This patch introduces the state machine for handling the RAID-6 parities
check and repair functionality.
Signed-off-by: Yuri Tikhonov <y...@emcraft.com>
Signed-off-by: Ilya Yanok <ya...@emcraft.com>
---
drivers/md/raid5.c | 164 +++++++++++++++++++++++++++++++++++-----------------
1 files changed, 111 insertions(+), 53 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 2e26e84..b8e37c8 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2620,91 +2620,149 @@ static void handle_parity_checks6(raid5_conf_t *conf,
struct stripe_head *sh,
struct r6_state *r6s, struct page *tmp_page,
int disks)
{
- int update_p = 0, update_q = 0;
- struct r5dev *dev;
+ int i;
+ struct r5dev *devs[2] = {NULL, NULL};
int pd_idx = sh->pd_idx;
int qd_idx = r6s->qd_idx;
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
*/
- /* If !tmp_page, we cannot do the calculations,
- * but as we have set STRIPE_HANDLE, we will soon be called
- * by stripe_handle with a tmp_page - just wait until then.
- */
- if (tmp_page) {
+ 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).
*/
- 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;
- }
+ sh->check_state = check_state_run;
+ set_bit(STRIPE_OP_CHECK_PP, &s->ops_request);
+ clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
+ s->uptodate--;
}
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;
- }
+ sh->check_state = check_state_run;
+ set_bit(STRIPE_OP_CHECK_QP, &s->ops_request);
+ clear_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
+ s->uptodate--;
}
- 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;
+ if (sh->check_state == check_state_run) {
+ break;
}
- /* now write out any block on a failed drive,
- * or P or Q if they need it
- */
+ /* we have 2-disk failure */
+ BUG_ON(s->failed != 2);
+ devs[0] = &sh->dev[r6s->failed_num[0]];
+ devs[1] = &sh->dev[r6s->failed_num[1]];
+ /* fall through */
+ case check_state_compute_result:
+ sh->check_state = check_state_idle;
- 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);
+ BUG_ON((devs[0] && !devs[1]) ||
+ (!devs[0] && devs[1]));
+
+ BUG_ON(s->uptodate < (disks - 1));
+
+ if (!devs[0]) {
+ if (s->failed >= 1)
+ devs[0] = &sh->dev[r6s->failed_num[0]];
+ else
+ devs[0] = &sh->dev[pd_idx];
}
- 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 (!devs[1]) {
+ if (s->failed >= 2)
+ devs[1] = &sh->dev[r6s->failed_num[1]];
+ else
+ devs[1] = &sh->dev[qd_idx];
}
- 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);
+ BUG_ON(!test_bit(R5_UPTODATE, &devs[0]->flags) &&
+ !test_bit(R5_UPTODATE, &devs[1]->flags));
+
+ /* check that a write has not made the stripe insync */
+ if (test_bit(STRIPE_INSYNC, &sh->state))
+ break;
+
+ for (i=0; i < 2; i++) {
+ if (test_bit(R5_UPTODATE, &devs[i]->flags)) {
+ s->locked++;
+ set_bit(R5_LOCKED, &devs[i]->flags);
+ set_bit(R5_Wantwrite, &devs[i]->flags);
+ }
}
- clear_bit(STRIPE_DEGRADED, &sh->state);
+ clear_bit(STRIPE_DEGRADED, &sh->state);
set_bit(STRIPE_INSYNC, &sh->state);
+ break;
+ case check_state_run:
+ break; /* we will be called again upon completion */
+ case check_state_check_result:
+ sh->check_state = check_state_idle;
+
+ /* if a failure occurred during the check operation, leave
+ * STRIPE_INSYNC not set and let the stripe be handled again
+ */
+ if (s->failed > 1) {
+ break;
+ }
+
+ /* 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 {
+ sh->check_state = check_state_compute_result;
+ }
+ } 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 {
+ 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 &
+ DMA_PCHECK_FAILED) {
+ set_bit(R5_Wantcompute,
+ &sh->dev[pd_idx].flags);
+ sh->ops.target = pd_idx;
+ s->uptodate++;
+ } else
+ sh->ops.target = -1;
+ if (sh->ops.zero_sum_result &
+ DMA_QCHECK_FAILED) {
+ set_bit(R5_Wantcompute,
+ &sh->dev[qd_idx].flags);
+ sh->ops.target2 = qd_idx;
+ s->uptodate++;
+ } else
+ sh->ops.target2 = -1;
+ }
+ }
+ 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();
}
}
--
1.6.0.6
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