virsh snapshot-create-as supports 'file' storage type in --diskspec by default. But it doesn't support 'block' storage type in the virshParseSnapshotDiskspec(). So if a snapshot on a block device (e.g. LV) was created, the type of current running storage source in dumpxml is inconsistent with the actual backend storage source. It will check file-system type mismatch failed and return an error message of 'Migration without shared storage is unsafe' when VM performs a live migration after this snapshot. Considering virsh has to be able to work remotely that recognizing a block device by prefix /dev/ or by stat() may be not suitable, so adding a "stype" field for the --diskspec string which will be either "file" or "block". e.g. --diskspec vda,snapshot=external,driver=qcow2,stype=block,file=/dev/xxx. Signed-off-by: Liu Dayu <liu.dayu@zte.com.cn> --- Patch v1: https://www.redhat.com/archives/libvir-list/2019-June/msg01248.html Changes in v2: - Adding a "stype" field for the --diskspec string which will indicate a "file" or "block" storage type. --- tools/virsh-snapshot.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/tools/virsh-snapshot.c b/tools/virsh-snapshot.c index e9f0ee0..ec965b2 100644 --- a/tools/virsh-snapshot.c +++ b/tools/virsh-snapshot.c @@ -251,10 +251,12 @@ virshParseSnapshotDiskspec(vshControl *ctl, virBufferPtr buf, const char *str) const char *name = NULL; const char *snapshot = NULL; const char *driver = NULL; + const char *stype = NULL; const char *file = NULL; char **array = NULL; int narray; size_t i; + bool isFile = true; narray = vshStringToArray(str, &array); if (narray <= 0) @@ -266,6 +268,8 @@ virshParseSnapshotDiskspec(vshControl *ctl, virBufferPtr buf, const char *str) snapshot = array[i] + strlen("snapshot="); else if (!driver && STRPREFIX(array[i], "driver=")) driver = array[i] + strlen("driver="); + else if (!stype && STRPREFIX(array[i], "stype=")) + stype = array[i] + strlen("stype="); else if (!file && STRPREFIX(array[i], "file=")) file = array[i] + strlen("file="); else @@ -275,13 +279,26 @@ virshParseSnapshotDiskspec(vshControl *ctl, virBufferPtr buf, const char *str) virBufferEscapeString(buf, "<disk name='%s'", name); if (snapshot) virBufferAsprintf(buf, " snapshot='%s'", snapshot); + if (stype) { + if (STREQ(stype, "block")) { + isFile = false; + } else if (STRNEQ(stype, "file")) { + vshError(ctl, _("Unknown storage type: '%s'"), stype); + goto cleanup; + } + virBufferAsprintf(buf, " type='%s'", stype); + } if (driver || file) { virBufferAddLit(buf, ">\n"); virBufferAdjustIndent(buf, 2); if (driver) virBufferAsprintf(buf, "<driver type='%s'/>\n", driver); - if (file) - virBufferEscapeString(buf, "<source file='%s'/>\n", file); + if (file) { + if (isFile) + virBufferEscapeString(buf, "<source file='%s'/>\n", file); + else + virBufferEscapeString(buf, "<source dev='%s'/>\n", file); + } virBufferAdjustIndent(buf, -2); virBufferAddLit(buf, "</disk>\n"); } else { @@ -351,7 +368,7 @@ static const vshCmdOptDef opts_snapshot_create_as[] = { }, {.name = "diskspec", .type = VSH_OT_ARGV, - .help = N_("disk attributes: disk[,snapshot=type][,driver=type][,file=name]") + .help = N_("disk attributes: disk[,snapshot=type][,driver=type][,stype=type][,file=name]") }, {.name = NULL} }; -- 1.8.3.1