[libvirt] [PATCH] storage: Ignore dangling symbol link for filesystem pool

[Osier Yang]

If there is a dangling symbol link in filesystem pool, the pool
will be failed to start or refresh, this patch is to fix it by
ignoring it with a warning log.

* src/storage/storage_backend.c
* src/storage/storage_backend_fs.c (update the comments)
---
 src/storage/storage_backend.c    |    9 ++++++++-
 src/storage/storage_backend_fs.c |    2 +-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
index 10ea33c..9504261 100644
--- a/src/storage/storage_backend.c
+++ b/src/storage/storage_backend.c
@@ -977,7 +977,8 @@ virStorageBackendForType(int type) {
 /*
  * Allows caller to silently ignore files with improper mode
  *
- * Returns -1 on error, -2 if file mode is unexpected.
+ * Returns -1 on error, -2 if file mode is unexpected or the file
+ * is symbol link, and it's dangling.
  */
 int
 virStorageBackendVolOpenCheckMode(const char *path, unsigned int flags)
@@ -986,6 +987,12 @@ virStorageBackendVolOpenCheckMode(const char *path, unsigned int flags)
     struct stat sb;

     if ((fd = open(path, O_RDONLY|O_NONBLOCK|O_NOCTTY)) < 0) {
+        if (areadlink(path) != NULL) {
+            VIR_WARN("cannot open volume '%s': %s", path,
+                     strerror(errno));
+            return -2;
+        }
+
         virReportSystemError(errno,
                              _("cannot open volume '%s'"),
                              path);
diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c
index d916d2d..242508c 100644
--- a/src/storage/storage_backend_fs.c
+++ b/src/storage/storage_backend_fs.c
@@ -651,7 +651,7 @@ virStorageBackendFileSystemRefresh(virConnectPtr conn ATTRIBUTE_UNUSED,
                 goto cleanup;
             else {
                 /* Silently ignore non-regular files,
-                 * eg '.' '..', 'lost+found' */
+                 * eg '.' '..', 'lost+found', dangling symbol link */
                 virStorageVolDefFree(vol);
                 vol = NULL;
                 continue;
--
1.7.3.2