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/file.h>
   9#include <linux/fs.h>
  10#include <linux/fsnotify.h>
  11#include <linux/pagemap.h>
  12#include <linux/highmem.h>
  13#include <linux/time.h>
 
  14#include <linux/string.h>
  15#include <linux/backing-dev.h>
  16#include <linux/mount.h>
 
  17#include <linux/namei.h>
 
  18#include <linux/writeback.h>
 
  19#include <linux/compat.h>
 
  20#include <linux/security.h>
  21#include <linux/xattr.h>
  22#include <linux/mm.h>
  23#include <linux/slab.h>
  24#include <linux/blkdev.h>
  25#include <linux/uuid.h>
  26#include <linux/btrfs.h>
  27#include <linux/uaccess.h>
  28#include <linux/iversion.h>
  29#include <linux/fileattr.h>
  30#include <linux/fsverity.h>
  31#include <linux/sched/xacct.h>
  32#include "ctree.h"
  33#include "disk-io.h"
  34#include "export.h"
  35#include "transaction.h"
  36#include "btrfs_inode.h"
  37#include "print-tree.h"
  38#include "volumes.h"
  39#include "locking.h"
 
  40#include "backref.h"
  41#include "rcu-string.h"
  42#include "send.h"
  43#include "dev-replace.h"
  44#include "props.h"
  45#include "sysfs.h"
  46#include "qgroup.h"
  47#include "tree-log.h"
  48#include "compression.h"
  49#include "space-info.h"
  50#include "delalloc-space.h"
  51#include "block-group.h"
  52#include "subpage.h"
  53#include "fs.h"
  54#include "accessors.h"
  55#include "extent-tree.h"
  56#include "root-tree.h"
  57#include "defrag.h"
  58#include "dir-item.h"
  59#include "uuid-tree.h"
  60#include "ioctl.h"
  61#include "file.h"
  62#include "scrub.h"
  63#include "super.h"
  64
  65#ifdef CONFIG_64BIT
  66/* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  67 * structures are incorrect, as the timespec structure from userspace
  68 * is 4 bytes too small. We define these alternatives here to teach
  69 * the kernel about the 32-bit struct packing.
  70 */
  71struct btrfs_ioctl_timespec_32 {
  72	__u64 sec;
  73	__u32 nsec;
  74} __attribute__ ((__packed__));
  75
  76struct btrfs_ioctl_received_subvol_args_32 {
  77	char	uuid[BTRFS_UUID_SIZE];	/* in */
  78	__u64	stransid;		/* in */
  79	__u64	rtransid;		/* out */
  80	struct btrfs_ioctl_timespec_32 stime; /* in */
  81	struct btrfs_ioctl_timespec_32 rtime; /* out */
  82	__u64	flags;			/* in */
  83	__u64	reserved[16];		/* in */
  84} __attribute__ ((__packed__));
  85
  86#define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  87				struct btrfs_ioctl_received_subvol_args_32)
  88#endif
  89
  90#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  91struct btrfs_ioctl_send_args_32 {
  92	__s64 send_fd;			/* in */
  93	__u64 clone_sources_count;	/* in */
  94	compat_uptr_t clone_sources;	/* in */
  95	__u64 parent_root;		/* in */
  96	__u64 flags;			/* in */
  97	__u32 version;			/* in */
  98	__u8  reserved[28];		/* in */
  99} __attribute__ ((__packed__));
 100
 101#define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
 102			       struct btrfs_ioctl_send_args_32)
 103
 104struct btrfs_ioctl_encoded_io_args_32 {
 105	compat_uptr_t iov;
 106	compat_ulong_t iovcnt;
 107	__s64 offset;
 108	__u64 flags;
 109	__u64 len;
 110	__u64 unencoded_len;
 111	__u64 unencoded_offset;
 112	__u32 compression;
 113	__u32 encryption;
 114	__u8 reserved[64];
 115};
 116
 117#define BTRFS_IOC_ENCODED_READ_32 _IOR(BTRFS_IOCTL_MAGIC, 64, \
 118				       struct btrfs_ioctl_encoded_io_args_32)
 119#define BTRFS_IOC_ENCODED_WRITE_32 _IOW(BTRFS_IOCTL_MAGIC, 64, \
 120					struct btrfs_ioctl_encoded_io_args_32)
 121#endif
 122
 123/* Mask out flags that are inappropriate for the given type of inode. */
 124static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
 125		unsigned int flags)
 126{
 127	if (S_ISDIR(inode->i_mode))
 128		return flags;
 129	else if (S_ISREG(inode->i_mode))
 130		return flags & ~FS_DIRSYNC_FL;
 131	else
 132		return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 133}
 134
 135/*
 136 * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 137 * ioctl.
 138 */
 139static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode)
 140{
 141	unsigned int iflags = 0;
 142	u32 flags = binode->flags;
 143	u32 ro_flags = binode->ro_flags;
 144
 145	if (flags & BTRFS_INODE_SYNC)
 146		iflags |= FS_SYNC_FL;
 147	if (flags & BTRFS_INODE_IMMUTABLE)
 148		iflags |= FS_IMMUTABLE_FL;
 149	if (flags & BTRFS_INODE_APPEND)
 150		iflags |= FS_APPEND_FL;
 151	if (flags & BTRFS_INODE_NODUMP)
 152		iflags |= FS_NODUMP_FL;
 153	if (flags & BTRFS_INODE_NOATIME)
 154		iflags |= FS_NOATIME_FL;
 155	if (flags & BTRFS_INODE_DIRSYNC)
 156		iflags |= FS_DIRSYNC_FL;
 157	if (flags & BTRFS_INODE_NODATACOW)
 158		iflags |= FS_NOCOW_FL;
 159	if (ro_flags & BTRFS_INODE_RO_VERITY)
 160		iflags |= FS_VERITY_FL;
 161
 162	if (flags & BTRFS_INODE_NOCOMPRESS)
 163		iflags |= FS_NOCOMP_FL;
 164	else if (flags & BTRFS_INODE_COMPRESS)
 165		iflags |= FS_COMPR_FL;
 
 
 166
 167	return iflags;
 168}
 169
 170/*
 171 * Update inode->i_flags based on the btrfs internal flags.
 172 */
 173void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 174{
 175	struct btrfs_inode *binode = BTRFS_I(inode);
 176	unsigned int new_fl = 0;
 177
 178	if (binode->flags & BTRFS_INODE_SYNC)
 179		new_fl |= S_SYNC;
 180	if (binode->flags & BTRFS_INODE_IMMUTABLE)
 181		new_fl |= S_IMMUTABLE;
 182	if (binode->flags & BTRFS_INODE_APPEND)
 183		new_fl |= S_APPEND;
 184	if (binode->flags & BTRFS_INODE_NOATIME)
 185		new_fl |= S_NOATIME;
 186	if (binode->flags & BTRFS_INODE_DIRSYNC)
 187		new_fl |= S_DIRSYNC;
 188	if (binode->ro_flags & BTRFS_INODE_RO_VERITY)
 189		new_fl |= S_VERITY;
 190
 191	set_mask_bits(&inode->i_flags,
 192		      S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC |
 193		      S_VERITY, new_fl);
 194}
 195
 196/*
 197 * Check if @flags are a supported and valid set of FS_*_FL flags and that
 198 * the old and new flags are not conflicting
 
 199 */
 200static int check_fsflags(unsigned int old_flags, unsigned int flags)
 201{
 202	if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 203		      FS_NOATIME_FL | FS_NODUMP_FL | \
 204		      FS_SYNC_FL | FS_DIRSYNC_FL | \
 205		      FS_NOCOMP_FL | FS_COMPR_FL |
 206		      FS_NOCOW_FL))
 207		return -EOPNOTSUPP;
 208
 209	/* COMPR and NOCOMP on new/old are valid */
 210	if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 211		return -EINVAL;
 212
 213	if ((flags & FS_COMPR_FL) && (flags & FS_NOCOW_FL))
 214		return -EINVAL;
 215
 216	/* NOCOW and compression options are mutually exclusive */
 217	if ((old_flags & FS_NOCOW_FL) && (flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
 218		return -EINVAL;
 219	if ((flags & FS_NOCOW_FL) && (old_flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
 220		return -EINVAL;
 
 
 221
 222	return 0;
 
 
 
 
 
 
 223}
 224
 225static int check_fsflags_compatible(struct btrfs_fs_info *fs_info,
 226				    unsigned int flags)
 227{
 228	if (btrfs_is_zoned(fs_info) && (flags & FS_NOCOW_FL))
 229		return -EPERM;
 230
 
 
 231	return 0;
 232}
 233
 234/*
 235 * Set flags/xflags from the internal inode flags. The remaining items of
 236 * fsxattr are zeroed.
 237 */
 238int btrfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 239{
 240	struct btrfs_inode *binode = BTRFS_I(d_inode(dentry));
 
 
 
 
 
 
 
 
 241
 242	fileattr_fill_flags(fa, btrfs_inode_flags_to_fsflags(binode));
 243	return 0;
 244}
 245
 246int btrfs_fileattr_set(struct mnt_idmap *idmap,
 247		       struct dentry *dentry, struct fileattr *fa)
 248{
 249	struct inode *inode = d_inode(dentry);
 250	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 251	struct btrfs_inode *binode = BTRFS_I(inode);
 252	struct btrfs_root *root = binode->root;
 253	struct btrfs_trans_handle *trans;
 254	unsigned int fsflags, old_fsflags;
 255	int ret;
 256	const char *comp = NULL;
 257	u32 binode_flags;
 
 
 
 
 258
 259	if (btrfs_root_readonly(root))
 260		return -EROFS;
 261
 262	if (fileattr_has_fsx(fa))
 263		return -EOPNOTSUPP;
 264
 265	fsflags = btrfs_mask_fsflags_for_type(inode, fa->flags);
 266	old_fsflags = btrfs_inode_flags_to_fsflags(binode);
 267	ret = check_fsflags(old_fsflags, fsflags);
 268	if (ret)
 269		return ret;
 270
 271	ret = check_fsflags_compatible(fs_info, fsflags);
 272	if (ret)
 273		return ret;
 274
 275	binode_flags = binode->flags;
 276	if (fsflags & FS_SYNC_FL)
 277		binode_flags |= BTRFS_INODE_SYNC;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 278	else
 279		binode_flags &= ~BTRFS_INODE_SYNC;
 280	if (fsflags & FS_IMMUTABLE_FL)
 281		binode_flags |= BTRFS_INODE_IMMUTABLE;
 282	else
 283		binode_flags &= ~BTRFS_INODE_IMMUTABLE;
 284	if (fsflags & FS_APPEND_FL)
 285		binode_flags |= BTRFS_INODE_APPEND;
 286	else
 287		binode_flags &= ~BTRFS_INODE_APPEND;
 288	if (fsflags & FS_NODUMP_FL)
 289		binode_flags |= BTRFS_INODE_NODUMP;
 290	else
 291		binode_flags &= ~BTRFS_INODE_NODUMP;
 292	if (fsflags & FS_NOATIME_FL)
 293		binode_flags |= BTRFS_INODE_NOATIME;
 294	else
 295		binode_flags &= ~BTRFS_INODE_NOATIME;
 296
 297	/* If coming from FS_IOC_FSSETXATTR then skip unconverted flags */
 298	if (!fa->flags_valid) {
 299		/* 1 item for the inode */
 300		trans = btrfs_start_transaction(root, 1);
 301		if (IS_ERR(trans))
 302			return PTR_ERR(trans);
 303		goto update_flags;
 304	}
 305
 306	if (fsflags & FS_DIRSYNC_FL)
 307		binode_flags |= BTRFS_INODE_DIRSYNC;
 308	else
 309		binode_flags &= ~BTRFS_INODE_DIRSYNC;
 310	if (fsflags & FS_NOCOW_FL) {
 311		if (S_ISREG(inode->i_mode)) {
 312			/*
 313			 * It's safe to turn csums off here, no extents exist.
 314			 * Otherwise we want the flag to reflect the real COW
 315			 * status of the file and will not set it.
 316			 */
 317			if (inode->i_size == 0)
 318				binode_flags |= BTRFS_INODE_NODATACOW |
 319						BTRFS_INODE_NODATASUM;
 320		} else {
 321			binode_flags |= BTRFS_INODE_NODATACOW;
 322		}
 323	} else {
 324		/*
 325		 * Revert back under same assumptions as above
 326		 */
 327		if (S_ISREG(inode->i_mode)) {
 328			if (inode->i_size == 0)
 329				binode_flags &= ~(BTRFS_INODE_NODATACOW |
 330						  BTRFS_INODE_NODATASUM);
 331		} else {
 332			binode_flags &= ~BTRFS_INODE_NODATACOW;
 333		}
 334	}
 335
 336	/*
 337	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 338	 * flag may be changed automatically if compression code won't make
 339	 * things smaller.
 340	 */
 341	if (fsflags & FS_NOCOMP_FL) {
 342		binode_flags &= ~BTRFS_INODE_COMPRESS;
 343		binode_flags |= BTRFS_INODE_NOCOMPRESS;
 344	} else if (fsflags & FS_COMPR_FL) {
 345
 346		if (IS_SWAPFILE(inode))
 347			return -ETXTBSY;
 348
 349		binode_flags |= BTRFS_INODE_COMPRESS;
 350		binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
 351
 352		comp = btrfs_compress_type2str(fs_info->compress_type);
 353		if (!comp || comp[0] == 0)
 354			comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 355	} else {
 356		binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 357	}
 358
 359	/*
 360	 * 1 for inode item
 361	 * 2 for properties
 362	 */
 363	trans = btrfs_start_transaction(root, 3);
 364	if (IS_ERR(trans))
 365		return PTR_ERR(trans);
 
 
 
 
 366
 367	if (comp) {
 368		ret = btrfs_set_prop(trans, inode, "btrfs.compression", comp,
 369				     strlen(comp), 0);
 370		if (ret) {
 371			btrfs_abort_transaction(trans, ret);
 372			goto out_end_trans;
 373		}
 374	} else {
 375		ret = btrfs_set_prop(trans, inode, "btrfs.compression", NULL,
 376				     0, 0);
 377		if (ret && ret != -ENODATA) {
 378			btrfs_abort_transaction(trans, ret);
 379			goto out_end_trans;
 380		}
 381	}
 382
 383update_flags:
 384	binode->flags = binode_flags;
 385	btrfs_sync_inode_flags_to_i_flags(inode);
 386	inode_inc_iversion(inode);
 387	inode_set_ctime_current(inode);
 388	ret = btrfs_update_inode(trans, BTRFS_I(inode));
 389
 390 out_end_trans:
 391	btrfs_end_transaction(trans);
 392	return ret;
 393}
 394
 395/*
 396 * Start exclusive operation @type, return true on success
 397 */
 398bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
 399			enum btrfs_exclusive_operation type)
 400{
 401	bool ret = false;
 402
 403	spin_lock(&fs_info->super_lock);
 404	if (fs_info->exclusive_operation == BTRFS_EXCLOP_NONE) {
 405		fs_info->exclusive_operation = type;
 406		ret = true;
 
 407	}
 408	spin_unlock(&fs_info->super_lock);
 409
 
 
 
 410	return ret;
 411}
 412
 413/*
 414 * Conditionally allow to enter the exclusive operation in case it's compatible
 415 * with the running one.  This must be paired with btrfs_exclop_start_unlock and
 416 * btrfs_exclop_finish.
 417 *
 418 * Compatibility:
 419 * - the same type is already running
 420 * - when trying to add a device and balance has been paused
 421 * - not BTRFS_EXCLOP_NONE - this is intentionally incompatible and the caller
 422 *   must check the condition first that would allow none -> @type
 423 */
 424bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info,
 425				 enum btrfs_exclusive_operation type)
 426{
 427	spin_lock(&fs_info->super_lock);
 428	if (fs_info->exclusive_operation == type ||
 429	    (fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED &&
 430	     type == BTRFS_EXCLOP_DEV_ADD))
 431		return true;
 432
 433	spin_unlock(&fs_info->super_lock);
 434	return false;
 435}
 436
 437void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info)
 438{
 439	spin_unlock(&fs_info->super_lock);
 440}
 441
 442void btrfs_exclop_finish(struct btrfs_fs_info *fs_info)
 443{
 444	spin_lock(&fs_info->super_lock);
 445	WRITE_ONCE(fs_info->exclusive_operation, BTRFS_EXCLOP_NONE);
 446	spin_unlock(&fs_info->super_lock);
 447	sysfs_notify(&fs_info->fs_devices->fsid_kobj, NULL, "exclusive_operation");
 448}
 449
 450void btrfs_exclop_balance(struct btrfs_fs_info *fs_info,
 451			  enum btrfs_exclusive_operation op)
 452{
 453	switch (op) {
 454	case BTRFS_EXCLOP_BALANCE_PAUSED:
 455		spin_lock(&fs_info->super_lock);
 456		ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE ||
 457		       fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD ||
 458		       fs_info->exclusive_operation == BTRFS_EXCLOP_NONE ||
 459		       fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED);
 460		fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE_PAUSED;
 461		spin_unlock(&fs_info->super_lock);
 462		break;
 463	case BTRFS_EXCLOP_BALANCE:
 464		spin_lock(&fs_info->super_lock);
 465		ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED);
 466		fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE;
 467		spin_unlock(&fs_info->super_lock);
 468		break;
 469	default:
 470		btrfs_warn(fs_info,
 471			"invalid exclop balance operation %d requested", op);
 472	}
 473}
 474
 475static int btrfs_ioctl_getversion(struct inode *inode, int __user *arg)
 476{
 477	return put_user(inode->i_generation, arg);
 478}
 479
 480static noinline int btrfs_ioctl_fitrim(struct btrfs_fs_info *fs_info,
 481					void __user *arg)
 482{
 
 483	struct btrfs_device *device;
 
 484	struct fstrim_range range;
 485	u64 minlen = ULLONG_MAX;
 486	u64 num_devices = 0;
 
 487	int ret;
 488
 489	if (!capable(CAP_SYS_ADMIN))
 490		return -EPERM;
 491
 492	/*
 493	 * btrfs_trim_block_group() depends on space cache, which is not
 494	 * available in zoned filesystem. So, disallow fitrim on a zoned
 495	 * filesystem for now.
 496	 */
 497	if (btrfs_is_zoned(fs_info))
 498		return -EOPNOTSUPP;
 499
 500	/*
 501	 * If the fs is mounted with nologreplay, which requires it to be
 502	 * mounted in RO mode as well, we can not allow discard on free space
 503	 * inside block groups, because log trees refer to extents that are not
 504	 * pinned in a block group's free space cache (pinning the extents is
 505	 * precisely the first phase of replaying a log tree).
 506	 */
 507	if (btrfs_test_opt(fs_info, NOLOGREPLAY))
 508		return -EROFS;
 509
 510	rcu_read_lock();
 511	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 512				dev_list) {
 513		if (!device->bdev || !bdev_max_discard_sectors(device->bdev))
 514			continue;
 515		num_devices++;
 516		minlen = min_t(u64, bdev_discard_granularity(device->bdev),
 517				    minlen);
 
 
 
 518	}
 519	rcu_read_unlock();
 520
 521	if (!num_devices)
 522		return -EOPNOTSUPP;
 523	if (copy_from_user(&range, arg, sizeof(range)))
 524		return -EFAULT;
 525
 526	/*
 527	 * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
 528	 * block group is in the logical address space, which can be any
 529	 * sectorsize aligned bytenr in  the range [0, U64_MAX].
 530	 */
 531	if (range.len < fs_info->sb->s_blocksize)
 532		return -EINVAL;
 533
 
 534	range.minlen = max(range.minlen, minlen);
 535	ret = btrfs_trim_fs(fs_info, &range);
 536	if (ret < 0)
 537		return ret;
 538
 539	if (copy_to_user(arg, &range, sizeof(range)))
 540		return -EFAULT;
 541
 542	return 0;
 543}
 544
 545int __pure btrfs_is_empty_uuid(u8 *uuid)
 546{
 547	int i;
 548
 549	for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 550		if (uuid[i])
 551			return 0;
 552	}
 553	return 1;
 554}
 555
 556/*
 557 * Calculate the number of transaction items to reserve for creating a subvolume
 558 * or snapshot, not including the inode, directory entries, or parent directory.
 559 */
 560static unsigned int create_subvol_num_items(struct btrfs_qgroup_inherit *inherit)
 561{
 562	/*
 563	 * 1 to add root block
 564	 * 1 to add root item
 565	 * 1 to add root ref
 566	 * 1 to add root backref
 567	 * 1 to add UUID item
 568	 * 1 to add qgroup info
 569	 * 1 to add qgroup limit
 570	 *
 571	 * Ideally the last two would only be accounted if qgroups are enabled,
 572	 * but that can change between now and the time we would insert them.
 573	 */
 574	unsigned int num_items = 7;
 575
 576	if (inherit) {
 577		/* 2 to add qgroup relations for each inherited qgroup */
 578		num_items += 2 * inherit->num_qgroups;
 579	}
 580	return num_items;
 581}
 582
 583static noinline int create_subvol(struct mnt_idmap *idmap,
 584				  struct inode *dir, struct dentry *dentry,
 585				  struct btrfs_qgroup_inherit *inherit)
 586{
 587	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 588	struct btrfs_trans_handle *trans;
 589	struct btrfs_key key;
 590	struct btrfs_root_item *root_item;
 591	struct btrfs_inode_item *inode_item;
 592	struct extent_buffer *leaf;
 593	struct btrfs_root *root = BTRFS_I(dir)->root;
 594	struct btrfs_root *new_root;
 595	struct btrfs_block_rsv block_rsv;
 596	struct timespec64 cur_time = current_time(dir);
 597	struct btrfs_new_inode_args new_inode_args = {
 598		.dir = dir,
 599		.dentry = dentry,
 600		.subvol = true,
 601	};
 602	unsigned int trans_num_items;
 603	int ret;
 604	dev_t anon_dev;
 605	u64 objectid;
 
 
 
 
 606
 607	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 608	if (!root_item)
 609		return -ENOMEM;
 610
 611	ret = btrfs_get_free_objectid(fs_info->tree_root, &objectid);
 612	if (ret)
 613		goto out_root_item;
 614
 615	/*
 616	 * Don't create subvolume whose level is not zero. Or qgroup will be
 617	 * screwed up since it assumes subvolume qgroup's level to be 0.
 618	 */
 619	if (btrfs_qgroup_level(objectid)) {
 620		ret = -ENOSPC;
 621		goto out_root_item;
 622	}
 623
 624	ret = get_anon_bdev(&anon_dev);
 625	if (ret < 0)
 626		goto out_root_item;
 627
 628	new_inode_args.inode = btrfs_new_subvol_inode(idmap, dir);
 629	if (!new_inode_args.inode) {
 630		ret = -ENOMEM;
 631		goto out_anon_dev;
 632	}
 633	ret = btrfs_new_inode_prepare(&new_inode_args, &trans_num_items);
 634	if (ret)
 635		goto out_inode;
 636	trans_num_items += create_subvol_num_items(inherit);
 637
 638	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 
 
 
 
 639	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 640					       trans_num_items, false);
 641	if (ret)
 642		goto out_new_inode_args;
 643
 644	trans = btrfs_start_transaction(root, 0);
 645	if (IS_ERR(trans)) {
 646		ret = PTR_ERR(trans);
 647		btrfs_subvolume_release_metadata(root, &block_rsv);
 648		goto out_new_inode_args;
 
 649	}
 650	trans->block_rsv = &block_rsv;
 651	trans->bytes_reserved = block_rsv.size;
 652	/* Tree log can't currently deal with an inode which is a new root. */
 653	btrfs_set_log_full_commit(trans);
 654
 655	ret = btrfs_qgroup_inherit(trans, 0, objectid, root->root_key.objectid, inherit);
 656	if (ret)
 657		goto out;
 658
 659	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
 660				      0, BTRFS_NESTING_NORMAL);
 661	if (IS_ERR(leaf)) {
 662		ret = PTR_ERR(leaf);
 663		goto out;
 664	}
 665
 666	btrfs_mark_buffer_dirty(trans, leaf);
 
 
 
 
 
 
 
 
 
 
 
 667
 668	inode_item = &root_item->inode;
 
 
 669	btrfs_set_stack_inode_generation(inode_item, 1);
 670	btrfs_set_stack_inode_size(inode_item, 3);
 671	btrfs_set_stack_inode_nlink(inode_item, 1);
 672	btrfs_set_stack_inode_nbytes(inode_item,
 673				     fs_info->nodesize);
 674	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 675
 676	btrfs_set_root_flags(root_item, 0);
 677	btrfs_set_root_limit(root_item, 0);
 678	btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 679
 680	btrfs_set_root_bytenr(root_item, leaf->start);
 681	btrfs_set_root_generation(root_item, trans->transid);
 682	btrfs_set_root_level(root_item, 0);
 683	btrfs_set_root_refs(root_item, 1);
 684	btrfs_set_root_used(root_item, leaf->len);
 685	btrfs_set_root_last_snapshot(root_item, 0);
 686
 687	btrfs_set_root_generation_v2(root_item,
 688			btrfs_root_generation(root_item));
 689	generate_random_guid(root_item->uuid);
 690	btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 691	btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 692	root_item->ctime = root_item->otime;
 693	btrfs_set_root_ctransid(root_item, trans->transid);
 694	btrfs_set_root_otransid(root_item, trans->transid);
 
 695
 696	btrfs_tree_unlock(leaf);
 
 
 697
 698	btrfs_set_root_dirid(root_item, BTRFS_FIRST_FREE_OBJECTID);
 699
 700	key.objectid = objectid;
 701	key.offset = 0;
 702	key.type = BTRFS_ROOT_ITEM_KEY;
 703	ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 704				root_item);
 705	if (ret) {
 706		/*
 707		 * Since we don't abort the transaction in this case, free the
 708		 * tree block so that we don't leak space and leave the
 709		 * filesystem in an inconsistent state (an extent item in the
 710		 * extent tree with a backreference for a root that does not
 711		 * exists).
 712		 */
 713		btrfs_tree_lock(leaf);
 714		btrfs_clear_buffer_dirty(trans, leaf);
 715		btrfs_tree_unlock(leaf);
 716		btrfs_free_tree_block(trans, objectid, leaf, 0, 1);
 717		free_extent_buffer(leaf);
 718		goto out;
 719	}
 720
 721	free_extent_buffer(leaf);
 722	leaf = NULL;
 723
 724	new_root = btrfs_get_new_fs_root(fs_info, objectid, &anon_dev);
 
 725	if (IS_ERR(new_root)) {
 726		ret = PTR_ERR(new_root);
 727		btrfs_abort_transaction(trans, ret);
 728		goto out;
 729	}
 730	/* anon_dev is owned by new_root now. */
 731	anon_dev = 0;
 732	BTRFS_I(new_inode_args.inode)->root = new_root;
 733	/* ... and new_root is owned by new_inode_args.inode now. */
 734
 735	ret = btrfs_record_root_in_trans(trans, new_root);
 
 
 736	if (ret) {
 737		btrfs_abort_transaction(trans, ret);
 738		goto out;
 
 739	}
 740
 741	ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 742				  BTRFS_UUID_KEY_SUBVOL, objectid);
 
 
 
 
 
 
 743	if (ret) {
 744		btrfs_abort_transaction(trans, ret);
 745		goto out;
 746	}
 747
 748	ret = btrfs_create_new_inode(trans, &new_inode_args);
 
 
 749	if (ret) {
 750		btrfs_abort_transaction(trans, ret);
 751		goto out;
 752	}
 753
 754	d_instantiate_new(dentry, new_inode_args.inode);
 755	new_inode_args.inode = NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 756
 757out:
 758	trans->block_rsv = NULL;
 759	trans->bytes_reserved = 0;
 760	btrfs_subvolume_release_metadata(root, &block_rsv);
 761
 762	btrfs_end_transaction(trans);
 763out_new_inode_args:
 764	btrfs_new_inode_args_destroy(&new_inode_args);
 765out_inode:
 766	iput(new_inode_args.inode);
 767out_anon_dev:
 768	if (anon_dev)
 769		free_anon_bdev(anon_dev);
 770out_root_item:
 771	kfree(root_item);
 
 
 
 
 
 
 
 772	return ret;
 773}
 774
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 775static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 776			   struct dentry *dentry, bool readonly,
 
 777			   struct btrfs_qgroup_inherit *inherit)
 778{
 779	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 780	struct inode *inode;
 781	struct btrfs_pending_snapshot *pending_snapshot;
 782	unsigned int trans_num_items;
 783	struct btrfs_trans_handle *trans;
 784	int ret;
 785
 786	/* We do not support snapshotting right now. */
 787	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
 788		btrfs_warn(fs_info,
 789			   "extent tree v2 doesn't support snapshotting yet");
 790		return -EOPNOTSUPP;
 791	}
 792
 793	if (btrfs_root_refs(&root->root_item) == 0)
 794		return -ENOENT;
 795
 796	if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
 797		return -EINVAL;
 798
 799	if (atomic_read(&root->nr_swapfiles)) {
 800		btrfs_warn(fs_info,
 801			   "cannot snapshot subvolume with active swapfile");
 802		return -ETXTBSY;
 803	}
 804
 805	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 806	if (!pending_snapshot)
 807		return -ENOMEM;
 808
 809	ret = get_anon_bdev(&pending_snapshot->anon_dev);
 810	if (ret < 0)
 811		goto free_pending;
 812	pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 813			GFP_KERNEL);
 814	pending_snapshot->path = btrfs_alloc_path();
 815	if (!pending_snapshot->root_item || !pending_snapshot->path) {
 816		ret = -ENOMEM;
 817		goto free_pending;
 818	}
 819
 
 
 
 
 
 
 
 
 
 
 820	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 821			     BTRFS_BLOCK_RSV_TEMP);
 822	/*
 823	 * 1 to add dir item
 824	 * 1 to add dir index
 825	 * 1 to update parent inode item
 
 
 
 826	 */
 827	trans_num_items = create_subvol_num_items(inherit) + 3;
 828	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 829					       &pending_snapshot->block_rsv,
 830					       trans_num_items, false);
 
 831	if (ret)
 832		goto free_pending;
 833
 834	pending_snapshot->dentry = dentry;
 835	pending_snapshot->root = root;
 836	pending_snapshot->readonly = readonly;
 837	pending_snapshot->dir = dir;
 838	pending_snapshot->inherit = inherit;
 839
 840	trans = btrfs_start_transaction(root, 0);
 841	if (IS_ERR(trans)) {
 842		ret = PTR_ERR(trans);
 843		goto fail;
 844	}
 845
 846	trans->pending_snapshot = pending_snapshot;
 847
 848	ret = btrfs_commit_transaction(trans);
 
 
 
 
 
 
 
 
 
 
 
 849	if (ret)
 850		goto fail;
 851
 852	ret = pending_snapshot->error;
 853	if (ret)
 854		goto fail;
 855
 856	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 857	if (ret)
 858		goto fail;
 859
 860	inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 861	if (IS_ERR(inode)) {
 862		ret = PTR_ERR(inode);
 863		goto fail;
 864	}
 865
 866	d_instantiate(dentry, inode);
 867	ret = 0;
 868	pending_snapshot->anon_dev = 0;
 869fail:
 870	/* Prevent double freeing of anon_dev */
 871	if (ret && pending_snapshot->snap)
 872		pending_snapshot->snap->anon_dev = 0;
 873	btrfs_put_root(pending_snapshot->snap);
 874	btrfs_subvolume_release_metadata(root, &pending_snapshot->block_rsv);
 
 875free_pending:
 876	if (pending_snapshot->anon_dev)
 877		free_anon_bdev(pending_snapshot->anon_dev);
 878	kfree(pending_snapshot->root_item);
 879	btrfs_free_path(pending_snapshot->path);
 880	kfree(pending_snapshot);
 881
 882	return ret;
 883}
 884
 885/*  copy of may_delete in fs/namei.c()
 886 *	Check whether we can remove a link victim from directory dir, check
 887 *  whether the type of victim is right.
 888 *  1. We can't do it if dir is read-only (done in permission())
 889 *  2. We should have write and exec permissions on dir
 890 *  3. We can't remove anything from append-only dir
 891 *  4. We can't do anything with immutable dir (done in permission())
 892 *  5. If the sticky bit on dir is set we should either
 893 *	a. be owner of dir, or
 894 *	b. be owner of victim, or
 895 *	c. have CAP_FOWNER capability
 896 *  6. If the victim is append-only or immutable we can't do anything with
 897 *     links pointing to it.
 898 *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 899 *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 900 *  9. We can't remove a root or mountpoint.
 901 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 902 *     nfs_async_unlink().
 903 */
 904
 905static int btrfs_may_delete(struct mnt_idmap *idmap,
 906			    struct inode *dir, struct dentry *victim, int isdir)
 907{
 908	int error;
 909
 910	if (d_really_is_negative(victim))
 911		return -ENOENT;
 912
 913	BUG_ON(d_inode(victim->d_parent) != dir);
 914	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 915
 916	error = inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 917	if (error)
 918		return error;
 919	if (IS_APPEND(dir))
 920		return -EPERM;
 921	if (check_sticky(idmap, dir, d_inode(victim)) ||
 922	    IS_APPEND(d_inode(victim)) || IS_IMMUTABLE(d_inode(victim)) ||
 923	    IS_SWAPFILE(d_inode(victim)))
 924		return -EPERM;
 925	if (isdir) {
 926		if (!d_is_dir(victim))
 927			return -ENOTDIR;
 928		if (IS_ROOT(victim))
 929			return -EBUSY;
 930	} else if (d_is_dir(victim))
 931		return -EISDIR;
 932	if (IS_DEADDIR(dir))
 933		return -ENOENT;
 934	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 935		return -EBUSY;
 936	return 0;
 937}
 938
 939/* copy of may_create in fs/namei.c() */
 940static inline int btrfs_may_create(struct mnt_idmap *idmap,
 941				   struct inode *dir, struct dentry *child)
 942{
 943	if (d_really_is_positive(child))
 944		return -EEXIST;
 945	if (IS_DEADDIR(dir))
 946		return -ENOENT;
 947	if (!fsuidgid_has_mapping(dir->i_sb, idmap))
 948		return -EOVERFLOW;
 949	return inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 950}
 951
 952/*
 953 * Create a new subvolume below @parent.  This is largely modeled after
 954 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 955 * inside this filesystem so it's quite a bit simpler.
 956 */
 957static noinline int btrfs_mksubvol(const struct path *parent,
 958				   struct mnt_idmap *idmap,
 959				   const char *name, int namelen,
 960				   struct btrfs_root *snap_src,
 961				   bool readonly,
 962				   struct btrfs_qgroup_inherit *inherit)
 963{
 964	struct inode *dir = d_inode(parent->dentry);
 965	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 966	struct dentry *dentry;
 967	struct fscrypt_str name_str = FSTR_INIT((char *)name, namelen);
 968	int error;
 969
 970	error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 971	if (error == -EINTR)
 972		return error;
 973
 974	dentry = lookup_one(idmap, name, parent->dentry, namelen);
 975	error = PTR_ERR(dentry);
 976	if (IS_ERR(dentry))
 977		goto out_unlock;
 978
 979	error = btrfs_may_create(idmap, dir, dentry);
 980	if (error)
 981		goto out_dput;
 982
 983	/*
 984	 * even if this name doesn't exist, we may get hash collisions.
 985	 * check for them now when we can safely fail
 986	 */
 987	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 988					       dir->i_ino, &name_str);
 
 989	if (error)
 990		goto out_dput;
 991
 992	down_read(&fs_info->subvol_sem);
 993
 994	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 995		goto out_up_read;
 996
 997	if (snap_src)
 998		error = create_snapshot(snap_src, dir, dentry, readonly, inherit);
 999	else
1000		error = create_subvol(idmap, dir, dentry, inherit);
1001
 
 
1002	if (!error)
1003		fsnotify_mkdir(dir, dentry);
1004out_up_read:
1005	up_read(&fs_info->subvol_sem);
1006out_dput:
1007	dput(dentry);
1008out_unlock:
1009	btrfs_inode_unlock(BTRFS_I(dir), 0);
1010	return error;
1011}
1012
1013static noinline int btrfs_mksnapshot(const struct path *parent,
1014				   struct mnt_idmap *idmap,
1015				   const char *name, int namelen,
1016				   struct btrfs_root *root,
1017				   bool readonly,
1018				   struct btrfs_qgroup_inherit *inherit)
 
 
1019{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1020	int ret;
1021	bool snapshot_force_cow = false;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1022
1023	/*
1024	 * Force new buffered writes to reserve space even when NOCOW is
1025	 * possible. This is to avoid later writeback (running dealloc) to
1026	 * fallback to COW mode and unexpectedly fail with ENOSPC.
1027	 */
1028	btrfs_drew_read_lock(&root->snapshot_lock);
 
 
1029
1030	ret = btrfs_start_delalloc_snapshot(root, false);
1031	if (ret)
1032		goto out;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1033
1034	/*
1035	 * All previous writes have started writeback in NOCOW mode, so now
1036	 * we force future writes to fallback to COW mode during snapshot
1037	 * creation.
1038	 */
1039	atomic_inc(&root->snapshot_force_cow);
1040	snapshot_force_cow = true;
 
 
 
 
 
 
 
 
 
 
 
 
1041
1042	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 
1043
1044	ret = btrfs_mksubvol(parent, idmap, name, namelen,
1045			     root, readonly, inherit);
 
 
 
 
 
 
1046out:
1047	if (snapshot_force_cow)
1048		atomic_dec(&root->snapshot_force_cow);
1049	btrfs_drew_read_unlock(&root->snapshot_lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1050	return ret;
1051}
1052
1053/*
1054 * Try to start exclusive operation @type or cancel it if it's running.
 
 
 
 
 
 
1055 *
1056 * Return:
1057 *   0        - normal mode, newly claimed op started
1058 *  >0        - normal mode, something else is running,
1059 *              return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS to user space
1060 * ECANCELED  - cancel mode, successful cancel
1061 * ENOTCONN   - cancel mode, operation not running anymore
1062 */
1063static int exclop_start_or_cancel_reloc(struct btrfs_fs_info *fs_info,
1064			enum btrfs_exclusive_operation type, bool cancel)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1065{
1066	if (!cancel) {
1067		/* Start normal op */
1068		if (!btrfs_exclop_start(fs_info, type))
1069			return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1070		/* Exclusive operation is now claimed */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1071		return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1072	}
 
 
 
 
 
 
 
 
 
1073
1074	/* Cancel running op */
1075	if (btrfs_exclop_start_try_lock(fs_info, type)) {
1076		/*
1077		 * This blocks any exclop finish from setting it to NONE, so we
1078		 * request cancellation. Either it runs and we will wait for it,
1079		 * or it has finished and no waiting will happen.
1080		 */
1081		atomic_inc(&fs_info->reloc_cancel_req);
1082		btrfs_exclop_start_unlock(fs_info);
1083
1084		if (test_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags))
1085			wait_on_bit(&fs_info->flags, BTRFS_FS_RELOC_RUNNING,
1086				    TASK_INTERRUPTIBLE);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1087
1088		return -ECANCELED;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1089	}
1090
1091	/* Something else is running or none */
1092	return -ENOTCONN;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1093}
1094
1095static noinline int btrfs_ioctl_resize(struct file *file,
1096					void __user *arg)
1097{
1098	BTRFS_DEV_LOOKUP_ARGS(args);
1099	struct inode *inode = file_inode(file);
1100	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1101	u64 new_size;
1102	u64 old_size;
1103	u64 devid = 1;
1104	struct btrfs_root *root = BTRFS_I(inode)->root;
1105	struct btrfs_ioctl_vol_args *vol_args;
1106	struct btrfs_trans_handle *trans;
1107	struct btrfs_device *device = NULL;
1108	char *sizestr;
1109	char *retptr;
1110	char *devstr = NULL;
1111	int ret = 0;
1112	int mod = 0;
1113	bool cancel;
1114
1115	if (!capable(CAP_SYS_ADMIN))
1116		return -EPERM;
1117
1118	ret = mnt_want_write_file(file);
1119	if (ret)
1120		return ret;
1121
1122	/*
1123	 * Read the arguments before checking exclusivity to be able to
1124	 * distinguish regular resize and cancel
1125	 */
 
 
 
1126	vol_args = memdup_user(arg, sizeof(*vol_args));
1127	if (IS_ERR(vol_args)) {
1128		ret = PTR_ERR(vol_args);
1129		goto out_drop;
1130	}
 
1131	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1132	sizestr = vol_args->name;
1133	cancel = (strcmp("cancel", sizestr) == 0);
1134	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_RESIZE, cancel);
1135	if (ret)
1136		goto out_free;
1137	/* Exclusive operation is now claimed */
1138
 
1139	devstr = strchr(sizestr, ':');
1140	if (devstr) {
1141		sizestr = devstr + 1;
1142		*devstr = '\0';
1143		devstr = vol_args->name;
1144		ret = kstrtoull(devstr, 10, &devid);
1145		if (ret)
1146			goto out_finish;
1147		if (!devid) {
1148			ret = -EINVAL;
1149			goto out_finish;
1150		}
1151		btrfs_info(fs_info, "resizing devid %llu", devid);
1152	}
1153
1154	args.devid = devid;
1155	device = btrfs_find_device(fs_info->fs_devices, &args);
1156	if (!device) {
1157		btrfs_info(fs_info, "resizer unable to find device %llu",
1158			   devid);
1159		ret = -ENODEV;
1160		goto out_finish;
1161	}
1162
1163	if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1164		btrfs_info(fs_info,
1165			   "resizer unable to apply on readonly device %llu",
1166		       devid);
1167		ret = -EPERM;
1168		goto out_finish;
1169	}
1170
1171	if (!strcmp(sizestr, "max"))
1172		new_size = bdev_nr_bytes(device->bdev);
1173	else {
1174		if (sizestr[0] == '-') {
1175			mod = -1;
1176			sizestr++;
1177		} else if (sizestr[0] == '+') {
1178			mod = 1;
1179			sizestr++;
1180		}
1181		new_size = memparse(sizestr, &retptr);
1182		if (*retptr != '\0' || new_size == 0) {
1183			ret = -EINVAL;
1184			goto out_finish;
1185		}
1186	}
1187
1188	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1189		ret = -EPERM;
1190		goto out_finish;
1191	}
1192
1193	old_size = btrfs_device_get_total_bytes(device);
1194
1195	if (mod < 0) {
1196		if (new_size > old_size) {
1197			ret = -EINVAL;
1198			goto out_finish;
1199		}
1200		new_size = old_size - new_size;
1201	} else if (mod > 0) {
1202		if (new_size > ULLONG_MAX - old_size) {
1203			ret = -ERANGE;
1204			goto out_finish;
1205		}
1206		new_size = old_size + new_size;
1207	}
1208
1209	if (new_size < SZ_256M) {
1210		ret = -EINVAL;
1211		goto out_finish;
1212	}
1213	if (new_size > bdev_nr_bytes(device->bdev)) {
1214		ret = -EFBIG;
1215		goto out_finish;
1216	}
1217
1218	new_size = round_down(new_size, fs_info->sectorsize);
 
 
 
 
1219
1220	if (new_size > old_size) {
1221		trans = btrfs_start_transaction(root, 0);
1222		if (IS_ERR(trans)) {
1223			ret = PTR_ERR(trans);
1224			goto out_finish;
1225		}
1226		ret = btrfs_grow_device(trans, device, new_size);
1227		btrfs_commit_transaction(trans);
1228	} else if (new_size < old_size) {
1229		ret = btrfs_shrink_device(device, new_size);
1230	} /* equal, nothing need to do */
1231
1232	if (ret == 0 && new_size != old_size)
1233		btrfs_info_in_rcu(fs_info,
1234			"resize device %s (devid %llu) from %llu to %llu",
1235			btrfs_dev_name(device), device->devid,
1236			old_size, new_size);
1237out_finish:
1238	btrfs_exclop_finish(fs_info);
1239out_free:
1240	kfree(vol_args);
1241out_drop:
 
 
1242	mnt_drop_write_file(file);
1243	return ret;
1244}
1245
1246static noinline int __btrfs_ioctl_snap_create(struct file *file,
1247				struct mnt_idmap *idmap,
1248				const char *name, unsigned long fd, int subvol,
1249				bool readonly,
1250				struct btrfs_qgroup_inherit *inherit)
1251{
1252	int namelen;
1253	int ret = 0;
1254
1255	if (!S_ISDIR(file_inode(file)->i_mode))
1256		return -ENOTDIR;
1257
1258	ret = mnt_want_write_file(file);
1259	if (ret)
1260		goto out;
1261
1262	namelen = strlen(name);
1263	if (strchr(name, '/')) {
1264		ret = -EINVAL;
1265		goto out_drop_write;
1266	}
1267
1268	if (name[0] == '.' &&
1269	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1270		ret = -EEXIST;
1271		goto out_drop_write;
1272	}
1273
1274	if (subvol) {
1275		ret = btrfs_mksubvol(&file->f_path, idmap, name,
1276				     namelen, NULL, readonly, inherit);
1277	} else {
1278		struct fd src = fdget(fd);
1279		struct inode *src_inode;
1280		if (!src.file) {
1281			ret = -EINVAL;
1282			goto out_drop_write;
1283		}
1284
1285		src_inode = file_inode(src.file);
1286		if (src_inode->i_sb != file_inode(file)->i_sb) {
1287			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1288				   "Snapshot src from another FS");
1289			ret = -EXDEV;
1290		} else if (!inode_owner_or_capable(idmap, src_inode)) {
1291			/*
1292			 * Subvolume creation is not restricted, but snapshots
1293			 * are limited to own subvolumes only
1294			 */
1295			ret = -EPERM;
1296		} else if (btrfs_ino(BTRFS_I(src_inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1297			/*
1298			 * Snapshots must be made with the src_inode referring
1299			 * to the subvolume inode, otherwise the permission
1300			 * checking above is useless because we may have
1301			 * permission on a lower directory but not the subvol
1302			 * itself.
1303			 */
1304			ret = -EINVAL;
1305		} else {
1306			ret = btrfs_mksnapshot(&file->f_path, idmap,
1307					       name, namelen,
1308					       BTRFS_I(src_inode)->root,
1309					       readonly, inherit);
1310		}
1311		fdput(src);
1312	}
1313out_drop_write:
1314	mnt_drop_write_file(file);
1315out:
1316	return ret;
1317}
1318
1319static noinline int btrfs_ioctl_snap_create(struct file *file,
1320					    void __user *arg, int subvol)
1321{
1322	struct btrfs_ioctl_vol_args *vol_args;
1323	int ret;
1324
1325	if (!S_ISDIR(file_inode(file)->i_mode))
1326		return -ENOTDIR;
1327
1328	vol_args = memdup_user(arg, sizeof(*vol_args));
1329	if (IS_ERR(vol_args))
1330		return PTR_ERR(vol_args);
1331	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1332
1333	ret = __btrfs_ioctl_snap_create(file, file_mnt_idmap(file),
1334					vol_args->name, vol_args->fd, subvol,
1335					false, NULL);
1336
1337	kfree(vol_args);
1338	return ret;
1339}
1340
1341static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1342					       void __user *arg, int subvol)
1343{
1344	struct btrfs_ioctl_vol_args_v2 *vol_args;
1345	int ret;
 
 
1346	bool readonly = false;
1347	struct btrfs_qgroup_inherit *inherit = NULL;
1348
1349	if (!S_ISDIR(file_inode(file)->i_mode))
1350		return -ENOTDIR;
1351
1352	vol_args = memdup_user(arg, sizeof(*vol_args));
1353	if (IS_ERR(vol_args))
1354		return PTR_ERR(vol_args);
1355	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1356
1357	if (vol_args->flags & ~BTRFS_SUBVOL_CREATE_ARGS_MASK) {
 
 
1358		ret = -EOPNOTSUPP;
1359		goto free_args;
1360	}
1361
 
 
1362	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1363		readonly = true;
1364	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1365		u64 nums;
1366
1367		if (vol_args->size < sizeof(*inherit) ||
1368		    vol_args->size > PAGE_SIZE) {
1369			ret = -EINVAL;
1370			goto free_args;
1371		}
1372		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1373		if (IS_ERR(inherit)) {
1374			ret = PTR_ERR(inherit);
1375			goto free_args;
1376		}
1377
1378		if (inherit->num_qgroups > PAGE_SIZE ||
1379		    inherit->num_ref_copies > PAGE_SIZE ||
1380		    inherit->num_excl_copies > PAGE_SIZE) {
1381			ret = -EINVAL;
1382			goto free_inherit;
1383		}
1384
1385		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
1386		       2 * inherit->num_excl_copies;
1387		if (vol_args->size != struct_size(inherit, qgroups, nums)) {
1388			ret = -EINVAL;
1389			goto free_inherit;
1390		}
1391	}
1392
1393	ret = __btrfs_ioctl_snap_create(file, file_mnt_idmap(file),
1394					vol_args->name, vol_args->fd, subvol,
1395					readonly, inherit);
1396	if (ret)
1397		goto free_inherit;
 
 
 
 
 
 
 
1398free_inherit:
1399	kfree(inherit);
1400free_args:
1401	kfree(vol_args);
1402	return ret;
1403}
1404
1405static noinline int btrfs_ioctl_subvol_getflags(struct inode *inode,
1406						void __user *arg)
1407{
1408	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1409	struct btrfs_root *root = BTRFS_I(inode)->root;
1410	int ret = 0;
1411	u64 flags = 0;
1412
1413	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1414		return -EINVAL;
1415
1416	down_read(&fs_info->subvol_sem);
1417	if (btrfs_root_readonly(root))
1418		flags |= BTRFS_SUBVOL_RDONLY;
1419	up_read(&fs_info->subvol_sem);
1420
1421	if (copy_to_user(arg, &flags, sizeof(flags)))
1422		ret = -EFAULT;
1423
1424	return ret;
1425}
1426
1427static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1428					      void __user *arg)
1429{
1430	struct inode *inode = file_inode(file);
1431	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1432	struct btrfs_root *root = BTRFS_I(inode)->root;
1433	struct btrfs_trans_handle *trans;
1434	u64 root_flags;
1435	u64 flags;
1436	int ret = 0;
1437
1438	if (!inode_owner_or_capable(file_mnt_idmap(file), inode))
1439		return -EPERM;
1440
1441	ret = mnt_want_write_file(file);
1442	if (ret)
1443		goto out;
1444
1445	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1446		ret = -EINVAL;
1447		goto out_drop_write;
1448	}
1449
1450	if (copy_from_user(&flags, arg, sizeof(flags))) {
1451		ret = -EFAULT;
1452		goto out_drop_write;
1453	}
1454
 
 
 
 
 
1455	if (flags & ~BTRFS_SUBVOL_RDONLY) {
1456		ret = -EOPNOTSUPP;
1457		goto out_drop_write;
1458	}
1459
1460	down_write(&fs_info->subvol_sem);
1461
1462	/* nothing to do */
1463	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1464		goto out_drop_sem;
1465
1466	root_flags = btrfs_root_flags(&root->root_item);
1467	if (flags & BTRFS_SUBVOL_RDONLY) {
1468		btrfs_set_root_flags(&root->root_item,
1469				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1470	} else {
1471		/*
1472		 * Block RO -> RW transition if this subvolume is involved in
1473		 * send
1474		 */
1475		spin_lock(&root->root_item_lock);
1476		if (root->send_in_progress == 0) {
1477			btrfs_set_root_flags(&root->root_item,
1478				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1479			spin_unlock(&root->root_item_lock);
1480		} else {
1481			spin_unlock(&root->root_item_lock);
1482			btrfs_warn(fs_info,
1483				   "Attempt to set subvolume %llu read-write during send",
1484				   root->root_key.objectid);
1485			ret = -EPERM;
1486			goto out_drop_sem;
1487		}
1488	}
1489
1490	trans = btrfs_start_transaction(root, 1);
1491	if (IS_ERR(trans)) {
1492		ret = PTR_ERR(trans);
1493		goto out_reset;
1494	}
1495
1496	ret = btrfs_update_root(trans, fs_info->tree_root,
1497				&root->root_key, &root->root_item);
1498	if (ret < 0) {
1499		btrfs_end_transaction(trans);
1500		goto out_reset;
1501	}
1502
1503	ret = btrfs_commit_transaction(trans);
1504
 
1505out_reset:
1506	if (ret)
1507		btrfs_set_root_flags(&root->root_item, root_flags);
1508out_drop_sem:
1509	up_write(&fs_info->subvol_sem);
1510out_drop_write:
1511	mnt_drop_write_file(file);
1512out:
1513	return ret;
1514}
1515
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1516static noinline int key_in_sk(struct btrfs_key *key,
1517			      struct btrfs_ioctl_search_key *sk)
1518{
1519	struct btrfs_key test;
1520	int ret;
1521
1522	test.objectid = sk->min_objectid;
1523	test.type = sk->min_type;
1524	test.offset = sk->min_offset;
1525
1526	ret = btrfs_comp_cpu_keys(key, &test);
1527	if (ret < 0)
1528		return 0;
1529
1530	test.objectid = sk->max_objectid;
1531	test.type = sk->max_type;
1532	test.offset = sk->max_offset;
1533
1534	ret = btrfs_comp_cpu_keys(key, &test);
1535	if (ret > 0)
1536		return 0;
1537	return 1;
1538}
1539
1540static noinline int copy_to_sk(struct btrfs_path *path,
 
1541			       struct btrfs_key *key,
1542			       struct btrfs_ioctl_search_key *sk,
1543			       u64 *buf_size,
1544			       char __user *ubuf,
1545			       unsigned long *sk_offset,
1546			       int *num_found)
1547{
1548	u64 found_transid;
1549	struct extent_buffer *leaf;
1550	struct btrfs_ioctl_search_header sh;
1551	struct btrfs_key test;
1552	unsigned long item_off;
1553	unsigned long item_len;
1554	int nritems;
1555	int i;
1556	int slot;
1557	int ret = 0;
1558
1559	leaf = path->nodes[0];
1560	slot = path->slots[0];
1561	nritems = btrfs_header_nritems(leaf);
1562
1563	if (btrfs_header_generation(leaf) > sk->max_transid) {
1564		i = nritems;
1565		goto advance_key;
1566	}
1567	found_transid = btrfs_header_generation(leaf);
1568
1569	for (i = slot; i < nritems; i++) {
1570		item_off = btrfs_item_ptr_offset(leaf, i);
1571		item_len = btrfs_item_size(leaf, i);
1572
1573		btrfs_item_key_to_cpu(leaf, key, i);
1574		if (!key_in_sk(key, sk))
1575			continue;
1576
1577		if (sizeof(sh) + item_len > *buf_size) {
1578			if (*num_found) {
1579				ret = 1;
1580				goto out;
1581			}
1582
1583			/*
1584			 * return one empty item back for v1, which does not
1585			 * handle -EOVERFLOW
1586			 */
1587
1588			*buf_size = sizeof(sh) + item_len;
1589			item_len = 0;
1590			ret = -EOVERFLOW;
1591		}
1592
1593		if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
1594			ret = 1;
1595			goto out;
1596		}
1597
1598		sh.objectid = key->objectid;
1599		sh.offset = key->offset;
1600		sh.type = key->type;
1601		sh.len = item_len;
1602		sh.transid = found_transid;
1603
1604		/*
1605		 * Copy search result header. If we fault then loop again so we
1606		 * can fault in the pages and -EFAULT there if there's a
1607		 * problem. Otherwise we'll fault and then copy the buffer in
1608		 * properly this next time through
1609		 */
1610		if (copy_to_user_nofault(ubuf + *sk_offset, &sh, sizeof(sh))) {
1611			ret = 0;
1612			goto out;
1613		}
1614
1615		*sk_offset += sizeof(sh);
1616
1617		if (item_len) {
1618			char __user *up = ubuf + *sk_offset;
1619			/*
1620			 * Copy the item, same behavior as above, but reset the
1621			 * * sk_offset so we copy the full thing again.
1622			 */
1623			if (read_extent_buffer_to_user_nofault(leaf, up,
1624						item_off, item_len)) {
1625				ret = 0;
1626				*sk_offset -= sizeof(sh);
1627				goto out;
1628			}
1629
1630			*sk_offset += item_len;
1631		}
1632		(*num_found)++;
1633
1634		if (ret) /* -EOVERFLOW from above */
1635			goto out;
1636
1637		if (*num_found >= sk->nr_items) {
1638			ret = 1;
1639			goto out;
1640		}
1641	}
1642advance_key:
1643	ret = 0;
1644	test.objectid = sk->max_objectid;
1645	test.type = sk->max_type;
1646	test.offset = sk->max_offset;
1647	if (btrfs_comp_cpu_keys(key, &test) >= 0)
1648		ret = 1;
1649	else if (key->offset < (u64)-1)
1650		key->offset++;
1651	else if (key->type < (u8)-1) {
1652		key->offset = 0;
1653		key->type++;
1654	} else if (key->objectid < (u64)-1) {
1655		key->offset = 0;
1656		key->type = 0;
1657		key->objectid++;
1658	} else
1659		ret = 1;
1660out:
1661	/*
1662	 *  0: all items from this leaf copied, continue with next
1663	 *  1: * more items can be copied, but unused buffer is too small
1664	 *     * all items were found
1665	 *     Either way, it will stops the loop which iterates to the next
1666	 *     leaf
1667	 *  -EOVERFLOW: item was to large for buffer
1668	 *  -EFAULT: could not copy extent buffer back to userspace
1669	 */
1670	return ret;
1671}
1672
1673static noinline int search_ioctl(struct inode *inode,
1674				 struct btrfs_ioctl_search_key *sk,
1675				 u64 *buf_size,
1676				 char __user *ubuf)
1677{
1678	struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
1679	struct btrfs_root *root;
1680	struct btrfs_key key;
1681	struct btrfs_path *path;
 
1682	int ret;
1683	int num_found = 0;
1684	unsigned long sk_offset = 0;
1685
1686	if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
1687		*buf_size = sizeof(struct btrfs_ioctl_search_header);
1688		return -EOVERFLOW;
1689	}
1690
1691	path = btrfs_alloc_path();
1692	if (!path)
1693		return -ENOMEM;
1694
1695	if (sk->tree_id == 0) {
1696		/* search the root of the inode that was passed */
1697		root = btrfs_grab_root(BTRFS_I(inode)->root);
1698	} else {
1699		root = btrfs_get_fs_root(info, sk->tree_id, true);
 
 
 
1700		if (IS_ERR(root)) {
1701			btrfs_free_path(path);
1702			return PTR_ERR(root);
1703		}
1704	}
1705
1706	key.objectid = sk->min_objectid;
1707	key.type = sk->min_type;
1708	key.offset = sk->min_offset;
1709
1710	while (1) {
1711		ret = -EFAULT;
1712		/*
1713		 * Ensure that the whole user buffer is faulted in at sub-page
1714		 * granularity, otherwise the loop may live-lock.
1715		 */
1716		if (fault_in_subpage_writeable(ubuf + sk_offset,
1717					       *buf_size - sk_offset))
1718			break;
1719
1720		ret = btrfs_search_forward(root, &key, path, sk->min_transid);
1721		if (ret != 0) {
1722			if (ret > 0)
1723				ret = 0;
1724			goto err;
1725		}
1726		ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
1727				 &sk_offset, &num_found);
1728		btrfs_release_path(path);
1729		if (ret)
1730			break;
1731
1732	}
1733	if (ret > 0)
1734		ret = 0;
1735err:
1736	sk->nr_items = num_found;
1737	btrfs_put_root(root);
1738	btrfs_free_path(path);
1739	return ret;
1740}
1741
1742static noinline int btrfs_ioctl_tree_search(struct inode *inode,
1743					    void __user *argp)
1744{
1745	struct btrfs_ioctl_search_args __user *uargs = argp;
1746	struct btrfs_ioctl_search_key sk;
 
1747	int ret;
1748	u64 buf_size;
1749
1750	if (!capable(CAP_SYS_ADMIN))
1751		return -EPERM;
1752
 
 
1753	if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
1754		return -EFAULT;
1755
1756	buf_size = sizeof(uargs->buf);
1757
 
1758	ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
1759
1760	/*
1761	 * In the origin implementation an overflow is handled by returning a
1762	 * search header with a len of zero, so reset ret.
1763	 */
1764	if (ret == -EOVERFLOW)
1765		ret = 0;
1766
1767	if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
1768		ret = -EFAULT;
1769	return ret;
1770}
1771
1772static noinline int btrfs_ioctl_tree_search_v2(struct inode *inode,
1773					       void __user *argp)
1774{
1775	struct btrfs_ioctl_search_args_v2 __user *uarg = argp;
1776	struct btrfs_ioctl_search_args_v2 args;
 
1777	int ret;
1778	u64 buf_size;
1779	const u64 buf_limit = SZ_16M;
1780
1781	if (!capable(CAP_SYS_ADMIN))
1782		return -EPERM;
1783
1784	/* copy search header and buffer size */
 
1785	if (copy_from_user(&args, uarg, sizeof(args)))
1786		return -EFAULT;
1787
1788	buf_size = args.buf_size;
1789
 
 
 
1790	/* limit result size to 16MB */
1791	if (buf_size > buf_limit)
1792		buf_size = buf_limit;
1793
 
1794	ret = search_ioctl(inode, &args.key, &buf_size,
1795			   (char __user *)(&uarg->buf[0]));
1796	if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
1797		ret = -EFAULT;
1798	else if (ret == -EOVERFLOW &&
1799		copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
1800		ret = -EFAULT;
1801
1802	return ret;
1803}
1804
1805/*
1806 * Search INODE_REFs to identify path name of 'dirid' directory
1807 * in a 'tree_id' tree. and sets path name to 'name'.
1808 */
1809static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1810				u64 tree_id, u64 dirid, char *name)
1811{
1812	struct btrfs_root *root;
1813	struct btrfs_key key;
1814	char *ptr;
1815	int ret = -1;
1816	int slot;
1817	int len;
1818	int total_len = 0;
1819	struct btrfs_inode_ref *iref;
1820	struct extent_buffer *l;
1821	struct btrfs_path *path;
1822
1823	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1824		name[0]='\0';
1825		return 0;
1826	}
1827
1828	path = btrfs_alloc_path();
1829	if (!path)
1830		return -ENOMEM;
1831
1832	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
1833
1834	root = btrfs_get_fs_root(info, tree_id, true);
 
 
 
1835	if (IS_ERR(root)) {
1836		ret = PTR_ERR(root);
1837		root = NULL;
1838		goto out;
1839	}
1840
1841	key.objectid = dirid;
1842	key.type = BTRFS_INODE_REF_KEY;
1843	key.offset = (u64)-1;
1844
1845	while (1) {
1846		ret = btrfs_search_backwards(root, &key, path);
1847		if (ret < 0)
1848			goto out;
1849		else if (ret > 0) {
1850			ret = -ENOENT;
1851			goto out;
 
 
 
 
 
 
1852		}
1853
1854		l = path->nodes[0];
1855		slot = path->slots[0];
 
1856
1857		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1858		len = btrfs_inode_ref_name_len(l, iref);
1859		ptr -= len + 1;
1860		total_len += len + 1;
1861		if (ptr < name) {
1862			ret = -ENAMETOOLONG;
1863			goto out;
1864		}
1865
1866		*(ptr + len) = '/';
1867		read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
1868
1869		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1870			break;
1871
1872		btrfs_release_path(path);
1873		key.objectid = key.offset;
1874		key.offset = (u64)-1;
1875		dirid = key.objectid;
1876	}
1877	memmove(name, ptr, total_len);
1878	name[total_len] = '\0';
1879	ret = 0;
1880out:
1881	btrfs_put_root(root);
1882	btrfs_free_path(path);
1883	return ret;
1884}
1885
1886static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
1887				struct inode *inode,
1888				struct btrfs_ioctl_ino_lookup_user_args *args)
1889{
1890	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1891	struct super_block *sb = inode->i_sb;
1892	struct btrfs_key upper_limit = BTRFS_I(inode)->location;
1893	u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
1894	u64 dirid = args->dirid;
1895	unsigned long item_off;
1896	unsigned long item_len;
1897	struct btrfs_inode_ref *iref;
1898	struct btrfs_root_ref *rref;
1899	struct btrfs_root *root = NULL;
1900	struct btrfs_path *path;
1901	struct btrfs_key key, key2;
1902	struct extent_buffer *leaf;
1903	struct inode *temp_inode;
1904	char *ptr;
1905	int slot;
1906	int len;
1907	int total_len = 0;
1908	int ret;
1909
1910	path = btrfs_alloc_path();
1911	if (!path)
1912		return -ENOMEM;
1913
1914	/*
1915	 * If the bottom subvolume does not exist directly under upper_limit,
1916	 * construct the path in from the bottom up.
1917	 */
1918	if (dirid != upper_limit.objectid) {
1919		ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
1920
1921		root = btrfs_get_fs_root(fs_info, treeid, true);
1922		if (IS_ERR(root)) {
1923			ret = PTR_ERR(root);
1924			goto out;
1925		}
1926
1927		key.objectid = dirid;
1928		key.type = BTRFS_INODE_REF_KEY;
1929		key.offset = (u64)-1;
1930		while (1) {
1931			ret = btrfs_search_backwards(root, &key, path);
1932			if (ret < 0)
1933				goto out_put;
1934			else if (ret > 0) {
1935				ret = -ENOENT;
1936				goto out_put;
1937			}
1938
1939			leaf = path->nodes[0];
1940			slot = path->slots[0];
1941
1942			iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
1943			len = btrfs_inode_ref_name_len(leaf, iref);
1944			ptr -= len + 1;
1945			total_len += len + 1;
1946			if (ptr < args->path) {
1947				ret = -ENAMETOOLONG;
1948				goto out_put;
1949			}
1950
1951			*(ptr + len) = '/';
1952			read_extent_buffer(leaf, ptr,
1953					(unsigned long)(iref + 1), len);
1954
1955			/* Check the read+exec permission of this directory */
1956			ret = btrfs_previous_item(root, path, dirid,
1957						  BTRFS_INODE_ITEM_KEY);
1958			if (ret < 0) {
1959				goto out_put;
1960			} else if (ret > 0) {
1961				ret = -ENOENT;
1962				goto out_put;
1963			}
1964
1965			leaf = path->nodes[0];
1966			slot = path->slots[0];
1967			btrfs_item_key_to_cpu(leaf, &key2, slot);
1968			if (key2.objectid != dirid) {
1969				ret = -ENOENT;
1970				goto out_put;
1971			}
1972
1973			/*
1974			 * We don't need the path anymore, so release it and
1975			 * avoid deadlocks and lockdep warnings in case
1976			 * btrfs_iget() needs to lookup the inode from its root
1977			 * btree and lock the same leaf.
1978			 */
1979			btrfs_release_path(path);
1980			temp_inode = btrfs_iget(sb, key2.objectid, root);
1981			if (IS_ERR(temp_inode)) {
1982				ret = PTR_ERR(temp_inode);
1983				goto out_put;
1984			}
1985			ret = inode_permission(idmap, temp_inode,
1986					       MAY_READ | MAY_EXEC);
1987			iput(temp_inode);
1988			if (ret) {
1989				ret = -EACCES;
1990				goto out_put;
1991			}
1992
1993			if (key.offset == upper_limit.objectid)
1994				break;
1995			if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
1996				ret = -EACCES;
1997				goto out_put;
1998			}
1999
2000			key.objectid = key.offset;
2001			key.offset = (u64)-1;
2002			dirid = key.objectid;
2003		}
2004
2005		memmove(args->path, ptr, total_len);
2006		args->path[total_len] = '\0';
2007		btrfs_put_root(root);
2008		root = NULL;
2009		btrfs_release_path(path);
2010	}
2011
2012	/* Get the bottom subvolume's name from ROOT_REF */
2013	key.objectid = treeid;
2014	key.type = BTRFS_ROOT_REF_KEY;
2015	key.offset = args->treeid;
2016	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2017	if (ret < 0) {
2018		goto out;
2019	} else if (ret > 0) {
2020		ret = -ENOENT;
2021		goto out;
2022	}
2023
2024	leaf = path->nodes[0];
2025	slot = path->slots[0];
2026	btrfs_item_key_to_cpu(leaf, &key, slot);
2027
2028	item_off = btrfs_item_ptr_offset(leaf, slot);
2029	item_len = btrfs_item_size(leaf, slot);
2030	/* Check if dirid in ROOT_REF corresponds to passed dirid */
2031	rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2032	if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2033		ret = -EINVAL;
2034		goto out;
2035	}
2036
2037	/* Copy subvolume's name */
2038	item_off += sizeof(struct btrfs_root_ref);
2039	item_len -= sizeof(struct btrfs_root_ref);
2040	read_extent_buffer(leaf, args->name, item_off, item_len);
2041	args->name[item_len] = 0;
2042
2043out_put:
2044	btrfs_put_root(root);
2045out:
2046	btrfs_free_path(path);
2047	return ret;
2048}
2049
2050static noinline int btrfs_ioctl_ino_lookup(struct btrfs_root *root,
2051					   void __user *argp)
2052{
2053	struct btrfs_ioctl_ino_lookup_args *args;
 
2054	int ret = 0;
2055
2056	args = memdup_user(argp, sizeof(*args));
2057	if (IS_ERR(args))
2058		return PTR_ERR(args);
2059
 
 
2060	/*
2061	 * Unprivileged query to obtain the containing subvolume root id. The
2062	 * path is reset so it's consistent with btrfs_search_path_in_tree.
2063	 */
2064	if (args->treeid == 0)
2065		args->treeid = root->root_key.objectid;
2066
2067	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2068		args->name[0] = 0;
2069		goto out;
2070	}
2071
2072	if (!capable(CAP_SYS_ADMIN)) {
2073		ret = -EPERM;
2074		goto out;
2075	}
2076
2077	ret = btrfs_search_path_in_tree(root->fs_info,
2078					args->treeid, args->objectid,
2079					args->name);
2080
2081out:
2082	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2083		ret = -EFAULT;
2084
2085	kfree(args);
2086	return ret;
2087}
2088
2089/*
2090 * Version of ino_lookup ioctl (unprivileged)
2091 *
2092 * The main differences from ino_lookup ioctl are:
2093 *
2094 *   1. Read + Exec permission will be checked using inode_permission() during
2095 *      path construction. -EACCES will be returned in case of failure.
2096 *   2. Path construction will be stopped at the inode number which corresponds
2097 *      to the fd with which this ioctl is called. If constructed path does not
2098 *      exist under fd's inode, -EACCES will be returned.
2099 *   3. The name of bottom subvolume is also searched and filled.
2100 */
2101static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2102{
2103	struct btrfs_ioctl_ino_lookup_user_args *args;
2104	struct inode *inode;
2105	int ret;
2106
2107	args = memdup_user(argp, sizeof(*args));
2108	if (IS_ERR(args))
2109		return PTR_ERR(args);
2110
2111	inode = file_inode(file);
2112
2113	if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2114	    BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2115		/*
2116		 * The subvolume does not exist under fd with which this is
2117		 * called
2118		 */
2119		kfree(args);
2120		return -EACCES;
2121	}
2122
2123	ret = btrfs_search_path_in_tree_user(file_mnt_idmap(file), inode, args);
2124
2125	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2126		ret = -EFAULT;
2127
2128	kfree(args);
2129	return ret;
2130}
2131
2132/* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2133static int btrfs_ioctl_get_subvol_info(struct inode *inode, void __user *argp)
2134{
2135	struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2136	struct btrfs_fs_info *fs_info;
2137	struct btrfs_root *root;
2138	struct btrfs_path *path;
2139	struct btrfs_key key;
2140	struct btrfs_root_item *root_item;
2141	struct btrfs_root_ref *rref;
2142	struct extent_buffer *leaf;
2143	unsigned long item_off;
2144	unsigned long item_len;
2145	int slot;
2146	int ret = 0;
2147
2148	path = btrfs_alloc_path();
2149	if (!path)
2150		return -ENOMEM;
2151
2152	subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2153	if (!subvol_info) {
2154		btrfs_free_path(path);
2155		return -ENOMEM;
2156	}
2157
2158	fs_info = BTRFS_I(inode)->root->fs_info;
2159
2160	/* Get root_item of inode's subvolume */
2161	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2162	root = btrfs_get_fs_root(fs_info, key.objectid, true);
2163	if (IS_ERR(root)) {
2164		ret = PTR_ERR(root);
2165		goto out_free;
2166	}
2167	root_item = &root->root_item;
2168
2169	subvol_info->treeid = key.objectid;
2170
2171	subvol_info->generation = btrfs_root_generation(root_item);
2172	subvol_info->flags = btrfs_root_flags(root_item);
2173
2174	memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2175	memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2176						    BTRFS_UUID_SIZE);
2177	memcpy(subvol_info->received_uuid, root_item->received_uuid,
2178						    BTRFS_UUID_SIZE);
2179
2180	subvol_info->ctransid = btrfs_root_ctransid(root_item);
2181	subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2182	subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2183
2184	subvol_info->otransid = btrfs_root_otransid(root_item);
2185	subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2186	subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2187
2188	subvol_info->stransid = btrfs_root_stransid(root_item);
2189	subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2190	subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2191
2192	subvol_info->rtransid = btrfs_root_rtransid(root_item);
2193	subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2194	subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2195
2196	if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2197		/* Search root tree for ROOT_BACKREF of this subvolume */
2198		key.type = BTRFS_ROOT_BACKREF_KEY;
2199		key.offset = 0;
2200		ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2201		if (ret < 0) {
2202			goto out;
2203		} else if (path->slots[0] >=
2204			   btrfs_header_nritems(path->nodes[0])) {
2205			ret = btrfs_next_leaf(fs_info->tree_root, path);
2206			if (ret < 0) {
2207				goto out;
2208			} else if (ret > 0) {
2209				ret = -EUCLEAN;
2210				goto out;
2211			}
2212		}
2213
2214		leaf = path->nodes[0];
2215		slot = path->slots[0];
2216		btrfs_item_key_to_cpu(leaf, &key, slot);
2217		if (key.objectid == subvol_info->treeid &&
2218		    key.type == BTRFS_ROOT_BACKREF_KEY) {
2219			subvol_info->parent_id = key.offset;
2220
2221			rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2222			subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2223
2224			item_off = btrfs_item_ptr_offset(leaf, slot)
2225					+ sizeof(struct btrfs_root_ref);
2226			item_len = btrfs_item_size(leaf, slot)
2227					- sizeof(struct btrfs_root_ref);
2228			read_extent_buffer(leaf, subvol_info->name,
2229					   item_off, item_len);
2230		} else {
2231			ret = -ENOENT;
2232			goto out;
2233		}
2234	}
2235
2236	btrfs_free_path(path);
2237	path = NULL;
2238	if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2239		ret = -EFAULT;
2240
2241out:
2242	btrfs_put_root(root);
2243out_free:
2244	btrfs_free_path(path);
2245	kfree(subvol_info);
2246	return ret;
2247}
2248
2249/*
2250 * Return ROOT_REF information of the subvolume containing this inode
2251 * except the subvolume name.
2252 */
2253static int btrfs_ioctl_get_subvol_rootref(struct btrfs_root *root,
2254					  void __user *argp)
2255{
2256	struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2257	struct btrfs_root_ref *rref;
2258	struct btrfs_path *path;
2259	struct btrfs_key key;
2260	struct extent_buffer *leaf;
2261	u64 objectid;
2262	int slot;
2263	int ret;
2264	u8 found;
2265
2266	path = btrfs_alloc_path();
2267	if (!path)
2268		return -ENOMEM;
2269
2270	rootrefs = memdup_user(argp, sizeof(*rootrefs));
2271	if (IS_ERR(rootrefs)) {
2272		btrfs_free_path(path);
2273		return PTR_ERR(rootrefs);
2274	}
2275
2276	objectid = root->root_key.objectid;
2277	key.objectid = objectid;
2278	key.type = BTRFS_ROOT_REF_KEY;
2279	key.offset = rootrefs->min_treeid;
2280	found = 0;
2281
2282	root = root->fs_info->tree_root;
2283	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2284	if (ret < 0) {
2285		goto out;
2286	} else if (path->slots[0] >=
2287		   btrfs_header_nritems(path->nodes[0])) {
2288		ret = btrfs_next_leaf(root, path);
2289		if (ret < 0) {
2290			goto out;
2291		} else if (ret > 0) {
2292			ret = -EUCLEAN;
2293			goto out;
2294		}
2295	}
2296	while (1) {
2297		leaf = path->nodes[0];
2298		slot = path->slots[0];
2299
2300		btrfs_item_key_to_cpu(leaf, &key, slot);
2301		if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2302			ret = 0;
2303			goto out;
2304		}
2305
2306		if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2307			ret = -EOVERFLOW;
2308			goto out;
2309		}
2310
2311		rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2312		rootrefs->rootref[found].treeid = key.offset;
2313		rootrefs->rootref[found].dirid =
2314				  btrfs_root_ref_dirid(leaf, rref);
2315		found++;
2316
2317		ret = btrfs_next_item(root, path);
2318		if (ret < 0) {
2319			goto out;
2320		} else if (ret > 0) {
2321			ret = -EUCLEAN;
2322			goto out;
2323		}
2324	}
2325
2326out:
2327	btrfs_free_path(path);
2328
2329	if (!ret || ret == -EOVERFLOW) {
2330		rootrefs->num_items = found;
2331		/* update min_treeid for next search */
2332		if (found)
2333			rootrefs->min_treeid =
2334				rootrefs->rootref[found - 1].treeid + 1;
2335		if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2336			ret = -EFAULT;
2337	}
2338
2339	kfree(rootrefs);
2340
2341	return ret;
2342}
2343
2344static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2345					     void __user *arg,
2346					     bool destroy_v2)
2347{
2348	struct dentry *parent = file->f_path.dentry;
2349	struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2350	struct dentry *dentry;
2351	struct inode *dir = d_inode(parent);
2352	struct inode *inode;
2353	struct btrfs_root *root = BTRFS_I(dir)->root;
2354	struct btrfs_root *dest = NULL;
2355	struct btrfs_ioctl_vol_args *vol_args = NULL;
2356	struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
2357	struct mnt_idmap *idmap = file_mnt_idmap(file);
2358	char *subvol_name, *subvol_name_ptr = NULL;
2359	int subvol_namelen;
 
 
2360	int err = 0;
2361	bool destroy_parent = false;
2362
2363	/* We don't support snapshots with extent tree v2 yet. */
2364	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
2365		btrfs_err(fs_info,
2366			  "extent tree v2 doesn't support snapshot deletion yet");
2367		return -EOPNOTSUPP;
2368	}
2369
2370	if (destroy_v2) {
2371		vol_args2 = memdup_user(arg, sizeof(*vol_args2));
2372		if (IS_ERR(vol_args2))
2373			return PTR_ERR(vol_args2);
2374
2375		if (vol_args2->flags & ~BTRFS_SUBVOL_DELETE_ARGS_MASK) {
2376			err = -EOPNOTSUPP;
2377			goto out;
2378		}
2379
2380		/*
2381		 * If SPEC_BY_ID is not set, we are looking for the subvolume by
2382		 * name, same as v1 currently does.
2383		 */
2384		if (!(vol_args2->flags & BTRFS_SUBVOL_SPEC_BY_ID)) {
2385			vol_args2->name[BTRFS_SUBVOL_NAME_MAX] = 0;
2386			subvol_name = vol_args2->name;
2387
2388			err = mnt_want_write_file(file);
2389			if (err)
2390				goto out;
2391		} else {
2392			struct inode *old_dir;
2393
2394			if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
2395				err = -EINVAL;
2396				goto out;
2397			}
2398
2399			err = mnt_want_write_file(file);
2400			if (err)
2401				goto out;
2402
2403			dentry = btrfs_get_dentry(fs_info->sb,
2404					BTRFS_FIRST_FREE_OBJECTID,
2405					vol_args2->subvolid, 0);
2406			if (IS_ERR(dentry)) {
2407				err = PTR_ERR(dentry);
2408				goto out_drop_write;
2409			}
2410
2411			/*
2412			 * Change the default parent since the subvolume being
2413			 * deleted can be outside of the current mount point.
2414			 */
2415			parent = btrfs_get_parent(dentry);
2416
2417			/*
2418			 * At this point dentry->d_name can point to '/' if the
2419			 * subvolume we want to destroy is outsite of the
2420			 * current mount point, so we need to release the
2421			 * current dentry and execute the lookup to return a new
2422			 * one with ->d_name pointing to the
2423			 * <mount point>/subvol_name.
2424			 */
2425			dput(dentry);
2426			if (IS_ERR(parent)) {
2427				err = PTR_ERR(parent);
2428				goto out_drop_write;
2429			}
2430			old_dir = dir;
2431			dir = d_inode(parent);
2432
2433			/*
2434			 * If v2 was used with SPEC_BY_ID, a new parent was
2435			 * allocated since the subvolume can be outside of the
2436			 * current mount point. Later on we need to release this
2437			 * new parent dentry.
2438			 */
2439			destroy_parent = true;
2440
2441			/*
2442			 * On idmapped mounts, deletion via subvolid is
2443			 * restricted to subvolumes that are immediate
2444			 * ancestors of the inode referenced by the file
2445			 * descriptor in the ioctl. Otherwise the idmapping
2446			 * could potentially be abused to delete subvolumes
2447			 * anywhere in the filesystem the user wouldn't be able
2448			 * to delete without an idmapped mount.
2449			 */
2450			if (old_dir != dir && idmap != &nop_mnt_idmap) {
2451				err = -EOPNOTSUPP;
2452				goto free_parent;
2453			}
2454
2455			subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
2456						fs_info, vol_args2->subvolid);
2457			if (IS_ERR(subvol_name_ptr)) {
2458				err = PTR_ERR(subvol_name_ptr);
2459				goto free_parent;
2460			}
2461			/* subvol_name_ptr is already nul terminated */
2462			subvol_name = (char *)kbasename(subvol_name_ptr);
2463		}
2464	} else {
2465		vol_args = memdup_user(arg, sizeof(*vol_args));
2466		if (IS_ERR(vol_args))
2467			return PTR_ERR(vol_args);
2468
2469		vol_args->name[BTRFS_PATH_NAME_MAX] = 0;
2470		subvol_name = vol_args->name;
2471
2472		err = mnt_want_write_file(file);
2473		if (err)
2474			goto out;
2475	}
2476
2477	subvol_namelen = strlen(subvol_name);
2478
2479	if (strchr(subvol_name, '/') ||
2480	    strncmp(subvol_name, "..", subvol_namelen) == 0) {
 
 
2481		err = -EINVAL;
2482		goto free_subvol_name;
2483	}
2484
2485	if (!S_ISDIR(dir->i_mode)) {
2486		err = -ENOTDIR;
2487		goto free_subvol_name;
2488	}
2489
2490	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 
2491	if (err == -EINTR)
2492		goto free_subvol_name;
2493	dentry = lookup_one(idmap, subvol_name, parent, subvol_namelen);
2494	if (IS_ERR(dentry)) {
2495		err = PTR_ERR(dentry);
2496		goto out_unlock_dir;
2497	}
2498
2499	if (d_really_is_negative(dentry)) {
2500		err = -ENOENT;
2501		goto out_dput;
2502	}
2503
2504	inode = d_inode(dentry);
2505	dest = BTRFS_I(inode)->root;
2506	if (!capable(CAP_SYS_ADMIN)) {
2507		/*
2508		 * Regular user.  Only allow this with a special mount
2509		 * option, when the user has write+exec access to the
2510		 * subvol root, and when rmdir(2) would have been
2511		 * allowed.
2512		 *
2513		 * Note that this is _not_ check that the subvol is
2514		 * empty or doesn't contain data that we wouldn't
2515		 * otherwise be able to delete.
2516		 *
2517		 * Users who want to delete empty subvols should try
2518		 * rmdir(2).
2519		 */
2520		err = -EPERM;
2521		if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2522			goto out_dput;
2523
2524		/*
2525		 * Do not allow deletion if the parent dir is the same
2526		 * as the dir to be deleted.  That means the ioctl
2527		 * must be called on the dentry referencing the root
2528		 * of the subvol, not a random directory contained
2529		 * within it.
2530		 */
2531		err = -EINVAL;
2532		if (root == dest)
2533			goto out_dput;
2534
2535		err = inode_permission(idmap, inode, MAY_WRITE | MAY_EXEC);
2536		if (err)
2537			goto out_dput;
2538	}
2539
2540	/* check if subvolume may be deleted by a user */
2541	err = btrfs_may_delete(idmap, dir, dentry, 1);
2542	if (err)
2543		goto out_dput;
2544
2545	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2546		err = -EINVAL;
2547		goto out_dput;
2548	}
2549
2550	btrfs_inode_lock(BTRFS_I(inode), 0);
2551	err = btrfs_delete_subvolume(BTRFS_I(dir), dentry);
2552	btrfs_inode_unlock(BTRFS_I(inode), 0);
2553	if (!err)
2554		d_delete_notify(dir, dentry);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2555
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2556out_dput:
2557	dput(dentry);
2558out_unlock_dir:
2559	btrfs_inode_unlock(BTRFS_I(dir), 0);
2560free_subvol_name:
2561	kfree(subvol_name_ptr);
2562free_parent:
2563	if (destroy_parent)
2564		dput(parent);
2565out_drop_write:
2566	mnt_drop_write_file(file);
2567out:
2568	kfree(vol_args2);
2569	kfree(vol_args);
2570	return err;
2571}
2572
2573static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2574{
2575	struct inode *inode = file_inode(file);
2576	struct btrfs_root *root = BTRFS_I(inode)->root;
2577	struct btrfs_ioctl_defrag_range_args range = {0};
2578	int ret;
2579
2580	ret = mnt_want_write_file(file);
2581	if (ret)
2582		return ret;
2583
2584	if (btrfs_root_readonly(root)) {
2585		ret = -EROFS;
2586		goto out;
2587	}
2588
2589	switch (inode->i_mode & S_IFMT) {
2590	case S_IFDIR:
2591		if (!capable(CAP_SYS_ADMIN)) {
2592			ret = -EPERM;
2593			goto out;
2594		}
2595		ret = btrfs_defrag_root(root);
 
 
 
2596		break;
2597	case S_IFREG:
2598		/*
2599		 * Note that this does not check the file descriptor for write
2600		 * access. This prevents defragmenting executables that are
2601		 * running and allows defrag on files open in read-only mode.
2602		 */
2603		if (!capable(CAP_SYS_ADMIN) &&
2604		    inode_permission(&nop_mnt_idmap, inode, MAY_WRITE)) {
2605			ret = -EPERM;
2606			goto out;
2607		}
2608
2609		if (argp) {
2610			if (copy_from_user(&range, argp, sizeof(range))) {
 
2611				ret = -EFAULT;
2612				goto out;
2613			}
2614			if (range.flags & ~BTRFS_DEFRAG_RANGE_FLAGS_SUPP) {
2615				ret = -EOPNOTSUPP;
2616				goto out;
2617			}
2618			/* compression requires us to start the IO */
2619			if ((range.flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2620				range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
2621				range.extent_thresh = (u32)-1;
2622			}
2623		} else {
2624			/* the rest are all set to zero by kzalloc */
2625			range.len = (u64)-1;
2626		}
2627		ret = btrfs_defrag_file(file_inode(file), &file->f_ra,
2628					&range, BTRFS_OLDEST_GENERATION, 0);
2629		if (ret > 0)
2630			ret = 0;
 
2631		break;
2632	default:
2633		ret = -EINVAL;
2634	}
2635out:
2636	mnt_drop_write_file(file);
2637	return ret;
2638}
2639
2640static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2641{
2642	struct btrfs_ioctl_vol_args *vol_args;
2643	bool restore_op = false;
2644	int ret;
2645
2646	if (!capable(CAP_SYS_ADMIN))
2647		return -EPERM;
2648
2649	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
2650		btrfs_err(fs_info, "device add not supported on extent tree v2 yet");
2651		return -EINVAL;
2652	}
2653
2654	if (fs_info->fs_devices->temp_fsid) {
2655		btrfs_err(fs_info,
2656			  "device add not supported on cloned temp-fsid mount");
2657		return -EINVAL;
2658	}
2659
2660	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD)) {
2661		if (!btrfs_exclop_start_try_lock(fs_info, BTRFS_EXCLOP_DEV_ADD))
2662			return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2663
2664		/*
2665		 * We can do the device add because we have a paused balanced,
2666		 * change the exclusive op type and remember we should bring
2667		 * back the paused balance
2668		 */
2669		fs_info->exclusive_operation = BTRFS_EXCLOP_DEV_ADD;
2670		btrfs_exclop_start_unlock(fs_info);
2671		restore_op = true;
2672	}
2673
 
2674	vol_args = memdup_user(arg, sizeof(*vol_args));
2675	if (IS_ERR(vol_args)) {
2676		ret = PTR_ERR(vol_args);
2677		goto out;
2678	}
2679
2680	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2681	ret = btrfs_init_new_device(fs_info, vol_args->name);
2682
2683	if (!ret)
2684		btrfs_info(fs_info, "disk added %s", vol_args->name);
2685
2686	kfree(vol_args);
2687out:
2688	if (restore_op)
2689		btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED);
2690	else
2691		btrfs_exclop_finish(fs_info);
2692	return ret;
2693}
2694
2695static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2696{
2697	BTRFS_DEV_LOOKUP_ARGS(args);
2698	struct inode *inode = file_inode(file);
2699	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2700	struct btrfs_ioctl_vol_args_v2 *vol_args;
2701	struct bdev_handle *bdev_handle = NULL;
2702	int ret;
2703	bool cancel = false;
2704
2705	if (!capable(CAP_SYS_ADMIN))
2706		return -EPERM;
2707
2708	vol_args = memdup_user(arg, sizeof(*vol_args));
2709	if (IS_ERR(vol_args))
2710		return PTR_ERR(vol_args);
2711
2712	if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
2713		ret = -EOPNOTSUPP;
2714		goto out;
2715	}
2716
2717	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
2718	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2719		args.devid = vol_args->devid;
2720	} else if (!strcmp("cancel", vol_args->name)) {
2721		cancel = true;
2722	} else {
2723		ret = btrfs_get_dev_args_from_path(fs_info, &args, vol_args->name);
2724		if (ret)
2725			goto out;
2726	}
2727
2728	ret = mnt_want_write_file(file);
2729	if (ret)
2730		goto out;
2731
2732	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
2733					   cancel);
2734	if (ret)
2735		goto err_drop;
2736
2737	/* Exclusive operation is now claimed */
2738	ret = btrfs_rm_device(fs_info, &args, &bdev_handle);
2739
2740	btrfs_exclop_finish(fs_info);
2741
2742	if (!ret) {
2743		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2744			btrfs_info(fs_info, "device deleted: id %llu",
2745					vol_args->devid);
2746		else
2747			btrfs_info(fs_info, "device deleted: %s",
2748					vol_args->name);
2749	}
2750err_drop:
2751	mnt_drop_write_file(file);
2752	if (bdev_handle)
2753		bdev_release(bdev_handle);
2754out:
2755	btrfs_put_dev_args_from_path(&args);
2756	kfree(vol_args);
2757	return ret;
2758}
2759
2760static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2761{
2762	BTRFS_DEV_LOOKUP_ARGS(args);
2763	struct inode *inode = file_inode(file);
2764	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2765	struct btrfs_ioctl_vol_args *vol_args;
2766	struct bdev_handle *bdev_handle = NULL;
2767	int ret;
2768	bool cancel = false;
2769
2770	if (!capable(CAP_SYS_ADMIN))
2771		return -EPERM;
2772
2773	vol_args = memdup_user(arg, sizeof(*vol_args));
2774	if (IS_ERR(vol_args))
2775		return PTR_ERR(vol_args);
2776
2777	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2778	if (!strcmp("cancel", vol_args->name)) {
2779		cancel = true;
2780	} else {
2781		ret = btrfs_get_dev_args_from_path(fs_info, &args, vol_args->name);
2782		if (ret)
2783			goto out;
2784	}
2785
2786	ret = mnt_want_write_file(file);
2787	if (ret)
 
2788		goto out;
2789
2790	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
2791					   cancel);
2792	if (ret == 0) {
2793		ret = btrfs_rm_device(fs_info, &args, &bdev_handle);
2794		if (!ret)
2795			btrfs_info(fs_info, "disk deleted %s", vol_args->name);
2796		btrfs_exclop_finish(fs_info);
2797	}
2798
2799	mnt_drop_write_file(file);
2800	if (bdev_handle)
2801		bdev_release(bdev_handle);
 
 
 
 
 
2802out:
2803	btrfs_put_dev_args_from_path(&args);
2804	kfree(vol_args);
 
 
2805	return ret;
2806}
2807
2808static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
2809				void __user *arg)
2810{
2811	struct btrfs_ioctl_fs_info_args *fi_args;
2812	struct btrfs_device *device;
2813	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2814	u64 flags_in;
2815	int ret = 0;
2816
2817	fi_args = memdup_user(arg, sizeof(*fi_args));
2818	if (IS_ERR(fi_args))
2819		return PTR_ERR(fi_args);
2820
2821	flags_in = fi_args->flags;
2822	memset(fi_args, 0, sizeof(*fi_args));
2823
2824	rcu_read_lock();
2825	fi_args->num_devices = fs_devices->num_devices;
 
2826
2827	list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
2828		if (device->devid > fi_args->max_id)
2829			fi_args->max_id = device->devid;
2830	}
2831	rcu_read_unlock();
2832
2833	memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
2834	fi_args->nodesize = fs_info->nodesize;
2835	fi_args->sectorsize = fs_info->sectorsize;
2836	fi_args->clone_alignment = fs_info->sectorsize;
2837
2838	if (flags_in & BTRFS_FS_INFO_FLAG_CSUM_INFO) {
2839		fi_args->csum_type = btrfs_super_csum_type(fs_info->super_copy);
2840		fi_args->csum_size = btrfs_super_csum_size(fs_info->super_copy);
2841		fi_args->flags |= BTRFS_FS_INFO_FLAG_CSUM_INFO;
2842	}
2843
2844	if (flags_in & BTRFS_FS_INFO_FLAG_GENERATION) {
2845		fi_args->generation = btrfs_get_fs_generation(fs_info);
2846		fi_args->flags |= BTRFS_FS_INFO_FLAG_GENERATION;
2847	}
2848
2849	if (flags_in & BTRFS_FS_INFO_FLAG_METADATA_UUID) {
2850		memcpy(&fi_args->metadata_uuid, fs_devices->metadata_uuid,
2851		       sizeof(fi_args->metadata_uuid));
2852		fi_args->flags |= BTRFS_FS_INFO_FLAG_METADATA_UUID;
2853	}
2854
2855	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2856		ret = -EFAULT;
2857
2858	kfree(fi_args);
2859	return ret;
2860}
2861
2862static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
2863				 void __user *arg)
2864{
2865	BTRFS_DEV_LOOKUP_ARGS(args);
2866	struct btrfs_ioctl_dev_info_args *di_args;
2867	struct btrfs_device *dev;
 
2868	int ret = 0;
 
2869
2870	di_args = memdup_user(arg, sizeof(*di_args));
2871	if (IS_ERR(di_args))
2872		return PTR_ERR(di_args);
2873
2874	args.devid = di_args->devid;
2875	if (!btrfs_is_empty_uuid(di_args->uuid))
2876		args.uuid = di_args->uuid;
 
 
 
2877
2878	rcu_read_lock();
2879	dev = btrfs_find_device(fs_info->fs_devices, &args);
2880	if (!dev) {
2881		ret = -ENODEV;
2882		goto out;
2883	}
2884
2885	di_args->devid = dev->devid;
2886	di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2887	di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2888	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2889	memcpy(di_args->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2890	if (dev->name)
2891		strscpy(di_args->path, btrfs_dev_name(dev), sizeof(di_args->path));
2892	else
 
 
 
 
 
2893		di_args->path[0] = '\0';
 
2894
2895out:
2896	rcu_read_unlock();
2897	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2898		ret = -EFAULT;
2899
2900	kfree(di_args);
2901	return ret;
2902}
2903
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2904static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2905{
2906	struct inode *inode = file_inode(file);
2907	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2908	struct btrfs_root *root = BTRFS_I(inode)->root;
2909	struct btrfs_root *new_root;
2910	struct btrfs_dir_item *di;
2911	struct btrfs_trans_handle *trans;
2912	struct btrfs_path *path = NULL;
 
2913	struct btrfs_disk_key disk_key;
2914	struct fscrypt_str name = FSTR_INIT("default", 7);
2915	u64 objectid = 0;
2916	u64 dir_id;
2917	int ret;
2918
2919	if (!capable(CAP_SYS_ADMIN))
2920		return -EPERM;
2921
2922	ret = mnt_want_write_file(file);
2923	if (ret)
2924		return ret;
2925
2926	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
2927		ret = -EFAULT;
2928		goto out;
2929	}
2930
2931	if (!objectid)
2932		objectid = BTRFS_FS_TREE_OBJECTID;
2933
2934	new_root = btrfs_get_fs_root(fs_info, objectid, true);
 
 
 
 
2935	if (IS_ERR(new_root)) {
2936		ret = PTR_ERR(new_root);
2937		goto out;
2938	}
2939	if (!is_fstree(new_root->root_key.objectid)) {
2940		ret = -ENOENT;
2941		goto out_free;
2942	}
2943
2944	path = btrfs_alloc_path();
2945	if (!path) {
2946		ret = -ENOMEM;
2947		goto out_free;
2948	}
 
2949
2950	trans = btrfs_start_transaction(root, 1);
2951	if (IS_ERR(trans)) {
 
2952		ret = PTR_ERR(trans);
2953		goto out_free;
2954	}
2955
2956	dir_id = btrfs_super_root_dir(fs_info->super_copy);
2957	di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
2958				   dir_id, &name, 1);
2959	if (IS_ERR_OR_NULL(di)) {
2960		btrfs_release_path(path);
2961		btrfs_end_transaction(trans);
2962		btrfs_err(fs_info,
2963			  "Umm, you don't have the default diritem, this isn't going to work");
2964		ret = -ENOENT;
2965		goto out_free;
2966	}
2967
2968	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2969	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2970	btrfs_mark_buffer_dirty(trans, path->nodes[0]);
2971	btrfs_release_path(path);
2972
2973	btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
2974	btrfs_end_transaction(trans);
2975out_free:
2976	btrfs_put_root(new_root);
2977	btrfs_free_path(path);
 
 
 
2978out:
2979	mnt_drop_write_file(file);
2980	return ret;
2981}
2982
2983static void get_block_group_info(struct list_head *groups_list,
2984				 struct btrfs_ioctl_space_info *space)
2985{
2986	struct btrfs_block_group *block_group;
2987
2988	space->total_bytes = 0;
2989	space->used_bytes = 0;
2990	space->flags = 0;
2991	list_for_each_entry(block_group, groups_list, list) {
2992		space->flags = block_group->flags;
2993		space->total_bytes += block_group->length;
2994		space->used_bytes += block_group->used;
 
2995	}
2996}
2997
2998static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
2999				   void __user *arg)
3000{
3001	struct btrfs_ioctl_space_args space_args = { 0 };
3002	struct btrfs_ioctl_space_info space;
3003	struct btrfs_ioctl_space_info *dest;
3004	struct btrfs_ioctl_space_info *dest_orig;
3005	struct btrfs_ioctl_space_info __user *user_dest;
3006	struct btrfs_space_info *info;
3007	static const u64 types[] = {
3008		BTRFS_BLOCK_GROUP_DATA,
3009		BTRFS_BLOCK_GROUP_SYSTEM,
3010		BTRFS_BLOCK_GROUP_METADATA,
3011		BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
3012	};
3013	int num_types = 4;
3014	int alloc_size;
3015	int ret = 0;
3016	u64 slot_count = 0;
3017	int i, c;
3018
3019	if (copy_from_user(&space_args,
3020			   (struct btrfs_ioctl_space_args __user *)arg,
3021			   sizeof(space_args)))
3022		return -EFAULT;
3023
3024	for (i = 0; i < num_types; i++) {
3025		struct btrfs_space_info *tmp;
3026
3027		info = NULL;
3028		list_for_each_entry(tmp, &fs_info->space_info, list) {
 
 
3029			if (tmp->flags == types[i]) {
3030				info = tmp;
3031				break;
3032			}
3033		}
 
3034
3035		if (!info)
3036			continue;
3037
3038		down_read(&info->groups_sem);
3039		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3040			if (!list_empty(&info->block_groups[c]))
3041				slot_count++;
3042		}
3043		up_read(&info->groups_sem);
3044	}
3045
3046	/*
3047	 * Global block reserve, exported as a space_info
3048	 */
3049	slot_count++;
3050
3051	/* space_slots == 0 means they are asking for a count */
3052	if (space_args.space_slots == 0) {
3053		space_args.total_spaces = slot_count;
3054		goto out;
3055	}
3056
3057	slot_count = min_t(u64, space_args.space_slots, slot_count);
3058
3059	alloc_size = sizeof(*dest) * slot_count;
3060
3061	/* we generally have at most 6 or so space infos, one for each raid
3062	 * level.  So, a whole page should be more than enough for everyone
3063	 */
3064	if (alloc_size > PAGE_SIZE)
3065		return -ENOMEM;
3066
3067	space_args.total_spaces = 0;
3068	dest = kmalloc(alloc_size, GFP_KERNEL);
3069	if (!dest)
3070		return -ENOMEM;
3071	dest_orig = dest;
3072
3073	/* now we have a buffer to copy into */
3074	for (i = 0; i < num_types; i++) {
3075		struct btrfs_space_info *tmp;
3076
3077		if (!slot_count)
3078			break;
3079
3080		info = NULL;
3081		list_for_each_entry(tmp, &fs_info->space_info, list) {
 
 
3082			if (tmp->flags == types[i]) {
3083				info = tmp;
3084				break;
3085			}
3086		}
 
3087
3088		if (!info)
3089			continue;
3090		down_read(&info->groups_sem);
3091		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3092			if (!list_empty(&info->block_groups[c])) {
3093				get_block_group_info(&info->block_groups[c],
3094						     &space);
3095				memcpy(dest, &space, sizeof(space));
3096				dest++;
3097				space_args.total_spaces++;
3098				slot_count--;
3099			}
3100			if (!slot_count)
3101				break;
3102		}
3103		up_read(&info->groups_sem);
3104	}
3105
3106	/*
3107	 * Add global block reserve
3108	 */
3109	if (slot_count) {
3110		struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3111
3112		spin_lock(&block_rsv->lock);
3113		space.total_bytes = block_rsv->size;
3114		space.used_bytes = block_rsv->size - block_rsv->reserved;
3115		spin_unlock(&block_rsv->lock);
3116		space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
3117		memcpy(dest, &space, sizeof(space));
3118		space_args.total_spaces++;
3119	}
3120
3121	user_dest = (struct btrfs_ioctl_space_info __user *)
3122		(arg + sizeof(struct btrfs_ioctl_space_args));
3123
3124	if (copy_to_user(user_dest, dest_orig, alloc_size))
3125		ret = -EFAULT;
3126
3127	kfree(dest_orig);
3128out:
3129	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3130		ret = -EFAULT;
3131
3132	return ret;
3133}
3134
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3135static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3136					    void __user *argp)
3137{
3138	struct btrfs_trans_handle *trans;
3139	u64 transid;
3140
3141	/*
3142	 * Start orphan cleanup here for the given root in case it hasn't been
3143	 * started already by other means. Errors are handled in the other
3144	 * functions during transaction commit.
3145	 */
3146	btrfs_orphan_cleanup(root);
3147
3148	trans = btrfs_attach_transaction_barrier(root);
3149	if (IS_ERR(trans)) {
3150		if (PTR_ERR(trans) != -ENOENT)
3151			return PTR_ERR(trans);
3152
3153		/* No running transaction, don't bother */
3154		transid = btrfs_get_last_trans_committed(root->fs_info);
3155		goto out;
3156	}
3157	transid = trans->transid;
3158	btrfs_commit_transaction_async(trans);
 
 
 
 
3159out:
3160	if (argp)
3161		if (copy_to_user(argp, &transid, sizeof(transid)))
3162			return -EFAULT;
3163	return 0;
3164}
3165
3166static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
3167					   void __user *argp)
3168{
3169	/* By default wait for the current transaction. */
3170	u64 transid = 0;
3171
3172	if (argp)
3173		if (copy_from_user(&transid, argp, sizeof(transid)))
3174			return -EFAULT;
3175
3176	return btrfs_wait_for_commit(fs_info, transid);
 
 
3177}
3178
3179static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3180{
3181	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
3182	struct btrfs_ioctl_scrub_args *sa;
3183	int ret;
3184
3185	if (!capable(CAP_SYS_ADMIN))
3186		return -EPERM;
3187
3188	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
3189		btrfs_err(fs_info, "scrub is not supported on extent tree v2 yet");
3190		return -EINVAL;
3191	}
3192
3193	sa = memdup_user(arg, sizeof(*sa));
3194	if (IS_ERR(sa))
3195		return PTR_ERR(sa);
3196
3197	if (sa->flags & ~BTRFS_SCRUB_SUPPORTED_FLAGS) {
3198		ret = -EOPNOTSUPP;
3199		goto out;
3200	}
3201
3202	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3203		ret = mnt_want_write_file(file);
3204		if (ret)
3205			goto out;
3206	}
3207
3208	ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
3209			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3210			      0);
3211
3212	/*
3213	 * Copy scrub args to user space even if btrfs_scrub_dev() returned an
3214	 * error. This is important as it allows user space to know how much
3215	 * progress scrub has done. For example, if scrub is canceled we get
3216	 * -ECANCELED from btrfs_scrub_dev() and return that error back to user
3217	 * space. Later user space can inspect the progress from the structure
3218	 * btrfs_ioctl_scrub_args and resume scrub from where it left off
3219	 * previously (btrfs-progs does this).
3220	 * If we fail to copy the btrfs_ioctl_scrub_args structure to user space
3221	 * then return -EFAULT to signal the structure was not copied or it may
3222	 * be corrupt and unreliable due to a partial copy.
3223	 */
3224	if (copy_to_user(arg, sa, sizeof(*sa)))
3225		ret = -EFAULT;
3226
3227	if (!(sa->flags & BTRFS_SCRUB_READONLY))
3228		mnt_drop_write_file(file);
3229out:
3230	kfree(sa);
3231	return ret;
3232}
3233
3234static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
3235{
3236	if (!capable(CAP_SYS_ADMIN))
3237		return -EPERM;
3238
3239	return btrfs_scrub_cancel(fs_info);
3240}
3241
3242static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
3243				       void __user *arg)
3244{
3245	struct btrfs_ioctl_scrub_args *sa;
3246	int ret;
3247
3248	if (!capable(CAP_SYS_ADMIN))
3249		return -EPERM;
3250
3251	sa = memdup_user(arg, sizeof(*sa));
3252	if (IS_ERR(sa))
3253		return PTR_ERR(sa);
3254
3255	ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
3256
3257	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3258		ret = -EFAULT;
3259
3260	kfree(sa);
3261	return ret;
3262}
3263
3264static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
3265				      void __user *arg)
3266{
3267	struct btrfs_ioctl_get_dev_stats *sa;
3268	int ret;
3269
3270	sa = memdup_user(arg, sizeof(*sa));
3271	if (IS_ERR(sa))
3272		return PTR_ERR(sa);
3273
3274	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3275		kfree(sa);
3276		return -EPERM;
3277	}
3278
3279	ret = btrfs_get_dev_stats(fs_info, sa);
3280
3281	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3282		ret = -EFAULT;
3283
3284	kfree(sa);
3285	return ret;
3286}
3287
3288static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
3289				    void __user *arg)
3290{
3291	struct btrfs_ioctl_dev_replace_args *p;
3292	int ret;
3293
3294	if (!capable(CAP_SYS_ADMIN))
3295		return -EPERM;
3296
3297	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
3298		btrfs_err(fs_info, "device replace not supported on extent tree v2 yet");
3299		return -EINVAL;
3300	}
3301
3302	p = memdup_user(arg, sizeof(*p));
3303	if (IS_ERR(p))
3304		return PTR_ERR(p);
3305
3306	switch (p->cmd) {
3307	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3308		if (sb_rdonly(fs_info->sb)) {
3309			ret = -EROFS;
3310			goto out;
3311		}
3312		if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) {
 
 
3313			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3314		} else {
3315			ret = btrfs_dev_replace_by_ioctl(fs_info, p);
3316			btrfs_exclop_finish(fs_info);
 
 
3317		}
3318		break;
3319	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3320		btrfs_dev_replace_status(fs_info, p);
3321		ret = 0;
3322		break;
3323	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3324		p->result = btrfs_dev_replace_cancel(fs_info);
3325		ret = 0;
3326		break;
3327	default:
3328		ret = -EINVAL;
3329		break;
3330	}
3331
3332	if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
3333		ret = -EFAULT;
3334out:
3335	kfree(p);
3336	return ret;
3337}
3338
3339static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3340{
3341	int ret = 0;
3342	int i;
3343	u64 rel_ptr;
3344	int size;
3345	struct btrfs_ioctl_ino_path_args *ipa = NULL;
3346	struct inode_fs_paths *ipath = NULL;
3347	struct btrfs_path *path;
3348
3349	if (!capable(CAP_DAC_READ_SEARCH))
3350		return -EPERM;
3351
3352	path = btrfs_alloc_path();
3353	if (!path) {
3354		ret = -ENOMEM;
3355		goto out;
3356	}
3357
3358	ipa = memdup_user(arg, sizeof(*ipa));
3359	if (IS_ERR(ipa)) {
3360		ret = PTR_ERR(ipa);
3361		ipa = NULL;
3362		goto out;
3363	}
3364
3365	size = min_t(u32, ipa->size, 4096);
3366	ipath = init_ipath(size, root, path);
3367	if (IS_ERR(ipath)) {
3368		ret = PTR_ERR(ipath);
3369		ipath = NULL;
3370		goto out;
3371	}
3372
3373	ret = paths_from_inode(ipa->inum, ipath);
3374	if (ret < 0)
3375		goto out;
3376
3377	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3378		rel_ptr = ipath->fspath->val[i] -
3379			  (u64)(unsigned long)ipath->fspath->val;
3380		ipath->fspath->val[i] = rel_ptr;
3381	}
3382
3383	btrfs_free_path(path);
3384	path = NULL;
3385	ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
3386			   ipath->fspath, size);
3387	if (ret) {
3388		ret = -EFAULT;
3389		goto out;
3390	}
3391
3392out:
3393	btrfs_free_path(path);
3394	free_ipath(ipath);
3395	kfree(ipa);
3396
3397	return ret;
3398}
3399
3400static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
3401					void __user *arg, int version)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3402{
3403	int ret = 0;
3404	int size;
3405	struct btrfs_ioctl_logical_ino_args *loi;
3406	struct btrfs_data_container *inodes = NULL;
3407	struct btrfs_path *path = NULL;
3408	bool ignore_offset;
3409
3410	if (!capable(CAP_SYS_ADMIN))
3411		return -EPERM;
3412
3413	loi = memdup_user(arg, sizeof(*loi));
3414	if (IS_ERR(loi))
3415		return PTR_ERR(loi);
 
 
 
3416
3417	if (version == 1) {
3418		ignore_offset = false;
3419		size = min_t(u32, loi->size, SZ_64K);
3420	} else {
3421		/* All reserved bits must be 0 for now */
3422		if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
3423			ret = -EINVAL;
3424			goto out_loi;
3425		}
3426		/* Only accept flags we have defined so far */
3427		if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
3428			ret = -EINVAL;
3429			goto out_loi;
3430		}
3431		ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
3432		size = min_t(u32, loi->size, SZ_16M);
3433	}
3434
 
3435	inodes = init_data_container(size);
3436	if (IS_ERR(inodes)) {
3437		ret = PTR_ERR(inodes);
3438		goto out_loi;
3439	}
3440
3441	path = btrfs_alloc_path();
3442	if (!path) {
3443		ret = -ENOMEM;
3444		goto out;
3445	}
3446	ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
3447					  inodes, ignore_offset);
3448	btrfs_free_path(path);
3449	if (ret == -EINVAL)
3450		ret = -ENOENT;
3451	if (ret < 0)
3452		goto out;
3453
3454	ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
3455			   size);
3456	if (ret)
3457		ret = -EFAULT;
3458
3459out:
3460	kvfree(inodes);
3461out_loi:
3462	kfree(loi);
3463
3464	return ret;
3465}
3466
3467void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
3468			       struct btrfs_ioctl_balance_args *bargs)
3469{
3470	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3471
3472	bargs->flags = bctl->flags;
3473
3474	if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
3475		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3476	if (atomic_read(&fs_info->balance_pause_req))
3477		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3478	if (atomic_read(&fs_info->balance_cancel_req))
3479		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3480
3481	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3482	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3483	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3484
3485	spin_lock(&fs_info->balance_lock);
3486	memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3487	spin_unlock(&fs_info->balance_lock);
3488}
3489
3490/*
3491 * Try to acquire fs_info::balance_mutex as well as set BTRFS_EXLCOP_BALANCE as
3492 * required.
3493 *
3494 * @fs_info:       the filesystem
3495 * @excl_acquired: ptr to boolean value which is set to false in case balance
3496 *                 is being resumed
3497 *
3498 * Return 0 on success in which case both fs_info::balance is acquired as well
3499 * as exclusive ops are blocked. In case of failure return an error code.
3500 */
3501static int btrfs_try_lock_balance(struct btrfs_fs_info *fs_info, bool *excl_acquired)
3502{
3503	int ret;
3504
3505	/*
3506	 * Exclusive operation is locked. Three possibilities:
3507	 *   (1) some other op is running
3508	 *   (2) balance is running
3509	 *   (3) balance is paused -- special case (think resume)
3510	 */
3511	while (1) {
3512		if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
3513			*excl_acquired = true;
3514			mutex_lock(&fs_info->balance_mutex);
3515			return 0;
3516		}
3517
3518		mutex_lock(&fs_info->balance_mutex);
3519		if (fs_info->balance_ctl) {
3520			/* This is either (2) or (3) */
3521			if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
3522				/* This is (2) */
3523				ret = -EINPROGRESS;
3524				goto out_failure;
3525
3526			} else {
3527				mutex_unlock(&fs_info->balance_mutex);
3528				/*
3529				 * Lock released to allow other waiters to
3530				 * continue, we'll reexamine the status again.
3531				 */
3532				mutex_lock(&fs_info->balance_mutex);
3533
3534				if (fs_info->balance_ctl &&
3535				    !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
3536					/* This is (3) */
3537					*excl_acquired = false;
3538					return 0;
3539				}
3540			}
3541		} else {
3542			/* This is (1) */
3543			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3544			goto out_failure;
3545		}
3546
3547		mutex_unlock(&fs_info->balance_mutex);
3548	}
3549
3550out_failure:
3551	mutex_unlock(&fs_info->balance_mutex);
3552	*excl_acquired = false;
3553	return ret;
3554}
3555
3556static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3557{
3558	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3559	struct btrfs_fs_info *fs_info = root->fs_info;
3560	struct btrfs_ioctl_balance_args *bargs;
3561	struct btrfs_balance_control *bctl;
3562	bool need_unlock = true;
3563	int ret;
3564
3565	if (!capable(CAP_SYS_ADMIN))
3566		return -EPERM;
3567
3568	ret = mnt_want_write_file(file);
3569	if (ret)
3570		return ret;
3571
3572	bargs = memdup_user(arg, sizeof(*bargs));
3573	if (IS_ERR(bargs)) {
3574		ret = PTR_ERR(bargs);
3575		bargs = NULL;
3576		goto out;
 
3577	}
3578
3579	ret = btrfs_try_lock_balance(fs_info, &need_unlock);
3580	if (ret)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3581		goto out;
 
3582
3583	lockdep_assert_held(&fs_info->balance_mutex);
 
3584
3585	if (bargs->flags & BTRFS_BALANCE_RESUME) {
3586		if (!fs_info->balance_ctl) {
3587			ret = -ENOTCONN;
 
3588			goto out_unlock;
3589		}
3590
3591		bctl = fs_info->balance_ctl;
3592		spin_lock(&fs_info->balance_lock);
3593		bctl->flags |= BTRFS_BALANCE_RESUME;
3594		spin_unlock(&fs_info->balance_lock);
3595		btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE);
3596
3597		goto do_balance;
3598	}
 
 
3599
3600	if (bargs->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
3601		ret = -EINVAL;
3602		goto out_unlock;
 
3603	}
3604
3605	if (fs_info->balance_ctl) {
3606		ret = -EINPROGRESS;
3607		goto out_unlock;
3608	}
3609
3610	bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
3611	if (!bctl) {
3612		ret = -ENOMEM;
3613		goto out_unlock;
 
 
 
 
 
 
 
 
 
 
 
 
3614	}
3615
3616	memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3617	memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3618	memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
 
3619
3620	bctl->flags = bargs->flags;
3621do_balance:
3622	/*
3623	 * Ownership of bctl and exclusive operation goes to btrfs_balance.
3624	 * bctl is freed in reset_balance_state, or, if restriper was paused
3625	 * all the way until unmount, in free_fs_info.  The flag should be
3626	 * cleared after reset_balance_state.
 
3627	 */
3628	need_unlock = false;
3629
3630	ret = btrfs_balance(fs_info, bctl, bargs);
3631	bctl = NULL;
3632
3633	if (ret == 0 || ret == -ECANCELED) {
3634		if (copy_to_user(arg, bargs, sizeof(*bargs)))
3635			ret = -EFAULT;
3636	}
3637
 
3638	kfree(bctl);
 
 
3639out_unlock:
3640	mutex_unlock(&fs_info->balance_mutex);
 
3641	if (need_unlock)
3642		btrfs_exclop_finish(fs_info);
3643out:
3644	mnt_drop_write_file(file);
3645	kfree(bargs);
3646	return ret;
3647}
3648
3649static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
3650{
3651	if (!capable(CAP_SYS_ADMIN))
3652		return -EPERM;
3653
3654	switch (cmd) {
3655	case BTRFS_BALANCE_CTL_PAUSE:
3656		return btrfs_pause_balance(fs_info);
3657	case BTRFS_BALANCE_CTL_CANCEL:
3658		return btrfs_cancel_balance(fs_info);
3659	}
3660
3661	return -EINVAL;
3662}
3663
3664static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
3665					 void __user *arg)
3666{
 
3667	struct btrfs_ioctl_balance_args *bargs;
3668	int ret = 0;
3669
3670	if (!capable(CAP_SYS_ADMIN))
3671		return -EPERM;
3672
3673	mutex_lock(&fs_info->balance_mutex);
3674	if (!fs_info->balance_ctl) {
3675		ret = -ENOTCONN;
3676		goto out;
3677	}
3678
3679	bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
3680	if (!bargs) {
3681		ret = -ENOMEM;
3682		goto out;
3683	}
3684
3685	btrfs_update_ioctl_balance_args(fs_info, bargs);
3686
3687	if (copy_to_user(arg, bargs, sizeof(*bargs)))
3688		ret = -EFAULT;
3689
3690	kfree(bargs);
3691out:
3692	mutex_unlock(&fs_info->balance_mutex);
3693	return ret;
3694}
3695
3696static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
3697{
3698	struct inode *inode = file_inode(file);
3699	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3700	struct btrfs_ioctl_quota_ctl_args *sa;
 
3701	int ret;
 
3702
3703	if (!capable(CAP_SYS_ADMIN))
3704		return -EPERM;
3705
3706	ret = mnt_want_write_file(file);
3707	if (ret)
3708		return ret;
3709
3710	sa = memdup_user(arg, sizeof(*sa));
3711	if (IS_ERR(sa)) {
3712		ret = PTR_ERR(sa);
3713		goto drop_write;
3714	}
3715
3716	down_write(&fs_info->subvol_sem);
 
 
 
 
 
3717
3718	switch (sa->cmd) {
3719	case BTRFS_QUOTA_CTL_ENABLE:
3720	case BTRFS_QUOTA_CTL_ENABLE_SIMPLE_QUOTA:
3721		ret = btrfs_quota_enable(fs_info, sa);
3722		break;
3723	case BTRFS_QUOTA_CTL_DISABLE:
3724		ret = btrfs_quota_disable(fs_info);
3725		break;
3726	default:
3727		ret = -EINVAL;
3728		break;
3729	}
3730
 
 
 
 
3731	kfree(sa);
3732	up_write(&fs_info->subvol_sem);
3733drop_write:
3734	mnt_drop_write_file(file);
3735	return ret;
3736}
3737
3738static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
3739{
3740	struct inode *inode = file_inode(file);
3741	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3742	struct btrfs_root *root = BTRFS_I(inode)->root;
3743	struct btrfs_ioctl_qgroup_assign_args *sa;
3744	struct btrfs_trans_handle *trans;
3745	int ret;
3746	int err;
3747
3748	if (!capable(CAP_SYS_ADMIN))
3749		return -EPERM;
3750
3751	ret = mnt_want_write_file(file);
3752	if (ret)
3753		return ret;
3754
3755	sa = memdup_user(arg, sizeof(*sa));
3756	if (IS_ERR(sa)) {
3757		ret = PTR_ERR(sa);
3758		goto drop_write;
3759	}
3760
3761	trans = btrfs_join_transaction(root);
3762	if (IS_ERR(trans)) {
3763		ret = PTR_ERR(trans);
3764		goto out;
3765	}
3766
 
3767	if (sa->assign) {
3768		ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
 
3769	} else {
3770		ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
 
3771	}
3772
3773	/* update qgroup status and info */
3774	mutex_lock(&fs_info->qgroup_ioctl_lock);
3775	err = btrfs_run_qgroups(trans);
3776	mutex_unlock(&fs_info->qgroup_ioctl_lock);
3777	if (err < 0)
3778		btrfs_handle_fs_error(fs_info, err,
3779				      "failed to update qgroup status and info");
3780	err = btrfs_end_transaction(trans);
3781	if (err && !ret)
3782		ret = err;
3783
3784out:
3785	kfree(sa);
3786drop_write:
3787	mnt_drop_write_file(file);
3788	return ret;
3789}
3790
3791static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
3792{
3793	struct inode *inode = file_inode(file);
3794	struct btrfs_root *root = BTRFS_I(inode)->root;
3795	struct btrfs_ioctl_qgroup_create_args *sa;
3796	struct btrfs_trans_handle *trans;
3797	int ret;
3798	int err;
3799
3800	if (!capable(CAP_SYS_ADMIN))
3801		return -EPERM;
3802
3803	ret = mnt_want_write_file(file);
3804	if (ret)
3805		return ret;
3806
3807	sa = memdup_user(arg, sizeof(*sa));
3808	if (IS_ERR(sa)) {
3809		ret = PTR_ERR(sa);
3810		goto drop_write;
3811	}
3812
3813	if (!sa->qgroupid) {
3814		ret = -EINVAL;
3815		goto out;
3816	}
3817
3818	if (sa->create && is_fstree(sa->qgroupid)) {
3819		ret = -EINVAL;
3820		goto out;
3821	}
3822
3823	trans = btrfs_join_transaction(root);
3824	if (IS_ERR(trans)) {
3825		ret = PTR_ERR(trans);
3826		goto out;
3827	}
3828
 
3829	if (sa->create) {
3830		ret = btrfs_create_qgroup(trans, sa->qgroupid);
3831	} else {
3832		ret = btrfs_remove_qgroup(trans, sa->qgroupid);
3833	}
3834
3835	err = btrfs_end_transaction(trans);
3836	if (err && !ret)
3837		ret = err;
3838
3839out:
3840	kfree(sa);
3841drop_write:
3842	mnt_drop_write_file(file);
3843	return ret;
3844}
3845
3846static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
3847{
3848	struct inode *inode = file_inode(file);
3849	struct btrfs_root *root = BTRFS_I(inode)->root;
3850	struct btrfs_ioctl_qgroup_limit_args *sa;
3851	struct btrfs_trans_handle *trans;
3852	int ret;
3853	int err;
3854	u64 qgroupid;
3855
3856	if (!capable(CAP_SYS_ADMIN))
3857		return -EPERM;
3858
3859	ret = mnt_want_write_file(file);
3860	if (ret)
3861		return ret;
3862
3863	sa = memdup_user(arg, sizeof(*sa));
3864	if (IS_ERR(sa)) {
3865		ret = PTR_ERR(sa);
3866		goto drop_write;
3867	}
3868
3869	trans = btrfs_join_transaction(root);
3870	if (IS_ERR(trans)) {
3871		ret = PTR_ERR(trans);
3872		goto out;
3873	}
3874
3875	qgroupid = sa->qgroupid;
3876	if (!qgroupid) {
3877		/* take the current subvol as qgroup */
3878		qgroupid = root->root_key.objectid;
3879	}
3880
3881	ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
 
3882
3883	err = btrfs_end_transaction(trans);
3884	if (err && !ret)
3885		ret = err;
3886
3887out:
3888	kfree(sa);
3889drop_write:
3890	mnt_drop_write_file(file);
3891	return ret;
3892}
3893
3894static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
3895{
3896	struct inode *inode = file_inode(file);
3897	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3898	struct btrfs_ioctl_quota_rescan_args *qsa;
3899	int ret;
3900
3901	if (!capable(CAP_SYS_ADMIN))
3902		return -EPERM;
3903
3904	ret = mnt_want_write_file(file);
3905	if (ret)
3906		return ret;
3907
3908	qsa = memdup_user(arg, sizeof(*qsa));
3909	if (IS_ERR(qsa)) {
3910		ret = PTR_ERR(qsa);
3911		goto drop_write;
3912	}
3913
3914	if (qsa->flags) {
3915		ret = -EINVAL;
3916		goto out;
3917	}
3918
3919	ret = btrfs_qgroup_rescan(fs_info);
3920
3921out:
3922	kfree(qsa);
3923drop_write:
3924	mnt_drop_write_file(file);
3925	return ret;
3926}
3927
3928static long btrfs_ioctl_quota_rescan_status(struct btrfs_fs_info *fs_info,
3929						void __user *arg)
3930{
3931	struct btrfs_ioctl_quota_rescan_args qsa = {0};
 
 
3932
3933	if (!capable(CAP_SYS_ADMIN))
3934		return -EPERM;
3935
3936	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3937		qsa.flags = 1;
3938		qsa.progress = fs_info->qgroup_rescan_progress.objectid;
 
 
 
 
3939	}
3940
3941	if (copy_to_user(arg, &qsa, sizeof(qsa)))
3942		return -EFAULT;
3943
3944	return 0;
 
3945}
3946
3947static long btrfs_ioctl_quota_rescan_wait(struct btrfs_fs_info *fs_info,
3948						void __user *arg)
3949{
 
 
3950	if (!capable(CAP_SYS_ADMIN))
3951		return -EPERM;
3952
3953	return btrfs_qgroup_wait_for_completion(fs_info, true);
3954}
3955
3956static long _btrfs_ioctl_set_received_subvol(struct file *file,
3957					    struct mnt_idmap *idmap,
3958					    struct btrfs_ioctl_received_subvol_args *sa)
3959{
3960	struct inode *inode = file_inode(file);
3961	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3962	struct btrfs_root *root = BTRFS_I(inode)->root;
3963	struct btrfs_root_item *root_item = &root->root_item;
3964	struct btrfs_trans_handle *trans;
3965	struct timespec64 ct = current_time(inode);
3966	int ret = 0;
3967	int received_uuid_changed;
3968
3969	if (!inode_owner_or_capable(idmap, inode))
3970		return -EPERM;
3971
3972	ret = mnt_want_write_file(file);
3973	if (ret < 0)
3974		return ret;
3975
3976	down_write(&fs_info->subvol_sem);
3977
3978	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
3979		ret = -EINVAL;
3980		goto out;
3981	}
3982
3983	if (btrfs_root_readonly(root)) {
3984		ret = -EROFS;
3985		goto out;
3986	}
3987
3988	/*
3989	 * 1 - root item
3990	 * 2 - uuid items (received uuid + subvol uuid)
3991	 */
3992	trans = btrfs_start_transaction(root, 3);
3993	if (IS_ERR(trans)) {
3994		ret = PTR_ERR(trans);
3995		trans = NULL;
3996		goto out;
3997	}
3998
3999	sa->rtransid = trans->transid;
4000	sa->rtime.sec = ct.tv_sec;
4001	sa->rtime.nsec = ct.tv_nsec;
4002
4003	received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
4004				       BTRFS_UUID_SIZE);
4005	if (received_uuid_changed &&
4006	    !btrfs_is_empty_uuid(root_item->received_uuid)) {
4007		ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
4008					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4009					  root->root_key.objectid);
4010		if (ret && ret != -ENOENT) {
4011		        btrfs_abort_transaction(trans, ret);
4012		        btrfs_end_transaction(trans);
4013		        goto out;
4014		}
4015	}
4016	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
4017	btrfs_set_root_stransid(root_item, sa->stransid);
4018	btrfs_set_root_rtransid(root_item, sa->rtransid);
4019	btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
4020	btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
4021	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
4022	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
4023
4024	ret = btrfs_update_root(trans, fs_info->tree_root,
4025				&root->root_key, &root->root_item);
4026	if (ret < 0) {
4027		btrfs_end_transaction(trans);
4028		goto out;
4029	}
4030	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
4031		ret = btrfs_uuid_tree_add(trans, sa->uuid,
 
4032					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4033					  root->root_key.objectid);
4034		if (ret < 0 && ret != -EEXIST) {
4035			btrfs_abort_transaction(trans, ret);
4036			btrfs_end_transaction(trans);
4037			goto out;
4038		}
4039	}
4040	ret = btrfs_commit_transaction(trans);
 
 
 
 
 
4041out:
4042	up_write(&fs_info->subvol_sem);
4043	mnt_drop_write_file(file);
4044	return ret;
4045}
4046
4047#ifdef CONFIG_64BIT
4048static long btrfs_ioctl_set_received_subvol_32(struct file *file,
4049						void __user *arg)
4050{
4051	struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
4052	struct btrfs_ioctl_received_subvol_args *args64 = NULL;
4053	int ret = 0;
4054
4055	args32 = memdup_user(arg, sizeof(*args32));
4056	if (IS_ERR(args32))
4057		return PTR_ERR(args32);
 
 
 
4058
4059	args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
4060	if (!args64) {
4061		ret = -ENOMEM;
4062		goto out;
4063	}
4064
4065	memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
4066	args64->stransid = args32->stransid;
4067	args64->rtransid = args32->rtransid;
4068	args64->stime.sec = args32->stime.sec;
4069	args64->stime.nsec = args32->stime.nsec;
4070	args64->rtime.sec = args32->rtime.sec;
4071	args64->rtime.nsec = args32->rtime.nsec;
4072	args64->flags = args32->flags;
4073
4074	ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_idmap(file), args64);
4075	if (ret)
4076		goto out;
4077
4078	memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
4079	args32->stransid = args64->stransid;
4080	args32->rtransid = args64->rtransid;
4081	args32->stime.sec = args64->stime.sec;
4082	args32->stime.nsec = args64->stime.nsec;
4083	args32->rtime.sec = args64->rtime.sec;
4084	args32->rtime.nsec = args64->rtime.nsec;
4085	args32->flags = args64->flags;
4086
4087	ret = copy_to_user(arg, args32, sizeof(*args32));
4088	if (ret)
4089		ret = -EFAULT;
4090
4091out:
4092	kfree(args32);
4093	kfree(args64);
4094	return ret;
4095}
4096#endif
4097
4098static long btrfs_ioctl_set_received_subvol(struct file *file,
4099					    void __user *arg)
4100{
4101	struct btrfs_ioctl_received_subvol_args *sa = NULL;
4102	int ret = 0;
4103
4104	sa = memdup_user(arg, sizeof(*sa));
4105	if (IS_ERR(sa))
4106		return PTR_ERR(sa);
 
 
 
4107
4108	ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_idmap(file), sa);
4109
4110	if (ret)
4111		goto out;
4112
4113	ret = copy_to_user(arg, sa, sizeof(*sa));
4114	if (ret)
4115		ret = -EFAULT;
4116
4117out:
4118	kfree(sa);
4119	return ret;
4120}
4121
4122static int btrfs_ioctl_get_fslabel(struct btrfs_fs_info *fs_info,
4123					void __user *arg)
4124{
 
4125	size_t len;
4126	int ret;
4127	char label[BTRFS_LABEL_SIZE];
4128
4129	spin_lock(&fs_info->super_lock);
4130	memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4131	spin_unlock(&fs_info->super_lock);
4132
4133	len = strnlen(label, BTRFS_LABEL_SIZE);
4134
4135	if (len == BTRFS_LABEL_SIZE) {
4136		btrfs_warn(fs_info,
4137			   "label is too long, return the first %zu bytes",
4138			   --len);
4139	}
4140
4141	ret = copy_to_user(arg, label, len);
4142
4143	return ret ? -EFAULT : 0;
4144}
4145
4146static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4147{
4148	struct inode *inode = file_inode(file);
4149	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4150	struct btrfs_root *root = BTRFS_I(inode)->root;
4151	struct btrfs_super_block *super_block = fs_info->super_copy;
4152	struct btrfs_trans_handle *trans;
4153	char label[BTRFS_LABEL_SIZE];
4154	int ret;
4155
4156	if (!capable(CAP_SYS_ADMIN))
4157		return -EPERM;
4158
4159	if (copy_from_user(label, arg, sizeof(label)))
4160		return -EFAULT;
4161
4162	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4163		btrfs_err(fs_info,
4164			  "unable to set label with more than %d bytes",
4165			  BTRFS_LABEL_SIZE - 1);
4166		return -EINVAL;
4167	}
4168
4169	ret = mnt_want_write_file(file);
4170	if (ret)
4171		return ret;
4172
4173	trans = btrfs_start_transaction(root, 0);
4174	if (IS_ERR(trans)) {
4175		ret = PTR_ERR(trans);
4176		goto out_unlock;
4177	}
4178
4179	spin_lock(&fs_info->super_lock);
4180	strcpy(super_block->label, label);
4181	spin_unlock(&fs_info->super_lock);
4182	ret = btrfs_commit_transaction(trans);
4183
4184out_unlock:
4185	mnt_drop_write_file(file);
4186	return ret;
4187}
4188
4189#define INIT_FEATURE_FLAGS(suffix) \
4190	{ .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
4191	  .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
4192	  .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
4193
4194int btrfs_ioctl_get_supported_features(void __user *arg)
4195{
4196	static const struct btrfs_ioctl_feature_flags features[3] = {
4197		INIT_FEATURE_FLAGS(SUPP),
4198		INIT_FEATURE_FLAGS(SAFE_SET),
4199		INIT_FEATURE_FLAGS(SAFE_CLEAR)
4200	};
4201
4202	if (copy_to_user(arg, &features, sizeof(features)))
4203		return -EFAULT;
4204
4205	return 0;
4206}
4207
4208static int btrfs_ioctl_get_features(struct btrfs_fs_info *fs_info,
4209					void __user *arg)
4210{
4211	struct btrfs_super_block *super_block = fs_info->super_copy;
 
4212	struct btrfs_ioctl_feature_flags features;
4213
4214	features.compat_flags = btrfs_super_compat_flags(super_block);
4215	features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
4216	features.incompat_flags = btrfs_super_incompat_flags(super_block);
4217
4218	if (copy_to_user(arg, &features, sizeof(features)))
4219		return -EFAULT;
4220
4221	return 0;
4222}
4223
4224static int check_feature_bits(struct btrfs_fs_info *fs_info,
4225			      enum btrfs_feature_set set,
4226			      u64 change_mask, u64 flags, u64 supported_flags,
4227			      u64 safe_set, u64 safe_clear)
4228{
4229	const char *type = btrfs_feature_set_name(set);
4230	char *names;
4231	u64 disallowed, unsupported;
4232	u64 set_mask = flags & change_mask;
4233	u64 clear_mask = ~flags & change_mask;
4234
4235	unsupported = set_mask & ~supported_flags;
4236	if (unsupported) {
4237		names = btrfs_printable_features(set, unsupported);
4238		if (names) {
4239			btrfs_warn(fs_info,
4240				   "this kernel does not support the %s feature bit%s",
4241				   names, strchr(names, ',') ? "s" : "");
4242			kfree(names);
4243		} else
4244			btrfs_warn(fs_info,
4245				   "this kernel does not support %s bits 0x%llx",
4246				   type, unsupported);
4247		return -EOPNOTSUPP;
4248	}
4249
4250	disallowed = set_mask & ~safe_set;
4251	if (disallowed) {
4252		names = btrfs_printable_features(set, disallowed);
4253		if (names) {
4254			btrfs_warn(fs_info,
4255				   "can't set the %s feature bit%s while mounted",
4256				   names, strchr(names, ',') ? "s" : "");
4257			kfree(names);
4258		} else
4259			btrfs_warn(fs_info,
4260				   "can't set %s bits 0x%llx while mounted",
4261				   type, disallowed);
4262		return -EPERM;
4263	}
4264
4265	disallowed = clear_mask & ~safe_clear;
4266	if (disallowed) {
4267		names = btrfs_printable_features(set, disallowed);
4268		if (names) {
4269			btrfs_warn(fs_info,
4270				   "can't clear the %s feature bit%s while mounted",
4271				   names, strchr(names, ',') ? "s" : "");
4272			kfree(names);
4273		} else
4274			btrfs_warn(fs_info,
4275				   "can't clear %s bits 0x%llx while mounted",
4276				   type, disallowed);
4277		return -EPERM;
4278	}
4279
4280	return 0;
4281}
4282
4283#define check_feature(fs_info, change_mask, flags, mask_base)	\
4284check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,	\
4285		   BTRFS_FEATURE_ ## mask_base ## _SUPP,	\
4286		   BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,	\
4287		   BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
4288
4289static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
4290{
4291	struct inode *inode = file_inode(file);
4292	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4293	struct btrfs_root *root = BTRFS_I(inode)->root;
4294	struct btrfs_super_block *super_block = fs_info->super_copy;
4295	struct btrfs_ioctl_feature_flags flags[2];
4296	struct btrfs_trans_handle *trans;
4297	u64 newflags;
4298	int ret;
4299
4300	if (!capable(CAP_SYS_ADMIN))
4301		return -EPERM;
4302
4303	if (copy_from_user(flags, arg, sizeof(flags)))
4304		return -EFAULT;
4305
4306	/* Nothing to do */
4307	if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
4308	    !flags[0].incompat_flags)
4309		return 0;
4310
4311	ret = check_feature(fs_info, flags[0].compat_flags,
4312			    flags[1].compat_flags, COMPAT);
4313	if (ret)
4314		return ret;
4315
4316	ret = check_feature(fs_info, flags[0].compat_ro_flags,
4317			    flags[1].compat_ro_flags, COMPAT_RO);
4318	if (ret)
4319		return ret;
4320
4321	ret = check_feature(fs_info, flags[0].incompat_flags,
4322			    flags[1].incompat_flags, INCOMPAT);
4323	if (ret)
4324		return ret;
4325
4326	ret = mnt_want_write_file(file);
4327	if (ret)
4328		return ret;
4329
4330	trans = btrfs_start_transaction(root, 0);
4331	if (IS_ERR(trans)) {
4332		ret = PTR_ERR(trans);
4333		goto out_drop_write;
4334	}
4335
4336	spin_lock(&fs_info->super_lock);
4337	newflags = btrfs_super_compat_flags(super_block);
4338	newflags |= flags[0].compat_flags & flags[1].compat_flags;
4339	newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
4340	btrfs_set_super_compat_flags(super_block, newflags);
4341
4342	newflags = btrfs_super_compat_ro_flags(super_block);
4343	newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
4344	newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
4345	btrfs_set_super_compat_ro_flags(super_block, newflags);
4346
4347	newflags = btrfs_super_incompat_flags(super_block);
4348	newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
4349	newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
4350	btrfs_set_super_incompat_flags(super_block, newflags);
4351	spin_unlock(&fs_info->super_lock);
4352
4353	ret = btrfs_commit_transaction(trans);
4354out_drop_write:
4355	mnt_drop_write_file(file);
4356
4357	return ret;
4358}
4359
4360static int _btrfs_ioctl_send(struct inode *inode, void __user *argp, bool compat)
4361{
4362	struct btrfs_ioctl_send_args *arg;
4363	int ret;
4364
4365	if (compat) {
4366#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4367		struct btrfs_ioctl_send_args_32 args32 = { 0 };
4368
4369		ret = copy_from_user(&args32, argp, sizeof(args32));
4370		if (ret)
4371			return -EFAULT;
4372		arg = kzalloc(sizeof(*arg), GFP_KERNEL);
4373		if (!arg)
4374			return -ENOMEM;
4375		arg->send_fd = args32.send_fd;
4376		arg->clone_sources_count = args32.clone_sources_count;
4377		arg->clone_sources = compat_ptr(args32.clone_sources);
4378		arg->parent_root = args32.parent_root;
4379		arg->flags = args32.flags;
4380		arg->version = args32.version;
4381		memcpy(arg->reserved, args32.reserved,
4382		       sizeof(args32.reserved));
4383#else
4384		return -ENOTTY;
4385#endif
4386	} else {
4387		arg = memdup_user(argp, sizeof(*arg));
4388		if (IS_ERR(arg))
4389			return PTR_ERR(arg);
4390	}
4391	ret = btrfs_ioctl_send(inode, arg);
4392	kfree(arg);
4393	return ret;
4394}
4395
4396static int btrfs_ioctl_encoded_read(struct file *file, void __user *argp,
4397				    bool compat)
4398{
4399	struct btrfs_ioctl_encoded_io_args args = { 0 };
4400	size_t copy_end_kernel = offsetofend(struct btrfs_ioctl_encoded_io_args,
4401					     flags);
4402	size_t copy_end;
4403	struct iovec iovstack[UIO_FASTIOV];
4404	struct iovec *iov = iovstack;
4405	struct iov_iter iter;
4406	loff_t pos;
4407	struct kiocb kiocb;
4408	ssize_t ret;
4409
4410	if (!capable(CAP_SYS_ADMIN)) {
4411		ret = -EPERM;
4412		goto out_acct;
4413	}
4414
4415	if (compat) {
4416#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4417		struct btrfs_ioctl_encoded_io_args_32 args32;
4418
4419		copy_end = offsetofend(struct btrfs_ioctl_encoded_io_args_32,
4420				       flags);
4421		if (copy_from_user(&args32, argp, copy_end)) {
4422			ret = -EFAULT;
4423			goto out_acct;
4424		}
4425		args.iov = compat_ptr(args32.iov);
4426		args.iovcnt = args32.iovcnt;
4427		args.offset = args32.offset;
4428		args.flags = args32.flags;
4429#else
4430		return -ENOTTY;
4431#endif
4432	} else {
4433		copy_end = copy_end_kernel;
4434		if (copy_from_user(&args, argp, copy_end)) {
4435			ret = -EFAULT;
4436			goto out_acct;
4437		}
4438	}
4439	if (args.flags != 0) {
4440		ret = -EINVAL;
4441		goto out_acct;
4442	}
4443
4444	ret = import_iovec(ITER_DEST, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
4445			   &iov, &iter);
4446	if (ret < 0)
4447		goto out_acct;
4448
4449	if (iov_iter_count(&iter) == 0) {
4450		ret = 0;
4451		goto out_iov;
4452	}
4453	pos = args.offset;
4454	ret = rw_verify_area(READ, file, &pos, args.len);
4455	if (ret < 0)
4456		goto out_iov;
4457
4458	init_sync_kiocb(&kiocb, file);
4459	kiocb.ki_pos = pos;
4460
4461	ret = btrfs_encoded_read(&kiocb, &iter, &args);
4462	if (ret >= 0) {
4463		fsnotify_access(file);
4464		if (copy_to_user(argp + copy_end,
4465				 (char *)&args + copy_end_kernel,
4466				 sizeof(args) - copy_end_kernel))
4467			ret = -EFAULT;
4468	}
4469
4470out_iov:
4471	kfree(iov);
4472out_acct:
4473	if (ret > 0)
4474		add_rchar(current, ret);
4475	inc_syscr(current);
4476	return ret;
4477}
4478
4479static int btrfs_ioctl_encoded_write(struct file *file, void __user *argp, bool compat)
4480{
4481	struct btrfs_ioctl_encoded_io_args args;
4482	struct iovec iovstack[UIO_FASTIOV];
4483	struct iovec *iov = iovstack;
4484	struct iov_iter iter;
4485	loff_t pos;
4486	struct kiocb kiocb;
4487	ssize_t ret;
4488
4489	if (!capable(CAP_SYS_ADMIN)) {
4490		ret = -EPERM;
4491		goto out_acct;
4492	}
4493
4494	if (!(file->f_mode & FMODE_WRITE)) {
4495		ret = -EBADF;
4496		goto out_acct;
4497	}
4498
4499	if (compat) {
4500#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4501		struct btrfs_ioctl_encoded_io_args_32 args32;
4502
4503		if (copy_from_user(&args32, argp, sizeof(args32))) {
4504			ret = -EFAULT;
4505			goto out_acct;
4506		}
4507		args.iov = compat_ptr(args32.iov);
4508		args.iovcnt = args32.iovcnt;
4509		args.offset = args32.offset;
4510		args.flags = args32.flags;
4511		args.len = args32.len;
4512		args.unencoded_len = args32.unencoded_len;
4513		args.unencoded_offset = args32.unencoded_offset;
4514		args.compression = args32.compression;
4515		args.encryption = args32.encryption;
4516		memcpy(args.reserved, args32.reserved, sizeof(args.reserved));
4517#else
4518		return -ENOTTY;
4519#endif
4520	} else {
4521		if (copy_from_user(&args, argp, sizeof(args))) {
4522			ret = -EFAULT;
4523			goto out_acct;
4524		}
4525	}
4526
4527	ret = -EINVAL;
4528	if (args.flags != 0)
4529		goto out_acct;
4530	if (memchr_inv(args.reserved, 0, sizeof(args.reserved)))
4531		goto out_acct;
4532	if (args.compression == BTRFS_ENCODED_IO_COMPRESSION_NONE &&
4533	    args.encryption == BTRFS_ENCODED_IO_ENCRYPTION_NONE)
4534		goto out_acct;
4535	if (args.compression >= BTRFS_ENCODED_IO_COMPRESSION_TYPES ||
4536	    args.encryption >= BTRFS_ENCODED_IO_ENCRYPTION_TYPES)
4537		goto out_acct;
4538	if (args.unencoded_offset > args.unencoded_len)
4539		goto out_acct;
4540	if (args.len > args.unencoded_len - args.unencoded_offset)
4541		goto out_acct;
4542
4543	ret = import_iovec(ITER_SOURCE, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
4544			   &iov, &iter);
4545	if (ret < 0)
4546		goto out_acct;
4547
4548	if (iov_iter_count(&iter) == 0) {
4549		ret = 0;
4550		goto out_iov;
4551	}
4552	pos = args.offset;
4553	ret = rw_verify_area(WRITE, file, &pos, args.len);
4554	if (ret < 0)
4555		goto out_iov;
4556
4557	init_sync_kiocb(&kiocb, file);
4558	ret = kiocb_set_rw_flags(&kiocb, 0);
4559	if (ret)
4560		goto out_iov;
4561	kiocb.ki_pos = pos;
4562
4563	file_start_write(file);
4564
4565	ret = btrfs_do_write_iter(&kiocb, &iter, &args);
4566	if (ret > 0)
4567		fsnotify_modify(file);
4568
4569	file_end_write(file);
4570out_iov:
4571	kfree(iov);
4572out_acct:
4573	if (ret > 0)
4574		add_wchar(current, ret);
4575	inc_syscw(current);
4576	return ret;
4577}
4578
4579long btrfs_ioctl(struct file *file, unsigned int
4580		cmd, unsigned long arg)
4581{
4582	struct inode *inode = file_inode(file);
4583	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4584	struct btrfs_root *root = BTRFS_I(inode)->root;
4585	void __user *argp = (void __user *)arg;
4586
4587	switch (cmd) {
 
 
 
 
4588	case FS_IOC_GETVERSION:
4589		return btrfs_ioctl_getversion(inode, argp);
4590	case FS_IOC_GETFSLABEL:
4591		return btrfs_ioctl_get_fslabel(fs_info, argp);
4592	case FS_IOC_SETFSLABEL:
4593		return btrfs_ioctl_set_fslabel(file, argp);
4594	case FITRIM:
4595		return btrfs_ioctl_fitrim(fs_info, argp);
4596	case BTRFS_IOC_SNAP_CREATE:
4597		return btrfs_ioctl_snap_create(file, argp, 0);
4598	case BTRFS_IOC_SNAP_CREATE_V2:
4599		return btrfs_ioctl_snap_create_v2(file, argp, 0);
4600	case BTRFS_IOC_SUBVOL_CREATE:
4601		return btrfs_ioctl_snap_create(file, argp, 1);
4602	case BTRFS_IOC_SUBVOL_CREATE_V2:
4603		return btrfs_ioctl_snap_create_v2(file, argp, 1);
4604	case BTRFS_IOC_SNAP_DESTROY:
4605		return btrfs_ioctl_snap_destroy(file, argp, false);
4606	case BTRFS_IOC_SNAP_DESTROY_V2:
4607		return btrfs_ioctl_snap_destroy(file, argp, true);
4608	case BTRFS_IOC_SUBVOL_GETFLAGS:
4609		return btrfs_ioctl_subvol_getflags(inode, argp);
4610	case BTRFS_IOC_SUBVOL_SETFLAGS:
4611		return btrfs_ioctl_subvol_setflags(file, argp);
4612	case BTRFS_IOC_DEFAULT_SUBVOL:
4613		return btrfs_ioctl_default_subvol(file, argp);
4614	case BTRFS_IOC_DEFRAG:
4615		return btrfs_ioctl_defrag(file, NULL);
4616	case BTRFS_IOC_DEFRAG_RANGE:
4617		return btrfs_ioctl_defrag(file, argp);
4618	case BTRFS_IOC_RESIZE:
4619		return btrfs_ioctl_resize(file, argp);
4620	case BTRFS_IOC_ADD_DEV:
4621		return btrfs_ioctl_add_dev(fs_info, argp);
4622	case BTRFS_IOC_RM_DEV:
4623		return btrfs_ioctl_rm_dev(file, argp);
4624	case BTRFS_IOC_RM_DEV_V2:
4625		return btrfs_ioctl_rm_dev_v2(file, argp);
4626	case BTRFS_IOC_FS_INFO:
4627		return btrfs_ioctl_fs_info(fs_info, argp);
4628	case BTRFS_IOC_DEV_INFO:
4629		return btrfs_ioctl_dev_info(fs_info, argp);
 
 
 
 
 
 
4630	case BTRFS_IOC_TREE_SEARCH:
4631		return btrfs_ioctl_tree_search(inode, argp);
4632	case BTRFS_IOC_TREE_SEARCH_V2:
4633		return btrfs_ioctl_tree_search_v2(inode, argp);
4634	case BTRFS_IOC_INO_LOOKUP:
4635		return btrfs_ioctl_ino_lookup(root, argp);
4636	case BTRFS_IOC_INO_PATHS:
4637		return btrfs_ioctl_ino_to_path(root, argp);
4638	case BTRFS_IOC_LOGICAL_INO:
4639		return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
4640	case BTRFS_IOC_LOGICAL_INO_V2:
4641		return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
4642	case BTRFS_IOC_SPACE_INFO:
4643		return btrfs_ioctl_space_info(fs_info, argp);
4644	case BTRFS_IOC_SYNC: {
4645		int ret;
4646
4647		ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false);
4648		if (ret)
4649			return ret;
4650		ret = btrfs_sync_fs(inode->i_sb, 1);
4651		/*
4652		 * The transaction thread may want to do more work,
4653		 * namely it pokes the cleaner kthread that will start
4654		 * processing uncleaned subvols.
4655		 */
4656		wake_up_process(fs_info->transaction_kthread);
4657		return ret;
4658	}
4659	case BTRFS_IOC_START_SYNC:
4660		return btrfs_ioctl_start_sync(root, argp);
4661	case BTRFS_IOC_WAIT_SYNC:
4662		return btrfs_ioctl_wait_sync(fs_info, argp);
4663	case BTRFS_IOC_SCRUB:
4664		return btrfs_ioctl_scrub(file, argp);
4665	case BTRFS_IOC_SCRUB_CANCEL:
4666		return btrfs_ioctl_scrub_cancel(fs_info);
4667	case BTRFS_IOC_SCRUB_PROGRESS:
4668		return btrfs_ioctl_scrub_progress(fs_info, argp);
4669	case BTRFS_IOC_BALANCE_V2:
4670		return btrfs_ioctl_balance(file, argp);
4671	case BTRFS_IOC_BALANCE_CTL:
4672		return btrfs_ioctl_balance_ctl(fs_info, arg);
4673	case BTRFS_IOC_BALANCE_PROGRESS:
4674		return btrfs_ioctl_balance_progress(fs_info, argp);
4675	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
4676		return btrfs_ioctl_set_received_subvol(file, argp);
4677#ifdef CONFIG_64BIT
4678	case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
4679		return btrfs_ioctl_set_received_subvol_32(file, argp);
4680#endif
4681	case BTRFS_IOC_SEND:
4682		return _btrfs_ioctl_send(inode, argp, false);
4683#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4684	case BTRFS_IOC_SEND_32:
4685		return _btrfs_ioctl_send(inode, argp, true);
4686#endif
4687	case BTRFS_IOC_GET_DEV_STATS:
4688		return btrfs_ioctl_get_dev_stats(fs_info, argp);
4689	case BTRFS_IOC_QUOTA_CTL:
4690		return btrfs_ioctl_quota_ctl(file, argp);
4691	case BTRFS_IOC_QGROUP_ASSIGN:
4692		return btrfs_ioctl_qgroup_assign(file, argp);
4693	case BTRFS_IOC_QGROUP_CREATE:
4694		return btrfs_ioctl_qgroup_create(file, argp);
4695	case BTRFS_IOC_QGROUP_LIMIT:
4696		return btrfs_ioctl_qgroup_limit(file, argp);
4697	case BTRFS_IOC_QUOTA_RESCAN:
4698		return btrfs_ioctl_quota_rescan(file, argp);
4699	case BTRFS_IOC_QUOTA_RESCAN_STATUS:
4700		return btrfs_ioctl_quota_rescan_status(fs_info, argp);
4701	case BTRFS_IOC_QUOTA_RESCAN_WAIT:
4702		return btrfs_ioctl_quota_rescan_wait(fs_info, argp);
4703	case BTRFS_IOC_DEV_REPLACE:
4704		return btrfs_ioctl_dev_replace(fs_info, argp);
 
 
 
 
4705	case BTRFS_IOC_GET_SUPPORTED_FEATURES:
4706		return btrfs_ioctl_get_supported_features(argp);
4707	case BTRFS_IOC_GET_FEATURES:
4708		return btrfs_ioctl_get_features(fs_info, argp);
4709	case BTRFS_IOC_SET_FEATURES:
4710		return btrfs_ioctl_set_features(file, argp);
4711	case BTRFS_IOC_GET_SUBVOL_INFO:
4712		return btrfs_ioctl_get_subvol_info(inode, argp);
4713	case BTRFS_IOC_GET_SUBVOL_ROOTREF:
4714		return btrfs_ioctl_get_subvol_rootref(root, argp);
4715	case BTRFS_IOC_INO_LOOKUP_USER:
4716		return btrfs_ioctl_ino_lookup_user(file, argp);
4717	case FS_IOC_ENABLE_VERITY:
4718		return fsverity_ioctl_enable(file, (const void __user *)argp);
4719	case FS_IOC_MEASURE_VERITY:
4720		return fsverity_ioctl_measure(file, argp);
4721	case BTRFS_IOC_ENCODED_READ:
4722		return btrfs_ioctl_encoded_read(file, argp, false);
4723	case BTRFS_IOC_ENCODED_WRITE:
4724		return btrfs_ioctl_encoded_write(file, argp, false);
4725#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4726	case BTRFS_IOC_ENCODED_READ_32:
4727		return btrfs_ioctl_encoded_read(file, argp, true);
4728	case BTRFS_IOC_ENCODED_WRITE_32:
4729		return btrfs_ioctl_encoded_write(file, argp, true);
4730#endif
4731	}
4732
4733	return -ENOTTY;
4734}
4735
4736#ifdef CONFIG_COMPAT
4737long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
4738{
4739	/*
4740	 * These all access 32-bit values anyway so no further
4741	 * handling is necessary.
4742	 */
4743	switch (cmd) {
4744	case FS_IOC32_GETVERSION:
4745		cmd = FS_IOC_GETVERSION;
4746		break;
4747	}
4748
4749	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
4750}
4751#endif