DISK: Avoid autosizing if file system can't be determined

Add DISKINFO command to display information about a disk container file.

scp.c

@@ -2411,7 +2411,11 @@ static const char simh_help2[] =
       " Switches can be used to influence the behavior of the TESTLIB command\n\n"
       "4-d\n"
       " Many tests are capable of producing various amounts of debug output\n"
-      " during their execution.  The -d switch enables that output\n";
+      " during their execution.  The -d switch enables that output\n"
+#define HLP_DISKINFO    "*Commands DISKINFO"
+      "2Disk Container Information\n"
+      " Information about a Disk Container can be displayed with the DISKINFO command:\n\n"
+      "++DISKINFO container-spec    show information about a disk container\n\n";
 
 
 static CTAB cmd_table[] = {
@@ -2486,6 +2490,8 @@ static CTAB cmd_table[] = {
     { "RUNLIMIT",   &runlimit_cmd,  1,          HLP_RUNLIMIT,   NULL, NULL },
     { "NORUNLIMIT", &runlimit_cmd,  0,          HLP_RUNLIMIT,   NULL, NULL },
     { "TESTLIB",    &test_lib_cmd,  0,          HLP_TESTLIB,    NULL, NULL },
+    { "DISKINFO",   &sim_disk_info_cmd,  0,     HLP_DISKINFO,   NULL, NULL },
+    { "ZAPTYPE",    &sim_disk_info_cmd,  1,     NULL,           NULL, NULL },
     { NULL,         NULL,           0,          NULL,           NULL, NULL }
     };
 

sim_disk.c

@@ -2708,9 +2708,8 @@ if (container_size && (container_size != (t_offset)-1)) {
     if (dontchangecapac) {
         t_addr saved_capac = uptr->capac;
 
-        if (filesystem_size == (t_offset)-1)    /* No file system found? */
-            filesystem_size = container_size;   /* Assume full container */
         if (drivetypes != NULL) {
+            if (filesystem_size != (t_offset)-1) {  /* File System found? */
                 /* Walk through all potential drive types until we find one the right size */
                 while (*drivetypes != NULL) {
                     char cmd[CBUFSIZE];
@@ -2737,6 +2736,9 @@ if (container_size && (container_size != (t_offset)-1)) {
                     return SCPE_FSSIZE;
                     }
                 }
+            else
+                sim_messagef (SCPE_OK, "%s: No File System found on '%s', skipping autosizing\.n", sim_uname (uptr), cptr);
+            }
         if ((container_size != current_unit_size) && 
             ((DKUF_F_VHD == DK_GET_FMT (uptr)) || (0 != (uptr->flags & UNIT_RO)) ||
              (ctx->footer))) {
@@ -5872,6 +5874,103 @@ return WriteVirtualDiskSectors(hVHD, buf, sects, sectswritten, ctx->sector_size,
 }
 #endif
 
+/*
+ * Zap Type command to remove incorrectly autosize information that
+ * may have been recorded at the end of a disk container file
+ */
+
+t_stat sim_disk_info_cmd (int32 flag, CONST char *cptr)
+{
+struct simh_disk_footer footer;
+struct simh_disk_footer *f = &footer;
+FILE *container;
+t_offset container_size;
+
+if (flag) {        /* zap type */
+    container = sim_vhd_disk_open (cptr, "r");
+    if (container != NULL) {
+        sim_vhd_disk_close (container);
+        return sim_messagef (SCPE_OPENERR, "Can't change the disk type of a VHD container file\n");
+        }
+    container = sim_fopen (cptr, "r+");
+    if (container == NULL)
+        return sim_messagef (SCPE_OPENERR, "Can't open container file '%s' - %s\n", cptr, strerror (errno));
+    container_size = sim_fsize_ex (container);
+    if ((container_size != (t_offset)-1) && (container_size > sizeof (*f)) &&
+        (sim_fseeko (container, container_size - sizeof (*f), SEEK_SET) == 0) &&
+        (sizeof (*f) == sim_fread (f, 1, sizeof (*f), container))) {
+        if (f->Checksum == NtoHl (eth_crc32 (0, f, sizeof (*f) - sizeof (f->Checksum)))) {
+            (void)sim_set_fsize (container, (t_addr)(container_size - sizeof (*f)));
+            fclose (container);
+            return sim_messagef (SCPE_OK, "Disk Type Removed from container '%s'\n", cptr);
+            }
+        }
+    fclose (container);
+    return sim_messagef (SCPE_ARG, "No footer found on disk container '%s'.\n", cptr);
+    }
+if (flag == 0) {
+    UNIT unit, *uptr = &unit;
+    struct disk_context disk_ctx;
+    struct disk_context *ctx = &disk_ctx;
+    t_offset (*size_function)(FILE *file);
+    int (*close_function)(FILE *f);
+    FILE *container;
+    t_offset container_size;
+
+    memset (&unit, 0, sizeof (unit));
+    memset (&disk_ctx, 0, sizeof (disk_ctx));
+    sim_switches |= SWMASK ('E') | SWMASK ('R');   /* Must exist, Read Only */
+    uptr->flags |= UNIT_ATTABLE;
+    uptr->disk_ctx = &disk_ctx;
+    sim_disk_set_fmt (uptr, 0, "VHD", NULL);
+    container = sim_vhd_disk_open (cptr, "r");
+    if (container == NULL) {
+        sim_disk_set_fmt (uptr, 0, "SIMH", NULL);
+        container = sim_fopen (cptr, "r+");
+        close_function = fclose;
+        size_function = sim_fsize_ex;
+        }
+    else {
+        close_function = sim_vhd_disk_close;
+        size_function = sim_vhd_disk_size;
+        }
+    if (container) {
+        container_size = size_function (container);
+        uptr->filename = strdup (cptr);
+        uptr->fileref = container;
+        uptr->flags |= UNIT_ATT;
+        get_disk_footer (uptr);
+        f = ctx->footer;
+        if (f) {
+            sim_printf ("Container:              %s\n"
+                        "   Simulator:           %s\n"
+                        "   DriveType:           %s\n"
+                        "   SectorSize:          %u\n"
+                        "   SectorCount:         %u\n"
+                        "   TransferElementSize: %u\n"
+                        "   AccessFormat:        %s\n"
+                        "   CreationTime:        %s",
+                        uptr->filename,
+                        f->CreatingSimulator, f->DriveType, NtoHl(f->SectorSize), NtoHl (f->SectorCount), 
+                        NtoHl (f->TransferElementSize), fmts[f->AccessFormat].name, f->CreationTime);
+            sim_printf ("Container Size: %s bytes\n", sim_fmt_numeric ((double)ctx->container_size));
+            }
+        else {
+            sim_printf ("Container Info for '%s' unavailable\n", uptr->filename);
+            sim_printf ("Container Size: %s bytes\n", sim_fmt_numeric ((double)container_size));
+            }
+        free (f);
+        free (uptr->filename);
+        close_function (container);
+        return SCPE_OK;
+        }
+    else
+        return sim_messagef (SCPE_OPENERR, "Can't open container file '%s' - %s\n", cptr, strerror (errno));
+    }
+return SCPE_NOFNC;
+}
+
+
 /* disk testing */
 
 #include <setjmp.h>

sim_disk.h

@@ -111,6 +111,7 @@ t_offset sim_disk_size (UNIT *uptr);
 t_bool sim_disk_vhd_support (void);
 t_bool sim_disk_raw_support (void);
 void sim_disk_data_trace (UNIT *uptr, const uint8 *data, size_t lba, size_t len, const char* txt, int detail, uint32 reason);
+t_stat sim_disk_info_cmd (int32 flag, CONST char *ptr);
 t_stat sim_disk_test (DEVICE *dptr);
 
 #ifdef  __cplusplus