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Jan Kara 617d2fd48d ocfs2: fix data corruption on truncate
commit 839b63860eb3835da165642923120d305925561d upstream.

Patch series "ocfs2: Truncate data corruption fix".

As further testing has shown, commit 5314454ea3f ("ocfs2: fix data
corruption after conversion from inline format") didn't fix all the data
corruption issues the customer started observing after 6dbf7bb555
("fs: Don't invalidate page buffers in block_write_full_page()") This
time I have tracked them down to two bugs in ocfs2 truncation code.

One bug (truncating page cache before clearing tail cluster and setting
i_size) could cause data corruption even before 6dbf7bb555, but before
that commit it needed a race with page fault, after 6dbf7bb555 it
started to be pretty deterministic.

Another bug (zeroing pages beyond old i_size) used to be harmless
inefficiency before commit 6dbf7bb555.  But after commit 6dbf7bb555
in combination with the first bug it resulted in deterministic data
corruption.

Although fixing only the first problem is needed to stop data
corruption, I've fixed both issues to make the code more robust.

This patch (of 2):

ocfs2_truncate_file() did unmap invalidate page cache pages before
zeroing partial tail cluster and setting i_size.  Thus some pages could
be left (and likely have left if the cluster zeroing happened) in the
page cache beyond i_size after truncate finished letting user possibly
see stale data once the file was extended again.  Also the tail cluster
zeroing was not guaranteed to finish before truncate finished causing
possible stale data exposure.  The problem started to be particularly
easy to hit after commit 6dbf7bb555 "fs: Don't invalidate page buffers
in block_write_full_page()" stopped invalidation of pages beyond i_size
from page writeback path.

Fix these problems by unmapping and invalidating pages in the page cache
after the i_size is reduced and tail cluster is zeroed out.

Link: https://lkml.kernel.org/r/20211025150008.29002-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20211025151332.11301-1-jack@suse.cz
Fixes: ccd979bdbc ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.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: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-17 09:48:17 +01:00
Documentation dt-bindings: mtd: gpmc: Fix the ECC bytes vs. OOB bytes equation 2021-09-22 12:26:43 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch Revert "x86/kvm: fix vcpu-id indexed array sizes" 2021-11-12 14:43:02 +01:00
block Revert "block, bfq: honor already-setup queue merges" 2021-10-06 15:42:34 +02:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:47:29 +02:00
crypto crypto: shash - avoid comparing pointers to exported functions under CFI 2021-07-14 16:53:13 +02:00
drivers libata: fix read log timeout value 2021-11-17 09:48:17 +01:00
fs ocfs2: fix data corruption on truncate 2021-11-17 09:48:17 +01:00
include libata: fix read log timeout value 2021-11-17 09:48:17 +01:00
init kbuild: add CONFIG_LD_IS_LLD 2021-06-30 08:47:44 -04:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel printk/console: Allow to disable console output by using console="" or console=null 2021-11-12 14:43:03 +01:00
lib Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH 2021-09-26 14:07:10 +02:00
mm mm, slub: fix potential memoryleak in kmem_cache_open() 2021-10-27 09:54:28 +02:00
net cfg80211: correct bridge/4addr mode check 2021-11-02 19:46:15 +01:00
samples samples: bpf: Fix tracex7 error raised on the missing argument 2021-09-22 12:26:30 +02:00
scripts gcc-plugins/structleak: add makefile var for disabling structleak 2021-10-27 09:54:28 +02:00
security binder: use cred instead of task for selinux checks 2021-11-17 09:48:16 +01:00
sound ALSA: hda: avoid write to STATESTS if controller is in reset 2021-10-27 09:54:29 +02:00
tools perf script: Check session->header.env.arch before using it 2021-11-02 19:46:15 +01:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: do not shrink halt_poll_ns below grow_start 2021-10-09 14:39:50 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-08-26 10:40:46 +02:00
Makefile Linux 5.4.159 2021-11-12 14:43:05 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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.