The RAID-6 driver shares handle_write_operations() with RAID-5. For this
purpose, some modifications to handle_write_operations5() had been made. The
function itself was renamed as well. The handle_write_operations() is being
triggered either from handle_stripe6() or handle_stripe5().
This patch introduces one more RAID-5/6 shared function, it is
handle_completed_postxor_requests(), to be called when either handle_stripe5()
or handle_stripe6() discover the completeness of a post-xor operation for the
stripe.
Signed-off-by: Yuri Tikhonov <yur@xxxxxxxxxxx>
Signed-off-by: Mikhail Cherkashin <mike@xxxxxxxxxxx>
--
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 2c6fee0..3e8f896 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2447,11 +2447,12 @@ static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
}
static int
-handle_write_operations5(struct stripe_head *sh, int rcw, int expand)
+handle_write_operations(struct stripe_head *sh, int rcw, int expand)
{
int locked = 0;
struct stripe_queue *sq = sh->sq;
int i, pd_idx = sq->pd_idx, disks = sq->disks;
+ int level = sq->raid_conf->level;
if (rcw) {
/* if we are not expanding this is a proper write request, and
@@ -2478,6 +2479,7 @@ handle_write_operations5(struct stripe_head *sh, int rcw, int expand)
}
}
} else {
+ BUG_ON(level == 6);
BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
@@ -2510,13 +2512,20 @@ handle_write_operations5(struct stripe_head *sh, int rcw, int expand)
}
}
- /* keep the parity disk locked while asynchronous operations
+ /* keep the parity disks locked while asynchronous operations
* are in flight
*/
set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
locked++;
+ if (level == 6) {
+ int qd_idx = raid6_next_disk(pd_idx, disks);
+ set_bit(R5_LOCKED, &sh->dev[qd_idx].flags);
+ clear_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
+ locked++;
+ }
+
pr_debug("%s: stripe %llu locked: %d pending: %lx\n",
__FUNCTION__, (unsigned long long)sh->sector,
locked, sh->ops.pending);
@@ -2881,6 +2890,47 @@ static void handle_issuing_new_read_requests6(struct stripe_head *sh,
set_bit(STRIPE_HANDLE, &sh->state);
}
+static void handle_completed_postxor_requests(struct stripe_head *sh,
+ struct stripe_head_state *s, int disks)
+{
+ struct stripe_queue *sq = sh->sq;
+ int i, pd_idx = sq->pd_idx;
+ int qd_idx = (sq->raid_conf->level != 6) ? -1 :
+ raid6_next_disk(pd_idx, disks);
+ struct r5dev *dev;
+
+ clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete);
+ clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.ack);
+ clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending);
+
+ clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
+ clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack);
+ clear_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
+
+ /* All the 'written' buffers and the parity block are ready to be
+ * written back to disk
+ */
+ BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags));
+ if (!(qd_idx < 0))
+ BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags));
+
+ for (i = disks; i--;) {
+ struct r5_queue_dev *dev_q = &sq->dev[i];
+
+ dev = &sh->dev[i];
+ if (test_bit(R5_LOCKED, &dev->flags) &&
+ (i == pd_idx || i == qd_idx || dev_q->written)) {
+ pr_debug("Writing block %d\n", i);
+ set_bit(R5_Wantwrite, &dev->flags);
+ if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
+ sh->ops.count++;
+ if (!test_bit(R5_Insync, &dev->flags) ||
+ ((i == pd_idx || i == qd_idx) &&
+ s->failed == 0))
+ set_bit(STRIPE_INSYNC, &sh->state);
+ }
+ }
+}
/* handle_completed_write_requests
* any written block on an uptodate or failed drive can be returned.
@@ -3016,7 +3066,7 @@ static void handle_issuing_new_write_requests5(raid5_conf_t *conf,
if ((s->req_compute ||
!test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending)) &&
(s->locked == 0 && (rcw == 0 || rmw == 0)))
- s->locked += handle_write_operations5(sh, rcw == 0, 0);
+ s->locked += handle_write_operations(sh, rcw == 0, 0);
}
static void handle_issuing_new_write_requests6(raid5_conf_t *conf,
@@ -3066,6 +3116,14 @@ static void handle_issuing_new_write_requests6(raid5_conf_t *conf,
/* now if nothing is locked, and if we have enough data, we can start a
* write request
*/
+ /* since handle_stripe can be called at any time we need to handle the case
+ * where a compute block operation has been submitted and then a subsequent
+ * call wants to start a write request. raid_run_ops only handles the case where
+ * compute block and postxor are requested simultaneously. If this
+ * is not the case then new writes need to be held off until the compute
+ * completes.
+ */
+
if (s->locked == 0 && rcw == 0) {
if (must_compute > 0) {
/* We have failed blocks and need to compute them */
@@ -3084,19 +3142,9 @@ static void handle_issuing_new_write_requests6(raid5_conf_t *conf,
}
}
- pr_debug("Computing parity for stripe %llu\n",
- (unsigned long long)sh->sector);
- compute_parity6(sh, RECONSTRUCT_WRITE);
- /* now every locked buffer is ready to be written */
- for (i = disks; i--; )
- if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
- pr_debug("Writing stripe %llu block %d\n",
- (unsigned long long)sh->sector, i);
- s->locked++;
- set_bit(R5_Wantwrite, &sh->dev[i].flags);
- }
- /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
- set_bit(STRIPE_INSYNC, &sh->state);
+ if (s->req_compute ||
+ !test_bit(STRIPE_OP_COMPUTE_BLK, &sh->ops.pending))
+ s->locked += handle_write_operations(sh, rcw == 0, 0);
}
}
@@ -3514,37 +3562,8 @@ static void handle_stripe5(struct stripe_head *sh)
/* if only POSTXOR is set then this is an 'expand' postxor */
if (test_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete) &&
- test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete)) {
-
- clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete);
- clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.ack);
- clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending);
-
- clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
- clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack);
- clear_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
-
- /* All the 'written' buffers and the parity block are ready to
- * be written back to disk
- */
- BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sq->pd_idx].flags));
- for (i = disks; i--; ) {
- struct r5_queue_dev *dev_q = &sq->dev[i];
-
- dev = &sh->dev[i];
- if (test_bit(R5_LOCKED, &dev->flags) &&
- (i == sq->pd_idx || dev_q->written)) {
- pr_debug("Writing block %d\n", i);
- set_bit(R5_Wantwrite, &dev->flags);
- if (!test_and_set_bit(
- STRIPE_OP_IO, &sh->ops.pending))
- sh->ops.count++;
- if (!test_bit(R5_Insync, &dev->flags) ||
- (i == sq->pd_idx && s.failed == 0))
- set_bit(STRIPE_INSYNC, &sh->state);
- }
- }
- }
+ test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete))
+ handle_completed_postxor_requests(sh, &s, disks);
/* Now to consider new write requests and what else, if anything
* should be read. We do not handle new writes when:
@@ -3624,7 +3643,7 @@ static void handle_stripe5(struct stripe_head *sh)
sq->disks = conf->raid_disks;
sq->pd_idx = stripe_to_pdidx(sh->sector, conf,
conf->raid_disks);
- s.locked += handle_write_operations5(sh, 1, 1);
+ s.locked += handle_write_operations(sh, 1, 1);
} else if (s.expanded &&
!test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
clear_bit(STRIPE_EXPAND_READY, &sh->state);
@@ -3787,8 +3806,23 @@ static void handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
(s.syncing && (s.uptodate < disks)) || s.expanding)
handle_issuing_new_read_requests6(sh, &s, &r6s, disks);
- /* now to consider writing and what else, if anything should be read */
- if (s.to_write)
+ /* Now we check to see if any write operations have recently
+ * completed
+ */
+
+ /* if only POSTXOR is set then this is an 'expand' postxor */
+ if (test_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete) &&
+ test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete))
+ handle_completed_postxor_requests(sh, &s, disks);
+
+ /* 1/ Now to consider new write requests and what else,
+ * if anything shuold be read
+ * 2/ Check operations clobber the parity block so do not start
+ * new writes while a check is in flight
+ * 3/ Write operations do not stack
+ */
+ if (s.to_write && !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending) &&
+ !test_bit(STRIPE_OP_CHECK, &sh->ops.pending))
handle_issuing_new_write_requests6(conf, sh, &s, &r6s, disks);
/* maybe we need to check and possibly fix the parity for this stripe
--
Yuri Tikhonov, Senior Software Engineer
Emcraft Systems, www.emcraft.com
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