md/raid5: fix FUA request handling in ops_run_io()

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@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index af8a9a89e4d..b7dcc677dda 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -514,7 +514,7 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
                 bi = &sh->dev[i].req;
 
                 bi->bi_rw = rw;
-                if (rw == WRITE)
+                if (rw & WRITE)
                         bi->bi_end_io = raid5_end_write_request;
                 else
                         bi->bi_end_io = raid5_end_read_request;
@@ -548,13 +548,13 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
                         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))
                                 atomic_add(STRIPE_SECTORS,
                                         &rdev->corrected_errors);
                         generic_make_request(bi);
                 } 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);