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BUG: KCSAN: data-race in __filemap_add_folio / file_write_and_wait_range

read-write to 0xffff88810692f528 of 8 bytes by task 8097 on cpu 1:
 __filemap_add_folio+0x4c1/0x730 mm/filemap.c:903
 filemap_add_folio+0x70/0x160 mm/filemap.c:938
 page_cache_ra_unbounded+0x15e/0x2e0 mm/readahead.c:250
 do_page_cache_ra mm/readahead.c:299 [inline]
 page_cache_ra_order mm/readahead.c:544 [inline]
 ondemand_readahead+0x50b/0x670 mm/readahead.c:666
 page_cache_sync_ra+0x27e/0x2a0 mm/readahead.c:693
 page_cache_sync_readahead include/linux/pagemap.h:1300 [inline]
 filemap_get_pages+0x251/0xf90 mm/filemap.c:2498
 filemap_splice_read+0x337/0x8f0 mm/filemap.c:2872
 ext4_file_splice_read+0x95/0xb0 fs/ext4/file.c:158
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x268/0x660 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3b9/0x960 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88810692f528 of 8 bytes by task 8099 on cpu 0:
 mapping_needs_writeback mm/filemap.c:626 [inline]
 file_write_and_wait_range+0x67/0x190 mm/filemap.c:778
 ext4_sync_file+0x133/0x6c0 fs/ext4/fsync.c:158
 vfs_fsync_range+0x111/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2734 [inline]
 iomap_dio_complete+0x36a/0x4c0 fs/iomap/direct-io.c:126
 iomap_dio_rw+0x62/0x90 fs/iomap/direct-io.c:752
 ext4_dio_write_iter fs/ext4/file.c:577 [inline]
 ext4_file_write_iter+0xa8a/0xe10 fs/ext4/file.c:696
 call_write_iter include/linux/fs.h:2087 [inline]
 iter_file_splice_write+0x5de/0x950 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x167/0x2c0 fs/splice.c:1164
 splice_direct_to_actor+0x2fb/0x660 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x3b9/0x960 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64 fs/read_write.c:1348 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x000000000000019c -> 0x00000000000001a3

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8099 Comm: syz-executor.1 Not tainted 6.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
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