[libvirt] [PATCHv3 18/36] storage: gluster: Add backend to return unique storage file path

[Peter Krempa]

Use virStorageFileSimplifyPathInternal to canonicalize gluster paths
via a callback and use it for the unique volume path retrieval API.
---
 src/storage/storage_backend_gluster.c | 81 +++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/src/storage/storage_backend_gluster.c b/src/storage/storage_backend_gluster.c
index 3db4e66..1e86383 100644
--- a/src/storage/storage_backend_gluster.c
+++ b/src/storage/storage_backend_gluster.c
@@ -533,6 +533,7 @@ typedef virStorageFileBackendGlusterPriv *virStorageFileBackendGlusterPrivPtr;

 struct _virStorageFileBackendGlusterPriv {
     glfs_t *vol;
+    char *uid;
 };


@@ -547,6 +548,7 @@ virStorageFileBackendGlusterDeinit(virStorageSourcePtr src)

     if (priv->vol)
         glfs_fini(priv->vol);
+    VIR_FREE(priv->uid);

     VIR_FREE(priv);
     src->drv->priv = NULL;
@@ -712,6 +714,81 @@ virStorageFileBackendGlusterAccess(virStorageSourcePtr src,
     return glfs_access(priv->vol, src->path, mode);
 }

+static int
+virStorageFileBackendGlusterReadlinkCallback(const char *path,
+                                             char **link,
+                                             void *data)
+{
+    virStorageFileBackendGlusterPrivPtr priv = data;
+    char *buf = NULL;
+    size_t bufsiz = 0;
+    ssize_t ret;
+    struct stat st;
+
+    *link = NULL;
+
+    if (glfs_stat(priv->vol, path, &st) < 0) {
+        virReportSystemError(errno,
+                             _("failed to stat gluster path '%s'"),
+                             path);
+        return -1;
+    }
+
+    if (!S_ISLNK(st.st_mode))
+        return 1;
+
+ realloc:
+    if (VIR_EXPAND_N(buf, bufsiz, 256) < 0)
+        goto error;
+
+    if ((ret = glfs_readlink(priv->vol, path, buf, bufsiz)) < 0) {
+        virReportSystemError(errno,
+                             _("failed to read link of gluster file '%s'"),
+                             path);
+        goto error;
+    }
+
+    if (ret == bufsiz)
+        goto realloc;
+
+    buf[ret] = '\0';
+
+    *link = buf;
+
+    return 0;
+
+ error:
+    VIR_FREE(buf);
+    return -1;
+}
+
+
+static const char *
+virStorageFileBackendGlusterGetUniqueIdentifier(virStorageSourcePtr src)
+{
+    virStorageFileBackendGlusterPrivPtr priv = src->drv->priv;
+    char *canonPath = NULL;
+
+    if (priv->uid)
+        return priv->uid;
+
+    if (!(canonPath = virStorageFileSimplifyPathInternal(src->path,
+                                                         false,
+                                                         virStorageFileBackendGlusterReadlinkCallback,
+                                                         priv)))
+        return NULL;
+
+    ignore_value(virAsprintf(&priv->uid, "gluster://%s:%s/%s/%s",
+                             src->hosts->name,
+                             src->hosts->port,
+                             src->volume,
+                             canonPath));
+
+    VIR_FREE(canonPath);
+
+    return priv->uid;
+}
+

 virStorageFileBackend virStorageFileBackendGluster = {
     .type = VIR_STORAGE_TYPE_NETWORK,
@@ -724,4 +801,8 @@ virStorageFileBackend virStorageFileBackendGluster = {
     .storageFileStat = virStorageFileBackendGlusterStat,
     .storageFileReadHeader = virStorageFileBackendGlusterReadHeader,
     .storageFileAccess = virStorageFileBackendGlusterAccess,
+
+    .storageFileGetUniqueIdentifier = virStorageFileBackendGlusterGetUniqueIdentifier,
+
+
 };
-- 
1.9.3