Shortcut the calls to linear_map and stripe_map, so that they don't suffer
the overhead of retpolines used for indirect calls.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-linear.c | 2 +-
drivers/md/dm-stripe.c | 2 +-
drivers/md/dm.c | 11 +++++++++--
drivers/md/dm.h | 2 ++
4 files changed, 13 insertions(+), 4 deletions(-)
Index: linux-2.6/drivers/md/dm-linear.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-linear.c
+++ linux-2.6/drivers/md/dm-linear.c
@@ -85,7 +85,7 @@ static sector_t linear_map_sector(struct
return lc->start + dm_target_offset(ti, bi_sector);
}
-static int linear_map(struct dm_target *ti, struct bio *bio)
+int linear_map(struct dm_target *ti, struct bio *bio)
{
struct linear_c *lc = ti->private;
Index: linux-2.6/drivers/md/dm-stripe.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-stripe.c
+++ linux-2.6/drivers/md/dm-stripe.c
@@ -268,7 +268,7 @@ static int stripe_map_range(struct strip
return DM_MAPIO_SUBMITTED;
}
-static int stripe_map(struct dm_target *ti, struct bio *bio)
+int stripe_map(struct dm_target *ti, struct bio *bio)
{
struct stripe_c *sc = ti->private;
uint32_t stripe;
Index: linux-2.6/drivers/md/dm.c
===================================================================
--- linux-2.6.orig/drivers/md/dm.c
+++ linux-2.6/drivers/md/dm.c
@@ -1424,9 +1424,16 @@ static void __map_bio(struct bio *clone)
if (unlikely(dm_emulate_zone_append(md)))
r = dm_zone_map_bio(tio);
else
+ goto do_map;
+ } else {
+do_map:
+ if (likely(ti->type->map == linear_map))
+ r = linear_map(ti, clone);
+ else if (ti->type->map == stripe_map)
+ r = stripe_map(ti, clone);
+ else
r = ti->type->map(ti, clone);
- } else
- r = ti->type->map(ti, clone);
+ }
switch (r) {
case DM_MAPIO_SUBMITTED:
Index: linux-2.6/drivers/md/dm.h
===================================================================
--- linux-2.6.orig/drivers/md/dm.h
+++ linux-2.6/drivers/md/dm.h
@@ -188,9 +188,11 @@ void dm_kobject_release(struct kobject *
/*
* Targets for linear and striped mappings
*/
+int linear_map(struct dm_target *ti, struct bio *bio);
int dm_linear_init(void);
void dm_linear_exit(void);
+int stripe_map(struct dm_target *ti, struct bio *bio);
int dm_stripe_init(void);
void dm_stripe_exit(void);
--
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