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Message-Id: <20200724172520.16318-5-logang@deltatee.com>
Date: Fri, 24 Jul 2020 11:25:15 -0600
From: Logan Gunthorpe <logang@...tatee.com>
To: linux-kernel@...r.kernel.org, linux-nvme@...ts.infradead.org
Cc: Christoph Hellwig <hch@....de>, Sagi Grimberg <sagi@...mberg.me>,
Keith Busch <kbusch@...nel.org>, Jens Axboe <axboe@...com>,
Chaitanya Kulkarni <Chaitanya.Kulkarni@....com>,
Max Gurtovoy <maxg@...lanox.com>,
Stephen Bates <sbates@...thlin.com>,
Logan Gunthorpe <logang@...tatee.com>
Subject: [PATCH v16 4/9] nvme-core: Introduce nvme_ctrl_get_by_path()
nvme_ctrl_get_by_path() is analogous 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
and is exported under the NVME_TARGET_PASSTHRU namespace.
Signed-off-by: Logan Gunthorpe <logang@...tatee.com>
Reviewed-by: Max Gurtovoy <maxg@...lanox.com>
Reviewed-by: Sagi Grimberg <sagi@...mberg.me>
---
drivers/nvme/host/core.c | 23 +++++++++++++++++++++++
drivers/nvme/host/nvme.h | 1 +
2 files changed, 24 insertions(+)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index ccca36f881d6..35b1d13db2e9 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4575,6 +4575,29 @@ void nvme_sync_queues(struct nvme_ctrl *ctrl)
}
EXPORT_SYMBOL_GPL(nvme_sync_queues);
+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_NS_GPL(nvme_ctrl_get_by_path, 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 c43e0e4e0b97..4bec44ab5a96 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -787,5 +787,6 @@ static inline void nvme_hwmon_init(struct nvme_ctrl *ctrl) { }
u32 nvme_command_effects(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
u8 opcode);
void nvme_execute_passthru_rq(struct request *rq);
+struct nvme_ctrl *nvme_ctrl_get_by_path(const char *path);
#endif /* _NVME_H */
--
2.20.1
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