Re: [PATCH 5/8] rbd: have rbd_add_parse_args() return error

[Josh Durgin <josh.durgin@inktank.com>]

Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

On 10/26/2012 04:02 PM, Alex Elder wrote:
> Change the interface to rbd_add_parse_args() so it returns an
> error code rather than a pointer.  Return the ceph_options result
> via a pointer whose address is passed as an argument.
>
> Signed-off-by: Alex Elder <elder@inktank.com>
> ---
>   drivers/block/rbd.c |   37 ++++++++++++++++++++-----------------
>   1 file changed, 20 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 392dded..388dd47 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -2841,30 +2841,31 @@ static inline char *dup_token(const char **buf,
> size_t *lenp)
>    *
>    * Note: rbd_dev is assumed to have been initially zero-filled.
>    */
> -static struct ceph_options *rbd_add_parse_args(struct rbd_device *rbd_dev,
> -						const char *buf,
> -						struct rbd_options **opts)
> +static int rbd_add_parse_args(struct rbd_device *rbd_dev,
> +				const char *buf,
> +				struct ceph_options **ceph_opts,
> +				struct rbd_options **opts)
>   {
>   	size_t len;
>   	const char *mon_addrs;
>   	size_t mon_addrs_size;
>   	char *options;
> -	struct ceph_options *err_ptr = ERR_PTR(-EINVAL);
> -	struct ceph_options *ceph_opts;
>   	struct rbd_options *rbd_opts = NULL;
> +	int ret;
>
>   	/* The first four tokens are required */
>
>   	len = next_token(&buf);
>   	if (!len)
> -		return err_ptr;	/* Missing monitor address(es) */
> +		return -EINVAL;	/* Missing monitor address(es) */
>   	mon_addrs = buf;
>   	mon_addrs_size = len + 1;
>   	buf += len;
>
> +	ret = -EINVAL;
>   	options = dup_token(&buf, NULL);
>   	if (!options)
> -		goto out_mem;
> +		return -ENOMEM;
>   	if (!*options)
>   		goto out_err;	/* Missing options */
>
> @@ -2889,7 +2890,7 @@ static struct ceph_options
> *rbd_add_parse_args(struct rbd_device *rbd_dev,
>   		buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
>   		len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
>   	} else if (len > RBD_MAX_SNAP_NAME_LEN) {
> -		err_ptr = ERR_PTR(-ENAMETOOLONG);
> +		ret = -ENAMETOOLONG;
>   		goto out_err;
>   	}
>   	rbd_dev->snap_name = kmalloc(len + 1, GFP_KERNEL);
> @@ -2906,15 +2907,19 @@ static struct ceph_options
> *rbd_add_parse_args(struct rbd_device *rbd_dev,
>
>   	rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
>
> -	ceph_opts = ceph_parse_options(options, mon_addrs,
> +	*ceph_opts = ceph_parse_options(options, mon_addrs,
>   					mon_addrs + mon_addrs_size - 1,
>   					parse_rbd_opts_token, rbd_opts);
>   	kfree(options);
> +	if (IS_ERR(*ceph_opts)) {
> +		ret = PTR_ERR(*ceph_opts);
> +		goto out_err;
> +	}
>   	*opts = rbd_opts;
>
> -	return ceph_opts;
> +	return 0;
>   out_mem:
> -	err_ptr = ERR_PTR(-ENOMEM);
> +	ret = -ENOMEM;
>   out_err:
>   	kfree(rbd_dev->image_name);
>   	rbd_dev->image_name = NULL;
> @@ -2923,7 +2928,7 @@ out_err:
>   	rbd_dev->pool_name = NULL;
>   	kfree(options);
>
> -	return err_ptr;
> +	return ret;
>   }
>
>   /*
> @@ -3131,7 +3136,7 @@ static ssize_t rbd_add(struct bus_type *bus,
>   		       size_t count)
>   {
>   	struct rbd_device *rbd_dev = NULL;
> -	struct ceph_options *ceph_opts;
> +	struct ceph_options *ceph_opts = NULL;
>   	struct rbd_options *rbd_opts = NULL;
>   	struct ceph_osd_client *osdc;
>   	int rc = -ENOMEM;
> @@ -3150,11 +3155,9 @@ static ssize_t rbd_add(struct bus_type *bus,
>   	init_rwsem(&rbd_dev->header_rwsem);
>
>   	/* parse add command */
> -	ceph_opts = rbd_add_parse_args(rbd_dev, buf, &rbd_opts);
> -	if (IS_ERR(ceph_opts)) {
> -		rc = PTR_ERR(ceph_opts);
> +	rc = rbd_add_parse_args(rbd_dev, buf, &ceph_opts, &rbd_opts);
> +	if (rc < 0)
>   		goto err_out_mem;
> -	}
>   	rbd_dev->mapping.read_only = rbd_opts->read_only;
>
>   	rc = rbd_get_client(rbd_dev, ceph_opts);
>