vldb_check: rebuild free list with -fix
[openafs.git] / src / vlserver / vldb_check.c
index 0f3f833..0a9d2e0 100644 (file)
@@ -59,7 +59,9 @@
 #define vldbread(x,y,z) vldbio(x,y,z,0)
 #define vldbwrite(x,y,z) vldbio(x,y,z,1)
 
-#define ADDR(x) (x/sizeof(struct nvlentry))
+#define HDRSIZE 64
+#define ADDR(x) ((x)/sizeof(struct nvlentry))
+#define OFFSET(addr) ((addr) + HDRSIZE)
 
 int fd;
 int listentries, listservers, listheader, listuheader, verbose, quiet;
@@ -77,6 +79,14 @@ struct er {
 } *record;
 afs_int32 maxentries;
 int serveraddrs[MAXSERVERID + 2];
+u_char serverxref[MAXSERVERID + 2];  /**< to resolve cross-linked mh entries */
+int serverref[MAXSERVERID + 2];      /**< which addrs are referenced by vl entries */
+
+struct mhinfo {
+    afs_uint32 addr;                   /**< vldb file record */
+    char orphan[VL_MHSRV_PERBLK];      /**< unreferenced mh enties */
+} mhinfo[VL_MAX_ADDREXTBLKS];
+
 
 /*  Used to control what goes to stdout based on quiet flag */
 void
@@ -103,7 +113,6 @@ log_error(int eval, const char *fmt, ...)
 }
 
 
-#define HDRSIZE 64
 int
 readUbikHeader(void)
 {
@@ -153,7 +162,7 @@ vldbio(int position, void *buffer, int size, int rdwr)
     int offset, r, p;
 
     /* seek to the correct spot. skip ubik stuff */
-    p = position + HDRSIZE;
+    p = OFFSET(position);
     offset = lseek(fd, p, 0);
     if (offset != p) {
        log_error(VLDB_CHECK_FATAL,"error: lseek to %d failed: %d %d\n", p, offset, errno);
@@ -218,6 +227,8 @@ InvalidVolname(char *volname)
     slen = strlen(volname);
     if (slen >= VL_MAXNAMELEN)
        return 1;
+    if (slen == 0)
+       return 1;
     return (slen != strspn(volname, map));
 }
 
@@ -335,18 +346,27 @@ writeheader(struct vlheader *headerp)
 }
 
 void
-readMH(afs_int32 addr, struct extentaddr *mhblockP)
+readMH(afs_uint32 addr, int block, struct extentaddr *mhblockP)
 {
     int i, j;
     struct extentaddr *e;
 
     vldbread(addr, (char *)mhblockP, VL_ADDREXTBLK_SIZE);
 
-    mhblockP->ex_count = ntohl(mhblockP->ex_count);
+    /* Every mh block has the VLCONTBLOCK flag set in the header to
+     * indicate the entry is an 8192 byte extended block. The
+     * VLCONTBLOCK flag is always clear in regular vl entries. The
+     * vlserver depends on the VLCONTBLOCK flag to correctly traverse
+     * the vldb. The flags field is in network byte order. */
     mhblockP->ex_hdrflags = ntohl(mhblockP->ex_hdrflags);
-    for (i = 0; i < VL_MAX_ADDREXTBLKS; i++)
-       mhblockP->ex_contaddrs[i] = ntohl(mhblockP->ex_contaddrs[i]);
 
+    if (block == 0) {
+        /* These header fields are only used in the first mh block. */
+        mhblockP->ex_count = ntohl(mhblockP->ex_count);
+        for (i = 0; i < VL_MAX_ADDREXTBLKS; i++) {
+           mhblockP->ex_contaddrs[i] = ntohl(mhblockP->ex_contaddrs[i]);
+        }
+    }
     for (i = 1; i < VL_MHSRV_PERBLK; i++) {
        e = &(mhblockP[i]);
 
@@ -390,7 +410,7 @@ readentry(afs_int32 addr, struct nvlentry *vlentryp, afs_int32 *type)
     }
 
     if (listentries) {
-       quiet_println("address %u: ", addr);
+       quiet_println("address %u (offset 0x%0x): ", addr, OFFSET(addr));
        if (vlentryp->flags == VLCONTBLOCK) {
            quiet_println("mh extension block\n");
        } else if (vlentryp->flags == VLFREE) {
@@ -451,6 +471,33 @@ readentry(afs_int32 addr, struct nvlentry *vlentryp, afs_int32 *type)
 }
 
 void
+writeMH(afs_int32 addr, int block, struct extentaddr *mhblockP)
+{
+    int i, j;
+    struct extentaddr *e;
+
+    if (verbose) {
+       quiet_println("Writing back MH block % at addr %u\n", block,  addr);
+    }
+    if (block == 0) {
+       mhblockP->ex_count = htonl(mhblockP->ex_count);
+       mhblockP->ex_hdrflags = htonl(mhblockP->ex_hdrflags);
+       for (i = 0; i < VL_MAX_ADDREXTBLKS; i++) {
+           mhblockP->ex_contaddrs[i] = htonl(mhblockP->ex_contaddrs[i]);
+       }
+    }
+    for (i = 1; i < VL_MHSRV_PERBLK; i++) {
+       e = &(mhblockP[i]);
+       /* hostuuid was not converted */
+       e->ex_uniquifier = htonl(e->ex_uniquifier);
+       for (j = 0; j < VL_MAXIPADDRS_PERMH; j++) {
+           e->ex_addrs[j] = htonl(e->ex_addrs[j]);
+       }
+    }
+    vldbwrite(addr, (char *)mhblockP, VL_ADDREXTBLK_SIZE);
+}
+
+void
 writeentry(afs_int32 addr, struct nvlentry *vlentryp)
 {
     int i;
@@ -497,9 +544,6 @@ ReadAllEntries(struct vlheader *header)
        /* Remember the highest volume id */
        readentry(addr, &vlentry, &type);
        if (type == VL) {
-           if (!(vlentry.flags & VLF_RWEXISTS))
-               log_error(VLDB_CHECK_WARNING,"VLDB_CHECK_WARNING: VLDB entry '%s' has no RW volume\n",
-                      vlentry.name);
 
            for (i = 0; i < MAXTYPES; i++)
                if (maxvolid < vlentry.volumeId[i])
@@ -525,8 +569,8 @@ ReadAllEntries(struct vlheader *header)
                }
                if (e) {
                   log_error
-                       (VLDB_CHECK_ERROR,"VLDB entry '%s' contains an unknown RW/RO index serverFlag\n",
-                        vlentry.name);
+                       (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): VLDB entry '%s' contains an unknown RW/RO index serverFlag\n",
+                       addr, OFFSET(addr), vlentry.name);
                    e = 0;
                }
                quiet_println
@@ -556,7 +600,7 @@ ReadAllEntries(struct vlheader *header)
            entrysize = VL_ADDREXTBLK_SIZE;
            mhcount++;
        } else {
-           log_error(VLDB_CHECK_ERROR, "Unknown entry at %u. Aborting\n", addr);
+           log_error(VLDB_CHECK_ERROR, "address %u (offset 0x%0x): Unknown entry. Aborting\n", addr, OFFSET(addr));
            break;
        }
     }
@@ -593,7 +637,7 @@ FollowNameHash(struct vlheader *header)
        chainlength = 0;
 
        if (!validVolumeAddr(header->VolnameHash[i])) {
-           log_error(VLDB_CHECK_ERROR,"Name Hash %d: Bad entry %u is out of range\n",
+           log_error(VLDB_CHECK_ERROR,"Name Hash index %d is out of range: %u\n",
                      i, header->VolnameHash[i]);
            continue;
        }
@@ -601,8 +645,8 @@ FollowNameHash(struct vlheader *header)
        for (addr = header->VolnameHash[i]; addr; addr = vlentry.nextNameHash) {
            readentry(addr, &vlentry, &type);
            if (type != VL) {
-               log_error(VLDB_CHECK_ERROR,"Name Hash %d: Bad entry at %u: Not a valid vlentry\n",
-                      i, addr);
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Name Hash %d: Not a vlentry\n",
+                      addr, OFFSET(addr), i);
                continue;
            }
 
@@ -619,15 +663,15 @@ FollowNameHash(struct vlheader *header)
            }
            if (record[rindex].type & NH) {
                log_error
-                   (VLDB_CHECK_ERROR,"Name Hash %d: Bad entry '%s': Already in the name hash\n",
-                    i, vlentry.name);
+                   (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Name Hash %d: volume name '%s' is already in the name hash\n",
+                    addr, OFFSET(addr), i, vlentry.name);
                record[rindex].type |= MULTN;
                break;
            }
 
            if (!validVolumeAddr(vlentry.nextNameHash)) {
-               log_error(VLDB_CHECK_ERROR,"Name Hash forward link of '%s' is out of range\n",
-                         vlentry.name);
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Name Hash forward link of '%s' is out of range\n",
+                         addr, OFFSET(addr), vlentry.name);
                record[rindex].type |= MULTN;
                break;
            }
@@ -641,8 +685,8 @@ FollowNameHash(struct vlheader *header)
            /* Hash the name and check if in correct hash table */
            if (NameHash(vlentry.name) != i) {
                log_error
-                   (VLDB_CHECK_ERROR,"Name Hash %d: Bad entry '%s': Incorrect name hash chain (should be in %d)\n",
-                    i, vlentry.name, NameHash(vlentry.name));
+                   (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Name Hash %d: volume name '%s': Incorrect name hash chain (should be in %d)\n",
+                    addr, OFFSET(addr), i, vlentry.name, NameHash(vlentry.name));
                record[rindex].type |= MULTN;
            }
        }
@@ -685,7 +729,7 @@ FollowIdHash(struct vlheader *header)
        for (j = 0; j < HASHSIZE; j++) {
            chainlength = 0;
            if (!validVolumeAddr(header->VolidHash[i][j])) {
-               log_error(VLDB_CHECK_ERROR,"%s Hash %d: Bad entry %u is out of range\n",
+               log_error(VLDB_CHECK_ERROR,"%s Hash index %d is out of range: %u\n",
                          vtype(i), j, header->VolidHash[i][j]);
                continue;
            }
@@ -695,8 +739,8 @@ FollowIdHash(struct vlheader *header)
                readentry(addr, &vlentry, &type);
                if (type != VL) {
                    log_error
-                       (VLDB_CHECK_ERROR,"%s Id Hash %d: Bad entry at %u: Not a valid vlentry\n",
-                        vtype(i), j, addr);
+                       (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): %s Id Hash %d: Not a vlentry\n",
+                        addr, OFFSET(addr), vtype(i), j);
                    continue;
                }
 
@@ -708,15 +752,15 @@ FollowIdHash(struct vlheader *header)
                }
                if (record[rindex].type & hash) {
                    log_error
-                       (VLDB_CHECK_ERROR,"%s Id Hash %d: Bad entry '%s': Already in the hash table\n",
-                        vtype(i), j, vlentry.name);
+                       (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): %s Id Hash %d: volume name '%s': Already in the hash table\n",
+                        addr, OFFSET(addr), vtype(i), j, vlentry.name);
                    record[rindex].type |= badref;
                    break;
                }
 
                if (!validVolumeAddr(vlentry.nextIdHash[i])) {
-                   log_error(VLDB_CHECK_ERROR,"%s Id Hash forward link of '%s' is out of range\n",
-                             vtype(i), vlentry.name);
+                   log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): %s Id Hash forward link of '%s' is out of range\n",
+                             addr, OFFSET(addr), vtype(i), vlentry.name);
                    record[rindex].type |= badref;
                    break;
                }
@@ -730,8 +774,8 @@ FollowIdHash(struct vlheader *header)
                /* Hash the id and check if in correct hash table */
                if (IdHash(vlentry.volumeId[i]) != j) {
                   log_error
-                       (VLDB_CHECK_ERROR,"%s Id Hash %d: Bad entry '%s': Incorrect Id hash chain (should be in %d)\n",
-                        vtype(i), j, vlentry.name,
+                       (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): %s Id Hash %d: volume name '%s': Incorrect Id hash chain (should be in %d)\n",
+                        addr, OFFSET(addr), vtype(i), j, vlentry.name,
                         IdHash(vlentry.volumeId[i]));
                    record[rindex].type |= badhash;
                }
@@ -770,20 +814,20 @@ FollowFreeChain(struct vlheader *header)
        readentry(addr, &vlentry, &type);
        if (type != FR) {
           log_error
-               (VLDB_CHECK_ERROR,"Free Chain %d: Bad entry at %u: Not a valid free vlentry (0x%x)\n",
-                count, addr, type);
+               (VLDB_CHECK_ERROR,"address %u (offset 0%0x): Free Chain %d: Not a free vlentry (0x%x)\n",
+                addr, OFFSET(addr), count, type);
            continue;
        }
 
        rindex = addr / sizeof(vlentry);
        if (record[rindex].addr != addr && record[rindex].addr) {
           log_error
-               (VLDB_CHECK_ERROR,"INTERNAL VLDB_CHECK_ERROR: addresses %u and %ld use same record slot %d\n",
-                record[rindex].addr, addr, rindex);
+               (VLDB_CHECK_ERROR,"INTERNAL VLDB_CHECK_ERROR: addresses %u (0x%0x) and %ld (0x%0x) use same record slot %d\n",
+                record[rindex].addr, OFFSET(record[rindex].addr), addr, OFFSET(addr), rindex);
        }
        if (record[rindex].type & FRC) {
-           log_error(VLDB_CHECK_ERROR,"Free Chain: Bad entry at %u: Already in the free chain\n",
-                  addr);
+           log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Free Chain: Already in the free chain\n",
+                  addr, OFFSET(addr));
            break;
        }
        record[rindex].type |= FRC;
@@ -817,7 +861,6 @@ CheckIpAddrs(struct vlheader *header)
     int mhblocks = 0;
     afs_int32 i, j, m, rindex;
     afs_int32 mhentries, regentries;
-    afs_uint32 caddrs[VL_MAX_ADDREXTBLKS];
     char mhblock[VL_ADDREXTBLK_SIZE];
     struct extentaddr *MHblock = (struct extentaddr *)mhblock;
     struct extentaddr *e;
@@ -833,45 +876,45 @@ CheckIpAddrs(struct vlheader *header)
        /* Read the first MH block and from it, gather the
         * addresses of all the mh blocks.
         */
-       readMH(header->SIT, MHblock);
+       readMH(header->SIT, 0, MHblock);
        if (MHblock->ex_hdrflags != VLCONTBLOCK) {
           log_error
-               (VLDB_CHECK_ERROR,"Multihomed Block 0: Bad entry at %u: Not a valid multihomed block\n",
-                header->SIT);
+               (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Multihomed Block 0: Not a multihomed block\n",
+                header->SIT, OFFSET(header->SIT));
        }
 
        for (i = 0; i < VL_MAX_ADDREXTBLKS; i++) {
-           caddrs[i] = MHblock->ex_contaddrs[i];
+           mhinfo[i].addr = MHblock->ex_contaddrs[i];
        }
 
-       if (header->SIT != caddrs[0]) {
+       if (header->SIT != mhinfo[0].addr) {
           log_error
-               (VLDB_CHECK_ERROR,"MH block does not point to self %u in header, %u in block\n",
-                header->SIT, caddrs[0]);
+               (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): MH block does not point to self in header, %u in block\n",
+                header->SIT, OFFSET(header->SIT), mhinfo[0].addr);
        }
 
        /* Now read each MH block and record it in the record array */
        for (i = 0; i < VL_MAX_ADDREXTBLKS; i++) {
-           if (!caddrs[i])
+           if (!mhinfo[i].addr)
                continue;
 
-           readMH(caddrs[i], MHblock);
+           readMH(mhinfo[i].addr, i, MHblock);
            if (MHblock->ex_hdrflags != VLCONTBLOCK) {
                log_error
-                   (VLDB_CHECK_ERROR,"Multihomed Block 0: Bad entry at %u: Not a valid multihomed block\n",
-                    header->SIT);
+                   (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Multihomed Block %d: Not a multihomed block\n",
+                    mhinfo[i].addr, OFFSET(mhinfo[i].addr), i);
            }
 
-           rindex = caddrs[i] / sizeof(vlentry);
-           if (record[rindex].addr != caddrs[i] && record[rindex].addr) {
+           rindex = mhinfo[i].addr / sizeof(vlentry);
+           if (record[rindex].addr != mhinfo[i].addr && record[rindex].addr) {
                log_error
-                   (VLDB_CHECK_ERROR,"INTERNAL VLDB_CHECK_ERROR: addresses %u and %u use same record slot %d\n",
-                    record[rindex].addr, caddrs[i], rindex);
+                   (VLDB_CHECK_ERROR,"INTERNAL VLDB_CHECK_ERROR: addresses %u (0x%0x) and %u (0x%0x) use same record slot %d\n",
+                    record[rindex].addr, OFFSET(record[rindex].addr), mhinfo[i].addr, OFFSET(mhinfo[i].addr), rindex);
            }
            if (record[rindex].type & FRC) {
                log_error
-                   (VLDB_CHECK_ERROR,"MH Blocks Chain %d: Bad entry at %ld: Already a MH block\n",
-                    i, record[rindex].addr);
+                   (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): MH Blocks Chain %d: Already a MH block\n",
+                    record[rindex].addr, OFFSET(record[rindex].addr), i);
                break;
            }
            record[rindex].type |= MHC;
@@ -884,23 +927,24 @@ CheckIpAddrs(struct vlheader *header)
             */
            mhentries = 0;
            for (j = 1; j < VL_MHSRV_PERBLK; j++) {
+               int first_ipindex = -1;
                e = (struct extentaddr *)&(MHblock[j]);
 
-               /* Search the IpMappedAddr array for the reference to this entry */
+               /* Search the IpMappedAddr array for all the references to this entry. */
+               /* Use the first reference for checking the ip addresses of this entry. */
                for (ipindex = 0; ipindex <= MAXSERVERID; ipindex++) {
-                   if (((header->IpMappedAddr[ipindex] & 0xff000000) ==
-                        0xff000000)
-                       &&
-                       (((header->
-                          IpMappedAddr[ipindex] & 0x00ff0000) >> 16) == i)
-                       && ((header->IpMappedAddr[ipindex] & 0x0000ffff) ==
-                           j)) {
-                       break;
+                   if (((header->IpMappedAddr[ipindex] & 0xff000000) == 0xff000000)
+                       && (((header-> IpMappedAddr[ipindex] & 0x00ff0000) >> 16) == i)
+                       && ((header->IpMappedAddr[ipindex] & 0x0000ffff) == j)) {
+                       if (first_ipindex == -1) {
+                           first_ipindex = ipindex;
+                       } else {
+                           serverxref[ipindex] = first_ipindex;
+                       }
                    }
                }
-               if (ipindex > MAXSERVERID)
-                   ipindex = -1;
-               else
+               ipindex = first_ipindex;
+               if (ipindex != -1)
                    serveraddrs[ipindex] = -1;
 
                if (memcmp(&e->ex_hostuuid, &nulluuid, sizeof(afsUUID)) == 0) {
@@ -924,6 +968,7 @@ CheckIpAddrs(struct vlheader *header)
                if (ipaddrs) {
                    mhentries++;
                    if (ipindex == -1) {
+                       mhinfo[i].orphan[j] = 1;
                        log_error
                            (VLDB_CHECK_ERROR,"MH block %d, index %d: Not referenced by server addrs\n",
                             i, j);
@@ -970,6 +1015,9 @@ CheckIpAddrs(struct vlheader *header)
                   log_error
                        (VLDB_CHECK_ERROR,"IP Addr for entry %d: Multihome block is bad (%d)\n",
                         i, ((header->IpMappedAddr[i] & 0x00ff0000) >> 16));
+               if (mhinfo[(header->IpMappedAddr[i] & 0x00ff0000) >> 16].addr == 0)
+                   log_error(VLDB_CHECK_ERROR,"IP Addr for entry %d: No such multihome block (%d)\n",
+                        i, ((header->IpMappedAddr[i] & 0x00ff0000) >> 16));
                if (((header->IpMappedAddr[i] & 0x0000ffff) > VL_MHSRV_PERBLK)
                    || ((header->IpMappedAddr[i] & 0x0000ffff) < 1))
                    log_error
@@ -981,6 +1029,17 @@ CheckIpAddrs(struct vlheader *header)
                         i);
                    serveraddrs[i] = 0;
                }
+               if (serverxref[i] != BADSERVERID) {
+                   log_error
+                       (VLDB_CHECK_WARNING,
+                       "warning: MH block %d, index %d is cross-linked by server numbers %d and %d.\n",
+                       (header->IpMappedAddr[i] & 0x00ff0000) >> 16,
+                       (header->IpMappedAddr[i] & 0x0000ffff),
+                       i, serverxref[i]);
+                   /* set addresses found/not found for this server number,
+                    * using the first index to the mh we found above. */
+                   serveraddrs[i] = serveraddrs[serverxref[i]];
+               }
                if (listservers) {
                    quiet_println("   Server ip addr %d = MH block %d, index %d\n",
                           i, (header->IpMappedAddr[i] & 0x00ff0000) >> 16,
@@ -1074,6 +1133,47 @@ reportHashChanges(struct vlheader *header, afs_uint32 oldnamehash[HASHSIZE], afs
     }
 }
 
+/**
+ * Remove unreferenced, duplicate multi-home address indices.
+ *
+ * Removes entries from IpMappedAddr which where found to be
+ * duplicates. Only entries which are not referenced by vl entries
+ * are removed on this pass.
+ *
+ * @param[inout] header the vldb header to be updated.
+ */
+void
+removeCrossLinkedAddresses(struct vlheader *header)
+{
+    int i;
+
+    for (i = 0; i <= MAXSERVERID; i++) {
+       if (serverref[i] == 0
+           && (header->IpMappedAddr[i] & 0xff000000) == 0xff000000
+           && serverxref[i] != BADSERVERID) {
+           if (serverxref[i] == i) {
+               log_error(VLDB_CHECK_ERROR,
+                         "INTERNAL VLDB_CHECK_ERROR: serverxref points to self; index %d\n",
+                         i);
+           } else if (header->IpMappedAddr[serverxref[i]] == 0) {
+               log_error(VLDB_CHECK_ERROR,
+                         "INTERNAL VLDB_CHECK_ERROR: serverxref points to empty addr; index %d, value %d\n",
+                         i, serverxref[i]);
+           } else if (header->IpMappedAddr[serverxref[i]] != header->IpMappedAddr[i]) {
+               log_error(VLDB_CHECK_ERROR,
+                         "INTERNAL VLDB_CHECK_ERROR: invalid serverxref; index %d, value %d\n",
+                         i, serverxref[i]);
+           } else {
+               quiet_println
+                   ("FIX: Removing unreferenced address index %d, which cross-links MH block %d, index %d\n",
+                    i, (header->IpMappedAddr[i] & 0x00ff0000) >> 16,
+                    (header->IpMappedAddr[i] & 0x0000ffff));
+               header->IpMappedAddr[i] = 0;
+           }
+       }
+    }
+}
+
 int
 WorkerBee(struct cmd_syndesc *as, void *arock)
 {
@@ -1081,7 +1181,7 @@ WorkerBee(struct cmd_syndesc *as, void *arock)
     afs_int32 type;
     struct vlheader header;
     struct nvlentry vlentry, vlentry2;
-    int i, j;
+    int i, j, k;
     afs_uint32 oldnamehash[HASHSIZE];
     afs_uint32 oldidhash[MAXTYPES][HASHSIZE];
 
@@ -1121,6 +1221,11 @@ WorkerBee(struct cmd_syndesc *as, void *arock)
     maxentries = (header.vital_header.eofPtr / sizeof(vlentry)) + 1;
     record = calloc(maxentries, sizeof(struct er));
     memset(serveraddrs, 0, sizeof(serveraddrs));
+    memset(mhinfo, 0, sizeof(mhinfo));
+    memset(serverref, 0, sizeof(serverref));
+    for (i = 0; i <= MAXSERVERID; i++) {
+       serverxref[i] = BADSERVERID;
+    }
 
     /* Will fill in the record array of entries it found */
     ReadAllEntries(&header);
@@ -1162,9 +1267,17 @@ WorkerBee(struct cmd_syndesc *as, void *arock)
 
            readentry(record[i].addr, &vlentry, &type);
 
+           if (!(vlentry.flags & VLF_RWEXISTS))
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Volume '%s' (%u) has no RW volume\n",
+                      record[i].addr, OFFSET(record[i].addr), vlentry.name, vlentry.volumeId[0]);
+
            if (InvalidVolname(vlentry.name))
-               log_error(VLDB_CHECK_ERROR,"Volume '%s' at addr %ld has an invalid name\n",
-                      vlentry.name, record[i].addr);
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Volume '%s' (%u) has an invalid name\n",
+                      record[i].addr, OFFSET(record[i].addr), vlentry.name, vlentry.volumeId[0]);
+
+           if (vlentry.volumeId[0] == 0)
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Volume '%s' (%u) has an invalid volume id\n",
+                      record[i].addr, OFFSET(record[i].addr), vlentry.name, vlentry.volumeId[0]);
 
            if (!(record[i].type & NH)) {
                hash = NameHash(vlentry.name);
@@ -1255,59 +1368,70 @@ WorkerBee(struct cmd_syndesc *as, void *arock)
            }
 
            if (foundbroken) {
-               log_error(VLDB_CHECK_ERROR, "%d: Volume '%s' %s forward link in %s hash chain is broken (hash %d != %d)\n", i,
-                         vlentry.name, volidbuf, which, hash, nexthash);
+               log_error(VLDB_CHECK_ERROR,
+                       "address %u (offset 0x%0x): Volume '%s' %s forward link in %s hash chain is broken (hash %d != %d)\n",
+                       record[i].addr, OFFSET(record[i].addr),
+                       vlentry.name, volidbuf, which, hash, nexthash);
            } else if (foundbad) {
-               log_error(VLDB_CHECK_ERROR, "%d: Volume '%s' %snot found in %s hash %d\n", i,
-                      vlentry.name, volidbuf, which, hash);
+               log_error(VLDB_CHECK_ERROR,
+                       "address %u (offset 0x%0x): Volume '%s' %snot found in %s hash %d\n",
+                       record[i].addr, OFFSET(record[i].addr),
+                       vlentry.name, volidbuf, which, hash);
            }
 
            for (j = 0; j < NMAXNSERVERS; j++) {
-               if ((vlentry.serverNumber[j] != 255)
-                   && (serveraddrs[vlentry.serverNumber[j]] == 0)) {
-                  log_error
-                       (VLDB_CHECK_ERROR,"Volume '%s', index %d points to empty server entry %d\n",
-                        vlentry.name, j, vlentry.serverNumber[j]);
+               if (vlentry.serverNumber[j] != BADSERVERID) {
+                   serverref[vlentry.serverNumber[j]] = 1;
+                   if (serveraddrs[vlentry.serverNumber[j]] == 0) {
+                       log_error
+                           (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Volume '%s', index %d points to empty server entry %d\n",
+                            record[i].addr, OFFSET(record[i].addr), vlentry.name, j, vlentry.serverNumber[j]);
+                   } else if (serverxref[vlentry.serverNumber[j]] != BADSERVERID) {
+                           log_error
+                           (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Volume '%s', index %d points to server entry %d, which is cross-linked by %d\n",
+                            record[i].addr, OFFSET(record[i].addr), vlentry.name, j, vlentry.serverNumber[j], serverxref[vlentry.serverNumber[j]]);
+                   }
                }
            }
 
            if (record[i].type & 0xffff0f00)
                log_error
-                   (VLDB_CHECK_ERROR,"Volume '%s' id %u also found on other chains (0x%x)\n",
-                    vlentry.name, vlentry.volumeId[0], record[i].type);
+                   (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Volume '%s' id %u also found on other chains (0x%x)\n",
+                    record[i].addr, OFFSET(record[i].addr), vlentry.name, vlentry.volumeId[0], record[i].type);
 
            /* A free entry */
        } else if (record[i].type & FR) {
            if (!(record[i].type & FRC))
-               log_error(VLDB_CHECK_ERROR,"Free vlentry at %ld not on free chain\n",
-                      record[i].addr);
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Free vlentry not on free chain\n",
+                      record[i].addr, OFFSET(record[i].addr));
 
            if (record[i].type & 0xfffffdf0)
                log_error
-                   (VLDB_CHECK_ERROR,"Free vlentry at %ld also found on other chains (0x%x)\n",
-                    record[i].addr, record[i].type);
+                   (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Free vlentry also found on other chains (0x%x)\n",
+                    record[i].addr, OFFSET(record[i].addr), record[i].type);
 
            /* A multihomed entry */
        } else if (record[i].type & MH) {
            if (!(record[i].type & MHC))
-               log_error(VLDB_CHECK_ERROR,"Multihomed block at %ld is orphaned\n",
-                      record[i].addr);
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Multihomed block is orphaned\n",
+                      record[i].addr, OFFSET(record[i].addr));
 
            if (record[i].type & 0xfffffef0)
                log_error
-                   (VLDB_CHECK_ERROR,"Multihomed block at %ld also found on other chains (0x%x)\n",
-                    record[i].addr, record[i].type);
+                   (VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Multihomed block also found on other chains (0x%x)\n",
+                    record[i].addr, OFFSET(record[i].addr), record[i].type);
 
        } else {
-           log_error(VLDB_CHECK_ERROR,"Unknown entry type at %u (0x%x)\n", record[i].addr,
-                  record[i].type);
+           log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Unknown entry type 0x%x\n",
+                  record[i].addr, OFFSET(record[i].addr), record[i].type);
        }
     }
 
     if (fix) {
        /*
-        * If we are fixing we will rebuild all the hash lists from the ground up
+        * If we are fixing we will rebuild the free and hash lists from the ground up.
         */
+       header.vital_header.freePtr = 0;
        memcpy(oldnamehash, header.VolnameHash, sizeof(oldnamehash));
        memset(header.VolnameHash, 0, sizeof(header.VolnameHash));
 
@@ -1322,20 +1446,20 @@ WorkerBee(struct cmd_syndesc *as, void *arock)
        if (record[i].type & VL) {
            readentry(record[i].addr, &vlentry, &type);
            if (!(record[i].type & REFN)) {
-               log_error(VLDB_CHECK_ERROR,"%d: Record %ld (type 0x%x) not in a name chain\n", i,
-                      record[i].addr, record[i].type);
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Record is not in a name chain (type 0x%0x)\n",
+                      record[i].addr, OFFSET(record[i].addr), record[i].type);
            }
            if (vlentry.volumeId[0] && !(record[i].type & REFRW)) {
-               log_error(VLDB_CHECK_ERROR,"%d: Record %ld (type 0x%x) not in a RW chain\n", i,
-                      record[i].addr, record[i].type);
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Record not in a RW chain (type 0x%0x)\n",
+                      record[i].addr, OFFSET(record[i].addr), record[i].type);
            }
            if (vlentry.volumeId[1] && !(record[i].type & REFRO)) {
-               log_error(VLDB_CHECK_ERROR,"%d: Record %ld (type 0x%x) not in a RO chain\n", i,
-                      record[i].addr, record[i].type);
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Record not in a RO chain (type 0x%0x)\n",
+                      record[i].addr, OFFSET(record[i].addr), record[i].type);
            }
            if (vlentry.volumeId[2] && !(record[i].type & REFBK)) {
-               log_error(VLDB_CHECK_ERROR,"%d: Record %ld (type 0x%x) not in a BK chain\n", i,
-                      record[i].addr, record[i].type);
+               log_error(VLDB_CHECK_ERROR,"address %u (offset 0x%0x): Record not in a BK chain (type 0x%0x)\n",
+                      record[i].addr, OFFSET(record[i].addr), record[i].type);
            }
            if (fix) {
                afs_uint32 oldhash, newhash;
@@ -1343,6 +1467,21 @@ WorkerBee(struct cmd_syndesc *as, void *arock)
                char newNameBuffer[10 + VL_MAXNAMELEN];
                char *oldname, *newname;
 
+               /* Fix broken names and numbers so entries can be inspected and deleted. */
+               if (InvalidVolname(vlentry.name)) {
+                   char bogus[VL_MAXNAMELEN];
+                   memset(bogus, 0, sizeof(bogus));
+                   snprintf(bogus, sizeof(bogus)-1, ".bogus.%ld", record[i].addr);
+                   strcpy(vlentry.name, bogus);
+                   quiet_println("FIX: Record %ld invalid volume name set to '%s'\n", record[i].addr, bogus);
+               }
+               if (vlentry.volumeId[0] == 0) {
+                   afs_uint32 next_volid = header.vital_header.MaxVolumeId++;
+                   vlentry.volumeId[0] = next_volid;
+                   quiet_println("FIX: Record %ld invalid volume id set to %ld. New max volid is %ld\n",
+                       record[i].addr, next_volid, header.vital_header.MaxVolumeId);
+               }
+
                /*
                 * Put the current hash table contexts into our 'next'
                 * and our address into the hash table.
@@ -1388,15 +1527,82 @@ WorkerBee(struct cmd_syndesc *as, void *arock)
                        }
                    }
 
+                   /* Consolidate server numbers which point to the same mh entry.
+                    * The serverref flags are not reset here, since we want to make
+                    * sure the data is actually written before the server number is
+                    * considered unreferenced. */
+                   for (k = 0; k < NMAXNSERVERS; k++) {
+                       if (vlentry.serverNumber[k] != BADSERVERID
+                           && serverxref[vlentry.serverNumber[k]] != BADSERVERID) {
+                           u_char oldsn = vlentry.serverNumber[k];
+                           u_char newsn = serverxref[oldsn];
+                           if (newsn == oldsn) {
+                               log_error(VLDB_CHECK_ERROR,
+                                         "INTERNAL VLDB_CHECK_ERROR: serverxref points to self; index %d\n",
+                                         oldsn);
+                           } else if (header.IpMappedAddr[oldsn] == 0) {
+                               log_error(VLDB_CHECK_ERROR,
+                                         "INTERNAL VLDB_CHECK_ERROR: serverxref; points to empty address; index %d, value %d\n",
+                                         oldsn, newsn);
+                           } else if (header.IpMappedAddr[newsn] != header.IpMappedAddr[oldsn]) {
+                               log_error(VLDB_CHECK_ERROR,
+                                         "INTERNAL VLDB_CHECK_ERROR: invalid serverxref; index %d\n",
+                                         oldsn);
+                           } else {
+                               quiet_println
+                                   ("FIX: Volume '%s', index %d, server number was %d, is now %d\n",
+                                    vlentry.name, k, oldsn, newsn);
+                               vlentry.serverNumber[k] = newsn;
+                           }
+                       }
+                   }
+
                    vlentry.nextIdHash[j] = header.VolidHash[j][hash];
                    header.VolidHash[j][hash] = record[i].addr;
                }
                writeentry(record[i].addr, &vlentry);
            }
        }
+       else if (record[i].type & MH) {
+           int block, index;
+           char mhblock[VL_ADDREXTBLK_SIZE];
+           struct extentaddr *MHblock = (struct extentaddr *)mhblock;
+
+           if (fix) {
+               for (block = 0; block < VL_MAX_ADDREXTBLKS; block++) {
+                   if (mhinfo[block].addr == record[i].addr)
+                       break;
+               }
+               if (block == VL_MAX_ADDREXTBLKS) {
+                   continue;  /* skip orphaned extent block */
+               }
+               readMH(record[i].addr, block, MHblock);
+               for (index = 0; index < VL_MHSRV_PERBLK; index++) {
+                   if (mhinfo[block].orphan[index]) {
+                       quiet_println("FIX: Removing unreferenced mh entry; block %d, index %d\n",
+                               block, index);
+                       memset(&(MHblock[index]), 0, sizeof(struct extentaddr));
+                   }
+               }
+               writeMH(record[i].addr, block, MHblock);
+           }
+       } else if (record[i].type & FR) {
+           if (fix) {
+               readentry(record[i].addr, &vlentry, &type);
+               vlentry.nextIdHash[0] = header.vital_header.freePtr;
+               header.vital_header.freePtr = record[i].addr;
+               if ((record[i].type & FRC) == 0) {
+                   quiet_println
+                       ("FIX: Putting free entry on the free chain: addr=%lu (offset 0x%0x)\n",
+                        record[i].addr, OFFSET(record[i].addr));
+               }
+               writeentry(record[i].addr, &vlentry);
+           }
+       }
     }
     if (fix) {
        reportHashChanges(&header, oldnamehash, oldidhash);
+       removeCrossLinkedAddresses(&header);
        writeheader(&header);
     }
 
@@ -1412,7 +1618,7 @@ main(int argc, char **argv)
 
     setlinebuf(stdout);
 
-    ts = cmd_CreateSyntax(NULL, WorkerBee, NULL, "vldb check");
+    ts = cmd_CreateSyntax(NULL, WorkerBee, NULL, 0, "vldb check");
     cmd_AddParm(ts, "-database", CMD_SINGLE, CMD_REQUIRED, "vldb_file");
     cmd_AddParm(ts, "-uheader", CMD_FLAG, CMD_OPTIONAL,
                "Display UBIK header");