kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-22 19:14:51 +00:00
Code Issues Releases Packages Activity
No description
1,154,526 commits 117 branches 5,803 tags 5.7 GiB
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Darrick J. Wong 5465403341 xfs: invalidate block device page cache during unmount 
[ Upstream commit 032e160305 ]

Every now and then I see fstests failures on aarch64 (64k pages) that
trigger on the following sequence:

mkfs.xfs $dev
mount $dev $mnt
touch $mnt/a
umount $mnt
xfs_db -c 'path /a' -c 'print' $dev

99% of the time this succeeds, but every now and then xfs_db cannot find
/a and fails.  This turns out to be a race involving udev/blkid, the
page cache for the block device, and the xfs_db process.

udev is triggered whenever anyone closes a block device or unmounts it.
The default udev rules invoke blkid to read the fs super and create
symlinks to the bdev under /dev/disk.  For this, it uses buffered reads
through the page cache.

xfs_db also uses buffered reads to examine metadata.  There is no
coordination between xfs_db and udev, which means that they can run
concurrently.  Note there is no coordination between the kernel and
blkid either.

On a system with 64k pages, the page cache can cache the superblock and
the root inode (and hence the root dir) with the same 64k page.  If
udev spawns blkid after the mkfs and the system is busy enough that it
is still running when xfs_db starts up, they'll both read from the same
page in the pagecache.

The unmount writes updated inode metadata to disk directly.  The XFS
buffer cache does not use the bdev pagecache, nor does it invalidate the
pagecache on umount.  If the above scenario occurs, the pagecache no
longer reflects what's on disk, xfs_db reads the stale metadata, and
fails to find /a.  Most of the time this succeeds because closing a bdev
invalidates the page cache, but when processes race, everyone loses.

Fix the problem by invalidating the bdev pagecache after flushing the
bdev, so that xfs_db will see up to date metadata.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Leah Rumancik <leah.rumancik@gmail.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2024-05-25 16:21:32 +02:00
arch ARM: 9381/1: kasan: clear stale stack poison 2024-05-17 11:56:10 +02:00
block blk-iocost: avoid out of bounds shift 2024-05-17 11:56:07 +02:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto Revert "crypto: api - Disallow identical driver names" 2024-05-02 16:29:27 +02:00
Documentation dt-bindings: iio: health: maxim,max30102: fix compatible check 2024-05-17 11:56:19 +02:00
drivers mmc: core: Add HS400 tuning in HS400es initialization 2024-05-25 16:21:30 +02:00
fs xfs: invalidate block device page cache during unmount 2024-05-25 16:21:32 +02:00
include iomap: write iomap validity checks 2024-05-25 16:21:31 +02:00
init rust: make mutually exclusive with CFI_CLANG 2024-05-02 16:29:27 +02:00
io_uring io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64() failure 2024-04-27 17:07:04 +02:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel timers: Rename del_timer() to timer_delete() 2024-05-17 11:56:13 +02:00
lib dyndbg: fix old BUG_ON in >control parser 2024-05-17 11:56:20 +02:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/hugetlb: fix DEBUG_LOCKS_WARN_ON(1) when dissolve_free_hugetlb_folio() 2024-05-17 11:56:24 +02:00
net nfsd: don't allow nfsd threads to be signalled. 2024-05-25 16:21:30 +02:00
rust rust: macros: fix soundness issue in module! macro 2024-05-17 11:56:17 +02:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-23 09:12:28 +01:00
scripts btf, scripts: rust: drop is_rust_module.sh 2024-05-17 11:56:17 +02:00
security KEYS: trusted: Fix memory leak in tpm2_key_encode() 2024-05-25 16:21:30 +02:00
sound ASoC: ti: davinci-mcasp: Fix race condition during probe 2024-05-17 11:56:20 +02:00
tools perf unwind-libdw: Handle JIT-generated DSOs properly 2024-05-17 11:56:10 +02:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-03 15:19:25 +02:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: add leah to 6.1 MAINTAINERS file 2024-05-17 11:56:16 +02:00
Makefile Linux 6.1.91 2024-05-17 11:56:25 +02:00
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.