[PATCH rhel5.4] Do not load storage drivers before loading DUD over network (#454478)

[Radek Vykydal <rvykydal redhat com>]

Modified patch by Jeff Bastian applied.

It should change behaviour when dd=<URL> with <URL> being http, ftp, or nfs
location is used. Original patch (its first version I guess) was tested by
customer for these cases, but it should get testing for other (non-network)
dd=<URL> cases -- I modified Jeff's 2nd vesrion patch as there was no busProbe
for this code path. Jeff's patch was reviewed:
https://www.redhat.com/archives/anaconda-devel-list/2008-July/msg00015.html

There is a concern if we can keep the functionality in rawhide (rhel6), where
we are using udev for module loading. I think we could use (in the worst case)
the same kludge by calling udevadm trigger --subsystem-match=net to get only
network drivers loaded before loading (storage) drivers from DUD over network.
I wasn't able to test this in rawhide (trying to replace loader in existing
image with patched-one gave me errors from NetworkManager - it happened also
when I replaced loader with newly-built loader without patch (tried with .52
ver), so I must be missing something or I have to build images with pungi to
test).

There is also suggestion to add new blacklist= parameter in rawhide to prevent
loading of storage drivers before loading DUD in BZ.
 

---
 loader2/loader.c |   21 ++++++++++++++++-----
 1 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/loader2/loader.c b/loader2/loader.c
index 297574d..25c4cec 100644
--- a/loader2/loader.c
+++ b/loader2/loader.c
@@ -1631,13 +1631,24 @@ int main(int argc, char ** argv) {
      *        but is done as a quick hack for the present.
      */
     earlyModuleLoad(modInfo, modLoaded, modDeps, 0);
-    busProbe(modInfo, modLoaded, modDeps, 0);
-
-    /* JKFIXME: we'd really like to do this before the busprobe, but then
-     * we won't have network devices available (and that's the only thing
-     * we support with this right now */
     if (loaderData.ddsrc != NULL) {
+	/* If we load DUD from ftp, http, or nfs location,
+         * do not load storage drivers so that thay can be updated
+	 * from DUD before loading (#454478).
+	 */
+        if (!strncmp(loaderData.ddsrc, "nfs:", 4) || 
+            !strncmp(loaderData.ddsrc, "ftp://";, 6) ||
+            !strncmp(loaderData.ddsrc, "http://";, 7)) {
+            uint64_t save_flags = flags;
+            flags |= LOADER_FLAGS_NOSTORAGE;
+            busProbe(modInfo, modLoaded, modDeps, 0);
+            flags = save_flags;
+        } else {
+            busProbe(modInfo, modLoaded, modDeps, 0);
+        }
         getDDFromSource(&loaderData, loaderData.ddsrc);
+    } else {
+        busProbe(modInfo, modLoaded, modDeps, 0);
     }
 
     /* JKFIXME: loaderData->ksFile is set to the arg from the command line,
-- 
1.5.4.3