==================================================================
BUG: KCSAN: data-race in p9_poll_workfn / p9_write_work

read to 0xffff88810b7f6894 of 4 bytes by task 8173 on cpu 0:
 p9_poll_mux net/9p/trans_fd.c:637 [inline]
 p9_poll_workfn+0xb9/0x350 net/9p/trans_fd.c:1122
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff88810b7f6894 of 4 bytes by task 2905 on cpu 1:
 p9_write_work+0x673/0x6d0 net/9p/trans_fd.c:490
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2905 Comm: kworker/1:2 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events p9_write_work
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 2905 Comm: kworker/1:2 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events p9_write_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xf5/0x159 lib/dump_stack.c:113
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0xe kernel/kcsan/report.c:302
 kcsan_setup_watchpoint+0x3fe/0x410 kernel/kcsan/core.c:357
 check_access kernel/kcsan/core.c:409 [inline]
 __tsan_unaligned_write4+0x143/0x1f0 kernel/kcsan/core.c:529
 p9_write_work+0x673/0x6d0 net/9p/trans_fd.c:490
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..