syzbot

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BUG: KCSAN: data-race in __jbd2_journal_temp_unlink_buffer / jbd2_journal_update_sb_log_tail

write to 0xffff888102a8a800 of 8 bytes by task 345 on cpu 1:
 jbd2_journal_update_sb_log_tail+0x176/0x1b0 fs/jbd2/journal.c:1689
 jbd2_journal_commit_transaction+0x21a/0x3430 fs/jbd2/commit.c:430
 kjournald2+0x268/0x490 fs/jbd2/journal.c:213
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30

read to 0xffff888102a8a800 of 8 bytes by task 7231 on cpu 0:
 is_journal_aborted include/linux/jbd2.h:1695 [inline]
 __jbd2_journal_temp_unlink_buffer+0x1f5/0x290 fs/jbd2/transaction.c:2040
 __jbd2_journal_file_buffer+0x175/0x380 fs/jbd2/transaction.c:2520
 jbd2_journal_dirty_metadata+0x458/0x720 fs/jbd2/transaction.c:1609
 __ext4_handle_dirty_metadata+0xfb/0x5a0 fs/ext4/ext4_jbd2.c:348
 ext4_do_update_inode fs/ext4/inode.c:5095 [inline]
 ext4_mark_iloc_dirty+0x12f8/0x1700 fs/ext4/inode.c:5683
 __ext4_mark_inode_dirty+0x4ec/0x5c0 fs/ext4/inode.c:5879
 ext4_dirty_inode+0x86/0xa0 fs/ext4/inode.c:5908
 __mark_inode_dirty+0x77/0x6a0 fs/fs-writeback.c:2398
 generic_update_time fs/inode.c:1776 [inline]
 update_time fs/inode.c:1789 [inline]
 touch_atime+0x185/0x250 fs/inode.c:1860
 pick_link fs/namei.c:1751 [inline]
 step_into+0x891/0xee0 fs/namei.c:1826
 walk_component+0x1a1/0x360 fs/namei.c:1976
 lookup_last fs/namei.c:2425 [inline]
 path_lookupat+0x12d/0x3d0 fs/namei.c:2449
 filename_lookup+0x130/0x310 fs/namei.c:2478
 user_path_at_empty+0x3e/0x110 fs/namei.c:2801
 user_path_at include/linux/namei.h:57 [inline]
 ksys_umount fs/namespace.c:1773 [inline]
 __do_sys_umount fs/namespace.c:1781 [inline]
 __se_sys_umount fs/namespace.c:1779 [inline]
 __x64_sys_umount+0x84/0xe0 fs/namespace.c:1779
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000038 -> 0x0000000000000230

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7231 Comm: syz-executor.5 Not tainted 5.15.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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