syzbot

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BUG: KCSAN: data-race in __mark_inode_dirty / writeback_sb_inodes

read-write to 0xffff888129d0f1c0 of 8 bytes by task 1837 on cpu 1:
 writeback_sb_inodes+0xaee/0xdd0 fs/fs-writeback.c:1894
 __writeback_inodes_wb+0xb0/0x2a0 fs/fs-writeback.c:1936
 wb_writeback+0x280/0x650 fs/fs-writeback.c:2041
 wb_check_start_all fs/fs-writeback.c:2163 [inline]
 wb_do_writeback+0x418/0x600 fs/fs-writeback.c:2189
 wb_workfn+0x88/0x260 fs/fs-writeback.c:2222
 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 0xffff888129d0f1c0 of 8 bytes by task 6731 on cpu 0:
 __mark_inode_dirty+0xd5/0x620 fs/fs-writeback.c:2402
 mark_buffer_dirty+0x176/0x390 fs/buffer.c:1109
 __block_commit_write+0xbb/0x190 fs/buffer.c:2080
 block_write_end fs/buffer.c:2159 [inline]
 generic_write_end+0x81/0x350 fs/buffer.c:2173
 ext4_da_write_end+0x26c/0x620 fs/ext4/inode.c:3089
 generic_perform_write+0x264/0x3f0 mm/filemap.c:3749
 ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:270
 ext4_file_write_iter+0x2e3/0x1210
 call_write_iter include/linux/fs.h:2192 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x468/0x760 fs/read_write.c:578
 ksys_write+0xe8/0x1a0 fs/read_write.c:631
 __do_sys_write fs/read_write.c:643 [inline]
 __se_sys_write fs/read_write.c:640 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:640
 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+0x63/0xcd

value changed: 0x0000000000020087 -> 0x0000000000000007

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6731 Comm: syz-executor.4 Not tainted 5.19.0-syzkaller-13616-gf41445645ab5-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
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