diff options
| author | Josef Bacik <josef@toxicpanda.com> | 2021-10-05 16:12:41 -0400 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2021-10-26 19:08:07 +0200 |
| commit | 8b41393fe7c3b180abadc26856fb653014733bb9 (patch) | |
| tree | d9c63ffcdd0109adffa37db7d0df4b4eb41b743c /fs/btrfs | |
| parent | add9745adc2fa13e6a6e2c26c78dcb05da031a44 (diff) | |
| download | linux-8b41393fe7c3b180abadc26856fb653014733bb9.tar.bz2 | |
btrfs: do not call close_fs_devices in btrfs_rm_device
There's a subtle case where if we're removing the seed device from a
file system we need to free its private copy of the fs_devices. However
we do not need to call close_fs_devices(), because at this point there
are no devices left to close as we've closed the last one. The only
thing that close_fs_devices() does is decrement ->opened, which should
be 1. We want to avoid calling close_fs_devices() here because it has a
lockdep_assert_held(&uuid_mutex), and we are going to stop holding the
uuid_mutex in this path.
So simply decrement the ->opened counter like we should, and then clean
up like normal. Also add a comment explaining what we're doing here as
I initially removed this code erroneously.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/volumes.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 0941f61d8071..918ad3790791 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2211,9 +2211,17 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path, synchronize_rcu(); btrfs_free_device(device); + /* + * This can happen if cur_devices is the private seed devices list. We + * cannot call close_fs_devices() here because it expects the uuid_mutex + * to be held, but in fact we don't need that for the private + * seed_devices, we can simply decrement cur_devices->opened and then + * remove it from our list and free the fs_devices. + */ if (cur_devices->num_devices == 0) { list_del_init(&cur_devices->seed_list); - close_fs_devices(cur_devices); + ASSERT(cur_devices->opened == 1); + cur_devices->opened--; free_fs_devices(cur_devices); } |