* Wen Congyang (we...@cn.fujitsu.com) wrote: > On 01/22/2016 11:14 PM, Dr. David Alan Gilbert wrote: > > Hi, > > I can trigger a segfault if I wire in the block replication together with > > a quorum instance; it only triggers with both of them present but, > > it looks like the problem is a disagreement about the number of quorum > > members; I'm triggering this on the 'colo-v2.4-periodic-mode' branch > > that is posted in the colo-framework set that I think includes this set > > (from https://github.com/coloft/qemu.git). > > > > To trigger: > > ./git/colo/jan-16/try/x86_64-softmmu/qemu-system-x86_64 -nographic -S > > > > (qemu) drive_add 0 > > if=none,id=colo-disk0,file.filename=/home/localvms/bugzilla.raw,driver=raw,node-name=node0 > > (qemu) drive_add 1 > > if=none,id=active-disk0,throttling.bps-total=70000000,driver=replication,mode=secondary,file.driver=qcow2,file.file.filename=/run/colo-active-disk.qcow2,file.backing.driver=qcow2,file.backing.file.filename=/run/colo-hidden-disk.qcow2,file.backing.backing=colo-disk0 > > (qemu) drive_add 2 > > if=none,id=top-quorum,driver=quorum,read-pattern=fifo,vote-threshold=1,children.0=active-disk0 > > (qemu) device_add virtio-blk-pci,drive=top-quorum,addr=9 > > > > *** Error in `/root/colo/jan-2016/./try/x86_64-softmmu/qemu-system-x86_64': > > free(): invalid pointer: 0x0000555555a8fdf0 *** > > ======= Backtrace: ========= > > /lib64/libc.so.6(+0x7cfe1)[0x7ffff110ffe1] > > /lib64/libglib-2.0.so.0(g_free+0xf)[0x7ffff1ecc36f] > > /root/colo/jan-2016/./try/x86_64-softmmu/qemu-system-x86_64 > > Program received signal SIGABRT, Aborted. > > 0x00007ffff10c85f7 in raise () from /lib64/libc.so.6 > > (gdb) where > > #0 0x00007ffff10c85f7 in raise () from /lib64/libc.so.6 > > #1 0x00007ffff10c9ce8 in abort () from /lib64/libc.so.6 > > #2 0x00007ffff1108317 in __libc_message () from /lib64/libc.so.6 > > #3 0x00007ffff110ffe1 in _int_free () from /lib64/libc.so.6 > > #4 0x00007ffff1ecc36f in g_free () from /lib64/libglib-2.0.so.0 > > #5 0x00005555559dfdd7 in qemu_iovec_destroy (qiov=0x555557815410) at > > /root/colo/jan-2016/qemu/util/iov.c:378 > > #6 0x0000555555989cce in quorum_aio_finalize (acb=0x555557815350) at > > /root/colo/jan-2016/qemu/block/quorum.c:171 > > 171 qemu_iovec_destroy(&acb->qcrs[i].qiov); > > (gdb) list > > 166 > > 167 if (acb->is_read) { > > 168 /* on the quorum case acb->child_iter == s->num_children - 1 */ > > 169 for (i = 0; i <= acb->child_iter; i++) { > > 170 qemu_vfree(acb->qcrs[i].buf); > > 171 qemu_iovec_destroy(&acb->qcrs[i].qiov); > > 172 } > > 173 } > > 174 > > 175 g_free(acb->qcrs); > > (gdb) p acb->child_iter > > $1 = 1 > > (gdb) p i > > $3 = 1 > > > > #7 0x000055555598afca in quorum_aio_cb (opaque=<optimized out>, ret=-5) > > at /root/colo/jan-2016/qemu/block/quorum.c:302 > > #8 0x00005555559990ee in bdrv_co_complete (acb=0x555557815410) at > > /root/colo/jan-2016/qemu/block/io.c:2122 > > ..... > > > > So I guess acb->child_iter is wrong, since we only have one child on that > > quorum? > > and we're trying to do a destroy on the second child. > > Can you try the following patch: > From 3f2c5ec288cd9a36afb392b4bba24029f3e9345a Mon Sep 17 00:00:00 2001 > From: Wen Congyang <we...@cn.fujitsu.com> > Date: Mon, 25 Jan 2016 09:18:09 +0800 > Subject: [PATCH] quorum: fix segfault when read fails in fifo mode > > Signed-off-by: Wen Congyang <we...@cn.fujitsu.com> > --- > block/quorum.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/block/quorum.c b/block/quorum.c > index a5ae4b8..0965277 100644 > --- a/block/quorum.c > +++ b/block/quorum.c > @@ -295,6 +295,9 @@ static void quorum_aio_cb(void *opaque, int ret) > quorum_copy_qiov(acb->qiov, &acb->qcrs[acb->child_iter].qiov); > } > acb->vote_ret = ret; > + if (ret < 0) { > + acb->child_iter--; > + } > quorum_aio_finalize(acb); > return; > }
Yes, that seems to fix it; thanks. Dave > -- > 2.5.0 > > > > > > > Dave > > -- > > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK > > > > > > . > > > > > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
