[libvirt] [PATCH 1/3] add percentage limit parse and define support for RAM filesystems

[Chen Hanxiao]

From: Chen Hanxiao <chenhanxiao at cn.fujitsu.com>

This patch enables percentage limit for ram filesystem

<filesystem type='ram'>
    <source usage='10%'/>
    <target dir='/mnt'/>
</filesystem>

Percentage limit would have more priority than size limit.

Signed-off-by: Chen Hanxiao <chenhanxiao at cn.fujitsu.com>
---
 src/conf/domain_conf.c | 21 +++++++++++++++++----
 src/conf/domain_conf.h |  1 +
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index d3f1ca2..25cfde2 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -6068,19 +6068,27 @@ virDomainFSDefParseXML(xmlNodePtr node,
     }
 
     if (def->type == VIR_DOMAIN_FS_TYPE_RAM) {
+        int len;
         if (!usage) {
             virReportError(VIR_ERR_XML_ERROR, "%s",
                            _("missing 'usage' attribute for RAM filesystem"));
             goto error;
         }
+        len = strlen(usage);
+        if ('%' == usage[len - 1]) {
+            VIR_DEBUG("usage is %s\n", usage);
+            *(usage + len - 1) = '\0';
+            def->usage_percentage = true;
+        }
+
         if (virStrToLong_ull(usage, NULL, 10, &def->usage) < 0) {
             virReportError(VIR_ERR_XML_ERROR,
                            _("cannot parse usage '%s' for RAM filesystem"),
                            usage);
             goto error;
         }
-        if (virScaleInteger(&def->usage, units,
-                            1024, ULLONG_MAX) < 0)
+        if (!(def->usage_percentage) &&
+            virScaleInteger(&def->usage, units, 1024, ULLONG_MAX) < 0)
             goto error;
     }
 
@@ -14866,8 +14874,13 @@ virDomainFSDefFormat(virBufferPtr buf,
         break;
 
     case VIR_DOMAIN_FS_TYPE_RAM:
-        virBufferAsprintf(buf, "      <source usage='%lld' units='KiB'/>\n",
-                          def->usage / 1024);
+        if (def->usage_percentage) {
+            virBufferAsprintf(buf, "      <source usage='%lld%%'/>\n",
+                              def->usage);
+        } else {
+            virBufferAsprintf(buf, "      <source usage='%lld' units='KiB'/>\n",
+                              def->usage / 1024);
+        }
         break;
     }
 
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 4561ccc..abfa756 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -891,6 +891,7 @@ struct _virDomainFSDef {
     int wrpolicy; /* enum virDomainFSWrpolicy */
     int format; /* enum virStorageFileFormat */
     unsigned long long usage; /* in bytes */
+    bool usage_percentage; /* flag for percentage limit */
     char *src;
     char *dst;
     bool readonly;
-- 
1.8.2.1