391b5d39fa
commit a1c6ae3d9f3dd6aa5981a332a6f700cf1c25edef upstream. In degraded raid5, we need to read parity to do reconstruct-write when data disks fail. However, we can not read parity from handle_stripe_dirtying() in force reconstruct-write mode. Reproducible Steps: 1. Create degraded raid5 mdadm -C /dev/md2 --assume-clean -l5 -n3 /dev/sda2 /dev/sdb2 missing 2. Set rmw_level to 0 echo 0 > /sys/block/md2/md/rmw_level 3. IO to raid5 Now some io may be stuck in raid5. We can use handle_stripe_fill() to read the parity in this situation. Cc: <stable@vger.kernel.org> # v4.4+ Reviewed-by: Alex Wu <alexwu@synology.com> Reviewed-by: BingJing Chang <bingjingc@synology.com> Reviewed-by: Danny Shih <dannyshih@synology.com> Signed-off-by: ChangSyun Peng <allenpeng@synology.com> Signed-off-by: Song Liu <songliubraving@fb.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.