md: use separate bio pool for each md device.

bio_clone and bio_alloc allocate from a common bio pool.
If an md device is stacked with other devices that use this pool, or under
something like swap which uses the pool, then the multiple calls on
the pool can cause deadlocks.

So allocate a local bio pool for each md array and use that rather
than the common pool.

This pool is used both for regular IO and metadata updates.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 08c66afea494..54f60c9e5f85 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -861,7 +861,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
                 }
                 r1_bio->read_disk = rdisk;
 
-                read_bio = bio_clone(bio, GFP_NOIO);
+                read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
 
                 r1_bio->bios[rdisk] = read_bio;
 
@@ -950,7 +950,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
                 if (!r1_bio->bios[i])
                         continue;
 
-                mbio = bio_clone(bio, GFP_NOIO);
+                mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
                 r1_bio->bios[i] = mbio;
 
                 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
@@ -1640,7 +1640,8 @@ static void raid1d(mddev_t *mddev)
                                         mddev->ro ? IO_BLOCKED : NULL;
                                 r1_bio->read_disk = disk;
                                 bio_put(bio);
-                                bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
+                                bio = bio_clone_mddev(r1_bio->master_bio,
+                                                      GFP_NOIO, mddev);
                                 r1_bio->bios[r1_bio->read_disk] = bio;
                                 rdev = conf->mirrors[disk].rdev;
                                 if (printk_ratelimit())