dm-__clone_and_map_empty_barrier.patch
Introduce __clone_and_map_empty_barrier that will pass empty barrier
to the targets. Each target receives as many requests as it set up
in num_flush_requests.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm.c | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
Index: linux-2.6.30-rc2-devel/drivers/md/dm.c
===================================================================
--- linux-2.6.30-rc2-devel.orig/drivers/md/dm.c 2009-04-15 16:35:46.000000000 +0200
+++ linux-2.6.30-rc2-devel/drivers/md/dm.c 2009-04-15 16:35:49.000000000 +0200
@@ -761,6 +761,8 @@ static struct bio *clone_bio(struct bio
return clone;
}
+static int __clone_and_map_empty_barrier(struct clone_info *ci);
+
static int __clone_and_map(struct clone_info *ci)
{
struct bio *clone, *bio = ci->bio;
@@ -768,6 +770,9 @@ static int __clone_and_map(struct clone_
sector_t len = 0, max;
struct dm_target_io *tio;
+ if (unlikely(bio_empty_barrier(bio)))
+ return __clone_and_map_empty_barrier(ci);
+
ti = dm_table_find_target(ci->map, ci->sector);
if (!dm_target_is_valid(ti))
return -EIO;
@@ -861,6 +866,31 @@ static int __clone_and_map(struct clone_
return 0;
}
+static int __clone_and_map_empty_barrier(struct clone_info *ci)
+{
+ unsigned i, j, n;
+ n = dm_table_get_num_targets(ci->map);
+ for (i = 0; i < n; i++) {
+ struct bio *clone;
+ struct dm_target *ti = dm_table_get_target(ci->map, i);
+ for (j = 0; j < ti->num_flush_requests; j++) {
+ struct dm_target_io *tio = alloc_tio(ci->md);
+ tio->io = ci->io;
+ tio->ti = ti;
+ memset(&tio->info, 0, sizeof(tio->info));
+ tio->info.flush_request = j;
+
+ clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
+ __bio_clone(clone, ci->bio);
+ clone->bi_destructor = dm_bio_destructor;
+
+ __map_bio(ti, clone, tio);
+ }
+ }
+ ci->sector_count = 0;
+ return 0;
+}
+
/*
* Split the bio into several clones and submit it to targets.
*/
@@ -888,6 +918,8 @@ static void __split_and_process_bio(stru
ci.io->md = md;
ci.sector = bio->bi_sector;
ci.sector_count = bio_sectors(bio);
+ if (unlikely(bio_empty_barrier(bio)))
+ ci.sector_count = 1;
ci.idx = bio->bi_idx;
start_io_acct(ci.io);
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
