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authorMikulas Patocka <mpatocka@redhat.com>2012-07-27 18:08:00 +0400
committerAlasdair G Kergon <agk@redhat.com>2012-07-27 18:08:00 +0400
commit1df05483d758ea43abc375869fbe06be506ba827 (patch)
tree230f9e574467fbe34cb5a96120b9466bbc27d5f8 /drivers
parentf14fa693c93078444b5e95d7cad78ead0383ad50 (diff)
downloadlinux-1df05483d758ea43abc375869fbe06be506ba827.tar.xz
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/md/dm-stripe.c9
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 1f6316ed2b31..6931bd18b615 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -26,7 +26,6 @@ struct stripe {
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 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
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 @@ static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
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;
}