[PATCH 4.12 51/52] md/raid1/10: reset bio allocated from mempool

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Shaohua Li <shli@fb.com>

commit 208410b546207cfc4c832635fa46419cfa86b4cd upstream.

Data allocated from mempool doesn't always get initialized, this happens when
the data is reused instead of fresh allocation. In the raid1/10 case, we must
reinitialize the bios.

Reported-by: Jonathan G. Underwood <jonathan.underwood@gmail.com>
Fixes: f0250618361d(md: raid10: don't use bio's vec table to manage resync pages)
Fixes: 98d30c5812c3(md: raid1: don't use bio's vec table to manage resync pages)
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/raid1.c  |   19 ++++++++++++++++++-
 drivers/md/raid10.c |   35 ++++++++++++++++++++++++++++++++---
 2 files changed, 50 insertions(+), 4 deletions(-)

--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2586,6 +2586,23 @@ static int init_resync(struct r1conf *co
 	return 0;
 }
 
+static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
+{
+	struct r1bio *r1bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
+	struct resync_pages *rps;
+	struct bio *bio;
+	int i;
+
+	for (i = conf->poolinfo->raid_disks; i--; ) {
+		bio = r1bio->bios[i];
+		rps = bio->bi_private;
+		bio_reset(bio);
+		bio->bi_private = rps;
+	}
+	r1bio->master_bio = NULL;
+	return r1bio;
+}
+
 /*
  * perform a "sync" on one "block"
  *
@@ -2671,7 +2688,7 @@ static sector_t raid1_sync_request(struc
 
 	bitmap_cond_end_sync(mddev->bitmap, sector_nr,
 		mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
-	r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
+	r1_bio = raid1_alloc_init_r1buf(conf);
 
 	raise_barrier(conf, sector_nr);
 
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2807,6 +2807,35 @@ static int init_resync(struct r10conf *c
 	return 0;
 }
 
+static struct r10bio *raid10_alloc_init_r10buf(struct r10conf *conf)
+{
+	struct r10bio *r10bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
+	struct rsync_pages *rp;
+	struct bio *bio;
+	int nalloc;
+	int i;
+
+	if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery) ||
+	    test_bit(MD_RECOVERY_RESHAPE, &conf->mddev->recovery))
+		nalloc = conf->copies; /* resync */
+	else
+		nalloc = 2; /* recovery */
+
+	for (i = 0; i < nalloc; i++) {
+		bio = r10bio->devs[i].bio;
+		rp = bio->bi_private;
+		bio_reset(bio);
+		bio->bi_private = rp;
+		bio = r10bio->devs[i].repl_bio;
+		if (bio) {
+			rp = bio->bi_private;
+			bio_reset(bio);
+			bio->bi_private = rp;
+		}
+	}
+	return r10bio;
+}
+
 /*
  * perform a "sync" on one "block"
  *
@@ -3036,7 +3065,7 @@ static sector_t raid10_sync_request(stru
 				atomic_inc(&mreplace->nr_pending);
 			rcu_read_unlock();
 
-			r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
+			r10_bio = raid10_alloc_init_r10buf(conf);
 			r10_bio->state = 0;
 			raise_barrier(conf, rb2 != NULL);
 			atomic_set(&r10_bio->remaining, 0);
@@ -3245,7 +3274,7 @@ static sector_t raid10_sync_request(stru
 		}
 		if (sync_blocks < max_sync)
 			max_sync = sync_blocks;
-		r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
+		r10_bio = raid10_alloc_init_r10buf(conf);
 		r10_bio->state = 0;
 
 		r10_bio->mddev = mddev;
@@ -4369,7 +4398,7 @@ static sector_t reshape_request(struct m
 
 read_more:
 	/* Now schedule reads for blocks from sector_nr to last */
-	r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
+	r10_bio = raid10_alloc_init_r10buf(conf);
 	r10_bio->state = 0;
 	raise_barrier(conf, sectors_done != 0);
 	atomic_set(&r10_bio->remaining, 0);