diff options
| -rw-r--r-- | drivers/nvme/host/multipath.c | 72 |
1 files changed, 66 insertions, 6 deletions
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 2db326d6114f..38b420fb63f0 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -10,10 +10,61 @@ #include "nvme.h" bool multipath = true; -module_param(multipath, bool, 0444); +static bool multipath_always_on; + +static int multipath_param_set(const char *val, const struct kernel_param *kp) +{ + int ret; + bool *arg = kp->arg; + + ret = param_set_bool(val, kp); + if (ret) + return ret; + + if (multipath_always_on && !*arg) { + pr_err("Can't disable multipath when multipath_always_on is configured.\n"); + *arg = true; + return -EINVAL; + } + + return 0; +} + +static const struct kernel_param_ops multipath_param_ops = { + .set = multipath_param_set, + .get = param_get_bool, +}; + +module_param_cb(multipath, &multipath_param_ops, &multipath, 0444); MODULE_PARM_DESC(multipath, "turn on native support for multiple controllers per subsystem"); +static int multipath_always_on_set(const char *val, + const struct kernel_param *kp) +{ + int ret; + bool *arg = kp->arg; + + ret = param_set_bool(val, kp); + if (ret < 0) + return ret; + + if (*arg) + multipath = true; + + return 0; +} + +static const struct kernel_param_ops multipath_always_on_ops = { + .set = multipath_always_on_set, + .get = param_get_bool, +}; + +module_param_cb(multipath_always_on, &multipath_always_on_ops, + &multipath_always_on, 0444); +MODULE_PARM_DESC(multipath_always_on, + "create multipath node always except for private namespace with non-unique nsid; note that this also implicitly enables native multipath support"); + static const char *nvme_iopolicy_names[] = { [NVME_IOPOLICY_NUMA] = "numa", [NVME_IOPOLICY_RR] = "round-robin", @@ -674,12 +725,21 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) head->delayed_removal_secs = 0; /* - * Add a multipath node if the subsystems supports multiple controllers. - * We also do this for private namespaces as the namespace sharing flag - * could change after a rescan. + * If "multipath_always_on" is enabled, a multipath node is added + * regardless of whether the disk is single/multi ported, and whether + * the namespace is shared or private. If "multipath_always_on" is not + * enabled, a multipath node is added only if the subsystem supports + * multiple controllers and the "multipath" option is configured. In + * either case, for private namespaces, we ensure that the NSID is + * unique. */ - if (!(ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) || - !nvme_is_unique_nsid(ctrl, head) || !multipath) + if (!multipath_always_on) { + if (!(ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) || + !multipath) + return 0; + } + + if (!nvme_is_unique_nsid(ctrl, head)) return 0; blk_set_stacking_limits(&lim); |