minor md cleanups

minor md cleanups

[Christoph Hellwig]

Hi Song,

this small series has a few random md cleanups.

Diffstat:
 md.c |   97 ++++++++++++++++++++++++-------------------------------------------
 md.h |    1 
 2 files changed, 36 insertions(+), 62 deletions(-)

[PATCH 1/3] md: remove lock_bdev / unlock_bdev

[Christoph Hellwig]

These wrappers for blkdev_get / blkdev_put just horribly confuse the
code with their odd naming.  Remove them and improve the error unwinding
in md_import_device with the now folded code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/md.c | 63 +++++++++++++++++--------------------------------
 1 file changed, 22 insertions(+), 41 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index f95b8644048597..27ce98b018aff9 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2493,34 +2493,6 @@ static void unbind_rdev_from_array(struct md_rdev *rdev)
 	queue_work(md_rdev_misc_wq, &rdev->del_work);
 }
 
-/*
- * prevent the device from being mounted, repartitioned or
- * otherwise reused by a RAID array (or any other kernel
- * subsystem), by bd_claiming the device.
- */
-static int lock_rdev(struct md_rdev *rdev, dev_t dev, int shared)
-{
-	int err = 0;
-	struct block_device *bdev;
-
-	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
-				 shared ? (struct md_rdev *)lock_rdev : rdev);
-	if (IS_ERR(bdev)) {
-		pr_warn("md: could not open device unknown-block(%u,%u).\n",
-			MAJOR(dev), MINOR(dev));
-		return PTR_ERR(bdev);
-	}
-	rdev->bdev = bdev;
-	return err;
-}
-
-static void unlock_rdev(struct md_rdev *rdev)
-{
-	struct block_device *bdev = rdev->bdev;
-	rdev->bdev = NULL;
-	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
-}
-
 void md_autodetect_dev(dev_t dev);
 
 static void export_rdev(struct md_rdev *rdev)
@@ -2531,7 +2503,8 @@ static void export_rdev(struct md_rdev *rdev)
 	if (test_bit(AutoDetected, &rdev->flags))
 		md_autodetect_dev(rdev->bdev->bd_dev);
 #endif
-	unlock_rdev(rdev);
+	blkdev_put(rdev->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
+	rdev->bdev = NULL;
 	kobject_put(&rdev->kobj);
 }
 
@@ -3675,9 +3648,10 @@ EXPORT_SYMBOL_GPL(md_rdev_init);
  */
 static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor)
 {
-	int err;
+	static struct md_rdev *claim_rdev; /* just for claiming the bdev */
 	struct md_rdev *rdev;
 	sector_t size;
+	int err;
 
 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
 	if (!rdev)
@@ -3685,14 +3659,20 @@ static struct md_rdev *md_import_device(dev_t newdev, int super_format, int supe
 
 	err = md_rdev_init(rdev);
 	if (err)
-		goto abort_free;
+		goto out_free_rdev;
 	err = alloc_disk_sb(rdev);
 	if (err)
-		goto abort_free;
+		goto out_clear_rdev;
 
-	err = lock_rdev(rdev, newdev, super_format == -2);
-	if (err)
-		goto abort_free;
+	rdev->bdev = blkdev_get_by_dev(newdev,
+			FMODE_READ | FMODE_WRITE | FMODE_EXCL,
+			super_format == -2 ? claim_rdev : rdev);
+	if (IS_ERR(rdev->bdev)) {
+		pr_warn("md: could not open device unknown-block(%u,%u).\n",
+			MAJOR(newdev), MINOR(newdev));
+		err = PTR_ERR(rdev->bdev);
+		goto out_clear_rdev;
+	}
 
 	kobject_init(&rdev->kobj, &rdev_ktype);
 
@@ -3701,7 +3681,7 @@ static struct md_rdev *md_import_device(dev_t newdev, int super_format, int supe
 		pr_warn("md: %pg has zero or unknown size, marking faulty!\n",
 			rdev->bdev);
 		err = -EINVAL;
-		goto abort_free;
+		goto out_blkdev_put;
 	}
 
 	if (super_format >= 0) {
@@ -3711,21 +3691,22 @@ static struct md_rdev *md_import_device(dev_t newdev, int super_format, int supe
 			pr_warn("md: %pg does not have a valid v%d.%d superblock, not importing!\n",
 				rdev->bdev,
 				super_format, super_minor);
-			goto abort_free;
+			goto out_blkdev_put;
 		}
 		if (err < 0) {
 			pr_warn("md: could not read %pg's sb, not importing!\n",
 				rdev->bdev);
-			goto abort_free;
+			goto out_blkdev_put;
 		}
 	}
 
 	return rdev;
 
-abort_free:
-	if (rdev->bdev)
-		unlock_rdev(rdev);
+out_blkdev_put:
+	blkdev_put(rdev->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
+out_clear_rdev:
 	md_rdev_clear(rdev);
+out_free_rdev:
 	kfree(rdev);
 	return ERR_PTR(err);
 }
-- 
2.30.2

[PATCH 2/3] md: mark md_kick_rdev_from_array static

[Christoph Hellwig]

md_kick_rdev_from_array is only used in md.c, so unexport it and mark
the symbol static.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/md.c | 3 +--
 drivers/md/md.h | 1 -
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 27ce98b018aff9..94adb403946534 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2508,12 +2508,11 @@ static void export_rdev(struct md_rdev *rdev)
 	kobject_put(&rdev->kobj);
 }
 
-void md_kick_rdev_from_array(struct md_rdev *rdev)
+static void md_kick_rdev_from_array(struct md_rdev *rdev)
 {
 	unbind_rdev_from_array(rdev);
 	export_rdev(rdev);
 }
-EXPORT_SYMBOL_GPL(md_kick_rdev_from_array);
 
 static void export_array(struct mddev *mddev)
 {
diff --git a/drivers/md/md.h b/drivers/md/md.h
index b4e2d8b87b6113..554a9026669ad9 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -782,7 +782,6 @@ extern void mddev_resume(struct mddev *mddev);
 
 extern void md_reload_sb(struct mddev *mddev, int raid_disk);
 extern void md_update_sb(struct mddev *mddev, int force);
-extern void md_kick_rdev_from_array(struct md_rdev * rdev);
 extern void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
 				     bool is_suspend);
 extern void mddev_destroy_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
-- 
2.30.2

[PATCH 3/3] md: fold unbind_rdev_from_array into md_kick_rdev_from_array

[Christoph Hellwig]

unbind_rdev_from_array is only called from md_kick_rdev_from_array, so
merge it into its only caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/md.c | 37 ++++++++++++++++---------------------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 94adb403946534..775f1dde190a2e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2468,7 +2468,22 @@ static void rdev_delayed_delete(struct work_struct *ws)
 	kobject_put(&rdev->kobj);
 }
 
-static void unbind_rdev_from_array(struct md_rdev *rdev)
+void md_autodetect_dev(dev_t dev);
+
+static void export_rdev(struct md_rdev *rdev)
+{
+	pr_debug("md: export_rdev(%pg)\n", rdev->bdev);
+	md_rdev_clear(rdev);
+#ifndef MODULE
+	if (test_bit(AutoDetected, &rdev->flags))
+		md_autodetect_dev(rdev->bdev->bd_dev);
+#endif
+	blkdev_put(rdev->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
+	rdev->bdev = NULL;
+	kobject_put(&rdev->kobj);
+}
+
+static void md_kick_rdev_from_array(struct md_rdev *rdev)
 {
 	bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
 	list_del_rcu(&rdev->same_set);
@@ -2491,26 +2506,6 @@ static void unbind_rdev_from_array(struct md_rdev *rdev)
 	INIT_WORK(&rdev->del_work, rdev_delayed_delete);
 	kobject_get(&rdev->kobj);
 	queue_work(md_rdev_misc_wq, &rdev->del_work);
-}
-
-void md_autodetect_dev(dev_t dev);
-
-static void export_rdev(struct md_rdev *rdev)
-{
-	pr_debug("md: export_rdev(%pg)\n", rdev->bdev);
-	md_rdev_clear(rdev);
-#ifndef MODULE
-	if (test_bit(AutoDetected, &rdev->flags))
-		md_autodetect_dev(rdev->bdev->bd_dev);
-#endif
-	blkdev_put(rdev->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
-	rdev->bdev = NULL;
-	kobject_put(&rdev->kobj);
-}
-
-static void md_kick_rdev_from_array(struct md_rdev *rdev)
-{
-	unbind_rdev_from_array(rdev);
 	export_rdev(rdev);
 }
 
-- 
2.30.2

Re: minor md cleanups

[Song Liu]

On Tue, Nov 29, 2022 at 5:33 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Hi Song,
>
> this small series has a few random md cleanups.

Applied to md-next. Thanks!

Song

>
> Diffstat:
>  md.c |   97 ++++++++++++++++++++++++-------------------------------------------
>  md.h |    1
>  2 files changed, 36 insertions(+), 62 deletions(-)