md/raid5: Make sure we clear R5_Discard when discard is finished.
commit 9e44476851e91c86c98eb92b9bc27fb801f89072
MD: raid5 avoid unnecessary zero page for trim
change raid5 to clear R5_Discard when the complete request is
handled rather than when submitting the per-device discard request.
However it did not clear R5_Discard for the parity device.
This means that if the stripe_head was reused before it expired from
the cache, the setting would be wrong and a hang would result.
Also if the R5_Uptodate bit happens to be set, R5_Discard again
won't be cleared. But R5_Uptodate really should be clear at this point.
So make sure R5_Discard is cleared in all cases, and clear
R5_Uptodate when a 'discard' completes.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 0fb9885..a450268 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2774,10 +2774,12 @@
dev = &sh->dev[i];
if (!test_bit(R5_LOCKED, &dev->flags) &&
(test_bit(R5_UPTODATE, &dev->flags) ||
- test_and_clear_bit(R5_Discard, &dev->flags))) {
+ test_bit(R5_Discard, &dev->flags))) {
/* We can return any write requests */
struct bio *wbi, *wbi2;
pr_debug("Return write for disc %d\n", i);
+ if (test_and_clear_bit(R5_Discard, &dev->flags))
+ clear_bit(R5_UPTODATE, &dev->flags);
wbi = dev->written;
dev->written = NULL;
while (wbi && wbi->bi_sector <
@@ -2795,7 +2797,8 @@
!test_bit(STRIPE_DEGRADED, &sh->state),
0);
}
- }
+ } else if (test_bit(R5_Discard, &sh->dev[i].flags))
+ clear_bit(R5_Discard, &sh->dev[i].flags);
if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
if (atomic_dec_and_test(&conf->pending_full_writes))