From f4cdf7ca9a1fdcca413157df19753f388a5a224e Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 19 Aug 2026 10:09:22 -0700 Subject: Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ... --- drivers/block/rnbd/README | 93 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 drivers/block/rnbd/README (limited to 'drivers/block/rnbd/README') diff --git a/drivers/block/rnbd/README b/drivers/block/rnbd/README new file mode 100644 index 000000000..080f58a54 --- /dev/null +++ b/drivers/block/rnbd/README @@ -0,0 +1,93 @@ +******************************** +RDMA Network Block Device (RNBD) +******************************** + +Introduction +------------ + +RNBD (RDMA Network Block Device) is a pair of kernel modules +(client and server) that allow for remote access of a block device on +the server over RTRS protocol using the RDMA (InfiniBand, RoCE, iWARP) +transport. After being mapped, the remote block devices can be accessed +on the client side as local block devices. + +I/O is transferred between client and server by the RTRS transport +modules. The administration of RNBD and RTRS modules is done via +sysfs entries. + +Requirements +------------ + + RTRS kernel modules + +Quick Start +----------- + +Server side: + # modprobe rnbd_server + +Client side: + # modprobe rnbd_client + # echo "sessname=blya path=ip:10.50.100.66 device_path=/dev/ram0" > \ + /sys/devices/virtual/rnbd-client/ctl/map_device + + Where "sessname=" is a session name, a string to identify the session + on client and on server sides; "path=" is a destination IP address or + a pair of a source and a destination IPs, separated by comma. Multiple + "path=" options can be specified in order to use multipath (see RTRS + description for details); "device_path=" is the block device to be + mapped from the server side. After the session to the server machine is + established, the mapped device will appear on the client side under + /dev/rnbd. + + +RNBD-Server Module Parameters +============================= + +dev_search_path +--------------- + +When a device is mapped from the client, the server generates the path +to the block device on the server side by concatenating dev_search_path +and the "device_path" that was specified in the map_device operation. + +The default dev_search_path is: "/". + +dev_search_path option can also contain %SESSNAME% in order to provide +different device namespaces for different sessions. See "device_path" +option for details. + +============================ +Protocol (rnbd/rnbd-proto.h) +============================ + +1. Before mapping first device from a given server, client sends an +RNBD_MSG_SESS_INFO to the server. Server responds with +RNBD_MSG_SESS_INFO_RSP. Currently the messages only contain the protocol +version for backward compatibility. + +2. Client requests to open a device by sending RNBD_MSG_OPEN message. This +contains the path to the device and access mode (read-only or writable). +Server responds to the message with RNBD_MSG_OPEN_RSP. This contains +a 32 bit device id to be used for IOs and device "geometry" related +information: side, max_hw_sectors, etc. + +3. Client attaches RNBD_MSG_IO to each IO message send to a device. This +message contains device id, provided by server in his rnbd_msg_open_rsp, +sector to be accessed, read-write flags and bi_size. + +4. Client closes a device by sending RNBD_MSG_CLOSE which contains only the +device id provided by the server. + +========================================= +Contributors List(in alphabetical order) +========================================= +Danil Kipnis +Fabian Holler +Guoqing Jiang +Jack Wang +Kleber Souza +Lutz Pogrell +Milind Dumbare +Roman Penyaev +Swapnil Ingle -- cgit v1.3.1