From: Christoph Hellwig <hch@lst.de>
Date: Fri, 7 May 2010 14:55:33 +0000 (+0200)
Subject: dmg: fix reading of uncompressed chunks
X-Git-Tag: v0.13.0-rc0~517^2~6
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cd02a24b6112da50816a8021d97a2b26038f7190;p=thirdparty%2Fqemu.git

dmg: fix reading of uncompressed chunks

When dmg_read_chunk encounters an uncompressed chunk it currently
calls read without any previous adjustment of the file postion.

This seems very wrong, and the "reference" implementation in
dmg2img does a search to the same offset as done in the various
compression cases, so do the same here.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---

diff --git a/block/dmg.c b/block/dmg.c
index d5c1a687e44..02a3d672060 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -239,7 +239,8 @@ static inline int dmg_read_chunk(BDRVDMGState *s,int sector_num)
 		return -1;
 	    break; }
 	case 1: /* copy */
-	    ret = read(s->fd, s->uncompressed_chunk, s->lengths[chunk]);
+	    ret = pread(s->fd, s->uncompressed_chunk, s->lengths[chunk],
+                        s->offsets[chunk]);
 	    if (ret != s->lengths[chunk])
 		return -1;
 	    break;