releases/4.9.96/jbd2-if-the-journal-is-aborted-then-don-t-allow-update-of-the-log-tail.patch

From 85e0c4e89c1b864e763c4e3bb15d0b6d501ad5d9 Mon Sep 17 00:00:00 2001
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

From: Theodore Ts'o <tytso@mit.edu>

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>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/jbd2/journal.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -951,7 +951,7 @@ 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.
  */
@@ -1394,6 +1394,9 @@ 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);