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Diffstat (limited to 'drivers/md/raid1.c')
-rw-r--r--drivers/md/raid1.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 51f2547c2007..19598bd38939 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -474,8 +474,6 @@ static void raid1_end_write_request(struct bio *bio)
/*
* When the device is faulty, it is not necessary to
* handle write error.
- * For failfast, this is the only remaining device,
- * We need to retry the write without FailFast.
*/
if (!test_bit(Faulty, &rdev->flags))
set_bit(R1BIO_WriteError, &r1_bio->state);
@@ -1331,6 +1329,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
struct raid1_plug_cb *plug = NULL;
int first_clone;
int max_sectors;
+ bool write_behind = false;
if (mddev_is_clustered(mddev) &&
md_cluster_ops->area_resyncing(mddev, WRITE,
@@ -1383,6 +1382,15 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
max_sectors = r1_bio->sectors;
for (i = 0; i < disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+
+ /*
+ * The write-behind io is only attempted on drives marked as
+ * write-mostly, which means we could allocate write behind
+ * bio later.
+ */
+ if (rdev && test_bit(WriteMostly, &rdev->flags))
+ write_behind = true;
+
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
atomic_inc(&rdev->nr_pending);
blocked_rdev = rdev;
@@ -1456,6 +1464,15 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
goto retry_write;
}
+ /*
+ * When using a bitmap, we may call alloc_behind_master_bio below.
+ * alloc_behind_master_bio allocates a copy of the data payload a page
+ * at a time and thus needs a new bio that can fit the whole payload
+ * this bio in page sized chunks.
+ */
+ if (write_behind && bitmap)
+ max_sectors = min_t(int, max_sectors,
+ BIO_MAX_VECS * (PAGE_SIZE >> 9));
if (max_sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, max_sectors,
GFP_NOIO, &conf->bio_split);