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From 53baacb72e8561391841363b2acbd85a783cbc66 Mon Sep 17 00:00:00 2001
From: Eric Blake <eblake@redhat.com>
Date: Tue, 2 Jun 2020 02:34:15 +0100
Subject: [PATCH 10/26] qemu-img: Add bitmap sub-command

RH-Author: Eric Blake <eblake@redhat.com>
Message-id: <20200602023420.2133649-8-eblake@redhat.com>
Patchwork-id: 97074
O-Subject: [RHEL-AV-8.2.1 qemu-kvm PATCH 07/12] qemu-img: Add bitmap sub-command
Bugzilla: 1779893 1779904
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>

Include actions for --add, --remove, --clear, --enable, --disable, and
--merge (note that --clear is a bit of fluff, because the same can be
accomplished by removing a bitmap and then adding a new one in its
place, but it matches what QMP commands exist).  Listing is omitted,
because it does not require a bitmap name and because it was already
possible with 'qemu-img info'.  A single command line can play one or
more bitmap commands in sequence on the same bitmap name (although all
added bitmaps share the same granularity, and and all merged bitmaps
come from the same source file).  Merge defaults to other bitmaps in
the primary image, but can also be told to merge bitmaps from a
distinct image.

While this supports --image-opts for the file being modified, I did
not think it worth the extra complexity to support that for the source
file in a cross-file merges.  Likewise, I chose to have --merge only
take a single source rather than following the QMP support for
multiple merges in one go (although you can still use more than one
--merge in the command line); in part because qemu-img is offline and
therefore atomicity is not an issue.

Upcoming patches will add iotest coverage of these commands while
also testing other features.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513011648.166876-7-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
(cherry picked from commit 3b51ab4bf0f49a01cc2db7b954e0669e081719b5)

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

Conflicts:
	docs/tools/qemu-img.rst - lives in qemu-img.texi instead; plus
	 fix a typo in the text for --merge rather than waiting for
	 a one-line upstream followup patch
	qemu-img-cmds.hx - context, use texi instead of rst
	qemu-img.c - context
Signed-off-by: Eric Blake <eblake@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 qemu-img-cmds.hx |   6 ++
 qemu-img.c       | 248 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-img.texi    |  27 ++++++
 3 files changed, 281 insertions(+)

diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index 1c93e6d..1a6a8e9 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -25,6 +25,12 @@ STEXI
 @item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [--flush-interval=@var{flush_interval}] [-n] [--no-drain] [-o @var{offset}] [--pattern=@var{pattern}] [-q] [-s @var{buffer_size}] [-S @var{step_size}] [-t @var{cache}] [-w] [-U] @var{filename}
 ETEXI
 
+DEF("bitmap", img_bitmap,
+    "bitmap (--merge SOURCE | --add | --remove | --clear | --enable | --disable)... [-b source_file [-F source_fmt]] [-g granularity] [--object objectdef] [--image-opts | -f fmt] filename bitmap")
+STEXI
+.. option:: bitmap (--merge @var{source} | --add | --remove | --clear | --enable | --disable)... [-b @var{source_file} [-F @var{source_fmt}]] [-g @var{granularity}] [--object @var{objectdef}] [--image-opts | -f @var{fmt}] @var{filename} @var{bitmap}
+ETEXI
+
 DEF("check", img_check,
     "check [--object objectdef] [--image-opts] [-q] [-f fmt] [--output=ofmt] [-r [leaks | all]] [-T src_cache] [-U] filename")
 STEXI
diff --git a/qemu-img.c b/qemu-img.c
index e69529b..11a4537 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -28,6 +28,7 @@
 #include "qemu-common.h"
 #include "qemu-version.h"
 #include "qapi/error.h"
+#include "qapi/qapi-commands-block-core.h"
 #include "qapi/qapi-visit-block-core.h"
 #include "qapi/qobject-output-visitor.h"
 #include "qapi/qmp/qjson.h"
@@ -70,6 +71,12 @@ enum {
     OPTION_PREALLOCATION = 265,
     OPTION_SHRINK = 266,
     OPTION_SALVAGE = 267,
+    OPTION_ADD = 269,
+    OPTION_REMOVE = 270,
+    OPTION_CLEAR = 271,
+    OPTION_ENABLE = 272,
+    OPTION_DISABLE = 273,
+    OPTION_MERGE = 274,
 };
 
 typedef enum OutputFormat {
@@ -168,6 +175,14 @@ static void QEMU_NORETURN help(void)
            "  '-n' skips the target volume creation (useful if the volume is created\n"
            "       prior to running qemu-img)\n"
            "\n"
+           "Parameters to bitmap subcommand:\n"
+           "  'bitmap' is the name of the bitmap to manipulate, through one or more\n"
+           "       actions from '--add', '--remove', '--clear', '--enable', '--disable',\n"
+           "       or '--merge source'\n"
+           "  '-g granularity' sets the granularity for '--add' actions\n"
+           "  '-b source' and '-F src_fmt' tell '--merge' actions to find the source\n"
+           "       bitmaps from an alternative file\n"
+           "\n"
            "Parameters to check subcommand:\n"
            "  '-r' tries to repair any inconsistencies that are found during the check.\n"
            "       '-r leaks' repairs only cluster leaks, whereas '-r all' fixes all\n"
@@ -4402,6 +4417,239 @@ out:
     return 0;
 }
 
+enum ImgBitmapAct {
+    BITMAP_ADD,
+    BITMAP_REMOVE,
+    BITMAP_CLEAR,
+    BITMAP_ENABLE,
+    BITMAP_DISABLE,
+    BITMAP_MERGE,
+};
+typedef struct ImgBitmapAction {
+    enum ImgBitmapAct act;
+    const char *src; /* only used for merge */
+    QSIMPLEQ_ENTRY(ImgBitmapAction) next;
+} ImgBitmapAction;
+
+static int img_bitmap(int argc, char **argv)
+{
+    Error *err = NULL;
+    int c, ret = 1;
+    QemuOpts *opts = NULL;
+    const char *fmt = NULL, *src_fmt = NULL, *src_filename = NULL;
+    const char *filename, *bitmap;
+    BlockBackend *blk = NULL, *src = NULL;
+    BlockDriverState *bs = NULL, *src_bs = NULL;
+    bool image_opts = false;
+    int64_t granularity = 0;
+    bool add = false, merge = false;
+    QSIMPLEQ_HEAD(, ImgBitmapAction) actions;
+    ImgBitmapAction *act, *act_next;
+    const char *op;
+
+    QSIMPLEQ_INIT(&actions);
+
+    for (;;) {
+        static const struct option long_options[] = {
+            {"help", no_argument, 0, 'h'},
+            {"object", required_argument, 0, OPTION_OBJECT},
+            {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
+            {"add", no_argument, 0, OPTION_ADD},
+            {"remove", no_argument, 0, OPTION_REMOVE},
+            {"clear", no_argument, 0, OPTION_CLEAR},
+            {"enable", no_argument, 0, OPTION_ENABLE},
+            {"disable", no_argument, 0, OPTION_DISABLE},
+            {"merge", required_argument, 0, OPTION_MERGE},
+            {"granularity", required_argument, 0, 'g'},
+            {"source-file", required_argument, 0, 'b'},
+            {"source-format", required_argument, 0, 'F'},
+            {0, 0, 0, 0}
+        };
+        c = getopt_long(argc, argv, ":b:f:F:g:h", long_options, NULL);
+        if (c == -1) {
+            break;
+        }
+
+        switch (c) {
+        case ':':
+            missing_argument(argv[optind - 1]);
+            break;
+        case '?':
+            unrecognized_option(argv[optind - 1]);
+            break;
+        case 'h':
+            help();
+            break;
+        case 'b':
+            src_filename = optarg;
+            break;
+        case 'f':
+            fmt = optarg;
+            break;
+        case 'F':
+            src_fmt = optarg;
+            break;
+        case 'g':
+            granularity = cvtnum("granularity", optarg);
+            if (granularity < 0) {
+                return 1;
+            }
+            break;
+        case OPTION_ADD:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_ADD;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            add = true;
+            break;
+        case OPTION_REMOVE:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_REMOVE;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            break;
+        case OPTION_CLEAR:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_CLEAR;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            break;
+        case OPTION_ENABLE:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_ENABLE;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            break;
+        case OPTION_DISABLE:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_DISABLE;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            break;
+        case OPTION_MERGE:
+            act = g_new0(ImgBitmapAction, 1);
+            act->act = BITMAP_MERGE;
+            act->src = optarg;
+            QSIMPLEQ_INSERT_TAIL(&actions, act, next);
+            merge = true;
+            break;
+        case OPTION_OBJECT:
+            opts = qemu_opts_parse_noisily(&qemu_object_opts, optarg, true);
+            if (!opts) {
+                goto out;
+            }
+            break;
+        case OPTION_IMAGE_OPTS:
+            image_opts = true;
+            break;
+        }
+    }
+
+    if (qemu_opts_foreach(&qemu_object_opts,
+                          user_creatable_add_opts_foreach,
+                          qemu_img_object_print_help, &error_fatal)) {
+        goto out;
+    }
+
+    if (QSIMPLEQ_EMPTY(&actions)) {
+        error_report("Need at least one of --add, --remove, --clear, "
+                     "--enable, --disable, or --merge");
+        goto out;
+    }
+
+    if (granularity && !add) {
+        error_report("granularity only supported with --add");
+        goto out;
+    }
+    if (src_fmt && !src_filename) {
+        error_report("-F only supported with -b");
+        goto out;
+    }
+    if (src_filename && !merge) {
+        error_report("Merge bitmap source file only supported with "
+                     "--merge");
+        goto out;
+    }
+
+    if (optind != argc - 2) {
+        error_report("Expecting filename and bitmap name");
+        goto out;
+    }
+
+    filename = argv[optind];
+    bitmap = argv[optind + 1];
+
+    blk = img_open(image_opts, filename, fmt, BDRV_O_RDWR, false, false,
+                   false);
+    if (!blk) {
+        goto out;
+    }
+    bs = blk_bs(blk);
+    if (src_filename) {
+        src = img_open(false, src_filename, src_fmt, 0, false, false, false);
+        if (!src) {
+            goto out;
+        }
+        src_bs = blk_bs(src);
+    } else {
+        src_bs = bs;
+    }
+
+    QSIMPLEQ_FOREACH_SAFE(act, &actions, next, act_next) {
+        switch (act->act) {
+        case BITMAP_ADD:
+            qmp_block_dirty_bitmap_add(bs->node_name, bitmap,
+                                       !!granularity, granularity, true, true,
+                                       false, false, &err);
+            op = "add";
+            break;
+        case BITMAP_REMOVE:
+            qmp_block_dirty_bitmap_remove(bs->node_name, bitmap, &err);
+            op = "remove";
+            break;
+        case BITMAP_CLEAR:
+            qmp_block_dirty_bitmap_clear(bs->node_name, bitmap, &err);
+            op = "clear";
+            break;
+        case BITMAP_ENABLE:
+            qmp_block_dirty_bitmap_enable(bs->node_name, bitmap, &err);
+            op = "enable";
+            break;
+        case BITMAP_DISABLE:
+            qmp_block_dirty_bitmap_disable(bs->node_name, bitmap, &err);
+            op = "disable";
+            break;
+        case BITMAP_MERGE: {
+            BlockDirtyBitmapMergeSource *merge_src;
+            BlockDirtyBitmapMergeSourceList *list;
+
+            merge_src = g_new0(BlockDirtyBitmapMergeSource, 1);
+            merge_src->type = QTYPE_QDICT;
+            merge_src->u.external.node = g_strdup(src_bs->node_name);
+            merge_src->u.external.name = g_strdup(act->src);
+            list = g_new0(BlockDirtyBitmapMergeSourceList, 1);
+            list->value = merge_src;
+            qmp_block_dirty_bitmap_merge(bs->node_name, bitmap, list, &err);
+            qapi_free_BlockDirtyBitmapMergeSourceList(list);
+            op = "merge";
+            break;
+        }
+        default:
+            g_assert_not_reached();
+        }
+
+        if (err) {
+            error_reportf_err(err, "Operation %s on bitmap %s failed: ",
+                              op, bitmap);
+            goto out;
+        }
+        g_free(act);
+    }
+
+    ret = 0;
+
+ out:
+    blk_unref(src);
+    blk_unref(blk);
+    qemu_opts_del(opts);
+    return ret;
+}
+
 #define C_BS      01
 #define C_COUNT   02
 #define C_IF      04
diff --git a/qemu-img.texi b/qemu-img.texi
index b5156d6..abf2771 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -230,6 +230,33 @@ specified as well.
 For write tests, by default a buffer filled with zeros is written. This can be
 overridden with a pattern byte specified by @var{pattern}.
 
+@item bitmap (--merge @var{source} | --add | --remove | --clear | --enable | --disable)... [-b @var{source_file} [-F @var{source_fmt}]] [-g @var{granularity}] [--object @var{objectdef}] [--image-opts | -f @var{fmt}] @var{filename} @var{bitmap}
+
+Perform one or more modifications of the persistent bitmap @var{bitmap}
+in the disk image @var{filename}.  The various modifications are:
+
+@table @option
+@item add
+create @var{bitmap}, enabled to record future edits.
+@item remove
+remove @var{bitmap}.
+@item clear
+clear @var{bitmap}.
+@item enable
+change @var{bitmap} to start recording future edits.
+@item disable
+change @var{bitmap} to stop recording future edits.
+@item merge @var{source}
+merge the contents of the @var{source} bitmap into @var{bitmap}.
+@end table
+
+Additional options include @option{-g} which sets a non-default
+@var{granularity} for @option{--add}, and @option{-b} and @option{-F}
+which select an alternative source file for all @var{source} bitmaps used by
+@option{--merge}.
+
+To see what bitmaps are present in an image, use @code{qemu-img info}.
+
 @item check [--object @var{objectdef}] [--image-opts] [-q] [-f @var{fmt}] [--output=@var{ofmt}] [-r [leaks | all]] [-T @var{src_cache}] [-U] @var{filename}
 
 Perform a consistency check on the disk image @var{filename}. The command can
-- 
1.8.3.1