On 8/23/19 6:31 PM, Jonathon Jongsma wrote:
Since version 3.0, qemu has returned disk usage statistics in
guest-get-fsinfo. And since 3.1, it has returned information about the
disk serial number and device node of disks that are targeted by the
filesystem.
Unfortunately, the public API virDomainGetFSInfo() returns the
filesystem info using a virDomainFSInfo struct, and due to API/ABI
guaranteeds it cannot be extended. So this new information cannot
easily be added to the public API. However, it is possible to add this
new filesystem information to a new virDomainGetGuestInfo() API which
will be based on typed parameters and is thus more extensible.
In order to support these two use cases, I added an internal struct
which the agent code uses to return all of the new data fields. This
internal struct can be converted to the public struct at a cost of some
extra memory allocation.
In a following commit, this additional information will be used within
virDomainGetGuestInfo().
Signed-off-by: Jonathon Jongsma <jjongsma@xxxxxxxxxx>
---
src/qemu/qemu_agent.c | 203 +++++++++++++++++++++++++++++++++++++-----
1 file changed, 182 insertions(+), 21 deletions(-)
diff --git a/src/qemu/qemu_agent.c b/src/qemu/qemu_agent.c
index e986204162..8d54979f89 100644
--- a/src/qemu/qemu_agent.c
+++ b/src/qemu/qemu_agent.c
@@ -1827,19 +1827,144 @@ qemuAgentSetTime(qemuAgentPtr mon,
return ret;
}
+typedef struct _qemuAgentDiskInfo qemuAgentDiskInfo;
+typedef qemuAgentDiskInfo *qemuAgentDiskInfoPtr;
+struct _qemuAgentDiskInfo {
+ char *alias;
+ char *serial;
+ char *devnode;
+};
+
+typedef struct _qemuAgentFSInfo qemuAgentFSInfo;
+typedef qemuAgentFSInfo *qemuAgentFSInfoPtr;
+struct _qemuAgentFSInfo {
+ char *mountpoint; /* path to mount point */
+ char *name; /* device name in the guest (e.g. "sda1") */
+ char *fstype; /* filesystem type */
+ long long total_bytes;
+ long long used_bytes;
+ size_t ndisks;
+ qemuAgentDiskInfoPtr *disks;
+};
+
+static void
+qemuAgentDiskInfoFree(qemuAgentDiskInfoPtr info)
+{
+ if (!info)
+ return;
+
+ VIR_FREE(info->serial);
+ VIR_FREE(info->alias);
+ VIR_FREE(info->devnode);
+ VIR_FREE(info);
+}
+
+static void
+qemuAgentFSInfoFree(qemuAgentFSInfoPtr info)
+{
+ size_t i;
+
+ if (!info)
+ return;
+
+ VIR_FREE(info->mountpoint);
+ VIR_FREE(info->name);
+ VIR_FREE(info->fstype);
+
+ for (i = 0; i < info->ndisks; i++)
+ qemuAgentDiskInfoFree(info->disks[i]);
+ VIR_FREE(info->disks);
+
+ VIR_FREE(info);
+}
+
+static virDomainFSInfoPtr
+qemuAgentFSInfoToPublic(qemuAgentFSInfoPtr agent)
+{
+ virDomainFSInfoPtr ret = NULL;
+ size_t n;
+
+ if (VIR_ALLOC(ret) < 0)
+ return NULL;
+ if (VIR_STRDUP(ret->name, agent->name) < 0)
+ goto error;
+ if (VIR_STRDUP(ret->mountpoint, agent->mountpoint) < 0)
+ goto error;
+ if (VIR_STRDUP(ret->fstype, agent->fstype) < 0)
+ goto error;
+
+ ret->ndevAlias = agent->ndisks;
+
+ if (ret->ndevAlias == 0)
+ return ret;
+
+ if (VIR_ALLOC_N(ret->devAlias, ret->ndevAlias) < 0)
+ goto error;
+
This is not safe. You set ret->ndevAlias before allocating
ret->devAlias. Just imagine this VIR_ALLOC_N() fails so that the control
jumps over to error label where virDomainFSInfoFree() is called which
sees nonzero info->ndevAlias and thus enters its loop and derefs
info->devAlias which is NULL.
+ for (n = 0; n < ret->ndevAlias; n++) {
+ if (VIR_STRDUP(ret->devAlias[n], agent->disks[n]->alias) < 0)
+ goto error;
+ }
+
+ return ret;
+
+ error:
+ virDomainFSInfoFree(ret);
+ return NULL;
+}
+
+static int
+qemuAgentGetFSInfoInternal(qemuAgentPtr mon, qemuAgentFSInfoPtr **info,
+ virDomainDefPtr vmdef);
No need for this prototype if you just switch the order.
int
qemuAgentGetFSInfo(qemuAgentPtr mon, virDomainFSInfoPtr **info,
virDomainDefPtr vmdef)
+{
+ int ret = -1;
+ qemuAgentFSInfoPtr *agentinfo = NULL;
+ virDomainFSInfoPtr *info_ret = NULL;
+ size_t i;
+ int nfs;
+
+ nfs = qemuAgentGetFSInfoInternal(mon, &agentinfo, vmdef);
+ if (nfs < 0)
+ return ret;
+ if (VIR_ALLOC_N(info_ret, nfs) < 0)
+ goto cleanup;
+
+ for (i = 0; i < nfs; i++) {
+ if (!(info_ret[i] = qemuAgentFSInfoToPublic(agentinfo[i])))
+ goto cleanup;
+ }
+
+ *info = info_ret;
+ info_ret = NULL;
+ ret = nfs;
+
+ cleanup:
+ for (i = 0; i < nfs; i++) {
+ qemuAgentFSInfoFree(agentinfo[i]);
+ /* if there was an error, free any memory we've allocated for the
+ * return value */
+ if (info_ret)
+ virDomainFSInfoFree(info_ret[i]);
Dont' forget to free @info_ret itself.
+ }
+ return ret;
+}
+
+
+static int
+qemuAgentGetFSInfoInternal(qemuAgentPtr mon, qemuAgentFSInfoPtr **info,
+ virDomainDefPtr vmdef)
{
size_t i, j, k;
int ret = -1;
- size_t ndata = 0, ndisk;
- char **alias;
+ size_t ndata = 0;
virJSONValuePtr cmd;
virJSONValuePtr reply = NULL;
virJSONValuePtr data;
- virDomainFSInfoPtr *info_ret = NULL;
+ qemuAgentFSInfoPtr *info_ret = NULL;
virPCIDeviceAddress pci_address;
const char *result = NULL;
@@ -1915,6 +2040,33 @@ qemuAgentGetFSInfo(qemuAgentPtr mon, virDomainFSInfoPtr **info,
if (VIR_STRDUP(info_ret[i]->fstype, result) < 0)
goto cleanup;
+
+ /* 'used-bytes' and 'total-bytes' were added in qemu-ga 3.0 */
+ unsigned long long bytes_val;
+ if (virJSONValueObjectHasKey(entry, "used-bytes")) {
+ if (virJSONValueObjectGetNumberUlong(entry, "used-bytes",
+ &bytes_val) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("Error getting 'used-bytes' in reply of guest-get-fsinfo"));
+ goto cleanup;
+ }
+ info_ret[i]->used_bytes = bytes_val;
+ } else {
+ info_ret[i]->used_bytes = -1;
+ }
+
+ if (virJSONValueObjectHasKey(entry, "total-bytes")) {
+ if (virJSONValueObjectGetNumberUlong(entry, "total-bytes",
+ &bytes_val) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("Error getting 'total-bytes' in reply of guest-get-fsinfo"));
+ goto cleanup;
+ }
+ info_ret[i]->total_bytes = bytes_val;
+ } else {
+ info_ret[i]->total_bytes = -1;
+ }
+
if (!(entry = virJSONValueObjectGet(entry, "disk"))) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("'disk' missing in reply of guest-get-fsinfo"));
@@ -1927,31 +2079,45 @@ qemuAgentGetFSInfo(qemuAgentPtr mon, virDomainFSInfoPtr **info,
goto cleanup;
}
- ndisk = virJSONValueArraySize(entry);
- if (ndisk == 0)
+ info_ret[i]->ndisks = virJSONValueArraySize(entry);
+ if (info_ret[i]->ndisks == 0)
continue;
- if (VIR_ALLOC_N(info_ret[i]->devAlias, ndisk) < 0)
+ if (VIR_ALLOC_N(info_ret[i]->disks, info_ret[i]->ndisks) < 0)
goto cleanup;
- alias = info_ret[i]->devAlias;
- info_ret[i]->ndevAlias = 0;
- for (j = 0; j < ndisk; j++) {
- virJSONValuePtr disk = virJSONValueArrayGet(entry, j);
+ for (j = 0; j < info_ret[i]->ndisks; j++) {
Ugrh. Gross. Not your fault, but I'm moving this into a separate
function, because this has grown over bearable limit.
+ virJSONValuePtr jsondisk = virJSONValueArrayGet(entry, j);
virJSONValuePtr pci;
int diskaddr[3], pciaddr[4];
const char *diskaddr_comp[] = {"bus", "target", "unit"};
const char *pciaddr_comp[] = {"domain", "bus", "slot", "function"};
Again, not your fault, but this looks very ugly to me. Will fix it though.
Michal
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