@samitouri / QOSamiQemu / commits / 7e8cc6c886

qemu-img: add sub-command --remove-all to 'qemu-img bitmap'

From time to time it is needed to remove all bitmaps from the image. Before this patch the process is not very convenient. One should perform qemu-img info and parse the output to obtain all names. After that one should sequentially call qemu-img bitmap --remove for each present bitmap. The patch adds --remove-all sub-command to 'qemu-img bitmap'. The new sub-command also composes with other bitmap actions in the same invocation, so a common "wipe and recreate" workflow can be expressed as qemu-img bitmap --remove-all --add NEW FILE instead of enumerating existing bitmaps, removing them one by one, and only then adding the fresh one. Cc: Kevin Wolf <kwolf@redhat.com> Cc: Hanna Czenczek <hreitz@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Message-ID: <20260520235952.500250-1-den@openvz.org> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Denis V. Lunev committed May 21, 2026 at 01:59 UTC 7e8cc6c886b7100ac4a7ff803562228fe3a6d4fd

4 files changed +125 -10

docs/tools/qemu-img.rst

+7 -3

@@ -301,15 +301,19 @@ Command description:

301 For write tests, by default a buffer filled with zeros is written. This can be

302 overridden with a pattern byte specified by *PATTERN*.

303

305

306 - Perform one or more modifications of the persistent bitmap *BITMAP*

307 - in the disk image *FILENAME*. The various modifications are:

306 + Perform one or more modifications of persistent bitmaps in the disk

307 + image *FILENAME*. Most operations require *BITMAP* to be specified;

308 + ``--remove-all`` operates on all bitmaps and does not take *BITMAP*.

309 + The various modifications are:

310

311 ``--add`` to create *BITMAP*, enabled to record future edits.

312

313 ``--remove`` to remove *BITMAP*.

314

315 + ``--remove-all`` to remove all bitmaps.

316 +

317 ``--clear`` to clear *BITMAP*.

318

319 ``--enable`` to change *BITMAP* to start recording future edits.

qemu-img.c

+48 -7

@@ -87,6 +87,7 @@ enum {

87 OPTION_FORCE = 276,

88 OPTION_SKIP_BROKEN = 277,

89 OPTION_LIMITS = 278,

90 + OPTION_REMOVE_ALL = 279,

91 };

93 typedef enum OutputFormat {

@@ -5018,6 +5019,7 @@ enum ImgBitmapAct {

5019 BITMAP_ENABLE,

5020 BITMAP_DISABLE,

5021 BITMAP_MERGE,

5022 + BITMAP_REMOVE_ALL,

5023 };

5024 typedef struct ImgBitmapAction {

5025 enum ImgBitmapAct act;

@@ -5036,7 +5038,7 @@ static int img_bitmap(const img_cmd_t *ccmd, int argc, char **argv)

5038 BlockDriverState *bs = NULL, *src_bs = NULL;

5039 bool image_opts = false;

5040 int64_t granularity = 0;

5039 - bool add = false, merge = false;

5041 + bool add = false, merge = false, need_bitmap_name = false;

5042 QSIMPLEQ_HEAD(, ImgBitmapAction) actions;

5043 ImgBitmapAction *act, *act_next;

5044 const char *op;

@@ -5052,6 +5054,7 @@ static int img_bitmap(const img_cmd_t *ccmd, int argc, char **argv)

5054 {"add", no_argument, 0, OPTION_ADD},

5055 {"granularity", required_argument, 0, 'g'},

5056 {"remove", no_argument, 0, OPTION_REMOVE},

5057 + {"remove-all", no_argument, 0, OPTION_REMOVE_ALL},

5058 {"clear", no_argument, 0, OPTION_CLEAR},

5059 {"enable", no_argument, 0, OPTION_ENABLE},

5060 {"disable", no_argument, 0, OPTION_DISABLE},

@@ -5070,9 +5073,9 @@ static int img_bitmap(const img_cmd_t *ccmd, int argc, char **argv)

5073 switch (c) {

5074 case 'h':

5075 cmd_help(ccmd, "[-f FMT | --image-opts]\n"

5074 -" --merge SOURCE [-b SRC_FILE [-F SRC_FMT]] )..\n"

5075 -" [--object OBJDEF] FILE BITMAP\n"

5077 +" --disable | --merge SOURCE [-b SRC_FILE [-F SRC_FMT]] )..\n"

5078 +" [--object OBJDEF] FILE [BITMAP]\n"

5079 ,

5080 " -f, --format FMT\n"

5081 " specify FILE format explicitly (default: probing is used)\n"

@@ -5086,6 +5089,8 @@ static int img_bitmap(const img_cmd_t *ccmd, int argc, char **argv)

5089 " with optional multiplier suffix (in powers of 1024)\n"

5090 " --remove\n"

5091 " removes BITMAP from FILE\n"

5092 +" --remove-all\n"

5093 +" removes all bitmaps from FILE\n"

5094 " --clear\n"

5095 " clears BITMAP in FILE\n"

5096 " --enable, --disable\n"

@@ -5116,6 +5121,7 @@ static int img_bitmap(const img_cmd_t *ccmd, int argc, char **argv)

5121 act->act = BITMAP_ADD;

5122 QSIMPLEQ_INSERT_TAIL(&actions, act, next);

5123 add = true;

5124 + need_bitmap_name = true;

5125 break;

5126 case 'g':

5127 granularity = cvtnum("granularity", optarg, true);

@@ -5127,21 +5133,30 @@ static int img_bitmap(const img_cmd_t *ccmd, int argc, char **argv)

5133 act = g_new0(ImgBitmapAction, 1);

5134 act->act = BITMAP_REMOVE;

5135 QSIMPLEQ_INSERT_TAIL(&actions, act, next);

5136 + need_bitmap_name = true;

5137 + break;

5138 + case OPTION_REMOVE_ALL:

5139 + act = g_new0(ImgBitmapAction, 1);

5140 + act->act = BITMAP_REMOVE_ALL;

5141 + QSIMPLEQ_INSERT_TAIL(&actions, act, next);

5142 break;

5143 case OPTION_CLEAR:

5144 act = g_new0(ImgBitmapAction, 1);

5145 act->act = BITMAP_CLEAR;

5146 QSIMPLEQ_INSERT_TAIL(&actions, act, next);

5147 + need_bitmap_name = true;

5148 break;

5149 case OPTION_ENABLE:

5150 act = g_new0(ImgBitmapAction, 1);

5151 act->act = BITMAP_ENABLE;

5152 QSIMPLEQ_INSERT_TAIL(&actions, act, next);

5153 + need_bitmap_name = true;

5154 break;

5155 case OPTION_DISABLE:

5156 act = g_new0(ImgBitmapAction, 1);

5157 act->act = BITMAP_DISABLE;

5158 QSIMPLEQ_INSERT_TAIL(&actions, act, next);

5159 + need_bitmap_name = true;

5160 break;

5161 case OPTION_MERGE:

5162 act = g_new0(ImgBitmapAction, 1);

@@ -5149,6 +5164,7 @@ static int img_bitmap(const img_cmd_t *ccmd, int argc, char **argv)

5164 act->src = optarg;

5165 QSIMPLEQ_INSERT_TAIL(&actions, act, next);

5166 merge = true;

5167 + need_bitmap_name = true;

5168 break;

5169 case 'b':

5170 src_filename = optarg;

@@ -5165,8 +5181,8 @@ static int img_bitmap(const img_cmd_t *ccmd, int argc, char **argv)

5181 }

5182

5183 if (QSIMPLEQ_EMPTY(&actions)) {

5168 - error_report("Need at least one of --add, --remove, --clear, "

5169 - "--enable, --disable, or --merge");

5184 + error_report("Need at least one of --add, --remove, --remove-all, "

5185 + "--clear, --enable, --disable, or --merge");

5186 goto out;

5187 }

5188

@@ -5184,11 +5200,22 @@ static int img_bitmap(const img_cmd_t *ccmd, int argc, char **argv)

5200 goto out;

5201 }

5202

5187 - if (optind != argc - 2) {

5203 + if (need_bitmap_name && optind != argc - 2) {

5204 error_report("Expecting filename and bitmap name");

5205 goto out;

5206 }

5207

5208 + /*

5209 + * Every action other than --remove-all sets need_bitmap_name, so

5210 + * !need_bitmap_name means the only action(s) given were --remove-all

5211 + * and the BITMAP positional argument must be omitted. Combinations

5212 + * like '--remove-all --add foo' remain valid via the branch above.

5213 + */

5214 + if (!need_bitmap_name && optind != argc - 1) {

5215 + error_report("Expecting filename");

5216 + goto out;

5217 + }

5218 +

5219 filename = argv[optind];

5220 bitmap = argv[optind + 1];

5221

@@ -5225,6 +5252,20 @@ static int img_bitmap(const img_cmd_t *ccmd, int argc, char **argv)

5252 qmp_block_dirty_bitmap_remove(bs->node_name, bitmap, &err);

5253 op = "remove";

5254 break;

5255 + case BITMAP_REMOVE_ALL: {

5256 + BdrvDirtyBitmap *bm;

5257 + while ((bm = bdrv_dirty_bitmap_first(bs))) {

5258 + const char *name = bdrv_dirty_bitmap_name(bm);

5259 + qmp_block_dirty_bitmap_remove(bs->node_name, name, &err);

5260 + if (err) {

5261 + /* Save name for proper error reporting */

5262 + bitmap = name;

5263 + break;

5264 + }

5265 + }

5266 + op = "remove-all";

5267 + break;

5268 + }

5269 case BITMAP_CLEAR:

5270 qmp_block_dirty_bitmap_clear(bs->node_name, bitmap, &err);

5271 op = "clear";

tests/qemu-iotests/tests/qemu-img-bitmaps

+24

@@ -161,6 +161,30 @@ $QEMU_IMG convert --bitmaps -O qcow2 "$TEST_IMG" "$TEST_IMG.copy"

161 TEST_IMG="$TEST_IMG.copy" _img_info --format-specific \

162 | _filter_irrelevant_img_info

163

164 +echo

165 +echo "=== Check --remove-all ==="

166 +echo

167 +

168 +# Start from a fresh image so prior state does not bleed into the assertions

169 +_rm_test_img "$TEST_IMG"

170 +_make_test_img 10M

171 +$QEMU_IMG bitmap --add -f $IMGFMT "$TEST_IMG" b0

172 +$QEMU_IMG bitmap --add -f $IMGFMT "$TEST_IMG" b1

173 +$QEMU_IMG bitmap --add -f $IMGFMT "$TEST_IMG" b2

174 +_img_info --format-specific | _filter_irrelevant_img_info

175 +

176 +# Sweep every bitmap in a single command, no BITMAP positional

177 +echo

178 +$QEMU_IMG bitmap --remove-all -f $IMGFMT "$TEST_IMG"

179 +_img_info --format-specific | _filter_irrelevant_img_info

180 +

181 +# Wipe + recreate in one invocation: only 'fresh' should remain

182 +echo

183 +$QEMU_IMG bitmap --add -f $IMGFMT "$TEST_IMG" b0

184 +$QEMU_IMG bitmap --add -f $IMGFMT "$TEST_IMG" b1

185 +$QEMU_IMG bitmap --remove-all --add -f $IMGFMT "$TEST_IMG" fresh

186 +_img_info --format-specific | _filter_irrelevant_img_info

187 +

188 # success, all done

189 echo '*** done'

190 rm -f $seq.full

tests/qemu-iotests/tests/qemu-img-bitmaps.out

+46

@@ -180,4 +180,50 @@ Format specific information:

180 name: b2

181 granularity: 65536

182 corrupt: false

183 +

184 +=== Check --remove-all ===

185 +

186 +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=10485760

187 +image: TEST_DIR/t.IMGFMT

188 +file format: IMGFMT

189 +virtual size: 10 MiB (10485760 bytes)

190 +cluster_size: 65536

191 +Format specific information:

192 + bitmaps:

193 + [0]:

194 + flags:

195 + [0]: auto

196 + name: b0

197 + granularity: 65536

198 + [1]:

199 + flags:

200 + [0]: auto

201 + name: b1

202 + granularity: 65536

203 + [2]:

204 + flags:

205 + [0]: auto

206 + name: b2

207 + granularity: 65536

208 + corrupt: false

209 +

210 +image: TEST_DIR/t.IMGFMT

211 +file format: IMGFMT

212 +virtual size: 10 MiB (10485760 bytes)

213 +cluster_size: 65536

214 +Format specific information:

215 + corrupt: false

216 +

217 +image: TEST_DIR/t.IMGFMT

218 +file format: IMGFMT

219 +virtual size: 10 MiB (10485760 bytes)

220 +cluster_size: 65536

221 +Format specific information:

222 + bitmaps:

223 + [0]:

224 + flags:

225 + [0]: auto

226 + name: fresh

227 + granularity: 65536

228 + corrupt: false

229 *** done