--- /dev/null
+From 9e1ddc6967e8739f4fa47fa4f6a767ebe319f6ff Mon Sep 17 00:00:00 2001
+From: Fam Zheng <famcool@gmail.com>
+Date: Tue, 12 Jul 2011 19:56:35 +0800
+Subject: [PATCH 09/12] VMDK: change get_cluster_offset return type
+
+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>
+---
+ block/vmdk.c | 79 ++++++++++++++++++++++++++++++++----------------------------
+ 1 file changed, 42 insertions(+), 37 deletions(-)
+
+--- a/block/vmdk.c
++++ b/block/vmdk.c
+@@ -665,26 +665,31 @@ static int vmdk_L2update(VmdkExtent *ext
+ 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(Block
+ 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(Block
+ * 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(Block
+ 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(BlockDriver
+ 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(BlockDriver
+ 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 *b
+ 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 *
+ {
+ 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 *
+ 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;
projects / openwrt / staging / mkresin.git / blobdiff