[PATCH] md: don't export bio_alloc_mddev

[Shaohua Li]

When mddev is running, it has a valid bio_set, so the bio_alloc_mddev
wrap is unncessary. The problem is we run some IO (eg, load superblock)
before mddev is fully initialized. At that time bio_set isn't
initialized. Moving bio_set creation to md_alloc doesn't help either,
because dm-raid doesn't use it.

Signed-off-by: Shaohua Li <shli@xxxxxx>
---
 drivers/md/md.c     | 12 ++++++------
 drivers/md/md.h     |  2 --
 drivers/md/raid1.c  |  2 +-
 drivers/md/raid10.c |  2 +-
 4 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 55e7e7a..bef1863 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -171,11 +171,12 @@ static const struct block_device_operations md_fops;
 
 static int start_readonly;
 
-/* bio_clone_mddev
- * like bio_clone, but with a local bio set
+/*
+ * This is only required for meta data related bio, where bio_set might not be
+ * initialized yet. dm-raid doesn't use md_alloc, so we can't alloc bio_set
+ * there.
  */
-
-struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
+static struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
 			    struct mddev *mddev)
 {
 	struct bio *b;
@@ -188,7 +189,6 @@ struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
 		return NULL;
 	return b;
 }
-EXPORT_SYMBOL_GPL(bio_alloc_mddev);
 
 /*
  * We have a system wide 'event count' that is incremented
@@ -393,7 +393,7 @@ static void submit_flushes(struct work_struct *ws)
 			atomic_inc(&rdev->nr_pending);
 			atomic_inc(&rdev->nr_pending);
 			rcu_read_unlock();
-			bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
+			bi = bio_alloc_bioset(GFP_NOIO, 0, mddev->bio_set);
 			bi->bi_end_io = md_end_flush;
 			bi->bi_private = rdev;
 			bi->bi_bdev = rdev->bdev;
diff --git a/drivers/md/md.h b/drivers/md/md.h
index b8859cb..44fe227 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -673,8 +673,6 @@ extern void md_rdev_clear(struct md_rdev *rdev);
 
 extern void mddev_suspend(struct mddev *mddev);
 extern void mddev_resume(struct mddev *mddev);
-extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
-				   struct mddev *mddev);
 
 extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule);
 extern void md_reload_sb(struct mddev *mddev, int raid_disk);
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index ad5c948..2180a9a 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2281,7 +2281,7 @@ static int narrow_write_error(struct r1bio *r1_bio, int i)
 				vcnt--;
 			}
 
-			wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev);
+			wbio = bio_alloc_bioset(GFP_NOIO, vcnt, mddev->bio_set);
 			memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec));
 
 			wbio->bi_vcnt = vcnt;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index ade7d69..a1f8e98 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -4473,7 +4473,7 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
 		return sectors_done;
 	}
 
-	read_bio = bio_alloc_mddev(GFP_KERNEL, RESYNC_PAGES, mddev);
+	read_bio = bio_alloc_bioset(GFP_KERNEL, RESYNC_PAGES, mddev->bio_set);
 
 	read_bio->bi_bdev = rdev->bdev;
 	read_bio->bi_iter.bi_sector = (r10_bio->devs[r10_bio->read_slot].addr
-- 
2.9.3