Patch "jbd2: fix incorrect unlock on j_list_lock" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

jbd2: fix incorrect unlock on j_list_lock

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
jbd2-fix-incorrect-unlock-on-j_list_lock.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Taesoo Kim <[email protected]>
Date: Wed, 12 Oct 2016 23:19:18 -0400
Subject: jbd2: fix incorrect unlock on j_list_lock

From: Taesoo Kim <[email protected]>

commit 559cce698eaf4ccecb2213b2519ea3a0413e5155 upstream.

When 'jh->b_transaction == transaction' (asserted by below)

J_ASSERT_JH(jh, (jh->b_transaction == transaction || ...

'journal->j_list_lock' will be incorrectly unlocked, since the the lock is aquired only at the end of if / else-if statements (missing the else case).

---
 fs/jbd2/transaction.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -1156,6 +1156,7 @@ int jbd2_journal_get_create_access(handl
 		JBUFFER_TRACE(jh, "file as BJ_Reserved");
 		spin_lock(&journal->j_list_lock);
 		__jbd2_journal_file_buffer(jh, transaction, BJ_Reserved);
+		spin_unlock(&journal->j_list_lock);
 	} else if (jh->b_transaction == journal->j_committing_transaction) {
 		/* first access by this transaction */
 		jh->b_modified = 0;

@@ -1163,8 +1164,8 @@ int jbd2_journal_get_create_access(handl
 		JBUFFER_TRACE(jh, "set next transaction");
 		spin_lock(&journal->j_list_lock);
 		jh->b_next_transaction = transaction;
+		spin_unlock(&journal->j_list_lock);
 	}
-	spin_unlock(&journal->j_list_lock);
 	jbd_unlock_bh_state(bh);
 
 	/*

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/jbd2-fix-incorrect-unlock-on-j_list_lock.patch