在 2022/7/7 20:49, Shinichiro Kawasaki 写道:
On Jul 07, 2022 / 11:56, Sun Ke wrote:
This is a regression test for commit 06c4da89c24e
nbd: call genl_unregister_family() first in nbd_cleanup()
Hello Sun, thanks for the patch.
I reverted the commit 06c4da89c24e from the kernel v5.19-rc5 and observed this
test case passes. I checked dmesg and saw kernel message below. Kernel did not
report the BUG which was noted in the commit 06c4da89c24e. Instead, nbd driver
printed out an error "couldn't allocate config".
Jul 07 20:47:01 redsun45q unknown: run blktests nbd/004 at 2022-07-07 20:47:01
Jul 07 20:47:01 redsun45q kernel: couldn't allocate config
Jul 07 20:47:01 redsun45q kernel: couldn't allocate config
Jul 07 20:47:01 redsun45q kernel: couldn't allocate config
Jul 07 20:47:01 redsun45q kernel: sysfs: cannot create duplicate filename '/devices/virtual/block/nbd0'
Jul 07 20:47:01 redsun45q kernel: CPU: 0 PID: 1043 Comm: modprobe Not tainted 5.19.0-rc5+ #2
Jul 07 20:47:01 redsun45q kernel: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Jul 07 20:47:01 redsun45q kernel: Call Trace:
Jul 07 20:47:01 redsun45q kernel: <TASK>
Jul 07 20:47:01 redsun45q kernel: dump_stack_lvl+0x5b/0x74
Jul 07 20:47:01 redsun45q kernel: sysfs_warn_dup.cold+0x17/0x23
...
or sysfs printed out an warning:
[ 366.098479] run blktests nbd/004 at 2022-07-07 21:17:22
[ 366.747180] sysfs: cannot create duplicate filename '/devices/virtual/block/nbd0'
[ 366.749653] CPU: 0 PID: 1508 Comm: modprobe Not tainted 5.19.0-rc5+ #2
[ 366.751680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebui
lt.qemu.org 04/01/2014
[ 366.755169] Call Trace:
[ 366.755991] <TASK>
[ 366.756722] dump_stack_lvl+0x5b/0x74
[ 366.757909] sysfs_warn_dup.cold+0x17/0x23
...
I retry it on commit 98d40e76652e, it can reproduce the Bug.
localhost login: [ 45.522685] run blktests nbd/004 at 2022-07-19 14:55:21
[ 45.622340] debugfs: Directory 'nbd0' with parent 'block' already
present!
[ 45.643911] BUG: kernel NULL pointer dereference, address:
0000000000000098
[ 45.645771] #PF: supervisor write access in kernel mode
[ 45.647176] #PF: error_code(0x0002) - not-present page
[ 45.648501] PGD 178ebf067 P4D 178ebf067 PUD 17486a067 PMD 0
[ 45.649830] Oops: 0002 [#1] PREEMPT SMP
[ 45.650732] CPU: 0 PID: 1620 Comm: nbd-client Not tainted
5.18.0-rc3-00087-g98d40e76652e #4
[ 45.652677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31
04/01/2014
[ 45.655724] RIP: 0010:down_write+0x2d/0x90
[ 45.656709] Code: 00 00 55 48 89 fd 48 83 05 1f 3e 19 09 01 e8 fa ad
ff ff 48 83 05 1a 3e 19 09 01 31 c0 ba 01 00 00 00 48 83 05 d3 3c 19 09
01 <f0> 48 00
[ 45.660640] RSP: 0018:ffffc90000663998 EFLAGS: 00010202
[ 45.661327] RAX: 0000000000000000 RBX: ffff8881029d03c0 RCX:
0000000000000000
[ 45.662252] RDX: 0000000000000001 RSI: ffffffffbfa44a80 RDI:
0000000000000098
[ 45.663172] RBP: 0000000000000098 R08: 0000000000000000 R09:
0000000000000228
[ 45.664090] R10: 0000000000000150 R11: ffff88817f6da850 R12:
0000000000000000
[ 45.665004] R13: ffff88817f6db00c R14: 0000000000000000 R15:
ffff88817f6daa00
[ 45.665926] FS: 00007f74958f7b40(0000) GS:ffff888237c00000(0000)
knlGS:0000000000000000
[ 45.666962] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 45.667707] CR2: 0000000000000098 CR3: 0000000174850000 CR4:
00000000000006f0
[ 45.668629] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 45.669548] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[ 45.670469] Call Trace:
[ 45.670810] <TASK>
[ 45.671098] start_creating+0xa2/0x1e0
[ 45.671601] debugfs_create_dir+0x1a/0x1e0
[ 45.672142] nbd_start_device+0x153/0x4c0 [nbd]
[ 45.672742] nbd_genl_connect+0x305/0xbd4 [nbd]
[ 45.673345] genl_family_rcv_msg_doit.isra.0+0x102/0x1b0
[ 45.674047] genl_rcv_msg+0xfc/0x2b0
[ 45.674521] ? nbd_genl_reconfigure+0xbe0/0xbe0 [nbd]
[ 45.675190] ? genl_family_rcv_msg_doit.isra.0+0x1b0/0x1b0
[ 45.675907] netlink_rcv_skb+0x62/0x180
[ 45.676420] genl_rcv+0x34/0x60
[ 45.676831] netlink_unicast+0x272/0x5a0
[ 45.677344] netlink_sendmsg+0x3a3/0x6e0
[ 45.677846] ? iovec_from_user+0x60/0x300
[ 45.678362] ? netlink_rcv_skb+0x180/0x180
[ 45.678885] ____sys_sendmsg+0x1da/0x300
[ 45.679391] ? ____sys_recvmsg+0x130/0x220
[ 45.679915] ___sys_sendmsg+0x8e/0xf0
[ 45.680394] ? ___sys_recvmsg+0xa2/0xf0
[ 45.680887] __sys_sendmsg+0x6d/0xe0
[ 45.681356] __x64_sys_sendmsg+0x23/0x30
[ 45.681858] do_syscall_64+0x35/0x80
[ 45.682318] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 45.682960] RIP: 0033:0x7f7494b11b87
It would be the better to catch these error and warning message in the test
case. For example, following hunk will catch it.
diff --git a/tests/nbd/004 b/tests/nbd/004
index 6b2c5ff..9277c10 100755
--- a/tests/nbd/004
+++ b/tests/nbd/004
@@ -47,6 +47,12 @@ test() {
} 2>/dev/null
_stop_nbd_server_netlink
+
+ if _dmesg_since_test_start | grep -q -e "couldn't allocate config" \
+ -e "cannot create duplicate filename"; then
+ echo "Fail"
+ fi
+
echo "Test complete"
}
Two concurrent processes，one load and unlock nbd module
cyclically, the other one connect and disconnect nbd device cyclically.
Last for 10 seconds.
Signed-off-by: Sun Ke <sunke32@xxxxxxxxxx>
---
v1->v2:
1.change install/uninstall to load/unlock
My guess is that Christoph meant "load/unload".
2.use _have_modules instead
tests/nbd/004 | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
tests/nbd/004.out | 2 ++
tests/nbd/rc | 18 ++++++++++++++++++
3 files changed, 72 insertions(+)
create mode 100755 tests/nbd/004
create mode 100644 tests/nbd/004.out
diff --git a/tests/nbd/004 b/tests/nbd/004
new file mode 100755
index 0000000..6b2c5ff
--- /dev/null
+++ b/tests/nbd/004
@@ -0,0 +1,52 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0+
+# Copyright (C) 2022 Sun Ke
+#
+# Regression test for commit 06c4da89c24e
+# nbd: call genl_unregister_family() first in nbd_cleanup()
+
+. tests/nbd/rc
+
+DESCRIPTION="module load/unlock concurrently with connect/disconnect"
+QUICK=1
+
+requires() {
+ _have_modules
This helper function needs an argument as the module name to check, nbd.
