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BUG: KCSAN: data-race in __filemap_add_folio / filemap_write_and_wait_range

read-write to 0xffff8881005f0bb8 of 8 bytes by task 3305 on cpu 1:
 __filemap_add_folio+0x5b9/0x7d0 mm/filemap.c:919
 filemap_add_folio+0x1d9/0x360 mm/filemap.c:966
 page_cache_ra_unbounded+0x205/0x450 mm/readahead.c:280
 do_page_cache_ra mm/readahead.c:332 [inline]
 force_page_cache_ra mm/readahead.c:361 [inline]
 page_cache_sync_ra+0x26e/0x6a0 mm/readahead.c:579
 filemap_get_pages+0x2d0/0x11c0 mm/filemap.c:2690
 filemap_read+0x231/0xa00 mm/filemap.c:2800
 blkdev_read_iter+0x22d/0x2e0 block/fops.c:860
 new_sync_read fs/read_write.c:491 [inline]
 vfs_read+0x64c/0x770 fs/read_write.c:572
 ksys_read+0xda/0x1a0 fs/read_write.c:715
 __do_sys_read fs/read_write.c:724 [inline]
 __se_sys_read fs/read_write.c:722 [inline]
 __x64_sys_read+0x40/0x50 fs/read_write.c:722
 x64_sys_call+0x2889/0x3000 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd8/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881005f0bb8 of 8 bytes by task 3314 on cpu 0:
 mapping_needs_writeback mm/filemap.c:634 [inline]
 filemap_write_and_wait_range+0x59/0x340 mm/filemap.c:683
 filemap_write_and_wait include/linux/pagemap.h:65 [inline]
 sync_blockdev+0x35/0x50 block/bdev.c:277
 sync_filesystem+0x162/0x190 fs/sync.c:70
 generic_shutdown_super+0x44/0x210 fs/super.c:622
 kill_block_super+0x2a/0x70 fs/super.c:1722
 deactivate_locked_super+0x75/0x1c0 fs/super.c:474
 deactivate_super+0x97/0xa0 fs/super.c:507
 cleanup_mnt+0x2a9/0x320 fs/namespace.c:1318
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1325
 task_work_run+0x131/0x1a0 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0x1fe/0x740 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x202/0x2a0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000017 -> 0x0000000000000018

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3314 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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