Patch "dm: cleanup open_table_device" has been added to the 6.0-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    dm: cleanup open_table_device

to the 6.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     dm-cleanup-open_table_device.patch
and it can be found in the queue-6.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 59f455a845a2554f4412de46c93889723f8b34ad
Author: Christoph Hellwig <hch@xxxxxx>
Date:   Tue Nov 15 22:10:47 2022 +0800

    dm: cleanup open_table_device
    
    [ Upstream commit b9a785d2dc6567b2fd9fc60057a6a945a276927a ]
    
    Move all the logic for allocation the table_device and linking it into
    the list into the open_table_device.  This keeps the code tidy and
    ensures that the table_devices only exist in fully initialized state.
    
    Signed-off-by: Christoph Hellwig <hch@xxxxxx>
    Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
    Reviewed-by: Mike Snitzer <snitzer@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20221115141054.1051801-4-yukuai1@xxxxxxxxxxxxxxx
    Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
    Stable-dep-of: 1a581b721699 ("dm: track per-add_disk holder relations in DM")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index b4a2cb5333fc..1903afa4618a 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -732,28 +732,41 @@ static char *_dm_claim_ptr = "I belong to device-mapper";
 /*
  * Open a table device so we can use it as a map destination.
  */
-static int open_table_device(struct table_device *td, dev_t dev,
-			     struct mapped_device *md)
+static struct table_device *open_table_device(struct mapped_device *md,
+		dev_t dev, fmode_t mode)
 {
+	struct table_device *td;
 	struct block_device *bdev;
 	u64 part_off;
 	int r;
 
-	BUG_ON(td->dm_dev.bdev);
+	td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
+	if (!td)
+		return ERR_PTR(-ENOMEM);
+	refcount_set(&td->count, 1);
 
-	bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _dm_claim_ptr);
-	if (IS_ERR(bdev))
-		return PTR_ERR(bdev);
+	bdev = blkdev_get_by_dev(dev, mode | FMODE_EXCL, _dm_claim_ptr);
+	if (IS_ERR(bdev)) {
+		r = PTR_ERR(bdev);
+		goto out_free_td;
+	}
 
 	r = bd_link_disk_holder(bdev, dm_disk(md));
-	if (r) {
-		blkdev_put(bdev, td->dm_dev.mode | FMODE_EXCL);
-		return r;
-	}
+	if (r)
+		goto out_blkdev_put;
 
+	td->dm_dev.mode = mode;
 	td->dm_dev.bdev = bdev;
 	td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev, &part_off, NULL, NULL);
-	return 0;
+	format_dev_t(td->dm_dev.name, dev);
+	list_add(&td->list, &md->table_devices);
+	return td;
+
+out_blkdev_put:
+	blkdev_put(bdev, mode | FMODE_EXCL);
+out_free_td:
+	kfree(td);
+	return ERR_PTR(r);
 }
 
 /*
@@ -786,31 +799,16 @@ static struct table_device *find_table_device(struct list_head *l, dev_t dev,
 int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
 			struct dm_dev **result)
 {
-	int r;
 	struct table_device *td;
 
 	mutex_lock(&md->table_devices_lock);
 	td = find_table_device(&md->table_devices, dev, mode);
 	if (!td) {
-		td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
-		if (!td) {
-			mutex_unlock(&md->table_devices_lock);
-			return -ENOMEM;
-		}
-
-		td->dm_dev.mode = mode;
-		td->dm_dev.bdev = NULL;
-
-		if ((r = open_table_device(td, dev, md))) {
+		td = open_table_device(md, dev, mode);
+		if (IS_ERR(td)) {
 			mutex_unlock(&md->table_devices_lock);
-			kfree(td);
-			return r;
+			return PTR_ERR(td);
 		}
-
-		format_dev_t(td->dm_dev.name, dev);
-
-		refcount_set(&td->count, 1);
-		list_add(&td->list, &md->table_devices);
 	} else {
 		refcount_inc(&td->count);
 	}

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