c230a4a85b
Ever since we added shadown format buffers to the log items, log items need to handle the item being released with shadow buffers attached. Due to the fact this requirement was added at the same time we added new rmap/reflink intents, we missed the cleanup of those items. In theory, this means shadow buffers can be leaked in a very small window when a shutdown is initiated. Testing with KASAN shows this leak does not happen in practice - we haven't identified a single leak in several years of shutdown testing since ~v4.8 kernels. However, the intent whiteout cleanup mechanism results in every cancelled intent in exactly the same state as this tiny race window creates and so if intents down clean up shadow buffers on final release we will leak the shadow buffer for just about every intent we create. Hence we start with this patch to close this condition off and ensure that when whiteouts start to be used we don't leak lots of memory. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
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.