import base_device.c for fsck

diff --git a/e2fsprogs/base_device.c b/e2fsprogs/base_device.c
new file mode 100644 (file)
index 0000000..d81bb09
--- /dev/null
+++ b/e2fsprogs/base_device.c
@@ -0,0 +1,147 @@
+/*
+ * base_device.c
+ *
+ * Return the "base device" given a particular device; this is used to
+ * assure that we only fsck one partition on a particular drive at any
+ * one time.  Otherwise, the disk heads will be seeking all over the
+ * place.  If the base device can not be determined, return NULL.
+ * 
+ * The base_device() function returns an allocated string which must
+ * be freed.
+ * 
+ * Written by Theodore Ts'o, <tytso@mit.edu>
+ * 
+ * Copyright (C) 2000 Theodore Ts'o.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+
+#include "busybox.h"
+
+#ifdef CONFIG_FEATURE_DEVFS
+/*
+ * Required for the uber-silly devfs /dev/ide/host1/bus2/target3/lun3
+ * pathames.
+ */
+static const char *devfs_hier[] = {
+       "host", "bus", "target", "lun", 0
+};
+#endif
+
+char *base_device(const char *device)
+{
+       char *str, *cp;
+#ifdef CONFIG_FEATURE_DEVFS
+       const char **hier, *disk;
+       int len;
+#endif
+
+       cp = str = bb_xstrdup(device);
+
+       /* Skip over /dev/; if it's not present, give up. */
+       if (strncmp(cp, "/dev/", 5) != 0)
+               goto errout;
+       cp += 5;
+
+#if 0  /* this is for old stuff no one uses anymore ? */
+       /* Skip over /dev/dsk/... */
+       if (strncmp(cp, "dsk/", 4) == 0)
+               cp += 4;
+#endif
+
+       /*
+        * For md devices, we treat them all as if they were all
+        * on one disk, since we don't know how to parallelize them.
+        */
+       if (cp[0] == 'm' && cp[1] == 'd') {
+               *(cp+2) = 0;
+               return str;
+       }
+
+       /* Handle DAC 960 devices */
+       if (strncmp(cp, "rd/", 3) == 0) {
+               cp += 3;
+               if (cp[0] != 'c' || cp[2] != 'd' ||
+                   !isdigit(cp[1]) || !isdigit(cp[3]))
+                       goto errout;
+               *(cp+4) = 0;
+               return str;
+       }
+
+       /* Now let's handle /dev/hd* and /dev/sd* devices.... */
+       if ((cp[0] == 'h' || cp[0] == 's') && (cp[1] == 'd')) {
+               cp += 2;
+               /* If there's a single number after /dev/hd, skip it */
+               if (isdigit(*cp))
+                       cp++;
+               /* What follows must be an alpha char, or give up */
+               if (!isalpha(*cp))
+                       goto errout;
+               *(cp + 1) = 0;
+               return str;
+       }
+
+#ifdef CONFIG_FEATURE_DEVFS
+       /* Now let's handle devfs (ugh) names */
+       len = 0;
+       if (strncmp(cp, "ide/", 4) == 0)
+               len = 4;
+       if (strncmp(cp, "scsi/", 5) == 0)
+               len = 5;
+       if (len) {
+               cp += len;
+               /*
+                * Now we proceed down the expected devfs hierarchy.
+                * i.e., .../host1/bus2/target3/lun4/...
+                * If we don't find the expected token, followed by
+                * some number of digits at each level, abort.
+                */
+               for (hier = devfs_hier; *hier; hier++) {
+                       len = strlen(*hier);
+                       if (strncmp(cp, *hier, len) != 0)
+                               goto errout;
+                       cp += len;
+                       while (*cp != '/' && *cp != 0) {
+                               if (!isdigit(*cp))
+                                       goto errout;
+                               cp++;
+                       }
+                       cp++;
+               }
+               *(cp - 1) = 0;
+               return str;
+       }
+
+       /* Now handle devfs /dev/disc or /dev/disk names */
+       disk = 0;
+       if (strncmp(cp, "discs/", 6) == 0)
+               disk = "disc";
+       else if (strncmp(cp, "disks/", 6) == 0)
+               disk = "disk";
+       if (disk) {
+               cp += 6;
+               if (strncmp(cp, disk, 4) != 0)
+                       goto errout;
+               cp += 4;
+               while (*cp != '/' && *cp != 0) {
+                       if (!isdigit(*cp))
+                               goto errout;
+                       cp++;
+               }
+               *cp = 0;
+               return str;
+       }
+#endif
+
+errout:
+       free(str);
+       return NULL;
+}