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| author | Yu Kuai <yukuai3@huawei.com> | 2022-05-21 10:37:47 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-14 17:59:38 +0300 |
| commit | 62d227f67a8c25d5e16f40e5290607f9306d2188 (patch) | |
| tree | b283e5d9a80c9a502603748598e1f960072b8627 /lib/nodemask.c | |
| parent | 2573f2375b64280be977431701ed5d33b75b9ad0 (diff) | |
| download | linux-62d227f67a8c25d5e16f40e5290607f9306d2188.tar.xz | |
nbd: fix io hung while disconnecting device
[ Upstream commit 09dadb5985023e27d4740ebd17e6fea4640110e5 ]
In our tests, "qemu-nbd" triggers a io hung:
INFO: task qemu-nbd:11445 blocked for more than 368 seconds.
Not tainted 5.18.0-rc3-next-20220422-00003-g2176915513ca #884
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:qemu-nbd state:D stack: 0 pid:11445 ppid: 1 flags:0x00000000
Call Trace:
<TASK>
__schedule+0x480/0x1050
? _raw_spin_lock_irqsave+0x3e/0xb0
schedule+0x9c/0x1b0
blk_mq_freeze_queue_wait+0x9d/0xf0
? ipi_rseq+0x70/0x70
blk_mq_freeze_queue+0x2b/0x40
nbd_add_socket+0x6b/0x270 [nbd]
nbd_ioctl+0x383/0x510 [nbd]
blkdev_ioctl+0x18e/0x3e0
__x64_sys_ioctl+0xac/0x120
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd8ff706577
RSP: 002b:00007fd8fcdfebf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000040000000 RCX: 00007fd8ff706577
RDX: 000000000000000d RSI: 000000000000ab00 RDI: 000000000000000f
RBP: 000000000000000f R08: 000000000000fbe8 R09: 000055fe497c62b0
R10: 00000002aff20000 R11: 0000000000000246 R12: 000000000000006d
R13: 0000000000000000 R14: 00007ffe82dc5e70 R15: 00007fd8fcdff9c0
"qemu-ndb -d" will call ioctl 'NBD_DISCONNECT' first, however, following
message was found:
block nbd0: Send disconnect failed -32
Which indicate that something is wrong with the server. Then,
"qemu-nbd -d" will call ioctl 'NBD_CLEAR_SOCK', however ioctl can't clear
requests after commit 2516ab1543fd("nbd: only clear the queue on device
teardown"). And in the meantime, request can't complete through timeout
because nbd_xmit_timeout() will always return 'BLK_EH_RESET_TIMER', which
means such request will never be completed in this situation.
Now that the flag 'NBD_CMD_INFLIGHT' can make sure requests won't
complete multiple times, switch back to call nbd_clear_sock() in
nbd_clear_sock_ioctl(), so that inflight requests can be cleared.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-5-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'lib/nodemask.c')
0 files changed, 0 insertions, 0 deletions