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 <[email protected]> Reviewed-by: Max Gurtovoy <[email protected]> Reviewed-by: Sagi Grimberg <[email protected]> --- drivers/nvme/host/core.c | 31 +++++++++++++++++++++++++++++++ drivers/nvme/host/nvme.h | 9 +++++++++ 2 files changed, 40 insertions(+) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 2ead7ad45a9d..2604971362d8 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -4305,6 +4305,37 @@ void nvme_sync_queues(struct nvme_ctrl *ctrl) } EXPORT_SYMBOL_GPL(nvme_sync_queues); +#ifdef CONFIG_NVME_TARGET_PASSTHRU +/* + * The exports that follow within this ifdef are only for + * use by the nvmet-passthru and should not be used for + * other things. + */ + +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); +#endif /* CONFIG_NVME_TARGET_PASSTHRU */ + /* * Check we didn't inadvertently grow the command structure sizes: */ diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 2e04a36296d9..9195dd97b61b 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -689,4 +689,13 @@ void nvme_hwmon_init(struct nvme_ctrl *ctrl); static inline void nvme_hwmon_init(struct nvme_ctrl *ctrl) { } #endif +#ifdef CONFIG_NVME_TARGET_PASSTHRU +/* + * The exports that follow within this ifdef are only for + * use by the nvmet-passthru and should not be used for + * other things. + */ +struct nvme_ctrl *nvme_ctrl_get_by_path(const char *path); +#endif /* CONFIG_NVME_TARGET_PASSTHRU */ + #endif /* _NVME_H */ -- 2.20.1
