Re: [PATCH] block: rbd: update sysfs interface
From: Ilya Dryomov
Date: Wed Feb 21 2018 - 11:07:52 EST
On Tue, Feb 20, 2018 at 10:08 AM, Aishwarya Pant <aishpant@xxxxxxxxx> wrote:
> The existing sysfs interface has been updated to be in the same format
> as described in Documentation/ABI/README. This will be useful for
> scripting and tracking changes in the ABI. Attributes have been grouped
> by functionality and/or the date on which they were added.
>
> There are a couple of more changes:
> - The attributes have been annotated with file permissions RO/RW/WO.
> - Added description of the bus attribute supported_features
>
> Signed-off-by: Aishwarya Pant <aishpant@xxxxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-bus-rbd | 202 +++++++++++++++++++-------------
> 1 file changed, 122 insertions(+), 80 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-rbd b/Documentation/ABI/testing/sysfs-bus-rbd
> index f208ac58d613..9549e9b0fcf8 100644
> --- a/Documentation/ABI/testing/sysfs-bus-rbd
> +++ b/Documentation/ABI/testing/sysfs-bus-rbd
> @@ -1,121 +1,163 @@
> -What: /sys/bus/rbd/
> -Date: November 2010
> +What: /sys/bus/rbd/add
> +What: /sys/bus/rbd/remove
Hi Aishwarya,
No need to group "add" and "remove" together. Do them separate, like
"add_single_major" and "remove_single_major".
> +Date: Jan, 2012
> +KernelVersion: v3.10
I think "add" and "remove" go back to v2.6.37.
> Contact: Yehuda Sadeh <yehuda@xxxxxxxxxxxx>,
> Sage Weil <sage@xxxxxxxxxxxx>
Remove Yehuda from the contact list here and everywhere else.
> Description:
> + add : (WO) Add rbd block device.
>
> -Being used for adding and removing rbd block devices.
> + Usage: <mon ip addr> <options> <pool name> <rbd image name> [<snap name>]
>
> -Usage: <mon ip addr> <options> <pool name> <rbd image name> [<snap name>]
> + $ echo "192.168.0.1 name=admin rbd foo" > /sys/bus/rbd/add
>
> - $ echo "192.168.0.1 name=admin rbd foo" > /sys/bus/rbd/add
> + The snapshot name can be "-" or omitted to map the image
> + read/write. A <dev-id> will be assigned for any registered block
> + device. If snapshot is used, it will be mapped read-only.
>
> -The snapshot name can be "-" or omitted to map the image read/write. A <dev-id>
> -will be assigned for any registered block device. If snapshot is used, it will
> -be mapped read-only.
> + remove: (WO) Remove rbd block device.
>
> -Usage: <dev-id> [force]
> + Usage: <dev-id> [force]
>
> - $ echo 2 > /sys/bus/rbd/remove
> + $ echo 2 > /sys/bus/rbd/remove
> +
> + Optional "force" argument which when passed will wait for
> + running requests and then unmap the image. Requests sent to the
> + driver after initiating the removal will be failed. (August
> + 2016, since 4.9.)
>
> -Optional "force" argument which when passed will wait for running requests and
> -then unmap the image. Requests sent to the driver after initiating the removal
> -will be failed. (August 2016, since 4.9.)
>
> What: /sys/bus/rbd/add_single_major
> -Date: December 2013
> -KernelVersion: 3.14
> -Contact: Sage Weil <sage@xxxxxxxxxxx>
> -Description: Available only if rbd module is inserted with single_major
> +Date: Dec, 2013
> +KernelVersion: v3.14
> +Contact: Yehuda Sadeh <yehuda@xxxxxxxxxxxx>,
> + Sage Weil <sage@xxxxxxxxxxxx>
> +Description:
> + (WO) Available only if rbd module is inserted with single_major
> parameter set to true.
> - Usage is the same as for /sys/bus/rbd/add. If present,
> +
> + Usage is the same as for /sys/bus/rbd/add. If present, this
> should be used instead of the latter: any attempts to use
> - /sys/bus/rbd/add if /sys/bus/rbd/add_single_major is
> - available will fail for backwards compatibility reasons.
> + /sys/bus/rbd/add if /sys/bus/rbd/add_single_major is available
> + will fail for backwards compatibility reasons.
> +
>
> What: /sys/bus/rbd/remove_single_major
> -Date: December 2013
> -KernelVersion: 3.14
> -Contact: Sage Weil <sage@xxxxxxxxxxx>
> -Description: Available only if rbd module is inserted with single_major
> +Date: Dec, 2013
> +KernelVersion: v3.14
> +Contact: Yehuda Sadeh <yehuda@xxxxxxxxxxxx>,
> + Sage Weil <sage@xxxxxxxxxxxx>
> +Description:
> + (WO) Available only if rbd module is inserted with single_major
> parameter set to true.
> - Usage is the same as for /sys/bus/rbd/remove. If present,
> +
> + Usage is the same as for /sys/bus/rbd/remove. If present, this
> should be used instead of the latter: any attempts to use
> /sys/bus/rbd/remove if /sys/bus/rbd/remove_single_major is
> available will fail for backwards compatibility reasons.
>
> -Entries under /sys/bus/rbd/devices/<dev-id>/
> ---------------------------------------------
> -
> -client_addr
> -
> - The ceph unique client entity_addr_t (address + nonce).
> - The format is <address>:<port>/<nonce>: '1.2.3.4:1234/5678' or
> - '[1:2:3:4:5:6:7:8]:1234/5678'. (August 2016, since 4.9.)
> -
> -client_id
> -
> - The ceph unique client id that was assigned for this specific session.
> -
> -cluster_fsid
> -
> - The ceph cluster UUID. (August 2016, since 4.9.)
> -
> -config_info
> -
> - The string written into /sys/bus/rbd/add{,_single_major}. (August
> - 2016, since 4.9.)
> -
> -features
> -
> - A hexadecimal encoding of the feature bits for this image.
>
> -major
> -
> - The block device major number.
> -
> -minor
> +What: /sys/bus/rbd/supported_features
> +Date: Mar, 2017
> +KernelVersion: v4.11
> +Contact: Yehuda Sadeh <yehuda@xxxxxxxxxxxx>,
> + Sage Weil <sage@xxxxxxxxxxxx>
> +Description:
> + (RO) Displays the features supported by the client software
the client software implementation -> rbd module
> + implementation so that userspace can generate meaningful error
> + messages and spell out unsupported features that need to be
> + disabled.
> +
> +
> +What: /sys/bus/rbd/devices/<dev-id>/size
> +What: /sys/bus/rbd/devices/<dev-id>/refresh
> +What: /sys/bus/rbd/devices/<dev-id>/current_snap
> +What: /sys/bus/rbd/devices/<dev-id>/name
> +What: /sys/bus/rbd/devices/<dev-id>/major
> +What: /sys/bus/rbd/devices/<dev-id>/client_id
> +Date: Aug, 2010
> +KernelVersion: v2.6.37
> +Contact: Yehuda Sadeh <yehuda@xxxxxxxxxxxx>,
> + Sage Weil <sage@xxxxxxxxxxxx>
> +Description:
> + size: (RO) The size (in bytes) of the mapped block
> + device.
>
> - The block device minor number. (December 2013, since 3.14.)
> + refresh: (WO) Writing to this file will reread the image
> + header data and set all relevant data structures
> + accordingly.
>
> -name
> + current_snap: (RO) The current snapshot for which the device
> + is mapped.
>
> - The name of the rbd image.
> + name: (RO) The name of the rbd image.
>
> -image_id
> + major: (RO) The block device major number.
>
> - The unique id for the rbd image. (For rbd image format 1
> - this is empty.)
> + client_id: (RO) The ceph unique client id that was assigned
> + for this specific session.
>
> -pool
>
> - The name of the storage pool where this rbd image resides.
> - An rbd image name is unique within its pool.
> +What: /sys/bus/rbd/devices/<dev-id>/pool
"pool" also goes back to v2.6.37.
> +What: /sys/bus/rbd/devices/<dev-id>/image_id
"image_id" was added in v3.7.
Having these documented is nice, but wrong versions and dates are worse
than none at all. Please cross check the rest with git log/blame.
> +What: /sys/bus/rbd/devices/<dev-id>/features
> +What: /sys/bus/rbd/devices/<dev-id>/pool_id
> +Date: Jul, 2012
> +KernelVersion: v3.10
> +Contact: Yehuda Sadeh <yehuda@xxxxxxxxxxxx>,
> + Sage Weil <sage@xxxxxxxxxxxx>
> +Description:
> + pool: (RO) The name of the storage pool where this rbd
> + image resides. An rbd image name is unique
> + within its pool.
>
> -pool_id
> + image_id: (WO) The unique id for the rbd image. (For rbd
> + image format 1 this is empty.)
image_id should be RO.
>
> - The unique identifier for the rbd image's pool. This is
> - a permanent attribute of the pool. A pool's id will never
> - change.
> + features: (RO) A hexadecimal encoding of the feature bits
> + for this image.
>
> -size
> + pool_idr: (RO) The unique identifier for the rbd image's
> + pool. This is a permanent attribute of the pool.
> + A pool's id will never change.
pool_idr -> pool_id
>
> - The size (in bytes) of the mapped block device.
>
> -refresh
> +What: /sys/bus/rbd/devices/<dev-id>/parent
> +Date: Oct, 2012
> +KernelVersion: v3.10
> +Contact: Yehuda Sadeh <yehuda@xxxxxxxxxxxx>,
> + Sage Weil <sage@xxxxxxxxxxxx>
> +Description:
> + (RO) Information identifying the chain of parent images in a
> + layered rbd image. Entries are separated by empty lines.
>
> - Writing to this file will reread the image header data and set
> - all relevant datastructures accordingly.
>
> -current_snap
> +What: /sys/bus/rbd/devices/<dev-id>/minor
> +Date: Dec, 2013
> +KernelVersion: v3.14
> +Contact: Yehuda Sadeh <yehuda@xxxxxxxxxxxx>,
> + Sage Weil <sage@xxxxxxxxxxxx>
> +Description:
> + (RO) The block device minor number.
>
> - The current snapshot for which the device is mapped.
>
> -snap_id
> +What: /sys/bus/rbd/devices/<dev-id>/snap_id
> +What: /sys/bus/rbd/devices/<dev-id>/config_info
> +What: /sys/bus/rbd/devices/<dev-id>/cluster_fsid
> +What: /sys/bus/rbd/devices/<dev-id>/client_addr
> +Date: Aug, 2016
> +KernelVersion: v4.9
> +Contact: Yehuda Sadeh <yehuda@xxxxxxxxxxxx>,
> + Sage Weil <sage@xxxxxxxxxxxx>
> +Description:
> + snap_id: (RO) The current snapshot's id.
>
> - The current snapshot's id. (August 2016, since 4.9.)
> + config_info: (RO) The string written into
> + /sys/bus/rbd/add{,_single_major}.
>
> -parent
> + cluster_fsid: (RO) The ceph cluster UUID.
>
> - Information identifying the chain of parent images in a layered rbd
> - image. Entries are separated by empty lines.
> + client_addr: (RO) The ceph unique client
> + entity_addr_t (address + nonce). The format is
> + <address>:<port>/<nonce>: '1.2.3.4:1234/5678' or
> + '[1:2:3:4:5:6:7:8]:1234/5678'.
Thanks,
Ilya