From: Paolo Bonzini <pbonzini@redhat.com>
Date: Tue, 8 May 2012 14:51:50 +0000 (+0200)
Subject: qemu-img: make "info" backing file output correct and easier to use
X-Git-Tag: v1.1-rc2~24^2~10
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dc5a137125d6ac641c566f10e68bf6e1fe31bcb5;p=thirdparty%2Fqemu.git

qemu-img: make "info" backing file output correct and easier to use

qemu-img info should use the same logic as qemu when printing the
backing file path, or debugging becomes quite tricky.  We can also
simplify the output in case the backing file has an absolute path
or a protocol.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---

diff --git a/block.c b/block.c
index 29869987a9f..af2ab4f3ea1 100644
--- a/block.c
+++ b/block.c
@@ -270,6 +270,15 @@ void path_combine(char *dest, int dest_size,
     }
 }
 
+void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz)
+{
+    if (bs->backing_file[0] == '\0' || path_has_protocol(bs->backing_file)) {
+        pstrcpy(dest, sz, bs->backing_file);
+    } else {
+        path_combine(dest, sz, bs->filename, bs->backing_file);
+    }
+}
+
 void bdrv_register(BlockDriver *bdrv)
 {
     /* Block drivers without coroutine functions need emulation */
@@ -796,14 +805,8 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         BlockDriver *back_drv = NULL;
 
         bs->backing_hd = bdrv_new("");
-
-        if (path_has_protocol(bs->backing_file)) {
-            pstrcpy(backing_filename, sizeof(backing_filename),
-                    bs->backing_file);
-        } else {
-            path_combine(backing_filename, sizeof(backing_filename),
-                         filename, bs->backing_file);
-        }
+        bdrv_get_full_backing_filename(bs, backing_filename,
+                                       sizeof(backing_filename));
 
         if (bs->backing_format[0] != '\0') {
             back_drv = bdrv_find_format(bs->backing_format);
diff --git a/block.h b/block.h
index f163e54b5f8..7408acc5cd3 100644
--- a/block.h
+++ b/block.h
@@ -303,6 +303,8 @@ int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
 void bdrv_get_backing_filename(BlockDriverState *bs,
                                char *filename, int filename_size);
+void bdrv_get_full_backing_filename(BlockDriverState *bs,
+                                    char *dest, size_t sz);
 int bdrv_can_snapshot(BlockDriverState *bs);
 int bdrv_is_snapshot(BlockDriverState *bs);
 BlockDriverState *bdrv_snapshots(void);
diff --git a/qemu-img.c b/qemu-img.c
index 0ae543cade9..5434ddc5ee2 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1138,11 +1138,13 @@ static int img_info(int argc, char **argv)
     }
     bdrv_get_backing_filename(bs, backing_filename, sizeof(backing_filename));
     if (backing_filename[0] != '\0') {
-        path_combine(backing_filename2, sizeof(backing_filename2),
-                     filename, backing_filename);
-        printf("backing file: %s (actual path: %s)\n",
-               backing_filename,
-               backing_filename2);
+        bdrv_get_full_backing_filename(bs, backing_filename2,
+                                       sizeof(backing_filename2));
+        printf("backing file: %s", backing_filename);
+        if (strcmp(backing_filename, backing_filename2) != 0) {
+            printf(" (actual path: %s)", backing_filename2);
+        }
+        putchar('\n');
     }
     dump_snapshots(bs);
     bdrv_delete(bs);