e.g:
$ pwd
/tmp
$ /opt/qemu-git-arm/bin/qemu-img create -f qcow2 ./test 5M
Formatting './test', fmt=qcow2 size=5242880 encryption=off cluster_size=65536
lazy_refcounts=off
$ /opt/qemu-git-arm/bin/qemu-img create -f qcow2 ./tmp/test1 -b ./test
Formatting './tmp/test1', fmt=qcow2 size=5242880 backing_file='./test'
encryption=off cluster_size=65536 lazy_refcounts=off
$ /opt/qemu-git-arm/bin/qemu-img create -f qcow2 ./tmp/test2 -b ./tmp/test1
qemu-img: ./tmp/test2: Could not open './tmp/test1': Could not open backing
file: Could not open './tmp/./test': No such file or directory: No such file
or directory
This patch also fixes the following bug:
https://bugzilla.redhat.com/show_bug.cgi?id=1161582#c2
Signed-off-by: Jun Li <address@hidden>
---
block.c | 28 +++++++++++++++++++++++++++-
include/block/block.h | 2 ++
2 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/block.c b/block.c
index dacd881..5e2f669 100644
--- a/block.c
+++ b/block.c
@@ -259,6 +259,32 @@ int path_is_absolute(const char *path)
#endif
}
+void get_localfile_absolute_path(char *dest, int dest_size,
+ const char *filename)
+{
+ struct stat sb;
+ char *linkname;
+
+ if (path_is_absolute(filename)) {
+ pstrcpy(dest, dest_size, filename);
+ } else {
+ if (lstat(filename, &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(filename, linkname, sb.st_size + 1);
+ linkname[sb.st_size] = '\0';
+ realpath(linkname, dest);
+ } else {
+ realpath(filename, dest);
+ }
+ }
+}
+
/* if filename is absolute, just copy it to dest. Otherwise, build a
path to it by considering it is relative to base_path. URL are
supported. */
@@ -308,7 +334,7 @@ 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);
+ get_localfile_absolute_path(dest, sz, bs->backing_file);
}
}
diff --git a/include/block/block.h b/include/block/block.h
index 13e4537..6ddb150 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -398,6 +398,8 @@ void bdrv_get_full_backing_filename(BlockDriverState *bs,
int bdrv_is_snapshot(BlockDriverState *bs);
int path_is_absolute(const char *path);
+void get_localfile_absolute_path(char *dest, int dest_size,
+ const char *filename);
void path_combine(char *dest, int dest_size,
const char *base_path,
const char *filename);