From: Max Reitz <mreitz@redhat.com>

bdrv_find_backing_image() should use bdrv_get_full_backing_filename() or
bdrv_make_absolute_filename() instead of trying to do what those
functions do by itself.

path_combine_deprecated() can now be dropped, so let's do that.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-14-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c | 33 ++++++++++-----------------------
 1 file changed, 10 insertions(+), 23 deletions(-)

diff --git a/block.c b/block.c
index c66cd111e1..d14ce1c98c 100644
--- a/block.c
+++ b/block.c
@@ -201,15 +201,6 @@ char *path_combine(const char *base_path, const char *filename)
     return result;
 }
 
-static void path_combine_deprecated(char *dest, int dest_size,
-                                    const char *base_path,
-                                    const char *filename)
-{
-    char *combined = path_combine(base_path, filename);
-    pstrcpy(dest, dest_size, combined);
-    g_free(combined);
-}
-
 /*
  * Helper function for bdrv_parse_filename() implementations to remove optional
  * protocol prefixes (especially "file:") from a filename and for putting the
@@ -4654,13 +4645,9 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 
     filename_full     = g_malloc(PATH_MAX);
     backing_file_full = g_malloc(PATH_MAX);
-    filename_tmp      = g_malloc(PATH_MAX);
 
     is_protocol = path_has_protocol(backing_file);
 
-    /* This will recursively refresh everything in the backing chain */
-    bdrv_refresh_filename(bs);
-
     for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) {
 
         /* If either of the filename paths is actually a protocol, then
@@ -4686,22 +4673,23 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
         } else {
             /* If not an absolute filename path, make it relative to the current
              * image's filename path */
-            path_combine_deprecated(filename_tmp, PATH_MAX, curr_bs->filename,
-                                    backing_file);
-
-            /* We are going to compare absolute pathnames */
-            if (!realpath(filename_tmp, filename_full)) {
+            filename_tmp = bdrv_make_absolute_filename(curr_bs, backing_file,
+                                                       NULL);
+            /* We are going to compare canonicalized absolute pathnames */
+            if (!filename_tmp || !realpath(filename_tmp, filename_full)) {
+                g_free(filename_tmp);
                 continue;
             }
+            g_free(filename_tmp);
 
             /* We need to make sure the backing filename we are comparing against
              * is relative to the current image filename (or absolute) */
-            path_combine_deprecated(filename_tmp, PATH_MAX, curr_bs->filename,
-                                    curr_bs->backing_file);
-
-            if (!realpath(filename_tmp, backing_file_full)) {
+            filename_tmp = bdrv_get_full_backing_filename(curr_bs, NULL);
+            if (!filename_tmp || !realpath(filename_tmp, backing_file_full)) {
+                g_free(filename_tmp);
                 continue;
             }
+            g_free(filename_tmp);
 
             if (strcmp(backing_file_full, filename_full) == 0) {
                 retval = curr_bs->backing->bs;
@@ -4712,7 +4700,6 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 
     g_free(filename_full);
     g_free(backing_file_full);
-    g_free(filename_tmp);
     return retval;
 }
 
-- 
2.20.1