Made mkfs a little smarter about how to report empty devices.

Also a little smarter about manually specified number of blocks that is
larger than the device capacity.

diff --git a/commands/simple/mkfs.c b/commands/simple/mkfs.c
index c5d0b4c8009e12708d33049aac19aac6920ad261..705deda6d93076e57cd091e58439e20fd3e817ff 100755 (executable)
--- a/commands/simple/mkfs.c
+++ b/commands/simple/mkfs.c
@@ -141,7 +141,7 @@ int argc;
 char *argv[];
 {
   int nread, mode, usrid, grpid, ch;
-  block_t blocks;
+  block_t blocks, maxblocks;
   block_t i;
   ino_t root_inum;
   ino_t inodes;
@@ -225,13 +225,30 @@ char *argv[];
   bzero(zero, block_size);
 
   /* Determine the size of the device if not specified as -b or proto. */
-  if (argc - optind == 1 && blocks == 0) blocks = sizeup(argv[optind]);
+  maxblocks = sizeup(argv[optind]);
+  if (argc - optind == 1 && blocks == 0) {
+       blocks = maxblocks;
+       /* blocks == 0 is checked later, but leads to a funny way of
+        * reporting a 0-sized device (displays usage).
+        */
+       if(blocks < 1) {
+               fprintf(stderr, "%s: this device can't hold a filesystem.\n",
+                       progname);
+               return 1;
+       }
+  }
 
   /* The remaining args must be 'special proto', or just 'special' if the
    * no. of blocks has already been specified.
    */
   if (argc - optind != 2 && (argc - optind != 1 || blocks == 0)) usage();
 
+  if (blocks > maxblocks) {
+       fprintf(stderr, "%s: number of blocks too large for device.\n",
+               progname);
+       return 1;
+  }
+
   /* Check special. */
   check_mtab(argv[optind]);