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-   -   Use WWID from C8 page instead of Subsystem id from C4 page to identify storage (http://www.linux-archive.org/device-mapper-development/556581-use-wwid-c8-page-instead-subsystem-id-c4-page-identify-storage.html)

"Moger, Babu" 07-25-2011 06:17 AM

Use WWID from C8 page instead of Subsystem id from C4 page to identify storage
 
Looks good..

> -----Original Message-----
> From: Chandra Seetharaman [mailto:sekharan@us.ibm.com]
> Sent: Wednesday, July 20, 2011 4:19 PM
> To: Linux SCSI Mailing list
> Cc: device-mapper development; Moger, Babu; Qi, Yanling; Stankey, Robert
> Subject: [PATCH] Use WWID from C8 page instead of Subsystem id from C4
> page to identify storage
>
> rdac hardware handler uses "Subsystem Identifier" from C4 inquiry page
> to uniquely identify a storage. The problem with that is that if any
> any of the bytes are non-ascii, subsys_id will all be spaces (hex
> 0x20). This creates lot of problems especially when there are multiple
> rdac storages are connected to the server.
>
> Use "Storage Array Unique Identifier" from C8 inquiry page, which is the
> world wide unique identifier for the storage array, to uniquely identify
> the storage.
>
> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>


Reviewed-by: Babu Moger <babu.moger@netapp.com>

> ---
> diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c
> b/drivers/scsi/device_handler/scsi_dh_rdac.c
> index e7fc70d..a5d1669 100644
> --- a/drivers/scsi/device_handler/scsi_dh_rdac.c
> +++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
> @@ -128,25 +128,7 @@ struct c4_inquiry {
> u8 reserved[2];
> };
>
> -struct rdac_controller {
> - u8 subsys_id[SUBSYS_ID_LEN];
> - u8 slot_id[SLOT_ID_LEN];
> - int use_ms10;
> - struct kref kref;
> - struct list_head node; /* list of all controllers */
> - union {
> - struct rdac_pg_legacy legacy;
> - struct rdac_pg_expanded expanded;
> - } mode_select;
> - u8 index;
> - u8 array_name[ARRAY_LABEL_LEN];
> - spinlock_t ms_lock;
> - int ms_queued;
> - struct work_struct ms_work;
> - struct scsi_device *ms_sdev;
> - struct list_head ms_head;
> -};
> -
> +#define UNIQUE_ID_LEN 16
> struct c8_inquiry {
> u8 peripheral_info;
> u8 page_code; /* 0xC8 */
> @@ -159,12 +141,30 @@ struct c8_inquiry {
> u8 vol_user_label_len;
> u8 vol_user_label[60];
> u8 array_uniq_id_len;
> - u8 array_unique_id[16];
> + u8 array_unique_id[UNIQUE_ID_LEN];
> u8 array_user_label_len;
> u8 array_user_label[60];
> u8 lun[8];
> };
>
> +struct rdac_controller {
> + u8 array_id[UNIQUE_ID_LEN];
> + int use_ms10;
> + struct kref kref;
> + struct list_head node; /* list of all controllers */
> + union {
> + struct rdac_pg_legacy legacy;
> + struct rdac_pg_expanded expanded;
> + } mode_select;
> + u8 index;
> + u8 array_name[ARRAY_LABEL_LEN];
> + spinlock_t ms_lock;
> + int ms_queued;
> + struct work_struct ms_work;
> + struct scsi_device *ms_sdev;
> + struct list_head ms_head;
> +};
> +
> struct c2_inquiry {
> u8 peripheral_info;
> u8 page_code; /* 0xC2 */
> @@ -369,16 +369,16 @@ static void release_controller(struct kref *kref)
> kfree(ctlr);
> }
>
> -static struct rdac_controller *get_controller(u8 *subsys_id, u8
> *slot_id,
> - char *array_name)
> +static struct rdac_controller *get_controller(int index, char
> *array_name,
> + u8 *array_id)
> {
> struct rdac_controller *ctlr, *tmp;
>
> spin_lock(&list_lock);
>
> list_for_each_entry(tmp, &ctlr_list, node) {
> - if ((memcmp(tmp->subsys_id, subsys_id, SUBSYS_ID_LEN) == 0)
> &&
> - (memcmp(tmp->slot_id, slot_id, SLOT_ID_LEN) == 0)) {
> + if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
> + (tmp->index == index)) {
> kref_get(&tmp->kref);
> spin_unlock(&list_lock);
> return tmp;
> @@ -389,16 +389,10 @@ static struct rdac_controller *get_controller(u8
> *subsys_id, u8 *slot_id,
> goto done;
>
> /* initialize fields of controller */
> - memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN);
> - memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN);
> + memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
> + ctlr->index = index;
> memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
>
> - /* update the controller index */
> - if (slot_id[1] == 0x31)
> - ctlr->index = 0;
> - else
> - ctlr->index = 1;
> -
> kref_init(&ctlr->kref);
> ctlr->use_ms10 = -1;
> ctlr->ms_queued = 0;
> @@ -444,7 +438,7 @@ done:
> }
>
> static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data
> *h,
> - char *array_name)
> + char *array_name, u8 *array_id)
> {
> int err, i;
> struct c8_inquiry *inqp;
> @@ -463,6 +457,8 @@ static int get_lun_info(struct scsi_device *sdev,
> struct rdac_dh_data *h,
> *(array_name+i) = inqp->array_user_label[(2*i)+1];
>
> *(array_name+ARRAY_LABEL_LEN-1) = '';
> + memset(array_id, 0, UNIQUE_ID_LEN);
> + memcpy(array_id, inqp->array_unique_id, inqp-
> >array_uniq_id_len);
> }
> return err;
> }
> @@ -504,16 +500,20 @@ static int check_ownership(struct scsi_device
> *sdev, struct rdac_dh_data *h)
> }
>
> static int initialize_controller(struct scsi_device *sdev,
> - struct rdac_dh_data *h, char *array_name)
> + struct rdac_dh_data *h, char *array_name, u8 *array_id)
> {
> - int err;
> + int err, index;
> struct c4_inquiry *inqp;
>
> err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h);
> if (err == SCSI_DH_OK) {
> inqp = &h->inq.c4;
> - h->ctlr = get_controller(inqp->subsys_id, inqp->slot_id,
> - array_name);
> + /* get the controller index */
> + if (inqp->slot_id[1] == 0x31)
> + index = 0;
> + else
> + index = 1;
> + h->ctlr = get_controller(index, array_name, array_id);
> if (!h->ctlr)
> err = SCSI_DH_RES_TEMP_UNAVAIL;
> }
> @@ -835,6 +835,7 @@ static int rdac_bus_attach(struct scsi_device *sdev)
> unsigned long flags;
> int err;
> char array_name[ARRAY_LABEL_LEN];
> + char array_id[UNIQUE_ID_LEN];
>
> scsi_dh_data = kzalloc(sizeof(*scsi_dh_data)
> + sizeof(*h) , GFP_KERNEL);
> @@ -849,11 +850,11 @@ static int rdac_bus_attach(struct scsi_device
> *sdev)
> h->lun = UNINITIALIZED_LUN;
> h->state = RDAC_STATE_ACTIVE;
>
> - err = get_lun_info(sdev, h, array_name);
> + err = get_lun_info(sdev, h, array_name, array_id);
> if (err != SCSI_DH_OK)
> goto failed;
>
> - err = initialize_controller(sdev, h, array_name);
> + err = initialize_controller(sdev, h, array_name, array_id);
> if (err != SCSI_DH_OK)
> goto failed;
>
>
>
> --
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