ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 312	}
 313
 314	trans = btrfs_start_transaction(root, 1);
 315	if (IS_ERR(trans)) {
 316		ret = PTR_ERR(trans);
 317		goto out_drop;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 318	}
 319
 320	btrfs_update_iflags(inode);
 
 
 321	inode_inc_iversion(inode);
 322	inode->i_ctime = current_time(inode);
 323	ret = btrfs_update_inode(trans, root, inode);
 324
 
 325	btrfs_end_transaction(trans);
 326 out_drop:
 327	if (ret) {
 328		ip->flags = ip_oldflags;
 329		inode->i_flags = i_oldflags;
 
 
 
 
 
 
 
 
 
 
 
 330	}
 
 331
 332 out_unlock:
 333	inode_unlock(inode);
 334	mnt_drop_write_file(file);
 335	return ret;
 336}
 337
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 338static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 339{
 340	struct inode *inode = file_inode(file);
 341
 342	return put_user(inode->i_generation, arg);
 343}
 344
 345static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 
 346{
 347	struct inode *inode = file_inode(file);
 348	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 349	struct btrfs_device *device;
 350	struct request_queue *q;
 351	struct fstrim_range range;
 352	u64 minlen = ULLONG_MAX;
 353	u64 num_devices = 0;
 354	u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 355	int ret;
 356
 357	if (!capable(CAP_SYS_ADMIN))
 358		return -EPERM;
 359
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 360	rcu_read_lock();
 361	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 362				dev_list) {
 363		if (!device->bdev)
 364			continue;
 365		q = bdev_get_queue(device->bdev);
 366		if (blk_queue_discard(q)) {
 367			num_devices++;
 368			minlen = min_t(u64, q->limits.discard_granularity,
 369				     minlen);
 370		}
 371	}
 372	rcu_read_unlock();
 373
 374	if (!num_devices)
 375		return -EOPNOTSUPP;
 376	if (copy_from_user(&range, arg, sizeof(range)))
 377		return -EFAULT;
 378	if (range.start > total_bytes ||
 379	    range.len < fs_info->sb->s_blocksize)
 
 
 
 
 
 380		return -EINVAL;
 381
 382	range.len = min(range.len, total_bytes - range.start);
 383	range.minlen = max(range.minlen, minlen);
 384	ret = btrfs_trim_fs(fs_info, &range);
 385	if (ret < 0)
 386		return ret;
 387
 388	if (copy_to_user(arg, &range, sizeof(range)))
 389		return -EFAULT;
 390
 391	return 0;
 392}
 393
 394int btrfs_is_empty_uuid(u8 *uuid)
 395{
 396	int i;
 397
 398	for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 399		if (uuid[i])
 400			return 0;
 401	}
 402	return 1;
 403}
 404
 405static noinline int create_subvol(struct inode *dir,
 406				  struct dentry *dentry,
 407				  const char *name, int namelen,
 408				  u64 *async_transid,
 409				  struct btrfs_qgroup_inherit *inherit)
 410{
 411	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 412	struct btrfs_trans_handle *trans;
 413	struct btrfs_key key;
 414	struct btrfs_root_item *root_item;
 415	struct btrfs_inode_item *inode_item;
 416	struct extent_buffer *leaf;
 417	struct btrfs_root *root = BTRFS_I(dir)->root;
 418	struct btrfs_root *new_root;
 419	struct btrfs_block_rsv block_rsv;
 420	struct timespec cur_time = current_time(dir);
 421	struct inode *inode;
 422	int ret;
 423	int err;
 
 424	u64 objectid;
 425	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 426	u64 index = 0;
 427	u64 qgroup_reserved;
 428	uuid_le new_uuid;
 429
 430	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 431	if (!root_item)
 432		return -ENOMEM;
 433
 434	ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 435	if (ret)
 436		goto fail_free;
 437
 
 
 
 
 438	/*
 439	 * Don't create subvolume whose level is not zero. Or qgroup will be
 440	 * screwed up since it assumes subvolume qgroup's level to be 0.
 441	 */
 442	if (btrfs_qgroup_level(objectid)) {
 443		ret = -ENOSPC;
 444		goto fail_free;
 445	}
 446
 447	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 448	/*
 449	 * The same as the snapshot creation, please see the comment
 450	 * of create_snapshot().
 451	 */
 452	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 453					       8, &qgroup_reserved, false);
 454	if (ret)
 455		goto fail_free;
 456
 457	trans = btrfs_start_transaction(root, 0);
 458	if (IS_ERR(trans)) {
 459		ret = PTR_ERR(trans);
 460		btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 461		goto fail_free;
 462	}
 463	trans->block_rsv = &block_rsv;
 464	trans->bytes_reserved = block_rsv.size;
 465
 466	ret = btrfs_qgroup_inherit(trans, fs_info, 0, objectid, inherit);
 467	if (ret)
 468		goto fail;
 469
 470	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 
 471	if (IS_ERR(leaf)) {
 472		ret = PTR_ERR(leaf);
 473		goto fail;
 474	}
 475
 476	memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
 477	btrfs_set_header_bytenr(leaf, leaf->start);
 478	btrfs_set_header_generation(leaf, trans->transid);
 479	btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 480	btrfs_set_header_owner(leaf, objectid);
 481
 482	write_extent_buffer_fsid(leaf, fs_info->fsid);
 483	write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
 484	btrfs_mark_buffer_dirty(leaf);
 485
 486	inode_item = &root_item->inode;
 487	btrfs_set_stack_inode_generation(inode_item, 1);
 488	btrfs_set_stack_inode_size(inode_item, 3);
 489	btrfs_set_stack_inode_nlink(inode_item, 1);
 490	btrfs_set_stack_inode_nbytes(inode_item,
 491				     fs_info->nodesize);
 492	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 493
 494	btrfs_set_root_flags(root_item, 0);
 495	btrfs_set_root_limit(root_item, 0);
 496	btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 497
 498	btrfs_set_root_bytenr(root_item, leaf->start);
 499	btrfs_set_root_generation(root_item, trans->transid);
 500	btrfs_set_root_level(root_item, 0);
 501	btrfs_set_root_refs(root_item, 1);
 502	btrfs_set_root_used(root_item, leaf->len);
 503	btrfs_set_root_last_snapshot(root_item, 0);
 504
 505	btrfs_set_root_generation_v2(root_item,
 506			btrfs_root_generation(root_item));
 507	uuid_le_gen(&new_uuid);
 508	memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 509	btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 510	btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 511	root_item->ctime = root_item->otime;
 512	btrfs_set_root_ctransid(root_item, trans->transid);
 513	btrfs_set_root_otransid(root_item, trans->transid);
 514
 515	btrfs_tree_unlock(leaf);
 516	free_extent_buffer(leaf);
 517	leaf = NULL;
 518
 519	btrfs_set_root_dirid(root_item, new_dirid);
 520
 521	key.objectid = objectid;
 522	key.offset = 0;
 523	key.type = BTRFS_ROOT_ITEM_KEY;
 524	ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 525				root_item);
 526	if (ret)
 
 
 
 
 
 
 
 
 
 
 527		goto fail;
 
 
 
 
 528
 529	key.offset = (u64)-1;
 530	new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 531	if (IS_ERR(new_root)) {
 
 532		ret = PTR_ERR(new_root);
 533		btrfs_abort_transaction(trans, ret);
 534		goto fail;
 535	}
 
 
 536
 537	btrfs_record_root_in_trans(trans, new_root);
 
 
 
 
 
 538
 539	ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 
 540	if (ret) {
 541		/* We potentially lose an unused inode item here */
 542		btrfs_abort_transaction(trans, ret);
 543		goto fail;
 544	}
 545
 546	mutex_lock(&new_root->objectid_mutex);
 547	new_root->highest_objectid = new_dirid;
 548	mutex_unlock(&new_root->objectid_mutex);
 549
 550	/*
 551	 * insert the directory item
 552	 */
 553	ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 554	if (ret) {
 555		btrfs_abort_transaction(trans, ret);
 556		goto fail;
 557	}
 558
 559	ret = btrfs_insert_dir_item(trans, root,
 560				    name, namelen, BTRFS_I(dir), &key,
 561				    BTRFS_FT_DIR, index);
 562	if (ret) {
 563		btrfs_abort_transaction(trans, ret);
 564		goto fail;
 565	}
 566
 567	btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 568	ret = btrfs_update_inode(trans, root, dir);
 569	BUG_ON(ret);
 
 
 
 570
 571	ret = btrfs_add_root_ref(trans, fs_info,
 572				 objectid, root->root_key.objectid,
 573				 btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 574	BUG_ON(ret);
 
 
 
 575
 576	ret = btrfs_uuid_tree_add(trans, fs_info, root_item->uuid,
 577				  BTRFS_UUID_KEY_SUBVOL, objectid);
 578	if (ret)
 579		btrfs_abort_transaction(trans, ret);
 580
 581fail:
 582	kfree(root_item);
 583	trans->block_rsv = NULL;
 584	trans->bytes_reserved = 0;
 585	btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 586
 587	if (async_transid) {
 588		*async_transid = trans->transid;
 589		err = btrfs_commit_transaction_async(trans, 1);
 590		if (err)
 591			err = btrfs_commit_transaction(trans);
 592	} else {
 593		err = btrfs_commit_transaction(trans);
 594	}
 595	if (err && !ret)
 596		ret = err;
 597
 598	if (!ret) {
 599		inode = btrfs_lookup_dentry(dir, dentry);
 600		if (IS_ERR(inode))
 601			return PTR_ERR(inode);
 602		d_instantiate(dentry, inode);
 603	}
 604	return ret;
 605
 606fail_free:
 
 
 607	kfree(root_item);
 608	return ret;
 609}
 610
 611static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 612			   struct dentry *dentry,
 613			   u64 *async_transid, bool readonly,
 614			   struct btrfs_qgroup_inherit *inherit)
 615{
 616	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 617	struct inode *inode;
 618	struct btrfs_pending_snapshot *pending_snapshot;
 619	struct btrfs_trans_handle *trans;
 620	int ret;
 621
 622	if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 623		return -EINVAL;
 624
 
 
 
 
 
 
 625	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 626	if (!pending_snapshot)
 627		return -ENOMEM;
 628
 
 
 
 629	pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 630			GFP_KERNEL);
 631	pending_snapshot->path = btrfs_alloc_path();
 632	if (!pending_snapshot->root_item || !pending_snapshot->path) {
 633		ret = -ENOMEM;
 634		goto free_pending;
 635	}
 636
 637	atomic_inc(&root->will_be_snapshotted);
 638	smp_mb__after_atomic();
 639	/* wait for no snapshot writes */
 640	wait_event(root->subv_writers->wait,
 641		   percpu_counter_sum(&root->subv_writers->counter) == 0);
 642
 643	ret = btrfs_start_delalloc_inodes(root, 0);
 644	if (ret)
 645		goto dec_and_free;
 646
 647	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 648
 649	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 650			     BTRFS_BLOCK_RSV_TEMP);
 651	/*
 652	 * 1 - parent dir inode
 653	 * 2 - dir entries
 654	 * 1 - root item
 655	 * 2 - root ref/backref
 656	 * 1 - root of snapshot
 657	 * 1 - UUID item
 658	 */
 659	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 660					&pending_snapshot->block_rsv, 8,
 661					&pending_snapshot->qgroup_reserved,
 662					false);
 663	if (ret)
 664		goto dec_and_free;
 665
 666	pending_snapshot->dentry = dentry;
 667	pending_snapshot->root = root;
 668	pending_snapshot->readonly = readonly;
 669	pending_snapshot->dir = dir;
 670	pending_snapshot->inherit = inherit;
 671
 672	trans = btrfs_start_transaction(root, 0);
 673	if (IS_ERR(trans)) {
 674		ret = PTR_ERR(trans);
 675		goto fail;
 676	}
 677
 678	spin_lock(&fs_info->trans_lock);
 679	list_add(&pending_snapshot->list,
 680		 &trans->transaction->pending_snapshots);
 681	spin_unlock(&fs_info->trans_lock);
 682	if (async_transid) {
 683		*async_transid = trans->transid;
 684		ret = btrfs_commit_transaction_async(trans, 1);
 685		if (ret)
 686			ret = btrfs_commit_transaction(trans);
 687	} else {
 688		ret = btrfs_commit_transaction(trans);
 689	}
 690	if (ret)
 691		goto fail;
 692
 693	ret = pending_snapshot->error;
 694	if (ret)
 695		goto fail;
 696
 697	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 698	if (ret)
 699		goto fail;
 700
 701	inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 702	if (IS_ERR(inode)) {
 703		ret = PTR_ERR(inode);
 704		goto fail;
 705	}
 706
 707	d_instantiate(dentry, inode);
 708	ret = 0;
 
 709fail:
 710	btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 711dec_and_free:
 712	if (atomic_dec_and_test(&root->will_be_snapshotted))
 713		wake_up_var(&root->will_be_snapshotted);
 
 714free_pending:
 
 
 715	kfree(pending_snapshot->root_item);
 716	btrfs_free_path(pending_snapshot->path);
 717	kfree(pending_snapshot);
 718
 719	return ret;
 720}
 721
 722/*  copy of may_delete in fs/namei.c()
 723 *	Check whether we can remove a link victim from directory dir, check
 724 *  whether the type of victim is right.
 725 *  1. We can't do it if dir is read-only (done in permission())
 726 *  2. We should have write and exec permissions on dir
 727 *  3. We can't remove anything from append-only dir
 728 *  4. We can't do anything with immutable dir (done in permission())
 729 *  5. If the sticky bit on dir is set we should either
 730 *	a. be owner of dir, or
 731 *	b. be owner of victim, or
 732 *	c. have CAP_FOWNER capability
 733 *  6. If the victim is append-only or immutable we can't do anything with
 734 *     links pointing to it.
 735 *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 736 *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 737 *  9. We can't remove a root or mountpoint.
 738 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 739 *     nfs_async_unlink().
 740 */
 741
 742static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 743{
 744	int error;
 745
 746	if (d_really_is_negative(victim))
 747		return -ENOENT;
 748
 749	BUG_ON(d_inode(victim->d_parent) != dir);
 750	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 751
 752	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 753	if (error)
 754		return error;
 755	if (IS_APPEND(dir))
 756		return -EPERM;
 757	if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 758	    IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 
 759		return -EPERM;
 760	if (isdir) {
 761		if (!d_is_dir(victim))
 762			return -ENOTDIR;
 763		if (IS_ROOT(victim))
 764			return -EBUSY;
 765	} else if (d_is_dir(victim))
 766		return -EISDIR;
 767	if (IS_DEADDIR(dir))
 768		return -ENOENT;
 769	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 770		return -EBUSY;
 771	return 0;
 772}
 773
 774/* copy of may_create in fs/namei.c() */
 775static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 776{
 777	if (d_really_is_positive(child))
 778		return -EEXIST;
 779	if (IS_DEADDIR(dir))
 780		return -ENOENT;
 781	return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 782}
 783
 784/*
 785 * Create a new subvolume below @parent.  This is largely modeled after
 786 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 787 * inside this filesystem so it's quite a bit simpler.
 788 */
 789static noinline int btrfs_mksubvol(const struct path *parent,
 790				   const char *name, int namelen,
 791				   struct btrfs_root *snap_src,
 792				   u64 *async_transid, bool readonly,
 793				   struct btrfs_qgroup_inherit *inherit)
 794{
 795	struct inode *dir = d_inode(parent->dentry);
 796	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 797	struct dentry *dentry;
 798	int error;
 799
 800	error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 801	if (error == -EINTR)
 802		return error;
 803
 804	dentry = lookup_one_len(name, parent->dentry, namelen);
 805	error = PTR_ERR(dentry);
 806	if (IS_ERR(dentry))
 807		goto out_unlock;
 808
 809	error = btrfs_may_create(dir, dentry);
 810	if (error)
 811		goto out_dput;
 812
 813	/*
 814	 * even if this name doesn't exist, we may get hash collisions.
 815	 * check for them now when we can safely fail
 816	 */
 817	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 818					       dir->i_ino, name,
 819					       namelen);
 820	if (error)
 821		goto out_dput;
 822
 823	down_read(&fs_info->subvol_sem);
 824
 825	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 826		goto out_up_read;
 827
 828	if (snap_src) {
 829		error = create_snapshot(snap_src, dir, dentry,
 830					async_transid, readonly, inherit);
 831	} else {
 832		error = create_subvol(dir, dentry, name, namelen,
 833				      async_transid, inherit);
 834	}
 835	if (!error)
 836		fsnotify_mkdir(dir, dentry);
 837out_up_read:
 838	up_read(&fs_info->subvol_sem);
 839out_dput:
 840	dput(dentry);
 841out_unlock:
 842	inode_unlock(dir);
 843	return error;
 844}
 845
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 846/*
 847 * When we're defragging a range, we don't want to kick it off again
 848 * if it is really just waiting for delalloc to send it down.
 849 * If we find a nice big extent or delalloc range for the bytes in the
 850 * file you want to defrag, we return 0 to let you know to skip this
 851 * part of the file
 852 */
 853static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 854{
 855	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 856	struct extent_map *em = NULL;
 857	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 858	u64 end;
 859
 860	read_lock(&em_tree->lock);
 861	em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 862	read_unlock(&em_tree->lock);
 863
 864	if (em) {
 865		end = extent_map_end(em);
 866		free_extent_map(em);
 867		if (end - offset > thresh)
 868			return 0;
 869	}
 870	/* if we already have a nice delalloc here, just stop */
 871	thresh /= 2;
 872	end = count_range_bits(io_tree, &offset, offset + thresh,
 873			       thresh, EXTENT_DELALLOC, 1);
 874	if (end >= thresh)
 875		return 0;
 876	return 1;
 877}
 878
 879/*
 880 * helper function to walk through a file and find extents
 881 * newer than a specific transid, and smaller than thresh.
 882 *
 883 * This is used by the defragging code to find new and small
 884 * extents
 885 */
 886static int find_new_extents(struct btrfs_root *root,
 887			    struct inode *inode, u64 newer_than,
 888			    u64 *off, u32 thresh)
 889{
 890	struct btrfs_path *path;
 891	struct btrfs_key min_key;
 892	struct extent_buffer *leaf;
 893	struct btrfs_file_extent_item *extent;
 894	int type;
 895	int ret;
 896	u64 ino = btrfs_ino(BTRFS_I(inode));
 897
 898	path = btrfs_alloc_path();
 899	if (!path)
 900		return -ENOMEM;
 901
 902	min_key.objectid = ino;
 903	min_key.type = BTRFS_EXTENT_DATA_KEY;
 904	min_key.offset = *off;
 905
 906	while (1) {
 907		ret = btrfs_search_forward(root, &min_key, path, newer_than);
 908		if (ret != 0)
 909			goto none;
 910process_slot:
 911		if (min_key.objectid != ino)
 912			goto none;
 913		if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 914			goto none;
 915
 916		leaf = path->nodes[0];
 917		extent = btrfs_item_ptr(leaf, path->slots[0],
 918					struct btrfs_file_extent_item);
 919
 920		type = btrfs_file_extent_type(leaf, extent);
 921		if (type == BTRFS_FILE_EXTENT_REG &&
 922		    btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 923		    check_defrag_in_cache(inode, min_key.offset, thresh)) {
 924			*off = min_key.offset;
 925			btrfs_free_path(path);
 926			return 0;
 927		}
 928
 929		path->slots[0]++;
 930		if (path->slots[0] < btrfs_header_nritems(leaf)) {
 931			btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 932			goto process_slot;
 933		}
 934
 935		if (min_key.offset == (u64)-1)
 936			goto none;
 937
 938		min_key.offset++;
 939		btrfs_release_path(path);
 940	}
 941none:
 942	btrfs_free_path(path);
 943	return -ENOENT;
 944}
 945
 946static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 947{
 948	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 949	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 950	struct extent_map *em;
 951	u64 len = PAGE_SIZE;
 952
 953	/*
 954	 * hopefully we have this extent in the tree already, try without
 955	 * the full extent lock
 956	 */
 957	read_lock(&em_tree->lock);
 958	em = lookup_extent_mapping(em_tree, start, len);
 959	read_unlock(&em_tree->lock);
 960
 961	if (!em) {
 962		struct extent_state *cached = NULL;
 963		u64 end = start + len - 1;
 964
 965		/* get the big lock and read metadata off disk */
 966		lock_extent_bits(io_tree, start, end, &cached);
 967		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
 968		unlock_extent_cached(io_tree, start, end, &cached);
 969
 970		if (IS_ERR(em))
 971			return NULL;
 972	}
 973
 974	return em;
 975}
 976
 977static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
 978{
 979	struct extent_map *next;
 980	bool ret = true;
 981
 982	/* this is the last extent */
 983	if (em->start + em->len >= i_size_read(inode))
 984		return false;
 985
 986	next = defrag_lookup_extent(inode, em->start + em->len);
 987	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
 988		ret = false;
 989	else if ((em->block_start + em->block_len == next->block_start) &&
 990		 (em->block_len > SZ_128K && next->block_len > SZ_128K))
 991		ret = false;
 992
 993	free_extent_map(next);
 994	return ret;
 995}
 996
 997static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
 998			       u64 *last_len, u64 *skip, u64 *defrag_end,
 999			       int compress)
1000{
1001	struct extent_map *em;
1002	int ret = 1;
1003	bool next_mergeable = true;
1004	bool prev_mergeable = true;
1005
1006	/*
1007	 * make sure that once we start defragging an extent, we keep on
1008	 * defragging it
1009	 */
1010	if (start < *defrag_end)
1011		return 1;
1012
1013	*skip = 0;
1014
1015	em = defrag_lookup_extent(inode, start);
1016	if (!em)
1017		return 0;
1018
1019	/* this will cover holes, and inline extents */
1020	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1021		ret = 0;
1022		goto out;
1023	}
1024
1025	if (!*defrag_end)
1026		prev_mergeable = false;
1027
1028	next_mergeable = defrag_check_next_extent(inode, em);
1029	/*
1030	 * we hit a real extent, if it is big or the next extent is not a
1031	 * real extent, don't bother defragging it
1032	 */
1033	if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1034	    (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1035		ret = 0;
1036out:
1037	/*
1038	 * last_len ends up being a counter of how many bytes we've defragged.
1039	 * every time we choose not to defrag an extent, we reset *last_len
1040	 * so that the next tiny extent will force a defrag.
1041	 *
1042	 * The end result of this is that tiny extents before a single big
1043	 * extent will force at least part of that big extent to be defragged.
1044	 */
1045	if (ret) {
1046		*defrag_end = extent_map_end(em);
1047	} else {
1048		*last_len = 0;
1049		*skip = extent_map_end(em);
1050		*defrag_end = 0;
1051	}
1052
1053	free_extent_map(em);
1054	return ret;
1055}
1056
1057/*
1058 * it doesn't do much good to defrag one or two pages
1059 * at a time.  This pulls in a nice chunk of pages
1060 * to COW and defrag.
1061 *
1062 * It also makes sure the delalloc code has enough
1063 * dirty data to avoid making new small extents as part
1064 * of the defrag
1065 *
1066 * It's a good idea to start RA on this range
1067 * before calling this.
1068 */
1069static int cluster_pages_for_defrag(struct inode *inode,
1070				    struct page **pages,
1071				    unsigned long start_index,
1072				    unsigned long num_pages)
1073{
1074	unsigned long file_end;
1075	u64 isize = i_size_read(inode);
1076	u64 page_start;
1077	u64 page_end;
1078	u64 page_cnt;
 
 
1079	int ret;
1080	int i;
1081	int i_done;
1082	struct btrfs_ordered_extent *ordered;
1083	struct extent_state *cached_state = NULL;
1084	struct extent_io_tree *tree;
1085	struct extent_changeset *data_reserved = NULL;
1086	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1087
1088	file_end = (isize - 1) >> PAGE_SHIFT;
1089	if (!isize || start_index > file_end)
1090		return 0;
1091
1092	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1093
1094	ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1095			start_index << PAGE_SHIFT,
1096			page_cnt << PAGE_SHIFT);
1097	if (ret)
1098		return ret;
1099	i_done = 0;
1100	tree = &BTRFS_I(inode)->io_tree;
1101
1102	/* step one, lock all the pages */
1103	for (i = 0; i < page_cnt; i++) {
1104		struct page *page;
1105again:
1106		page = find_or_create_page(inode->i_mapping,
1107					   start_index + i, mask);
1108		if (!page)
1109			break;
1110
 
 
 
 
 
 
 
1111		page_start = page_offset(page);
1112		page_end = page_start + PAGE_SIZE - 1;
1113		while (1) {
1114			lock_extent_bits(tree, page_start, page_end,
1115					 &cached_state);
1116			ordered = btrfs_lookup_ordered_extent(inode,
1117							      page_start);
1118			unlock_extent_cached(tree, page_start, page_end,
1119					     &cached_state);
1120			if (!ordered)
1121				break;
1122
1123			unlock_page(page);
1124			btrfs_start_ordered_extent(inode, ordered, 1);
1125			btrfs_put_ordered_extent(ordered);
1126			lock_page(page);
1127			/*
1128			 * we unlocked the page above, so we need check if
1129			 * it was released or not.
1130			 */
1131			if (page->mapping != inode->i_mapping) {
1132				unlock_page(page);
1133				put_page(page);
1134				goto again;
1135			}
1136		}
1137
1138		if (!PageUptodate(page)) {
1139			btrfs_readpage(NULL, page);
1140			lock_page(page);
1141			if (!PageUptodate(page)) {
1142				unlock_page(page);
1143				put_page(page);
1144				ret = -EIO;
1145				break;
1146			}
1147		}
1148
1149		if (page->mapping != inode->i_mapping) {
1150			unlock_page(page);
1151			put_page(page);
1152			goto again;
1153		}
1154
1155		pages[i] = page;
1156		i_done++;
1157	}
1158	if (!i_done || ret)
1159		goto out;
1160
1161	if (!(inode->i_sb->s_flags & SB_ACTIVE))
1162		goto out;
1163
1164	/*
1165	 * so now we have a nice long stream of locked
1166	 * and up to date pages, lets wait on them
1167	 */
1168	for (i = 0; i < i_done; i++)
1169		wait_on_page_writeback(pages[i]);
1170
1171	page_start = page_offset(pages[0]);
1172	page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1173
1174	lock_extent_bits(&BTRFS_I(inode)->io_tree,
1175			 page_start, page_end - 1, &cached_state);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1176	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1177			  page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1178			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1179			  &cached_state);
1180
1181	if (i_done != page_cnt) {
1182		spin_lock(&BTRFS_I(inode)->lock);
1183		BTRFS_I(inode)->outstanding_extents++;
1184		spin_unlock(&BTRFS_I(inode)->lock);
1185		btrfs_delalloc_release_space(inode, data_reserved,
1186				start_index << PAGE_SHIFT,
1187				(page_cnt - i_done) << PAGE_SHIFT, true);
1188	}
1189
1190
1191	set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1192			  &cached_state);
1193
1194	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1195			     page_start, page_end - 1, &cached_state);
1196
1197	for (i = 0; i < i_done; i++) {
1198		clear_page_dirty_for_io(pages[i]);
1199		ClearPageChecked(pages[i]);
1200		set_page_extent_mapped(pages[i]);
1201		set_page_dirty(pages[i]);
1202		unlock_page(pages[i]);
1203		put_page(pages[i]);
1204	}
1205	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1206				       false);
1207	extent_changeset_free(data_reserved);
1208	return i_done;
 
 
 
 
1209out:
1210	for (i = 0; i < i_done; i++) {
1211		unlock_page(pages[i]);
1212		put_page(pages[i]);
1213	}
1214	btrfs_delalloc_release_space(inode, data_reserved,
1215			start_index << PAGE_SHIFT,
1216			page_cnt << PAGE_SHIFT, true);
1217	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1218				       true);
1219	extent_changeset_free(data_reserved);
1220	return ret;
1221
1222}
1223
1224int btrfs_defrag_file(struct inode *inode, struct file *file,
1225		      struct btrfs_ioctl_defrag_range_args *range,
1226		      u64 newer_than, unsigned long max_to_defrag)
1227{
1228	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1229	struct btrfs_root *root = BTRFS_I(inode)->root;
1230	struct file_ra_state *ra = NULL;
1231	unsigned long last_index;
1232	u64 isize = i_size_read(inode);
1233	u64 last_len = 0;
1234	u64 skip = 0;
1235	u64 defrag_end = 0;
1236	u64 newer_off = range->start;
1237	unsigned long i;
1238	unsigned long ra_index = 0;
1239	int ret;
1240	int defrag_count = 0;
1241	int compress_type = BTRFS_COMPRESS_ZLIB;
1242	u32 extent_thresh = range->extent_thresh;
1243	unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1244	unsigned long cluster = max_cluster;
1245	u64 new_align = ~((u64)SZ_128K - 1);
1246	struct page **pages = NULL;
1247	bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1248
1249	if (isize == 0)
1250		return 0;
1251
1252	if (range->start >= isize)
1253		return -EINVAL;
1254
1255	if (do_compress) {
1256		if (range->compress_type > BTRFS_COMPRESS_TYPES)
1257			return -EINVAL;
1258		if (range->compress_type)
1259			compress_type = range->compress_type;
1260	}
1261
1262	if (extent_thresh == 0)
1263		extent_thresh = SZ_256K;
1264
1265	/*
1266	 * If we were not given a file, allocate a readahead context. As
1267	 * readahead is just an optimization, defrag will work without it so
1268	 * we don't error out.
1269	 */
1270	if (!file) {
1271		ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1272		if (ra)
1273			file_ra_state_init(ra, inode->i_mapping);
1274	} else {
1275		ra = &file->f_ra;
1276	}
1277
1278	pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1279	if (!pages) {
1280		ret = -ENOMEM;
1281		goto out_ra;
1282	}
1283
1284	/* find the last page to defrag */
1285	if (range->start + range->len > range->start) {
1286		last_index = min_t(u64, isize - 1,
1287			 range->start + range->len - 1) >> PAGE_SHIFT;
1288	} else {
1289		last_index = (isize - 1) >> PAGE_SHIFT;
1290	}
1291
1292	if (newer_than) {
1293		ret = find_new_extents(root, inode, newer_than,
1294				       &newer_off, SZ_64K);
1295		if (!ret) {
1296			range->start = newer_off;
1297			/*
1298			 * we always align our defrag to help keep
1299			 * the extents in the file evenly spaced
1300			 */
1301			i = (newer_off & new_align) >> PAGE_SHIFT;
1302		} else
1303			goto out_ra;
1304	} else {
1305		i = range->start >> PAGE_SHIFT;
1306	}
1307	if (!max_to_defrag)
1308		max_to_defrag = last_index - i + 1;
1309
1310	/*
1311	 * make writeback starts from i, so the defrag range can be
1312	 * written sequentially.
1313	 */
1314	if (i < inode->i_mapping->writeback_index)
1315		inode->i_mapping->writeback_index = i;
1316
1317	while (i <= last_index && defrag_count < max_to_defrag &&
1318	       (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1319		/*
1320		 * make sure we stop running if someone unmounts
1321		 * the FS
1322		 */
1323		if (!(inode->i_sb->s_flags & SB_ACTIVE))
1324			break;
1325
1326		if (btrfs_defrag_cancelled(fs_info)) {
1327			btrfs_debug(fs_info, "defrag_file cancelled");
1328			ret = -EAGAIN;
1329			break;
1330		}
1331
1332		if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1333					 extent_thresh, &last_len, &skip,
1334					 &defrag_end, do_compress)){
1335			unsigned long next;
1336			/*
1337			 * the should_defrag function tells us how much to skip
1338			 * bump our counter by the suggested amount
1339			 */
1340			next = DIV_ROUND_UP(skip, PAGE_SIZE);
1341			i = max(i + 1, next);
1342			continue;
1343		}
1344
1345		if (!newer_than) {
1346			cluster = (PAGE_ALIGN(defrag_end) >>
1347				   PAGE_SHIFT) - i;
1348			cluster = min(cluster, max_cluster);
1349		} else {
1350			cluster = max_cluster;
1351		}
1352
1353		if (i + cluster > ra_index) {
1354			ra_index = max(i, ra_index);
1355			if (ra)
1356				page_cache_sync_readahead(inode->i_mapping, ra,
1357						file, ra_index, cluster);
1358			ra_index += cluster;
1359		}
1360
1361		inode_lock(inode);
1362		if (do_compress)
1363			BTRFS_I(inode)->defrag_compress = compress_type;
1364		ret = cluster_pages_for_defrag(inode, pages, i, cluster);
 
 
 
 
1365		if (ret < 0) {
1366			inode_unlock(inode);
1367			goto out_ra;
1368		}
1369
1370		defrag_count += ret;
1371		balance_dirty_pages_ratelimited(inode->i_mapping);
1372		inode_unlock(inode);
1373
1374		if (newer_than) {
1375			if (newer_off == (u64)-1)
1376				break;
1377
1378			if (ret > 0)
1379				i += ret;
1380
1381			newer_off = max(newer_off + 1,
1382					(u64)i << PAGE_SHIFT);
1383
1384			ret = find_new_extents(root, inode, newer_than,
1385					       &newer_off, SZ_64K);
1386			if (!ret) {
1387				range->start = newer_off;
1388				i = (newer_off & new_align) >> PAGE_SHIFT;
1389			} else {
1390				break;
1391			}
1392		} else {
1393			if (ret > 0) {
1394				i += ret;
1395				last_len += ret << PAGE_SHIFT;
1396			} else {
1397				i++;
1398				last_len = 0;
1399			}
1400		}
1401	}
1402
 
 
1403	if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1404		filemap_flush(inode->i_mapping);
1405		if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1406			     &BTRFS_I(inode)->runtime_flags))
1407			filemap_flush(inode->i_mapping);
1408	}
1409
1410	if (range->compress_type == BTRFS_COMPRESS_LZO) {
1411		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1412	} else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1413		btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1414	}
1415
1416	ret = defrag_count;
1417
1418out_ra:
1419	if (do_compress) {
1420		inode_lock(inode);
1421		BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1422		inode_unlock(inode);
1423	}
1424	if (!file)
1425		kfree(ra);
1426	kfree(pages);
1427	return ret;
1428}
1429
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1430static noinline int btrfs_ioctl_resize(struct file *file,
1431					void __user *arg)
1432{
1433	struct inode *inode = file_inode(file);
1434	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1435	u64 new_size;
1436	u64 old_size;
1437	u64 devid = 1;
1438	struct btrfs_root *root = BTRFS_I(inode)->root;
1439	struct btrfs_ioctl_vol_args *vol_args;
1440	struct btrfs_trans_handle *trans;
1441	struct btrfs_device *device = NULL;
1442	char *sizestr;
1443	char *retptr;
1444	char *devstr = NULL;
1445	int ret = 0;
1446	int mod = 0;
 
1447
1448	if (!capable(CAP_SYS_ADMIN))
1449		return -EPERM;
1450
1451	ret = mnt_want_write_file(file);
1452	if (ret)
1453		return ret;
1454
1455	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1456		mnt_drop_write_file(file);
1457		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1458	}
1459
1460	mutex_lock(&fs_info->volume_mutex);
1461	vol_args = memdup_user(arg, sizeof(*vol_args));
1462	if (IS_ERR(vol_args)) {
1463		ret = PTR_ERR(vol_args);
1464		goto out;
1465	}
1466
1467	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1468
1469	sizestr = vol_args->name;
 
 
 
 
 
 
1470	devstr = strchr(sizestr, ':');
1471	if (devstr) {
1472		sizestr = devstr + 1;
1473		*devstr = '\0';
1474		devstr = vol_args->name;
1475		ret = kstrtoull(devstr, 10, &devid);
1476		if (ret)
1477			goto out_free;
1478		if (!devid) {
1479			ret = -EINVAL;
1480			goto out_free;
1481		}
1482		btrfs_info(fs_info, "resizing devid %llu", devid);
1483	}
1484
1485	device = btrfs_find_device(fs_info, devid, NULL, NULL);
1486	if (!device) {
1487		btrfs_info(fs_info, "resizer unable to find device %llu",
1488			   devid);
1489		ret = -ENODEV;
1490		goto out_free;
1491	}
1492
1493	if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1494		btrfs_info(fs_info,
1495			   "resizer unable to apply on readonly device %llu",
1496		       devid);
1497		ret = -EPERM;
1498		goto out_free;
1499	}
1500
1501	if (!strcmp(sizestr, "max"))
1502		new_size = device->bdev->bd_inode->i_size;
1503	else {
1504		if (sizestr[0] == '-') {
1505			mod = -1;
1506			sizestr++;
1507		} else if (sizestr[0] == '+') {
1508			mod = 1;
1509			sizestr++;
1510		}
1511		new_size = memparse(sizestr, &retptr);
1512		if (*retptr != '\0' || new_size == 0) {
1513			ret = -EINVAL;
1514			goto out_free;
1515		}
1516	}
1517
1518	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1519		ret = -EPERM;
1520		goto out_free;
1521	}
1522
1523	old_size = btrfs_device_get_total_bytes(device);
1524
1525	if (mod < 0) {
1526		if (new_size > old_size) {
1527			ret = -EINVAL;
1528			goto out_free;
1529		}
1530		new_size = old_size - new_size;
1531	} else if (mod > 0) {
1532		if (new_size > ULLONG_MAX - old_size) {
1533			ret = -ERANGE;
1534			goto out_free;
1535		}
1536		new_size = old_size + new_size;
1537	}
1538
1539	if (new_size < SZ_256M) {
1540		ret = -EINVAL;
1541		goto out_free;
1542	}
1543	if (new_size > device->bdev->bd_inode->i_size) {
1544		ret = -EFBIG;
1545		goto out_free;
1546	}
1547
1548	new_size = round_down(new_size, fs_info->sectorsize);
1549
1550	btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1551			  rcu_str_deref(device->name), new_size);
1552
1553	if (new_size > old_size) {
1554		trans = btrfs_start_transaction(root, 0);
1555		if (IS_ERR(trans)) {
1556			ret = PTR_ERR(trans);
1557			goto out_free;
1558		}
1559		ret = btrfs_grow_device(trans, device, new_size);
1560		btrfs_commit_transaction(trans);
1561	} else if (new_size < old_size) {
1562		ret = btrfs_shrink_device(device, new_size);
1563	} /* equal, nothing need to do */
1564
 
 
 
 
 
 
 
1565out_free:
1566	kfree(vol_args);
1567out:
1568	mutex_unlock(&fs_info->volume_mutex);
1569	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1570	mnt_drop_write_file(file);
1571	return ret;
1572}
1573
1574static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1575				const char *name, unsigned long fd, int subvol,
1576				u64 *transid, bool readonly,
1577				struct btrfs_qgroup_inherit *inherit)
1578{
1579	int namelen;
1580	int ret = 0;
1581
1582	if (!S_ISDIR(file_inode(file)->i_mode))
1583		return -ENOTDIR;
1584
1585	ret = mnt_want_write_file(file);
1586	if (ret)
1587		goto out;
1588
1589	namelen = strlen(name);
1590	if (strchr(name, '/')) {
1591		ret = -EINVAL;
1592		goto out_drop_write;
1593	}
1594
1595	if (name[0] == '.' &&
1596	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1597		ret = -EEXIST;
1598		goto out_drop_write;
1599	}
1600
1601	if (subvol) {
1602		ret = btrfs_mksubvol(&file->f_path, name, namelen,
1603				     NULL, transid, readonly, inherit);
1604	} else {
1605		struct fd src = fdget(fd);
1606		struct inode *src_inode;
1607		if (!src.file) {
1608			ret = -EINVAL;
1609			goto out_drop_write;
1610		}
1611
1612		src_inode = file_inode(src.file);
1613		if (src_inode->i_sb != file_inode(file)->i_sb) {
1614			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1615				   "Snapshot src from another FS");
1616			ret = -EXDEV;
1617		} else if (!inode_owner_or_capable(src_inode)) {
1618			/*
1619			 * Subvolume creation is not restricted, but snapshots
1620			 * are limited to own subvolumes only
1621			 */
1622			ret = -EPERM;
1623		} else {
1624			ret = btrfs_mksubvol(&file->f_path, name, namelen,
1625					     BTRFS_I(src_inode)->root,
1626					     transid, readonly, inherit);
1627		}
1628		fdput(src);
1629	}
1630out_drop_write:
1631	mnt_drop_write_file(file);
1632out:
1633	return ret;
1634}
1635
1636static noinline int btrfs_ioctl_snap_create(struct file *file,
1637					    void __user *arg, int subvol)
1638{
1639	struct btrfs_ioctl_vol_args *vol_args;
1640	int ret;
1641
1642	if (!S_ISDIR(file_inode(file)->i_mode))
1643		return -ENOTDIR;
1644
1645	vol_args = memdup_user(arg, sizeof(*vol_args));
1646	if (IS_ERR(vol_args))
1647		return PTR_ERR(vol_args);
1648	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1649
1650	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1651					      vol_args->fd, subvol,
1652					      NULL, false, NULL);
1653
1654	kfree(vol_args);
1655	return ret;
1656}
1657
1658static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1659					       void __user *arg, int subvol)
1660{
1661	struct btrfs_ioctl_vol_args_v2 *vol_args;
1662	int ret;
1663	u64 transid = 0;
1664	u64 *ptr = NULL;
1665	bool readonly = false;
1666	struct btrfs_qgroup_inherit *inherit = NULL;
1667
1668	if (!S_ISDIR(file_inode(file)->i_mode))
1669		return -ENOTDIR;
1670
1671	vol_args = memdup_user(arg, sizeof(*vol_args));
1672	if (IS_ERR(vol_args))
1673		return PTR_ERR(vol_args);
1674	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1675
1676	if (vol_args->flags &
1677	    ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1678	      BTRFS_SUBVOL_QGROUP_INHERIT)) {
1679		ret = -EOPNOTSUPP;
1680		goto free_args;
1681	}
1682
1683	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1684		ptr = &transid;
1685	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1686		readonly = true;
1687	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1688		if (vol_args->size > PAGE_SIZE) {
 
 
 
1689			ret = -EINVAL;
1690			goto free_args;
1691		}
1692		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1693		if (IS_ERR(inherit)) {
1694			ret = PTR_ERR(inherit);
1695			goto free_args;
1696		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1697	}
1698
1699	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1700					      vol_args->fd, subvol, ptr,
1701					      readonly, inherit);
1702	if (ret)
1703		goto free_inherit;
1704
1705	if (ptr && copy_to_user(arg +
1706				offsetof(struct btrfs_ioctl_vol_args_v2,
1707					transid),
1708				ptr, sizeof(*ptr)))
1709		ret = -EFAULT;
1710
1711free_inherit:
1712	kfree(inherit);
1713free_args:
1714	kfree(vol_args);
1715	return ret;
1716}
1717
1718static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1719						void __user *arg)
1720{
1721	struct inode *inode = file_inode(file);
1722	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1723	struct btrfs_root *root = BTRFS_I(inode)->root;
1724	int ret = 0;
1725	u64 flags = 0;
1726
1727	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1728		return -EINVAL;
1729
1730	down_read(&fs_info->subvol_sem);
1731	if (btrfs_root_readonly(root))
1732		flags |= BTRFS_SUBVOL_RDONLY;
1733	up_read(&fs_info->subvol_sem);
1734
1735	if (copy_to_user(arg, &flags, sizeof(flags)))
1736		ret = -EFAULT;
1737
1738	return ret;
1739}
1740
1741static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1742					      void __user *arg)
1743{
1744	struct inode *inode = file_inode(file);
1745	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1746	struct btrfs_root *root = BTRFS_I(inode)->root;
1747	struct btrfs_trans_handle *trans;
1748	u64 root_flags;
1749	u64 flags;
1750	int ret = 0;
1751
1752	if (!inode_owner_or_capable(inode))
1753		return -EPERM;
1754
1755	ret = mnt_want_write_file(file);
1756	if (ret)
1757		goto out;
1758
1759	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1760		ret = -EINVAL;
1761		goto out_drop_write;
1762	}
1763
1764	if (copy_from_user(&flags, arg, sizeof(flags))) {
1765		ret = -EFAULT;
1766		goto out_drop_write;
1767	}
1768
1769	if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1770		ret = -EINVAL;
1771		goto out_drop_write;
1772	}
1773
1774	if (flags & ~BTRFS_SUBVOL_RDONLY) {
1775		ret = -EOPNOTSUPP;
1776		goto out_drop_write;
1777	}
1778
1779	down_write(&fs_info->subvol_sem);
1780
1781	/* nothing to do */
1782	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1783		goto out_drop_sem;
1784
1785	root_flags = btrfs_root_flags(&root->root_item);
1786	if (flags & BTRFS_SUBVOL_RDONLY) {
1787		btrfs_set_root_flags(&root->root_item,
1788				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1789	} else {
1790		/*
1791		 * Block RO -> RW transition if this subvolume is involved in
1792		 * send
1793		 */
1794		spin_lock(&root->root_item_lock);
1795		if (root->send_in_progress == 0) {
1796			btrfs_set_root_flags(&root->root_item,
1797				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1798			spin_unlock(&root->root_item_lock);
1799		} else {
1800			spin_unlock(&root->root_item_lock);
1801			btrfs_warn(fs_info,
1802				   "Attempt to set subvolume %llu read-write during send",
1803				   root->root_key.objectid);
1804			ret = -EPERM;
1805			goto out_drop_sem;
1806		}
1807	}
1808
1809	trans = btrfs_start_transaction(root, 1);
1810	if (IS_ERR(trans)) {
1811		ret = PTR_ERR(trans);
1812		goto out_reset;
1813	}
1814
1815	ret = btrfs_update_root(trans, fs_info->tree_root,
1816				&root->root_key, &root->root_item);
1817	if (ret < 0) {
1818		btrfs_end_transaction(trans);
1819		goto out_reset;
1820	}
1821
1822	ret = btrfs_commit_transaction(trans);
1823
1824out_reset:
1825	if (ret)
1826		btrfs_set_root_flags(&root->root_item, root_flags);
1827out_drop_sem:
1828	up_write(&fs_info->subvol_sem);
1829out_drop_write:
1830	mnt_drop_write_file(file);
1831out:
1832	return ret;
1833}
1834
1835/*
1836 * helper to check if the subvolume references other subvolumes
1837 */
1838static noinline int may_destroy_subvol(struct btrfs_root *root)
1839{
1840	struct btrfs_fs_info *fs_info = root->fs_info;
1841	struct btrfs_path *path;
1842	struct btrfs_dir_item *di;
1843	struct btrfs_key key;
1844	u64 dir_id;
1845	int ret;
1846
1847	path = btrfs_alloc_path();
1848	if (!path)
1849		return -ENOMEM;
1850
1851	/* Make sure this root isn't set as the default subvol */
1852	dir_id = btrfs_super_root_dir(fs_info->super_copy);
1853	di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
1854				   dir_id, "default", 7, 0);
1855	if (di && !IS_ERR(di)) {
1856		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1857		if (key.objectid == root->root_key.objectid) {
1858			ret = -EPERM;
1859			btrfs_err(fs_info,
1860				  "deleting default subvolume %llu is not allowed",
1861				  key.objectid);
1862			goto out;
1863		}
1864		btrfs_release_path(path);
1865	}
1866
1867	key.objectid = root->root_key.objectid;
1868	key.type = BTRFS_ROOT_REF_KEY;
1869	key.offset = (u64)-1;
1870
1871	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1872	if (ret < 0)
1873		goto out;
1874	BUG_ON(ret == 0);
1875
1876	ret = 0;
1877	if (path->slots[0] > 0) {
1878		path->slots[0]--;
1879		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1880		if (key.objectid == root->root_key.objectid &&
1881		    key.type == BTRFS_ROOT_REF_KEY)
1882			ret = -ENOTEMPTY;
1883	}
1884out:
1885	btrfs_free_path(path);
1886	return ret;
1887}
1888
1889static noinline int key_in_sk(struct btrfs_key *key,
1890			      struct btrfs_ioctl_search_key *sk)
1891{
1892	struct btrfs_key test;
1893	int ret;
1894
1895	test.objectid = sk->min_objectid;
1896	test.type = sk->min_type;
1897	test.offset = sk->min_offset;
1898
1899	ret = btrfs_comp_cpu_keys(key, &test);
1900	if (ret < 0)
1901		return 0;
1902
1903	test.objectid = sk->max_objectid;
1904	test.type = sk->max_type;
1905	test.offset = sk->max_offset;
1906
1907	ret = btrfs_comp_cpu_keys(key, &test);
1908	if (ret > 0)
1909		return 0;
1910	return 1;
1911}
1912
1913static noinline int copy_to_sk(struct btrfs_path *path,
1914			       struct btrfs_key *key,
1915			       struct btrfs_ioctl_search_key *sk,
1916			       size_t *buf_size,
1917			       char __user *ubuf,
1918			       unsigned long *sk_offset,
1919			       int *num_found)
1920{
1921	u64 found_transid;
1922	struct extent_buffer *leaf;
1923	struct btrfs_ioctl_search_header sh;
1924	struct btrfs_key test;
1925	unsigned long item_off;
1926	unsigned long item_len;
1927	int nritems;
1928	int i;
1929	int slot;
1930	int ret = 0;
1931
1932	leaf = path->nodes[0];
1933	slot = path->slots[0];
1934	nritems = btrfs_header_nritems(leaf);
1935
1936	if (btrfs_header_generation(leaf) > sk->max_transid) {
1937		i = nritems;
1938		goto advance_key;
1939	}
1940	found_transid = btrfs_header_generation(leaf);
1941
1942	for (i = slot; i < nritems; i++) {
1943		item_off = btrfs_item_ptr_offset(leaf, i);
1944		item_len = btrfs_item_size_nr(leaf, i);
1945
1946		btrfs_item_key_to_cpu(leaf, key, i);
1947		if (!key_in_sk(key, sk))
1948			continue;
1949
1950		if (sizeof(sh) + item_len > *buf_size) {
1951			if (*num_found) {
1952				ret = 1;
1953				goto out;
1954			}
1955
1956			/*
1957			 * return one empty item back for v1, which does not
1958			 * handle -EOVERFLOW
1959			 */
1960
1961			*buf_size = sizeof(sh) + item_len;
1962			item_len = 0;
1963			ret = -EOVERFLOW;
1964		}
1965
1966		if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
1967			ret = 1;
1968			goto out;
1969		}
1970
1971		sh.objectid = key->objectid;
1972		sh.offset = key->offset;
1973		sh.type = key->type;
1974		sh.len = item_len;
1975		sh.transid = found_transid;
1976
1977		/* copy search result header */
1978		if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
1979			ret = -EFAULT;
 
 
 
 
 
1980			goto out;
1981		}
1982
1983		*sk_offset += sizeof(sh);
1984
1985		if (item_len) {
1986			char __user *up = ubuf + *sk_offset;
1987			/* copy the item */
1988			if (read_extent_buffer_to_user(leaf, up,
1989						       item_off, item_len)) {
1990				ret = -EFAULT;
 
 
 
 
1991				goto out;
1992			}
1993
1994			*sk_offset += item_len;
1995		}
1996		(*num_found)++;
1997
1998		if (ret) /* -EOVERFLOW from above */
1999			goto out;
2000
2001		if (*num_found >= sk->nr_items) {
2002			ret = 1;
2003			goto out;
2004		}
2005	}
2006advance_key:
2007	ret = 0;
2008	test.objectid = sk->max_objectid;
2009	test.type = sk->max_type;
2010	test.offset = sk->max_offset;
2011	if (btrfs_comp_cpu_keys(key, &test) >= 0)
2012		ret = 1;
2013	else if (key->offset < (u64)-1)
2014		key->offset++;
2015	else if (key->type < (u8)-1) {
2016		key->offset = 0;
2017		key->type++;
2018	} else if (key->objectid < (u64)-1) {
2019		key->offset = 0;
2020		key->type = 0;
2021		key->objectid++;
2022	} else
2023		ret = 1;
2024out:
2025	/*
2026	 *  0: all items from this leaf copied, continue with next
2027	 *  1: * more items can be copied, but unused buffer is too small
2028	 *     * all items were found
2029	 *     Either way, it will stops the loop which iterates to the next
2030	 *     leaf
2031	 *  -EOVERFLOW: item was to large for buffer
2032	 *  -EFAULT: could not copy extent buffer back to userspace
2033	 */
2034	return ret;
2035}
2036
2037static noinline int search_ioctl(struct inode *inode,
2038				 struct btrfs_ioctl_search_key *sk,
2039				 size_t *buf_size,
2040				 char __user *ubuf)
2041{
2042	struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2043	struct btrfs_root *root;
2044	struct btrfs_key key;
2045	struct btrfs_path *path;
2046	int ret;
2047	int num_found = 0;
2048	unsigned long sk_offset = 0;
2049
2050	if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2051		*buf_size = sizeof(struct btrfs_ioctl_search_header);
2052		return -EOVERFLOW;
2053	}
2054
2055	path = btrfs_alloc_path();
2056	if (!path)
2057		return -ENOMEM;
2058
2059	if (sk->tree_id == 0) {
2060		/* search the root of the inode that was passed */
2061		root = BTRFS_I(inode)->root;
2062	} else {
2063		key.objectid = sk->tree_id;
2064		key.type = BTRFS_ROOT_ITEM_KEY;
2065		key.offset = (u64)-1;
2066		root = btrfs_read_fs_root_no_name(info, &key);
2067		if (IS_ERR(root)) {
2068			btrfs_free_path(path);
2069			return -ENOENT;
2070		}
2071	}
2072
2073	key.objectid = sk->min_objectid;
2074	key.type = sk->min_type;
2075	key.offset = sk->min_offset;
2076
2077	while (1) {
 
 
 
 
 
2078		ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2079		if (ret != 0) {
2080			if (ret > 0)
2081				ret = 0;
2082			goto err;
2083		}
2084		ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2085				 &sk_offset, &num_found);
2086		btrfs_release_path(path);
2087		if (ret)
2088			break;
2089
2090	}
2091	if (ret > 0)
2092		ret = 0;
2093err:
2094	sk->nr_items = num_found;
 
2095	btrfs_free_path(path);
2096	return ret;
2097}
2098
2099static noinline int btrfs_ioctl_tree_search(struct file *file,
2100					   void __user *argp)
2101{
2102	struct btrfs_ioctl_search_args __user *uargs;
2103	struct btrfs_ioctl_search_key sk;
2104	struct inode *inode;
2105	int ret;
2106	size_t buf_size;
2107
2108	if (!capable(CAP_SYS_ADMIN))
2109		return -EPERM;
2110
2111	uargs = (struct btrfs_ioctl_search_args __user *)argp;
2112
2113	if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2114		return -EFAULT;
2115
2116	buf_size = sizeof(uargs->buf);
2117
2118	inode = file_inode(file);
2119	ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2120
2121	/*
2122	 * In the origin implementation an overflow is handled by returning a
2123	 * search header with a len of zero, so reset ret.
2124	 */
2125	if (ret == -EOVERFLOW)
2126		ret = 0;
2127
2128	if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2129		ret = -EFAULT;
2130	return ret;
2131}
2132
2133static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2134					       void __user *argp)
2135{
2136	struct btrfs_ioctl_search_args_v2 __user *uarg;
2137	struct btrfs_ioctl_search_args_v2 args;
2138	struct inode *inode;
2139	int ret;
2140	size_t buf_size;
2141	const size_t buf_limit = SZ_16M;
2142
2143	if (!capable(CAP_SYS_ADMIN))
2144		return -EPERM;
2145
2146	/* copy search header and buffer size */
2147	uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2148	if (copy_from_user(&args, uarg, sizeof(args)))
2149		return -EFAULT;
2150
2151	buf_size = args.buf_size;
2152
2153	/* limit result size to 16MB */
2154	if (buf_size > buf_limit)
2155		buf_size = buf_limit;
2156
2157	inode = file_inode(file);
2158	ret = search_ioctl(inode, &args.key, &buf_size,
2159			   (char __user *)(&uarg->buf[0]));
2160	if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2161		ret = -EFAULT;
2162	else if (ret == -EOVERFLOW &&
2163		copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2164		ret = -EFAULT;
2165
2166	return ret;
2167}
2168
2169/*
2170 * Search INODE_REFs to identify path name of 'dirid' directory
2171 * in a 'tree_id' tree. and sets path name to 'name'.
2172 */
2173static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2174				u64 tree_id, u64 dirid, char *name)
2175{
2176	struct btrfs_root *root;
2177	struct btrfs_key key;
2178	char *ptr;
2179	int ret = -1;
2180	int slot;
2181	int len;
2182	int total_len = 0;
2183	struct btrfs_inode_ref *iref;
2184	struct extent_buffer *l;
2185	struct btrfs_path *path;
2186
2187	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2188		name[0]='\0';
2189		return 0;
2190	}
2191
2192	path = btrfs_alloc_path();
2193	if (!path)
2194		return -ENOMEM;
2195
2196	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2197
2198	key.objectid = tree_id;
2199	key.type = BTRFS_ROOT_ITEM_KEY;
2200	key.offset = (u64)-1;
2201	root = btrfs_read_fs_root_no_name(info, &key);
2202	if (IS_ERR(root)) {
2203		btrfs_err(info, "could not find root %llu", tree_id);
2204		ret = -ENOENT;
2205		goto out;
2206	}
2207
2208	key.objectid = dirid;
2209	key.type = BTRFS_INODE_REF_KEY;
2210	key.offset = (u64)-1;
2211
2212	while (1) {
2213		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2214		if (ret < 0)
2215			goto out;
2216		else if (ret > 0) {
2217			ret = btrfs_previous_item(root, path, dirid,
2218						  BTRFS_INODE_REF_KEY);
2219			if (ret < 0)
2220				goto out;
2221			else if (ret > 0) {
2222				ret = -ENOENT;
2223				goto out;
2224			}
2225		}
2226
2227		l = path->nodes[0];
2228		slot = path->slots[0];
2229		btrfs_item_key_to_cpu(l, &key, slot);
2230
2231		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2232		len = btrfs_inode_ref_name_len(l, iref);
2233		ptr -= len + 1;
2234		total_len += len + 1;
2235		if (ptr < name) {
2236			ret = -ENAMETOOLONG;
2237			goto out;
2238		}
2239
2240		*(ptr + len) = '/';
2241		read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2242
2243		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2244			break;
2245
2246		btrfs_release_path(path);
2247		key.objectid = key.offset;
2248		key.offset = (u64)-1;
2249		dirid = key.objectid;
2250	}
2251	memmove(name, ptr, total_len);
2252	name[total_len] = '\0';
2253	ret = 0;
2254out:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2255	btrfs_free_path(path);
2256	return ret;
2257}
2258
2259static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2260					   void __user *argp)
2261{
2262	 struct btrfs_ioctl_ino_lookup_args *args;
2263	 struct inode *inode;
2264	int ret = 0;
2265
2266	args = memdup_user(argp, sizeof(*args));
2267	if (IS_ERR(args))
2268		return PTR_ERR(args);
2269
2270	inode = file_inode(file);
2271
2272	/*
2273	 * Unprivileged query to obtain the containing subvolume root id. The
2274	 * path is reset so it's consistent with btrfs_search_path_in_tree.
2275	 */
2276	if (args->treeid == 0)
2277		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2278
2279	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2280		args->name[0] = 0;
2281		goto out;
2282	}
2283
2284	if (!capable(CAP_SYS_ADMIN)) {
2285		ret = -EPERM;
2286		goto out;
2287	}
2288
2289	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2290					args->treeid, args->objectid,
2291					args->name);
2292
2293out:
2294	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2295		ret = -EFAULT;
2296
2297	kfree(args);
2298	return ret;
2299}
2300
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2301static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2302					     void __user *arg)
 
2303{
2304	struct dentry *parent = file->f_path.dentry;
2305	struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2306	struct dentry *dentry;
2307	struct inode *dir = d_inode(parent);
2308	struct inode *inode;
2309	struct btrfs_root *root = BTRFS_I(dir)->root;
2310	struct btrfs_root *dest = NULL;
2311	struct btrfs_ioctl_vol_args *vol_args;
2312	struct btrfs_trans_handle *trans;
2313	struct btrfs_block_rsv block_rsv;
2314	u64 root_flags;
2315	u64 qgroup_reserved;
2316	int namelen;
2317	int ret;
2318	int err = 0;
 
2319
2320	if (!S_ISDIR(dir->i_mode))
2321		return -ENOTDIR;
 
 
2322
2323	vol_args = memdup_user(arg, sizeof(*vol_args));
2324	if (IS_ERR(vol_args))
2325		return PTR_ERR(vol_args);
 
2326
2327	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2328	namelen = strlen(vol_args->name);
2329	if (strchr(vol_args->name, '/') ||
2330	    strncmp(vol_args->name, "..", namelen) == 0) {
2331		err = -EINVAL;
2332		goto out;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2333	}
2334
2335	err = mnt_want_write_file(file);
2336	if (err)
2337		goto out;
2338
 
 
 
 
 
 
 
 
 
 
2339
2340	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2341	if (err == -EINTR)
2342		goto out_drop_write;
2343	dentry = lookup_one_len(vol_args->name, parent, namelen);
2344	if (IS_ERR(dentry)) {
2345		err = PTR_ERR(dentry);
2346		goto out_unlock_dir;
2347	}
2348
2349	if (d_really_is_negative(dentry)) {
2350		err = -ENOENT;
2351		goto out_dput;
2352	}
2353
2354	inode = d_inode(dentry);
2355	dest = BTRFS_I(inode)->root;
2356	if (!capable(CAP_SYS_ADMIN)) {
2357		/*
2358		 * Regular user.  Only allow this with a special mount
2359		 * option, when the user has write+exec access to the
2360		 * subvol root, and when rmdir(2) would have been
2361		 * allowed.
2362		 *
2363		 * Note that this is _not_ check that the subvol is
2364		 * empty or doesn't contain data that we wouldn't
2365		 * otherwise be able to delete.
2366		 *
2367		 * Users who want to delete empty subvols should try
2368		 * rmdir(2).
2369		 */
2370		err = -EPERM;
2371		if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2372			goto out_dput;
2373
2374		/*
2375		 * Do not allow deletion if the parent dir is the same
2376		 * as the dir to be deleted.  That means the ioctl
2377		 * must be called on the dentry referencing the root
2378		 * of the subvol, not a random directory contained
2379		 * within it.
2380		 */
2381		err = -EINVAL;
2382		if (root == dest)
2383			goto out_dput;
2384
2385		err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
 
2386		if (err)
2387			goto out_dput;
2388	}
2389
2390	/* check if subvolume may be deleted by a user */
2391	err = btrfs_may_delete(dir, dentry, 1);
2392	if (err)
2393		goto out_dput;
2394
2395	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2396		err = -EINVAL;
2397		goto out_dput;
2398	}
2399
2400	inode_lock(inode);
2401
2402	/*
2403	 * Don't allow to delete a subvolume with send in progress. This is
2404	 * inside the i_mutex so the error handling that has to drop the bit
2405	 * again is not run concurrently.
2406	 */
2407	spin_lock(&dest->root_item_lock);
2408	root_flags = btrfs_root_flags(&dest->root_item);
2409	if (dest->send_in_progress == 0) {
2410		btrfs_set_root_flags(&dest->root_item,
2411				root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2412		spin_unlock(&dest->root_item_lock);
2413	} else {
2414		spin_unlock(&dest->root_item_lock);
2415		btrfs_warn(fs_info,
2416			   "Attempt to delete subvolume %llu during send",
2417			   dest->root_key.objectid);
2418		err = -EPERM;
2419		goto out_unlock_inode;
2420	}
2421
2422	down_write(&fs_info->subvol_sem);
2423
2424	err = may_destroy_subvol(dest);
2425	if (err)
2426		goto out_up_write;
2427
2428	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2429	/*
2430	 * One for dir inode, two for dir entries, two for root
2431	 * ref/backref.
2432	 */
2433	err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2434					       5, &qgroup_reserved, true);
2435	if (err)
2436		goto out_up_write;
2437
2438	trans = btrfs_start_transaction(root, 0);
2439	if (IS_ERR(trans)) {
2440		err = PTR_ERR(trans);
2441		goto out_release;
2442	}
2443	trans->block_rsv = &block_rsv;
2444	trans->bytes_reserved = block_rsv.size;
2445
2446	btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
2447
2448	ret = btrfs_unlink_subvol(trans, root, dir,
2449				dest->root_key.objectid,
2450				dentry->d_name.name,
2451				dentry->d_name.len);
2452	if (ret) {
2453		err = ret;
2454		btrfs_abort_transaction(trans, ret);
2455		goto out_end_trans;
2456	}
2457
2458	btrfs_record_root_in_trans(trans, dest);
2459
2460	memset(&dest->root_item.drop_progress, 0,
2461		sizeof(dest->root_item.drop_progress));
2462	dest->root_item.drop_level = 0;
2463	btrfs_set_root_refs(&dest->root_item, 0);
2464
2465	if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2466		ret = btrfs_insert_orphan_item(trans,
2467					fs_info->tree_root,
2468					dest->root_key.objectid);
2469		if (ret) {
2470			btrfs_abort_transaction(trans, ret);
2471			err = ret;
2472			goto out_end_trans;
2473		}
2474	}
2475
2476	ret = btrfs_uuid_tree_rem(trans, fs_info, dest->root_item.uuid,
2477				  BTRFS_UUID_KEY_SUBVOL,
2478				  dest->root_key.objectid);
2479	if (ret && ret != -ENOENT) {
2480		btrfs_abort_transaction(trans, ret);
2481		err = ret;
2482		goto out_end_trans;
2483	}
2484	if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2485		ret = btrfs_uuid_tree_rem(trans, fs_info,
2486					  dest->root_item.received_uuid,
2487					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2488					  dest->root_key.objectid);
2489		if (ret && ret != -ENOENT) {
2490			btrfs_abort_transaction(trans, ret);
2491			err = ret;
2492			goto out_end_trans;
2493		}
2494	}
2495
2496out_end_trans:
2497	trans->block_rsv = NULL;
2498	trans->bytes_reserved = 0;
2499	ret = btrfs_end_transaction(trans);
2500	if (ret && !err)
2501		err = ret;
2502	inode->i_flags |= S_DEAD;
2503out_release:
2504	btrfs_subvolume_release_metadata(fs_info, &block_rsv);
2505out_up_write:
2506	up_write(&fs_info->subvol_sem);
2507	if (err) {
2508		spin_lock(&dest->root_item_lock);
2509		root_flags = btrfs_root_flags(&dest->root_item);
2510		btrfs_set_root_flags(&dest->root_item,
2511				root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2512		spin_unlock(&dest->root_item_lock);
2513	}
2514out_unlock_inode:
2515	inode_unlock(inode);
2516	if (!err) {
2517		d_invalidate(dentry);
2518		btrfs_invalidate_inodes(dest);
2519		d_delete(dentry);
2520		ASSERT(dest->send_in_progress == 0);
2521
2522		/* the last ref */
2523		if (dest->ino_cache_inode) {
2524			iput(dest->ino_cache_inode);
2525			dest->ino_cache_inode = NULL;
2526		}
2527	}
 
2528out_dput:
2529	dput(dentry);
2530out_unlock_dir:
2531	inode_unlock(dir);
 
 
 
 
 
2532out_drop_write:
2533	mnt_drop_write_file(file);
2534out:
 
2535	kfree(vol_args);
2536	return err;
2537}
2538
2539static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2540{
2541	struct inode *inode = file_inode(file);
2542	struct btrfs_root *root = BTRFS_I(inode)->root;
2543	struct btrfs_ioctl_defrag_range_args *range;
2544	int ret;
2545
2546	ret = mnt_want_write_file(file);
2547	if (ret)
2548		return ret;
2549
2550	if (btrfs_root_readonly(root)) {
2551		ret = -EROFS;
2552		goto out;
2553	}
2554
2555	switch (inode->i_mode & S_IFMT) {
2556	case S_IFDIR:
2557		if (!capable(CAP_SYS_ADMIN)) {
2558			ret = -EPERM;
2559			goto out;
2560		}
2561		ret = btrfs_defrag_root(root);
2562		break;
2563	case S_IFREG:
2564		if (!(file->f_mode & FMODE_WRITE)) {
2565			ret = -EINVAL;
 
 
 
 
 
 
2566			goto out;
2567		}
2568
2569		range = kzalloc(sizeof(*range), GFP_KERNEL);
2570		if (!range) {
2571			ret = -ENOMEM;
2572			goto out;
2573		}
2574
2575		if (argp) {
2576			if (copy_from_user(range, argp,
2577					   sizeof(*range))) {
2578				ret = -EFAULT;
2579				kfree(range);
2580				goto out;
2581			}
2582			/* compression requires us to start the IO */
2583			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2584				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2585				range->extent_thresh = (u32)-1;
2586			}
2587		} else {
2588			/* the rest are all set to zero by kzalloc */
2589			range->len = (u64)-1;
2590		}
2591		ret = btrfs_defrag_file(file_inode(file), file,
2592					range, BTRFS_OLDEST_GENERATION, 0);
2593		if (ret > 0)
2594			ret = 0;
2595		kfree(range);
2596		break;
2597	default:
2598		ret = -EINVAL;
2599	}
2600out:
2601	mnt_drop_write_file(file);
2602	return ret;
2603}
2604
2605static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2606{
2607	struct btrfs_ioctl_vol_args *vol_args;
2608	int ret;
2609
2610	if (!capable(CAP_SYS_ADMIN))
2611		return -EPERM;
2612
2613	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
2614		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2615
2616	mutex_lock(&fs_info->volume_mutex);
2617	vol_args = memdup_user(arg, sizeof(*vol_args));
2618	if (IS_ERR(vol_args)) {
2619		ret = PTR_ERR(vol_args);
2620		goto out;
2621	}
2622
2623	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2624	ret = btrfs_init_new_device(fs_info, vol_args->name);
2625
2626	if (!ret)
2627		btrfs_info(fs_info, "disk added %s", vol_args->name);
2628
2629	kfree(vol_args);
2630out:
2631	mutex_unlock(&fs_info->volume_mutex);
2632	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2633	return ret;
2634}
2635
2636static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2637{
2638	struct inode *inode = file_inode(file);
2639	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2640	struct btrfs_ioctl_vol_args_v2 *vol_args;
 
 
2641	int ret;
 
2642
2643	if (!capable(CAP_SYS_ADMIN))
2644		return -EPERM;
2645
2646	ret = mnt_want_write_file(file);
2647	if (ret)
2648		return ret;
2649
2650	vol_args = memdup_user(arg, sizeof(*vol_args));
2651	if (IS_ERR(vol_args)) {
2652		ret = PTR_ERR(vol_args);
2653		goto err_drop;
2654	}
2655
2656	/* Check for compatibility reject unknown flags */
2657	if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED)
2658		return -EOPNOTSUPP;
2659
2660	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
2661		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2662		goto out;
2663	}
 
 
 
 
2664
2665	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2666		ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
2667	} else {
2668		vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
2669		ret = btrfs_rm_device(fs_info, vol_args->name, 0);
2670	}
2671	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
 
 
 
 
 
2672
2673	if (!ret) {
2674		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2675			btrfs_info(fs_info, "device deleted: id %llu",
2676					vol_args->devid);
2677		else
2678			btrfs_info(fs_info, "device deleted: %s",
2679					vol_args->name);
2680	}
2681out:
2682	kfree(vol_args);
2683err_drop:
2684	mnt_drop_write_file(file);
 
 
2685	return ret;
2686}
2687
2688static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2689{
2690	struct inode *inode = file_inode(file);
2691	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2692	struct btrfs_ioctl_vol_args *vol_args;
 
 
2693	int ret;
 
2694
2695	if (!capable(CAP_SYS_ADMIN))
2696		return -EPERM;
2697
2698	ret = mnt_want_write_file(file);
2699	if (ret)
2700		return ret;
2701
2702	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
2703		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2704		goto out_drop_write;
2705	}
2706
2707	vol_args = memdup_user(arg, sizeof(*vol_args));
2708	if (IS_ERR(vol_args)) {
2709		ret = PTR_ERR(vol_args);
2710		goto out;
2711	}
2712
2713	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2714	ret = btrfs_rm_device(fs_info, vol_args->name, 0);
 
 
 
 
 
 
 
 
 
2715
2716	if (!ret)
2717		btrfs_info(fs_info, "disk deleted %s", vol_args->name);
2718	kfree(vol_args);
2719out:
2720	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
2721out_drop_write:
2722	mnt_drop_write_file(file);
2723
 
2724	return ret;
2725}
2726
2727static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
2728				void __user *arg)
2729{
2730	struct btrfs_ioctl_fs_info_args *fi_args;
2731	struct btrfs_device *device;
2732	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 
2733	int ret = 0;
2734
2735	fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2736	if (!fi_args)
2737		return -ENOMEM;
 
 
 
2738
2739	rcu_read_lock();
2740	fi_args->num_devices = fs_devices->num_devices;
2741
2742	list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
2743		if (device->devid > fi_args->max_id)
2744			fi_args->max_id = device->devid;
2745	}
2746	rcu_read_unlock();
2747
2748	memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
2749	fi_args->nodesize = fs_info->nodesize;
2750	fi_args->sectorsize = fs_info->sectorsize;
2751	fi_args->clone_alignment = fs_info->sectorsize;
2752
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2753	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2754		ret = -EFAULT;
2755
2756	kfree(fi_args);
2757	return ret;
2758}
2759
2760static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
2761				 void __user *arg)
2762{
2763	struct btrfs_ioctl_dev_info_args *di_args;
2764	struct btrfs_device *dev;
2765	int ret = 0;
2766	char *s_uuid = NULL;
2767
2768	di_args = memdup_user(arg, sizeof(*di_args));
2769	if (IS_ERR(di_args))
2770		return PTR_ERR(di_args);
2771
2772	if (!btrfs_is_empty_uuid(di_args->uuid))
2773		s_uuid = di_args->uuid;
2774
2775	rcu_read_lock();
2776	dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
 
2777
2778	if (!dev) {
2779		ret = -ENODEV;
2780		goto out;
2781	}
2782
2783	di_args->devid = dev->devid;
2784	di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2785	di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2786	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2787	if (dev->name) {
2788		struct rcu_string *name;
2789
2790		name = rcu_dereference(dev->name);
2791		strncpy(di_args->path, name->str, sizeof(di_args->path) - 1);
2792		di_args->path[sizeof(di_args->path) - 1] = 0;
2793	} else {
2794		di_args->path[0] = '\0';
2795	}
2796
2797out:
2798	rcu_read_unlock();
2799	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2800		ret = -EFAULT;
2801
2802	kfree(di_args);
2803	return ret;
2804}
2805
2806static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
2807{
2808	struct page *page;
2809
2810	page = grab_cache_page(inode->i_mapping, index);
2811	if (!page)
2812		return ERR_PTR(-ENOMEM);
2813
2814	if (!PageUptodate(page)) {
2815		int ret;
2816
2817		ret = btrfs_readpage(NULL, page);
2818		if (ret)
2819			return ERR_PTR(ret);
2820		lock_page(page);
2821		if (!PageUptodate(page)) {
2822			unlock_page(page);
2823			put_page(page);
2824			return ERR_PTR(-EIO);
2825		}
2826		if (page->mapping != inode->i_mapping) {
2827			unlock_page(page);
2828			put_page(page);
2829			return ERR_PTR(-EAGAIN);
2830		}
2831	}
2832
2833	return page;
2834}
2835
2836static int gather_extent_pages(struct inode *inode, struct page **pages,
2837			       int num_pages, u64 off)
2838{
2839	int i;
2840	pgoff_t index = off >> PAGE_SHIFT;
2841
2842	for (i = 0; i < num_pages; i++) {
2843again:
2844		pages[i] = extent_same_get_page(inode, index + i);
2845		if (IS_ERR(pages[i])) {
2846			int err = PTR_ERR(pages[i]);
2847
2848			if (err == -EAGAIN)
2849				goto again;
2850			pages[i] = NULL;
2851			return err;
2852		}
2853	}
2854	return 0;
2855}
2856
2857static int lock_extent_range(struct inode *inode, u64 off, u64 len,
2858			     bool retry_range_locking)
2859{
2860	/*
2861	 * Do any pending delalloc/csum calculations on inode, one way or
2862	 * another, and lock file content.
2863	 * The locking order is:
2864	 *
2865	 *   1) pages
2866	 *   2) range in the inode's io tree
2867	 */
2868	while (1) {
2869		struct btrfs_ordered_extent *ordered;
2870		lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2871		ordered = btrfs_lookup_first_ordered_extent(inode,
2872							    off + len - 1);
2873		if ((!ordered ||
2874		     ordered->file_offset + ordered->len <= off ||
2875		     ordered->file_offset >= off + len) &&
2876		    !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2877				    off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2878			if (ordered)
2879				btrfs_put_ordered_extent(ordered);
2880			break;
2881		}
2882		unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2883		if (ordered)
2884			btrfs_put_ordered_extent(ordered);
2885		if (!retry_range_locking)
2886			return -EAGAIN;
2887		btrfs_wait_ordered_range(inode, off, len);
2888	}
2889	return 0;
2890}
2891
2892static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2893{
2894	inode_unlock(inode1);
2895	inode_unlock(inode2);
2896}
2897
2898static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2899{
2900	if (inode1 < inode2)
2901		swap(inode1, inode2);
2902
2903	inode_lock_nested(inode1, I_MUTEX_PARENT);
2904	inode_lock_nested(inode2, I_MUTEX_CHILD);
2905}
2906
2907static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2908				      struct inode *inode2, u64 loff2, u64 len)
2909{
2910	unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2911	unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2912}
2913
2914static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2915				    struct inode *inode2, u64 loff2, u64 len,
2916				    bool retry_range_locking)
2917{
2918	int ret;
2919
2920	if (inode1 < inode2) {
2921		swap(inode1, inode2);
2922		swap(loff1, loff2);
2923	}
2924	ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
2925	if (ret)
2926		return ret;
2927	ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
2928	if (ret)
2929		unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
2930			      loff1 + len - 1);
2931	return ret;
2932}
2933
2934struct cmp_pages {
2935	int		num_pages;
2936	struct page	**src_pages;
2937	struct page	**dst_pages;
2938};
2939
2940static void btrfs_cmp_data_free(struct cmp_pages *cmp)
2941{
2942	int i;
2943	struct page *pg;
2944
2945	for (i = 0; i < cmp->num_pages; i++) {
2946		pg = cmp->src_pages[i];
2947		if (pg) {
2948			unlock_page(pg);
2949			put_page(pg);
2950		}
2951		pg = cmp->dst_pages[i];
2952		if (pg) {
2953			unlock_page(pg);
2954			put_page(pg);
2955		}
2956	}
2957	kfree(cmp->src_pages);
2958	kfree(cmp->dst_pages);
2959}
2960
2961static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
2962				  struct inode *dst, u64 dst_loff,
2963				  u64 len, struct cmp_pages *cmp)
2964{
2965	int ret;
2966	int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
2967	struct page **src_pgarr, **dst_pgarr;
2968
2969	/*
2970	 * We must gather up all the pages before we initiate our
2971	 * extent locking. We use an array for the page pointers. Size
2972	 * of the array is bounded by len, which is in turn bounded by
2973	 * BTRFS_MAX_DEDUPE_LEN.
2974	 */
2975	src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
2976	dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
2977	if (!src_pgarr || !dst_pgarr) {
2978		kfree(src_pgarr);
2979		kfree(dst_pgarr);
2980		return -ENOMEM;
2981	}
2982	cmp->num_pages = num_pages;
2983	cmp->src_pages = src_pgarr;
2984	cmp->dst_pages = dst_pgarr;
2985
2986	/*
2987	 * If deduping ranges in the same inode, locking rules make it mandatory
2988	 * to always lock pages in ascending order to avoid deadlocks with
2989	 * concurrent tasks (such as starting writeback/delalloc).
2990	 */
2991	if (src == dst && dst_loff < loff) {
2992		swap(src_pgarr, dst_pgarr);
2993		swap(loff, dst_loff);
2994	}
2995
2996	ret = gather_extent_pages(src, src_pgarr, cmp->num_pages, loff);
2997	if (ret)
2998		goto out;
2999
3000	ret = gather_extent_pages(dst, dst_pgarr, cmp->num_pages, dst_loff);
3001
3002out:
3003	if (ret)
3004		btrfs_cmp_data_free(cmp);
3005	return ret;
3006}
3007
3008static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3009{
3010	int ret = 0;
3011	int i;
3012	struct page *src_page, *dst_page;
3013	unsigned int cmp_len = PAGE_SIZE;
3014	void *addr, *dst_addr;
3015
3016	i = 0;
3017	while (len) {
3018		if (len < PAGE_SIZE)
3019			cmp_len = len;
3020
3021		BUG_ON(i >= cmp->num_pages);
3022
3023		src_page = cmp->src_pages[i];
3024		dst_page = cmp->dst_pages[i];
3025		ASSERT(PageLocked(src_page));
3026		ASSERT(PageLocked(dst_page));
3027
3028		addr = kmap_atomic(src_page);
3029		dst_addr = kmap_atomic(dst_page);
3030
3031		flush_dcache_page(src_page);
3032		flush_dcache_page(dst_page);
3033
3034		if (memcmp(addr, dst_addr, cmp_len))
3035			ret = -EBADE;
3036
3037		kunmap_atomic(addr);
3038		kunmap_atomic(dst_addr);
3039
3040		if (ret)
3041			break;
3042
3043		len -= cmp_len;
3044		i++;
3045	}
3046
3047	return ret;
3048}
3049
3050static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3051				     u64 olen)
3052{
3053	u64 len = *plen;
3054	u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3055
3056	if (off + olen > inode->i_size || off + olen < off)
3057		return -EINVAL;
3058
3059	/* if we extend to eof, continue to block boundary */
3060	if (off + len == inode->i_size)
3061		*plen = len = ALIGN(inode->i_size, bs) - off;
3062
3063	/* Check that we are block aligned - btrfs_clone() requires this */
3064	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3065		return -EINVAL;
3066
3067	return 0;
3068}
3069
3070static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3071			     struct inode *dst, u64 dst_loff)
3072{
3073	int ret;
3074	u64 len = olen;
3075	struct cmp_pages cmp;
3076	bool same_inode = (src == dst);
3077	u64 same_lock_start = 0;
3078	u64 same_lock_len = 0;
3079
3080	if (len == 0)
3081		return 0;
3082
3083	if (same_inode)
3084		inode_lock(src);
3085	else
3086		btrfs_double_inode_lock(src, dst);
3087
3088	ret = extent_same_check_offsets(src, loff, &len, olen);
3089	if (ret)
3090		goto out_unlock;
3091
3092	ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3093	if (ret)
3094		goto out_unlock;
3095
3096	if (same_inode) {
3097		/*
3098		 * Single inode case wants the same checks, except we
3099		 * don't want our length pushed out past i_size as
3100		 * comparing that data range makes no sense.
3101		 *
3102		 * extent_same_check_offsets() will do this for an
3103		 * unaligned length at i_size, so catch it here and
3104		 * reject the request.
3105		 *
3106		 * This effectively means we require aligned extents
3107		 * for the single-inode case, whereas the other cases
3108		 * allow an unaligned length so long as it ends at
3109		 * i_size.
3110		 */
3111		if (len != olen) {
3112			ret = -EINVAL;
3113			goto out_unlock;
3114		}
3115
3116		/* Check for overlapping ranges */
3117		if (dst_loff + len > loff && dst_loff < loff + len) {
3118			ret = -EINVAL;
3119			goto out_unlock;
3120		}
3121
3122		same_lock_start = min_t(u64, loff, dst_loff);
3123		same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3124	}
3125
3126	/* don't make the dst file partly checksummed */
3127	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3128	    (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3129		ret = -EINVAL;
3130		goto out_unlock;
3131	}
3132
3133again:
3134	ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
3135	if (ret)
3136		goto out_unlock;
3137
3138	if (same_inode)
3139		ret = lock_extent_range(src, same_lock_start, same_lock_len,
3140					false);
3141	else
3142		ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3143					       false);
3144	/*
3145	 * If one of the inodes has dirty pages in the respective range or
3146	 * ordered extents, we need to flush dellaloc and wait for all ordered
3147	 * extents in the range. We must unlock the pages and the ranges in the
3148	 * io trees to avoid deadlocks when flushing delalloc (requires locking
3149	 * pages) and when waiting for ordered extents to complete (they require
3150	 * range locking).
3151	 */
3152	if (ret == -EAGAIN) {
3153		/*
3154		 * Ranges in the io trees already unlocked. Now unlock all
3155		 * pages before waiting for all IO to complete.
3156		 */
3157		btrfs_cmp_data_free(&cmp);
3158		if (same_inode) {
3159			btrfs_wait_ordered_range(src, same_lock_start,
3160						 same_lock_len);
3161		} else {
3162			btrfs_wait_ordered_range(src, loff, len);
3163			btrfs_wait_ordered_range(dst, dst_loff, len);
3164		}
3165		goto again;
3166	}
3167	ASSERT(ret == 0);
3168	if (WARN_ON(ret)) {
3169		/* ranges in the io trees already unlocked */
3170		btrfs_cmp_data_free(&cmp);
3171		return ret;
3172	}
3173
3174	/* pass original length for comparison so we stay within i_size */
3175	ret = btrfs_cmp_data(olen, &cmp);
3176	if (ret == 0)
3177		ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3178
3179	if (same_inode)
3180		unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3181			      same_lock_start + same_lock_len - 1);
3182	else
3183		btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3184
3185	btrfs_cmp_data_free(&cmp);
3186out_unlock:
3187	if (same_inode)
3188		inode_unlock(src);
3189	else
3190		btrfs_double_inode_unlock(src, dst);
3191
3192	return ret;
3193}
3194
3195#define BTRFS_MAX_DEDUPE_LEN	SZ_16M
3196
3197ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3198				struct file *dst_file, u64 dst_loff)
3199{
3200	struct inode *src = file_inode(src_file);
3201	struct inode *dst = file_inode(dst_file);
3202	u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3203	ssize_t res;
3204
3205	if (olen > BTRFS_MAX_DEDUPE_LEN)
3206		olen = BTRFS_MAX_DEDUPE_LEN;
3207
3208	if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3209		/*
3210		 * Btrfs does not support blocksize < page_size. As a
3211		 * result, btrfs_cmp_data() won't correctly handle
3212		 * this situation without an update.
3213		 */
3214		return -EINVAL;
3215	}
3216
3217	res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3218	if (res)
3219		return res;
3220	return olen;
3221}
3222
3223static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3224				     struct inode *inode,
3225				     u64 endoff,
3226				     const u64 destoff,
3227				     const u64 olen,
3228				     int no_time_update)
3229{
3230	struct btrfs_root *root = BTRFS_I(inode)->root;
3231	int ret;
3232
3233	inode_inc_iversion(inode);
3234	if (!no_time_update)
3235		inode->i_mtime = inode->i_ctime = current_time(inode);
3236	/*
3237	 * We round up to the block size at eof when determining which
3238	 * extents to clone above, but shouldn't round up the file size.
3239	 */
3240	if (endoff > destoff + olen)
3241		endoff = destoff + olen;
3242	if (endoff > inode->i_size)
3243		btrfs_i_size_write(BTRFS_I(inode), endoff);
3244
3245	ret = btrfs_update_inode(trans, root, inode);
3246	if (ret) {
3247		btrfs_abort_transaction(trans, ret);
3248		btrfs_end_transaction(trans);
3249		goto out;
3250	}
3251	ret = btrfs_end_transaction(trans);
3252out:
3253	return ret;
3254}
3255
3256static void clone_update_extent_map(struct btrfs_inode *inode,
3257				    const struct btrfs_trans_handle *trans,
3258				    const struct btrfs_path *path,
3259				    const u64 hole_offset,
3260				    const u64 hole_len)
3261{
3262	struct extent_map_tree *em_tree = &inode->extent_tree;
3263	struct extent_map *em;
3264	int ret;
3265
3266	em = alloc_extent_map();
3267	if (!em) {
3268		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3269		return;
3270	}
3271
3272	if (path) {
3273		struct btrfs_file_extent_item *fi;
3274
3275		fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3276				    struct btrfs_file_extent_item);
3277		btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3278		em->generation = -1;
3279		if (btrfs_file_extent_type(path->nodes[0], fi) ==
3280		    BTRFS_FILE_EXTENT_INLINE)
3281			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3282					&inode->runtime_flags);
3283	} else {
3284		em->start = hole_offset;
3285		em->len = hole_len;
3286		em->ram_bytes = em->len;
3287		em->orig_start = hole_offset;
3288		em->block_start = EXTENT_MAP_HOLE;
3289		em->block_len = 0;
3290		em->orig_block_len = 0;
3291		em->compress_type = BTRFS_COMPRESS_NONE;
3292		em->generation = trans->transid;
3293	}
3294
3295	while (1) {
3296		write_lock(&em_tree->lock);
3297		ret = add_extent_mapping(em_tree, em, 1);
3298		write_unlock(&em_tree->lock);
3299		if (ret != -EEXIST) {
3300			free_extent_map(em);
3301			break;
3302		}
3303		btrfs_drop_extent_cache(inode, em->start,
3304					em->start + em->len - 1, 0);
3305	}
3306
3307	if (ret)
3308		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3309}
3310
3311/*
3312 * Make sure we do not end up inserting an inline extent into a file that has
3313 * already other (non-inline) extents. If a file has an inline extent it can
3314 * not have any other extents and the (single) inline extent must start at the
3315 * file offset 0. Failing to respect these rules will lead to file corruption,
3316 * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3317 *
3318 * We can have extents that have been already written to disk or we can have
3319 * dirty ranges still in delalloc, in which case the extent maps and items are
3320 * created only when we run delalloc, and the delalloc ranges might fall outside
3321 * the range we are currently locking in the inode's io tree. So we check the
3322 * inode's i_size because of that (i_size updates are done while holding the
3323 * i_mutex, which we are holding here).
3324 * We also check to see if the inode has a size not greater than "datal" but has
3325 * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3326 * protected against such concurrent fallocate calls by the i_mutex).
3327 *
3328 * If the file has no extents but a size greater than datal, do not allow the
3329 * copy because we would need turn the inline extent into a non-inline one (even
3330 * with NO_HOLES enabled). If we find our destination inode only has one inline
3331 * extent, just overwrite it with the source inline extent if its size is less
3332 * than the source extent's size, or we could copy the source inline extent's
3333 * data into the destination inode's inline extent if the later is greater then
3334 * the former.
3335 */
3336static int clone_copy_inline_extent(struct inode *dst,
3337				    struct btrfs_trans_handle *trans,
3338				    struct btrfs_path *path,
3339				    struct btrfs_key *new_key,
3340				    const u64 drop_start,
3341				    const u64 datal,
3342				    const u64 skip,
3343				    const u64 size,
3344				    char *inline_data)
3345{
3346	struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3347	struct btrfs_root *root = BTRFS_I(dst)->root;
3348	const u64 aligned_end = ALIGN(new_key->offset + datal,
3349				      fs_info->sectorsize);
3350	int ret;
3351	struct btrfs_key key;
3352
3353	if (new_key->offset > 0)
3354		return -EOPNOTSUPP;
3355
3356	key.objectid = btrfs_ino(BTRFS_I(dst));
3357	key.type = BTRFS_EXTENT_DATA_KEY;
3358	key.offset = 0;
3359	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3360	if (ret < 0) {
3361		return ret;
3362	} else if (ret > 0) {
3363		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3364			ret = btrfs_next_leaf(root, path);
3365			if (ret < 0)
3366				return ret;
3367			else if (ret > 0)
3368				goto copy_inline_extent;
3369		}
3370		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3371		if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3372		    key.type == BTRFS_EXTENT_DATA_KEY) {
3373			ASSERT(key.offset > 0);
3374			return -EOPNOTSUPP;
3375		}
3376	} else if (i_size_read(dst) <= datal) {
3377		struct btrfs_file_extent_item *ei;
3378		u64 ext_len;
3379
3380		/*
3381		 * If the file size is <= datal, make sure there are no other
3382		 * extents following (can happen do to an fallocate call with
3383		 * the flag FALLOC_FL_KEEP_SIZE).
3384		 */
3385		ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3386				    struct btrfs_file_extent_item);
3387		/*
3388		 * If it's an inline extent, it can not have other extents
3389		 * following it.
3390		 */
3391		if (btrfs_file_extent_type(path->nodes[0], ei) ==
3392		    BTRFS_FILE_EXTENT_INLINE)
3393			goto copy_inline_extent;
3394
3395		ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3396		if (ext_len > aligned_end)
3397			return -EOPNOTSUPP;
3398
3399		ret = btrfs_next_item(root, path);
3400		if (ret < 0) {
3401			return ret;
3402		} else if (ret == 0) {
3403			btrfs_item_key_to_cpu(path->nodes[0], &key,
3404					      path->slots[0]);
3405			if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3406			    key.type == BTRFS_EXTENT_DATA_KEY)
3407				return -EOPNOTSUPP;
3408		}
3409	}
3410
3411copy_inline_extent:
3412	/*
3413	 * We have no extent items, or we have an extent at offset 0 which may
3414	 * or may not be inlined. All these cases are dealt the same way.
3415	 */
3416	if (i_size_read(dst) > datal) {
3417		/*
3418		 * If the destination inode has an inline extent...
3419		 * This would require copying the data from the source inline
3420		 * extent into the beginning of the destination's inline extent.
3421		 * But this is really complex, both extents can be compressed
3422		 * or just one of them, which would require decompressing and
3423		 * re-compressing data (which could increase the new compressed
3424		 * size, not allowing the compressed data to fit anymore in an
3425		 * inline extent).
3426		 * So just don't support this case for now (it should be rare,
3427		 * we are not really saving space when cloning inline extents).
3428		 */
3429		return -EOPNOTSUPP;
3430	}
3431
3432	btrfs_release_path(path);
3433	ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3434	if (ret)
3435		return ret;
3436	ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3437	if (ret)
3438		return ret;
3439
3440	if (skip) {
3441		const u32 start = btrfs_file_extent_calc_inline_size(0);
3442
3443		memmove(inline_data + start, inline_data + start + skip, datal);
3444	}
3445
3446	write_extent_buffer(path->nodes[0], inline_data,
3447			    btrfs_item_ptr_offset(path->nodes[0],
3448						  path->slots[0]),
3449			    size);
3450	inode_add_bytes(dst, datal);
3451
3452	return 0;
3453}
3454
3455/**
3456 * btrfs_clone() - clone a range from inode file to another
3457 *
3458 * @src: Inode to clone from
3459 * @inode: Inode to clone to
3460 * @off: Offset within source to start clone from
3461 * @olen: Original length, passed by user, of range to clone
3462 * @olen_aligned: Block-aligned value of olen
3463 * @destoff: Offset within @inode to start clone
3464 * @no_time_update: Whether to update mtime/ctime on the target inode
3465 */
3466static int btrfs_clone(struct inode *src, struct inode *inode,
3467		       const u64 off, const u64 olen, const u64 olen_aligned,
3468		       const u64 destoff, int no_time_update)
3469{
3470	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3471	struct btrfs_root *root = BTRFS_I(inode)->root;
3472	struct btrfs_path *path = NULL;
3473	struct extent_buffer *leaf;
3474	struct btrfs_trans_handle *trans;
3475	char *buf = NULL;
3476	struct btrfs_key key;
3477	u32 nritems;
3478	int slot;
3479	int ret;
3480	const u64 len = olen_aligned;
3481	u64 last_dest_end = destoff;
3482
3483	ret = -ENOMEM;
3484	buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3485	if (!buf)
3486		return ret;
3487
3488	path = btrfs_alloc_path();
3489	if (!path) {
3490		kvfree(buf);
3491		return ret;
3492	}
3493
3494	path->reada = READA_FORWARD;
3495	/* clone data */
3496	key.objectid = btrfs_ino(BTRFS_I(src));
3497	key.type = BTRFS_EXTENT_DATA_KEY;
3498	key.offset = off;
3499
3500	while (1) {
3501		u64 next_key_min_offset = key.offset + 1;
3502
3503		/*
3504		 * note the key will change type as we walk through the
3505		 * tree.
3506		 */
3507		path->leave_spinning = 1;
3508		ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3509				0, 0);
3510		if (ret < 0)
3511			goto out;
3512		/*
3513		 * First search, if no extent item that starts at offset off was
3514		 * found but the previous item is an extent item, it's possible
3515		 * it might overlap our target range, therefore process it.
3516		 */
3517		if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3518			btrfs_item_key_to_cpu(path->nodes[0], &key,
3519					      path->slots[0] - 1);
3520			if (key.type == BTRFS_EXTENT_DATA_KEY)
3521				path->slots[0]--;
3522		}
3523
3524		nritems = btrfs_header_nritems(path->nodes[0]);
3525process_slot:
3526		if (path->slots[0] >= nritems) {
3527			ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3528			if (ret < 0)
3529				goto out;
3530			if (ret > 0)
3531				break;
3532			nritems = btrfs_header_nritems(path->nodes[0]);
3533		}
3534		leaf = path->nodes[0];
3535		slot = path->slots[0];
3536
3537		btrfs_item_key_to_cpu(leaf, &key, slot);
3538		if (key.type > BTRFS_EXTENT_DATA_KEY ||
3539		    key.objectid != btrfs_ino(BTRFS_I(src)))
3540			break;
3541
3542		if (key.type == BTRFS_EXTENT_DATA_KEY) {
3543			struct btrfs_file_extent_item *extent;
3544			int type;
3545			u32 size;
3546			struct btrfs_key new_key;
3547			u64 disko = 0, diskl = 0;
3548			u64 datao = 0, datal = 0;
3549			u8 comp;
3550			u64 drop_start;
3551
3552			extent = btrfs_item_ptr(leaf, slot,
3553						struct btrfs_file_extent_item);
3554			comp = btrfs_file_extent_compression(leaf, extent);
3555			type = btrfs_file_extent_type(leaf, extent);
3556			if (type == BTRFS_FILE_EXTENT_REG ||
3557			    type == BTRFS_FILE_EXTENT_PREALLOC) {
3558				disko = btrfs_file_extent_disk_bytenr(leaf,
3559								      extent);
3560				diskl = btrfs_file_extent_disk_num_bytes(leaf,
3561								 extent);
3562				datao = btrfs_file_extent_offset(leaf, extent);
3563				datal = btrfs_file_extent_num_bytes(leaf,
3564								    extent);
3565			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
3566				/* take upper bound, may be compressed */
3567				datal = btrfs_file_extent_ram_bytes(leaf,
3568								    extent);
3569			}
3570
3571			/*
3572			 * The first search might have left us at an extent
3573			 * item that ends before our target range's start, can
3574			 * happen if we have holes and NO_HOLES feature enabled.
3575			 */
3576			if (key.offset + datal <= off) {
3577				path->slots[0]++;
3578				goto process_slot;
3579			} else if (key.offset >= off + len) {
3580				break;
3581			}
3582			next_key_min_offset = key.offset + datal;
3583			size = btrfs_item_size_nr(leaf, slot);
3584			read_extent_buffer(leaf, buf,
3585					   btrfs_item_ptr_offset(leaf, slot),
3586					   size);
3587
3588			btrfs_release_path(path);
3589			path->leave_spinning = 0;
3590
3591			memcpy(&new_key, &key, sizeof(new_key));
3592			new_key.objectid = btrfs_ino(BTRFS_I(inode));
3593			if (off <= key.offset)
3594				new_key.offset = key.offset + destoff - off;
3595			else
3596				new_key.offset = destoff;
3597
3598			/*
3599			 * Deal with a hole that doesn't have an extent item
3600			 * that represents it (NO_HOLES feature enabled).
3601			 * This hole is either in the middle of the cloning
3602			 * range or at the beginning (fully overlaps it or
3603			 * partially overlaps it).
3604			 */
3605			if (new_key.offset != last_dest_end)
3606				drop_start = last_dest_end;
3607			else
3608				drop_start = new_key.offset;
3609
3610			/*
3611			 * 1 - adjusting old extent (we may have to split it)
3612			 * 1 - add new extent
3613			 * 1 - inode update
3614			 */
3615			trans = btrfs_start_transaction(root, 3);
3616			if (IS_ERR(trans)) {
3617				ret = PTR_ERR(trans);
3618				goto out;
3619			}
3620
3621			if (type == BTRFS_FILE_EXTENT_REG ||
3622			    type == BTRFS_FILE_EXTENT_PREALLOC) {
3623				/*
3624				 *    a  | --- range to clone ---|  b
3625				 * | ------------- extent ------------- |
3626				 */
3627
3628				/* subtract range b */
3629				if (key.offset + datal > off + len)
3630					datal = off + len - key.offset;
3631
3632				/* subtract range a */
3633				if (off > key.offset) {
3634					datao += off - key.offset;
3635					datal -= off - key.offset;
3636				}
3637
3638				ret = btrfs_drop_extents(trans, root, inode,
3639							 drop_start,
3640							 new_key.offset + datal,
3641							 1);
3642				if (ret) {
3643					if (ret != -EOPNOTSUPP)
3644						btrfs_abort_transaction(trans,
3645									ret);
3646					btrfs_end_transaction(trans);
3647					goto out;
3648				}
3649
3650				ret = btrfs_insert_empty_item(trans, root, path,
3651							      &new_key, size);
3652				if (ret) {
3653					btrfs_abort_transaction(trans, ret);
3654					btrfs_end_transaction(trans);
3655					goto out;
3656				}
3657
3658				leaf = path->nodes[0];
3659				slot = path->slots[0];
3660				write_extent_buffer(leaf, buf,
3661					    btrfs_item_ptr_offset(leaf, slot),
3662					    size);
3663
3664				extent = btrfs_item_ptr(leaf, slot,
3665						struct btrfs_file_extent_item);
3666
3667				/* disko == 0 means it's a hole */
3668				if (!disko)
3669					datao = 0;
3670
3671				btrfs_set_file_extent_offset(leaf, extent,
3672							     datao);
3673				btrfs_set_file_extent_num_bytes(leaf, extent,
3674								datal);
3675
3676				if (disko) {
3677					inode_add_bytes(inode, datal);
3678					ret = btrfs_inc_extent_ref(trans,
3679							root,
3680							disko, diskl, 0,
3681							root->root_key.objectid,
3682							btrfs_ino(BTRFS_I(inode)),
3683							new_key.offset - datao);
3684					if (ret) {
3685						btrfs_abort_transaction(trans,
3686									ret);
3687						btrfs_end_transaction(trans);
3688						goto out;
3689
3690					}
3691				}
3692			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
3693				u64 skip = 0;
3694				u64 trim = 0;
3695
3696				if (off > key.offset) {
3697					skip = off - key.offset;
3698					new_key.offset += skip;
3699				}
3700
3701				if (key.offset + datal > off + len)
3702					trim = key.offset + datal - (off + len);
3703
3704				if (comp && (skip || trim)) {
3705					ret = -EINVAL;
3706					btrfs_end_transaction(trans);
3707					goto out;
3708				}
3709				size -= skip + trim;
3710				datal -= skip + trim;
3711
3712				ret = clone_copy_inline_extent(inode,
3713							       trans, path,
3714							       &new_key,
3715							       drop_start,
3716							       datal,
3717							       skip, size, buf);
3718				if (ret) {
3719					if (ret != -EOPNOTSUPP)
3720						btrfs_abort_transaction(trans,
3721									ret);
3722					btrfs_end_transaction(trans);
3723					goto out;
3724				}
3725				leaf = path->nodes[0];
3726				slot = path->slots[0];
3727			}
3728
3729			/* If we have an implicit hole (NO_HOLES feature). */
3730			if (drop_start < new_key.offset)
3731				clone_update_extent_map(BTRFS_I(inode), trans,
3732						NULL, drop_start,
3733						new_key.offset - drop_start);
3734
3735			clone_update_extent_map(BTRFS_I(inode), trans,
3736					path, 0, 0);
3737
3738			btrfs_mark_buffer_dirty(leaf);
3739			btrfs_release_path(path);
3740
3741			last_dest_end = ALIGN(new_key.offset + datal,
3742					      fs_info->sectorsize);
3743			ret = clone_finish_inode_update(trans, inode,
3744							last_dest_end,
3745							destoff, olen,
3746							no_time_update);
3747			if (ret)
3748				goto out;
3749			if (new_key.offset + datal >= destoff + len)
3750				break;
3751		}
3752		btrfs_release_path(path);
3753		key.offset = next_key_min_offset;
3754
3755		if (fatal_signal_pending(current)) {
3756			ret = -EINTR;
3757			goto out;
3758		}
3759	}
3760	ret = 0;
3761
3762	if (last_dest_end < destoff + len) {
3763		/*
3764		 * We have an implicit hole (NO_HOLES feature is enabled) that
3765		 * fully or partially overlaps our cloning range at its end.
3766		 */
3767		btrfs_release_path(path);
3768
3769		/*
3770		 * 1 - remove extent(s)
3771		 * 1 - inode update
3772		 */
3773		trans = btrfs_start_transaction(root, 2);
3774		if (IS_ERR(trans)) {
3775			ret = PTR_ERR(trans);
3776			goto out;
3777		}
3778		ret = btrfs_drop_extents(trans, root, inode,
3779					 last_dest_end, destoff + len, 1);
3780		if (ret) {
3781			if (ret != -EOPNOTSUPP)
3782				btrfs_abort_transaction(trans, ret);
3783			btrfs_end_transaction(trans);
3784			goto out;
3785		}
3786		clone_update_extent_map(BTRFS_I(inode), trans, NULL,
3787				last_dest_end,
3788				destoff + len - last_dest_end);
3789		ret = clone_finish_inode_update(trans, inode, destoff + len,
3790						destoff, olen, no_time_update);
3791	}
3792
3793out:
3794	btrfs_free_path(path);
3795	kvfree(buf);
3796	return ret;
3797}
3798
3799static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3800					u64 off, u64 olen, u64 destoff)
3801{
3802	struct inode *inode = file_inode(file);
3803	struct inode *src = file_inode(file_src);
3804	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3805	struct btrfs_root *root = BTRFS_I(inode)->root;
3806	int ret;
3807	u64 len = olen;
3808	u64 bs = fs_info->sb->s_blocksize;
3809	int same_inode = src == inode;
3810
3811	/*
3812	 * TODO:
3813	 * - split compressed inline extents.  annoying: we need to
3814	 *   decompress into destination's address_space (the file offset
3815	 *   may change, so source mapping won't do), then recompress (or
3816	 *   otherwise reinsert) a subrange.
3817	 *
3818	 * - split destination inode's inline extents.  The inline extents can
3819	 *   be either compressed or non-compressed.
3820	 */
3821
3822	if (btrfs_root_readonly(root))
3823		return -EROFS;
3824
3825	if (file_src->f_path.mnt != file->f_path.mnt ||
3826	    src->i_sb != inode->i_sb)
3827		return -EXDEV;
3828
3829	/* don't make the dst file partly checksummed */
3830	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3831	    (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3832		return -EINVAL;
3833
3834	if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3835		return -EISDIR;
3836
3837	if (!same_inode) {
3838		btrfs_double_inode_lock(src, inode);
3839	} else {
3840		inode_lock(src);
3841	}
3842
3843	/* determine range to clone */
3844	ret = -EINVAL;
3845	if (off + len > src->i_size || off + len < off)
3846		goto out_unlock;
3847	if (len == 0)
3848		olen = len = src->i_size - off;
3849	/* if we extend to eof, continue to block boundary */
3850	if (off + len == src->i_size)
3851		len = ALIGN(src->i_size, bs) - off;
3852
3853	if (len == 0) {
3854		ret = 0;
3855		goto out_unlock;
3856	}
3857
3858	/* verify the end result is block aligned */
3859	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3860	    !IS_ALIGNED(destoff, bs))
3861		goto out_unlock;
3862
3863	/* verify if ranges are overlapped within the same file */
3864	if (same_inode) {
3865		if (destoff + len > off && destoff < off + len)
3866			goto out_unlock;
3867	}
3868
3869	if (destoff > inode->i_size) {
3870		ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3871		if (ret)
3872			goto out_unlock;
3873	}
3874
3875	/*
3876	 * Lock the target range too. Right after we replace the file extent
3877	 * items in the fs tree (which now point to the cloned data), we might
3878	 * have a worker replace them with extent items relative to a write
3879	 * operation that was issued before this clone operation (i.e. confront
3880	 * with inode.c:btrfs_finish_ordered_io).
3881	 */
3882	if (same_inode) {
3883		u64 lock_start = min_t(u64, off, destoff);
3884		u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3885
3886		ret = lock_extent_range(src, lock_start, lock_len, true);
3887	} else {
3888		ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
3889					       true);
3890	}
3891	ASSERT(ret == 0);
3892	if (WARN_ON(ret)) {
3893		/* ranges in the io trees already unlocked */
3894		goto out_unlock;
3895	}
3896
3897	ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3898
3899	if (same_inode) {
3900		u64 lock_start = min_t(u64, off, destoff);
3901		u64 lock_end = max_t(u64, off, destoff) + len - 1;
3902
3903		unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3904	} else {
3905		btrfs_double_extent_unlock(src, off, inode, destoff, len);
3906	}
3907	/*
3908	 * Truncate page cache pages so that future reads will see the cloned
3909	 * data immediately and not the previous data.
3910	 */
3911	truncate_inode_pages_range(&inode->i_data,
3912				round_down(destoff, PAGE_SIZE),
3913				round_up(destoff + len, PAGE_SIZE) - 1);
3914out_unlock:
3915	if (!same_inode)
3916		btrfs_double_inode_unlock(src, inode);
3917	else
3918		inode_unlock(src);
3919	return ret;
3920}
3921
3922int btrfs_clone_file_range(struct file *src_file, loff_t off,
3923		struct file *dst_file, loff_t destoff, u64 len)
3924{
3925	return btrfs_clone_files(dst_file, src_file, off, len, destoff);
3926}
3927
3928static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3929{
3930	struct inode *inode = file_inode(file);
3931	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3932	struct btrfs_root *root = BTRFS_I(inode)->root;
3933	struct btrfs_root *new_root;
3934	struct btrfs_dir_item *di;
3935	struct btrfs_trans_handle *trans;
3936	struct btrfs_path *path;
3937	struct btrfs_key location;
3938	struct btrfs_disk_key disk_key;
3939	u64 objectid = 0;
3940	u64 dir_id;
3941	int ret;
3942
3943	if (!capable(CAP_SYS_ADMIN))
3944		return -EPERM;
3945
3946	ret = mnt_want_write_file(file);
3947	if (ret)
3948		return ret;
3949
3950	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3951		ret = -EFAULT;
3952		goto out;
3953	}
3954
3955	if (!objectid)
3956		objectid = BTRFS_FS_TREE_OBJECTID;
3957
3958	location.objectid = objectid;
3959	location.type = BTRFS_ROOT_ITEM_KEY;
3960	location.offset = (u64)-1;
3961
3962	new_root = btrfs_read_fs_root_no_name(fs_info, &location);
3963	if (IS_ERR(new_root)) {
3964		ret = PTR_ERR(new_root);
3965		goto out;
3966	}
3967	if (!is_fstree(new_root->objectid)) {
3968		ret = -ENOENT;
3969		goto out;
3970	}
3971
3972	path = btrfs_alloc_path();
3973	if (!path) {
3974		ret = -ENOMEM;
3975		goto out;
3976	}
3977	path->leave_spinning = 1;
3978
3979	trans = btrfs_start_transaction(root, 1);
3980	if (IS_ERR(trans)) {
3981		btrfs_free_path(path);
3982		ret = PTR_ERR(trans);
3983		goto out;
3984	}
3985
3986	dir_id = btrfs_super_root_dir(fs_info->super_copy);
3987	di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
3988				   dir_id, "default", 7, 1);
3989	if (IS_ERR_OR_NULL(di)) {
3990		btrfs_free_path(path);
3991		btrfs_end_transaction(trans);
3992		btrfs_err(fs_info,
3993			  "Umm, you don't have the default diritem, this isn't going to work");
3994		ret = -ENOENT;
3995		goto out;
3996	}
3997
3998	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3999	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4000	btrfs_mark_buffer_dirty(path->nodes[0]);
4001	btrfs_free_path(path);
4002
4003	btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4004	btrfs_end_transaction(trans);
 
 
 
4005out:
4006	mnt_drop_write_file(file);
4007	return ret;
4008}
4009
4010void btrfs_get_block_group_info(struct list_head *groups_list,
4011				struct btrfs_ioctl_space_info *space)
4012{
4013	struct btrfs_block_group_cache *block_group;
4014
4015	space->total_bytes = 0;
4016	space->used_bytes = 0;
4017	space->flags = 0;
4018	list_for_each_entry(block_group, groups_list, list) {
4019		space->flags = block_group->flags;
4020		space->total_bytes += block_group->key.offset;
4021		space->used_bytes +=
4022			btrfs_block_group_used(&block_group->item);
4023	}
4024}
4025
4026static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4027				   void __user *arg)
4028{
4029	struct btrfs_ioctl_space_args space_args;
4030	struct btrfs_ioctl_space_info space;
4031	struct btrfs_ioctl_space_info *dest;
4032	struct btrfs_ioctl_space_info *dest_orig;
4033	struct btrfs_ioctl_space_info __user *user_dest;
4034	struct btrfs_space_info *info;
4035	static const u64 types[] = {
4036		BTRFS_BLOCK_GROUP_DATA,
4037		BTRFS_BLOCK_GROUP_SYSTEM,
4038		BTRFS_BLOCK_GROUP_METADATA,
4039		BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4040	};
4041	int num_types = 4;
4042	int alloc_size;
4043	int ret = 0;
4044	u64 slot_count = 0;
4045	int i, c;
4046
4047	if (copy_from_user(&space_args,
4048			   (struct btrfs_ioctl_space_args __user *)arg,
4049			   sizeof(space_args)))
4050		return -EFAULT;
4051
4052	for (i = 0; i < num_types; i++) {
4053		struct btrfs_space_info *tmp;
4054
4055		info = NULL;
4056		rcu_read_lock();
4057		list_for_each_entry_rcu(tmp, &fs_info->space_info,
4058					list) {
4059			if (tmp->flags == types[i]) {
4060				info = tmp;
4061				break;
4062			}
4063		}
4064		rcu_read_unlock();
4065
4066		if (!info)
4067			continue;
4068
4069		down_read(&info->groups_sem);
4070		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4071			if (!list_empty(&info->block_groups[c]))
4072				slot_count++;
4073		}
4074		up_read(&info->groups_sem);
4075	}
4076
4077	/*
4078	 * Global block reserve, exported as a space_info
4079	 */
4080	slot_count++;
4081
4082	/* space_slots == 0 means they are asking for a count */
4083	if (space_args.space_slots == 0) {
4084		space_args.total_spaces = slot_count;
4085		goto out;
4086	}
4087
4088	slot_count = min_t(u64, space_args.space_slots, slot_count);
4089
4090	alloc_size = sizeof(*dest) * slot_count;
4091
4092	/* we generally have at most 6 or so space infos, one for each raid
4093	 * level.  So, a whole page should be more than enough for everyone
4094	 */
4095	if (alloc_size > PAGE_SIZE)
4096		return -ENOMEM;
4097
4098	space_args.total_spaces = 0;
4099	dest = kmalloc(alloc_size, GFP_KERNEL);
4100	if (!dest)
4101		return -ENOMEM;
4102	dest_orig = dest;
4103
4104	/* now we have a buffer to copy into */
4105	for (i = 0; i < num_types; i++) {
4106		struct btrfs_space_info *tmp;
4107
4108		if (!slot_count)
4109			break;
4110
4111		info = NULL;
4112		rcu_read_lock();
4113		list_for_each_entry_rcu(tmp, &fs_info->space_info,
4114					list) {
4115			if (tmp->flags == types[i]) {
4116				info = tmp;
4117				break;
4118			}
4119		}
4120		rcu_read_unlock();
4121
4122		if (!info)
4123			continue;
4124		down_read(&info->groups_sem);
4125		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4126			if (!list_empty(&info->block_groups[c])) {
4127				btrfs_get_block_group_info(
4128					&info->block_groups[c], &space);
4129				memcpy(dest, &space, sizeof(space));
4130				dest++;
4131				space_args.total_spaces++;
4132				slot_count--;
4133			}
4134			if (!slot_count)
4135				break;
4136		}
4137		up_read(&info->groups_sem);
4138	}
4139
4140	/*
4141	 * Add global block reserve
4142	 */
4143	if (slot_count) {
4144		struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4145
4146		spin_lock(&block_rsv->lock);
4147		space.total_bytes = block_rsv->size;
4148		space.used_bytes = block_rsv->size - block_rsv->reserved;
4149		spin_unlock(&block_rsv->lock);
4150		space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4151		memcpy(dest, &space, sizeof(space));
4152		space_args.total_spaces++;
4153	}
4154
4155	user_dest = (struct btrfs_ioctl_space_info __user *)
4156		(arg + sizeof(struct btrfs_ioctl_space_args));
4157
4158	if (copy_to_user(user_dest, dest_orig, alloc_size))
4159		ret = -EFAULT;
4160
4161	kfree(dest_orig);
4162out:
4163	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4164		ret = -EFAULT;
4165
4166	return ret;
4167}
4168
4169static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4170					    void __user *argp)
4171{
4172	struct btrfs_trans_handle *trans;
4173	u64 transid;
4174	int ret;
4175
4176	trans = btrfs_attach_transaction_barrier(root);
4177	if (IS_ERR(trans)) {
4178		if (PTR_ERR(trans) != -ENOENT)
4179			return PTR_ERR(trans);
4180
4181		/* No running transaction, don't bother */
4182		transid = root->fs_info->last_trans_committed;
4183		goto out;
4184	}
4185	transid = trans->transid;
4186	ret = btrfs_commit_transaction_async(trans, 0);
4187	if (ret) {
4188		btrfs_end_transaction(trans);
4189		return ret;
4190	}
4191out:
4192	if (argp)
4193		if (copy_to_user(argp, &transid, sizeof(transid)))
4194			return -EFAULT;
4195	return 0;
4196}
4197
4198static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4199					   void __user *argp)
4200{
4201	u64 transid;
4202
4203	if (argp) {
4204		if (copy_from_user(&transid, argp, sizeof(transid)))
4205			return -EFAULT;
4206	} else {
4207		transid = 0;  /* current trans */
4208	}
4209	return btrfs_wait_for_commit(fs_info, transid);
4210}
4211
4212static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4213{
4214	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4215	struct btrfs_ioctl_scrub_args *sa;
4216	int ret;
4217
4218	if (!capable(CAP_SYS_ADMIN))
4219		return -EPERM;
4220
4221	sa = memdup_user(arg, sizeof(*sa));
4222	if (IS_ERR(sa))
4223		return PTR_ERR(sa);
4224
4225	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4226		ret = mnt_want_write_file(file);
4227		if (ret)
4228			goto out;
4229	}
4230
4231	ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4232			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4233			      0);
4234
 
 
 
 
 
 
 
 
 
 
 
 
4235	if (copy_to_user(arg, sa, sizeof(*sa)))
4236		ret = -EFAULT;
4237
4238	if (!(sa->flags & BTRFS_SCRUB_READONLY))
4239		mnt_drop_write_file(file);
4240out:
4241	kfree(sa);
4242	return ret;
4243}
4244
4245static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4246{
4247	if (!capable(CAP_SYS_ADMIN))
4248		return -EPERM;
4249
4250	return btrfs_scrub_cancel(fs_info);
4251}
4252
4253static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4254				       void __user *arg)
4255{
4256	struct btrfs_ioctl_scrub_args *sa;
4257	int ret;
4258
4259	if (!capable(CAP_SYS_ADMIN))
4260		return -EPERM;
4261
4262	sa = memdup_user(arg, sizeof(*sa));
4263	if (IS_ERR(sa))
4264		return PTR_ERR(sa);
4265
4266	ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4267
4268	if (copy_to_user(arg, sa, sizeof(*sa)))
4269		ret = -EFAULT;
4270
4271	kfree(sa);
4272	return ret;
4273}
4274
4275static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4276				      void __user *arg)
4277{
4278	struct btrfs_ioctl_get_dev_stats *sa;
4279	int ret;
4280
4281	sa = memdup_user(arg, sizeof(*sa));
4282	if (IS_ERR(sa))
4283		return PTR_ERR(sa);
4284
4285	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4286		kfree(sa);
4287		return -EPERM;
4288	}
4289
4290	ret = btrfs_get_dev_stats(fs_info, sa);
4291
4292	if (copy_to_user(arg, sa, sizeof(*sa)))
4293		ret = -EFAULT;
4294
4295	kfree(sa);
4296	return ret;
4297}
4298
4299static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4300				    void __user *arg)
4301{
4302	struct btrfs_ioctl_dev_replace_args *p;
4303	int ret;
4304
4305	if (!capable(CAP_SYS_ADMIN))
4306		return -EPERM;
4307
4308	p = memdup_user(arg, sizeof(*p));
4309	if (IS_ERR(p))
4310		return PTR_ERR(p);
4311
4312	switch (p->cmd) {
4313	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4314		if (sb_rdonly(fs_info->sb)) {
4315			ret = -EROFS;
4316			goto out;
4317		}
4318		if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4319			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4320		} else {
4321			ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4322			clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4323		}
4324		break;
4325	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4326		btrfs_dev_replace_status(fs_info, p);
4327		ret = 0;
4328		break;
4329	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4330		p->result = btrfs_dev_replace_cancel(fs_info);
4331		ret = 0;
4332		break;
4333	default:
4334		ret = -EINVAL;
4335		break;
4336	}
4337
4338	if (copy_to_user(arg, p, sizeof(*p)))
4339		ret = -EFAULT;
4340out:
4341	kfree(p);
4342	return ret;
4343}
4344
4345static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4346{
4347	int ret = 0;
4348	int i;
4349	u64 rel_ptr;
4350	int size;
4351	struct btrfs_ioctl_ino_path_args *ipa = NULL;
4352	struct inode_fs_paths *ipath = NULL;
4353	struct btrfs_path *path;
4354
4355	if (!capable(CAP_DAC_READ_SEARCH))
4356		return -EPERM;
4357
4358	path = btrfs_alloc_path();
4359	if (!path) {
4360		ret = -ENOMEM;
4361		goto out;
4362	}
4363
4364	ipa = memdup_user(arg, sizeof(*ipa));
4365	if (IS_ERR(ipa)) {
4366		ret = PTR_ERR(ipa);
4367		ipa = NULL;
4368		goto out;
4369	}
4370
4371	size = min_t(u32, ipa->size, 4096);
4372	ipath = init_ipath(size, root, path);
4373	if (IS_ERR(ipath)) {
4374		ret = PTR_ERR(ipath);
4375		ipath = NULL;
4376		goto out;
4377	}
4378
4379	ret = paths_from_inode(ipa->inum, ipath);
4380	if (ret < 0)
4381		goto out;
4382
4383	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4384		rel_ptr = ipath->fspath->val[i] -
4385			  (u64)(unsigned long)ipath->fspath->val;
4386		ipath->fspath->val[i] = rel_ptr;
4387	}
4388
4389	ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4390			   ipath->fspath, size);
4391	if (ret) {
4392		ret = -EFAULT;
4393		goto out;
4394	}
4395
4396out:
4397	btrfs_free_path(path);
4398	free_ipath(ipath);
4399	kfree(ipa);
4400
4401	return ret;
4402}
4403
4404static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4405{
4406	struct btrfs_data_container *inodes = ctx;
4407	const size_t c = 3 * sizeof(u64);
4408
4409	if (inodes->bytes_left >= c) {
4410		inodes->bytes_left -= c;
4411		inodes->val[inodes->elem_cnt] = inum;
4412		inodes->val[inodes->elem_cnt + 1] = offset;
4413		inodes->val[inodes->elem_cnt + 2] = root;
4414		inodes->elem_cnt += 3;
4415	} else {
4416		inodes->bytes_missing += c - inodes->bytes_left;
4417		inodes->bytes_left = 0;
4418		inodes->elem_missed += 3;
4419	}
4420
4421	return 0;
4422}
4423
4424static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4425					void __user *arg, int version)
4426{
4427	int ret = 0;
4428	int size;
4429	struct btrfs_ioctl_logical_ino_args *loi;
4430	struct btrfs_data_container *inodes = NULL;
4431	struct btrfs_path *path = NULL;
4432	bool ignore_offset;
4433
4434	if (!capable(CAP_SYS_ADMIN))
4435		return -EPERM;
4436
4437	loi = memdup_user(arg, sizeof(*loi));
4438	if (IS_ERR(loi))
4439		return PTR_ERR(loi);
4440
4441	if (version == 1) {
4442		ignore_offset = false;
4443		size = min_t(u32, loi->size, SZ_64K);
4444	} else {
4445		/* All reserved bits must be 0 for now */
4446		if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4447			ret = -EINVAL;
4448			goto out_loi;
4449		}
4450		/* Only accept flags we have defined so far */
4451		if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4452			ret = -EINVAL;
4453			goto out_loi;
4454		}
4455		ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4456		size = min_t(u32, loi->size, SZ_16M);
4457	}
4458
4459	path = btrfs_alloc_path();
4460	if (!path) {
4461		ret = -ENOMEM;
4462		goto out;
4463	}
4464
4465	inodes = init_data_container(size);
4466	if (IS_ERR(inodes)) {
4467		ret = PTR_ERR(inodes);
4468		inodes = NULL;
4469		goto out;
4470	}
4471
4472	ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4473					  build_ino_list, inodes, ignore_offset);
4474	if (ret == -EINVAL)
4475		ret = -ENOENT;
4476	if (ret < 0)
4477		goto out;
4478
4479	ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4480			   size);
4481	if (ret)
4482		ret = -EFAULT;
4483
4484out:
4485	btrfs_free_path(path);
4486	kvfree(inodes);
4487out_loi:
4488	kfree(loi);
4489
4490	return ret;
4491}
4492
4493void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4494			       struct btrfs_ioctl_balance_args *bargs)
4495{
4496	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4497
4498	bargs->flags = bctl->flags;
4499
4500	if (atomic_read(&fs_info->balance_running))
4501		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4502	if (atomic_read(&fs_info->balance_pause_req))
4503		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4504	if (atomic_read(&fs_info->balance_cancel_req))
4505		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4506
4507	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4508	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4509	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4510
4511	if (lock) {
4512		spin_lock(&fs_info->balance_lock);
4513		memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4514		spin_unlock(&fs_info->balance_lock);
4515	} else {
4516		memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4517	}
4518}
4519
4520static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4521{
4522	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4523	struct btrfs_fs_info *fs_info = root->fs_info;
4524	struct btrfs_ioctl_balance_args *bargs;
4525	struct btrfs_balance_control *bctl;
4526	bool need_unlock; /* for mut. excl. ops lock */
4527	int ret;
4528
4529	if (!capable(CAP_SYS_ADMIN))
4530		return -EPERM;
4531
4532	ret = mnt_want_write_file(file);
4533	if (ret)
4534		return ret;
4535
4536again:
4537	if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4538		mutex_lock(&fs_info->volume_mutex);
4539		mutex_lock(&fs_info->balance_mutex);
4540		need_unlock = true;
4541		goto locked;
4542	}
4543
4544	/*
4545	 * mut. excl. ops lock is locked.  Three possibilities:
4546	 *   (1) some other op is running
4547	 *   (2) balance is running
4548	 *   (3) balance is paused -- special case (think resume)
4549	 */
4550	mutex_lock(&fs_info->balance_mutex);
4551	if (fs_info->balance_ctl) {
4552		/* this is either (2) or (3) */
4553		if (!atomic_read(&fs_info->balance_running)) {
4554			mutex_unlock(&fs_info->balance_mutex);
4555			if (!mutex_trylock(&fs_info->volume_mutex))
4556				goto again;
 
 
4557			mutex_lock(&fs_info->balance_mutex);
4558
4559			if (fs_info->balance_ctl &&
4560			    !atomic_read(&fs_info->balance_running)) {
4561				/* this is (3) */
4562				need_unlock = false;
4563				goto locked;
4564			}
4565
4566			mutex_unlock(&fs_info->balance_mutex);
4567			mutex_unlock(&fs_info->volume_mutex);
4568			goto again;
4569		} else {
4570			/* this is (2) */
4571			mutex_unlock(&fs_info->balance_mutex);
4572			ret = -EINPROGRESS;
4573			goto out;
4574		}
4575	} else {
4576		/* this is (1) */
4577		mutex_unlock(&fs_info->balance_mutex);
4578		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4579		goto out;
4580	}
4581
4582locked:
4583	BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4584
4585	if (arg) {
4586		bargs = memdup_user(arg, sizeof(*bargs));
4587		if (IS_ERR(bargs)) {
4588			ret = PTR_ERR(bargs);
4589			goto out_unlock;
4590		}
4591
4592		if (bargs->flags & BTRFS_BALANCE_RESUME) {
4593			if (!fs_info->balance_ctl) {
4594				ret = -ENOTCONN;
4595				goto out_bargs;
4596			}
4597
4598			bctl = fs_info->balance_ctl;
4599			spin_lock(&fs_info->balance_lock);
4600			bctl->flags |= BTRFS_BALANCE_RESUME;
4601			spin_unlock(&fs_info->balance_lock);
4602
4603			goto do_balance;
4604		}
4605	} else {
4606		bargs = NULL;
4607	}
4608
4609	if (fs_info->balance_ctl) {
4610		ret = -EINPROGRESS;
4611		goto out_bargs;
4612	}
4613
4614	bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4615	if (!bctl) {
4616		ret = -ENOMEM;
4617		goto out_bargs;
4618	}
4619
4620	bctl->fs_info = fs_info;
4621	if (arg) {
4622		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4623		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4624		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4625
4626		bctl->flags = bargs->flags;
4627	} else {
4628		/* balance everything - no filters */
4629		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4630	}
4631
4632	if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4633		ret = -EINVAL;
4634		goto out_bctl;
4635	}
4636
4637do_balance:
4638	/*
4639	 * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP
4640	 * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
4641	 * or, if restriper was paused all the way until unmount, in
4642	 * free_fs_info.  The flag is cleared in __cancel_balance.
4643	 */
4644	need_unlock = false;
4645
4646	ret = btrfs_balance(bctl, bargs);
4647	bctl = NULL;
4648
4649	if (arg) {
4650		if (copy_to_user(arg, bargs, sizeof(*bargs)))
4651			ret = -EFAULT;
4652	}
4653
4654out_bctl:
4655	kfree(bctl);
4656out_bargs:
4657	kfree(bargs);
4658out_unlock:
4659	mutex_unlock(&fs_info->balance_mutex);
4660	mutex_unlock(&fs_info->volume_mutex);
4661	if (need_unlock)
4662		clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4663out:
4664	mnt_drop_write_file(file);
4665	return ret;
4666}
4667
4668static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4669{
4670	if (!capable(CAP_SYS_ADMIN))
4671		return -EPERM;
4672
4673	switch (cmd) {
4674	case BTRFS_BALANCE_CTL_PAUSE:
4675		return btrfs_pause_balance(fs_info);
4676	case BTRFS_BALANCE_CTL_CANCEL:
4677		return btrfs_cancel_balance(fs_info);
4678	}
4679
4680	return -EINVAL;
4681}
4682
4683static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4684					 void __user *arg)
4685{
4686	struct btrfs_ioctl_balance_args *bargs;
4687	int ret = 0;
4688
4689	if (!capable(CAP_SYS_ADMIN))
4690		return -EPERM;
4691
4692	mutex_lock(&fs_info->balance_mutex);
4693	if (!fs_info->balance_ctl) {
4694		ret = -ENOTCONN;
4695		goto out;
4696	}
4697
4698	bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4699	if (!bargs) {
4700		ret = -ENOMEM;
4701		goto out;
4702	}
4703
4704	update_ioctl_balance_args(fs_info, 1, bargs);
4705
4706	if (copy_to_user(arg, bargs, sizeof(*bargs)))
4707		ret = -EFAULT;
4708
4709	kfree(bargs);
4710out:
4711	mutex_unlock(&fs_info->balance_mutex);
4712	return ret;
4713}
4714
4715static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4716{
4717	struct inode *inode = file_inode(file);
4718	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4719	struct btrfs_ioctl_quota_ctl_args *sa;
4720	struct btrfs_trans_handle *trans = NULL;
4721	int ret;
4722	int err;
4723
4724	if (!capable(CAP_SYS_ADMIN))
4725		return -EPERM;
4726
4727	ret = mnt_want_write_file(file);
4728	if (ret)
4729		return ret;
4730
4731	sa = memdup_user(arg, sizeof(*sa));
4732	if (IS_ERR(sa)) {
4733		ret = PTR_ERR(sa);
4734		goto drop_write;
4735	}
4736
4737	down_write(&fs_info->subvol_sem);
4738	trans = btrfs_start_transaction(fs_info->tree_root, 2);
4739	if (IS_ERR(trans)) {
4740		ret = PTR_ERR(trans);
4741		goto out;
4742	}
4743
4744	switch (sa->cmd) {
4745	case BTRFS_QUOTA_CTL_ENABLE:
4746		ret = btrfs_quota_enable(trans, fs_info);
4747		break;
4748	case BTRFS_QUOTA_CTL_DISABLE:
4749		ret = btrfs_quota_disable(trans, fs_info);
4750		break;
4751	default:
4752		ret = -EINVAL;
4753		break;
4754	}
4755
4756	err = btrfs_commit_transaction(trans);
4757	if (err && !ret)
4758		ret = err;
4759out:
4760	kfree(sa);
4761	up_write(&fs_info->subvol_sem);
4762drop_write:
4763	mnt_drop_write_file(file);
4764	return ret;
4765}
4766
4767static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4768{
4769	struct inode *inode = file_inode(file);
4770	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4771	struct btrfs_root *root = BTRFS_I(inode)->root;
4772	struct btrfs_ioctl_qgroup_assign_args *sa;
4773	struct btrfs_trans_handle *trans;
4774	int ret;
4775	int err;
4776
4777	if (!capable(CAP_SYS_ADMIN))
4778		return -EPERM;
4779
4780	ret = mnt_want_write_file(file);
4781	if (ret)
4782		return ret;
4783
4784	sa = memdup_user(arg, sizeof(*sa));
4785	if (IS_ERR(sa)) {
4786		ret = PTR_ERR(sa);
4787		goto drop_write;
4788	}
4789
4790	trans = btrfs_join_transaction(root);
4791	if (IS_ERR(trans)) {
4792		ret = PTR_ERR(trans);
4793		goto out;
4794	}
4795
4796	if (sa->assign) {
4797		ret = btrfs_add_qgroup_relation(trans, fs_info,
4798						sa->src, sa->dst);
4799	} else {
4800		ret = btrfs_del_qgroup_relation(trans, fs_info,
4801						sa->src, sa->dst);
4802	}
4803
4804	/* update qgroup status and info */
4805	err = btrfs_run_qgroups(trans, fs_info);
4806	if (err < 0)
4807		btrfs_handle_fs_error(fs_info, err,
4808				      "failed to update qgroup status and info");
4809	err = btrfs_end_transaction(trans);
4810	if (err && !ret)
4811		ret = err;
4812
4813out:
4814	kfree(sa);
4815drop_write:
4816	mnt_drop_write_file(file);
4817	return ret;
4818}
4819
4820static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4821{
4822	struct inode *inode = file_inode(file);
4823	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4824	struct btrfs_root *root = BTRFS_I(inode)->root;
4825	struct btrfs_ioctl_qgroup_create_args *sa;
4826	struct btrfs_trans_handle *trans;
4827	int ret;
4828	int err;
4829
4830	if (!capable(CAP_SYS_ADMIN))
4831		return -EPERM;
4832
4833	ret = mnt_want_write_file(file);
4834	if (ret)
4835		return ret;
4836
4837	sa = memdup_user(arg, sizeof(*sa));
4838	if (IS_ERR(sa)) {
4839		ret = PTR_ERR(sa);
4840		goto drop_write;
4841	}
4842
4843	if (!sa->qgroupid) {
4844		ret = -EINVAL;
4845		goto out;
4846	}
4847
4848	trans = btrfs_join_transaction(root);
4849	if (IS_ERR(trans)) {
4850		ret = PTR_ERR(trans);
4851		goto out;
4852	}
4853
4854	if (sa->create) {
4855		ret = btrfs_create_qgroup(trans, fs_info, sa->qgroupid);
4856	} else {
4857		ret = btrfs_remove_qgroup(trans, fs_info, sa->qgroupid);
4858	}
4859
4860	err = btrfs_end_transaction(trans);
4861	if (err && !ret)
4862		ret = err;
4863
4864out:
4865	kfree(sa);
4866drop_write:
4867	mnt_drop_write_file(file);
4868	return ret;
4869}
4870
4871static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4872{
4873	struct inode *inode = file_inode(file);
4874	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4875	struct btrfs_root *root = BTRFS_I(inode)->root;
4876	struct btrfs_ioctl_qgroup_limit_args *sa;
4877	struct btrfs_trans_handle *trans;
4878	int ret;
4879	int err;
4880	u64 qgroupid;
4881
4882	if (!capable(CAP_SYS_ADMIN))
4883		return -EPERM;
4884
4885	ret = mnt_want_write_file(file);
4886	if (ret)
4887		return ret;
4888
4889	sa = memdup_user(arg, sizeof(*sa));
4890	if (IS_ERR(sa)) {
4891		ret = PTR_ERR(sa);
4892		goto drop_write;
4893	}
4894
4895	trans = btrfs_join_transaction(root);
4896	if (IS_ERR(trans)) {
4897		ret = PTR_ERR(trans);
4898		goto out;
4899	}
4900
4901	qgroupid = sa->qgroupid;
4902	if (!qgroupid) {
4903		/* take the current subvol as qgroup */
4904		qgroupid = root->root_key.objectid;
4905	}
4906
4907	ret = btrfs_limit_qgroup(trans, fs_info, qgroupid, &sa->lim);
4908
4909	err = btrfs_end_transaction(trans);
4910	if (err && !ret)
4911		ret = err;
4912
4913out:
4914	kfree(sa);
4915drop_write:
4916	mnt_drop_write_file(file);
4917	return ret;
4918}
4919
4920static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4921{
4922	struct inode *inode = file_inode(file);
4923	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4924	struct btrfs_ioctl_quota_rescan_args *qsa;
4925	int ret;
4926
4927	if (!capable(CAP_SYS_ADMIN))
4928		return -EPERM;
4929
4930	ret = mnt_want_write_file(file);
4931	if (ret)
4932		return ret;
4933
4934	qsa = memdup_user(arg, sizeof(*qsa));
4935	if (IS_ERR(qsa)) {
4936		ret = PTR_ERR(qsa);
4937		goto drop_write;
4938	}
4939
4940	if (qsa->flags) {
4941		ret = -EINVAL;
4942		goto out;
4943	}
4944
4945	ret = btrfs_qgroup_rescan(fs_info);
4946
4947out:
4948	kfree(qsa);
4949drop_write:
4950	mnt_drop_write_file(file);
4951	return ret;
4952}
4953
4954static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
 
4955{
4956	struct inode *inode = file_inode(file);
4957	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4958	struct btrfs_ioctl_quota_rescan_args *qsa;
4959	int ret = 0;
4960
4961	if (!capable(CAP_SYS_ADMIN))
4962		return -EPERM;
4963
4964	qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
4965	if (!qsa)
4966		return -ENOMEM;
4967
4968	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4969		qsa->flags = 1;
4970		qsa->progress = fs_info->qgroup_rescan_progress.objectid;
4971	}
4972
4973	if (copy_to_user(arg, qsa, sizeof(*qsa)))
4974		ret = -EFAULT;
4975
4976	kfree(qsa);
4977	return ret;
4978}
4979
4980static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
 
4981{
4982	struct inode *inode = file_inode(file);
4983	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4984
4985	if (!capable(CAP_SYS_ADMIN))
4986		return -EPERM;
4987
4988	return btrfs_qgroup_wait_for_completion(fs_info, true);
4989}
4990
4991static long _btrfs_ioctl_set_received_subvol(struct file *file,
4992					    struct btrfs_ioctl_received_subvol_args *sa)
4993{
4994	struct inode *inode = file_inode(file);
4995	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4996	struct btrfs_root *root = BTRFS_I(inode)->root;
4997	struct btrfs_root_item *root_item = &root->root_item;
4998	struct btrfs_trans_handle *trans;
4999	struct timespec ct = current_time(inode);
5000	int ret = 0;
5001	int received_uuid_changed;
5002
5003	if (!inode_owner_or_capable(inode))
5004		return -EPERM;
5005
5006	ret = mnt_want_write_file(file);
5007	if (ret < 0)
5008		return ret;
5009
5010	down_write(&fs_info->subvol_sem);
5011
5012	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5013		ret = -EINVAL;
5014		goto out;
5015	}
5016
5017	if (btrfs_root_readonly(root)) {
5018		ret = -EROFS;
5019		goto out;
5020	}
5021
5022	/*
5023	 * 1 - root item
5024	 * 2 - uuid items (received uuid + subvol uuid)
5025	 */
5026	trans = btrfs_start_transaction(root, 3);
5027	if (IS_ERR(trans)) {
5028		ret = PTR_ERR(trans);
5029		trans = NULL;
5030		goto out;
5031	}
5032
5033	sa->rtransid = trans->transid;
5034	sa->rtime.sec = ct.tv_sec;
5035	sa->rtime.nsec = ct.tv_nsec;
5036
5037	received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5038				       BTRFS_UUID_SIZE);
5039	if (received_uuid_changed &&
5040	    !btrfs_is_empty_uuid(root_item->received_uuid)) {
5041		ret = btrfs_uuid_tree_rem(trans, fs_info,
5042					  root_item->received_uuid,
5043					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5044					  root->root_key.objectid);
5045		if (ret && ret != -ENOENT) {
5046		        btrfs_abort_transaction(trans, ret);
5047		        btrfs_end_transaction(trans);
5048		        goto out;
5049		}
5050	}
5051	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5052	btrfs_set_root_stransid(root_item, sa->stransid);
5053	btrfs_set_root_rtransid(root_item, sa->rtransid);
5054	btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5055	btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5056	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5057	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5058
5059	ret = btrfs_update_root(trans, fs_info->tree_root,
5060				&root->root_key, &root->root_item);
5061	if (ret < 0) {
5062		btrfs_end_transaction(trans);
5063		goto out;
5064	}
5065	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5066		ret = btrfs_uuid_tree_add(trans, fs_info, sa->uuid,
5067					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5068					  root->root_key.objectid);
5069		if (ret < 0 && ret != -EEXIST) {
5070			btrfs_abort_transaction(trans, ret);
5071			btrfs_end_transaction(trans);
5072			goto out;
5073		}
5074	}
5075	ret = btrfs_commit_transaction(trans);
5076out:
5077	up_write(&fs_info->subvol_sem);
5078	mnt_drop_write_file(file);
5079	return ret;
5080}
5081
5082#ifdef CONFIG_64BIT
5083static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5084						void __user *arg)
5085{
5086	struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5087	struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5088	int ret = 0;
5089
5090	args32 = memdup_user(arg, sizeof(*args32));
5091	if (IS_ERR(args32))
5092		return PTR_ERR(args32);
5093
5094	args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5095	if (!args64) {
5096		ret = -ENOMEM;
5097		goto out;
5098	}
5099
5100	memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5101	args64->stransid = args32->stransid;
5102	args64->rtransid = args32->rtransid;
5103	args64->stime.sec = args32->stime.sec;
5104	args64->stime.nsec = args32->stime.nsec;
5105	args64->rtime.sec = args32->rtime.sec;
5106	args64->rtime.nsec = args32->rtime.nsec;
5107	args64->flags = args32->flags;
5108
5109	ret = _btrfs_ioctl_set_received_subvol(file, args64);
5110	if (ret)
5111		goto out;
5112
5113	memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5114	args32->stransid = args64->stransid;
5115	args32->rtransid = args64->rtransid;
5116	args32->stime.sec = args64->stime.sec;
5117	args32->stime.nsec = args64->stime.nsec;
5118	args32->rtime.sec = args64->rtime.sec;
5119	args32->rtime.nsec = args64->rtime.nsec;
5120	args32->flags = args64->flags;
5121
5122	ret = copy_to_user(arg, args32, sizeof(*args32));
5123	if (ret)
5124		ret = -EFAULT;
5125
5126out:
5127	kfree(args32);
5128	kfree(args64);
5129	return ret;
5130}
5131#endif
5132
5133static long btrfs_ioctl_set_received_subvol(struct file *file,
5134					    void __user *arg)
5135{
5136	struct btrfs_ioctl_received_subvol_args *sa = NULL;
5137	int ret = 0;
5138
5139	sa = memdup_user(arg, sizeof(*sa));
5140	if (IS_ERR(sa))
5141		return PTR_ERR(sa);
5142
5143	ret = _btrfs_ioctl_set_received_subvol(file, sa);
5144
5145	if (ret)
5146		goto out;
5147
5148	ret = copy_to_user(arg, sa, sizeof(*sa));
5149	if (ret)
5150		ret = -EFAULT;
5151
5152out:
5153	kfree(sa);
5154	return ret;
5155}
5156
5157static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
 
5158{
5159	struct inode *inode = file_inode(file);
5160	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5161	size_t len;
5162	int ret;
5163	char label[BTRFS_LABEL_SIZE];
5164
5165	spin_lock(&fs_info->super_lock);
5166	memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5167	spin_unlock(&fs_info->super_lock);
5168
5169	len = strnlen(label, BTRFS_LABEL_SIZE);
5170
5171	if (len == BTRFS_LABEL_SIZE) {
5172		btrfs_warn(fs_info,
5173			   "label is too long, return the first %zu bytes",
5174			   --len);
5175	}
5176
5177	ret = copy_to_user(arg, label, len);
5178
5179	return ret ? -EFAULT : 0;
5180}
5181
5182static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5183{
5184	struct inode *inode = file_inode(file);
5185	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5186	struct btrfs_root *root = BTRFS_I(inode)->root;
5187	struct btrfs_super_block *super_block = fs_info->super_copy;
5188	struct btrfs_trans_handle *trans;
5189	char label[BTRFS_LABEL_SIZE];
5190	int ret;
5191
5192	if (!capable(CAP_SYS_ADMIN))
5193		return -EPERM;
5194
5195	if (copy_from_user(label, arg, sizeof(label)))
5196		return -EFAULT;
5197
5198	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5199		btrfs_err(fs_info,
5200			  "unable to set label with more than %d bytes",
5201			  BTRFS_LABEL_SIZE - 1);
5202		return -EINVAL;
5203	}
5204
5205	ret = mnt_want_write_file(file);
5206	if (ret)
5207		return ret;
5208
5209	trans = btrfs_start_transaction(root, 0);
5210	if (IS_ERR(trans)) {
5211		ret = PTR_ERR(trans);
5212		goto out_unlock;
5213	}
5214
5215	spin_lock(&fs_info->super_lock);
5216	strcpy(super_block->label, label);
5217	spin_unlock(&fs_info->super_lock);
5218	ret = btrfs_commit_transaction(trans);
5219
5220out_unlock:
5221	mnt_drop_write_file(file);
5222	return ret;
5223}
5224
5225#define INIT_FEATURE_FLAGS(suffix) \
5226	{ .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5227	  .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5228	  .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5229
5230int btrfs_ioctl_get_supported_features(void __user *arg)
5231{
5232	static const struct btrfs_ioctl_feature_flags features[3] = {
5233		INIT_FEATURE_FLAGS(SUPP),
5234		INIT_FEATURE_FLAGS(SAFE_SET),
5235		INIT_FEATURE_FLAGS(SAFE_CLEAR)
5236	};
5237
5238	if (copy_to_user(arg, &features, sizeof(features)))
5239		return -EFAULT;
5240
5241	return 0;
5242}
5243
5244static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
 
5245{
5246	struct inode *inode = file_inode(file);
5247	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5248	struct btrfs_super_block *super_block = fs_info->super_copy;
5249	struct btrfs_ioctl_feature_flags features;
5250
5251	features.compat_flags = btrfs_super_compat_flags(super_block);
5252	features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5253	features.incompat_flags = btrfs_super_incompat_flags(super_block);
5254
5255	if (copy_to_user(arg, &features, sizeof(features)))
5256		return -EFAULT;
5257
5258	return 0;
5259}
5260
5261static int check_feature_bits(struct btrfs_fs_info *fs_info,
5262			      enum btrfs_feature_set set,
5263			      u64 change_mask, u64 flags, u64 supported_flags,
5264			      u64 safe_set, u64 safe_clear)
5265{
5266	const char *type = btrfs_feature_set_names[set];
5267	char *names;
5268	u64 disallowed, unsupported;
5269	u64 set_mask = flags & change_mask;
5270	u64 clear_mask = ~flags & change_mask;
5271
5272	unsupported = set_mask & ~supported_flags;
5273	if (unsupported) {
5274		names = btrfs_printable_features(set, unsupported);
5275		if (names) {
5276			btrfs_warn(fs_info,
5277				   "this kernel does not support the %s feature bit%s",
5278				   names, strchr(names, ',') ? "s" : "");
5279			kfree(names);
5280		} else
5281			btrfs_warn(fs_info,
5282				   "this kernel does not support %s bits 0x%llx",
5283				   type, unsupported);
5284		return -EOPNOTSUPP;
5285	}
5286
5287	disallowed = set_mask & ~safe_set;
5288	if (disallowed) {
5289		names = btrfs_printable_features(set, disallowed);
5290		if (names) {
5291			btrfs_warn(fs_info,
5292				   "can't set the %s feature bit%s while mounted",
5293				   names, strchr(names, ',') ? "s" : "");
5294			kfree(names);
5295		} else
5296			btrfs_warn(fs_info,
5297				   "can't set %s bits 0x%llx while mounted",
5298				   type, disallowed);
5299		return -EPERM;
5300	}
5301
5302	disallowed = clear_mask & ~safe_clear;
5303	if (disallowed) {
5304		names = btrfs_printable_features(set, disallowed);
5305		if (names) {
5306			btrfs_warn(fs_info,
5307				   "can't clear the %s feature bit%s while mounted",
5308				   names, strchr(names, ',') ? "s" : "");
5309			kfree(names);
5310		} else
5311			btrfs_warn(fs_info,
5312				   "can't clear %s bits 0x%llx while mounted",
5313				   type, disallowed);
5314		return -EPERM;
5315	}
5316
5317	return 0;
5318}
5319
5320#define check_feature(fs_info, change_mask, flags, mask_base)	\
5321check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,	\
5322		   BTRFS_FEATURE_ ## mask_base ## _SUPP,	\
5323		   BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,	\
5324		   BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5325
5326static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5327{
5328	struct inode *inode = file_inode(file);
5329	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5330	struct btrfs_root *root = BTRFS_I(inode)->root;
5331	struct btrfs_super_block *super_block = fs_info->super_copy;
5332	struct btrfs_ioctl_feature_flags flags[2];
5333	struct btrfs_trans_handle *trans;
5334	u64 newflags;
5335	int ret;
5336
5337	if (!capable(CAP_SYS_ADMIN))
5338		return -EPERM;
5339
5340	if (copy_from_user(flags, arg, sizeof(flags)))
5341		return -EFAULT;
5342
5343	/* Nothing to do */
5344	if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5345	    !flags[0].incompat_flags)
5346		return 0;
5347
5348	ret = check_feature(fs_info, flags[0].compat_flags,
5349			    flags[1].compat_flags, COMPAT);
5350	if (ret)
5351		return ret;
5352
5353	ret = check_feature(fs_info, flags[0].compat_ro_flags,
5354			    flags[1].compat_ro_flags, COMPAT_RO);
5355	if (ret)
5356		return ret;
5357
5358	ret = check_feature(fs_info, flags[0].incompat_flags,
5359			    flags[1].incompat_flags, INCOMPAT);
5360	if (ret)
5361		return ret;
5362
5363	ret = mnt_want_write_file(file);
5364	if (ret)
5365		return ret;
5366
5367	trans = btrfs_start_transaction(root, 0);
5368	if (IS_ERR(trans)) {
5369		ret = PTR_ERR(trans);
5370		goto out_drop_write;
5371	}
5372
5373	spin_lock(&fs_info->super_lock);
5374	newflags = btrfs_super_compat_flags(super_block);
5375	newflags |= flags[0].compat_flags & flags[1].compat_flags;
5376	newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5377	btrfs_set_super_compat_flags(super_block, newflags);
5378
5379	newflags = btrfs_super_compat_ro_flags(super_block);
5380	newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5381	newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5382	btrfs_set_super_compat_ro_flags(super_block, newflags);
5383
5384	newflags = btrfs_super_incompat_flags(super_block);
5385	newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5386	newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5387	btrfs_set_super_incompat_flags(super_block, newflags);
5388	spin_unlock(&fs_info->super_lock);
5389
5390	ret = btrfs_commit_transaction(trans);
5391out_drop_write:
5392	mnt_drop_write_file(file);
5393
5394	return ret;
5395}
5396
5397static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5398{
5399	struct btrfs_ioctl_send_args *arg;
5400	int ret;
5401
5402	if (compat) {
5403#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5404		struct btrfs_ioctl_send_args_32 args32;
5405
5406		ret = copy_from_user(&args32, argp, sizeof(args32));
5407		if (ret)
5408			return -EFAULT;
5409		arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5410		if (!arg)
5411			return -ENOMEM;
5412		arg->send_fd = args32.send_fd;
5413		arg->clone_sources_count = args32.clone_sources_count;
5414		arg->clone_sources = compat_ptr(args32.clone_sources);
5415		arg->parent_root = args32.parent_root;
5416		arg->flags = args32.flags;
5417		memcpy(arg->reserved, args32.reserved,
5418		       sizeof(args32.reserved));
5419#else
5420		return -ENOTTY;
5421#endif
5422	} else {
5423		arg = memdup_user(argp, sizeof(*arg));
5424		if (IS_ERR(arg))
5425			return PTR_ERR(arg);
5426	}
5427	ret = btrfs_ioctl_send(file, arg);
5428	kfree(arg);
5429	return ret;
5430}
5431
5432long btrfs_ioctl(struct file *file, unsigned int
5433		cmd, unsigned long arg)
5434{
5435	struct inode *inode = file_inode(file);
5436	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5437	struct btrfs_root *root = BTRFS_I(inode)->root;
5438	void __user *argp = (void __user *)arg;
5439
5440	switch (cmd) {
5441	case FS_IOC_GETFLAGS:
5442		return btrfs_ioctl_getflags(file, argp);
5443	case FS_IOC_SETFLAGS:
5444		return btrfs_ioctl_setflags(file, argp);
5445	case FS_IOC_GETVERSION:
5446		return btrfs_ioctl_getversion(file, argp);
 
 
 
 
5447	case FITRIM:
5448		return btrfs_ioctl_fitrim(file, argp);
5449	case BTRFS_IOC_SNAP_CREATE:
5450		return btrfs_ioctl_snap_create(file, argp, 0);
5451	case BTRFS_IOC_SNAP_CREATE_V2:
5452		return btrfs_ioctl_snap_create_v2(file, argp, 0);
5453	case BTRFS_IOC_SUBVOL_CREATE:
5454		return btrfs_ioctl_snap_create(file, argp, 1);
5455	case BTRFS_IOC_SUBVOL_CREATE_V2:
5456		return btrfs_ioctl_snap_create_v2(file, argp, 1);
5457	case BTRFS_IOC_SNAP_DESTROY:
5458		return btrfs_ioctl_snap_destroy(file, argp);
 
 
5459	case BTRFS_IOC_SUBVOL_GETFLAGS:
5460		return btrfs_ioctl_subvol_getflags(file, argp);
5461	case BTRFS_IOC_SUBVOL_SETFLAGS:
5462		return btrfs_ioctl_subvol_setflags(file, argp);
5463	case BTRFS_IOC_DEFAULT_SUBVOL:
5464		return btrfs_ioctl_default_subvol(file, argp);
5465	case BTRFS_IOC_DEFRAG:
5466		return btrfs_ioctl_defrag(file, NULL);
5467	case BTRFS_IOC_DEFRAG_RANGE:
5468		return btrfs_ioctl_defrag(file, argp);
5469	case BTRFS_IOC_RESIZE:
5470		return btrfs_ioctl_resize(file, argp);
5471	case BTRFS_IOC_ADD_DEV:
5472		return btrfs_ioctl_add_dev(fs_info, argp);
5473	case BTRFS_IOC_RM_DEV:
5474		return btrfs_ioctl_rm_dev(file, argp);
5475	case BTRFS_IOC_RM_DEV_V2:
5476		return btrfs_ioctl_rm_dev_v2(file, argp);
5477	case BTRFS_IOC_FS_INFO:
5478		return btrfs_ioctl_fs_info(fs_info, argp);
5479	case BTRFS_IOC_DEV_INFO:
5480		return btrfs_ioctl_dev_info(fs_info, argp);
5481	case BTRFS_IOC_BALANCE:
5482		return btrfs_ioctl_balance(file, NULL);
5483	case BTRFS_IOC_TREE_SEARCH:
5484		return btrfs_ioctl_tree_search(file, argp);
5485	case BTRFS_IOC_TREE_SEARCH_V2:
5486		return btrfs_ioctl_tree_search_v2(file, argp);
5487	case BTRFS_IOC_INO_LOOKUP:
5488		return btrfs_ioctl_ino_lookup(file, argp);
5489	case BTRFS_IOC_INO_PATHS:
5490		return btrfs_ioctl_ino_to_path(root, argp);
5491	case BTRFS_IOC_LOGICAL_INO:
5492		return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5493	case BTRFS_IOC_LOGICAL_INO_V2:
5494		return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5495	case BTRFS_IOC_SPACE_INFO:
5496		return btrfs_ioctl_space_info(fs_info, argp);
5497	case BTRFS_IOC_SYNC: {
5498		int ret;
5499
5500		ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
5501		if (ret)
5502			return ret;
5503		ret = btrfs_sync_fs(inode->i_sb, 1);
5504		/*
5505		 * The transaction thread may want to do more work,
5506		 * namely it pokes the cleaner kthread that will start
5507		 * processing uncleaned subvols.
5508		 */
5509		wake_up_process(fs_info->transaction_kthread);
5510		return ret;
5511	}
5512	case BTRFS_IOC_START_SYNC:
5513		return btrfs_ioctl_start_sync(root, argp);
5514	case BTRFS_IOC_WAIT_SYNC:
5515		return btrfs_ioctl_wait_sync(fs_info, argp);
5516	case BTRFS_IOC_SCRUB:
5517		return btrfs_ioctl_scrub(file, argp);
5518	case BTRFS_IOC_SCRUB_CANCEL:
5519		return btrfs_ioctl_scrub_cancel(fs_info);
5520	case BTRFS_IOC_SCRUB_PROGRESS:
5521		return btrfs_ioctl_scrub_progress(fs_info, argp);
5522	case BTRFS_IOC_BALANCE_V2:
5523		return btrfs_ioctl_balance(file, argp);
5524	case BTRFS_IOC_BALANCE_CTL:
5525		return btrfs_ioctl_balance_ctl(fs_info, arg);
5526	case BTRFS_IOC_BALANCE_PROGRESS:
5527		return btrfs_ioctl_balance_progress(fs_info, argp);
5528	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5529		return btrfs_ioctl_set_received_subvol(file, argp);
5530#ifdef CONFIG_64BIT
5531	case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5532		return btrfs_ioctl_set_received_subvol_32(file, argp);
5533#endif
5534	case BTRFS_IOC_SEND:
5535		return _btrfs_ioctl_send(file, argp, false);
5536#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5537	case BTRFS_IOC_SEND_32:
5538		return _btrfs_ioctl_send(file, argp, true);
5539#endif
5540	case BTRFS_IOC_GET_DEV_STATS:
5541		return btrfs_ioctl_get_dev_stats(fs_info, argp);
5542	case BTRFS_IOC_QUOTA_CTL:
5543		return btrfs_ioctl_quota_ctl(file, argp);
5544	case BTRFS_IOC_QGROUP_ASSIGN:
5545		return btrfs_ioctl_qgroup_assign(file, argp);
5546	case BTRFS_IOC_QGROUP_CREATE:
5547		return btrfs_ioctl_qgroup_create(file, argp);
5548	case BTRFS_IOC_QGROUP_LIMIT:
5549		return btrfs_ioctl_qgroup_limit(file, argp);
5550	case BTRFS_IOC_QUOTA_RESCAN:
5551		return btrfs_ioctl_quota_rescan(file, argp);
5552	case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5553		return btrfs_ioctl_quota_rescan_status(file, argp);
5554	case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5555		return btrfs_ioctl_quota_rescan_wait(file, argp);
5556	case BTRFS_IOC_DEV_REPLACE:
5557		return btrfs_ioctl_dev_replace(fs_info, argp);
5558	case BTRFS_IOC_GET_FSLABEL:
5559		return btrfs_ioctl_get_fslabel(file, argp);
5560	case BTRFS_IOC_SET_FSLABEL:
5561		return btrfs_ioctl_set_fslabel(file, argp);
5562	case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5563		return btrfs_ioctl_get_supported_features(argp);
5564	case BTRFS_IOC_GET_FEATURES:
5565		return btrfs_ioctl_get_features(file, argp);
5566	case BTRFS_IOC_SET_FEATURES:
5567		return btrfs_ioctl_set_features(file, argp);
 
 
 
 
 
 
5568	}
5569
5570	return -ENOTTY;
5571}
5572
5573#ifdef CONFIG_COMPAT
5574long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5575{
5576	/*
5577	 * These all access 32-bit values anyway so no further
5578	 * handling is necessary.
5579	 */
5580	switch (cmd) {
5581	case FS_IOC32_GETFLAGS:
5582		cmd = FS_IOC_GETFLAGS;
5583		break;
5584	case FS_IOC32_SETFLAGS:
5585		cmd = FS_IOC_SETFLAGS;
5586		break;
5587	case FS_IOC32_GETVERSION:
5588		cmd = FS_IOC_GETVERSION;
5589		break;
5590	}
5591
5592	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5593}
5594#endif