* [Qemu-devel] [PATCH 2/2] block: VHDX endian fixes
2014-08-06 19:54 [Qemu-devel] [PATCH 0/2] VHDX endian fixes, error reporting Jeff Cody
2014-08-06 19:54 ` [Qemu-devel] [PATCH 1/2] block: vhdx - add error check Jeff Cody
@ 2014-08-06 19:54 ` Jeff Cody
2014-08-07 10:05 ` [Qemu-devel] [PATCH 0/2] VHDX endian fixes, error reporting Stefan Hajnoczi
2 siblings, 0 replies; 5+ messages in thread
From: Jeff Cody @ 2014-08-06 19:54 UTC (permalink / raw)
To: qemu-devel; +Cc: kwolf, pbonzini, armbru, stefanha
This patch contains several changes for endian conversion fixes for
VHDX, particularly for big-endian machines (multibyte values in VHDX are
all on disk in LE format).
Tests were done with existing qemu-iotests on an IBM POWER7 (8406-71Y).
This includes sample images created by Hyper-V, both with dirty logs and
without.
In addition, VHDX image files created (and written to) on a BE machine
were tested on a LE machine, and vice-versa.
Reported-by: Markus Armburster <armbru@redhat.com>
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
block/vhdx-endian.c | 11 +++++--
block/vhdx-log.c | 43 +++++++++++++++-----------
block/vhdx.c | 89 +++++++++++++++++++++++++++++++----------------------
block/vhdx.h | 1 +
4 files changed, 88 insertions(+), 56 deletions(-)
diff --git a/block/vhdx-endian.c b/block/vhdx-endian.c
index fe879ed..0640d3f 100644
--- a/block/vhdx-endian.c
+++ b/block/vhdx-endian.c
@@ -82,8 +82,6 @@ void vhdx_log_desc_le_import(VHDXLogDescriptor *d)
assert(d != NULL);
le32_to_cpus(&d->signature);
- le32_to_cpus(&d->trailing_bytes);
- le64_to_cpus(&d->leading_bytes);
le64_to_cpus(&d->file_offset);
le64_to_cpus(&d->sequence_number);
}
@@ -99,6 +97,15 @@ void vhdx_log_desc_le_export(VHDXLogDescriptor *d)
cpu_to_le64s(&d->sequence_number);
}
+void vhdx_log_data_le_import(VHDXLogDataSector *d)
+{
+ assert(d != NULL);
+
+ le32_to_cpus(&d->data_signature);
+ le32_to_cpus(&d->sequence_high);
+ le32_to_cpus(&d->sequence_low);
+}
+
void vhdx_log_data_le_export(VHDXLogDataSector *d)
{
assert(d != NULL);
diff --git a/block/vhdx-log.c b/block/vhdx-log.c
index 7c2630d..0088be8 100644
--- a/block/vhdx-log.c
+++ b/block/vhdx-log.c
@@ -84,6 +84,7 @@ static int vhdx_log_peek_hdr(BlockDriverState *bs, VHDXLogEntries *log,
if (ret < 0) {
goto exit;
}
+ vhdx_log_entry_hdr_le_import(hdr);
exit:
return ret;
@@ -211,7 +212,7 @@ static bool vhdx_log_hdr_is_valid(VHDXLogEntries *log, VHDXLogEntryHeader *hdr,
{
int valid = false;
- if (memcmp(&hdr->signature, "loge", 4)) {
+ if (hdr->signature != VHDX_LOG_SIGNATURE) {
goto exit;
}
@@ -275,12 +276,12 @@ static bool vhdx_log_desc_is_valid(VHDXLogDescriptor *desc,
goto exit;
}
- if (!memcmp(&desc->signature, "zero", 4)) {
+ if (desc->signature == VHDX_LOG_ZERO_SIGNATURE) {
if (desc->zero_length % VHDX_LOG_SECTOR_SIZE == 0) {
/* valid */
ret = true;
}
- } else if (!memcmp(&desc->signature, "desc", 4)) {
+ } else if (desc->signature == VHDX_LOG_DESC_SIGNATURE) {
/* valid */
ret = true;
}
@@ -327,13 +328,15 @@ static int vhdx_compute_desc_sectors(uint32_t desc_cnt)
* passed into this function. Each descriptor will also be validated,
* and error returned if any are invalid. */
static int vhdx_log_read_desc(BlockDriverState *bs, BDRVVHDXState *s,
- VHDXLogEntries *log, VHDXLogDescEntries **buffer)
+ VHDXLogEntries *log, VHDXLogDescEntries **buffer,
+ bool convert_endian)
{
int ret = 0;
uint32_t desc_sectors;
uint32_t sectors_read;
VHDXLogEntryHeader hdr;
VHDXLogDescEntries *desc_entries = NULL;
+ VHDXLogDescriptor desc;
int i;
assert(*buffer == NULL);
@@ -342,7 +345,7 @@ static int vhdx_log_read_desc(BlockDriverState *bs, BDRVVHDXState *s,
if (ret < 0) {
goto exit;
}
- vhdx_log_entry_hdr_le_import(&hdr);
+
if (vhdx_log_hdr_is_valid(log, &hdr, s) == false) {
ret = -EINVAL;
goto exit;
@@ -363,12 +366,19 @@ static int vhdx_log_read_desc(BlockDriverState *bs, BDRVVHDXState *s,
/* put in proper endianness, and validate each desc */
for (i = 0; i < hdr.descriptor_count; i++) {
- vhdx_log_desc_le_import(&desc_entries->desc[i]);
- if (vhdx_log_desc_is_valid(&desc_entries->desc[i], &hdr) == false) {
+ desc = desc_entries->desc[i];
+ vhdx_log_desc_le_import(&desc);
+ if (convert_endian) {
+ desc_entries->desc[i] = desc;
+ }
+ if (vhdx_log_desc_is_valid(&desc, &hdr) == false) {
ret = -EINVAL;
goto free_and_exit;
}
}
+ if (convert_endian) {
+ desc_entries->hdr = hdr;
+ }
*buffer = desc_entries;
goto exit;
@@ -403,7 +413,7 @@ static int vhdx_log_flush_desc(BlockDriverState *bs, VHDXLogDescriptor *desc,
buffer = qemu_blockalign(bs, VHDX_LOG_SECTOR_SIZE);
- if (!memcmp(&desc->signature, "desc", 4)) {
+ if (desc->signature == VHDX_LOG_DESC_SIGNATURE) {
/* data sector */
if (data == NULL) {
ret = -EFAULT;
@@ -431,7 +441,7 @@ static int vhdx_log_flush_desc(BlockDriverState *bs, VHDXLogDescriptor *desc,
memcpy(buffer+offset, &desc->trailing_bytes, 4);
- } else if (!memcmp(&desc->signature, "zero", 4)) {
+ } else if (desc->signature == VHDX_LOG_ZERO_SIGNATURE) {
/* write 'count' sectors of sector */
memset(buffer, 0, VHDX_LOG_SECTOR_SIZE);
count = desc->zero_length / VHDX_LOG_SECTOR_SIZE;
@@ -498,13 +508,13 @@ static int vhdx_log_flush(BlockDriverState *bs, BDRVVHDXState *s,
goto exit;
}
- ret = vhdx_log_read_desc(bs, s, &logs->log, &desc_entries);
+ ret = vhdx_log_read_desc(bs, s, &logs->log, &desc_entries, true);
if (ret < 0) {
goto exit;
}
for (i = 0; i < desc_entries->hdr.descriptor_count; i++) {
- if (!memcmp(&desc_entries->desc[i].signature, "desc", 4)) {
+ if (desc_entries->desc[i].signature == VHDX_LOG_DESC_SIGNATURE) {
/* data sector, so read a sector to flush */
ret = vhdx_log_read_sectors(bs, &logs->log, §ors_read,
data, 1, false);
@@ -515,6 +525,7 @@ static int vhdx_log_flush(BlockDriverState *bs, BDRVVHDXState *s,
ret = -EINVAL;
goto exit;
}
+ vhdx_log_data_le_import(data);
}
ret = vhdx_log_flush_desc(bs, &desc_entries->desc[i], data);
@@ -563,9 +574,6 @@ static int vhdx_validate_log_entry(BlockDriverState *bs, BDRVVHDXState *s,
goto inc_and_exit;
}
- vhdx_log_entry_hdr_le_import(&hdr);
-
-
if (vhdx_log_hdr_is_valid(log, &hdr, s) == false) {
goto inc_and_exit;
}
@@ -578,13 +586,13 @@ static int vhdx_validate_log_entry(BlockDriverState *bs, BDRVVHDXState *s,
desc_sectors = vhdx_compute_desc_sectors(hdr.descriptor_count);
- /* Read desc sectors, and calculate log checksum */
+ /* Read all log sectors, and calculate log checksum */
total_sectors = hdr.entry_length / VHDX_LOG_SECTOR_SIZE;
/* read_desc() will increment the read idx */
- ret = vhdx_log_read_desc(bs, s, log, &desc_buffer);
+ ret = vhdx_log_read_desc(bs, s, log, &desc_buffer, false);
if (ret < 0) {
goto free_and_exit;
}
@@ -607,7 +615,7 @@ static int vhdx_validate_log_entry(BlockDriverState *bs, BDRVVHDXState *s,
}
}
crc ^= 0xffffffff;
- if (crc != desc_buffer->hdr.checksum) {
+ if (crc != hdr.checksum) {
goto free_and_exit;
}
@@ -967,7 +975,6 @@ static int vhdx_log_write(BlockDriverState *bs, BDRVVHDXState *s,
* last data sector */
vhdx_update_checksum(buffer, total_length,
offsetof(VHDXLogEntryHeader, checksum));
- cpu_to_le32s((uint32_t *)(buffer + 4));
/* now write to the log */
ret = vhdx_log_write_sectors(bs, &s->log, §ors_written, buffer,
diff --git a/block/vhdx.c b/block/vhdx.c
index fedcf9f..febce21 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -135,10 +135,8 @@ typedef struct VHDXSectorInfo {
* buf: buffer pointer
* size: size of buffer (must be > crc_offset+4)
*
- * Note: The resulting checksum is in the CPU endianness, not necessarily
- * in the file format endianness (LE). Any header export to disk should
- * make sure that vhdx_header_le_export() is used to convert to the
- * correct endianness
+ * Note: The buffer should have all multi-byte data in little-endian format,
+ * and the resulting checksum is in little endian format.
*/
uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset)
{
@@ -149,6 +147,7 @@ uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset)
memset(buf + crc_offset, 0, sizeof(crc));
crc = crc32c(0xffffffff, buf, size);
+ cpu_to_le32s(&crc);
memcpy(buf + crc_offset, &crc, sizeof(crc));
return crc;
@@ -300,7 +299,7 @@ static int vhdx_write_header(BlockDriverState *bs_file, VHDXHeader *hdr,
{
uint8_t *buffer = NULL;
int ret;
- VHDXHeader header_le;
+ VHDXHeader *header_le;
assert(bs_file != NULL);
assert(hdr != NULL);
@@ -321,11 +320,12 @@ static int vhdx_write_header(BlockDriverState *bs_file, VHDXHeader *hdr,
}
/* overwrite the actual VHDXHeader portion */
- memcpy(buffer, hdr, sizeof(VHDXHeader));
- hdr->checksum = vhdx_update_checksum(buffer, VHDX_HEADER_SIZE,
- offsetof(VHDXHeader, checksum));
- vhdx_header_le_export(hdr, &header_le);
- ret = bdrv_pwrite_sync(bs_file, offset, &header_le, sizeof(VHDXHeader));
+ header_le = (VHDXHeader *)buffer;
+ memcpy(header_le, hdr, sizeof(VHDXHeader));
+ vhdx_header_le_export(hdr, header_le);
+ vhdx_update_checksum(buffer, VHDX_HEADER_SIZE,
+ offsetof(VHDXHeader, checksum));
+ ret = bdrv_pwrite_sync(bs_file, offset, header_le, sizeof(VHDXHeader));
exit:
qemu_vfree(buffer);
@@ -432,13 +432,14 @@ static void vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s,
}
/* copy over just the relevant portion that we need */
memcpy(header1, buffer, sizeof(VHDXHeader));
- vhdx_header_le_import(header1);
- if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4) &&
- !memcmp(&header1->signature, "head", 4) &&
- header1->version == 1) {
- h1_seq = header1->sequence_number;
- h1_valid = true;
+ if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) {
+ vhdx_header_le_import(header1);
+ if (header1->signature == VHDX_HEADER_SIGNATURE &&
+ header1->version == 1) {
+ h1_seq = header1->sequence_number;
+ h1_valid = true;
+ }
}
ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, VHDX_HEADER_SIZE);
@@ -447,13 +448,14 @@ static void vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s,
}
/* copy over just the relevant portion that we need */
memcpy(header2, buffer, sizeof(VHDXHeader));
- vhdx_header_le_import(header2);
- if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4) &&
- !memcmp(&header2->signature, "head", 4) &&
- header2->version == 1) {
- h2_seq = header2->sequence_number;
- h2_valid = true;
+ if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) {
+ vhdx_header_le_import(header2);
+ if (header2->signature == VHDX_HEADER_SIGNATURE &&
+ header2->version == 1) {
+ h2_seq = header2->sequence_number;
+ h2_valid = true;
+ }
}
/* If there is only 1 valid header (or no valid headers), we
@@ -519,15 +521,21 @@ static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s)
goto fail;
}
memcpy(&s->rt, buffer, sizeof(s->rt));
- vhdx_region_header_le_import(&s->rt);
offset += sizeof(s->rt);
- if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4) ||
- memcmp(&s->rt.signature, "regi", 4)) {
+ if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4)) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ vhdx_region_header_le_import(&s->rt);
+
+ if (s->rt.signature != VHDX_REGION_SIGNATURE) {
ret = -EINVAL;
goto fail;
}
+
/* Per spec, maximum region table entry count is 2047 */
if (s->rt.entry_count > 2047) {
ret = -EINVAL;
@@ -630,7 +638,7 @@ static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s)
vhdx_metadata_header_le_import(&s->metadata_hdr);
- if (memcmp(&s->metadata_hdr.signature, "metadata", 8)) {
+ if (s->metadata_hdr.signature != VHDX_METADATA_SIGNATURE) {
ret = -EINVAL;
goto exit;
}
@@ -951,7 +959,6 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags,
/* s->bat is freed in vhdx_close() */
s->bat = qemu_blockalign(bs, s->bat_rt.length);
-
ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length);
if (ret < 0) {
goto fail;
@@ -1540,7 +1547,8 @@ exit:
*/
static int vhdx_create_bat(BlockDriverState *bs, BDRVVHDXState *s,
uint64_t image_size, VHDXImageType type,
- bool use_zero_blocks, VHDXRegionTableEntry *rt_bat)
+ bool use_zero_blocks, uint64_t file_offset,
+ uint32_t length)
{
int ret = 0;
uint64_t data_file_offset;
@@ -1555,7 +1563,7 @@ static int vhdx_create_bat(BlockDriverState *bs, BDRVVHDXState *s,
/* this gives a data start after BAT/bitmap entries, and well
* past any metadata entries (with a 4 MB buffer for future
* expansion */
- data_file_offset = rt_bat->file_offset + rt_bat->length + 5 * MiB;
+ data_file_offset = file_offset + length + 5 * MiB;
total_sectors = image_size >> s->logical_sector_size_bits;
if (type == VHDX_TYPE_DYNAMIC) {
@@ -1579,7 +1587,7 @@ static int vhdx_create_bat(BlockDriverState *bs, BDRVVHDXState *s,
use_zero_blocks ||
bdrv_has_zero_init(bs) == 0) {
/* for a fixed file, the default BAT entry is not zero */
- s->bat = g_malloc0(rt_bat->length);
+ s->bat = g_malloc0(length);
block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT :
PAYLOAD_BLOCK_NOT_PRESENT;
block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state;
@@ -1594,7 +1602,7 @@ static int vhdx_create_bat(BlockDriverState *bs, BDRVVHDXState *s,
cpu_to_le64s(&s->bat[sinfo.bat_idx]);
sector_num += s->sectors_per_block;
}
- ret = bdrv_pwrite(bs, rt_bat->file_offset, s->bat, rt_bat->length);
+ ret = bdrv_pwrite(bs, file_offset, s->bat, length);
if (ret < 0) {
goto exit;
}
@@ -1626,6 +1634,8 @@ static int vhdx_create_new_region_table(BlockDriverState *bs,
int ret = 0;
uint32_t offset = 0;
void *buffer = NULL;
+ uint64_t bat_file_offset;
+ uint32_t bat_length;
BDRVVHDXState *s = NULL;
VHDXRegionTableHeader *region_table;
VHDXRegionTableEntry *rt_bat;
@@ -1674,19 +1684,26 @@ static int vhdx_create_new_region_table(BlockDriverState *bs,
rt_metadata->length = 1 * MiB; /* min size, and more than enough */
*metadata_offset = rt_metadata->file_offset;
+ bat_file_offset = rt_bat->file_offset;
+ bat_length = rt_bat->length;
+
+ vhdx_region_header_le_export(region_table);
+ vhdx_region_entry_le_export(rt_bat);
+ vhdx_region_entry_le_export(rt_metadata);
+
vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE,
offsetof(VHDXRegionTableHeader, checksum));
/* The region table gives us the data we need to create the BAT,
* so do that now */
- ret = vhdx_create_bat(bs, s, image_size, type, use_zero_blocks, rt_bat);
+ ret = vhdx_create_bat(bs, s, image_size, type, use_zero_blocks,
+ bat_file_offset, bat_length);
+ if (ret < 0) {
+ goto exit;
+ }
/* Now write out the region headers to disk */
- vhdx_region_header_le_export(region_table);
- vhdx_region_entry_le_export(rt_bat);
- vhdx_region_entry_le_export(rt_metadata);
-
ret = bdrv_pwrite(bs, VHDX_REGION_TABLE_OFFSET, buffer,
VHDX_HEADER_BLOCK_SIZE);
if (ret < 0) {
diff --git a/block/vhdx.h b/block/vhdx.h
index 5370010..b4a12a0 100644
--- a/block/vhdx.h
+++ b/block/vhdx.h
@@ -435,6 +435,7 @@ void vhdx_header_le_import(VHDXHeader *h);
void vhdx_header_le_export(VHDXHeader *orig_h, VHDXHeader *new_h);
void vhdx_log_desc_le_import(VHDXLogDescriptor *d);
void vhdx_log_desc_le_export(VHDXLogDescriptor *d);
+void vhdx_log_data_le_import(VHDXLogDataSector *d);
void vhdx_log_data_le_export(VHDXLogDataSector *d);
void vhdx_log_entry_hdr_le_import(VHDXLogEntryHeader *hdr);
void vhdx_log_entry_hdr_le_export(VHDXLogEntryHeader *hdr);
--
1.9.3
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