@@ -304,10 +304,26 @@ void path_combine(char *dest, int dest_size,
void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz)
{
+ struct stat sb;
+ char *linkname;
+
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);
+ if (lstat(bs->backing_file, &sb) == -1) {
+ perror("lstat");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Check linkname is a link or not */
+ if (S_ISLNK(sb.st_mode)) {
+ linkname = malloc(sb.st_size + 1);
+ readlink(bs->backing_file, linkname, sb.st_size + 1);
+ linkname[sb.st_size] = '\0';
+ realpath(linkname, dest);
+ } else {
+ realpath(bs->backing_file, dest);
+ }
}
}
This patch fixed the following bug: https://bugzilla.redhat.com/show_bug.cgi?id=1084302 . path_combine can not calculate the correct full path name for backing_file. Such as: create a snapshot chain: sn2->sn1->$BASE_IMG backing file is : /home/wookpecker/img.qcow2 sn1 : /home/woodpecker/tmp/sn1 sn2 : /home/woodpecker/tmp/sn2 when create sn2, path_combine can not got a correct path for $BASE_IMG. In this patch, will check the backing_filename is a symlink or not firstly, then return the full(absolute) path via realpath. Signed-off-by: Jun Li <junmuzi@gmail.com> --- block.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)