blob: efd5d6e9589e0936a8f596ce72b9ce0e5e415223 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <linux/kernel.h>
#include <linux/bio.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/fsnotify.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/writeback.h>
#include <linux/compat.h>
#include <linux/security.h>
#include <linux/xattr.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/uuid.h>
#include <linux/btrfs.h>
#include <linux/uaccess.h>
#include <linux/iversion.h>
#include <linux/fileattr.h>
#include <linux/fsverity.h>
#include <linux/sched/xacct.h>
#include "ctree.h"
#include "disk-io.h"
#include "export.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "volumes.h"
#include "locking.h"
#include "backref.h"
#include "send.h"
#include "dev-replace.h"
#include "props.h"
#include "sysfs.h"
#include "qgroup.h"
#include "tree-log.h"
#include "compression.h"
#include "space-info.h"
#include "block-group.h"
#include "fs.h"
#include "accessors.h"
#include "extent-tree.h"
#include "root-tree.h"
#include "defrag.h"
#include "dir-item.h"
#include "uuid-tree.h"
#include "ioctl.h"
#include "file.h"
#include "scrub.h"
#include "super.h"
#ifdef CONFIG_64BIT
/* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
* structures are incorrect, as the timespec structure from userspace
* is 4 bytes too small. We define these alternatives here to teach
* the kernel about the 32-bit struct packing.
*/
struct btrfs_ioctl_timespec_32 {
__u64 sec;
__u32 nsec;
} __attribute__ ((__packed__));
struct btrfs_ioctl_received_subvol_args_32 {
char uuid[BTRFS_UUID_SIZE]; /* in */
__u64 stransid; /* in */
__u64 rtransid; /* out */
struct btrfs_ioctl_timespec_32 stime; /* in */
struct btrfs_ioctl_timespec_32 rtime; /* out */
__u64 flags; /* in */
__u64 reserved[16]; /* in */
} __attribute__ ((__packed__));
#define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
struct btrfs_ioctl_received_subvol_args_32)
#endif
#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
struct btrfs_ioctl_send_args_32 {
__s64 send_fd; /* in */
__u64 clone_sources_count; /* in */
compat_uptr_t clone_sources; /* in */
__u64 parent_root; /* in */
__u64 flags; /* in */
__u32 version; /* in */
__u8 reserved[28]; /* in */
} __attribute__ ((__packed__));
#define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
struct btrfs_ioctl_send_args_32)
struct btrfs_ioctl_encoded_io_args_32 {
compat_uptr_t iov;
compat_ulong_t iovcnt;
__s64 offset;
__u64 flags;
__u64 len;
__u64 unencoded_len;
__u64 unencoded_offset;
__u32 compression;
__u32 encryption;
__u8 reserved[64];
};
#define BTRFS_IOC_ENCODED_READ_32 _IOR(BTRFS_IOCTL_MAGIC, 64, \
struct btrfs_ioctl_encoded_io_args_32)
#define BTRFS_IOC_ENCODED_WRITE_32 _IOW(BTRFS_IOCTL_MAGIC, 64, \
struct btrfs_ioctl_encoded_io_args_32)
#endif
/* Mask out flags that are inappropriate for the given type of inode. */
static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
unsigned int flags)
{
if (S_ISDIR(inode->i_mode))
return flags;
else if (S_ISREG(inode->i_mode))
return flags & ~FS_DIRSYNC_FL;
else
return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
}
/*
* Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
* ioctl.
*/
static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode)
{
unsigned int iflags = 0;
u32 flags = binode->flags;
u32 ro_flags = binode->ro_flags;
if (flags & BTRFS_INODE_SYNC)
iflags |= FS_SYNC_FL;
if (flags & BTRFS_INODE_IMMUTABLE)
iflags |= FS_IMMUTABLE_FL;
if (flags & BTRFS_INODE_APPEND)
iflags |= FS_APPEND_FL;
if (flags & BTRFS_INODE_NODUMP)
iflags |= FS_NODUMP_FL;
if (flags & BTRFS_INODE_NOATIME)
iflags |= FS_NOATIME_FL;
if (flags & BTRFS_INODE_DIRSYNC)
iflags |= FS_DIRSYNC_FL;
if (flags & BTRFS_INODE_NODATACOW)
iflags |= FS_NOCOW_FL;
if (ro_flags & BTRFS_INODE_RO_VERITY)
iflags |= FS_VERITY_FL;
if (flags & BTRFS_INODE_NOCOMPRESS)
iflags |= FS_NOCOMP_FL;
else if (flags & BTRFS_INODE_COMPRESS)
iflags |= FS_COMPR_FL;
return iflags;
}
/*
* Update inode->i_flags based on the btrfs internal flags.
*/
void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
{
struct btrfs_inode *binode = BTRFS_I(inode);
unsigned int new_fl = 0;
if (binode->flags & BTRFS_INODE_SYNC)
new_fl |= S_SYNC;
if (binode->flags & BTRFS_INODE_IMMUTABLE)
new_fl |= S_IMMUTABLE;
if (binode->flags & BTRFS_INODE_APPEND)
new_fl |= S_APPEND;
if (binode->flags & BTRFS_INODE_NOATIME)
new_fl |= S_NOATIME;
if (binode->flags & BTRFS_INODE_DIRSYNC)
new_fl |= S_DIRSYNC;
if (binode->ro_flags & BTRFS_INODE_RO_VERITY)
new_fl |= S_VERITY;
set_mask_bits(&inode->i_flags,
S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC |
S_VERITY, new_fl);
}
/*
* Check if @flags are a supported and valid set of FS_*_FL flags and that
* the old and new flags are not conflicting
*/
static int check_fsflags(unsigned int old_flags, unsigned int flags)
{
if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
FS_NOATIME_FL | FS_NODUMP_FL | \
FS_SYNC_FL | FS_DIRSYNC_FL | \
FS_NOCOMP_FL | FS_COMPR_FL |
FS_NOCOW_FL))
return -EOPNOTSUPP;
/* COMPR and NOCOMP on new/old are valid */
if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
return -EINVAL;
if ((flags & FS_COMPR_FL) && (flags & FS_NOCOW_FL))
return -EINVAL;
/* NOCOW and compression options are mutually exclusive */
if ((old_flags & FS_NOCOW_FL) && (flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
return -EINVAL;
if ((flags & FS_NOCOW_FL) && (old_flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
return -EINVAL;
return 0;
}
static int check_fsflags_compatible(struct btrfs_fs_info *fs_info,
unsigned int flags)
{
if (btrfs_is_zoned(fs_info) && (flags & FS_NOCOW_FL))
return -EPERM;
return 0;
}
int btrfs_check_ioctl_vol_args_path(const struct btrfs_ioctl_vol_args *vol_args)
{
if (memchr(vol_args->name, 0, sizeof(vol_args->name)) == NULL)
return -ENAMETOOLONG;
return 0;
}
static int btrfs_check_ioctl_vol_args2_subvol_name(const struct btrfs_ioctl_vol_args_v2 *vol_args2)
{
if (memchr(vol_args2->name, 0, sizeof(vol_args2->name)) == NULL)
return -ENAMETOOLONG;
return 0;
}
/*
* Set flags/xflags from the internal inode flags. The remaining items of
* fsxattr are zeroed.
*/
int btrfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
{
struct btrfs_inode *binode = BTRFS_I(d_inode(dentry));
fileattr_fill_flags(fa, btrfs_inode_flags_to_fsflags(binode));
return 0;
}
int btrfs_fileattr_set(struct mnt_idmap *idmap,
struct dentry *dentry, struct fileattr *fa)
{
struct inode *inode = d_inode(dentry);
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
struct btrfs_inode *binode = BTRFS_I(inode);
struct btrfs_root *root = binode->root;
struct btrfs_trans_handle *trans;
unsigned int fsflags, old_fsflags;
int ret;
const char *comp = NULL;
u32 binode_flags;
if (btrfs_root_readonly(root))
return -EROFS;
if (fileattr_has_fsx(fa))
return -EOPNOTSUPP;
fsflags = btrfs_mask_fsflags_for_type(inode, fa->flags);
old_fsflags = btrfs_inode_flags_to_fsflags(binode);
ret = check_fsflags(old_fsflags, fsflags);
if (ret)
return ret;
ret = check_fsflags_compatible(fs_info, fsflags);
if (ret)
return ret;
binode_flags = binode->flags;
if (fsflags & FS_SYNC_FL)
binode_flags |= BTRFS_INODE_SYNC;
else
binode_flags &= ~BTRFS_INODE_SYNC;
if (fsflags & FS_IMMUTABLE_FL)
binode_flags |= BTRFS_INODE_IMMUTABLE;
else
binode_flags &= ~BTRFS_INODE_IMMUTABLE;
if (fsflags & FS_APPEND_FL)
binode_flags |= BTRFS_INODE_APPEND;
else
binode_flags &= ~BTRFS_INODE_APPEND;
if (fsflags & FS_NODUMP_FL)
binode_flags |= BTRFS_INODE_NODUMP;
else
binode_flags &= ~BTRFS_INODE_NODUMP;
if (fsflags & FS_NOATIME_FL)
binode_flags |= BTRFS_INODE_NOATIME;
else
binode_flags &= ~BTRFS_INODE_NOATIME;
/* If coming from FS_IOC_FSSETXATTR then skip unconverted flags */
if (!fa->flags_valid) {
/* 1 item for the inode */
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans))
return PTR_ERR(trans);
goto update_flags;
}
if (fsflags & FS_DIRSYNC_FL)
binode_flags |= BTRFS_INODE_DIRSYNC;
else
binode_flags &= ~BTRFS_INODE_DIRSYNC;
if (fsflags & FS_NOCOW_FL) {
if (S_ISREG(inode->i_mode)) {
/*
* It's safe to turn csums off here, no extents exist.
* Otherwise we want the flag to reflect the real COW
* status of the file and will not set it.
*/
if (inode->i_size == 0)
binode_flags |= BTRFS_INODE_NODATACOW |
BTRFS_INODE_NODATASUM;
} else {
binode_flags |= BTRFS_INODE_NODATACOW;
}
} else {
/*
* Revert back under same assumptions as above
*/
if (S_ISREG(inode->i_mode)) {
if (inode->i_size == 0)
binode_flags &= ~(BTRFS_INODE_NODATACOW |
BTRFS_INODE_NODATASUM);
} else {
binode_flags &= ~BTRFS_INODE_NODATACOW;
}
}
/*
* The COMPRESS flag can only be changed by users, while the NOCOMPRESS
* flag may be changed automatically if compression code won't make
* things smaller.
*/
if (fsflags & FS_NOCOMP_FL) {
binode_flags &= ~BTRFS_INODE_COMPRESS;
binode_flags |= BTRFS_INODE_NOCOMPRESS;
} else if (fsflags & FS_COMPR_FL) {
if (IS_SWAPFILE(inode))
return -ETXTBSY;
binode_flags |= BTRFS_INODE_COMPRESS;
binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
comp = btrfs_compress_type2str(fs_info->compress_type);
if (!comp || comp[0] == 0)
comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
} else {
binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
}
/*
* 1 for inode item
* 2 for properties
*/
trans = btrfs_start_transaction(root, 3);
if (IS_ERR(trans))
return PTR_ERR(trans);
if (comp) {
ret = btrfs_set_prop(trans, inode, "btrfs.compression", comp,
strlen(comp), 0);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
} else {
ret = btrfs_set_prop(trans, inode, "btrfs.compression", NULL,
0, 0);
if (ret && ret != -ENODATA) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
}
update_flags:
binode->flags = binode_flags;
btrfs_sync_inode_flags_to_i_flags(inode);
inode_inc_iversion(inode);
inode_set_ctime_current(inode);
ret = btrfs_update_inode(trans, BTRFS_I(inode));
out_end_trans:
btrfs_end_transaction(trans);
return ret;
}
/*
* Start exclusive operation @type, return true on success
*/
bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
enum btrfs_exclusive_operation type)
{
bool ret = false;
spin_lock(&fs_info->super_lock);
if (fs_info->exclusive_operation == BTRFS_EXCLOP_NONE) {
fs_info->exclusive_operation = type;
ret = true;
}
spin_unlock(&fs_info->super_lock);
return ret;
}
/*
* Conditionally allow to enter the exclusive operation in case it's compatible
* with the running one. This must be paired with btrfs_exclop_start_unlock and
* btrfs_exclop_finish.
*
* Compatibility:
* - the same type is already running
* - when trying to add a device and balance has been paused
* - not BTRFS_EXCLOP_NONE - this is intentionally incompatible and the caller
* must check the condition first that would allow none -> @type
*/
bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info,
enum btrfs_exclusive_operation type)
{
spin_lock(&fs_info->super_lock);
if (fs_info->exclusive_operation == type ||
(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED &&
type == BTRFS_EXCLOP_DEV_ADD))
return true;
spin_unlock(&fs_info->super_lock);
return false;
}
void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info)
{
spin_unlock(&fs_info->super_lock);
}
void btrfs_exclop_finish(struct btrfs_fs_info *fs_info)
{
spin_lock(&fs_info->super_lock);
WRITE_ONCE(fs_info->exclusive_operation, BTRFS_EXCLOP_NONE);
spin_unlock(&fs_info->super_lock);
sysfs_notify(&fs_info->fs_devices->fsid_kobj, NULL, "exclusive_operation");
}
void btrfs_exclop_balance(struct btrfs_fs_info *fs_info,
enum btrfs_exclusive_operation op)
{
switch (op) {
case BTRFS_EXCLOP_BALANCE_PAUSED:
spin_lock(&fs_info->super_lock);
ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE ||
fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD ||
fs_info->exclusive_operation == BTRFS_EXCLOP_NONE ||
fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED);
fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE_PAUSED;
spin_unlock(&fs_info->super_lock);
break;
case BTRFS_EXCLOP_BALANCE:
spin_lock(&fs_info->super_lock);
ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED);
fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE;
spin_unlock(&fs_info->super_lock);
break;
default:
btrfs_warn(fs_info,
"invalid exclop balance operation %d requested", op);
}
}
static int btrfs_ioctl_getversion(struct inode *inode, int __user *arg)
{
return put_user(inode->i_generation, arg);
}
static noinline int btrfs_ioctl_fitrim(struct btrfs_fs_info *fs_info,
void __user *arg)
{
struct btrfs_device *device;
struct fstrim_range range;
u64 minlen = ULLONG_MAX;
u64 num_devices = 0;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
/*
* btrfs_trim_block_group() depends on space cache, which is not
* available in zoned filesystem. So, disallow fitrim on a zoned
* filesystem for now.
*/
if (btrfs_is_zoned(fs_info))
return -EOPNOTSUPP;
/*
* If the fs is mounted with nologreplay, which requires it to be
* mounted in RO mode as well, we can not allow discard on free space
* inside block groups, because log trees refer to extents that are not
* pinned in a block group's free space cache (pinning the extents is
* precisely the first phase of replaying a log tree).
*/
if (btrfs_test_opt(fs_info, NOLOGREPLAY))
return -EROFS;
rcu_read_lock();
list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
dev_list) {
if (!device->bdev || !bdev_max_discard_sectors(device->bdev))
continue;
num_devices++;
minlen = min_t(u64, bdev_discard_granularity(device->bdev),
minlen);
}
rcu_read_unlock();
if (!num_devices)
return -EOPNOTSUPP;
if (copy_from_user(&range, arg, sizeof(range)))
return -EFAULT;
/*
* NOTE: Don't truncate the range using super->total_bytes. Bytenr of
* block group is in the logical address space, which can be any
* sectorsize aligned bytenr in the range [0, U64_MAX].
*/
if (range.len < fs_info->sectorsize)
return -EINVAL;
range.minlen = max(range.minlen, minlen);
ret = btrfs_trim_fs(fs_info, &range);
if (ret < 0)
return ret;
if (copy_to_user(arg, &range, sizeof(range)))
return -EFAULT;
return 0;
}
int __pure btrfs_is_empty_uuid(u8 *uuid)
{
int i;
for (i = 0; i < BTRFS_UUID_SIZE; i++) {
if (uuid[i])
return 0;
}
return 1;
}
/*
* Calculate the number of transaction items to reserve for creating a subvolume
* or snapshot, not including the inode, directory entries, or parent directory.
*/
static unsigned int create_subvol_num_items(struct btrfs_qgroup_inherit *inherit)
{
/*
* 1 to add root block
* 1 to add root item
* 1 to add root ref
* 1 to add root backref
* 1 to add UUID item
* 1 to add qgroup info
* 1 to add qgroup limit
*
* Ideally the last two would only be accounted if qgroups are enabled,
* but that can change between now and the time we would insert them.
*/
unsigned int num_items = 7;
if (inherit) {
/* 2 to add qgroup relations for each inherited qgroup */
num_items += 2 * inherit->num_qgroups;
}
return num_items;
}
static noinline int create_subvol(struct mnt_idmap *idmap,
struct inode *dir, struct dentry *dentry,
struct btrfs_qgroup_inherit *inherit)
{
struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
struct btrfs_trans_handle *trans;
struct btrfs_key key;
struct btrfs_root_item *root_item;
struct btrfs_inode_item *inode_item;
struct extent_buffer *leaf;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *new_root;
struct btrfs_block_rsv block_rsv;
struct timespec64 cur_time = current_time(dir);
struct btrfs_new_inode_args new_inode_args = {
.dir = dir,
.dentry = dentry,
.subvol = true,
};
unsigned int trans_num_items;
int ret;
dev_t anon_dev;
u64 objectid;
u64 qgroup_reserved = 0;
root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
if (!root_item)
return -ENOMEM;
ret = btrfs_get_free_objectid(fs_info->tree_root, &objectid);
if (ret)
goto out_root_item;
/*
* Don't create subvolume whose level is not zero. Or qgroup will be
* screwed up since it assumes subvolume qgroup's level to be 0.
*/
if (btrfs_qgroup_level(objectid)) {
ret = -ENOSPC;
goto out_root_item;
}
ret = get_anon_bdev(&anon_dev);
if (ret < 0)
goto out_root_item;
new_inode_args.inode = btrfs_new_subvol_inode(idmap, dir);
if (!new_inode_args.inode) {
ret = -ENOMEM;
goto out_anon_dev;
}
ret = btrfs_new_inode_prepare(&new_inode_args, &trans_num_items);
if (ret)
goto out_inode;
trans_num_items += create_subvol_num_items(inherit);
btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
trans_num_items, false);
if (ret)
goto out_new_inode_args;
qgroup_reserved = block_rsv.qgroup_rsv_reserved;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_release_rsv;
}
ret = btrfs_record_root_in_trans(trans, BTRFS_I(dir)->root);
if (ret)
goto out;
btrfs_qgroup_convert_reserved_meta(root, qgroup_reserved);
qgroup_reserved = 0;
trans->block_rsv = &block_rsv;
trans->bytes_reserved = block_rsv.size;
/* Tree log can't currently deal with an inode which is a new root. */
btrfs_set_log_full_commit(trans);
ret = btrfs_qgroup_inherit(trans, 0, objectid, btrfs_root_id(root), inherit);
if (ret)
goto out;
leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
0, BTRFS_NESTING_NORMAL);
if (IS_ERR(leaf)) {
ret = PTR_ERR(leaf);
goto out;
}
btrfs_mark_buffer_dirty(trans, leaf);
inode_item = &root_item->inode;
btrfs_set_stack_inode_generation(inode_item, 1);
btrfs_set_stack_inode_size(inode_item, 3);
btrfs_set_stack_inode_nlink(inode_item, 1);
btrfs_set_stack_inode_nbytes(inode_item,
fs_info->nodesize);
btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
btrfs_set_root_flags(root_item, 0);
btrfs_set_root_limit(root_item, 0);
btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
btrfs_set_root_bytenr(root_item, leaf->start);
btrfs_set_root_generation(root_item, trans->transid);
btrfs_set_root_level(root_item, 0);
btrfs_set_root_refs(root_item, 1);
btrfs_set_root_used(root_item, leaf->len);
btrfs_set_root_last_snapshot(root_item, 0);
btrfs_set_root_generation_v2(root_item,
btrfs_root_generation(root_item));
generate_random_guid(root_item->uuid);
btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
root_item->ctime = root_item->otime;
btrfs_set_root_ctransid(root_item, trans->transid);
btrfs_set_root_otransid(root_item, trans->transid);
btrfs_tree_unlock(leaf);
btrfs_set_root_dirid(root_item, BTRFS_FIRST_FREE_OBJECTID);
key.objectid = objectid;
key.offset = 0;
key.type = BTRFS_ROOT_ITEM_KEY;
ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
root_item);
if (ret) {
/*
* Since we don't abort the transaction in this case, free the
* tree block so that we don't leak space and leave the
* filesystem in an inconsistent state (an extent item in the
* extent tree with a backreference for a root that does not
* exists).
*/
btrfs_tree_lock(leaf);
btrfs_clear_buffer_dirty(trans, leaf);
btrfs_tree_unlock(leaf);
btrfs_free_tree_block(trans, objectid, leaf, 0, 1);
free_extent_buffer(leaf);
goto out;
}
free_extent_buffer(leaf);
leaf = NULL;
new_root = btrfs_get_new_fs_root(fs_info, objectid, &anon_dev);
if (IS_ERR(new_root)) {
ret = PTR_ERR(new_root);
btrfs_abort_transaction(trans, ret);
goto out;
}
/* anon_dev is owned by new_root now. */
anon_dev = 0;
BTRFS_I(new_inode_args.inode)->root = new_root;
/* ... and new_root is owned by new_inode_args.inode now. */
ret = btrfs_record_root_in_trans(trans, new_root);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = btrfs_uuid_tree_add(trans, root_item->uuid,
BTRFS_UUID_KEY_SUBVOL, objectid);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = btrfs_create_new_inode(trans, &new_inode_args);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
d_instantiate_new(dentry, new_inode_args.inode);
new_inode_args.inode = NULL;
out:
trans->block_rsv = NULL;
trans->bytes_reserved = 0;
btrfs_end_transaction(trans);
out_release_rsv:
btrfs_block_rsv_release(fs_info, &block_rsv, (u64)-1, NULL);
if (qgroup_reserved)
btrfs_qgroup_free_meta_prealloc(root, qgroup_reserved);
out_new_inode_args:
btrfs_new_inode_args_destroy(&new_inode_args);
out_inode:
iput(new_inode_args.inode);
out_anon_dev:
if (anon_dev)
free_anon_bdev(anon_dev);
out_root_item:
kfree(root_item);
return ret;
}
static int create_snapshot(struct btrfs_root *root, struct inode *dir,
struct dentry *dentry, bool readonly,
struct btrfs_qgroup_inherit *inherit)
{
struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
struct inode *inode;
struct btrfs_pending_snapshot *pending_snapshot;
unsigned int trans_num_items;
struct btrfs_trans_handle *trans;
struct btrfs_block_rsv *block_rsv;
u64 qgroup_reserved = 0;
int ret;
/* We do not support snapshotting right now. */
if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
btrfs_warn(fs_info,
"extent tree v2 doesn't support snapshotting yet");
return -EOPNOTSUPP;
}
if (btrfs_root_refs(&root->root_item) == 0)
return -ENOENT;
if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
return -EINVAL;
if (atomic_read(&root->nr_swapfiles)) {
btrfs_warn(fs_info,
"cannot snapshot subvolume with active swapfile");
return -ETXTBSY;
}
pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
if (!pending_snapshot)
return -ENOMEM;
ret = get_anon_bdev(&pending_snapshot->anon_dev);
if (ret < 0)
goto free_pending;
pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
GFP_KERNEL);
pending_snapshot->path = btrfs_alloc_path();
if (!pending_snapshot->root_item || !pending_snapshot->path) {
ret = -ENOMEM;
goto free_pending;
}
block_rsv = &pending_snapshot->block_rsv;
btrfs_init_block_rsv(block_rsv, BTRFS_BLOCK_RSV_TEMP);
/*
* 1 to add dir item
* 1 to add dir index
* 1 to update parent inode item
*/
trans_num_items = create_subvol_num_items(inherit) + 3;
ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root, block_rsv,
trans_num_items, false);
if (ret)
goto free_pending;
qgroup_reserved = block_rsv->qgroup_rsv_reserved;
pending_snapshot->dentry = dentry;
pending_snapshot->root = root;
pending_snapshot->readonly = readonly;
pending_snapshot->dir = dir;
pending_snapshot->inherit = inherit;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto fail;
}
ret = btrfs_record_root_in_trans(trans, BTRFS_I(dir)->root);
if (ret) {
btrfs_end_transaction(trans);
goto fail;
}
btrfs_qgroup_convert_reserved_meta(root, qgroup_reserved);
qgroup_reserved = 0;
trans->pending_snapshot = pending_snapshot;
ret = btrfs_commit_transaction(trans);
if (ret)
goto fail;
ret = pending_snapshot->error;
if (ret)
goto fail;
ret = btrfs_orphan_cleanup(pending_snapshot->snap);
if (ret)
goto fail;
inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
goto fail;
}
d_instantiate(dentry, inode);
ret = 0;
pending_snapshot->anon_dev = 0;
fail:
/* Prevent double freeing of anon_dev */
if (ret && pending_snapshot->snap)
pending_snapshot->snap->anon_dev = 0;
btrfs_put_root(pending_snapshot->snap);
btrfs_block_rsv_release(fs_info, block_rsv, (u64)-1, NULL);
if (qgroup_reserved)
btrfs_qgroup_free_meta_prealloc(root, qgroup_reserved);
free_pending:
if (pending_snapshot->anon_dev)
free_anon_bdev(pending_snapshot->anon_dev);
kfree(pending_snapshot->root_item);
btrfs_free_path(pending_snapshot->path);
kfree(pending_snapshot);
return ret;
}
/* copy of may_delete in fs/namei.c()
* Check whether we can remove a link victim from directory dir, check
* whether the type of victim is right.
* 1. We can't do it if dir is read-only (done in permission())
* 2. We should have write and exec permissions on dir
* 3. We can't remove anything from append-only dir
* 4. We can't do anything with immutable dir (done in permission())
* 5. If the sticky bit on dir is set we should either
* a. be owner of dir, or
* b. be owner of victim, or
* c. have CAP_FOWNER capability
* 6. If the victim is append-only or immutable we can't do anything with
* links pointing to it.
* 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
* 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
* 9. We can't remove a root or mountpoint.
* 10. We don't allow removal of NFS sillyrenamed files; it's handled by
* nfs_async_unlink().
*/
static int btrfs_may_delete(struct mnt_idmap *idmap,
struct inode *dir, struct dentry *victim, int isdir)
{
int error;
if (d_really_is_negative(victim))
return -ENOENT;
/* The @victim is not inside @dir. */
if (d_inode(victim->d_parent) != dir)
return -EINVAL;
audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
error = inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
if (error)
return error;
if (IS_APPEND(dir))
return -EPERM;
if (check_sticky(idmap, dir, d_inode(victim)) ||
IS_APPEND(d_inode(victim)) || IS_IMMUTABLE(d_inode(victim)) ||
IS_SWAPFILE(d_inode(victim)))
return -EPERM;
if (isdir) {
if (!d_is_dir(victim))
return -ENOTDIR;
if (IS_ROOT(victim))
return -EBUSY;
} else if (d_is_dir(victim))
return -EISDIR;
if (IS_DEADDIR(dir))
return -ENOENT;
if (victim->d_flags & DCACHE_NFSFS_RENAMED)
return -EBUSY;
return 0;
}
/* copy of may_create in fs/namei.c() */
static inline int btrfs_may_create(struct mnt_idmap *idmap,
struct inode *dir, struct dentry *child)
{
if (d_really_is_positive(child))
return -EEXIST;
if (IS_DEADDIR(dir))
return -ENOENT;
if (!fsuidgid_has_mapping(dir->i_sb, idmap))
return -EOVERFLOW;
return inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
}
/*
* Create a new subvolume below @parent. This is largely modeled after
* sys_mkdirat and vfs_mkdir, but we only do a single component lookup
* inside this filesystem so it's quite a bit simpler.
*/
static noinline int btrfs_mksubvol(const struct path *parent,
struct mnt_idmap *idmap,
const char *name, int namelen,
struct btrfs_root *snap_src,
bool readonly,
struct btrfs_qgroup_inherit *inherit)
{
struct inode *dir = d_inode(parent->dentry);
struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
struct dentry *dentry;
struct fscrypt_str name_str = FSTR_INIT((char *)name, namelen);
int error;
error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
if (error == -EINTR)
return error;
dentry = lookup_one(idmap, name, parent->dentry, namelen);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_unlock;
error = btrfs_may_create(idmap, dir, dentry);
if (error)
goto out_dput;
/*
* even if this name doesn't exist, we may get hash collisions.
* check for them now when we can safely fail
*/
error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
dir->i_ino, &name_str);
if (error)
goto out_dput;
down_read(&fs_info->subvol_sem);
if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
goto out_up_read;
if (snap_src)
error = create_snapshot(snap_src, dir, dentry, readonly, inherit);
else
error = create_subvol(idmap, dir, dentry, inherit);
if (!error)
fsnotify_mkdir(dir, dentry);
out_up_read:
up_read(&fs_info->subvol_sem);
out_dput:
dput(dentry);
out_unlock:
btrfs_inode_unlock(BTRFS_I(dir), 0);
return error;
}
static noinline int btrfs_mksnapshot(const struct path *parent,
struct mnt_idmap *idmap,
const char *name, int namelen,
struct btrfs_root *root,
bool readonly,
struct btrfs_qgroup_inherit *inherit)
{
int ret;
bool snapshot_force_cow = false;
/*
* Force new buffered writes to reserve space even when NOCOW is
* possible. This is to avoid later writeback (running dealloc) to
* fallback to COW mode and unexpectedly fail with ENOSPC.
*/
btrfs_drew_read_lock(&root->snapshot_lock);
ret = btrfs_start_delalloc_snapshot(root, false);
if (ret)
goto out;
/*
* All previous writes have started writeback in NOCOW mode, so now
* we force future writes to fallback to COW mode during snapshot
* creation.
*/
atomic_inc(&root->snapshot_force_cow);
snapshot_force_cow = true;
btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
ret = btrfs_mksubvol(parent, idmap, name, namelen,
root, readonly, inherit);
out:
if (snapshot_force_cow)
atomic_dec(&root->snapshot_force_cow);
btrfs_drew_read_unlock(&root->snapshot_lock);
return ret;
}
/*
* Try to start exclusive operation @type or cancel it if it's running.
*
* Return:
* 0 - normal mode, newly claimed op started
* >0 - normal mode, something else is running,
* return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS to user space
* ECANCELED - cancel mode, successful cancel
* ENOTCONN - cancel mode, operation not running anymore
*/
static int exclop_start_or_cancel_reloc(struct btrfs_fs_info *fs_info,
enum btrfs_exclusive_operation type, bool cancel)
{
if (!cancel) {
/* Start normal op */
if (!btrfs_exclop_start(fs_info, type))
return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
/* Exclusive operation is now claimed */
return 0;
}
/* Cancel running op */
if (btrfs_exclop_start_try_lock(fs_info, type)) {
/*
* This blocks any exclop finish from setting it to NONE, so we
* request cancellation. Either it runs and we will wait for it,
* or it has finished and no waiting will happen.
*/
atomic_inc(&fs_info->reloc_cancel_req);
btrfs_exclop_start_unlock(fs_info);
if (test_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags))
wait_on_bit(&fs_info->flags, BTRFS_FS_RELOC_RUNNING,
TASK_INTERRUPTIBLE);
return -ECANCELED;
}
/* Something else is running or none */
return -ENOTCONN;
}
static noinline int btrfs_ioctl_resize(struct file *file,
void __user *arg)
{
BTRFS_DEV_LOOKUP_ARGS(args);
struct inode *inode = file_inode(file);
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
u64 new_size;
u64 old_size;
u64 devid = 1;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_ioctl_vol_args *vol_args;
struct btrfs_trans_handle *trans;
struct btrfs_device *device = NULL;
char *sizestr;
char *retptr;
char *devstr = NULL;
int ret = 0;
int mod = 0;
bool cancel;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
ret = mnt_want_write_file(file);
if (ret)
return ret;
/*
* Read the arguments before checking exclusivity to be able to
* distinguish regular resize and cancel
*/
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args)) {
ret = PTR_ERR(vol_args);
goto out_drop;
}
ret = btrfs_check_ioctl_vol_args_path(vol_args);
if (ret < 0)
goto out_free;
sizestr = vol_args->name;
cancel = (strcmp("cancel", sizestr) == 0);
ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_RESIZE, cancel);
if (ret)
goto out_free;
/* Exclusive operation is now claimed */
devstr = strchr(sizestr, ':');
if (devstr) {
sizestr = devstr + 1;
*devstr = '\0';
devstr = vol_args->name;
ret = kstrtoull(devstr, 10, &devid);
if (ret)
goto out_finish;
if (!devid) {
ret = -EINVAL;
goto out_finish;
}
btrfs_info(fs_info, "resizing devid %llu", devid);
}
args.devid = devid;
device = btrfs_find_device(fs_info->fs_devices, &args);
if (!device) {
btrfs_info(fs_info, "resizer unable to find device %llu",
devid);
ret = -ENODEV;
goto out_finish;
}
if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
btrfs_info(fs_info,
"resizer unable to apply on readonly device %llu",
devid);
ret = -EPERM;
goto out_finish;
}
if (!strcmp(sizestr, "max"))
new_size = bdev_nr_bytes(device->bdev);
else {
if (sizestr[0] == '-') {
mod = -1;
sizestr++;
} else if (sizestr[0] == '+') {
mod = 1;
sizestr++;
}
new_size = memparse(sizestr, &retptr);
if (*retptr != '\0' || new_size == 0) {
ret = -EINVAL;
goto out_finish;
}
}
if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
ret = -EPERM;
goto out_finish;
}
old_size = btrfs_device_get_total_bytes(device);
if (mod < 0) {
if (new_size > old_size) {
ret = -EINVAL;
goto out_finish;
}
new_size = old_size - new_size;
} else if (mod > 0) {
if (new_size > ULLONG_MAX - old_size) {
ret = -ERANGE;
goto out_finish;
}
new_size = old_size + new_size;
}
if (new_size < SZ_256M) {
ret = -EINVAL;
goto out_finish;
}
if (new_size > bdev_nr_bytes(device->bdev)) {
ret = -EFBIG;
goto out_finish;
}
new_size = round_down(new_size, fs_info->sectorsize);
if (new_size > old_size) {
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_finish;
}
ret = btrfs_grow_device(trans, device, new_size);
btrfs_commit_transaction(trans);
} else if (new_size < old_size) {
ret = btrfs_shrink_device(device, new_size);
} /* equal, nothing need to do */
if (ret == 0 && new_size != old_size)
btrfs_info_in_rcu(fs_info,
"resize device %s (devid %llu) from %llu to %llu",
btrfs_dev_name(device), device->devid,
old_size, new_size);
out_finish:
btrfs_exclop_finish(fs_info);
out_free:
kfree(vol_args);
out_drop:
mnt_drop_write_file(file);
return ret;
}
static noinline int __btrfs_ioctl_snap_create(struct file *file,
struct mnt_idmap *idmap,
const char *name, unsigned long fd, int subvol,
bool readonly,
struct btrfs_qgroup_inherit *inherit)
{
int namelen;
int ret = 0;
if (!S_ISDIR(file_inode(file)->i_mode))
return -ENOTDIR;
ret = mnt_want_write_file(file);
if (ret)
goto out;
namelen = strlen(name);
if (strchr(name, '/')) {
ret = -EINVAL;
goto out_drop_write;
}
if (name[0] == '.' &&
(namelen == 1 || (name[1] == '.' && namelen == 2))) {
ret = -EEXIST;
goto out_drop_write;
}
if (subvol) {
ret = btrfs_mksubvol(&file->f_path, idmap, name,
namelen, NULL, readonly, inherit);
} else {
struct fd src = fdget(fd);
struct inode *src_inode;
if (!src.file) {
ret = -EINVAL;
goto out_drop_write;
}
src_inode = file_inode(src.file);
if (src_inode->i_sb != file_inode(file)->i_sb) {
btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
"Snapshot src from another FS");
ret = -EXDEV;
} else if (!inode_owner_or_capable(idmap, src_inode)) {
/*
* Subvolume creation is not restricted, but snapshots
* are limited to own subvolumes only
*/
ret = -EPERM;
} else if (btrfs_ino(BTRFS_I(src_inode)) != BTRFS_FIRST_FREE_OBJECTID) {
/*
* Snapshots must be made with the src_inode referring
* to the subvolume inode, otherwise the permission
* checking above is useless because we may have
* permission on a lower directory but not the subvol
* itself.
*/
ret = -EINVAL;
} else {
ret = btrfs_mksnapshot(&file->f_path, idmap,
name, namelen,
BTRFS_I(src_inode)->root,
readonly, inherit);
}
fdput(src);
}
out_drop_write:
mnt_drop_write_file(file);
out:
return ret;
}
static noinline int btrfs_ioctl_snap_create(struct file *file,
void __user *arg, int subvol)
{
struct btrfs_ioctl_vol_args *vol_args;
int ret;
if (!S_ISDIR(file_inode(file)->i_mode))
return -ENOTDIR;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
ret = btrfs_check_ioctl_vol_args_path(vol_args);
if (ret < 0)
goto out;
ret = __btrfs_ioctl_snap_create(file, file_mnt_idmap(file),
vol_args->name, vol_args->fd, subvol,
false, NULL);
out:
kfree(vol_args);
return ret;
}
static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
void __user *arg, int subvol)
{
struct btrfs_ioctl_vol_args_v2 *vol_args;
int ret;
bool readonly = false;
struct btrfs_qgroup_inherit *inherit = NULL;
if (!S_ISDIR(file_inode(file)->i_mode))
return -ENOTDIR;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
ret = btrfs_check_ioctl_vol_args2_subvol_name(vol_args);
if (ret < 0)
goto free_args;
if (vol_args->flags & ~BTRFS_SUBVOL_CREATE_ARGS_MASK) {
ret = -EOPNOTSUPP;
goto free_args;
}
if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
readonly = true;
if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
struct btrfs_fs_info *fs_info = inode_to_fs_info(file_inode(file));
if (vol_args->size < sizeof(*inherit) ||
vol_args->size > PAGE_SIZE) {
ret = -EINVAL;
goto free_args;
}
inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
if (IS_ERR(inherit)) {
ret = PTR_ERR(inherit);
goto free_args;
}
ret = btrfs_qgroup_check_inherit(fs_info, inherit, vol_args->size);
if (ret < 0)
goto free_inherit;
}
ret = __btrfs_ioctl_snap_create(file, file_mnt_idmap(file),
vol_args->name, vol_args->fd, subvol,
readonly, inherit);
if (ret)
goto free_inherit;
free_inherit:
kfree(inherit);
free_args:
kfree(vol_args);
return ret;
}
static noinline int btrfs_ioctl_subvol_getflags(struct inode *inode,
void __user *arg)
{
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret = 0;
u64 flags = 0;
if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
return -EINVAL;
down_read(&fs_info->subvol_sem);
if (btrfs_root_readonly(root))
flags |= BTRFS_SUBVOL_RDONLY;
up_read(&fs_info->subvol_sem);
if (copy_to_user(arg, &flags, sizeof(flags)))
ret = -EFAULT;
return ret;
}
static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
void __user *arg)
{
struct inode *inode = file_inode(file);
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
u64 root_flags;
u64 flags;
int ret = 0;
if (!inode_owner_or_capable(file_mnt_idmap(file), inode))
return -EPERM;
ret = mnt_want_write_file(file);
if (ret)
goto out;
if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
ret = -EINVAL;
goto out_drop_write;
}
if (copy_from_user(&flags, arg, sizeof(flags))) {
ret = -EFAULT;
goto out_drop_write;
}
if (flags & ~BTRFS_SUBVOL_RDONLY) {
ret = -EOPNOTSUPP;
goto out_drop_write;
}
down_write(&fs_info->subvol_sem);
/* nothing to do */
if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
goto out_drop_sem;
root_flags = btrfs_root_flags(&root->root_item);
if (flags & BTRFS_SUBVOL_RDONLY) {
btrfs_set_root_flags(&root->root_item,
root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
} else {
/*
* Block RO -> RW transition if this subvolume is involved in
* send
*/
spin_lock(&root->root_item_lock);
if (root->send_in_progress == 0) {
btrfs_set_root_flags(&root->root_item,
root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
spin_unlock(&root->root_item_lock);
} else {
spin_unlock(&root->root_item_lock);
btrfs_warn(fs_info,
"Attempt to set subvolume %llu read-write during send",
btrfs_root_id(root));
ret = -EPERM;
goto out_drop_sem;
}
}
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_reset;
}
ret = btrfs_update_root(trans, fs_info->tree_root,
&root->root_key, &root->root_item);
if (ret < 0) {
btrfs_end_transaction(trans);
goto out_reset;
}
ret = btrfs_commit_transaction(trans);
out_reset:
if (ret)
btrfs_set_root_flags(&root->root_item, root_flags);
out_drop_sem:
up_write(&fs_info->subvol_sem);
out_drop_write:
mnt_drop_write_file(file);
out:
return ret;
}
static noinline int key_in_sk(struct btrfs_key *key,
struct btrfs_ioctl_search_key *sk)
{
struct btrfs_key test;
int ret;
test.objectid = sk->min_objectid;
test.type = sk->min_type;
test.offset = sk->min_offset;
ret = btrfs_comp_cpu_keys(key, &test);
if (ret < 0)
return 0;
test.objectid = sk->max_objectid;
test.type = sk->max_type;
test.offset = sk->max_offset;
ret = btrfs_comp_cpu_keys(key, &test);
if (ret > 0)
return 0;
return 1;
}
static noinline int copy_to_sk(struct btrfs_path *path,
struct btrfs_key *key,
struct btrfs_ioctl_search_key *sk,
u64 *buf_size,
char __user *ubuf,
unsigned long *sk_offset,
int *num_found)
{
u64 found_transid;
struct extent_buffer *leaf;
struct btrfs_ioctl_search_header sh;
struct btrfs_key test;
unsigned long item_off;
unsigned long item_len;
int nritems;
int i;
int slot;
int ret = 0;
leaf = path->nodes[0];
slot = path->slots[0];
nritems = btrfs_header_nritems(leaf);
if (btrfs_header_generation(leaf) > sk->max_transid) {
i = nritems;
goto advance_key;
}
found_transid = btrfs_header_generation(leaf);
for (i = slot; i < nritems; i++) {
item_off = btrfs_item_ptr_offset(leaf, i);
item_len = btrfs_item_size(leaf, i);
btrfs_item_key_to_cpu(leaf, key, i);
if (!key_in_sk(key, sk))
continue;
if (sizeof(sh) + item_len > *buf_size) {
if (*num_found) {
ret = 1;
goto out;
}
/*
* return one empty item back for v1, which does not
* handle -EOVERFLOW
*/
*buf_size = sizeof(sh) + item_len;
item_len = 0;
ret = -EOVERFLOW;
}
if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
ret = 1;
goto out;
}
sh.objectid = key->objectid;
sh.offset = key->offset;
sh.type = key->type;
sh.len = item_len;
sh.transid = found_transid;
/*
* Copy search result header. If we fault then loop again so we
* can fault in the pages and -EFAULT there if there's a
* problem. Otherwise we'll fault and then copy the buffer in
* properly this next time through
*/
if (copy_to_user_nofault(ubuf + *sk_offset, &sh, sizeof(sh))) {
ret = 0;
goto out;
}
*sk_offset += sizeof(sh);
if (item_len) {
char __user *up = ubuf + *sk_offset;
/*
* Copy the item, same behavior as above, but reset the
* * sk_offset so we copy the full thing again.
*/
if (read_extent_buffer_to_user_nofault(leaf, up,
item_off, item_len)) {
ret = 0;
*sk_offset -= sizeof(sh);
goto out;
}
*sk_offset += item_len;
}
(*num_found)++;
if (ret) /* -EOVERFLOW from above */
goto out;
if (*num_found >= sk->nr_items) {
ret = 1;
goto out;
}
}
advance_key:
ret = 0;
test.objectid = sk->max_objectid;
test.type = sk->max_type;
test.offset = sk->max_offset;
if (btrfs_comp_cpu_keys(key, &test) >= 0)
ret = 1;
else if (key->offset < (u64)-1)
key->offset++;
else if (key->type < (u8)-1) {
key->offset = 0;
key->type++;
} else if (key->objectid < (u64)-1) {
key->offset = 0;
key->type = 0;
key->objectid++;
} else
ret = 1;
out:
/*
* 0: all items from this leaf copied, continue with next
* 1: * more items can be copied, but unused buffer is too small
* * all items were found
* Either way, it will stops the loop which iterates to the next
* leaf
* -EOVERFLOW: item was to large for buffer
* -EFAULT: could not copy extent buffer back to userspace
*/
return ret;
}
static noinline int search_ioctl(struct inode *inode,
struct btrfs_ioctl_search_key *sk,
u64 *buf_size,
char __user *ubuf)
{
struct btrfs_fs_info *info = inode_to_fs_info(inode);
struct btrfs_root *root;
struct btrfs_key key;
struct btrfs_path *path;
int ret;
int num_found = 0;
unsigned long sk_offset = 0;
if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
*buf_size = sizeof(struct btrfs_ioctl_search_header);
return -EOVERFLOW;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (sk->tree_id == 0) {
/* search the root of the inode that was passed */
root = btrfs_grab_root(BTRFS_I(inode)->root);
} else {
root = btrfs_get_fs_root(info, sk->tree_id, true);
if (IS_ERR(root)) {
btrfs_free_path(path);
return PTR_ERR(root);
}
}
key.objectid = sk->min_objectid;
key.type = sk->min_type;
key.offset = sk->min_offset;
while (1) {
ret = -EFAULT;
/*
* Ensure that the whole user buffer is faulted in at sub-page
* granularity, otherwise the loop may live-lock.
*/
if (fault_in_subpage_writeable(ubuf + sk_offset,
*buf_size - sk_offset))
break;
ret = btrfs_search_forward(root, &key, path, sk->min_transid);
if (ret != 0) {
if (ret > 0)
ret = 0;
goto err;
}
ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
&sk_offset, &num_found);
btrfs_release_path(path);
if (ret)
break;
}
if (ret > 0)
ret = 0;
err:
sk->nr_items = num_found;
btrfs_put_root(root);
btrfs_free_path(path);
return ret;
}
static noinline int btrfs_ioctl_tree_search(struct inode *inode,
void __user *argp)
{
struct btrfs_ioctl_search_args __user *uargs = argp;
struct btrfs_ioctl_search_key sk;
int ret;
u64 buf_size;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
return -EFAULT;
buf_size = sizeof(uargs->buf);
ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
/*
* In the origin implementation an overflow is handled by returning a
* search header with a len of zero, so reset ret.
*/
if (ret == -EOVERFLOW)
ret = 0;
if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
ret = -EFAULT;
return ret;
}
static noinline int btrfs_ioctl_tree_search_v2(struct inode *inode,
void __user *argp)
{
struct btrfs_ioctl_search_args_v2 __user *uarg = argp;
struct btrfs_ioctl_search_args_v2 args;
int ret;
u64 buf_size;
const u64 buf_limit = SZ_16M;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
/* copy search header and buffer size */
if (copy_from_user(&args, uarg, sizeof(args)))
return -EFAULT;
buf_size = args.buf_size;
/* limit result size to 16MB */
if (buf_size > buf_limit)
buf_size = buf_limit;
ret = search_ioctl(inode, &args.key, &buf_size,
(char __user *)(&uarg->buf[0]));
if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
ret = -EFAULT;
else if (ret == -EOVERFLOW &&
copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
ret = -EFAULT;
return ret;
}
/*
* Search INODE_REFs to identify path name of 'dirid' directory
* in a 'tree_id' tree. and sets path name to 'name'.
*/
static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
u64 tree_id, u64 dirid, char *name)
{
struct btrfs_root *root;
struct btrfs_key key;
char *ptr;
int ret = -1;
int slot;
int len;
int total_len = 0;
struct btrfs_inode_ref *iref;
struct extent_buffer *l;
struct btrfs_path *path;
if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
name[0]='\0';
return 0;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
root = btrfs_get_fs_root(info, tree_id, true);
if (IS_ERR(root)) {
ret = PTR_ERR(root);
root = NULL;
goto out;
}
key.objectid = dirid;
key.type = BTRFS_INODE_REF_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_backwards(root, &key, path);
if (ret < 0)
goto out;
else if (ret > 0) {
ret = -ENOENT;
goto out;
}
l = path->nodes[0];
slot = path->slots[0];
iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
len = btrfs_inode_ref_name_len(l, iref);
ptr -= len + 1;
total_len += len + 1;
if (ptr < name) {
ret = -ENAMETOOLONG;
goto out;
}
*(ptr + len) = '/';
read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
break;
btrfs_release_path(path);
key.objectid = key.offset;
key.offset = (u64)-1;
dirid = key.objectid;
}
memmove(name, ptr, total_len);
name[total_len] = '\0';
ret = 0;
out:
btrfs_put_root(root);
btrfs_free_path(path);
return ret;
}
static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
struct inode *inode,
struct btrfs_ioctl_ino_lookup_user_args *args)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct super_block *sb = inode->i_sb;
struct btrfs_key upper_limit = BTRFS_I(inode)->location;
u64 treeid = btrfs_root_id(BTRFS_I(inode)->root);
u64 dirid = args->dirid;
unsigned long item_off;
unsigned long item_len;
struct btrfs_inode_ref *iref;
struct btrfs_root_ref *rref;
struct btrfs_root *root = NULL;
struct btrfs_path *path;
struct btrfs_key key, key2;
struct extent_buffer *leaf;
struct inode *temp_inode;
char *ptr;
int slot;
int len;
int total_len = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* If the bottom subvolume does not exist directly under upper_limit,
* construct the path in from the bottom up.
*/
if (dirid != upper_limit.objectid) {
ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
root = btrfs_get_fs_root(fs_info, treeid, true);
if (IS_ERR(root)) {
ret = PTR_ERR(root);
goto out;
}
key.objectid = dirid;
key.type = BTRFS_INODE_REF_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_backwards(root, &key, path);
if (ret < 0)
goto out_put;
else if (ret > 0) {
ret = -ENOENT;
goto out_put;
}
leaf = path->nodes[0];
slot = path->slots[0];
iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
len = btrfs_inode_ref_name_len(leaf, iref);
ptr -= len + 1;
total_len += len + 1;
if (ptr < args->path) {
ret = -ENAMETOOLONG;
goto out_put;
}
*(ptr + len) = '/';
read_extent_buffer(leaf, ptr,
(unsigned long)(iref + 1), len);
/* Check the read+exec permission of this directory */
ret = btrfs_previous_item(root, path, dirid,
BTRFS_INODE_ITEM_KEY);
if (ret < 0) {
goto out_put;
} else if (ret > 0) {
ret = -ENOENT;
goto out_put;
}
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &key2, slot);
if (key2.objectid != dirid) {
ret = -ENOENT;
goto out_put;
}
/*
* We don't need the path anymore, so release it and
* avoid deadlocks and lockdep warnings in case
* btrfs_iget() needs to lookup the inode from its root
* btree and lock the same leaf.
*/
btrfs_release_path(path);
temp_inode = btrfs_iget(sb, key2.objectid, root);
if (IS_ERR(temp_inode)) {
ret = PTR_ERR(temp_inode);
goto out_put;
}
ret = inode_permission(idmap, temp_inode,
MAY_READ | MAY_EXEC);
iput(temp_inode);
if (ret) {
ret = -EACCES;
goto out_put;
}
if (key.offset == upper_limit.objectid)
break;
if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
ret = -EACCES;
goto out_put;
}
key.objectid = key.offset;
key.offset = (u64)-1;
dirid = key.objectid;
}
memmove(args->path, ptr, total_len);
args->path[total_len] = '\0';
btrfs_put_root(root);
root = NULL;
btrfs_release_path(path);
}
/* Get the bottom subvolume's name from ROOT_REF */
key.objectid = treeid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = args->treeid;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret < 0) {
goto out;
} else if (ret > 0) {
ret = -ENOENT;
goto out;
}
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
item_off = btrfs_item_ptr_offset(leaf, slot);
item_len = btrfs_item_size(leaf, slot);
/* Check if dirid in ROOT_REF corresponds to passed dirid */
rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
ret = -EINVAL;
goto out;
}
/* Copy subvolume's name */
item_off += sizeof(struct btrfs_root_ref);
item_len -= sizeof(struct btrfs_root_ref);
read_extent_buffer(leaf, args->name, item_off, item_len);
args->name[item_len] = 0;
out_put:
btrfs_put_root(root);
out:
btrfs_free_path(path);
return ret;
}
static noinline int btrfs_ioctl_ino_lookup(struct btrfs_root *root,
void __user *argp)
{
struct btrfs_ioctl_ino_lookup_args *args;
int ret = 0;
args = memdup_user(argp, sizeof(*args));
if (IS_ERR(args))
return PTR_ERR(args);
/*
* Unprivileged query to obtain the containing subvolume root id. The
* path is reset so it's consistent with btrfs_search_path_in_tree.
*/
if (args->treeid == 0)
args->treeid = btrfs_root_id(root);
if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
args->name[0] = 0;
goto out;
}
if (!capable(CAP_SYS_ADMIN)) {
ret = -EPERM;
goto out;
}
ret = btrfs_search_path_in_tree(root->fs_info,
args->treeid, args->objectid,
args->name);
out:
if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
ret = -EFAULT;
kfree(args);
return ret;
}
/*
* Version of ino_lookup ioctl (unprivileged)
*
* The main differences from ino_lookup ioctl are:
*
* 1. Read + Exec permission will be checked using inode_permission() during
* path construction. -EACCES will be returned in case of failure.
* 2. Path construction will be stopped at the inode number which corresponds
* to the fd with which this ioctl is called. If constructed path does not
* exist under fd's inode, -EACCES will be returned.
* 3. The name of bottom subvolume is also searched and filled.
*/
static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
{
struct btrfs_ioctl_ino_lookup_user_args *args;
struct inode *inode;
int ret;
args = memdup_user(argp, sizeof(*args));
if (IS_ERR(args))
return PTR_ERR(args);
inode = file_inode(file);
if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
/*
* The subvolume does not exist under fd with which this is
* called
*/
kfree(args);
return -EACCES;
}
ret = btrfs_search_path_in_tree_user(file_mnt_idmap(file), inode, args);
if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
ret = -EFAULT;
kfree(args);
return ret;
}
/* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
static int btrfs_ioctl_get_subvol_info(struct inode *inode, void __user *argp)
{
struct btrfs_ioctl_get_subvol_info_args *subvol_info;
struct btrfs_fs_info *fs_info;
struct btrfs_root *root;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_root_item *root_item;
struct btrfs_root_ref *rref;
struct extent_buffer *leaf;
unsigned long item_off;
unsigned long item_len;
int slot;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
if (!subvol_info) {
btrfs_free_path(path);
return -ENOMEM;
}
fs_info = BTRFS_I(inode)->root->fs_info;
/* Get root_item of inode's subvolume */
key.objectid = btrfs_root_id(BTRFS_I(inode)->root);
root = btrfs_get_fs_root(fs_info, key.objectid, true);
if (IS_ERR(root)) {
ret = PTR_ERR(root);
goto out_free;
}
root_item = &root->root_item;
subvol_info->treeid = key.objectid;
subvol_info->generation = btrfs_root_generation(root_item);
subvol_info->flags = btrfs_root_flags(root_item);
memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
BTRFS_UUID_SIZE);
memcpy(subvol_info->received_uuid, root_item->received_uuid,
BTRFS_UUID_SIZE);
subvol_info->ctransid = btrfs_root_ctransid(root_item);
subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
subvol_info->otransid = btrfs_root_otransid(root_item);
subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
subvol_info->stransid = btrfs_root_stransid(root_item);
subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
subvol_info->rtransid = btrfs_root_rtransid(root_item);
subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
/* Search root tree for ROOT_BACKREF of this subvolume */
key.type = BTRFS_ROOT_BACKREF_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret < 0) {
goto out;
} else if (path->slots[0] >=
btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_leaf(fs_info->tree_root, path);
if (ret < 0) {
goto out;
} else if (ret > 0) {
ret = -EUCLEAN;
goto out;
}
}
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid == subvol_info->treeid &&
key.type == BTRFS_ROOT_BACKREF_KEY) {
subvol_info->parent_id = key.offset;
rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
item_off = btrfs_item_ptr_offset(leaf, slot)
+ sizeof(struct btrfs_root_ref);
item_len = btrfs_item_size(leaf, slot)
- sizeof(struct btrfs_root_ref);
read_extent_buffer(leaf, subvol_info->name,
item_off, item_len);
} else {
ret = -ENOENT;
goto out;
}
}
btrfs_free_path(path);
path = NULL;
if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
ret = -EFAULT;
out:
btrfs_put_root(root);
out_free:
btrfs_free_path(path);
kfree(subvol_info);
return ret;
}
/*
* Return ROOT_REF information of the subvolume containing this inode
* except the subvolume name.
*/
static int btrfs_ioctl_get_subvol_rootref(struct btrfs_root *root,
void __user *argp)
{
struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
struct btrfs_root_ref *rref;
struct btrfs_path *path;
struct btrfs_key key;
struct extent_buffer *leaf;
u64 objectid;
int slot;
int ret;
u8 found;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
rootrefs = memdup_user(argp, sizeof(*rootrefs));
if (IS_ERR(rootrefs)) {
btrfs_free_path(path);
return PTR_ERR(rootrefs);
}
objectid = btrfs_root_id(root);
key.objectid = objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = rootrefs->min_treeid;
found = 0;
root = root->fs_info->tree_root;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
goto out;
} else if (path->slots[0] >=
btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
goto out;
} else if (ret > 0) {
ret = -EUCLEAN;
goto out;
}
}
while (1) {
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
ret = 0;
goto out;
}
if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
ret = -EOVERFLOW;
goto out;
}
rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
rootrefs->rootref[found].treeid = key.offset;
rootrefs->rootref[found].dirid =
btrfs_root_ref_dirid(leaf, rref);
found++;
ret = btrfs_next_item(root, path);
if (ret < 0) {
goto out;
} else if (ret > 0) {
ret = -EUCLEAN;
goto out;
}
}
out:
btrfs_free_path(path);
if (!ret || ret == -EOVERFLOW) {
rootrefs->num_items = found;
/* update min_treeid for next search */
if (found)
rootrefs->min_treeid =
rootrefs->rootref[found - 1].treeid + 1;
if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
ret = -EFAULT;
}
kfree(rootrefs);
return ret;
}
static noinline int btrfs_ioctl_snap_destroy(struct file *file,
void __user *arg,
bool destroy_v2)
{
struct dentry *parent = file->f_path.dentry;
struct dentry *dentry;
struct inode *dir = d_inode(parent);
struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
struct inode *inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *dest = NULL;
struct btrfs_ioctl_vol_args *vol_args = NULL;
struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
struct mnt_idmap *idmap = file_mnt_idmap(file);
char *subvol_name, *subvol_name_ptr = NULL;
int subvol_namelen;
int ret = 0;
bool destroy_parent = false;
/* We don't support snapshots with extent tree v2 yet. */
if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
btrfs_err(fs_info,
"extent tree v2 doesn't support snapshot deletion yet");
return -EOPNOTSUPP;
}
if (destroy_v2) {
vol_args2 = memdup_user(arg, sizeof(*vol_args2));
if (IS_ERR(vol_args2))
return PTR_ERR(vol_args2);
if (vol_args2->flags & ~BTRFS_SUBVOL_DELETE_ARGS_MASK) {
ret = -EOPNOTSUPP;
goto out;
}
/*
* If SPEC_BY_ID is not set, we are looking for the subvolume by
* name, same as v1 currently does.
*/
if (!(vol_args2->flags & BTRFS_SUBVOL_SPEC_BY_ID)) {
ret = btrfs_check_ioctl_vol_args2_subvol_name(vol_args2);
if (ret < 0)
goto out;
subvol_name = vol_args2->name;
ret = mnt_want_write_file(file);
if (ret)
goto out;
} else {
struct inode *old_dir;
if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
ret = -EINVAL;
goto out;
}
ret = mnt_want_write_file(file);
if (ret)
goto out;
dentry = btrfs_get_dentry(fs_info->sb,
BTRFS_FIRST_FREE_OBJECTID,
vol_args2->subvolid, 0);
if (IS_ERR(dentry)) {
ret = PTR_ERR(dentry);
goto out_drop_write;
}
/*
* Change the default parent since the subvolume being
* deleted can be outside of the current mount point.
*/
parent = btrfs_get_parent(dentry);
/*
* At this point dentry->d_name can point to '/' if the
* subvolume we want to destroy is outsite of the
* current mount point, so we need to release the
* current dentry and execute the lookup to return a new
* one with ->d_name pointing to the
* <mount point>/subvol_name.
*/
dput(dentry);
if (IS_ERR(parent)) {
ret = PTR_ERR(parent);
goto out_drop_write;
}
old_dir = dir;
dir = d_inode(parent);
/*
* If v2 was used with SPEC_BY_ID, a new parent was
* allocated since the subvolume can be outside of the
* current mount point. Later on we need to release this
* new parent dentry.
*/
destroy_parent = true;
/*
* On idmapped mounts, deletion via subvolid is
* restricted to subvolumes that are immediate
* ancestors of the inode referenced by the file
* descriptor in the ioctl. Otherwise the idmapping
* could potentially be abused to delete subvolumes
* anywhere in the filesystem the user wouldn't be able
* to delete without an idmapped mount.
*/
if (old_dir != dir && idmap != &nop_mnt_idmap) {
ret = -EOPNOTSUPP;
goto free_parent;
}
subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
fs_info, vol_args2->subvolid);
if (IS_ERR(subvol_name_ptr)) {
ret = PTR_ERR(subvol_name_ptr);
goto free_parent;
}
/* subvol_name_ptr is already nul terminated */
subvol_name = (char *)kbasename(subvol_name_ptr);
}
} else {
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
ret = btrfs_check_ioctl_vol_args_path(vol_args);
if (ret < 0)
goto out;
subvol_name = vol_args->name;
ret = mnt_want_write_file(file);
if (ret)
goto out;
}
subvol_namelen = strlen(subvol_name);
if (strchr(subvol_name, '/') ||
strncmp(subvol_name, "..", subvol_namelen) == 0) {
ret = -EINVAL;
goto free_subvol_name;
}
if (!S_ISDIR(dir->i_mode)) {
ret = -ENOTDIR;
goto free_subvol_name;
}
ret = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
if (ret == -EINTR)
goto free_subvol_name;
dentry = lookup_one(idmap, subvol_name, parent, subvol_namelen);
if (IS_ERR(dentry)) {
ret = PTR_ERR(dentry);
goto out_unlock_dir;
}
if (d_really_is_negative(dentry)) {
ret = -ENOENT;
goto out_dput;
}
inode = d_inode(dentry);
dest = BTRFS_I(inode)->root;
if (!capable(CAP_SYS_ADMIN)) {
/*
* Regular user. Only allow this with a special mount
* option, when the user has write+exec access to the
* subvol root, and when rmdir(2) would have been
* allowed.
*
* Note that this is _not_ check that the subvol is
* empty or doesn't contain data that we wouldn't
* otherwise be able to delete.
*
* Users who want to delete empty subvols should try
* rmdir(2).
*/
ret = -EPERM;
if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
goto out_dput;
/*
* Do not allow deletion if the parent dir is the same
* as the dir to be deleted. That means the ioctl
* must be called on the dentry referencing the root
* of the subvol, not a random directory contained
* within it.
*/
ret = -EINVAL;
if (root == dest)
goto out_dput;
ret = inode_permission(idmap, inode, MAY_WRITE | MAY_EXEC);
if (ret)
goto out_dput;
}
/* check if subvolume may be deleted by a user */
ret = btrfs_may_delete(idmap, dir, dentry, 1);
if (ret)
goto out_dput;
if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
ret = -EINVAL;
goto out_dput;
}
btrfs_inode_lock(BTRFS_I(inode), 0);
ret = btrfs_delete_subvolume(BTRFS_I(dir), dentry);
btrfs_inode_unlock(BTRFS_I(inode), 0);
if (!ret)
d_delete_notify(dir, dentry);
out_dput:
dput(dentry);
out_unlock_dir:
btrfs_inode_unlock(BTRFS_I(dir), 0);
free_subvol_name:
kfree(subvol_name_ptr);
free_parent:
if (destroy_parent)
dput(parent);
out_drop_write:
mnt_drop_write_file(file);
out:
kfree(vol_args2);
kfree(vol_args);
return ret;
}
static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
{
struct inode *inode = file_inode(file);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_ioctl_defrag_range_args range = {0};
int ret;
ret = mnt_want_write_file(file);
if (ret)
return ret;
if (btrfs_root_readonly(root)) {
ret = -EROFS;
goto out;
}
switch (inode->i_mode & S_IFMT) {
case S_IFDIR:
if (!capable(CAP_SYS_ADMIN)) {
ret = -EPERM;
goto out;
}
ret = btrfs_defrag_root(root);
break;
case S_IFREG:
/*
* Note that this does not check the file descriptor for write
* access. This prevents defragmenting executables that are
* running and allows defrag on files open in read-only mode.
*/
if (!capable(CAP_SYS_ADMIN) &&
inode_permission(&nop_mnt_idmap, inode, MAY_WRITE)) {
ret = -EPERM;
goto out;
}
if (argp) {
if (copy_from_user(&range, argp, sizeof(range))) {
ret = -EFAULT;
goto out;
}
if (range.flags & ~BTRFS_DEFRAG_RANGE_FLAGS_SUPP) {
ret = -EOPNOTSUPP;
goto out;
}
/* compression requires us to start the IO */
if ((range.flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
range.extent_thresh = (u32)-1;
}
} else {
/* the rest are all set to zero by kzalloc */
range.len = (u64)-1;
}
ret = btrfs_defrag_file(file_inode(file), &file->f_ra,
&range, BTRFS_OLDEST_GENERATION, 0);
if (ret > 0)
ret = 0;
break;
default:
ret = -EINVAL;
}
out:
mnt_drop_write_file(file);
return ret;
}
static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
{
struct btrfs_ioctl_vol_args *vol_args;
bool restore_op = false;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
btrfs_err(fs_info, "device add not supported on extent tree v2 yet");
return -EINVAL;
}
if (fs_info->fs_devices->temp_fsid) {
btrfs_err(fs_info,
"device add not supported on cloned temp-fsid mount");
return -EINVAL;
}
if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD)) {
if (!btrfs_exclop_start_try_lock(fs_info, BTRFS_EXCLOP_DEV_ADD))
return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
/*
* We can do the device add because we have a paused balanced,
* change the exclusive op type and remember we should bring
* back the paused balance
*/
fs_info->exclusive_operation = BTRFS_EXCLOP_DEV_ADD;
btrfs_exclop_start_unlock(fs_info);
restore_op = true;
}
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args)) {
ret = PTR_ERR(vol_args);
goto out;
}
ret = btrfs_check_ioctl_vol_args_path(vol_args);
if (ret < 0)
goto out_free;
ret = btrfs_init_new_device(fs_info, vol_args->name);
if (!ret)
btrfs_info(fs_info, "disk added %s", vol_args->name);
out_free:
kfree(vol_args);
out:
if (restore_op)
btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED);
else
btrfs_exclop_finish(fs_info);
return ret;
}
static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
{
BTRFS_DEV_LOOKUP_ARGS(args);
struct inode *inode = file_inode(file);
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
struct btrfs_ioctl_vol_args_v2 *vol_args;
struct file *bdev_file = NULL;
int ret;
bool cancel = false;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
ret = -EOPNOTSUPP;
goto out;
}
ret = btrfs_check_ioctl_vol_args2_subvol_name(vol_args);
if (ret < 0)
goto out;
if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
args.devid = vol_args->devid;
} else if (!strcmp("cancel", vol_args->name)) {
cancel = true;
} else {
ret = btrfs_get_dev_args_from_path(fs_info, &args, vol_args->name);
if (ret)
goto out;
}
ret = mnt_want_write_file(file);
if (ret)
goto out;
ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
cancel);
if (ret)
goto err_drop;
/* Exclusive operation is now claimed */
ret = btrfs_rm_device(fs_info, &args, &bdev_file);
btrfs_exclop_finish(fs_info);
if (!ret) {
if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
btrfs_info(fs_info, "device deleted: id %llu",
vol_args->devid);
else
btrfs_info(fs_info, "device deleted: %s",
vol_args->name);
}
err_drop:
mnt_drop_write_file(file);
if (bdev_file)
fput(bdev_file);
out:
btrfs_put_dev_args_from_path(&args);
kfree(vol_args);
return ret;
}
static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
{
BTRFS_DEV_LOOKUP_ARGS(args);
struct inode *inode = file_inode(file);
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
struct btrfs_ioctl_vol_args *vol_args;
struct file *bdev_file = NULL;
int ret;
bool cancel = false;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
ret = btrfs_check_ioctl_vol_args_path(vol_args);
if (ret < 0)
goto out_free;
if (!strcmp("cancel", vol_args->name)) {
cancel = true;
} else {
ret = btrfs_get_dev_args_from_path(fs_info, &args, vol_args->name);
if (ret)
goto out;
}
ret = mnt_want_write_file(file);
if (ret)
goto out;
ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
cancel);
if (ret == 0) {
ret = btrfs_rm_device(fs_info, &args, &bdev_file);
if (!ret)
btrfs_info(fs_info, "disk deleted %s", vol_args->name);
btrfs_exclop_finish(fs_info);
}
mnt_drop_write_file(file);
if (bdev_file)
fput(bdev_file);
out:
btrfs_put_dev_args_from_path(&args);
out_free:
kfree(vol_args);
return ret;
}
static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
void __user *arg)
{
struct btrfs_ioctl_fs_info_args *fi_args;
struct btrfs_device *device;
struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
u64 flags_in;
int ret = 0;
fi_args = memdup_user(arg, sizeof(*fi_args));
if (IS_ERR(fi_args))
return PTR_ERR(fi_args);
flags_in = fi_args->flags;
memset(fi_args, 0, sizeof(*fi_args));
rcu_read_lock();
fi_args->num_devices = fs_devices->num_devices;
list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
if (device->devid > fi_args->max_id)
fi_args->max_id = device->devid;
}
rcu_read_unlock();
memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
fi_args->nodesize = fs_info->nodesize;
fi_args->sectorsize = fs_info->sectorsize;
fi_args->clone_alignment = fs_info->sectorsize;
if (flags_in & BTRFS_FS_INFO_FLAG_CSUM_INFO) {
fi_args->csum_type = btrfs_super_csum_type(fs_info->super_copy);
fi_args->csum_size = btrfs_super_csum_size(fs_info->super_copy);
fi_args->flags |= BTRFS_FS_INFO_FLAG_CSUM_INFO;
}
if (flags_in & BTRFS_FS_INFO_FLAG_GENERATION) {
fi_args->generation = btrfs_get_fs_generation(fs_info);
fi_args->flags |= BTRFS_FS_INFO_FLAG_GENERATION;
}
if (flags_in & BTRFS_FS_INFO_FLAG_METADATA_UUID) {
memcpy(&fi_args->metadata_uuid, fs_devices->metadata_uuid,
sizeof(fi_args->metadata_uuid));
fi_args->flags |= BTRFS_FS_INFO_FLAG_METADATA_UUID;
}
if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
ret = -EFAULT;
kfree(fi_args);
return ret;
}
static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
void __user *arg)
{
BTRFS_DEV_LOOKUP_ARGS(args);
struct btrfs_ioctl_dev_info_args *di_args;
struct btrfs_device *dev;
int ret = 0;
di_args = memdup_user(arg, sizeof(*di_args));
if (IS_ERR(di_args))
return PTR_ERR(di_args);
args.devid = di_args->devid;
if (!btrfs_is_empty_uuid(di_args->uuid))
args.uuid = di_args->uuid;
rcu_read_lock();
dev = btrfs_find_device(fs_info->fs_devices, &args);
if (!dev) {
ret = -ENODEV;
goto out;
}
di_args->devid = dev->devid;
di_args->bytes_used = btrfs_device_get_bytes_used(dev);
di_args->total_bytes = btrfs_device_get_total_bytes(dev);
memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
memcpy(di_args->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
if (dev->name)
strscpy(di_args->path, btrfs_dev_name(dev), sizeof(di_args->path));
else
di_args->path[0] = '\0';
out:
rcu_read_unlock();
if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
ret = -EFAULT;
kfree(di_args);
return ret;
}
static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
{
struct inode *inode = file_inode(file);
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_root *new_root;
struct btrfs_dir_item *di;
struct btrfs_trans_handle *trans;
struct btrfs_path *path = NULL;
struct btrfs_disk_key disk_key;
struct fscrypt_str name = FSTR_INIT("default", 7);
u64 objectid = 0;
u64 dir_id;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
ret = mnt_want_write_file(file);
if (ret)
return ret;
if (copy_from_user(&objectid, argp, sizeof(objectid))) {
ret = -EFAULT;
goto out;
}
if (!objectid)
objectid = BTRFS_FS_TREE_OBJECTID;
new_root = btrfs_get_fs_root(fs_info, objectid, true);
if (IS_ERR(new_root)) {
ret = PTR_ERR(new_root);
goto out;
}
if (!is_fstree(btrfs_root_id(new_root))) {
ret = -ENOENT;
goto out_free;
}
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out_free;
}
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_free;
}
dir_id = btrfs_super_root_dir(fs_info->super_copy);
di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
dir_id, &name, 1);
if (IS_ERR_OR_NULL(di)) {
btrfs_release_path(path);
btrfs_end_transaction(trans);
btrfs_err(fs_info,
"Umm, you don't have the default diritem, this isn't going to work");
ret = -ENOENT;
goto out_free;
}
btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
btrfs_mark_buffer_dirty(trans, path->nodes[0]);
btrfs_release_path(path);
btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
btrfs_end_transaction(trans);
out_free:
btrfs_put_root(new_root);
btrfs_free_path(path);
out:
mnt_drop_write_file(file);
return ret;
}
static void get_block_group_info(struct list_head *groups_list,
struct btrfs_ioctl_space_info *space)
{
struct btrfs_block_group *block_group;
space->total_bytes = 0;
space->used_bytes = 0;
space->flags = 0;
list_for_each_entry(block_group, groups_list, list) {
space->flags = block_group->flags;
space->total_bytes += block_group->length;
space->used_bytes += block_group->used;
}
}
static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
void __user *arg)
{
struct btrfs_ioctl_space_args space_args = { 0 };
struct btrfs_ioctl_space_info space;
struct btrfs_ioctl_space_info *dest;
struct btrfs_ioctl_space_info *dest_orig;
struct btrfs_ioctl_space_info __user *user_dest;
struct btrfs_space_info *info;
static const u64 types[] = {
BTRFS_BLOCK_GROUP_DATA,
BTRFS_BLOCK_GROUP_SYSTEM,
BTRFS_BLOCK_GROUP_METADATA,
BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
};
int num_types = 4;
int alloc_size;
int ret = 0;
u64 slot_count = 0;
int i, c;
if (copy_from_user(&space_args,
(struct btrfs_ioctl_space_args __user *)arg,
sizeof(space_args)))
return -EFAULT;
for (i = 0; i < num_types; i++) {
struct btrfs_space_info *tmp;
info = NULL;
list_for_each_entry(tmp, &fs_info->space_info, list) {
if (tmp->flags == types[i]) {
info = tmp;
break;
}
}
if (!info)
continue;
down_read(&info->groups_sem);
for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
if (!list_empty(&info->block_groups[c]))
slot_count++;
}