From: Steven Whitehouse Date: Mon, 7 Jul 2008 09:02:36 +0000 (+0100) Subject: [GFS2] Fix delayed demote race X-Git-Tag: v2.6.27-rc1~1083^2~5 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=265d529cef6fd57698d79b3c0edd3a8178059ea6;p=linux-2.6 [GFS2] Fix delayed demote race 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 8d5450f3c3..cd0aa213fb 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))