[JFFS2] Calculate CRC check starting point correctly

When data starts from the beginning of NAND page, 'len' must be zero, not
c->wbuf_page.

Thanks to Zoltan Sogor for reporting this problem.
Signed-off-by: NArtem B. Bityutskiy <dedekind@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

fs/jffs2/nodelist.c

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: nodelist.c,v 1.110 2005/08/17 14:13:45 dedekind Exp $
+ * $Id: nodelist.c,v 1.111 2005/08/17 14:57:39 dedekind Exp $
  *
  */
 
@@ -413,7 +413,8 @@ static int check_node_data(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info
 	/* Calculate how many bytes were already checked */
 	ofs = ref_offset(ref) + sizeof(struct jffs2_raw_inode);
 	len = ofs & (c->wbuf_pagesize - 1);
-	len = c->wbuf_pagesize - len;
+	if (likely(len))
+		len = c->wbuf_pagesize - len;
 
 	if (len >= tn->csize) {
 		JFFS2_DBG_READINODE("no need to check node at %#08x, data length %u, data starts at %#08x - it has already been checked.\n",

fs/jffs2/readinode.c

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: readinode.c,v 1.140 2005/08/17 13:46:23 dedekind Exp $
+ * $Id: readinode.c,v 1.141 2005/08/17 14:57:39 dedekind Exp $
  *
  */
 
@@ -272,9 +272,9 @@ static inline int read_dnode(struct jffs2_sb_info *c, struct jffs2_raw_node_ref
 			buf = (unsigned char *)rd + sizeof(*rd);
 			/* len will be the read data length */
 			len = min_t(uint32_t, rdlen - sizeof(*rd), csize);
-			
-			if (len)
-				tn->partial_crc = crc = crc32(0, buf, len);
+			tn->partial_crc = crc32(0, buf, len);
+
+			JFFS2_DBG_READINODE("Calculates CRC (%#08x) for %d bytes, csize %d\n", tn->partial_crc, len, csize);
 
 			/* If we actually calculated the whole data CRC
 			 * and it is wrong, drop the node. */
@@ -327,8 +327,8 @@ static inline int read_dnode(struct jffs2_sb_info *c, struct jffs2_raw_node_ref
 	else // normal case...
 		tn->fn->size = je32_to_cpu(rd->dsize);
 
-	JFFS2_DBG_READINODE("dnode @%08x: ver %u, offset %#04x, dsize %#04x\n",
-		  ref_offset(ref), je32_to_cpu(rd->version), je32_to_cpu(rd->offset), je32_to_cpu(rd->dsize));
+	JFFS2_DBG_READINODE("dnode @%08x: ver %u, offset %#04x, dsize %#04x, csize %#04x\n",
+		  ref_offset(ref), je32_to_cpu(rd->version), je32_to_cpu(rd->offset), je32_to_cpu(rd->dsize), csize);
 	
 	jffs2_add_tn_to_tree(tn, tnp);