syzbot

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BUG: KCSAN: data-race in __mark_inode_dirty / redirty_tail_locked

read-write to 0xffff888106205890 of 8 bytes by task 49 on cpu 1:
 redirty_tail_locked+0x56/0x270 fs/fs-writeback.c:1347
 requeue_inode fs/fs-writeback.c:1608 [inline]
 writeback_sb_inodes+0x893/0xaa0 fs/fs-writeback.c:1970
 wb_writeback+0x252/0x6f0 fs/fs-writeback.c:2117
 wb_do_writeback fs/fs-writeback.c:2264 [inline]
 wb_workfn+0x1a8/0x940 fs/fs-writeback.c:2304
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

read to 0xffff888106205890 of 8 bytes by task 7384 on cpu 0:
 __mark_inode_dirty+0x19f/0x7e0 fs/fs-writeback.c:2499
 mark_buffer_dirty+0x165/0x250 fs/buffer.c:1204
 __block_commit_write fs/buffer.c:2177 [inline]
 block_write_end+0x158/0x2e0 fs/buffer.c:2253
 ext4_da_do_write_end fs/ext4/inode.c:2955 [inline]
 ext4_da_write_end+0x1ad/0x860 fs/ext4/inode.c:3028
 generic_perform_write+0x276/0x410 mm/filemap.c:3985
 ext4_buffered_write_iter+0x1f6/0x380 fs/ext4/file.c:299
 ext4_file_write_iter+0x29f/0xe30
 __kernel_write_iter+0x265/0x490 fs/read_write.c:523
 dump_emit_page fs/coredump.c:890 [inline]
 dump_user_range+0x3a7/0x550 fs/coredump.c:951
 elf_core_dump+0x1aa6/0x1bc0 fs/binfmt_elf.c:2077
 do_coredump+0x1033/0x1890 fs/coredump.c:764
 get_signal+0xdc1/0x1080 kernel/signal.c:2896
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
 do_syscall_64+0xe2/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

value changed: 0x0000000000020084 -> 0x0000000000000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7384 Comm: syz-executor.4 Tainted: G        W          6.9.0-rc1-syzkaller-00206-g4535e1a4174c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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