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block: vhdx - log support struct and defines

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This adds some magic number defines, and internal structure definitions
for VHDX log replay support.  The struct VHDXLogEntries does not reflect
an on-disk data structure, and thus does not need to be packed.

Some minor code style fixes are applied as well.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Jeff Cody 2013-10-30 10:44:41 -04:00 committed by Stefan Hajnoczi
parent 28541d4628
commit 625565d27e
1 changed files with 30 additions and 16 deletions
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46
block/vhdx.h
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@ -30,12 +30,12 @@
* 0.........64KB...........128KB........192KB..........256KB................1MB * 0.........64KB...........128KB........192KB..........256KB................1MB
*/ */
#define VHDX_HEADER_BLOCK_SIZE (64*1024) #define VHDX_HEADER_BLOCK_SIZE (64 * 1024)
#define VHDX_FILE_ID_OFFSET 0 #define VHDX_FILE_ID_OFFSET 0
#define VHDX_HEADER1_OFFSET (VHDX_HEADER_BLOCK_SIZE*1) #define VHDX_HEADER1_OFFSET (VHDX_HEADER_BLOCK_SIZE * 1)
#define VHDX_HEADER2_OFFSET (VHDX_HEADER_BLOCK_SIZE*2) #define VHDX_HEADER2_OFFSET (VHDX_HEADER_BLOCK_SIZE * 2)
#define VHDX_REGION_TABLE_OFFSET (VHDX_HEADER_BLOCK_SIZE*3) #define VHDX_REGION_TABLE_OFFSET (VHDX_HEADER_BLOCK_SIZE * 3)
/* /*
@ -77,10 +77,10 @@ typedef struct QEMU_PACKED MSGUID {
#define guid_eq(a, b) \ #define guid_eq(a, b) \
(memcmp(&(a), &(b), sizeof(MSGUID)) == 0) (memcmp(&(a), &(b), sizeof(MSGUID)) == 0)
#define VHDX_HEADER_SIZE (4*1024) /* although the vhdx_header struct in disk #define VHDX_HEADER_SIZE (4 * 1024) /* although the vhdx_header struct in disk
is only 582 bytes, for purposes of crc is only 582 bytes, for purposes of crc
the header is the first 4KB of the 64KB the header is the first 4KB of the 64KB
block */ block */
/* The full header is 4KB, although the actual header data is much smaller. /* The full header is 4KB, although the actual header data is much smaller.
* But for the checksum calculation, it is over the entire 4KB structure, * But for the checksum calculation, it is over the entire 4KB structure,
@ -92,7 +92,7 @@ typedef struct QEMU_PACKED VHDXHeader {
VHDX file has 2 of these headers, VHDX file has 2 of these headers,
and only the header with the highest and only the header with the highest
sequence number is valid */ sequence number is valid */
MSGUID file_write_guid; /* 128 bit unique identifier. Must be MSGUID file_write_guid; /* 128 bit unique identifier. Must be
updated to new, unique value before updated to new, unique value before
the first modification is made to the first modification is made to
file */ file */
@ -151,7 +151,10 @@ typedef struct QEMU_PACKED VHDXRegionTableEntry {
/* ---- LOG ENTRY STRUCTURES ---- */ /* ---- LOG ENTRY STRUCTURES ---- */
#define VHDX_LOG_MIN_SIZE (1024 * 1024)
#define VHDX_LOG_SECTOR_SIZE 4096
#define VHDX_LOG_HDR_SIZE 64 #define VHDX_LOG_HDR_SIZE 64
#define VHDX_LOG_SIGNATURE 0x65676f6c
typedef struct QEMU_PACKED VHDXLogEntryHeader { typedef struct QEMU_PACKED VHDXLogEntryHeader {
uint32_t signature; /* "loge" in ASCII */ uint32_t signature; /* "loge" in ASCII */
uint32_t checksum; /* CRC-32C hash of the 64KB table */ uint32_t checksum; /* CRC-32C hash of the 64KB table */
@ -174,7 +177,8 @@ typedef struct QEMU_PACKED VHDXLogEntryHeader {
} VHDXLogEntryHeader; } VHDXLogEntryHeader;
#define VHDX_LOG_DESC_SIZE 32 #define VHDX_LOG_DESC_SIZE 32
#define VHDX_LOG_DESC_SIGNATURE 0x63736564
#define VHDX_LOG_ZERO_SIGNATURE 0x6f72657a
typedef struct QEMU_PACKED VHDXLogDescriptor { typedef struct QEMU_PACKED VHDXLogDescriptor {
uint32_t signature; /* "zero" or "desc" in ASCII */ uint32_t signature; /* "zero" or "desc" in ASCII */
union { union {
@ -194,6 +198,7 @@ typedef struct QEMU_PACKED VHDXLogDescriptor {
vhdx_log_entry_header */ vhdx_log_entry_header */
} VHDXLogDescriptor; } VHDXLogDescriptor;
#define VHDX_LOG_DATA_SIGNATURE 0x61746164
typedef struct QEMU_PACKED VHDXLogDataSector { typedef struct QEMU_PACKED VHDXLogDataSector {
uint32_t data_signature; /* "data" in ASCII */ uint32_t data_signature; /* "data" in ASCII */
uint32_t sequence_high; /* 4 MSB of 8 byte sequence_number */ uint32_t sequence_high; /* 4 MSB of 8 byte sequence_number */
@ -219,12 +224,12 @@ typedef struct QEMU_PACKED VHDXLogDataSector {
#define SB_BLOCK_PRESENT 6 #define SB_BLOCK_PRESENT 6
/* per the spec */ /* per the spec */
#define VHDX_MAX_SECTORS_PER_BLOCK (1<<23) #define VHDX_MAX_SECTORS_PER_BLOCK (1 << 23)
/* upper 44 bits are the file offset in 1MB units lower 3 bits are the state /* upper 44 bits are the file offset in 1MB units lower 3 bits are the state
other bits are reserved */ other bits are reserved */
#define VHDX_BAT_STATE_BIT_MASK 0x07 #define VHDX_BAT_STATE_BIT_MASK 0x07
#define VHDX_BAT_FILE_OFF_BITS (64-44) #define VHDX_BAT_FILE_OFF_BITS (64 - 44)
typedef uint64_t VHDXBatEntry; typedef uint64_t VHDXBatEntry;
/* ---- METADATA REGION STRUCTURES ---- */ /* ---- METADATA REGION STRUCTURES ---- */
@ -252,8 +257,8 @@ typedef struct QEMU_PACKED VHDXMetadataTableEntry {
metadata region */ metadata region */
/* note: if length = 0, so is offset */ /* note: if length = 0, so is offset */
uint32_t length; /* length of metadata. <= 1MB. */ uint32_t length; /* length of metadata. <= 1MB. */
uint32_t data_bits; /* least-significant 3 bits are flags, the uint32_t data_bits; /* least-significant 3 bits are flags,
rest are reserved (see above) */ the rest are reserved (see above) */
uint32_t reserved2; uint32_t reserved2;
} VHDXMetadataTableEntry; } VHDXMetadataTableEntry;
@ -265,8 +270,8 @@ typedef struct QEMU_PACKED VHDXMetadataTableEntry {
typedef struct QEMU_PACKED VHDXFileParameters { typedef struct QEMU_PACKED VHDXFileParameters {
uint32_t block_size; /* size of each payload block, always uint32_t block_size; /* size of each payload block, always
power of 2, <= 256MB and >= 1MB. */ power of 2, <= 256MB and >= 1MB. */
uint32_t data_bits; /* least-significant 2 bits are flags, the rest uint32_t data_bits; /* least-significant 2 bits are flags,
are reserved (see above) */ the rest are reserved (see above) */
} VHDXFileParameters; } VHDXFileParameters;
typedef struct QEMU_PACKED VHDXVirtualDiskSize { typedef struct QEMU_PACKED VHDXVirtualDiskSize {
@ -318,6 +323,13 @@ typedef struct VHDXMetadataEntries {
uint16_t present; uint16_t present;
} VHDXMetadataEntries; } VHDXMetadataEntries;
typedef struct VHDXLogEntries {
uint64_t offset;
uint64_t length;
uint32_t head;
uint32_t tail;
} VHDXLogEntries;
typedef struct BDRVVHDXState { typedef struct BDRVVHDXState {
CoMutex lock; CoMutex lock;
@ -351,6 +363,8 @@ typedef struct BDRVVHDXState {
MSGUID session_guid; MSGUID session_guid;
VHDXLogEntries log;
VHDXParentLocatorHeader parent_header; VHDXParentLocatorHeader parent_header;
VHDXParentLocatorEntry *parent_entries; VHDXParentLocatorEntry *parent_entries;