[dm-devel] [PATCH 1/2] dm: update max_io_len to support a split_io that is not a power of 2

[Mike Snitzer]

Required to support a target's use of a non power of 2 blocksize.

Signed-off-by: Mike Snitzer <snitzer at redhat.com>
---
 drivers/md/dm.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index e24143c..fe57285 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -973,10 +973,10 @@ static sector_t max_io_len(sector_t sector, struct dm_target *ti)
 	 * Does the target need to split even further ?
 	 */
 	if (ti->split_io) {
-		sector_t boundary;
 		sector_t offset = dm_target_offset(ti, sector);
-		boundary = ((offset + ti->split_io) & ~(ti->split_io - 1))
-			   - offset;
+		sector_t boundary, tmp = offset + ti->split_io;
+
+		boundary = ti->split_io - do_div(tmp, ti->split_io);
 		if (len > boundary)
 			len = boundary;
 	}
-- 
1.7.1