Add support to set the multipath iopolicy. The iopolicy member is per scsi_mpath_head structure.
A module param is added so that the default iopolicy may be set. Signed-off-by: John Garry <[email protected]> --- drivers/scsi/scsi_multipath.c | 57 +++++++++++++++++++++++++++++++++++ include/scsi/scsi_multipath.h | 1 + 2 files changed, 58 insertions(+) diff --git a/drivers/scsi/scsi_multipath.c b/drivers/scsi/scsi_multipath.c index ac55f9f39a5b2..4b7984e7e74ba 100644 --- a/drivers/scsi/scsi_multipath.c +++ b/drivers/scsi/scsi_multipath.c @@ -72,6 +72,23 @@ module_param_cb(scsi_multipath_always, &multipath_always_on_ops, MODULE_PARM_DESC(scsi_multipath_always, "create multipath node always even for no ALUA support"); +static int iopolicy = MPATH_IOPOLICY_NUMA; + +static int scsi_set_iopolicy(const char *val, const struct kernel_param *kp) +{ + return mpath_set_iopolicy(val, &iopolicy); +} + +static int scsi_get_iopolicy(char *buf, const struct kernel_param *kp) +{ + return mpath_get_iopolicy(buf, iopolicy); +} + +module_param_call(iopolicy, scsi_set_iopolicy, scsi_get_iopolicy, + &iopolicy, 0644); +MODULE_PARM_DESC(iopolicy, + "Default multipath I/O policy; 'numa' (default), 'round-robin' or 'queue-depth'"); + static int scsi_mpath_unique_lun_id(struct scsi_device *sdev) { struct scsi_mpath_device *scsi_mpath_dev = sdev->scsi_mpath_dev; @@ -116,8 +133,40 @@ static ssize_t scsi_mpath_device_wwid_show(struct device *dev, static DEVICE_ATTR(wwid, S_IRUGO, scsi_mpath_device_wwid_show, NULL); +static void scsi_mpath_device_iopolicy_store_update(void *data) +{ + struct scsi_mpath_head *scsi_mpath_head = data; + struct mpath_head *mpath_head = scsi_mpath_head->mpath_head; + + mpath_clear_paths(mpath_head); + kblockd_schedule_work(&mpath_head->requeue_work); +} + +static ssize_t scsi_mpath_device_iopolicy_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct scsi_mpath_head *scsi_mpath_head = + container_of(dev, struct scsi_mpath_head, dev); + + return mpath_iopolicy_store(&scsi_mpath_head->iopolicy, buf, count, + scsi_mpath_device_iopolicy_store_update, scsi_mpath_head); +} + +static ssize_t scsi_mpath_device_iopolicy_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct scsi_mpath_head *scsi_mpath_head = + container_of(dev, struct scsi_mpath_head, dev); + + return mpath_iopolicy_show(&scsi_mpath_head->iopolicy, buf); +} + +static DEVICE_ATTR(iopolicy, S_IRUGO | S_IWUSR, + scsi_mpath_device_iopolicy_show, scsi_mpath_device_iopolicy_store); + static struct attribute *scsi_mpath_device_attrs[] = { &dev_attr_wwid.attr, + &dev_attr_iopolicy.attr, NULL }; @@ -211,7 +260,15 @@ static int scsi_multipath_sdev_init(struct scsi_device *sdev) return 0; } +static enum mpath_iopolicy_e scsi_mpath_get_iopolicy(struct mpath_head *mpath_head) +{ + struct scsi_mpath_head *scsi_mpath_head = mpath_head->drvdata; + + return mpath_read_iopolicy(&scsi_mpath_head->iopolicy); +} + struct mpath_head_template smpdt_pr = { + .get_iopolicy = scsi_mpath_get_iopolicy, }; static struct scsi_mpath_head *scsi_mpath_alloc_head(void) diff --git a/include/scsi/scsi_multipath.h b/include/scsi/scsi_multipath.h index d8102df329d6b..8dbe1c3784d2c 100644 --- a/include/scsi/scsi_multipath.h +++ b/include/scsi/scsi_multipath.h @@ -25,6 +25,7 @@ struct scsi_mpath_head { int dev_count; struct ida ida; struct mutex lock; + struct mpath_iopolicy iopolicy; struct mpath_head *mpath_head; struct device dev; int index; -- 2.43.5
