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

Jan Kara
2020-11-30T09:10:08Z

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
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR