It's possible several tasks are waiting for stripe overlap. We clear R5_Overlap
bit and wake_up, but wake_up just wakes one task. So if there are several tasks
in the wait queue, some tasks will not be woken up even its strip R5_Overlap
clear. The end result is tasks hang in make_request.
wake_up_all should not introduce performance issue here, since overlap case is
rare.
Signed-off-by: Shaohua Li <shli@xxxxxxxxxxxx>
---
drivers/md/raid5.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
Index: linux/drivers/md/raid5.c
===================================================================
--- linux.orig/drivers/md/raid5.c 2012-06-19 08:11:10.021688417 +0800
+++ linux/drivers/md/raid5.c 2012-06-19 08:11:29.833439339 +0800
@@ -1399,7 +1399,7 @@ static void __raid_run_ops(struct stripe
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (test_and_clear_bit(R5_Overlap, &dev->flags))
- wake_up(&sh->raid_conf->wait_for_overlap);
+ wake_up_all(&sh->raid_conf->wait_for_overlap);
}
put_cpu();
}
@@ -2436,7 +2436,7 @@ handle_failed_stripe(struct r5conf *conf
}
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
- wake_up(&conf->wait_for_overlap);
+ wake_up_all(&conf->wait_for_overlap);
while (bi && bi->bi_sector <
sh->dev[i].sector + STRIPE_SECTORS) {
@@ -2474,7 +2474,7 @@ handle_failed_stripe(struct r5conf *conf
bi = sh->dev[i].toread;
sh->dev[i].toread = NULL;
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
- wake_up(&conf->wait_for_overlap);
+ wake_up_all(&conf->wait_for_overlap);
if (bi) s->to_read--;
while (bi && bi->bi_sector <
sh->dev[i].sector + STRIPE_SECTORS) {
@@ -3572,7 +3572,7 @@ static void handle_stripe(struct stripe_
} else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
clear_bit(STRIPE_EXPAND_READY, &sh->state);
atomic_dec(&conf->reshape_stripes);
- wake_up(&conf->wait_for_overlap);
+ wake_up_all(&conf->wait_for_overlap);
md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
}
@@ -4249,7 +4249,7 @@ static sector_t reshape_request(struct m
spin_lock_irq(&conf->device_lock);
conf->reshape_safe = mddev->reshape_position;
spin_unlock_irq(&conf->device_lock);
- wake_up(&conf->wait_for_overlap);
+ wake_up_all(&conf->wait_for_overlap);
sysfs_notify(&mddev->kobj, NULL, "sync_completed");
}
@@ -4340,7 +4340,7 @@ static sector_t reshape_request(struct m
spin_lock_irq(&conf->device_lock);
conf->reshape_safe = mddev->reshape_position;
spin_unlock_irq(&conf->device_lock);
- wake_up(&conf->wait_for_overlap);
+ wake_up_all(&conf->wait_for_overlap);
sysfs_notify(&mddev->kobj, NULL, "sync_completed");
}
return reshape_sectors;
@@ -5718,7 +5718,7 @@ static void end_reshape(struct r5conf *c
smp_wmb();
conf->reshape_progress = MaxSector;
spin_unlock_irq(&conf->device_lock);
- wake_up(&conf->wait_for_overlap);
+ wake_up_all(&conf->wait_for_overlap);
/* read-ahead size must cover two whole stripes, which is
* 2 * (datadisks) * chunksize where 'n' is the number of raid devices
@@ -5776,7 +5776,7 @@ static void raid5_quiesce(struct mddev *
switch(state) {
case 2: /* resume for a suspend */
- wake_up(&conf->wait_for_overlap);
+ wake_up_all(&conf->wait_for_overlap);
break;
case 1: /* stop all writes */
@@ -5792,14 +5792,14 @@ static void raid5_quiesce(struct mddev *
conf->quiesce = 1;
spin_unlock_irq(&conf->device_lock);
/* allow reshape to continue */
- wake_up(&conf->wait_for_overlap);
+ wake_up_all(&conf->wait_for_overlap);
break;
case 0: /* re-enable writes */
spin_lock_irq(&conf->device_lock);
conf->quiesce = 0;
wake_up(&conf->wait_for_stripe);
- wake_up(&conf->wait_for_overlap);
+ wake_up_all(&conf->wait_for_overlap);
spin_unlock_irq(&conf->device_lock);
break;
}
--
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