Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 133 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-rnbd-client b/Documentation/ABI/testing/sysfs-class-rnbd-client
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+What:		/sys/class/rnbd-client
+Date:		Feb 2020
+KernelVersion:	5.7
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	Provide information about RNBD-client.
+		All sysfs files that are not read-only provide the usage information on read:
+
+		Example::
+
+		    # cat /sys/class/rnbd-client/ctl/map_device
+
+		    > Usage: echo "sessname=<name of the rtrs session> path=<[srcaddr,]dstaddr>
+		    > [path=<[srcaddr,]dstaddr>] device_path=<full path on remote side>
+		    > [access_mode=<ro|rw|migration>] > map_device
+		    >
+		    > addr ::= [ ip:<ipv4> | ip:<ipv6> | gid:<gid> ]
+
+What:		/sys/class/rnbd-client/ctl/map_device
+Date:		Feb 2020
+KernelVersion:	5.7
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	Expected format is the following::
+
+		    sessname=<name of the rtrs session>
+		    path=<[srcaddr,]dstaddr> [path=<[srcaddr,]dstaddr> ...]
+		    device_path=<full path on remote side>
+		    [access_mode=<ro|rw|migration>]
+
+		Where:
+
+		sessname:
+		    accepts a string not bigger than 256 chars, which identifies
+		    a given session on the client and on the server.
+		    I.e. "clt_hostname-srv_hostname" could be a natural choice.
+
+		path:
+		    describes a connection between the client and the server by
+		    specifying destination and, when required, the source address.
+		    The addresses are to be provided in the following format::
+
+			ip:<IPv6>
+			ip:<IPv4>
+			gid:<GID>
+
+		for example::
+
+		    path=ip:10.0.0.66
+
+		The single addr is treated as the destination.
+		The connection will be established to this server from any client IP address.
+
+		::
+
+		    path=ip:10.0.0.66,ip:10.0.1.66
+
+		First addr is the source address and the second is the destination.
+
+		If multiple "path=" options are specified multiple connection
+		will be established and data will be sent according to
+		the selected multipath policy (see RTRS mp_policy sysfs entry description).
+
+		device_path:
+		    Path to the block device on the server side. Path is specified
+		    relative to the directory on server side configured in the
+		    'dev_search_path' module parameter of the rnbd_server.
+		    The rnbd_server prepends the <device_path> received from client
+		    with <dev_search_path> and tries to open the
+		    <dev_search_path>/<device_path> block device.  On success,
+		    a /dev/rnbd<N> device file, a /sys/block/rnbd<N>/
+		    directory and an entry in /sys/class/rnbd-client/ctl/devices
+		    will be created.
+
+		If 'dev_search_path' contains '%SESSNAME%', then each session can
+		have different devices namespace, e.g. server was configured with
+		the following parameter "dev_search_path=/run/rnbd-devs/%SESSNAME%",
+		client has this string "sessname=blya device_path=sda", then server
+		will try to open: /run/rnbd-devs/blya/sda.
+
+		access_mode:
+		    the access_mode parameter specifies if the device is to be
+		    mapped as "ro" read-only or "rw" read-write. The server allows
+		    a device to be exported in rw mode only once. The "migration"
+		    access mode has to be specified if a second mapping in read-write
+		    mode is desired.
+
+		By default "rw" is used.
+
+		nr_poll_queues
+		  specifies the number of poll-mode queues. If the IO has HIPRI flag,
+		  the block-layer will send the IO via the poll-mode queue.
+		  For fast network and device the polling is faster than interrupt-base
+		  IO handling because it saves time for context switching, switching to
+		  another process, handling the interrupt and switching back to the
+		  issuing process.
+
+		  Set -1 if you want to set it as the number of CPUs
+		  By default rnbd client creates only irq-mode queues.
+
+		  NOTICE: MUST make a unique session for a device using the poll-mode queues.
+
+		Exit Codes:
+
+		If the device is already mapped it will fail with EEXIST. If the input
+		has an invalid format it will return EINVAL. If the device path cannot
+		be found on the server, it will fail with ENOENT.
+
+		Finding device file after mapping
+		---------------------------------
+
+		After mapping, the device file can be found by:
+		o  The symlink /sys/class/rnbd-client/ctl/devices/<device_id>@<session_name>
+		points to /sys/block/<dev-name>. The last part of the symlink destination
+		is the same as the device name.  By extracting the last part of the
+		path the path to the device /dev/<dev-name> can be build.
+
+		* /dev/block/$(cat /sys/class/rnbd-client/ctl/devices/<device_id>@<session_name>/dev)
+
+		How to find the <device_id> of the device is described on the next
+		section.
+
+What:		/sys/class/rnbd-client/ctl/devices/
+Date:		Feb 2020
+KernelVersion:	5.7
+Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
+Description:	For each device mapped on the client a new symbolic link is created as
+		/sys/class/rnbd-client/ctl/devices/<device_id>@<session_name>, which points
+		to the block device created by rnbd (/sys/block/rnbd<N>/).
+		The <device_id> of each device is created as follows:
+
+		- If the 'device_path' provided during mapping contains slashes ("/"),
+		  they are replaced by exclamation mark ("!") and used as as the
+		  <device_id>. Otherwise, the <device_id> will be the same as the
+		  "device_path" provided.