libblkid: improve MD 0.90.0 detection (use sb->size)

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

diff --git a/shlibs/blkid/src/superblocks/linux_raid.c b/shlibs/blkid/src/superblocks/linux_raid.c
index 41ef261a04b1f72ea576097357e5353668b3efd8..b73214a41235baf2db5bd09babf1a78593710428 100644 (file)
--- a/shlibs/blkid/src/superblocks/linux_raid.c
+++ b/shlibs/blkid/src/superblocks/linux_raid.c
@@ -99,7 +99,7 @@ struct mdp1_super_block {
 #define MD_RESERVED_BYTES              0x10000
 #define MD_SB_MAGIC                    0xa92b4efc
 
-static int probe_raid0(blkid_probe pr, off_t off)
+static int probe_raid0(blkid_probe pr, blkid_loff_t off)
 {
        struct mdp0_super_block *mdp0;
        union {
@@ -107,8 +107,9 @@ static int probe_raid0(blkid_probe pr, off_t off)
                uint8_t bytes[16];
        } uuid;
        uint32_t ma, mi, pa;
+       uint64_t size;
 
-       if (pr->size < 0x10000)
+       if (pr->size < MD_RESERVED_BYTES)
                return -1;
        mdp0 = (struct mdp0_super_block *)
                        blkid_probe_get_buffer(pr,
@@ -129,6 +130,7 @@ static int probe_raid0(blkid_probe pr, off_t off)
                ma = le32_to_cpu(mdp0->major_version);
                mi = le32_to_cpu(mdp0->minor_version);
                pa = le32_to_cpu(mdp0->patch_version);
+               size = le32_to_cpu(mdp0->size);
 
        } else if (be32_to_cpu(mdp0->md_magic) == MD_SB_MAGIC) {
                uuid.ints[0] = mdp0->set_uuid0;
@@ -140,14 +142,31 @@ static int probe_raid0(blkid_probe pr, off_t off)
                ma = be32_to_cpu(mdp0->major_version);
                mi = be32_to_cpu(mdp0->minor_version);
                pa = be32_to_cpu(mdp0->patch_version);
+               size = be32_to_cpu(mdp0->size);
        } else
                return 1;
 
+       size <<= 10;    /* convert KiB to bytes */
+
+       if (pr->size < size + MD_RESERVED_BYTES)
+               /* device is too small */
+               return 1;
+
+       if (off < size)
+               /* no space before superblock */
+               return 1;
+
        /*
         * Check for collisions between RAID and partition table
+        *
+        * For example the superblock is at the end of the last partition, it's
+        * the same possition as at the end of the disk...
         */
        if ((S_ISREG(pr->mode) || blkid_probe_is_wholedisk(pr)) &&
-           blkid_probe_is_covered_by_pt(pr, off, 0x200)) {
+           blkid_probe_is_covered_by_pt(pr,
+                       off - size,                             /* min. start  */
+                       size + MD_RESERVED_BYTES)) {            /* min. length */
+
                /* ignore this superblock, it's within any partition and
                 * we are working with whole-disk now */
                return 1;