Compressed metadata support

diff --git a/grub-core/fs/squash4.c b/grub-core/fs/squash4.c
index 5bb128f584b4399eeb9b22d2b77e10810c6d9de9..8eca185f3d8a68d654c1d1063146e6fcf74a0662 100644 (file)
--- a/grub-core/fs/squash4.c
+++ b/grub-core/fs/squash4.c
@@ -79,23 +79,19 @@ struct grub_squash_inode
   grub_uint32_t size;
 } __attribute__ ((packed));
 
-static inline unsigned
-decode_chunk_number (grub_uint16_t in)
-{
-  return (grub_le_to_cpu16 (in) & 0xff) / 2;
-}
-
 /* Chunk-based.  */
 struct grub_squash_dirent_header
 {
   /* Actually the value is the number of elements - 1.  */
   grub_uint16_t nelems;
-  grub_uint16_t dummy[5];
+  grub_uint16_t dummy1;
+  grub_uint32_t ino_chunk;
+  grub_uint16_t dummy2[2];
 };
 
 struct grub_squash_dirent
 {
-  grub_uint16_t ino;
+  grub_uint16_t ino_offset;
   grub_uint16_t dummy;
   grub_uint16_t type;
 #define SQUASH_TYPE_DIR 1
@@ -131,7 +127,7 @@ struct grub_fshelp_node
 
 static grub_err_t
 read_chunk (grub_disk_t disk, void *buf, grub_size_t len,
-           grub_uint64_t chunk, unsigned nchunk, grub_off_t offset)
+           grub_uint64_t chunk, grub_off_t offset)
 {
   grub_uint64_t chunk_start;
   chunk_start = grub_le_to_cpu64 (chunk);
@@ -147,12 +143,9 @@ read_chunk (grub_disk_t disk, void *buf, grub_size_t len,
                                sizeof (d), &d);
          if (err)
            return err;
-         if (!nchunk && offset < SQUASH_CHUNK_SIZE)
+         if (offset < SQUASH_CHUNK_SIZE)
            break;
-         if (nchunk)
-           nchunk--;
-         else
-           offset -= SQUASH_CHUNK_SIZE;
+         offset -= SQUASH_CHUNK_SIZE;
          chunk_start += 2 + (grub_le_to_cpu16 (d) & ~SQUASH_CHUNK_FLAGS);
        }
 
@@ -171,8 +164,29 @@ read_chunk (grub_disk_t disk, void *buf, grub_size_t len,
        }
       else
        {
-         return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
-                            "compression not implemented yet");
+         char *tmp;
+         grub_size_t bsize = grub_le_to_cpu16 (d) & ~SQUASH_CHUNK_FLAGS; 
+         grub_disk_addr_t a = chunk_start + 2;
+         tmp = grub_malloc (bsize);
+         if (!tmp)
+           return grub_errno;
+         /* FIXME: buffer uncompressed data.  */
+         err = grub_disk_read (disk, (a >> GRUB_DISK_SECTOR_BITS),
+                               a & (GRUB_DISK_SECTOR_SIZE - 1),
+                               bsize, tmp);
+         if (err)
+           {
+             grub_free (tmp);
+             return err;
+           }
+
+         if (grub_zlib_decompress (tmp, bsize, offset,
+                                   buf, csize) < 0)
+           {
+             grub_free (tmp);
+             return grub_errno;
+           }
+         grub_free (tmp);
        }
       len -= csize;
       offset += csize;
@@ -239,8 +253,8 @@ grub_squash_iterate_dir (grub_fshelp_node_t dir,
       grub_err_t err;
 
       err = read_chunk (dir->data->disk, &dh, sizeof (dh),
-                       dir->data->sb.diroffset,
-                       decode_chunk_number (dir->ino.chunk), off);
+                       grub_le_to_cpu64 (dir->data->sb.diroffset)
+                       + grub_le_to_cpu32 (dir->ino.chunk), off);
       if (err)
        return 0;
       off += sizeof (dh);
@@ -254,16 +268,16 @@ grub_squash_iterate_dir (grub_fshelp_node_t dir,
          struct grub_squash_inode ino;
 
          err = read_chunk (dir->data->disk, &di, sizeof (di),
-                           dir->data->sb.diroffset,
-                           decode_chunk_number (dir->ino.chunk), off);
+                           grub_le_to_cpu64 (dir->data->sb.diroffset)
+                           + grub_le_to_cpu32 (dir->ino.chunk), off);
          if (err)
            return 0;
          off += sizeof (di);
 
          err = read_chunk (dir->data->disk, &ino, sizeof (ino),
-                           dir->data->sb.inodeoffset,
-                           0,
-                           grub_cpu_to_le16 (di.ino));
+                           grub_le_to_cpu64 (dir->data->sb.inodeoffset)
+                           + grub_le_to_cpu32 (dh.ino_chunk),
+                           grub_cpu_to_le16 (di.ino_offset));
          if (err)
            return 0;
 
@@ -272,14 +286,14 @@ grub_squash_iterate_dir (grub_fshelp_node_t dir,
            return 0;
          err = read_chunk (dir->data->disk, buf,
                            grub_le_to_cpu16 (di.namelen) + 1,
-                           dir->data->sb.diroffset, 
-                           decode_chunk_number (dir->ino.chunk), off);
+                           grub_le_to_cpu64 (dir->data->sb.diroffset)
+                           + grub_le_to_cpu32 (dir->ino.chunk), off);
          if (err)
            return 0;
 
          off += grub_le_to_cpu16 (di.namelen) + 1;
          buf[grub_le_to_cpu16 (di.namelen) + 1] = 0;
-         if (grub_le_to_cpu16 (ino.type) == SQUASH_TYPE_DIR)
+         if (grub_le_to_cpu16 (di.type) == SQUASH_TYPE_DIR)
            filetype = GRUB_FSHELP_DIR;
          node = grub_malloc (sizeof (*node));
          if (! node)
@@ -303,9 +317,9 @@ make_root_node (struct grub_squash_data *data, struct grub_fshelp_node *root)
   root->data = data;
  
  return read_chunk (data->disk, &root->ino, sizeof (root->ino),
-                    data->sb.inodeoffset,
-                    decode_chunk_number (data->sb.root_ino_chunk),
-                    grub_cpu_to_le16 (data->sb.root_ino_offset));
+                   grub_le_to_cpu64 (data->sb.inodeoffset) 
+                   + grub_le_to_cpu16 (data->sb.root_ino_chunk),
+                   grub_cpu_to_le16 (data->sb.root_ino_offset));
 }
 
 static grub_err_t
@@ -400,7 +414,7 @@ grub_squash_read (grub_file_t file, char *buf, grub_size_t len)
     {
       struct grub_squash_frag_desc frag;
       err = read_chunk (file->device->disk, &frag, sizeof (frag),
-                       data->fragments, 0, sizeof (frag)
+                       data->fragments, sizeof (frag)
                        * grub_le_to_cpu16 (data->ino.fragment));
       if (err)
        return -1;