fish: Keep device names in options drives list.

In the 'struct drv *drvs' structure, keep a list of the
device name(s) for each added drive or guest.  The device name
is the canonical name as that drive would be known inside
libguestfs, eg. "/dev/sda"

fish/fish.c

@@ -339,6 +339,8 @@ main (int argc, char *argv[])
         exit (EXIT_FAILURE);
       }
       drv->type = drv_N;
+      drv->device = NULL;
+      drv->nr_drives = -1;
       if (asprintf (&drv->N.filename, "test%d.img",
                     next_prepared_drive++) == -1) {
         perror ("asprintf");
@@ -346,7 +348,6 @@ main (int argc, char *argv[])
       }
       drv->N.data = create_prepared_file (optarg, drv->N.filename);
       drv->N.data_free = free_prep_data;
-      drv->N.device = NULL;     /* filled in by add_drives */
       drv->next = drvs;
       drvs = drv;
       break;
@@ -554,7 +555,7 @@ prepare_drives (struct drv *drv)
   if (drv) {
     prepare_drives (drv->next);
     if (drv->type == drv_N)
-      prepare_drive (drv->N.filename, drv->N.data, drv->N.device);
+      prepare_drive (drv->N.filename, drv->N.data, drv->device);
   }
 }
 

fish/options.c

@@ -41,6 +41,11 @@ add_drives (struct drv *drv, char next_drive)
   if (drv) {
     next_drive = add_drives (drv->next, next_drive);
 
+    if (asprintf (&drv->device, "/dev/sd%c", next_drive) == -1) {
+      perror ("asprintf");
+      exit (EXIT_FAILURE);
+    }
+
     switch (drv->type) {
     case drv_a:
       ad_optargs.bitmask = 0;
@@ -56,6 +61,7 @@ add_drives (struct drv *drv, char next_drive)
       if (r == -1)
         exit (EXIT_FAILURE);
 
+      drv->nr_drives = 1;
       next_drive++;
       break;
 
@@ -64,6 +70,7 @@ add_drives (struct drv *drv, char next_drive)
       if (r == -1)
         exit (EXIT_FAILURE);
 
+      drv->nr_drives = r;
       next_drive += r;
       break;
 
@@ -78,11 +85,7 @@ add_drives (struct drv *drv, char next_drive)
       if (r == -1)
         exit (EXIT_FAILURE);
 
-      if (asprintf (&drv->N.device, "/dev/sd%c", next_drive) == -1) {
-        perror ("asprintf");
-        exit (EXIT_FAILURE);
-      }
-
+      drv->nr_drives = 1;
       next_drive++;
       break;
 
@@ -133,12 +136,13 @@ free_drives (struct drv *drv)
   if (!drv) return;
   free_drives (drv->next);
 
+  free (drv->device);
+
   switch (drv->type) {
   case drv_a: /* a.filename and a.format are optargs, don't free them */ break;
   case drv_d: /* d.filename is optarg, don't free it */ break;
   case drv_N:
     free (drv->N.filename);
-    free (drv->N.device);
     drv->N.data_free (drv->N.data);
     break;
   default: ;                    /* keep GCC happy */

fish/options.h

@@ -77,6 +77,16 @@ extern const char *program_name;
 /* List of drives added via -a, -d or -N options. */
 struct drv {
   struct drv *next;
+
+  char *device;    /* Device name inside the appliance (eg. /dev/sda).
+                    * This is filled in when we add the drives in
+                    * add_drives.  Note that guests (-d option) may
+                    * have multiple drives, in which case this is the
+                    * first drive, and nr_drives is the number of
+                    * drives used.
+                    */
+  int nr_drives;   /* number of drives for this guest */
+
   enum { drv_a, drv_d, drv_N } type;
   union {
     struct {
@@ -90,7 +100,6 @@ struct drv {
       char *filename;       /* disk filename (testX.img) */
       void *data;           /* prepared type */
       void (*data_free)(void*); /* function to free 'data' */
-      char *device;         /* device inside the appliance */
     } N;
   };
 };
@@ -131,6 +140,8 @@ extern int add_libvirt_drives (const char *guest);
     exit (EXIT_FAILURE);                        \
   }                                             \
   drv->type = drv_a;                            \
+  drv->device = NULL;                           \
+  drv->nr_drives = -1;                          \
   drv->a.filename = optarg;                     \
   drv->a.format = format;                       \
   drv->next = drvs;                             \
@@ -146,6 +157,8 @@ extern int add_libvirt_drives (const char *guest);
     exit (EXIT_FAILURE);                        \
   }                                             \
   drv->type = drv_d;                            \
+  drv->device = NULL;                           \
+  drv->nr_drives = -1;                          \
   drv->d.guest = optarg;                        \
   drv->next = drvs;                             \
   drvs = drv