From: Gabriel de Perthuis <g2p.code@gmail.com>
Date: Fri, 6 Sep 2013 17:18:15 +0000 (+0200)
Subject: wipefs: Also wipe superblocks with bad checksums
X-Git-Tag: v2.24-rc1~279
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=02f3c12a5f71b3e70f8ccbf311b88808756b5d17;p=thirdparty%2Futil-linux.git

wipefs: Also wipe superblocks with bad checksums

[kzak@redhat.com: - move BLKID_SUBLKS_BADCSUM login to
                    blkid_probe_verify_csum()]

Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libblkid/src/blkid.h.in b/libblkid/src/blkid.h.in
index 2a7d6b47c3..c140fc6b2c 100644
--- a/libblkid/src/blkid.h.in
+++ b/libblkid/src/blkid.h.in
@@ -260,6 +260,7 @@ extern int blkid_probe_enable_superblocks(blkid_probe pr, int enable);
 #define BLKID_SUBLKS_USAGE	(1 << 7) /* define USAGE result value */
 #define BLKID_SUBLKS_VERSION	(1 << 8) /* read FS type from superblock */
 #define BLKID_SUBLKS_MAGIC	(1 << 9) /* define SBMAGIC and SBMAGIC_OFFSET */
+#define BLKID_SUBLKS_BADCSUM	(1 << 10) /* allow a bad checksum */
 
 #define BLKID_SUBLKS_DEFAULT	(BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID | \
 				 BLKID_SUBLKS_TYPE | BLKID_SUBLKS_SECTYPE)
diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index 6e3ae42dc7..29223a664d 100644
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -1354,15 +1354,19 @@ int blkid_probe_set_magic(blkid_probe pr, blkid_loff_t offset,
 int blkid_probe_verify_csum(blkid_probe pr, uint64_t csum, uint64_t expected)
 {
 	if (csum != expected) {
+		struct blkid_chain *chn = blkid_probe_get_chain(pr);
+
 		DBG(LOWPROBE, blkid_debug(
 				"incorrect checksum for type %s,"
 				" got %jX, expected %jX",
 				blkid_probe_get_probername(pr),
 				csum, expected));
-		return 0;
+
+		if (!(chn->flags & BLKID_SUBLKS_BADCSUM))
+			return 0;
 	}
 
-	return 1;
+	return 1;	/* checksum accepted */
 }
 
 /**
diff --git a/misc-utils/wipefs.c b/misc-utils/wipefs.c
index 2cfad7c1ca..ff2f62fbc5 100644
--- a/misc-utils/wipefs.c
+++ b/misc-utils/wipefs.c
@@ -248,7 +248,8 @@ new_probe(const char *devname, int mode)
 	blkid_probe_enable_superblocks(pr, 1);
 	blkid_probe_set_superblocks_flags(pr, BLKID_SUBLKS_MAGIC |
 			BLKID_SUBLKS_TYPE | BLKID_SUBLKS_USAGE |
-			BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID);
+			BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID |
+			BLKID_SUBLKS_BADCSUM);
 
 	blkid_probe_enable_partitions(pr, 1);
 	blkid_probe_set_partitions_flags(pr, BLKID_PARTS_MAGIC);