github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-31 11:37:06 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph
Linux kernel source tree
1,090,608 Commits 1 Branch 940 Tags 24 GiB
C 96.9%
Assembly 0.9%
Rust 0.6%
Shell 0.6%
Python 0.5%
Other 0.3%
c9583ada8c
Go to file
Qu Wenruo c9583ada8c btrfs: avoid double clean up when submit_one_bio() failed 
[BUG]
When running generic/475 with 64K page size and 4K sector size, it has a
very high chance (almost 100%) to hang, with mostly data page locked but
no one is going to unlock it.

[CAUSE]
With commit 1784b7d502 ("btrfs: handle csum lookup errors properly on
reads"), if we failed to lookup checksum due to metadata IO error, we
will return error for btrfs_submit_data_bio().

This will cause the page to be unlocked twice in btrfs_do_readpage():

 btrfs_do_readpage()
 |- submit_extent_page()
 |  |- submit_one_bio()
 |     |- btrfs_submit_data_bio()
 |        |- if (ret) {
 |        |-     bio->bi_status = ret;
 |        |-     bio_endio(bio); }
 |               In the endio function, we will call end_page_read()
 |               and unlock_extent() to cleanup the subpage range.
 |
 |- if (ret) {
 |-        unlock_extent(); end_page_read() }
           Here we unlock the extent and cleanup the subpage range
           again.

For unlock_extent(), it's mostly double unlock safe.

But for end_page_read(), it's not, especially for subpage case,
as for subpage case we will call btrfs_subpage_end_reader() to reduce
the reader number, and use that to number to determine if we need to
unlock the full page.

If double accounted, it can underflow the number and leave the page
locked without anyone to unlock it.

[FIX]
The commit 1784b7d502 ("btrfs: handle csum lookup errors properly on
reads") itself is completely fine, it's our existing code not properly
handling the error from bio submission hook properly.

This patch will make submit_one_bio() to return void so that the callers
will never be able to do cleanup when bio submission hook fails.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-05-16 17:03:13 +02:00
arch powerpc fixes for 5.18 #5 2022-05-15 06:46:03 -07:00
block Revert "block: release rq qos structures for queue without disk" 2022-05-02 10:06:40 -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 Driver core fixes for 5.18-rc7 2022-05-15 08:08:51 -07:00
drivers Driver core fixes for 5.18-rc7 2022-05-15 08:08:51 -07:00
fs btrfs: avoid double clean up when submit_one_bio() failed 2022-05-16 17:03:13 +02:00
include fs: add a lockdep check function for sb_start_write() 2022-05-16 17:03:10 +02:00
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 The recent expansion of the sched switch tracepoint inserted a new argument 2022-05-15 06:40:11 -07:00
lib dim: initialize all struct fields 2022-05-09 17:20:37 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm hotfixes for 5.18-rc7 2022-05-13 10:22:37 -07:00
net NFS client bugfixes for Linux 5.18 2022-05-13 11:04:37 -07:00
samples sched/tracing: Append prev_state to tp args instead 2022-05-12 00:37:11 +02:00
scripts objtool: Enable unreachable warnings for CLANG LTO 2022-04-19 21:58:48 +02:00
security hardening updates for v5.18-rc1-fix1 2022-03-31 11:43:01 -07:00
sound ASoC: Fixes for v5.18 2022-05-08 10:49:25 +02:00
tools perf tools fixes for v5.18: 5th batch 2022-05-14 11:43:47 -07:00
usr Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
virt Merge branch 'kvm-fixes-for-5.18-rc5' into HEAD 2022-04-29 12:39:34 -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 hotfixes for 5.18-rc7 2022-05-13 10:22:37 -07:00
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 perf tools fixes for v5.18: 5th batch 2022-05-14 11:43:47 -07:00
Makefile Linux 5.18-rc7 2022-05-15 18:08:58 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

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.