[Libguestfs] [PATCH] lib: create: avoid one extra string allocation
When creating the qemu-img command, use the guestfs_int_cmd_add_arg &
guestfs_int_cmd_add_arg_format APIs to add the proper filename directly,
without creating a string for it.
This should cause no functional change.
---
lib/create.c | 25 +++++++++++--------------
1 file changed, 11 insertions(+), 14 deletions(-)
diff --git a/lib/create.c b/lib/create.c
index 60e467fb6..fcc5855e0 100644
--- a/lib/create.c
+++ b/lib/create.c
@@ -250,11 +250,10 @@ is_power_of_2 (unsigned v)
VALID_FLAG_ALPHA|VALID_FLAG_DIGIT, "")
static int
-disk_create_qcow2 (guestfs_h *g, const char *orig_filename, int64_t size,
+disk_create_qcow2 (guestfs_h *g, const char *filename, int64_t size,
const char *backingfile,
const struct guestfs_disk_create_argv *optargs)
{
- CLEANUP_FREE char *filename = NULL;
const char *backingformat = NULL;
const char *preallocation = NULL;
const char *compat = NULL;
@@ -263,16 +262,6 @@ disk_create_qcow2 (guestfs_h *g, const char *orig_filename, int64_t
size,
CLEANUP_CMD_CLOSE struct command *cmd = guestfs_int_new_command (g);
int r;
- /* If the filename is something like "file:foo" then qemu-img will
- * try to interpret that as "foo" in the file:/// protocol. To
- * avoid that, if the path is relative prefix it with "./" since
- * qemu-img won't try to interpret such a path.
- */
- if (orig_filename[0] != '/')
- filename = safe_asprintf (g, "./%s", orig_filename);
- else
- filename = safe_strdup (g, orig_filename);
-
if (optargs->bitmask & GUESTFS_DISK_CREATE_BACKINGFORMAT_BITMASK) {
backingformat = optargs->backingformat;
if (!VALID_FORMAT (backingformat)) {
@@ -341,13 +330,21 @@ disk_create_qcow2 (guestfs_h *g, const char *orig_filename, int64_t
size,
}
/* Complete the command line. */
- guestfs_int_cmd_add_arg (cmd, filename);
+ /* If the filename is something like "file:foo" then qemu-img will
+ * try to interpret that as "foo" in the file:/// protocol. To
+ * avoid that, if the path is relative prefix it with "./" since
+ * qemu-img won't try to interpret such a path.
+ */
+ if (filename[0] == '/')
+ guestfs_int_cmd_add_arg (cmd, filename);
+ else
+ guestfs_int_cmd_add_arg_format (cmd, "./%s", filename);
if (size >= 0)
guestfs_int_cmd_add_arg_format (cmd, "%" PRIi64, size);
r = guestfs_int_cmd_run (cmd);
if (!WIFEXITED (r) || WEXITSTATUS (r) != 0) {
- guestfs_int_external_command_failed (g, r, "qemu-img", orig_filename);
+ guestfs_int_external_command_failed (g, r, "qemu-img", filename);
return -1;
}
--
2.17.1