From 77b7ebc5f8cf950257ce9f39a7a107bb82a43627 Mon Sep 17 00:00:00 2001 From: Ashok Vairavan Date: Mon, 10 Oct 2016 12:13:01 -0700 Subject: [PATCH] NVMe: Implement namespace list scanning The NVMe 1.1 specification provides an identify mode to return a list of active namespaces. This is more efficient to discover which namespace identifiers are active on a controller, providing potentially significant improvement in scan time for controllers with sparesly populated namespaces. Signed-off-by: Keith Busch [hch: add quirk for the broken Qemu Identify implementation. To be relaxed later] Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe (cherry picked from commit 540c801c65eb58e05e0ca38b6fd644a83d7e2b33) Orabug: 24583236 Signed-off-by: Ashok Vairavan --- drivers/nvme/host/pci.c | 93 ++++++++++++++++++++++++++++++++++------- 1 file changed, 79 insertions(+), 14 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 4e506649a7fb..81606e1de21d 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -1186,6 +1186,16 @@ int nvme_identify_ctrl(struct nvme_dev *dev, struct nvme_id_ctrl **id) return error; } +static int nvme_identify_ns_list(struct nvme_dev *dev, unsigned nsid, __le32 *ns_list) +{ + struct nvme_command c = { }; + + c.identify.opcode = nvme_admin_identify; + c.identify.cns = cpu_to_le32(2); + c.identify.nsid = cpu_to_le32(nsid); + return nvme_submit_sync_cmd(dev->admin_q, &c, ns_list, 0x1000); +} + int nvme_identify_ns(struct nvme_dev *dev, unsigned nsid, struct nvme_id_ns **id) { @@ -2420,37 +2430,92 @@ static void nvme_ns_remove(struct nvme_ns *ns) kref_put(&ns->kref, nvme_free_ns); } -static void nvme_scan_namespaces(struct nvme_dev *dev, unsigned nn) +static void nvme_validate_ns(struct nvme_dev *dev, unsigned nsid) { - struct nvme_ns *ns, *next; - unsigned i; + struct nvme_ns *ns; - for (i = 1; i <= nn; i++) { - ns = nvme_find_ns(dev, i); - if (ns) { - if (revalidate_disk(ns->disk)) - nvme_ns_remove(ns); + ns = nvme_find_ns(dev, nsid); + if (ns) { + if (revalidate_disk(ns->disk)) + nvme_ns_remove(ns); } else - nvme_alloc_ns(dev, i); + nvme_alloc_ns(dev, nsid); +} + +static int nvme_scan_ns_list(struct nvme_dev *dev, unsigned nn) +{ + struct nvme_ns *ns; + __le32 *ns_list; + unsigned i, j, nsid, prev = 0, num_lists = DIV_ROUND_UP(nn, 1024); + int ret = 0; + + ns_list = kzalloc(0x1000, GFP_KERNEL); + if (!ns_list) + return -ENOMEM; + + for (i = 0; i < num_lists; i++) { + ret = nvme_identify_ns_list(dev, prev, ns_list); + if (ret) + goto out; + + for (j = 0; j < min(nn, 1024U); j++) { + nsid = le32_to_cpu(ns_list[j]); + if (!nsid) + goto out; + + nvme_validate_ns(dev, nsid); + + while (++prev < nsid) { + ns = nvme_find_ns(dev, prev); + if (ns) + nvme_ns_remove(ns); + } + } + nn -= j; } + out: + kfree(ns_list); + return ret; +} + +static void __nvme_scan_namespaces(struct nvme_dev *dev, unsigned nn) +{ + struct nvme_ns *ns, *next; + unsigned i; + + for (i = 1; i <= nn; i++) + nvme_validate_ns(dev, i); + list_for_each_entry_safe(ns, next, &dev->namespaces, list) { if (ns->ns_id > nn) nvme_ns_remove(ns); } +} + +void nvme_scan_namespaces(struct nvme_dev *dev) +{ + struct nvme_id_ctrl *id; + unsigned nn; + + if (nvme_identify_ctrl(dev, &id)) + return; + + nn = le32_to_cpu(id->nn); + if (!nvme_scan_ns_list(dev, nn)) + goto done; + __nvme_scan_namespaces(dev, le32_to_cpup(&id->nn)); +done: list_sort(NULL, &dev->namespaces, ns_cmp); + kfree(id); } static void nvme_dev_scan(struct work_struct *work) { struct nvme_dev *dev = container_of(work, struct nvme_dev, scan_work); - struct nvme_id_ctrl *ctrl; if (!dev->tagset.tags) return; - if (nvme_identify_ctrl(dev, &ctrl)) - return; - nvme_scan_namespaces(dev, le32_to_cpup(&ctrl->nn)); - kfree(ctrl); + nvme_scan_namespaces(dev); } /* -- 2.50.1