diff options
Diffstat (limited to 'drivers/md/dm-mpath-hp-sw.c')
| -rw-r--r-- | drivers/md/dm-mpath-hp-sw.c | 247 |
1 files changed, 0 insertions, 247 deletions
diff --git a/drivers/md/dm-mpath-hp-sw.c b/drivers/md/dm-mpath-hp-sw.c deleted file mode 100644 index b63a0ab..0000000 --- a/drivers/md/dm-mpath-hp-sw.c +++ /dev/null @@ -1,247 +0,0 @@ -/* - * Copyright (C) 2005 Mike Christie, All rights reserved. - * Copyright (C) 2007 Red Hat, Inc. All rights reserved. - * Authors: Mike Christie - * Dave Wysochanski - * - * This file is released under the GPL. - * - * This module implements the specific path activation code for - * HP StorageWorks and FSC FibreCat Asymmetric (Active/Passive) - * storage arrays. - * These storage arrays have controller-based failover, not - * LUN-based failover. However, LUN-based failover is the design - * of dm-multipath. Thus, this module is written for LUN-based failover. - */ -#include <linux/blkdev.h> -#include <linux/list.h> -#include <linux/types.h> -#include <scsi/scsi.h> -#include <scsi/scsi_cmnd.h> -#include <scsi/scsi_dbg.h> - -#include "dm.h" -#include "dm-hw-handler.h" - -#define DM_MSG_PREFIX "multipath hp-sw" -#define DM_HP_HWH_NAME "hp-sw" -#define DM_HP_HWH_VER "1.0.0" - -struct hp_sw_context { - unsigned char sense[SCSI_SENSE_BUFFERSIZE]; -}; - -/* - * hp_sw_error_is_retryable - Is an HP-specific check condition retryable? - * @req: path activation request - * - * Examine error codes of request and determine whether the error is retryable. - * Some error codes are already retried by scsi-ml (see - * scsi_decide_disposition), but some HP specific codes are not. - * The intent of this routine is to supply the logic for the HP specific - * check conditions. - * - * Returns: - * 1 - command completed with retryable error - * 0 - command completed with non-retryable error - * - * Possible optimizations - * 1. More hardware-specific error codes - */ -static int hp_sw_error_is_retryable(struct request *req) -{ - /* - * NOT_READY is known to be retryable - * For now we just dump out the sense data and call it retryable - */ - if (status_byte(req->errors) == CHECK_CONDITION) - __scsi_print_sense(DM_HP_HWH_NAME, req->sense, req->sense_len); - - /* - * At this point we don't have complete information about all the error - * codes from this hardware, so we are just conservative and retry - * when in doubt. - */ - return 1; -} - -/* - * hp_sw_end_io - Completion handler for HP path activation. - * @req: path activation request - * @error: scsi-ml error - * - * Check sense data, free request structure, and notify dm that - * pg initialization has completed. - * - * Context: scsi-ml softirq - * - */ -static void hp_sw_end_io(struct request *req, int error) -{ - struct dm_path *path = req->end_io_data; - unsigned err_flags = 0; - - if (!error) { - DMDEBUG("%s path activation command - success", - path->dev->name); - goto out; - } - - if (hp_sw_error_is_retryable(req)) { - DMDEBUG("%s path activation command - retry", - path->dev->name); - err_flags = MP_RETRY; - goto out; - } - - DMWARN("%s path activation fail - error=0x%x", - path->dev->name, error); - err_flags = MP_FAIL_PATH; - -out: - req->end_io_data = NULL; - __blk_put_request(req->q, req); - dm_pg_init_complete(path, err_flags); -} - -/* - * hp_sw_get_request - Allocate an HP specific path activation request - * @path: path on which request will be sent (needed for request queue) - * - * The START command is used for path activation request. - * These arrays are controller-based failover, not LUN based. - * One START command issued to a single path will fail over all - * LUNs for the same controller. - * - * Possible optimizations - * 1. Make timeout configurable - * 2. Preallocate request - */ -static struct request *hp_sw_get_request(struct dm_path *path) -{ - struct request *req; - struct block_device *bdev = path->dev->bdev; - struct request_queue *q = bdev_get_queue(bdev); - struct hp_sw_context *h = path->hwhcontext; - - req = blk_get_request(q, WRITE, GFP_NOIO); - if (!req) - goto out; - - req->timeout = 60 * HZ; - - req->errors = 0; - req->cmd_type = REQ_TYPE_BLOCK_PC; - req->cmd_flags |= REQ_FAILFAST | REQ_NOMERGE; - req->end_io_data = path; - req->sense = h->sense; - memset(req->sense, 0, SCSI_SENSE_BUFFERSIZE); - - req->cmd[0] = START_STOP; - req->cmd[4] = 1; - req->cmd_len = COMMAND_SIZE(req->cmd[0]); - -out: - return req; -} - -/* - * hp_sw_pg_init - HP path activation implementation. - * @hwh: hardware handler specific data - * @bypassed: unused; is the path group bypassed? (see dm-mpath.c) - * @path: path to send initialization command - * - * Send an HP-specific path activation command on 'path'. - * Do not try to optimize in any way, just send the activation command. - * More than one path activation command may be sent to the same controller. - * This seems to work fine for basic failover support. - * - * Possible optimizations - * 1. Detect an in-progress activation request and avoid submitting another one - * 2. Model the controller and only send a single activation request at a time - * 3. Determine the state of a path before sending an activation request - * - * Context: kmpathd (see process_queued_ios() in dm-mpath.c) - */ -static void hp_sw_pg_init(struct hw_handler *hwh, unsigned bypassed, - struct dm_path *path) -{ - struct request *req; - struct hp_sw_context *h; - - path->hwhcontext = hwh->context; - h = hwh->context; - - req = hp_sw_get_request(path); - if (!req) { - DMERR("%s path activation command - allocation fail", - path->dev->name); - goto retry; - } - - DMDEBUG("%s path activation command - sent", path->dev->name); - - blk_execute_rq_nowait(req->q, NULL, req, 1, hp_sw_end_io); - return; - -retry: - dm_pg_init_complete(path, MP_RETRY); -} - -static int hp_sw_create(struct hw_handler *hwh, unsigned argc, char **argv) -{ - struct hp_sw_context *h; - - h = kmalloc(sizeof(*h), GFP_KERNEL); - if (!h) - return -ENOMEM; - - hwh->context = h; - - return 0; -} - -static void hp_sw_destroy(struct hw_handler *hwh) -{ - struct hp_sw_context *h = hwh->context; - - kfree(h); -} - -static struct hw_handler_type hp_sw_hwh = { - .name = DM_HP_HWH_NAME, - .module = THIS_MODULE, - .create = hp_sw_create, - .destroy = hp_sw_destroy, - .pg_init = hp_sw_pg_init, -}; - -static int __init hp_sw_init(void) -{ - int r; - - r = dm_register_hw_handler(&hp_sw_hwh); - if (r < 0) - DMERR("register failed %d", r); - else - DMINFO("version " DM_HP_HWH_VER " loaded"); - - return r; -} - -static void __exit hp_sw_exit(void) -{ - int r; - - r = dm_unregister_hw_handler(&hp_sw_hwh); - if (r < 0) - DMERR("unregister failed %d", r); -} - -module_init(hp_sw_init); -module_exit(hp_sw_exit); - -MODULE_DESCRIPTION("DM Multipath HP StorageWorks / FSC FibreCat (A/P) support"); -MODULE_AUTHOR("Mike Christie, Dave Wysochanski <dm-devel@redhat.com>"); -MODULE_LICENSE("GPL"); -MODULE_VERSION(DM_HP_HWH_VER); |
