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 | 54 +++++++++++++++++++++++++++++++++++ include/scsi/scsi_multipath.h | 1 + 2 files changed, 55 insertions(+) diff --git a/drivers/scsi/scsi_multipath.c b/drivers/scsi/scsi_multipath.c index 31ab1d477c686..c6ae02644fdf4 100644 --- a/drivers/scsi/scsi_multipath.c +++ b/drivers/scsi/scsi_multipath.c @@ -60,6 +60,23 @@ static const struct kernel_param_ops multipath_param_ops = { module_param_cb(multipath, &multipath_param_ops, &scsi_multipath, 0444); MODULE_PARM_DESC(multipath, "turn on native multipath support, options: on, off, always"); +static int iopolicy = MPATH_IOPOLICY_NUMA; + +static int scsi_mpath_set_iopolicy_param(const char *val, const struct kernel_param *kp) +{ + return mpath_set_iopolicy(val, &iopolicy); +} + +static int scsi_mpath_get_iopolicy_param(char *buf, const struct kernel_param *kp) +{ + return mpath_get_iopolicy(buf, iopolicy); +} + +module_param_call(multipath_iopolicy, scsi_mpath_set_iopolicy_param, + scsi_mpath_get_iopolicy_param, &iopolicy, 0644); +MODULE_PARM_DESC(multipath_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; @@ -95,8 +112,36 @@ static ssize_t scsi_mpath_device_vpd_id_show(struct device *dev, } static DEVICE_ATTR(vpd_id, S_IRUGO, scsi_mpath_device_vpd_id_show, NULL); +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); + struct mpath_head *mpath_head = scsi_mpath_head->mpath_head; + + if (!mpath_iopolicy_store(&scsi_mpath_head->iopolicy, buf, count)) + return -EINVAL; + + mpath_clear_paths(mpath_head); + mpath_schedule_requeue_work(mpath_head); + return count; +} + +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_vpd_id.attr, + &dev_attr_iopolicy.attr, NULL }; @@ -185,7 +230,15 @@ 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 = { + .get_iopolicy = scsi_mpath_get_iopolicy, }; static struct scsi_mpath_head *scsi_mpath_alloc_head(void) @@ -204,6 +257,7 @@ static struct scsi_mpath_head *scsi_mpath_alloc_head(void) goto out_free; scsi_mpath_head->mpath_head->mpdt = &smpdt; scsi_mpath_head->mpath_head->drvdata = scsi_mpath_head; + scsi_mpath_head->iopolicy.iopolicy = iopolicy; scsi_mpath_head->index = ida_alloc(&scsi_multipath_dev_ida, GFP_KERNEL); if (scsi_mpath_head->index < 0) diff --git a/include/scsi/scsi_multipath.h b/include/scsi/scsi_multipath.h index 9e92d949392d4..de6339989d2a2 100644 --- a/include/scsi/scsi_multipath.h +++ b/include/scsi/scsi_multipath.h @@ -24,6 +24,7 @@ struct scsi_mpath_head { struct list_head entry; struct ida ida; struct kref ref; + struct mpath_iopolicy iopolicy; struct mpath_head *mpath_head; struct device dev; int index; -- 2.43.5
