[qemu.git] / block / qed.h

/*
 * QEMU Enhanced Disk Format
 *
 * Copyright IBM, Corp. 2010
 *
 * Authors:
 *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
 *  Anthony Liguori   <aliguori@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
 * See the COPYING.LIB file in the top-level directory.
 *
 */

#ifndef BLOCK_QED_H
#define BLOCK_QED_H

#include "block/block_int.h"

/* The layout of a QED file is as follows:
 *
 * +--------+----------+----------+----------+-----+
 * | header | L1 table | cluster0 | cluster1 | ... |
 * +--------+----------+----------+----------+-----+
 *
 * There is a 2-level pagetable for cluster allocation:
 *
 *                     +----------+
 *                     | L1 table |
 *                     +----------+
 *                ,------'  |  '------.
 *           +----------+   |    +----------+
 *           | L2 table |  ...   | L2 table |
 *           +----------+        +----------+
 *       ,------'  |  '------.
 *  +----------+   |    +----------+
 *  |   Data   |  ...   |   Data   |
 *  +----------+        +----------+
 *
 * The L1 table is fixed size and always present.  L2 tables are allocated on
 * demand.  The L1 table size determines the maximum possible image size; it
 * can be influenced using the cluster_size and table_size values.
 *
 * All fields are little-endian on disk.
 */

enum {
    QED_MAGIC = 'Q' | 'E' << 8 | 'D' << 16 | '\0' << 24,

    /* The image supports a backing file */
    QED_F_BACKING_FILE = 0x01,

    /* The image needs a consistency check before use */
    QED_F_NEED_CHECK = 0x02,

    /* The backing file format must not be probed, treat as raw image */
    QED_F_BACKING_FORMAT_NO_PROBE = 0x04,

    /* Feature bits must be used when the on-disk format changes */
    QED_FEATURE_MASK = QED_F_BACKING_FILE | /* supported feature bits */
                       QED_F_NEED_CHECK |
                       QED_F_BACKING_FORMAT_NO_PROBE,
    QED_COMPAT_FEATURE_MASK = 0,            /* supported compat feature bits */
    QED_AUTOCLEAR_FEATURE_MASK = 0,         /* supported autoclear feature bits */

    /* Data is stored in groups of sectors called clusters.  Cluster size must
     * be large to avoid keeping too much metadata.  I/O requests that have
     * sub-cluster size will require read-modify-write.
     */
    QED_MIN_CLUSTER_SIZE = 4 * 1024, /* in bytes */
    QED_MAX_CLUSTER_SIZE = 64 * 1024 * 1024,
    QED_DEFAULT_CLUSTER_SIZE = 64 * 1024,

    /* Allocated clusters are tracked using a 2-level pagetable.  Table size is
     * a multiple of clusters so large maximum image sizes can be supported
     * without jacking up the cluster size too much.
     */
    QED_MIN_TABLE_SIZE = 1,        /* in clusters */
    QED_MAX_TABLE_SIZE = 16,
    QED_DEFAULT_TABLE_SIZE = 4,

    /* Delay to flush and clean image after last allocating write completes */
    QED_NEED_CHECK_TIMEOUT = 5,    /* in seconds */
};

typedef struct {
    uint32_t magic;                 /* QED\0 */

    uint32_t cluster_size;          /* in bytes */
    uint32_t table_size;            /* for L1 and L2 tables, in clusters */
    uint32_t header_size;           /* in clusters */

    uint64_t features;              /* format feature bits */
    uint64_t compat_features;       /* compatible feature bits */
    uint64_t autoclear_features;    /* self-resetting feature bits */

    uint64_t l1_table_offset;       /* in bytes */
    uint64_t image_size;            /* total logical image size, in bytes */

    /* if (features & QED_F_BACKING_FILE) */
    uint32_t backing_filename_offset; /* in bytes from start of header */
    uint32_t backing_filename_size;   /* in bytes */
} QEDHeader;

typedef struct {
    uint64_t offsets[0];            /* in bytes */
} QEDTable;

/* The L2 cache is a simple write-through cache for L2 structures */
typedef struct CachedL2Table {
    QEDTable *table;
    uint64_t offset;    /* offset=0 indicates an invalidate entry */
    QTAILQ_ENTRY(CachedL2Table) node;
    int ref;
} CachedL2Table;

typedef struct {
    QTAILQ_HEAD(, CachedL2Table) entries;
    unsigned int n_entries;
} L2TableCache;

typedef struct QEDRequest {
    CachedL2Table *l2_table;
} QEDRequest;

enum {
    QED_AIOCB_WRITE = 0x0001,       /* read or write? */
    QED_AIOCB_ZERO  = 0x0002,       /* zero write, used with QED_AIOCB_WRITE */
};

typedef struct QEDAIOCB {
    BlockDriverAIOCB common;
    QEMUBH *bh;
    int bh_ret;                     /* final return status for completion bh */
    QSIMPLEQ_ENTRY(QEDAIOCB) next;  /* next request */
    int flags;                      /* QED_AIOCB_* bits ORed together */
    bool *finished;                 /* signal for cancel completion */
    uint64_t end_pos;               /* request end on block device, in bytes */

    /* User scatter-gather list */
    QEMUIOVector *qiov;
    size_t qiov_offset;             /* byte count already processed */

    /* Current cluster scatter-gather list */
    QEMUIOVector cur_qiov;
    uint64_t cur_pos;               /* position on block device, in bytes */
    uint64_t cur_cluster;           /* cluster offset in image file */
    unsigned int cur_nclusters;     /* number of clusters being accessed */
    int find_cluster_ret;           /* used for L1/L2 update */

    QEDRequest request;
} QEDAIOCB;

typedef struct {
    BlockDriverState *bs;           /* device */
    uint64_t file_size;             /* length of image file, in bytes */

    QEDHeader header;               /* always cpu-endian */
    QEDTable *l1_table;
    L2TableCache l2_cache;          /* l2 table cache */
    uint32_t table_nelems;
    uint32_t l1_shift;
    uint32_t l2_shift;
    uint32_t l2_mask;

    /* Allocating write request queue */
    QSIMPLEQ_HEAD(, QEDAIOCB) allocating_write_reqs;
    bool allocating_write_reqs_plugged;

    /* Periodic flush and clear need check flag */
    QEMUTimer *need_check_timer;
} BDRVQEDState;

enum {
    QED_CLUSTER_FOUND,         /* cluster found */
    QED_CLUSTER_ZERO,          /* zero cluster found */
    QED_CLUSTER_L2,            /* cluster missing in L2 */
    QED_CLUSTER_L1,            /* cluster missing in L1 */
};

/**
 * qed_find_cluster() completion callback
 *
 * @opaque:     User data for completion callback
 * @ret:        QED_CLUSTER_FOUND   Success
 *              QED_CLUSTER_L2      Data cluster unallocated in L2
 *              QED_CLUSTER_L1      L2 unallocated in L1
 *              -errno              POSIX error occurred
 * @offset:     Data cluster offset
 * @len:        Contiguous bytes starting from cluster offset
 *
 * This function is invoked when qed_find_cluster() completes.
 *
 * On success ret is QED_CLUSTER_FOUND and offset/len are a contiguous range
 * in the image file.
 *
 * On failure ret is QED_CLUSTER_L2 or QED_CLUSTER_L1 for missing L2 or L1
 * table offset, respectively.  len is number of contiguous unallocated bytes.
 */
typedef void QEDFindClusterFunc(void *opaque, int ret, uint64_t offset, size_t len);

/**
 * Generic callback for chaining async callbacks
 */
typedef struct {
    BlockDriverCompletionFunc *cb;
    void *opaque;
} GenericCB;

void *gencb_alloc(size_t len, BlockDriverCompletionFunc *cb, void *opaque);
void gencb_complete(void *opaque, int ret);

/**
 * Header functions
 */
int qed_write_header_sync(BDRVQEDState *s);

/**
 * L2 cache functions
 */
void qed_init_l2_cache(L2TableCache *l2_cache);
void qed_free_l2_cache(L2TableCache *l2_cache);
CachedL2Table *qed_alloc_l2_cache_entry(L2TableCache *l2_cache);
void qed_unref_l2_cache_entry(CachedL2Table *entry);
CachedL2Table *qed_find_l2_cache_entry(L2TableCache *l2_cache, uint64_t offset);
void qed_commit_l2_cache_entry(L2TableCache *l2_cache, CachedL2Table *l2_table);

/**
 * Table I/O functions
 */
int qed_read_l1_table_sync(BDRVQEDState *s);
void qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n,
                        BlockDriverCompletionFunc *cb, void *opaque);
int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index,
                            unsigned int n);
int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
                           uint64_t offset);
void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset,
                       BlockDriverCompletionFunc *cb, void *opaque);
void qed_write_l2_table(BDRVQEDState *s, QEDRequest *request,
                        unsigned int index, unsigned int n, bool flush,
                        BlockDriverCompletionFunc *cb, void *opaque);
int qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request,
                            unsigned int index, unsigned int n, bool flush);

/**
 * Cluster functions
 */
void qed_find_cluster(BDRVQEDState *s, QEDRequest *request, uint64_t pos,
                      size_t len, QEDFindClusterFunc *cb, void *opaque);

/**
 * Consistency check
 */
int qed_check(BDRVQEDState *s, BdrvCheckResult *result, bool fix);

QEDTable *qed_alloc_table(BDRVQEDState *s);

/**
 * Round down to the start of a cluster
 */
static inline uint64_t qed_start_of_cluster(BDRVQEDState *s, uint64_t offset)
{
    return offset & ~(uint64_t)(s->header.cluster_size - 1);
}

static inline uint64_t qed_offset_into_cluster(BDRVQEDState *s, uint64_t offset)
{
    return offset & (s->header.cluster_size - 1);
}

static inline uint64_t qed_bytes_to_clusters(BDRVQEDState *s, uint64_t bytes)
{
    return qed_start_of_cluster(s, bytes + (s->header.cluster_size - 1)) /
           (s->header.cluster_size - 1);
}

static inline unsigned int qed_l1_index(BDRVQEDState *s, uint64_t pos)
{
    return pos >> s->l1_shift;
}

static inline unsigned int qed_l2_index(BDRVQEDState *s, uint64_t pos)
{
    return (pos >> s->l2_shift) & s->l2_mask;
}

/**
 * Test if a cluster offset is valid
 */
static inline bool qed_check_cluster_offset(BDRVQEDState *s, uint64_t offset)
{
    uint64_t header_size = (uint64_t)s->header.header_size *
                           s->header.cluster_size;

    if (offset & (s->header.cluster_size - 1)) {
        return false;
    }
    return offset >= header_size && offset < s->file_size;
}

/**
 * Test if a table offset is valid
 */
static inline bool qed_check_table_offset(BDRVQEDState *s, uint64_t offset)
{
    uint64_t end_offset = offset + (s->header.table_size - 1) *
                          s->header.cluster_size;

    /* Overflow check */
    if (end_offset <= offset) {
        return false;
    }

    return qed_check_cluster_offset(s, offset) &&
           qed_check_cluster_offset(s, end_offset);
}

static inline bool qed_offset_is_cluster_aligned(BDRVQEDState *s,
                                                 uint64_t offset)
{
    if (qed_offset_into_cluster(s, offset)) {
        return false;
    }
    return true;
}

static inline bool qed_offset_is_unalloc_cluster(uint64_t offset)
{
    if (offset == 0) {
        return true;
    }
    return false;
}

static inline bool qed_offset_is_zero_cluster(uint64_t offset)
{
    if (offset == 1) {
        return true;
    }
    return false;
}

#endif /* BLOCK_QED_H */
Commit	Line	Data
	1	/*
	2	* QEMU Enhanced Disk Format
	3	*
	4	* Copyright IBM, Corp. 2010
	5	*
	6	* Authors:
	7	* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
	8	* Anthony Liguori <aliguori@us.ibm.com>
	9	*
	10	* This work is licensed under the terms of the GNU LGPL, version 2 or later.
	11	* See the COPYING.LIB file in the top-level directory.
	12	*
	13	*/
	14
	15	#ifndef BLOCK_QED_H
	16	#define BLOCK_QED_H
	17
	18	#include "block/block_int.h"
	19
	20	/* The layout of a QED file is as follows:
	21	*
	22	* +--------+----------+----------+----------+-----+
	23	* \| header \| L1 table \| cluster0 \| cluster1 \| ... \|
	24	* +--------+----------+----------+----------+-----+
	25	*
	26	* There is a 2-level pagetable for cluster allocation:
	27	*
	28	* +----------+
	29	* \| L1 table \|
	30	* +----------+
	31	* ,------' \| '------.
	32	* +----------+ \| +----------+
	33	* \| L2 table \| ... \| L2 table \|
	34	* +----------+ +----------+
	35	* ,------' \| '------.
	36	* +----------+ \| +----------+
	37	* \| Data \| ... \| Data \|
	38	* +----------+ +----------+
	39	*
	40	* The L1 table is fixed size and always present. L2 tables are allocated on
	41	* demand. The L1 table size determines the maximum possible image size; it
	42	* can be influenced using the cluster_size and table_size values.
	43	*
	44	* All fields are little-endian on disk.
	45	*/
	46
	47	enum {
	48	QED_MAGIC = 'Q' \| 'E' << 8 \| 'D' << 16 \| '\0' << 24,
	49
	50	/* The image supports a backing file */
	51	QED_F_BACKING_FILE = 0x01,
	52
	53	/* The image needs a consistency check before use */
	54	QED_F_NEED_CHECK = 0x02,
	55
	56	/* The backing file format must not be probed, treat as raw image */
	57	QED_F_BACKING_FORMAT_NO_PROBE = 0x04,
	58
	59	/* Feature bits must be used when the on-disk format changes */
	60	QED_FEATURE_MASK = QED_F_BACKING_FILE \| /* supported feature bits */
	61	QED_F_NEED_CHECK \|
	62	QED_F_BACKING_FORMAT_NO_PROBE,
	63	QED_COMPAT_FEATURE_MASK = 0, /* supported compat feature bits */
	64	QED_AUTOCLEAR_FEATURE_MASK = 0, /* supported autoclear feature bits */
	65
	66	/* Data is stored in groups of sectors called clusters. Cluster size must
	67	* be large to avoid keeping too much metadata. I/O requests that have
	68	* sub-cluster size will require read-modify-write.
	69	*/
	70	QED_MIN_CLUSTER_SIZE = 4 * 1024, /* in bytes */
	71	QED_MAX_CLUSTER_SIZE = 64 * 1024 * 1024,
	72	QED_DEFAULT_CLUSTER_SIZE = 64 * 1024,
	73
	74	/* Allocated clusters are tracked using a 2-level pagetable. Table size is
	75	* a multiple of clusters so large maximum image sizes can be supported
	76	* without jacking up the cluster size too much.
	77	*/
	78	QED_MIN_TABLE_SIZE = 1, /* in clusters */
	79	QED_MAX_TABLE_SIZE = 16,
	80	QED_DEFAULT_TABLE_SIZE = 4,
	81
	82	/* Delay to flush and clean image after last allocating write completes */
	83	QED_NEED_CHECK_TIMEOUT = 5, /* in seconds */
	84	};
	85
	86	typedef struct {
	87	uint32_t magic; /* QED\0 */
	88
	89	uint32_t cluster_size; /* in bytes */
	90	uint32_t table_size; /* for L1 and L2 tables, in clusters */
	91	uint32_t header_size; /* in clusters */
	92
	93	uint64_t features; /* format feature bits */
	94	uint64_t compat_features; /* compatible feature bits */
	95	uint64_t autoclear_features; /* self-resetting feature bits */
	96
	97	uint64_t l1_table_offset; /* in bytes */
	98	uint64_t image_size; /* total logical image size, in bytes */
	99
	100	/* if (features & QED_F_BACKING_FILE) */
	101	uint32_t backing_filename_offset; /* in bytes from start of header */
	102	uint32_t backing_filename_size; /* in bytes */
	103	} QEDHeader;
	104
	105	typedef struct {
	106	uint64_t offsets[0]; /* in bytes */
	107	} QEDTable;
	108
	109	/* The L2 cache is a simple write-through cache for L2 structures */
	110	typedef struct CachedL2Table {
	111	QEDTable *table;
	112	uint64_t offset; /* offset=0 indicates an invalidate entry */
	113	QTAILQ_ENTRY(CachedL2Table) node;
	114	int ref;
	115	} CachedL2Table;
	116
	117	typedef struct {
	118	QTAILQ_HEAD(, CachedL2Table) entries;
	119	unsigned int n_entries;
	120	} L2TableCache;
	121
	122	typedef struct QEDRequest {
	123	CachedL2Table *l2_table;
	124	} QEDRequest;
	125
	126	enum {
	127	QED_AIOCB_WRITE = 0x0001, /* read or write? */
	128	QED_AIOCB_ZERO = 0x0002, /* zero write, used with QED_AIOCB_WRITE */
	129	};
	130
	131	typedef struct QEDAIOCB {
	132	BlockDriverAIOCB common;
	133	QEMUBH *bh;
	134	int bh_ret; /* final return status for completion bh */
	135	QSIMPLEQ_ENTRY(QEDAIOCB) next; /* next request */
	136	int flags; /* QED_AIOCB_* bits ORed together */
	137	bool finished; / signal for cancel completion */
	138	uint64_t end_pos; /* request end on block device, in bytes */
	139
	140	/* User scatter-gather list */
	141	QEMUIOVector *qiov;
	142	size_t qiov_offset; /* byte count already processed */
	143
	144	/* Current cluster scatter-gather list */
	145	QEMUIOVector cur_qiov;
	146	uint64_t cur_pos; /* position on block device, in bytes */
	147	uint64_t cur_cluster; /* cluster offset in image file */
	148	unsigned int cur_nclusters; /* number of clusters being accessed */
	149	int find_cluster_ret; /* used for L1/L2 update */
	150
	151	QEDRequest request;
	152	} QEDAIOCB;
	153
	154	typedef struct {
	155	BlockDriverState bs; / device */
	156	uint64_t file_size; /* length of image file, in bytes */
	157
	158	QEDHeader header; /* always cpu-endian */
	159	QEDTable *l1_table;
	160	L2TableCache l2_cache; /* l2 table cache */
	161	uint32_t table_nelems;
	162	uint32_t l1_shift;
	163	uint32_t l2_shift;
	164	uint32_t l2_mask;
	165
	166	/* Allocating write request queue */
	167	QSIMPLEQ_HEAD(, QEDAIOCB) allocating_write_reqs;
	168	bool allocating_write_reqs_plugged;
	169
	170	/* Periodic flush and clear need check flag */
	171	QEMUTimer *need_check_timer;
	172	} BDRVQEDState;
	173
	174	enum {
	175	QED_CLUSTER_FOUND, /* cluster found */
	176	QED_CLUSTER_ZERO, /* zero cluster found */
	177	QED_CLUSTER_L2, /* cluster missing in L2 */
	178	QED_CLUSTER_L1, /* cluster missing in L1 */
	179	};
	180
	181	/**
	182	* qed_find_cluster() completion callback
	183	*
	184	* @opaque: User data for completion callback
	185	* @ret: QED_CLUSTER_FOUND Success
	186	* QED_CLUSTER_L2 Data cluster unallocated in L2
	187	* QED_CLUSTER_L1 L2 unallocated in L1
	188	* -errno POSIX error occurred
	189	* @offset: Data cluster offset
	190	* @len: Contiguous bytes starting from cluster offset
	191	*
	192	* This function is invoked when qed_find_cluster() completes.
	193	*
	194	* On success ret is QED_CLUSTER_FOUND and offset/len are a contiguous range
	195	* in the image file.
	196	*
	197	* On failure ret is QED_CLUSTER_L2 or QED_CLUSTER_L1 for missing L2 or L1
	198	* table offset, respectively. len is number of contiguous unallocated bytes.
	199	*/
	200	typedef void QEDFindClusterFunc(void *opaque, int ret, uint64_t offset, size_t len);
	201
	202	/**
	203	* Generic callback for chaining async callbacks
	204	*/
	205	typedef struct {
	206	BlockDriverCompletionFunc *cb;
	207	void *opaque;
	208	} GenericCB;
	209
	210	void gencb_alloc(size_t len, BlockDriverCompletionFunc cb, void *opaque);
	211	void gencb_complete(void *opaque, int ret);
	212
	213	/**
	214	* Header functions
	215	*/
	216	int qed_write_header_sync(BDRVQEDState *s);
	217
	218	/**
	219	* L2 cache functions
	220	*/
	221	void qed_init_l2_cache(L2TableCache *l2_cache);
	222	void qed_free_l2_cache(L2TableCache *l2_cache);
	223	CachedL2Table qed_alloc_l2_cache_entry(L2TableCache l2_cache);
	224	void qed_unref_l2_cache_entry(CachedL2Table *entry);
	225	CachedL2Table qed_find_l2_cache_entry(L2TableCache l2_cache, uint64_t offset);
	226	void qed_commit_l2_cache_entry(L2TableCache l2_cache, CachedL2Table l2_table);
	227
	228	/**
	229	* Table I/O functions
	230	*/
	231	int qed_read_l1_table_sync(BDRVQEDState *s);
	232	void qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n,
	233	BlockDriverCompletionFunc cb, void opaque);
	234	int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index,
	235	unsigned int n);
	236	int qed_read_l2_table_sync(BDRVQEDState s, QEDRequest request,
	237	uint64_t offset);
	238	void qed_read_l2_table(BDRVQEDState s, QEDRequest request, uint64_t offset,
	239	BlockDriverCompletionFunc cb, void opaque);
	240	void qed_write_l2_table(BDRVQEDState s, QEDRequest request,
	241	unsigned int index, unsigned int n, bool flush,
	242	BlockDriverCompletionFunc cb, void opaque);
	243	int qed_write_l2_table_sync(BDRVQEDState s, QEDRequest request,
	244	unsigned int index, unsigned int n, bool flush);
	245
	246	/**
	247	* Cluster functions
	248	*/
	249	void qed_find_cluster(BDRVQEDState s, QEDRequest request, uint64_t pos,
	250	size_t len, QEDFindClusterFunc cb, void opaque);
	251
	252	/**
	253	* Consistency check
	254	*/
	255	int qed_check(BDRVQEDState s, BdrvCheckResult result, bool fix);
	256
	257	QEDTable qed_alloc_table(BDRVQEDState s);
	258
	259	/**
	260	* Round down to the start of a cluster
	261	*/
	262	static inline uint64_t qed_start_of_cluster(BDRVQEDState *s, uint64_t offset)
	263	{
	264	return offset & ~(uint64_t)(s->header.cluster_size - 1);
	265	}
	266
	267	static inline uint64_t qed_offset_into_cluster(BDRVQEDState *s, uint64_t offset)
	268	{
	269	return offset & (s->header.cluster_size - 1);
	270	}
	271
	272	static inline uint64_t qed_bytes_to_clusters(BDRVQEDState *s, uint64_t bytes)
	273	{
	274	return qed_start_of_cluster(s, bytes + (s->header.cluster_size - 1)) /
	275	(s->header.cluster_size - 1);
	276	}
	277
	278	static inline unsigned int qed_l1_index(BDRVQEDState *s, uint64_t pos)
	279	{
	280	return pos >> s->l1_shift;
	281	}
	282
	283	static inline unsigned int qed_l2_index(BDRVQEDState *s, uint64_t pos)
	284	{
	285	return (pos >> s->l2_shift) & s->l2_mask;
	286	}
	287
	288	/**
	289	* Test if a cluster offset is valid
	290	*/
	291	static inline bool qed_check_cluster_offset(BDRVQEDState *s, uint64_t offset)
	292	{
	293	uint64_t header_size = (uint64_t)s->header.header_size *
	294	s->header.cluster_size;
	295
	296	if (offset & (s->header.cluster_size - 1)) {
	297	return false;
	298	}
	299	return offset >= header_size && offset < s->file_size;
	300	}
	301
	302	/**
	303	* Test if a table offset is valid
	304	*/
	305	static inline bool qed_check_table_offset(BDRVQEDState *s, uint64_t offset)
	306	{
	307	uint64_t end_offset = offset + (s->header.table_size - 1) *
	308	s->header.cluster_size;
	309
	310	/* Overflow check */
	311	if (end_offset <= offset) {
	312	return false;
	313	}
	314
	315	return qed_check_cluster_offset(s, offset) &&
	316	qed_check_cluster_offset(s, end_offset);
	317	}
	318
	319	static inline bool qed_offset_is_cluster_aligned(BDRVQEDState *s,
	320	uint64_t offset)
	321	{
	322	if (qed_offset_into_cluster(s, offset)) {
	323	return false;
	324	}
	325	return true;
	326	}
	327
	328	static inline bool qed_offset_is_unalloc_cluster(uint64_t offset)
	329	{
	330	if (offset == 0) {
	331	return true;
	332	}
	333	return false;
	334	}
	335
	336	static inline bool qed_offset_is_zero_cluster(uint64_t offset)
	337	{
	338	if (offset == 1) {
	339	return true;
	340	}
	341	return false;
	342	}
	343
	344	#endif /* BLOCK_QED_H */