[Qemu-block] [PATCH 10/25] qcow2: autoloading dirty bitmaps
Auto loading bitmaps are bitmaps in Qcow2, with the AUTO flag set. They
are loaded when the image is opened and become BdrvDirtyBitmaps for the
corresponding drive.
Extra data in bitmaps is not supported for now.
Signed-off-by: Vladimir Sementsov-Ogievskiy
---
block/qcow2-bitmap.c | 387 +++
block/qcow2.c| 17 ++-
block/qcow2.h| 2 +
3 files changed, 404 insertions(+), 2 deletions(-)
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index b8e472b3e8..a2522d7ccf 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -44,6 +44,8 @@
/* Bitmap directory entry flags */
#define BME_RESERVED_FLAGS 0xfffcU
+#define BME_FLAG_IN_USE (1U << 0)
+#define BME_FLAG_AUTO (1U << 1)
/* bits [1, 8] U [56, 63] are reserved */
#define BME_TABLE_ENTRY_RESERVED_MASK 0xff0001feULL
@@ -85,6 +87,23 @@ typedef enum BitmapType {
BT_DIRTY_TRACKING_BITMAP = 1
} BitmapType;
+static inline bool can_write(BlockDriverState *bs)
+{
+return !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE);
+}
+
+static int update_header_sync(BlockDriverState *bs)
+{
+int ret;
+
+ret = qcow2_update_header(bs);
+if (ret < 0) {
+return ret;
+}
+
+return bdrv_flush(bs);
+}
+
static int check_table_entry(uint64_t entry, int cluster_size)
{
uint64_t offset;
@@ -146,6 +165,120 @@ fail:
return ret;
}
+/* This function returns the number of disk sectors covered by a single qcow2
+ * cluster of bitmap data. */
+static uint64_t sectors_covered_by_bitmap_cluster(const BDRVQcow2State *s,
+ const BdrvDirtyBitmap
*bitmap)
+{
+uint32_t sector_granularity =
+bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
+
+return (uint64_t)sector_granularity * (s->cluster_size << 3);
+}
+
+/* load_bitmap_data
+ * @bitmap_table entries must satisfy specification constraints.
+ * @bitmap must be cleared */
+static int load_bitmap_data(BlockDriverState *bs,
+const uint64_t *bitmap_table,
+uint32_t bitmap_table_size,
+BdrvDirtyBitmap *bitmap)
+{
+int ret = 0;
+BDRVQcow2State *s = bs->opaque;
+uint64_t sector, sbc;
+uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
+uint8_t *buf = NULL;
+uint64_t i, tab_size =
+size_to_clusters(s,
+bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size));
+
+if (tab_size != bitmap_table_size || tab_size > BME_MAX_TABLE_SIZE) {
+return -EINVAL;
+}
+
+buf = g_malloc(s->cluster_size);
+sbc = sectors_covered_by_bitmap_cluster(s, bitmap);
+for (i = 0, sector = 0; i < tab_size; ++i, sector += sbc) {
+uint64_t count = MIN(bm_size - sector, sbc);
+uint64_t entry = bitmap_table[i];
+uint64_t offset = entry & BME_TABLE_ENTRY_OFFSET_MASK;
+
+assert(check_table_entry(entry, s->cluster_size) == 0);
+
+if (offset == 0) {
+if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) {
+bdrv_dirty_bitmap_deserialize_ones(bitmap, sector, count,
+ false);
+} else {
+/* No need to deserialize zeros because the dirty bitmap is
+ * already cleared */
+}
+} else {
+ret = bdrv_pread(bs->file, offset, buf, s->cluster_size);
+if (ret < 0) {
+goto finish;
+}
+bdrv_dirty_bitmap_deserialize_part(bitmap, buf, sector, count,
+ false);
+}
+}
+ret = 0;
+
+bdrv_dirty_bitmap_deserialize_finish(bitmap);
+
+finish:
+g_free(buf);
+
+return ret;
+}
+
+static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs,
+Qcow2Bitmap *bm, Error **errp)
+{
+int ret;
+uint64_t *bitmap_table = NULL;
+uint32_t granularity;
+BdrvDirtyBitmap *bitmap = NULL;
+
+if (bm->flags & BME_FLAG_IN_USE) {
+error_setg(errp, "Bitmap '%s' is in use", bm->name);
+goto fail;
+}
+
+ret = bitmap_table_load(bs, &bm->table, &bitmap_table);
+if (ret < 0) {
+error_setg_errno(errp, -ret,
+ "Could not read bitmap_table table from image for "
+ "bitmap '%s'", bm->name);
+goto fail;
+}
+
+granularity = 1U << bm->granularity_bits;
+bitmap = bdrv_create_dirty_bitmap(bs, granularity, bm->name, errp);
+if (bitmap == NULL) {
+goto fail;
+}
+
+ret = load_bitmap_data(bs, bitmap_table, bm->table.size, bitmap);
+if (ret < 0) {
+error_setg_errno(errp, -ret, "Could not read bitmap '%s' from image",
+ bm->name);
+goto fail;
+}
+
+g_free(bitmap_table);
+return bitmap;
+
+fail:
+g_free(bitmap_table);
+
[Qemu-block] [PATCH 10/25] qcow2: autoloading dirty bitmaps
Auto loading bitmaps are bitmaps in Qcow2, with the AUTO flag set. They
are loaded when the image is opened and become BdrvDirtyBitmaps for the
corresponding drive.
Extra data in bitmaps is not supported for now.
Signed-off-by: Vladimir Sementsov-Ogievskiy
Reviewed-by: Max Reitz
---
block/qcow2-bitmap.c | 388 +++
block/qcow2.c| 17 ++-
block/qcow2.h| 2 +
3 files changed, 405 insertions(+), 2 deletions(-)
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index b8e472b3e8..cb596c2a85 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -44,6 +44,8 @@
/* Bitmap directory entry flags */
#define BME_RESERVED_FLAGS 0xfffcU
+#define BME_FLAG_IN_USE (1U << 0)
+#define BME_FLAG_AUTO (1U << 1)
/* bits [1, 8] U [56, 63] are reserved */
#define BME_TABLE_ENTRY_RESERVED_MASK 0xff0001feULL
@@ -85,6 +87,23 @@ typedef enum BitmapType {
BT_DIRTY_TRACKING_BITMAP = 1
} BitmapType;
+static inline bool can_write(BlockDriverState *bs)
+{
+return !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE);
+}
+
+static int update_header_sync(BlockDriverState *bs)
+{
+int ret;
+
+ret = qcow2_update_header(bs);
+if (ret < 0) {
+return ret;
+}
+
+return bdrv_flush(bs);
+}
+
static int check_table_entry(uint64_t entry, int cluster_size)
{
uint64_t offset;
@@ -146,6 +165,120 @@ fail:
return ret;
}
+/* This function returns the number of disk sectors covered by a single qcow2
+ * cluster of bitmap data. */
+static uint64_t sectors_covered_by_bitmap_cluster(const BDRVQcow2State *s,
+ const BdrvDirtyBitmap
*bitmap)
+{
+uint32_t sector_granularity =
+bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
+
+return (uint64_t)sector_granularity * (s->cluster_size << 3);
+}
+
+/* load_bitmap_data
+ * @bitmap_table entries must satisfy specification constraints.
+ * @bitmap must be cleared */
+static int load_bitmap_data(BlockDriverState *bs,
+const uint64_t *bitmap_table,
+uint32_t bitmap_table_size,
+BdrvDirtyBitmap *bitmap)
+{
+int ret = 0;
+BDRVQcow2State *s = bs->opaque;
+uint64_t sector, sbc;
+uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
+uint8_t *buf = NULL;
+uint64_t i, tab_size =
+size_to_clusters(s,
+bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size));
+
+if (tab_size != bitmap_table_size || tab_size > BME_MAX_TABLE_SIZE) {
+return -EINVAL;
+}
+
+buf = g_malloc(s->cluster_size);
+sbc = sectors_covered_by_bitmap_cluster(s, bitmap);
+for (i = 0, sector = 0; i < tab_size; ++i, sector += sbc) {
+uint64_t count = MIN(bm_size - sector, sbc);
+uint64_t entry = bitmap_table[i];
+uint64_t offset = entry & BME_TABLE_ENTRY_OFFSET_MASK;
+
+assert(check_table_entry(entry, s->cluster_size) == 0);
+
+if (offset == 0) {
+if (entry & BME_TABLE_ENTRY_FLAG_ALL_ONES) {
+bdrv_dirty_bitmap_deserialize_ones(bitmap, sector, count,
+ false);
+} else {
+/* No need to deserialize zeros because the dirty bitmap is
+ * already cleared */
+}
+} else {
+ret = bdrv_pread(bs->file, offset, buf, s->cluster_size);
+if (ret < 0) {
+goto finish;
+}
+bdrv_dirty_bitmap_deserialize_part(bitmap, buf, sector, count,
+ false);
+}
+}
+ret = 0;
+
+bdrv_dirty_bitmap_deserialize_finish(bitmap);
+
+finish:
+g_free(buf);
+
+return ret;
+}
+
+static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs,
+Qcow2Bitmap *bm, Error **errp)
+{
+int ret;
+uint64_t *bitmap_table = NULL;
+uint32_t granularity;
+BdrvDirtyBitmap *bitmap = NULL;
+
+if (bm->flags & BME_FLAG_IN_USE) {
+error_setg(errp, "Bitmap '%s' is in use", bm->name);
+goto fail;
+}
+
+ret = bitmap_table_load(bs, &bm->table, &bitmap_table);
+if (ret < 0) {
+error_setg_errno(errp, -ret,
+ "Could not read bitmap_table table from image for "
+ "bitmap '%s'", bm->name);
+goto fail;
+}
+
+granularity = 1U << bm->granularity_bits;
+bitmap = bdrv_create_dirty_bitmap(bs, granularity, bm->name, errp);
+if (bitmap == NULL) {
+goto fail;
+}
+
+ret = load_bitmap_data(bs, bitmap_table, bm->table.size, bitmap);
+if (ret < 0) {
+error_setg_errno(errp, -ret, "Could not read bitmap '%s' from image",
+ bm->name);
+goto fail;
+}
+
+g_free(bitmap_table);
+return bitmap;
+
+fail:
+g
Re: [Qemu-block] [PATCH 10/25] qcow2: autoloading dirty bitmaps
On 2017-05-03 14:25, Vladimir Sementsov-Ogievskiy wrote:
> Auto loading bitmaps are bitmaps in Qcow2, with the AUTO flag set. They
> are loaded when the image is opened and become BdrvDirtyBitmaps for the
> corresponding drive.
>
> Extra data in bitmaps is not supported for now.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy
> ---
> block/qcow2-bitmap.c | 387
> +++
> block/qcow2.c| 17 ++-
> block/qcow2.h| 2 +
> 3 files changed, 404 insertions(+), 2 deletions(-)
>
> diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
> index b8e472b3e8..a2522d7ccf 100644
> --- a/block/qcow2-bitmap.c
> +++ b/block/qcow2-bitmap.c
[...]
> @@ -437,3 +602,225 @@ out:
[...]
> +/* for g_slist_foreach for GSList of BdrvDirtyBitmap* elements */
> +static void set_readonly_helper(gpointer bitmap, gpointer unused)
> +{
> +bdrv_dirty_bitmap_set_readonly(bitmap);
> +}
> +
> +/* qcow2_load_autoloading_dirty_bitmaps()
> + * Return value is a hint for caller: true means that Qcow2 header was
> updated.
"...that the Qcow2 header..."
> + * (false doesn't mean that header should be updated by caller, it just means
"...that the header...", "...by the caller, ..."
> + * that updating was not needed or image can not be written).
"...or the image cannot be written [to]"
> + * On fail the function returns false.
"On failure..."
With these fixed:
Reviewed-by: Max Reitz
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