On 1/18/24 14:27, Denis V. Lunev wrote:
On 12/28/23 11:12, Alexander Ivanov wrote:
Now dirty bitmaps can be loaded but there is no their saving. Add
code for
dirty bitmap storage.
Signed-off-by: Alexander Ivanov <[email protected]>
---
block/parallels-ext.c | 168 ++++++++++++++++++++++++++++++++++++++++++
block/parallels.c | 16 +++-
block/parallels.h | 5 ++
3 files changed, 187 insertions(+), 2 deletions(-)
diff --git a/block/parallels-ext.c b/block/parallels-ext.c
index b4e14c88f2..c83d1ea393 100644
--- a/block/parallels-ext.c
+++ b/block/parallels-ext.c
@@ -24,6 +24,7 @@
*/
#include "qemu/osdep.h"
+#include "qemu/error-report.h"
#include "qapi/error.h"
#include "block/block-io.h"
#include "block/block_int.h"
@@ -300,3 +301,170 @@ out:
return ret;
}
+
+static void GRAPH_RDLOCK parallels_save_bitmap(BlockDriverState *bs,
+ BdrvDirtyBitmap *bitmap,
+ uint8_t **buf, int
*buf_size)
Do we need a error?
I think no. We save bitmaps in a loop. If some bitmap has a problem it
would be better
just to print an error message and try to save other bitmaps.
+{
+ BDRVParallelsState *s = bs->opaque;
+ ParallelsFeatureHeader *fh;
+ ParallelsDirtyBitmapFeature *bh;
+ uint64_t *l1_table, l1_size, granularity, limit;
I would say that 'limit' here means 'bits_in_cluster'
We are writing the new code and I would prefer if we
would have bits, bytes, clusters, sectors etc are
clearly seen in variable names. It is quite complex
to track various measurables.
OK
+ int64_t bm_size, ser_size, offset, buf_used;
+ int64_t alloc_size = 1;
+ const char *name;
+ uint8_t *bm_buf;
+ QemuUUID uuid;
+ int ret = 0;
+
+ if (!bdrv_dirty_bitmap_get_persistence(bitmap) ||
+ bdrv_dirty_bitmap_inconsistent(bitmap)) {
+ return;
+ }
+
+ bm_size = bdrv_dirty_bitmap_size(bitmap);
+ granularity = bdrv_dirty_bitmap_granularity(bitmap);
+ limit =
bdrv_dirty_bitmap_serialization_coverage(s->cluster_size, bitmap);
+ ser_size = bdrv_dirty_bitmap_serialization_size(bitmap, 0,
bm_size);
+ l1_size = DIV_ROUND_UP(ser_size, s->cluster_size);
+
+ buf_used = l1_size * 8 + sizeof(*fh) + sizeof(*bh);
As far as I can see, bdrv_dirty_bitmap_serialization_size() returns
bytes.
That is correct. Thus multiplying it by 8 seems fatal mistake.
l1_size is amount of entries in l1_table. Every entry has 8 bytes size
and corresponds
to one cluster containing a part of a bitmap.
I am also quite unsure that we should roundup to the cluster, that
will occupy more clusters than needed. Can you please take a look
here
https://src.openvz.org/users/ibazhitov/repos/ploop/browse/tools/ploop-cbt.c
Why shouldn't we? We need to have l1_table which should be able to contain
all the bitmap data. Note: there is not a ROUND_UP(), but DIV_ROUND_UP().
+ /* Check if there is enough space for the final section */
+ if (*buf_size - buf_used < sizeof(*fh)) {
+ return;
+ }
+
+ name = bdrv_dirty_bitmap_name(bitmap);
+ ret = qemu_uuid_parse(name, &uuid);
+ if (ret < 0) {
+ error_report("Can't save dirty bitmap: ID parsing error:
'%s'", name);
+ return;
+ }
+
+ fh = (ParallelsFeatureHeader *)*buf;
+ bh = (ParallelsDirtyBitmapFeature *)(*buf + sizeof(*fh));
bh = fh + 1 ?
+ l1_table = (uint64_t *)((uint8_t *)bh + sizeof(*bh));
l1_table = bh + 1 ?
Yes, it's better.
+
+ fh->magic = cpu_to_le64(PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC);
+ fh->data_size = cpu_to_le32(l1_size * 8 + sizeof(*bh));
I am quite concerned here. Please compare with
int save_dirty_bitmap(int devfd, struct delta *delta, off_t offset,
void *buf, __u32 *size, void *or_data, writer_fn wr,
void *data)
{
int ret = 0;
struct ploop_pvd_header *vh;
size_t block_size;
__u64 bits, bytes, *p;
__u32 byte_granularity;
void *block;
struct ploop_pvd_dirty_bitmap_raw *raw = (struct
ploop_pvd_dirty_bitmap_raw *)buf;
char x[50];
vh = (struct ploop_pvd_header *)delta->hdr0;
/* granularity and uuid */
if ((ret = cbt_get_dirty_bitmap_metadata(devfd, raw->m_Id,
&raw->m_Granularity)))
return ret;
raw->m_Granularity /= SECTOR_SIZE;
block_size = vh->m_Sectors * SECTOR_SIZE;
if (p_memalign((void **)&block, 4096, block_size))
return SYSEXIT_MALLOC;
raw->m_Size = vh->m_SizeInSectors_v2;
byte_granularity = raw->m_Granularity * SECTOR_SIZE;
bits = ((raw->m_Size + raw->m_Granularity - 1) / raw->m_Granularity);
bytes = (bits + 7) >> 3;
raw->m_L1Size = (bytes + block_size - 1) / block_size;
which means that the header is rotten. In that case can you pls
take a look why this has not been caught by tests?
It looks the same if block_size is cluster size in bytes.
bytes - bitmap size in bytes
raw->m_L1Size - bitmap size in clusters
In my code fh->data_size is l1_table size (8 bytes entry for each bitmap
cluster) plus
dirty bitmap feature header.
+
+ bh->l1_size = cpu_to_le32(l1_size);
+ bh->size = cpu_to_le64(bm_size >> BDRV_SECTOR_BITS);
+ bh->granularity = cpu_to_le32(granularity >> BDRV_SECTOR_BITS);
+ memcpy(bh->id, &uuid, sizeof(uuid));
+
+ bm_buf = qemu_blockalign(bs, s->cluster_size);
+
+ offset = 0;
+ while ((offset = bdrv_dirty_bitmap_next_dirty(bitmap, offset,
bm_size)) >= 0) {
+ uint64_t idx = offset / limit;
+ int64_t cluster_off, end, write_size;
+
+ offset = QEMU_ALIGN_DOWN(offset, limit);
+ end = MIN(bm_size, offset + limit);
+ write_size = bdrv_dirty_bitmap_serialization_size(bitmap,
offset,
+ end -
offset);
+ assert(write_size <= s->cluster_size);
+
+ bdrv_dirty_bitmap_serialize_part(bitmap, bm_buf, offset, end
- offset);
+ if (write_size < s->cluster_size) {
+ memset(bm_buf + write_size, 0, s->cluster_size -
write_size);
+ }
+
+ cluster_off = parallels_allocate_host_clusters(bs,
&alloc_size);
+ if (cluster_off <= 0) {
+ goto end;
+ }
+
+ ret = bdrv_pwrite(bs->file, cluster_off, s->cluster_size,
bm_buf, 0);
+ if (ret < 0) {
+ memset(&fh->magic, 0, sizeof(fh->magic));
+ parallels_mark_unused(bs, s->used_bmap, s->used_bmap_size,
+ cluster_off, 1);
That is incomplete. You have to clean all clusters inside of the
extension.
OK
+ goto end;
+ }
+
+ l1_table[idx] = cpu_to_le64(cluster_off >> BDRV_SECTOR_BITS);
+ offset = end;
+ }
+
+ *buf_size -= buf_used;
+ *buf += buf_used;
+
+end:
+ qemu_vfree(bm_buf);
+}
+
+void GRAPH_RDLOCK
+parallels_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error
**errp)
+{
+ BDRVParallelsState *s = bs->opaque;
+ BdrvDirtyBitmap *bitmap;
+ ParallelsFormatExtensionHeader *eh;
+ int remaining = s->cluster_size;
+ uint8_t *buf, *pos;
+ int64_t header_off, alloc_size = 1;
+ g_autofree uint8_t *hash = NULL;
+ size_t hash_len = 0;
+ int ret;
+
+ s->header->ext_off = 0;
+
+ if (!bdrv_has_named_bitmaps(bs)) {
+ return;
+ }
+
+ buf = qemu_blockalign0(bs, s->cluster_size);
+
+ eh = (ParallelsFormatExtensionHeader *)buf;
+ pos = buf + sizeof(*eh);
+
+ eh->magic = cpu_to_le64(PARALLELS_FORMAT_EXTENSION_MAGIC);
+
+ FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
+ parallels_save_bitmap(bs, bitmap, &pos, &remaining);
+ }
+
+ header_off = parallels_allocate_host_clusters(bs, &alloc_size);
+ if (header_off < 0) {
+ error_report("Can't save dirty bitmap: cluster allocation
error");
+ ret = header_off;
+ goto end;
+ }
+
+ ret = qcrypto_hash_bytes(QCRYPTO_HASH_ALG_MD5,
+ (const char *)(buf + sizeof(*eh)),
+ s->cluster_size - sizeof(*eh),
+ &hash, &hash_len, errp);
+ if (ret < 0 || hash_len != sizeof(eh->check_sum)) {
+ error_report("Can't save dirty bitmap: hash error");
+ ret = -EINVAL;
+ goto end;
+ }
+ memcpy(eh->check_sum, hash, hash_len);
+
+ ret = bdrv_pwrite(bs->file, header_off, s->cluster_size, buf, 0);
+ if (ret < 0) {
+ error_report("Can't save dirty bitmap: IO error");
+ parallels_mark_unused(bs, s->used_bmap, s->used_bmap_size,
+ header_off, 1);
+ goto end;
+ }
+
+ s->header->ext_off = cpu_to_le64(header_off / BDRV_SECTOR_SIZE);
+end:
+ qemu_vfree(buf);
+}
+
+bool coroutine_fn
parallels_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
+ const char
*name,
+ uint32_t granularity,
+ Error **errp)
+{
+ if (bdrv_find_dirty_bitmap(bs, name)) {
+ error_setg(errp, "Bitmap already exists: %s", name);
+ return false;
+ }
+
+ return true;
+}
diff --git a/block/parallels.c b/block/parallels.c
index f38dd2309c..a49922c6a7 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -1466,14 +1466,25 @@ fail:
static int GRAPH_RDLOCK parallels_inactivate(BlockDriverState *bs)
{
BDRVParallelsState *s = bs->opaque;
+ Error *err = NULL;
int ret;
+ parallels_store_persistent_dirty_bitmaps(bs, &err);
+ if (err != NULL) {
For me this looks quite odd, indirect check for error. Not good
Will add return value;
+ error_reportf_err(err, "Lost persistent bitmaps during "
+ "inactivation of node '%s': ",
+ bdrv_get_device_or_node_name(bs));
+ }
+
s->header->inuse = 0;
parallels_update_header(bs);
/* errors are ignored, so we might as well pass exact=true */
- ret = bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS,
true,
- PREALLOC_MODE_OFF, 0, NULL);
+ ret = bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS,
+ true, PREALLOC_MODE_OFF, 0, NULL);
+ if (ret < 0) {
+ error_report("Failed to truncate image: %s", strerror(-ret));
+ }
return ret;
}
@@ -1525,6 +1536,7 @@ static BlockDriver bdrv_parallels = {
.bdrv_co_pdiscard = parallels_co_pdiscard,
.bdrv_co_pwrite_zeroes = parallels_co_pwrite_zeroes,
.bdrv_inactivate = parallels_inactivate,
+ .bdrv_co_can_store_new_dirty_bitmap =
parallels_co_can_store_new_dirty_bitmap,
};
static void bdrv_parallels_init(void)
diff --git a/block/parallels.h b/block/parallels.h
index 493c89e976..9db4f5c908 100644
--- a/block/parallels.h
+++ b/block/parallels.h
@@ -101,5 +101,10 @@ int64_t GRAPH_RDLOCK
parallels_allocate_host_clusters(BlockDriverState *bs,
int GRAPH_RDLOCK
parallels_read_format_extension(BlockDriverState *bs, int64_t ext_off,
Error **errp);
+void GRAPH_RDLOCK
+parallels_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error
**errp);
+bool coroutine_fn
+parallels_co_can_store_new_dirty_bitmap(BlockDriverState *bs, const
char *name,
+ uint32_t granularity, Error
**errp);
#endif
--
Best regards,
Alexander Ivanov
