EXT4-fs (loop2): Block reservation details
EXT4-fs (loop2): i_reserved_data_blocks=36
EXT4-fs (loop2): Delayed block allocation failed for inode 18 at logical offset 262 with max blocks 310 with error 28
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BUG: KCSAN: data-race in __xa_set_mark / xas_find_marked

read-write to 0xffff88810ce158f8 of 8 bytes by task 18107 on cpu 0:
 instrument_read_write include/linux/instrumented.h:56 [inline]
 __instrument_read_write_bitop include/asm-generic/bitops/instrumented-non-atomic.h:84 [inline]
 ___test_and_set_bit include/asm-generic/bitops/instrumented-non-atomic.h:99 [inline]
 node_set_mark lib/xarray.c:95 [inline]
 xas_set_mark lib/xarray.c:893 [inline]
 __xa_set_mark+0xd2/0x1a0 lib/xarray.c:2082
 __folio_mark_dirty+0x42c/0x520 mm/page-writeback.c:2689
 mark_buffer_dirty+0x120/0x1f0 fs/buffer.c:1116
 folio_zero_new_buffers+0x272/0x2d0 fs/buffer.c:2010
 block_write_end+0x200/0x210 fs/buffer.c:2267
 ext4_da_do_write_end fs/ext4/inode.c:3241 [inline]
 ext4_da_write_end+0x1e4/0x7b0 fs/ext4/inode.c:3311
 generic_perform_write+0x314/0x490 mm/filemap.c:4379
 ext4_buffered_write_iter+0x2e2/0x480 fs/ext4/file.c:316
 ext4_file_write_iter+0x38e/0xef0 fs/ext4/file.c:-1
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x57d/0x990 fs/read_write.c:687
 ksys_write+0xdc/0x1a0 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:747
 x64_sys_call+0x27e1/0x3020 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810ce158f8 of 8 bytes by task 14279 on cpu 1:
 xas_find_chunk include/linux/xarray.h:1752 [inline]
 xas_find_marked+0x211/0x650 lib/xarray.c:1510
 find_get_entry mm/filemap.c:2081 [inline]
 filemap_get_folios_tag+0xf7/0x400 mm/filemap.c:2348
 mpage_prepare_extent_to_map+0x2f8/0xc00 fs/ext4/inode.c:2656
 ext4_do_writepages+0x9e5/0x2720 fs/ext4/inode.c:2947
 ext4_writepages+0x18f/0x300 fs/ext4/inode.c:3043
 do_writepages+0x1b9/0x300 mm/page-writeback.c:2571
 __writeback_single_inode+0x7b/0x660 fs/fs-writeback.c:1787
 writeback_sb_inodes+0x4d9/0xaa0 fs/fs-writeback.c:2079
 __writeback_inodes_wb+0x8a/0x180 fs/fs-writeback.c:2155
 wb_writeback+0x21e/0x510 fs/fs-writeback.c:2266
 wb_check_start_all fs/fs-writeback.c:2392 [inline]
 wb_do_writeback fs/fs-writeback.c:2439 [inline]
 wb_workfn+0x4f4/0xa50 fs/fs-writeback.c:2477
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0x4d4/0x9a0 kernel/workqueue.c:3405
 worker_thread+0x569/0x750 kernel/workqueue.c:3486
 kthread+0x221/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00003fffffffffff -> 0x0000ffffffffffff

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 14279 Comm: kworker/u8:0 Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: writeback wb_workfn (flush-7:2)
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