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BUG: KCSAN: data-race in __xa_set_mark / xas_find_marked

write to 0xffff888116adbd24 of 4 bytes by task 4006 on cpu 1:
 xa_mark_set lib/xarray.c:71 [inline]
 xas_set_mark lib/xarray.c:893 [inline]
 __xa_set_mark+0x182/0x1b0 lib/xarray.c:1939
 __folio_mark_dirty+0x3b5/0x4e0 mm/page-writeback.c:2819
 mark_buffer_dirty+0x134/0x230 fs/buffer.c:1196
 __block_commit_write fs/buffer.c:2189 [inline]
 block_write_end+0x123/0x210 fs/buffer.c:2265
 ext4_write_end+0x148/0x770 fs/ext4/inode.c:1304
 generic_perform_write+0x33c/0x4a0 mm/filemap.c:4147
 ext4_buffered_write_iter+0x1ea/0x370 fs/ext4/file.c:299
 ext4_file_write_iter+0x383/0xf20
 iter_file_splice_write+0x5f1/0x980 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x160/0x2c0 fs/splice.c:1164
 splice_direct_to_actor+0x302/0x670 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x398/0x660 fs/read_write.c:1363
 __do_sys_sendfile64 fs/read_write.c:1424 [inline]
 __se_sys_sendfile64 fs/read_write.c:1410 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1410
 x64_sys_call+0xfbd/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888116adbd24 of 4 bytes by task 3998 on cpu 0:
 xa_marked include/linux/xarray.h:424 [inline]
 xas_find_marked+0x60a/0x660 lib/xarray.c:1343
 find_get_entry+0x54/0x390 mm/filemap.c:1985
 filemap_get_folios_tag+0x9e/0x210 mm/filemap.c:2252
 __filemap_fdatawait_range mm/filemap.c:515 [inline]
 filemap_fdatawait_range+0x89/0x1f0 mm/filemap.c:550
 filemap_fdatawait include/linux/pagemap.h:50 [inline]
 __writeback_single_inode+0xe8/0x850 fs/fs-writeback.c:1690
 writeback_single_inode+0x16c/0x3f0 fs/fs-writeback.c:1801
 sync_inode_metadata+0x5c/0x90 fs/fs-writeback.c:2871
 generic_buffers_fsync_noflush+0xd8/0x120 fs/buffer.c:610
 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
 ext4_sync_file+0x1ff/0x6c0 fs/ext4/fsync.c:151
 vfs_fsync_range+0x116/0x130 fs/sync.c:187
 generic_write_sync include/linux/fs.h:2956 [inline]
 ext4_buffered_write_iter+0x326/0x370 fs/ext4/file.c:305
 ext4_file_write_iter+0x383/0xf20
 iter_file_splice_write+0x5f1/0x980 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x160/0x2c0 fs/splice.c:1164
 splice_direct_to_actor+0x302/0x670 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x398/0x660 fs/read_write.c:1363
 __do_sys_sendfile64 fs/read_write.c:1424 [inline]
 __se_sys_sendfile64 fs/read_write.c:1410 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1410
 x64_sys_call+0xfbd/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000021 -> 0x0a000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3998 Comm: syz.1.114 Not tainted 6.13.0-syzkaller-07632-gaa22f4da2a46 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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