[libvirt] [PATCHv4] Ignore missing files on pool refresh

[Ján Tomko]

If we cannot stat/open a file on pool refresh, returning -1 aborts
the refresh and the pool is undefined.

Don't treat missing files as fatal unless VolOpenCheckMode is called
with the VIR_STORAGE_VOL_OPEN_ERROR flag.

https://bugzilla.redhat.com/show_bug.cgi?id=977706
---
v1: https://www.redhat.com/archives/libvir-list/2013-July/msg00635.html
v2: https://www.redhat.com/archives/libvir-list/2013-July/msg00639.html
v3: https://www.redhat.com/archives/libvir-list/2013-July/msg01026.html
(by Guanan Ren, also checked the 'open' call)
v4: do not call open on sockets and fifos and only skip missing files
    if we're doing a pool refresh, otherwise 'vol-info' on a missing
    volume returns 'unknown error'

 src/storage/storage_backend.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
index d14e633..97ab7b8 100644
--- a/src/storage/storage_backend.c
+++ b/src/storage/storage_backend.c
@@ -1212,6 +1212,10 @@ virStorageBackendVolOpenCheckMode(const char *path, struct stat *sb,
     char *base = last_component(path);
 
     if (lstat(path, sb) < 0) {
+        if (errno == ENOENT && !(flags & VIR_STORAGE_VOL_OPEN_ERROR)) {
+            VIR_WARN("ignoring missing file '%s'", path);
+            return -2;
+        }
         virReportSystemError(errno,
                              _("cannot stat file '%s'"),
                              path);
@@ -1238,6 +1242,10 @@ virStorageBackendVolOpenCheckMode(const char *path, struct stat *sb,
             VIR_WARN("ignoring dangling symlink '%s'", path);
             return -2;
         }
+        if (errno == ENOENT && !(flags & VIR_STORAGE_VOL_OPEN_ERROR)) {
+            VIR_WARN("ignoring missing file '%s'", path);
+            return -2;
+        }
 
         virReportSystemError(errno,
                              _("cannot open volume '%s'"),
-- 
1.8.3.2