md/raid5: suspend shouldn't affect read requests.

md allows write to regions on an array to be suspended temporarily.
This allows user-space to participate is aspects of reshape.
In particular, data can be copied with not risk of a race.
We should not be blocking read requests though, so don't.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 92ef9b6..1f444ae 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3702,7 +3702,8 @@ static int make_request(struct request_queue *q, struct bio * bi)
                        /* FIXME what if we get a false positive because these
                         * are being updated.
                         */
-                       if (logical_sector >= mddev->suspend_lo &&
+                       if (bio_data_dir(bi) == WRITE &&
+                           logical_sector >= mddev->suspend_lo &&
                            logical_sector < mddev->suspend_hi) {
                                release_stripe(sh);
                                schedule();