salvager: Implement AskDAFS via SYNC flags

Instead of probing the DAFS-ness of the fileserver by probing which
FSSYNC opcodes it supports, detect DAFS-ness by looking at the SYNC
response header flags, which explicitly state whether or not the
endpoint is DAFS. This avoids unnecessary "protocol mismatch" log
messages when the endpoint is not DAFS.

Change-Id: Ie05a587951d6d5f69ae03cf3749f8c53e1eb6b62
Reviewed-on: http://gerrit.openafs.org/5800
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>

diff --git a/src/vol/vol-salvage.c b/src/vol/vol-salvage.c
index b8c3f3e3c755ef22acbba3a3dc6ea48f695da8dd..097573fb0fb9d15fe9f5d721589794dc4862a5ee 100644 (file)
--- a/src/vol/vol-salvage.c
+++ b/src/vol/vol-salvage.c
@@ -165,6 +165,7 @@ Vnodes with 0 inode pointers in RW volumes are now deleted.
 #include "daemon_com.h"
 #include "daemon_com_inline.h"
 #include "fssync.h"
+#include "fssync_inline.h"
 #include "volume_inline.h"
 #include "salvsync.h"
 #include "viceinode.h"
@@ -4442,8 +4443,8 @@ static int isDAFS = -1;
 int
 AskDAFS(void)
 {
-    afs_int32 code, i, ret = 0;
     SYNC_response res;
+    afs_int32 code = 1, i;
 
     /* we don't care if we race. the answer shouldn't change */
     if (isDAFS != -1)
@@ -4451,35 +4452,29 @@ AskDAFS(void)
 
     memset(&res, 0, sizeof(res));
 
-    for (i = 0; i < 3; i++) {
-       code = FSYNC_VolOp(1, NULL,
-                          FSYNC_VOL_QUERY_VOP, FSYNC_SALVAGE, &res);
-
-       if (code == SYNC_OK) {
-           ret = 1;
-           break;
-       } else if (code == SYNC_DENIED) {
-           ret = 1;
-           break;
-       } else if (code == SYNC_BAD_COMMAND) {
-           ret = 0;
-           break;
-       } else if (code == SYNC_FAILED) {
-           if (res.hdr.reason == FSYNC_UNKNOWN_VOLID)
-               ret = 1;
-           else
-               ret = 0;
-           break;
-       } else if (i < 2) {
-           /* try it again */
-           Log("AskDAFS:  request to query fileserver failed; trying again...\n");
+    for (i = 0; code && i < 3; i++) {
+       code = FSYNC_VolOp(0, NULL, FSYNC_VOL_LISTVOLUMES, FSYNC_SALVAGE, &res);
+       if (code) {
+           Log("AskDAFS: FSYNC_VOL_LISTVOLUMES failed with code %ld reason "
+               "%ld (%s); trying again...\n", (long)code, (long)res.hdr.reason,
+               FSYNC_reason2string(res.hdr.reason));
            FSYNC_clientFinis();
            FSYNC_clientInit();
        }
     }
 
-    isDAFS = ret;
-    return ret;
+    if (code) {
+       Log("AskDAFS: could not determine DAFS-ness, assuming not DAFS\n");
+       res.hdr.flags = 0;
+    }
+
+    if ((res.hdr.flags & SYNC_FLAG_DAFS_EXTENSIONS)) {
+       isDAFS = 1;
+    } else {
+       isDAFS = 0;
+    }
+
+    return isDAFS;
 }
 
 static void