From mboxrd@z Thu Jan 1 00:00:00 1970 From: swhiteho@redhat.com Date: Fri, 11 Jul 2008 11:11:15 +0100 Subject: [Cluster-devel] [PATCH 14/18] [GFS2] Fix delayed demote race In-Reply-To: <12157711093284-git-send-email-swhiteho@redhat.com> References: <121577107950-git-send-email-swhiteho@redhat.com> <12157710872782-git-send-email-swhiteho@redhat.com> <1215771089769-git-send-email-swhiteho@redhat.com> <1215771091790-git-send-email-swhiteho@redhat.com> <12157710931623-git-send-email-swhiteho@redhat.com> <12157710954145-git-send-email-swhiteho@redhat.com> <12157710973601-git-send-email-swhiteho@redhat.com> <12157710983282-git-send-email-swhiteho@redhat.com> <12157711013356-git-send-email-swhiteho@redhat.com> <12157711023743-git-send-email-swhiteho@redhat.com> <12157711041157-git-send-email-swhiteho@redhat.com> <1215771106247-git-send-email-swhiteho@redhat.com> <12157711073280-git-send-email-swhiteho@redhat.com> <12157711093284-git-send-email-swhiteho@redhat.com> Message-ID: <12157711133727-git-send-email-swhiteho@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit From: Steven Whitehouse There is a race in the delayed demote code where it does the wrong thing if a demotion to UN has occurred for other reasons before the delay has expired. This patch adds an assert to catch that condition as well as fixing the root cause by adding an additional check for the UN state. Signed-off-by: Steven Whitehouse Cc: Bob Peterson diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 8d5450f..cd0aa21 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -587,6 +587,7 @@ static void run_queue(struct gfs2_glock *gl, const int nonblock) if (nonblock) goto out_sched; set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); + GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); gl->gl_target = gl->gl_demote_state; } else { if (test_bit(GLF_DEMOTE, &gl->gl_flags)) @@ -617,7 +618,9 @@ static void glock_work_func(struct work_struct *work) if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) finish_xmote(gl, gl->gl_reply); spin_lock(&gl->gl_spin); - if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags)) { + if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && + gl->gl_state != LM_ST_UNLOCKED && + gl->gl_demote_state != LM_ST_EXCLUSIVE) { unsigned long holdtime, now = jiffies; holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time; if (time_before(now, holdtime)) -- 1.5.1.2