[PATCH] NVMe: Asynchronous device scan
Swati
s.chawdhary at samsung.com
Wed Dec 10 06:43:07 PST 2014
Hi Keith,
Is there any feedback on this patch?
Are we going for the asynchronous add_disk approach, is somebody working on
that?
Regards,
Swati
-----Original Message-----
From: Vinayak Holikatti [mailto:h.vinayak at samsung.com]
Sent: Wednesday, November 05, 2014 9:50 PM
To: linux-nvme at lists.infradead.org
Cc: Vinayak Holikatti; Swati C
Subject: [PATCH] NVMe: Asynchronous device scan
This patch provides asynchronous device enumeration capablity.
This patch is based on Keiths patch of Asynchronous namespace discovery
http://lists.infradead.org/pipermail/linux-nvme/2013-September/000470.html
Signed-off-by: Vinayak Holikatti <h.vinayak at samsung.com>
Signed-off-by: Swati C <s.chawdhary at samsung.com>
---
drivers/block/nvme-core.c | 207
+++++++++++++++++++++++++++++++++++++---------
include/linux/nvme.h | 11 +++
2 files changed, 181 insertions(+), 37 deletions(-)
diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index
00fa5d2..11286c0 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -2336,6 +2336,85 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
return result;
}
+struct nvme_discover_event {
+ struct async_cmd_info cmdinfo;
+ struct nvme_dev *dev;
+ unsigned nsid;
+ void *mem;
+ dma_addr_t dma_addr;
+};
+
+static void free_disco_event(struct nvme_discover_event *event) {
+ dma_free_coherent(&event->dev->pci_dev->dev, 8192, event->mem,
+ event->dma_addr);
+ kfree(event);
+}
+
+void nvme_discovery_work_handler(struct kthread_work *work) {
+ struct nvme_ns *ns;
+ struct nvme_discover_event *event = container_of(work,
+ struct nvme_discover_event, cmdinfo.work);
+
+ if (test_bit(NVME_NN_PROBE_STOP, &event->dev->probe_work_stop))
+ goto free;
+
+ if (!event->cmdinfo.status) {
+ struct nvme_id_ns *id_ns = event->mem;
+
+ if (!id_ns->ncap)
+ goto free;
+ memset(event->mem + 4096, 0x0, 4096);
+ ns = nvme_alloc_ns(event->dev, event->nsid, event->mem,
+ event->mem + 4096);
+ if (ns) {
+ list_add_tail(&ns->list, &event->dev->namespaces);
+ add_disk(ns->disk);
+ event->dev->nvme_nn_probed = ns->ns_id;
+ }
+ }
+ free:
+ free_disco_event(event);
+}
+
+struct nvme_discover_event *alloc_disco_event(struct nvme_dev *dev,
+ unsigned
nsid)
+{
+ struct nvme_discover_event *event;
+
+ event = kzalloc(sizeof(*event), GFP_KERNEL);
+ if (!event)
+ return NULL;
+
+ event->mem = dma_alloc_coherent(&dev->pci_dev->dev, 8192,
+ &event->dma_addr, GFP_KERNEL);
+ if (!event->mem) {
+ kfree(event);
+ return NULL;
+ }
+ event->dev = dev;
+ event->nsid = nsid;
+ event->cmdinfo.worker = &dev->discovery_worker;
+ init_kthread_work(&event->cmdinfo.work,
nvme_discovery_work_handler);
+
+ return event;
+}
+
+static int nvme_identify_async(struct nvme_dev *dev,
+ struct nvme_discover_event *event)
+{
+ struct nvme_command c;
+
+ memset(&c, 0, sizeof(c));
+ c.identify.opcode = nvme_admin_identify;
+ c.identify.nsid = cpu_to_le32(event->nsid);
+ c.identify.prp1 = cpu_to_le64(event->dma_addr);
+ c.identify.cns = cpu_to_le32(0);
+
+ return nvme_submit_admin_cmd_async(dev, &c, &event->cmdinfo); }
+
/*
* Return: error value if an error occurred setting up the queues or
calling
* Identify Device. 0 if these succeeded, even if adding some of the @@
-2345,24 +2424,24 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
static int nvme_dev_add(struct nvme_dev *dev) {
struct pci_dev *pdev = dev->pci_dev;
+ struct nvme_discover_event *event;
int res;
unsigned nn, i;
- struct nvme_ns *ns;
struct nvme_id_ctrl *ctrl;
- struct nvme_id_ns *id_ns;
void *mem;
dma_addr_t dma_addr;
int shift = NVME_CAP_MPSMIN(readq(&dev->bar->cap)) + 12;
- mem = dma_alloc_coherent(&pdev->dev, 8192, &dma_addr, GFP_KERNEL);
+ mem = dma_alloc_coherent(&dev->pci_dev->dev, 4096, &dma_addr,
+ GFP_KERNEL);
if (!mem)
return -ENOMEM;
res = nvme_identify(dev, 0, 1, dma_addr);
if (res) {
dev_err(&pdev->dev, "Identify Controller failed (%d)\n",
res);
- res = -EIO;
- goto out;
+ dma_free_coherent(&dev->pci_dev->dev, 4096, mem, dma_addr);
+ return -EIO;
}
ctrl = mem;
@@ -2380,30 +2459,31 @@ static int nvme_dev_add(struct nvme_dev *dev)
(pdev->device == 0x0953) && ctrl->vs[3])
dev->stripe_size = 1 << (ctrl->vs[3] + shift);
- id_ns = mem;
- for (i = 1; i <= nn; i++) {
- res = nvme_identify(dev, i, 0, dma_addr);
- if (res)
- continue;
+ dma_free_coherent(&dev->pci_dev->dev, 4096, mem, dma_addr);
- if (id_ns->ncap == 0)
- continue;
+ if (nn == dev->nvme_nn_probed)
+ return 0;
- res = nvme_get_features(dev, NVME_FEAT_LBA_RANGE, i,
- dma_addr + 4096,
NULL);
- if (res)
- memset(mem + 4096, 0, 4096);
- ns = nvme_alloc_ns(dev, i, mem, mem + 4096);
- if (ns)
- list_add_tail(&ns->list, &dev->namespaces);
+ for (i = (dev->nvme_nn_probed + 1); i <= nn; i++) {
+
+ if (kthread_should_stop())
+ return -EIO;
+
+
+ event = alloc_disco_event(dev, i);
+ if (!event) {
+ res = -ENOMEM;
+ break;
+ }
+ res = nvme_identify_async(dev, event);
+ if (res) {
+ free_disco_event(event);
+ break;
+ }
}
- list_for_each_entry(ns, &dev->namespaces, list)
- add_disk(ns->disk);
- res = 0;
- out:
- dma_free_coherent(&dev->pci_dev->dev, 8192, mem, dma_addr);
+ res = 0;
return res;
}
@@ -2642,6 +2722,8 @@ static void nvme_dev_shutdown(struct nvme_dev *dev)
}
} else {
nvme_disable_io_queues(dev);
+ flush_kthread_worker(&dev->discovery_worker);
+ kthread_stop(dev->discovery_worker_task);
nvme_shutdown_ctrl(dev);
nvme_disable_queue(dev, 0);
}
@@ -2811,12 +2893,23 @@ static int nvme_dev_start(struct nvme_dev *dev)
}
nvme_init_queue(raw_nvmeq(dev, 0), 0);
+ init_kthread_worker(&dev->discovery_worker);
+ dev->discovery_worker_task = kthread_run(kthread_worker_fn,
+ &dev->discovery_worker, "nvme%d", dev->instance);
+ if (IS_ERR_OR_NULL(dev->discovery_worker_task)) {
+ result = PTR_ERR(dev->discovery_worker_task);
+ goto disable;
+ }
+
result = nvme_setup_io_queues(dev);
if (result)
- goto disable;
+ goto stop_discovery;
return result;
+stop_discovery:
+ flush_kthread_worker(&dev->discovery_worker);
+ kthread_stop(dev->discovery_worker_task);
disable:
nvme_disable_queue(dev, 0);
nvme_dev_list_remove(dev);
@@ -2825,6 +2918,24 @@ static int nvme_dev_start(struct nvme_dev *dev)
return result;
}
+static int nvme_probe_workfn(void *data) {
+ struct nvme_dev *dev = data;
+ int result = -ENOMEM;
+
+ result = nvme_dev_add(dev);
+ if (result == -EIO) {
+ dev->nvme_probe_thread = NULL;
+ return result;
+ }
+
+ flush_kthread_worker(&dev->discovery_worker);
+ dev->initialized = 1;
+ dev->nvme_probe_thread = NULL;
+ return result;
+
+}
+
static int nvme_remove_dead_ctrl(void *arg) {
struct nvme_dev *dev = (struct nvme_dev *)arg; @@ -2857,7 +2968,16
@@ static int nvme_dev_resume(struct nvme_dev *dev)
queue_work(nvme_workq, &dev->reset_work);
spin_unlock(&dev_list_lock);
}
- dev->initialized = 1;
+
+ if (dev->online_queues > 1) {
+ dev->nvme_probe_thread = kthread_run(nvme_probe_workfn,
+ dev,
+
"nvme_namespace_probe%d",
+ dev->instance);
+ if (dev->nvme_probe_thread == ERR_PTR(-ENOMEM))
+ dev_err(&dev->pci_dev->dev,
+ "Failed to invoke
nvme_probe_work");
+ }
return 0;
}
@@ -2927,11 +3047,6 @@ static int nvme_probe(struct pci_dev *pdev, const
struct pci_device_id *id)
if (result)
goto release_pools;
- if (dev->online_queues > 1)
- result = nvme_dev_add(dev);
- if (result)
- goto shutdown;
-
scnprintf(dev->name, sizeof(dev->name), "nvme%d", dev->instance);
dev->miscdev.minor = MISC_DYNAMIC_MINOR;
dev->miscdev.parent = &pdev->dev;
@@ -2939,14 +3054,20 @@ static int nvme_probe(struct pci_dev *pdev, const
struct pci_device_id *id)
dev->miscdev.fops = &nvme_dev_fops;
result = misc_register(&dev->miscdev);
if (result)
- goto remove;
+ goto shutdown;
- dev->initialized = 1;
+ if (dev->online_queues > 1) {
+ dev->nvme_probe_thread = kthread_run(nvme_probe_workfn,
+ dev,
+
"nvme_namespace_probe%d",
+ dev->instance);
+ if (dev->nvme_probe_thread == ERR_PTR(-ENOMEM)) {
+ dev_err(&dev->pci_dev->dev,
+ "Failed to invoke
nvme_probe_work");
+ goto shutdown;
+ }
+ }
return 0;
-
- remove:
- nvme_dev_remove(dev);
- nvme_free_namespaces(dev);
shutdown:
nvme_dev_shutdown(dev);
release_pools:
@@ -2984,10 +3105,15 @@ static void nvme_remove(struct pci_dev *pdev) {
struct nvme_dev *dev = pci_get_drvdata(pdev);
+ set_bit(NVME_NN_PROBE_STOP, &dev->probe_work_stop);
spin_lock(&dev_list_lock);
list_del_init(&dev->node);
spin_unlock(&dev_list_lock);
+ if (dev->nvme_probe_thread) {
+ kthread_stop(dev->nvme_probe_thread);
+ dev->nvme_probe_thread = NULL;
+ }
pci_set_drvdata(pdev, NULL);
flush_work(&dev->reset_work);
flush_work(&dev->cpu_work);
@@ -3013,6 +3139,12 @@ static int nvme_suspend(struct device *dev)
struct pci_dev *pdev = to_pci_dev(dev);
struct nvme_dev *ndev = pci_get_drvdata(pdev);
+ set_bit(NVME_NN_PROBE_STOP, &ndev->probe_work_stop);
+ if (ndev->nvme_probe_thread) {
+ kthread_stop(ndev->nvme_probe_thread);
+ ndev->nvme_probe_thread = NULL;
+ }
+
nvme_dev_shutdown(ndev);
return 0;
}
@@ -3022,6 +3154,7 @@ static int nvme_resume(struct device *dev)
struct pci_dev *pdev = to_pci_dev(dev);
struct nvme_dev *ndev = pci_get_drvdata(pdev);
+ clear_bit(NVME_NN_PROBE_STOP, &ndev->probe_work_stop);
if (nvme_dev_resume(ndev) && !work_busy(&ndev->reset_work)) {
ndev->reset_workfn = nvme_reset_failed_dev;
queue_work(nvme_workq, &ndev->reset_work); diff --git
a/include/linux/nvme.h b/include/linux/nvme.h index ed09074..130ab4a 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -18,6 +18,7 @@
#include <uapi/linux/nvme.h>
#include <linux/pci.h>
#include <linux/miscdevice.h>
+#include <linux/kthread.h>
#include <linux/kref.h>
struct nvme_bar {
@@ -61,6 +62,11 @@ enum {
NVME_CSTS_SHST_MASK = 3 << 2,
};
+enum {
+ NVME_NN_PROBE_STOP
+
+};
+
#define NVME_VS(major, minor) (major << 16 | minor)
extern unsigned char nvme_io_timeout;
@@ -92,6 +98,7 @@ struct nvme_dev {
work_func_t reset_workfn;
struct work_struct reset_work;
struct work_struct cpu_work;
+ struct task_struct *nvme_probe_thread;
char name[12];
char serial[20];
char model[40];
@@ -99,11 +106,15 @@ struct nvme_dev {
u32 max_hw_sectors;
u32 stripe_size;
u32 page_size;
+ u32 nvme_nn_probed;
u16 oncs;
+ struct kthread_worker discovery_worker;
+ struct task_struct *discovery_worker_task;
u16 abort_limit;
u8 event_limit;
u8 vwc;
u8 initialized;
+ unsigned long probe_work_stop;
};
/*
--
1.8.3.2
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