[PATCH] bdev: fix ->bd_part_count leak

[PATCH] bdev: fix ->bd_part_count leak

[Peter Zijlstra]

Don't leak a ->bd_part_count when the partition open fails with -ENXIO.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 fs/block_dev.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: linux-2.6-mm/fs/block_dev.c
===================================================================
--- linux-2.6-mm.orig/fs/block_dev.c
+++ linux-2.6-mm/fs/block_dev.c
@@ -907,6 +907,7 @@ EXPORT_SYMBOL(bd_set_size);
 
 static int __blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags,
 			int for_part);
+static int __blkdev_put(struct block_device *bdev, int for_part);
 
 static int do_open(struct block_device *bdev, struct file *file, int for_part)
 {
@@ -992,7 +993,7 @@ out_first:
 	bdev->bd_disk = NULL;
 	bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
 	if (bdev != bdev->bd_contains)
-		blkdev_put(bdev->bd_contains);
+		__blkdev_put(bdev->bd_contains, 1);
 	bdev->bd_contains = NULL;
 	put_disk(disk);
 	module_put(owner);

Re: [PATCH] bdev: fix ->bd_part_count leak

[Neil Brown]

On Thursday November 2, a.p.zijlstra@chello.nl wrote:
> 
> Don't leak a ->bd_part_count when the partition open fails with -ENXIO.
> 

Acked-by: NeilBrown <neilb@suse.de>

Thanks.  It took me a while to see why that was a correct fix.  I
wasn't noticing the 'if (bdev != bdev->bd_contains)' which is only
true after __blkdev_get(whole, ...., 1) has been called.

NeilBrown

> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> ---
>  fs/block_dev.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> Index: linux-2.6-mm/fs/block_dev.c
> ===================================================================
> --- linux-2.6-mm.orig/fs/block_dev.c
> +++ linux-2.6-mm/fs/block_dev.c
> @@ -907,6 +907,7 @@ EXPORT_SYMBOL(bd_set_size);
>  
>  static int __blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags,
>  			int for_part);
> +static int __blkdev_put(struct block_device *bdev, int for_part);
>  
>  static int do_open(struct block_device *bdev, struct file *file, int for_part)
>  {
> @@ -992,7 +993,7 @@ out_first:
>  	bdev->bd_disk = NULL;
>  	bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
>  	if (bdev != bdev->bd_contains)
> -		blkdev_put(bdev->bd_contains);
> +		__blkdev_put(bdev->bd_contains, 1);
>  	bdev->bd_contains = NULL;
>  	put_disk(disk);
>  	module_put(owner);
>