diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 08f806379b074..3c31f7f8aa654 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2901,91 +2901,163 @@ static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
struct stripe_head_state *s,
struct r6_state *r6s, int disks)
{
- int update_p = 0, update_q = 0;
- struct r5dev *dev;
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
- unsigned long cpu;
- struct page *tmp_page;
+ struct r5dev *dev;
set_bit(STRIPE_HANDLE, &sh->state);
BUG_ON(s->failed > 2);
- BUG_ON(s->uptodate < disks);
+
/* Want to check and possibly repair P and Q.
* However there could be one 'failed' device, in which
* case we can only check one of them, possibly using the
* other to generate missing data
*/
- cpu = get_cpu();
- tmp_page = per_cpu_ptr(conf->percpu, cpu)->spare_page;
- if (s->failed == r6s->q_failed) {
- /* The only possible failed device holds 'Q', so it
- * makes sense to check P (If anything else were failed,
- * we would have used P to recreate it).
- */
- compute_block_1(sh, pd_idx, 1);
- if (!page_is_zero(sh->dev[pd_idx].page)) {
- compute_block_1(sh, pd_idx, 0);
- update_p = 1;
+
+ switch (sh->check_state) {
+ case check_state_idle:
+ /* start a new check operation if there are < 2 failures */
+ if (s->failed == r6s->q_failed) {
+ /* The only possible failed device holds Q, so it
+ * makes sense to check P (If anything else were failed,
+ * we would have used P to recreate it).
+ */
+ sh->check_state = check_state_run;
}
- }
- if (!r6s->q_failed && s->failed < 2) {
- /* q is not failed, and we didn't use it to generate
- * anything, so it makes sense to check it
- */
- memcpy(page_address(tmp_page),
- page_address(sh->dev[qd_idx].page),
- STRIPE_SIZE);
- compute_parity6(sh, UPDATE_PARITY);
- if (memcmp(page_address(tmp_page),
- page_address(sh->dev[qd_idx].page),
- STRIPE_SIZE) != 0) {
- clear_bit(STRIPE_INSYNC, &sh->state);
- update_q = 1;
+ if (!r6s->q_failed && s->failed < 2) {
+ /* Q is not failed, and we didn't use it to generate
+ * anything, so it makes sense to check it
+ */
+ if (sh->check_state == check_state_run)
+ sh->check_state = check_state_run_pq;
+ else
+ sh->check_state = check_state_run_q;
}
- }
- put_cpu();
- if (update_p || update_q) {
- conf->mddev->resync_mismatches += STRIPE_SECTORS;
- if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
- /* don't try to repair!! */
- update_p = update_q = 0;
- }
+ /* discard potentially stale zero_sum_result */
+ sh->ops.zero_sum_result = 0;
- /* now write out any block on a failed drive,
- * or P or Q if they need it
- */
+ if (sh->check_state == check_state_run) {
+ /* async_xor_zero_sum destroys the contents of P */
+ clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
+ s->uptodate--;
+ }
+ if (sh->check_state >= check_state_run &&
+ sh->check_state <= check_state_run_pq) {
+ /* async_syndrome_zero_sum preserves P and Q, so
+ * no need to mark them !uptodate here
+ */
+ set_bit(STRIPE_OP_CHECK, &s->ops_request);
+ break;
+ }
- if (s->failed == 2) {
- dev = &sh->dev[r6s->failed_num[1]];
- s->locked++;
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantwrite, &dev->flags);
- }
- if (s->failed >= 1) {
- dev = &sh->dev[r6s->failed_num[0]];
- s->locked++;
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantwrite, &dev->flags);
- }
+ /* we have 2-disk failure */
+ BUG_ON(s->failed != 2);
+ /* fall through */
+ case check_state_compute_result:
+ sh->check_state = check_state_idle;
- if (update_p) {
- dev = &sh->dev[pd_idx];
- s->locked++;
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantwrite, &dev->flags);
- }
- if (update_q) {
- dev = &sh->dev[qd_idx];
- s->locked++;
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantwrite, &dev->flags);
- }
- clear_bit(STRIPE_DEGRADED, &sh->state);
+ /* check that a write has not made the stripe insync */
+ if (test_bit(STRIPE_INSYNC, &sh->state))
+ break;
- set_bit(STRIPE_INSYNC, &sh->state);
+ /* now write out any block on a failed drive,
+ * or P or Q if they were recomputed
+ */
+ BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
+ if (s->failed == 2) {
+ dev = &sh->dev[r6s->failed_num[1]];
+ s->locked++;
+ set_bit(R5_LOCKED, &dev->flags);
+ set_bit(R5_Wantwrite, &dev->flags);
+ }
+ if (s->failed >= 1) {
+ dev = &sh->dev[r6s->failed_num[0]];
+ s->locked++;
+ set_bit(R5_LOCKED, &dev->flags);
+ set_bit(R5_Wantwrite, &dev->flags);
+ }
+ if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
+ dev = &sh->dev[pd_idx];
+ s->locked++;
+ set_bit(R5_LOCKED, &dev->flags);
+ set_bit(R5_Wantwrite, &dev->flags);
+ }
+ if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
+ dev = &sh->dev[qd_idx];
+ s->locked++;
+ set_bit(R5_LOCKED, &dev->flags);
+ set_bit(R5_Wantwrite, &dev->flags);
+ }
+ clear_bit(STRIPE_DEGRADED, &sh->state);
+
+ set_bit(STRIPE_INSYNC, &sh->state);
+ break;
+ case check_state_run:
+ case check_state_run_q:
+ case check_state_run_pq:
+ break; /* we will be called again upon completion */
+ case check_state_check_result:
+ sh->check_state = check_state_idle;
+
+ /* handle a successful check operation, if parity is correct
+ * we are done. Otherwise update the mismatch count and repair
+ * parity if !MD_RECOVERY_CHECK
+ */
+ if (sh->ops.zero_sum_result == 0) {
+ /* both parities are correct */
+ if (!s->failed)
+ set_bit(STRIPE_INSYNC, &sh->state);
+ else {
+ /* in contrast to the raid5 case we can validate
+ * parity, but still have a failure to write
+ * back
+ */
+ sh->check_state = check_state_compute_result;
+ /* Returning at this point means that we may go
+ * off and bring p and/or q uptodate again so
+ * we make sure to check zero_sum_result again
+ * to verify if p or q need writeback
+ */
+ }
+ } else {
+ conf->mddev->resync_mismatches += STRIPE_SECTORS;
+ if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
+ /* don't try to repair!! */
+ set_bit(STRIPE_INSYNC, &sh->state);
+ else {
+ int *target = &sh->ops.target;
+
+ sh->ops.target = -1;
+ sh->ops.target2 = -1;
+ sh->check_state = check_state_compute_run;
+ set_bit(STRIPE_COMPUTE_RUN, &sh->state);
+ set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
+ if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
+ set_bit(R5_Wantcompute,
+ &sh->dev[pd_idx].flags);
+ *target = pd_idx;
+ target = &sh->ops.target2;
+ s->uptodate++;
+ }
+ if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
+ set_bit(R5_Wantcompute,
+ &sh->dev[qd_idx].flags);
+ *target = qd_idx;
+ s->uptodate++;
+ }
+ }
+ }
+ break;
+ case check_state_compute_run:
+ break;
+ default:
+ printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
+ __func__, sh->check_state,
+ (unsigned long long) sh->sector);
+ BUG();
+ }
}
static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,