From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Whitehouse Date: Thu, 10 Jan 2008 15:59:18 +0000 Subject: [Cluster-devel] [GFS2] Fix assert in log code Message-ID: <1199980758.3728.2.camel@localhost.localdomain> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit >From 3a46e3bef51f7a1feffafcac855c1b252fcc5877 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Thu, 10 Jan 2008 14:49:43 +0000 Subject: [PATCH] [GFS2] Fix assert in log code Although the values were all being calculated correctly, there was a race in the assert due to the way it was using atomic variables. This changes the value we assert on so that we get the same effect by testing a different variable. This prevents the assert triggering when it shouldn't. Signed-off-by: Steven Whitehouse diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index 40c51bf..6e6a104 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -749,7 +749,7 @@ void __gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl) static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr) { unsigned int reserved; - unsigned int old; + unsigned int unused; gfs2_log_lock(sdp); @@ -761,14 +761,11 @@ static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr) sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm; gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0); reserved = calc_reserved(sdp); - old = atomic_read(&sdp->sd_log_blks_free); - atomic_add(tr->tr_reserved - (reserved - sdp->sd_log_blks_reserved), - &sdp->sd_log_blks_free); - - gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) >= old); + unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved; + gfs2_assert_withdraw(sdp, unused >= 0); + atomic_add(unused, &sdp->sd_log_blks_free); gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= sdp->sd_jdesc->jd_blocks); - sdp->sd_log_blks_reserved = reserved; gfs2_log_unlock(sdp); -- 1.5.1.2