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util: add support for qcow2v3 image detection

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Detect qcow2 images with version 3 in the image header as
VIR_STORAGE_FILE_QCOW2.

These images have a feature bitfield, with just one feature supported
so far: lazy_refcounts.

The header length changed too, moving the location of the backing
format name.
This commit is contained in:
Ján Tomko 2013-05-07 17:27:43 +02:00
parent 19f75d5eeb
commit a1ee8e18c9
2 changed files with 144 additions and 37 deletions
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169
src/util/virstoragefile.c
View File

@ -59,6 +59,11 @@ VIR_ENUM_IMPL(virStorageFileFormat,
"qcow", "qcow2", "qed", "vmdk", "vpc",
"fat", "vhd", "vdi")
VIR_ENUM_IMPL(virStorageFileFeature,
VIR_STORAGE_FILE_FEATURE_LAST,
"lazy_refcounts",
)
enum lv_endian {
LV_LITTLE_ENDIAN = 1, /* 1234 */
LV_BIG_ENDIAN /* 4321 */
@ -70,6 +75,8 @@ enum {
BACKING_STORE_ERROR,
};
#define FILE_TYPE_VERSIONS_LAST 2
/* Either 'magic' or 'extension' *must* be provided */
struct FileTypeInfo {
int magicOffset; /* Byte offset of the magic */
@ -81,7 +88,8 @@ struct FileTypeInfo {
* where we find version number,
* -1 to always fail the version test,
* -2 to always pass the version test */
int versionNumber; /* Version number to validate */
int versionNumbers[FILE_TYPE_VERSIONS_LAST];
/* Version numbers to validate. Zeroes are ignored. */
int sizeOffset; /* Byte offset from start of file
* where we find capacity info,
* -1 to use st_size as capacity */
@ -95,6 +103,8 @@ struct FileTypeInfo {
* -1 if encryption is not used */
int (*getBackingStore)(char **res, int *format,
const unsigned char *buf, size_t buf_size);
int (*getFeatures)(virBitmapPtr *features, int format,
unsigned char *buf, ssize_t len);
};
static int cowGetBackingStore(char **, int *,
@ -103,6 +113,8 @@ static int qcow1GetBackingStore(char **, int *,
const unsigned char *, size_t);
static int qcow2GetBackingStore(char **, int *,
const unsigned char *, size_t);
static int qcow2GetFeatures(virBitmapPtr *features, int format,
unsigned char *buf, ssize_t len);
static int vmdk4GetBackingStore(char **, int *,
const unsigned char *, size_t);
static int
@ -122,6 +134,13 @@ qedGetBackingStore(char **, int *, const unsigned char *, size_t);
#define QCOW2_HDR_EXTENSION_END 0
#define QCOW2_HDR_EXTENSION_BACKING_FORMAT 0xE2792ACA
#define QCOW2v3_HDR_FEATURES_INCOMPATIBLE (QCOW2_HDR_TOTAL_SIZE)
#define QCOW2v3_HDR_FEATURES_COMPATIBLE (QCOW2v3_HDR_FEATURES_INCOMPATIBLE+8)
#define QCOW2v3_HDR_FEATURES_AUTOCLEAR (QCOW2v3_HDR_FEATURES_COMPATIBLE+8)
/* The location of the header size [4 bytes] */
#define QCOW2v3_HDR_SIZE (QCOW2_HDR_TOTAL_SIZE+8+8+8+4)
#define QED_HDR_FEATURES_OFFSET (4+4+4+4)
#define QED_HDR_IMAGE_SIZE (QED_HDR_FEATURES_OFFSET+8+8+8+8)
#define QED_HDR_BACKING_FILE_OFFSET (QED_HDR_IMAGE_SIZE+8)
@ -137,16 +156,16 @@ qedGetBackingStore(char **, int *, const unsigned char *, size_t);
static struct FileTypeInfo const fileTypeInfo[] = {
[VIR_STORAGE_FILE_NONE] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, 0, 0, 0, 0, 0, NULL },
-1, {0}, 0, 0, 0, 0, NULL, NULL },
[VIR_STORAGE_FILE_RAW] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, 0, 0, 0, 0, 0, NULL },
-1, {0}, 0, 0, 0, 0, NULL, NULL },
[VIR_STORAGE_FILE_DIR] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, 0, 0, 0, 0, 0, NULL },
-1, {0}, 0, 0, 0, 0, NULL, NULL },
[VIR_STORAGE_FILE_BOCHS] = {
/*"Bochs Virtual HD Image", */ /* Untested */
0, NULL, NULL,
LV_LITTLE_ENDIAN, 64, 0x20000,
32+16+16+4+4+4+4+4, 8, 1, -1, NULL
LV_LITTLE_ENDIAN, 64, {0x20000},
32+16+16+4+4+4+4+4, 8, 1, -1, NULL, NULL
},
[VIR_STORAGE_FILE_CLOOP] = {
/* #!/bin/sh
@ -154,67 +173,82 @@ static struct FileTypeInfo const fileTypeInfo[] = {
modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1
*/ /* Untested */
0, NULL, NULL,
LV_LITTLE_ENDIAN, -1, 0,
-1, 0, 0, -1, NULL
LV_LITTLE_ENDIAN, -1, {0},
-1, 0, 0, -1, NULL, NULL
},
[VIR_STORAGE_FILE_COW] = {
0, "OOOM", NULL,
LV_BIG_ENDIAN, 4, 2,
4+4+1024+4, 8, 1, -1, cowGetBackingStore
LV_BIG_ENDIAN, 4, {2},
4+4+1024+4, 8, 1, -1, cowGetBackingStore, NULL
},
[VIR_STORAGE_FILE_DMG] = {
/* XXX QEMU says there's no magic for dmg,
* /usr/share/misc/magic lists double magic (both offsets
* would have to match) but then disables that check. */
0, NULL, ".dmg",
0, -1, 0,
-1, 0, 0, -1, NULL
0, -1, {0},
-1, 0, 0, -1, NULL, NULL
},
[VIR_STORAGE_FILE_ISO] = {
32769, "CD001", ".iso",
LV_LITTLE_ENDIAN, -2, 0,
-1, 0, 0, -1, NULL
LV_LITTLE_ENDIAN, -2, {0},
-1, 0, 0, -1, NULL, NULL
},
[VIR_STORAGE_FILE_QCOW] = {
0, "QFI", NULL,
LV_BIG_ENDIAN, 4, 1,
QCOWX_HDR_IMAGE_SIZE, 8, 1, QCOW1_HDR_CRYPT, qcow1GetBackingStore,
LV_BIG_ENDIAN, 4, {1},
QCOWX_HDR_IMAGE_SIZE, 8, 1, QCOW1_HDR_CRYPT, qcow1GetBackingStore, NULL
},
[VIR_STORAGE_FILE_QCOW2] = {
0, "QFI", NULL,
LV_BIG_ENDIAN, 4, 2,
LV_BIG_ENDIAN, 4, {2, 3},
QCOWX_HDR_IMAGE_SIZE, 8, 1, QCOW2_HDR_CRYPT, qcow2GetBackingStore,
qcow2GetFeatures
},
[VIR_STORAGE_FILE_QED] = {
/* http://wiki.qemu.org/Features/QED */
0, "QED", NULL,
LV_LITTLE_ENDIAN, -2, -1,
QED_HDR_IMAGE_SIZE, 8, 1, -1, qedGetBackingStore,
LV_LITTLE_ENDIAN, -2, {0},
QED_HDR_IMAGE_SIZE, 8, 1, -1, qedGetBackingStore, NULL
},
[VIR_STORAGE_FILE_VMDK] = {
0, "KDMV", NULL,
LV_LITTLE_ENDIAN, 4, 1,
4+4+4, 8, 512, -1, vmdk4GetBackingStore
LV_LITTLE_ENDIAN, 4, {1},
4+4+4, 8, 512, -1, vmdk4GetBackingStore, NULL
},
[VIR_STORAGE_FILE_VPC] = {
0, "conectix", NULL,
LV_BIG_ENDIAN, 12, 0x10000,
8 + 4 + 4 + 8 + 4 + 4 + 2 + 2 + 4, 8, 1, -1, NULL
LV_BIG_ENDIAN, 12, {0x10000},
8 + 4 + 4 + 8 + 4 + 4 + 2 + 2 + 4, 8, 1, -1, NULL, NULL
},
/* TODO: add getBackingStore function */
[VIR_STORAGE_FILE_VDI] = {
64, "\x7f\x10\xda\xbe", ".vdi",
LV_LITTLE_ENDIAN, 68, 0x00010001,
64 + 5 * 4 + 256 + 7 * 4, 8, 1, -1, NULL},
LV_LITTLE_ENDIAN, 68, {0x00010001},
64 + 5 * 4 + 256 + 7 * 4, 8, 1, -1, NULL, NULL},
/* Not direct file formats, but used for various drivers */
[VIR_STORAGE_FILE_FAT] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, 0, 0, 0, 0, 0, NULL },
-1, {0}, 0, 0, 0, 0, NULL, NULL },
[VIR_STORAGE_FILE_VHD] = { 0, NULL, NULL, LV_LITTLE_ENDIAN,
-1, 0, 0, 0, 0, 0, NULL },
-1, {0}, 0, 0, 0, 0, NULL, NULL },
};
verify(ARRAY_CARDINALITY(fileTypeInfo) == VIR_STORAGE_FILE_LAST);
/* qcow2 compatible features in the order they appear on-disk */
enum qcow2CompatibleFeature {
QCOW2_COMPATIBLE_FEATURE_LAZY_REFCOUNTS = 0,
QCOW2_COMPATIBLE_FEATURE_LAST
};
/* conversion to virStorageFileFeature */
static const int qcow2CompatibleFeatureArray[] = {
VIR_STORAGE_FILE_FEATURE_LAZY_REFCOUNTS,
};
verify(ARRAY_CARDINALITY(qcow2CompatibleFeatureArray) ==
QCOW2_COMPATIBLE_FEATURE_LAST);
static int
cowGetBackingStore(char **res,
int *format,
@ -301,6 +335,8 @@ qcowXGetBackingStore(char **res,
{
unsigned long long offset;
unsigned int size;
unsigned long long start;
int version;
*res = NULL;
if (format)
@ -351,11 +387,20 @@ qcowXGetBackingStore(char **res,
* Thus the file region to search for extensions is
* between the end of the header (QCOW2_HDR_TOTAL_SIZE)
* and the start of the backingStoreName (offset)
*
* for qcow2 v3 images, the length of the header
* is stored at QCOW2v3_HDR_SIZE
*/
if (isQCow2 && format &&
qcow2GetBackingStoreFormat(format, buf, buf_size, QCOW2_HDR_TOTAL_SIZE,
offset) < 0)
return BACKING_STORE_INVALID;
if (isQCow2 && format) {
version = virReadBufInt32BE(buf + QCOWX_HDR_VERSION);
if (version == 2)
start = QCOW2_HDR_TOTAL_SIZE;
else
start = virReadBufInt32BE(buf + QCOW2v3_HDR_SIZE);
if (qcow2GetBackingStoreFormat(format, buf, buf_size,
start, offset) < 0)
return BACKING_STORE_INVALID;
}
return BACKING_STORE_OK;
}
@ -593,7 +638,7 @@ virStorageFileMatchesVersion(int format,
unsigned char *buf,
size_t buflen)
{
int version;
int version, i;
/* Validate version number info */
if (fileTypeInfo[format].versionOffset == -1)
@ -611,12 +656,16 @@ virStorageFileMatchesVersion(int format,
else
version = virReadBufInt32BE(buf + fileTypeInfo[format].versionOffset);
VIR_DEBUG("Compare detected version %d vs expected version %d",
version, fileTypeInfo[format].versionNumber);
if (version != fileTypeInfo[format].versionNumber)
return false;
for (i = 0;
i < FILE_TYPE_VERSIONS_LAST && fileTypeInfo[format].versionNumbers[i];
i++) {
VIR_DEBUG("Compare detected version %d vs one of the expected versions %d",
version, fileTypeInfo[format].versionNumbers[i]);
if (version == fileTypeInfo[format].versionNumbers[i])
return true;
}
return true;
return false;
}
static bool
@ -669,6 +718,42 @@ cleanup:
}
static int
qcow2GetFeatures(virBitmapPtr *features,
int format,
unsigned char *buf,
ssize_t len)
{
int version = -1;
virBitmapPtr feat = NULL;
uint64_t bits;
int i;
version = virReadBufInt32BE(buf + fileTypeInfo[format].versionOffset);
if (version == 2)
return 0;
if (len < QCOW2v3_HDR_SIZE)
return -1;
if (!(feat = virBitmapNew(VIR_STORAGE_FILE_FEATURE_LAST))) {
virReportOOMError();
return -1;
}
/* todo: check for incompatible or autoclear features? */
bits = virReadBufInt64BE(buf + QCOW2v3_HDR_FEATURES_COMPATIBLE);
for (i = 0; i < QCOW2_COMPATIBLE_FEATURE_LAST; i++) {
if (bits & ((uint64_t) 1 << i))
ignore_value(virBitmapSetBit(feat, qcow2CompatibleFeatureArray[i]));
}
*features = feat;
return 0;
}
/* Given a file descriptor FD open on PATH, and optionally opened from
* a given DIRECTORY, return metadata about that file, assuming it has
* the given FORMAT. */
@ -803,6 +888,14 @@ virStorageFileGetMetadataInternal(const char *path,
}
}
if (fileTypeInfo[format].getFeatures != NULL &&
fileTypeInfo[format].getFeatures(&meta->features, format, buf, len) < 0)
goto cleanup;
if (format == VIR_STORAGE_FILE_QCOW2 && meta->features &&
VIR_STRDUP(meta->compat, "1.1") < 0)
goto cleanup;
done:
ret = meta;
meta = NULL;
@ -1032,7 +1125,9 @@ virStorageFileFreeMetadata(virStorageFileMetadata *meta)
virStorageFileFreeMetadata(meta->backingMeta);
VIR_FREE(meta->backingStore);
VIR_FREE(meta->backingStoreRaw);
VIR_FREE(meta->compat);
VIR_FREE(meta->directory);
virBitmapFree(meta->features);
VIR_FREE(meta);
}

12
src/util/virstoragefile.h
View File

@ -24,6 +24,7 @@
#ifndef __VIR_STORAGE_FILE_H__
# define __VIR_STORAGE_FILE_H__
# include "virbitmap.h"
# include "virutil.h"
enum virStorageFileFormat {
@ -51,6 +52,15 @@ enum virStorageFileFormat {
VIR_ENUM_DECL(virStorageFileFormat);
enum virStorageFileFeature {
VIR_STORAGE_FILE_FEATURE_NONE = -1,
VIR_STORAGE_FILE_FEATURE_LAZY_REFCOUNTS,
VIR_STORAGE_FILE_FEATURE_LAST
};
VIR_ENUM_DECL(virStorageFileFeature);
typedef struct _virStorageFileMetadata virStorageFileMetadata;
typedef virStorageFileMetadata *virStorageFileMetadataPtr;
struct _virStorageFileMetadata {
@ -62,6 +72,8 @@ struct _virStorageFileMetadata {
virStorageFileMetadataPtr backingMeta;
unsigned long long capacity;
bool encrypted;
virBitmapPtr features; /* bits described by enum virStorageFileFeature */
char *compat;
};
# ifndef DEV_BSIZE