hw/i386/Makefile.obj: use $(PYTHON) to run .py scripts consistently

[qemu.git] / block.c

diff --git a/block.c b/block.c
index beea0274f813c324ec2f0db4eeb66deeb2799257..58efb5b4e474b30c87692557c6bd63e526ad693a 100644 (file)
--- a/block.c
+++ b/block.c
@@ -769,13 +769,22 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
     bs->read_only = !(open_flags & BDRV_O_RDWR);
 
     if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
-        error_setg(errp, "Driver '%s' is not whitelisted", drv->format_name);
+        error_setg(errp,
+                   !bs->read_only && bdrv_is_whitelisted(drv, true)
+                        ? "Driver '%s' can only be used for read-only devices"
+                        : "Driver '%s' is not whitelisted",
+                   drv->format_name);
         return -ENOTSUP;
     }
 
     assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */
-    if (!bs->read_only && (flags & BDRV_O_COPY_ON_READ)) {
-        bdrv_enable_copy_on_read(bs);
+    if (flags & BDRV_O_COPY_ON_READ) {
+        if (!bs->read_only) {
+            bdrv_enable_copy_on_read(bs);
+        } else {
+            error_setg(errp, "Can't use copy-on-read on read-only device");
+            return -EINVAL;
+        }
     }
 
     if (filename != NULL) {
@@ -881,7 +890,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
     /* Find the right block driver */
     drvname = qdict_get_try_str(options, "driver");
     if (drvname) {
-        drv = bdrv_find_whitelisted_format(drvname, !(flags & BDRV_O_RDWR));
+        drv = bdrv_find_format(drvname);
         if (!drv) {
             error_setg(errp, "Unknown driver '%s'", drvname);
         }
@@ -990,13 +999,12 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
     }
 
     /* backing files always opened read-only */
-    back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT);
+    back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT |
+                                    BDRV_O_COPY_ON_READ);
 
     ret = bdrv_open(bs->backing_hd,
                     *backing_filename ? backing_filename : NULL, options,
                     back_flags, back_drv, &local_err);
-    pstrcpy(bs->backing_file, sizeof(bs->backing_file),
-            bs->backing_hd->file->filename);
     if (ret < 0) {
         bdrv_unref(bs->backing_hd);
         bs->backing_hd = NULL;
@@ -1004,6 +1012,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
         error_propagate(errp, local_err);
         return ret;
     }
+    pstrcpy(bs->backing_file, sizeof(bs->backing_file),
+            bs->backing_hd->file->filename);
     return 0;
 }
 
@@ -1123,7 +1133,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
     /* Find the right image format driver */
     drvname = qdict_get_try_str(options, "driver");
     if (drvname) {
-        drv = bdrv_find_whitelisted_format(drvname, !(flags & BDRV_O_RDWR));
+        drv = bdrv_find_format(drvname);
         qdict_del(options, "driver");
     }
 
@@ -2859,9 +2869,10 @@ int64_t bdrv_getlength(BlockDriverState *bs)
     if (!drv)
         return -ENOMEDIUM;
 
-    if (bdrv_dev_has_removable_media(bs)) {
-        if (drv->bdrv_getlength) {
-            return drv->bdrv_getlength(bs);
+    if (drv->has_variable_length) {
+        int ret = refresh_total_sectors(bs, bs->total_sectors);
+        if (ret < 0) {
+            return ret;
         }
     }
     return bs->total_sectors * BDRV_SECTOR_SIZE;