[libvirt] [PATCH v2 5/5] qemu: Combine the various ways to call query-block
John Ferlan
jferlan at redhat.com
Fri Sep 30 18:39:21 UTC 2016
Now that each of the 3 callers to "query-block" has relatively the same
flow, combine the remaining flow into qemuMonitorJSONQueryBlock and of
course rework the function comments to describe the expectations.
The qemuMonitorJSONQueryBlock will now take multiple parameters and call
the helper that exists to fill just the specific data requested.
Each of the callers is essentially reduced to a shim calling the common
function with its specific qemuMonitorJSONQueryBlockFill* helper to
handle the needs for the specific caller.
NB: Also adjust the first "error message in the devices parsing loop
to make it easier to distinguish which failure occurred.
Signed-off-by: John Ferlan <jferlan at redhat.com>
---
src/qemu/qemu_monitor_json.c | 242 ++++++++++++++++++++-----------------------
1 file changed, 112 insertions(+), 130 deletions(-)
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 2b03f86..e7dec88 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -129,6 +129,20 @@ static qemuEventHandler eventHandlers[] = {
/* We use bsearch, so keep this list sorted. */
};
+typedef int
+(*qemuMonitorJSONQueryBlockFillTableCallback)(virJSONValuePtr dev,
+ const char *thisdev,
+ virHashTablePtr table,
+ bool backingChain);
+
+typedef int
+(*qemuMonitorJSONQueryBlockFillSearchCallback)(virJSONValuePtr dev,
+ const char *thisdev,
+ const char *searchDevice,
+ virStorageSourcePtr top,
+ virStorageSourcePtr target,
+ char **foundDevice);
+
static int
qemuMonitorEventCompare(const void *key, const void *elt)
{
@@ -1774,29 +1788,107 @@ qemuMonitorJSONSetMemoryStatsPeriod(qemuMonitorPtr mon,
/* qemuMonitorJSONQueryBlock:
* @mon: Monitor pointer
+ * @table: The hash table pointer to insert a device into
+ * @backingChain: Boolean whether to follow backing chaing
+ * @searchDevice: Specific device name to search on
+ * @top: Top of a chain to start looking
+ * @target: The backing element target
+ * @foundDevice: Pointer to address of returned found device string
+ * @tablecb: Callback function for hash table usage
+ * @searchcb: Callback function for searchDevice search
+ *
+ * This helper will attempt to make a "query-block" call, check for
+ * errors, and scan the reply list of devices calling out the either the
+ * @tablecb or @searchcb helper in order to perform the action on the element.
+ *
+ * The function can be used in one of two ways:
+ *
+ * 1. Passing a hash @table and @tablecb in order to add each device
+ * in the returned list into the hash table. This option also provides
+ * the capability to pass a @backingChain boolean to search the backing
+ * chains as well.
+ *
+ * 2. Passing a @searchDevice and @searchcb in order to search the returned
+ * data for a specific device and then call the @searchcb with the @top
+ * and @target parameters in order to return a @foundDevice.
*
- * This helper will attempt to make a "query-block" call and check for
- * errors before returning with the reply.
+ * The @tablecb program is expected to return -1 for error and quit, 0 for
+ * good status and continue.
*
- * Returns: NULL on error, reply on success
+ * The @searchcb program is expected to return -1 for error and quit, 0 for
+ * good status and continue, and 1 for good status and return. The caller
+ * for usage of @foundDevice is expected to pass a non-NULL argument.
+ *
+ * Returns: -1 on error, 0 on success
*/
-static virJSONValuePtr
-qemuMonitorJSONQueryBlock(qemuMonitorPtr mon)
+static int
+qemuMonitorJSONQueryBlock(qemuMonitorPtr mon,
+ virHashTablePtr table,
+ bool backingChain,
+ const char *searchDevice,
+ virStorageSourcePtr top,
+ virStorageSourcePtr target,
+ char **foundDevice,
+ qemuMonitorJSONQueryBlockFillTableCallback tablecb,
+ qemuMonitorJSONQueryBlockFillSearchCallback searchcb)
{
+ int ret = -1;
+ size_t i;
virJSONValuePtr cmd;
virJSONValuePtr reply = NULL;
+ virJSONValuePtr devices;
if (!(cmd = qemuMonitorJSONMakeCommand("query-block", NULL)))
- return NULL;
+ return -1;
if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0 ||
- qemuMonitorJSONCheckError(cmd, reply) < 0) {
- virJSONValueFree(reply);
- reply = NULL;
+ qemuMonitorJSONCheckError(cmd, reply) < 0)
+ goto cleanup;
+
+ if (!(devices = virJSONValueObjectGetArray(reply, "return"))) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("block info reply was missing device list"));
+ goto cleanup;
+ }
+
+ for (i = 0; i < virJSONValueArraySize(devices); i++) {
+ virJSONValuePtr dev;
+ const char *thisdev;
+ int rc;
+
+ dev = virJSONValueArrayGet(devices, i);
+ if (!dev || dev->type != VIR_JSON_TYPE_OBJECT) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("block info device or type was not in "
+ "expected format"));
+ goto cleanup;
+ }
+
+ if (!(thisdev = virJSONValueObjectGetString(dev, "device"))) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("block info device entry was not in "
+ "expected format"));
+ goto cleanup;
+ }
+
+ if (tablecb) {
+ if (tablecb(dev, thisdev, table, backingChain) < 0)
+ goto cleanup;
+ } else if (searchcb) {
+ if ((rc = searchcb(dev, thisdev, searchDevice, top,
+ target, foundDevice) < 0))
+ goto cleanup;
+
+ if (rc == 1)
+ break;
+ }
}
+ ret = 0;
+ cleanup:
+ virJSONValueFree(reply);
virJSONValueFree(cmd);
- return reply;
+ return ret;
}
@@ -1808,7 +1900,8 @@ qemuMonitorJSONQueryBlock(qemuMonitorPtr mon)
static int
qemuMonitorJSONQueryBlockFillInfo(virJSONValuePtr dev,
const char *thisdev,
- virHashTablePtr table)
+ virHashTablePtr table,
+ bool backingChain ATTRIBUTE_UNUSED)
{
int ret = -1;
struct qemuDomainDiskInfo *info;
@@ -1861,45 +1954,8 @@ qemuMonitorJSONQueryBlockFillInfo(virJSONValuePtr dev,
int qemuMonitorJSONGetBlockInfo(qemuMonitorPtr mon,
virHashTablePtr table)
{
- int ret = -1;
- size_t i;
-
- virJSONValuePtr reply;
- virJSONValuePtr devices;
-
- if (!(reply = qemuMonitorJSONQueryBlock(mon)))
- return -1;
-
- if (!(devices = virJSONValueObjectGetArray(reply, "return"))) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("block info reply was missing device list"));
- goto cleanup;
- }
-
- for (i = 0; i < virJSONValueArraySize(devices); i++) {
- virJSONValuePtr dev = virJSONValueArrayGet(devices, i);
- const char *thisdev;
-
- if (!dev || dev->type != VIR_JSON_TYPE_OBJECT) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("block info device entry was not in expected format"));
- goto cleanup;
- }
-
- if ((thisdev = virJSONValueObjectGetString(dev, "device")) == NULL) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("block info device entry was not in expected format"));
- goto cleanup;
- }
-
- if (qemuMonitorJSONQueryBlockFillInfo(dev, thisdev, table) < 0)
- goto cleanup;
- }
-
- ret = 0;
- cleanup:
- virJSONValueFree(reply);
- return ret;
+ return qemuMonitorJSONQueryBlock(mon, table, false, NULL, NULL, NULL, NULL,
+ qemuMonitorJSONQueryBlockFillInfo, NULL);
}
@@ -2122,48 +2178,9 @@ qemuMonitorJSONBlockStatsUpdateCapacity(qemuMonitorPtr mon,
virHashTablePtr stats,
bool backingChain)
{
- int ret = -1;
- size_t i;
- virJSONValuePtr reply;
- virJSONValuePtr devices;
-
- if (!(reply = qemuMonitorJSONQueryBlock(mon)))
- return -1;
-
- if (!(devices = virJSONValueObjectGetArray(reply, "return"))) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("query-block reply was missing device list"));
- goto cleanup;
- }
-
- for (i = 0; i < virJSONValueArraySize(devices); i++) {
- virJSONValuePtr dev = virJSONValueArrayGet(devices, i);
- const char *dev_name;
-
- if (!dev || dev->type != VIR_JSON_TYPE_OBJECT) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("query-block device entry was not "
- "in expected format"));
- goto cleanup;
- }
-
- if (!(dev_name = virJSONValueObjectGetString(dev, "device"))) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("query-block device entry was not "
- "in expected format"));
- goto cleanup;
- }
-
- if (qemuMonitorJSONQueryBlockFillStats(dev, dev_name, stats,
- backingChain) < 0)
- goto cleanup;
- }
-
- ret = 0;
-
- cleanup:
- virJSONValueFree(reply);
- return ret;
+ return qemuMonitorJSONQueryBlock(mon, stats, backingChain,
+ NULL, NULL, NULL, NULL,
+ qemuMonitorJSONQueryBlockFillStats, NULL);
}
@@ -4065,44 +4082,12 @@ qemuMonitorJSONDiskNameLookup(qemuMonitorPtr mon,
virStorageSourcePtr target)
{
char *ret = NULL;
- virJSONValuePtr reply;
- virJSONValuePtr devices;
- size_t i;
- if (!(reply = qemuMonitorJSONQueryBlock(mon)))
+ if (qemuMonitorJSONQueryBlock(mon, NULL, false,
+ device, top, target, &ret, NULL,
+ qemuMonitorJSONQueryBlockFillDiskNameLookup) < 0)
return NULL;
- if (!(devices = virJSONValueObjectGetArray(reply, "return"))) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("block info reply was missing device list"));
- goto cleanup;
- }
-
- for (i = 0; i < virJSONValueArraySize(devices); i++) {
- virJSONValuePtr dev = virJSONValueArrayGet(devices, i);
- const char *thisdev;
- int rc;
-
- if (!dev || dev->type != VIR_JSON_TYPE_OBJECT) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("block info device entry was not in expected format"));
- goto cleanup;
- }
-
- if (!(thisdev = virJSONValueObjectGetString(dev, "device"))) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("block info device entry was not in expected format"));
- goto cleanup;
- }
-
- if ((rc = qemuMonitorJSONQueryBlockFillDiskNameLookup(dev, thisdev,
- device, top,
- target,
- &ret)) < 0)
- goto cleanup;
- if (rc == 1)
- break;
- }
/* Guarantee an error when returning NULL, but don't override a
* more specific error if one was already generated. */
if (!ret && !virGetLastError())
@@ -4110,9 +4095,6 @@ qemuMonitorJSONDiskNameLookup(qemuMonitorPtr mon,
_("unable to find backing name for device %s"),
device);
- cleanup:
- virJSONValueFree(reply);
-
return ret;
}
--
2.7.4
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