[PATCH] xl: Special case tap/aio for disk validation

[Kamala Narasimhan <kamala.narasimhan@gmail.com>]

Current disk validation code will fail when the disk file path is prefixed with tap:aio:vhd in the disk configuration file option.  This patch special cases tap:aio validation.

Note:  It appears qcow/qcow2 file format does not work with the current tapdisk.  So, I am checking only for vhd file format.  If there are other formats to check also, let me know.

Signed-off-by: Kamala Narasimhan <kamala.narasimhan@citrix.com>

Kamala

diff -r 67d5b8004947 tools/libxl/libxl.c
--- a/tools/libxl/libxl.c       Wed Jan 26 11:58:45 2011 +0000
+++ b/tools/libxl/libxl.c       Wed Jan 26 14:26:57 2011 -0500
@@ -836,22 +836,40 @@ static int validate_virtual_disk(libxl_c
 static int validate_virtual_disk(libxl_ctx *ctx, char *file_name, libxl_disk_phystype disk_type)
 {
     struct stat stat_buf;
+    const char *fname;

     if ( (file_name[0] == '\0') && (disk_type == PHYSTYPE_EMPTY) )
         return 0;

-    if ( stat(file_name, &stat_buf) != 0 ) {
-        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "failed to stat %s", file_name);
+    if ( disk_type == PHYSTYPE_AIO ) {
+        fname = strchr(file_name, ':');
+        if ( fname == NULL ) {
+            LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "missing file format prefix!"
+                   " tap:aio disk option must be followed by file format type");
+            return ERROR_INVAL;
+        }
+        fname++;
+        if ( strncmp(file_name, "vhd:", sizeof("vhd:")-1) != 0 ) {
+            LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Only vhd file format supported"
+                   " with tapdisk");
+            return ERROR_INVAL;
+        }
+    }
+    else
+        fname = file_name;
+
+    if ( stat(fname, &stat_buf) != 0 ) {
+        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "failed to stat %s", fname);
         return ERROR_INVAL;
     }
     if ( disk_type == PHYSTYPE_PHY ) {
         if ( !(S_ISBLK(stat_buf.st_mode)) ) {
             LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Virtual disk %s is not a block device!\n",
-                file_name);
+                fname);
             return ERROR_INVAL;
         }
     } else if ( S_ISREG(stat_buf.st_mode) && stat_buf.st_size == 0 ) {
-        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Virtual disk %s size is 0!\n", file_name);
+        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Virtual disk %s size is 0!\n", fname);
         return ERROR_INVAL;
     }