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BUG: KCSAN: data-race in __mark_inode_dirty / __writeback_single_inode

read-write to 0xffff88811b67ca50 of 4 bytes by task 31 on cpu 0:
 __writeback_single_inode+0x1e3/0x7c0 fs/fs-writeback.c:1755
 writeback_sb_inodes+0x48f/0xa30 fs/fs-writeback.c:2015
 wb_writeback+0x252/0x5c0 fs/fs-writeback.c:2195
 wb_do_writeback fs/fs-writeback.c:2342 [inline]
 wb_workfn+0x194/0x910 fs/fs-writeback.c:2382
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x486/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff88811b67ca50 of 4 bytes by task 16640 on cpu 1:
 __mark_inode_dirty+0x55/0x750 fs/fs-writeback.c:2548
 mark_inode_dirty_sync include/linux/fs.h:2619 [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:6650 [inline]
 ext4_free_blocks+0xea9/0x1480 fs/ext4/mballoc.c:6770
 ext4_remove_blocks fs/ext4/extents.c:2551 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2716 [inline]
 ext4_ext_remove_space+0x177b/0x2900 fs/ext4/extents.c:2965
 ext4_ext_truncate+0xc7/0x170 fs/ext4/extents.c:4484
 ext4_truncate+0x70d/0xae0 fs/ext4/inode.c:4614
 ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline]
 ext4_write_end+0x549/0x730 fs/ext4/inode.c:1486
 ext4_da_write_end+0x65/0x800 fs/ext4/inode.c:3277
 generic_perform_write+0x30f/0x490 mm/filemap.c:4263
 ext4_buffered_write_iter+0x1ee/0x3c0 fs/ext4/file.c:299
 ext4_dio_write_iter fs/ext4/file.c:613 [inline]
 ext4_file_write_iter+0xe27/0xf60 fs/ext4/file.c:721
 do_iter_readv_writev+0x49e/0x540 fs/read_write.c:-1
 vfs_writev+0x2df/0x8b0 fs/read_write.c:1057
 do_writev+0xe7/0x210 fs/read_write.c:1103
 __do_sys_writev fs/read_write.c:1171 [inline]
 __se_sys_writev fs/read_write.c:1168 [inline]
 __x64_sys_writev+0x45/0x50 fs/read_write.c:1168
 x64_sys_call+0x1e9a/0x3000 arch/x86/include/generated/asm/syscalls_64.h:21
 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: 0x00020072 -> 0x00000040

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 16640 Comm: syz.5.3610 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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