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Subject[PATCH -next] btrfs: lzo: Mask instead of divide to fix 32-bit build
Date
On 32-bit builds (e.g. m68k):

ERROR: modpost: "__umoddi3" [fs/btrfs/btrfs.ko] undefined!

"cur_in - start" is 64-bit, while sectorsize is u32.

As sectorsize is always a power of two, the 64-by-32 modulo operation
can be replaced by a much cheaper bitwise AND with "sectorsize - 1".

Fixes: 0078783c7089fc83 ("btrfs: rework lzo_compress_pages() to make it subpage compatible")
Reported-by: noreply@ellerman.id.au
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
Compile-tested only.
---
fs/btrfs/lzo.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index 47003cec4046f13e..d08f9eba49dab3cd 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -211,7 +211,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
*/
cur_out += LZO_LEN;
while (cur_in < start + len) {
- u32 sector_off = (cur_in - start) % sectorsize;
+ u32 sector_off = (cur_in - start) & (sectorsize - 1);
u32 in_len;
size_t out_len;

--
2.25.1
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