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Linus Torvalds 279b83c673 fs.fixes.v5.18-rc4
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Merge tag 'fs.fixes.v5.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull mount_setattr fix from Christian Brauner:
 "The recent cleanup in e257039f0f ("mount_setattr(): clean the
  control flow and calling conventions") switched the mount attribute
  codepaths from do-while to for loops as they are more idiomatic when
  walking mounts.

  However, we did originally choose do-while constructs because if we
  request a mount or mount tree to be made read-only we need to hold
  writers in the following way: The mount attribute code will grab
  lock_mount_hash() and then call mnt_hold_writers() which will
  _unconditionally_ set MNT_WRITE_HOLD on the mount.

  Any callers that need write access have to call mnt_want_write(). They
  will immediately see that MNT_WRITE_HOLD is set on the mount and the
  caller will then either spin (on non-preempt-rt) or wait on
  lock_mount_hash() (on preempt-rt).

  The fact that MNT_WRITE_HOLD is set unconditionally means that once
  mnt_hold_writers() returns we need to _always_ pair it with
  mnt_unhold_writers() in both the failure and success paths.

  The do-while constructs did take care of this. But Al's change to a
  for loop in the failure path stops on the first mount we failed to
  change mount attributes _without_ going into the loop to call
  mnt_unhold_writers().

  This in turn means that once we failed to make a mount read-only via
  mount_setattr() - i.e. there are already writers on that mount - we
  will block any writers indefinitely. Fix this by ensuring that the for
  loop always unsets MNT_WRITE_HOLD including the first mount we failed
  to change to read-only. Also sprinkle a few comments into the cleanup
  code to remind people about what is happening including myself. After
  all, I didn't catch it during review.

  This is only relevant on mainline and was reported by syzbot. Details
  about the syzbot reports are all in the commit message"

* tag 'fs.fixes.v5.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  fs: unset MNT_WRITE_HOLD on failure
2022-04-22 13:17:19 -07:00
arch Xtensa fixes for v5.18: 2022-04-20 12:43:27 -07:00
block block: don't print I/O error warning for dead disks 2022-04-15 06:33:03 -06:00
certs Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
crypto for-5.18/64bit-pi-2022-03-25 2022-03-26 12:01:35 -07:00
Documentation dmaengine fixes for v5.17 2022-04-21 16:24:31 -07:00
drivers sound fixes for 5.18-rc4 2022-04-22 13:11:38 -07:00
fs fs.fixes.v5.18-rc4 2022-04-22 13:17:19 -07:00
include sound fixes for 5.18-rc4 2022-04-22 13:11:38 -07:00
init Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
ipc fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
kernel kcov: don't generate a warning on vm_insert_page()'s failure 2022-04-21 20:01:10 -07:00
lib Driver core changes for 5.18-rc2 2022-04-10 09:55:09 -10:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm Merge branch 'akpm' (patches from Andrew) 2022-04-22 10:10:43 -07:00
net netlink: reset network and mac headers in netlink_dump() 2022-04-19 15:05:03 +02:00
samples dma-mapping updates for Linux 5.18 2022-03-29 08:50:14 -07:00
scripts hardening fixes for v5.18-rc3 2022-04-12 14:29:40 -10:00
security hardening updates for v5.18-rc1-fix1 2022-03-31 11:43:01 -07:00
sound ALSA: hda/realtek: Add quirk for Clevo NP70PNP 2022-04-21 21:23:47 +02:00
tools Merge branch 'akpm' (patches from Andrew) 2022-04-22 10:10:43 -07:00
usr Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
virt KVM/arm64 fixes for 5.18, take #1 2022-04-08 12:30:04 -04:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
.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: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update Vasily Averin's email address 2022-04-08 14:20:36 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
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 Merge branch 'akpm' (patches from Andrew) 2022-04-22 10:10:43 -07:00
Makefile Linux 5.18-rc3 2022-04-17 13:57:31 -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.