block: Don't parse protocol from file.filename

One of the major reasons for doing something new for -blockdev and
blockdev-add was that the old block layer code parses filenames instead
of just taking them literally. So we should really leave it untouched
when it's passing using the new interfaces (like -drive
file.filename=...).

This allows opening relative file names that contain a colon.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

block.c

@@ -417,7 +417,7 @@ int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
 {
     BlockDriver *drv;
 
-    drv = bdrv_find_protocol(filename);
+    drv = bdrv_find_protocol(filename, true);
     if (drv == NULL) {
         return -ENOENT;
     }
@@ -482,7 +482,8 @@ static BlockDriver *find_hdev_driver(const char *filename)
     return drv;
 }
 
-BlockDriver *bdrv_find_protocol(const char *filename)
+BlockDriver *bdrv_find_protocol(const char *filename,
+                                bool allow_protocol_prefix)
 {
     BlockDriver *drv1;
     char protocol[128];
@@ -503,9 +504,10 @@ BlockDriver *bdrv_find_protocol(const char *filename)
         return drv1;
     }
 
-    if (!path_has_protocol(filename)) {
+    if (!path_has_protocol(filename) || !allow_protocol_prefix) {
         return bdrv_find_format("file");
     }
+
     p = strchr(filename, ':');
     assert(p != NULL);
     len = p - filename;
@@ -784,6 +786,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
     BlockDriverState *bs;
     BlockDriver *drv;
     const char *drvname;
+    bool allow_protocol_prefix = false;
     int ret;
 
     /* NULL means an empty set of options */
@@ -800,6 +803,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
         filename = qdict_get_try_str(options, "filename");
     } else if (filename && !qdict_haskey(options, "filename")) {
         qdict_put(options, "filename", qstring_from_str(filename));
+        allow_protocol_prefix = true;
     } else {
         qerror_report(ERROR_CLASS_GENERIC_ERROR, "Can't specify 'file' and "
                       "'filename' options at the same time");
@@ -813,7 +817,10 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
         drv = bdrv_find_whitelisted_format(drvname, !(flags & BDRV_O_RDWR));
         qdict_del(options, "driver");
     } else if (filename) {
-        drv = bdrv_find_protocol(filename);
+        drv = bdrv_find_protocol(filename, allow_protocol_prefix);
+        if (!drv) {
+            qerror_report(ERROR_CLASS_GENERIC_ERROR, "Unknown protocol");
+        }
     } else {
         qerror_report(ERROR_CLASS_GENERIC_ERROR,
                       "Must specify either driver or file");
@@ -4452,7 +4459,7 @@ void bdrv_img_create(const char *filename, const char *fmt,
         return;
     }
 
-    proto_drv = bdrv_find_protocol(filename);
+    proto_drv = bdrv_find_protocol(filename, true);
     if (!proto_drv) {
         error_setg(errp, "Unknown protocol '%s'", filename);
         return;

block/sheepdog.c

@@ -1510,7 +1510,7 @@ static int sd_create(const char *filename, QEMUOptionParameter *options)
         BlockDriver *drv;
 
         /* Currently, only Sheepdog backing image is supported. */
-        drv = bdrv_find_protocol(backing_file);
+        drv = bdrv_find_protocol(backing_file, true);
         if (!drv || strcmp(drv->protocol_name, "sheepdog") != 0) {
             error_report("backing_file must be a sheepdog image");
             ret = -EINVAL;

include/block/block.h

@@ -111,7 +111,8 @@ bool bdrv_io_limits_enabled(BlockDriverState *bs);
 
 void bdrv_init(void);
 void bdrv_init_with_whitelist(void);
-BlockDriver *bdrv_find_protocol(const char *filename);
+BlockDriver *bdrv_find_protocol(const char *filename,
+                                bool allow_protocol_prefix);
 BlockDriver *bdrv_find_format(const char *format_name);
 BlockDriver *bdrv_find_whitelisted_format(const char *format_name,
                                           bool readonly);

qemu-img.c

@@ -240,7 +240,7 @@ static int print_block_option_help(const char *filename, const char *fmt)
         return 1;
     }
 
-    proto_drv = bdrv_find_protocol(filename);
+    proto_drv = bdrv_find_protocol(filename, true);
     if (!proto_drv) {
         error_report("Unknown protocol '%s'", filename);
         return 1;
@@ -1261,7 +1261,7 @@ static int img_convert(int argc, char **argv)
         goto out;
     }
 
-    proto_drv = bdrv_find_protocol(out_filename);
+    proto_drv = bdrv_find_protocol(out_filename, true);
     if (!proto_drv) {
         error_report("Unknown protocol '%s'", out_filename);
         ret = -1;

tests/qemu-iotests/051

@@ -149,6 +149,18 @@ echo
 run_qemu -drive file=$TEST_IMG,file.driver=file
 run_qemu -drive file=$TEST_IMG,file.driver=qcow2
 
+echo
+echo === Parsing protocol from file name ===
+echo
+
+# Protocol strings are supposed to be parsed from traditional option strings,
+# but not when using driver-specific options. We can distinguish them by the
+# error message for non-existing files.
+
+run_qemu -hda foo:bar
+run_qemu -drive file=foo:bar
+run_qemu -drive file.filename=foo:bar
+
 # success, all done
 echo "*** done"
 rm -f $seq.full

tests/qemu-iotests/051.out

@@ -169,4 +169,18 @@ Testing: -drive file=TEST_DIR/t.qcow2,file.driver=qcow2
 QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.driver=qcow2: Can't use 'qcow2' as a block driver for the protocol level
 QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.driver=qcow2: could not open disk image TEST_DIR/t.qcow2: Invalid argument
 
+
+=== Parsing protocol from file name ===
+
+Testing: -hda foo:bar
+QEMU_PROG: -hda foo:bar: Unknown protocol
+QEMU_PROG: -hda foo:bar: could not open disk image foo:bar: No such file or directory
+
+Testing: -drive file=foo:bar
+QEMU_PROG: -drive file=foo:bar: Unknown protocol
+QEMU_PROG: -drive file=foo:bar: could not open disk image foo:bar: No such file or directory
+
+Testing: -drive file.filename=foo:bar
+QEMU_PROG: -drive file.filename=foo:bar: could not open disk image ide0-hd0: No such file or directory
+
 *** done