Rename the existing get_cluster_offset() function to
vmdk_get_cluster_offset() and have it make use of the new
get_cluster_table() to load the cluster tables. Also, it is no longer
used to allocate new clusters and hence perform COW. Make the necessary
renames at all the occurrences of get_cluster_offset().
Signed-off-by: Ashijeet Acharya <ashijeetacha...@gmail.com>
---
block/vmdk.c | 117 +++++++++++------------------------------------------------
1 file changed, 21 insertions(+), 96 deletions(-)
diff --git a/block/vmdk.c b/block/vmdk.c
index 5a95929..387e45b 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1419,7 +1419,7 @@ static int vmdk_alloc_cluster_offset(BlockDriverState *bs,
}
/**
- * get_cluster_offset
+ * vmdk_get_cluster_offset
*
* Look up cluster offset in extent file by sector number, and store in
* @cluster_offset.
@@ -1427,84 +1427,34 @@ static int vmdk_alloc_cluster_offset(BlockDriverState
*bs,
* For flat extents, the start offset as parsed from the description file is
* returned.
*
- * For sparse extents, look up in L1, L2 table. If allocate is true, return an
- * offset for a new cluster and update L2 cache. If there is a backing file,
- * COW is done before returning; otherwise, zeroes are written to the allocated
- * cluster. Both COW and zero writing skips the sector range
- * [@skip_start_sector, @skip_end_sector) passed in by caller, because caller
- * has new data to write there.
+ * For sparse extents, look up in L1, L2 table.
*
* Returns: VMDK_OK if cluster exists and mapped in the image.
- * VMDK_UNALLOC if cluster is not mapped and @allocate is false.
- * VMDK_ERROR if failed.
+ * VMDK_UNALLOC if cluster is not mapped.
+ * VMDK_ERROR if failed
*/
-static int get_cluster_offset(BlockDriverState *bs,
- VmdkExtent *extent,
- VmdkMetaData *m_data,
- uint64_t offset,
- bool allocate,
- uint64_t *cluster_offset,
- uint64_t skip_start_bytes,
- uint64_t skip_end_bytes)
+static int vmdk_get_cluster_offset(BlockDriverState *bs,
+ VmdkExtent *extent,
+ uint64_t offset,
+ uint64_t *cluster_offset)
{
- unsigned int l1_index, l2_offset, l2_index;
- int min_index, i, j;
- uint32_t min_count, *l2_table;
+ int l1_index, l2_offset, l2_index;
+ uint32_t *l2_table;
bool zeroed = false;
int64_t ret;
int64_t cluster_sector;
- if (m_data) {
- m_data->valid = 0;
- }
if (extent->flat) {
*cluster_offset = extent->flat_start_offset;
return VMDK_OK;
}
- offset -= (extent->end_sector - extent->sectors) * SECTOR_SIZE;
- l1_index = (offset >> 9) / extent->l1_entry_sectors;
- if (l1_index >= extent->l1_size) {
- return VMDK_ERROR;
- }
- l2_offset = extent->l1_table[l1_index];
- if (!l2_offset) {
- return VMDK_UNALLOC;
- }
- for (i = 0; i < L2_CACHE_SIZE; i++) {
- if (l2_offset == extent->l2_cache_offsets[i]) {
- /* increment the hit count */
- if (++extent->l2_cache_counts[i] == 0xffffffff) {
- for (j = 0; j < L2_CACHE_SIZE; j++) {
- extent->l2_cache_counts[j] >>= 1;
- }
- }
- l2_table = extent->l2_cache + (i * extent->l2_size);
- goto found;
- }
- }
- /* not found: load a new entry in the least used one */
- min_index = 0;
- min_count = 0xffffffff;
- for (i = 0; i < L2_CACHE_SIZE; i++) {
- if (extent->l2_cache_counts[i] < min_count) {
- min_count = extent->l2_cache_counts[i];
- min_index = i;
- }
- }
- l2_table = extent->l2_cache + (min_index * extent->l2_size);
- if (bdrv_pread(extent->file,
- (int64_t)l2_offset * 512,
- l2_table,
- extent->l2_size * sizeof(uint32_t)
- ) != extent->l2_size * sizeof(uint32_t)) {
- return VMDK_ERROR;
+ ret = get_cluster_table(extent, offset, &l1_index, &l2_offset,
+ &l2_index, &l2_table);
+ if (ret < 0) {
+ return ret;
}
- extent->l2_cache_offsets[min_index] = l2_offset;
- extent->l2_cache_counts[min_index] = 1;
- found:
- l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size;
cluster_sector = le32_to_cpu(l2_table[l2_index]);
if (extent->has_zero_grain && cluster_sector == VMDK_GTE_ZEROED) {
@@ -1512,31 +1462,9 @@ static int get_cluster_offset(BlockDriverState *bs,
}
if (!cluster_sector || zeroed) {
- if (!allocate) {
- return zeroed ? VMDK_ZEROED : VMDK_UNALLOC;
- }
-
- cluster_sector = extent->next_cluster_sector;
- extent->next_cluster_sector += extent->cluster_sectors;
-
- /* First of all we write grain itself, to avoid race condition
- * that may to corrupt the image.
- * This problem may occur because of insufficient space on host disk
- * or inappropriate VM shutdown.
- */
- ret = get_whole_cluster(bs, extent, cluster_sector * BDRV_SECTOR_SIZE,
- offset, skip_start_bytes, skip_end_bytes);
- if (ret) {
- return ret;
- }
- if (m_data) {
- m_data->valid = 1;
- m_data->l1_index = l1_index;
- m_data->l2_index = l2_index;
- m_data->l2_offset = l2_offset;
- m_data->l2_cache_entry = &l2_table[l2_index];
- }
+ return zeroed ? VMDK_ZEROED : VMDK_UNALLOC;
}
+
*cluster_offset = cluster_sector << BDRV_SECTOR_BITS;
return VMDK_OK;
}
@@ -1579,9 +1507,7 @@ static int64_t coroutine_fn
vmdk_co_get_block_status(BlockDriverState *bs,
return 0;
}
qemu_co_mutex_lock(&s->lock);
- ret = get_cluster_offset(bs, extent, NULL,
- sector_num * 512, false, &offset,
- 0, 0);
+ ret = vmdk_get_cluster_offset(bs, extent, sector_num * 512, &offset);
qemu_co_mutex_unlock(&s->lock);
index_in_cluster = vmdk_find_index_in_cluster(extent, sector_num);
@@ -1772,13 +1698,13 @@ vmdk_co_preadv(BlockDriverState *bs, uint64_t offset,
uint64_t bytes,
ret = -EIO;
goto fail;
}
- ret = get_cluster_offset(bs, extent, NULL,
- offset, false, &cluster_offset, 0, 0);
offset_in_cluster = vmdk_find_offset_in_cluster(extent, offset);
n_bytes = MIN(bytes, extent->cluster_sectors * BDRV_SECTOR_SIZE
- offset_in_cluster);
+ ret = vmdk_get_cluster_offset(bs, extent, offset, &cluster_offset);
+
if (ret != VMDK_OK) {
/* if not allocated, try to read from parent image, if exist */
if (bs->backing && ret != VMDK_ZEROED) {
@@ -2504,9 +2430,8 @@ static int vmdk_check(BlockDriverState *bs,
BdrvCheckResult *result,
sector_num);
break;
}
- ret = get_cluster_offset(bs, extent, NULL,
- sector_num << BDRV_SECTOR_BITS,
- false, &cluster_offset, 0, 0);
+ ret = vmdk_get_cluster_offset(bs, extent,
+ sector_num << BDRV_SECTOR_BITS, &cluster_offset);
if (ret == VMDK_ERROR) {
fprintf(stderr,
"ERROR: could not get cluster_offset for sector %"
--
2.6.2
