* [Qemu-devel] [Bug 1179219] [NEW] segfault in alloc_refcount_block
@ 2013-05-12 13:59 Brian J. Murrell
2013-05-12 21:14 ` [Qemu-devel] [Bug 1179219] " Michael Tokarev
0 siblings, 1 reply; 5+ messages in thread
From: Brian J. Murrell @ 2013-05-12 13:59 UTC (permalink / raw)
To: qemu-devel
Public bug reported:
On CentOS-6.4.latest, I am trying to run several KVM VMs with snapshots
of a single qcow2 image. Randomly some VMs will crash though. There's
a downstream bug report at http://bugs.centos.org/view.php?id=6441 and
included in that is an "abrt" crash report that contains the full stack
trace as well as disassembly etc. That report is at
http://bugs.centos.org/file_download.php?file_id=1486&type=bug
For convenience I will paste the segfaulting thread's stack trace here:
:#0 0x00007f0d4d9fadd5 in alloc_refcount_block (bs=0x7f0d4fc38010, offset=864752701576067072, length=<value optimized out>, addend=-1) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:335
: refcount_table_index = 402681856
: new_block = 131072
: table_size = <value optimized out>
: new_table = <value optimized out>
: old_table_offset = <value optimized out>
: old_free_cluster_index = <value optimized out>
: last_table_size = <value optimized out>
: refcount_block_clusters = <value optimized out>
: meta_offset = 2147483648
: table_offset = 2147614720
: s = 0x10000
: blocks_used = 1
: old_table_size = <value optimized out>
: ret = <value optimized out>
: new_blocks = 0x7f0d504babd0
: i = <value optimized out>
: table_clusters = <value optimized out>
: data = "\000\000\000\000\000\000\000\000e\240Y\003"
: blocks_clusters = <value optimized out>
: block = <value optimized out>
:#1 update_refcount (bs=0x7f0d4fc38010, offset=864752701576067072, length=<value optimized out>, addend=-1) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:460
: block_index = <value optimized out>
: refcount = <value optimized out>
: cluster_index = 13195079064576
: table_index = 402681856
: s = 0x7f0d4fc35770
: start = 864752701576052736
: last = 864752701576118272
: cluster_offset = 864752701576052736
: refcount_block = 0x0
: old_table_index = <value optimized out>
: ret = <value optimized out>
:#2 0x00007f0d4d9fb710 in qcow2_free_clusters (bs=0x7f0d4fc38010, offset=864752701576067072, size=65536) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:640
: ret = <value optimized out>
:#3 0x00007f0d4d9fd03e in qcow2_alloc_cluster_link_l2 (bs=0x7f0d4fc38010, m=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-cluster.c:674
: s = <value optimized out>
: i = <value optimized out>
: j = <value optimized out>
: l2_index = 2032
: ret = <value optimized out>
: old_cluster = 0x7f0d4fd2b5e0
: start_sect = <value optimized out>
: l2_offset = 145358848
: l2_table = 0x0
: cluster_offset = <value optimized out>
: cow = <value optimized out>
:#4 0x00007f0d4d9f7d39 in qcow2_co_writev (bs=0x7f0d4fc38010, sector_num=<value optimized out>, remaining_sectors=216, qiov=0x7f0d40051b40) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2.c:632
: s = 0x7f0d4fc35770
: index_in_cluster = 120
: n_end = <value optimized out>
: ret = <value optimized out>
: cur_nr_sectors = 8
: cluster_offset = 274333696
: hd_qiov = {iov = 0x7f0d4001bcb0, niov = 1, nalloc = 26, size = 4096}
: bytes_done = <value optimized out>
: cluster_data = 0x0
: l2meta = {offset = 2817585152, cluster_offset = 274333696, n_start = 120, nb_available = 128, nb_clusters = 1, depends_on = 0x0, dependent_requests = {entries = {tqh_first = 0x0, tqh_last = 0x7f0cf43dde78}}, next_in_flight = {le_next = 0x0, le_prev = 0x7f0cefffee88}}
: __PRETTY_FUNCTION__ = "qcow2_co_writev"
:#5 0x00007f0d4d9e20b9 in bdrv_co_do_writev (bs=0x7f0d4fc38010, sector_num=5503096, nb_sectors=216, qiov=0x7f0d40051b40, flags=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/block.c:2081
: drv = 0x7f0d4de96f80
: req = {bs = 0x7f0d4fc38010, sector_num = 5503096, nb_sectors = 216, is_write = true, list = {le_next = 0x0, le_prev = 0x7f0cefffef28}, co = 0x7f0d40002af0, wait_queue = {entries = {tqh_first = 0x0, tqh_last = 0x7f0cf43ddf40}}}
: ret = <value optimized out>
:#6 0x00007f0d4d9e2161 in bdrv_co_do_rw (opaque=0x7f0d4003ced0) at /usr/src/debug/qemu-kvm-0.12.1.2/block.c:3497
: acb = 0x7f0d4003ced0
: bs = <value optimized out>
:#7 0x00007f0d4d9e7eeb in coroutine_trampoline (i0=<value optimized out>, i1=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/coroutine-ucontext.c:129
: self = 0x7f0d40002af0
: co = 0x7f0d40002af0
:#8 0x00007f0d4b31bb70 in ?? () from /lib64/libc-2.12.so
:No symbol table info available.
:#9 0x00007f0d44c0eed0 in ?? ()
:No symbol table info available.
:#10 0x0000000000000000 in ?? ()
It would appear, according to RPM at least that I am using 0.12.1.2 of
qemu/kvm on this machine.
I'm happy to provide any additional information test patches, etc.
** Affects: qemu
Importance: Undecided
Status: New
--
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https://bugs.launchpad.net/bugs/1179219
Title:
segfault in alloc_refcount_block
Status in QEMU:
New
Bug description:
On CentOS-6.4.latest, I am trying to run several KVM VMs with
snapshots of a single qcow2 image. Randomly some VMs will crash
though. There's a downstream bug report at
http://bugs.centos.org/view.php?id=6441 and included in that is an
"abrt" crash report that contains the full stack trace as well as
disassembly etc. That report is at
http://bugs.centos.org/file_download.php?file_id=1486&type=bug
For convenience I will paste the segfaulting thread's stack trace
here:
:#0 0x00007f0d4d9fadd5 in alloc_refcount_block (bs=0x7f0d4fc38010, offset=864752701576067072, length=<value optimized out>, addend=-1) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:335
: refcount_table_index = 402681856
: new_block = 131072
: table_size = <value optimized out>
: new_table = <value optimized out>
: old_table_offset = <value optimized out>
: old_free_cluster_index = <value optimized out>
: last_table_size = <value optimized out>
: refcount_block_clusters = <value optimized out>
: meta_offset = 2147483648
: table_offset = 2147614720
: s = 0x10000
: blocks_used = 1
: old_table_size = <value optimized out>
: ret = <value optimized out>
: new_blocks = 0x7f0d504babd0
: i = <value optimized out>
: table_clusters = <value optimized out>
: data = "\000\000\000\000\000\000\000\000e\240Y\003"
: blocks_clusters = <value optimized out>
: block = <value optimized out>
:#1 update_refcount (bs=0x7f0d4fc38010, offset=864752701576067072, length=<value optimized out>, addend=-1) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:460
: block_index = <value optimized out>
: refcount = <value optimized out>
: cluster_index = 13195079064576
: table_index = 402681856
: s = 0x7f0d4fc35770
: start = 864752701576052736
: last = 864752701576118272
: cluster_offset = 864752701576052736
: refcount_block = 0x0
: old_table_index = <value optimized out>
: ret = <value optimized out>
:#2 0x00007f0d4d9fb710 in qcow2_free_clusters (bs=0x7f0d4fc38010, offset=864752701576067072, size=65536) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:640
: ret = <value optimized out>
:#3 0x00007f0d4d9fd03e in qcow2_alloc_cluster_link_l2 (bs=0x7f0d4fc38010, m=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-cluster.c:674
: s = <value optimized out>
: i = <value optimized out>
: j = <value optimized out>
: l2_index = 2032
: ret = <value optimized out>
: old_cluster = 0x7f0d4fd2b5e0
: start_sect = <value optimized out>
: l2_offset = 145358848
: l2_table = 0x0
: cluster_offset = <value optimized out>
: cow = <value optimized out>
:#4 0x00007f0d4d9f7d39 in qcow2_co_writev (bs=0x7f0d4fc38010, sector_num=<value optimized out>, remaining_sectors=216, qiov=0x7f0d40051b40) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2.c:632
: s = 0x7f0d4fc35770
: index_in_cluster = 120
: n_end = <value optimized out>
: ret = <value optimized out>
: cur_nr_sectors = 8
: cluster_offset = 274333696
: hd_qiov = {iov = 0x7f0d4001bcb0, niov = 1, nalloc = 26, size = 4096}
: bytes_done = <value optimized out>
: cluster_data = 0x0
: l2meta = {offset = 2817585152, cluster_offset = 274333696, n_start = 120, nb_available = 128, nb_clusters = 1, depends_on = 0x0, dependent_requests = {entries = {tqh_first = 0x0, tqh_last = 0x7f0cf43dde78}}, next_in_flight = {le_next = 0x0, le_prev = 0x7f0cefffee88}}
: __PRETTY_FUNCTION__ = "qcow2_co_writev"
:#5 0x00007f0d4d9e20b9 in bdrv_co_do_writev (bs=0x7f0d4fc38010, sector_num=5503096, nb_sectors=216, qiov=0x7f0d40051b40, flags=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/block.c:2081
: drv = 0x7f0d4de96f80
: req = {bs = 0x7f0d4fc38010, sector_num = 5503096, nb_sectors = 216, is_write = true, list = {le_next = 0x0, le_prev = 0x7f0cefffef28}, co = 0x7f0d40002af0, wait_queue = {entries = {tqh_first = 0x0, tqh_last = 0x7f0cf43ddf40}}}
: ret = <value optimized out>
:#6 0x00007f0d4d9e2161 in bdrv_co_do_rw (opaque=0x7f0d4003ced0) at /usr/src/debug/qemu-kvm-0.12.1.2/block.c:3497
: acb = 0x7f0d4003ced0
: bs = <value optimized out>
:#7 0x00007f0d4d9e7eeb in coroutine_trampoline (i0=<value optimized out>, i1=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/coroutine-ucontext.c:129
: self = 0x7f0d40002af0
: co = 0x7f0d40002af0
:#8 0x00007f0d4b31bb70 in ?? () from /lib64/libc-2.12.so
:No symbol table info available.
:#9 0x00007f0d44c0eed0 in ?? ()
:No symbol table info available.
:#10 0x0000000000000000 in ?? ()
It would appear, according to RPM at least that I am using 0.12.1.2 of
qemu/kvm on this machine.
I'm happy to provide any additional information test patches, etc.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1179219/+subscriptions
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Qemu-devel] [Bug 1179219] Re: segfault in alloc_refcount_block
2013-05-12 13:59 [Qemu-devel] [Bug 1179219] [NEW] segfault in alloc_refcount_block Brian J. Murrell
@ 2013-05-12 21:14 ` Michael Tokarev
2013-05-12 23:43 ` Brian J. Murrell
0 siblings, 1 reply; 5+ messages in thread
From: Michael Tokarev @ 2013-05-12 21:14 UTC (permalink / raw)
To: qemu-devel
First, having a single qcow2 file open for read-write access by more
than one process in unsupported.
Second, this version of qemu/kvm is too old to be supported upstream,
it's a few years old already and there has been *lots* of changes since
that version.
** Changed in: qemu
Status: New => Invalid
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1179219
Title:
segfault in alloc_refcount_block
Status in QEMU:
Invalid
Bug description:
On CentOS-6.4.latest, I am trying to run several KVM VMs with
snapshots of a single qcow2 image. Randomly some VMs will crash
though. There's a downstream bug report at
http://bugs.centos.org/view.php?id=6441 and included in that is an
"abrt" crash report that contains the full stack trace as well as
disassembly etc. That report is at
http://bugs.centos.org/file_download.php?file_id=1486&type=bug
For convenience I will paste the segfaulting thread's stack trace
here:
:#0 0x00007f0d4d9fadd5 in alloc_refcount_block (bs=0x7f0d4fc38010, offset=864752701576067072, length=<value optimized out>, addend=-1) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:335
: refcount_table_index = 402681856
: new_block = 131072
: table_size = <value optimized out>
: new_table = <value optimized out>
: old_table_offset = <value optimized out>
: old_free_cluster_index = <value optimized out>
: last_table_size = <value optimized out>
: refcount_block_clusters = <value optimized out>
: meta_offset = 2147483648
: table_offset = 2147614720
: s = 0x10000
: blocks_used = 1
: old_table_size = <value optimized out>
: ret = <value optimized out>
: new_blocks = 0x7f0d504babd0
: i = <value optimized out>
: table_clusters = <value optimized out>
: data = "\000\000\000\000\000\000\000\000e\240Y\003"
: blocks_clusters = <value optimized out>
: block = <value optimized out>
:#1 update_refcount (bs=0x7f0d4fc38010, offset=864752701576067072, length=<value optimized out>, addend=-1) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:460
: block_index = <value optimized out>
: refcount = <value optimized out>
: cluster_index = 13195079064576
: table_index = 402681856
: s = 0x7f0d4fc35770
: start = 864752701576052736
: last = 864752701576118272
: cluster_offset = 864752701576052736
: refcount_block = 0x0
: old_table_index = <value optimized out>
: ret = <value optimized out>
:#2 0x00007f0d4d9fb710 in qcow2_free_clusters (bs=0x7f0d4fc38010, offset=864752701576067072, size=65536) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:640
: ret = <value optimized out>
:#3 0x00007f0d4d9fd03e in qcow2_alloc_cluster_link_l2 (bs=0x7f0d4fc38010, m=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-cluster.c:674
: s = <value optimized out>
: i = <value optimized out>
: j = <value optimized out>
: l2_index = 2032
: ret = <value optimized out>
: old_cluster = 0x7f0d4fd2b5e0
: start_sect = <value optimized out>
: l2_offset = 145358848
: l2_table = 0x0
: cluster_offset = <value optimized out>
: cow = <value optimized out>
:#4 0x00007f0d4d9f7d39 in qcow2_co_writev (bs=0x7f0d4fc38010, sector_num=<value optimized out>, remaining_sectors=216, qiov=0x7f0d40051b40) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2.c:632
: s = 0x7f0d4fc35770
: index_in_cluster = 120
: n_end = <value optimized out>
: ret = <value optimized out>
: cur_nr_sectors = 8
: cluster_offset = 274333696
: hd_qiov = {iov = 0x7f0d4001bcb0, niov = 1, nalloc = 26, size = 4096}
: bytes_done = <value optimized out>
: cluster_data = 0x0
: l2meta = {offset = 2817585152, cluster_offset = 274333696, n_start = 120, nb_available = 128, nb_clusters = 1, depends_on = 0x0, dependent_requests = {entries = {tqh_first = 0x0, tqh_last = 0x7f0cf43dde78}}, next_in_flight = {le_next = 0x0, le_prev = 0x7f0cefffee88}}
: __PRETTY_FUNCTION__ = "qcow2_co_writev"
:#5 0x00007f0d4d9e20b9 in bdrv_co_do_writev (bs=0x7f0d4fc38010, sector_num=5503096, nb_sectors=216, qiov=0x7f0d40051b40, flags=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/block.c:2081
: drv = 0x7f0d4de96f80
: req = {bs = 0x7f0d4fc38010, sector_num = 5503096, nb_sectors = 216, is_write = true, list = {le_next = 0x0, le_prev = 0x7f0cefffef28}, co = 0x7f0d40002af0, wait_queue = {entries = {tqh_first = 0x0, tqh_last = 0x7f0cf43ddf40}}}
: ret = <value optimized out>
:#6 0x00007f0d4d9e2161 in bdrv_co_do_rw (opaque=0x7f0d4003ced0) at /usr/src/debug/qemu-kvm-0.12.1.2/block.c:3497
: acb = 0x7f0d4003ced0
: bs = <value optimized out>
:#7 0x00007f0d4d9e7eeb in coroutine_trampoline (i0=<value optimized out>, i1=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/coroutine-ucontext.c:129
: self = 0x7f0d40002af0
: co = 0x7f0d40002af0
:#8 0x00007f0d4b31bb70 in ?? () from /lib64/libc-2.12.so
:No symbol table info available.
:#9 0x00007f0d44c0eed0 in ?? ()
:No symbol table info available.
:#10 0x0000000000000000 in ?? ()
It would appear, according to RPM at least that I am using 0.12.1.2 of
qemu/kvm on this machine.
I'm happy to provide any additional information test patches, etc.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1179219/+subscriptions
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [Bug 1179219] Re: segfault in alloc_refcount_block
2013-05-12 21:14 ` [Qemu-devel] [Bug 1179219] " Michael Tokarev
@ 2013-05-12 23:43 ` Brian J. Murrell
2013-05-15 8:45 ` Stefan Hajnoczi
0 siblings, 1 reply; 5+ messages in thread
From: Brian J. Murrell @ 2013-05-12 23:43 UTC (permalink / raw)
To: qemu-devel
On 13-05-12 05:14 PM, Michael Tokarev wrote:
> First, having a single qcow2 file open for read-write access by more
> than one process in unsupported.
But I don't, if I understand how qcow2 snapshots work. Let me apologize
if I was not clear. Each of the VMs have their own snapshot of the
common "origin" qcow2 disk. If I understand correctly in such a
configuration, only one VM has each snapshot qcow2 open for read-write
access and they all have the "origin" open read-only, is that correct?
Surely that must be supported, yes?
> Second, this version of qemu/kvm is too old to be supported upstream,
> it's a few years old already and there has been *lots* of changes since
> that version.
That's fair enough. It's unfortunate that this is the version that
Redhat supply with current EL6. I am working on standing up an FC18
host instead.
Cheers.
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1179219
Title:
segfault in alloc_refcount_block
Status in QEMU:
Invalid
Bug description:
On CentOS-6.4.latest, I am trying to run several KVM VMs with
snapshots of a single qcow2 image. Randomly some VMs will crash
though. There's a downstream bug report at
http://bugs.centos.org/view.php?id=6441 and included in that is an
"abrt" crash report that contains the full stack trace as well as
disassembly etc. That report is at
http://bugs.centos.org/file_download.php?file_id=1486&type=bug
For convenience I will paste the segfaulting thread's stack trace
here:
:#0 0x00007f0d4d9fadd5 in alloc_refcount_block (bs=0x7f0d4fc38010, offset=864752701576067072, length=<value optimized out>, addend=-1) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:335
: refcount_table_index = 402681856
: new_block = 131072
: table_size = <value optimized out>
: new_table = <value optimized out>
: old_table_offset = <value optimized out>
: old_free_cluster_index = <value optimized out>
: last_table_size = <value optimized out>
: refcount_block_clusters = <value optimized out>
: meta_offset = 2147483648
: table_offset = 2147614720
: s = 0x10000
: blocks_used = 1
: old_table_size = <value optimized out>
: ret = <value optimized out>
: new_blocks = 0x7f0d504babd0
: i = <value optimized out>
: table_clusters = <value optimized out>
: data = "\000\000\000\000\000\000\000\000e\240Y\003"
: blocks_clusters = <value optimized out>
: block = <value optimized out>
:#1 update_refcount (bs=0x7f0d4fc38010, offset=864752701576067072, length=<value optimized out>, addend=-1) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:460
: block_index = <value optimized out>
: refcount = <value optimized out>
: cluster_index = 13195079064576
: table_index = 402681856
: s = 0x7f0d4fc35770
: start = 864752701576052736
: last = 864752701576118272
: cluster_offset = 864752701576052736
: refcount_block = 0x0
: old_table_index = <value optimized out>
: ret = <value optimized out>
:#2 0x00007f0d4d9fb710 in qcow2_free_clusters (bs=0x7f0d4fc38010, offset=864752701576067072, size=65536) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:640
: ret = <value optimized out>
:#3 0x00007f0d4d9fd03e in qcow2_alloc_cluster_link_l2 (bs=0x7f0d4fc38010, m=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-cluster.c:674
: s = <value optimized out>
: i = <value optimized out>
: j = <value optimized out>
: l2_index = 2032
: ret = <value optimized out>
: old_cluster = 0x7f0d4fd2b5e0
: start_sect = <value optimized out>
: l2_offset = 145358848
: l2_table = 0x0
: cluster_offset = <value optimized out>
: cow = <value optimized out>
:#4 0x00007f0d4d9f7d39 in qcow2_co_writev (bs=0x7f0d4fc38010, sector_num=<value optimized out>, remaining_sectors=216, qiov=0x7f0d40051b40) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2.c:632
: s = 0x7f0d4fc35770
: index_in_cluster = 120
: n_end = <value optimized out>
: ret = <value optimized out>
: cur_nr_sectors = 8
: cluster_offset = 274333696
: hd_qiov = {iov = 0x7f0d4001bcb0, niov = 1, nalloc = 26, size = 4096}
: bytes_done = <value optimized out>
: cluster_data = 0x0
: l2meta = {offset = 2817585152, cluster_offset = 274333696, n_start = 120, nb_available = 128, nb_clusters = 1, depends_on = 0x0, dependent_requests = {entries = {tqh_first = 0x0, tqh_last = 0x7f0cf43dde78}}, next_in_flight = {le_next = 0x0, le_prev = 0x7f0cefffee88}}
: __PRETTY_FUNCTION__ = "qcow2_co_writev"
:#5 0x00007f0d4d9e20b9 in bdrv_co_do_writev (bs=0x7f0d4fc38010, sector_num=5503096, nb_sectors=216, qiov=0x7f0d40051b40, flags=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/block.c:2081
: drv = 0x7f0d4de96f80
: req = {bs = 0x7f0d4fc38010, sector_num = 5503096, nb_sectors = 216, is_write = true, list = {le_next = 0x0, le_prev = 0x7f0cefffef28}, co = 0x7f0d40002af0, wait_queue = {entries = {tqh_first = 0x0, tqh_last = 0x7f0cf43ddf40}}}
: ret = <value optimized out>
:#6 0x00007f0d4d9e2161 in bdrv_co_do_rw (opaque=0x7f0d4003ced0) at /usr/src/debug/qemu-kvm-0.12.1.2/block.c:3497
: acb = 0x7f0d4003ced0
: bs = <value optimized out>
:#7 0x00007f0d4d9e7eeb in coroutine_trampoline (i0=<value optimized out>, i1=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/coroutine-ucontext.c:129
: self = 0x7f0d40002af0
: co = 0x7f0d40002af0
:#8 0x00007f0d4b31bb70 in ?? () from /lib64/libc-2.12.so
:No symbol table info available.
:#9 0x00007f0d44c0eed0 in ?? ()
:No symbol table info available.
:#10 0x0000000000000000 in ?? ()
It would appear, according to RPM at least that I am using 0.12.1.2 of
qemu/kvm on this machine.
I'm happy to provide any additional information test patches, etc.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1179219/+subscriptions
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [Bug 1179219] Re: segfault in alloc_refcount_block
2013-05-12 23:43 ` Brian J. Murrell
@ 2013-05-15 8:45 ` Stefan Hajnoczi
2013-05-15 11:07 ` Brian J. Murrell
0 siblings, 1 reply; 5+ messages in thread
From: Stefan Hajnoczi @ 2013-05-15 8:45 UTC (permalink / raw)
To: Bug 1179219; +Cc: qemu-devel
On Sun, May 12, 2013 at 11:43:31PM -0000, Brian J. Murrell wrote:
> On 13-05-12 05:14 PM, Michael Tokarev wrote:
> > First, having a single qcow2 file open for read-write access by more
> > than one process in unsupported.
>
> But I don't, if I understand how qcow2 snapshots work. Let me apologize
> if I was not clear. Each of the VMs have their own snapshot of the
> common "origin" qcow2 disk. If I understand correctly in such a
> configuration, only one VM has each snapshot qcow2 open for read-write
> access and they all have the "origin" open read-only, is that correct?
> Surely that must be supported, yes?
$ qemu-img create -f qcow2 -b template.img vm001.qcow2
$ qemu-img create -f qcow2 -b template.img vm002.qcow2
$ qemu-img create -f qcow2 -b template.img vm003.qcow2
$ ...launch vm001-vm002...
This is safe. The template.img backing file is open read-only.
Did you do anything else?
Stefan
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [Bug 1179219] Re: segfault in alloc_refcount_block
2013-05-15 8:45 ` Stefan Hajnoczi
@ 2013-05-15 11:07 ` Brian J. Murrell
0 siblings, 0 replies; 5+ messages in thread
From: Brian J. Murrell @ 2013-05-15 11:07 UTC (permalink / raw)
To: qemu-devel
On 13-05-15 04:45 AM, Stefan Hajnoczi wrote:
>
> $ qemu-img create -f qcow2 -b template.img vm001.qcow2
> $ qemu-img create -f qcow2 -b template.img vm002.qcow2
> $ qemu-img create -f qcow2 -b template.img vm003.qcow2
> $ ...launch vm001-vm002...
>
> This is safe.
Yes. This is exactly what I did.
> The template.img backing file is open read-only.
That was my understanding also.
> Did you do anything else?
No, not other than just run the VMs on the snapshot volumes.
In any case, I have moved my host from EL6 to Fedora 18 and things seem
more stable, at least in these early days. :-)
--
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https://bugs.launchpad.net/bugs/1179219
Title:
segfault in alloc_refcount_block
Status in QEMU:
Invalid
Bug description:
On CentOS-6.4.latest, I am trying to run several KVM VMs with
snapshots of a single qcow2 image. Randomly some VMs will crash
though. There's a downstream bug report at
http://bugs.centos.org/view.php?id=6441 and included in that is an
"abrt" crash report that contains the full stack trace as well as
disassembly etc. That report is at
http://bugs.centos.org/file_download.php?file_id=1486&type=bug
For convenience I will paste the segfaulting thread's stack trace
here:
:#0 0x00007f0d4d9fadd5 in alloc_refcount_block (bs=0x7f0d4fc38010, offset=864752701576067072, length=<value optimized out>, addend=-1) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:335
: refcount_table_index = 402681856
: new_block = 131072
: table_size = <value optimized out>
: new_table = <value optimized out>
: old_table_offset = <value optimized out>
: old_free_cluster_index = <value optimized out>
: last_table_size = <value optimized out>
: refcount_block_clusters = <value optimized out>
: meta_offset = 2147483648
: table_offset = 2147614720
: s = 0x10000
: blocks_used = 1
: old_table_size = <value optimized out>
: ret = <value optimized out>
: new_blocks = 0x7f0d504babd0
: i = <value optimized out>
: table_clusters = <value optimized out>
: data = "\000\000\000\000\000\000\000\000e\240Y\003"
: blocks_clusters = <value optimized out>
: block = <value optimized out>
:#1 update_refcount (bs=0x7f0d4fc38010, offset=864752701576067072, length=<value optimized out>, addend=-1) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:460
: block_index = <value optimized out>
: refcount = <value optimized out>
: cluster_index = 13195079064576
: table_index = 402681856
: s = 0x7f0d4fc35770
: start = 864752701576052736
: last = 864752701576118272
: cluster_offset = 864752701576052736
: refcount_block = 0x0
: old_table_index = <value optimized out>
: ret = <value optimized out>
:#2 0x00007f0d4d9fb710 in qcow2_free_clusters (bs=0x7f0d4fc38010, offset=864752701576067072, size=65536) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-refcount.c:640
: ret = <value optimized out>
:#3 0x00007f0d4d9fd03e in qcow2_alloc_cluster_link_l2 (bs=0x7f0d4fc38010, m=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2-cluster.c:674
: s = <value optimized out>
: i = <value optimized out>
: j = <value optimized out>
: l2_index = 2032
: ret = <value optimized out>
: old_cluster = 0x7f0d4fd2b5e0
: start_sect = <value optimized out>
: l2_offset = 145358848
: l2_table = 0x0
: cluster_offset = <value optimized out>
: cow = <value optimized out>
:#4 0x00007f0d4d9f7d39 in qcow2_co_writev (bs=0x7f0d4fc38010, sector_num=<value optimized out>, remaining_sectors=216, qiov=0x7f0d40051b40) at /usr/src/debug/qemu-kvm-0.12.1.2/block/qcow2.c:632
: s = 0x7f0d4fc35770
: index_in_cluster = 120
: n_end = <value optimized out>
: ret = <value optimized out>
: cur_nr_sectors = 8
: cluster_offset = 274333696
: hd_qiov = {iov = 0x7f0d4001bcb0, niov = 1, nalloc = 26, size = 4096}
: bytes_done = <value optimized out>
: cluster_data = 0x0
: l2meta = {offset = 2817585152, cluster_offset = 274333696, n_start = 120, nb_available = 128, nb_clusters = 1, depends_on = 0x0, dependent_requests = {entries = {tqh_first = 0x0, tqh_last = 0x7f0cf43dde78}}, next_in_flight = {le_next = 0x0, le_prev = 0x7f0cefffee88}}
: __PRETTY_FUNCTION__ = "qcow2_co_writev"
:#5 0x00007f0d4d9e20b9 in bdrv_co_do_writev (bs=0x7f0d4fc38010, sector_num=5503096, nb_sectors=216, qiov=0x7f0d40051b40, flags=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/block.c:2081
: drv = 0x7f0d4de96f80
: req = {bs = 0x7f0d4fc38010, sector_num = 5503096, nb_sectors = 216, is_write = true, list = {le_next = 0x0, le_prev = 0x7f0cefffef28}, co = 0x7f0d40002af0, wait_queue = {entries = {tqh_first = 0x0, tqh_last = 0x7f0cf43ddf40}}}
: ret = <value optimized out>
:#6 0x00007f0d4d9e2161 in bdrv_co_do_rw (opaque=0x7f0d4003ced0) at /usr/src/debug/qemu-kvm-0.12.1.2/block.c:3497
: acb = 0x7f0d4003ced0
: bs = <value optimized out>
:#7 0x00007f0d4d9e7eeb in coroutine_trampoline (i0=<value optimized out>, i1=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/coroutine-ucontext.c:129
: self = 0x7f0d40002af0
: co = 0x7f0d40002af0
:#8 0x00007f0d4b31bb70 in ?? () from /lib64/libc-2.12.so
:No symbol table info available.
:#9 0x00007f0d44c0eed0 in ?? ()
:No symbol table info available.
:#10 0x0000000000000000 in ?? ()
It would appear, according to RPM at least that I am using 0.12.1.2 of
qemu/kvm on this machine.
I'm happy to provide any additional information test patches, etc.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1179219/+subscriptions
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2013-05-15 11:15 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-05-12 13:59 [Qemu-devel] [Bug 1179219] [NEW] segfault in alloc_refcount_block Brian J. Murrell
2013-05-12 21:14 ` [Qemu-devel] [Bug 1179219] " Michael Tokarev
2013-05-12 23:43 ` Brian J. Murrell
2013-05-15 8:45 ` Stefan Hajnoczi
2013-05-15 11:07 ` Brian J. Murrell
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