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[Qemu-devel] [PATCH 2/8] qcow2: add dirty-bitmaps feature
|
From: |
Vladimir Sementsov-Ogievskiy |
|
Subject: |
[Qemu-devel] [PATCH 2/8] qcow2: add dirty-bitmaps feature |
|
Date: |
Mon, 8 Jun 2015 18:21:20 +0300 |
From: Vladimir Sementsov-Ogievskiy <address@hidden>
Adds dirty-bitmaps feature to qcow2 format as specified in
docs/specs/qcow2.txt
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
block/Makefile.objs | 2 +-
block/qcow2-dirty-bitmap.c | 503 +++++++++++++++++++++++++++++++++++++++++++++
block/qcow2.c | 56 +++++
block/qcow2.h | 50 +++++
include/block/block_int.h | 10 +
5 files changed, 620 insertions(+), 1 deletion(-)
create mode 100644 block/qcow2-dirty-bitmap.c
diff --git a/block/Makefile.objs b/block/Makefile.objs
index 0d8c2a4..bff12b4 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -1,5 +1,5 @@
block-obj-y += raw_bsd.o qcow.o vdi.o vmdk.o cloop.o bochs.o vpc.o vvfat.o
-block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o
qcow2-cache.o
+block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o
qcow2-cache.o qcow2-dirty-bitmap.o
block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o
block-obj-y += qed-check.o
block-obj-$(CONFIG_VHDX) += vhdx.o vhdx-endian.o vhdx-log.o
diff --git a/block/qcow2-dirty-bitmap.c b/block/qcow2-dirty-bitmap.c
new file mode 100644
index 0000000..bc0167c
--- /dev/null
+++ b/block/qcow2-dirty-bitmap.c
@@ -0,0 +1,503 @@
+/*
+ * Dirty bitmpas for the QCOW version 2 format
+ *
+ * Copyright (c) 2014-2015 Vladimir Sementsov-Ogievskiy
+ *
+ * This file is derived from qcow2-snapshot.c, original copyright:
+ * Copyright (c) 2004-2006 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu-common.h"
+#include "block/block_int.h"
+#include "block/qcow2.h"
+
+void qcow2_free_dirty_bitmaps(BlockDriverState *bs)
+{
+ BDRVQcowState *s = bs->opaque;
+ int i;
+
+ for (i = 0; i < s->nb_dirty_bitmaps; i++) {
+ g_free(s->dirty_bitmaps[i].name);
+ }
+ g_free(s->dirty_bitmaps);
+ s->dirty_bitmaps = NULL;
+ s->nb_dirty_bitmaps = 0;
+}
+
+int qcow2_read_dirty_bitmaps(BlockDriverState *bs)
+{
+ BDRVQcowState *s = bs->opaque;
+ QCowDirtyBitmapHeader h;
+ QCowDirtyBitmap *bm;
+ int i, name_size;
+ int64_t offset;
+ int ret;
+
+ if (!s->nb_dirty_bitmaps) {
+ s->dirty_bitmaps = NULL;
+ s->dirty_bitmaps_size = 0;
+ return 0;
+ }
+
+ offset = s->dirty_bitmaps_offset;
+ s->dirty_bitmaps = g_new0(QCowDirtyBitmap, s->nb_dirty_bitmaps);
+
+ for (i = 0; i < s->nb_dirty_bitmaps; i++) {
+ /* Read statically sized part of the dirty_bitmap header */
+ offset = align_offset(offset, 8);
+ ret = bdrv_pread(bs->file, offset, &h, sizeof(h));
+ if (ret < 0) {
+ goto fail;
+ }
+
+ offset += sizeof(h);
+ bm = s->dirty_bitmaps + i;
+ bm->l1_table_offset = be64_to_cpu(h.l1_table_offset);
+ bm->l1_size = be32_to_cpu(h.l1_size);
+ bm->bitmap_granularity = be32_to_cpu(h.bitmap_granularity);
+ bm->bitmap_size = be64_to_cpu(h.bitmap_size);
+
+ name_size = be16_to_cpu(h.name_size);
+
+ /* Read dirty_bitmap name */
+ bm->name = g_malloc(name_size + 1);
+ ret = bdrv_pread(bs->file, offset, bm->name, name_size);
+ if (ret < 0) {
+ goto fail;
+ }
+ offset += name_size;
+ bm->name[name_size] = '\0';
+
+ if (offset - s->dirty_bitmaps_offset > QCOW_MAX_DIRTY_BITMAPS_SIZE) {
+ ret = -EFBIG;
+ goto fail;
+ }
+ }
+
+ assert(offset - s->dirty_bitmaps_offset <= INT_MAX);
+ s->dirty_bitmaps_size = offset - s->dirty_bitmaps_offset;
+ return 0;
+
+fail:
+ qcow2_free_dirty_bitmaps(bs);
+ return ret;
+}
+
+/* Add at the end of the file a new table of dirty bitmaps */
+static int qcow2_write_dirty_bitmaps(BlockDriverState *bs)
+{
+ BDRVQcowState *s = bs->opaque;
+ QCowDirtyBitmap *bm;
+ QCowDirtyBitmapHeader h;
+ int i, name_size, dirty_bitmaps_size;
+ int64_t offset, dirty_bitmaps_offset = 0;
+ int ret;
+
+ int old_dirty_bitmaps_size = s->dirty_bitmaps_size;
+ int64_t old_dirty_bitmaps_offset = s->dirty_bitmaps_offset;
+
+ /* Compute the size of the dirty bitmaps table */
+ offset = 0;
+ for (i = 0; i < s->nb_dirty_bitmaps; i++) {
+ bm = s->dirty_bitmaps + i;
+ offset = align_offset(offset, 8);
+ offset += sizeof(h);
+ offset += strlen(bm->name);
+
+ if (offset > QCOW_MAX_DIRTY_BITMAPS_SIZE) {
+ ret = -EFBIG;
+ goto fail;
+ }
+ }
+
+ assert(offset <= INT_MAX);
+ dirty_bitmaps_size = offset;
+
+ /* Allocate space for the new dirty bitmap table */
+ dirty_bitmaps_offset = qcow2_alloc_clusters(bs, dirty_bitmaps_size);
+ offset = dirty_bitmaps_offset;
+ if (offset < 0) {
+ ret = offset;
+ goto fail;
+ }
+ ret = bdrv_flush(bs);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ /* The dirty bitmap table position has not yet been updated, so these
+ * clusters must indeed be completely free */
+ ret = qcow2_pre_write_overlap_check(bs, 0, offset, dirty_bitmaps_size);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ /* Write all dirty bitmaps to the new table */
+ for (i = 0; i < s->nb_dirty_bitmaps; i++) {
+ bm = s->dirty_bitmaps + i;
+ memset(&h, 0, sizeof(h));
+ h.l1_table_offset = cpu_to_be64(bm->l1_table_offset);
+ h.l1_size = cpu_to_be32(bm->l1_size);
+ h.bitmap_granularity = cpu_to_be32(bm->bitmap_granularity);
+ h.bitmap_size = cpu_to_be64(bm->bitmap_size);
+
+ name_size = strlen(bm->name);
+ assert(name_size <= UINT16_MAX);
+ h.name_size = cpu_to_be16(name_size);
+ offset = align_offset(offset, 8);
+
+ ret = bdrv_pwrite(bs->file, offset, &h, sizeof(h));
+ if (ret < 0) {
+ goto fail;
+ }
+ offset += sizeof(h);
+
+ ret = bdrv_pwrite(bs->file, offset, bm->name, name_size);
+ if (ret < 0) {
+ goto fail;
+ }
+ offset += name_size;
+ }
+
+ /*
+ * Update the header extension to point to the new dirty bitmap table. This
+ * requires the new table and its refcounts to be stable on disk.
+ */
+ ret = bdrv_flush(bs);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ s->dirty_bitmaps_offset = dirty_bitmaps_offset;
+ s->dirty_bitmaps_size = dirty_bitmaps_size;
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ fprintf(stderr, "Could not update qcow2 header\n");
+ goto fail;
+ }
+
+ /* Free old dirty bitmap table */
+ qcow2_free_clusters(bs, old_dirty_bitmaps_offset, old_dirty_bitmaps_size,
+ QCOW2_DISCARD_ALWAYS);
+ return 0;
+
+fail:
+ if (dirty_bitmaps_offset > 0) {
+ qcow2_free_clusters(bs, dirty_bitmaps_offset, dirty_bitmaps_size,
+ QCOW2_DISCARD_ALWAYS);
+ }
+ return ret;
+}
+
+static int find_dirty_bitmap_by_name(BlockDriverState *bs,
+ const char *name)
+{
+ BDRVQcowState *s = bs->opaque;
+ int i;
+
+ for (i = 0; i < s->nb_dirty_bitmaps; i++) {
+ if (!strcmp(s->dirty_bitmaps[i].name, name)) {
+ return i;
+ }
+ }
+
+ return -1;
+}
+
+uint8_t *qcow2_dirty_bitmap_load(BlockDriverState *bs,
+ const char *name, uint64_t size,
+ int granularity)
+{
+ BDRVQcowState *s = bs->opaque;
+ int i, dirty_bitmap_index, ret;
+ uint64_t offset;
+ QCowDirtyBitmap *bm;
+ uint64_t *l1_table;
+ uint8_t *buf;
+
+ dirty_bitmap_index = find_dirty_bitmap_by_name(bs, name);
+ if (dirty_bitmap_index < 0) {
+ return NULL;
+ }
+ bm = &s->dirty_bitmaps[dirty_bitmap_index];
+
+ if (size != bm->bitmap_size || granularity != bm->bitmap_granularity) {
+ return NULL;
+ }
+
+ l1_table = g_malloc(bm->l1_size * sizeof(uint64_t));
+ ret = bdrv_pread(bs->file, bm->l1_table_offset, l1_table,
+ bm->l1_size * sizeof(uint64_t));
+ if (ret < 0) {
+ goto fail;
+ }
+
+ buf = g_malloc0(bm->l1_size * s->cluster_size);
+ for (i = 0; i < bm->l1_size; ++i) {
+ offset = be64_to_cpu(l1_table[i]);
+ if (!(offset & 1)) {
+ ret = bdrv_pread(bs->file, offset, buf + i * s->cluster_size,
+ s->cluster_size);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+ }
+
+ g_free(l1_table);
+ return buf;
+
+fail:
+ g_free(l1_table);
+ return NULL;
+}
+
+int qcow2_dirty_bitmap_store(BlockDriverState *bs, uint8_t *buf,
+ const char *name, uint64_t size,
+ int granularity)
+{
+ BDRVQcowState *s = bs->opaque;
+ int cl_size = s->cluster_size;
+ int i, dirty_bitmap_index, ret = 0, n;
+ uint64_t *l1_table;
+ QCowDirtyBitmap *bm;
+ uint64_t buf_size;
+ uint8_t *p;
+ int sector_granularity = granularity >> BDRV_SECTOR_BITS;
+
+ /* find/create dirty bitmap */
+ dirty_bitmap_index = find_dirty_bitmap_by_name(bs, name);
+ if (dirty_bitmap_index >= 0) {
+ bm = s->dirty_bitmaps + dirty_bitmap_index;
+
+ if (size != bm->bitmap_size ||
+ granularity != bm->bitmap_granularity) {
+ qcow2_dirty_bitmap_delete(bs, name, NULL);
+ dirty_bitmap_index = -1;
+ }
+ }
+ if (dirty_bitmap_index < 0) {
+ qcow2_dirty_bitmap_create(bs, name, size, granularity);
+ dirty_bitmap_index = s->nb_dirty_bitmaps - 1;
+ }
+ bm = s->dirty_bitmaps + dirty_bitmap_index;
+
+ /* read l1 table */
+ l1_table = g_malloc(bm->l1_size * sizeof(uint64_t));
+ ret = bdrv_pread(bs->file, bm->l1_table_offset, l1_table,
+ bm->l1_size * sizeof(uint64_t));
+ if (ret < 0) {
+ goto finish;
+ }
+
+ buf_size = (((size - 1) / sector_granularity) >> 3) + 1;
+ buf_size = align_offset(buf_size, 4);
+ n = buf_size / cl_size;
+ p = buf;
+ for (i = 0; i < bm->l1_size; ++i) {
+ uint64_t addr = be64_to_cpu(l1_table[i]) & ~511;
+ int write_size = (i == n ? (buf_size % cl_size) : cl_size);
+
+ if (buffer_is_zero(p, write_size)) {
+ if (addr) {
+ qcow2_free_clusters(bs, addr, cl_size,
+ QCOW2_DISCARD_ALWAYS);
+ }
+ l1_table[i] = cpu_to_be64(1);
+ } else {
+ if (!addr) {
+ addr = qcow2_alloc_clusters(bs, cl_size);
+ l1_table[i] = cpu_to_be64(addr);
+ }
+
+ ret = bdrv_pwrite(bs->file, addr, p, write_size);
+ if (ret < 0) {
+ goto finish;
+ }
+ }
+
+ p += cl_size;
+ }
+
+ ret = bdrv_pwrite(bs->file, bm->l1_table_offset, l1_table,
+ bm->l1_size * sizeof(uint64_t));
+ if (ret < 0) {
+ goto finish;
+ }
+
+finish:
+ g_free(l1_table);
+ return ret;
+}
+/* if no id is provided, a new one is constructed */
+int qcow2_dirty_bitmap_create(BlockDriverState *bs, const char *name,
+ uint64_t size, int granularity)
+{
+ BDRVQcowState *s = bs->opaque;
+ QCowDirtyBitmap *new_dirty_bitmap_list = NULL;
+ QCowDirtyBitmap *old_dirty_bitmap_list = NULL;
+ QCowDirtyBitmap sn1, *bm = &sn1;
+ int i, ret;
+ uint64_t *l1_table = NULL;
+ int64_t l1_table_offset;
+ int sector_granularity = granularity >> BDRV_SECTOR_BITS;
+
+ if (s->nb_dirty_bitmaps >= QCOW_MAX_DIRTY_BITMAPS) {
+ return -EFBIG;
+ }
+
+ memset(bm, 0, sizeof(*bm));
+
+ /* Check that the ID is unique */
+ if (find_dirty_bitmap_by_name(bs, name) >= 0) {
+ return -EEXIST;
+ }
+
+ /* Populate bm with passed data */
+ bm->name = g_strdup(name);
+ bm->bitmap_granularity = granularity;
+ bm->bitmap_size = size;
+
+ bm->l1_size =
+ size_to_clusters(s, (((size - 1) / sector_granularity) >> 3) + 1);
+ l1_table_offset =
+ qcow2_alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
+ if (l1_table_offset < 0) {
+ ret = l1_table_offset;
+ goto fail;
+ }
+ bm->l1_table_offset = l1_table_offset;
+
+ l1_table = g_try_new(uint64_t, bm->l1_size);
+ if (l1_table == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ /* initialize with zero clusters */
+ for (i = 0; i < s->l1_size; i++) {
+ l1_table[i] = cpu_to_be64(1);
+ }
+
+ ret = qcow2_pre_write_overlap_check(bs, 0, bm->l1_table_offset,
+ s->l1_size * sizeof(uint64_t));
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = bdrv_pwrite(bs->file, bm->l1_table_offset, l1_table,
+ s->l1_size * sizeof(uint64_t));
+ if (ret < 0) {
+ goto fail;
+ }
+
+ g_free(l1_table);
+ l1_table = NULL;
+
+ /* Append the new dirty bitmap to the dirty bitmap list */
+ new_dirty_bitmap_list = g_new(QCowDirtyBitmap, s->nb_dirty_bitmaps + 1);
+ if (s->dirty_bitmaps) {
+ memcpy(new_dirty_bitmap_list, s->dirty_bitmaps,
+ s->nb_dirty_bitmaps * sizeof(QCowDirtyBitmap));
+ old_dirty_bitmap_list = s->dirty_bitmaps;
+ }
+ s->dirty_bitmaps = new_dirty_bitmap_list;
+ s->dirty_bitmaps[s->nb_dirty_bitmaps++] = *bm;
+
+ ret = qcow2_write_dirty_bitmaps(bs);
+ if (ret < 0) {
+ g_free(s->dirty_bitmaps);
+ s->dirty_bitmaps = old_dirty_bitmap_list;
+ s->nb_dirty_bitmaps--;
+ goto fail;
+ }
+
+ g_free(old_dirty_bitmap_list);
+
+ return 0;
+
+fail:
+ g_free(bm->name);
+ g_free(l1_table);
+
+ return ret;
+}
+
+static int qcow2_dirty_bitmap_free_clusters(BlockDriverState *bs,
+ QCowDirtyBitmap *bm)
+{
+ BDRVQcowState *s = bs->opaque;
+ int ret, i;
+ uint64_t *l1_table = g_new(uint64_t, bm->l1_size);
+
+ ret = bdrv_pread(bs->file, bm->l1_table_offset, l1_table,
+ bm->l1_size * sizeof(uint64_t));
+ if (ret < 0) {
+ g_free(l1_table);
+ return ret;
+ }
+
+ for (i = 0; i < bm->l1_size; ++i) {
+ uint64_t addr = be64_to_cpu(l1_table[i]);
+ qcow2_free_clusters(bs, addr, s->cluster_size, QCOW2_DISCARD_ALWAYS);
+ }
+
+ qcow2_free_clusters(bs, bm->l1_table_offset, bm->l1_size *
sizeof(uint64_t),
+ QCOW2_DISCARD_ALWAYS);
+
+ g_free(l1_table);
+ return 0;
+}
+
+int qcow2_dirty_bitmap_delete(BlockDriverState *bs,
+ const char *name,
+ Error **errp)
+{
+ BDRVQcowState *s = bs->opaque;
+ QCowDirtyBitmap bm;
+ int dirty_bitmap_index, ret = 0;
+
+ /* Search the dirty_bitmap */
+ dirty_bitmap_index = find_dirty_bitmap_by_name(bs, name);
+ if (dirty_bitmap_index < 0) {
+ error_setg(errp, "Can't find the dirty bitmap");
+ return -ENOENT;
+ }
+ bm = s->dirty_bitmaps[dirty_bitmap_index];
+
+ /* Remove it from the dirty_bitmap list */
+ memmove(s->dirty_bitmaps + dirty_bitmap_index,
+ s->dirty_bitmaps + dirty_bitmap_index + 1,
+ (s->nb_dirty_bitmaps - dirty_bitmap_index - 1) * sizeof(bm));
+ s->nb_dirty_bitmaps--;
+ ret = qcow2_write_dirty_bitmaps(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "Failed to remove dirty bitmap"
+ " from dirty bitmap list");
+ return ret;
+ }
+
+ qcow2_dirty_bitmap_free_clusters(bs, &bm);
+ g_free(bm.name);
+
+ return ret;
+}
diff --git a/block/qcow2.c b/block/qcow2.c
index b9a72e3..406e55d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -61,6 +61,7 @@ typedef struct {
#define QCOW2_EXT_MAGIC_END 0
#define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
+#define QCOW2_EXT_MAGIC_DIRTY_BITMAPS 0x23852875
static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
{
@@ -90,6 +91,7 @@ static int qcow2_read_extensions(BlockDriverState *bs,
uint64_t start_offset,
QCowExtension ext;
uint64_t offset;
int ret;
+ Qcow2DirtyBitmapHeaderExt dirty_bitmaps_ext;
#ifdef DEBUG_EXT
printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset,
end_offset);
@@ -160,6 +162,33 @@ static int qcow2_read_extensions(BlockDriverState *bs,
uint64_t start_offset,
}
break;
+ case QCOW2_EXT_MAGIC_DIRTY_BITMAPS:
+ ret = bdrv_pread(bs->file, offset, &dirty_bitmaps_ext, ext.len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "ERROR: dirty_bitmaps_ext: "
+ "Could not read ext header");
+ return ret;
+ }
+
+ be64_to_cpus(&dirty_bitmaps_ext.dirty_bitmaps_offset);
+ be32_to_cpus(&dirty_bitmaps_ext.nb_dirty_bitmaps);
+
+ s->dirty_bitmaps_offset = dirty_bitmaps_ext.dirty_bitmaps_offset;
+ s->nb_dirty_bitmaps = dirty_bitmaps_ext.nb_dirty_bitmaps;
+
+ ret = qcow2_read_dirty_bitmaps(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not read dirty bitmaps");
+ return ret;
+ }
+
+#ifdef DEBUG_EXT
+ printf("Qcow2: Got dirty bitmaps extension:"
+ " offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n",
+ s->dirty_bitmaps_offset, s->nb_dirty_bitmaps);
+#endif
+ break;
+
default:
/* unknown magic - save it in case we need to rewrite the header */
{
@@ -1000,6 +1029,7 @@ static int qcow2_open(BlockDriverState *bs, QDict
*options, int flags,
g_free(s->unknown_header_fields);
cleanup_unknown_header_ext(bs);
qcow2_free_snapshots(bs);
+ qcow2_free_dirty_bitmaps(bs);
qcow2_refcount_close(bs);
qemu_vfree(s->l1_table);
/* else pre-write overlap checks in cache_destroy may crash */
@@ -1466,6 +1496,7 @@ static void qcow2_close(BlockDriverState *bs)
qemu_vfree(s->cluster_data);
qcow2_refcount_close(bs);
qcow2_free_snapshots(bs);
+ qcow2_free_dirty_bitmaps(bs);
}
static void qcow2_invalidate_cache(BlockDriverState *bs, Error **errp)
@@ -1667,6 +1698,21 @@ int qcow2_update_header(BlockDriverState *bs)
buf += ret;
buflen -= ret;
+ if (s->nb_dirty_bitmaps > 0) {
+ Qcow2DirtyBitmapHeaderExt dirty_bitmaps_header = {
+ .nb_dirty_bitmaps = cpu_to_be32(s->nb_dirty_bitmaps),
+ .dirty_bitmaps_offset = cpu_to_be64(s->dirty_bitmaps_offset)
+ };
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DIRTY_BITMAPS,
+ &dirty_bitmaps_header,
sizeof(dirty_bitmaps_header),
+ buflen);
+ if (ret < 0) {
+ goto fail;
+ }
+ buf += ret;
+ buflen -= ret;
+ }
+
/* Keep unknown header extensions */
QLIST_FOREACH(uext, &s->unknown_header_ext, next) {
ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen);
@@ -2176,6 +2222,12 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t
offset)
return -ENOTSUP;
}
+ /* cannot proceed if image has dirty_bitmaps */
+ if (s->nb_dirty_bitmaps) {
+ error_report("Can't resize an image which has dirty bitmaps");
+ return -ENOTSUP;
+ }
+
/* shrinking is currently not supported */
if (offset < bs->total_sectors * 512) {
error_report("qcow2 doesn't support shrinking images yet");
@@ -2952,6 +3004,10 @@ BlockDriver bdrv_qcow2 = {
.bdrv_get_info = qcow2_get_info,
.bdrv_get_specific_info = qcow2_get_specific_info,
+ .bdrv_dirty_bitmap_load = qcow2_dirty_bitmap_load,
+ .bdrv_dirty_bitmap_store = qcow2_dirty_bitmap_store,
+ .bdrv_dirty_bitmap_delete = qcow2_dirty_bitmap_delete,
+
.bdrv_save_vmstate = qcow2_save_vmstate,
.bdrv_load_vmstate = qcow2_load_vmstate,
diff --git a/block/qcow2.h b/block/qcow2.h
index 422b825..24beee0 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -39,6 +39,7 @@
#define QCOW_MAX_CRYPT_CLUSTERS 32
#define QCOW_MAX_SNAPSHOTS 65536
+#define QCOW_MAX_DIRTY_BITMAPS 65536
/* 8 MB refcount table is enough for 2 PB images at 64k cluster size
* (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
@@ -52,6 +53,8 @@
* space for snapshot names and IDs */
#define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)
+#define QCOW_MAX_DIRTY_BITMAPS_SIZE (1024 * QCOW_MAX_DIRTY_BITMAPS)
+
/* indicate that the refcount of the referenced cluster is exactly one. */
#define QCOW_OFLAG_COPIED (1ULL << 63)
/* indicate that the cluster is compressed (they never have the copied flag) */
@@ -138,6 +141,19 @@ typedef struct QEMU_PACKED QCowSnapshotHeader {
/* name follows */
} QCowSnapshotHeader;
+typedef struct QEMU_PACKED QCowDirtyBitmapHeader {
+ /* header is 8 byte aligned */
+ uint64_t l1_table_offset;
+
+ uint32_t l1_size;
+ uint32_t bitmap_granularity;
+
+ uint64_t bitmap_size;
+ uint16_t name_size;
+
+ /* name follows */
+} QCowDirtyBitmapHeader;
+
typedef struct QEMU_PACKED QCowSnapshotExtraData {
uint64_t vm_state_size_large;
uint64_t disk_size;
@@ -156,6 +172,14 @@ typedef struct QCowSnapshot {
uint64_t vm_clock_nsec;
} QCowSnapshot;
+typedef struct QCowDirtyBitmap {
+ uint64_t l1_table_offset;
+ uint32_t l1_size;
+ char *name;
+ int bitmap_granularity;
+ uint64_t bitmap_size;
+} QCowDirtyBitmap;
+
struct Qcow2Cache;
typedef struct Qcow2Cache Qcow2Cache;
@@ -218,6 +242,11 @@ typedef uint64_t Qcow2GetRefcountFunc(const void
*refcount_array,
typedef void Qcow2SetRefcountFunc(void *refcount_array,
uint64_t index, uint64_t value);
+typedef struct Qcow2DirtyBitmapHeaderExt {
+ uint32_t nb_dirty_bitmaps;
+ uint64_t dirty_bitmaps_offset;
+} QEMU_PACKED Qcow2DirtyBitmapHeaderExt;
+
typedef struct BDRVQcowState {
int cluster_bits;
int cluster_size;
@@ -259,6 +288,11 @@ typedef struct BDRVQcowState {
unsigned int nb_snapshots;
QCowSnapshot *snapshots;
+ uint64_t dirty_bitmaps_offset;
+ int dirty_bitmaps_size;
+ unsigned int nb_dirty_bitmaps;
+ QCowDirtyBitmap *dirty_bitmaps;
+
int flags;
int qcow_version;
bool use_lazy_refcounts;
@@ -570,6 +604,22 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs,
void qcow2_free_snapshots(BlockDriverState *bs);
int qcow2_read_snapshots(BlockDriverState *bs);
+/* qcow2-dirty-bitmap.c functions */
+int qcow2_dirty_bitmap_store(BlockDriverState *bs, uint8_t *buf,
+ const char *name, uint64_t size,
+ int granularity);
+uint8_t *qcow2_dirty_bitmap_load(BlockDriverState *bs,
+ const char *name, uint64_t size,
+ int granularity);
+int qcow2_dirty_bitmap_create(BlockDriverState *bs, const char *name,
+ uint64_t size, int granularity);
+int qcow2_dirty_bitmap_delete(BlockDriverState *bs,
+ const char *name,
+ Error **errp);
+
+void qcow2_free_dirty_bitmaps(BlockDriverState *bs);
+int qcow2_read_dirty_bitmaps(BlockDriverState *bs);
+
/* qcow2-cache.c functions */
Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables);
int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index db29b74..88855b4 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -206,6 +206,16 @@ struct BlockDriver {
int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
+ int (*bdrv_dirty_bitmap_store)(BlockDriverState *bs, uint8_t *buf,
+ const char *name, uint64_t size,
+ int granularity);
+ uint8_t *(*bdrv_dirty_bitmap_load)(BlockDriverState *bs,
+ const char *name, uint64_t size,
+ int granularity);
+ int (*bdrv_dirty_bitmap_delete)(BlockDriverState *bs,
+ const char *name,
+ Error **errp);
+
int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
int64_t pos);
int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
--
1.9.1
Re: [Qemu-devel] [PATCH 2/8] qcow2: add dirty-bitmaps feature, John Snow, 2015/06/11
Re: [Qemu-devel] [PATCH 2/8] qcow2: add dirty-bitmaps feature, John Snow, 2015/06/12