[libvirt] [PATCH 05/12] storage: On error unlink created file in virFileOpen{As|Forked}

[John Ferlan]

After a successful creation of a file, if some other call results
in returning a failure, let's unlink the file we created to prevent
another round trip or confusion in the caller. In particular, this
function can be called during a storage backend buildVol, so in order
to ensure that caller doesn't need to distinguish between failed create
or some other failure after create, just remove the volume we created.

Signed-off-by: John Ferlan <jferlan at redhat.com>
---
 src/util/virfile.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/util/virfile.c b/src/util/virfile.c
index a81f04c..51198e2 100644
--- a/src/util/virfile.c
+++ b/src/util/virfile.c
@@ -2069,6 +2069,7 @@ virFileOpenForked(const char *path, int openflags, mode_t mode,
     int pair[2] = { -1, -1 };
     gid_t *groups;
     int ngroups;
+    bool created = false;
 
     /* parent is running as root, but caller requested that the
      * file be opened as some other user and/or group). The
@@ -2113,6 +2114,8 @@ virFileOpenForked(const char *path, int openflags, mode_t mode,
                                  path);
             goto childerror;
         }
+        if (openflags & O_CREAT)
+            created = true;
 
         /* File is successfully open. Set permissions if requested. */
         ret = virFileOpenForceOwnerMode(path, fd, mode, uid, gid, flags);
@@ -2141,8 +2144,11 @@ virFileOpenForked(const char *path, int openflags, mode_t mode,
         /* XXX This makes assumptions about errno being < 255, which is
          * not true on Hurd.  */
         VIR_FORCE_CLOSE(pair[1]);
-        if (ret < 0)
+        if (ret < 0) {
             VIR_FORCE_CLOSE(fd);
+            if (created)
+                unlink(path);
+        }
         ret = -ret;
         if ((ret & 0xff) != ret) {
             VIR_WARN("unable to pass desired return value %d", ret);
@@ -2225,6 +2231,7 @@ virFileOpenAs(const char *path, int openflags, mode_t mode,
               uid_t uid, gid_t gid, unsigned int flags)
 {
     int ret = 0, fd = -1;
+    bool created = false;
 
     /* allow using -1 to mean "current value" */
     if (uid == (uid_t) -1)
@@ -2246,6 +2253,8 @@ virFileOpenAs(const char *path, int openflags, mode_t mode,
             if (!(flags & VIR_FILE_OPEN_FORK))
                 goto error;
         } else {
+            if (openflags & O_CREAT)
+                created = true;
             ret = virFileOpenForceOwnerMode(path, fd, mode, uid, gid, flags);
             if (ret < 0)
                 goto error;
@@ -2288,6 +2297,8 @@ virFileOpenAs(const char *path, int openflags, mode_t mode,
     if (fd >= 0) {
         /* some other failure after the open succeeded */
         VIR_FORCE_CLOSE(fd);
+        if (created)
+            unlink(path);
     }
     /* whoever failed the open last has already set ret = -errno */
     return ret;
-- 
2.1.0