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Yu Kuai 5f0f96c1c9 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>
2022-11-14 19:33:10 +08:00
Documentation docs/bpf: Add BPF ring buffer design notes 2022-08-30 11:33:29 +08:00
LICENSES Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
arch dist: tk4: fix debugedit compact issue 2022-10-17 17:31:28 +08:00
block Add sysfs attribute to hide disk devices 2022-07-25 16:24:47 +08:00
certs certs: Fix blacklist flag type confusion 2021-04-12 12:52:25 +08:00
crypto crypto: rng - fix crypto_rng_reset() refcounting when !CRYPTO_STATS 2021-05-20 16:07:34 +08:00
dist dist: fix remote name in check-commits 2022-10-18 11:37:20 +08:00
drivers nbd: fix io hung while disconnecting device 2022-11-14 19:33:10 +08:00
fs bpf: Refactor to provide aux info to bpf_iter_init_seq_priv_t 2022-08-30 11:33:28 +08:00
include raw: convert raw sockets to RCU 2022-11-03 14:14:19 +08:00
init bpf: Introduce BPF_PROG_TYPE_LSM 2022-08-30 11:33:21 +08:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2021-03-16 16:27:51 +08:00
kernel sli: fix the compiling error caused by memory access out of range 2022-10-14 16:20:22 +08:00
lib bug: Remove redundant condition check in report_bug 2021-05-20 16:07:55 +08:00
mm Revert "mm/lru: introduce TestClearPageLRU" 2022-09-05 20:56:40 +08:00
net raw: convert raw sockets to RCU 2022-11-03 14:14:19 +08:00
package configs: set EDD, RAID, CRAMFS as modules 2022-10-25 15:15:58 +08:00
samples kfifo: fix ternary sign extension bugs 2021-05-20 16:08:01 +08:00
scripts bpf: fix selftest case compile error for bpf_timer 2022-08-30 11:33:34 +08:00
security bpf: Implement bpf_local_storage for inodes 2022-08-30 11:33:29 +08:00
sound ALSA: usb: midi: don't return -ENOMEM when usb_urb_ep_type_check fails 2021-05-20 16:07:59 +08:00
tools bpf, selftests: Add redirect_peer selftest 2022-08-30 11:33:35 +08:00
usr Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
virt KVM: Stop looking for coalesced MMIO zones if the bus is destroyed 2021-05-20 16:07:44 +08:00
.clang-format Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
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.gitattributes dist: hook into kernel build system 2022-10-17 02:25:35 +08:00
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COPYING Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
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MAINTAINERS bpf: Introduce BPF_PROG_TYPE_LSM 2022-08-30 11:33:21 +08:00
Makefile dist: hook into kernel build system 2022-10-17 02:25:35 +08:00
README Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
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README.md

Tencent Linux Kernel 4.0