1 files changed, 63 insertions, 10 deletions

diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index 64f8d7add7e..ec99c8ec83a 100644
--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -220,6 +220,47 @@ static struct jffs2_raw_node_ref **jffs2_incore_replace_raw(struct jffs2_sb_info
 	return NULL;
 }
 
+#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
+static int jffs2_verify_write(struct jffs2_sb_info *c, unsigned char *buf,
+			      uint32_t ofs)
+{
+	int ret;
+	size_t retlen;
+	char *eccstr;
+
+	ret = c->mtd->read(c->mtd, ofs, c->wbuf_pagesize, &retlen, c->wbuf_verify);
+	if (ret && ret != -EUCLEAN && ret != -EBADMSG) {
+		printk(KERN_WARNING "jffs2_verify_write(): Read back of page at %08x failed: %d\n", c->wbuf_ofs, ret);
+		return ret;
+	} else if (retlen != c->wbuf_pagesize) {
+		printk(KERN_WARNING "jffs2_verify_write(): Read back of page at %08x gave short read: %zd not %d.\n", ofs, retlen, c->wbuf_pagesize);
+		return -EIO;
+	}
+	if (!memcmp(buf, c->wbuf_verify, c->wbuf_pagesize))
+		return 0;
+
+	if (ret == -EUCLEAN)
+		eccstr = "corrected";
+	else if (ret == -EBADMSG)
+		eccstr = "correction failed";
+	else
+		eccstr = "OK or unused";
+
+	printk(KERN_WARNING "Write verify error (ECC %s) at %08x. Wrote:\n",
+	       eccstr, c->wbuf_ofs);
+	print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1,
+		       c->wbuf, c->wbuf_pagesize, 0);
+
+	printk(KERN_WARNING "Read back:\n");
+	print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1,
+		       c->wbuf_verify, c->wbuf_pagesize, 0);
+
+	return -EIO;
+}
+#else
+#define jffs2_verify_write(c,b,o) (0)
+#endif
+
 /* Recover from failure to write wbuf. Recover the nodes up to the
  * wbuf, not the one which we were starting to try to write. */
 
@@ -380,7 +421,7 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
 			ret = c->mtd->write(c->mtd, ofs, towrite, &retlen,
 					    rewrite_buf);
 
-		if (ret || retlen != towrite) {
+		if (ret || retlen != towrite || jffs2_verify_write(c, rewrite_buf, ofs)) {
 			/* Argh. We tried. Really we did. */
 			printk(KERN_CRIT "Recovery of wbuf failed due to a second write error\n");
 			kfree(buf);
@@ -587,15 +628,16 @@ static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
 
 		ret = c->mtd->write(c->mtd, c->wbuf_ofs, c->wbuf_pagesize, &retlen, c->wbuf);
 
-	if (ret || retlen != c->wbuf_pagesize) {
-		if (ret)
-			printk(KERN_WARNING "jffs2_flush_wbuf(): Write failed with %d\n",ret);
-		else {
-			printk(KERN_WARNING "jffs2_flush_wbuf(): Write was short: %zd instead of %d\n",
-				retlen, c->wbuf_pagesize);
-			ret = -EIO;
-		}
-
+	if (ret) {
+		printk(KERN_WARNING "jffs2_flush_wbuf(): Write failed with %d\n", ret);
+		goto wfail;
+	} else if (retlen != c->wbuf_pagesize) {
+		printk(KERN_WARNING "jffs2_flush_wbuf(): Write was short: %zd instead of %d\n",
+		       retlen, c->wbuf_pagesize);
+		ret = -EIO;
+		goto wfail;
+	} else if ((ret = jffs2_verify_write(c, c->wbuf, c->wbuf_ofs))) {
+	wfail:
 		jffs2_wbuf_recover(c);
 
 		return ret;
@@ -1138,11 +1180,22 @@ int jffs2_nand_flash_setup(struct jffs2_sb_info *c)
 		return -ENOMEM;
 	}
 
+#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
+	c->wbuf_verify = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
+	if (!c->wbuf_verify) {
+		kfree(c->oobbuf);
+		kfree(c->wbuf);
+		return -ENOMEM;
+	}
+#endif
 	return 0;
 }
 
 void jffs2_nand_flash_cleanup(struct jffs2_sb_info *c)
 {
+#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
+	kfree(c->wbuf_verify);
+#endif
 	kfree(c->wbuf);
 	kfree(c->oobbuf);
 }