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]>
---
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 e6ee6f2a3da6..f72334f34a30 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2817,6 +2817,30 @@ 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 ecbd90c31d0d..7e827c9e892c 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -484,6 +484,8 @@ 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)
{
--
2.20.1
On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
> 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]>
> ---
> drivers/nvme/host/core.c | 24 ++++++++++++++++++++++++
> drivers/nvme/host/nvme.h | 2 ++
> 2 files changed, 26 insertions(+)
Looks good,
Reviewed-by: Max Gurtovoy <[email protected]>
On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
> 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]>
> ---
> 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 e6ee6f2a3da6..f72334f34a30 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -2817,6 +2817,30 @@ 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;
> + }
Logan,
this means that the PT is for nvme-pci and also nvme-fabrics as well.
Is this the intention ? or we want to restrict it to pci only.
> +
> + 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 ecbd90c31d0d..7e827c9e892c 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -484,6 +484,8 @@ 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)
> {
On 2019-08-15 5:46 a.m., Max Gurtovoy wrote:
>
> On 8/2/2019 2:45 AM, Logan Gunthorpe wrote:
>> 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]>
>> ---
>> 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 e6ee6f2a3da6..f72334f34a30 100644
>> --- a/drivers/nvme/host/core.c
>> +++ b/drivers/nvme/host/core.c
>> @@ -2817,6 +2817,30 @@ 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;
>> + }
>
> Logan,
>
> this means that the PT is for nvme-pci and also nvme-fabrics as well.
>
> Is this the intention ? or we want to restrict it to pci only.
Yes, in theory, someone could passthru an nvme-fabrics controller or
they could passthru a passthru'd passthru'd nvme-fabrics controller.
This probably isn't a good idea but I don't know that we need to
specifically reject it. If you think we should I could figure out a way
to filter by pci controllers only.
Logan