[dm-devel] RE: [PATCH 1/4] scsi_dh: Change the scsidh_activate interface to be asynchronous
Moger, Babu
Babu.Moger at lsi.com
Thu Oct 22 23:26:56 UTC 2009
I have tested this patch on LSI rdac storage. It works pretty well..
> -----Original Message-----
> From: linux-scsi-owner at vger.kernel.org [mailto:linux-scsi-
> owner at vger.kernel.org] On Behalf Of Chandra Seetharaman
> Sent: Wednesday, October 21, 2009 11:23 AM
> To: linux-scsi at vger.kernel.org
> Cc: dm-devel at redhat.com; Moger, Babu; michaelc at cs.wisc.edu;
> Benoit_Arthur at emc.com; Eddie.Williams at steeleye.com;
> berthiaume_wayne at emc.com; Chandra Seetharaman
> Subject: [PATCH 1/4] scsi_dh: Change the scsidh_activate interface to
> be asynchronous
>
> Make scsi_dh_activate() function asynchronous, by taking in two
> additional
> parameters, one is the callback function and the other is the data to
> call
> the callback function with.
>
> Signed-off-by: Chandra Seetharaman <sekharan at us.ibm.com>
Tested-by: Babu Moger at lsi.com
>
> --------------
> drivers/md/dm-mpath.c | 8 ++++----
> drivers/scsi/device_handler/scsi_dh.c | 17 ++++++++++++-----
> drivers/scsi/device_handler/scsi_dh_alua.c | 7 +++++--
> drivers/scsi/device_handler/scsi_dh_emc.c | 7 +++++--
> drivers/scsi/device_handler/scsi_dh_hp_sw.c | 7 +++++--
> drivers/scsi/device_handler/scsi_dh_rdac.c | 7 +++++--
> include/scsi/scsi_device.h | 3 ++-
> include/scsi/scsi_dh.h | 6 ++++--
> 8 files changed, 42 insertions(+), 20 deletions(-)
>
> Index: linux-2.6.32-rc5/include/scsi/scsi_dh.h
> ===================================================================
> --- linux-2.6.32-rc5.orig/include/scsi/scsi_dh.h 2009-10-20
> 18:26:03.000000000 -0700
> +++ linux-2.6.32-rc5/include/scsi/scsi_dh.h 2009-10-20
> 18:26:14.000000000 -0700
> @@ -56,14 +56,16 @@
> SCSI_DH_DRIVER_MAX,
> };
> #if defined(CONFIG_SCSI_DH) || defined(CONFIG_SCSI_DH_MODULE)
> -extern int scsi_dh_activate(struct request_queue *);
> +extern int scsi_dh_activate(struct request_queue *, activate_complete,
> void *);
> extern int scsi_dh_handler_exist(const char *);
> extern int scsi_dh_attach(struct request_queue *, const char *);
> extern void scsi_dh_detach(struct request_queue *);
> extern int scsi_dh_set_params(struct request_queue *, const char *);
> #else
> -static inline int scsi_dh_activate(struct request_queue *req)
> +static inline int scsi_dh_activate(struct request_queue *req,
> + activate_complete fn, void *data)
> {
> + fn(data, 0);
> return 0;
> }
> static inline int scsi_dh_handler_exist(const char *name)
> Index: linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh.c
> ===================================================================
> --- linux-2.6.32-rc5.orig/drivers/scsi/device_handler/scsi_dh.c 2009-
> 10-20 18:26:03.000000000 -0700
> +++ linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh.c 2009-10-20
> 18:26:14.000000000 -0700
> @@ -226,7 +226,7 @@
> * Activate a device handler
> */
> if (scsi_dh->activate)
> - err = scsi_dh->activate(sdev);
> + err = scsi_dh->activate(sdev, NULL, NULL);
> else
> err = 0;
> }
> @@ -423,10 +423,17 @@
> /*
> * scsi_dh_activate - activate the path associated with the
> scsi_device
> * corresponding to the given request queue.
> - * @q - Request queue that is associated with the scsi_device to be
> - * activated.
> + * Returns immediately without waiting for activation to be
> completed.
> + * @q - Request queue that is associated with the scsi_device to be
> + * activated.
> + * @fn - Function to be called upon completion of the activation.
> + * Function fn is called with data (below) and the error code.
> + * Function fn may be called from the same calling context.
> So,
> + * do not hold the lock in the caller which may be needed in
> fn.
> + * @data - data passed to the function fn upon completion.
> + *
> */
> -int scsi_dh_activate(struct request_queue *q)
> +int scsi_dh_activate(struct request_queue *q, activate_complete fn,
> void *data)
> {
> int err = 0;
> unsigned long flags;
> @@ -445,7 +452,7 @@
> return err;
>
> if (scsi_dh->activate)
> - err = scsi_dh->activate(sdev);
> + err = scsi_dh->activate(sdev, fn, data);
> put_device(&sdev->sdev_gendev);
> return err;
> }
> Index: linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh_rdac.c
> ===================================================================
> --- linux-2.6.32-rc5.orig/drivers/scsi/device_handler/scsi_dh_rdac.c
> 2009-10-20 18:26:03.000000000 -0700
> +++ linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh_rdac.c 2009-
> 10-20 18:26:14.000000000 -0700
> @@ -568,7 +568,8 @@
> return err;
> }
>
> -static int rdac_activate(struct scsi_device *sdev)
> +static int rdac_activate(struct scsi_device *sdev,
> + activate_complete fn, void *data)
> {
> struct rdac_dh_data *h = get_rdac_data(sdev);
> int err = SCSI_DH_OK;
> @@ -580,7 +581,9 @@
> if (h->lun_state == RDAC_LUN_UNOWNED)
> err = send_mode_select(sdev, h);
> done:
> - return err;
> + if (fn)
> + fn(data, err);
> + return 0;
> }
>
> static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
> Index: linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh_alua.c
> ===================================================================
> --- linux-2.6.32-rc5.orig/drivers/scsi/device_handler/scsi_dh_alua.c
> 2009-10-20 18:26:03.000000000 -0700
> +++ linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh_alua.c 2009-
> 10-20 18:26:14.000000000 -0700
> @@ -652,7 +652,8 @@
> * based on a certain policy. But until we actually encounter them it
> * should be okay.
> */
> -static int alua_activate(struct scsi_device *sdev)
> +static int alua_activate(struct scsi_device *sdev,
> + activate_complete fn, void *data)
> {
> struct alua_dh_data *h = get_alua_data(sdev);
> int err = SCSI_DH_OK;
> @@ -667,7 +668,9 @@
> err = alua_stpg(sdev, TPGS_STATE_OPTIMIZED, h);
>
> out:
> - return err;
> + if (fn)
> + fn(data, err);
> + return 0;
> }
>
> /*
> Index: linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh_emc.c
> ===================================================================
> --- linux-2.6.32-rc5.orig/drivers/scsi/device_handler/scsi_dh_emc.c
> 2009-10-20 18:26:03.000000000 -0700
> +++ linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh_emc.c 2009-
> 10-20 18:26:14.000000000 -0700
> @@ -528,7 +528,8 @@
> return err;
> }
>
> -static int clariion_activate(struct scsi_device *sdev)
> +static int clariion_activate(struct scsi_device *sdev,
> + activate_complete fn, void *data)
> {
> struct clariion_dh_data *csdev = get_clariion_data(sdev);
> int result;
> @@ -559,7 +560,9 @@
> csdev->port, lun_state[csdev->lun_state],
> csdev->default_sp + 'A');
>
> - return result;
> + if (fn)
> + fn(data, result);
> + return 0;
> }
> /*
> * params - parameters in the following format
> Index: linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh_hp_sw.c
> ===================================================================
> --- linux-2.6.32-rc5.orig/drivers/scsi/device_handler/scsi_dh_hp_sw.c
> 2009-10-20 18:26:03.000000000 -0700
> +++ linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh_hp_sw.c 2009-
> 10-20 18:26:14.000000000 -0700
> @@ -268,7 +268,8 @@
> * activate the passive path (and deactivate the
> * previously active one).
> */
> -static int hp_sw_activate(struct scsi_device *sdev)
> +static int hp_sw_activate(struct scsi_device *sdev,
> + activate_complete fn, void *data)
> {
> int ret = SCSI_DH_OK;
> struct hp_sw_dh_data *h = get_hp_sw_data(sdev);
> @@ -283,7 +284,9 @@
> HP_SW_NAME);
> }
>
> - return ret;
> + if (fn)
> + fn(data, ret);
> + return 0;
> }
>
> static const struct scsi_dh_devlist hp_sw_dh_data_list[] = {
> Index: linux-2.6.32-rc5/include/scsi/scsi_device.h
> ===================================================================
> --- linux-2.6.32-rc5.orig/include/scsi/scsi_device.h 2009-10-20
> 18:26:03.000000000 -0700
> +++ linux-2.6.32-rc5/include/scsi/scsi_device.h 2009-10-20
> 18:26:14.000000000 -0700
> @@ -174,6 +174,7 @@
> char *model;
> };
>
> +typedef void (*activate_complete)(void *, int);
> struct scsi_device_handler {
> /* Used by the infrastructure */
> struct list_head list; /* list of scsi_device_handlers */
> @@ -185,7 +186,7 @@
> int (*check_sense)(struct scsi_device *, struct scsi_sense_hdr
> *);
> int (*attach)(struct scsi_device *);
> void (*detach)(struct scsi_device *);
> - int (*activate)(struct scsi_device *);
> + int (*activate)(struct scsi_device *, activate_complete, void *);
> int (*prep_fn)(struct scsi_device *, struct request *);
> int (*set_params)(struct scsi_device *, const char *);
> };
> Index: linux-2.6.32-rc5/drivers/md/dm-mpath.c
> ===================================================================
> --- linux-2.6.32-rc5.orig/drivers/md/dm-mpath.c 2009-10-20
> 18:26:03.000000000 -0700
> +++ linux-2.6.32-rc5/drivers/md/dm-mpath.c 2009-10-20
> 18:26:14.000000000 -0700
> @@ -1116,8 +1116,9 @@
> return limit_reached;
> }
>
> -static void pg_init_done(struct dm_path *path, int errors)
> +static void pg_init_done(void *data, int errors)
> {
> + struct dm_path *path = data;
> struct pgpath *pgpath = path_to_pgpath(path);
> struct priority_group *pg = pgpath->pg;
> struct multipath *m = pg->m;
> @@ -1183,12 +1184,11 @@
>
> static void activate_path(struct work_struct *work)
> {
> - int ret;
> struct pgpath *pgpath =
> container_of(work, struct pgpath, activate_path);
>
> - ret = scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev));
> - pg_init_done(&pgpath->path, ret);
> + scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev),
> + pg_init_done, &pgpath->path);
> }
>
> /*
> --
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