Commit 540c801c authored by Keith Busch's avatar Keith Busch Committed by Jens Axboe
Browse files

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: default avatarKeith Busch <keith.busch@intel.com>
[hch: add quirk for the broken Qemu Identify implementation.  To be relaxed
 later]
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 6bf25d16

drivers/nvme/host/core.c

+71 −9
Original line number Diff line number Diff line
@@ -256,6 +256,16 @@ int nvme_identify_ctrl(struct nvme_ctrl *dev, struct nvme_id_ctrl **id) 
	return error;

}



static int nvme_identify_ns_list(struct nvme_ctrl *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_ctrl *dev, unsigned nsid,

		struct nvme_id_ns **id)

{
@@ -1071,33 +1081,85 @@ static void nvme_ns_remove(struct nvme_ns *ns) 
	nvme_put_ns(ns);

}



static void __nvme_scan_namespaces(struct nvme_ctrl *ctrl, unsigned nn)

static void nvme_validate_ns(struct nvme_ctrl *ctrl, unsigned nsid)

{

	struct nvme_ns *ns, *next;

	unsigned i;

	struct nvme_ns *ns;



	for (i = 1; i <= nn; i++) {

		ns = nvme_find_ns(ctrl, i);

	ns = nvme_find_ns(ctrl, nsid);

	if (ns) {

		if (revalidate_disk(ns->disk))

			nvme_ns_remove(ns);

	} else

			nvme_alloc_ns(ctrl, i);

		nvme_alloc_ns(ctrl, nsid);

}



static int nvme_scan_ns_list(struct nvme_ctrl *ctrl, 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(ctrl, 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(ctrl, nsid);



			while (++prev < nsid) {

				ns = nvme_find_ns(ctrl, prev);

				if (ns)

					nvme_ns_remove(ns);

			}

		}

		nn -= j;

	}

 out:

	kfree(ns_list);

	return ret;

}



static void __nvme_scan_namespaces(struct nvme_ctrl *ctrl, unsigned nn)

{

	struct nvme_ns *ns, *next;

	unsigned i;



	for (i = 1; i <= nn; i++)

		nvme_validate_ns(ctrl, i);



	list_for_each_entry_safe(ns, next, &ctrl->namespaces, list) {

		if (ns->ns_id > nn)

			nvme_ns_remove(ns);

	}

	list_sort(NULL, &ctrl->namespaces, ns_cmp);

}



void nvme_scan_namespaces(struct nvme_ctrl *ctrl)

{

	struct nvme_id_ctrl *id;

	unsigned nn;



	if (nvme_identify_ctrl(ctrl, &id))

		return;



	nn = le32_to_cpu(id->nn);

	if (ctrl->vs >= NVME_VS(1, 1) &&

	    !(ctrl->quirks & NVME_QUIRK_IDENTIFY_CNS)) {

		if (!nvme_scan_ns_list(ctrl, nn))

			goto done;

	}

	__nvme_scan_namespaces(ctrl, le32_to_cpup(&id->nn));

 done:

	list_sort(NULL, &ctrl->namespaces, ns_cmp);

	kfree(id);

}

drivers/nvme/host/nvme.h

+6 −0
Original line number Diff line number Diff line
@@ -53,6 +53,12 @@ enum nvme_quirks { 
	 * specific Identify field.

	 */

	NVME_QUIRK_STRIPE_SIZE			= (1 << 0),



	/*

	 * The controller doesn't handle Identify value others than 0 or 1

	 * correctly.

	 */

	NVME_QUIRK_IDENTIFY_CNS			= (1 << 1),

};



struct nvme_ctrl {

drivers/nvme/host/pci.c

+2 −0
Original line number Diff line number Diff line
@@ -2425,6 +2425,8 @@ static const struct pci_error_handlers nvme_err_handler = { 
static const struct pci_device_id nvme_id_table[] = {

	{ PCI_VDEVICE(INTEL, 0x0953),

		.driver_data = NVME_QUIRK_STRIPE_SIZE, },

	{ PCI_VDEVICE(INTEL, 0x5845),	/* Qemu emulated controller */

		.driver_data = NVME_QUIRK_IDENTIFY_CNS, },

	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },

	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },

	{ 0, }

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