KCSAN: data-race in __ext4_update_other_inode_time / __ext4_update_other_inode_time

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 131ad0b6 Merge tag 'acpi-5.10-rc5' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1576ccb6500000
kernel config: https://syzkaller.appspot.com/x/.config?x=e9a6e9171a00e85a
dashboard link: https://syzkaller.appspot.com/bug?extid=9adc47c3254935447e45
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [adilger...@dilger.ca linux...@vger.kernel.org linux-...@vger.kernel.org ty...@mit.edu]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9adc47...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __ext4_update_other_inode_time / __ext4_update_other_inode_time

write to 0xffff88803ba0c778 of 8 bytes by task 8455 on cpu 1:
__ext4_update_other_inode_time+0xc1/0x550 fs/ext4/inode.c:4966
ext4_update_other_inodes_time fs/ext4/inode.c:5002 [inline]
ext4_do_update_inode fs/ext4/inode.c:5131 [inline]
ext4_mark_iloc_dirty+0x1286/0x1650 fs/ext4/inode.c:5712
__ext4_mark_inode_dirty+0x450/0x610 fs/ext4/inode.c:5906
__ext4_unlink+0x636/0x670 fs/ext4/namei.c:3226
ext4_unlink+0x1e2/0x3e0 fs/ext4/namei.c:3274
vfs_unlink+0x232/0x3b0 fs/namei.c:3833
do_unlinkat+0x28a/0x4d0 fs/namei.c:3897
__do_sys_unlink fs/namei.c:3943 [inline]
__se_sys_unlink fs/namei.c:3941 [inline]
__x64_sys_unlink+0x2c/0x30 fs/namei.c:3941
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88803ba0c778 of 8 bytes by task 26128 on cpu 0:
__ext4_update_other_inode_time+0x45/0x550 fs/ext4/inode.c:4955
ext4_update_other_inodes_time fs/ext4/inode.c:5002 [inline]
ext4_do_update_inode fs/ext4/inode.c:5131 [inline]
ext4_mark_iloc_dirty+0x1286/0x1650 fs/ext4/inode.c:5712
__ext4_mark_inode_dirty+0x450/0x610 fs/ext4/inode.c:5906
__ext4_unlink+0x4e5/0x670 fs/ext4/namei.c:3240
ext4_unlink+0x1e2/0x3e0 fs/ext4/namei.c:3274
vfs_unlink+0x232/0x3b0 fs/namei.c:3833
do_unlinkat+0x28a/0x4d0 fs/namei.c:3897
__do_sys_unlink fs/namei.c:3943 [inline]
__se_sys_unlink fs/namei.c:3941 [inline]
__x64_sys_unlink+0x2c/0x30 fs/namei.c:3941
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26128 Comm: syz-executor.1 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.