syzbot

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BUG: KCSAN: data-race in __mark_inode_dirty / move_expired_inodes

read-write to 0xffff888106bf05f8 of 4 bytes by task 31 on cpu 0:
 move_expired_inodes+0x17a/0x400 fs/fs-writeback.c:1457
 queue_io+0xd9/0x2c0 fs/fs-writeback.c:1509
 wb_writeback+0x226/0x5c0 fs/fs-writeback.c:2152
 wb_check_start_all fs/fs-writeback.c:2284 [inline]
 wb_do_writeback fs/fs-writeback.c:2310 [inline]
 wb_workfn+0x4c9/0x910 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888106bf05f8 of 4 bytes by task 5903 on cpu 1:
 __mark_inode_dirty+0x18e/0x760 fs/fs-writeback.c:2549
 mark_inode_dirty_sync include/linux/fs.h:2603 [inline]
 dquot_free_space include/linux/quotaops.h:380 [inline]
 dquot_free_block include/linux/quotaops.h:390 [inline]
 ext4_mb_clear_bb fs/ext4/mballoc.c:6531 [inline]
 ext4_free_blocks+0xe3f/0x1400 fs/ext4/mballoc.c:6651
 ext4_clear_blocks+0x2a2/0x2c0 fs/ext4/indirect.c:888
 ext4_free_data+0x1a1/0x2a0 fs/ext4/indirect.c:962
 ext4_free_branches+0x62/0x410 fs/ext4/indirect.c:1108
 ext4_ind_truncate+0x503/0x830 fs/ext4/indirect.c:1181
 ext4_truncate+0x6d7/0xad0 fs/ext4/inode.c:4576
 ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline]
 ext4_write_end+0x44b/0x730 fs/ext4/inode.c:1465
 generic_perform_write+0x30f/0x490 mm/filemap.c:4133
 ext4_buffered_write_iter+0x1ee/0x3c0 fs/ext4/file.c:299
 ext4_file_write_iter+0x383/0xf00 fs/ext4/file.c:-1
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x4a0/0x8e0 fs/read_write.c:686
 ksys_pwrite64 fs/read_write.c:793 [inline]
 __do_sys_pwrite64 fs/read_write.c:801 [inline]
 __se_sys_pwrite64 fs/read_write.c:798 [inline]
 __x64_sys_pwrite64+0xfd/0x150 fs/read_write.c:798
 x64_sys_call+0xe45/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:19
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000038 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 5903 Comm: syz.2.545 Not tainted 6.16.0-rc3-syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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