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VMDK: change get_cluster_offset return type

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The return type of get_cluster_offset was an offset that use 0 to denote
'not allocated', this will be no longer true for flat extents, as we see
flat extent file as a single huge cluster whose offset is 0 and length
is the whole file length.
So now we use int return value, 0 means success and otherwise offset
invalid.

Signed-off-by: Fam Zheng <famcool@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Fam Zheng 2011-07-12 19:56:35 +08:00 committed by Kevin Wolf
parent 69b4d86d9f
commit 91b85bd388
1 changed files with 42 additions and 37 deletions
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79
block/vmdk.c
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@ -665,26 +665,31 @@ static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data)
return 0;
}
static uint64_t get_cluster_offset(BlockDriverState *bs,
static int get_cluster_offset(BlockDriverState *bs,
VmdkExtent *extent,
VmdkMetaData *m_data,
uint64_t offset, int allocate)
uint64_t offset,
int allocate,
uint64_t *cluster_offset)
{
unsigned int l1_index, l2_offset, l2_index;
int min_index, i, j;
uint32_t min_count, *l2_table, tmp = 0;
uint64_t cluster_offset;
if (m_data)
m_data->valid = 0;
if (extent->flat) {
*cluster_offset = 0;
return 0;
}
l1_index = (offset >> 9) / extent->l1_entry_sectors;
if (l1_index >= extent->l1_size) {
return 0;
return -1;
}
l2_offset = extent->l1_table[l1_index];
if (!l2_offset) {
return 0;
return -1;
}
for (i = 0; i < L2_CACHE_SIZE; i++) {
if (l2_offset == extent->l2_cache_offsets[i]) {
@ -714,28 +719,29 @@ static uint64_t get_cluster_offset(BlockDriverState *bs,
l2_table,
extent->l2_size * sizeof(uint32_t)
) != extent->l2_size * sizeof(uint32_t)) {
return 0;
return -1;
}
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_offset = le32_to_cpu(l2_table[l2_index]);
*cluster_offset = le32_to_cpu(l2_table[l2_index]);
if (!cluster_offset) {
if (!allocate)
return 0;
if (!*cluster_offset) {
if (!allocate) {
return -1;
}
// Avoid the L2 tables update for the images that have snapshots.
cluster_offset = bdrv_getlength(extent->file);
*cluster_offset = bdrv_getlength(extent->file);
bdrv_truncate(
extent->file,
cluster_offset + (extent->cluster_sectors << 9)
*cluster_offset + (extent->cluster_sectors << 9)
);
cluster_offset >>= 9;
tmp = cpu_to_le32(cluster_offset);
*cluster_offset >>= 9;
tmp = cpu_to_le32(*cluster_offset);
l2_table[l2_index] = tmp;
/* First of all we write grain itself, to avoid race condition
@ -744,8 +750,8 @@ static uint64_t get_cluster_offset(BlockDriverState *bs,
* or inappropriate VM shutdown.
*/
if (get_whole_cluster(
bs, extent, cluster_offset, offset, allocate) == -1)
return 0;
bs, extent, *cluster_offset, offset, allocate) == -1)
return -1;
if (m_data) {
m_data->offset = tmp;
@ -755,8 +761,8 @@ static uint64_t get_cluster_offset(BlockDriverState *bs,
m_data->valid = 1;
}
}
cluster_offset <<= 9;
return cluster_offset;
*cluster_offset <<= 9;
return 0;
}
static VmdkExtent *find_extent(BDRVVmdkState *s,
@ -780,7 +786,6 @@ static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum)
{
BDRVVmdkState *s = bs->opaque;
int64_t index_in_cluster, n, ret;
uint64_t offset;
VmdkExtent *extent;
@ -789,15 +794,13 @@ static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
if (!extent) {
return 0;
}
if (extent->flat) {
n = extent->end_sector - sector_num;
ret = 1;
} else {
offset = get_cluster_offset(bs, extent, NULL, sector_num * 512, 0);
index_in_cluster = sector_num % extent->cluster_sectors;
n = extent->cluster_sectors - index_in_cluster;
ret = offset ? 1 : 0;
}
ret = get_cluster_offset(bs, extent, NULL,
sector_num * 512, 0, &offset);
/* get_cluster_offset returning 0 means success */
ret = !ret;
index_in_cluster = sector_num % extent->cluster_sectors;
n = extent->cluster_sectors - index_in_cluster;
if (n > nb_sectors)
n = nb_sectors;
*pnum = n;
@ -818,14 +821,15 @@ static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
if (!extent) {
return -EIO;
}
cluster_offset = get_cluster_offset(
bs, extent, NULL, sector_num << 9, 0);
ret = get_cluster_offset(
bs, extent, NULL,
sector_num << 9, 0, &cluster_offset);
index_in_cluster = sector_num % extent->cluster_sectors;
n = extent->cluster_sectors - index_in_cluster;
if (n > nb_sectors)
n = nb_sectors;
if (!cluster_offset) {
// try to read from parent image, if exist
if (ret) {
/* if not allocated, try to read from parent image, if exist */
if (bs->backing_hd) {
if (!vmdk_is_cid_valid(bs))
return -1;
@ -851,7 +855,7 @@ static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
{
BDRVVmdkState *s = bs->opaque;
VmdkExtent *extent = NULL;
int n;
int n, ret;
int64_t index_in_cluster;
uint64_t cluster_offset;
VmdkMetaData m_data;
@ -869,13 +873,14 @@ static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
if (!extent) {
return -EIO;
}
cluster_offset = get_cluster_offset(
ret = get_cluster_offset(
bs,
extent,
&m_data,
sector_num << 9, 1);
if (!cluster_offset) {
return -1;
sector_num << 9, 1,
&cluster_offset);
if (ret) {
return -EINVAL;
}
index_in_cluster = sector_num % extent->cluster_sectors;
n = extent->cluster_sectors - index_in_cluster;