Hi Christoph, Mike and Hannes On 2017/10/29 18:01, Hannes Reinecke wrote: > After all, Linux is about choice, not about forcing users to do things > in one way only.
I have added an option CONFIG_NVME_SHOW_CTRL_BLK_DEV to show per-controller block devices nodes. It is tested simply that dm-multipath and nvme-mpath can coexist. This patch, based on the Christoph V5 of nvme-mpath, is in the following. Does it look good for you ? Regards Guan -- >From de3f446af6591d68ef84333138e744f12db4d695 Mon Sep 17 00:00:00 2001 From: Junxiong Guan <[email protected]> Date: Mon, 30 Oct 2017 04:59:20 -0400 Subject: [PATCH] nvme: add an option to show per-controller block devices nodes Signed-off-by: Junxiong Guan <[email protected]> --- drivers/nvme/host/Kconfig | 9 ++++++ drivers/nvme/host/core.c | 80 +++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 87 insertions(+), 2 deletions(-) diff --git a/drivers/nvme/host/Kconfig b/drivers/nvme/host/Kconfig index 46d6cb1e03bd..725bff035f38 100644 --- a/drivers/nvme/host/Kconfig +++ b/drivers/nvme/host/Kconfig @@ -13,6 +13,15 @@ config BLK_DEV_NVME To compile this driver as a module, choose M here: the module will be called nvme. +config NVME_SHOW_CTRL_BLK_DEV + bool "Show per-controller block devices of NVMe" + depends on NVME_CORE + ---help--- + This adds support to show per-controller block devices nodes in + the user space. + + If unsure, say N. + config NVME_FABRICS tristate diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 334735db90c8..ae37e274108c 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -72,6 +72,9 @@ static DEFINE_IDA(nvme_subsystems_ida); static LIST_HEAD(nvme_subsystems); static DEFINE_MUTEX(nvme_subsystems_lock); +#ifdef CONFIG_NVME_SHOW_CTRL_BLK_DEV +static DEFINE_SPINLOCK(dev_list_lock); +#endif static DEFINE_IDA(nvme_instance_ida); static dev_t nvme_chr_devt; static struct class *nvme_class; @@ -357,6 +360,14 @@ static void nvme_free_ns(struct kref *kref) if (ns->ndev) nvme_nvm_unregister(ns); + +#ifdef CONFIG_NVME_SHOW_CTRL_BLK_DEV + if (ns->disk) { + spin_lock(&dev_list_lock); + ns->disk->private_data = NULL; + spin_unlock(&dev_list_lock); + } +#endif put_disk(ns->disk); nvme_put_ns_head(ns->head); nvme_put_ctrl(ns->ctrl); @@ -1127,10 +1138,32 @@ static int nvme_ns_ioctl(struct nvme_ns *ns, unsigned int cmd, } } -/* should never be called due to GENHD_FL_HIDDEN */ static int nvme_open(struct block_device *bdev, fmode_t mode) { +#ifdef CONFIG_NVME_SHOW_CTRL_BLK_DEV + struct nvme_ns *ns; + + spin_lock(&dev_list_lock); + ns = bdev->bd_disk->private_data; + if (ns) { + if (!kref_get_unless_zero(&ns->kref)) + goto fail; + if (!try_module_get(ns->ctrl->ops->module)) + goto fail_put_ns; + } + spin_unlock(&dev_list_lock); + + return ns ? 0 : -ENXIO; + +fail_put_ns: + kref_put(&ns->kref, nvme_free_ns); +fail: + spin_unlock(&dev_list_lock); + return -ENXIO; +#else + /* should never be called due to GENHD_FL_HIDDEN */ return WARN_ON_ONCE(-ENXIO); +#endif /* CONFIG_NVME_SHOW_CTRL_BLK_DEV */ } static int nvme_getgeo(struct block_device *bdev, struct hd_geometry *geo) @@ -1392,10 +1425,15 @@ static char nvme_pr_type(enum pr_type type) static int nvme_pr_command(struct block_device *bdev, u32 cdw10, u64 key, u64 sa_key, u8 op) { +#ifdef CONFIG_NVME_SHOW_CTRL_BLK_DEV + struct nvme_ns *ns = bdev->bd_disk->private_data; + struct nvme_ns_head *head = ns->head; +#else struct nvme_ns_head *head = bdev->bd_disk->private_data; struct nvme_ns *ns; - struct nvme_command c; int srcu_idx, ret; +#endif + struct nvme_command c; u8 data[16] = { 0, }; put_unaligned_le64(key, &data[0]); @@ -1406,6 +1444,9 @@ static int nvme_pr_command(struct block_device *bdev, u32 cdw10, c.common.nsid = cpu_to_le32(head->ns_id); c.common.cdw10[0] = cpu_to_le32(cdw10); +#ifdef CONFIG_NVME_SHOW_CTRL_BLK_DEV + return nvme_submit_sync_cmd(ns->queue, &c, data, 16); +#else srcu_idx = srcu_read_lock(&head->srcu); ns = nvme_find_path(head); if (likely(ns)) @@ -1413,7 +1454,9 @@ static int nvme_pr_command(struct block_device *bdev, u32 cdw10, else ret = -EWOULDBLOCK; srcu_read_unlock(&head->srcu, srcu_idx); + return ret; +#endif } static int nvme_pr_register(struct block_device *bdev, u64 old, @@ -1492,6 +1535,34 @@ int nvme_sec_submit(void *data, u16 spsp, u8 secp, void *buffer, size_t len, EXPORT_SYMBOL_GPL(nvme_sec_submit); #endif /* CONFIG_BLK_SED_OPAL */ +#ifdef CONFIG_NVME_SHOW_CTRL_BLK_DEV +static void nvme_release(struct gendisk *disk, fmode_t mode) +{ + struct nvme_ns *ns = disk->private_data; + + module_put(ns->ctrl->ops->module); + nvme_put_ns(ns); +} + +static int nvme_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + struct nvme_ns *ns = bdev->bd_disk->private_data; + + return nvme_ns_ioctl(ns, cmd, arg); +} + +static const struct block_device_operations nvme_fops = { + .owner = THIS_MODULE, + .ioctl = nvme_ioctl, + .compat_ioctl = nvme_ioctl, + .open = nvme_open, + .release = nvme_release, + .getgeo = nvme_getgeo, + .revalidate_disk= nvme_revalidate_disk, + .pr_ops =&nvme_pr_ops, +}; +#else /* * While we don't expose the per-controller devices to userspace we still * need valid file operations for them, for one because the block layer @@ -1503,6 +1574,7 @@ static const struct block_device_operations nvme_fops = { .open = nvme_open, .revalidate_disk= nvme_revalidate_disk, }; +#endif /* CONFIG_NVME_SHOW_CTRL_BLK_DEV */ static int nvme_wait_ready(struct nvme_ctrl *ctrl, u64 cap, bool enabled) { @@ -2875,7 +2947,11 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) disk->fops = &nvme_fops; disk->private_data = ns; disk->queue = ns->queue; +#ifdef CONFIG_NVME_SHOW_CTRL_BLK_DEV + disk->flags = GENHD_FL_EXT_DEVT; +#else disk->flags = GENHD_FL_HIDDEN; +#endif memcpy(disk->disk_name, disk_name, DISK_NAME_LEN); ns->disk = disk; -- 2.11.1
