Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Tue 18 Jul 2017 14:29:59 BST
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (21 commits)
  qemu-img: Check for backing image if specified during create
  blockdev: move BDRV_O_NO_BACKING option forward
  block/vvfat: Fix compiler warning with gcc 7
  vvfat: initialize memory after allocating it
  vvfat: correctly parse non-ASCII short and long file names
  vvfat: add a constant for bootsector name
  vvfat: add constants for special values of name[0]
  qemu-iotests: Test unplug of -device without drive
  qemu-iotests: Test 'info block'
  scsi-disk: bdrv_attach_dev() for empty CD-ROM
  ide: bdrv_attach_dev() for empty CD-ROM
  block: List anonymous device BBs in query-block
  block/qapi: Use blk_all_next() for query-block
  block: Make blk_all_next() public
  block/qapi: Add qdev device name to query-block
  block: Make blk_get_attached_dev_id() public
  block/vpc.c: Handle write failures in get_image_offset()
  block/vmdk: Report failures in vmdk_read_cid()
  block: remove timer canceling in throttle_config()
  block: add clock_type field to ThrottleGroup
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 11 insertions, 5 deletions

diff --git a/qemu-img.c b/qemu-img.c
index 182e697f81..eb32b93e90 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -150,9 +150,11 @@ static void QEMU_NORETURN help(void)
            "  'snapshot_id_or_name' is deprecated, use 'snapshot_param'\n"
            "    instead\n"
            "  '-c' indicates that target image must be compressed (qcow format only)\n"
-           "  '-u' enables unsafe rebasing. It is assumed that old and new backing file\n"
-           "       match exactly. The image doesn't need a working backing file before\n"
-           "       rebasing in this case (useful for renaming the backing file)\n"
+           "  '-u' allows unsafe backing chains. For rebasing, it is assumed that old and\n"
+           "       new backing file match exactly. The image doesn't need a working\n"
+           "       backing file before rebasing in this case (useful for renaming the\n"
+           "       backing file). For image creation, allow creating without attempting\n"
+           "       to open the backing file.\n"
            "  '-h' with or without a command shows this help and lists the supported formats\n"
            "  '-p' show progress of command (only certain commands)\n"
            "  '-q' use Quiet mode - do not print any output (except errors)\n"
@@ -429,6 +431,7 @@ static int img_create(int argc, char **argv)
     char *options = NULL;
     Error *local_err = NULL;
     bool quiet = false;
+    int flags = 0;
 
     for(;;) {
         static const struct option long_options[] = {
@@ -436,7 +439,7 @@ static int img_create(int argc, char **argv)
             {"object", required_argument, 0, OPTION_OBJECT},
             {0, 0, 0, 0}
         };
-        c = getopt_long(argc, argv, ":F:b:f:ho:q",
+        c = getopt_long(argc, argv, ":F:b:f:ho:qu",
                         long_options, NULL);
         if (c == -1) {
             break;
@@ -476,6 +479,9 @@ static int img_create(int argc, char **argv)
         case 'q':
             quiet = true;
             break;
+        case 'u':
+            flags |= BDRV_O_NO_BACKING;
+            break;
         case OPTION_OBJECT: {
             QemuOpts *opts;
             opts = qemu_opts_parse_noisily(&qemu_object_opts,
@@ -528,7 +534,7 @@ static int img_create(int argc, char **argv)
     }
 
     bdrv_img_create(filename, fmt, base_filename, base_fmt,
-                    options, img_size, 0, quiet, &local_err);
+                    options, img_size, flags, quiet, &local_err);
     if (local_err) {
         error_reportf_err(local_err, "%s: ", filename);
         goto fail;