Re: [PATCH 3/7] nvme-fcloop: use IDA for port ids

[James Smart <james.smart@broadcom.com>]

[-- Attachment #1.1: Type: text/plain, Size: 5991 bytes --]

On 9/22/2020 5:14 AM, Hannes Reinecke wrote:
> Use an IDA to register port IDs to avoid duplicate port IDs. It
> also will generate a unique port ID if none is specified.

I'd prefer a little more description as I didn't pick up what this 
actually did from the comment.  Meaning: Add auto-address assignment if 
one isn't specified. Use an ida for allocation for uniqueness. Use 
user-supplied addresses as long as not in use and within range supported 
for ida.

> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
>   drivers/nvme/target/fcloop.c | 51 +++++++++++++++++++++++++++++++++++++-------
>   1 file changed, 43 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/nvme/target/fcloop.c b/drivers/nvme/target/fcloop.c
> index 082aa4dee406..e56f323fa7d4 100644
> --- a/drivers/nvme/target/fcloop.c
> +++ b/drivers/nvme/target/fcloop.c
> @@ -12,6 +12,7 @@
>   #include <linux/nvme-fc-driver.h>
>   #include <linux/nvme-fc.h>
>   
> +#define FCLOOP_MAX_AL_PA 0xEF

This is odd - no reason to bring in ALPA's and arb loop.   Please rename 
it to state it's the max address value allowed.  I'd prefer if this was 
a 24 bit value, but that won't matter much and 255 is fine.

>   
>   enum {
>   	NVMF_OPT_ERR		= 0,
> @@ -63,6 +64,9 @@ fcloop_parse_options(struct fcloop_ctrl_options *opts,
>   	int token, ret = 0;
>   	u64 token64;
>   
> +	/* Default setting */
> +	opts->fcaddr = 1;
> +
>   	options = o = kstrdup(buf, GFP_KERNEL);
>   	if (!options)
>   		return -ENOMEM;
> @@ -102,6 +106,10 @@ fcloop_parse_options(struct fcloop_ctrl_options *opts,
>   				ret = -EINVAL;
>   				goto out_free_options;
>   			}
> +			if (!token || token > FCLOOP_MAX_AL_PA) {
> +				ret = -EINVAL;
> +				goto out_free_options;
> +			}
>   			opts->fcaddr = token;
>   			break;
>   		case NVMF_OPT_LPWWNN:
> @@ -203,11 +211,13 @@ fcloop_parse_nm_options(struct device *dev, u64 *nname, u64 *pname,
>   static DEFINE_SPINLOCK(fcloop_lock);
>   static LIST_HEAD(fcloop_lports);
>   static LIST_HEAD(fcloop_nports);
> +static DEFINE_IDA(fcloop_portid_ida);
>   
>   struct fcloop_lport {
>   	struct nvme_fc_local_port *localport;
>   	struct list_head lport_list;
>   	struct completion unreg_done;
> +	u32 port_id;
>   };
>   
>   struct fcloop_lport_priv {
> @@ -949,6 +959,8 @@ fcloop_nport_free(struct kref *ref)
>   	list_del(&nport->nport_list);
>   	spin_unlock_irqrestore(&fcloop_lock, flags);
>   
> +	ida_free(&fcloop_portid_ida, nport->port_id);
> +
>   	kfree(nport);
>   }
>   
> @@ -1047,7 +1059,7 @@ fcloop_create_local_port(struct device *dev, struct device_attribute *attr,
>   	struct fcloop_lport *lport;
>   	struct fcloop_lport_priv *lport_priv;
>   	unsigned long flags;
> -	int ret = -ENOMEM;
> +	int ret = -ENOMEM, port_id;
>   
>   	lport = kzalloc(sizeof(*lport), GFP_KERNEL);
>   	if (!lport)
> @@ -1067,11 +1079,22 @@ fcloop_create_local_port(struct device *dev, struct device_attribute *attr,
>   		goto out_free_opts;
>   	}
>   
> +	port_id = ida_alloc_range(&fcloop_portid_ida,
> +				  opts->fcaddr, FCLOOP_MAX_AL_PA, GFP_KERNEL);
> +	if (port_id < 0) {
> +		ret = port_id;
> +		goto out_free_opts;
> +	}
> +	if ((opts->mask & NVMF_OPT_FCADDR) && opts->fcaddr != port_id) {
> +		ret = -EINVAL;
> +		goto out_free_ida;
> +	}
> +
>   	memset(&pinfo, 0, sizeof(pinfo));
>   	pinfo.node_name = opts->wwnn;
>   	pinfo.port_name = opts->wwpn;
>   	pinfo.port_role = opts->roles;
> -	pinfo.port_id = opts->fcaddr;
> +	pinfo.port_id = port_id;
>   
>   	ret = nvme_fc_register_localport(&pinfo, &fctemplate, NULL, &localport);
>   	if (!ret) {
> @@ -1086,7 +1109,9 @@ fcloop_create_local_port(struct device *dev, struct device_attribute *attr,
>   		list_add_tail(&lport->lport_list, &fcloop_lports);
>   		spin_unlock_irqrestore(&fcloop_lock, flags);
>   	}
> -
> +out_free_ida:
> +	if (ret)
> +		ida_free(&fcloop_portid_ida, port_id);
>   out_free_opts:
>   	kfree(opts);
>   out_free_lport:
> @@ -1115,6 +1140,8 @@ __wait_localport_unreg(struct fcloop_lport *lport)
>   
>   	wait_for_completion(&lport->unreg_done);
>   
> +	ida_free(&fcloop_portid_ida, lport->port_id);
> +
>   	kfree(lport);
>   
>   	return ret;
> @@ -1162,7 +1189,7 @@ fcloop_alloc_nport(const char *buf, size_t count, bool remoteport)
>   	struct fcloop_ctrl_options *opts;
>   	unsigned long flags;
>   	u32 opts_mask = (remoteport) ? RPORT_OPTS : TGTPORT_OPTS;
> -	int ret;
> +	int ret, port_id;
>   
>   	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
>   	if (!opts)
> @@ -1182,13 +1209,21 @@ fcloop_alloc_nport(const char *buf, size_t count, bool remoteport)
>   	if (!newnport)
>   		goto out_free_opts;
>   
> +	port_id = ida_alloc_range(&fcloop_portid_ida,
> +				  opts->fcaddr, FCLOOP_MAX_AL_PA, GFP_KERNEL);
> +	if (port_id < 0)
> +		goto out_free_newnport;
> +
> +	if ((opts->mask & NVMF_OPT_FCADDR) && opts->fcaddr != port_id)
> +		goto out_free_ida;
> +
>   	INIT_LIST_HEAD(&newnport->nport_list);
>   	newnport->node_name = opts->wwnn;
>   	newnport->port_name = opts->wwpn;
> +	newnport->port_id = port_id;
>   	if (opts->mask & NVMF_OPT_ROLES)
>   		newnport->port_role = opts->roles;
> -	if (opts->mask & NVMF_OPT_FCADDR)
> -		newnport->port_id = opts->fcaddr;
> +
>   	kref_init(&newnport->ref);
>   
>   	spin_lock_irqsave(&fcloop_lock, flags);
> @@ -1226,8 +1261,6 @@ fcloop_alloc_nport(const char *buf, size_t count, bool remoteport)
>   				nport->lport = lport;
>   			if (opts->mask & NVMF_OPT_ROLES)
>   				nport->port_role = opts->roles;
> -			if (opts->mask & NVMF_OPT_FCADDR)
> -				nport->port_id = opts->fcaddr;
>   			goto out_free_newnport;
>   		}
>   	}
> @@ -1241,6 +1274,8 @@ fcloop_alloc_nport(const char *buf, size_t count, bool remoteport)
>   
>   out_invalid_opts:
>   	spin_unlock_irqrestore(&fcloop_lock, flags);
> +out_free_ida:
> +	ida_free(&fcloop_portid_ida, port_id);
>   out_free_newnport:
>   	kfree(newnport);
>   out_free_opts:

These are minor nits - I'm good with the patch

Reviewed-by: James Smart <james.smart@broadcom.com>

-- james

[-- Attachment #1.2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 4163 bytes --]

[-- Attachment #2: Type: text/plain, Size: 158 bytes --]

_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme