syzbot

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BUG: KCSAN: data-race in filemap_write_and_wait_range / xas_set_mark

write to 0xffff888106618714 of 4 bytes by task 8047 on cpu 0:
 xa_mark_set lib/xarray.c:71 [inline]
 xas_set_mark+0x13d/0x150 lib/xarray.c:899
 __folio_start_writeback+0x1ea/0x440 mm/page-writeback.c:3126
 ext4_bio_write_folio+0x591/0x9d0 fs/ext4/page-io.c:583
 mpage_submit_folio fs/ext4/inode.c:1934 [inline]
 mpage_process_page_bufs+0x488/0x5d0 fs/ext4/inode.c:2047
 mpage_prepare_extent_to_map+0x791/0xb80 fs/ext4/inode.c:2548
 ext4_do_writepages+0xa3b/0x21d0 fs/ext4/inode.c:2734
 ext4_writepages+0x183/0x320 fs/ext4/inode.c:2826
 do_writepages+0x1d8/0x480 mm/page-writeback.c:2687
 filemap_fdatawrite_wbc mm/filemap.c:389 [inline]
 __filemap_fdatawrite_range mm/filemap.c:422 [inline]
 file_write_and_wait_range+0x16e/0x2f0 mm/filemap.c:797
 generic_buffers_fsync_noflush+0x46/0x120 fs/buffer.c:600
 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
 ext4_sync_file+0x1c3/0x6c0 fs/ext4/fsync.c:147
 vfs_fsync_range+0x116/0x130 fs/sync.c:187
 generic_write_sync include/linux/fs.h:2976 [inline]
 ext4_buffered_write_iter+0x358/0x3c0 fs/ext4/file.c:305
 ext4_dio_write_iter fs/ext4/file.c:608 [inline]
 ext4_file_write_iter+0xe49/0xf80 fs/ext4/file.c:716
 iter_file_splice_write+0x5f2/0x980 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0x160/0x2c0 fs/splice.c:1158
 splice_direct_to_actor+0x305/0x680 fs/splice.c:1102
 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 0xffff888106618714 of 4 bytes by task 8050 on cpu 1:
 xa_marked include/linux/xarray.h:424 [inline]
 mapping_tagged include/linux/fs.h:540 [inline]
 filemap_fdatawrite_wbc mm/filemap.c:385 [inline]
 __filemap_fdatawrite_range mm/filemap.c:422 [inline]
 filemap_write_and_wait_range+0x105/0x370 mm/filemap.c:694
 filemap_invalidate_pages+0xa8/0x1a0 mm/filemap.c:2817
 kiocb_invalidate_pages+0x6c/0x80 mm/filemap.c:2836
 __iomap_dio_rw+0x5d4/0x12a0 fs/iomap/direct-io.c:703
 iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:823
 ext4_dio_write_iter fs/ext4/file.c:575 [inline]
 ext4_file_write_iter+0xba9/0xf80 fs/ext4/file.c:716
 iter_file_splice_write+0x5f2/0x980 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0x160/0x2c0 fs/splice.c:1158
 splice_direct_to_actor+0x305/0x680 fs/splice.c:1102
 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

value changed: 0x0a000021 -> 0x04000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 8050 Comm: syz.4.1512 Not tainted 6.14.0-syzkaller-11270-g08733088b566 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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