EXT4-fs (loop7): i_reserved_data_blocks=36
EXT4-fs (loop7): Delayed block allocation failed for inode 18 at logical offset 84 with max blocks 484 with error 28
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BUG: KCSAN: data-race in __xa_set_mark / xas_find_marked

read-write to 0xffff88810b538228 of 8 bytes by task 6969 on cpu 1:
 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
 block_commit_write fs/buffer.c:2196 [inline]
 block_page_mkwrite+0x261/0x300 fs/buffer.c:2645
 ext4_page_mkwrite+0x824/0xa90 fs/ext4/inode.c:6826
 do_page_mkwrite mm/memory.c:3684 [inline]
 do_shared_fault mm/memory.c:5936 [inline]
 do_fault mm/memory.c:5998 [inline]
 do_pte_missing mm/memory.c:4566 [inline]
 handle_pte_fault mm/memory.c:6379 [inline]
 __handle_mm_fault mm/memory.c:6517 [inline]
 handle_mm_fault+0x1b3d/0x2da0 mm/memory.c:6686
 do_user_addr_fault+0x634/0x1060 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595

read to 0xffff88810b538228 of 8 bytes by task 12 on cpu 0:
 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+0x6ec/0x2720 fs/ext4/inode.c:2895
 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: 0x7e00000000000000 -> 0x7f80000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: writeback wb_workfn (flush-8:0)
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