[libvirt] [PATCH] cmdMigrate: move vshConnect before vshWatchJob
A possible fix to issue: http://www.redhat.com/archives/libvir-list/2014-August/thread.html#00227 While doing migration on KVM host, found problem sometimes: VM is already running on the target host and disappears from source host, but 'virsh migrate' command line hangs, cannot exit normally. If pressing "ENTER" key, it will exit. The code hangs at tools/virsh-domain.c: cmdMigrate ->vshWatchJob->poll(): poll() is trying to select pipe_fd, which is used to receive message from doMigrate thread. In debugging, found that doMigrate finishes and at the end it does call safewrite() to write the retval ('0' or '1') to pipe_fd, and the write is completed. But cmdMigrate poll() cannot get the event. If pressing "ENTER" key, poll() can get the event and select pipe_fd, then command line can exit. In current code, authentication thread which is called by vshConnect will use stdin, and at the same time, in cmdMigrate main process, poll() is listening to stdin, that probably affect poll() to get pipe_fd event. Better to move authentication before vshWatchJob. With this change, above problem does not exist. Signed-off-by: Chunyan Liu <cyliu@suse.com> --- tools/virsh-domain.c | 26 ++++++++++++++++++++------ tools/virsh.h | 1 + 2 files changed, 21 insertions(+), 6 deletions(-) diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index f7193cb..2562326 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -8965,6 +8965,7 @@ doMigrate(void *opaque) virTypedParameterPtr params = NULL; int nparams = 0; int maxparams = 0; + virConnectPtr dconn = data->dconn; sigemptyset(&sigmask); sigaddset(&sigmask, SIGINT); @@ -9079,18 +9080,12 @@ doMigrate(void *opaque) ret = '0'; } else { /* For traditional live migration, connect to the destination host directly. */ - virConnectPtr dconn = NULL; virDomainPtr ddom = NULL; - dconn = vshConnect(ctl, desturi, false); - if (!dconn) - goto out; - if ((ddom = virDomainMigrate3(dom, dconn, params, nparams, flags))) { virDomainFree(ddom); ret = '0'; } - virConnectClose(dconn); } out: @@ -9152,6 +9147,23 @@ cmdMigrate(vshControl *ctl, const vshCmd *cmd) data.cmd = cmd; data.writefd = p[1]; + if (vshCommandOptBool(cmd, "p2p") || vshCommandOptBool(cmd, "direct")) { + data.dconn = NULL; + } else { + /* For traditional live migration, connect to the destination host. */ + virConnectPtr dconn = NULL; + const char *desturi = NULL; + + if (vshCommandOptStringReq(ctl, cmd, "desturi", &desturi) < 0) + goto cleanup; + + dconn = vshConnect(ctl, desturi, false); + if (!dconn) + goto cleanup; + + data.dconn = dconn; + } + if (virThreadCreate(&workerThread, true, doMigrate, @@ -9163,6 +9175,8 @@ cmdMigrate(vshControl *ctl, const vshCmd *cmd) virThreadJoin(&workerThread); cleanup: + if (data.dconn) + virConnectClose(data.dconn); virDomainFree(dom); VIR_FORCE_CLOSE(p[0]); VIR_FORCE_CLOSE(p[1]); diff --git a/tools/virsh.h b/tools/virsh.h index 7656407..b4df24b 100644 --- a/tools/virsh.h +++ b/tools/virsh.h @@ -371,6 +371,7 @@ struct _vshCtrlData { vshControl *ctl; const vshCmd *cmd; int writefd; + virConnectPtr dconn; }; /* error handling */ -- 1.8.4.5
On 8/8/2014 at 04:44 PM, in message <1407487476-28077-1-git-send-email-cyliu@suse.com>, Chunyan Liu <cyliu@suse.com> wrote: A possible fix to issue: http://www.redhat.com/archives/libvir-list/2014-August/thread.html#00227
While doing migration on KVM host, found problem sometimes: VM is already running on the target host and disappears from source host, but 'virsh migrate' command line hangs, cannot exit normally. If pressing "ENTER" key, it will exit.
The code hangs at tools/virsh-domain.c: cmdMigrate ->vshWatchJob->poll(): poll() is trying to select pipe_fd, which is used to receive message from doMigrate thread. In debugging, found that doMigrate finishes and at the end it does call safewrite() to write the retval ('0' or '1') to pipe_fd, and the write is completed. But cmdMigrate poll() cannot get the event. If pressing "ENTER" key, poll() can get the event and select pipe_fd, then command line can exit.
In current code, authentication thread which is called by vshConnect will use stdin, and at the same time, in cmdMigrate main process, poll() is listening to stdin, that probably affect poll() to get pipe_fd event. Better to move authentication before vshWatchJob. With this change, above problem does not exist.
Any comments about this patch?
Signed-off-by: Chunyan Liu <cyliu@suse.com> --- tools/virsh-domain.c | 26 ++++++++++++++++++++------ tools/virsh.h | 1 + 2 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index f7193cb..2562326 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -8965,6 +8965,7 @@ doMigrate(void *opaque) virTypedParameterPtr params = NULL; int nparams = 0; int maxparams = 0; + virConnectPtr dconn = data->dconn;
sigemptyset(&sigmask); sigaddset(&sigmask, SIGINT); @@ -9079,18 +9080,12 @@ doMigrate(void *opaque) ret = '0'; } else { /* For traditional live migration, connect to the destination host directly. */ - virConnectPtr dconn = NULL; virDomainPtr ddom = NULL;
- dconn = vshConnect(ctl, desturi, false); - if (!dconn) - goto out; - if ((ddom = virDomainMigrate3(dom, dconn, params, nparams, flags))) { virDomainFree(ddom); ret = '0'; } - virConnectClose(dconn); }
out: @@ -9152,6 +9147,23 @@ cmdMigrate(vshControl *ctl, const vshCmd *cmd) data.cmd = cmd; data.writefd = p[1];
+ if (vshCommandOptBool(cmd, "p2p") || vshCommandOptBool(cmd, "direct")) { + data.dconn = NULL; + } else { + /* For traditional live migration, connect to the destination host. */ + virConnectPtr dconn = NULL; + const char *desturi = NULL; + + if (vshCommandOptStringReq(ctl, cmd, "desturi", &desturi) < 0) + goto cleanup; + + dconn = vshConnect(ctl, desturi, false); + if (!dconn) + goto cleanup; + + data.dconn = dconn; + } + if (virThreadCreate(&workerThread, true, doMigrate, @@ -9163,6 +9175,8 @@ cmdMigrate(vshControl *ctl, const vshCmd *cmd) virThreadJoin(&workerThread);
cleanup: + if (data.dconn) + virConnectClose(data.dconn); virDomainFree(dom); VIR_FORCE_CLOSE(p[0]); VIR_FORCE_CLOSE(p[1]); diff --git a/tools/virsh.h b/tools/virsh.h index 7656407..b4df24b 100644 --- a/tools/virsh.h +++ b/tools/virsh.h @@ -371,6 +371,7 @@ struct _vshCtrlData { vshControl *ctl; const vshCmd *cmd; int writefd; + virConnectPtr dconn; };
/* error handling */
On 08/08/2014 10:44 AM, Chunyan Liu wrote:
A possible fix to issue: http://www.redhat.com/archives/libvir-list/2014-August/thread.html#00227
While doing migration on KVM host, found problem sometimes: VM is already running on the target host and disappears from source host, but 'virsh migrate' command line hangs, cannot exit normally. If pressing "ENTER" key, it will exit.
The code hangs at tools/virsh-domain.c: cmdMigrate ->vshWatchJob->poll(): poll() is trying to select pipe_fd, which is used to receive message from doMigrate thread. In debugging, found that doMigrate finishes and at the end it does call safewrite() to write the retval ('0' or '1') to pipe_fd, and the write is completed. But cmdMigrate poll() cannot get the event. If pressing "ENTER" key, poll() can get the event and select pipe_fd, then command line can exit.
In current code, authentication thread which is called by vshConnect will use stdin, and at the same time, in cmdMigrate main process, poll() is listening to stdin, that probably affect poll() to get pipe_fd event. Better to move authentication before vshWatchJob. With this change, above problem does not exist.
Signed-off-by: Chunyan Liu <cyliu@suse.com> --- tools/virsh-domain.c | 26 ++++++++++++++++++++------ tools/virsh.h | 1 + 2 files changed, 21 insertions(+), 6 deletions(-)
ACK
diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index f7193cb..2562326 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -8965,6 +8965,7 @@ doMigrate(void *opaque) virTypedParameterPtr params = NULL; int nparams = 0; int maxparams = 0; + virConnectPtr dconn = data->dconn;
sigemptyset(&sigmask); sigaddset(&sigmask, SIGINT); @@ -9079,18 +9080,12 @@ doMigrate(void *opaque) ret = '0'; } else {
I'd rather rewrite this condition as: if (dconn) { /* Traditional live migration */ } else { /* peer2peer or direct */ }
Hi Jan, Is the auto login a pre-requisite for p2p & direct migration ? The current patch mostly focus on avoiding the virsh migrate hang. Thanks, Shiva On Thu, Aug 14, 2014 at 9:40 PM, Ján Tomko <jtomko@redhat.com> wrote:
On 08/08/2014 10:44 AM, Chunyan Liu wrote:
A possible fix to issue: http://www.redhat.com/archives/libvir-list/2014-August/thread.html#00227
While doing migration on KVM host, found problem sometimes: VM is already running on the target host and disappears from source host, but 'virsh migrate' command line hangs, cannot exit normally. If pressing "ENTER" key, it will exit.
The code hangs at tools/virsh-domain.c: cmdMigrate ->vshWatchJob->poll(): poll() is trying to select pipe_fd, which is used to receive message from doMigrate thread. In debugging, found that doMigrate finishes and at the end it does call safewrite() to write the retval ('0' or '1') to pipe_fd, and the write is completed. But cmdMigrate poll() cannot get the event. If pressing "ENTER" key, poll() can get the event and select pipe_fd, then command line can exit.
In current code, authentication thread which is called by vshConnect will use stdin, and at the same time, in cmdMigrate main process, poll() is listening to stdin, that probably affect poll() to get pipe_fd event. Better to move authentication before vshWatchJob. With this change, above problem does not exist.
Signed-off-by: Chunyan Liu <cyliu@suse.com> --- tools/virsh-domain.c | 26 ++++++++++++++++++++------ tools/virsh.h | 1 + 2 files changed, 21 insertions(+), 6 deletions(-)
ACK
diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index f7193cb..2562326 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -8965,6 +8965,7 @@ doMigrate(void *opaque) virTypedParameterPtr params = NULL; int nparams = 0; int maxparams = 0; + virConnectPtr dconn = data->dconn;
sigemptyset(&sigmask); sigaddset(&sigmask, SIGINT); @@ -9079,18 +9080,12 @@ doMigrate(void *opaque) ret = '0'; } else {
I'd rather rewrite this condition as: if (dconn) { /* Traditional live migration */ } else { /* peer2peer or direct */ }
On 08/14/2014 07:08 PM, Shivaprasad bhat wrote:
Hi Jan,
Is the auto login a pre-requisite for p2p & direct migration ? The current patch mostly focus on avoiding the virsh migrate hang.
Yes. With p2p and direct migration libvirtd is the one connecting to the destination and there is no way to give it the password from virsh. Btw: I've pushed the patch now. Jan
participants (4)
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Chun Yan Liu -
Chunyan Liu
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Ján Tomko -
Shivaprasad bhat