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4e163c39dd
xfstests generic/363 was failing due to unzeroed post-EOF page
cache that allowed mmap writes beyond EOF to become visible
after file extension.
For example, in following xfs_io sequence, 0x22 should not be
written to the file but would become visible after the extension:
xfs_io -f -t -c "pwrite -S 0x11 0 8" \
-c "mmap 0 4096" \
-c "mwrite -S 0x22 32 32" \
-c "munmap" \
-c "pwrite -S 0x33 512 32" \
$testfile
This violates the expected behavior where writes beyond EOF via
mmap should not persist after the file is extended. Instead, the
extended region should contain zeros.
Fix this by using truncate_pagecache() to truncate the page cache
after the current EOF when extending the file.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.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 reStructuredText 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.