Imported from util-linux-2.11q 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 988974f77c08c8cbf927479f5743fe0c5ec4afa7..ee3b1d52e80c6871bad603544ccee2457a2433b8 100644 (file)
--- a/mount/mount_by_label.c
+++ b/mount/mount_by_label.c
@@ -11,6 +11,8 @@
  * - Added XFS support
  * 2001-11-22 Kirby Bohling <kbohling@birddog.com>
  * - Added support of labels on LVM
+ * 2002-03-21 Christoph Hellwig <hch@infradead.org>
+ * - Added JFS support
  */
 
 #include <stdio.h>
@@ -48,6 +50,7 @@ get_label_uuid(const char *device, char **label, char *uuid) {
        size_t namesize;
        struct ext2_super_block e2sb;
        struct xfs_super_block xfsb;
+       struct jfs_super_block jfssb;
 
        fd = open(device, O_RDONLY);
        if (fd < 0)
@@ -71,6 +74,16 @@ get_label_uuid(const char *device, char **label, char *uuid) {
                        memcpy(*label, xfsb.s_fname, namesize);
                rv = 0;
        }
+       else if (lseek(fd, JFS_SUPER1_OFF, SEEK_SET) == JFS_SUPER1_OFF
+           && read(fd, (char *) &jfssb, sizeof(jfssb)) == sizeof(jfssb)
+               && (strncmp(jfssb.s_magic, JFS_MAGIC, 4) == 0)) {
+               /* what to do with non-existant UUID?  --hch */
+               memset(uuid, 0, 16);
+               namesize = sizeof(jfssb.s_fpack);
+               if ((*label = calloc(namesize + 1, 1)) != NULL)
+                       memcpy(*label, jfssb.s_fpack, namesize);
+               rv = 0;
+       }
 
        close(fd);
        return rv;
@@ -83,7 +96,7 @@ uuidcache_addentry(char *device, char *label, char *uuid) {
        if (!uuidCache) {
                last = uuidCache = malloc(sizeof(*uuidCache));
        } else {
-               for (last = uuidCache; last->next; last = last->next) ;
+               for (last = uuidCache; last->next; last = last->next);
                last->next = malloc(sizeof(*uuidCache));
                last = last->next;
        }
@@ -142,6 +155,9 @@ uuidcache_init(void) {
        char device[110];
        int firstPass;
        int handleOnFirst;
+#if 0
+       char *iobuf = 0;
+#endif
 
        if (uuidCache)
                return;
@@ -155,6 +171,24 @@ uuidcache_init(void) {
                       PROC_PARTITIONS);
                return;
        }
+#if 0
+/* Ugly kludge - the contents of /proc/partitions change in time,
+   and this causes failures when the file is not read in one go.
+   In particular, one cannot use stdio on /proc/partitions.
+   Doing this ourselves is not easy either, since stat returns 0
+   so the size is unknown. We might try increasing buffer sizes
+   until a single read gets all. For now only pick a largish buffer size. */
+/* All these troubles are mainly caused by people who patch the kernel
+   to keep statistics in /proc/partitions. Of course, statistics belong
+   in some /proc/diskstats, not in some /proc file that happened to
+   exist already. */
+   {
+#define CBBUF  (16 * 1024)
+       iobuf = (char *) malloc(CBBUF);
+       if (iobuf)
+               setvbuf(procpt, iobuf, _IOFBF, CBBUF);
+   }
+#endif
 
        for (firstPass = 1; firstPass >= 0; firstPass--) {
            fseek(procpt, 0, SEEK_SET);
@@ -176,6 +210,7 @@ uuidcache_init(void) {
                /* skip entire disk (minor 0, 64, ... on ide;
                   0, 16, ... on sd) */
                /* heuristic: partition name ends in a digit */
+               /* devfs has .../disc and .../part1 etc. */
 
                for(s = ptname; *s; s++);
                if (isdigit(s[-1])) {
@@ -196,7 +231,10 @@ uuidcache_init(void) {
        }
 
        fclose(procpt);
-
+#if 0
+       if (iobuf)
+               free(iobuf);
+#endif
        uuidcache_init_lvm();
 }
 
@@ -273,7 +311,32 @@ get_volume_label_by_spec(const char *spec) {
        while(uc) {
                if (!strcmp(spec, uc->device))
                        return uc->label;
-               uc = uc->next;
+               uc = uc->next;
        }
        return NULL;
 }
+
+/*
+ * second_occurrence_of_vol_label()
+ * As labels are user defined they are not necessarily 
+ * system-wide unique. Make sure that they are.
+ */
+const char *
+second_occurrence_of_vol_label (const char *label) {
+       struct uuidCache_s *last;
+        int occurrences = 0;
+
+        uuidcache_init();
+
+        for (last = uuidCache; last->next; last = last->next) {
+               if (!strcmp(last->label, label)) {
+                       occurrences++;
+                       if (occurrences == 2)
+                               return last->device;
+               }
+        }
+        
+        return NULL;
+}
+
+