Commit Graph

9535 Commits

Author SHA1 Message Date
Filipe Manana
c1ea39a77c btrfs: return -EAGAIN for NOWAIT dio reads/writes on compressed and inline extents
commit a4527e1853f8ff6e0b7c2dadad6268bd38427a31 upstream.

When doing a direct IO read or write, we always return -ENOTBLK when we
find a compressed extent (or an inline extent) so that we fallback to
buffered IO. This however is not ideal in case we are in a NOWAIT context
(io_uring for example), because buffered IO can block and we currently
have no support for NOWAIT semantics for buffered IO, so if we need to
fallback to buffered IO we should first signal the caller that we may
need to block by returning -EAGAIN instead.

This behaviour can also result in short reads being returned to user
space, which although it's not incorrect and user space should be able
to deal with partial reads, it's somewhat surprising and even some popular
applications like QEMU (Link tag #1) and MariaDB (Link tag #2) don't
deal with short reads properly (or at all).

The short read case happens when we try to read from a range that has a
non-compressed and non-inline extent followed by a compressed extent.
After having read the first extent, when we find the compressed extent we
return -ENOTBLK from btrfs_dio_iomap_begin(), which results in iomap to
treat the request as a short read, returning 0 (success) and waiting for
previously submitted bios to complete (this happens at
fs/iomap/direct-io.c:__iomap_dio_rw()). After that, and while at
btrfs_file_read_iter(), we call filemap_read() to use buffered IO to
read the remaining data, and pass it the number of bytes we were able to
read with direct IO. Than at filemap_read() if we get a page fault error
when accessing the read buffer, we return a partial read instead of an
-EFAULT error, because the number of bytes previously read is greater
than zero.

So fix this by returning -EAGAIN for NOWAIT direct IO when we find a
compressed or an inline extent.

Reported-by: Dominique MARTINET <dominique.martinet@atmark-techno.com>
Link: https://lore.kernel.org/linux-btrfs/YrrFGO4A1jS0GI0G@atmark-techno.com/
Link: https://jira.mariadb.org/browse/MDEV-27900?focusedCommentId=216582&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-216582
Tested-by: Dominique MARTINET <dominique.martinet@atmark-techno.com>
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Christoph Hellwig <hch@lst.de>
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>
2022-07-21 21:20:01 +02:00
David Sterba
0ae82e1ccb btrfs: add error messages to all unrecognized mount options
commit e3a4167c880cf889f66887a152799df4d609dd21 upstream.

Almost none of the errors stemming from a valid mount option but wrong
value prints a descriptive message which would help to identify why
mount failed. Like in the linked report:

  $ uname -r
  v4.19
  $ mount -o compress=zstd /dev/sdb /mnt
  mount: /mnt: wrong fs type, bad option, bad superblock on
  /dev/sdb, missing codepage or helper program, or other error.
  $ dmesg
  ...
  BTRFS error (device sdb): open_ctree failed

Errors caused by memory allocation failures are left out as it's not a
user error so reporting that would be confusing.

Link: https://lore.kernel.org/linux-btrfs/9c3fec36-fc61-3a33-4977-a7e207c3fa4e@gmx.de/
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-29 08:59:45 +02:00
Qu Wenruo
509e9710b8 btrfs: repair super block num_devices automatically
commit d201238ccd2f30b9bfcfadaeae0972e3a486a176 upstream.

[BUG]
There is a report that a btrfs has a bad super block num devices.

This makes btrfs to reject the fs completely.

  BTRFS error (device sdd3): super_num_devices 3 mismatch with num_devices 2 found here
  BTRFS error (device sdd3): failed to read chunk tree: -22
  BTRFS error (device sdd3): open_ctree failed

[CAUSE]
During btrfs device removal, chunk tree and super block num devs are
updated in two different transactions:

  btrfs_rm_device()
  |- btrfs_rm_dev_item(device)
  |  |- trans = btrfs_start_transaction()
  |  |  Now we got transaction X
  |  |
  |  |- btrfs_del_item()
  |  |  Now device item is removed from chunk tree
  |  |
  |  |- btrfs_commit_transaction()
  |     Transaction X got committed, super num devs untouched,
  |     but device item removed from chunk tree.
  |     (AKA, super num devs is already incorrect)
  |
  |- cur_devices->num_devices--;
  |- cur_devices->total_devices--;
  |- btrfs_set_super_num_devices()
     All those operations are not in transaction X, thus it will
     only be written back to disk in next transaction.

So after the transaction X in btrfs_rm_dev_item() committed, but before
transaction X+1 (which can be minutes away), a power loss happen, then
we got the super num mismatch.

This has been fixed by commit bbac58698a55 ("btrfs: remove device item
and update super block in the same transaction").

[FIX]
Make the super_num_devices check less strict, converting it from a hard
error to a warning, and reset the value to a correct one for the current
or next transaction commit.

As the number of device items is the critical information where the
super block num_devices is only a cached value (and also useful for
cross checking), it's safe to automatically update it. Other device
related problems like missing device are handled after that and may
require other means to resolve, like degraded mount. With this fix,
potentially affected filesystems won't fail mount and require the manual
repair by btrfs check.

Reported-by: Luca Béla Palkovics <luca.bela.palkovics@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CA+8xDSpvdm_U0QLBAnrH=zqDq_cWCOH5TiV46CKmp3igr44okQ@mail.gmail.com/
CC: stable@vger.kernel.org # 4.14+
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>
2022-06-09 10:20:49 +02:00
Qu Wenruo
4093eea47d 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>
2022-06-09 10:20:49 +02:00
Filipe Manana
4fd45ef704 btrfs: always log symlinks in full mode
commit d0e64a981fd841cb0f28fcd6afcac55e6f1e6994 upstream.

On Linux, empty symlinks are invalid, and attempting to create one with
the system call symlink(2) results in an -ENOENT error and this is
explicitly documented in the man page.

If we rename a symlink that was created in the current transaction and its
parent directory was logged before, we actually end up logging the symlink
without logging its content, which is stored in an inline extent. That
means that after a power failure we can end up with an empty symlink,
having no content and an i_size of 0 bytes.

It can be easily reproduced like this:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt

  $ mkdir /mnt/testdir
  $ sync

  # Create a file inside the directory and fsync the directory.
  $ touch /mnt/testdir/foo
  $ xfs_io -c "fsync" /mnt/testdir

  # Create a symlink inside the directory and then rename the symlink.
  $ ln -s /mnt/testdir/foo /mnt/testdir/bar
  $ mv /mnt/testdir/bar /mnt/testdir/baz

  # Now fsync again the directory, this persist the log tree.
  $ xfs_io -c "fsync" /mnt/testdir

  <power failure>

  $ mount /dev/sdc /mnt
  $ stat -c %s /mnt/testdir/baz
  0
  $ readlink /mnt/testdir/baz
  $

Fix this by always logging symlinks in full mode (LOG_INODE_ALL), so that
their content is also logged.

A test case for fstests will follow.

CC: stable@vger.kernel.org # 4.9+
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>
2022-05-12 12:25:43 +02:00
Naohiro Aota
5e4dd17998 btrfs: mark resumed async balance as writing
commit a690e5f2db4d1dca742ce734aaff9f3112d63764 upstream.

When btrfs balance is interrupted with umount, the background balance
resumes on the next mount. There is a potential deadlock with FS freezing
here like as described in commit 26559780b953 ("btrfs: zoned: mark
relocation as writing"). Mark the process as sb_writing to avoid it.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.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>
2022-04-20 09:23:27 +02:00
Jia-Ju Bai
1d2eda18f6 btrfs: fix root ref counts in error handling in btrfs_get_root_ref
commit 168a2f776b9762f4021421008512dd7ab7474df1 upstream.

In btrfs_get_root_ref(), when btrfs_insert_fs_root() fails,
btrfs_put_root() can happen for two reasons:

- the root already exists in the tree, in that case it returns the
  reference obtained in btrfs_lookup_fs_root()

- another error so the cleanup is done in the fail label

Calling btrfs_put_root() unconditionally would lead to double decrement
of the root reference possibly freeing it in the second case.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Fixes: bc44d7c4b2 ("btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root")
CC: stable@vger.kernel.org # 5.10+
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.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>
2022-04-20 09:23:27 +02:00
Josef Bacik
76e086ce7b btrfs: do not warn for free space inode in cow_file_range
[ Upstream commit a7d16d9a07bbcb7dcd5214a1bea75c808830bc0d ]

This is a long time leftover from when I originally added the free space
inode, the point was to catch cases where we weren't honoring the NOCOW
flag.  However there exists a race with relocation, if we allocate our
free space inode in a block group that is about to be relocated, we
could trigger the COW path before the relocation has the opportunity to
find the extents and delete the free space cache.  In production where
we have auto-relocation enabled we're seeing this WARN_ON_ONCE() around
5k times in a 2 week period, so not super common but enough that it's at
the top of our metrics.

We're properly handling the error here, and with us phasing out v1 space
cache anyway just drop the WARN_ON_ONCE.

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>
2022-04-20 09:23:19 +02:00
Darrick J. Wong
217190dc66 btrfs: fix fallocate to use file_modified to update permissions consistently
[ Upstream commit 05fd9564e9faf0f23b4676385e27d9405cef6637 ]

Since the initial introduction of (posix) fallocate back at the turn of
the century, it has been possible to use this syscall to change the
user-visible contents of files.  This can happen by extending the file
size during a preallocation, or through any of the newer modes (punch,
zero range).  Because the call can be used to change file contents, we
should treat it like we do any other modification to a file -- update
the mtime, and drop set[ug]id privileges/capabilities.

The VFS function file_modified() does all this for us if pass it a
locked inode, so let's make fallocate drop permissions correctly.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20 09:23:19 +02:00
Nathan Chancellor
921fdc45a0 btrfs: remove unused variable in btrfs_{start,write}_dirty_block_groups()
commit 6d4a6b515c39f1f8763093e0f828959b2fbc2f45 upstream.

Clang's version of -Wunused-but-set-variable recently gained support for
unary operations, which reveals two unused variables:

  fs/btrfs/block-group.c:2949:6: error: variable 'num_started' set but not used [-Werror,-Wunused-but-set-variable]
          int num_started = 0;
              ^
  fs/btrfs/block-group.c:3116:6: error: variable 'num_started' set but not used [-Werror,-Wunused-but-set-variable]
          int num_started = 0;
              ^
  2 errors generated.

These variables appear to be unused from their introduction, so just
remove them to silence the warnings.

Fixes: c9dc4c6578 ("Btrfs: two stage dirty block group writeout")
Fixes: 1bbc621ef2 ("Btrfs: allow block group cache writeout outside critical section in commit")
CC: stable@vger.kernel.org # 5.4+
Link: https://github.com/ClangBuiltLinux/linux/issues/1614
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20 09:23:10 +02:00
Kaiwen Hu
a044bca8ef btrfs: prevent subvol with swapfile from being deleted
commit 60021bd754c6ca0addc6817994f20290a321d8d6 upstream.

A subvolume with an active swapfile must not be deleted otherwise it
would not be possible to deactivate it.

After the subvolume is deleted, we cannot swapoff the swapfile in this
deleted subvolume because the path is unreachable.  The swapfile is
still active and holding references, the filesystem cannot be unmounted.

The test looks like this:

  mkfs.btrfs -f $dev > /dev/null
  mount $dev $mnt

  btrfs sub create $mnt/subvol
  touch $mnt/subvol/swapfile
  chmod 600 $mnt/subvol/swapfile
  chattr +C $mnt/subvol/swapfile
  dd if=/dev/zero of=$mnt/subvol/swapfile bs=1K count=4096
  mkswap $mnt/subvol/swapfile
  swapon $mnt/subvol/swapfile

  btrfs sub delete $mnt/subvol
  swapoff $mnt/subvol/swapfile  # failed: No such file or directory
  swapoff --all

  unmount $mnt                  # target is busy.

To prevent above issue, we simply check that whether the subvolume
contains any active swapfile, and stop the deleting process.  This
behavior is like snapshot ioctl dealing with a swapfile.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Kaiwen Hu <kevinhu@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-13 21:01:08 +02:00
Ethan Lien
82ae73ac96 btrfs: fix qgroup reserve overflow the qgroup limit
commit b642b52d0b50f4d398cb4293f64992d0eed2e2ce upstream.

We use extent_changeset->bytes_changed in qgroup_reserve_data() to record
how many bytes we set for EXTENT_QGROUP_RESERVED state. Currently the
bytes_changed is set as "unsigned int", and it will overflow if we try to
fallocate a range larger than 4GiB. The result is we reserve less bytes
and eventually break the qgroup limit.

Unlike regular buffered/direct write, which we use one changeset for
each ordered extent, which can never be larger than 256M.  For
fallocate, we use one changeset for the whole range, thus it no longer
respects the 256M per extent limit, and caused the problem.

The following example test script reproduces the problem:

  $ cat qgroup-overflow.sh
  #!/bin/bash

  DEV=/dev/sdj
  MNT=/mnt/sdj

  mkfs.btrfs -f $DEV
  mount $DEV $MNT

  # Set qgroup limit to 2GiB.
  btrfs quota enable $MNT
  btrfs qgroup limit 2G $MNT

  # Try to fallocate a 3GiB file. This should fail.
  echo
  echo "Try to fallocate a 3GiB file..."
  fallocate -l 3G $MNT/3G.file

  # Try to fallocate a 5GiB file.
  echo
  echo "Try to fallocate a 5GiB file..."
  fallocate -l 5G $MNT/5G.file

  # See we break the qgroup limit.
  echo
  sync
  btrfs qgroup show -r $MNT

  umount $MNT

When running the test:

  $ ./qgroup-overflow.sh
  (...)

  Try to fallocate a 3GiB file...
  fallocate: fallocate failed: Disk quota exceeded

  Try to fallocate a 5GiB file...

  qgroupid         rfer         excl     max_rfer
  --------         ----         ----     --------
  0/5           5.00GiB      5.00GiB      2.00GiB

Since we have no control of how bytes_changed is used, it's better to
set it to u64.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Ethan Lien <ethanlien@synology.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>
2022-04-13 21:01:08 +02:00
Filipe Manana
2c4741d1b0 btrfs: fix unexpected error path when reflinking an inline extent
[ Upstream commit 1f4613cdbe7739ce291554b316bff8e551383389 ]

When reflinking an inline extent, we assert that its file offset is 0 and
that its uncompressed length is not greater than the sector size. We then
return an error if one of those conditions is not satisfied. However we
use a return statement, which results in returning from btrfs_clone()
without freeing the path and buffer that were allocated before, as well as
not clearing the flag BTRFS_INODE_NO_DELALLOC_FLUSH for the destination
inode.

Fix that by jumping to the 'out' label instead, and also add a WARN_ON()
for each condition so that in case assertions are disabled, we get to
known which of the unexpected conditions triggered the error.

Fixes: a61e1e0df9 ("Btrfs: simplify inline extent handling when doing reflinks")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:40:04 +02:00
Filipe Manana
292e1c88b8 btrfs: add missing run of delayed items after unlink during log replay
commit 4751dc99627e4d1465c5bfa8cb7ab31ed418eff5 upstream.

During log replay, whenever we need to check if a name (dentry) exists in
a directory we do searches on the subvolume tree for inode references or
or directory entries (BTRFS_DIR_INDEX_KEY keys, and BTRFS_DIR_ITEM_KEY
keys as well, before kernel 5.17). However when during log replay we
unlink a name, through btrfs_unlink_inode(), we may not delete inode
references and dir index keys from a subvolume tree and instead just add
the deletions to the delayed inode's delayed items, which will only be
run when we commit the transaction used for log replay. This means that
after an unlink operation during log replay, if we attempt to search for
the same name during log replay, we will not see that the name was already
deleted, since the deletion is recorded only on the delayed items.

We run delayed items after every unlink operation during log replay,
except at unlink_old_inode_refs() and at add_inode_ref(). This was due
to an overlook, as delayed items should be run after evert unlink, for
the reasons stated above.

So fix those two cases.

Fixes: 0d836392ca ("Btrfs: fix mount failure after fsync due to hard link recreation")
Fixes: 1f250e929a ("Btrfs: fix log replay failure after unlink and link combination")
CC: stable@vger.kernel.org # 4.19+
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>
2022-03-08 19:09:38 +01:00
Sidong Yang
41712c5fa5 btrfs: qgroup: fix deadlock between rescan worker and remove qgroup
commit d4aef1e122d8bbdc15ce3bd0bc813d6b44a7d63a upstream.

The commit e804861bd4e6 ("btrfs: fix deadlock between quota disable and
qgroup rescan worker") by Kawasaki resolves deadlock between quota
disable and qgroup rescan worker. But also there is a deadlock case like
it. It's about enabling or disabling quota and creating or removing
qgroup. It can be reproduced in simple script below.

for i in {1..100}
do
    btrfs quota enable /mnt &
    btrfs qgroup create 1/0 /mnt &
    btrfs qgroup destroy 1/0 /mnt &
    btrfs quota disable /mnt &
done

Here's why the deadlock happens:

1) The quota rescan task is running.

2) Task A calls btrfs_quota_disable(), locks the qgroup_ioctl_lock
   mutex, and then calls btrfs_qgroup_wait_for_completion(), to wait for
   the quota rescan task to complete.

3) Task B calls btrfs_remove_qgroup() and it blocks when trying to lock
   the qgroup_ioctl_lock mutex, because it's being held by task A. At that
   point task B is holding a transaction handle for the current transaction.

4) The quota rescan task calls btrfs_commit_transaction(). This results
   in it waiting for all other tasks to release their handles on the
   transaction, but task B is blocked on the qgroup_ioctl_lock mutex
   while holding a handle on the transaction, and that mutex is being held
   by task A, which is waiting for the quota rescan task to complete,
   resulting in a deadlock between these 3 tasks.

To resolve this issue, the thread disabling quota should unlock
qgroup_ioctl_lock before waiting rescan completion. Move
btrfs_qgroup_wait_for_completion() after unlock of qgroup_ioctl_lock.

Fixes: e804861bd4e6 ("btrfs: fix deadlock between quota disable and qgroup rescan worker")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Sidong Yang <realwakka@gmail.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>
2022-03-08 19:09:38 +01:00
Filipe Manana
6e0319e770 btrfs: fix lost prealloc extents beyond eof after full fsync
commit d99478874355d3a7b9d86dfb5d7590d5b1754b1f upstream.

When doing a full fsync, if we have prealloc extents beyond (or at) eof,
and the leaves that contain them were not modified in the current
transaction, we end up not logging them. This results in losing those
extents when we replay the log after a power failure, since the inode is
truncated to the current value of the logged i_size.

Just like for the fast fsync path, we need to always log all prealloc
extents starting at or beyond i_size. The fast fsync case was fixed in
commit 471d557afe ("Btrfs: fix loss of prealloc extents past i_size
after fsync log replay") but it missed the full fsync path. The problem
exists since the very early days, when the log tree was added by
commit e02119d5a7 ("Btrfs: Add a write ahead tree log to optimize
synchronous operations").

Example reproducer:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt

  # Create our test file with many file extent items, so that they span
  # several leaves of metadata, even if the node/page size is 64K. Use
  # direct IO and not fsync/O_SYNC because it's both faster and it avoids
  # clearing the full sync flag from the inode - we want the fsync below
  # to trigger the slow full sync code path.
  $ xfs_io -f -d -c "pwrite -b 4K 0 16M" /mnt/foo

  # Now add two preallocated extents to our file without extending the
  # file's size. One right at i_size, and another further beyond, leaving
  # a gap between the two prealloc extents.
  $ xfs_io -c "falloc -k 16M 1M" /mnt/foo
  $ xfs_io -c "falloc -k 20M 1M" /mnt/foo

  # Make sure everything is durably persisted and the transaction is
  # committed. This makes all created extents to have a generation lower
  # than the generation of the transaction used by the next write and
  # fsync.
  sync

  # Now overwrite only the first extent, which will result in modifying
  # only the first leaf of metadata for our inode. Then fsync it. This
  # fsync will use the slow code path (inode full sync bit is set) because
  # it's the first fsync since the inode was created/loaded.
  $ xfs_io -c "pwrite 0 4K" -c "fsync" /mnt/foo

  # Extent list before power failure.
  $ xfs_io -c "fiemap -v" /mnt/foo
  /mnt/foo:
   EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
     0: [0..7]:          2178048..2178055     8   0x0
     1: [8..16383]:      26632..43007     16376   0x0
     2: [16384..32767]:  2156544..2172927 16384   0x0
     3: [32768..34815]:  2172928..2174975  2048 0x800
     4: [34816..40959]:  hole              6144
     5: [40960..43007]:  2174976..2177023  2048 0x801

  <power fail>

  # Mount fs again, trigger log replay.
  $ mount /dev/sdc /mnt

  # Extent list after power failure and log replay.
  $ xfs_io -c "fiemap -v" /mnt/foo
  /mnt/foo:
   EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
     0: [0..7]:          2178048..2178055     8   0x0
     1: [8..16383]:      26632..43007     16376   0x0
     2: [16384..32767]:  2156544..2172927 16384   0x1

  # The prealloc extents at file offsets 16M and 20M are missing.

So fix this by calling btrfs_log_prealloc_extents() when we are doing a
full fsync, so that we always log all prealloc extents beyond eof.

A test case for fstests will follow soon.

CC: stable@vger.kernel.org # 4.19+
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>
2022-03-08 19:09:38 +01:00
Su Yue
72a5b01875 btrfs: tree-checker: check item_size for dev_item
commit ea1d1ca4025ac6c075709f549f9aa036b5b6597d upstream.

Check item size before accessing the device item to avoid out of bound
access, similar to inode_item check.

Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:42:45 +01:00
Su Yue
5c967dd073 btrfs: tree-checker: check item_size for inode_item
commit 0c982944af27d131d3b74242f3528169f66950ad upstream.

while mounting the crafted image, out-of-bounds access happens:

  [350.429619] UBSAN: array-index-out-of-bounds in fs/btrfs/struct-funcs.c:161:1
  [350.429636] index 1048096 is out of range for type 'page *[16]'
  [350.429650] CPU: 0 PID: 9 Comm: kworker/u8:1 Not tainted 5.16.0-rc4 #1
  [350.429652] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
  [350.429653] Workqueue: btrfs-endio-meta btrfs_work_helper [btrfs]
  [350.429772] Call Trace:
  [350.429774]  <TASK>
  [350.429776]  dump_stack_lvl+0x47/0x5c
  [350.429780]  ubsan_epilogue+0x5/0x50
  [350.429786]  __ubsan_handle_out_of_bounds+0x66/0x70
  [350.429791]  btrfs_get_16+0xfd/0x120 [btrfs]
  [350.429832]  check_leaf+0x754/0x1a40 [btrfs]
  [350.429874]  ? filemap_read+0x34a/0x390
  [350.429878]  ? load_balance+0x175/0xfc0
  [350.429881]  validate_extent_buffer+0x244/0x310 [btrfs]
  [350.429911]  btrfs_validate_metadata_buffer+0xf8/0x100 [btrfs]
  [350.429935]  end_bio_extent_readpage+0x3af/0x850 [btrfs]
  [350.429969]  ? newidle_balance+0x259/0x480
  [350.429972]  end_workqueue_fn+0x29/0x40 [btrfs]
  [350.429995]  btrfs_work_helper+0x71/0x330 [btrfs]
  [350.430030]  ? __schedule+0x2fb/0xa40
  [350.430033]  process_one_work+0x1f6/0x400
  [350.430035]  ? process_one_work+0x400/0x400
  [350.430036]  worker_thread+0x2d/0x3d0
  [350.430037]  ? process_one_work+0x400/0x400
  [350.430038]  kthread+0x165/0x190
  [350.430041]  ? set_kthread_struct+0x40/0x40
  [350.430043]  ret_from_fork+0x1f/0x30
  [350.430047]  </TASK>
  [350.430077] BTRFS warning (device loop0): bad eb member start: ptr 0xffe20f4e start 20975616 member offset 4293005178 size 2

check_leaf() is checking the leaf:

  corrupt leaf: root=4 block=29396992 slot=1, bad key order, prev (16140901064495857664 1 0) current (1 204 12582912)
  leaf 29396992 items 6 free space 3565 generation 6 owner DEV_TREE
  leaf 29396992 flags 0x1(WRITTEN) backref revision 1
  fs uuid a62e00e8-e94e-4200-8217-12444de93c2e
  chunk uuid cecbd0f7-9ca0-441e-ae9f-f782f9732bd8
	  item 0 key (16140901064495857664 INODE_ITEM 0) itemoff 3955 itemsize 40
		  generation 0 transid 0 size 0 nbytes 17592186044416
		  block group 0 mode 52667 links 33 uid 0 gid 2104132511 rdev 94223634821136
		  sequence 100305 flags 0x2409000(none)
		  atime 0.0 (1970-01-01 08:00:00)
		  ctime 2973280098083405823.4294967295 (-269783007-01-01 21:37:03)
		  mtime 18446744071572723616.4026825121 (1902-04-16 12:40:00)
		  otime 9249929404488876031.4294967295 (622322949-04-16 04:25:58)
	  item 1 key (1 DEV_EXTENT 12582912) itemoff 3907 itemsize 48
		  dev extent chunk_tree 3
		  chunk_objectid 256 chunk_offset 12582912 length 8388608
		  chunk_tree_uuid cecbd0f7-9ca0-441e-ae9f-f782f9732bd8

The corrupted leaf of device tree has an inode item. The leaf passed
checksum and others checks in validate_extent_buffer until check_leaf_item().
Because of the key type BTRFS_INODE_ITEM, check_inode_item() is called even we
are in the device tree. Since the
item offset + sizeof(struct btrfs_inode_item) > eb->len, out-of-bounds access
is triggered.

The item end vs leaf boundary check has been done before
check_leaf_item(), so fix it by checking item size in check_inode_item()
before access of the inode item in extent buffer.

Other check functions except check_dev_item() in check_leaf_item()
have their item size checks.
The commit for check_dev_item() is followed.

No regression observed during running fstests.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215299
CC: stable@vger.kernel.org # 5.10+
CC: Wenqing Liu <wenqingliu0120@gmail.com>
Signed-off-by: Su Yue <l@damenly.su>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:42:45 +01:00
Dāvis Mosāns
0b17d4b51c btrfs: send: in case of IO error log it
commit 2e7be9db125a0bf940c5d65eb5c40d8700f738b5 upstream.

Currently if we get IO error while doing send then we abort without
logging information about which file caused issue.  So log it to help
with debugging.

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Dāvis Mosāns <davispuh@gmail.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>
2022-02-23 12:00:58 +01:00
Shin'ichiro Kawasaki
32747e0143 btrfs: fix deadlock between quota disable and qgroup rescan worker
commit e804861bd4e69cc5fe1053eedcb024982dde8e48 upstream.

Quota disable ioctl starts a transaction before waiting for the qgroup
rescan worker completes. However, this wait can be infinite and results
in deadlock because of circular dependency among the quota disable
ioctl, the qgroup rescan worker and the other task with transaction such
as block group relocation task.

The deadlock happens with the steps following:

1) Task A calls ioctl to disable quota. It starts a transaction and
   waits for qgroup rescan worker completes.
2) Task B such as block group relocation task starts a transaction and
   joins to the transaction that task A started. Then task B commits to
   the transaction. In this commit, task B waits for a commit by task A.
3) Task C as the qgroup rescan worker starts its job and starts a
   transaction. In this transaction start, task C waits for completion
   of the transaction that task A started and task B committed.

This deadlock was found with fstests test case btrfs/115 and a zoned
null_blk device. The test case enables and disables quota, and the
block group reclaim was triggered during the quota disable by chance.
The deadlock was also observed by running quota enable and disable in
parallel with 'btrfs balance' command on regular null_blk devices.

An example report of the deadlock:

  [372.469894] INFO: task kworker/u16:6:103 blocked for more than 122 seconds.
  [372.479944]       Not tainted 5.16.0-rc8 #7
  [372.485067] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [372.493898] task:kworker/u16:6   state:D stack:    0 pid:  103 ppid:     2 flags:0x00004000
  [372.503285] Workqueue: btrfs-qgroup-rescan btrfs_work_helper [btrfs]
  [372.510782] Call Trace:
  [372.514092]  <TASK>
  [372.521684]  __schedule+0xb56/0x4850
  [372.530104]  ? io_schedule_timeout+0x190/0x190
  [372.538842]  ? lockdep_hardirqs_on+0x7e/0x100
  [372.547092]  ? _raw_spin_unlock_irqrestore+0x3e/0x60
  [372.555591]  schedule+0xe0/0x270
  [372.561894]  btrfs_commit_transaction+0x18bb/0x2610 [btrfs]
  [372.570506]  ? btrfs_apply_pending_changes+0x50/0x50 [btrfs]
  [372.578875]  ? free_unref_page+0x3f2/0x650
  [372.585484]  ? finish_wait+0x270/0x270
  [372.591594]  ? release_extent_buffer+0x224/0x420 [btrfs]
  [372.599264]  btrfs_qgroup_rescan_worker+0xc13/0x10c0 [btrfs]
  [372.607157]  ? lock_release+0x3a9/0x6d0
  [372.613054]  ? btrfs_qgroup_account_extent+0xda0/0xda0 [btrfs]
  [372.620960]  ? do_raw_spin_lock+0x11e/0x250
  [372.627137]  ? rwlock_bug.part.0+0x90/0x90
  [372.633215]  ? lock_is_held_type+0xe4/0x140
  [372.639404]  btrfs_work_helper+0x1ae/0xa90 [btrfs]
  [372.646268]  process_one_work+0x7e9/0x1320
  [372.652321]  ? lock_release+0x6d0/0x6d0
  [372.658081]  ? pwq_dec_nr_in_flight+0x230/0x230
  [372.664513]  ? rwlock_bug.part.0+0x90/0x90
  [372.670529]  worker_thread+0x59e/0xf90
  [372.676172]  ? process_one_work+0x1320/0x1320
  [372.682440]  kthread+0x3b9/0x490
  [372.687550]  ? _raw_spin_unlock_irq+0x24/0x50
  [372.693811]  ? set_kthread_struct+0x100/0x100
  [372.700052]  ret_from_fork+0x22/0x30
  [372.705517]  </TASK>
  [372.709747] INFO: task btrfs-transacti:2347 blocked for more than 123 seconds.
  [372.729827]       Not tainted 5.16.0-rc8 #7
  [372.745907] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [372.767106] task:btrfs-transacti state:D stack:    0 pid: 2347 ppid:     2 flags:0x00004000
  [372.787776] Call Trace:
  [372.801652]  <TASK>
  [372.812961]  __schedule+0xb56/0x4850
  [372.830011]  ? io_schedule_timeout+0x190/0x190
  [372.852547]  ? lockdep_hardirqs_on+0x7e/0x100
  [372.871761]  ? _raw_spin_unlock_irqrestore+0x3e/0x60
  [372.886792]  schedule+0xe0/0x270
  [372.901685]  wait_current_trans+0x22c/0x310 [btrfs]
  [372.919743]  ? btrfs_put_transaction+0x3d0/0x3d0 [btrfs]
  [372.938923]  ? finish_wait+0x270/0x270
  [372.959085]  ? join_transaction+0xc75/0xe30 [btrfs]
  [372.977706]  start_transaction+0x938/0x10a0 [btrfs]
  [372.997168]  transaction_kthread+0x19d/0x3c0 [btrfs]
  [373.013021]  ? btrfs_cleanup_transaction.isra.0+0xfc0/0xfc0 [btrfs]
  [373.031678]  kthread+0x3b9/0x490
  [373.047420]  ? _raw_spin_unlock_irq+0x24/0x50
  [373.064645]  ? set_kthread_struct+0x100/0x100
  [373.078571]  ret_from_fork+0x22/0x30
  [373.091197]  </TASK>
  [373.105611] INFO: task btrfs:3145 blocked for more than 123 seconds.
  [373.114147]       Not tainted 5.16.0-rc8 #7
  [373.120401] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [373.130393] task:btrfs           state:D stack:    0 pid: 3145 ppid:  3141 flags:0x00004000
  [373.140998] Call Trace:
  [373.145501]  <TASK>
  [373.149654]  __schedule+0xb56/0x4850
  [373.155306]  ? io_schedule_timeout+0x190/0x190
  [373.161965]  ? lockdep_hardirqs_on+0x7e/0x100
  [373.168469]  ? _raw_spin_unlock_irqrestore+0x3e/0x60
  [373.175468]  schedule+0xe0/0x270
  [373.180814]  wait_for_commit+0x104/0x150 [btrfs]
  [373.187643]  ? test_and_set_bit+0x20/0x20 [btrfs]
  [373.194772]  ? kmem_cache_free+0x124/0x550
  [373.201191]  ? btrfs_put_transaction+0x69/0x3d0 [btrfs]
  [373.208738]  ? finish_wait+0x270/0x270
  [373.214704]  ? __btrfs_end_transaction+0x347/0x7b0 [btrfs]
  [373.222342]  btrfs_commit_transaction+0x44d/0x2610 [btrfs]
  [373.230233]  ? join_transaction+0x255/0xe30 [btrfs]
  [373.237334]  ? btrfs_record_root_in_trans+0x4d/0x170 [btrfs]
  [373.245251]  ? btrfs_apply_pending_changes+0x50/0x50 [btrfs]
  [373.253296]  relocate_block_group+0x105/0xc20 [btrfs]
  [373.260533]  ? mutex_lock_io_nested+0x1270/0x1270
  [373.267516]  ? btrfs_wait_nocow_writers+0x85/0x180 [btrfs]
  [373.275155]  ? merge_reloc_roots+0x710/0x710 [btrfs]
  [373.283602]  ? btrfs_wait_ordered_extents+0xd30/0xd30 [btrfs]
  [373.291934]  ? kmem_cache_free+0x124/0x550
  [373.298180]  btrfs_relocate_block_group+0x35c/0x930 [btrfs]
  [373.306047]  btrfs_relocate_chunk+0x85/0x210 [btrfs]
  [373.313229]  btrfs_balance+0x12f4/0x2d20 [btrfs]
  [373.320227]  ? lock_release+0x3a9/0x6d0
  [373.326206]  ? btrfs_relocate_chunk+0x210/0x210 [btrfs]
  [373.333591]  ? lock_is_held_type+0xe4/0x140
  [373.340031]  ? rcu_read_lock_sched_held+0x3f/0x70
  [373.346910]  btrfs_ioctl_balance+0x548/0x700 [btrfs]
  [373.354207]  btrfs_ioctl+0x7f2/0x71b0 [btrfs]
  [373.360774]  ? lockdep_hardirqs_on_prepare+0x410/0x410
  [373.367957]  ? lockdep_hardirqs_on_prepare+0x410/0x410
  [373.375327]  ? btrfs_ioctl_get_supported_features+0x20/0x20 [btrfs]
  [373.383841]  ? find_held_lock+0x2c/0x110
  [373.389993]  ? lock_release+0x3a9/0x6d0
  [373.395828]  ? mntput_no_expire+0xf7/0xad0
  [373.402083]  ? lock_is_held_type+0xe4/0x140
  [373.408249]  ? vfs_fileattr_set+0x9f0/0x9f0
  [373.414486]  ? selinux_file_ioctl+0x349/0x4e0
  [373.420938]  ? trace_raw_output_lock+0xb4/0xe0
  [373.427442]  ? selinux_inode_getsecctx+0x80/0x80
  [373.434224]  ? lockdep_hardirqs_on+0x7e/0x100
  [373.440660]  ? force_qs_rnp+0x2a0/0x6b0
  [373.446534]  ? lock_is_held_type+0x9b/0x140
  [373.452763]  ? __blkcg_punt_bio_submit+0x1b0/0x1b0
  [373.459732]  ? security_file_ioctl+0x50/0x90
  [373.466089]  __x64_sys_ioctl+0x127/0x190
  [373.472022]  do_syscall_64+0x3b/0x90
  [373.477513]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [373.484823] RIP: 0033:0x7f8f4af7e2bb
  [373.490493] RSP: 002b:00007ffcbf936178 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [373.500197] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f8f4af7e2bb
  [373.509451] RDX: 00007ffcbf936220 RSI: 00000000c4009420 RDI: 0000000000000003
  [373.518659] RBP: 00007ffcbf93774a R08: 0000000000000013 R09: 00007f8f4b02d4e0
  [373.527872] R10: 00007f8f4ae87740 R11: 0000000000000246 R12: 0000000000000001
  [373.537222] R13: 00007ffcbf936220 R14: 0000000000000000 R15: 0000000000000002
  [373.546506]  </TASK>
  [373.550878] INFO: task btrfs:3146 blocked for more than 123 seconds.
  [373.559383]       Not tainted 5.16.0-rc8 #7
  [373.565748] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [373.575748] task:btrfs           state:D stack:    0 pid: 3146 ppid:  2168 flags:0x00000000
  [373.586314] Call Trace:
  [373.590846]  <TASK>
  [373.595121]  __schedule+0xb56/0x4850
  [373.600901]  ? __lock_acquire+0x23db/0x5030
  [373.607176]  ? io_schedule_timeout+0x190/0x190
  [373.613954]  schedule+0xe0/0x270
  [373.619157]  schedule_timeout+0x168/0x220
  [373.625170]  ? usleep_range_state+0x150/0x150
  [373.631653]  ? mark_held_locks+0x9e/0xe0
  [373.637767]  ? do_raw_spin_lock+0x11e/0x250
  [373.643993]  ? lockdep_hardirqs_on_prepare+0x17b/0x410
  [373.651267]  ? _raw_spin_unlock_irq+0x24/0x50
  [373.657677]  ? lockdep_hardirqs_on+0x7e/0x100
  [373.664103]  wait_for_completion+0x163/0x250
  [373.670437]  ? bit_wait_timeout+0x160/0x160
  [373.676585]  btrfs_quota_disable+0x176/0x9a0 [btrfs]
  [373.683979]  ? btrfs_quota_enable+0x12f0/0x12f0 [btrfs]
  [373.691340]  ? down_write+0xd0/0x130
  [373.696880]  ? down_write_killable+0x150/0x150
  [373.703352]  btrfs_ioctl+0x3945/0x71b0 [btrfs]
  [373.710061]  ? find_held_lock+0x2c/0x110
  [373.716192]  ? lock_release+0x3a9/0x6d0
  [373.722047]  ? __handle_mm_fault+0x23cd/0x3050
  [373.728486]  ? btrfs_ioctl_get_supported_features+0x20/0x20 [btrfs]
  [373.737032]  ? set_pte+0x6a/0x90
  [373.742271]  ? do_raw_spin_unlock+0x55/0x1f0
  [373.748506]  ? lock_is_held_type+0xe4/0x140
  [373.754792]  ? vfs_fileattr_set+0x9f0/0x9f0
  [373.761083]  ? selinux_file_ioctl+0x349/0x4e0
  [373.767521]  ? selinux_inode_getsecctx+0x80/0x80
  [373.774247]  ? __up_read+0x182/0x6e0
  [373.780026]  ? count_memcg_events.constprop.0+0x46/0x60
  [373.787281]  ? up_write+0x460/0x460
  [373.792932]  ? security_file_ioctl+0x50/0x90
  [373.799232]  __x64_sys_ioctl+0x127/0x190
  [373.805237]  do_syscall_64+0x3b/0x90
  [373.810947]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [373.818102] RIP: 0033:0x7f1383ea02bb
  [373.823847] RSP: 002b:00007fffeb4d71f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
  [373.833641] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1383ea02bb
  [373.842961] RDX: 00007fffeb4d7210 RSI: 00000000c0109428 RDI: 0000000000000003
  [373.852179] RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000078
  [373.861408] R10: 00007f1383daec78 R11: 0000000000000202 R12: 00007fffeb4d874a
  [373.870647] R13: 0000000000493099 R14: 0000000000000001 R15: 0000000000000000
  [373.879838]  </TASK>
  [373.884018]
               Showing all locks held in the system:
  [373.894250] 3 locks held by kworker/4:1/58:
  [373.900356] 1 lock held by khungtaskd/63:
  [373.906333]  #0: ffffffff8945ff60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260
  [373.917307] 3 locks held by kworker/u16:6/103:
  [373.923938]  #0: ffff888127b4f138 ((wq_completion)btrfs-qgroup-rescan){+.+.}-{0:0}, at: process_one_work+0x712/0x1320
  [373.936555]  #1: ffff88810b817dd8 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work+0x73f/0x1320
  [373.951109]  #2: ffff888102dd4650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_qgroup_rescan_worker+0x1f6/0x10c0 [btrfs]
  [373.964027] 2 locks held by less/1803:
  [373.969982]  #0: ffff88813ed56098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80
  [373.981295]  #1: ffffc90000b3b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x9e2/0x1060
  [373.992969] 1 lock held by btrfs-transacti/2347:
  [373.999893]  #0: ffff88813d4887a8 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0xe3/0x3c0 [btrfs]
  [374.015872] 3 locks held by btrfs/3145:
  [374.022298]  #0: ffff888102dd4460 (sb_writers#18){.+.+}-{0:0}, at: btrfs_ioctl_balance+0xc3/0x700 [btrfs]
  [374.034456]  #1: ffff88813d48a0a0 (&fs_info->reclaim_bgs_lock){+.+.}-{3:3}, at: btrfs_balance+0xfe5/0x2d20 [btrfs]
  [374.047646]  #2: ffff88813d488838 (&fs_info->cleaner_mutex){+.+.}-{3:3}, at: btrfs_relocate_block_group+0x354/0x930 [btrfs]
  [374.063295] 4 locks held by btrfs/3146:
  [374.069647]  #0: ffff888102dd4460 (sb_writers#18){.+.+}-{0:0}, at: btrfs_ioctl+0x38b1/0x71b0 [btrfs]
  [374.081601]  #1: ffff88813d488bb8 (&fs_info->subvol_sem){+.+.}-{3:3}, at: btrfs_ioctl+0x38fd/0x71b0 [btrfs]
  [374.094283]  #2: ffff888102dd4650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_quota_disable+0xc8/0x9a0 [btrfs]
  [374.106885]  #3: ffff88813d489800 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_disable+0xd5/0x9a0 [btrfs]

  [374.126780] =============================================

To avoid the deadlock, wait for the qgroup rescan worker to complete
before starting the transaction for the quota disable ioctl. Clear
BTRFS_FS_QUOTA_ENABLE flag before the wait and the transaction to
request the worker to complete. On transaction start failure, set the
BTRFS_FS_QUOTA_ENABLE flag again. These BTRFS_FS_QUOTA_ENABLE flag
changes can be done safely since the function btrfs_quota_disable is not
called concurrently because of fs_info->subvol_sem.

Also check the BTRFS_FS_QUOTA_ENABLE flag in qgroup_rescan_init to avoid
another qgroup rescan worker to start after the previous qgroup worker
completed.

CC: stable@vger.kernel.org # 5.4+
Suggested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-08 18:30:35 +01:00
Amir Goldstein
0b4e82403c fsnotify: invalidate dcache before IN_DELETE event
commit a37d9a17f099072fe4d3a9048b0321978707a918 upstream.

Apparently, there are some applications that use IN_DELETE event as an
invalidation mechanism and expect that if they try to open a file with
the name reported with the delete event, that it should not contain the
content of the deleted file.

Commit 49246466a9 ("fsnotify: move fsnotify_nameremove() hook out of
d_delete()") moved the fsnotify delete hook before d_delete() so fsnotify
will have access to a positive dentry.

This allowed a race where opening the deleted file via cached dentry
is now possible after receiving the IN_DELETE event.

To fix the regression, create a new hook fsnotify_delete() that takes
the unlinked inode as an argument and use a helper d_delete_notify() to
pin the inode, so we can pass it to fsnotify_delete() after d_delete().

Backporting hint: this regression is from v5.3. Although patch will
apply with only trivial conflicts to v5.4 and v5.10, it won't build,
because fsnotify_delete() implementation is different in each of those
versions (see fsnotify_link()).

A follow up patch will fix the fsnotify_unlink/rmdir() calls in pseudo
filesystem that do not need to call d_delete().

Link: https://lore.kernel.org/r/20220120215305.282577-1-amir73il@gmail.com
Reported-by: Ivan Delalande <colona@arista.com>
Link: https://lore.kernel.org/linux-fsdevel/YeNyzoDM5hP5LtGW@visor/
Fixes: 49246466a9 ("fsnotify: move fsnotify_nameremove() hook out of d_delete()")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01 17:25:48 +01:00
Filipe Manana
f8c3ec2e21 btrfs: respect the max size in the header when activating swap file
commit c2f822635df873c510bda6fb7fd1b10b7c31be2d upstream.

If we extended the size of a swapfile after its header was created (by the
mkswap utility) and then try to activate it, we will map the entire file
when activating the swap file, instead of limiting to the max size defined
in the swap file's header.

Currently test case generic/643 from fstests fails because we do not
respect that size limit defined in the swap file's header.

So fix this by not mapping file ranges beyond the max size defined in the
swap header.

This is the same type of bug that iomap used to have, and was fixed in
commit 36ca7943ac18ae ("mm/swap: consider max pages in
iomap_swapfile_add_extent").

Fixes: ed46ff3d42 ("Btrfs: support swap files")
CC: stable@vger.kernel.org # 5.4+
Reviewed-and-tested-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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 10:54:27 +01:00
Josef Bacik
e7764bccae btrfs: check the root node for uptodate before returning it
commit 120de408e4b97504a2d9b5ca534b383de2c73d49 upstream.

Now that we clear the extent buffer uptodate if we fail to write it out
we need to check to see if our root node is uptodate before we search
down it.  Otherwise we could return stale data (or potentially corrupt
data that was caught by the write verification step) and think that the
path is OK to search down.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 10:54:27 +01:00
Filipe Manana
09e0ef287e btrfs: fix deadlock between quota enable and other quota operations
commit 232796df8c1437c41d308d161007f0715bac0a54 upstream.

When enabling quotas, we attempt to commit a transaction while holding the
mutex fs_info->qgroup_ioctl_lock. This can result on a deadlock with other
quota operations such as:

- qgroup creation and deletion, ioctl BTRFS_IOC_QGROUP_CREATE;

- adding and removing qgroup relations, ioctl BTRFS_IOC_QGROUP_ASSIGN.

This is because these operations join a transaction and after that they
attempt to lock the mutex fs_info->qgroup_ioctl_lock. Acquiring that mutex
after joining or starting a transaction is a pattern followed everywhere
in qgroups, so the quota enablement operation is the one at fault here,
and should not commit a transaction while holding that mutex.

Fix this by making the transaction commit while not holding the mutex.
We are safe from two concurrent tasks trying to enable quotas because
we are serialized by the rw semaphore fs_info->subvol_sem at
btrfs_ioctl_quota_ctl(), which is the only call site for enabling
quotas.

When this deadlock happens, it produces a trace like the following:

  INFO: task syz-executor:25604 blocked for more than 143 seconds.
  Not tainted 5.15.0-rc6 #4
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor state:D stack:24800 pid:25604 ppid: 24873 flags:0x00004004
  Call Trace:
  context_switch kernel/sched/core.c:4940 [inline]
  __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
  schedule+0xd3/0x270 kernel/sched/core.c:6366
  btrfs_commit_transaction+0x994/0x2e90 fs/btrfs/transaction.c:2201
  btrfs_quota_enable+0x95c/0x1790 fs/btrfs/qgroup.c:1120
  btrfs_ioctl_quota_ctl fs/btrfs/ioctl.c:4229 [inline]
  btrfs_ioctl+0x637e/0x7b70 fs/btrfs/ioctl.c:5010
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:874 [inline]
  __se_sys_ioctl fs/ioctl.c:860 [inline]
  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f86920b2c4d
  RSP: 002b:00007f868f61ac58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007f86921d90a0 RCX: 00007f86920b2c4d
  RDX: 0000000020005e40 RSI: 00000000c0109428 RDI: 0000000000000008
  RBP: 00007f869212bd80 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f86921d90a0
  R13: 00007fff6d233e4f R14: 00007fff6d233ff0 R15: 00007f868f61adc0
  INFO: task syz-executor:25628 blocked for more than 143 seconds.
  Not tainted 5.15.0-rc6 #4
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:syz-executor state:D stack:29080 pid:25628 ppid: 24873 flags:0x00004004
  Call Trace:
  context_switch kernel/sched/core.c:4940 [inline]
  __schedule+0xcd9/0x2530 kernel/sched/core.c:6287
  schedule+0xd3/0x270 kernel/sched/core.c:6366
  schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
  __mutex_lock_common kernel/locking/mutex.c:669 [inline]
  __mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729
  btrfs_remove_qgroup+0xb7/0x7d0 fs/btrfs/qgroup.c:1548
  btrfs_ioctl_qgroup_create fs/btrfs/ioctl.c:4333 [inline]
  btrfs_ioctl+0x683c/0x7b70 fs/btrfs/ioctl.c:5014
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:874 [inline]
  __se_sys_ioctl fs/ioctl.c:860 [inline]
  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsZQF19bQ1C6=yetF3BvL10OSORpFUcWXTP6HErshDB4dQ@mail.gmail.com/
Fixes: 340f1aa27f ("btrfs: qgroups: Move transaction management inside btrfs_quota_enable/disable")
CC: stable@vger.kernel.org # 4.19
Reviewed-by: Qu Wenruo <wqu@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>
2022-01-27 10:54:27 +01:00
Josef Bacik
6b22c9824d btrfs: remove BUG_ON(!eie) in find_parent_nodes
[ Upstream commit 9f05c09d6baef789726346397438cca4ec43c3ee ]

If we're looking for leafs that point to a data extent we want to record
the extent items that point at our bytenr.  At this point we have the
reference and we know for a fact that this leaf should have a reference
to our bytenr.  However if there's some sort of corruption we may not
find any references to our leaf, and thus could end up with eie == NULL.
Replace this BUG_ON() with an ASSERT() and then return -EUCLEAN for the
mortals.

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>
2022-01-27 10:54:19 +01:00
Josef Bacik
623c65bc73 btrfs: remove BUG_ON() in find_parent_nodes()
[ Upstream commit fcba0120edf88328524a4878d1d6f4ad39f2ec81 ]

We search for an extent entry with .offset = -1, which shouldn't be a
thing, but corruption happens.  Add an ASSERT() for the developers,
return -EUCLEAN for mortals.

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>
2022-01-27 10:54:19 +01:00
Filipe Manana
1c414ff63b btrfs: fix double free of anon_dev after failure to create subvolume
commit 33fab972497ae66822c0b6846d4f9382938575b6 upstream.

When creating a subvolume, at create_subvol(), we allocate an anonymous
device and later call btrfs_get_new_fs_root(), which in turn just calls
btrfs_get_root_ref(). There we call btrfs_init_fs_root() which assigns
the anonymous device to the root, but if after that call there's an error,
when we jump to 'fail' label, we call btrfs_put_root(), which frees the
anonymous device and then returns an error that is propagated back to
create_subvol(). Than create_subvol() frees the anonymous device again.

When this happens, if the anonymous device was not reallocated after
the first time it was freed with btrfs_put_root(), we get a kernel
message like the following:

  (...)
  [13950.282466] BTRFS: error (device dm-0) in create_subvol:663: errno=-5 IO failure
  [13950.283027] ida_free called for id=65 which is not allocated.
  [13950.285974] BTRFS info (device dm-0): forced readonly
  (...)

If the anonymous device gets reallocated by another btrfs filesystem
or any other kernel subsystem, then bad things can happen.

So fix this by setting the root's anonymous device to 0 at
btrfs_get_root_ref(), before we call btrfs_put_root(), if an error
happened.

Fixes: 2dfb1e43f5 ("btrfs: preallocate anon block device at first phase of snapshot creation")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
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>
2021-12-22 09:30:57 +01:00
Jianglei Nie
005d9292b5 btrfs: fix memory leak in __add_inode_ref()
commit f35838a6930296fc1988764cfa54cb3f705c0665 upstream.

Line 1169 (#3) allocates a memory chunk for victim_name by kmalloc(),
but  when the function returns in line 1184 (#4) victim_name allocated
by line 1169 (#3) is not freed, which will lead to a memory leak.
There is a similar snippet of code in this function as allocating a memory
chunk for victim_name in line 1104 (#1) as well as releasing the memory
in line 1116 (#2).

We should kfree() victim_name when the return value of backref_in_log()
is less than zero and before the function returns in line 1184 (#4).

1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
1058 				  struct btrfs_root *root,
1059 				  struct btrfs_path *path,
1060 				  struct btrfs_root *log_root,
1061 				  struct btrfs_inode *dir,
1062 				  struct btrfs_inode *inode,
1063 				  u64 inode_objectid, u64 parent_objectid,
1064 				  u64 ref_index, char *name, int namelen,
1065 				  int *search_done)
1066 {

1104 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #1: kmalloc (victim_name-1)
1105 	if (!victim_name)
1106 		return -ENOMEM;

1112	ret = backref_in_log(log_root, &search_key,
1113			parent_objectid, victim_name,
1114			victim_name_len);
1115	if (ret < 0) {
1116		kfree(victim_name); // #2: kfree (victim_name-1)
1117		return ret;
1118	} else if (!ret) {

1169 	victim_name = kmalloc(victim_name_len, GFP_NOFS);
	// #3: kmalloc (victim_name-2)
1170 	if (!victim_name)
1171 		return -ENOMEM;

1180 	ret = backref_in_log(log_root, &search_key,
1181 			parent_objectid, victim_name,
1182 			victim_name_len);
1183 	if (ret < 0) {
1184 		return ret; // #4: missing kfree (victim_name-2)
1185 	} else if (!ret) {

1241 	return 0;
1242 }

Fixes: d3316c8233 ("btrfs: Properly handle backref_in_log retval")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Jianglei Nie <niejianglei2021@163.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>
2021-12-22 09:30:57 +01:00
Qu Wenruo
caf9b352dc btrfs: replace the BUG_ON in btrfs_del_root_ref with proper error handling
commit 8289ed9f93bef2762f9184e136d994734b16d997 upstream.

I hit the BUG_ON() with generic/475 test case, and to my surprise, all
callers of btrfs_del_root_ref() are already aborting transaction, thus
there is not need for such BUG_ON(), just go to @out label and caller
will properly handle the error.

CC: stable@vger.kernel.org # 5.4+
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>
2021-12-14 11:32:38 +01:00
Josef Bacik
41b3cc57d6 btrfs: clear extent buffer uptodate when we fail to write it
commit c2e39305299f0118298c2201f6d6cc7d3485f29e upstream.

I got dmesg errors on generic/281 on our overnight fstests.  Looking at
the history this happens occasionally, with errors like this

  WARNING: CPU: 0 PID: 673217 at fs/btrfs/extent_io.c:6848 assert_eb_page_uptodate+0x3f/0x50
  CPU: 0 PID: 673217 Comm: kworker/u4:13 Tainted: G        W         5.16.0-rc2+ #469
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Workqueue: btrfs-cache btrfs_work_helper
  RIP: 0010:assert_eb_page_uptodate+0x3f/0x50
  RSP: 0018:ffffae598230bc60 EFLAGS: 00010246
  RAX: 0017ffffc0002112 RBX: ffffebaec4100900 RCX: 0000000000001000
  RDX: ffffebaec45733c7 RSI: ffffebaec4100900 RDI: ffff9fd98919f340
  RBP: 0000000000000d56 R08: ffff9fd98e300000 R09: 0000000000000000
  R10: 0001207370a91c50 R11: 0000000000000000 R12: 00000000000007b0
  R13: ffff9fd98919f340 R14: 0000000001500000 R15: 0000000001cb0000
  FS:  0000000000000000(0000) GS:ffff9fd9fbc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f549fcf8940 CR3: 0000000114908004 CR4: 0000000000370ef0
  Call Trace:

   extent_buffer_test_bit+0x3f/0x70
   free_space_test_bit+0xa6/0xc0
   load_free_space_tree+0x1d6/0x430
   caching_thread+0x454/0x630
   ? rcu_read_lock_sched_held+0x12/0x60
   ? rcu_read_lock_sched_held+0x12/0x60
   ? rcu_read_lock_sched_held+0x12/0x60
   ? lock_release+0x1f0/0x2d0
   btrfs_work_helper+0xf2/0x3e0
   ? lock_release+0x1f0/0x2d0
   ? finish_task_switch.isra.0+0xf9/0x3a0
   process_one_work+0x270/0x5a0
   worker_thread+0x55/0x3c0
   ? process_one_work+0x5a0/0x5a0
   kthread+0x174/0x1a0
   ? set_kthread_struct+0x40/0x40
   ret_from_fork+0x1f/0x30

This happens because we're trying to read from a extent buffer page that
is !PageUptodate.  This happens because we will clear the page uptodate
when we have an IO error, but we don't clear the extent buffer uptodate.
If we do a read later and find this extent buffer we'll think its valid
and not return an error, and then trip over this warning.

Fix this by also clearing uptodate on the extent buffer when this
happens, so that we get an error when we do a btrfs_search_slot() and
find this block later.

CC: stable@vger.kernel.org # 5.4+
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>
2021-12-14 11:32:38 +01:00
Wang Yugui
8e4d2ac434 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 09:03:19 +01:00
Josef Bacik
2ec78af152 btrfs: update device path inode time instead of bd_inode
commit 54fde91f52f515e0b1514f0f0fa146e87a672227 upstream.

Christoph pointed out that I'm updating bdev->bd_inode for the device
time when we remove block devices from a btrfs file system, however this
isn't actually exposed to anything.  The inode we want to update is the
one that's associated with the path to the device, usually on devtmpfs,
so that blkid notices the difference.

We still don't want to do the blkdev_open, so use kern_path() to get the
path to the given device and do the update time on that inode.

Fixes: 8f96a5bfa150 ("btrfs: update the bdev time directly when closing")
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26 10:39:22 +01:00
Nikolay Borisov
6adbc07ebc btrfs: fix memory ordering between normal and ordered work functions
commit 45da9c1767ac31857df572f0a909fbe88fd5a7e9 upstream.

Ordered work functions aren't guaranteed to be handled by the same thread
which executed the normal work functions. The only way execution between
normal/ordered functions is synchronized is via the WORK_DONE_BIT,
unfortunately the used bitops don't guarantee any ordering whatsoever.

This manifested as seemingly inexplicable crashes on ARM64, where
async_chunk::inode is seen as non-null in async_cow_submit which causes
submit_compressed_extents to be called and crash occurs because
async_chunk::inode suddenly became NULL. The call trace was similar to:

    pc : submit_compressed_extents+0x38/0x3d0
    lr : async_cow_submit+0x50/0xd0
    sp : ffff800015d4bc20

    <registers omitted for brevity>

    Call trace:
     submit_compressed_extents+0x38/0x3d0
     async_cow_submit+0x50/0xd0
     run_ordered_work+0xc8/0x280
     btrfs_work_helper+0x98/0x250
     process_one_work+0x1f0/0x4ac
     worker_thread+0x188/0x504
     kthread+0x110/0x114
     ret_from_fork+0x10/0x18

Fix this by adding respective barrier calls which ensure that all
accesses preceding setting of WORK_DONE_BIT are strictly ordered before
setting the flag. At the same time add a read barrier after reading of
WORK_DONE_BIT in run_ordered_work which ensures all subsequent loads
would be strictly ordered after reading the bit. This in turn ensures
are all accesses before WORK_DONE_BIT are going to be strictly ordered
before any access that can occur in ordered_func.

Reported-by: Chris Murphy <lists@colorremedies.com>
Fixes: 08a9ff3264 ("btrfs: Added btrfs_workqueue_struct implemented ordered execution based on kernel workqueue")
CC: stable@vger.kernel.org # 4.4+
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2011928
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Chris Murphy <chris@colorremedies.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26 10:39:20 +01:00
Josef Bacik
b917f9b946 btrfs: do not take the uuid_mutex in btrfs_rm_device
[ Upstream commit 8ef9dc0f14ba6124c62547a4fdc59b163d8b864e ]

We got the following lockdep splat while running fstests (specifically
btrfs/003 and btrfs/020 in a row) with the new rc.  This was uncovered
by 87579e9b7d8d ("loop: use worker per cgroup instead of kworker") which
converted loop to using workqueues, which comes with lockdep
annotations that don't exist with kworkers.  The lockdep splat is as
follows:

  WARNING: possible circular locking dependency detected
  5.14.0-rc2-custom+ #34 Not tainted
  ------------------------------------------------------
  losetup/156417 is trying to acquire lock:
  ffff9c7645b02d38 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x84/0x600

  but task is already holding lock:
  ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #5 (&lo->lo_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 lo_open+0x28/0x60 [loop]
	 blkdev_get_whole+0x28/0xf0
	 blkdev_get_by_dev.part.0+0x168/0x3c0
	 blkdev_open+0xd2/0xe0
	 do_dentry_open+0x163/0x3a0
	 path_openat+0x74d/0xa40
	 do_filp_open+0x9c/0x140
	 do_sys_openat2+0xb1/0x170
	 __x64_sys_openat+0x54/0x90
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #4 (&disk->open_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 blkdev_get_by_dev.part.0+0xd1/0x3c0
	 blkdev_get_by_path+0xc0/0xd0
	 btrfs_scan_one_device+0x52/0x1f0 [btrfs]
	 btrfs_control_ioctl+0xac/0x170 [btrfs]
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #3 (uuid_mutex){+.+.}-{3:3}:
	 __mutex_lock+0xba/0x7c0
	 btrfs_rm_device+0x48/0x6a0 [btrfs]
	 btrfs_ioctl+0x2d1c/0x3110 [btrfs]
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  -> #2 (sb_writers#11){.+.+}-{0:0}:
	 lo_write_bvec+0x112/0x290 [loop]
	 loop_process_work+0x25f/0xcb0 [loop]
	 process_one_work+0x28f/0x5d0
	 worker_thread+0x55/0x3c0
	 kthread+0x140/0x170
	 ret_from_fork+0x22/0x30

  -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
	 process_one_work+0x266/0x5d0
	 worker_thread+0x55/0x3c0
	 kthread+0x140/0x170
	 ret_from_fork+0x22/0x30

  -> #0 ((wq_completion)loop0){+.+.}-{0:0}:
	 __lock_acquire+0x1130/0x1dc0
	 lock_acquire+0xf5/0x320
	 flush_workqueue+0xae/0x600
	 drain_workqueue+0xa0/0x110
	 destroy_workqueue+0x36/0x250
	 __loop_clr_fd+0x9a/0x650 [loop]
	 lo_ioctl+0x29d/0x780 [loop]
	 block_ioctl+0x3f/0x50
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x3b/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xae

  other info that might help us debug this:
  Chain exists of:
    (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex
   Possible unsafe locking scenario:
	 CPU0                    CPU1
	 ----                    ----
    lock(&lo->lo_mutex);
				 lock(&disk->open_mutex);
				 lock(&lo->lo_mutex);
    lock((wq_completion)loop0);

   *** DEADLOCK ***
  1 lock held by losetup/156417:
   #0: ffff9c7647395468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x650 [loop]

  stack backtrace:
  CPU: 8 PID: 156417 Comm: losetup Not tainted 5.14.0-rc2-custom+ #34
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Call Trace:
   dump_stack_lvl+0x57/0x72
   check_noncircular+0x10a/0x120
   __lock_acquire+0x1130/0x1dc0
   lock_acquire+0xf5/0x320
   ? flush_workqueue+0x84/0x600
   flush_workqueue+0xae/0x600
   ? flush_workqueue+0x84/0x600
   drain_workqueue+0xa0/0x110
   destroy_workqueue+0x36/0x250
   __loop_clr_fd+0x9a/0x650 [loop]
   lo_ioctl+0x29d/0x780 [loop]
   ? __lock_acquire+0x3a0/0x1dc0
   ? update_dl_rq_load_avg+0x152/0x360
   ? lock_is_held_type+0xa5/0x120
   ? find_held_lock.constprop.0+0x2b/0x80
   block_ioctl+0x3f/0x50
   __x64_sys_ioctl+0x83/0xb0
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x7f645884de6b

Usually the uuid_mutex exists to protect the fs_devices that map
together all of the devices that match a specific uuid.  In rm_device
we're messing with the uuid of a device, so it makes sense to protect
that here.

However in doing that it pulls in a whole host of lockdep dependencies,
as we call mnt_may_write() on the sb before we grab the uuid_mutex, thus
we end up with the dependency chain under the uuid_mutex being added
under the normal sb write dependency chain, which causes problems with
loop devices.

We don't need the uuid mutex here however.  If we call
btrfs_scan_one_device() before we scratch the super block we will find
the fs_devices and not find the device itself and return EBUSY because
the fs_devices is open.  If we call it after the scratch happens it will
not appear to be a valid btrfs file system.

We do not need to worry about other fs_devices modifying operations here
because we're protected by the exclusive operations locking.

So drop the uuid_mutex here in order to fix the lockdep splat.

A more detailed explanation from the discussion:

We are worried about rm and scan racing with each other, before this
change we'll zero the device out under the UUID mutex so when scan does
run it'll make sure that it can go through the whole device scan thing
without rm messing with us.

We aren't worried if the scratch happens first, because the result is we
don't think this is a btrfs device and we bail out.

The only case we are concerned with is we scratch _after_ scan is able
to read the superblock and gets a seemingly valid super block, so lets
consider this case.

Scan will call device_list_add() with the device we're removing.  We'll
call find_fsid_with_metadata_uuid() and get our fs_devices for this
UUID.  At this point we lock the fs_devices->device_list_mutex.  This is
what protects us in this case, but we have two cases here.

1. We aren't to the device removal part of the RM.  We found our device,
   and device name matches our path, we go down and we set total_devices
   to our super number of devices, which doesn't affect anything because
   we haven't done the remove yet.

2. We are past the device removal part, which is protected by the
   device_list_mutex.  Scan doesn't find the device, it goes down and
   does the

   if (fs_devices->opened)
	   return -EBUSY;

   check and we bail out.

Nothing about this situation is ideal, but the lockdep splat is real,
and the fix is safe, tho admittedly a bit scary looking.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copy more from the discussion ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:00 +01:00
Sidong Yang
428bb3d71e btrfs: reflink: initialize return value to 0 in btrfs_extent_same()
[ Upstream commit 44bee215f72f13874c0e734a0712c2e3264c0108 ]

Fix a warning reported by smatch that ret could be returned without
initialized.  The dedupe operations are supposed to to return 0 for a 0
length range but the caller does not pass olen == 0. To keep this
behaviour and also fix the warning initialize ret to 0.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Sidong Yang <realwakka@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:00 +01:00
Anand Jain
b4a4c9dc44 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>
2021-11-18 14:03:44 +01:00
Filipe Manana
b406439afe btrfs: fix lost error handling when replaying directory deletes
commit 10adb1152d957a4d570ad630f93a88bb961616c1 upstream.

At replay_dir_deletes(), if find_dir_range() returns an error we break out
of the main while loop and then assign a value of 0 (success) to the 'ret'
variable, resulting in completely ignoring that an error happened. Fix
that by jumping to the 'out' label when find_dir_range() returns an error
(negative value).

CC: stable@vger.kernel.org # 4.4+
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>
2021-11-18 14:03:44 +01:00
Li Zhang
8992aab294 btrfs: clear MISSING device status bit in btrfs_close_one_device
commit 5d03dbebba2594d2e6fbf3b5dd9060c5a835de3b upstream.

Reported bug: https://github.com/kdave/btrfs-progs/issues/389

There's a problem with scrub reporting aborted status but returning
error code 0, on a filesystem with missing and readded device.

Roughly these steps:

- mkfs -d raid1 dev1 dev2
- fill with data
- unmount
- make dev1 disappear
- mount -o degraded
- copy more data
- make dev1 appear again

Running scrub afterwards reports that the command was aborted, but the
system log message says the exit code was 0.

It seems that the cause of the error is decrementing
fs_devices->missing_devices but not clearing device->dev_state.  Every
time we umount filesystem, it would call close_ctree, And it would
eventually involve btrfs_close_one_device to close the device, but it
only decrements fs_devices->missing_devices but does not clear the
device BTRFS_DEV_STATE_MISSING bit. Worse, this bug will cause Integer
Overflow, because every time umount, fs_devices->missing_devices will
decrease. If fs_devices->missing_devices value hit 0, it would overflow.

With added debugging:

   loop1: detected capacity change from 0 to 20971520
   BTRFS: device fsid 56ad51f1-5523-463b-8547-c19486c51ebb devid 1 transid 21 /dev/loop1 scanned by systemd-udevd (2311)
   loop2: detected capacity change from 0 to 20971520
   BTRFS: device fsid 56ad51f1-5523-463b-8547-c19486c51ebb devid 2 transid 17 /dev/loop2 scanned by systemd-udevd (2313)
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): using free space tree
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000f706684d /dev/loop1 0
   BTRFS warning (device loop1): devid 2 uuid 6635ac31-56dd-4852-873b-c60f5e2d53d2 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 1
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): using free space tree
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000f706684d /dev/loop1 0
   BTRFS warning (device loop1): devid 2 uuid 6635ac31-56dd-4852-873b-c60f5e2d53d2 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 0
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): using free space tree
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000f706684d /dev/loop1 18446744073709551615
   BTRFS warning (device loop1): devid 2 uuid 6635ac31-56dd-4852-873b-c60f5e2d53d2 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 18446744073709551615

If fs_devices->missing_devices is 0, next time it would be 18446744073709551615

After apply this patch, the fs_devices->missing_devices seems to be
right:

  $ truncate -s 10g test1
  $ truncate -s 10g test2
  $ losetup /dev/loop1 test1
  $ losetup /dev/loop2 test2
  $ mkfs.btrfs -draid1 -mraid1 /dev/loop1 /dev/loop2 -f
  $ losetup -d /dev/loop2
  $ mount -o degraded /dev/loop1 /mnt/1
  $ umount /mnt/1
  $ mount -o degraded /dev/loop1 /mnt/1
  $ umount /mnt/1
  $ mount -o degraded /dev/loop1 /mnt/1
  $ umount /mnt/1
  $ dmesg

   loop1: detected capacity change from 0 to 20971520
   loop2: detected capacity change from 0 to 20971520
   BTRFS: device fsid 15aa1203-98d3-4a66-bcae-ca82f629c2cd devid 1 transid 5 /dev/loop1 scanned by mkfs.btrfs (1863)
   BTRFS: device fsid 15aa1203-98d3-4a66-bcae-ca82f629c2cd devid 2 transid 5 /dev/loop2 scanned by mkfs.btrfs (1863)
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): disk space caching is enabled
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000975bd577 /dev/loop1 0
   BTRFS warning (device loop1): devid 2 uuid 8b333791-0b3f-4f57-b449-1c1ab6b51f38 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 1
   BTRFS info (device loop1): checking UUID tree
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): disk space caching is enabled
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000975bd577 /dev/loop1 0
   BTRFS warning (device loop1): devid 2 uuid 8b333791-0b3f-4f57-b449-1c1ab6b51f38 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 1
   BTRFS info (device loop1): flagging fs with big metadata feature
   BTRFS info (device loop1): allowing degraded mounts
   BTRFS info (device loop1): disk space caching is enabled
   BTRFS info (device loop1): has skinny extents
   BTRFS info (device loop1):  before clear_missing.00000000975bd577 /dev/loop1 0
   BTRFS warning (device loop1): devid 2 uuid 8b333791-0b3f-4f57-b449-1c1ab6b51f38 is missing
   BTRFS info (device loop1):  before clear_missing.0000000000000000 /dev/loop2 1

CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Li Zhang <zhanglikernel@gmail.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>
2021-11-18 14:03:44 +01:00
Filipe Manana
f9d16a4284 btrfs: deal with errors when checking if a dir entry exists during log replay
[ Upstream commit 77a5b9e3d14cbce49ceed2766b2003c034c066dc ]

Currently inode_in_dir() ignores errors returned from
btrfs_lookup_dir_index_item() and from btrfs_lookup_dir_item(), treating
any errors as if the directory entry does not exists in the fs/subvolume
tree, which is obviously not correct, as we can get errors such as -EIO
when reading extent buffers while searching the fs/subvolume's tree.

Fix that by making inode_in_dir() return the errors and making its only
caller, add_inode_ref(), deal with returned errors as well.

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: Sasha Levin <sashal@kernel.org>
2021-10-27 09:56:54 +02:00
Josef Bacik
0e32a2b85c btrfs: fix abort logic in btrfs_replace_file_extents
commit 4afb912f439c4bc4e6a4f3e7547f2e69e354108f upstream.

Error injection testing uncovered a case where we'd end up with a
corrupt file system with a missing extent in the middle of a file.  This
occurs because the if statement to decide if we should abort is wrong.

The only way we would abort in this case is if we got a ret !=
-EOPNOTSUPP and we called from the file clone code.  However the
prealloc code uses this path too.  Instead we need to abort if there is
an error, and the only error we _don't_ abort on is -EOPNOTSUPP and only
if we came from the clone file code.

CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-20 11:44:59 +02:00
Josef Bacik
52924879ed btrfs: update refs for any root except tree log roots
commit d175209be04d7d263fa1a54cde7608c706c9d0d7 upstream.

I hit a stuck relocation on btrfs/061 during my overnight testing.  This
turned out to be because we had left over extent entries in our extent
root for a data reloc inode that no longer existed.  This happened
because in btrfs_drop_extents() we only update refs if we have SHAREABLE
set or we are the tree_root.  This regression was introduced by
aeb935a455 ("btrfs: don't set SHAREABLE flag for data reloc tree")
where we stopped setting SHAREABLE for the data reloc tree.

The problem here is we actually do want to update extent references for
data extents in the data reloc tree, in fact we only don't want to
update extent references if the file extents are in the log tree.
Update this check to only skip updating references in the case of the
log tree.

This is relatively rare, because you have to be running scrub at the
same time, which is what btrfs/061 does.  The data reloc inode has its
extents pre-allocated, and then we copy the extent into the
pre-allocated chunks.  We theoretically should never be calling
btrfs_drop_extents() on a data reloc inode.  The exception of course is
with scrub, if our pre-allocated extent falls inside of the block group
we are scrubbing, then the block group will be marked read only and we
will be forced to cow that extent.  This means we will call
btrfs_drop_extents() on that range when we COW that file extent.

This isn't really problematic if we do this, the data reloc inode
requires that our extent lengths match exactly with the extent we are
copying, thankfully we validate the extent is correct with
get_new_location(), so if we happen to COW only part of the extent we
won't link it in when we do the relocation, so we are safe from any
other shenanigans that arise because of this interaction with scrub.

Fixes: aeb935a455 ("btrfs: don't set SHAREABLE flag for data reloc tree")
CC: stable@vger.kernel.org # 5.8+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-20 11:44:59 +02:00
Filipe Manana
352349aa49 btrfs: check for error when looking up inode during dir entry replay
commit cfd312695b71df04c3a2597859ff12c470d1e2e4 upstream.

At replay_one_name(), we are treating any error from btrfs_lookup_inode()
as if the inode does not exists. Fix this by checking for an error and
returning it to the caller.

CC: stable@vger.kernel.org # 4.14+
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>
2021-10-20 11:44:59 +02:00
Filipe Manana
4ed68471bc btrfs: deal with errors when adding inode reference during log replay
commit 52db77791fe24538c8aa2a183248399715f6b380 upstream.

At __inode_add_ref(), we treating any error returned from
btrfs_lookup_dir_item() or from btrfs_lookup_dir_index_item() as meaning
that there is no existing directory entry in the fs/subvolume tree.
This is not correct since we can get errors such as, for example, -EIO
when reading extent buffers while searching the fs/subvolume's btree.

So fix that and return the error to the caller when it is not -ENOENT.

CC: stable@vger.kernel.org # 4.14+
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>
2021-10-20 11:44:59 +02:00
Filipe Manana
95d3aba5fe btrfs: deal with errors when replaying dir entry during log replay
commit e15ac6413745e3def00e663de00aea5a717311c1 upstream.

At replay_one_one(), we are treating any error returned from
btrfs_lookup_dir_item() or from btrfs_lookup_dir_index_item() as meaning
that there is no existing directory entry in the fs/subvolume tree.
This is not correct since we can get errors such as, for example, -EIO
when reading extent buffers while searching the fs/subvolume's btree.

So fix that and return the error to the caller when it is not -ENOENT.

CC: stable@vger.kernel.org # 4.14+
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>
2021-10-20 11:44:59 +02:00
Qu Wenruo
206868a5b6 btrfs: unlock newly allocated extent buffer after error
commit 19ea40dddf1833db868533958ca066f368862211 upstream.

[BUG]
There is a bug report that injected ENOMEM error could leave a tree
block locked while we return to user-space:

  BTRFS info (device loop0): enabling ssd optimizations
  FAULT_INJECTION: forcing a failure.
  name failslab, interval 1, probability 0, space 0, times 0
  CPU: 0 PID: 7579 Comm: syz-executor Not tainted 5.15.0-rc1 #16
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
  Call Trace:
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x8d/0xcf lib/dump_stack.c:106
   fail_dump lib/fault-inject.c:52 [inline]
   should_fail+0x13c/0x160 lib/fault-inject.c:146
   should_failslab+0x5/0x10 mm/slab_common.c:1328
   slab_pre_alloc_hook.constprop.99+0x4e/0xc0 mm/slab.h:494
   slab_alloc_node mm/slub.c:3120 [inline]
   slab_alloc mm/slub.c:3214 [inline]
   kmem_cache_alloc+0x44/0x280 mm/slub.c:3219
   btrfs_alloc_delayed_extent_op fs/btrfs/delayed-ref.h:299 [inline]
   btrfs_alloc_tree_block+0x38c/0x670 fs/btrfs/extent-tree.c:4833
   __btrfs_cow_block+0x16f/0x7d0 fs/btrfs/ctree.c:415
   btrfs_cow_block+0x12a/0x300 fs/btrfs/ctree.c:570
   btrfs_search_slot+0x6b0/0xee0 fs/btrfs/ctree.c:1768
   btrfs_insert_empty_items+0x80/0xf0 fs/btrfs/ctree.c:3905
   btrfs_new_inode+0x311/0xa60 fs/btrfs/inode.c:6530
   btrfs_create+0x12b/0x270 fs/btrfs/inode.c:6783
   lookup_open+0x660/0x780 fs/namei.c:3282
   open_last_lookups fs/namei.c:3352 [inline]
   path_openat+0x465/0xe20 fs/namei.c:3557
   do_filp_open+0xe3/0x170 fs/namei.c:3588
   do_sys_openat2+0x357/0x4a0 fs/open.c:1200
   do_sys_open+0x87/0xd0 fs/open.c:1216
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x34/0xb0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x46ae99
  Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48
  89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d
  01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007f46711b9c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
  RAX: ffffffffffffffda RBX: 000000000078c0a0 RCX: 000000000046ae99
  RDX: 0000000000000000 RSI: 00000000000000a1 RDI: 0000000020005800
  RBP: 00007f46711b9c80 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000017
  R13: 0000000000000000 R14: 000000000078c0a0 R15: 00007ffc129da6e0

  ================================================
  WARNING: lock held when returning to user space!
  5.15.0-rc1 #16 Not tainted
  ------------------------------------------------
  syz-executor/7579 is leaving the kernel with locks still held!
  1 lock held by syz-executor/7579:
   #0: ffff888104b73da8 (btrfs-tree-01/1){+.+.}-{3:3}, at:
  __btrfs_tree_lock+0x2e/0x1a0 fs/btrfs/locking.c:112

[CAUSE]
In btrfs_alloc_tree_block(), after btrfs_init_new_buffer(), the new
extent buffer @buf is locked, but if later operations like adding
delayed tree ref fail, we just free @buf without unlocking it,
resulting above warning.

[FIX]
Unlock @buf in out_free_buf: label.

Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsZ9O6Zr0KK1yGn=1rQi6Crh1yeCRdTSBxx9R99L4xdn-Q@mail.gmail.com/
CC: stable@vger.kernel.org # 5.4+
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>
2021-10-20 11:44:59 +02:00
Filipe Manana
63c89930d4 btrfs: fix mount failure due to past and transient device flush error
[ Upstream commit 6b225baababf1e3d41a4250e802cbd193e1343fb ]

When we get an error flushing one device, during a super block commit, we
record the error in the device structure, in the field 'last_flush_error'.
This is used to later check if we should error out the super block commit,
depending on whether the number of flush errors is greater than or equals
to the maximum tolerated device failures for a raid profile.

However if we get a transient device flush error, unmount the filesystem
and later try to mount it, we can fail the mount because we treat that
past error as critical and consider the device is missing. Even if it's
very likely that the error will happen again, as it's probably due to a
hardware related problem, there may be cases where the error might not
happen again. One example is during testing, and a test case like the
new generic/648 from fstests always triggers this. The test cases
generic/019 and generic/475 also trigger this scenario, but very
sporadically.

When this happens we get an error like this:

  $ mount /dev/sdc /mnt
  mount: /mnt wrong fs type, bad option, bad superblock on /dev/sdc, missing codepage or helper program, or other error.

  $ dmesg
  (...)
  [12918.886926] BTRFS warning (device sdc): chunk 13631488 missing 1 devices, max tolerance is 0 for writable mount
  [12918.888293] BTRFS warning (device sdc): writable mount is not allowed due to too many missing devices
  [12918.890853] BTRFS error (device sdc): open_ctree failed

The failure happens because when btrfs_check_rw_degradable() is called at
mount time, or at remount from RO to RW time, is sees a non zero value in
a device's ->last_flush_error attribute, and therefore considers that the
device is 'missing'.

Fix this by setting a device's ->last_flush_error to zero when we close a
device, making sure the error is not seen on the next mount attempt. We
only need to track flush errors during the current mount, so that we never
commit a super block if such errors happened.

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: Sasha Levin <sashal@kernel.org>
2021-10-09 14:40:56 +02:00
Qu Wenruo
50628b06e6 btrfs: replace BUG_ON() in btrfs_csum_one_bio() with proper error handling
[ Upstream commit bbc9a6eb5eec03dcafee266b19f56295e3b2aa8f ]

There is a BUG_ON() in btrfs_csum_one_bio() to catch code logic error.
It has indeed caught several bugs during subpage development.
But the BUG_ON() itself will bring down the whole system which is
an overkill.

Replace it with a WARN() and exit gracefully, so that it won't crash the
whole system while we can still catch the code logic error.

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: Sasha Levin <sashal@kernel.org>
2021-10-09 14:40:56 +02:00
Sami Tolvanen
55e6f8b3c0 treewide: Change list_sort to use const pointers
[ Upstream commit 4f0f586bf0c898233d8f316f471a21db2abd522d ]

list_sort() internally casts the comparison function passed to it
to a different type with constant struct list_head pointers, and
uses this pointer to call the functions, which trips indirect call
Control-Flow Integrity (CFI) checking.

Instead of removing the consts, this change defines the
list_cmp_func_t type and changes the comparison function types of
all list_sort() callers to use const pointers, thus avoiding type
mismatches.

Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30 10:11:04 +02:00
Qu Wenruo
80af86c122 btrfs: prevent __btrfs_dump_space_info() to underflow its free space
commit 0619b7901473c380abc05d45cf9c70bee0707db3 upstream.

It's not uncommon where __btrfs_dump_space_info() gets called
under over-commit situations.

In that case free space would underflow as total allocated space is not
enough to handle all the over-committed space.

Such underflow values can sometimes cause confusion for users enabled
enospc_debug mount option, and takes some seconds for developers to
convert the underflow value to signed result.

Just output the free space as s64 to avoid such problem.

Reported-by: Eli V <eliventer@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAJtFHUSy4zgyhf-4d9T+KdJp9w=UgzC2A0V=VtmaeEpcGgm1-Q@mail.gmail.com/
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Anand Jain <anand.jain@oracle.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>
2021-09-30 10:11:00 +02:00
Anand Jain
aa1af89a66 btrfs: fix lockdep warning while mounting sprout fs
[ Upstream commit c124706900c20dee70f921bb3a90492431561a0a ]

Following test case reproduces lockdep warning.

  Test case:

  $ mkfs.btrfs -f <dev1>
  $ btrfstune -S 1 <dev1>
  $ mount <dev1> <mnt>
  $ btrfs device add <dev2> <mnt> -f
  $ umount <mnt>
  $ mount <dev2> <mnt>
  $ umount <mnt>

The warning claims a possible ABBA deadlock between the threads
initiated by [#1] btrfs device add and [#0] the mount.

  [ 540.743122] WARNING: possible circular locking dependency detected
  [ 540.743129] 5.11.0-rc7+ #5 Not tainted
  [ 540.743135] ------------------------------------------------------
  [ 540.743142] mount/2515 is trying to acquire lock:
  [ 540.743149] ffffa0c5544c2ce0 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: clone_fs_devices+0x6d/0x210 [btrfs]
  [ 540.743458] but task is already holding lock:
  [ 540.743461] ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs]
  [ 540.743541] which lock already depends on the new lock.
  [ 540.743543] the existing dependency chain (in reverse order) is:

  [ 540.743546] -> #1 (btrfs-chunk-00){++++}-{4:4}:
  [ 540.743566] down_read_nested+0x48/0x2b0
  [ 540.743585] __btrfs_tree_read_lock+0x32/0x200 [btrfs]
  [ 540.743650] btrfs_read_lock_root_node+0x70/0x200 [btrfs]
  [ 540.743733] btrfs_search_slot+0x6c6/0xe00 [btrfs]
  [ 540.743785] btrfs_update_device+0x83/0x260 [btrfs]
  [ 540.743849] btrfs_finish_chunk_alloc+0x13f/0x660 [btrfs] <--- device_list_mutex
  [ 540.743911] btrfs_create_pending_block_groups+0x18d/0x3f0 [btrfs]
  [ 540.743982] btrfs_commit_transaction+0x86/0x1260 [btrfs]
  [ 540.744037] btrfs_init_new_device+0x1600/0x1dd0 [btrfs]
  [ 540.744101] btrfs_ioctl+0x1c77/0x24c0 [btrfs]
  [ 540.744166] __x64_sys_ioctl+0xe4/0x140
  [ 540.744170] do_syscall_64+0x4b/0x80
  [ 540.744174] entry_SYSCALL_64_after_hwframe+0x44/0xa9

  [ 540.744180] -> #0 (&fs_devs->device_list_mutex){+.+.}-{4:4}:
  [ 540.744184] __lock_acquire+0x155f/0x2360
  [ 540.744188] lock_acquire+0x10b/0x5c0
  [ 540.744190] __mutex_lock+0xb1/0xf80
  [ 540.744193] mutex_lock_nested+0x27/0x30
  [ 540.744196] clone_fs_devices+0x6d/0x210 [btrfs]
  [ 540.744270] btrfs_read_chunk_tree+0x3c7/0xbb0 [btrfs]
  [ 540.744336] open_ctree+0xf6e/0x2074 [btrfs]
  [ 540.744406] btrfs_mount_root.cold.72+0x16/0x127 [btrfs]
  [ 540.744472] legacy_get_tree+0x38/0x90
  [ 540.744475] vfs_get_tree+0x30/0x140
  [ 540.744478] fc_mount+0x16/0x60
  [ 540.744482] vfs_kern_mount+0x91/0x100
  [ 540.744484] btrfs_mount+0x1e6/0x670 [btrfs]
  [ 540.744536] legacy_get_tree+0x38/0x90
  [ 540.744537] vfs_get_tree+0x30/0x140
  [ 540.744539] path_mount+0x8d8/0x1070
  [ 540.744541] do_mount+0x8d/0xc0
  [ 540.744543] __x64_sys_mount+0x125/0x160
  [ 540.744545] do_syscall_64+0x4b/0x80
  [ 540.744547] entry_SYSCALL_64_after_hwframe+0x44/0xa9

  [ 540.744551] other info that might help us debug this:
  [ 540.744552] Possible unsafe locking scenario:

  [ 540.744553] CPU0 				CPU1
  [ 540.744554] ---- 				----
  [ 540.744555] lock(btrfs-chunk-00);
  [ 540.744557] 					lock(&fs_devs->device_list_mutex);
  [ 540.744560] 					lock(btrfs-chunk-00);
  [ 540.744562] lock(&fs_devs->device_list_mutex);
  [ 540.744564]
   *** DEADLOCK ***

  [ 540.744565] 3 locks held by mount/2515:
  [ 540.744567] #0: ffffa0c56bf7a0e0 (&type->s_umount_key#42/1){+.+.}-{4:4}, at: alloc_super.isra.16+0xdf/0x450
  [ 540.744574] #1: ffffffffc05a9628 (uuid_mutex){+.+.}-{4:4}, at: btrfs_read_chunk_tree+0x63/0xbb0 [btrfs]
  [ 540.744640] #2: ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs]
  [ 540.744708]
   stack backtrace:
  [ 540.744712] CPU: 2 PID: 2515 Comm: mount Not tainted 5.11.0-rc7+ #5

But the device_list_mutex in clone_fs_devices() is redundant, as
explained below.  Two threads [1]  and [2] (below) could lead to
clone_fs_device().

  [1]
  open_ctree <== mount sprout fs
   btrfs_read_chunk_tree()
    mutex_lock(&uuid_mutex) <== global lock
    read_one_dev()
     open_seed_devices()
      clone_fs_devices() <== seed fs_devices
       mutex_lock(&orig->device_list_mutex) <== seed fs_devices

  [2]
  btrfs_init_new_device() <== sprouting
   mutex_lock(&uuid_mutex); <== global lock
   btrfs_prepare_sprout()
     lockdep_assert_held(&uuid_mutex)
     clone_fs_devices(seed_fs_device) <== seed fs_devices

Both of these threads hold uuid_mutex which is sufficient to protect
getting the seed device(s) freed while we are trying to clone it for
sprouting [2] or mounting a sprout [1] (as above). A mounted seed device
can not free/write/replace because it is read-only. An unmounted seed
device can be freed by btrfs_free_stale_devices(), but it needs
uuid_mutex.  So this patch removes the unnecessary device_list_mutex in
clone_fs_devices().  And adds a lockdep_assert_held(&uuid_mutex) in
clone_fs_devices().

Reported-by: Su Yue <l@damenly.su>
Tested-by: Su Yue <l@damenly.su>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26 14:09:00 +02:00