Go to file
Damien Le Moal 09fad23a1a zonefs: Improve error handling
commit 14db5f64a9 upstream.

Write error handling is racy and can sometime lead to the error recovery
path wrongly changing the inode size of a sequential zone file to an
incorrect value  which results in garbage data being readable at the end
of a file. There are 2 problems:

1) zonefs_file_dio_write() updates a zone file write pointer offset
   after issuing a direct IO with iomap_dio_rw(). This update is done
   only if the IO succeed for synchronous direct writes. However, for
   asynchronous direct writes, the update is done without waiting for
   the IO completion so that the next asynchronous IO can be
   immediately issued. However, if an asynchronous IO completes with a
   failure right before the i_truncate_mutex lock protecting the update,
   the update may change the value of the inode write pointer offset
   that was corrected by the error path (zonefs_io_error() function).

2) zonefs_io_error() is called when a read or write error occurs. This
   function executes a report zone operation using the callback function
   zonefs_io_error_cb(), which does all the error recovery handling
   based on the current zone condition, write pointer position and
   according to the mount options being used. However, depending on the
   zoned device being used, a report zone callback may be executed in a
   context that is different from the context of __zonefs_io_error(). As
   a result, zonefs_io_error_cb() may be executed without the inode
   truncate mutex lock held, which can lead to invalid error processing.

Fix both problems as follows:
- Problem 1: Perform the inode write pointer offset update before a
  direct write is issued with iomap_dio_rw(). This is safe to do as
  partial direct writes are not supported (IOMAP_DIO_PARTIAL is not
  set) and any failed IO will trigger the execution of zonefs_io_error()
  which will correct the inode write pointer offset to reflect the
  current state of the one on the device.
- Problem 2: Change zonefs_io_error_cb() into zonefs_handle_io_error()
  and call this function directly from __zonefs_io_error() after
  obtaining the zone information using blkdev_report_zones() with a
  simple callback function that copies to a local stack variable the
  struct blk_zone obtained from the device. This ensures that error
  handling is performed holding the inode truncate mutex.
  This change also simplifies error handling for conventional zone files
  by bypassing the execution of report zones entirely. This is safe to
  do because the condition of conventional zones cannot be read-only or
  offline and conventional zone files are always fully mapped with a
  constant file size.

Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: 8dcc1a9d90 ("fs: New zonefs file system")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:12:45 +01:00
arch x86/mm/ident_map: Use gbpages only where full GB page should be mapped. 2024-02-23 09:12:43 +01:00
block block: treat poll queue enter similarly to timeouts 2024-02-16 19:06:31 +01:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto crypto: api - Disallow identical driver names 2024-01-31 16:16:58 -08:00
Documentation net: sysfs: Fix /sys/class/net/<iface> path for statistics 2024-02-23 09:12:31 +01:00
drivers irqchip/gic-v3-its: Fix GICv4.1 VPE affinity update 2024-02-23 09:12:45 +01:00
fs zonefs: Improve error handling 2024-02-23 09:12:45 +01:00
include iio: imu: adis: ensure proper DMA alignment 2024-02-23 09:12:40 +01:00
init update workarounds for gcc "asm goto" issue 2024-02-23 09:12:28 +01:00
io_uring io_uring/net: fix multishot accept overflow handling 2024-02-23 09:12:43 +01:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel ring-buffer: Clean ring_buffer_poll_wait() error return 2024-02-23 09:12:42 +01:00
lib debugobjects: Stop accessing objects after releasing hash bucket lock 2024-02-05 20:12:47 +00:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again 2024-02-23 09:12:32 +01:00
net wifi: mac80211: reload info pointer in ieee80211_tx_dequeue() 2024-02-23 09:12:44 +01:00
rust rust: allocator: Prevent mis-aligned allocation 2023-08-11 12:08:18 +02:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-23 09:12:28 +01:00
scripts modpost: Add '.ltext' and '.ltext.*' to TEXT_SECTIONS 2024-02-23 09:12:38 +01:00
security lsm: fix the logic in security_inode_getsecctx() 2024-02-23 09:12:37 +01:00
sound ALSA: hda/conexant: Add quirk for SWS JS201D 2024-02-23 09:12:44 +01:00
tools selftests: mptcp: increase timeout to 30 min 2024-02-23 09:12:36 +01:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add() 2023-09-13 09:42:46 +02:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig
.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 genirq/affinity: Move group_cpus_evenly() into lib/ 2024-01-10 17:10:33 +01:00
Makefile Linux 6.1.78 2024-02-16 19:06:32 +01:00
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.