syzbot

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BUG: KCSAN: data-race in __mark_inode_dirty / writeback_sb_inodes

write to 0xffff8881368e2ce0 of 8 bytes by task 1847 on cpu 1:
 writeback_sb_inodes+0x494/0xdd0 fs/fs-writeback.c:1847
 wb_writeback+0x26b/0x650 fs/fs-writeback.c:2030
 wb_do_writeback+0x101/0x600 fs/fs-writeback.c:2173
 wb_workfn+0x88/0x260 fs/fs-writeback.c:2213
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

read to 0xffff8881368e2ce0 of 8 bytes by task 20466 on cpu 0:
 __mark_inode_dirty+0xd5/0x5f0 fs/fs-writeback.c:2392
 mark_inode_dirty_sync include/linux/fs.h:2329 [inline]
 dquot_free_space include/linux/quotaops.h:382 [inline]
 dquot_free_block include/linux/quotaops.h:392 [inline]
 ext4_mb_new_blocks+0x845/0xae0 fs/ext4/mballoc.c:5664
 ext4_ext_map_blocks+0x9e2/0x1560 fs/ext4/extents.c:4281
 ext4_map_blocks+0x57e/0xbb0 fs/ext4/inode.c:636
 ext4_alloc_file_blocks+0x1b3/0x580 fs/ext4/extents.c:4466
 ext4_fallocate+0x2eb/0x3a0 fs/ext4/extents.c:4751
 vfs_fallocate+0x355/0x3d0 fs/open.c:308
 ksys_fallocate fs/open.c:331 [inline]
 __do_sys_fallocate fs/open.c:339 [inline]
 __se_sys_fallocate fs/open.c:337 [inline]
 __x64_sys_fallocate+0x75/0xc0 fs/open.c:337
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 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: 20466 Comm: syz-executor.2 Not tainted 5.18.0-rc7-syzkaller-00048-gf993aed406ea-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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