7cea2a3c50
Add limited support for unprivileged fanotify groups. An unprivileged users is not allowed to get an open file descriptor in the event nor the process pid of another process. An unprivileged user cannot request permission events, cannot set mount/filesystem marks and cannot request unlimited queue/marks. This enables the limited functionality similar to inotify when watching a set of files and directories for OPEN/ACCESS/MODIFY/CLOSE events, without requiring SYS_CAP_ADMIN privileges. The FAN_REPORT_DFID_NAME init flag, provide a method for an unprivileged listener watching a set of directories (with FAN_EVENT_ON_CHILD) to monitor all changes inside those directories. This typically requires that the listener keeps a map of watched directory fid to dirfd (O_PATH), where fid is obtained with name_to_handle_at() before starting to watch for changes. When getting an event, the reported fid of the parent should be resolved to dirfd and fstatsat(2) with dirfd and name should be used to query the state of the filesystem entry. Link: https://lore.kernel.org/r/20210304112921.3996419-3-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.