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BUG: KCSAN: data-race in __mark_inode_dirty / __writeback_single_inode

read-write to 0xffff8881059328b8 of 4 bytes by task 3498 on cpu 0:
 __writeback_single_inode+0x1e3/0x7c0 fs/fs-writeback.c:1716
 writeback_sb_inodes+0x48f/0xa30 fs/fs-writeback.c:1976
 __writeback_inodes_wb+0x94/0x1a0 fs/fs-writeback.c:2047
 wb_writeback+0x266/0x5c0 fs/fs-writeback.c:2158
 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:3236 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x486/0x510 kernel/kthread.c:463
 ret_from_fork+0xdd/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff8881059328b8 of 4 bytes by task 11483 on cpu 1:
 __mark_inode_dirty+0x18e/0x760 fs/fs-writeback.c:2549
 mark_buffer_dirty+0x133/0x210 fs/buffer.c:1209
 block_commit_write fs/buffer.c:2218 [inline]
 block_page_mkwrite+0x287/0x3d0 fs/buffer.c:2643
 ext4_page_mkwrite+0x859/0xb90 fs/ext4/inode.c:6725
 do_page_mkwrite mm/memory.c:3361 [inline]
 wp_page_shared mm/memory.c:3762 [inline]
 do_wp_page+0xdd8/0x24e0 mm/memory.c:3981
 handle_pte_fault mm/memory.c:6068 [inline]
 __handle_mm_fault mm/memory.c:6195 [inline]
 handle_mm_fault+0x77d/0x2c20 mm/memory.c:6364
 do_user_addr_fault+0x636/0x1090 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

value changed: 0x0001002a -> 0x00000020

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 11483 Comm: syz.5.3047 Tainted: G        W           6.16.0-syzkaller-11699-g7e161a991ea7 #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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