[PATCH 2.6.20-rc5 08/12] md: satisfy raid5 read requests via raid5_run_ops

[PATCH 2.6.20-rc5 08/12] md: satisfy raid5 read requests via raid5_run_ops

Post by Dan Willia » Thu, 25 Jan 2007 04:00:19


From: Dan Williams < XXXX@XXXXX.COM >

Use raid5_run_ops to carry out the memory copies for a raid5 read request.

Signed-off-by: Dan Williams < XXXX@XXXXX.COM >
---

drivers/md/raid5.c | 40 +++++++++++++++-------------------------
1 files changed, 15 insertions(+), 25 deletions(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 2422253..db8925f 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1980,7 +1980,7 @@ static void handle_stripe5(struct stripe_head *sh)
int i;
int syncing, expanding, expanded;
int locked=0, uptodate=0, to_read=0, to_write=0, failed=0, written=0;
- int compute=0, req_compute=0, non_overwrite=0;
+ int to_fill=0, compute=0, req_compute=0, non_overwrite=0;
int failed_num=0;
struct r5dev *dev;
unsigned long pending=0;
@@ -2004,34 +2004,20 @@ static void handle_stripe5(struct stripe_head *sh)
dev = &sh->dev[i];
clear_bit(R5_Insync, &dev->flags);

- PRINTK("check %d: state 0x%lx read %p write %p written %p\n",
- i, dev->flags, dev->toread, dev->towrite, dev->written);
- /* maybe we can reply to a read */
+ PRINTK("check %d: state 0x%lx toread %p read %p write %p written %p\n",
+ i, dev->flags, dev->toread, dev->read, dev->towrite, dev->written);
+
+ /* maybe we can start a biofill operation */
if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
- struct bio *rbi, *rbi2;
- PRINTK("Return read for disc %d\n", i);
- spin_lock_irq(&conf->device_lock);
- rbi = dev->toread;
- dev->toread = NULL;
- if (test_and_clear_bit(R5_Overlap, &dev->flags))
- wake_up(&conf->wait_for_overlap);
- spin_unlock_irq(&conf->device_lock);
- while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
- copy_data(0, rbi, dev->page, dev->sector);
- 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;
- }
+ to_read--;
+ if (!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)) locked++;
if (test_bit(R5_UPTODATE, &dev->flags)) uptodate++;
+ if (test_bit(R5_Wantfill, &dev->flags)) to_fill++;
if (test_bit(R5_Wantcompute, &dev->flags)) BUG_ON(++compute > 1);

if (dev->toread) to_read++;
@@ -2055,9 +2041,13 @@ static void handle_stripe5(struct stripe_head *sh)
set_bit(R5_Insync, &dev->flags);
}
rcu_read_unlock();
+
+ if (to_fill && !test_and_set_bit(STRIPE_OP_BIOFILL, &sh->ops.pending))
+ sh->ops.count++;
+
PRINTK("locked=%d uptodate=%d to_read=%d"
- " to_write=%d failed=%d failed_num=%d\n",
- locked, uptodate, to_read, to_write, failed, failed_num);
+ " to_write=%d to_fill=%d failed=%d failed_num=%d\n",
+ locked, uptodate, to_read, to_write, to_fill, failed, failed_num);
/* check if the array has lost two devices and, if so, some requests might
* need to be failed
*/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to XXXX@XXXXX.COM
More majordomo info at http://www.yqcomputer.com/
Please read the FAQ at http://www.yqcomputer.com/