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Joe Thornber 95ab80a8a0 dm cache: free background tracker's queued work in btracker_destroy
Otherwise the kernel can BUG with:

[ 2245.426978] =============================================================================
[ 2245.435155] BUG bt_work (Tainted: G    B   W         ): Objects remaining in bt_work on __kmem_cache_shutdown()
[ 2245.445233] -----------------------------------------------------------------------------
[ 2245.445233]
[ 2245.454879] Slab 0x00000000b0ce2b30 objects=64 used=2 fp=0x000000000a3c6a4e flags=0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff)
[ 2245.467300] CPU: 7 PID: 10805 Comm: lvm Kdump: loaded Tainted: G    B   W          6.0.0-rc2 #19
[ 2245.476078] Hardware name: Dell Inc. PowerEdge R7525/0590KW, BIOS 2.5.6 10/06/2021
[ 2245.483646] Call Trace:
[ 2245.486100]  <TASK>
[ 2245.488206]  dump_stack_lvl+0x34/0x48
[ 2245.491878]  slab_err+0x95/0xcd
[ 2245.495028]  __kmem_cache_shutdown.cold+0x31/0x136
[ 2245.499821]  kmem_cache_destroy+0x49/0x130
[ 2245.503928]  btracker_destroy+0x12/0x20 [dm_cache]
[ 2245.508728]  smq_destroy+0x15/0x60 [dm_cache_smq]
[ 2245.513435]  dm_cache_policy_destroy+0x12/0x20 [dm_cache]
[ 2245.518834]  destroy+0xc0/0x110 [dm_cache]
[ 2245.522933]  dm_table_destroy+0x5c/0x120 [dm_mod]
[ 2245.527649]  __dm_destroy+0x10e/0x1c0 [dm_mod]
[ 2245.532102]  dev_remove+0x117/0x190 [dm_mod]
[ 2245.536384]  ctl_ioctl+0x1a2/0x290 [dm_mod]
[ 2245.540579]  dm_ctl_ioctl+0xa/0x20 [dm_mod]
[ 2245.544773]  __x64_sys_ioctl+0x8a/0xc0
[ 2245.548524]  do_syscall_64+0x5c/0x90
[ 2245.552104]  ? syscall_exit_to_user_mode+0x12/0x30
[ 2245.556897]  ? do_syscall_64+0x69/0x90
[ 2245.560648]  ? do_syscall_64+0x69/0x90
[ 2245.564394]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 2245.569447] RIP: 0033:0x7fe52583ec6b
...
[ 2245.646771] ------------[ cut here ]------------
[ 2245.651395] kmem_cache_destroy bt_work: Slab cache still has objects when called from btracker_destroy+0x12/0x20 [dm_cache]
[ 2245.651408] WARNING: CPU: 7 PID: 10805 at mm/slab_common.c:478 kmem_cache_destroy+0x128/0x130

Found using: lvm2-testsuite --only "cache-single-split.sh"

Ben bisected and found that commit 0495e337b7 ("mm/slab_common:
Deleting kobject in kmem_cache_destroy() without holding
slab_mutex/cpu_hotplug_lock") first exposed dm-cache's incomplete
cleanup of its background tracker work objects.

Reported-by: Benjamin Marzinski <bmarzins@redhat.com>
Tested-by: Benjamin Marzinski <bmarzins@redhat.com>
Cc: stable@vger.kernel.org # 6.0+
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-01-30 14:20:04 -05:00
arch - Start checking for -mindirect-branch-cs-prefix clang support too now that LLVM 2023-01-29 11:17:34 -08:00
block block: Default to use cgroup support for BFQ 2023-01-30 09:42:42 -07:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto This update includes the following changes: 2022-12-14 12:31:09 -08:00
Documentation block: ublk: fix doc build warning 2023-01-29 15:18:34 -07:00
drivers dm cache: free background tracker's queued work in btracker_destroy 2023-01-30 14:20:04 -05:00
fs 4 smb3 server fixes, all also for stable 2023-01-28 10:52:51 -08:00
include blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy() 2023-01-29 15:19:04 -07:00
init Kbuild fixes for v6.2 (3rd) 2023-01-21 10:56:37 -08:00
io_uring io_uring: always prep_async for drain requests 2023-01-27 06:29:29 -07:00
ipc Non-MM patches for 6.2-rc1. 2022-12-12 17:28:58 -08:00
kernel - Cleanup the firmware node for the new IRQ MSI domain properly, to 2023-01-29 11:26:49 -08:00
lib sbitmap: correct wake_batch recalculation to avoid potential IO hung 2023-01-29 20:03:01 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm Revert "mm/compaction: fix set skip in fast_find_migrateblock" 2023-01-29 10:38:43 -08:00
net net: mctp: mark socks as dead on unhash, prevent re-add 2023-01-25 13:07:37 +00:00
rust rust: print: avoid evaluating arguments in pr_* macros in unsafe blocks 2023-01-16 00:54:35 +01:00
samples ftrace: Export ftrace_free_filter() to modules 2023-01-24 11:20:58 -05:00
scripts Fix up more non-executable files marked executable 2023-01-28 11:17:57 -08:00
security tomoyo: Update website link 2023-01-13 23:11:38 +09:00
sound treewide: fix up files incorrectly marked executable 2023-01-26 10:05:39 -08:00
tools gpio fixes for v6.2-rc6 2023-01-27 13:47:40 -08:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt VFIO fixes for v6.2-rc6 2023-01-23 11:56:07 -08:00
.clang-format iommufd for 6.2 2022-12-14 09:15:43 -08:00
.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 .gitignore: ignore *.rpm 2022-12-30 17:22:14 +09:00
.mailmap 21 hotfixes. Thirteen of these address pre-6.1 issues and hence have 2023-01-16 16:36:39 -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: Update MPTCP maintainer list and CREDITS 2023-01-23 21:42:13 -08:00
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 drbd headers 2023-01-29 15:18:33 -07:00
Makefile Linux 6.2-rc6 2023-01-29 13:59:43 -08:00
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.