linux-ext4 - [PATCH 13/22] jbd2: Drop pointless check from jbd2_journal

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20191003220613.10791-13-jack@suse.cz>
Date:   Fri,  4 Oct 2019 00:05:59 +0200
From:   Jan Kara <jack@...e.cz>
To:     <linux-ext4@...r.kernel.org>
Cc:     Ted Tso <tytso@....edu>, Jan Kara <jack@...e.cz>
Subject: [PATCH 13/22] jbd2: Drop pointless check from jbd2_journal_stop()

If a transaction is larger than journal->j_max_transaction_buffers, that
is a bug and not a trigger for transaction commit. Also the very next
attempt to start new handle will start transaction commit anyway. So
just remove the pointless check. Arguably, we could start transaction
commit whenever the transaction size is *close* to
journal->j_max_transaction_buffers. This has a potential to reduce
latency of the next jbd2_journal_start() at the cost of somewhat smaller
transactions. However for this to have any effect, it would mean that
there isn't someone already waiting in jbd2_journal_start() which means
metadata load for the fs is pretty light anyway so probably this
optimization is not worth it.

Signed-off-by: Jan Kara <jack@...e.cz>
---
 fs/jbd2/transaction.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 6f560713f7f0..a160c3f665f9 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1803,13 +1803,10 @@ int jbd2_journal_stop(handle_t *handle)

 	/*
 	 * If the handle is marked SYNC, we need to set another commit
-	 * going!  We also want to force a commit if the current
-	 * transaction is occupying too much of the log, or if the
-	 * transaction is too old now.
+	 * going!  We also want to force a commit if the transaction is too
+	 * old now.
 	 */
 	if (handle->h_sync ||
-	    (atomic_read(&transaction->t_outstanding_credits) >
-	     journal->j_max_transaction_buffers) ||
 	    time_after_eq(jiffies, transaction->t_expires)) {
 		/* Do this even for aborted journals: an abort still
 		 * completes the commit thread, it just doesn't write
-- 
2.16.4