No description
Find a file
Qu Wenruo 6927a91ccf btrfs: make found_logical_ret parameter mandatory for function queue_scrub_stripe()
[ Upstream commit 47e2b06b7b ]

[BUG]
There is a compilation warning reported on commit ae76d8e3e1 ("btrfs:
scrub: fix grouping of read IO"), where gcc (14.0.0 20231022 experimental)
is reporting the following uninitialized variable:

  fs/btrfs/scrub.c: In function ‘scrub_simple_mirror.isra’:
  fs/btrfs/scrub.c:2075:29: error: ‘found_logical’ may be used uninitialized [-Werror=maybe-uninitialized[https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wmaybe-uninitialized]]
   2075 |                 cur_logical = found_logical + BTRFS_STRIPE_LEN;
  fs/btrfs/scrub.c:2040:21: note: ‘found_logical’ was declared here
   2040 |                 u64 found_logical;
        |                     ^~~~~~~~~~~~~

[CAUSE]
This is a false alert, as @found_logical is passed as parameter
@found_logical_ret of function queue_scrub_stripe().

As long as queue_scrub_stripe() returned 0, we would update
@found_logical_ret.  And if queue_scrub_stripe() returned >0 or <0, the
caller would not utilized @found_logical, thus there should be nothing
wrong.

Although the triggering gcc is still experimental, it looks like the
extra check on "if (found_logical_ret)" can sometimes confuse the
compiler.

Meanwhile the only caller of queue_scrub_stripe() is always passing a
valid pointer, there is no need for such check at all.

[FIX]
Although the report itself is a false alert, we can still make it more
explicit by:

- Replace the check for @found_logical_ret with ASSERT()

- Initialize @found_logical to U64_MAX

- Add one extra ASSERT() to make sure @found_logical got updated

Link: https://lore.kernel.org/linux-btrfs/87fs1x1p93.fsf@gentoo.org/
Fixes: ae76d8e3e1 ("btrfs: scrub: fix grouping of read IO")
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:39 +01:00
arch x86/amd_nb: Use Family 19h Models 60h-7Fh Function 4 IDs 2023-11-20 11:59:38 +01:00
block blk-core: use pr_warn_ratelimited() in bio_check_ro() 2023-11-20 11:59:36 +01:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto certs: Break circular dependency when selftest is modular 2023-11-20 11:59:23 +01:00
Documentation dt-bindings: mfd: mt6397: Split out compatible for MediaTek MT6366 PMIC 2023-11-20 11:59:24 +01:00
drivers Revert "mmc: core: Capture correct oemid-bits for eMMC cards" 2023-11-20 11:59:39 +01:00
fs btrfs: make found_logical_ret parameter mandatory for function queue_scrub_stripe() 2023-11-20 11:59:39 +01:00
include net/sched: act_ct: Always fill offloading tuple iifidx 2023-11-20 11:59:37 +01:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring io_uring/net: ensure socket is marked connected on connect retry 2023-11-20 11:59:38 +01:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel tracing/kprobes: Fix the order of argument descriptions 2023-11-20 11:59:38 +01:00
lib kunit: test: Fix the possible memory leak in executor_test 2023-11-20 11:59:15 +01:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm vfs: fix readahead(2) on block devices 2023-11-20 11:58:52 +01:00
net net/sched: act_ct: Always fill offloading tuple iifidx 2023-11-20 11:59:37 +01:00
rust rust: docs: fix logo replacement 2023-10-19 16:40:00 +02:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts modpost: fix ishtp MODULE_DEVICE_TABLE built on big-endian host 2023-11-20 11:59:28 +01:00
security apparmor: fix invalid reference on profile->disconnected 2023-11-20 11:59:24 +01:00
sound ALSA: hda/realtek: Add support dual speaker for Dell 2023-11-20 11:59:38 +01:00
tools selftests: mptcp: fix wait_rm_addr/sf parameters 2023-11-20 11:59:38 +01:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.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
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.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 USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
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 Char/Misc driver fixes for 6.6-final 2023-10-28 07:51:27 -10:00
Makefile Linux 6.6.1 2023-11-08 11:56:25 +01:00
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.