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authorAlasdair G Kergon <agk@redhat.com>2006-03-22 00:07:42 -0800
committerGreg Kroah-Hartman <gregkh@suse.de>2006-03-27 22:47:31 -0800
commit0f73ea05d9c95cdf483c3f51f65979a8a752744e (patch)
tree965dda92217f609626916fa414085295c945b96b
parente699844c7b6621f8307ac088735becc3d827ca24 (diff)
[PATCH] dm: bio split bvec fix
The code that handles bios that span table target boundaries by breaking them up into smaller bios will not split an individual struct bio_vec into more than two pieces. Sometimes more than that are required. This patch adds a loop to break the second piece up into as many pieces as are necessary. Cc: "Abhishek Gupta" <abhishekgupt@gmail.com> Cc: Dan Smith <danms@us.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/md/dm.c43
1 files changed, 24 insertions, 19 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 745ca1f67b14..d559569646bf 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -533,30 +533,35 @@ static void __clone_and_map(struct clone_info *ci)
} else {
/*
- * Create two copy bios to deal with io that has
- * been split across a target.
+ * Handle a bvec that must be split between two or more targets.
*/
struct bio_vec *bv = bio->bi_io_vec + ci->idx;
+ sector_t remaining = to_sector(bv->bv_len);
+ unsigned int offset = 0;
- clone = split_bvec(bio, ci->sector, ci->idx,
- bv->bv_offset, max);
- __map_bio(ti, clone, tio);
+ do {
+ if (offset) {
+ ti = dm_table_find_target(ci->map, ci->sector);
+ max = max_io_len(ci->md, ci->sector, ti);
- ci->sector += max;
- ci->sector_count -= max;
- ti = dm_table_find_target(ci->map, ci->sector);
-
- len = to_sector(bv->bv_len) - max;
- clone = split_bvec(bio, ci->sector, ci->idx,
- bv->bv_offset + to_bytes(max), len);
- tio = alloc_tio(ci->md);
- tio->io = ci->io;
- tio->ti = ti;
- memset(&tio->info, 0, sizeof(tio->info));
- __map_bio(ti, clone, tio);
+ tio = alloc_tio(ci->md);
+ tio->io = ci->io;
+ tio->ti = ti;
+ memset(&tio->info, 0, sizeof(tio->info));
+ }
+
+ len = min(remaining, max);
+
+ clone = split_bvec(bio, ci->sector, ci->idx,
+ bv->bv_offset + offset, len);
+
+ __map_bio(ti, clone, tio);
+
+ ci->sector += len;
+ ci->sector_count -= len;
+ offset += to_bytes(len);
+ } while (remaining -= len);
- ci->sector += len;
- ci->sector_count -= len;
ci->idx++;
}
}