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BUG: KCSAN: data-race in __writeback_single_inode / xas_clear_mark

read to 0xffff8881255782a4 of 4 bytes by task 7523 on cpu 0:
 mapping_tagged include/linux/fs.h:521 [inline]
 __writeback_single_inode+0x367/0x8e0 fs/fs-writeback.c:1502
 writeback_single_inode+0x232/0x310 fs/fs-writeback.c:1565
 sync_inode fs/fs-writeback.c:2602 [inline]
 sync_inode_metadata+0x74/0xa0 fs/fs-writeback.c:2622
 __generic_file_fsync+0x122/0x190 fs/libfs.c:1011
 ext4_sync_file+0x48e/0xb00 fs/ext4/fsync.c:120
 vfs_fsync_range+0x82/0x150 fs/sync.c:197
 generic_write_sync include/linux/fs.h:2853 [inline]
 ext4_file_write_iter+0x45b/0xa00 fs/ext4/file.c:279
 call_write_iter include/linux/fs.h:1895 [inline]
 new_sync_write+0x388/0x4a0 fs/read_write.c:483
 __vfs_write+0xb1/0xc0 fs/read_write.c:496
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x18a/0x390 fs/read_write.c:542
 ksys_write+0xd5/0x1b0 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8881255782a4 of 4 bytes by interrupt on cpu 1:
 xa_mark_clear lib/xarray.c:74 [inline]
 xas_clear_mark lib/xarray.c:917 [inline]
 xas_clear_mark+0x171/0x180 lib/xarray.c:898
 __xa_clear_mark+0xd3/0x100 lib/xarray.c:1717
 test_clear_page_writeback+0x44c/0x790 mm/page-writeback.c:2731
 end_page_writeback+0x9e/0x190 mm/filemap.c:1339
 ext4_finish_bio+0x40d/0x520 fs/ext4/page-io.c:110
 ext4_end_bio+0xd2/0x320 fs/ext4/page-io.c:334
 bio_endio+0x3a8/0x4f0 block/bio.c:1818
 req_bio_endio block/blk-core.c:242 [inline]
 blk_update_request+0x427/0x7b0 block/blk-core.c:1462
 scsi_end_request+0x6b/0x3e0 drivers/scsi/scsi_lib.c:579
 scsi_io_completion+0x11d/0xc80 drivers/scsi/scsi_lib.c:963
 scsi_finish_command+0x280/0x380 drivers/scsi/scsi.c:228
 scsi_softirq_done+0x259/0x280 drivers/scsi/scsi_lib.c:1477
 blk_done_softirq+0x1eb/0x250 block/blk-softirq.c:37
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0xbb/0xe0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 do_IRQ+0x81/0x130 arch/x86/kernel/irq.c:263
 ret_from_intr+0x0/0x19
 tomoyo_check_acl+0x9d/0x270 security/tomoyo/domain.c:170
 tomoyo_path_permission security/tomoyo/file.c:586 [inline]
 tomoyo_path_permission+0xe3/0x160 security/tomoyo/file.c:573
 tomoyo_path_perm+0x23e/0x390 security/tomoyo/file.c:838
 tomoyo_path_unlink+0x63/0x90 security/tomoyo/tomoyo.c:156
 security_path_unlink+0xa3/0xd0 security/security.c:1044
 do_unlinkat+0x2f1/0x530 fs/namei.c:4052
 __do_sys_unlink fs/namei.c:4102 [inline]
 __se_sys_unlink fs/namei.c:4100 [inline]
 __x64_sys_unlink+0x3b/0x50 fs/namei.c:4100
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7659 Comm: syz-executor.1 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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