Commit Graph

896 Commits

Author SHA1 Message Date
Nikolay Borisov c0a4360305 btrfs: remove inode argument from btrfs_start_ordered_extent
The passed in ordered_extent struct is always well-formed and contains
the inode making the explicit argument redundant.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:13:22 +02:00
Josef Bacik 7280490500 btrfs: kill the RCU protection for fs_info->space_info
We have this thing wrapped in an RCU lock, but it's really not needed.
We create all the space_info's on mount, and we destroy them on unmount.
The list never changes and we're protected from messing with it by the
normal mount/umount path, so kill the RCU stuff around it.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:13:19 +02:00
Goldwyn Rodrigues 66a2823c54 btrfs: sysfs: export currently running exclusive operation
/sys/fs/<fsid>/exclusive_operation contains the currently executing
exclusive operation. Add a sysfs_notify() when operation end, so
userspace can be notified of exclusive operation is finished.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:12:20 +02:00
Goldwyn Rodrigues c3e1f96c37 btrfs: enumerate the type of exclusive operation in progress
Instead of using a flag bit for exclusive operation, use a variable to
store which exclusive operation is being performed.  Introduce an API
to start and finish an exclusive operation.

This would enable another way for tools to check which operation is
running on why starting an exclusive operation failed. The followup
patch adds a sysfs_notify() to alert userspace when the state changes, so
userspace can perform select() on it to get notified of the change.

This would enable us to enqueue a command which will wait for current
exclusive operation to complete before issuing the next exclusive
operation. This has been done synchronously as opposed to a background
process, or else error collection (if any) will become difficult.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:12:20 +02:00
Josef Bacik 9631e4cc1a btrfs: introduce BTRFS_NESTING_COW for cow'ing blocks
When we COW a block we are holding a lock on the original block, and
then we lock the new COW block.  Because our lockdep maps are based on
root + level, this will make lockdep complain.  We need a way to
indicate a subclass for locking the COW'ed block, so plumb through our
btrfs_lock_nesting from btrfs_cow_block down to the btrfs_init_buffer,
and then introduce BTRFS_NESTING_COW to be used for cow'ing blocks.

The reason I've added all this extra infrastructure is because there
will be need of different nesting classes in follow up patches.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:12:16 +02:00
Qu Wenruo e85fde5162 btrfs: qgroup: fix qgroup meta rsv leak for subvolume operations
[BUG]
When quota is enabled for TEST_DEV, generic/013 sometimes fails like this:

  generic/013 14s ... _check_dmesg: something found in dmesg (see xfstests-dev/results//generic/013.dmesg)

And with the following metadata leak:

  BTRFS warning (device dm-3): qgroup 0/1370 has unreleased space, type 2 rsv 49152
  ------------[ cut here ]------------
  WARNING: CPU: 2 PID: 47912 at fs/btrfs/disk-io.c:4078 close_ctree+0x1dc/0x323 [btrfs]
  Call Trace:
   btrfs_put_super+0x15/0x17 [btrfs]
   generic_shutdown_super+0x72/0x110
   kill_anon_super+0x18/0x30
   btrfs_kill_super+0x17/0x30 [btrfs]
   deactivate_locked_super+0x3b/0xa0
   deactivate_super+0x40/0x50
   cleanup_mnt+0x135/0x190
   __cleanup_mnt+0x12/0x20
   task_work_run+0x64/0xb0
   __prepare_exit_to_usermode+0x1bc/0x1c0
   __syscall_return_slowpath+0x47/0x230
   do_syscall_64+0x64/0xb0
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  ---[ end trace a6cfd45ba80e4e06 ]---
  BTRFS error (device dm-3): qgroup reserved space leaked
  BTRFS info (device dm-3): disk space caching is enabled
  BTRFS info (device dm-3): has skinny extents

[CAUSE]
The qgroup preallocated meta rsv operations of that offending root are:

  btrfs_delayed_inode_reserve_metadata: rsv_meta_prealloc root=1370 num_bytes=131072
  btrfs_delayed_inode_reserve_metadata: rsv_meta_prealloc root=1370 num_bytes=131072
  btrfs_subvolume_reserve_metadata: rsv_meta_prealloc root=1370 num_bytes=49152
  btrfs_delayed_inode_release_metadata: convert_meta_prealloc root=1370 num_bytes=-131072
  btrfs_delayed_inode_release_metadata: convert_meta_prealloc root=1370 num_bytes=-131072

It's pretty obvious that, we reserve qgroup meta rsv in
btrfs_subvolume_reserve_metadata(), but doesn't have corresponding
release/convert calls in btrfs_subvolume_release_metadata().

This leads to the leakage.

[FIX]
To fix this bug, we should follow what we're doing in
btrfs_delalloc_reserve_metadata(), where we reserve qgroup space, and
add it to block_rsv->qgroup_rsv_reserved.

And free the qgroup reserved metadata space when releasing the
block_rsv.

To do this, we need to change the btrfs_subvolume_release_metadata() to
accept btrfs_root, and record the qgroup_to_release number, and call
btrfs_qgroup_convert_reserved_meta() for it.

Fixes: 733e03a0b2 ("btrfs: qgroup: Split meta rsv type into meta_prealloc and meta_pertrans")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:12:13 +02:00
Josef Bacik b49121393f btrfs: change nr to u64 in btrfs_start_delalloc_roots
We have btrfs_wait_ordered_roots() which takes a u64 for nr, but
btrfs_start_delalloc_roots() that takes an int for nr, which makes using
them in conjunction, especially for something like (u64)-1, annoying and
inconsistent.  Fix btrfs_start_delalloc_roots() to take a u64 for nr and
adjust start_delalloc_inodes() and it's callers appropriately.

This means we've adjusted start_delalloc_inodes() to take a pointer of
nr since we want to preserve the ability for start-delalloc_inodes() to
return an error, so simply make it do the nr adjusting as necessary.

Part of adjusting the callers to this means changing
btrfs_writeback_inodes_sb_nr() to take a u64 for items.  This may be
confusing because it seems unrelated, but the caller of
btrfs_writeback_inodes_sb_nr() already passes in a u64, it's just the
function variable that needs to be changed.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:06:50 +02:00
Filipe Manana 1c78544eaa btrfs: fix wrong address when faulting in pages in the search ioctl
When faulting in the pages for the user supplied buffer for the search
ioctl, we are passing only the base address of the buffer to the function
fault_in_pages_writeable(). This means that after the first iteration of
the while loop that searches for leaves, when we have a non-zero offset,
stored in 'sk_offset', we try to fault in a wrong page range.

So fix this by adding the offset in 'sk_offset' to the base address of the
user supplied buffer when calling fault_in_pages_writeable().

Several users have reported that the applications compsize and bees have
started to operate incorrectly since commit a48b73eca4 ("btrfs: fix
potential deadlock in the search ioctl") was added to stable trees, and
these applications make heavy use of the search ioctls. This fixes their
issues.

Link: https://lore.kernel.org/linux-btrfs/632b888d-a3c3-b085-cdf5-f9bb61017d92@lechevalier.se/
Link: https://github.com/kilobyte/compsize/issues/34
Fixes: a48b73eca4 ("btrfs: fix potential deadlock in the search ioctl")
CC: stable@vger.kernel.org # 4.4+
Tested-by: A L <mail@lechevalier.se>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-09-14 17:27:16 +02:00
Josef Bacik a48b73eca4 btrfs: fix potential deadlock in the search ioctl
With the conversion of the tree locks to rwsem I got the following
lockdep splat:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.8.0-rc7-00165-g04ec4da5f45f-dirty #922 Not tainted
  ------------------------------------------------------
  compsize/11122 is trying to acquire lock:
  ffff889fabca8768 (&mm->mmap_lock#2){++++}-{3:3}, at: __might_fault+0x3e/0x90

  but task is already holding lock:
  ffff889fe720fe40 (btrfs-fs-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (btrfs-fs-00){++++}-{3:3}:
	 down_write_nested+0x3b/0x70
	 __btrfs_tree_lock+0x24/0x120
	 btrfs_search_slot+0x756/0x990
	 btrfs_lookup_inode+0x3a/0xb4
	 __btrfs_update_delayed_inode+0x93/0x270
	 btrfs_async_run_delayed_root+0x168/0x230
	 btrfs_work_helper+0xd4/0x570
	 process_one_work+0x2ad/0x5f0
	 worker_thread+0x3a/0x3d0
	 kthread+0x133/0x150
	 ret_from_fork+0x1f/0x30

  -> #1 (&delayed_node->mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_delayed_update_inode+0x50/0x440
	 btrfs_update_inode+0x8a/0xf0
	 btrfs_dirty_inode+0x5b/0xd0
	 touch_atime+0xa1/0xd0
	 btrfs_file_mmap+0x3f/0x60
	 mmap_region+0x3a4/0x640
	 do_mmap+0x376/0x580
	 vm_mmap_pgoff+0xd5/0x120
	 ksys_mmap_pgoff+0x193/0x230
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #0 (&mm->mmap_lock#2){++++}-{3:3}:
	 __lock_acquire+0x1272/0x2310
	 lock_acquire+0x9e/0x360
	 __might_fault+0x68/0x90
	 _copy_to_user+0x1e/0x80
	 copy_to_sk.isra.32+0x121/0x300
	 search_ioctl+0x106/0x200
	 btrfs_ioctl_tree_search_v2+0x7b/0xf0
	 btrfs_ioctl+0x106f/0x30a0
	 ksys_ioctl+0x83/0xc0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  other info that might help us debug this:

  Chain exists of:
    &mm->mmap_lock#2 --> &delayed_node->mutex --> btrfs-fs-00

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(btrfs-fs-00);
				 lock(&delayed_node->mutex);
				 lock(btrfs-fs-00);
    lock(&mm->mmap_lock#2);

   *** DEADLOCK ***

  1 lock held by compsize/11122:
   #0: ffff889fe720fe40 (btrfs-fs-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180

  stack backtrace:
  CPU: 17 PID: 11122 Comm: compsize Kdump: loaded Not tainted 5.8.0-rc7-00165-g04ec4da5f45f-dirty #922
  Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
  Call Trace:
   dump_stack+0x78/0xa0
   check_noncircular+0x165/0x180
   __lock_acquire+0x1272/0x2310
   lock_acquire+0x9e/0x360
   ? __might_fault+0x3e/0x90
   ? find_held_lock+0x72/0x90
   __might_fault+0x68/0x90
   ? __might_fault+0x3e/0x90
   _copy_to_user+0x1e/0x80
   copy_to_sk.isra.32+0x121/0x300
   ? btrfs_search_forward+0x2a6/0x360
   search_ioctl+0x106/0x200
   btrfs_ioctl_tree_search_v2+0x7b/0xf0
   btrfs_ioctl+0x106f/0x30a0
   ? __do_sys_newfstat+0x5a/0x70
   ? ksys_ioctl+0x83/0xc0
   ksys_ioctl+0x83/0xc0
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x50/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

The problem is we're doing a copy_to_user() while holding tree locks,
which can deadlock if we have to do a page fault for the copy_to_user().
This exists even without my locking changes, so it needs to be fixed.
Rework the search ioctl to do the pre-fault and then
copy_to_user_nofault for the copying.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-08-27 13:56:27 +02:00
David Sterba f37c563bab btrfs: add missing check for nocow and compression inode flags
User Forza reported on IRC that some invalid combinations of file
attributes are accepted by chattr.

The NODATACOW and compression file flags/attributes are mutually
exclusive, but they could be set by 'chattr +c +C' on an empty file. The
nodatacow will be in effect because it's checked first in
btrfs_run_delalloc_range.

Extend the flag validation to catch the following cases:

  - input flags are conflicting
  - old and new flags are conflicting
  - initialize the local variable with inode flags after inode ls locked

Inode attributes take precedence over mount options and are an
independent setting.

Nocompress would be a no-op with nodatacow, but we don't want to mix
any compression-related options with nodatacow.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:44 +02:00
Johannes Thumshirn 49bac89768 btrfs: add metadata_uuid to FS_INFO ioctl
Add retrieval of the filesystem's metadata UUID to the fsinfo ioctl.
This is driven by setting the BTRFS_FS_INFO_FLAG_METADATA_UUID flag in
btrfs_ioctl_fs_info_args::flags.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:43 +02:00
Johannes Thumshirn 0fb408a558 btrfs: add filesystem generation to FS_INFO ioctl
Add retrieval of the filesystem's generation to the fsinfo ioctl. This is
driven by setting the BTRFS_FS_INFO_FLAG_GENERATION flag in
btrfs_ioctl_fs_info_args::flags.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:43 +02:00
Johannes Thumshirn 137c541821 btrfs: pass checksum type via BTRFS_IOC_FS_INFO ioctl
With the recent addition of filesystem checksum types other than CRC32c,
it is not anymore hard-coded which checksum type a btrfs filesystem uses.

Up to now there is no good way to read the filesystem checksum, apart from
reading the filesystem UUID and then query sysfs for the checksum type.

Add a new csum_type and csum_size fields to the BTRFS_IOC_FS_INFO ioctl
command which usually is used to query filesystem features. Also add a
flags member indicating that the kernel responded with a set csum_type and
csum_size field.

For compatibility reasons, only return the csum_type and csum_size if
the BTRFS_FS_INFO_FLAG_CSUM_INFO flag was passed to the kernel. Also
clear any unknown flags so we don't pass false positives to user-space
newer than the kernel.

To simplify further additions to the ioctl, also switch the padding to a
u8 array. Pahole was used to verify the result of this switch:

The csum members are added before flags, which might look odd, but this
is to keep the alignment requirements and not to introduce holes in the
structure.

  $ pahole -C btrfs_ioctl_fs_info_args fs/btrfs/btrfs.ko
  struct btrfs_ioctl_fs_info_args {
	  __u64                      max_id;               /*     0     8 */
	  __u64                      num_devices;          /*     8     8 */
	  __u8                       fsid[16];             /*    16    16 */
	  __u32                      nodesize;             /*    32     4 */
	  __u32                      sectorsize;           /*    36     4 */
	  __u32                      clone_alignment;      /*    40     4 */
	  __u16                      csum_type;            /*    44     2 */
	  __u16                      csum_size;            /*    46     2 */
	  __u64                      flags;                /*    48     8 */
	  __u8                       reserved[968];        /*    56   968 */

	  /* size: 1024, cachelines: 16, members: 10 */
  };

Fixes: 3951e7f050 ("btrfs: add xxhash64 to checksumming algorithms")
Fixes: 3831bf0094 ("btrfs: add sha256 to checksumming algorithm")
CC: stable@vger.kernel.org # 5.5+
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:43 +02:00
Qu Wenruo 2dfb1e43f5 btrfs: preallocate anon block device at first phase of snapshot creation
[BUG]
When the anonymous block device pool is exhausted, subvolume/snapshot
creation fails with EMFILE (Too many files open). This has been reported
by a user. The allocation happens in the second phase during transaction
commit where it's only way out is to abort the transaction

  BTRFS: Transaction aborted (error -24)
  WARNING: CPU: 17 PID: 17041 at fs/btrfs/transaction.c:1576 create_pending_snapshot+0xbc4/0xd10 [btrfs]
  RIP: 0010:create_pending_snapshot+0xbc4/0xd10 [btrfs]
  Call Trace:
   create_pending_snapshots+0x82/0xa0 [btrfs]
   btrfs_commit_transaction+0x275/0x8c0 [btrfs]
   btrfs_mksubvol+0x4b9/0x500 [btrfs]
   btrfs_ioctl_snap_create_transid+0x174/0x180 [btrfs]
   btrfs_ioctl_snap_create_v2+0x11c/0x180 [btrfs]
   btrfs_ioctl+0x11a4/0x2da0 [btrfs]
   do_vfs_ioctl+0xa9/0x640
   ksys_ioctl+0x67/0x90
   __x64_sys_ioctl+0x1a/0x20
   do_syscall_64+0x5a/0x110
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  ---[ end trace 33f2f83f3d5250e9 ]---
  BTRFS: error (device sda1) in create_pending_snapshot:1576: errno=-24 unknown
  BTRFS info (device sda1): forced readonly
  BTRFS warning (device sda1): Skipping commit of aborted transaction.
  BTRFS: error (device sda1) in cleanup_transaction:1831: errno=-24 unknown

[CAUSE]
When the global anonymous block device pool is exhausted, the following
call chain will fail, and lead to transaction abort:

 btrfs_ioctl_snap_create_v2()
 |- btrfs_ioctl_snap_create_transid()
    |- btrfs_mksubvol()
       |- btrfs_commit_transaction()
          |- create_pending_snapshot()
             |- btrfs_get_fs_root()
                |- btrfs_init_fs_root()
                   |- get_anon_bdev()

[FIX]
Although we can't enlarge the anonymous block device pool, at least we
can preallocate anon_dev for subvolume/snapshot in the first phase,
outside of transaction context and exactly at the moment the user calls
the creation ioctl.

Reported-by: Greed Rong <greedrong@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CA+UqX+NTrZ6boGnWHhSeZmEY5J76CTqmYjO2S+=tHJX7nb9DPw@mail.gmail.com/
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:38 +02:00
Nikolay Borisov e5b7231e20 btrfs: make btrfs_delalloc_reserve_space take btrfs_inode
All of its children take btrfs_inode so bubble up this requirement to
btrfs_delalloc_reserve_space's interface and stop calling BTRFS_I
internally.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:36 +02:00
Nikolay Borisov 86d52921a2 btrfs: make btrfs_delalloc_release_space take btrfs_inode
It needs btrfs_inode so take it as a parameter directly.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:36 +02:00
Nikolay Borisov c350437269 btrfs: make btrfs_lookup_ordered_extent take btrfs_inode
It doesn't use the generic vfs inode for anything use btrfs_inode
directly.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-07-27 12:55:25 +02:00
Waiman Long b091f7fede btrfs: use kfree() in btrfs_ioctl_get_subvol_info()
In btrfs_ioctl_get_subvol_info(), there is a classic case where kzalloc()
was incorrectly paired with kzfree(). According to David Sterba, there
isn't any sensitive information in the subvol_info that needs to be
cleared before freeing. So kzfree() isn't really needed, use kfree()
instead.

Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-06-16 19:24:03 +02:00
David Sterba 0202e83fda btrfs: simplify iget helpers
The inode lookup starting at btrfs_iget takes the full location key,
while only the objectid is used to match the inode, because the lookup
happens inside the given root thus the inode number is unique.
The entire location key is properly set up in btrfs_init_locked_inode.

Simplify the helpers and pass only inode number, renaming it to 'ino'
instead of 'objectid'. This allows to remove temporary variables key,
saving some stack space.

Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25 11:25:37 +02:00
David Sterba 56e9357a1e btrfs: simplify root lookup by id
The main function to lookup a root by its id btrfs_get_fs_root takes the
whole key, while only using the objectid. The value of offset is preset
to (u64)-1 but not actually used until btrfs_find_root that does the
actual search.

Switch btrfs_get_fs_root to use only objectid and remove all local
variables that existed just for the lookup. The actual key for search is
set up in btrfs_get_fs_root, reusing another key variable.

Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25 11:25:36 +02:00
Robbie Ko c11fbb6ed0 btrfs: reduce lock contention when creating snapshot
When creating a snapshot, ordered extents need to be flushed and this
can take a long time.

In create_snapshot there are two locks held when this happens:

  1. Destination directory inode lock
  2. Global subvolume semaphore

This will unnecessarily block other operations like subvolume destroy,
create, or setflag until the snapshot is created.

We can fix that by moving the flush outside the locked section as this
does not depend on the aforementioned locks.  The code factors out the
snapshot related work from create_snapshot to btrfs_mksnapshot.

__btrfs_ioctl_snap_create
  btrfs_mksubvol
    create_subvol
  btrfs_mksnapshot
    <flush>
    btrfs_mksubvol
      create_snapshot

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25 11:25:36 +02:00
Qu Wenruo 92a7cc4252 btrfs: rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE
The name BTRFS_ROOT_REF_COWS is not very clear about the meaning.

In fact, that bit can only be set to those trees:

- Subvolume roots
- Data reloc root
- Reloc roots for above roots

All other trees won't get this bit set.  So just by the result, it is
obvious that, roots with this bit set can have tree blocks shared with
other trees.  Either shared by snapshots, or by reloc roots (an special
snapshot created by relocation).

This patch will rename BTRFS_ROOT_REF_COWS to BTRFS_ROOT_SHAREABLE to
make it easier to understand, and update all comment mentioning
"reference counted" to follow the rename.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-25 11:25:35 +02:00
Nikolay Borisov 9babda9f33 btrfs: Remove async_transid from btrfs_mksubvol/create_subvol/create_snapshot
With BTRFS_SUBVOL_CREATE_ASYNC support remove it's no longer required to
pass the async_transid parameter so remove it and any code using it.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:02:00 +01:00
Nikolay Borisov 5d54c67ecc btrfs: Remove transid argument from btrfs_ioctl_snap_create_transid
btrfs_ioctl_snap_create_transid no longer takes a transid argument, so
remove it and rename the function to __btrfs_ioctl_snap_create to
reflect it's an internal, worker function.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:02:00 +01:00
Nikolay Borisov 9c1036fdb1 btrfs: Remove BTRFS_SUBVOL_CREATE_ASYNC support
This functionality was deprecated in kernel 5.4. Since no one has
complained of the impending removal it's time we did so.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:02:00 +01:00
Filipe Manana 6a17738100 Btrfs: move all reflink implementation code into its own file
The reflink code is quite large and has been living in ioctl.c since ever.
It has grown over the years after many bug fixes and improvements, and
since I'm planning on making some further improvements on it, it's time
to get it better organized by moving into its own file, reflink.c
(similar to what xfs does for example).

This change only moves the code out of ioctl.c into the new file, it
doesn't do any other change.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:54 +01:00
Andy Shevchenko 807fc790aa btrfs: switch to use new generic UUID API
There are new types and helpers that are supposed to be used in new code.

As a preparation to get rid of legacy types and API functions do
the conversion here.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:47 +01:00
Marcos Paulo de Souza faf8f7b957 btrfs: ioctl: resize: only show message if size is changed
There is no point to inform the user about size change if there's none.
Update the message to conform to a commonly used format where the path
and devid are printed and also print old and new sizes.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Marcos Paulo de Souza <marcos@mpdesouza.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ enhance message ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:46 +01:00
Nikolay Borisov dcc3eb9638 btrfs: convert snapshot/nocow exlcusion to drew lock
This patch removes all haphazard code implementing nocow writers
exclusion from pending snapshot creation and switches to using the drew
lock to ensure this invariant still holds.

'Readers' are snapshot creators from create_snapshot and 'writers' are
nocow writers from buffered write path or btrfs_setsize. This locking
scheme allows for multiple snapshots to happen while any nocow writers
are blocked, since writes to page cache in the nocow path will make
snapshots inconsistent.

So for performance reasons we'd like to have the ability to run multiple
concurrent snapshots and also favors readers in this case. And in case
there aren't pending snapshots (which will be the majority of the cases)
we rely on the percpu's writers counter to avoid cacheline contention.

The main gain from using the drew lock is it's now a lot easier to
reason about the guarantees of the locking scheme and whether there is
some silent breakage lurking.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:44 +01:00
Marcos Paulo de Souza 949964c928 btrfs: add new BTRFS_IOC_SNAP_DESTROY_V2 ioctl
This ioctl will be responsible for deleting a subvolume using its id.
This can be used when a system has a file system mounted from a
subvolume, rather than the root file system, like below:

/
@subvol1/
@subvol2/
@subvol_default/

If only @subvol_default is mounted, we have no path to reach @subvol1
and @subvol2, thus no way to delete them. Current subvolume delete ioctl
takes a file handle point as argument, and if @subvol_default is
mounted, we can't reach @subvol1 and @subvol2 from the same mount point.

This patch introduces a new ioctl BTRFS_IOC_SNAP_DESTROY_V2 that takes
the extended structure with flags to allow to delete subvolume using
subvolid.

Now, we can use this new ioctl specifying the subvolume id and refer to
the same mount point. It doesn't matter which subvolume was mounted,
since we can reach to the desired one using the subvolume id, and then
delete it.

The full path to the subvolume id is resolved internally and access is
verified as if the subvolume was accessed by path.

The volume args v2 structure is extended to use the existing union for
subvolume id specification, that's valid in case the
BTRFS_SUBVOL_SPEC_BY_ID is set.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:42 +01:00
David Sterba 748449cdbe btrfs: use ioctl args support mask for device delete
When the device remove v2 ioctl was added, the full support mask was
added to sanity check the flags. However this would allow to let the
subvolume related flags to be accepted. This is not supposed to happen.

Use the correct support mask, which means that now any of
BTRFS_SUBVOL_CREATE_ASYNC, BTRFS_SUBVOL_RDONLY or
BTRFS_SUBVOL_QGROUP_INHERIT will be rejected as ENOTSUPP. Though this is
a user-visible change, specifying subvolume flags for device deletion
does not make sense and there are hopefully no applications doing that.

Reviewed-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:42 +01:00
David Sterba 673990dba3 btrfs: use ioctl args support mask for subvolume create/delete
Using the defined mask instead of flag enumeration in the ioctl handler
is preferred. No functional changes.

Reviewed-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:42 +01:00
Josef Bacik 0024652895 btrfs: rename btrfs_put_fs_root and btrfs_grab_fs_root
We are now using these for all roots, rename them to btrfs_put_root()
and btrfs_grab_root();

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:33 +01:00
Josef Bacik bc44d7c4b2 btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root
Now that all callers of btrfs_get_fs_root are subsequently calling
btrfs_grab_fs_root and handling dropping the ref when they are done
appropriately, go ahead and push btrfs_grab_fs_root up into
btrfs_get_fs_root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:32 +01:00
Josef Bacik 5119cfc36f btrfs: hold a ref on the root in create_pending_snapshot
We create the snapshot and then use it for a bunch of things, we need to
hold a ref on it while we're messing with it.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:31 +01:00
Josef Bacik 2a2b5d6202 btrfs: hold ref on root in btrfs_ioctl_default_subvol
We look up an arbitrary fs root here, we need to hold a ref on the root
for the duration.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:29 +01:00
Josef Bacik 04734e8448 btrfs: hold a ref on the root in btrfs_ioctl_get_subvol_info
We look up whatever root userspace has given us, we need to hold a ref
throughout this operation. Use 'root' only for the on fs root and not as
a temporary variable elsewhere.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik b8a49ae191 btrfs: hold a ref on the root in btrfs_search_path_in_tree_user
We can wander into a different root, so grab a ref on the root we look
up.  Later on we make root = fs_info->tree_root so we need this separate
out label to make sure we do the right cleanup only in the case we're
looking up a different root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik 88234012be btrfs: hold a ref on the root in btrfs_search_path_in_tree
We look up an arbitrary fs root, we need to hold a ref on it while we're
doing our search.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik 3ca35e839e btrfs: hold a ref on the root in search_ioctl
We lookup a arbitrary fs root, we need to hold a ref on that root.  If
we're using our own inodes root then grab a ref on that as well to make
the cleanup easier.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik fc92f79856 btrfs: hold a ref on the root in create_subvol
We're creating the new root here, but we should hold the ref until after
we've initialized the inode for it.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik 3619c94f07 btrfs: open code btrfs_read_fs_root_no_name
All this does is call btrfs_get_fs_root() with check_ref == true.  Just
use btrfs_get_fs_root() so we don't have a bunch of different helpers
that do the same thing.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:26 +01:00
Josef Bacik d923afe96d btrfs: replace all uses of btrfs_ordered_update_i_size
Now that we have a safe way to update the i_size, replace all uses of
btrfs_ordered_update_i_size with btrfs_inode_safe_disk_i_size_write.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:24 +01:00
Josef Bacik 790a1d44f9 btrfs: use btrfs_ordered_update_i_size in clone_finish_inode_update
We were using btrfs_i_size_write(), which unconditionally jacks up
inode->disk_i_size.  However since clone can operate on ranges we could
have pending ordered extents for a range prior to the start of our clone
operation and thus increase disk_i_size too far and have a hole with no
file extent.

Fix this by using the btrfs_ordered_update_i_size helper which will do
the right thing in the face of pending ordered extents outside of our
clone range.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:24 +01:00
Linus Torvalds b5f7ab6b1c fs-dedupe-last-block-tag
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Merge tag 'fs-dedupe-last-block-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull fs deduplication fix from David Sterba:
 "This is a fix for deduplication bug: the last block of two files is
  allowed to deduplicated. This got broken in 5.1 by lifting some
  generic checks to VFS layer. The affected filesystems are btrfs and
  xfs.

  The patches are marked for stable as the bug decreases deduplication
  effectivity"

* tag 'fs-dedupe-last-block-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: make deduplication with range including the last block work
  fs: allow deduplication of eof block into the end of the destination file
2020-01-28 15:18:23 -08:00
Filipe Manana 831d2fa25a Btrfs: make deduplication with range including the last block work
Since btrfs was migrated to use the generic VFS helpers for clone and
deduplication, it stopped allowing for the last block of a file to be
deduplicated when the source file size is not sector size aligned (when
eof is somewhere in the middle of the last block). There are two reasons
for that:

1) The generic code always rounds down, to a multiple of the block size,
   the range's length for deduplications. This means we end up never
   deduplicating the last block when the eof is not block size aligned,
   even for the safe case where the destination range's end offset matches
   the destination file's size. That rounding down operation is done at
   generic_remap_check_len();

2) Because of that, the btrfs specific code does not expect anymore any
   non-aligned range length's for deduplication and therefore does not
   work if such nona-aligned length is given.

This patch addresses that second part, and it depends on a patch that
fixes generic_remap_check_len(), in the VFS, which was submitted ealier
and has the following subject:

  "fs: allow deduplication of eof block into the end of the destination file"

These two patches address reports from users that started seeing lower
deduplication rates due to the last block never being deduplicated when
the file size is not aligned to the filesystem's block size.

Link: https://lore.kernel.org/linux-btrfs/2019-1576167349.500456@svIo.N5dq.dFFD/
CC: stable@vger.kernel.org # 5.1+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 18:24:07 +01:00
Omar Sandoval 39b07b5d70 btrfs: drop create parameter to btrfs_get_extent()
We only pass this as 1 from __extent_writepage_io(). The parameter
basically means "pretend I didn't pass in a page". This is silly since
we can simply not pass in the page. Get rid of the parameter from
btrfs_get_extent(), and since it's used as a get_extent_t callback,
remove it from get_extent_t and btree_get_extent(), neither of which
need it.

While we're here, let's document btrfs_get_extent().

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:55 +01:00
Filipe Manana 5afe6ce748 Btrfs: always copy scrub arguments back to user space
If scrub returns an error we are not copying back the scrub arguments
structure to user space. This prevents user space to know how much
progress scrub has done if an error happened - this includes -ECANCELED
which is returned when users ask for scrub to stop. A particular use
case, which is used in btrfs-progs, is to resume scrub after it is
canceled, in that case it relies on checking the progress from the scrub
arguments structure and then use that progress in a call to resume
scrub.

So fix this by always copying the scrub arguments structure to user
space, overwriting the value returned to user space with -EFAULT only if
copying the structure failed to let user space know that either that
copying did not happen, and therefore the structure is stale, or it
happened partially and the structure is probably not valid and corrupt
due to the partial copy.

Reported-by: Graham Cobb <g.btrfs@cobb.uk.net>
Link: https://lore.kernel.org/linux-btrfs/d0a97688-78be-08de-ca7d-bcb4c7fb397e@cobb.uk.net/
Fixes: 06fe39ab15 ("Btrfs: do not overwrite scrub error with fault error in scrub ioctl")
CC: stable@vger.kernel.org # 5.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-by: Graham Cobb <g.btrfs@cobb.uk.net>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-17 15:28:52 +01:00
Josef Bacik c7e54b5102 btrfs: abort transaction after failed inode updates in create_subvol
We can just abort the transaction here, and in fact do that for every
other failure in this function except these two cases.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-12-13 14:10:44 +01:00
Filipe Manana 147271e35b Btrfs: fix hole extent items with a zero size after range cloning
Normally when cloning a file range if we find an implicit hole at the end
of the range we assume it is because the NO_HOLES feature is enabled.
However that is not always the case. One well known case [1] is when we
have a power failure after mixing buffered and direct IO writes against
the same file.

In such cases we need to punch a hole in the destination file, and if
the NO_HOLES feature is not enabled, we need to insert explicit file
extent items to represent the hole. After commit 690a5dbfc5
("Btrfs: fix ENOSPC errors, leading to transaction aborts, when cloning
extents"), we started to insert file extent items representing the hole
with an item size of 0, which is invalid and should be 53 bytes (the size
of a btrfs_file_extent_item structure), resulting in all sorts of
corruptions and invalid memory accesses. This is detected by the tree
checker when we attempt to write a leaf to disk.

The problem can be sporadically triggered by test case generic/561 from
fstests. That test case does not exercise power failure and creates a new
filesystem when it starts, so it does not use a filesystem created by any
previous test that tests power failure. However the test does both
buffered and direct IO writes (through fsstress) and it's precisely that
which is creating the implicit holes in files. That happens even before
the commit mentioned earlier. I need to investigate why we get those
implicit holes to check if there is a real problem or not. For now this
change fixes the regression of introducing file extent items with an item
size of 0 bytes.

Fix the issue by calling btrfs_punch_hole_range() without passing a
btrfs_clone_extent_info structure, which ensures file extent items are
inserted to represent the hole with a correct item size. We were passing
a btrfs_clone_extent_info with a value of 0 for its 'item_size' field,
which was causing the insertion of file extent items with an item size
of 0.

[1] https://www.spinics.net/lists/linux-btrfs/msg75350.html

Reported-by: David Sterba <dsterba@suse.com>
Fixes: 690a5dbfc5 ("Btrfs: fix ENOSPC errors, leading to transaction aborts, when cloning extents")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-12-13 14:10:28 +01:00