From 4cc06521ee1f153e0d292413a5bff7bbbdee92d0 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Fri, 5 Jun 2015 10:30:08 -0600 Subject: [PATCH] NVMe: add sysfs and ioctl controller reset We need the ability to perform an nvme controller reset as discussed on the mailing list thread: http://lists.infradead.org/pipermail/linux-nvme/2015-March/001585.html This adds a sysfs entry that when written to will reset perform an NVMe controller reset if the controller was successfully initialized in the first place. This also adds locking around resetting the device in the async probe method so the driver can't schedule two resets. Signed-off-by: Keith Busch Cc: Brandon Schultz Cc: David Sariel Updated by Jens to: 1) Merge this with the ioctl reset patch from David Sariel. The ioctl path now shares the reset code from the sysfs path. 2) Don't flush work if we fail issuing the reset. Signed-off-by: Jens Axboe --- drivers/block/nvme-core.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/nvme.h | 1 + 2 files changed, 54 insertions(+) diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index 513908ff46c4..9682e29b4171 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -80,6 +80,7 @@ static wait_queue_head_t nvme_kthread_wait; static struct class *nvme_class; static void nvme_reset_failed_dev(struct work_struct *ws); +static int nvme_reset(struct nvme_dev *dev); static int nvme_process_cq(struct nvme_queue *nvmeq); struct async_cmd_info { @@ -2689,6 +2690,9 @@ static long nvme_dev_ioctl(struct file *f, unsigned int cmd, unsigned long arg) return -ENOTTY; ns = list_first_entry(&dev->namespaces, struct nvme_ns, list); return nvme_user_cmd(dev, ns, (void __user *)arg); + case NVME_IOCTL_RESET: + dev_warn(dev->dev, "resetting controller\n"); + return nvme_reset(dev); default: return -ENOTTY; } @@ -2839,6 +2843,44 @@ static void nvme_reset_workfn(struct work_struct *work) dev->reset_workfn(work); } +static int nvme_reset(struct nvme_dev *dev) +{ + int ret = -EBUSY; + + if (!dev->admin_q || blk_queue_dying(dev->admin_q)) + return -ENODEV; + + spin_lock(&dev_list_lock); + if (!work_pending(&dev->reset_work)) { + dev->reset_workfn = nvme_reset_failed_dev; + queue_work(nvme_workq, &dev->reset_work); + ret = 0; + } + spin_unlock(&dev_list_lock); + + if (!ret) { + flush_work(&dev->reset_work); + return 0; + } + + return ret; +} + +static ssize_t nvme_sysfs_reset(struct device *dev, + struct device_attribute *attr, const char *buf, + size_t count) +{ + struct nvme_dev *ndev = dev_get_drvdata(dev); + int ret; + + ret = nvme_reset(ndev); + if (ret < 0) + return ret; + + return count; +} +static DEVICE_ATTR(reset_controller, S_IWUSR, NULL, nvme_sysfs_reset); + static void nvme_async_probe(struct work_struct *work); static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id) { @@ -2883,12 +2925,20 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id) goto release_pools; } get_device(dev->device); + dev_set_drvdata(dev->device, dev); + + result = device_create_file(dev->device, &dev_attr_reset_controller); + if (result) + goto put_dev; INIT_LIST_HEAD(&dev->node); INIT_WORK(&dev->probe_work, nvme_async_probe); schedule_work(&dev->probe_work); return 0; + put_dev: + device_destroy(nvme_class, MKDEV(nvme_char_major, dev->instance)); + put_device(dev->device); release_pools: nvme_release_prp_pools(dev); release: @@ -2919,10 +2969,12 @@ static void nvme_async_probe(struct work_struct *work) nvme_set_irq_hints(dev); return; reset: + spin_lock(&dev_list_lock); if (!work_busy(&dev->reset_work)) { dev->reset_workfn = nvme_reset_failed_dev; queue_work(nvme_workq, &dev->reset_work); } + spin_unlock(&dev_list_lock); } static void nvme_reset_notify(struct pci_dev *pdev, bool prepare) @@ -2952,6 +3004,7 @@ static void nvme_remove(struct pci_dev *pdev) pci_set_drvdata(pdev, NULL); flush_work(&dev->probe_work); flush_work(&dev->reset_work); + device_remove_file(dev->device, &dev_attr_reset_controller); nvme_dev_shutdown(dev); nvme_dev_remove(dev); nvme_dev_remove_admin(dev); diff --git a/include/uapi/linux/nvme.h b/include/uapi/linux/nvme.h index aef9a81b2d75..b660dc2fadfb 100644 --- a/include/uapi/linux/nvme.h +++ b/include/uapi/linux/nvme.h @@ -579,5 +579,6 @@ struct nvme_passthru_cmd { #define NVME_IOCTL_ADMIN_CMD _IOWR('N', 0x41, struct nvme_admin_cmd) #define NVME_IOCTL_SUBMIT_IO _IOW('N', 0x42, struct nvme_user_io) #define NVME_IOCTL_IO_CMD _IOWR('N', 0x43, struct nvme_passthru_cmd) +#define NVME_IOCTL_RESET _IO('N', 0x44) #endif /* _UAPI_LINUX_NVME_H */ -- 2.11.0