[34-longterm 065/179] md/raid5: fix raid5_set_bi_hw_segments

From: Paul Gortmaker
Date: Mon May 14 2012 - 23:03:38 EST

From: Namhyung Kim <namhyung@xxxxxxxxx>

This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.

commit 9b2dc8b665932a8e681a7ab3237f60475e75e161 upstream.

The @bio->bi_phys_segments consists of active stripes count in the
lower 16 bits and processed stripes count in the upper 16 bits. So
logical-OR operator should be bitwise one.

This bug has been present since 2.6.27 and the fix is suitable for any
-stable kernel since then. Fortunately the bad code is only used on
error paths and is relatively unlikely to be hit.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
drivers/md/raid5.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 6af0a6d..de7984d 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -128,7 +128,7 @@ static inline int raid5_dec_bi_hw_segments(struct bio *bio)

static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
- bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16);
+ bio->bi_phys_segments = raid5_bi_phys_segments(bio) | (cnt << 16);

/* Find first data disk in a raid6 stripe */

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