ext4: fix zeroing of page during writeback

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commit eeece469de upstream.

Tail of a page straddling inode size must be zeroed when being written
out due to POSIX requirement that modifications of mmaped page beyond
inode size must not be written to the file. ext4_bio_write_page() did
this only for blocks fully beyond inode size but didn't properly zero
blocks partially beyond inode size. Fix this.

The problem has been uncovered by mmap_11-4 test in openposix test suite
(part of LTP).

Reported-by: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
Fixes: 5a0dc7365c
Fixes: bd2d0210cf
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Jan Kara 2014-05-27 12:48:55 -04:00 • committed by Greg Kroah-Hartman

parent ba6eb3c3ac

commit f70b5876eb

1 changed files with 11 additions and 13 deletions

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fs/ext4/page-io.c

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