When a read bio is attached to the stripe and the corresponding block is
marked as R5_UPTODATE, then a biofill operation is scheduled to copy
the data from the stripe cache to the bio buffer.
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 9856a91..88f7e06 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3854,6 +3854,14 @@ static void handle_stripe6(struct stripe_head *sh)
s.syncing = test_bit(STRIPE_SYNCING, &sh->state);
s.expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state);
s.expanded = test_bit(STRIPE_EXPAND_READY, &sh->state);
+
+ /* clean-up completed biofill operations */
+ if (test_bit(STRIPE_OP_BIOFILL, &sh->ops.complete)) {
+ clear_bit(STRIPE_OP_BIOFILL, &sh->ops.pending);
+ clear_bit(STRIPE_OP_BIOFILL, &sh->ops.ack);
+ clear_bit(STRIPE_OP_BIOFILL, &sh->ops.complete);
+ }
+
/* Now to look around and see what can be done */
rcu_read_lock();
@@ -3866,33 +3874,16 @@ static void handle_stripe6(struct stripe_head *sh)
if (test_and_clear_bit(i, sq->overwrite))
set_bit(R5_OVERWRITE, &dev->flags);
- pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
- i, dev->flags, dev_q->toread, dev_q->towrite,
- dev_q->written);
- /* maybe we can reply to a read */
- if (test_bit(R5_UPTODATE, &dev->flags) && dev_q->toread) {
- struct bio *rbi, *rbi2;
- pr_debug("Return read for disc %d\n", i);
- spin_lock_irq(&conf->device_lock);
- rbi = dev_q->toread;
- dev_q->toread = NULL;
- clear_bit(i, sq->to_read);
- if (test_and_clear_bit(i, sq->overlap))
- wake_up(&conf->wait_for_overlap);
- spin_unlock_irq(&conf->device_lock);
- while (rbi && rbi->bi_sector <
- dev_q->sector + STRIPE_SECTORS) {
- copy_data(0, rbi, dev->page, dev_q->sector);
- rbi2 = r5_next_bio(rbi, dev_q->sector);
- spin_lock_irq(&conf->device_lock);
- if (--rbi->bi_phys_segments == 0) {
- rbi->bi_next = return_bi;
- return_bi = rbi;
- }
- spin_unlock_irq(&conf->device_lock);
- rbi = rbi2;
- }
- }
+ pr_debug("check %d: state 0x%lx toread %p write %p "
+ "written %p\n", i, dev->flags, dev_q->toread,
+ dev_q->towrite, dev_q->written);
+ /* maybe we can reply to a read
+ * new wantfill requests are only permitted while
+ * STRIPE_OP_BIOFILL is clear
+ */
+ if (test_bit(R5_UPTODATE, &dev->flags) && dev_q->toread &&
+ !test_bit(STRIPE_OP_BIOFILL, &sh->ops.pending))
+ set_bit(R5_Wantfill, &dev->flags);
/* now count some things */
if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
@@ -3925,6 +3916,10 @@ static void handle_stripe6(struct stripe_head *sh)
set_bit(R5_Insync, &dev->flags);
}
rcu_read_unlock();
+
+ if (s.to_fill && !test_and_set_bit(STRIPE_OP_BIOFILL, &sh->ops.pending))
+ sh->ops.count++;
+
pr_debug("locked=%d uptodate=%d to_read=%d"
" to_write=%d failed=%d failed_num=%d,%d\n",
s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
--
Yuri Tikhonov, Senior Software Engineer
Emcraft Systems, www.emcraft.com
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