The patch titled md: fix possible raid1/raid10 deadlock on read error during resync has been removed from the -mm tree. Its filename was md-fix-possible-raid1-raid10-deadlock-on-read-error-during-resync.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: md: fix possible raid1/raid10 deadlock on read error during resync From: NeilBrown <neilb@xxxxxxx> Thanks to K.Tanaka and the scsi fault injection framework, here is a fix for another possible deadlock in raid1/raid10 error handing. If a read request returns an error while a resync is happening and a resync request is pending, the attempt to fix the error will block until the resync progresses, and the resync will block until the read request completes. Thus a deadlock. This patch fixes the problem. Cc: "K.Tanaka" <k-tanaka@xxxxxxxxxxxxx> Signed-off-by: Neil Brown <neilb@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/md/raid1.c | 11 +++++++++-- drivers/md/raid10.c | 11 +++++++++-- 2 files changed, 18 insertions(+), 4 deletions(-) diff -puN drivers/md/raid1.c~md-fix-possible-raid1-raid10-deadlock-on-read-error-during-resync drivers/md/raid1.c --- a/drivers/md/raid1.c~md-fix-possible-raid1-raid10-deadlock-on-read-error-during-resync +++ a/drivers/md/raid1.c @@ -704,13 +704,20 @@ static void freeze_array(conf_t *conf) /* stop syncio and normal IO and wait for everything to * go quite. * We increment barrier and nr_waiting, and then - * wait until barrier+nr_pending match nr_queued+2 + * wait until nr_pending match nr_queued+1 + * This is called in the context of one normal IO request + * that has failed. Thus any sync request that might be pending + * will be blocked by nr_pending, and we need to wait for + * pending IO requests to complete or be queued for re-try. + * Thus the number queued (nr_queued) plus this request (1) + * must match the number of pending IOs (nr_pending) before + * we continue. */ spin_lock_irq(&conf->resync_lock); conf->barrier++; conf->nr_waiting++; wait_event_lock_irq(conf->wait_barrier, - conf->barrier+conf->nr_pending == conf->nr_queued+2, + conf->nr_pending == conf->nr_queued+1, conf->resync_lock, ({ flush_pending_writes(conf); raid1_unplug(conf->mddev->queue); })); diff -puN drivers/md/raid10.c~md-fix-possible-raid1-raid10-deadlock-on-read-error-during-resync drivers/md/raid10.c --- a/drivers/md/raid10.c~md-fix-possible-raid1-raid10-deadlock-on-read-error-during-resync +++ a/drivers/md/raid10.c @@ -747,13 +747,20 @@ static void freeze_array(conf_t *conf) /* stop syncio and normal IO and wait for everything to * go quiet. * We increment barrier and nr_waiting, and then - * wait until barrier+nr_pending match nr_queued+2 + * wait until nr_pending match nr_queued+1 + * This is called in the context of one normal IO request + * that has failed. Thus any sync request that might be pending + * will be blocked by nr_pending, and we need to wait for + * pending IO requests to complete or be queued for re-try. + * Thus the number queued (nr_queued) plus this request (1) + * must match the number of pending IOs (nr_pending) before + * we continue. */ spin_lock_irq(&conf->resync_lock); conf->barrier++; conf->nr_waiting++; wait_event_lock_irq(conf->wait_barrier, - conf->barrier+conf->nr_pending == conf->nr_queued+2, + conf->nr_pending == conf->nr_queued+1, conf->resync_lock, ({ flush_pending_writes(conf); raid10_unplug(conf->mddev->queue); })); _ Patches currently in -mm which might be from neilb@xxxxxxx are git-nfsd.patch md-fix-integer-as-null-pointer-warnings-in-mdc.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html