qemu-img: add support for rate limit in qemu-img commit

add support for rate limit in qemu-img commit.

Signed-off-by: Zhengui <lizhengui@huawei.com>
Message-Id: <1603205264-17424-2-git-send-email-lizhengui@huawei.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

docs/tools/qemu-img.rst

@@ -349,7 +349,7 @@ Command description:
   state after (the attempt at) repairing it. That is, a successful ``-r all``
   will yield the exit code 0, independently of the image state before.
 
-.. option:: commit [--object OBJECTDEF] [--image-opts] [-q] [-f FMT] [-t CACHE] [-b BASE] [-d] [-p] FILENAME
+.. option:: commit [--object OBJECTDEF] [--image-opts] [-q] [-f FMT] [-t CACHE] [-b BASE] [-r RATE_LIMIT] [-d] [-p] FILENAME
 
   Commit the changes recorded in *FILENAME* in its base image or backing file.
   If the backing file is smaller than the snapshot, then the backing file will be
@@ -371,6 +371,8 @@ Command description:
   garbage data when read. For this reason, ``-b`` implies ``-d`` (so that
   the top image stays valid).
 
+  The rate limit for the commit process is specified by ``-r``.
+
 .. option:: compare [--object OBJECTDEF] [--image-opts] [-f FMT] [-F FMT] [-T SRC_CACHE] [-p] [-q] [-s] [-U] FILENAME1 FILENAME2
 
   Check if two images have the same content. You can compare images with

qemu-img-cmds.hx

@@ -34,9 +34,9 @@ SRST
 ERST
 
 DEF("commit", img_commit,
-    "commit [--object objectdef] [--image-opts] [-q] [-f fmt] [-t cache] [-b base] [-d] [-p] filename")
+    "commit [--object objectdef] [--image-opts] [-q] [-f fmt] [-t cache] [-b base] [-r rate_limit] [-d] [-p] filename")
 SRST
-.. option:: commit [--object OBJECTDEF] [--image-opts] [-q] [-f FMT] [-t CACHE] [-b BASE] [-d] [-p] FILENAME
+.. option:: commit [--object OBJECTDEF] [--image-opts] [-q] [-f FMT] [-t CACHE] [-b BASE] [-r RATE_LIMIT] [-d] [-p] FILENAME
 ERST
 
 DEF("compare", img_compare,

qemu-img.c

@@ -980,6 +980,7 @@ static int img_commit(int argc, char **argv)
     CommonBlockJobCBInfo cbi;
     bool image_opts = false;
     AioContext *aio_context;
+    int64_t rate_limit = 0;
 
     fmt = NULL;
     cache = BDRV_DEFAULT_CACHE;
@@ -991,7 +992,7 @@ static int img_commit(int argc, char **argv)
             {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
             {0, 0, 0, 0}
         };
-        c = getopt_long(argc, argv, ":f:ht:b:dpq",
+        c = getopt_long(argc, argv, ":f:ht:b:dpqr:",
                         long_options, NULL);
         if (c == -1) {
             break;
@@ -1026,6 +1027,12 @@ static int img_commit(int argc, char **argv)
         case 'q':
             quiet = true;
             break;
+        case 'r':
+            rate_limit = cvtnum("rate limit", optarg);
+            if (rate_limit < 0) {
+                return 1;
+            }
+            break;
         case OPTION_OBJECT: {
             QemuOpts *opts;
             opts = qemu_opts_parse_noisily(&qemu_object_opts,
@@ -1099,7 +1106,7 @@ static int img_commit(int argc, char **argv)
 
     aio_context = bdrv_get_aio_context(bs);
     aio_context_acquire(aio_context);
-    commit_active_start("commit", bs, base_bs, JOB_DEFAULT, 0,
+    commit_active_start("commit", bs, base_bs, JOB_DEFAULT, rate_limit,
                         BLOCKDEV_ON_ERROR_REPORT, NULL, common_block_job_cb,
                         &cbi, false, &local_err);
     aio_context_release(aio_context);