ext4: bail early when clearing inode journal flag fails

When clearing inode journal flag, we call jbd2_journal_flush() to force
all the journalled data to their final locations. Currently we ignore
when this fails and continue clearing inode journal flag. This isn't a
big problem because when jbd2_journal_flush() fails, journal is likely
aborted anyway. But it can still lead to somewhat confusing results so
rather bail out early.

Coverity-id: 989044
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

fs/ext4/inode.c

@@ -4959,7 +4959,12 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
 	if (val)
 		ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
 	else {
-		jbd2_journal_flush(journal);
+		err = jbd2_journal_flush(journal);
+		if (err < 0) {
+			jbd2_journal_unlock_updates(journal);
+			ext4_inode_resume_unlocked_dio(inode);
+			return err;
+		}
 		ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
 	}
 	ext4_set_aops(inode);