libxl: Accept disk name in libxl_devid_to_device_disk

Accept disk name in xl block-detach.

Signed-off-by: Marek Marczykowski <marmarek@mimuw.edu.pl>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>

tools/libxl/libxl_device.c

@@ -198,7 +198,8 @@ static int device_virtdisk_matches(const char *virtpath, const char *devtype,
     return 1;
 }
 
-int libxl__device_disk_dev_number(char *virtpath, int *pdisk, int *ppartition)
+int libxl__device_disk_dev_number(const char *virtpath, int *pdisk,
+                                  int *ppartition)
 {
     int disk, partition;
     char *ep;

tools/libxl/libxl_internal.h

@@ -207,7 +207,7 @@ _hidden char *libxl__device_disk_string_of_backend(libxl_disk_backend backend);
 _hidden char *libxl__device_disk_string_of_format(libxl_disk_format format);
 
 _hidden int libxl__device_physdisk_major_minor(const char *physpath, int *major, int *minor);
-_hidden int libxl__device_disk_dev_number(char *virtpath,
+_hidden int libxl__device_disk_dev_number(const char *virtpath,
                                           int *pdisk, int *ppartition);
 
 _hidden int libxl__device_console_add(libxl__gc *gc, uint32_t domid,

tools/libxl/libxl_utils.c

@@ -530,18 +530,18 @@ int libxl_devid_to_device_disk(libxl_ctx *ctx, uint32_t domid,
                                const char *devid, libxl_device_disk *disk)
 {
     libxl__gc gc = LIBXL_INIT_GC(ctx);
-    char *endptr, *val;
+    char *val;
     char *dompath, *diskpath, *be_path;
     unsigned int devid_n;
     int rc = ERROR_INVAL;
 
-    devid_n = strtoul(devid, &endptr, 10);
-    if (devid == endptr) {
+    devid_n = libxl__device_disk_dev_number(devid, NULL, NULL);
+    if (devid_n < 0) {
         goto out;
     }
     rc = ERROR_FAIL;
     dompath = libxl__xs_get_dompath(&gc, domid);
-    diskpath = libxl__sprintf(&gc, "%s/device/vbd/%s", dompath, devid);
+    diskpath = libxl__sprintf(&gc, "%s/device/vbd/%d", dompath, devid_n);
     if (!diskpath) {
         goto out;
     }