diff mbox series

[16/45] block: switch bdgrab to use igrab

Message ID 20201128161510.347752-17-hch@lst.de (mailing list archive)
State New
Headers show
Series [01/45] blk-cgroup: fix a hd_struct leak in blkcg_fill_root_iostats | expand

Commit Message

Christoph Hellwig Nov. 28, 2020, 4:14 p.m. UTC
All of the current callers already have a reference, but to prepare for
additional users ensure bdgrab returns NULL if the block device is beeing
freed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/block_dev.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Hannes Reinecke Nov. 30, 2020, 7:14 a.m. UTC | #1
On 11/28/20 5:14 PM, Christoph Hellwig wrote:
> All of the current callers already have a reference, but to prepare for
> additional users ensure bdgrab returns NULL if the block device is beeing
> freed.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   fs/block_dev.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index d707ab376da86e..962fabe8a67b83 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -894,10 +894,14 @@ static struct block_device *bdget(dev_t dev)
>   /**
>    * bdgrab -- Grab a reference to an already referenced block device
>    * @bdev:	Block device to grab a reference to.
> + *
> + * Returns the block_device with an additional reference when successful,
> + * or NULL if the inode is already beeing freed.
>    */
>   struct block_device *bdgrab(struct block_device *bdev)
>   {
> -	ihold(bdev->bd_inode);
> +	if (!igrab(bdev->bd_inode))
> +		return NULL;
>   	return bdev;
>   }
>   EXPORT_SYMBOL(bdgrab);
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
Jan Kara Nov. 30, 2020, 9:09 a.m. UTC | #2
On Sat 28-11-20 17:14:41, Christoph Hellwig wrote:
> All of the current callers already have a reference, but to prepare for
> additional users ensure bdgrab returns NULL if the block device is beeing
								     ^^^ being

> freed.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Otherwise looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/block_dev.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index d707ab376da86e..962fabe8a67b83 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -894,10 +894,14 @@ static struct block_device *bdget(dev_t dev)
>  /**
>   * bdgrab -- Grab a reference to an already referenced block device
>   * @bdev:	Block device to grab a reference to.
> + *
> + * Returns the block_device with an additional reference when successful,
> + * or NULL if the inode is already beeing freed.
>   */
>  struct block_device *bdgrab(struct block_device *bdev)
>  {
> -	ihold(bdev->bd_inode);
> +	if (!igrab(bdev->bd_inode))
> +		return NULL;
>  	return bdev;
>  }
>  EXPORT_SYMBOL(bdgrab);
> -- 
> 2.29.2
>
Johannes Thumshirn Nov. 30, 2020, 2:52 p.m. UTC | #3
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
diff mbox series

Patch

diff --git a/fs/block_dev.c b/fs/block_dev.c
index d707ab376da86e..962fabe8a67b83 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -894,10 +894,14 @@  static struct block_device *bdget(dev_t dev)
 /**
  * bdgrab -- Grab a reference to an already referenced block device
  * @bdev:	Block device to grab a reference to.
+ *
+ * Returns the block_device with an additional reference when successful,
+ * or NULL if the inode is already beeing freed.
  */
 struct block_device *bdgrab(struct block_device *bdev)
 {
-	ihold(bdev->bd_inode);
+	if (!igrab(bdev->bd_inode))
+		return NULL;
 	return bdev;
 }
 EXPORT_SYMBOL(bdgrab);