From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Sun, 9 Nov 2014 02:19:01 +0000 (+0100)
Subject: libfdisk: fdisk_read_firstsector should seek to offset 0
X-Git-Tag: v2.26-rc1~228
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a56b70f8ffb658a5a722c47cf77ea04c143fa0d9;p=thirdparty%2Futil-linux.git

libfdisk: fdisk_read_firstsector should seek to offset 0

The current offset of cxt->dev_fd may not be still 0, notably when
blkdev_get_size has to resort to using blkdev_find_size

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org
---

diff --git a/libfdisk/src/utils.c b/libfdisk/src/utils.c
index 732b0adeb3..7b62bf0ada 100644
--- a/libfdisk/src/utils.c
+++ b/libfdisk/src/utils.c
@@ -50,6 +50,13 @@ int fdisk_read_firstsector(struct fdisk_context *cxt)
 	DBG(CXT, ul_debugobj(cxt, "reading first sector "
 				"buffer [sector_size=%lu]", cxt->sector_size));
 
+	r = lseek(cxt->dev_fd, 0, SEEK_SET);
+	if (r == -1)
+	{
+		DBG(CXT, ul_debugobj(cxt, "failed to seek to first sector %m"));
+		return -errno;
+	}
+
 	r = read(cxt->dev_fd, cxt->firstsector, cxt->sector_size);
 
 	if (r != cxt->sector_size) {