dm: convert ffs to __ffs
ffs counts bit starting with 1 (for the least significant bit), __ffs
counts bits starting with 0. This patch changes various occurrences of ffs
to __ffs and removes subtraction of 1 from the result.
Note that __ffs (unlike ffs) is not defined when called with zero
argument, but it is not called with zero argument in any of these cases.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index e1547d0..2dd3308 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1598,11 +1598,11 @@
c->bdev = bdev;
c->block_size = block_size;
- c->sectors_per_block_bits = ffs(block_size) - 1 - SECTOR_SHIFT;
- c->pages_per_block_bits = (ffs(block_size) - 1 >= PAGE_SHIFT) ?
- ffs(block_size) - 1 - PAGE_SHIFT : 0;
- c->blocks_per_page_bits = (ffs(block_size) - 1 < PAGE_SHIFT ?
- PAGE_SHIFT - (ffs(block_size) - 1) : 0);
+ c->sectors_per_block_bits = __ffs(block_size) - SECTOR_SHIFT;
+ c->pages_per_block_bits = (__ffs(block_size) >= PAGE_SHIFT) ?
+ __ffs(block_size) - PAGE_SHIFT : 0;
+ c->blocks_per_page_bits = (__ffs(block_size) < PAGE_SHIFT ?
+ PAGE_SHIFT - __ffs(block_size) : 0);
c->aux_size = aux_size;
c->alloc_callback = alloc_callback;