1c675c937c
commit 7c53e847ff5e97f033fdd31f71949807633d506b upstream. All posix lock ops, for all lockspaces (gfs2 file systems) are sent to userspace (dlm_controld) through a single misc device. The dlm_controld daemon reads the ops from the misc device and sends them to other cluster nodes using separate, per-lockspace cluster api communication channels. The ops for a single lockspace are ordered at this level, so that the results are received in the same sequence that the requests were sent. When the results are sent back to the kernel via the misc device, they are again funneled through the single misc device for all lockspaces. When the dlm code in the kernel processes the results from the misc device, these results will be returned in the same sequence that the requests were sent, on a per-lockspace basis. A recent change in this request/reply matching code missed the "per-lockspace" check (fsid comparison) when matching request and reply, so replies could be incorrectly matched to requests from other lockspaces. Cc: stable@vger.kernel.org Reported-by: Barry Marson <bmarson@redhat.com> Fixes: 57e2c2f2d94c ("fs: dlm: fix mismatch of plock results from userspace") Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.