Imported from util-linux-2.11t tarball.

[thirdparty/util-linux.git] / mount / mount_by_label.c

diff --git a/mount/mount_by_label.c b/mount/mount_by_label.c
index ee3b1d52e80c6871bad603544ccee2457a2433b8..2ae351d10e9ee6e838eb80f0f39db8744bafe91c 100644 (file)
--- a/mount/mount_by_label.c
+++ b/mount/mount_by_label.c
@@ -39,6 +39,30 @@ static struct uuidCache_s {
        char *device;
 } *uuidCache = NULL;
 
+/*
+ * See whether this device has (the magic of) a RAID superblock at the end.
+ * If so, it probably is, or has been, part of a RAID array.
+ */
+static int
+is_raid_partition(int fd) {
+       struct mdp_super_block mdsb;
+       int n;
+
+       /* hardcode 4096 here in various places, because that's
+          what it's defined to be.  Note that even if we used
+          the actual kernel headers, sizeof(mdp_super_t) is
+          slightly larger in the 2.2 kernel on 64-bit archs,
+          so using that wouldn't work. */
+       lseek(fd, -4096, SEEK_END);     /* Ignore possible error
+                                          about return value overflow */
+       n = 4096;
+       if (sizeof(mdsb) < n)
+               n = sizeof(mdsb);
+       if (read(fd, &mdsb, n) != n)
+               return 1;               /* error */
+       return (mdsbmagic(mdsb) == MD_SB_MAGIC);
+}
+
 /* for now, only ext2, ext3 and xfs are supported */
 static int
 get_label_uuid(const char *device, char **label, char *uuid) {
@@ -56,6 +80,12 @@ get_label_uuid(const char *device, char **label, char *uuid) {
        if (fd < 0)
                return rv;
 
+       /* If there is a RAID partition, or an error, ignore this partition */
+       if (is_raid_partition(fd)) {
+               close(fd);
+               return rv;
+       }
+
        if (lseek(fd, 1024, SEEK_SET) == 1024
            && read(fd, (char *) &e2sb, sizeof(e2sb)) == sizeof(e2sb)
            && (ext2magic(e2sb) == EXT2_SUPER_MAGIC)) {