Commit a638b2dc authored by Paul Clements's avatar Paul Clements Committed by Linus Torvalds
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[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: default avatarNeil Brown <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 14f50b49
......@@ -1444,8 +1444,7 @@ int bitmap_create(mddev_t *mddev)
if (err)
goto error;
bitmap->chunkshift = find_first_bit(&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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