dm stripe: remove stripes_mask
The structure stripe_c contains a stripes_mask field. This field is
useless because it can be trivially calculated by subtracting one from
stripes. It is used only at one place. This patch removes it.
The patch also changes ffs(stripes) - 1 to __ffs(stripes).
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 1f6316e..6931bd1 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -26,7 +26,6 @@
struct stripe_c {
uint32_t stripes;
int stripes_shift;
- sector_t stripes_mask;
/* The size of this target / num. stripes */
sector_t stripe_width;
@@ -163,10 +162,8 @@
if (stripes & (stripes - 1))
sc->stripes_shift = -1;
- else {
- sc->stripes_shift = ffs(stripes) - 1;
- sc->stripes_mask = ((sector_t) stripes) - 1;
- }
+ else
+ sc->stripes_shift = __ffs(stripes);
ti->split_io = chunk_size;
ti->num_flush_requests = stripes;
@@ -218,7 +215,7 @@
if (sc->stripes_shift < 0)
*stripe = sector_div(chunk, sc->stripes);
else {
- *stripe = chunk & sc->stripes_mask;
+ *stripe = chunk & (sc->stripes - 1);
chunk >>= sc->stripes_shift;
}