jbd2: add the missing unlock_buffer() in the error path of jbd2_write_superblock()

jbd2_write_superblock() is under the buffer lock of journal superblock
before ending that superblock write, so add a missing unlock_buffer() in
in the error path before submitting buffer.

Fixes: 742b06b5628f ("jbd2: check superblock mapped prior to committing")
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20200620061948.2049579-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index e494443..5493a0d 100644 (file)
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1367,8 +1367,10 @@ static int jbd2_write_superblock(journal_t *journal, int write_flags)
        int ret;
 
        /* Buffer got discarded which means block device got invalidated */
-       if (!buffer_mapped(bh))
+       if (!buffer_mapped(bh)) {
+               unlock_buffer(bh);
                return -EIO;
+       }
 
        trace_jbd2_write_superblock(journal, write_flags);
        if (!(journal->j_flags & JBD2_BARRIER))