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Damien Le Moal fe9da61ffc zonefs: fix synchronous direct writes to sequential files
Commit 16d7fd3cfa ("zonefs: use iomap for synchronous direct writes")
changes zonefs code from a self-built zone append BIO to using iomap for
synchronous direct writes. This change relies on iomap submit BIO
callback to change the write BIO built by iomap to a zone append BIO.
However, this change overlooked the fact that a write BIO may be very
large as it is split when issued. The change from a regular write to a
zone append operation for the built BIO can result in a block layer
warning as zone append BIO are not allowed to be split.

WARNING: CPU: 18 PID: 202210 at block/bio.c:1644 bio_split+0x288/0x350
Call Trace:
? __warn+0xc9/0x2b0
? bio_split+0x288/0x350
? report_bug+0x2e6/0x390
? handle_bug+0x41/0x80
? exc_invalid_op+0x13/0x40
? asm_exc_invalid_op+0x16/0x20
? bio_split+0x288/0x350
bio_split_rw+0x4bc/0x810
? __pfx_bio_split_rw+0x10/0x10
? lockdep_unlock+0xf2/0x250
__bio_split_to_limits+0x1d8/0x900
blk_mq_submit_bio+0x1cf/0x18a0
? __pfx_iov_iter_extract_pages+0x10/0x10
? __pfx_blk_mq_submit_bio+0x10/0x10
? find_held_lock+0x2d/0x110
? lock_release+0x362/0x620
? mark_held_locks+0x9e/0xe0
__submit_bio+0x1ea/0x290
? __pfx___submit_bio+0x10/0x10
? seqcount_lockdep_reader_access.constprop.0+0x82/0x90
submit_bio_noacct_nocheck+0x675/0xa20
? __pfx_bio_iov_iter_get_pages+0x10/0x10
? __pfx_submit_bio_noacct_nocheck+0x10/0x10
iomap_dio_bio_iter+0x624/0x1280
__iomap_dio_rw+0xa22/0x18a0
? lock_is_held_type+0xe3/0x140
? __pfx___iomap_dio_rw+0x10/0x10
? lock_release+0x362/0x620
? zonefs_file_write_iter+0x74c/0xc80 [zonefs]
? down_write+0x13d/0x1e0
iomap_dio_rw+0xe/0x40
zonefs_file_write_iter+0x5ea/0xc80 [zonefs]
do_iter_readv_writev+0x18b/0x2c0
? __pfx_do_iter_readv_writev+0x10/0x10
? inode_security+0x54/0xf0
do_iter_write+0x13b/0x7c0
? lock_is_held_type+0xe3/0x140
vfs_writev+0x185/0x550
? __pfx_vfs_writev+0x10/0x10
? __handle_mm_fault+0x9bd/0x1c90
? find_held_lock+0x2d/0x110
? lock_release+0x362/0x620
? find_held_lock+0x2d/0x110
? lock_release+0x362/0x620
? __up_read+0x1ea/0x720
? do_pwritev+0x136/0x1f0
do_pwritev+0x136/0x1f0
? __pfx_do_pwritev+0x10/0x10
? syscall_enter_from_user_mode+0x22/0x90
? lockdep_hardirqs_on+0x7d/0x100
do_syscall_64+0x58/0x80

This error depends on the hardware used, specifically on the max zone
append bytes and max_[hw_]sectors limits. Tests using AMD Epyc machines
that have low limits did not reveal this issue while runs on Intel Xeon
machines with larger limits trigger it.

Manually splitting the zone append BIO using bio_split_rw() can solve
this issue but also requires issuing the fragment BIOs synchronously
with submit_bio_wait(), to avoid potential reordering of the zone append
BIO fragments, which would lead to data corruption. That is, this
solution is not better than using regular write BIOs which are subject
to serialization using zone write locking at the IO scheduler level.

Given this, fix the issue by removing zone append support and using
regular write BIOs for synchronous direct writes. This allows preseving
the use of iomap and having identical synchronous and asynchronous
sequential file write path. Zone append support will be reintroduced
later through io_uring commands to ensure that the needed special
handling is done correctly.

Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: 16d7fd3cfa ("zonefs: use iomap for synchronous direct writes")
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: Christoph Hellwig <hch@lst.de>
2023-08-10 12:59:47 +09:00
arch powerpc fixes for 6.5 #5 2023-08-05 13:16:17 -07:00
block block-6.5-2023-07-21 2023-07-22 11:05:15 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto crypto: algif_hash - Fix race between MORE and non-MORE sends 2023-07-08 22:48:42 +10:00
Documentation vfs: get rid of old '->iterate' directory operation 2023-08-06 15:08:35 +02:00
drivers ata fixes for 6.5-rc5 2023-08-05 18:45:18 -07:00
fs zonefs: fix synchronous direct writes to sequential files 2023-08-10 12:59:47 +09:00
include v6.5-rc5.vfs.fixes 2023-08-06 10:43:52 -07:00
init Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
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ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel Including fixes from bpf and wireless. 2023-08-03 14:00:02 -07:00
lib bitmap fixes for v6.5 2023-08-02 18:10:26 -07:00
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mm 11 hotfixes. Five are cc:stable and the remainder address post-6.4 issues 2023-07-28 17:19:52 -07:00
net Two patches to improve RBD exclusive lock interaction with 2023-08-04 11:29:38 -07:00
rust rust: fix bindgen build error with UBSAN_BOUNDS_STRICT 2023-08-04 17:10:50 +02:00
samples arm64: ftrace: Add direct call trampoline samples support 2023-07-10 17:51:54 -04:00
scripts x86: 2023-07-30 11:19:08 -07:00
security security: keys: perform capable check only on privileged operations 2023-07-28 18:07:41 +00:00
sound ASoC: Fixes for v6.5 2023-07-27 14:54:23 +02:00
tools hyperv-fixes for 6.5-rc5 2023-08-04 17:16:14 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Grab a reference to KVM for VM and vCPU stats file descriptors 2023-07-29 11:05:28 -04:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
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.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 - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
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 Raw NAND fixes: 2023-08-04 12:01:26 -07:00
Makefile Linux 6.5-rc5 2023-08-06 15:07:51 -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.