From d934f9848a77be4afe0ca336ea419dd066c934f3 Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn Date: Wed, 7 Jun 2017 11:45:35 +0200 Subject: [PATCH] nvme: provide UUID value to userspace Now that we have a way for getting the UUID from a target, provide it to userspace as well. Unfortunately there is already a sysfs attribute called UUID which is a misnomer as it holds the NGUID value. So instead of creating yet another wrong name, create a new 'nguid' sysfs attribute for the NGUID. For the UUID attribute add a check wheter the namespace has a UUID assigned to it and return this or return the NGUID to maintain backwards compatibility. This should give userspace a chance to catch up. Signed-off-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Sagi Grimberg Signed-off-by: Christoph Hellwig --- drivers/nvme/host/core.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 17118ef63c59..89a7fe422e1a 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1879,11 +1879,28 @@ static ssize_t wwid_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR(wwid, S_IRUGO, wwid_show, NULL); +static ssize_t nguid_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct nvme_ns *ns = nvme_get_ns_from_dev(dev); + return sprintf(buf, "%pU\n", ns->nguid); +} +static DEVICE_ATTR(nguid, S_IRUGO, nguid_show, NULL); + static ssize_t uuid_show(struct device *dev, struct device_attribute *attr, char *buf) { struct nvme_ns *ns = nvme_get_ns_from_dev(dev); - return sprintf(buf, "%pU\n", ns->nguid); + + /* For backward compatibility expose the NGUID to userspace if + * we have no UUID set + */ + if (uuid_is_null(&ns->uuid)) { + printk_ratelimited(KERN_WARNING + "No UUID available providing old NGUID\n"); + return sprintf(buf, "%pU\n", ns->nguid); + } + return sprintf(buf, "%pU\n", &ns->uuid); } static DEVICE_ATTR(uuid, S_IRUGO, uuid_show, NULL); @@ -1906,6 +1923,7 @@ static DEVICE_ATTR(nsid, S_IRUGO, nsid_show, NULL); static struct attribute *nvme_ns_attrs[] = { &dev_attr_wwid.attr, &dev_attr_uuid.attr, + &dev_attr_nguid.attr, &dev_attr_eui.attr, &dev_attr_nsid.attr, NULL, @@ -1918,6 +1936,11 @@ static umode_t nvme_ns_attrs_are_visible(struct kobject *kobj, struct nvme_ns *ns = nvme_get_ns_from_dev(dev); if (a == &dev_attr_uuid.attr) { + if (uuid_is_null(&ns->uuid) || + !memchr_inv(ns->nguid, 0, sizeof(ns->nguid))) + return 0; + } + if (a == &dev_attr_nguid.attr) { if (!memchr_inv(ns->nguid, 0, sizeof(ns->nguid))) return 0; } -- 2.30.2