releases/3.16.60/jbd2-if-the-journal-is-aborted-then-don-t-allow-update-of-the-log.patch

From: Theodore Ts'o <tytso@mit.edu>
Date: Mon, 19 Feb 2018 12:22:53 -0500
Subject: jbd2: if the journal is aborted then don't allow update of the log
 tail

commit 85e0c4e89c1b864e763c4e3bb15d0b6d501ad5d9 upstream.

This updates the jbd2 superblock unnecessarily, and on an abort we
shouldn't truncate the log.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 fs/jbd2/journal.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -923,7 +923,7 @@ out:
 }
 
 /*
- * This is a variaon of __jbd2_update_log_tail which checks for validity of
+ * This is a variation of __jbd2_update_log_tail which checks for validity of
  * provided log tail and locks j_checkpoint_mutex. So it is safe against races
  * with other threads updating log tail.
  */
@@ -1399,6 +1399,9 @@ int jbd2_journal_update_sb_log_tail(jour
 	journal_superblock_t *sb = journal->j_superblock;
 	int ret;
 
+	if (is_journal_aborted(journal))
+		return -EIO;
+
 	BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
 	jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n",
 		  tail_block, tail_tid);