dm: abstract clone_rq
This patch factors out the request cloning code in dm_prep_fn()
as clone_rq(). No functional change.
This patch is a preparation for a later patch in this series which needs to
make clones from an original barrier request.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index a42dfb7..30f5dc8 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1445,6 +1445,32 @@
return 0;
}
+static struct request *clone_rq(struct request *rq, struct mapped_device *md,
+ gfp_t gfp_mask)
+{
+ struct request *clone;
+ struct dm_rq_target_io *tio;
+
+ tio = alloc_rq_tio(md, gfp_mask);
+ if (!tio)
+ return NULL;
+
+ tio->md = md;
+ tio->ti = NULL;
+ tio->orig = rq;
+ tio->error = 0;
+ memset(&tio->info, 0, sizeof(tio->info));
+
+ clone = &tio->clone;
+ if (setup_clone(clone, rq, tio)) {
+ /* -ENOMEM */
+ free_rq_tio(tio);
+ return NULL;
+ }
+
+ return clone;
+}
+
static int dm_rq_flush_suspending(struct mapped_device *md)
{
return !md->suspend_rq.special;
@@ -1456,7 +1482,6 @@
static int dm_prep_fn(struct request_queue *q, struct request *rq)
{
struct mapped_device *md = q->queuedata;
- struct dm_rq_target_io *tio;
struct request *clone;
if (unlikely(rq == &md->suspend_rq)) {
@@ -1472,24 +1497,10 @@
return BLKPREP_KILL;
}
- tio = alloc_rq_tio(md, GFP_ATOMIC);
- if (!tio)
- /* -ENOMEM */
+ clone = clone_rq(rq, md, GFP_ATOMIC);
+ if (!clone)
return BLKPREP_DEFER;
- tio->md = md;
- tio->ti = NULL;
- tio->orig = rq;
- tio->error = 0;
- memset(&tio->info, 0, sizeof(tio->info));
-
- clone = &tio->clone;
- if (setup_clone(clone, rq, tio)) {
- /* -ENOMEM */
- free_rq_tio(tio);
- return BLKPREP_DEFER;
- }
-
rq->special = clone;
rq->cmd_flags |= REQ_DONTPREP;