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2023-08-18Documentation: Fix typosBjorn Helgaas1-1/+1
Fix typos in Documentation. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230814212822.193684-4-helgaas@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-01-30block: ublk: fix doc build warningMing Lei1-0/+6
Fix the following warning: Documentation/block/ublk.rst:157: WARNING: Enumerated list ends without a blank line; unexpected unindent. Documentation/block/ublk.rst:171: WARNING: Enumerated list ends without a blank line; unexpected unindent. Fixes: 56f5160bc1b8 ("ublk_drv: add mechanism for supporting unprivileged ublk device") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20230118042318.127900-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30ublk_drv: add mechanism for supporting unprivileged ublk deviceMing Lei1-9/+40
unprivileged ublk device is helpful for container use case, such as: ublk device created in one unprivileged container can be controlled and accessed by this container only. Implement this feature by adding flag of UBLK_F_UNPRIVILEGED_DEV, and if this flag isn't set, any control command has been run from privileged user. Otherwise, any control command can be sent from any unprivileged user, but the user has to be permitted to access the ublk char device to be controlled. In case of UBLK_F_UNPRIVILEGED_DEV: 1) for command UBLK_CMD_ADD_DEV, it is always allowed, and user needs to provide owner's uid/gid in this command, so that udev can set correct ownership for the created ublk device, since the device owner uid/gid can be queried via command of UBLK_CMD_GET_DEV_INFO. 2) for other control commands, they can only be run successfully if the current user is allowed to access the specified ublk char device, for running the permission check, path of the ublk char device has to be provided by these commands. Also add one control of command UBLK_CMD_GET_DEV_INFO2 which always include the char dev path in payload since userspace may not have knowledge if this device is created in unprivileged mode. For applying this mechanism, system administrator needs to take the following policies: 1) chmod 0666 /dev/ublk-control 2) change ownership of ublkcN & ublkbN - chown owner_uid:owner_gid /dev/ublkcN - chown owner_uid:owner_gid /dev/ublkbN Both can be done via one simple udev rule. Userspace: https://github.com/ming1/ubdsrv/tree/unprivileged-ublk 'ublk add -t $TYPE --un_privileged=1' is for creating one un-privileged ublk device if the user is un-privileged. Link: https://lore.kernel.org/linux-block/YoOr6jBfgVm8GvWg@stefanha-x1.localdomain/ Suggested-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20230106041711.914434-7-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-18Documentation: document ublk user recovery featureZiyangZhang1-0/+36
Add documentation for user recovery feature of ublk subsystem. Signed-off-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20221018045346.99706-2-ZiyangZhang@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-02Documentation: document ublkMing Lei1-0/+253
Add documentation for ublk subsystem. It was supposed to be documented when merging the driver, but missing at that time. Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Richard W.M. Jones <rjones@redhat.com> Cc: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> [axboe: correct MAINTAINERS addition] Signed-off-by: Jens Axboe <axboe@kernel.dk>