On 11/01/2012 10:22 AM, Peter Krempa wrote:
The current snapshot reverting api supported changing the state of the machine after the snapshot was reverted to either started or paused.
This patch adds the ability to revert the state but to stopped state. --- include/libvirt/libvirt.h.in | 1 + src/libvirt.c | 9 +++++---- tools/virsh-snapshot.c | 3 +++ tools/virsh.pod | 15 +++++++++------ 4 files changed, 18 insertions(+), 10 deletions(-)
diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index fe58c08..ea57d00 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -3872,6 +3872,7 @@ typedef enum { VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING = 1 << 0, /* Run after revert */ VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED = 1 << 1, /* Pause after revert */ VIR_DOMAIN_SNAPSHOT_REVERT_FORCE = 1 << 2, /* Allow risky reverts */ + VIR_DOMAIN_SNAPSHOT_REVERT_STOPPED = 1 << 3, /* Revert into stopped state */
Hmm, this might even be the argument I was looking for earlier about whether it makes sense to mix QUIESCE and memory state (still, using QUIESCE only makes sense for non-LIVE checkpoints). If we are going to revert into a stopped state, that means that we are going to be using the disk state without any memory and so no in-flight I/O; if that is to be allowed, we want a way to quiesce then pause the domain then save state, so we can make up our mind whether to restore just the disk state or everything; but it would also mean that the saved ram state needs to flag that it was done while the guest was quiesced, so that the first thing done on a non-stopped revert is to thaw the guest file system. On the other hand, I don't know how many people will revert to just disk state and not also load up the associated RAM state. This flag might not get much use.
+++ b/src/libvirt.c @@ -18698,11 +18698,12 @@ virDomainRevertToSnapshot(virDomainSnapshotPtr snapshot, goto error; }
- if ((flags & VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING) && - (flags & VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED)) { + if ((!!(flags & VIR_DOMAIN_SNAPSHOT_REVERT_RUNNING) + + !!(flags & VIR_DOMAIN_SNAPSHOT_REVERT_PAUSED) + + !!(flags & VIR_DOMAIN_SNAPSHOT_REVERT_STOPPED)) > 1) { virReportInvalidArg(flags, - _("running and paused flags in %s are mutually exclusive"), - __FUNCTION__); + _("running, paused and stopped flags in %s are " + "mutually exclusive"), __FUNCTION__);
Also needs documentation several lines earlier.
+++ b/tools/virsh.pod @@ -2803,7 +2803,7 @@ Output the name of the parent snapshot, if any, for the given I<snapshot>, or for the current snapshot with I<--current>.
=item B<snapshot-revert> I<domain> {I<snapshot> | I<--current>} -[{I<--running> | I<--paused>}] [I<--force>] +[{I<--running> | I<--paused>} | I<--stopped>] [I<--force>]
Since it is mutually exclusive, this should be: [{I<--running> | I<--paused> | I<--stopped>}] [I<--force>] ACK with the 2 doc changes; we can save decisions about use of quiesce for later. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org