From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: [PATCH 08/23] scsi_dh_alua: use unique device id Date: Mon, 8 Feb 2016 15:34:31 +0100 Message-ID: <1454942086-128704-9-git-send-email-hare@suse.de> References: <1454942086-128704-1-git-send-email-hare@suse.de> Return-path: Received: from mx2.suse.de ([195.135.220.15]:42664 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753427AbcBHOew (ORCPT ); Mon, 8 Feb 2016 09:34:52 -0500 In-Reply-To: <1454942086-128704-1-git-send-email-hare@suse.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Martin K. Petersen" Cc: Christoph Hellwig , Bart van Assche , James Bottomley , linux-scsi@vger.kernel.org, Ewan Milne , Hannes Reinecke Use scsi_vpd_lun_id() to assign a unique device identification to the alua port group structure. Reviewed-by: Christoph Hellwig Signed-off-by: Hannes Reinecke --- drivers/scsi/device_handler/scsi_dh_alua.c | 55 +++++++++++++++++++++++++++--- 1 file changed, 50 insertions(+), 5 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index 5c8d0d3..25d0a92 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -70,6 +70,8 @@ static DEFINE_SPINLOCK(port_group_lock); struct alua_port_group { struct kref kref; struct list_head node; + unsigned char device_id_str[256]; + int device_id_len; int group_id; int tpgs; int state; @@ -162,6 +164,26 @@ static int submit_stpg(struct scsi_device *sdev, int group_id, ALUA_FAILOVER_RETRIES, NULL, req_flags); } +struct alua_port_group *alua_find_get_pg(char *id_str, size_t id_size, + int group_id) +{ + struct alua_port_group *pg; + + list_for_each_entry(pg, &port_group_list, node) { + if (pg->group_id != group_id) + continue; + if (pg->device_id_len != id_size) + continue; + if (strncmp(pg->device_id_str, id_str, id_size)) + continue; + if (!kref_get_unless_zero(&pg->kref)) + continue; + return pg; + } + + return NULL; +} + /* * alua_alloc_pg - Allocate a new port_group structure * @sdev: scsi device @@ -174,17 +196,39 @@ static int submit_stpg(struct scsi_device *sdev, int group_id, struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev, int group_id, int tpgs) { - struct alua_port_group *pg; + struct alua_port_group *pg, *tmp_pg; pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL); if (!pg) - return NULL; + return ERR_PTR(-ENOMEM); + pg->device_id_len = scsi_vpd_lun_id(sdev, pg->device_id_str, + sizeof(pg->device_id_str)); + if (pg->device_id_len <= 0) { + /* + * Internal error: TPGS supported but no device + * identifcation found. Disable ALUA support. + */ + kfree(pg); + sdev_printk(KERN_INFO, sdev, + "%s: No device descriptors found\n", + ALUA_DH_NAME); + return ERR_PTR(-ENXIO); + } pg->group_id = group_id; pg->tpgs = tpgs; pg->state = TPGS_STATE_OPTIMIZED; kref_init(&pg->kref); + spin_lock(&port_group_lock); + tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len, + group_id); + if (tmp_pg) { + spin_unlock(&port_group_lock); + kfree(pg); + return tmp_pg; + } + list_add(&pg->node, &port_group_list); spin_unlock(&port_group_lock); @@ -269,7 +313,7 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h) h->group_id = group_id; sdev_printk(KERN_INFO, sdev, - "%s: port group %02x rel port %02x\n", + "%s: port group %x rel port %x\n", ALUA_DH_NAME, h->group_id, h->rel_port); return 0; @@ -599,8 +643,9 @@ static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) goto out; h->pg = alua_alloc_pg(sdev, h->group_id, tpgs); - if (!h->pg) { - err = SCSI_DH_NOMEM; + if (IS_ERR(h->pg)) { + if (PTR_ERR(h->pg) == -ENOMEM) + err = SCSI_DH_NOMEM; goto out; } kref_get(&h->pg->kref); -- 1.8.5.6