[libvirt] [PATCH] storage: Inherit permissions of parent pool if they are not specified

[Osier Yang]

If permissions (mode, uid, gid) are not specified, a new created vol
will get the permissions like:

    mode = 0600
    uid = -1
    gid = -1

This will be a bit surprised if the user define the pool with a
non-root uid/gid, but the new created vol is still defined as
root/root.

This patch changes the behaviour so that the new created vol will
inherit the permissions of parent pool if permission are not
specified.
---
 src/conf/storage_conf.c |   32 ++++++++++++++++++++------------
 1 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/src/conf/storage_conf.c b/src/conf/storage_conf.c
index e893b2d..18675ad 100644
--- a/src/conf/storage_conf.c
+++ b/src/conf/storage_conf.c
@@ -539,6 +539,7 @@ static int
 virStorageDefParsePerms(xmlXPathContextPtr ctxt,
                         virStoragePermsPtr perms,
                         const char *permxpath,
+                        virStoragePermsPtr pool_perms,
                         int defaultmode) {
     char *mode;
     long v;
@@ -560,9 +561,8 @@ virStorageDefParsePerms(xmlXPathContextPtr ctxt,
     ctxt->node = node;
 
     mode = virXPathString("string(./mode)", ctxt);
-    if (!mode) {
-        perms->mode = defaultmode;
-    } else {
+
+    if (mode) {
         char *end = NULL;
         perms->mode = strtol(mode, &end, 8);
         if (*end || perms->mode < 0 || perms->mode > 0777) {
@@ -572,28 +572,32 @@ virStorageDefParsePerms(xmlXPathContextPtr ctxt,
             goto error;
         }
         VIR_FREE(mode);
+    } else if (pool_perms) {
+        perms->mode = pool_perms->mode;
+    } else {
+        perms->mode = defaultmode;
     }
 
-    if (virXPathNode("./owner", ctxt) == NULL) {
-        perms->uid = -1;
-    } else {
+    if (virXPathNode("./owner", ctxt)) {
         if (virXPathLong("number(./owner)", ctxt, &v) < 0) {
             virStorageReportError(VIR_ERR_XML_ERROR,
                                   "%s", _("malformed owner element"));
             goto error;
         }
         perms->uid = (int)v;
+    } else if (pool_perms)  {
+        perms->uid = pool_perms->uid;
     }
 
-    if (virXPathNode("./group", ctxt) == NULL) {
-        perms->gid = -1;
-    } else {
+    if (virXPathNode("./group", ctxt)) {
         if (virXPathLong("number(./group)", ctxt, &v) < 0) {
             virStorageReportError(VIR_ERR_XML_ERROR,
                                   "%s", _("malformed group element"));
             goto error;
         }
         perms->gid = (int)v;
+    } else if (pool_perms) {
+        perms->gid = pool_perms->gid;
     }
 
     /* NB, we're ignoring missing labels here - they'll simply inherit */
@@ -722,7 +726,7 @@ virStoragePoolDefParseXML(xmlXPathContextPtr ctxt) {
 
 
     if (virStorageDefParsePerms(ctxt, &ret->target.perms,
-                                "./target/permissions", 0700) < 0)
+                                "./target/permissions", NULL, 0700) < 0)
         goto cleanup;
 
     return ret;
@@ -1069,7 +1073,9 @@ virStorageVolDefParseXML(virStoragePoolDefPtr pool,
     }
 
     if (virStorageDefParsePerms(ctxt, &ret->target.perms,
-                                "./target/permissions", 0600) < 0)
+                                "./target/permissions",
+                                &pool->target.perms,
+                                0600) < 0)
         goto cleanup;
 
     node = virXPathNode("./target/encryption", ctxt);
@@ -1100,7 +1106,9 @@ virStorageVolDefParseXML(virStoragePoolDefPtr pool,
     }
 
     if (virStorageDefParsePerms(ctxt, &ret->backingStore.perms,
-                                "./backingStore/permissions", 0600) < 0)
+                                "./backingStore/permissions",
+                                &pool->target.perms,
+                                0600) < 0)
         goto cleanup;
 
     return ret;
-- 
1.7.6