[77/85] md/raid5: fix FUA request handling in ops_run_io()

From: Greg KH
Date: Thu Jun 16 2011 - 03:12:00 EST

2.6.33-longterm review patch. If anyone has any objections, please let us know.


From: Namhyung Kim <namhyung@xxxxxxxxx>

commit b062962edb086011e94ec4d9eb3f6a6d814f2a8f upstream.

Commit e9c7469bb4f5 ("md: implment REQ_FLUSH/FUA support")
introduced R5_WantFUA flag and set rw to WRITE_FUA in that case.
However remaining code still checks whether rw is exactly same
as WRITE or not, so FUAed-write ends up with being treated as
READ. Fix it.

This bug has been present since 2.6.37 and the fix is suitable for any
-stable kernel since then. It is not clear why this has not caused
more problems.

Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

drivers/md/raid5.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -446,7 +446,7 @@ static void ops_run_io(struct stripe_hea
bi = &sh->dev[i].req;

bi->bi_rw = rw;
- if (rw == WRITE)
+ if (rw & WRITE)
bi->bi_end_io = raid5_end_write_request;
bi->bi_end_io = raid5_end_read_request;
@@ -480,13 +480,13 @@ static void ops_run_io(struct stripe_hea
bi->bi_io_vec[0].bv_offset = 0;
bi->bi_size = STRIPE_SIZE;
bi->bi_next = NULL;
- if (rw == WRITE &&
+ if ((rw & WRITE) &&
test_bit(R5_ReWrite, &sh->dev[i].flags))
} else {
- if (rw == WRITE)
+ if (rw & WRITE)
set_bit(STRIPE_DEGRADED, &sh->state);
pr_debug("skip op %ld on disc %d for sector %llu\n",
bi->bi_rw, i, (unsigned long long)sh->sector);

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