/*
* 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);
}
static void emc_pg_init(struct hw_handler *hwh, unsigned bypassed,
struct path *path)
{
struct request *rq;
struct request_queue *q = bdev_get_queue(path->dev->bdev);
/*
* We can either blindly init the pg (then look at the sense),
* or we can send some commands to get the state here (then
* possibly send the fo cmnd), or we can also have the
* initial state passed into us and then get an update here.
*/
if (!q) {
DMINFO("dm-emc: emc_pg_init: no queue");
goto fail_path;
}
/* FIXME: The request should be pre-allocated. */
rq = emc_trespass_get(hwh->context, path);
if (!rq) {
DMERR("dm-emc: emc_pg_init: no rq");
goto fail_path;
}
DMINFO("dm-emc: emc_pg_init: sending switch-over command");
elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
return;
fail_path:
dm_pg_init_complete(path, MP_FAIL_PATH);
}
static void emc_endio(struct bio *bio, int error)
{
struct dm_path *path = bio->bi_private;
/* We also need to look at the sense keys here whether or not to
* switch to the next PG etc.
*
* For now simple logic: either it works or it doesn't.
*/
if (error)
dm_pg_init_complete(path, MP_FAIL_PATH);
else
dm_pg_init_complete(path, 0);
/* request is freed in block layer */
free_bio(bio);
}
/*
* 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 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;
}
blk_execute_rq_nowait(req->q, NULL, req, 1, hp_sw_end_io);
return;
retry:
dm_pg_init_complete(path, MP_RETRY);
}