Go to file
Chengming Zhou d0321c812d block: fix request.queuelist usage in flush
Friedrich Weber reported a kernel crash problem and bisected to commit
81ada09cc2 ("blk-flush: reuse rq queuelist in flush state machine").

The root cause is that we use "list_move_tail(&rq->queuelist, pending)"
in the PREFLUSH/POSTFLUSH sequences. But rq->queuelist.next == xxx since
it's popped out from plug->cached_rq in __blk_mq_alloc_requests_batch().
We don't initialize its queuelist just for this first request, although
the queuelist of all later popped requests will be initialized.

Fix it by changing to use "list_add_tail(&rq->queuelist, pending)" so
rq->queuelist doesn't need to be initialized. It should be ok since rq
can't be on any list when PREFLUSH or POSTFLUSH, has no move actually.

Please note the commit 81ada09cc2 ("blk-flush: reuse rq queuelist in
flush state machine") also has another requirement that no drivers would
touch rq->queuelist after blk_mq_end_request() since we will reuse it to
add rq to the post-flush pending list in POSTFLUSH. If this is not true,
we will have to revert that commit IMHO.

This updated version adds "list_del_init(&rq->queuelist)" in flush rq
callback since the dm layer may submit request of a weird invalid format
(REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH), which causes double list_add
if without this "list_del_init(&rq->queuelist)". The weird invalid format
problem should be fixed in dm layer.

Reported-by: Friedrich Weber <f.weber@proxmox.com>
Closes: https://lore.kernel.org/lkml/14b89dfb-505c-49f7-aebb-01c54451db40@proxmox.com/
Closes: https://lore.kernel.org/lkml/c9d03ff7-27c5-4ebd-b3f6-5a90d96f35ba@proxmox.com/
Fixes: 81ada09cc2 ("blk-flush: reuse rq queuelist in flush state machine")
Cc: Christoph Hellwig <hch@lst.de>
Cc: ming.lei@redhat.com
Cc: bvanassche@acm.org
Tested-by: Friedrich Weber <f.weber@proxmox.com>
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240608143115.972486-1-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-12 10:58:11 -06:00
arch 16 hotfixes, 11 of which are cc:stable. 2024-05-25 15:10:33 -07:00
block block: fix request.queuelist usage in flush 2024-06-12 10:58:11 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto This push fixes a bug in the new ecc P521 code as well as a buggy 2024-05-20 08:47:54 -07:00
Documentation 16 hotfixes, 11 of which are cc:stable. 2024-05-25 15:10:33 -07:00
drivers nvme fixes Linux 6.10 2024-06-05 12:13:00 -06:00
fs four smb client fixes, including two important netfs integration fixes 2024-05-25 22:33:10 -07:00
include block: Fix zone write plugging handling of devices with a runt zone 2024-05-30 15:03:52 -06:00
init Driver core changes for 6.10-rc1 2024-05-22 12:13:40 -07:00
io_uring io_uring-6.10-20240523 2024-05-23 13:41:49 -07:00
ipc Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
kernel Misc fixes: 2024-05-25 14:48:40 -07:00
lib 16 hotfixes, 11 of which are cc:stable. 2024-05-25 15:10:33 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm 16 hotfixes, 11 of which are cc:stable. 2024-05-25 15:10:33 -07:00
net NFS client updates for Linux 6.10 2024-05-23 13:51:09 -07:00
rust LoongArch changes for v6.10 2024-05-22 09:43:07 -07:00
samples tracing/treewide: Remove second parameter of __assign_str() 2024-05-22 20:14:47 -04:00
scripts - A series ("kbuild: enable more warnings by default") from Arnd 2024-05-22 18:59:29 -07:00
security hardening fixes for v6.10-rc1 2024-05-24 08:33:44 -07:00
sound sound fixes for 6.10-rc1 2024-05-24 08:48:51 -07:00
tools Revert a patch causing a regression as described in the cset: 2024-05-26 09:54:26 -07:00
usr kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
virt The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap mailmap: update email address for Satya Priya 2024-05-24 11:55:05 -07:00
.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: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
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 RTC for 6.10 2024-05-25 13:33:53 -07:00
Makefile Linux 6.10-rc1 2024-05-26 15:20:12 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -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 reStructuredText 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.