debug: dump dir-iter state under -o debug

When -o debug is set, log the FID being read in ops_readdir, the
HEAD's filechar/efblk/hiblk/ffb/rtype/rattr right after accessfile,
the iterate_dir block-by-block progress and every dir record / entry
emitted to filler.  Lets us trace why an MFD lookup yields an empty
listing on a real Alpha system disk.

Author: mancausoft

src/lookup.c

@@ -229,6 +229,10 @@ vmscond_t ods2_iterate_dir( struct FCB *dir_fcb, int latest_only,
 
     uint32_t efblk = F11SWAP( dir_fcb->head->fh2$w_recattr.fat$l_efblk );
     uint16_t ffb   = F11WORD( dir_fcb->head->fh2$w_recattr.fat$w_ffbyte );
+    if( ods2_rt.debug )
+        fprintf( stderr,
+                 "fuse-ods2: iterate_dir efblk=%u ffb=%u latest_only=%d\n",
+                 (unsigned)efblk, (unsigned)ffb, latest_only );
     if( efblk == 0 )
         return SS$_NORMAL;
     if( ffb == 0 )
@@ -257,23 +261,52 @@ vmscond_t ods2_iterate_dir( struct FCB *dir_fcb, int latest_only,
 
         char *p   = buf;
         char *end = buf + BLOCKSIZE;
+        if( ods2_rt.debug )
+            fprintf( stderr,
+                     "fuse-ods2: iterate_dir: block %u loaded blocks=%u\n",
+                     (unsigned)blk, (unsigned)blocks );
 
         while( p + sizeof(struct dir$r_rec) <= end ) {
             struct dir$r_rec *dr = (struct dir$r_rec *)p;
             uint16_t size = F11WORD( dr->dir$w_size );
 
             /* End-of-block sentinel: 0xffff. */
-            if( size == 0xffff )
+            if( size == 0xffff ) {
+                if( ods2_rt.debug )
+                    fprintf( stderr,
+                             "fuse-ods2: iterate_dir:   end-of-block at offs=%ld\n",
+                             (long)(p - buf) );
                 break;
-            if( size + 2 > BLOCKSIZE )
+            }
+            if( size + 2 > BLOCKSIZE ) {
+                if( ods2_rt.debug )
+                    fprintf( stderr,
+                             "fuse-ods2: iterate_dir:   record size=%u too big at offs=%ld\n",
+                             (unsigned)size, (long)(p - buf) );
                 break;
-            if( p + size + 2 > end )
+            }
+            if( p + size + 2 > end ) {
+                if( ods2_rt.debug )
+                    fprintf( stderr,
+                             "fuse-ods2: iterate_dir:   record overruns block at offs=%ld size=%u\n",
+                             (long)(p - buf), (unsigned)size );
                 break;
+            }
 
             uint8_t namecount = dr->dir$b_namecount;
             char   *namebase  = dr->dir$t_name;
-            if( namebase + namecount > end )
+            if( namebase + namecount > end ) {
+                if( ods2_rt.debug )
+                    fprintf( stderr,
+                             "fuse-ods2: iterate_dir:   name overruns block (count=%u)\n",
+                             (unsigned)namecount );
                 break;
+            }
+            if( ods2_rt.debug )
+                fprintf( stderr,
+                         "fuse-ods2: iterate_dir:   record offs=%ld size=%u namecount=%u name='%.*s'\n",
+                         (long)(p - buf), (unsigned)size,
+                         (unsigned)namecount, namecount, namebase );
 
             /* Skip a record whose name we already emitted (split). */
             int same_as_last = ( latest_only

src/ops.c

@@ -143,6 +143,11 @@ static int readdir_cb( const char *name, int namelen, int version,
                ods2_rt.allversions, ods2_rt.lower,
                display, sizeof display );
 
+    if( ods2_rt.debug )
+        fprintf( stderr,
+                 "fuse-ods2: readdir entry: '%.*s';%d -> '%s'\n",
+                 namelen, name, version, display );
+
     memset( &st, 0, sizeof st );
     st.st_ino = ods2_fid_to_inode( fid );
     /* We don't know if it's a directory without reading the HEAD; let
@@ -165,16 +170,51 @@ int ods2_readdir( const char *path, void *buf, fuse_fill_dir_t filler,
     vmscond_t     sts;
 
     sts = ods2_path_to_fid( path, &fid, NULL );
-    if( !$SUCCESSFUL(sts) )
+    if( !$SUCCESSFUL(sts) ) {
+        if( ods2_rt.debug )
+            fprintf( stderr,
+                     "fuse-ods2: readdir('%s') path_to_fid failed (%08x)\n",
+                     path, (unsigned)(sts & STS$M_COND_ID) );
         return -ENOENT;
+    }
+
+    if( ods2_rt.debug )
+        fprintf( stderr,
+                 "fuse-ods2: readdir('%s') fid=(%u,%u,%u,%u)\n",
+                 path,
+                 (unsigned)F11WORD(fid.fid$w_num),
+                 (unsigned)F11WORD(fid.fid$w_seq),
+                 (unsigned)fid.fid$b_rvn,
+                 (unsigned)fid.fid$b_nmx );
 
     struct FCB *dfcb = NULL;
     sts = accessfile( ods2_vcb, &fid, &dfcb, 0 );
-    if( !$SUCCESSFUL(sts) )
+    if( !$SUCCESSFUL(sts) ) {
+        if( ods2_rt.debug )
+            fprintf( stderr,
+                     "fuse-ods2: readdir accessfile failed (%08x)\n",
+                     (unsigned)(sts & STS$M_COND_ID) );
         return -EIO;
+    }
+
+    if( ods2_rt.debug ) {
+        struct HEAD *h = dfcb->head;
+        fprintf( stderr,
+                 "fuse-ods2: readdir filechar=%08x efblk=%u hiblk=%u ffb=%u "
+                 "rtype=0x%02x rattr=0x%02x\n",
+                 (unsigned)F11LONG(h->fh2$l_filechar),
+                 (unsigned)F11SWAP(h->fh2$w_recattr.fat$l_efblk),
+                 (unsigned)F11SWAP(h->fh2$w_recattr.fat$l_hiblk),
+                 (unsigned)F11WORD(h->fh2$w_recattr.fat$w_ffbyte),
+                 (unsigned)h->fh2$w_recattr.fat$b_rtype,
+                 (unsigned)h->fh2$w_recattr.fat$b_rattrib );
+    }
 
     /* Reject non-directories. */
     if( !(F11LONG( dfcb->head->fh2$l_filechar ) & FH2$M_DIRECTORY) ) {
+        if( ods2_rt.debug )
+            fprintf( stderr,
+                     "fuse-ods2: readdir: target is not a directory\n" );
         deaccessfile( dfcb );
         return -ENOTDIR;
     }
@@ -188,6 +228,11 @@ int ods2_readdir( const char *path, void *buf, fuse_fill_dir_t filler,
                             ods2_rt.allversions ? 0 : 1,
                             readdir_cb, &ctx );
 
+    if( ods2_rt.debug )
+        fprintf( stderr,
+                 "fuse-ods2: readdir iterate done sts=%08x\n",
+                 (unsigned)(sts & STS$M_COND_ID) );
+
     deaccessfile( dfcb );
     return $SUCCESSFUL(sts) ? 0 : -EIO;
 }