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BUG: KCSAN: data-race in __filemap_add_folio / filemap_write_and_wait_range

read-write to 0xffff8881005f1e78 of 8 bytes by task 3698 on cpu 0:
 __filemap_add_folio+0x5b9/0x7d0 mm/filemap.c:931
 filemap_add_folio+0x1d9/0x360 mm/filemap.c:978
 page_cache_ra_unbounded+0x203/0x450 mm/readahead.c:280
 do_page_cache_ra mm/readahead.c:332 [inline]
 page_cache_ra_order+0x145/0x220 mm/readahead.c:535
 page_cache_sync_ra+0x52d/0x6a0 mm/readahead.c:626
 filemap_get_pages+0x2d0/0x11b0 mm/filemap.c:2638
 filemap_splice_read+0x3a9/0x740 mm/filemap.c:3027
 do_splice_read fs/splice.c:982 [inline]
 splice_direct_to_actor+0x26f/0x680 fs/splice.c:1086
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1230
 do_sendfile+0x380/0x650 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1417
 x64_sys_call+0x2bb4/0x3000 arch/x86/include/generated/asm/syscalls_64.h:41
 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 0xffff8881005f1e78 of 8 bytes by task 3306 on cpu 1:
 mapping_needs_writeback mm/filemap.c:644 [inline]
 filemap_write_and_wait_range+0x59/0x340 mm/filemap.c:693
 filemap_write_and_wait include/linux/pagemap.h:68 [inline]
 sync_blockdev+0x35/0x50 block/bdev.c:260
 bdev_disk_changed+0xdb/0xcb0 block/partitions/core.c:656
 blkdev_get_whole+0x1f5/0x2d0 block/bdev.c:748
 bdev_open+0x280/0x7e0 block/bdev.c:957
 blkdev_open+0x259/0x290 block/fops.c:701
 do_dentry_open+0x649/0xa20 fs/open.c:965
 vfs_open+0x37/0x1e0 fs/open.c:1097
 do_open fs/namei.c:3975 [inline]
 path_openat+0x1c5e/0x2170 fs/namei.c:4134
 do_filp_open+0x109/0x230 fs/namei.c:4161
 do_sys_openat2+0xa6/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1463
 x64_sys_call+0x2eab/0x3000 arch/x86/include/generated/asm/syscalls_64.h:258
 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: 0x000000000000000f -> 0x000000000000001e

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3306 Comm: udevd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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