[PATCH 1/2] md/raid5: fix IO hang with degraded array with llbitmap
Yu Kuai <[email protected]>
| Newsgroups | gmane.linux.raid,gmane.linux.block,gmane.linux.kernel |
|---|---|
| Message-ID | <[email protected]> |
When llbitmap bit state is still unwritten, any new write should force
rcw, as bitmap_ops->blocks_synced() is checked in handle_stripe_dirting().
However, later the same check is missing in need_this_block(), causing
stripe to deadloop during handling because handle_stripe() will decide
to go to handle_stripe_fill(), meanwhile need_this_block() always return
0 and nothing is handled.
Fixes: 5ab829f1971d ("md/md-llbitmap: introduce new lockless bitmap")
Signed-off-by: Yu Kuai <[email protected]>
---
drivers/md/raid5.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 8dc98f545969..93e672b3432b 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3751,9 +3751,14 @@ static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s,
struct r5dev *dev = &sh->dev[disk_idx];
struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
&sh->dev[s->failed_num[1]] };
+ struct mddev *mddev = sh->raid_conf->mddev;
+ bool force_rcw = false;
int i;
- bool force_rcw = (sh->raid_conf->rmw_level == PARITY_DISABLE_RMW);
+ if (sh->raid_conf->rmw_level == PARITY_DISABLE_RMW ||
+ (mddev->bitmap_ops && mddev->bitmap_ops->blocks_synced &&
+ !mddev->bitmap_ops->blocks_synced(mddev, sh->sector)))
+ force_rcw = true;
if (test_bit(R5_LOCKED, &dev->flags) ||
test_bit(R5_UPTODATE, &dev->flags))
--
2.51.0