[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-block] [PATCH 06/22] qcow2: add dirty bitmaps extension
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[Qemu-block] [PATCH 06/22] qcow2: add dirty bitmaps extension |
Date: |
Fri, 30 Sep 2016 13:53:12 +0300 |
Add dirty bitmap extension as specified in docs/specs/qcow2.txt.
For now, just mirror extension header into Qcow2 state and check
constraints.
For now, disable image resize if it has bitmaps. It will be fixed later.
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
block/qcow2.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
block/qcow2.h | 4 +++
2 files changed, 87 insertions(+)
diff --git a/block/qcow2.c b/block/qcow2.c
index c079aa8..08c4ef9 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -63,6 +63,7 @@ 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)
{
@@ -92,6 +93,7 @@ static int qcow2_read_extensions(BlockDriverState *bs,
uint64_t start_offset,
QCowExtension ext;
uint64_t offset;
int ret;
+ Qcow2BitmapHeaderExt bitmaps_ext;
#ifdef DEBUG_EXT
printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset,
end_offset);
@@ -162,6 +164,62 @@ static int qcow2_read_extensions(BlockDriverState *bs,
uint64_t start_offset,
}
break;
+ case QCOW2_EXT_MAGIC_DIRTY_BITMAPS:
+ ret = bdrv_pread(bs->file, offset, &bitmaps_ext, ext.len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "ERROR: bitmaps_ext: "
+ "Could not read ext header");
+ return ret;
+ }
+
+ if (bitmaps_ext.reserved32 != 0) {
+ error_setg_errno(errp, -ret, "ERROR: bitmaps_ext: "
+ "Reserved field is not zero.");
+ return -EINVAL;
+ }
+
+ be32_to_cpus(&bitmaps_ext.nb_bitmaps);
+ be64_to_cpus(&bitmaps_ext.bitmap_directory_size);
+ be64_to_cpus(&bitmaps_ext.bitmap_directory_offset);
+
+ if (bitmaps_ext.nb_bitmaps > QCOW_MAX_DIRTY_BITMAPS) {
+ error_setg(errp, "ERROR: bitmaps_ext: "
+ "too many dirty bitmaps");
+ return -EINVAL;
+ }
+
+ if (bitmaps_ext.nb_bitmaps == 0) {
+ error_setg(errp, "ERROR: bitmaps_ext: "
+ "found bitmaps extension with zero bitmaps");
+ return -EINVAL;
+ }
+
+ if (bitmaps_ext.bitmap_directory_offset & (s->cluster_size - 1)) {
+ error_setg(errp, "ERROR: bitmaps_ext: "
+ "wrong dirty bitmap directory offset");
+ return -EINVAL;
+ }
+
+ if (bitmaps_ext.bitmap_directory_size >
+ QCOW_MAX_DIRTY_BITMAP_DIRECTORY_SIZE) {
+ error_setg(errp, "ERROR: bitmaps_ext: "
+ "too large dirty bitmap directory");
+ return -EINVAL;
+ }
+
+ s->nb_bitmaps = bitmaps_ext.nb_bitmaps;
+ s->bitmap_directory_offset =
+ bitmaps_ext.bitmap_directory_offset;
+ s->bitmap_directory_size =
+ bitmaps_ext.bitmap_directory_size;
+
+#ifdef DEBUG_EXT
+ printf("Qcow2: Got dirty bitmaps extension:"
+ " offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n",
+ s->bitmap_directory_offset, s->nb_bitmaps);
+#endif
+ break;
+
default:
/* unknown magic - save it in case we need to rewrite the header */
{
@@ -1939,6 +1997,24 @@ int qcow2_update_header(BlockDriverState *bs)
buflen -= ret;
}
+ if (s->nb_bitmaps > 0) {
+ Qcow2BitmapHeaderExt bitmaps_header = {
+ .nb_bitmaps = cpu_to_be32(s->nb_bitmaps),
+ .bitmap_directory_size =
+ cpu_to_be64(s->bitmap_directory_size),
+ .bitmap_directory_offset =
+ cpu_to_be64(s->bitmap_directory_offset)
+ };
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DIRTY_BITMAPS,
+ &bitmaps_header, sizeof(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);
@@ -2509,6 +2585,13 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t
offset)
return -ENOTSUP;
}
+ /* cannot proceed if image has bitmaps */
+ if (s->nb_bitmaps) {
+ /* FIXME */
+ error_report("Can't resize an image which has bitmaps");
+ return -ENOTSUP;
+ }
+
/* shrinking is currently not supported */
if (offset < bs->total_sectors * 512) {
error_report("qcow2 doesn't support shrinking images yet");
diff --git a/block/qcow2.h b/block/qcow2.h
index 0480b8b..c068b2c 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -292,6 +292,10 @@ typedef struct BDRVQcow2State {
unsigned int nb_snapshots;
QCowSnapshot *snapshots;
+ uint64_t bitmap_directory_offset;
+ uint64_t bitmap_directory_size;
+ uint32_t nb_bitmaps;
+
int flags;
int qcow_version;
bool use_lazy_refcounts;
--
1.8.3.1
- [Qemu-block] [PATCH 11/22] qcow2-bitmap: add qcow2_store_persistent_bitmaps(), (continued)
- [Qemu-block] [PATCH 11/22] qcow2-bitmap: add qcow2_store_persistent_bitmaps(), Vladimir Sementsov-Ogievskiy, 2016/09/30
- [Qemu-block] [PATCH 08/22] block/dirty-bitmap: add autoload field to BdrvDirtyBitmap, Vladimir Sementsov-Ogievskiy, 2016/09/30
- [Qemu-block] [PATCH 20/22] qcow2-dirty-bitmap: refcounts, Vladimir Sementsov-Ogievskiy, 2016/09/30
- [Qemu-block] [PATCH 04/22] block/dirty-bitmap: add deserialize_ones func, Vladimir Sementsov-Ogievskiy, 2016/09/30
- [Qemu-block] [PATCH 09/22] block: introduce persistent dirty bitmaps, Vladimir Sementsov-Ogievskiy, 2016/09/30
- [Qemu-block] [PATCH 18/22] qapi: add md5 checksum of last dirty bitmap level to query-block, Vladimir Sementsov-Ogievskiy, 2016/09/30
- [Qemu-block] [PATCH 22/22] specs/qcow2: do not use wording 'bitmap header', Vladimir Sementsov-Ogievskiy, 2016/09/30
- [Qemu-block] [PATCH 07/22] qcow2-bitmap: introduce auto-loading bitmaps, Vladimir Sementsov-Ogievskiy, 2016/09/30
- [Qemu-block] [PATCH 02/22] tests: add hbitmap iter test, Vladimir Sementsov-Ogievskiy, 2016/09/30
- [Qemu-block] [PATCH 17/22] qmp: add autoload parameter to block-dirty-bitmap-add, Vladimir Sementsov-Ogievskiy, 2016/09/30
- [Qemu-block] [PATCH 06/22] qcow2: add dirty bitmaps extension,
Vladimir Sementsov-Ogievskiy <=
- [Qemu-block] [PATCH 05/22] qcow2-bitmap: structs and consts, Vladimir Sementsov-Ogievskiy, 2016/09/30