ChangeLog, Makefile.in, e2label.c:

  e2label.c: New file contributed by Andries Brouwer which provides an
  easy-to-use interface to modify the filesystem label.

diff --git a/misc/ChangeLog b/misc/ChangeLog
index 37a9dec..e98d756 100644 (file)
--- a/misc/ChangeLog
+++ b/misc/ChangeLog
@@ -1,3 +1,11 @@
+Mon Jul 14 15:27:29 1997  Theodore Y. Ts'o  <tytso@mit.edu>
+
+       * e2label.c: New file contributed by Andries Brouwer which
+               provides an easy-to-use interface to modify the filesystem
+               label.
+       
+       * Makefile.in (SPROGS): Add Makefile support to build e2label
+
 Tue Jun 17 01:33:20 1997  Theodore Ts'o  <tytso@rsts-11.mit.edu>
 
        * Release of E2fsprogs 1.11

diff --git a/misc/Makefile.in b/misc/Makefile.in
index b0d06a2..0c3126a 100644 (file)
--- a/misc/Makefile.in
+++ b/misc/Makefile.in
@@ -11,7 +11,7 @@ INSTALL = @INSTALL@
 
 @MCONFIG@
 
-SPROGS=                mke2fs badblocks tune2fs dumpe2fs @FSCK_PROG@
+SPROGS=                mke2fs badblocks tune2fs dumpe2fs e2label @FSCK_PROG@
 USPROGS=       mklost+found
 SMANPAGES=     tune2fs.8 mklost+found.8 mke2fs.8 dumpe2fs.8 badblocks.8 \
                        @FSCK_MAN@
@@ -26,6 +26,7 @@ CHATTR_OBJS=  chattr.o
 LSATTR_OBJS=   lsattr.o
 DUMPE2FS_OBJS= dumpe2fs.o
 BADBLOCKS_OBJS=        badblocks.o
+E2LABEL_OBJS=  e2label.o
 FSCK_OBJS=     fsck.o
 
 SRCS=  $(srcdir)/tune2fs.c $(srcdir)/mklost+found.c $(srcdir)/mke2fs.c \
@@ -49,6 +50,9 @@ all:: $(SPROGS) $(UPROGS) $(USPROGS) fix_substitute $(SMANPAGES) $(UMANPAGES)
 tune2fs: $(TUNE2FS_OBJS) $(DEPLIBS_E2P) $(LIBUUID)
        $(CC) $(ALL_LDFLAGS) -o tune2fs $(TUNE2FS_OBJS) $(LIBS_E2P) $(LIBUUID)
 
+e2label: $(E2LABEL_OBJS) 
+       $(CC) $(ALL_LDFLAGS) -o e2label $(E2LABEL_OBJS) 
+
 mklost+found: $(MKLPF_OBJS)
        $(CC) $(ALL_LDFLAGS) -o mklost+found $(MKLPF_OBJS)
 

diff --git a/misc/e2label.c b/misc/e2label.c
new file mode 100644 (file)
index 0000000..2b4f171
--- /dev/null
+++ b/misc/e2label.c
@@ -0,0 +1,92 @@
+/*
+ * e2label.c           - Print or change the volume label on an ext2 fs
+ *
+ * aeb, 970714
+ *
+ */
+
+#include <fcntl.h>
+#include <stdio.h>
+
+#define EXT2_SUPER_MAGIC 0xEF53
+
+#define VOLNAMSZ 16
+
+struct ext2_super_block {
+       char  s_dummy0[56];
+       unsigned char  s_magic[2];
+       char  s_dummy1[62];
+       char  s_volume_name[VOLNAMSZ];
+       char  s_last_mounted[64];
+       char  s_dummy2[824];
+} sb;
+
+int
+open_e2fs (char *dev, int mode) {
+       int fd;
+
+       fd = open(dev, mode);
+       if (fd < 0) {
+            perror(dev);
+            fprintf (stderr, "e2label: cannot open %s\n", dev);
+            exit(1);
+       }
+       if (lseek(fd, 1024, SEEK_SET) != 1024) {
+            perror(dev);
+            fprintf (stderr, "e2label: cannot seek to superblock\n");
+            exit(1);
+       }
+       if (read(fd, (char *) &sb, sizeof(sb)) != sizeof(sb)) {
+            perror(dev);
+            fprintf (stderr, "e2label: error reading superblock\n");
+            exit(1);
+       }
+       if (sb.s_magic[0] + 256*sb.s_magic[1] != EXT2_SUPER_MAGIC) {
+            fprintf (stderr, "e2label: not an ext2 filesystem\n");
+            exit(1);
+       }
+
+       return fd;
+}
+
+void
+print_label (char *dev) {
+       char label[VOLNAMSZ+1];
+
+       open_e2fs (dev, O_RDONLY);
+       label[VOLNAMSZ] = 0;
+       strncpy(label, sb.s_volume_name, VOLNAMSZ);
+       printf("%s\n", label);
+}
+
+void
+change_label (char *dev, char *label) {
+       int fd;
+
+       fd = open_e2fs(dev, O_RDWR);
+       memset(sb.s_volume_name, 0, VOLNAMSZ);
+       strncpy(sb.s_volume_name, label, VOLNAMSZ);
+       if (lseek(fd, 1024, SEEK_SET) != 1024) {
+            perror(dev);
+            fprintf (stderr, "e2label: cannot seek to superblock again\n");
+            exit(1);
+       }
+       if (write(fd, (char *) &sb, sizeof(sb)) != sizeof(sb)) {
+            perror(dev);
+            fprintf (stderr, "e2label: error writing superblock\n");
+            exit(1);
+       }
+}
+
+int
+main (int argc, char ** argv) {
+       if (argc == 2)
+            print_label(argv[1]);
+       else if (argc == 3)
+            change_label(argv[1], argv[2]);
+       else {
+            fprintf(stderr, "Usage: e2label device [newlabel]\n");
+            exit(1);
+       }
+       return 0;
+}