qemu: add support for new fields in FSInfo

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
guarantees 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: NJonathon Jongsma <jjongsma@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: NDaniel Henrique Barboza <danielhb413@gmail.com>

src/qemu/qemu_agent.c

@@ -1827,21 +1827,196 @@ qemuAgentSetTime(qemuAgentPtr mon,
     return ret;
 }
 
+typedef struct _qemuAgentDiskInfo qemuAgentDiskInfo;
+typedef qemuAgentDiskInfo *qemuAgentDiskInfoPtr;
+struct _qemuAgentDiskInfo {
+    char *alias;
+    char *serial;
+    char *devnode;
+};
 
-int
-qemuAgentGetFSInfo(qemuAgentPtr mon, virDomainFSInfoPtr **info,
-                   virDomainDefPtr vmdef)
+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 i;
+
+    if (VIR_ALLOC(ret) < 0 ||
+        VIR_STRDUP(ret->mountpoint, agent->mountpoint) < 0 ||
+        VIR_STRDUP(ret->name, agent->name) < 0 ||
+        VIR_STRDUP(ret->fstype, agent->fstype) < 0)
+        goto error;
+
+    if (agent->disks &&
+        VIR_ALLOC_N(ret->devAlias, agent->ndisks) < 0)
+        goto error;
+
+    ret->ndevAlias = agent->ndisks;
+
+    for (i = 0; i < ret->ndevAlias; i++) {
+        if (VIR_STRDUP(ret->devAlias[i], agent->disks[i]->alias) < 0)
+            goto error;
+    }
+
+    return ret;
+
+ error:
+    virDomainFSInfoFree(ret);
+    return NULL;
+}
+
+static int
+qemuAgentGetFSInfoInternalDisk(virJSONValuePtr jsondisks,
+                               qemuAgentFSInfoPtr fsinfo,
+                               virDomainDefPtr vmdef)
 {
-    size_t i, j, k;
+    size_t ndisks;
+    size_t i;
+
+    if (!virJSONValueIsArray(jsondisks)) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Malformed guest-get-fsinfo 'disk' data array"));
+        return -1;
+    }
+
+    ndisks = virJSONValueArraySize(jsondisks);
+
+    if (ndisks &&
+        VIR_ALLOC_N(fsinfo->disks, ndisks) < 0)
+        return -1;
+
+    fsinfo->ndisks = ndisks;
+
+    for (i = 0; i < fsinfo->ndisks; i++) {
+        virJSONValuePtr jsondisk = virJSONValueArrayGet(jsondisks, i);
+        virJSONValuePtr pci;
+        qemuAgentDiskInfoPtr disk;
+        virDomainDiskDefPtr diskDef;
+        const char *val;
+        unsigned int bus;
+        unsigned int target;
+        unsigned int unit;
+        virPCIDeviceAddress pci_address;
+
+        if (!jsondisk) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("array element '%zd' of '%zd' missing in "
+                             "guest-get-fsinfo 'disk' data"),
+                           i, fsinfo->ndisks);
+            return -1;
+        }
+
+        if (VIR_ALLOC(fsinfo->disks[i]) < 0)
+            return -1;
+        disk = fsinfo->disks[i];
+
+        if ((val = virJSONValueObjectGetString(jsondisk, "serial"))) {
+            if (VIR_STRDUP(disk->serial, val) < 0)
+                return -1;
+        }
+
+        if ((val = virJSONValueObjectGetString(jsondisk, "dev"))) {
+            if (VIR_STRDUP(disk->devnode, val) < 0)
+                return -1;
+        }
+
+#define GET_DISK_ADDR(jsonObject, var, name) \
+        do { \
+            if (virJSONValueObjectGetNumberUint(jsonObject, name, var) < 0) { \
+                virReportError(VIR_ERR_INTERNAL_ERROR, \
+                               _("'%s' missing in guest-get-fsinfo " \
+                                 "'disk' data"), name); \
+                return -1; \
+            } \
+        } while (0)
+
+        GET_DISK_ADDR(jsondisk, &bus, "bus");
+        GET_DISK_ADDR(jsondisk, &target, "target");
+        GET_DISK_ADDR(jsondisk, &unit, "unit");
+
+        if (!(pci = virJSONValueObjectGet(jsondisk, "pci-controller"))) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("'pci-controller' missing in guest-get-fsinfo "
+                             "'disk' data"));
+            return -1;
+        }
+
+        GET_DISK_ADDR(pci, &pci_address.domain, "domain");
+        GET_DISK_ADDR(pci, &pci_address.bus, "bus");
+        GET_DISK_ADDR(pci, &pci_address.slot, "slot");
+        GET_DISK_ADDR(pci, &pci_address.function, "function");
+
+#undef GET_DISK_ADDR
+
+        if (!(diskDef = virDomainDiskByAddress(vmdef,
+                                               &pci_address,
+                                               bus,
+                                               target,
+                                               unit)))
+            continue;
+
+        if (VIR_STRDUP(disk->alias, diskDef->dst) < 0)
+            return -1;
+    }
+
+    return 0;
+}
+
+static int
+qemuAgentGetFSInfoInternal(qemuAgentPtr mon,
+                           qemuAgentFSInfoPtr **info,
+                           virDomainDefPtr vmdef)
+{
+    size_t i;
     int ret = -1;
-    size_t ndata = 0, ndisk;
-    char **alias;
-    virJSONValuePtr cmd;
-    virJSONValuePtr reply = NULL;
+    VIR_AUTOPTR(virJSONValue) cmd = NULL;
+    VIR_AUTOPTR(virJSONValue) reply = NULL;
     virJSONValuePtr data;
-    virDomainFSInfoPtr *info_ret = NULL;
-    virPCIDeviceAddress pci_address;
-    const char *result = NULL;
+    size_t ndata = 0;
+    qemuAgentFSInfoPtr *info_ret = NULL;
 
     cmd = qemuAgentMakeCommand("guest-get-fsinfo", NULL);
     if (!cmd)
@@ -1875,6 +2050,9 @@ qemuAgentGetFSInfo(qemuAgentPtr mon, virDomainFSInfoPtr **info,
     for (i = 0; i < ndata; i++) {
         /* Reverse the order to arrange in mount order */
         virJSONValuePtr entry = virJSONValueArrayGet(data, ndata - 1 - i);
+        virJSONValuePtr disk;
+        unsigned long long bytes_val;
+        const char *result = NULL;
 
         if (!entry) {
             virReportError(VIR_ERR_INTERNAL_ERROR,
@@ -1915,99 +2093,88 @@ qemuAgentGetFSInfo(qemuAgentPtr mon, virDomainFSInfoPtr **info,
         if (VIR_STRDUP(info_ret[i]->fstype, result) < 0)
             goto cleanup;
 
-        if (!(entry = virJSONValueObjectGet(entry, "disk"))) {
-            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                           _("'disk' missing in reply of guest-get-fsinfo"));
-            goto cleanup;
-        }
-
-        if (!virJSONValueIsArray(entry)) {
-            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                           _("Malformed guest-get-fsinfo 'disk' data array"));
-            goto cleanup;
-        }
 
-        ndisk = virJSONValueArraySize(entry);
-        if (ndisk == 0)
-            continue;
-        if (VIR_ALLOC_N(info_ret[i]->devAlias, ndisk) < 0)
-            goto cleanup;
-
-        alias = info_ret[i]->devAlias;
-        info_ret[i]->ndevAlias = 0;
-        for (j = 0; j < ndisk; j++) {
-            virJSONValuePtr disk = 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"};
-            virDomainDiskDefPtr diskDef;
-
-            if (!disk) {
-                virReportError(VIR_ERR_INTERNAL_ERROR,
-                               _("array element '%zd' of '%zd' missing in "
-                                 "guest-get-fsinfo 'disk' data"),
-                               j, ndisk);
+        /* 'used-bytes' and 'total-bytes' were added in qemu-ga 3.0 */
+        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 (!(pci = virJSONValueObjectGet(disk, "pci-controller"))) {
+        if (virJSONValueObjectHasKey(entry, "total-bytes")) {
+            if (virJSONValueObjectGetNumberUlong(entry, "total-bytes",
+                                                 &bytes_val) < 0) {
                 virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                               _("'pci-controller' missing in guest-get-fsinfo "
-                                 "'disk' data"));
+                               _("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;
+        }
 
-            for (k = 0; k < 3; k++) {
-                if (virJSONValueObjectGetNumberInt(
-                        disk, diskaddr_comp[k], &diskaddr[k]) < 0) {
-                    virReportError(VIR_ERR_INTERNAL_ERROR,
-                                   _("'%s' missing in guest-get-fsinfo "
-                                     "'disk' data"), diskaddr_comp[k]);
-                    goto cleanup;
-                }
-            }
-            for (k = 0; k < 4; k++) {
-                if (virJSONValueObjectGetNumberInt(
-                        pci, pciaddr_comp[k], &pciaddr[k]) < 0) {
-                    virReportError(VIR_ERR_INTERNAL_ERROR,
-                                   _("'%s' missing in guest-get-fsinfo "
-                                     "'pci-address' data"), pciaddr_comp[k]);
-                    goto cleanup;
-                }
-            }
-
-            pci_address.domain = pciaddr[0];
-            pci_address.bus = pciaddr[1];
-            pci_address.slot = pciaddr[2];
-            pci_address.function = pciaddr[3];
-            if (!(diskDef = virDomainDiskByAddress(
-                     vmdef, &pci_address,
-                     diskaddr[0], diskaddr[1], diskaddr[2])))
-                continue;
-
-            if (VIR_STRDUP(*alias, diskDef->dst) < 0)
-                goto cleanup;
-
-            if (*alias) {
-                alias++;
-                info_ret[i]->ndevAlias++;
-            }
+        if (!(disk = virJSONValueObjectGet(entry, "disk"))) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("'disk' missing in reply of guest-get-fsinfo"));
+            goto cleanup;
         }
+
+        if (qemuAgentGetFSInfoInternalDisk(disk, info_ret[i], vmdef) < 0)
+            goto cleanup;
     }
 
-    *info = info_ret;
-    info_ret = NULL;
+    VIR_STEAL_PTR(*info, info_ret);
     ret = ndata;
 
  cleanup:
     if (info_ret) {
         for (i = 0; i < ndata; i++)
-            virDomainFSInfoFree(info_ret[i]);
+            qemuAgentFSInfoFree(info_ret[i]);
         VIR_FREE(info_ret);
     }
-    virJSONValueFree(cmd);
-    virJSONValueFree(reply);
+    return ret;
+}
+
+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;
+    }
+
+    VIR_STEAL_PTR(*info, info_ret);
+    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]);
+    }
+    VIR_FREE(agentinfo);
     return ret;
 }