volserver-split-volume-functionality-20090324

[openafs.git] / src / dir / dir.c

diff --git a/src/dir/dir.c b/src/dir/dir.c
index a6ca6bf..4b0477c 100644 (file)
--- a/src/dir/dir.c
+++ b/src/dir/dir.c
@@ -85,6 +85,7 @@ extern void *DNew(register afs_int32 *fid, register int page);
 #define        LookupOffset    afs_dir_LookupOffset
 #define        EnumerateDir    afs_dir_EnumerateDir
 #define        IsEmpty         afs_dir_IsEmpty
+#define InverseLookup   afs_dir_InverseLookup
 
 #if defined(AFS_DISCON_ENV)
 #define ChangeFid      afs_dir_ChangeFid
@@ -545,6 +546,65 @@ FindItem(void *dir, char *ename, unsigned short **previtem)
     }
 }
 
+static struct DirEntry *
+FindFid (void *dir, afs_uint32 vnode, afs_uint32 unique)
+{
+    /* Find a directory entry, given the vnode and uniquifier of a object.  
+     * This entry returns a pointer to a locked buffer.  If no entry is found,
+     * however, no items are left locked, and a null pointer is returned 
+     * instead. 
+     */
+    register int i;
+    register struct DirHeader *dhp;
+    register unsigned short *lp;
+    register struct DirEntry *tp;
+    dhp = (struct DirHeader *) DRead(dir,0);
+    if (!dhp) return 0;
+    for (i=0; i<NHASHENT; i++) {
+       if (dhp->hashTable[i] != 0) {
+           tp = GetBlob(dir,(u_short)ntohs(dhp->hashTable[i]));
+           if (!tp) { /* should not happen */
+               DRelease(dhp, 0);
+               return 0;
+           }
+           while(tp) {
+               if (vnode == ntohl(tp->fid.vnode) 
+                   && unique == ntohl(tp->fid.vunique)) { 
+                   DRelease(dhp,0);
+                   return tp;
+               }
+               lp = &(tp->next);
+               if (tp->next == 0)
+                   break;
+               tp = GetBlob(dir,(u_short)ntohs(tp->next));
+               DRelease(lp,0);
+           }
+           DRelease(lp,0);
+       }
+    }
+    DRelease(dhp,0);
+    return (struct DirEntry *)0;
+}
+
+int
+InverseLookup (void *dir, afs_uint32 vnode, afs_uint32 unique, char *name, 
+              afs_uint32 length)
+{
+    /* Look for the name pointing to given vnode and unique in a directory */
+    register struct DirEntry *entry;
+    int code = 0;
+    
+    entry = FindFid(dir, vnode, unique);
+    if (!entry)
+       return ENOENT;
+    if (strlen(entry->name) >= length)
+       code = E2BIG;
+    else
+       strcpy(name, entry->name);
+    DRelease(entry, 0);
+    return code;
+}
+
 #if defined(AFS_DISCON_ENV)
 /*!
  * Change an entry fid.