Xen project Mailing List

Re: [Xen-devel] Creating a vm with a non-existent /dev/mapper/ tap2 device effectively hangs dom0 system

To: Nathan March <nathan@xxxxxx>, daniel.stodden@xxxxxxxxxx

From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

Date: Fri, 29 Jul 2011 12:23:19 -0400

Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>

Delivery-date: Fri, 29 Jul 2011 09:24:12 -0700

List-id: Xen developer discussion <xen-devel.lists.xensource.com>

On Thu, Jul 28, 2011 at 12:00:53PM -0700, Nathan March wrote: > On 7/27/2011 4:29 PM, Nathan March wrote: > >Have an interesting one here, originally found on xen 4.1.0 but > >just upgraded to xen 4.1.1 and it's still here. > > > >Creating a VM with a tap2 device pointed at /dev/mapper/something, > >when that device doesn't exist, causes the tapdisk2 process to go > >into D mode and also manages to take out any process that queries > >it. Daniel, any ideas? [edit: Asked Nathan to pull latest Jermey's with your blktap fix] > > > > This also happens on proper shutdown of a VM, so I must have done > something crazy to the setup here since other people haven't been > complaining. If I start a VM, strace it's tapdisk2 and then send the > VM a shutdown, the strace shows tapdisk2 hanging here: > > 12037 gettimeofday({1311879426, 739622}, NULL) = 0 > 12037 gettimeofday({1311879426, 739717}, NULL) = 0 > 12037 select(8, [3 4 7], [], [], {600, 0}) = 1 (in [3], left {599, 993029}) > 12037 gettimeofday({1311879426, 746896}, NULL) = 0 > 12037 accept(3, 0, NULL) = 6 > 12037 gettimeofday({1311879426, 747079}, NULL) = 0 > 12037 gettimeofday({1311879426, 747169}, NULL) = 0 > 12037 gettimeofday({1311879426, 747257}, NULL) = 0 > 12037 select(8, [3 4 6 7], [], [], {600, 0}) = 1 (in [6], left {599, > 999948}) > 12037 gettimeofday({1311879426, 747544}, NULL) = 0 > 12037 select(7, [6], NULL, NULL, {2, 0}) = 1 (in [6], left {1, 999998}) > 12037 read(6, > "\r\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", > 280) = 280 > 12037 gettimeofday({1311879426, 747932}, NULL) = 0 > 12037 sendto(5, "<30>Jul 28 11:57:06 tapdisk2[12036]: received > 'close' message (uuid = 0)\n", 73, MSG_NOSIGNAL, NULL, 0) = 73 > 12037 close(8) = 0 > 12037 gettimeofday({1311879426, 749118}, NULL) = 0 > 12037 sendto(5, "<30>Jul 28 11:57:06 tapdisk2[12036]: closed image > /dev/mapper/nathanxenuk1 (0 users, state: 0x00000000, type: 0)\n", > 113, MSG_NOSIGNAL, NULL, 0) = 113 > 12037 gettimeofday({1311879426, 749536}, NULL) = 0 > 12037 sendto(5, "<30>Jul 28 11:57:06 tapdisk2[12036]: sending 'close > response' message (uuid = 0)\n", 81, MSG_NOSIGNAL, NULL, 0) = 81 > 12037 select(7, NULL, [6], NULL, {2, 0}) = 1 (out [6], left {1, 999998}) > 12037 write(6, > "\16\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", > 280) = 280 > 12037 close(6) = 0 > 12037 gettimeofday({1311879426, 750295}, NULL) = 0 > 12037 gettimeofday({1311879426, 750384}, NULL) = 0 > 12037 select(8, [3 4 7], [], [], {600, 0}) = 1 (in [3], left {599, 999936}) > 12037 gettimeofday({1311879426, 750690}, NULL) = 0 > 12037 accept(3, 0, NULL) = 6 > 12037 gettimeofday({1311879426, 750801}, NULL) = 0 > 12037 gettimeofday({1311879426, 750854}, NULL) = 0 > 12037 gettimeofday({1311879426, 750905}, NULL) = 0 > 12037 select(8, [3 4 6 7], [], [], {600, 0}) = 1 (in [6], left {599, > 999946}) > 12037 gettimeofday({1311879426, 751085}, NULL) = 0 > 12037 select(7, [6], NULL, NULL, {2, 0}) = 1 (in [6], left {1, 999998}) > 12037 read(6, > "\17\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", > 280) = 280 > 12037 gettimeofday({1311879426, 751550}, NULL) = 0 > 12037 sendto(5, "<30>Jul 28 11:57:06 tapdisk2[12036]: received > 'detach' message (uuid = 0)\n", 74, MSG_NOSIGNAL, NULL, 0) = 74 > 12037 close(7) = 0 > 12037 munmap(0x7ffc389d7000, 1445888 > > COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME > tapdisk2 12037 root cwd DIR 8,1 4096 2 / > tapdisk2 12037 root rtd DIR 8,1 4096 2 / > tapdisk2 12037 root txt REG 8,1 496268 180124 > /usr/sbin/tapdisk2 > tapdisk2 12037 root mem REG 8,1 1412272 268124 > /lib64/libc-2.11.2.so > tapdisk2 12037 root mem REG 8,1 534648 267759 > /lib64/libm-2.11.2.so > tapdisk2 12037 root mem REG 8,1 137732 267539 > /lib64/libpthread-2.11.2.so > tapdisk2 12037 root mem REG 8,1 14512 267757 > /lib64/libdl-2.11.2.so > tapdisk2 12037 root mem REG 8,1 164708 180168 > /usr/lib64/libxenctrl.so.4.0.0 > tapdisk2 12037 root mem REG 8,1 18832 267724 > /lib64/libuuid.so.1.3.0 > tapdisk2 12037 root mem REG 8,1 410267 180118 > /usr/lib64/libvhd.so.1.0.0 > tapdisk2 12037 root mem REG 8,1 88368 268110 > /lib64/libz.so.1.2.3 > tapdisk2 12037 root mem REG 8,1 35656 267750 > /lib64/librt-2.11.2.so > tapdisk2 12037 root mem REG 8,1 128416 267762 > /lib64/ld-2.11.2.so > tapdisk2 12037 root mem CHR 251,0 44028 > /dev/xen/blktap-2/blktap0 > tapdisk2 12037 root 0u CHR 1,3 0t0 1539 /dev/null > tapdisk2 12037 root 1u CHR 1,3 0t0 1539 /dev/null > tapdisk2 12037 root 2u CHR 1,3 0t0 1539 /dev/null > tapdisk2 12037 root 3u unix 0xffff880039c862c0 0t0 44033 > /var/run/blktap-control/ctl12037 > tapdisk2 12037 root 4u 0000 0,8 0 1000 > anon_inode > tapdisk2 12037 root 5u unix 0xffff880039cbe840 0t0 44036 socket > tapdisk2 12037 root 7u CHR 251,0 0t0 44028 > /dev/xen/blktap-2/blktap0 > tapdisk2 12037 root 8u BLK 252,0 0t0 36899 > /dev/mapper/nathanxenuk1 > > The /dev/mapper devices are coming from a dell md3200i, using > open-iscsi 2.0.871 and multipath-tools-0.4.9-r2. > > This is using the main xen 4.1.1 release, with jeremy's git dom0 > kernel (2.6.32.43). Oh, wait. Did you update it to the latest Jeremy pulled in a blktap fix. > > Anyone have any idea what might be happening here? > > - Nathan > > _______________________________________________ > Xen-devel mailing list > Xen-devel@xxxxxxxxxxxxxxxxxxx > http://lists.xensource.com/xen-devel _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel

©2013 Xen Project, A Linux Foundation Collaborative Project. All Rights Reserved.
Linux Foundation is a registered trademark of The Linux Foundation.
Xen Project is a trademark of The Linux Foundation.