syzbot

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BUG: KCSAN: data-race in __ext4_update_other_inode_time / __writeback_single_inode

write to 0xffff888106a2c788 of 8 bytes by task 29714 on cpu 0:
 __writeback_single_inode+0x1e9/0x450 fs/fs-writeback.c:1503
 writeback_sb_inodes+0x564/0xf10 fs/fs-writeback.c:1732
 wb_writeback+0x28e/0x700 fs/fs-writeback.c:1905
 wb_do_writeback+0x101/0x510 fs/fs-writeback.c:2050
 wb_workfn+0xc8/0x520 fs/fs-writeback.c:2091
 process_one_work+0x3e9/0x8f0 kernel/workqueue.c:2276
 worker_thread+0x636/0xae0 kernel/workqueue.c:2422
 kthread+0x1d0/0x1f0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff888106a2c788 of 8 bytes by task 17862 on cpu 1:
 inode_is_dirtytime_only include/linux/fs.h:2423 [inline]
 __ext4_update_other_inode_time+0x48/0x5c0 fs/ext4/inode.c:4963
 ext4_update_other_inodes_time fs/ext4/inode.c:5006 [inline]
 ext4_do_update_inode fs/ext4/inode.c:5135 [inline]
 ext4_mark_iloc_dirty+0x12b6/0x1750 fs/ext4/inode.c:5724
 __ext4_mark_inode_dirty+0x4db/0x5b0 fs/ext4/inode.c:5918
 ext4_dirty_inode+0x86/0xa0 fs/ext4/inode.c:5947
 __mark_inode_dirty+0x77/0x6c0 fs/fs-writeback.c:2274
 mark_inode_dirty include/linux/fs.h:2404 [inline]
 dquot_alloc_space include/linux/quotaops.h:317 [inline]
 dquot_alloc_block include/linux/quotaops.h:334 [inline]
 ext4_mb_new_blocks+0x116b/0x1f90 fs/ext4/mballoc.c:5476
 ext4_ext_map_blocks+0x1569/0x1f00 fs/ext4/extents.c:4241
 ext4_map_blocks+0x70d/0xef0 fs/ext4/inode.c:638
 _ext4_get_block+0xf6/0x290 fs/ext4/inode.c:794
 ext4_get_block_unwritten+0x26/0x30 fs/ext4/inode.c:825
 __block_write_begin_int+0x4a2/0x1060 fs/buffer.c:2031
 __block_write_begin+0x2b/0x40 fs/buffer.c:2081
 ext4_write_begin+0x41b/0xcc0 fs/ext4/ext4_jbd2.h:498
 ext4_da_write_begin+0x20e/0x820 fs/ext4/inode.c:2960
 generic_perform_write+0x196/0x3a0 mm/filemap.c:3660
 ext4_buffered_write_iter+0x2f2/0x3f0 fs/ext4/file.c:269
 ext4_file_write_iter+0x2e7/0x11d0 fs/ext4/file.c:519
 call_write_iter include/linux/fs.h:2114 [inline]
 aio_write+0x287/0x360 fs/aio.c:1578
 __io_submit_one fs/aio.c:1837 [inline]
 io_submit_one+0x82f/0x1350 fs/aio.c:1880
 __do_sys_io_submit fs/aio.c:1939 [inline]
 __se_sys_io_submit+0xf5/0x260 fs/aio.c:1909
 __x64_sys_io_submit+0x3f/0x50 fs/aio.c:1909
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000020087 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17862 Comm: syz-executor.0 Tainted: G        W         5.13.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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