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BUG: KCSAN: data-race in __filemap_add_folio / filemap_write_and_wait_range

read-write to 0xffff88810048eb78 of 8 bytes by task 3289 on cpu 0:
 __filemap_add_folio+0x671/0x880 mm/filemap.c:920
 filemap_add_folio+0x1d3/0x350 mm/filemap.c:967
 page_cache_ra_unbounded+0x20e/0x420 mm/readahead.c:282
 do_page_cache_ra mm/readahead.c:334 [inline]
 force_page_cache_ra+0x18d/0x1d0 mm/readahead.c:364
 page_cache_sync_ra+0x10e/0x530 mm/readahead.c:582
 filemap_get_pages+0x30a/0x1250 mm/filemap.c:2696
 filemap_read+0x231/0xa10 mm/filemap.c:2806
 blkdev_read_iter+0x22d/0x2e0 block/fops.c:855
 new_sync_read fs/read_write.c:493 [inline]
 vfs_read+0x6c0/0x7f0 fs/read_write.c:574
 ksys_read+0xdc/0x1a0 fs/read_write.c:717
 __do_sys_read fs/read_write.c:726 [inline]
 __se_sys_read fs/read_write.c:724 [inline]
 __x64_sys_read+0x40/0x50 fs/read_write.c:724
 x64_sys_call+0x2886/0x3020 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810048eb78 of 8 bytes by task 3989 on cpu 1:
 mapping_needs_writeback mm/filemap.c:635 [inline]
 filemap_write_and_wait_range+0x59/0x370 mm/filemap.c:684
 filemap_write_and_wait include/linux/pagemap.h:65 [inline]
 sync_blockdev+0x35/0x50 block/bdev.c:276
 sync_filesystem+0x162/0x190 fs/sync.c:70
 generic_shutdown_super+0x4c/0x220 fs/super.c:625
 kill_block_super+0x2a/0x70 fs/super.c:1725
 deactivate_locked_super+0x75/0x1c0 fs/super.c:476
 deactivate_super+0x97/0xa0 fs/super.c:509
 cleanup_mnt+0x2bb/0x330 fs/namespace.c:1312
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1319
 task_work_run+0x130/0x1a0 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:67 [inline]
 exit_to_user_mode_loop+0x211/0x820 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x232/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000007 -> 0x0000000000000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3989 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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