Commit e3d34794 authored by Hannes Reinecke's avatar Hannes Reinecke Committed by Christoph Hellwig
Browse files

nvme: add 'iopolicy' module parameter 



While the 'iopolicy' sysfs attribute can be set at runtime, most
storage arrays prefer to use the 'round-robin' iopolicy per default.
We can use udev rules to set this, but is getting rather unwieldy
for rebranded arrays as we would have to update the udev rules
anytime a new array shows up, leading to the same mess we currently
have in multipathd for configuring the RDAC arrays.

Hence this patch adds a module parameter 'iopolicy' to allow the
admin to switch the default, and to do away with the need for a
udev rule here.

Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Reviewed-by: default avatarDaniel Wagner <dwagner@suse.de>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 3a605e32

drivers/nvme/host/core.c

+1 −3
Original line number Diff line number Diff line
@@ -2746,9 +2746,7 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) 
		return -EINVAL;

	}

	subsys->awupf = le16_to_cpu(id->awupf);

#ifdef CONFIG_NVME_MULTIPATH

	subsys->iopolicy = NVME_IOPOLICY_NUMA;

#endif

	nvme_mpath_default_iopolicy(subsys);



	subsys->dev.class = nvme_subsys_class;

	subsys->dev.release = nvme_release_subsystem;

drivers/nvme/host/multipath.c

+36 −5
Original line number Diff line number Diff line
@@ -13,6 +13,42 @@ module_param(multipath, bool, 0444); 
MODULE_PARM_DESC(multipath,

	"turn on native support for multiple controllers per subsystem");



static const char *nvme_iopolicy_names[] = {

	[NVME_IOPOLICY_NUMA]	= "numa",

	[NVME_IOPOLICY_RR]	= "round-robin",

};



static int iopolicy = NVME_IOPOLICY_NUMA;



static int nvme_set_iopolicy(const char *val, const struct kernel_param *kp)

{

	if (!val)

		return -EINVAL;

	if (!strncmp(val, "numa", 4))

		iopolicy = NVME_IOPOLICY_NUMA;

	else if (!strncmp(val, "round-robin", 11))

		iopolicy = NVME_IOPOLICY_RR;

	else

		return -EINVAL;



	return 0;

}



static int nvme_get_iopolicy(char *buf, const struct kernel_param *kp)

{

	return sprintf(buf, "%s\n", nvme_iopolicy_names[iopolicy]);

}



module_param_call(iopolicy, nvme_set_iopolicy, nvme_get_iopolicy,

	&iopolicy, 0644);

MODULE_PARM_DESC(iopolicy,

	"Default multipath I/O policy; 'numa' (default) or 'round-robin'");



void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys)

{

	subsys->iopolicy = iopolicy;

}



void nvme_mpath_unfreeze(struct nvme_subsystem *subsys)

{

	struct nvme_ns_head *h;
@@ -706,11 +742,6 @@ void nvme_mpath_stop(struct nvme_ctrl *ctrl) 
	struct device_attribute subsys_attr_##_name =	\

		__ATTR(_name, _mode, _show, _store)



static const char *nvme_iopolicy_names[] = {

	[NVME_IOPOLICY_NUMA]	= "numa",

	[NVME_IOPOLICY_RR]	= "round-robin",

};



static ssize_t nvme_subsys_iopolicy_show(struct device *dev,

		struct device_attribute *attr, char *buf)

{

drivers/nvme/host/nvme.h

+4 −0
Original line number Diff line number Diff line
@@ -767,6 +767,7 @@ static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl) 
void nvme_mpath_unfreeze(struct nvme_subsystem *subsys);

void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys);

void nvme_mpath_start_freeze(struct nvme_subsystem *subsys);

void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys);

bool nvme_mpath_set_disk_name(struct nvme_ns *ns, char *disk_name, int *flags);

void nvme_failover_req(struct request *req);

void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl);
@@ -864,6 +865,9 @@ static inline void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys) 
static inline void nvme_mpath_start_freeze(struct nvme_subsystem *subsys)

{

}

static inline void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys)

{

}

#endif /* CONFIG_NVME_MULTIPATH */



int nvme_revalidate_zones(struct nvme_ns *ns);