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| author | Josef Bacik <josef@toxicpanda.com> | 2019-11-19 13:59:20 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-31 16:34:41 +0100 |
| commit | 06f9b11e1ae6199c923232f7d585a6a5baa78158 (patch) | |
| tree | 6212d4f16ce9221b3f8d9b785645a2b33d65b75c /fs | |
| parent | 2dfbfb88b0b41083aa7bc77355a37f601b962b49 (diff) | |
| download | linux-stable-06f9b11e1ae6199c923232f7d585a6a5baa78158.tar.gz linux-stable-06f9b11e1ae6199c923232f7d585a6a5baa78158.tar.bz2 linux-stable-06f9b11e1ae6199c923232f7d585a6a5baa78158.zip | |
btrfs: don't double lock the subvol_sem for rename exchange
commit 943eb3bf25f4a7b745dd799e031be276aa104d82 upstream.
If we're rename exchanging two subvols we'll try to lock this lock
twice, which is bad. Just lock once if either of the ino's are subvols.
Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT")
CC: stable@vger.kernel.org # 4.4+
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>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/inode.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 7fd4458cf0a7..ebdb93b47ce7 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9491,9 +9491,8 @@ static int btrfs_rename_exchange(struct inode *old_dir, btrfs_init_log_ctx(&ctx_dest, new_inode); /* close the race window with snapshot create/destroy ioctl */ - if (old_ino == BTRFS_FIRST_FREE_OBJECTID) - down_read(&fs_info->subvol_sem); - if (new_ino == BTRFS_FIRST_FREE_OBJECTID) + if (old_ino == BTRFS_FIRST_FREE_OBJECTID || + new_ino == BTRFS_FIRST_FREE_OBJECTID) down_read(&fs_info->subvol_sem); /* @@ -9727,9 +9726,8 @@ out_fail: ret = ret ? ret : ret2; } out_notrans: - if (new_ino == BTRFS_FIRST_FREE_OBJECTID) - up_read(&fs_info->subvol_sem); - if (old_ino == BTRFS_FIRST_FREE_OBJECTID) + if (new_ino == BTRFS_FIRST_FREE_OBJECTID || + old_ino == BTRFS_FIRST_FREE_OBJECTID) up_read(&fs_info->subvol_sem); ASSERT(list_empty(&ctx_root.list)); |