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BUG: KCSAN: data-race in __filemap_add_folio / filemap_write_and_wait_range

read-write to 0xffff8881006e9d78 of 8 bytes by task 3287 on cpu 1:
 __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 0xffff8881006e9d78 of 8 bytes by task 7010 on cpu 0:
 mapping_needs_writeback mm/filemap.c:635 [inline]
 filemap_write_and_wait_range+0x59/0x370 mm/filemap.c:684
 kiocb_write_and_wait+0x7a/0x110 mm/filemap.c:2896
 blkdev_read_iter+0xf9/0x2e0 block/fops.c:834
 copy_splice_read+0x471/0x6c0 fs/splice.c:362
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x28f/0x670 fs/splice.c:1084
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1228
 do_sendfile+0x382/0x650 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64 fs/read_write.c:1419 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1419
 x64_sys_call+0x2dc4/0x3020 arch/x86/include/generated/asm/syscalls_64.h:41
 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

value changed: 0x000000000000000b -> 0x000000000000000c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 7010 Comm: syz.3.1017 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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