[PATCH] md: use ffz instead of find_first_set to convert multiplier to shift

find_first_set doesn't find the least-significant bit on bigendian machines,
so it is really wrong to use it.

ffs is closer, but takes an 'int' and we have a 'unsigned long'.  So use
ffz(~X) to convert a chunksize into a chunkshift.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Paul Clements 2006-10-03 01:16:01 -07:00 committed by Linus Torvalds
parent 14f50b49fd
commit a638b2dc95

View file

@ -1444,8 +1444,7 @@ int bitmap_create(mddev_t *mddev)
if (err)
goto error;
bitmap->chunkshift = find_first_bit(&bitmap->chunksize,
sizeof(bitmap->chunksize));
bitmap->chunkshift = ffz(~bitmap->chunksize);
/* now that chunksize and chunkshift are set, we can use these macros */
chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) /