Patchwork [v3,10/21] block: Allow block devices without files

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Submitter Max Reitz
Date Dec. 11, 2013, 6:11 p.m.
Message ID <1386785473-26157-11-git-send-email-mreitz@redhat.com>
Download mbox | patch
Permalink /patch/300247/
State New
Headers show

Comments

Max Reitz - Dec. 11, 2013, 6:11 p.m.
blkdebug and blkverify will, in order to retain compatibility, not
support the field "file" implicitly through bdrv_open(). In order to be
able to use those drivers without giving a filename anyway, it is
necessary to be able to have block devices without files implicitly
opened by bdrv_open(). This is the case, if there was neither a file
name, a reference to an existing block device to use as a file nor
options specific to the file.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

Patch

diff --git a/block.c b/block.c
index 4a2c251..33ef995 100644
--- a/block.c
+++ b/block.c
@@ -1147,11 +1147,14 @@  int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
     qdict_extract_subqdict(options, &file_options, "file.");
     file_reference = qdict_get_try_str(options, "file");
 
-    ret = bdrv_file_open(&file, filename, file_reference, file_options,
-                         bdrv_open_flags(bs, flags | BDRV_O_UNMAP), &local_err);
-    qdict_del(options, "file");
-    if (ret < 0) {
-        goto fail;
+    if (filename || file_reference || qdict_size(file_options)) {
+        ret = bdrv_file_open(&file, filename, file_reference, file_options,
+                             bdrv_open_flags(bs, flags | BDRV_O_UNMAP),
+                             &local_err);
+        qdict_del(options, "file");
+        if (ret < 0) {
+            goto fail;
+        }
     }
 
     /* Find the right image format driver */
@@ -1180,7 +1183,7 @@  int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
         goto unlink_and_fail;
     }
 
-    if (bs->file != file) {
+    if (file && (bs->file != file)) {
         bdrv_unref(file);
         file = NULL;
     }