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BUG: KCSAN: data-race in __filemap_add_folio / filemap_write_and_wait_range

read-write to 0xffff8881004c11f0 of 8 bytes by task 12024 on cpu 1:
 __filemap_add_folio+0x5b5/0x7f0 mm/filemap.c:928
 filemap_add_folio+0x9f/0x1b0 mm/filemap.c:969
 page_cache_ra_unbounded+0x1c1/0x350 mm/readahead.c:275
 do_page_cache_ra mm/readahead.c:327 [inline]
 page_cache_ra_order mm/readahead.c:532 [inline]
 page_cache_async_ra+0x41d/0x450 mm/readahead.c:687
 filemap_readahead mm/filemap.c:2559 [inline]
 filemap_get_pages+0x512/0x11b0 mm/filemap.c:2604
 filemap_splice_read+0x35a/0x930 mm/filemap.c:2980
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x26c/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xd9/0x150 fs/splice.c:1227
 do_sendfile+0x40a/0x690 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x113/0x160 fs/read_write.c:1415
 x64_sys_call+0xfc3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881004c11f0 of 8 bytes by task 12033 on cpu 0:
 mapping_needs_writeback mm/filemap.c:641 [inline]
 filemap_write_and_wait_range+0x5c/0x370 mm/filemap.c:690
 filemap_write_and_wait include/linux/pagemap.h:68 [inline]
 sync_blockdev+0x35/0x50 block/bdev.c:222
 loop_set_status+0x119/0x5d0 drivers/block/loop.c:1286
 lo_ioctl+0x81a/0x1570 drivers/block/loop.c:-1
 blkdev_ioctl+0x35b/0x450 block/ioctl.c:698
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xc9/0x140 fs/ioctl.c:892
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:892
 x64_sys_call+0x168d/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000000003f1 -> 0x00000000000003f8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 12033 Comm: syz.7.2996 Not tainted 6.15.0-rc1-syzkaller-00246-g900241a5cc15 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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loop7: detected capacity change from 16384 to 16383