Commit Graph

1293 Commits

Author SHA1 Message Date
Josef Bacik
a9f5423460 btrfs: use nofs when cleaning up aborted transactions
commit 597441b3436a43011f31ce71dc0a6c0bf5ce958a upstream.

Our CI system caught a lockdep splat:

  ======================================================
  WARNING: possible circular locking dependency detected
  6.3.0-rc7+ #1167 Not tainted
  ------------------------------------------------------
  kswapd0/46 is trying to acquire lock:
  ffff8c6543abd650 (sb_internal#2){++++}-{0:0}, at: btrfs_commit_inode_delayed_inode+0x5f/0x120

  but task is already holding lock:
  ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #1 (fs_reclaim){+.+.}-{0:0}:
	 fs_reclaim_acquire+0xa5/0xe0
	 kmem_cache_alloc+0x31/0x2c0
	 alloc_extent_state+0x1d/0xd0
	 __clear_extent_bit+0x2e0/0x4f0
	 try_release_extent_mapping+0x216/0x280
	 btrfs_release_folio+0x2e/0x90
	 invalidate_inode_pages2_range+0x397/0x470
	 btrfs_cleanup_dirty_bgs+0x9e/0x210
	 btrfs_cleanup_one_transaction+0x22/0x760
	 btrfs_commit_transaction+0x3b7/0x13a0
	 create_subvol+0x59b/0x970
	 btrfs_mksubvol+0x435/0x4f0
	 __btrfs_ioctl_snap_create+0x11e/0x1b0
	 btrfs_ioctl_snap_create_v2+0xbf/0x140
	 btrfs_ioctl+0xa45/0x28f0
	 __x64_sys_ioctl+0x88/0xc0
	 do_syscall_64+0x38/0x90
	 entry_SYSCALL_64_after_hwframe+0x72/0xdc

  -> #0 (sb_internal#2){++++}-{0:0}:
	 __lock_acquire+0x1435/0x21a0
	 lock_acquire+0xc2/0x2b0
	 start_transaction+0x401/0x730
	 btrfs_commit_inode_delayed_inode+0x5f/0x120
	 btrfs_evict_inode+0x292/0x3d0
	 evict+0xcc/0x1d0
	 inode_lru_isolate+0x14d/0x1e0
	 __list_lru_walk_one+0xbe/0x1c0
	 list_lru_walk_one+0x58/0x80
	 prune_icache_sb+0x39/0x60
	 super_cache_scan+0x161/0x1f0
	 do_shrink_slab+0x163/0x340
	 shrink_slab+0x1d3/0x290
	 shrink_node+0x300/0x720
	 balance_pgdat+0x35c/0x7a0
	 kswapd+0x205/0x410
	 kthread+0xf0/0x120
	 ret_from_fork+0x29/0x50

  other info that might help us debug this:

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(fs_reclaim);
				 lock(sb_internal#2);
				 lock(fs_reclaim);
    lock(sb_internal#2);

   *** DEADLOCK ***

  3 locks held by kswapd0/46:
   #0: ffffffffabe61b40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x4aa/0x7a0
   #1: ffffffffabe50270 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x113/0x290
   #2: ffff8c6543abd0e0 (&type->s_umount_key#44){++++}-{3:3}, at: super_cache_scan+0x38/0x1f0

  stack backtrace:
  CPU: 0 PID: 46 Comm: kswapd0 Not tainted 6.3.0-rc7+ #1167
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x58/0x90
   check_noncircular+0xd6/0x100
   ? save_trace+0x3f/0x310
   ? add_lock_to_list+0x97/0x120
   __lock_acquire+0x1435/0x21a0
   lock_acquire+0xc2/0x2b0
   ? btrfs_commit_inode_delayed_inode+0x5f/0x120
   start_transaction+0x401/0x730
   ? btrfs_commit_inode_delayed_inode+0x5f/0x120
   btrfs_commit_inode_delayed_inode+0x5f/0x120
   btrfs_evict_inode+0x292/0x3d0
   ? lock_release+0x134/0x270
   ? __pfx_wake_bit_function+0x10/0x10
   evict+0xcc/0x1d0
   inode_lru_isolate+0x14d/0x1e0
   __list_lru_walk_one+0xbe/0x1c0
   ? __pfx_inode_lru_isolate+0x10/0x10
   ? __pfx_inode_lru_isolate+0x10/0x10
   list_lru_walk_one+0x58/0x80
   prune_icache_sb+0x39/0x60
   super_cache_scan+0x161/0x1f0
   do_shrink_slab+0x163/0x340
   shrink_slab+0x1d3/0x290
   shrink_node+0x300/0x720
   balance_pgdat+0x35c/0x7a0
   kswapd+0x205/0x410
   ? __pfx_autoremove_wake_function+0x10/0x10
   ? __pfx_kswapd+0x10/0x10
   kthread+0xf0/0x120
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x29/0x50
   </TASK>

This happens because when we abort the transaction in the transaction
commit path we call invalidate_inode_pages2_range on our block group
cache inodes (if we have space cache v1) and any delalloc inodes we may
have.  The plain invalidate_inode_pages2_range() call passes through
GFP_KERNEL, which makes sense in most cases, but not here.  Wrap these
two invalidate callees with memalloc_nofs_save/memalloc_nofs_restore to
make sure we don't end up with the fs reclaim dependency under the
transaction dependency.

CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30 12:44:09 +01:00
Christoph Hellwig
50dbfd9dac btrfs: fix fast csum implementation detection
commit 68d99ab0e9221ef54506f827576c5a914680eeaf upstream.

The BTRFS_FS_CSUM_IMPL_FAST flag is currently set whenever a non-generic
crc32c is detected, which is the incorrect check if the file system uses
a different checksumming algorithm.  Refactor the code to only check
this if crc32c is actually used.  Note that in an ideal world the
information if an algorithm is hardware accelerated or not should be
provided by the crypto API instead, but that's left for another day.

CC: stable@vger.kernel.org # 5.4.x: c8a5f8ca9a9c: btrfs: print checksum type and implementation at mount time
CC: stable@vger.kernel.org # 5.4.x
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:35 +02:00
David Sterba
c6db5f2a31 btrfs: print checksum type and implementation at mount time
commit c8a5f8ca9a9c7d5c5bc31d54f47ea9d86f93ed69 upstream.

Per user request, print the checksum type and implementation at mount
time among the messages. The checksum is user configurable and the
actual crypto implementation is useful to see for performance reasons.
The same information is also available after mount in
/sys/fs/FSID/checksum file.

Example:

  [25.323662] BTRFS info (device vdb): using sha256 (sha256-generic) checksum algorithm

Link: https://github.com/kdave/btrfs-progs/issues/483
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:35 +02:00
Qu Wenruo
8659026858 btrfs: reject log replay if there is unsupported RO compat flag
commit dc4d31684974d140250f3ee612c3f0cab13b3146 upstream.

[BUG]
If we have a btrfs image with dirty log, along with an unsupported RO
compatible flag:

log_root		30474240
...
compat_flags		0x0
compat_ro_flags		0x40000003
			( FREE_SPACE_TREE |
			  FREE_SPACE_TREE_VALID |
			  unknown flag: 0x40000000 )

Then even if we can only mount it RO, we will still cause metadata
update for log replay:

  BTRFS info (device dm-1): flagging fs with big metadata feature
  BTRFS info (device dm-1): using free space tree
  BTRFS info (device dm-1): has skinny extents
  BTRFS info (device dm-1): start tree-log replay

This is definitely against RO compact flag requirement.

[CAUSE]
RO compact flag only forces us to do RO mount, but we will still do log
replay for plain RO mount.

Thus this will result us to do log replay and update metadata.

This can be very problematic for new RO compat flag, for example older
kernel can not understand v2 cache, and if we allow metadata update on
RO mount and invalidate/corrupt v2 cache.

[FIX]
Just reject the mount unless rescue=nologreplay is provided:

  BTRFS error (device dm-1): cannot replay dirty log with unsupport optional features (0x40000000), try rescue=nologreplay instead

We don't want to set rescue=nologreply directly, as this would make the
end user to read the old data, and cause confusion.

Since the such case is really rare, we're mostly fine to just reject the
mount with an error message, which also includes the proper workaround.

CC: stable@vger.kernel.org #4.9+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:18:16 +02:00
Qu Wenruo
622ced791e btrfs: add "0x" prefix for unsupported optional features
commit d5321a0fa8bc49f11bea0b470800962c17d92d8f upstream.

The following error message lack the "0x" obviously:

  cannot mount because of unsupported optional features (4000)

Add the prefix to make it less confusing. This can happen on older
kernels that try to mount a filesystem with newer features so it makes
sense to backport to older trees.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14 18:11:24 +02:00
Wang Yugui
ebc8aed3b9 btrfs: check-integrity: fix a warning on write caching disabled disk
[ Upstream commit a91cf0ffbc244792e0b3ecf7d0fddb2f344b461f ]

When a disk has write caching disabled, we skip submission of a bio with
flush and sync requests before writing the superblock, since it's not
needed. However when the integrity checker is enabled, this results in
reports that there are metadata blocks referred by a superblock that
were not properly flushed. So don't skip the bio submission only when
the integrity checker is enabled for the sake of simplicity, since this
is a debug tool and not meant for use in non-debug builds.

fstests/btrfs/220 trigger a check-integrity warning like the following
when CONFIG_BTRFS_FS_CHECK_INTEGRITY=y and the disk with WCE=0.

  btrfs: attempt to write superblock which references block M @5242880 (sdb2/5242880/0) which is not flushed out of disk's write cache (block flush_gen=1, dev->flush_gen=0)!
  ------------[ cut here ]------------
  WARNING: CPU: 28 PID: 843680 at fs/btrfs/check-integrity.c:2196 btrfsic_process_written_superblock+0x22a/0x2a0 [btrfs]
  CPU: 28 PID: 843680 Comm: umount Not tainted 5.15.0-0.rc5.39.el8.x86_64 #1
  Hardware name: Dell Inc. Precision T7610/0NK70N, BIOS A18 09/11/2019
  RIP: 0010:btrfsic_process_written_superblock+0x22a/0x2a0 [btrfs]
  RSP: 0018:ffffb642afb47940 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000
  RDX: 00000000ffffffff RSI: ffff8b722fc97d00 RDI: ffff8b722fc97d00
  RBP: ffff8b5601c00000 R08: 0000000000000000 R09: c0000000ffff7fff
  R10: 0000000000000001 R11: ffffb642afb476f8 R12: ffffffffffffffff
  R13: ffffb642afb47974 R14: ffff8b5499254c00 R15: 0000000000000003
  FS:  00007f00a06d4080(0000) GS:ffff8b722fc80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fff5cff5ff0 CR3: 00000001c0c2a006 CR4: 00000000001706e0
  Call Trace:
   btrfsic_process_written_block+0x2f7/0x850 [btrfs]
   __btrfsic_submit_bio.part.19+0x310/0x330 [btrfs]
   ? bio_associate_blkg_from_css+0xa4/0x2c0
   btrfsic_submit_bio+0x18/0x30 [btrfs]
   write_dev_supers+0x81/0x2a0 [btrfs]
   ? find_get_pages_range_tag+0x219/0x280
   ? pagevec_lookup_range_tag+0x24/0x30
   ? __filemap_fdatawait_range+0x6d/0xf0
   ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e
   ? find_first_extent_bit+0x9b/0x160 [btrfs]
   ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e
   write_all_supers+0x1b3/0xa70 [btrfs]
   ? __raw_callee_save___native_queued_spin_unlock+0x11/0x1e
   btrfs_commit_transaction+0x59d/0xac0 [btrfs]
   close_ctree+0x11d/0x339 [btrfs]
   generic_shutdown_super+0x71/0x110
   kill_anon_super+0x14/0x30
   btrfs_kill_super+0x12/0x20 [btrfs]
   deactivate_locked_super+0x31/0x70
   cleanup_mnt+0xb8/0x140
   task_work_run+0x6d/0xb0
   exit_to_user_mode_prepare+0x1f0/0x200
   syscall_exit_to_user_mode+0x12/0x30
   do_syscall_64+0x46/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f009f711dfb
  RSP: 002b:00007fff5cff7928 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
  RAX: 0000000000000000 RBX: 000055b68c6c9970 RCX: 00007f009f711dfb
  RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000055b68c6c9b50
  RBP: 0000000000000000 R08: 000055b68c6ca900 R09: 00007f009f795580
  R10: 0000000000000000 R11: 0000000000000246 R12: 000055b68c6c9b50
  R13: 00007f00a04bf184 R14: 0000000000000000 R15: 00000000ffffffff
  ---[ end trace 2c4b82abcef9eec4 ]---
  S-65536(sdb2/65536/1)
   -->
  M-1064960(sdb2/1064960/1)

Reviewed-by: Filipe Manana <fdmanana@gmail.com>
Signed-off-by: Wang Yugui <wangyugui@e16-tech.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08 09:01:09 +01:00
Anand Jain
ddb54bf3b7 btrfs: call btrfs_check_rw_degradable only if there is a missing device
commit 5c78a5e7aa835c4f08a7c90fe02d19f95a776f29 upstream.

In open_ctree() in btrfs_check_rw_degradable() [1], we check each block
group individually if at least the minimum number of devices is available
for that profile. If all the devices are available, then we don't have to
check degradable.

[1]
open_ctree()
::
3559 if (!sb_rdonly(sb) && !btrfs_check_rw_degradable(fs_info, NULL)) {

Also before calling btrfs_check_rw_degradable() in open_ctee() at the
line number shown below [2] we call btrfs_read_chunk_tree() and down to
add_missing_dev() to record number of missing devices.

[2]
open_ctree()
::
3454         ret = btrfs_read_chunk_tree(fs_info);

btrfs_read_chunk_tree()
  read_one_chunk() / read_one_dev()
    add_missing_dev()

So, check if there is any missing device before btrfs_check_rw_degradable()
in open_ctree().

Also, with this the mount command could save ~16ms.[3] in the most
common case, that is no device is missing.

[3]
 1) * 16934.96 us | btrfs_check_rw_degradable [btrfs]();

CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-17 09:48:22 +01:00
Anand Jain
c7fab1f536 btrfs: fix upper limit for max_inline for page size 64K
commit 6f93e834fa7c5faa0372e46828b4b2a966ac61d7 upstream.

The mount option max_inline ranges from 0 to the sectorsize (which is
now equal to page size). But we parse the mount options too early and
before the actual sectorsize is read from the superblock. So the upper
limit of max_inline is unaware of the actual sectorsize and is limited
by the temporary sectorsize 4096, even on a system where the default
sectorsize is 64K.

Fix this by reading the superblock sectorsize before the mount option
parse.

Reported-by: Alexander Tsvetkov <alexander.tsvetkov@oracle.com>
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22 12:26:38 +02:00
Qu Wenruo
c55442cdfd btrfs: qgroup: remove ASYNC_COMMIT mechanism in favor of reserve retry-after-EDQUOT
commit adca4d945c8dca28a85df45c5b117e6dac2e77f1 upstream

commit a514d63882 ("btrfs: qgroup: Commit transaction in advance to
reduce early EDQUOT") tries to reduce the early EDQUOT problems by
checking the qgroup free against threshold and tries to wake up commit
kthread to free some space.

The problem of that mechanism is, it can only free qgroup per-trans
metadata space, can't do anything to data, nor prealloc qgroup space.

Now since we have the ability to flush qgroup space, and implemented
retry-after-EDQUOT behavior, such mechanism can be completely replaced.

So this patch will cleanup such mechanism in favor of
retry-after-EDQUOT.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-15 13:08:05 +02:00
Qu Wenruo
fdaf6a322f btrfs: transaction: Cleanup unused TRANS_STATE_BLOCKED
commit 3296bf562443a8ca35aaad959a76a49e9b412760 upstream

The state was introduced in commit 4a9d8bdee3 ("Btrfs: make the state
of the transaction more readable"), then in commit 302167c50b
("btrfs: don't end the transaction for delayed refs in throttle") the
state is completely removed.

So we can just clean up the state since it's only compared but never
set.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-15 13:08:05 +02:00
Qu Wenruo
36af2de520 btrfs: qgroup: try to flush qgroup space when we get -EDQUOT
commit c53e9653605dbf708f5be02902de51831be4b009 upstream

[PROBLEM]
There are known problem related to how btrfs handles qgroup reserved
space.  One of the most obvious case is the the test case btrfs/153,
which do fallocate, then write into the preallocated range.

#  btrfs/153 1s ... - output mismatch (see xfstests-dev/results//btrfs/153.out.bad)
#      --- tests/btrfs/153.out     2019-10-22 15:18:14.068965341 +0800
#      +++ xfstests-dev/results//btrfs/153.out.bad      2020-07-01 20:24:40.730000089 +0800
#      @@ -1,2 +1,5 @@
#       QA output created by 153
#      +pwrite: Disk quota exceeded
#      +/mnt/scratch/testfile2: Disk quota exceeded
#      +/mnt/scratch/testfile2: Disk quota exceeded
#       Silence is golden
#      ...
#      (Run 'diff -u xfstests-dev/tests/btrfs/153.out xfstests-dev/results//btrfs/153.out.bad'  to see the entire diff)

[CAUSE]
Since commit c6887cd111 ("Btrfs: don't do nocow check unless we have to"),
we always reserve space no matter if it's COW or not.

Such behavior change is mostly for performance, and reverting it is not
a good idea anyway.

For preallcoated extent, we reserve qgroup data space for it already,
and since we also reserve data space for qgroup at buffered write time,
it needs twice the space for us to write into preallocated space.

This leads to the -EDQUOT in buffered write routine.

And we can't follow the same solution, unlike data/meta space check,
qgroup reserved space is shared between data/metadata.
The EDQUOT can happen at the metadata reservation, so doing NODATACOW
check after qgroup reservation failure is not a solution.

[FIX]
To solve the problem, we don't return -EDQUOT directly, but every time
we got a -EDQUOT, we try to flush qgroup space:

- Flush all inodes of the root
  NODATACOW writes will free the qgroup reserved at run_dealloc_range().
  However we don't have the infrastructure to only flush NODATACOW
  inodes, here we flush all inodes anyway.

- Wait for ordered extents
  This would convert the preallocated metadata space into per-trans
  metadata, which can be freed in later transaction commit.

- Commit transaction
  This will free all per-trans metadata space.

Also we don't want to trigger flush multiple times, so here we introduce
a per-root wait list and a new root status, to ensure only one thread
starts the flushing.

Fixes: c6887cd111 ("Btrfs: don't do nocow check unless we have to")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-15 13:08:05 +02:00
Randy Dunlap
174c27d0f9 btrfs: delete duplicated words + other fixes in comments
[ Upstream commit 260db43cd2f556677f6ae818ba09f997eed81004 ]

Delete repeated words in fs/btrfs/.
{to, the, a, and old}
and change "into 2 part" to "into 2 parts".

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-08 09:04:07 +02:00
Nikolay Borisov
298499d73d btrfs: promote debugging asserts to full-fledged checks in validate_super
commit aefd7f7065567a4666f42c0fc8cdb379d2e036bf upstream.

Syzbot managed to trigger this assert while performing its fuzzing.
Turns out it's better to have those asserts turned into full-fledged
checks so that in case buggy btrfs images are mounted the users gets
an error and mounting is stopped. Alternatively with CONFIG_BTRFS_ASSERT
disabled such image would have been erroneously allowed to be mounted.

Reported-by: syzbot+a6bf271c02e4fe66b4e4@syzkaller.appspotmail.com
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add uuids to the messages ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-16 11:59:40 +02:00
Johannes Thumshirn
aded5dee7f btrfs: fix overflow when copying corrupt csums for a message
commit 35be8851d172c6e3db836c0f28c19087b10c9e00 upstream.

Syzkaller reported a buffer overflow in btree_readpage_end_io_hook()
when loop mounting a crafted image:

  detected buffer overflow in memcpy
  ------------[ cut here ]------------
  kernel BUG at lib/string.c:1129!
  invalid opcode: 0000 [#1] PREEMPT SMP KASAN
  CPU: 1 PID: 26 Comm: kworker/u4:2 Not tainted 5.9.0-rc4-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Workqueue: btrfs-endio-meta btrfs_work_helper
  RIP: 0010:fortify_panic+0xf/0x20 lib/string.c:1129
  RSP: 0018:ffffc90000e27980 EFLAGS: 00010286
  RAX: 0000000000000022 RBX: ffff8880a80dca64 RCX: 0000000000000000
  RDX: ffff8880a90860c0 RSI: ffffffff815dba07 RDI: fffff520001c4f22
  RBP: ffff8880a80dca00 R08: 0000000000000022 R09: ffff8880ae7318e7
  R10: 0000000000000000 R11: 0000000000077578 R12: 00000000ffffff6e
  R13: 0000000000000008 R14: ffffc90000e27a40 R15: 1ffff920001c4f3c
  FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000557335f440d0 CR3: 000000009647d000 CR4: 00000000001506e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   memcpy include/linux/string.h:405 [inline]
   btree_readpage_end_io_hook.cold+0x206/0x221 fs/btrfs/disk-io.c:642
   end_bio_extent_readpage+0x4de/0x10c0 fs/btrfs/extent_io.c:2854
   bio_endio+0x3cf/0x7f0 block/bio.c:1449
   end_workqueue_fn+0x114/0x170 fs/btrfs/disk-io.c:1695
   btrfs_work_helper+0x221/0xe20 fs/btrfs/async-thread.c:318
   process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
   worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
   kthread+0x3b5/0x4a0 kernel/kthread.c:292
   ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
  Modules linked in:
  ---[ end trace b68924293169feef ]---
  RIP: 0010:fortify_panic+0xf/0x20 lib/string.c:1129
  RSP: 0018:ffffc90000e27980 EFLAGS: 00010286
  RAX: 0000000000000022 RBX: ffff8880a80dca64 RCX: 0000000000000000
  RDX: ffff8880a90860c0 RSI: ffffffff815dba07 RDI: fffff520001c4f22
  RBP: ffff8880a80dca00 R08: 0000000000000022 R09: ffff8880ae7318e7
  R10: 0000000000000000 R11: 0000000000077578 R12: 00000000ffffff6e
  R13: 0000000000000008 R14: ffffc90000e27a40 R15: 1ffff920001c4f3c
  FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f95b7c4d008 CR3: 000000009647d000 CR4: 00000000001506e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

The overflow happens, because in btree_readpage_end_io_hook() we assume
that we have found a 4 byte checksum instead of the real possible 32
bytes we have for the checksums.

With the fix applied:

[   35.726623] BTRFS: device fsid 815caf9a-dc43-4d2a-ac54-764b8333d765 devid 1 transid 5 /dev/loop0 scanned by syz-repro (215)
[   35.738994] BTRFS info (device loop0): disk space caching is enabled
[   35.738998] BTRFS info (device loop0): has skinny extents
[   35.743337] BTRFS warning (device loop0): loop0 checksum verify failed on 1052672 wanted 0xf9c035fc8d239a54 found 0x67a25c14b7eabcf9 level 0
[   35.743420] BTRFS error (device loop0): failed to read chunk root
[   35.745899] BTRFS error (device loop0): open_ctree failed

Reported-by: syzbot+e864a35d361e1d4e29a5@syzkaller.appspotmail.com
Fixes: d5178578bc ("btrfs: directly call into crypto framework for checksumming")
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01 13:18:24 +02:00
Filipe Manana
eb576fc43a btrfs: fix space cache memory leak after transaction abort
commit bbc37d6e475eee8ffa2156ec813efc6bbb43c06d upstream.

If a transaction aborts it can cause a memory leak of the pages array of
a block group's io_ctl structure. The following steps explain how that can
happen:

1) Transaction N is committing, currently in state TRANS_STATE_UNBLOCKED
   and it's about to start writing out dirty extent buffers;

2) Transaction N + 1 already started and another task, task A, just called
   btrfs_commit_transaction() on it;

3) Block group B was dirtied (extents allocated from it) by transaction
   N + 1, so when task A calls btrfs_start_dirty_block_groups(), at the
   very beginning of the transaction commit, it starts writeback for the
   block group's space cache by calling btrfs_write_out_cache(), which
   allocates the pages array for the block group's io_ctl with a call to
   io_ctl_init(). Block group A is added to the io_list of transaction
   N + 1 by btrfs_start_dirty_block_groups();

4) While transaction N's commit is writing out the extent buffers, it gets
   an IO error and aborts transaction N, also setting the file system to
   RO mode;

5) Task A has already returned from btrfs_start_dirty_block_groups(), is at
   btrfs_commit_transaction() and has set transaction N + 1 state to
   TRANS_STATE_COMMIT_START. Immediately after that it checks that the
   filesystem was turned to RO mode, due to transaction N's abort, and
   jumps to the "cleanup_transaction" label. After that we end up at
   btrfs_cleanup_one_transaction() which calls btrfs_cleanup_dirty_bgs().
   That helper finds block group B in the transaction's io_list but it
   never releases the pages array of the block group's io_ctl, resulting in
   a memory leak.

In fact at the point when we are at btrfs_cleanup_dirty_bgs(), the pages
array points to pages that were already released by us at
__btrfs_write_out_cache() through the call to io_ctl_drop_pages(). We end
up freeing the pages array only after waiting for the ordered extent to
complete through btrfs_wait_cache_io(), which calls io_ctl_free() to do
that. But in the transaction abort case we don't wait for the space cache's
ordered extent to complete through a call to btrfs_wait_cache_io(), so
that's why we end up with a memory leak - we wait for the ordered extent
to complete indirectly by shutting down the work queues and waiting for
any jobs in them to complete before returning from close_ctree().

We can solve the leak simply by freeing the pages array right after
releasing the pages (with the call to io_ctl_drop_pages()) at
__btrfs_write_out_cache(), since we will never use it anymore after that
and the pages array points to already released pages at that point, which
is currently not a problem since no one will use it after that, but not a
good practice anyway since it can easily lead to use-after-free issues.

So fix this by freeing the pages array right after releasing the pages at
__btrfs_write_out_cache().

This issue can often be reproduced with test case generic/475 from fstests
and kmemleak can detect it and reports it with the following trace:

unreferenced object 0xffff9bbf009fa600 (size 512):
  comm "fsstress", pid 38807, jiffies 4298504428 (age 22.028s)
  hex dump (first 32 bytes):
    00 a0 7c 4d 3d ed ff ff 40 a0 7c 4d 3d ed ff ff  ..|M=...@.|M=...
    80 a0 7c 4d 3d ed ff ff c0 a0 7c 4d 3d ed ff ff  ..|M=.....|M=...
  backtrace:
    [<00000000f4b5cfe2>] __kmalloc+0x1a8/0x3e0
    [<0000000028665e7f>] io_ctl_init+0xa7/0x120 [btrfs]
    [<00000000a1f95b2d>] __btrfs_write_out_cache+0x86/0x4a0 [btrfs]
    [<00000000207ea1b0>] btrfs_write_out_cache+0x7f/0xf0 [btrfs]
    [<00000000af21f534>] btrfs_start_dirty_block_groups+0x27b/0x580 [btrfs]
    [<00000000c3c23d44>] btrfs_commit_transaction+0xa6f/0xe70 [btrfs]
    [<000000009588930c>] create_subvol+0x581/0x9a0 [btrfs]
    [<000000009ef2fd7f>] btrfs_mksubvol+0x3fb/0x4a0 [btrfs]
    [<00000000474e5187>] __btrfs_ioctl_snap_create+0x119/0x1a0 [btrfs]
    [<00000000708ee349>] btrfs_ioctl_snap_create_v2+0xb0/0xf0 [btrfs]
    [<00000000ea60106f>] btrfs_ioctl+0x12c/0x3130 [btrfs]
    [<000000005c923d6d>] __x64_sys_ioctl+0x83/0xb0
    [<0000000043ace2c9>] do_syscall_64+0x33/0x80
    [<00000000904efbce>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03 11:27:02 +02:00
Qu Wenruo
c16ba06f52 btrfs: don't allocate anonymous block device for user invisible roots
commit 851fd730a743e072badaf67caf39883e32439431 upstream.

[BUG]
When a lot of subvolumes are created, there is a user report about
transaction aborted:

  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]
The error is EMFILE (Too many files open) and comes from the anonymous
block device allocation. The ids are in a shared pool of size 1<<20.

The ids are assigned to live subvolumes, ie. the root structure exists
in memory (eg. after creation or after the root appears in some path).
The pool could be exhausted if the numbers are not reclaimed fast
enough, after subvolume deletion or if other system component uses the
anon block devices.

[WORKAROUND]
Since it's not possible to completely solve the problem, we can only
minimize the time the id is allocated to a subvolume root.

Firstly, we can reduce the use of anon_dev by trees that are not
subvolume roots, like data reloc tree.

This patch will do extra check on root objectid, to skip roots that
don't need anon_dev.  Currently it's only data reloc tree and orphan
roots.

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+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 13:05:21 +02:00
Josef Bacik
dd68ba0d73 btrfs: set update the uuid generation as soon as possible
commit 75ec1db8717a8f0a9d9c8d033e542fdaa7b73898 upstream.

In my EIO stress testing I noticed I was getting forced to rescan the
uuid tree pretty often, which was weird.  This is because my error
injection stuff would sometimes inject an error after log replay but
before we loaded the UUID tree.  If log replay committed the transaction
it wouldn't have updated the uuid tree generation, but the tree was
valid and didn't change, so there's no reason to not update the
generation here.

Fix this by setting the BTRFS_FS_UPDATE_UUID_TREE_GEN bit immediately
after reading all the fs roots if the uuid tree generation matches the
fs generation.  Then any transaction commits that happen during mount
won't screw up our uuid tree state, forcing us to do needless uuid
rescans.

Fixes: 70f8017547 ("Btrfs: check UUID tree during mount if required")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:15 +02:00
Filipe Manana
1bd44cada4 Btrfs: fix crash during unmount due to race with delayed inode workers
commit f0cc2cd70164efe8f75c5d99560f0f69969c72e4 upstream.

During unmount we can have a job from the delayed inode items work queue
still running, that can lead to at least two bad things:

1) A crash, because the worker can try to create a transaction just
   after the fs roots were freed;

2) A transaction leak, because the worker can create a transaction
   before the fs roots are freed and just after we committed the last
   transaction and after we stopped the transaction kthread.

A stack trace example of the crash:

 [79011.691214] kernel BUG at lib/radix-tree.c:982!
 [79011.692056] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
 [79011.693180] CPU: 3 PID: 1394 Comm: kworker/u8:2 Tainted: G        W         5.6.0-rc2-btrfs-next-54 #2
 (...)
 [79011.696789] Workqueue: btrfs-delayed-meta btrfs_work_helper [btrfs]
 [79011.697904] RIP: 0010:radix_tree_tag_set+0xe7/0x170
 (...)
 [79011.702014] RSP: 0018:ffffb3c84a317ca0 EFLAGS: 00010293
 [79011.702949] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
 [79011.704202] RDX: ffffb3c84a317cb0 RSI: ffffb3c84a317ca8 RDI: ffff8db3931340a0
 [79011.705463] RBP: 0000000000000005 R08: 0000000000000005 R09: ffffffff974629d0
 [79011.706756] R10: ffffb3c84a317bc0 R11: 0000000000000001 R12: ffff8db393134000
 [79011.708010] R13: ffff8db3931340a0 R14: ffff8db393134068 R15: 0000000000000001
 [79011.709270] FS:  0000000000000000(0000) GS:ffff8db3b6a00000(0000) knlGS:0000000000000000
 [79011.710699] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [79011.711710] CR2: 00007f22c2a0a000 CR3: 0000000232ad4005 CR4: 00000000003606e0
 [79011.712958] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [79011.714205] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [79011.715448] Call Trace:
 [79011.715925]  record_root_in_trans+0x72/0xf0 [btrfs]
 [79011.716819]  btrfs_record_root_in_trans+0x4b/0x70 [btrfs]
 [79011.717925]  start_transaction+0xdd/0x5c0 [btrfs]
 [79011.718829]  btrfs_async_run_delayed_root+0x17e/0x2b0 [btrfs]
 [79011.719915]  btrfs_work_helper+0xaa/0x720 [btrfs]
 [79011.720773]  process_one_work+0x26d/0x6a0
 [79011.721497]  worker_thread+0x4f/0x3e0
 [79011.722153]  ? process_one_work+0x6a0/0x6a0
 [79011.722901]  kthread+0x103/0x140
 [79011.723481]  ? kthread_create_worker_on_cpu+0x70/0x70
 [79011.724379]  ret_from_fork+0x3a/0x50
 (...)

The following diagram shows a sequence of steps that lead to the crash
during ummount of the filesystem:

        CPU 1                                             CPU 2                                CPU 3

 btrfs_punch_hole()
   btrfs_btree_balance_dirty()
     btrfs_balance_delayed_items()
       --> sees
           fs_info->delayed_root->items
           with value 200, which is greater
           than
           BTRFS_DELAYED_BACKGROUND (128)
           and smaller than
           BTRFS_DELAYED_WRITEBACK (512)
       btrfs_wq_run_delayed_node()
         --> queues a job for
             fs_info->delayed_workers to run
             btrfs_async_run_delayed_root()

                                                                                            btrfs_async_run_delayed_root()
                                                                                              --> job queued by CPU 1

                                                                                              --> starts picking and running
                                                                                                  delayed nodes from the
                                                                                                  prepare_list list

                                                 close_ctree()

                                                   btrfs_delete_unused_bgs()

                                                   btrfs_commit_super()

                                                     btrfs_join_transaction()
                                                       --> gets transaction N

                                                     btrfs_commit_transaction(N)
                                                       --> set transaction state
                                                        to TRANTS_STATE_COMMIT_START

                                                                                             btrfs_first_prepared_delayed_node()
                                                                                               --> picks delayed node X through
                                                                                                   the prepared_list list

                                                       btrfs_run_delayed_items()

                                                         btrfs_first_delayed_node()
                                                           --> also picks delayed node X
                                                               but through the node_list
                                                               list

                                                         __btrfs_commit_inode_delayed_items()
                                                            --> runs all delayed items from
                                                                this node and drops the
                                                                node's item count to 0
                                                                through call to
                                                                btrfs_release_delayed_inode()

                                                         --> finishes running any remaining
                                                             delayed nodes

                                                       --> finishes transaction commit

                                                   --> stops cleaner and transaction threads

                                                   btrfs_free_fs_roots()
                                                     --> frees all roots and removes them
                                                         from the radix tree
                                                         fs_info->fs_roots_radix

                                                                                             btrfs_join_transaction()
                                                                                               start_transaction()
                                                                                                 btrfs_record_root_in_trans()
                                                                                                   record_root_in_trans()
                                                                                                     radix_tree_tag_set()
                                                                                                       --> crashes because
                                                                                                           the root is not in
                                                                                                           the radix tree
                                                                                                           anymore

If the worker is able to call btrfs_join_transaction() before the unmount
task frees the fs roots, we end up leaking a transaction and all its
resources, since after the call to btrfs_commit_super() and stopping the
transaction kthread, we don't expect to have any transaction open anymore.

When this situation happens the worker has a delayed node that has no
more items to run, since the task calling btrfs_run_delayed_items(),
which is doing a transaction commit, picks the same node and runs all
its items first.

We can not wait for the worker to complete when running delayed items
through btrfs_run_delayed_items(), because we call that function in
several phases of a transaction commit, and that could cause a deadlock
because the worker calls btrfs_join_transaction() and the task doing the
transaction commit may have already set the transaction state to
TRANS_STATE_COMMIT_DOING.

Also it's not possible to get into a situation where only some of the
items of a delayed node are added to the fs/subvolume tree in the current
transaction and the remaining ones in the next transaction, because when
running the items of a delayed inode we lock its mutex, effectively
waiting for the worker if the worker is running the items of the delayed
node already.

Since this can only cause issues when unmounting a filesystem, fix it in
a simple way by waiting for any jobs on the delayed workers queue before
calling btrfs_commit_supper() at close_ctree(). This works because at this
point no one can call btrfs_btree_balance_dirty() or
btrfs_balance_delayed_items(), and if we end up waiting for any worker to
complete, btrfs_commit_super() will commit the transaction created by the
worker.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:15 +02:00
Josef Bacik
9af8e25889 btrfs: do not check delayed items are empty for single transaction cleanup
commit 1e90315149f3fe148e114a5de86f0196d1c21fa5 upstream.

btrfs_assert_delayed_root_empty() will check if the delayed root is
completely empty, but this is a filesystem-wide check.  On cleanup we
may have allowed other transactions to begin, for whatever reason, and
thus the delayed root is not empty.

So remove this check from cleanup_one_transation().  This however can
stay in btrfs_cleanup_transaction(), because it checks only after all of
the transactions have been properly cleaned up, and thus is valid.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28 17:22:24 +01:00
Josef Bacik
6065ca5d01 btrfs: reset fs_root to NULL on error in open_ctree
commit 315bf8ef914f31d51d084af950703aa1e09a728c upstream.

While running my error injection script I hit a panic when we tried to
clean up the fs_root when freeing the fs_root.  This is because
fs_info->fs_root == PTR_ERR(-EIO), which isn't great.  Fix this by
setting fs_info->fs_root = NULL; if we fail to read the root.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28 17:22:24 +01:00
Jeff Mahoney
40ea30638d btrfs: destroy qgroup extent records on transaction abort
commit 81f7eb00ff5bb8326e82503a32809421d14abb8a upstream.

We clean up the delayed references when we abort a transaction but we
leave the pending qgroup extent records behind, leaking memory.

This patch destroys the extent records when we destroy the delayed refs
and makes sure ensure they're gone before releasing the transaction.

Fixes: 3368d001ba ("btrfs: qgroup: Record possible quota-related extent for qgroup.")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
[ Rebased to latest upstream, remove to_qgroup() helper, use
  rbtree_postorder_for_each_entry_safe() wrapper ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28 17:22:23 +01:00
David Sterba
2655c88c03 btrfs: print message when tree-log replay starts
commit e8294f2f6aa6208ed0923aa6d70cea3be178309a upstream.

There's no logged information about tree-log replay although this is
something that points to previous unclean unmount. Other filesystems
report that as well.

Suggested-by: Chris Murphy <lists@colorremedies.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19 19:53:00 +01:00
Josef Bacik
4987426257 btrfs: free block groups after free'ing fs trees
[ Upstream commit 4e19443da1941050b346f8fc4c368aa68413bc88 ]

Sometimes when running generic/475 we would trip the
WARN_ON(cache->reserved) check when free'ing the block groups on umount.
This is because sometimes we don't commit the transaction because of IO
errors and thus do not cleanup the tree logs until at umount time.

These blocks are still reserved until they are cleaned up, but they
aren't cleaned up until _after_ we do the free block groups work.  Fix
this by moving the free after free'ing the fs roots, that way all of the
tree logs are cleaned up and we have a properly cleaned fs.  A bunch of
loops of generic/475 confirmed this fixes the problem.

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-11 04:35:53 -08:00
Anand Jain
26ca39ac55 btrfs: use bool argument in free_root_pointers()
[ Upstream commit 4273eaff9b8d5e141113a5bdf9628c02acf3afe5 ]

We don't need int argument bool shall do in free_root_pointers().  And
rename the argument as it confused two people.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-11 04:35:52 -08:00
Filipe Manana
5e7a9ad78d Btrfs: fix race between adding and putting tree mod seq elements and nodes
commit 7227ff4de55d931bbdc156c8ef0ce4f100c78a5b upstream.

There is a race between adding and removing elements to the tree mod log
list and rbtree that can lead to use-after-free problems.

Consider the following example that explains how/why the problems happens:

1) Task A has mod log element with sequence number 200. It currently is
   the only element in the mod log list;

2) Task A calls btrfs_put_tree_mod_seq() because it no longer needs to
   access the tree mod log. When it enters the function, it initializes
   'min_seq' to (u64)-1. Then it acquires the lock 'tree_mod_seq_lock'
   before checking if there are other elements in the mod seq list.
   Since the list it empty, 'min_seq' remains set to (u64)-1. Then it
   unlocks the lock 'tree_mod_seq_lock';

3) Before task A acquires the lock 'tree_mod_log_lock', task B adds
   itself to the mod seq list through btrfs_get_tree_mod_seq() and gets a
   sequence number of 201;

4) Some other task, name it task C, modifies a btree and because there
   elements in the mod seq list, it adds a tree mod elem to the tree
   mod log rbtree. That node added to the mod log rbtree is assigned
   a sequence number of 202;

5) Task B, which is doing fiemap and resolving indirect back references,
   calls btrfs get_old_root(), with 'time_seq' == 201, which in turn
   calls tree_mod_log_search() - the search returns the mod log node
   from the rbtree with sequence number 202, created by task C;

6) Task A now acquires the lock 'tree_mod_log_lock', starts iterating
   the mod log rbtree and finds the node with sequence number 202. Since
   202 is less than the previously computed 'min_seq', (u64)-1, it
   removes the node and frees it;

7) Task B still has a pointer to the node with sequence number 202, and
   it dereferences the pointer itself and through the call to
   __tree_mod_log_rewind(), resulting in a use-after-free problem.

This issue can be triggered sporadically with the test case generic/561
from fstests, and it happens more frequently with a higher number of
duperemove processes. When it happens to me, it either freezes the VM or
it produces a trace like the following before crashing:

  [ 1245.321140] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
  [ 1245.321200] CPU: 1 PID: 26997 Comm: pool Not tainted 5.5.0-rc6-btrfs-next-52 #1
  [ 1245.321235] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
  [ 1245.321287] RIP: 0010:rb_next+0x16/0x50
  [ 1245.321307] Code: ....
  [ 1245.321372] RSP: 0018:ffffa151c4d039b0 EFLAGS: 00010202
  [ 1245.321388] RAX: 6b6b6b6b6b6b6b6b RBX: ffff8ae221363c80 RCX: 6b6b6b6b6b6b6b6b
  [ 1245.321409] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8ae221363c80
  [ 1245.321439] RBP: ffff8ae20fcc4688 R08: 0000000000000002 R09: 0000000000000000
  [ 1245.321475] R10: ffff8ae20b120910 R11: 00000000243f8bb1 R12: 0000000000000038
  [ 1245.321506] R13: ffff8ae221363c80 R14: 000000000000075f R15: ffff8ae223f762b8
  [ 1245.321539] FS:  00007fdee1ec7700(0000) GS:ffff8ae236c80000(0000) knlGS:0000000000000000
  [ 1245.321591] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 1245.321614] CR2: 00007fded4030c48 CR3: 000000021da16003 CR4: 00000000003606e0
  [ 1245.321642] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [ 1245.321668] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [ 1245.321706] Call Trace:
  [ 1245.321798]  __tree_mod_log_rewind+0xbf/0x280 [btrfs]
  [ 1245.321841]  btrfs_search_old_slot+0x105/0xd00 [btrfs]
  [ 1245.321877]  resolve_indirect_refs+0x1eb/0xc60 [btrfs]
  [ 1245.321912]  find_parent_nodes+0x3dc/0x11b0 [btrfs]
  [ 1245.321947]  btrfs_check_shared+0x115/0x1c0 [btrfs]
  [ 1245.321980]  ? extent_fiemap+0x59d/0x6d0 [btrfs]
  [ 1245.322029]  extent_fiemap+0x59d/0x6d0 [btrfs]
  [ 1245.322066]  do_vfs_ioctl+0x45a/0x750
  [ 1245.322081]  ksys_ioctl+0x70/0x80
  [ 1245.322092]  ? trace_hardirqs_off_thunk+0x1a/0x1c
  [ 1245.322113]  __x64_sys_ioctl+0x16/0x20
  [ 1245.322126]  do_syscall_64+0x5c/0x280
  [ 1245.322139]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [ 1245.322155] RIP: 0033:0x7fdee3942dd7
  [ 1245.322177] Code: ....
  [ 1245.322258] RSP: 002b:00007fdee1ec6c88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [ 1245.322294] RAX: ffffffffffffffda RBX: 00007fded40210d8 RCX: 00007fdee3942dd7
  [ 1245.322314] RDX: 00007fded40210d8 RSI: 00000000c020660b RDI: 0000000000000004
  [ 1245.322337] RBP: 0000562aa89e7510 R08: 0000000000000000 R09: 00007fdee1ec6d44
  [ 1245.322369] R10: 0000000000000073 R11: 0000000000000246 R12: 00007fdee1ec6d48
  [ 1245.322390] R13: 00007fdee1ec6d40 R14: 00007fded40210d0 R15: 00007fdee1ec6d50
  [ 1245.322423] Modules linked in: ....
  [ 1245.323443] ---[ end trace 01de1e9ec5dff3cd ]---

Fix this by ensuring that btrfs_put_tree_mod_seq() computes the minimum
sequence number and iterates the rbtree while holding the lock
'tree_mod_log_lock' in write mode. Also get rid of the 'tree_mod_seq_lock'
lock, since it is now redundant.

Fixes: bd989ba359 ("Btrfs: add tree modification log functions")
Fixes: 097b8a7c9e ("Btrfs: join tree mod log code with the code holding back delayed refs")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:34 -08:00
Omar Sandoval
2bae3ee327 btrfs: get rid of unique workqueue helper functions
[ Upstream commit a0cac0ec961f0d42828eeef196ac2246a2f07659 ]

Commit 9e0af23764 ("Btrfs: fix task hang under heavy compressed
write") worked around the issue that a recycled work item could get a
false dependency on the original work item due to how the workqueue code
guarantees non-reentrancy. It did so by giving different work functions
to different types of work.

However, the fixes in the previous few patches are more complete, as
they prevent a work item from being recycled at all (except for a tiny
window that the kernel workqueue code handles for us). This obsoletes
the previous fix, so we don't need the unique helpers for correctness.
The only other reason to keep them would be so they show up in stack
traces, but they always seem to be optimized to a tail call, so they
don't show up anyways. So, let's just get rid of the extra indirection.

While we're here, rename normal_work_helper() to the more informative
btrfs_work_helper().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-09 10:20:06 +01:00
Omar Sandoval
4b3bd1615e btrfs: don't prematurely free work in end_workqueue_fn()
[ Upstream commit 9be490f1e15c34193b1aae17da58e14dd9f55a95 ]

Currently, end_workqueue_fn() frees the end_io_wq entry (which embeds
the work item) and then calls bio_endio(). This is another potential
instance of the bug in "btrfs: don't prematurely free work in
run_ordered_work()".

In particular, the endio call may depend on other work items. For
example, btrfs_end_dio_bio() can call btrfs_subio_endio_read() ->
__btrfs_correct_data_nocsum() -> dio_read_error() ->
submit_dio_repair_bio(), which submits a bio that is also completed
through a end_workqueue_fn() work item. However,
__btrfs_correct_data_nocsum() waits for the newly submitted bio to
complete, thus it depends on another work item.

This example currently usually works because we use different workqueue
helper functions for BTRFS_WQ_ENDIO_DATA and BTRFS_WQ_ENDIO_DIO_REPAIR.
However, it may deadlock with stacked filesystems and is fragile
overall. The proper fix is to free the work item at the very end of the
work function, so let's do that.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:45:36 +01:00
David Sterba
80ed4548d0 btrfs: don't needlessly create extent-refs kernel thread
The patch 32b593bfcb ("Btrfs: remove no longer used function to run
delayed refs asynchronously") removed the async delayed refs but the
thread has been created, without any use. Remove it to avoid resource
consumption.

Fixes: 32b593bfcb ("Btrfs: remove no longer used function to run delayed refs asynchronously")
CC: stable@vger.kernel.org # 5.2+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-10-15 15:43:29 +02:00
Qu Wenruo
62fdaa52a3 btrfs: Detect unbalanced tree with empty leaf before crashing btree operations
[BUG]
With crafted image, btrfs will panic at btree operations:

  kernel BUG at fs/btrfs/ctree.c:3894!
  invalid opcode: 0000 [#1] SMP PTI
  CPU: 0 PID: 1138 Comm: btrfs-transacti Not tainted 5.0.0-rc8+ #9
  RIP: 0010:__push_leaf_left+0x6b6/0x6e0
  RSP: 0018:ffffc0bd4128b990 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffffa0a4ab8f0e38 RCX: 0000000000000000
  RDX: ffffa0a280000000 RSI: 0000000000000000 RDI: ffffa0a4b3814000
  RBP: ffffc0bd4128ba38 R08: 0000000000001000 R09: ffffc0bd4128b948
  R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000240
  R13: ffffa0a4b556fb60 R14: ffffa0a4ab8f0af0 R15: ffffa0a4ab8f0af0
  FS: 0000000000000000(0000) GS:ffffa0a4b7a00000(0000) knlGS:0000000000000000
  CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f2461c80020 CR3: 000000022b32a006 CR4: 00000000000206f0
  Call Trace:
  ? _cond_resched+0x1a/0x50
  push_leaf_left+0x179/0x190
  btrfs_del_items+0x316/0x470
  btrfs_del_csums+0x215/0x3a0
  __btrfs_free_extent.isra.72+0x5a7/0xbe0
  __btrfs_run_delayed_refs+0x539/0x1120
  btrfs_run_delayed_refs+0xdb/0x1b0
  btrfs_commit_transaction+0x52/0x950
  ? start_transaction+0x94/0x450
  transaction_kthread+0x163/0x190
  kthread+0x105/0x140
  ? btrfs_cleanup_transaction+0x560/0x560
  ? kthread_destroy_worker+0x50/0x50
  ret_from_fork+0x35/0x40
  Modules linked in:
  ---[ end trace c2425e6e89b5558f ]---

[CAUSE]
The offending csum tree looks like this:

  checksum tree key (CSUM_TREE ROOT_ITEM 0)
  node 29741056 level 1 items 14 free 107 generation 19 owner CSUM_TREE
	  ...
	  key (EXTENT_CSUM EXTENT_CSUM 85975040) block 29630464 gen 17
	  key (EXTENT_CSUM EXTENT_CSUM 89911296) block 29642752 gen 17 <<<
	  key (EXTENT_CSUM EXTENT_CSUM 92274688) block 29646848 gen 17
	  ...

  leaf 29630464 items 6 free space 1 generation 17 owner CSUM_TREE
	  item 0 key (EXTENT_CSUM EXTENT_CSUM 85975040) itemoff 3987 itemsize 8
		  range start 85975040 end 85983232 length 8192
	  ...
  leaf 29642752 items 0 free space 3995 generation 17 owner 0
		      ^ empty leaf            invalid owner ^

  leaf 29646848 items 1 free space 602 generation 17 owner CSUM_TREE
	  item 0 key (EXTENT_CSUM EXTENT_CSUM 92274688) itemoff 627 itemsize 3368
		  range start 92274688 end 95723520 length 3448832

So we have a corrupted csum tree where one tree leaf is completely
empty, causing unbalanced btree, thus leading to unexpected btree
balance error.

[FIX]
For this particular case, we handle it in two directions to catch it:
- Check if the tree block is empty through btrfs_verify_level_key()
  So that invalid tree blocks won't be read out through
  btrfs_search_slot() and its variants.

- Check 0 tree owner in tree checker
  NO tree is using 0 as its tree owner, detect it and reject at tree
  block read time.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202821
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:14 +02:00
Nikolay Borisov
4f84bd7f99 btrfs: Make reada_tree_block_flagged private
This function is used only for the readahead machinery. It makes no
sense to keep it external to reada.c file. Place it above its sole
caller and make it static. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:11 +02:00
Josef Bacik
aac0023c21 btrfs: move basic block_group definitions to their own header
This is prep work for moving all of the block group cache code into its
own file.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor comment updates ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-09 14:59:03 +02:00
Filipe Manana
d7cd4dd907 Btrfs: fix sysfs warning and missing raid sysfs directories
In the 5.3 merge window, commit 7c7e301406 ("btrfs: sysfs: Replace
default_attrs in ktypes with groups"), we started using the member
"defaults_groups" for the kobject type "btrfs_raid_ktype". That leads
to a series of warnings when running some test cases of fstests, such
as btrfs/027, btrfs/124 and btrfs/176. The traces produced by those
warnings are like the following:

  [116648.059212] kernfs: can not remove 'total_bytes', no directory
  [116648.060112] WARNING: CPU: 3 PID: 28500 at fs/kernfs/dir.c:1504 kernfs_remove_by_name_ns+0x75/0x80
  (...)
  [116648.066482] CPU: 3 PID: 28500 Comm: umount Tainted: G        W         5.3.0-rc3-btrfs-next-54 #1
  (...)
  [116648.069376] RIP: 0010:kernfs_remove_by_name_ns+0x75/0x80
  (...)
  [116648.072385] RSP: 0018:ffffabfd0090bd08 EFLAGS: 00010282
  [116648.073437] RAX: 0000000000000000 RBX: ffffffffc0c11998 RCX: 0000000000000000
  [116648.074201] RDX: ffff9fff603a7a00 RSI: ffff9fff603978a8 RDI: ffff9fff603978a8
  [116648.074956] RBP: ffffffffc0b9ca2f R08: 0000000000000000 R09: 0000000000000001
  [116648.075708] R10: ffff9ffe1f72e1c0 R11: 0000000000000000 R12: ffffffffc0b94120
  [116648.076434] R13: ffffffffb3d9b4e0 R14: 0000000000000000 R15: dead000000000100
  [116648.077143] FS:  00007f9cdc78a2c0(0000) GS:ffff9fff60380000(0000) knlGS:0000000000000000
  [116648.077852] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [116648.078546] CR2: 00007f9fc4747ab4 CR3: 00000005c7832003 CR4: 00000000003606e0
  [116648.079235] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [116648.079907] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [116648.080585] Call Trace:
  [116648.081262]  remove_files+0x31/0x70
  [116648.081929]  sysfs_remove_group+0x38/0x80
  [116648.082596]  sysfs_remove_groups+0x34/0x70
  [116648.083258]  kobject_del+0x20/0x60
  [116648.083933]  btrfs_free_block_groups+0x405/0x430 [btrfs]
  [116648.084608]  close_ctree+0x19a/0x380 [btrfs]
  [116648.085278]  generic_shutdown_super+0x6c/0x110
  [116648.085951]  kill_anon_super+0xe/0x30
  [116648.086621]  btrfs_kill_super+0x12/0xa0 [btrfs]
  [116648.087289]  deactivate_locked_super+0x3a/0x70
  [116648.087956]  cleanup_mnt+0xb4/0x160
  [116648.088620]  task_work_run+0x7e/0xc0
  [116648.089285]  exit_to_usermode_loop+0xfa/0x100
  [116648.089933]  do_syscall_64+0x1cb/0x220
  [116648.090567]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [116648.091197] RIP: 0033:0x7f9cdc073b37
  (...)
  [116648.100046] ---[ end trace 22e24db328ccadf8 ]---
  [116648.100618] ------------[ cut here ]------------
  [116648.101175] kernfs: can not remove 'used_bytes', no directory
  [116648.101731] WARNING: CPU: 3 PID: 28500 at fs/kernfs/dir.c:1504 kernfs_remove_by_name_ns+0x75/0x80
  (...)
  [116648.105649] CPU: 3 PID: 28500 Comm: umount Tainted: G        W         5.3.0-rc3-btrfs-next-54 #1
  (...)
  [116648.107461] RIP: 0010:kernfs_remove_by_name_ns+0x75/0x80
  (...)
  [116648.109336] RSP: 0018:ffffabfd0090bd08 EFLAGS: 00010282
  [116648.109979] RAX: 0000000000000000 RBX: ffffffffc0c119a0 RCX: 0000000000000000
  [116648.110625] RDX: ffff9fff603a7a00 RSI: ffff9fff603978a8 RDI: ffff9fff603978a8
  [116648.111283] RBP: ffffffffc0b9ca41 R08: 0000000000000000 R09: 0000000000000001
  [116648.111940] R10: ffff9ffe1f72e1c0 R11: 0000000000000000 R12: ffffffffc0b94120
  [116648.112603] R13: ffffffffb3d9b4e0 R14: 0000000000000000 R15: dead000000000100
  [116648.113268] FS:  00007f9cdc78a2c0(0000) GS:ffff9fff60380000(0000) knlGS:0000000000000000
  [116648.113939] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [116648.114607] CR2: 00007f9fc4747ab4 CR3: 00000005c7832003 CR4: 00000000003606e0
  [116648.115286] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [116648.115966] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [116648.116649] Call Trace:
  [116648.117326]  remove_files+0x31/0x70
  [116648.117997]  sysfs_remove_group+0x38/0x80
  [116648.118671]  sysfs_remove_groups+0x34/0x70
  [116648.119342]  kobject_del+0x20/0x60
  [116648.120022]  btrfs_free_block_groups+0x405/0x430 [btrfs]
  [116648.120707]  close_ctree+0x19a/0x380 [btrfs]
  [116648.121396]  generic_shutdown_super+0x6c/0x110
  [116648.122057]  kill_anon_super+0xe/0x30
  [116648.122702]  btrfs_kill_super+0x12/0xa0 [btrfs]
  [116648.123335]  deactivate_locked_super+0x3a/0x70
  [116648.123961]  cleanup_mnt+0xb4/0x160
  [116648.124586]  task_work_run+0x7e/0xc0
  [116648.125210]  exit_to_usermode_loop+0xfa/0x100
  [116648.125830]  do_syscall_64+0x1cb/0x220
  [116648.126463]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [116648.127080] RIP: 0033:0x7f9cdc073b37
  (...)
  [116648.135923] ---[ end trace 22e24db328ccadf9 ]---

These happen because, during the unmount path, we call kobject_del() for
raid kobjects that are not fully initialized, meaning that we set their
ktype (as btrfs_raid_ktype) through link_block_group() but we didn't set
their parent kobject, which is done through btrfs_add_raid_kobjects().

We have this split raid kobject setup since commit 75cb379d26
("btrfs: defer adding raid type kobject until after chunk relocation") in
order to avoid triggering reclaim during contextes where we can not
(either we are holding a transaction handle or some lock required by
the transaction commit path), so that we do the calls to kobject_add(),
which triggers GFP_KERNEL allocations, through btrfs_add_raid_kobjects()
in contextes where it is safe to trigger reclaim. That change expected
that a new raid kobject can only be created either when mounting the
filesystem or after raid profile conversion through the relocation path.
However, we can have new raid kobject created in other two cases at least:

1) During device replace (or scrub) after adding a device a to the
   filesystem. The replace procedure (and scrub) do calls to
   btrfs_inc_block_group_ro() which can allocate a new block group
   with a new raid profile (because we now have more devices). This
   can be triggered by test cases btrfs/027 and btrfs/176.

2) During a degraded mount trough any write path. This can be triggered
   by test case btrfs/124.

Fixing this by adding extra calls to btrfs_add_raid_kobjects(), not only
makes things more complex and fragile, can also introduce deadlocks with
reclaim the following way:

1) Calling btrfs_add_raid_kobjects() at btrfs_inc_block_group_ro() or
   anywhere in the replace/scrub path will cause a deadlock with reclaim
   because if reclaim happens and a transaction commit is triggered,
   the transaction commit path will block at btrfs_scrub_pause().

2) During degraded mounts it is essentially impossible to figure out where
   to add extra calls to btrfs_add_raid_kobjects(), because allocation of
   a block group with a new raid profile can happen anywhere, which means
   we can't safely figure out which contextes are safe for reclaim, as
   we can either hold a transaction handle or some lock needed by the
   transaction commit path.

So it is too complex and error prone to have this split setup of raid
kobjects. So fix the issue by consolidating the setup of the kobjects in a
single place, at link_block_group(), and setup a nofs context there in
order to prevent reclaim being triggered by the memory allocations done
through the call chain of kobject_add().

Besides fixing the sysfs warnings during kobject_del(), this also ensures
the sysfs directories for the new raid profiles end up created and visible
to users (a bug that existed before the 5.3 commit 7c7e301406
("btrfs: sysfs: Replace default_attrs in ktypes with groups")).

Fixes: 75cb379d26 ("btrfs: defer adding raid type kobject until after chunk relocation")
Fixes: 7c7e301406 ("btrfs: sysfs: Replace default_attrs in ktypes with groups")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-08-07 16:25:44 +02:00
Johannes Thumshirn
bfcea1c661 btrfs: free checksum hash on in close_ctree
fs_info::csum_hash gets initialized in btrfs_init_csum_hash() which is
called by open_ctree().

But it only gets freed if open_ctree() fails, not on normal operation.

This leads to a memory leak like the following found by kmemleak:
unreferenced object 0xffff888132cb8720 (size 96):

  comm "mount", pid 450, jiffies 4294912436 (age 17.584s)
  hex dump (first 32 bytes):
    04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000000c9643d4>] crypto_create_tfm+0x2d/0xd0
    [<00000000ae577f68>] crypto_alloc_tfm+0x4b/0xb0
    [<000000002b5cdf30>] open_ctree+0xb84/0x2060 [btrfs]
    [<0000000043204297>] btrfs_mount_root+0x552/0x640 [btrfs]
    [<00000000c99b10ea>] legacy_get_tree+0x22/0x40
    [<0000000071a6495f>] vfs_get_tree+0x1f/0xc0
    [<00000000f180080e>] fc_mount+0x9/0x30
    [<000000009e36cebd>] vfs_kern_mount.part.11+0x6a/0x80
    [<0000000004594c05>] btrfs_mount+0x174/0x910 [btrfs]
    [<00000000c99b10ea>] legacy_get_tree+0x22/0x40
    [<0000000071a6495f>] vfs_get_tree+0x1f/0xc0
    [<00000000b86e92c5>] do_mount+0x6b0/0x940
    [<0000000097464494>] ksys_mount+0x7b/0xd0
    [<0000000057213c80>] __x64_sys_mount+0x1c/0x20
    [<00000000cb689b5e>] do_syscall_64+0x43/0x130
    [<000000002194e289>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Free fs_info::csum_hash in close_ctree() to avoid the memory leak.

Fixes: 6d97c6e31b ("btrfs: add boilerplate code for directly including the crypto framework")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-17 17:03:33 +02:00
Filipe Manana
9e967495e0 Btrfs: prevent send failures and crashes due to concurrent relocation
Send always operates on read-only trees and always expected that while it
is in progress, nothing changes in those trees. Due to that expectation
and the fact that send is a read-only operation, it operates on commit
roots and does not hold transaction handles. However relocation can COW
nodes and leafs from read-only trees, which can cause unexpected failures
and crashes (hitting BUG_ONs). while send using a node/leaf, it gets
COWed, the transaction used to COW it is committed, a new transaction
starts, the extent previously used for that node/leaf gets allocated,
possibly for another tree, and the respective extent buffer' content
changes while send is still using it. When this happens send normally
fails with EIO being returned to user space and messages like the
following are found in dmesg/syslog:

  [ 3408.699121] BTRFS error (device sdc): parent transid verify failed on 58703872 wanted 250 found 253
  [ 3441.523123] BTRFS error (device sdc): did not find backref in send_root. inode=63211, offset=0, disk_byte=5222825984 found extent=5222825984

Other times, less often, we hit a BUG_ON() because an extent buffer that
send is using used to be a node, and while send is still using it, it
got COWed and got reused as a leaf while send is still using, producing
the following trace:

 [ 3478.466280] ------------[ cut here ]------------
 [ 3478.466282] kernel BUG at fs/btrfs/ctree.c:1806!
 [ 3478.466965] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
 [ 3478.467635] CPU: 0 PID: 2165 Comm: btrfs Not tainted 5.0.0-btrfs-next-46 #1
 [ 3478.468311] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
 [ 3478.469681] RIP: 0010:read_node_slot+0x122/0x130 [btrfs]
 (...)
 [ 3478.471758] RSP: 0018:ffffa437826bfaa0 EFLAGS: 00010246
 [ 3478.472457] RAX: ffff961416ed7000 RBX: 000000000000003d RCX: 0000000000000002
 [ 3478.473151] RDX: 000000000000003d RSI: ffff96141e387408 RDI: ffff961599b30000
 [ 3478.473837] RBP: ffffa437826bfb8e R08: 0000000000000001 R09: ffffa437826bfb8e
 [ 3478.474515] R10: ffffa437826bfa70 R11: 0000000000000000 R12: ffff9614385c8708
 [ 3478.475186] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 [ 3478.475840] FS:  00007f8e0e9cc8c0(0000) GS:ffff9615b6a00000(0000) knlGS:0000000000000000
 [ 3478.476489] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [ 3478.477127] CR2: 00007f98b67a056e CR3: 0000000005df6005 CR4: 00000000003606f0
 [ 3478.477762] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [ 3478.478385] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [ 3478.479003] Call Trace:
 [ 3478.479600]  ? do_raw_spin_unlock+0x49/0xc0
 [ 3478.480202]  tree_advance+0x173/0x1d0 [btrfs]
 [ 3478.480810]  btrfs_compare_trees+0x30c/0x690 [btrfs]
 [ 3478.481388]  ? process_extent+0x1280/0x1280 [btrfs]
 [ 3478.481954]  btrfs_ioctl_send+0x1037/0x1270 [btrfs]
 [ 3478.482510]  _btrfs_ioctl_send+0x80/0x110 [btrfs]
 [ 3478.483062]  btrfs_ioctl+0x13fe/0x3120 [btrfs]
 [ 3478.483581]  ? rq_clock_task+0x2e/0x60
 [ 3478.484086]  ? wake_up_new_task+0x1f3/0x370
 [ 3478.484582]  ? do_vfs_ioctl+0xa2/0x6f0
 [ 3478.485075]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
 [ 3478.485552]  do_vfs_ioctl+0xa2/0x6f0
 [ 3478.486016]  ? __fget+0x113/0x200
 [ 3478.486467]  ksys_ioctl+0x70/0x80
 [ 3478.486911]  __x64_sys_ioctl+0x16/0x20
 [ 3478.487337]  do_syscall_64+0x60/0x1b0
 [ 3478.487751]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [ 3478.488159] RIP: 0033:0x7f8e0d7d4dd7
 (...)
 [ 3478.489349] RSP: 002b:00007ffcf6fb4908 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
 [ 3478.489742] RAX: ffffffffffffffda RBX: 0000000000000105 RCX: 00007f8e0d7d4dd7
 [ 3478.490142] RDX: 00007ffcf6fb4990 RSI: 0000000040489426 RDI: 0000000000000005
 [ 3478.490548] RBP: 0000000000000005 R08: 00007f8e0d6f3700 R09: 00007f8e0d6f3700
 [ 3478.490953] R10: 00007f8e0d6f39d0 R11: 0000000000000202 R12: 0000000000000005
 [ 3478.491343] R13: 00005624e0780020 R14: 0000000000000000 R15: 0000000000000001
 (...)
 [ 3478.493352] ---[ end trace d5f537302be4f8c8 ]---

Another possibility, much less likely to happen, is that send will not
fail but the contents of the stream it produces may not be correct.

To avoid this, do not allow send and relocation (balance) to run in
parallel. In the long term the goal is to allow for both to be able to
run concurrently without any problems, but that will take a significant
effort in development and testing.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
Johannes Thumshirn
d5178578bc btrfs: directly call into crypto framework for checksumming
Currently btrfs_csum_data() relied on the crc32c() wrapper around the
crypto framework for calculating the CRCs.

As we have our own crypto_shash structure in the fs_info now, we can
directly call into the crypto framework without going trough the wrapper.

This way we can even remove the btrfs_csum_data() and btrfs_csum_final()
wrappers.

The module dependency on crc32c is preserved via MODULE_SOFTDEP("pre:
crc32c"), which was previously provided by LIBCRC32C config option doing
the same.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:02 +02:00
Johannes Thumshirn
6d97c6e31b btrfs: add boilerplate code for directly including the crypto framework
Add boilerplate code for directly including the crypto framework.  This
helps us flipping the switch for new algorithms.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
Johannes Thumshirn
51bce6c9b9 btrfs: Simplify btrfs_check_super_csum() and get rid of size assumptions
Now that we have already checked for a valid checksum type before
calling btrfs_check_super_csum(), it can be simplified even further.

While at it get rid of the implicit size assumption of the resulting
checksum as well.

This is a preparation for changing all checksum functionality to use the
crypto layer later.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
Johannes Thumshirn
8dc3f22c8b btrfs: check for supported superblock checksum type before checksum validation
Now that we have factorerd out the superblock checksum type validation,
we can check for supported superblock checksum types before doing the
actual validation of the superblock read from disk.

This leads the path to further simplifications of
btrfs_check_super_csum() later on.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
Johannes Thumshirn
e7e16f4882 btrfs: add common checksum type validation
Currently btrfs is only supporting CRC32C as checksumming algorithm. As
this is about to change provide a function to validate the checksum type
in the superblock against all possible algorithms.

This makes adding new algorithms easier as there are fewer places to
adjust when adding new algorithms.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
David Sterba
8c3e3582a4 btrfs: use u8 for raid_array members
The raid_attr table is now 7 * 56 = 392 bytes long, consisting of just
small numbers so we don't have to use ints. New size is 7 * 32 = 224,
saving 3 cachelines.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:57 +02:00
David Sterba
c8bf1b6703 btrfs: remove mapping tree structures indirection
fs_info::mapping_tree is the physical<->logical mapping tree and uses
the same underlying structure as extents, but is embedded to another
structure. There are no other members and this indirection is useless.
No functional change.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:56 +02:00
David Sterba
9b4e675a99 btrfs: detect fast implementation of crc32c on all architectures
Currently, there's only check for fast crc32c implementation on X86,
based on the CPU flags. This is used to decide if checksumming should be
offloaded to worker threads or can be calculated by the caller.

As there are more architectures that implement a faster version of
crc32c (ARM, SPARC, s390, MIPS, PowerPC), also there are specialized hw
cards.

The detection is based on driver name, all generic C implementations
contain 'generic', while the specialized versions do not. Alternatively
the priority could be used, but this is not currently provided by the
crypto API.

The flag is set per-filesystem at mount time and used for the offloading
decisions.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:53 +02:00
Linus Torvalds
67a2422239 for-5.2/block-20190507
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAlzR0AAQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpo0MD/47D1kBK9rGzkAwIz1Jkh1Qy/ITVaDJzmHJ
 UP5uncQsgKFLKMR1LbRcrWtmk2MwFDNULGbteHFeCYE1ypCrTgpWSp5+SJluKd1Q
 hma9krLSAXO9QiSaZ4jafshXFIZxz6IjakOW8c9LrT80Ze47yh7AxiLwDafcp/Jj
 x6NW790qB7ENDtfarDkZk14NCS8HGLRHO5B21LB+hT0Kfbh0XZaLzJdj7Mck1wPA
 VT8hL9mPuA++AjF7Ra4kUjwSakgmajTa3nS2fpkwTYdztQfas7x5Jiv7FWxrrelb
 qbabkNkWKepcHAPEiZR7o53TyfCucGeSK/jG+dsJ9KhNp26kl1ci3frl5T6PfVMP
 SPPDjsKIHs+dqFrU9y5rSGhLJqewTs96hHthnLGxyF67+5sRb5+YIy+dcqgiyc/b
 TUVyjCD6r0cO2q4v9VhwnhOyeBUA9Rwbu8nl7JV5Q45uG7qI4BC39l1jfubMNDPO
 GLNGUUzb6ER7z6lYINjRSF2Jhejsx8SR9P7jhpb1Q7k/VvDDxO1T4FpwvqWFz9+s
 Gn+s6//+cA6LL+42eZkQjvwF2CUNE7TaVT8zdb+s5HP1RQkZToqUnsQCGeRTrFni
 RqWXfW9o9+awYRp431417oMdX/LvLGq9+ZtifRk9DqDcowXevTaf0W2RpplWSuiX
 RcCuPeLAVg==
 =Ot0g
 -----END PGP SIGNATURE-----

Merge tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Nothing major in this series, just fixes and improvements all over the
  map. This contains:

   - Series of fixes for sed-opal (David, Jonas)

   - Fixes and performance tweaks for BFQ (via Paolo)

   - Set of fixes for bcache (via Coly)

   - Set of fixes for md (via Song)

   - Enabling multi-page for passthrough requests (Ming)

   - Queue release fix series (Ming)

   - Device notification improvements (Martin)

   - Propagate underlying device rotational status in loop (Holger)

   - Removal of mtip32xx trim support, which has been disabled for years
     (Christoph)

   - Improvement and cleanup of nvme command handling (Christoph)

   - Add block SPDX tags (Christoph)

   - Cleanup/hardening of bio/bvec iteration (Christoph)

   - A few NVMe pull requests (Christoph)

   - Removal of CONFIG_LBDAF (Christoph)

   - Various little fixes here and there"

* tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block: (164 commits)
  block: fix mismerge in bvec_advance
  block: don't drain in-progress dispatch in blk_cleanup_queue()
  blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_release
  blk-mq: always free hctx after request queue is freed
  blk-mq: split blk_mq_alloc_and_init_hctx into two parts
  blk-mq: free hw queue's resource in hctx's release handler
  blk-mq: move cancel of requeue_work into blk_mq_release
  blk-mq: grab .q_usage_counter when queuing request from plug code path
  block: fix function name in comment
  nvmet: protect discovery change log event list iteration
  nvme: mark nvme_core_init and nvme_core_exit static
  nvme: move command size checks to the core
  nvme-fabrics: check more command sizes
  nvme-pci: check more command sizes
  nvme-pci: remove an unneeded variable initialization
  nvme-pci: unquiesce admin queue on shutdown
  nvme-pci: shutdown on timeout during deletion
  nvme-pci: fix psdt field for single segment sgls
  nvme-multipath: don't print ANA group state by default
  nvme-multipath: split bios with the ns_head bio_set before submitting
  ...
2019-05-07 18:14:36 -07:00
Christoph Hellwig
2b070cfe58 block: remove the i argument to bio_for_each_segment_all
We only have two callers that need the integer loop iterator, and they
can easily maintain it themselves.

Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Coly Li <colyli@suse.de>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 09:26:13 -06:00
Josef Bacik
4297ff84dc btrfs: track DIO bytes in flight
When diagnosing a slowdown of generic/224 I noticed we were not doing
anything when calling into shrink_delalloc().  This is because all
writes in 224 are O_DIRECT, not delalloc, and thus our delalloc_bytes
counter is 0, which short circuits most of the work inside of
shrink_delalloc().  However O_DIRECT writes still consume metadata
resources and generate ordered extents, which we can still wait on.

Fix this by tracking outstanding DIO write bytes, and use this as well
as the delalloc bytes counter to decide if we need to lookup and wait on
any ordered extents.  If we have more DIO writes than delalloc bytes
we'll go ahead and wait on any ordered extents regardless of our flush
state as flushing delalloc is likely to not gain us anything.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ use dio instead of odirect in identifiers ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:25:37 +02:00
Nikolay Borisov
50489a5734 btrfs: Remove bio_offset argument from submit_bio_hook
None of the implementers of the submit_bio_hook use the bio_offset
parameter, simply remove it. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:47 +02:00
Nikolay Borisov
e68f2ee721 btrfs: Always pass 0 bio_offset for btree_submit_bio_start
The btree submit hook queues the async csum and forwards the bio_offset
parameter passed to btree_submit_bio_hook. This is redundant since
btree_submit_bio_start calls btree_csum_one_bio which doesn't use the
offset at all. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:47 +02:00
Nikolay Borisov
c2ccfbc62e btrfs: Remove 'tree' argument from read_extent_buffer_pages
This function always uses the btree inode's io_tree. Stop taking the
tree as a function argument and instead access it internally from
read_extent_buffer_pages. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:46 +02:00
Nikolay Borisov
a56b1c7bc8 btrfs: Change submit_bio_hook to taking an inode directly
The only possible 'private_data' that is passed to this function is
actually an inode. Make that explicit by changing the signature of the
call back. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:46 +02:00
David Sterba
9b7a2440ae btrfs: get fs_info from trans in btrfs_create_tree
We can read fs_info from the transaction and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:41 +02:00