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BUG: KCSAN: data-race in delete_from_page_cache_batch / folio_mapping

write to 0xffffea0004a42998 of 8 bytes by task 4686 on cpu 0:
 page_cache_delete_batch mm/filemap.c:309 [inline]
 delete_from_page_cache_batch+0x2f6/0x6f0 mm/filemap.c:335
 truncate_inode_pages_range+0x1ba/0x780 mm/truncate.c:380
 truncate_inode_pages+0x24/0x30 mm/truncate.c:460
 ext4_truncate_failed_write fs/ext4/truncate.h:21 [inline]
 ext4_write_end+0x541/0x730 fs/ext4/inode.c:1486
 generic_perform_write+0x30f/0x490 mm/filemap.c:4263
 ext4_buffered_write_iter+0x1ee/0x3c0 fs/ext4/file.c:299
 ext4_file_write_iter+0x387/0xf60 fs/ext4/file.c:-1
 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

read to 0xffffea0004a42998 of 8 bytes by task 1035 on cpu 1:
 folio_mapping+0xa1/0xe0 mm/util.c:702
 folio_evictable mm/internal.h:499 [inline]
 lru_add+0x8d/0x480 mm/swap.c:136
 folio_batch_move_lru+0x1c2/0x280 mm/swap.c:172
 lru_add_drain_cpu+0x77/0x250 mm/swap.c:648
 lru_add_and_bh_lrus_drain mm/swap.c:751 [inline]
 lru_add_drain_per_cpu+0x25/0x70 mm/swap.c:772
 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

value changed: 0xffff88811a9e4b30 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 1035 Comm: kworker/1:2 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: mm_percpu_wq lru_add_drain_per_cpu
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