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From: Logan Gunthorpe <logang@deltatee.com>
To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org
Cc: Sagi Grimberg <sagi@grimberg.me>,
	Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
	Stephen Bates <sbates@raithlin.com>, Jens Axboe <axboe@fb.com>,
	Keith Busch <kbusch@kernel.org>, Max Gurtovoy <maxg@mellanox.com>,
	Logan Gunthorpe <logang@deltatee.com>,
	Christoph Hellwig <hch@lst.de>
Subject: [PATCH v11 5/9] nvme-core: Introduce nvme_ctrl_get_by_path()
Date: Thu, 20 Feb 2020 13:36:48 -0700
Message-ID: <20200220203652.26734-6-logang@deltatee.com> (raw)
In-Reply-To: <20200220203652.26734-1-logang@deltatee.com>

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 <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
---
 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 219e24304b4e..756f8ee201d9 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4227,6 +4227,37 @@ 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 1024fec7914c..196a0d38e19c 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -687,4 +687,13 @@ 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


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  parent reply index

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-20 20:36 [PATCH v11 0/9] nvmet: add target passthru commands support Logan Gunthorpe
2020-02-20 20:36 ` [PATCH v11 1/9] nvme-core: Clear any SGL flags in passthru commands Logan Gunthorpe
2020-02-26 23:08   ` Sagi Grimberg
2020-02-20 20:36 ` [PATCH v11 2/9] nvme: Create helper function to obtain command effects Logan Gunthorpe
2020-02-26 23:09   ` Sagi Grimberg
2020-02-20 20:36 ` [PATCH v11 3/9] nvme: Move nvme_passthru_[start|end]() calls to common helper Logan Gunthorpe
2020-02-26 23:10   ` Sagi Grimberg
2020-02-20 20:36 ` [PATCH v11 4/9] nvmet-passthru: Introduce NVMet passthru Kconfig option Logan Gunthorpe
2020-02-26 23:12   ` Sagi Grimberg
2020-02-20 20:36 ` Logan Gunthorpe [this message]
2020-02-20 20:36 ` [PATCH v11 6/9] nvme: Export existing nvme core functions Logan Gunthorpe
2020-02-26 23:13   ` Sagi Grimberg
2020-02-20 20:36 ` [PATCH v11 7/9] nvmet-passthru: Add passthru code to process commands Logan Gunthorpe
2020-02-26 23:28   ` Sagi Grimberg
2020-02-27 17:33     ` Logan Gunthorpe
2020-02-20 20:36 ` [PATCH v11 8/9] nvmet-passthru: Add enable/disable helpers Logan Gunthorpe
2020-02-26 23:33   ` Sagi Grimberg
2020-02-27 17:37     ` Logan Gunthorpe
2020-02-27 23:13       ` Sagi Grimberg
2020-02-20 20:36 ` [PATCH v11 9/9] nvmet-configfs: Introduce passthru configfs interface Logan Gunthorpe
2020-02-26 23:35   ` Sagi Grimberg

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