Fixed a MAJOR BUG in VMDK files on file boundaries on reads
and ALSO ON WRITES WHICH MIGHT CORRUPT THE IMAGE AND DATA!!!!!!
Triggered for example with the following VMDK file (partly listed):
# Extent description
RW 4193792 FLAT "XP-W1-f001.vmdk" 0
RW 2097664 FLAT "XP-W1-f002.vmdk" 0
RW 4193792 FLAT "XP-W1-f003.vmdk" 0
RW 512 FLAT "XP-W1-f004.vmdk" 0
RW 4193792 FLAT "XP-W1-f005.vmdk" 0
RW 2097664 FLAT "XP-W1-f006.vmdk" 0
RW 4193792 FLAT "XP-W1-f007.vmdk" 0
RW 512 FLAT "XP-W1-f008.vmdk" 0
Patch includes:
1.) Patch fixes wrong calculation on extent boundaries. Especially it fixes
the relativeness of the sector number to the current extent.
2.) Added debug code to block.c and to block/vmdk.c to verify correctness
3.) Also optimized code which avoids multiplication and uses shifts.
Verfied correctness with:
1.) Converted either with Virtualbox to VDI and then with qemu-img and then
with qemu-img only
VBoxManage clonehd --format vdi /VM/XP-W/new/XP-W1.vmdk
~/.VirtualBox/Harddisks/XP-W1-new-test.vdi
./qemu-img convert -O raw ~/.VirtualBox/Harddisks/XP-W1-new-test.vdi
/root/QEMU/VM-XP-W1/XP-W1-via-VBOX.img
md5sum /root/QEMU/VM-XP-W/XP-W1-direct.img
md5sum /root/QEMU/VM-XP-W/XP-W1-via-VBOX.img
=> same MD5 hash
2.) Verified debug log files
3.) Run Windows XP successfully
4.) chkdsk run successfully without any errors
Signed-off-by: Gerhard Wiesinger <address@hidden>
---
block.c | 50 +++++++++++++++++++++++
block/vmdk.c | 129
++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 170 insertions(+), 9 deletions(-)
diff --git a/block.c b/block.c
index da1fdca..69259f2 100644
--- a/block.c
+++ b/block.c
@@ -49,6 +49,12 @@
#include <windows.h>
#endif
+#if 0
+ #define DEBUG_BLOCK
+#endif
+
+#define DEBUG_BLOCK_PREFIX "BLOCK: "
+
#define NOT_DONE 0x7fffffff /* used while emulated sync operation in
progress */
typedef enum {
@@ -789,6 +795,18 @@ int bdrv_open(BlockDriverState *bs, const char
*filename, int flags,
int ret;
char tmp_filename[PATH_MAX];
+#ifdef DEBUG_BLOCK
+ const char *format = "(nil)";
+ if (drv) {
+ format = drv->format_name;
+ }
+
+ printf(DEBUG_BLOCK
+ "bdrv_open: filename=%s, BlockDriver=%p, format=%s\n",
+ filename, drv, format
+ );
+#endif
+
if (flags & BDRV_O_SNAPSHOT) {
BlockDriverState *bs1;
int64_t total_size;
@@ -2004,6 +2022,22 @@ static int bdrv_rw_co(BlockDriverState *bs, int64_t
sector_num, uint8_t *buf,
int bdrv_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
+#ifdef DEBUG_BLOCK
+ BlockDriver *drv = bs->drv;
+ const char *format_name = "(nil)";
+ if (drv) {
+ if (drv->format_name) {
+ format_name = drv->format_name;
+ }
+ }
+
+ printf(DEBUG_BLOCK
+ "bdrv_read: driver=%s, filename=%s, sector_num=%" PRId64
+ ", nb_sectors=%i\n",
+ format_name, bs->filename, sector_num, nb_sectors
+ );
+#endif
+
return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false);
}
@@ -2060,6 +2094,22 @@ static void set_dirty_bitmap(BlockDriverState *bs,
int64_t sector_num,
int bdrv_write(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
+#ifdef DEBUG_BLOCK
+ BlockDriver *drv = bs->drv;
+ const char *format_name = "(nil)";
+ if (drv) {
+ if (drv->format_name) {
+ format_name = drv->format_name;
+ }
+ }
+
+ printf(DEBUG_BLOCK
+ "bdrv_write: driver=%s, filename=%s, sector_num=%" PRId64
+ ", nb_sectors=%i\n",
+ format_name, bs->filename, sector_num, nb_sectors
+ );
+#endif
+
return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true);
}
diff --git a/block/vmdk.c b/block/vmdk.c
index 1a80e5a..92ab92c 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -29,6 +29,15 @@
#include "migration.h"
#include <zlib.h>
+#if 0
+ #define DEBUG_VMDK
+#endif
+
+#define DEBUG_VMDK_PREFIX "VMDK: "
+#define DEBUG_VMDK_SEPARATOR \
+ "########################################" \
+ "########################################"
+
#define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D')
#define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V')
#define VMDK4_COMPRESSION_DEFLATE 1
@@ -377,6 +386,16 @@ static VmdkExtent *vmdk_add_extent(BlockDriverState
*bs,
VmdkExtent *extent;
BDRVVmdkState *s = bs->opaque;
+#ifdef DEBUG_VMDK
+ printf(DEBUG_VMDK_PREFIX
+ "vmdk_add_extent: flat=%i, sectors=%" PRId64
+ ", l1_backup_offset=%" PRId64
+ ", l1_size=%u, l2_size=%i, cluster_sectors=%u\n",
+ (int)flat, sectors, l1_backup_offset,
+ l1_size, l2_size, cluster_sectors
+ );
+#endif
+
s->extents = g_realloc(s->extents,
(s->num_extents + 1) * sizeof(VmdkExtent));
extent = &s->extents[s->num_extents];
@@ -674,6 +693,14 @@ static int vmdk_parse_extents(const char *desc,
BlockDriverState *bs,
return ret;
}
+#ifdef DEBUG_VMDK
+ printf(DEBUG_VMDK_PREFIX
+ "valid extent found: access=%s, sectors=%" PRId64
+ ", type=%s, filename=%s, flat_offset=%" PRId64 "\n",
+ access, sectors, type, fname, flat_offset
+ );
+#endif
+
/* save to extents array */
if (!strcmp(type, "FLAT")) {
/* FLAT extent */
@@ -704,6 +731,45 @@ next_line:
return 0;
}
+#ifdef DEBUG_VMDK
+static void vmdk_debug_print_one_extent(VmdkExtent *extent)
+{
+ printf(DEBUG_VMDK_PREFIX DEBUG_VMDK_SEPARATOR "\n");
+ printf(DEBUG_VMDK_PREFIX "filename%s\n", extent->file->filename);
+ printf(DEBUG_VMDK_PREFIX "flat=%i\n", (int)extent->flat);
+ printf(DEBUG_VMDK_PREFIX "compressed=%i\n", (int)extent->compressed);
+ printf(DEBUG_VMDK_PREFIX "has_marker=%i\n", (int)extent->has_marker);
+ printf(DEBUG_VMDK_PREFIX "sectors=%" PRId64 "\n", extent->sectors);
+ printf(DEBUG_VMDK_PREFIX "end_sector=%" PRId64 "\n",
extent->end_sector);
+ printf(DEBUG_VMDK_PREFIX "flat_start_offset=%" PRId64 "\n",
+ extent->flat_start_offset);
+ printf(DEBUG_VMDK_PREFIX "l1_table_offsett=%" PRId64 "\n",
+ extent->l1_table_offset);
+ printf(DEBUG_VMDK_PREFIX "l1_backup_table_offsett=%"
+ PRId64 "\n", extent->l1_backup_table_offset);
+ printf(DEBUG_VMDK_PREFIX "l1_size=%u\n", extent->l1_size);
+ printf(DEBUG_VMDK_PREFIX "l1_entry_sectors=%u\n",
extent->l1_entry_sectors);
+ printf(DEBUG_VMDK_PREFIX "l2_size=%u\n", extent->l2_size);
+ printf(DEBUG_VMDK_PREFIX "cluster_sectors=%u\n",
extent->cluster_sectors);
+ fflush(stdout);
+}
+
+static void vmdk_debug_print_extents(BlockDriverState *bs)
+{
+ BDRVVmdkState *s = bs->opaque;
+ VmdkExtent *extent = &s->extents[0];
+
+ printf(DEBUG_VMDK_PREFIX DEBUG_VMDK_SEPARATOR "\n");
+ printf(DEBUG_VMDK_PREFIX "total_sectors=%" PRId64 "\n",
bs->total_sectors);
+ printf(DEBUG_VMDK_PREFIX "num_extents=%u\n", s->num_extents);
+
+ while (extent < &s->extents[s->num_extents]) {
+ vmdk_debug_print_one_extent(extent);
+ extent++;
+ }
+}
+#endif
+
static int vmdk_open_desc_file(BlockDriverState *bs, int flags,
int64_t desc_offset)
{
@@ -728,7 +794,13 @@ static int vmdk_open_desc_file(BlockDriverState *bs,
int flags,
return -ENOTSUP;
}
s->desc_offset = 0;
- return vmdk_parse_extents(buf, bs, bs->file->filename);
+ ret = vmdk_parse_extents(buf, bs, bs->file->filename);
+
+#ifdef DEBUG_VMDK
+ vmdk_debug_print_extents(bs);
+#endif
+
+ return ret;
}
static int vmdk_open(BlockDriverState *bs, int flags)
@@ -774,6 +846,14 @@ static int get_whole_cluster(BlockDriverState *bs,
/* 128 sectors * 512 bytes each = grain size 64KB */
uint8_t whole_grain[extent->cluster_sectors * 512];
+#ifdef DEBUG_VMDK
+ printf(DEBUG_VMDK_PREFIX
+ "vmdk_get_whole_cluster: filename=%s, cluster_offset=%" PRId64
+ ", offset=%" PRId64 "\n",
+ extent->file->filename, cluster_offset, offset
+ );
+#endif
+
/* we will be here if it's first write on non-exist grain(cluster).
* try to read from parent image, if exist */
if (bs->backing_hd) {
@@ -1032,18 +1112,35 @@ static int vmdk_read_extent(VmdkExtent *extent,
int64_t cluster_offset,
VmdkGrainMarker *marker;
uLongf buf_len;
+#ifdef DEBUG_VMDK
+ printf(DEBUG_VMDK_PREFIX
+ "vmdk_read_extent: filename=%s, cluster_offset=%" PRId64
+ ", offset_in_cluster=%" PRId64 ", nb_sectors=%i\n",
+ extent->file->filename, cluster_offset,
+ offset_in_cluster, nb_sectors
+ );
+#endif
if (!extent->compressed) {
+
+#ifdef DEBUG_VMDK
+ printf(DEBUG_VMDK_PREFIX
+ "vmdk_read_extent:bdrv_pread filename=%s, offset=%" PRId64
+ ", length=%i\n",
+ extent->file->filename, offset_in_cluster, nb_sectors << 9
+ );
+#endif
+
ret = bdrv_pread(extent->file,
cluster_offset + offset_in_cluster,
- buf, nb_sectors * 512);
- if (ret == nb_sectors * 512) {
+ buf, nb_sectors << 9);
+ if (ret == nb_sectors << 9) {
return 0;
} else {
return -EIO;
}
}
- cluster_bytes = extent->cluster_sectors * 512;
+ cluster_bytes = extent->cluster_sectors << 9;
/* Read two clusters in case GrainMarker + compressed data > one
cluster */
buf_bytes = cluster_bytes * 2;
cluster_buf = g_malloc(buf_bytes);
@@ -1092,9 +1189,18 @@ static int vmdk_read(BlockDriverState *bs, int64_t
sector_num,
BDRVVmdkState *s = bs->opaque;
int ret;
uint64_t n, index_in_cluster;
+ uint64_t extent_begin_sector, extent_relative_sector_num;
VmdkExtent *extent = NULL;
uint64_t cluster_offset;
+#ifdef DEBUG_VMDK
+ printf(DEBUG_VMDK_PREFIX
+ "vmdk_read: sectornum=%" PRId64
+ ", nb_sectors=%i\n",
+ sector_num, nb_sectors
+ );
+#endif
+
while (nb_sectors > 0) {
extent = find_extent(s, sector_num, extent);
if (!extent) {
@@ -1103,7 +1209,9 @@ static int vmdk_read(BlockDriverState *bs, int64_t
sector_num,
ret = get_cluster_offset(
bs, extent, NULL,
sector_num << 9, 0, &cluster_offset);
- index_in_cluster = sector_num % extent->cluster_sectors;
+ extent_begin_sector = extent->end_sector - extent->sectors;
+ extent_relative_sector_num = sector_num - extent_begin_sector;
+ index_in_cluster = extent_relative_sector_num %
extent->cluster_sectors;
n = extent->cluster_sectors - index_in_cluster;
if (n > nb_sectors) {
n = nb_sectors;
@@ -1119,11 +1227,11 @@ static int vmdk_read(BlockDriverState *bs, int64_t
sector_num,
return ret;
}
} else {
- memset(buf, 0, 512 * n);
+ memset(buf, 0, n << 9);
}
} else {
ret = vmdk_read_extent(extent,
- cluster_offset, index_in_cluster * 512,
+ cluster_offset, index_in_cluster << 9,
buf, n);
if (ret) {
return ret;
@@ -1131,7 +1239,7 @@ static int vmdk_read(BlockDriverState *bs, int64_t
sector_num,
}
nb_sectors -= n;
sector_num += n;
- buf += n * 512;
+ buf += n << 9;
}
return 0;
}
@@ -1154,6 +1262,7 @@ static int vmdk_write(BlockDriverState *bs, int64_t
sector_num,
VmdkExtent *extent = NULL;
int n, ret;
int64_t index_in_cluster;
+ uint64_t extent_begin_sector, extent_relative_sector_num;
uint64_t cluster_offset;
VmdkMetaData m_data;
@@ -1196,7 +1305,9 @@ static int vmdk_write(BlockDriverState *bs, int64_t
sector_num,
if (ret) {
return -EINVAL;
}
- index_in_cluster = sector_num % extent->cluster_sectors;
+ extent_begin_sector = extent->end_sector - extent->sectors;
+ extent_relative_sector_num = sector_num - extent_begin_sector;
+ index_in_cluster = extent_relative_sector_num %
extent->cluster_sectors;
n = extent->cluster_sectors - index_in_cluster;
if (n > nb_sectors) {
n = nb_sectors;
--
1.7.11.7