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Jan Kara 5314454ea3 ocfs2: fix data corruption after conversion from inline format
Commit 6dbf7bb555 ("fs: Don't invalidate page buffers in
block_write_full_page()") uncovered a latent bug in ocfs2 conversion
from inline inode format to a normal inode format.

The code in ocfs2_convert_inline_data_to_extents() attempts to zero out
the whole cluster allocated for file data by grabbing, zeroing, and
dirtying all pages covering this cluster.  However these pages are
beyond i_size, thus writeback code generally ignores these dirty pages
and no blocks were ever actually zeroed on the disk.

This oversight was fixed by commit 693c241a5f ("ocfs2: No need to zero
pages past i_size.") for standard ocfs2 write path, inline conversion
path was apparently forgotten; the commit log also has a reasoning why
the zeroing actually is not needed.

After commit 6dbf7bb555, things became worse as writeback code stopped
invalidating buffers on pages beyond i_size and thus these pages end up
with clean PageDirty bit but with buffers attached to these pages being
still dirty.  So when a file is converted from inline format, then
writeback triggers, and then the file is grown so that these pages
become valid, the invalid dirtiness state is preserved,
mark_buffer_dirty() does nothing on these pages (buffers are already
dirty) but page is never written back because it is clean.  So data
written to these pages is lost once pages are reclaimed.

Simple reproducer for the problem is:

  xfs_io -f -c "pwrite 0 2000" -c "pwrite 2000 2000" -c "fsync" \
    -c "pwrite 4000 2000" ocfs2_file

After unmounting and mounting the fs again, you can observe that end of
'ocfs2_file' has lost its contents.

Fix the problem by not doing the pointless zeroing during conversion
from inline format similarly as in the standard write path.

[akpm@linux-foundation.org: fix whitespace, per Joseph]

Link: https://lkml.kernel.org/r/20210930095405.21433-1-jack@suse.cz
Fixes: 6dbf7bb555 ("fs: Don't invalidate page buffers in block_write_full_page()")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Gang He <ghe@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: "Markov, Andrey" <Markov.Andrey@Dell.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-10-18 20:22:03 -10:00
arch powerpc fixes for 5.15 #4 2021-10-17 18:01:32 -10:00
block block-5.15-2021-10-17 2021-10-17 19:25:20 -10:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2021-08-30 12:57:10 -07:00
Documentation virtio,vdpa: fixes 2021-10-17 18:17:19 -10:00
drivers libata fixes for 5.15-rc6 2021-10-17 19:39:22 -10:00
fs ocfs2: fix data corruption after conversion from inline format 2021-10-18 20:22:03 -10:00
include mm/migrate: fix CPUHP state to update node demotion order 2021-10-18 20:22:03 -10:00
init bootconfig: init: Fix memblock leak in xbc_make_cmdline() 2021-10-10 22:27:40 -04:00
ipc ipc: remove memcg accounting for sops objects in do_semtimedop() 2021-09-14 10:22:11 -07:00
kernel Tracing fixes for 5.15: 2021-10-16 10:51:41 -07:00
lib linux-kselftest-kunit-fixes-5.15-rc6 2021-10-11 17:25:08 -07:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm/migrate: fix CPUHP state to update node demotion order 2021-10-18 20:22:03 -10:00
net icmp: fix icmp_ext_echo_iio parsing in icmp_build_probe 2021-10-14 07:54:47 -07:00
samples samples/bpf: Relicense bpf_insn.h as GPL-2.0-only OR BSD-2-Clause 2021-09-29 16:03:55 +02:00
scripts Tracing fixes for 5.15: 2021-10-16 10:51:41 -07:00
security Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ 2021-10-07 12:44:41 +01:00
sound ALSA: usb-audio: Add quirk for VF0770 2021-10-12 22:13:11 +02:00
tools mm/userfaultfd: selftests: fix memory corruption with thp enabled 2021-10-18 20:22:02 -10:00
usr .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
virt KVM: Remove tlbs_dirty 2021-09-23 11:01:12 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update email address of Matthias Fuchs and Thomas Körper 2021-08-19 09:39:44 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Char/Misc driver fixes for 5.15-rc6 2021-10-17 17:14:00 -10:00
Makefile Linux 5.15-rc6 2021-10-17 20:00:13 -10:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.