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qemu/block/qcow2.h
Alberto Garcia bfd0989acf qcow2: Convert qcow2_alloc_cluster_offset() into qcow2_alloc_host_offset() 
qcow2_alloc_cluster_offset() takes an (unaligned) guest offset and
returns the (aligned) offset of the corresponding cluster in the qcow2
image.

In practice none of the callers need to know where the cluster starts
so this patch makes the function calculate and return the final host
offset directly. The function is also renamed accordingly.

See 388e581615 for a similar change to qcow2_get_cluster_offset().

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <9bfef50ec9200d752413be4fc2aeb22a28378817.1599833007.git.berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-09-15 11:31:10 +02:00

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/*
* Block driver for the QCOW version 2 format
*
* Copyright (c) 2004-2006 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef BLOCK_QCOW2_H
#define BLOCK_QCOW2_H
#include "crypto/block.h"
#include "qemu/coroutine.h"
#include "qemu/units.h"
#include "block/block_int.h"
//#define DEBUG_ALLOC
//#define DEBUG_ALLOC2
//#define DEBUG_EXT
#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
#define QCOW_CRYPT_NONE 0
#define QCOW_CRYPT_AES 1
#define QCOW_CRYPT_LUKS 2
#define QCOW_MAX_CRYPT_CLUSTERS 32
#define QCOW_MAX_SNAPSHOTS 65536
/* Field widths in qcow2 mean normal cluster offsets cannot reach
* 64PB; depending on cluster size, compressed clusters can have a
* smaller limit (64PB for up to 16k clusters, then ramps down to
* 512TB for 2M clusters). */
#define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1)
/* 8 MB refcount table is enough for 2 PB images at 64k cluster size
* (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
#define QCOW_MAX_REFTABLE_SIZE (8 * MiB)
/* 32 MB L1 table is enough for 2 PB images at 64k cluster size
* (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
#define QCOW_MAX_L1_SIZE (32 * MiB)
/* Allow for an average of 1k per snapshot table entry, should be plenty of
* space for snapshot names and IDs */
#define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)
/* Maximum amount of extra data per snapshot table entry to accept */
#define QCOW_MAX_SNAPSHOT_EXTRA_DATA 1024
/* Bitmap header extension constraints */
#define QCOW2_MAX_BITMAPS 65535
#define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
/* Maximum of parallel sub-request per guest request */
#define QCOW2_MAX_WORKERS 8
/* indicate that the refcount of the referenced cluster is exactly one. */
#define QCOW_OFLAG_COPIED (1ULL << 63)
/* indicate that the cluster is compressed (they never have the copied flag) */
#define QCOW_OFLAG_COMPRESSED (1ULL << 62)
/* The cluster reads as all zeros */
#define QCOW_OFLAG_ZERO (1ULL << 0)
#define QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER 32
/* The subcluster X [0..31] is allocated */
#define QCOW_OFLAG_SUB_ALLOC(X) (1ULL << (X))
/* The subcluster X [0..31] reads as zeroes */
#define QCOW_OFLAG_SUB_ZERO(X) (QCOW_OFLAG_SUB_ALLOC(X) << 32)
/* Subclusters [X, Y) (0 <= X <= Y <= 32) are allocated */
#define QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) \
(QCOW_OFLAG_SUB_ALLOC(Y) - QCOW_OFLAG_SUB_ALLOC(X))
/* Subclusters [X, Y) (0 <= X <= Y <= 32) read as zeroes */
#define QCOW_OFLAG_SUB_ZERO_RANGE(X, Y) \
(QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) << 32)
/* L2 entry bitmap with all allocation bits set */
#define QCOW_L2_BITMAP_ALL_ALLOC (QCOW_OFLAG_SUB_ALLOC_RANGE(0, 32))
/* L2 entry bitmap with all "read as zeroes" bits set */
#define QCOW_L2_BITMAP_ALL_ZEROES (QCOW_OFLAG_SUB_ZERO_RANGE(0, 32))
/* Size of normal and extended L2 entries */
#define L2E_SIZE_NORMAL (sizeof(uint64_t))
#define L2E_SIZE_EXTENDED (sizeof(uint64_t) * 2)
/* Size of L1 table entries */
#define L1E_SIZE (sizeof(uint64_t))
/* Size of reftable entries */
#define REFTABLE_ENTRY_SIZE (sizeof(uint64_t))
#define MIN_CLUSTER_BITS 9
#define MAX_CLUSTER_BITS 21
/* Defined in the qcow2 spec (compressed cluster descriptor) */
#define QCOW2_COMPRESSED_SECTOR_SIZE 512U
#define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1ULL))
/* Must be at least 2 to cover COW */
#define MIN_L2_CACHE_SIZE 2 /* cache entries */
/* Must be at least 4 to cover all cases of refcount table growth */
#define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
#ifdef CONFIG_LINUX
#define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
#define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */
#else
#define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
/* Cache clean interval is currently available only on Linux, so must be 0 */
#define DEFAULT_CACHE_CLEAN_INTERVAL 0
#endif
#define DEFAULT_CLUSTER_SIZE 65536
#define QCOW2_OPT_DATA_FILE "data-file"
#define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
#define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
#define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
#define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
#define QCOW2_OPT_OVERLAP "overlap-check"
#define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
#define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
#define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
#define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
#define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
#define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
#define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
#define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
#define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
#define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
#define QCOW2_OPT_CACHE_SIZE "cache-size"
#define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
#define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
#define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
#define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
typedef struct QCowHeader {
uint32_t magic;
uint32_t version;
uint64_t backing_file_offset;
uint32_t backing_file_size;
uint32_t cluster_bits;
uint64_t size; /* in bytes */
uint32_t crypt_method;
uint32_t l1_size; /* XXX: save number of clusters instead ? */
uint64_t l1_table_offset;
uint64_t refcount_table_offset;
uint32_t refcount_table_clusters;
uint32_t nb_snapshots;
uint64_t snapshots_offset;
/* The following fields are only valid for version >= 3 */
uint64_t incompatible_features;
uint64_t compatible_features;
uint64_t autoclear_features;
uint32_t refcount_order;
uint32_t header_length;
/* Additional fields */
uint8_t compression_type;
/* header must be a multiple of 8 */
uint8_t padding[7];
} QEMU_PACKED QCowHeader;
QEMU_BUILD_BUG_ON(!QEMU_IS_ALIGNED(sizeof(QCowHeader), 8));
typedef struct QEMU_PACKED QCowSnapshotHeader {
/* header is 8 byte aligned */
uint64_t l1_table_offset;
uint32_t l1_size;
uint16_t id_str_size;
uint16_t name_size;
uint32_t date_sec;
uint32_t date_nsec;
uint64_t vm_clock_nsec;
uint32_t vm_state_size;
uint32_t extra_data_size; /* for extension */
/* extra data follows */
/* id_str follows */
/* name follows */
} QCowSnapshotHeader;
typedef struct QEMU_PACKED QCowSnapshotExtraData {
uint64_t vm_state_size_large;
uint64_t disk_size;
} QCowSnapshotExtraData;
typedef struct QCowSnapshot {
uint64_t l1_table_offset;
uint32_t l1_size;
char *id_str;
char *name;
uint64_t disk_size;
uint64_t vm_state_size;
uint32_t date_sec;
uint32_t date_nsec;
uint64_t vm_clock_nsec;
/* Size of all extra data, including QCowSnapshotExtraData if available */
uint32_t extra_data_size;
/* Data beyond QCowSnapshotExtraData, if any */
void *unknown_extra_data;
} QCowSnapshot;
struct Qcow2Cache;
typedef struct Qcow2Cache Qcow2Cache;
typedef struct Qcow2CryptoHeaderExtension {
uint64_t offset;
uint64_t length;
} QEMU_PACKED Qcow2CryptoHeaderExtension;
typedef struct Qcow2UnknownHeaderExtension {
uint32_t magic;
uint32_t len;
QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
uint8_t data[];
} Qcow2UnknownHeaderExtension;
enum {
QCOW2_FEAT_TYPE_INCOMPATIBLE = 0,
QCOW2_FEAT_TYPE_COMPATIBLE = 1,
QCOW2_FEAT_TYPE_AUTOCLEAR = 2,
};
/* Incompatible feature bits */
enum {
QCOW2_INCOMPAT_DIRTY_BITNR = 0,
QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
QCOW2_INCOMPAT_DATA_FILE_BITNR = 2,
QCOW2_INCOMPAT_COMPRESSION_BITNR = 3,
QCOW2_INCOMPAT_EXTL2_BITNR = 4,
QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
QCOW2_INCOMPAT_DATA_FILE = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
QCOW2_INCOMPAT_COMPRESSION = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR,
QCOW2_INCOMPAT_EXTL2 = 1 << QCOW2_INCOMPAT_EXTL2_BITNR,
QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY
| QCOW2_INCOMPAT_CORRUPT
| QCOW2_INCOMPAT_DATA_FILE
| QCOW2_INCOMPAT_COMPRESSION
| QCOW2_INCOMPAT_EXTL2,
};
/* Compatible feature bits */
enum {
QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS,
};
/* Autoclear feature bits */
enum {
QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
QCOW2_AUTOCLEAR_BITMAPS = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
QCOW2_AUTOCLEAR_DATA_FILE_RAW = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
QCOW2_AUTOCLEAR_MASK = QCOW2_AUTOCLEAR_BITMAPS
| QCOW2_AUTOCLEAR_DATA_FILE_RAW,
};
enum qcow2_discard_type {
QCOW2_DISCARD_NEVER = 0,
QCOW2_DISCARD_ALWAYS,
QCOW2_DISCARD_REQUEST,
QCOW2_DISCARD_SNAPSHOT,
QCOW2_DISCARD_OTHER,
QCOW2_DISCARD_MAX
};
typedef struct Qcow2Feature {
uint8_t type;
uint8_t bit;
char name[46];
} QEMU_PACKED Qcow2Feature;
typedef struct Qcow2DiscardRegion {
BlockDriverState *bs;
uint64_t offset;
uint64_t bytes;
QTAILQ_ENTRY(Qcow2DiscardRegion) next;
} Qcow2DiscardRegion;
typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
uint64_t index);
typedef void Qcow2SetRefcountFunc(void *refcount_array,
uint64_t index, uint64_t value);
typedef struct Qcow2BitmapHeaderExt {
uint32_t nb_bitmaps;
uint32_t reserved32;
uint64_t bitmap_directory_size;
uint64_t bitmap_directory_offset;
} QEMU_PACKED Qcow2BitmapHeaderExt;
#define QCOW2_MAX_THREADS 4
typedef struct BDRVQcow2State {
int cluster_bits;
int cluster_size;
int l2_slice_size;
int subcluster_bits;
int subcluster_size;
int subclusters_per_cluster;
int l2_bits;
int l2_size;
int l1_size;
int l1_vm_state_index;
int refcount_block_bits;
int refcount_block_size;
int csize_shift;
int csize_mask;
uint64_t cluster_offset_mask;
uint64_t l1_table_offset;
uint64_t *l1_table;
Qcow2Cache* l2_table_cache;
Qcow2Cache* refcount_block_cache;
QEMUTimer *cache_clean_timer;
unsigned cache_clean_interval;
QLIST_HEAD(, QCowL2Meta) cluster_allocs;
uint64_t *refcount_table;
uint64_t refcount_table_offset;
uint32_t refcount_table_size;
uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
uint64_t free_cluster_index;
uint64_t free_byte_offset;
CoMutex lock;
Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
QCryptoBlock *crypto; /* Disk encryption format driver */
bool crypt_physical_offset; /* Whether to use virtual or physical offset
for encryption initialization vector tweak */
uint32_t crypt_method_header;
uint64_t snapshots_offset;
int snapshots_size;
unsigned int nb_snapshots;
QCowSnapshot *snapshots;
uint32_t nb_bitmaps;
uint64_t bitmap_directory_size;
uint64_t bitmap_directory_offset;
int flags;
int qcow_version;
bool use_lazy_refcounts;
int refcount_order;
int refcount_bits;
uint64_t refcount_max;
Qcow2GetRefcountFunc *get_refcount;
Qcow2SetRefcountFunc *set_refcount;
bool discard_passthrough[QCOW2_DISCARD_MAX];
int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
bool signaled_corruption;
uint64_t incompatible_features;
uint64_t compatible_features;
uint64_t autoclear_features;
size_t unknown_header_fields_size;
void* unknown_header_fields;
QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
bool cache_discards;
/* Backing file path and format as stored in the image (this is not the
* effective path/format, which may be the result of a runtime option
* override) */
char *image_backing_file;
char *image_backing_format;
char *image_data_file;
CoQueue thread_task_queue;
int nb_threads;
BdrvChild *data_file;
bool metadata_preallocation_checked;
bool metadata_preallocation;
/*
* Compression type used for the image. Default: 0 - ZLIB
* The image compression type is set on image creation.
* For now, the only way to change the compression type
* is to convert the image with the desired compression type set.
*/
Qcow2CompressionType compression_type;
} BDRVQcow2State;
typedef struct Qcow2COWRegion {
/**
* Offset of the COW region in bytes from the start of the first cluster
* touched by the request.
*/
unsigned offset;
/** Number of bytes to copy */
unsigned nb_bytes;
} Qcow2COWRegion;
/**
* Describes an in-flight (part of a) write request that writes to clusters
* that are not referenced in their L2 table yet.
*/
typedef struct QCowL2Meta
{
/** Guest offset of the first newly allocated cluster */
uint64_t offset;
/** Host offset of the first newly allocated cluster */
uint64_t alloc_offset;
/** Number of newly allocated clusters */
int nb_clusters;
/** Do not free the old clusters */
bool keep_old_clusters;
/**
* Requests that overlap with this allocation and wait to be restarted
* when the allocating request has completed.
*/
CoQueue dependent_requests;
/**
* The COW Region between the start of the first allocated cluster and the
* area the guest actually writes to.
*/
Qcow2COWRegion cow_start;
/**
* The COW Region between the area the guest actually writes to and the
* end of the last allocated cluster.
*/
Qcow2COWRegion cow_end;
/*
* Indicates that COW regions are already handled and do not require
* any more processing.
*/
bool skip_cow;
/**
* Indicates that this is not a normal write request but a preallocation.
* If the image has extended L2 entries this means that no new individual
* subclusters will be marked as allocated in the L2 bitmap (but any
* existing contents of that bitmap will be kept).
*/
bool prealloc;
/**
* The I/O vector with the data from the actual guest write request.
* If non-NULL, this is meant to be merged together with the data
* from @cow_start and @cow_end into one single write operation.
*/
QEMUIOVector *data_qiov;
size_t data_qiov_offset;
/** Pointer to next L2Meta of the same write request */
struct QCowL2Meta *next;
QLIST_ENTRY(QCowL2Meta) next_in_flight;
} QCowL2Meta;
/*
* In images with standard L2 entries all clusters are treated as if
* they had one subcluster so QCow2ClusterType and QCow2SubclusterType
* can be mapped to each other and have the exact same meaning
* (QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC cannot happen in these images).
*
* In images with extended L2 entries QCow2ClusterType refers to the
* complete cluster and QCow2SubclusterType to each of the individual
* subclusters, so there are several possible combinations:
*
* |--------------+---------------------------|
* | Cluster type | Possible subcluster types |
* |--------------+---------------------------|
* | UNALLOCATED | UNALLOCATED_PLAIN |
* | | ZERO_PLAIN |
* |--------------+---------------------------|
* | NORMAL | UNALLOCATED_ALLOC |
* | | ZERO_ALLOC |
* | | NORMAL |
* |--------------+---------------------------|
* | COMPRESSED | COMPRESSED |
* |--------------+---------------------------|
*
* QCOW2_SUBCLUSTER_INVALID means that the L2 entry is incorrect and
* the image should be marked corrupt.
*/
typedef enum QCow2ClusterType {
QCOW2_CLUSTER_UNALLOCATED,
QCOW2_CLUSTER_ZERO_PLAIN,
QCOW2_CLUSTER_ZERO_ALLOC,
QCOW2_CLUSTER_NORMAL,
QCOW2_CLUSTER_COMPRESSED,
} QCow2ClusterType;
typedef enum QCow2SubclusterType {
QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN,
QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC,
QCOW2_SUBCLUSTER_ZERO_PLAIN,
QCOW2_SUBCLUSTER_ZERO_ALLOC,
QCOW2_SUBCLUSTER_NORMAL,
QCOW2_SUBCLUSTER_COMPRESSED,
QCOW2_SUBCLUSTER_INVALID,
} QCow2SubclusterType;
typedef enum QCow2MetadataOverlap {
QCOW2_OL_MAIN_HEADER_BITNR = 0,
QCOW2_OL_ACTIVE_L1_BITNR = 1,
QCOW2_OL_ACTIVE_L2_BITNR = 2,
QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
QCOW2_OL_INACTIVE_L1_BITNR = 6,
QCOW2_OL_INACTIVE_L2_BITNR = 7,
QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
QCOW2_OL_MAX_BITNR = 9,
QCOW2_OL_NONE = 0,
QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
/* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
* reads. */
QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
} QCow2MetadataOverlap;
/* Perform all overlap checks which can be done in constant time */
#define QCOW2_OL_CONSTANT \
(QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
/* Perform all overlap checks which don't require disk access */
#define QCOW2_OL_CACHED \
(QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
QCOW2_OL_INACTIVE_L1)
/* Perform all overlap checks */
#define QCOW2_OL_ALL \
(QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
#define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
#define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
#define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
#define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
#define INV_OFFSET (-1ULL)
static inline bool has_subclusters(BDRVQcow2State *s)
{
return s->incompatible_features & QCOW2_INCOMPAT_EXTL2;
}
static inline size_t l2_entry_size(BDRVQcow2State *s)
{
return has_subclusters(s) ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
}
static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
int idx)
{
idx *= l2_entry_size(s) / sizeof(uint64_t);
return be64_to_cpu(l2_slice[idx]);
}
static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
int idx)
{
if (has_subclusters(s)) {
idx *= l2_entry_size(s) / sizeof(uint64_t);
return be64_to_cpu(l2_slice[idx + 1]);
} else {
return 0; /* For convenience only; this value has no meaning. */
}
}
static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
int idx, uint64_t entry)
{
idx *= l2_entry_size(s) / sizeof(uint64_t);
l2_slice[idx] = cpu_to_be64(entry);
}
static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
int idx, uint64_t bitmap)
{
assert(has_subclusters(s));
idx *= l2_entry_size(s) / sizeof(uint64_t);
l2_slice[idx + 1] = cpu_to_be64(bitmap);
}
static inline bool has_data_file(BlockDriverState *bs)
{
BDRVQcow2State *s = bs->opaque;
return (s->data_file != bs->file);
}
static inline bool data_file_is_raw(BlockDriverState *bs)
{
BDRVQcow2State *s = bs->opaque;
return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
}
static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
{
return offset & ~(s->cluster_size - 1);
}
static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
{
return offset & (s->cluster_size - 1);
}
static inline int64_t offset_into_subcluster(BDRVQcow2State *s, int64_t offset)
{
return offset & (s->subcluster_size - 1);
}
static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
{
return (size + (s->cluster_size - 1)) >> s->cluster_bits;
}
static inline uint64_t size_to_subclusters(BDRVQcow2State *s, uint64_t size)
{
return (size + (s->subcluster_size - 1)) >> s->subcluster_bits;
}
static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
{
int shift = s->cluster_bits + s->l2_bits;
return (size + (1ULL << shift) - 1) >> shift;
}
static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
{
return offset >> (s->l2_bits + s->cluster_bits);
}
static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
{
return (offset >> s->cluster_bits) & (s->l2_size - 1);
}
static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
{
return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
}
static inline int offset_to_sc_index(BDRVQcow2State *s, int64_t offset)
{
return (offset >> s->subcluster_bits) & (s->subclusters_per_cluster - 1);
}
static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
{
return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
}
static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
uint64_t l2_entry)
{
BDRVQcow2State *s = bs->opaque;
if (l2_entry & QCOW_OFLAG_COMPRESSED) {
return QCOW2_CLUSTER_COMPRESSED;
} else if ((l2_entry & QCOW_OFLAG_ZERO) && !has_subclusters(s)) {
if (l2_entry & L2E_OFFSET_MASK) {
return QCOW2_CLUSTER_ZERO_ALLOC;
}
return QCOW2_CLUSTER_ZERO_PLAIN;
} else if (!(l2_entry & L2E_OFFSET_MASK)) {
/* Offset 0 generally means unallocated, but it is ambiguous with
* external data files because 0 is a valid offset there. However, all
* clusters in external data files always have refcount 1, so we can
* rely on QCOW_OFLAG_COPIED to disambiguate. */
if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
return QCOW2_CLUSTER_NORMAL;
} else {
return QCOW2_CLUSTER_UNALLOCATED;
}
} else {
return QCOW2_CLUSTER_NORMAL;
}
}
/*
* In an image without subsclusters @l2_bitmap is ignored and
* @sc_index must be 0.
* Return QCOW2_SUBCLUSTER_INVALID if an invalid l2 entry is detected
* (this checks the whole entry and bitmap, not only the bits related
* to subcluster @sc_index).
*/
static inline
QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs,
uint64_t l2_entry,
uint64_t l2_bitmap,
unsigned sc_index)
{
BDRVQcow2State *s = bs->opaque;
QCow2ClusterType type = qcow2_get_cluster_type(bs, l2_entry);
assert(sc_index < s->subclusters_per_cluster);
if (has_subclusters(s)) {
switch (type) {
case QCOW2_CLUSTER_COMPRESSED:
return QCOW2_SUBCLUSTER_COMPRESSED;
case QCOW2_CLUSTER_NORMAL:
if ((l2_bitmap >> 32) & l2_bitmap) {
return QCOW2_SUBCLUSTER_INVALID;
} else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
return QCOW2_SUBCLUSTER_ZERO_ALLOC;
} else if (l2_bitmap & QCOW_OFLAG_SUB_ALLOC(sc_index)) {
return QCOW2_SUBCLUSTER_NORMAL;
} else {
return QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC;
}
case QCOW2_CLUSTER_UNALLOCATED:
if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) {
return QCOW2_SUBCLUSTER_INVALID;
} else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
return QCOW2_SUBCLUSTER_ZERO_PLAIN;
} else {
return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
}
default:
g_assert_not_reached();
}
} else {
switch (type) {
case QCOW2_CLUSTER_COMPRESSED:
return QCOW2_SUBCLUSTER_COMPRESSED;
case QCOW2_CLUSTER_ZERO_PLAIN:
return QCOW2_SUBCLUSTER_ZERO_PLAIN;
case QCOW2_CLUSTER_ZERO_ALLOC:
return QCOW2_SUBCLUSTER_ZERO_ALLOC;
case QCOW2_CLUSTER_NORMAL:
return QCOW2_SUBCLUSTER_NORMAL;
case QCOW2_CLUSTER_UNALLOCATED:
return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
default:
g_assert_not_reached();
}
}
}
static inline bool qcow2_cluster_is_allocated(QCow2ClusterType type)
{
return (type == QCOW2_CLUSTER_COMPRESSED || type == QCOW2_CLUSTER_NORMAL ||
type == QCOW2_CLUSTER_ZERO_ALLOC);
}
/* Check whether refcounts are eager or lazy */
static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
{
return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
}
static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
{
return m->offset + m->cow_start.offset;
}
static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
{
return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
}
static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
{
return r1 > r2 ? r1 - r2 : r2 - r1;
}
static inline
uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
{
return offset >> (s->refcount_block_bits + s->cluster_bits);
}
/* qcow2.c functions */
int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
int refcount_order, bool generous_increase,
uint64_t *refblock_count);
int qcow2_mark_dirty(BlockDriverState *bs);
int qcow2_mark_corrupt(BlockDriverState *bs);
int qcow2_mark_consistent(BlockDriverState *bs);
int qcow2_update_header(BlockDriverState *bs);
void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
int64_t size, const char *message_format, ...)
GCC_FMT_ATTR(5, 6);
int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
uint64_t entries, size_t entry_len,
int64_t max_size_bytes, const char *table_name,
Error **errp);
/* qcow2-refcount.c functions */
int qcow2_refcount_init(BlockDriverState *bs);
void qcow2_refcount_close(BlockDriverState *bs);
int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
uint64_t *refcount);
int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
uint64_t addend, bool decrease,
enum qcow2_discard_type type);
int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
uint64_t additional_clusters, bool exact_size,
int new_refblock_index,
uint64_t new_refblock_offset);
int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
int64_t nb_clusters);
int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
void qcow2_free_clusters(BlockDriverState *bs,
int64_t offset, int64_t size,
enum qcow2_discard_type type);
void qcow2_free_any_cluster(BlockDriverState *bs, uint64_t l2_entry,
enum qcow2_discard_type type);
int qcow2_update_snapshot_refcount(BlockDriverState *bs,
int64_t l1_table_offset, int l1_size, int addend);
int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix);
void qcow2_process_discards(BlockDriverState *bs, int ret);
int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
int64_t size);
int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
int64_t size, bool data_file);
int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
void **refcount_table,
int64_t *refcount_table_size,
int64_t offset, int64_t size);
int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
BlockDriverAmendStatusCB *status_cb,
void *cb_opaque, Error **errp);
int qcow2_shrink_reftable(BlockDriverState *bs);
int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
int qcow2_detect_metadata_preallocation(BlockDriverState *bs);
/* qcow2-cluster.c functions */
int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
bool exact_size);
int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
uint8_t *buf, int nb_sectors, bool enc, Error **errp);
int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
unsigned int *bytes, uint64_t *host_offset,
QCow2SubclusterType *subcluster_type);
int qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset,
unsigned int *bytes, uint64_t *host_offset,
QCowL2Meta **m);
int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
uint64_t offset,
int compressed_size,
uint64_t *host_offset);
int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, enum qcow2_discard_type type,
bool full_discard);
int qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, int flags);
int qcow2_expand_zero_clusters(BlockDriverState *bs,
BlockDriverAmendStatusCB *status_cb,
void *cb_opaque);
/* qcow2-snapshot.c functions */
int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
int qcow2_snapshot_delete(BlockDriverState *bs,
const char *snapshot_id,
const char *name,
Error **errp);
int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
int qcow2_snapshot_load_tmp(BlockDriverState *bs,
const char *snapshot_id,
const char *name,
Error **errp);
void qcow2_free_snapshots(BlockDriverState *bs);
int qcow2_read_snapshots(BlockDriverState *bs, Error **errp);
int qcow2_write_snapshots(BlockDriverState *bs);
int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs,
BdrvCheckResult *result,
BdrvCheckMode fix);
int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs,
BdrvCheckResult *result,
BdrvCheckMode fix);
/* qcow2-cache.c functions */
Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
unsigned table_size);
int qcow2_cache_destroy(Qcow2Cache *c);
void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
Qcow2Cache *dependency);
void qcow2_cache_depends_on_flush(Qcow2Cache *c);
void qcow2_cache_clean_unused(Qcow2Cache *c);
int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
void **table);
int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
void **table);
void qcow2_cache_put(Qcow2Cache *c, void **table);
void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
void qcow2_cache_discard(Qcow2Cache *c, void *table);
/* qcow2-bitmap.c functions */
int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
void **refcount_table,
int64_t *refcount_table_size);
bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
Error **errp);
int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
bool release_stored, Error **errp);
int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
bool qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
const char *name,
uint32_t granularity,
Error **errp);
int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
const char *name,
Error **errp);
bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
uint32_t cluster_size);
ssize_t coroutine_fn
qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
const void *src, size_t src_size);
ssize_t coroutine_fn
qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
const void *src, size_t src_size);
int coroutine_fn
qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
uint64_t guest_offset, void *buf, size_t len);
int coroutine_fn
qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
uint64_t guest_offset, void *buf, size_t len);
#endif
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