qemu-img: snapshot: allow specifying -f fmt

For consistency with other commands, and since it already
accepts --image-opts, allow specifying -f fmt too.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-ID: <20250531171609.197078-16-mjt@tls.msk.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

docs/tools/qemu-img.rst

@@ -663,7 +663,7 @@ Command description:
   bitmap support, or 0 if bitmaps are supported but there is nothing
   to copy.
 
-.. option:: snapshot [--object OBJECTDEF] [--image-opts] [-U] [-q] [-l | -a SNAPSHOT | -c SNAPSHOT | -d SNAPSHOT] FILENAME
+.. option:: snapshot [--object OBJECTDEF] [-f FMT | --image-opts] [-U] [-q] [-l | -a SNAPSHOT | -c SNAPSHOT | -d SNAPSHOT] FILENAME
 
   List, apply, create or delete snapshots in image *FILENAME*.
 

qemu-img-cmds.hx

@@ -84,9 +84,9 @@ SRST
 ERST
 
 DEF("snapshot", img_snapshot,
-    "snapshot [--object objectdef] [--image-opts] [-U] [-q] [-l | -a snapshot | -c snapshot | -d snapshot] filename")
+    "snapshot [--object objectdef] [-f fmt | --image-opts] [-U] [-q] [-l | -a snapshot | -c snapshot | -d snapshot] filename")
 SRST
-.. option:: snapshot [--object OBJECTDEF] [--image-opts] [-U] [-q] [-l | -a SNAPSHOT | -c SNAPSHOT | -d SNAPSHOT] FILENAME
+.. option:: snapshot [--object OBJECTDEF] [-f FMT | --image-opts] [-U] [-q] [-l | -a SNAPSHOT | -c SNAPSHOT | -d SNAPSHOT] FILENAME
 ERST
 
 DEF("rebase", img_rebase,

qemu-img.c

@@ -3597,7 +3597,7 @@ static int img_snapshot(const img_cmd_t *ccmd, int argc, char **argv)
     BlockBackend *blk;
     BlockDriverState *bs;
     QEMUSnapshotInfo sn;
-    char *filename, *snapshot_name = NULL;
+    char *filename, *fmt = NULL, *snapshot_name = NULL;
     int c, ret = 0, bdrv_oflags;
     int action = 0;
     bool quiet = false;
@@ -3616,7 +3616,7 @@ static int img_snapshot(const img_cmd_t *ccmd, int argc, char **argv)
             {"force-share", no_argument, 0, 'U'},
             {0, 0, 0, 0}
         };
-        c = getopt_long(argc, argv, ":la:c:d:hqU",
+        c = getopt_long(argc, argv, ":la:c:d:f:hqU",
                         long_options, NULL);
         if (c == -1) {
             break;
@@ -3631,6 +3631,9 @@ static int img_snapshot(const img_cmd_t *ccmd, int argc, char **argv)
         case 'h':
             help();
             return 0;
+        case 'f':
+            fmt = optarg;
+            break;
         case 'l':
             if (action) {
                 error_exit(argv[0], "Cannot mix '-l', '-a', '-c', '-d'");
@@ -3684,7 +3687,7 @@ static int img_snapshot(const img_cmd_t *ccmd, int argc, char **argv)
     filename = argv[optind++];
 
     /* Open the image */
-    blk = img_open(image_opts, filename, NULL, bdrv_oflags, false, quiet,
+    blk = img_open(image_opts, filename, fmt, bdrv_oflags, false, quiet,
                    force_share);
     if (!blk) {
         return 1;