[dm-devel] [PATCH 1/4] scsi_dh: Change the scsidh_activate interface to be asynchronous
Chandra Seetharaman
sekharan at us.ibm.com
Wed Oct 21 16:22:46 UTC 2009
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>
--------------
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);
}
/*
More information about the dm-devel
mailing list