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

[Jan Kara]

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 at lst.de>

Otherwise looks good. Feel free to add:

Reviewed-by: Jan Kara <jack at 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
> 
-- 
Jan Kara <jack at suse.com>
SUSE Labs, CR