[PATCH v8 01/13] nvme-core: introduce nvme_ctrl_get_by_path()
From: Logan Gunthorpe <logang@deltatee.com>
Date: 2019-08-28 21:55:46
Also in:
linux-fsdevel, lkml
Subsystem:
nvm express driver, the rest · Maintainers:
Keith Busch, Jens Axboe, Christoph Hellwig, Sagi Grimberg, Linus Torvalds
nvme_ctrl_get_by_path() is analagous to blkdev_get_by_path() except it gets a struct nvme_ctrl from the path to its char dev (/dev/nvme0). It makes use of filp_open() to open the file and uses the private data to obtain a pointer to the struct nvme_ctrl. If the fops of the file do not match, -EINVAL is returned. The purpose of this function is to support NVMe-OF target passthru. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Max Gurtovoy <redacted> --- drivers/nvme/host/core.c | 24 ++++++++++++++++++++++++ drivers/nvme/host/nvme.h | 2 ++ 2 files changed, 26 insertions(+)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d3d6b7bd6903..776eff8c5ba7 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c@@ -2834,6 +2834,30 @@ static const struct file_operations nvme_dev_fops = { .compat_ioctl = nvme_dev_ioctl, }; +struct nvme_ctrl *nvme_ctrl_get_by_path(const char *path) +{ + struct nvme_ctrl *ctrl; + struct file *f; + + f = filp_open(path, O_RDWR, 0); + if (IS_ERR(f)) + return ERR_CAST(f); + + if (f->f_op != &nvme_dev_fops) { + ctrl = ERR_PTR(-EINVAL); + goto out_close; + } + + ctrl = f->private_data; + nvme_get_ctrl(ctrl); + +out_close: + filp_close(f, NULL); + + return ctrl; +} +EXPORT_SYMBOL_GPL(nvme_ctrl_get_by_path); + static ssize_t nvme_sysfs_reset(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 2d678fb968c7..42d59445ae6b 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h@@ -489,6 +489,8 @@ int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp, extern const struct attribute_group *nvme_ns_id_attr_groups[]; extern const struct block_device_operations nvme_ns_head_ops; +struct nvme_ctrl *nvme_ctrl_get_by_path(const char *path); + #ifdef CONFIG_NVME_MULTIPATH static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl) {
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2.20.1