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authorDan Williams <dan.j.williams@intel.com>2008-05-12 14:02:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-05-13 08:02:24 -0700
commitc8894419acf5e56851de9741c5047bebd78acd1f (patch)
tree6294b87ebf31d577cd48880a201ff4b1a6a50ffc /drivers/md
parent3f275ea3086054205795972b8e87f2046fd3de98 (diff)
md: fix raid5 'repair' operations
commit bd2ab67030e9116f1e4aae1289220255412b37fd "md: close a livelock window in handle_parity_checks5" introduced a bug in handling 'repair' operations. After a repair operation completes we clear the state bits tracking this operation. However, they are cleared too early and this results in the code deciding to re-run the parity check operation. Since we have done the repair in memory the second check does not find a mismatch and thus does not do a writeback. Test results: $ echo repair > /sys/block/md0/md/sync_action $ cat /sys/block/md0/md/mismatch_cnt 51072 $ echo repair > /sys/block/md0/md/sync_action $ cat /sys/block/md0/md/mismatch_cnt 0 (also fix incorrect indentation) Cc: <stable@kernel.org> Tested-by: George Spelvin <linux@horizon.com> Acked-by: NeilBrown <neilb@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/raid5.c25
1 files changed, 13 insertions, 12 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 087eee0cb80..ee0ea918308 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2369,8 +2369,8 @@ static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
/* complete a check operation */
if (test_and_clear_bit(STRIPE_OP_CHECK, &sh->ops.complete)) {
- clear_bit(STRIPE_OP_CHECK, &sh->ops.ack);
- clear_bit(STRIPE_OP_CHECK, &sh->ops.pending);
+ clear_bit(STRIPE_OP_CHECK, &sh->ops.ack);
+ clear_bit(STRIPE_OP_CHECK, &sh->ops.pending);
if (s->failed == 0) {
if (sh->ops.zero_sum_result == 0)
/* parity is correct (on disc,
@@ -2400,16 +2400,6 @@ static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
canceled_check = 1; /* STRIPE_INSYNC is not set */
}
- /* check if we can clear a parity disk reconstruct */
- if (test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete) &&
- test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending)) {
-
- clear_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending);
- clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete);
- clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.ack);
- clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending);
- }
-
/* start a new check operation if there are no failures, the stripe is
* not insync, and a repair is not in flight
*/
@@ -2424,6 +2414,17 @@ static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
}
}
+ /* check if we can clear a parity disk reconstruct */
+ if (test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete) &&
+ test_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending)) {
+
+ clear_bit(STRIPE_OP_MOD_REPAIR_PD, &sh->ops.pending);
+ clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.complete);
+ clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.ack);
+ clear_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending);
+ }
+
+
/* Wait for check parity and compute block operations to complete
* before write-back. If a failure occurred while the check operation
* was in flight we need to cycle this stripe through handle_stripe