@@ -233,7 +233,8 @@ static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename)
*
* - non-current header is updated with largest sequence number
*/
-static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, bool rw)
+static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, bool rw,
+ MSGUID *log_guid)
{
int ret = 0;
int hdr_idx = 0;
@@ -266,6 +267,11 @@ static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, bool rw)
vhdx_guid_generate(&inactive_header->data_write_guid);
}
+ /* update the log guid if present */
+ if (log_guid) {
+ memcpy(&inactive_header->log_guid, log_guid, sizeof(MSGUID));
+ }
+
/* the header checksum is not over just the packed size of VHDXHeader,
* but rather over the entire 'reserved' range for the header, which is
* 4KB (VHDX_HEADER_SIZE). */
@@ -293,15 +299,16 @@ exit:
* The VHDX spec calls for header updates to be performed twice, so that both
* the current and non-current header have valid info
*/
-static int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, bool rw)
+int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, bool rw,
+ MSGUID *log_guid)
{
int ret;
- ret = vhdx_update_header(bs, s, rw);
+ ret = vhdx_update_header(bs, s, rw, log_guid);
if (ret < 0) {
return ret;
}
- ret = vhdx_update_header(bs, s, rw);
+ ret = vhdx_update_header(bs, s, rw, log_guid);
return ret;
}
@@ -781,6 +788,7 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags)
s->bat = NULL;
+ s->first_visible_write = true;
qemu_co_mutex_init(&s->lock);
@@ -861,7 +869,7 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags)
}
if (flags & BDRV_O_RDWR) {
- vhdx_update_headers(bs, s, false);
+ vhdx_update_headers(bs, s, false, NULL);
}
/* TODO: differencing files, write */
@@ -998,6 +1006,16 @@ exit:
+/* Per the spec, on the first write of guest-visible data to the file the
+ * data write guid must be updated in the header */
+void vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s)
+{
+ if (s->first_visible_write) {
+ s->first_visible_write = false;
+ vhdx_update_headers(bs, s, true, NULL);
+ }
+}
+
static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, QEMUIOVector *qiov)
{
@@ -366,6 +366,7 @@ typedef struct BDRVVHDXState {
VHDXBatEntry *bat;
uint64_t bat_offset;
+ bool first_visible_write;
MSGUID session_guid;
VHDXLogEntries log;
@@ -377,6 +378,9 @@ typedef struct BDRVVHDXState {
void vhdx_guid_generate(MSGUID *guid);
+int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, bool rw,
+ MSGUID *log_guid);
+
uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset);
uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size,
int crc_offset);
@@ -406,8 +410,7 @@ 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);
-
-
+void vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s);
Allow tracking of first file write in the VHDX image, as well as the ability to update the GUID in the header. This is in preparation for log support. Signed-off-by: Jeff Cody <jcody@redhat.com> --- block/vhdx.c | 28 +++++++++++++++++++++++----- block/vhdx.h | 7 +++++-- 2 files changed, 28 insertions(+), 7 deletions(-)