syzbot

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BUG: KCSAN: data-race in __filemap_add_folio / filemap_write_and_wait_range

read-write to 0xffff88813e6950a8 of 8 bytes by task 5308 on cpu 0:
 __filemap_add_folio+0x3c3/0x750 mm/filemap.c:904
 filemap_add_folio+0x70/0x160 mm/filemap.c:939
 page_cache_ra_unbounded+0x15e/0x2e0 mm/readahead.c:250
 do_page_cache_ra+0xa7/0xc0 mm/readahead.c:299
 ondemand_readahead+0x682/0x690 mm/readahead.c:641
 page_cache_sync_ra+0x27e/0x2a0 mm/readahead.c:695
 page_cache_sync_readahead include/linux/pagemap.h:1293 [inline]
 filemap_get_pages+0x251/0xe90 mm/filemap.c:2556
 filemap_splice_read+0x238/0x7f0 mm/filemap.c:2919
 ext4_file_splice_read+0x95/0xb0 fs/ext4/file.c:158
 vfs_splice_read fs/splice.c:993 [inline]
 splice_direct_to_actor+0x28c/0x690 fs/splice.c:1069
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3b6/0x9a0 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88813e6950a8 of 8 bytes by task 5314 on cpu 1:
 mapping_needs_writeback mm/filemap.c:628 [inline]
 filemap_write_and_wait_range+0x51/0x210 mm/filemap.c:677
 kiocb_invalidate_pages+0x87/0x1e0 mm/filemap.c:2753
 __iomap_dio_rw+0x5a7/0x1080 fs/iomap/direct-io.c:638
 iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:748
 ext4_dio_write_iter fs/ext4/file.c:605 [inline]
 ext4_file_write_iter+0xaaa/0x1200 fs/ext4/file.c:715
 do_iter_write+0x4b4/0x7b0 fs/read_write.c:860
 vfs_iter_write+0x56/0x70 fs/read_write.c:901
 iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
 do_splice_from fs/splice.c:933 [inline]
 direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
 splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3b6/0x9a0 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000229 -> 0x0000000000000231

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5314 Comm: syz-executor.2 Tainted: G        W          6.6.0-rc3-syzkaller-00165-g3b517966c561 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
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