[patch 145/149] dm snapshot: simplify sector_to_chunk expression

Greg KH
2010-07-01T18:26:05Z

2.6.32-stable review patch. If anyone has any objections, please let us know.

------------------

From: Mikulas Patocka <mpatocka@redhat.com>

commit 102c6ddb1d081a6a1fede38c43a42c9811313ec7 upstream.

Removed unnecessary 'and' masking: The right shift discards the lower
bits so there is no need to clear them.

(A later patch needs this change to support a 32-bit chunk_mask.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/md/dm-exception-store.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/md/dm-exception-store.h
+++ b/drivers/md/dm-exception-store.h
@@ -162,7 +162,7 @@ static inline sector_t get_dev_size(stru
static inline chunk_t sector_to_chunk(struct dm_exception_store *store,
sector_t sector)
{
- return (sector & ~store->chunk_mask) >> store->chunk_shift;
+ return sector >> store->chunk_shift;
}

int dm_exception_store_type_register(struct dm_exception_store_type *type);