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qemu/block/qcow2.h
Kevin Wolf 8f8973416e qcow2: Take locks for accessing bs->file 
This updates the qcow2 code to add GRAPH_RDLOCK annotations for all
places that read bs->file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-22-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-08 17:56:17 +01:00

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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
/* 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_DISCARD_NO_UNREF "discard-no-unref"
#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;
uint64_t icount;
} 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;
/* icount value for the moment when snapshot was taken */
uint64_t icount;
/* 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];
bool discard_no_unref;
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 need to have their L2 table entries updated (because they are
* newly allocated or need changes in their L2 bitmaps)
*/
typedef struct QCowL2Meta
{
/** Guest offset of the first updated cluster */
uint64_t offset;
/** Host offset of the first updated cluster */
uint64_t alloc_offset;
/** Number of updated 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 immediately before the area the guest actually
* writes to. This (part of the) write request starts at
* cow_start.offset + cow_start.nb_bytes.
*/
Qcow2COWRegion cow_start;
/**
* The COW Region immediately after the area the guest actually
* writes to. This (part of the) write request ends at cow_end.offset
* (which must always be set even when cow_end.nb_bytes is 0).
*/
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 L1E_RESERVED_MASK 0x7f000000000001ffULL
#define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
#define L2E_STD_RESERVED_MASK 0x3f000000000001feULL
#define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
#define REFT_RESERVED_MASK 0x1ffULL
#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 GRAPH_RDLOCK 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 GRAPH_RDLOCK
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 GRAPH_RDLOCK
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 GRAPH_RDLOCK qcow2_mark_dirty(BlockDriverState *bs);
int GRAPH_RDLOCK qcow2_mark_corrupt(BlockDriverState *bs);
int GRAPH_RDLOCK qcow2_update_header(BlockDriverState *bs);
void GRAPH_RDLOCK
qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
int64_t size, const char *message_format, ...)
G_GNUC_PRINTF(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 coroutine_fn GRAPH_RDLOCK qcow2_refcount_init(BlockDriverState *bs);
void qcow2_refcount_close(BlockDriverState *bs);
int GRAPH_RDLOCK qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
uint64_t *refcount);
int GRAPH_RDLOCK
qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
uint64_t addend, bool decrease,
enum qcow2_discard_type type);
int64_t GRAPH_RDLOCK
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 GRAPH_RDLOCK
qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
int64_t GRAPH_RDLOCK coroutine_fn
qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
int64_t nb_clusters);
int64_t coroutine_fn GRAPH_RDLOCK qcow2_alloc_bytes(BlockDriverState *bs, int size);
void GRAPH_RDLOCK qcow2_free_clusters(BlockDriverState *bs,
int64_t offset, int64_t size,
enum qcow2_discard_type type);
void GRAPH_RDLOCK
qcow2_free_any_cluster(BlockDriverState *bs, uint64_t l2_entry,
enum qcow2_discard_type type);
int GRAPH_RDLOCK
qcow2_update_snapshot_refcount(BlockDriverState *bs, int64_t l1_table_offset,
int l1_size, int addend);
int GRAPH_RDLOCK qcow2_flush_caches(BlockDriverState *bs);
int GRAPH_RDLOCK qcow2_write_caches(BlockDriverState *bs);
int coroutine_fn qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
BdrvCheckMode fix);
void GRAPH_RDLOCK qcow2_process_discards(BlockDriverState *bs, int ret);
int GRAPH_RDLOCK
qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
int64_t size);
int GRAPH_RDLOCK
qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
int64_t size, bool data_file);
int coroutine_fn qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
void **refcount_table,
int64_t *refcount_table_size,
int64_t offset, int64_t size);
int GRAPH_RDLOCK
qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
BlockDriverAmendStatusCB *status_cb,
void *cb_opaque, Error **errp);
int coroutine_fn GRAPH_RDLOCK qcow2_shrink_reftable(BlockDriverState *bs);
int64_t coroutine_fn GRAPH_RDLOCK
qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
int coroutine_fn GRAPH_RDLOCK
qcow2_detect_metadata_preallocation(BlockDriverState *bs);
/* qcow2-cluster.c functions */
int GRAPH_RDLOCK
qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, bool exact_size);
int coroutine_fn GRAPH_RDLOCK
qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
int GRAPH_RDLOCK 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 GRAPH_RDLOCK
qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
unsigned int *bytes, uint64_t *host_offset,
QCow2SubclusterType *subcluster_type);
int coroutine_fn GRAPH_RDLOCK
qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset,
unsigned int *bytes, uint64_t *host_offset,
QCowL2Meta **m);
int coroutine_fn GRAPH_RDLOCK
qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, uint64_t offset,
int compressed_size, uint64_t *host_offset);
void GRAPH_RDLOCK
qcow2_parse_compressed_l2_entry(BlockDriverState *bs, uint64_t l2_entry,
uint64_t *coffset, int *csize);
int coroutine_fn GRAPH_RDLOCK
qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
void coroutine_fn GRAPH_RDLOCK
qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
int GRAPH_RDLOCK
qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
enum qcow2_discard_type type, bool full_discard);
int coroutine_fn GRAPH_RDLOCK
qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
int flags);
int GRAPH_RDLOCK
qcow2_expand_zero_clusters(BlockDriverState *bs,
BlockDriverAmendStatusCB *status_cb,
void *cb_opaque);
/* qcow2-snapshot.c functions */
int GRAPH_RDLOCK
qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
int GRAPH_RDLOCK
qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
int GRAPH_RDLOCK
qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id,
const char *name, Error **errp);
int GRAPH_RDLOCK
qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
int GRAPH_RDLOCK
qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_id,
const char *name, Error **errp);
void qcow2_free_snapshots(BlockDriverState *bs);
int coroutine_fn GRAPH_RDLOCK
qcow2_read_snapshots(BlockDriverState *bs, Error **errp);
int GRAPH_RDLOCK qcow2_write_snapshots(BlockDriverState *bs);
int coroutine_fn GRAPH_RDLOCK
qcow2_check_read_snapshot_table(BlockDriverState *bs, BdrvCheckResult *result,
BdrvCheckMode fix);
int coroutine_fn GRAPH_RDLOCK
qcow2_check_fix_snapshot_table(BlockDriverState *bs, BdrvCheckResult *result,
BdrvCheckMode fix);
/* qcow2-cache.c functions */
Qcow2Cache * GRAPH_RDLOCK
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 GRAPH_RDLOCK qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
int GRAPH_RDLOCK qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
int GRAPH_RDLOCK 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 GRAPH_RDLOCK qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
int GRAPH_RDLOCK
qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
void **table);
int GRAPH_RDLOCK
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 coroutine_fn GRAPH_RDLOCK
qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
void **refcount_table,
int64_t *refcount_table_size);
bool coroutine_fn GRAPH_RDLOCK
qcow2_load_dirty_bitmaps(BlockDriverState *bs, bool *header_updated,
Error **errp);
bool GRAPH_RDLOCK
qcow2_get_bitmap_info_list(BlockDriverState *bs,
Qcow2BitmapInfoList **info_list, Error **errp);
int GRAPH_RDLOCK qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
int GRAPH_RDLOCK qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
int coroutine_fn GRAPH_RDLOCK
qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
bool GRAPH_RDLOCK
qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, bool release_stored,
Error **errp);
bool coroutine_fn GRAPH_RDLOCK
qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
uint32_t granularity, Error **errp);
int coroutine_fn GRAPH_RDLOCK
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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