jbd: Check return value of __getblk()

Fail journal creation if __getblk() returns NULL.  unlikely() is
added because it is called in a loop and we've been OK without
the check until now.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index e56117651826..ac1840415a65 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -952,6 +952,8 @@ int journal_create(journal_t *journal)
                 if (err)
                         return err;
                 bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
+                if (unlikely(!bh))
+                        return -ENOMEM;
                 lock_buffer(bh);
                 memset (bh->b_data, 0, journal->j_blocksize);
                 BUFFER_TRACE(bh, "marking dirty");