syzbot

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BUG: KCSAN: data-race in __mark_inode_dirty / writeback_sb_inodes

write to 0xffff888137c8bb90 of 8 bytes by task 8 on cpu 1:
 writeback_sb_inodes+0x481/0xdf0 fs/fs-writeback.c:1870
 wb_writeback+0x26b/0x650 fs/fs-writeback.c:2054
 wb_do_writeback+0x101/0x560 fs/fs-writeback.c:2197
 wb_workfn+0xc8/0x440 fs/fs-writeback.c:2238
 process_one_work+0x3fc/0x980 kernel/workqueue.c:2298
 worker_thread+0x616/0xa70 kernel/workqueue.c:2445
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

read to 0xffff888137c8bb90 of 8 bytes by task 9307 on cpu 0:
 __mark_inode_dirty+0xd7/0x6c0 fs/fs-writeback.c:2420
 mark_inode_dirty_sync include/linux/fs.h:2456 [inline]
 dquot_free_space include/linux/quotaops.h:382 [inline]
 dquot_free_block include/linux/quotaops.h:392 [inline]
 ext4_mb_new_blocks+0x1631/0x1ee0 fs/ext4/mballoc.c:5634
 ext4_ext_map_blocks+0x1658/0x2120 fs/ext4/extents.c:4285
 ext4_map_blocks+0x71e/0xf00 fs/ext4/inode.c:637
 ext4_alloc_file_blocks+0x281/0x730 fs/ext4/extents.c:4472
 ext4_fallocate+0x2a7/0x540 fs/ext4/extents.c:4753
 vfs_fallocate+0x486/0x720 fs/open.c:307
 ksys_fallocate fs/open.c:330 [inline]
 __do_sys_fallocate fs/open.c:338 [inline]
 __se_sys_fallocate fs/open.c:336 [inline]
 __x64_sys_fallocate+0x75/0xc0 fs/open.c:336
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000020007 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9307 Comm: syz-executor.5 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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