From: Karel Zak <kzak@redhat.com>
Date: Tue, 19 Feb 2013 14:51:51 +0000 (+0100)
Subject: libblkid: make backup superblock visible for wipefs(8) only
X-Git-Tag: v2.23-rc1~202
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6c4581b6950ac478f29cb12c92dd3d9beff0d53f;p=thirdparty%2Futil-linux.git

libblkid: make backup superblock visible for wipefs(8) only

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/libblkid/src/blkidP.h b/libblkid/src/blkidP.h
index ed0c68c43a..2d5e8cb78a 100644
--- a/libblkid/src/blkidP.h
+++ b/libblkid/src/blkidP.h
@@ -224,6 +224,9 @@ struct blkid_struct_probe
 
 /* private per-probing flags */
 #define BLKID_PROBE_FL_IGNORE_PT (1 << 1)	/* ignore partition table */
+#define BLKID_PROBE_FL_IGNORE_BACKUP (1 << 2)	/* ignore backup superblocks or PT */
+
+extern int blkid_probe_ignore_backup(blkid_probe pr);
 
 extern blkid_probe blkid_clone_probe(blkid_probe parent);
 extern blkid_probe blkid_probe_get_wholedisk_probe(blkid_probe pr);
diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index dd3ebcadec..e0ac8ebac7 100644
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -1129,6 +1129,8 @@ int blkid_do_safeprobe(blkid_probe pr)
 
 	blkid_probe_start(pr);
 
+	pr->prob_flags |= BLKID_PROBE_FL_IGNORE_BACKUP;
+
 	for (i = 0; i < BLKID_NCHAINS; i++) {
 		struct blkid_chain *chn;
 
@@ -1769,3 +1771,7 @@ void blkid_probe_use_wiper(blkid_probe pr, blkid_loff_t off, blkid_loff_t size)
 	}
 }
 
+int blkid_probe_ignore_backup(blkid_probe pr)
+{
+	return pr && (pr->prob_flags & BLKID_PROBE_FL_IGNORE_BACKUP);
+}
diff --git a/libblkid/src/superblocks/btrfs.c b/libblkid/src/superblocks/btrfs.c
index 3c60ef57eb..552097b979 100644
--- a/libblkid/src/superblocks/btrfs.c
+++ b/libblkid/src/superblocks/btrfs.c
@@ -63,6 +63,9 @@ static int probe_btrfs(blkid_probe pr, const struct blkid_idmag *mag)
 {
 	struct btrfs_super_block *bfs;
 
+	if (mag->kboff > 64 && blkid_probe_ignore_backup(pr))
+		return 1;
+
 	bfs = blkid_probe_get_sb(pr, mag, struct btrfs_super_block);
 	if (!bfs)
 		return -1;