From 66d8e050ca3c243094545ce8b0e4c53d54a11715 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Tue, 18 May 2010 12:13:48 +0200
Subject: [PATCH] libblkid: improve MD 0.90 detection

We don't have to check for collision between partition table and RAID
on all RAIDs. This problem is specific to MD, where underlying device
could be a partition. The RAIDs like via, intel, ... always use
whole-disks only.

Signed-off-by: Karel Zak <kzak@redhat.com>
---
 shlibs/blkid/src/partitions/partitions.c   | 13 +++++++++
 shlibs/blkid/src/superblocks/linux_raid.c  | 31 ++++++++++++++--------
 shlibs/blkid/src/superblocks/superblocks.c | 16 -----------
 3 files changed, 33 insertions(+), 27 deletions(-)

diff --git a/shlibs/blkid/src/partitions/partitions.c b/shlibs/blkid/src/partitions/partitions.c
index c670cc18..5597181a 100644
--- a/shlibs/blkid/src/partitions/partitions.c
+++ b/shlibs/blkid/src/partitions/partitions.c
@@ -829,6 +829,19 @@ int blkid_probe_is_covered_by_pt(blkid_probe pr,
 	end = (offset + size) >> 9;
 	start = offset >> 9;
 
+	/* check if the partition table fits into the device */
+	for (i = 0; i < nparts; i++) {
+		blkid_partition par = &ls->parts[i];
+
+		if (par->start + par->size > pr->size) {
+			DBG(DEBUG_LOWPROBE, printf("partition #%d overflows "
+					"device (off=%lu size=%lu)\n",
+					par->partno, par->start, par->size));
+			goto done;
+		}
+	}
+
+	/* check if the requested area is covered by PT */
 	for (i = 0; i < nparts; i++) {
 		blkid_partition par = &ls->parts[i];
 
diff --git a/shlibs/blkid/src/superblocks/linux_raid.c b/shlibs/blkid/src/superblocks/linux_raid.c
index d25b3959..41ef261a 100644
--- a/shlibs/blkid/src/superblocks/linux_raid.c
+++ b/shlibs/blkid/src/superblocks/linux_raid.c
@@ -106,6 +106,7 @@ static int probe_raid0(blkid_probe pr, off_t off)
 		uint32_t ints[4];
 		uint8_t bytes[16];
 	} uuid;
+	uint32_t ma, mi, pa;
 
 	if (pr->size < 0x10000)
 		return -1;
@@ -125,11 +126,9 @@ static int probe_raid0(blkid_probe pr, off_t off)
 			uuid.ints[2] = swab32(mdp0->set_uuid2);
 			uuid.ints[3] = swab32(mdp0->set_uuid3);
 		}
-		if (blkid_probe_sprintf_version(pr, "%u.%u.%u",
-				le32_to_cpu(mdp0->major_version),
-				le32_to_cpu(mdp0->minor_version),
-				le32_to_cpu(mdp0->patch_version)) != 0)
-			return -1;
+		ma = le32_to_cpu(mdp0->major_version);
+		mi = le32_to_cpu(mdp0->minor_version);
+		pa = le32_to_cpu(mdp0->patch_version);
 
 	} else if (be32_to_cpu(mdp0->md_magic) == MD_SB_MAGIC) {
 		uuid.ints[0] = mdp0->set_uuid0;
@@ -138,14 +137,24 @@ static int probe_raid0(blkid_probe pr, off_t off)
 			uuid.ints[2] = mdp0->set_uuid2;
 			uuid.ints[3] = mdp0->set_uuid3;
 		}
-		if (blkid_probe_sprintf_version(pr, "%u.%u.%u",
-				be32_to_cpu(mdp0->major_version),
-				be32_to_cpu(mdp0->minor_version),
-				be32_to_cpu(mdp0->patch_version)) != 0)
-			return -1;
+		ma = be32_to_cpu(mdp0->major_version);
+		mi = be32_to_cpu(mdp0->minor_version);
+		pa = be32_to_cpu(mdp0->patch_version);
 	} else
-		return -1;
+		return 1;
 
+	/*
+	 * Check for collisions between RAID and partition table
+	 */
+	if ((S_ISREG(pr->mode) || blkid_probe_is_wholedisk(pr)) &&
+	    blkid_probe_is_covered_by_pt(pr, off, 0x200)) {
+		/* ignore this superblock, it's within any partition and
+		 * we are working with whole-disk now */
+		return 1;
+	}
+
+	if (blkid_probe_sprintf_version(pr, "%u.%u.%u", ma, mi, pa) != 0)
+		return -1;
 	if (blkid_probe_set_uuid(pr, (unsigned char *) uuid.bytes) != 0)
 		return -1;
 	if (blkid_probe_set_magic(pr, off, sizeof(mdp0->md_magic),
diff --git a/shlibs/blkid/src/superblocks/superblocks.c b/shlibs/blkid/src/superblocks/superblocks.c
index 1d952737..2a463c85 100644
--- a/shlibs/blkid/src/superblocks/superblocks.c
+++ b/shlibs/blkid/src/superblocks/superblocks.c
@@ -527,22 +527,6 @@ static int superblocks_safeprobe(blkid_probe pr, struct blkid_chain *chn)
 		superblocks_copy_data(chn->data, sb);
 	chn->idx = idx;
 
-	/*
-	 * Check for collisions between RAID and partition table
-	 */
-	if (sb && sb->usage == BLKID_USAGE_RAID &&
-	    sb->magic_off > pr->size / 2 &&
-	    (S_ISREG(pr->mode) || blkid_probe_is_wholedisk(pr)) &&
-	    blkid_probe_is_covered_by_pt(pr, sb->magic_off, 0x200)) {
-		/*
-		 * Ignore the result if the detected RAID superblock is
-		 * within some existing partition (for example RAID on
-		 * the last partition).
-		 */
-		blkid_probe_chain_reset_vals(pr, chn);
-		return 1;
-	}
-
 	/*
 	 * The RAID device could be partitioned. The problem are RAID1 devices
 	 * where the partition table is visible from underlaying devices. We
-- 
2.39.5