No description
Find a file
Mauricio Faria de Oliveira afb585a97f ext4: data=journal: write-protect pages on j_submit_inode_data_buffers()
This implements journal callbacks j_submit|finish_inode_data_buffers()
with different behavior for data=journal: to write-protect pages under
commit, preventing changes to buffers writeably mapped to userspace.

If a buffer's content changes between commit's checksum calculation
and write-out to disk, it can cause journal recovery/mount failures
upon a kernel crash or power loss.

    [   27.334874] EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, and O_DIRECT support!
    [   27.339492] JBD2: Invalid checksum recovering data block 8705 in log
    [   27.342716] JBD2: recovery failed
    [   27.343316] EXT4-fs (loop0): error loading journal
    mount: /ext4: can't read superblock on /dev/loop0.

In j_submit_inode_data_buffers() we write-protect the inode's pages
with write_cache_pages() and redirty w/ writepage callback if needed.

In j_finish_inode_data_buffers() there is nothing do to.

And in order to use the callbacks, inodes are added to the inode list
in transaction in __ext4_journalled_writepage() and ext4_page_mkwrite().

In ext4_page_mkwrite() we must make sure that the buffers are attached
to the transaction as jbddirty with write_end_fn(), as already done in
__ext4_journalled_writepage().

Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Reported-by: Dann Frazier <dann.frazier@canonical.com>
Reported-by: kernel test robot <lkp@intel.com> # wbc.nr_to_write
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20201006004841.600488-5-mfo@canonical.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18 10:37:15 -04:00
arch Two fixes for the x86 interrupt code: 2020-09-27 12:15:21 -07:00
block SCSI fixes on 20200926 2020-09-26 11:18:37 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2020-08-30 15:53:44 -07:00
Documentation Kbuild fixes for v5.9 (4th) 2020-09-27 12:18:57 -07:00
drivers A set of clocksource/clockevents updates: 2020-09-27 12:11:35 -07:00
fs ext4: data=journal: write-protect pages on j_submit_inode_data_buffers() 2020-10-18 10:37:15 -04:00
include jbd2, ext4, ocfs2: introduce/use journal callbacks j_submit|finish_inode_data_buffers() 2020-10-18 10:37:15 -04:00
init bootconfig: init: make xbc_namebuf static 2020-09-18 22:17:05 -04:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel mm/fork: Pass new vma pointer into copy_page_range() 2020-09-27 11:21:35 -07:00
lib lib/memregion.c: include memregion.h 2020-09-26 10:33:57 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm/thp: Split huge pmds/puds if they're pinned when fork() 2020-09-27 11:21:35 -07:00
net Fixes: 2020-09-25 10:46:11 -07:00
samples treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
scripts scripts/kallsyms: skip ppc compiler stub *.long_branch.* / *.plt_branch.* 2020-09-25 00:41:54 +09:00
security device_cgroup RCU warning fix from Amol Grover <frextrite@gmail.com> 2020-09-15 16:26:57 -07:00
sound sound fixes for 5.9-rc7 2020-09-24 09:00:05 -07:00
tools Five small fixes. The nested migration bug will be fixed 2020-09-25 17:15:19 -07:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: fix memory leak in kvm_io_bus_unregister_dev() 2020-09-11 13:15:11 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2020-09-01 12:53:42 +02:00
.cocciconfig
.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: Add ZSTD-compressed files 2020-07-31 11:50:49 +02:00
.mailmap mailmap: add older email addresses for Kees Cook 2020-09-19 13:13:38 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS CREDITS: Replace HTTP links with HTTPS ones 2020-07-23 14:53:58 -06:00
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 media fixes for v5.9-rc7 2020-09-24 09:05:04 -07:00
Makefile Linux 5.9-rc7 2020-09-27 14:38:10 -07:00
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.