Commit a638b2dc authored Oct 03, 2006 by Paul Clements Committed by Linus Torvalds Oct 03, 2006

[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>

parent 14f50b49

drivers/md/bitmap.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -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) /

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