Parse vmdk decriptor file and open mono flat image.
Read/write the flat extent.
Signed-off-by: Fam Zheng <famc...@gmail.com>
---
block/vmdk.c | 185 +++++++++++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 172 insertions(+), 13 deletions(-)
diff --git a/block/vmdk.c b/block/vmdk.c
index c84ea90..d162dc0 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -65,6 +65,7 @@ typedef struct VmdkExtent {
bool flat;
int64_t sectors;
int64_t end_sector;
+ int64_t flat_start_offset;
int64_t l1_table_offset;
int64_t l1_backup_table_offset;
uint32_t *l1_table;
@@ -390,9 +391,10 @@ fail:
static int vmdk_parent_open(BlockDriverState *bs)
{
char *p_name;
- char desc[DESC_SIZE];
+ char desc[DESC_SIZE + 1];
BDRVVmdkState *s = bs->opaque;
+ desc[DESC_SIZE] = '\0';
if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {
return -1;
}
@@ -588,6 +590,157 @@ static int vmdk_open_vmdk4(BlockDriverState *bs, int
flags)
return ret;
}
+/* find an option value out of descriptor file */
+static int vmdk_parse_description(const char *desc, const char *opt_name,
+ char *buf, int buf_size)
+{
+ char *opt_pos, *opt_end;
+ const char *end = desc + strlen(desc);
+
+ opt_pos = strstr(desc, opt_name);
+ if (!opt_pos) {
+ return -1;
+ }
+ /* Skip "=\"" following opt_name */
+ opt_pos += strlen(opt_name) + 2;
+ if (opt_pos >= end) {
+ return -1;
+ }
+ opt_end = opt_pos;
+ while (opt_end < end && *opt_end != '"') {
+ opt_end++;
+ }
+ if (opt_end == end || buf_size < opt_end - opt_pos + 1) {
+ return -1;
+ }
+ pstrcpy(buf, opt_end - opt_pos, opt_pos);
+ return 0;
+}
+
+static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
+ const char *desc_file_path)
+{
+ int ret = 0;
+ int r;
+ char access[11];
+ char type[11];
+ char fname[512];
+ const char *p = desc;
+ int64_t sectors = 0;
+ int64_t flat_offset;
+
+ while (*p) {
+ if (strncmp(p, "RW", strlen("RW"))) {
+ goto next_line;
+ }
+ /* parse extent line:
+ * RW [size in sectors] FLAT "file-name.vmdk" OFFSET
+ * or
+ * RW [size in sectors] SPARSE "file-name.vmdk"
+ */
+ flat_offset = -1;
+ sscanf(p, "%10s %lld %10s %512s",
+ access, §ors, type, fname);
+ if (!strcmp(type, "FLAT")) {
+ sscanf(p, "%10s %lld %10s %512s %lld",
+ access, §ors, type, fname, &flat_offset);
+ if (flat_offset == -1) {
+ return -EINVAL;
+ }
+ }
+
+ /* trim the quotation marks around */
+ if (fname[0] == '"') {
+ memmove(fname, fname + 1, strlen(fname) + 1);
+ if (fname[strlen(fname) - 1] == '"') {
+ fname[strlen(fname) - 1] = '\0';
+ }
+ }
+ if (!(strlen(access) && sectors && strlen(type) && strlen(fname))) {
+ goto next_line;
+ }
+ if (strcmp(type, "FLAT") && strcmp(type, "SPARSE")) {
+ goto next_line;
+ }
+ if (strcmp(access, "RW")) {
+ goto next_line;
+ }
+ ret++;
+
+ /* save to extents array */
+ if (!strcmp(type, "FLAT")) {
+ /* FLAT extent */
+ char extent_path[PATH_MAX];
+ BlockDriverState *extent_file;
+ BlockDriver *drv;
+ VmdkExtent *extent;
+
+ extent_file = bdrv_new("");
+ drv = bdrv_find_format("file");
+ if (!drv) {
+ return -EINVAL;
+ }
+ path_combine(extent_path, sizeof(extent_path),
+ desc_file_path, fname);
+ r = bdrv_open(extent_file, extent_path,
+ BDRV_O_RDWR | BDRV_O_NO_BACKING, drv);
+ if (r) {
+ return -EINVAL;
+ }
+ extent = vmdk_add_extent(bs, extent_file, true, sectors,
+ 0, 0, 0, 0, sectors);
+ extent->flat_start_offset = flat_offset;
+ } else {
+ /* SPARSE extent, not supported for now */
+ fprintf(stderr,
+ "VMDK: Not supported extent type \"%s\""".\n", type);
+ return -ENOTSUP;
+ }
+next_line:
+ /* move to next line */
+ while (*p && *p != '\n') {
+ p++;
+ }
+ p++;
+ }
+ return 0;
+}
+
+static int vmdk_open_desc_file(BlockDriverState *bs, int flags)
+{
+ int ret;
+ char buf[2048];
+ char ct[128];
+ BDRVVmdkState *s = bs->opaque;
+
+ ret = bdrv_pread(bs->file, 0, buf, sizeof(buf));
+ if (ret < 0) {
+ return ret;
+ }
+ buf[2047] = '\0';
+ if (vmdk_parse_description(buf, "createType", ct, sizeof(ct))) {
+ return -EINVAL;
+ }
+ if (strcmp(ct, "monolithicFlat")) {
+ fprintf(stderr,
+ "VMDK: Not supported image type \"%s\""".\n", ct);
+ return -ENOTSUP;
+ }
+ s->desc_offset = 0;
+ ret = vmdk_parse_extents(buf, bs, bs->file->filename);
+ if (ret) {
+ return ret;
+ }
+
+ /* try to open parent images, if exist */
+ if (vmdk_parent_open(bs)) {
+ qemu_free(s->extents);
+ return -EINVAL;
+ }
+ s->parent_cid = vmdk_read_cid(bs, 1);
+ return 0;
+}
+
static int vmdk_open(BlockDriverState *bs, int flags)
{
uint32_t magic;
@@ -602,7 +755,7 @@ static int vmdk_open(BlockDriverState *bs, int flags)
} else if (magic == VMDK4_MAGIC) {
return vmdk_open_vmdk4(bs, flags);
} else {
- return -EINVAL;
+ return vmdk_open_desc_file(bs, flags);
}
}
@@ -683,7 +836,7 @@ static int get_cluster_offset(BlockDriverState *bs,
if (m_data)
m_data->valid = 0;
if (extent->flat) {
- *cluster_offset = 0;
+ *cluster_offset = extent->flat_start_offset;
return 0;
}
@@ -836,16 +989,20 @@ static int vmdk_read(BlockDriverState *bs, int64_t
sector_num,
/* if not allocated, try to read from parent image, if exist */
if (bs->backing_hd) {
if (!vmdk_is_cid_valid(bs))
- return -1;
+ return -EINVAL;
ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
if (ret < 0)
- return -1;
+ return ret;
} else {
memset(buf, 0, 512 * n);
}
} else {
- if(bdrv_pread(bs->file, cluster_offset + index_in_cluster * 512,
buf, n * 512) != n * 512)
- return -1;
+ ret = bdrv_pread(extent->file,
+ cluster_offset + index_in_cluster * 512,
+ buf, n * 512);
+ if (ret != n * 512) {
+ return ret;
+ }
}
nb_sectors -= n;
sector_num += n;
@@ -869,7 +1026,7 @@ static int vmdk_write(BlockDriverState *bs, int64_t
sector_num,
"(VMDK) Wrong offset: sector_num=0x%" PRIx64
" total_sectors=0x%" PRIx64 "\n",
sector_num, bs->total_sectors);
- return -1;
+ return -EIO;
}
while (nb_sectors > 0) {
@@ -892,16 +1049,18 @@ static int vmdk_write(BlockDriverState *bs, int64_t
sector_num,
n = nb_sectors;
}
- if (bdrv_pwrite(bs->file,
+ ret = bdrv_pwrite(extent->file,
cluster_offset + index_in_cluster * 512,
- buf, n * 512)
- != n * 512) {
- return -1;
+ buf,
+ n * 512);
+ if (ret != n * 512) {
+ ret = ret < 0 ? ret : 0;
+ return ret;
}
if (m_data.valid) {
/* update L2 tables */
if (vmdk_L2update(extent, &m_data) == -1) {
- return -1;
+ return -EIO;
}
}
nb_sectors -= n;
