4a2d01b076
xfs_reflink_convert_cow() manipulates the incore extent list in GFP_KERNEL context in the IO submission path whilst holding locked pages under writeback. This is a memory reclaim deadlock vector. This code is not in a transaction, so any memory allocations it makes aren't protected via the memalloc_nofs_save() context that transactions carry. Hence we need to run this call under memalloc_nofs_save() context to prevent potential memory allocations from being run as GFP_KERNEL and deadlocking. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.