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Message-Id: <1080627065157.10707@suse.de>
Date: Fri, 27 Jun 2008 16:51:57 +1000
From: NeilBrown <neilb@...e.de>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Dan Williams <dan.j.williams@...el.com>
Subject: [PATCH 024 of 29] md: md: replace STRIPE_OP_BIOFILL with STRIPE_BIOFILL_RUN
From: Dan Williams <dan.j.williams@...el.com>
Track the state of read operations (copying data from the stripe cache to bio
buffers outside the lock) with a state flag. Reduce the scope of the
STRIPE_OP_BIOFILL flag to only tracking whether a biofill operation has been
requested via the ops_request field of struct stripe_head_state.
This is another step towards the removal of ops.{pending,ack,complete,count},
i.e. STRIPE_OP_BIOFILL only requests an operation and does not track the state
of the operation.
Signed-off-by: Dan Williams <dan.j.williams@...el.com>
Signed-off-by: Neil Brown <neilb@...e.de>
### Diffstat output
./drivers/md/raid5.c | 33 ++++++++++++---------------------
1 file changed, 12 insertions(+), 21 deletions(-)
diff .prev/drivers/md/raid5.c ./drivers/md/raid5.c
--- .prev/drivers/md/raid5.c 2008-06-27 16:22:05.000000000 +1000
+++ ./drivers/md/raid5.c 2008-06-27 16:22:05.000000000 +1000
@@ -523,38 +523,34 @@ static void ops_complete_biofill(void *s
(unsigned long long)sh->sector);
/* clear completed biofills */
+ spin_lock_irq(&conf->device_lock);
for (i = sh->disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
/* acknowledge completion of a biofill operation */
/* and check if we need to reply to a read request,
* new R5_Wantfill requests are held off until
- * !test_bit(STRIPE_OP_BIOFILL, &sh->ops.pending)
+ * !STRIPE_BIOFILL_RUN
*/
if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
struct bio *rbi, *rbi2;
- /* The access to dev->read is outside of the
- * spin_lock_irq(&conf->device_lock), but is protected
- * by the STRIPE_OP_BIOFILL pending bit
- */
BUG_ON(!dev->read);
rbi = dev->read;
dev->read = NULL;
while (rbi && rbi->bi_sector <
dev->sector + STRIPE_SECTORS) {
rbi2 = r5_next_bio(rbi, dev->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;
}
}
}
- set_bit(STRIPE_OP_BIOFILL, &sh->ops.complete);
+ spin_unlock_irq(&conf->device_lock);
+ clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
return_io(return_bi);
@@ -880,7 +876,7 @@ static void raid5_run_ops(struct stripe_
int overlap_clear = 0, i, disks = sh->disks;
struct dma_async_tx_descriptor *tx = NULL;
- if (test_bit(STRIPE_OP_BIOFILL, &pending)) {
+ if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
ops_run_biofill(sh);
overlap_clear++;
}
@@ -2630,15 +2626,8 @@ static void handle_stripe5(struct stripe
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);
- /* Now to look around and see what can be done */
-
- /* 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();
for (i=disks; i--; ) {
mdk_rdev_t *rdev;
@@ -2652,10 +2641,10 @@ static void handle_stripe5(struct stripe
/* maybe we can request a biofill operation
*
* new wantfill requests are only permitted while
- * STRIPE_OP_BIOFILL is clear
+ * ops_complete_biofill is guaranteed to be inactive
*/
if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
- !test_bit(STRIPE_OP_BIOFILL, &sh->ops.pending))
+ !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
set_bit(R5_Wantfill, &dev->flags);
/* now count some things */
@@ -2699,8 +2688,10 @@ static void handle_stripe5(struct stripe
goto unlock;
}
- if (s.to_fill && !test_and_set_bit(STRIPE_OP_BIOFILL, &sh->ops.pending))
- sh->ops.count++;
+ if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
+ set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
+ set_bit(STRIPE_BIOFILL_RUN, &sh->state);
+ }
pr_debug("locked=%d uptodate=%d to_read=%d"
" to_write=%d failed=%d failed_num=%d\n",
--
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