Re: Memory leak when raid10 takeover raid0

[Xiao Ni <xni@redhat.com>]

How about something like this?

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 857c49399c28..c263173a142f 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -393,6 +393,9 @@ static int raid0_run(struct mddev *mddev)
                mddev->private = conf;
        }
        conf = mddev->private;
+
+       init_waitqueue_head(&conf->wait_for_quiescent);
+
        if (mddev->queue) {
                struct md_rdev *rdev;

@@ -512,6 +515,18 @@ static void raid0_handle_discard(struct mddev
*mddev, struct bio *bio)
        bio_endio(bio);
 }

+static void raid0_end_request(struct bio *bio)
+{
+       struct bio *orig_bio = bio->bi_private;
+       struct gendisk *disk = orig_bio->bi_bdev->bd_disk;
+       struct mddev *mddev = disk->private;
+       struct r0conf *conf = mddev->private;
+
+       atomic_dec(&conf->bios);
+       bio_put(bio);
+       bio_endio(orig_bio);
+}
+
 static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
 {
        struct r0conf *conf = mddev->private;
@@ -522,6 +537,7 @@ static bool raid0_make_request(struct mddev
*mddev, struct bio *bio)
        sector_t orig_sector;
        unsigned chunk_sects;
        unsigned sectors;
+       struct bio *r0_bio;

        if (unlikely(bio->bi_opf & REQ_PREFLUSH)
            && md_flush_request(mddev, bio))
@@ -575,15 +591,20 @@ static bool raid0_make_request(struct mddev
*mddev, struct bio *bio)
                return true;
        }

-       bio_set_dev(bio, tmp_dev->bdev);
-       bio->bi_iter.bi_sector = sector + zone->dev_start +
+       r0_bio = bio_alloc_clone(tmp_dev->bdev, bio, GFP_NOIO,
+                                       &mddev->bio_set);
+
+       r0_bio->bi_private = bio;
+       r0_bio->bi_end_io = raid0_end_request;
+       r0_bio->bi_iter.bi_sector = sector + zone->dev_start +
                tmp_dev->data_offset;

        if (mddev->gendisk)
-               trace_block_bio_remap(bio, disk_devt(mddev->gendisk),
+               trace_block_bio_remap(r0_bio, disk_devt(mddev->gendisk),
                                      bio_sector);
-       mddev_check_write_zeroes(mddev, bio);
-       submit_bio_noacct(bio);
+       mddev_check_write_zeroes(mddev, r0_bio);
+       atomic_inc(&conf->bios);
+       submit_bio_noacct(r0_bio);
        return true;
 }

@@ -754,6 +775,10 @@ static void *raid0_takeover(struct mddev *mddev)

 static void raid0_quiesce(struct mddev *mddev, int quiesce)
 {
+       struct r0conf *conf = mddev->private;
+
+       if (quiesce)
+               wait_event(&conf->wait_for_quiescent,
atomic_read(&conf->bios)==0);
 }

 static struct md_personality raid0_personality=
diff --git a/drivers/md/raid0.h b/drivers/md/raid0.h
index 3816e5477db1..a0ec5c235962 100644
--- a/drivers/md/raid0.h
+++ b/drivers/md/raid0.h
@@ -27,6 +27,9 @@ struct r0conf {
                                            * by strip_zone->dev */
        int                     nr_strip_zones;
        enum r0layout           layout;
+       atomic_t                bios;   /* The bios that submit to
+                                        * member disks */
+       struct wait_queue_head_t        wait_for_quiescent;
 };

Regards
Xiao