#include "module.h"
#include <zlib.h>
#include "aes.h"
+#include "block/qcow2.h"
/*
Differences with QCOW:
- L2 tables have always a size of one cluster.
*/
-//#define DEBUG_ALLOC
-//#define DEBUG_ALLOC2
-//#define DEBUG_EXT
-
-#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
-#define QCOW_VERSION 2
-
-#define QCOW_CRYPT_NONE 0
-#define QCOW_CRYPT_AES 1
-
-#define QCOW_MAX_CRYPT_CLUSTERS 32
-
-/* indicate that the refcount of the referenced cluster is exactly one. */
-#define QCOW_OFLAG_COPIED (1LL << 63)
-/* indicate that the cluster is compressed (they never have the copied flag) */
-#define QCOW_OFLAG_COMPRESSED (1LL << 62)
-
-#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */
-
-#define MIN_CLUSTER_BITS 9
-#define MAX_CLUSTER_BITS 16
-
-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;
-} QCowHeader;
-
typedef struct {
uint32_t magic;
#define QCOW_EXT_MAGIC_END 0
#define QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
-
-typedef struct __attribute__((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;
-
-#define L2_CACHE_SIZE 16
-
-typedef struct QCowSnapshot {
- uint64_t l1_table_offset;
- uint32_t l1_size;
- char *id_str;
- char *name;
- uint32_t vm_state_size;
- uint32_t date_sec;
- uint32_t date_nsec;
- uint64_t vm_clock_nsec;
-} QCowSnapshot;
-
-typedef struct BDRVQcowState {
- BlockDriverState *hd;
- int cluster_bits;
- int cluster_size;
- int cluster_sectors;
- int l2_bits;
- int l2_size;
- int l1_size;
- int l1_vm_state_index;
- int csize_shift;
- int csize_mask;
- uint64_t cluster_offset_mask;
- uint64_t l1_table_offset;
- uint64_t *l1_table;
- uint64_t *l2_cache;
- uint64_t l2_cache_offsets[L2_CACHE_SIZE];
- uint32_t l2_cache_counts[L2_CACHE_SIZE];
- uint8_t *cluster_cache;
- uint8_t *cluster_data;
- uint64_t cluster_cache_offset;
-
- uint64_t *refcount_table;
- uint64_t refcount_table_offset;
- uint32_t refcount_table_size;
- uint64_t refcount_block_cache_offset;
- uint16_t *refcount_block_cache;
- int64_t free_cluster_index;
- int64_t free_byte_offset;
-
- uint32_t crypt_method; /* current crypt method, 0 if no key yet */
- uint32_t crypt_method_header;
- AES_KEY aes_encrypt_key;
- AES_KEY aes_decrypt_key;
- uint64_t snapshots_offset;
- int snapshots_size;
- int nb_snapshots;
- QCowSnapshot *snapshots;
-} BDRVQcowState;
-
-static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset);
-static int qcow_read(BlockDriverState *bs, int64_t sector_num,
- uint8_t *buf, int nb_sectors);
-static int qcow_read_snapshots(BlockDriverState *bs);
-static void qcow_free_snapshots(BlockDriverState *bs);
-static int refcount_init(BlockDriverState *bs);
-static void refcount_close(BlockDriverState *bs);
-static int get_refcount(BlockDriverState *bs, int64_t cluster_index);
-static int update_cluster_refcount(BlockDriverState *bs,
- int64_t cluster_index,
- int addend);
-static int update_refcount(BlockDriverState *bs,
- int64_t offset, int64_t length,
- int addend);
-static int64_t alloc_clusters(BlockDriverState *bs, int64_t size);
-static int64_t alloc_bytes(BlockDriverState *bs, int size);
-static void free_clusters(BlockDriverState *bs,
- int64_t offset, int64_t size);
-static int check_refcounts(BlockDriverState *bs);
-
static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
{
const QCowHeader *cow_header = (const void *)buf;
static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset,
uint64_t end_offset)
{
- BDRVQcowState *s = bs->opaque;
QCowExtension ext;
uint64_t offset;
printf("attemting to read extended header in offset %lu\n", offset);
#endif
- if (bdrv_pread(s->hd, offset, &ext, sizeof(ext)) != sizeof(ext)) {
- fprintf(stderr, "qcow_handle_extension: ERROR: pread fail from offset %llu\n",
- (unsigned long long)offset);
+ if (bdrv_pread(bs->file, offset, &ext, sizeof(ext)) != sizeof(ext)) {
+ fprintf(stderr, "qcow_handle_extension: ERROR: "
+ "pread fail from offset %" PRIu64 "\n",
+ offset);
return 1;
}
be32_to_cpus(&ext.magic);
ext.len, sizeof(bs->backing_format));
return 2;
}
- if (bdrv_pread(s->hd, offset , bs->backing_format,
+ if (bdrv_pread(bs->file, offset , bs->backing_format,
ext.len) != ext.len)
return 3;
bs->backing_format[ext.len] = '\0';
#ifdef DEBUG_EXT
printf("Qcow2: Got format extension %s\n", bs->backing_format);
#endif
- offset += ((ext.len + 7) & ~7);
+ offset = ((offset + ext.len + 7) & ~7);
break;
default:
/* unknown magic -- just skip it */
- offset += ((ext.len + 7) & ~7);
+ offset = ((offset + ext.len + 7) & ~7);
break;
}
}
}
-static int qcow_open(BlockDriverState *bs, const char *filename, int flags)
+static int qcow_open(BlockDriverState *bs, int flags)
{
BDRVQcowState *s = bs->opaque;
- int len, i, shift, ret;
+ int len, i;
QCowHeader header;
uint64_t ext_end;
- /* Performance is terrible right now with cache=writethrough due mainly
- * to reference count updates. If the user does not explicitly specify
- * a caching type, force to writeback caching.
- */
- if ((flags & BDRV_O_CACHE_DEF)) {
- flags |= BDRV_O_CACHE_WB;
- flags &= ~BDRV_O_CACHE_DEF;
- }
- ret = bdrv_file_open(&s->hd, filename, flags);
- if (ret < 0)
- return ret;
- if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header))
+ if (bdrv_pread(bs->file, 0, &header, sizeof(header)) != sizeof(header))
goto fail;
be32_to_cpus(&header.magic);
be32_to_cpus(&header.version);
if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
goto fail;
- if (header.size <= 1 ||
- header.cluster_bits < MIN_CLUSTER_BITS ||
+ if (header.cluster_bits < MIN_CLUSTER_BITS ||
header.cluster_bits > MAX_CLUSTER_BITS)
goto fail;
if (header.crypt_method > QCOW_CRYPT_AES)
/* read the level 1 table */
s->l1_size = header.l1_size;
- shift = s->cluster_bits + s->l2_bits;
- s->l1_vm_state_index = (header.size + (1LL << shift) - 1) >> shift;
+ s->l1_vm_state_index = size_to_l1(s, header.size);
/* the L1 table must contain at least enough entries to put
header.size bytes */
if (s->l1_size < s->l1_vm_state_index)
goto fail;
s->l1_table_offset = header.l1_table_offset;
- s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
- if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) !=
- s->l1_size * sizeof(uint64_t))
- goto fail;
- for(i = 0;i < s->l1_size; i++) {
- be64_to_cpus(&s->l1_table[i]);
+ if (s->l1_size > 0) {
+ s->l1_table = qemu_mallocz(
+ align_offset(s->l1_size * sizeof(uint64_t), 512));
+ if (bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) !=
+ s->l1_size * sizeof(uint64_t))
+ goto fail;
+ for(i = 0;i < s->l1_size; i++) {
+ be64_to_cpus(&s->l1_table[i]);
+ }
}
/* alloc L2 cache */
s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
+ 512);
s->cluster_cache_offset = -1;
- if (refcount_init(bs) < 0)
+ if (qcow2_refcount_init(bs) < 0)
goto fail;
+ QLIST_INIT(&s->cluster_allocs);
+
/* read qcow2 extensions */
if (header.backing_file_offset)
ext_end = header.backing_file_offset;
len = header.backing_file_size;
if (len > 1023)
len = 1023;
- if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len)
+ if (bdrv_pread(bs->file, header.backing_file_offset, bs->backing_file, len) != len)
goto fail;
bs->backing_file[len] = '\0';
}
- if (qcow_read_snapshots(bs) < 0)
+ if (qcow2_read_snapshots(bs) < 0)
goto fail;
#ifdef DEBUG_ALLOC
- check_refcounts(bs);
+ qcow2_check_refcounts(bs);
#endif
return 0;
fail:
- qcow_free_snapshots(bs);
- refcount_close(bs);
+ qcow2_free_snapshots(bs);
+ qcow2_refcount_close(bs);
qemu_free(s->l1_table);
qemu_free(s->l2_cache);
qemu_free(s->cluster_cache);
qemu_free(s->cluster_data);
- bdrv_delete(s->hd);
return -1;
}
return 0;
}
-/* The crypt function is compatible with the linux cryptoloop
- algorithm for < 4 GB images. NOTE: out_buf == in_buf is
- supported */
-static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
- uint8_t *out_buf, const uint8_t *in_buf,
- int nb_sectors, int enc,
- const AES_KEY *key)
-{
- union {
- uint64_t ll[2];
- uint8_t b[16];
- } ivec;
- int i;
-
- for(i = 0; i < nb_sectors; i++) {
- ivec.ll[0] = cpu_to_le64(sector_num);
- ivec.ll[1] = 0;
- AES_cbc_encrypt(in_buf, out_buf, 512, key,
- ivec.b, enc);
- sector_num++;
- in_buf += 512;
- out_buf += 512;
- }
-}
-
-static int copy_sectors(BlockDriverState *bs, uint64_t start_sect,
- uint64_t cluster_offset, int n_start, int n_end)
+static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors, int *pnum)
{
- BDRVQcowState *s = bs->opaque;
- int n, ret;
+ uint64_t cluster_offset;
+ int ret;
- n = n_end - n_start;
- if (n <= 0)
- return 0;
- ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n);
- if (ret < 0)
- return ret;
- if (s->crypt_method) {
- encrypt_sectors(s, start_sect + n_start,
- s->cluster_data,
- s->cluster_data, n, 1,
- &s->aes_encrypt_key);
+ *pnum = nb_sectors;
+ /* FIXME We can get errors here, but the bdrv_is_allocated interface can't
+ * pass them on today */
+ ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
+ if (ret < 0) {
+ *pnum = 0;
}
- ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start,
- s->cluster_data, n);
- if (ret < 0)
- return ret;
- return 0;
+
+ return (cluster_offset != 0);
}
-static void l2_cache_reset(BlockDriverState *bs)
+/* handle reading after the end of the backing file */
+int qcow2_backing_read1(BlockDriverState *bs,
+ int64_t sector_num, uint8_t *buf, int nb_sectors)
{
- BDRVQcowState *s = bs->opaque;
-
- memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
- memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
- memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
+ int n1;
+ if ((sector_num + nb_sectors) <= bs->total_sectors)
+ return nb_sectors;
+ if (sector_num >= bs->total_sectors)
+ n1 = 0;
+ else
+ n1 = bs->total_sectors - sector_num;
+ memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1));
+ return n1;
}
-static inline int l2_cache_new_entry(BlockDriverState *bs)
+typedef struct QCowAIOCB {
+ BlockDriverAIOCB common;
+ int64_t sector_num;
+ QEMUIOVector *qiov;
+ uint8_t *buf;
+ void *orig_buf;
+ int remaining_sectors;
+ int cur_nr_sectors; /* number of sectors in current iteration */
+ uint64_t cluster_offset;
+ uint8_t *cluster_data;
+ BlockDriverAIOCB *hd_aiocb;
+ struct iovec hd_iov;
+ QEMUIOVector hd_qiov;
+ QEMUBH *bh;
+ QCowL2Meta l2meta;
+ QLIST_ENTRY(QCowAIOCB) next_depend;
+} QCowAIOCB;
+
+static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
{
- BDRVQcowState *s = bs->opaque;
- uint32_t min_count;
- int min_index, i;
-
- /* find a new entry in the least used one */
- min_index = 0;
- min_count = 0xffffffff;
- for(i = 0; i < L2_CACHE_SIZE; i++) {
- if (s->l2_cache_counts[i] < min_count) {
- min_count = s->l2_cache_counts[i];
- min_index = i;
- }
- }
- return min_index;
+ QCowAIOCB *acb = container_of(blockacb, QCowAIOCB, common);
+ if (acb->hd_aiocb)
+ bdrv_aio_cancel(acb->hd_aiocb);
+ qemu_aio_release(acb);
}
-static int64_t align_offset(int64_t offset, int n)
+static AIOPool qcow_aio_pool = {
+ .aiocb_size = sizeof(QCowAIOCB),
+ .cancel = qcow_aio_cancel,
+};
+
+static void qcow_aio_read_cb(void *opaque, int ret);
+static void qcow_aio_read_bh(void *opaque)
{
- offset = (offset + n - 1) & ~(n - 1);
- return offset;
+ QCowAIOCB *acb = opaque;
+ qemu_bh_delete(acb->bh);
+ acb->bh = NULL;
+ qcow_aio_read_cb(opaque, 0);
}
-static int grow_l1_table(BlockDriverState *bs, int min_size)
+static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb)
{
- BDRVQcowState *s = bs->opaque;
- int new_l1_size, new_l1_size2, ret, i;
- uint64_t *new_l1_table;
- uint64_t new_l1_table_offset;
- uint8_t data[12];
-
- new_l1_size = s->l1_size;
- if (min_size <= new_l1_size)
- return 0;
- while (min_size > new_l1_size) {
- new_l1_size = (new_l1_size * 3 + 1) / 2;
- }
-#ifdef DEBUG_ALLOC2
- printf("grow l1_table from %d to %d\n", s->l1_size, new_l1_size);
-#endif
+ if (acb->bh)
+ return -EIO;
- new_l1_size2 = sizeof(uint64_t) * new_l1_size;
- new_l1_table = qemu_mallocz(new_l1_size2);
- memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
+ acb->bh = qemu_bh_new(cb, acb);
+ if (!acb->bh)
+ return -EIO;
- /* write new table (align to cluster) */
- new_l1_table_offset = alloc_clusters(bs, new_l1_size2);
+ qemu_bh_schedule(acb->bh);
- for(i = 0; i < s->l1_size; i++)
- new_l1_table[i] = cpu_to_be64(new_l1_table[i]);
- ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2);
- if (ret != new_l1_size2)
- goto fail;
- for(i = 0; i < s->l1_size; i++)
- new_l1_table[i] = be64_to_cpu(new_l1_table[i]);
-
- /* set new table */
- cpu_to_be32w((uint32_t*)data, new_l1_size);
- cpu_to_be64w((uint64_t*)(data + 4), new_l1_table_offset);
- if (bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size), data,
- sizeof(data)) != sizeof(data))
- goto fail;
- qemu_free(s->l1_table);
- free_clusters(bs, s->l1_table_offset, s->l1_size * sizeof(uint64_t));
- s->l1_table_offset = new_l1_table_offset;
- s->l1_table = new_l1_table;
- s->l1_size = new_l1_size;
return 0;
- fail:
- qemu_free(s->l1_table);
- return -EIO;
}
-/*
- * seek_l2_table
- *
- * seek l2_offset in the l2_cache table
- * if not found, return NULL,
- * if found,
- * increments the l2 cache hit count of the entry,
- * if counter overflow, divide by two all counters
- * return the pointer to the l2 cache entry
- *
- */
-
-static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset)
+static void qcow_aio_read_cb(void *opaque, int ret)
{
- int i, j;
-
- for(i = 0; i < L2_CACHE_SIZE; i++) {
- if (l2_offset == s->l2_cache_offsets[i]) {
- /* increment the hit count */
- if (++s->l2_cache_counts[i] == 0xffffffff) {
- for(j = 0; j < L2_CACHE_SIZE; j++) {
- s->l2_cache_counts[j] >>= 1;
- }
- }
- return s->l2_cache + (i << s->l2_bits);
+ QCowAIOCB *acb = opaque;
+ BlockDriverState *bs = acb->common.bs;
+ BDRVQcowState *s = bs->opaque;
+ int index_in_cluster, n1;
+
+ acb->hd_aiocb = NULL;
+ if (ret < 0)
+ goto done;
+
+ /* post process the read buffer */
+ if (!acb->cluster_offset) {
+ /* nothing to do */
+ } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
+ /* nothing to do */
+ } else {
+ if (s->crypt_method) {
+ qcow2_encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
+ acb->cur_nr_sectors, 0,
+ &s->aes_decrypt_key);
}
}
- return NULL;
-}
-/*
- * l2_load
- *
- * Loads a L2 table into memory. If the table is in the cache, the cache
- * is used; otherwise the L2 table is loaded from the image file.
- *
- * Returns a pointer to the L2 table on success, or NULL if the read from
- * the image file failed.
- */
+ acb->remaining_sectors -= acb->cur_nr_sectors;
+ acb->sector_num += acb->cur_nr_sectors;
+ acb->buf += acb->cur_nr_sectors * 512;
-static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
-{
- BDRVQcowState *s = bs->opaque;
- int min_index;
- uint64_t *l2_table;
+ if (acb->remaining_sectors == 0) {
+ /* request completed */
+ ret = 0;
+ goto done;
+ }
- /* seek if the table for the given offset is in the cache */
+ /* prepare next AIO request */
+ acb->cur_nr_sectors = acb->remaining_sectors;
+ ret = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
+ &acb->cur_nr_sectors, &acb->cluster_offset);
+ if (ret < 0) {
+ goto done;
+ }
- l2_table = seek_l2_table(s, l2_offset);
- if (l2_table != NULL)
- return l2_table;
+ index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
- /* not found: load a new entry in the least used one */
+ if (!acb->cluster_offset) {
+ if (bs->backing_hd) {
+ /* read from the base image */
+ n1 = qcow2_backing_read1(bs->backing_hd, acb->sector_num,
+ acb->buf, acb->cur_nr_sectors);
+ if (n1 > 0) {
+ acb->hd_iov.iov_base = (void *)acb->buf;
+ acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
+ qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
+ acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
+ &acb->hd_qiov, acb->cur_nr_sectors,
+ qcow_aio_read_cb, acb);
+ if (acb->hd_aiocb == NULL)
+ goto done;
+ } else {
+ ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
+ if (ret < 0)
+ goto done;
+ }
+ } else {
+ /* Note: in this case, no need to wait */
+ memset(acb->buf, 0, 512 * acb->cur_nr_sectors);
+ ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
+ if (ret < 0)
+ goto done;
+ }
+ } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
+ /* add AIO support for compressed blocks ? */
+ if (qcow2_decompress_cluster(bs, acb->cluster_offset) < 0)
+ goto done;
+ memcpy(acb->buf, s->cluster_cache + index_in_cluster * 512,
+ 512 * acb->cur_nr_sectors);
+ ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
+ if (ret < 0)
+ goto done;
+ } else {
+ if ((acb->cluster_offset & 511) != 0) {
+ ret = -EIO;
+ goto done;
+ }
- min_index = l2_cache_new_entry(bs);
- l2_table = s->l2_cache + (min_index << s->l2_bits);
- if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) !=
- s->l2_size * sizeof(uint64_t))
- return NULL;
- s->l2_cache_offsets[min_index] = l2_offset;
- s->l2_cache_counts[min_index] = 1;
+ acb->hd_iov.iov_base = (void *)acb->buf;
+ acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
+ qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
+ acb->hd_aiocb = bdrv_aio_readv(bs->file,
+ (acb->cluster_offset >> 9) + index_in_cluster,
+ &acb->hd_qiov, acb->cur_nr_sectors,
+ qcow_aio_read_cb, acb);
+ if (acb->hd_aiocb == NULL) {
+ ret = -EIO;
+ goto done;
+ }
+ }
- return l2_table;
+ return;
+done:
+ if (acb->qiov->niov > 1) {
+ qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
+ qemu_vfree(acb->orig_buf);
+ }
+ acb->common.cb(acb->common.opaque, ret);
+ qemu_aio_release(acb);
}
-/*
- * l2_allocate
- *
- * Allocate a new l2 entry in the file. If l1_index points to an already
- * used entry in the L2 table (i.e. we are doing a copy on write for the L2
- * table) copy the contents of the old L2 table into the newly allocated one.
- * Otherwise the new table is initialized with zeros.
- *
- */
-
-static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index)
+static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque, int is_write)
{
- BDRVQcowState *s = bs->opaque;
- int min_index;
- uint64_t old_l2_offset, tmp;
- uint64_t *l2_table, l2_offset;
-
- old_l2_offset = s->l1_table[l1_index];
-
- /* allocate a new l2 entry */
-
- l2_offset = alloc_clusters(bs, s->l2_size * sizeof(uint64_t));
-
- /* update the L1 entry */
-
- s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED;
+ QCowAIOCB *acb;
- tmp = cpu_to_be64(l2_offset | QCOW_OFLAG_COPIED);
- if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp),
- &tmp, sizeof(tmp)) != sizeof(tmp))
+ acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque);
+ if (!acb)
return NULL;
-
- /* allocate a new entry in the l2 cache */
-
- min_index = l2_cache_new_entry(bs);
- l2_table = s->l2_cache + (min_index << s->l2_bits);
-
- if (old_l2_offset == 0) {
- /* if there was no old l2 table, clear the new table */
- memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
+ acb->hd_aiocb = NULL;
+ acb->sector_num = sector_num;
+ acb->qiov = qiov;
+ if (qiov->niov > 1) {
+ acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
+ if (is_write)
+ qemu_iovec_to_buffer(qiov, acb->buf);
} else {
- /* if there was an old l2 table, read it from the disk */
- if (bdrv_pread(s->hd, old_l2_offset,
- l2_table, s->l2_size * sizeof(uint64_t)) !=
- s->l2_size * sizeof(uint64_t))
- return NULL;
+ acb->buf = (uint8_t *)qiov->iov->iov_base;
}
- /* write the l2 table to the file */
- if (bdrv_pwrite(s->hd, l2_offset,
- l2_table, s->l2_size * sizeof(uint64_t)) !=
- s->l2_size * sizeof(uint64_t))
- return NULL;
+ acb->remaining_sectors = nb_sectors;
+ acb->cur_nr_sectors = 0;
+ acb->cluster_offset = 0;
+ acb->l2meta.nb_clusters = 0;
+ QLIST_INIT(&acb->l2meta.dependent_requests);
+ return acb;
+}
- /* update the l2 cache entry */
+static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque)
+{
+ QCowAIOCB *acb;
- s->l2_cache_offsets[min_index] = l2_offset;
- s->l2_cache_counts[min_index] = 1;
+ acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
+ if (!acb)
+ return NULL;
- return l2_table;
+ qcow_aio_read_cb(acb, 0);
+ return &acb->common;
}
-static int size_to_clusters(BDRVQcowState *s, int64_t size)
-{
- return (size + (s->cluster_size - 1)) >> s->cluster_bits;
-}
+static void qcow_aio_write_cb(void *opaque, int ret);
-static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size,
- uint64_t *l2_table, uint64_t start, uint64_t mask)
+static void run_dependent_requests(QCowL2Meta *m)
{
- int i;
- uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask;
+ QCowAIOCB *req;
+ QCowAIOCB *next;
- if (!offset)
- return 0;
+ /* Take the request off the list of running requests */
+ if (m->nb_clusters != 0) {
+ QLIST_REMOVE(m, next_in_flight);
+ }
- for (i = start; i < start + nb_clusters; i++)
- if (offset + i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask))
- break;
+ /* Restart all dependent requests */
+ QLIST_FOREACH_SAFE(req, &m->dependent_requests, next_depend, next) {
+ qcow_aio_write_cb(req, 0);
+ }
- return (i - start);
+ /* Empty the list for the next part of the request */
+ QLIST_INIT(&m->dependent_requests);
}
-static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table)
+static void qcow_aio_write_cb(void *opaque, int ret)
{
- int i = 0;
+ QCowAIOCB *acb = opaque;
+ BlockDriverState *bs = acb->common.bs;
+ BDRVQcowState *s = bs->opaque;
+ int index_in_cluster;
+ const uint8_t *src_buf;
+ int n_end;
- while(nb_clusters-- && l2_table[i] == 0)
- i++;
+ acb->hd_aiocb = NULL;
- return i;
-}
+ if (ret >= 0) {
+ ret = qcow2_alloc_cluster_link_l2(bs, &acb->l2meta);
+ }
-/*
- * get_cluster_offset
- *
- * For a given offset of the disk image, return cluster offset in
- * qcow2 file.
- *
- * on entry, *num is the number of contiguous clusters we'd like to
- * access following offset.
- *
- * on exit, *num is the number of contiguous clusters we can read.
- *
- * Return 1, if the offset is found
- * Return 0, otherwise.
- *
- */
+ run_dependent_requests(&acb->l2meta);
-static uint64_t get_cluster_offset(BlockDriverState *bs,
- uint64_t offset, int *num)
-{
- BDRVQcowState *s = bs->opaque;
- int l1_index, l2_index;
- uint64_t l2_offset, *l2_table, cluster_offset;
- int l1_bits, c;
- int index_in_cluster, nb_available, nb_needed, nb_clusters;
-
- index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1);
- nb_needed = *num + index_in_cluster;
-
- l1_bits = s->l2_bits + s->cluster_bits;
-
- /* compute how many bytes there are between the offset and
- * the end of the l1 entry
- */
-
- nb_available = (1 << l1_bits) - (offset & ((1 << l1_bits) - 1));
-
- /* compute the number of available sectors */
+ if (ret < 0)
+ goto done;
- nb_available = (nb_available >> 9) + index_in_cluster;
+ acb->remaining_sectors -= acb->cur_nr_sectors;
+ acb->sector_num += acb->cur_nr_sectors;
+ acb->buf += acb->cur_nr_sectors * 512;
- if (nb_needed > nb_available) {
- nb_needed = nb_available;
+ if (acb->remaining_sectors == 0) {
+ /* request completed */
+ ret = 0;
+ goto done;
}
- cluster_offset = 0;
-
- /* seek the the l2 offset in the l1 table */
-
- l1_index = offset >> l1_bits;
- if (l1_index >= s->l1_size)
- goto out;
-
- l2_offset = s->l1_table[l1_index];
-
- /* seek the l2 table of the given l2 offset */
-
- if (!l2_offset)
- goto out;
+ index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
+ n_end = index_in_cluster + acb->remaining_sectors;
+ if (s->crypt_method &&
+ n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors)
+ n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
- /* load the l2 table in memory */
+ ret = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9,
+ index_in_cluster, n_end, &acb->cur_nr_sectors, &acb->l2meta);
+ if (ret < 0) {
+ goto done;
+ }
- l2_offset &= ~QCOW_OFLAG_COPIED;
- l2_table = l2_load(bs, l2_offset);
- if (l2_table == NULL)
- return 0;
+ acb->cluster_offset = acb->l2meta.cluster_offset;
- /* find the cluster offset for the given disk offset */
+ /* Need to wait for another request? If so, we are done for now. */
+ if (acb->l2meta.nb_clusters == 0 && acb->l2meta.depends_on != NULL) {
+ QLIST_INSERT_HEAD(&acb->l2meta.depends_on->dependent_requests,
+ acb, next_depend);
+ return;
+ }
- l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
- cluster_offset = be64_to_cpu(l2_table[l2_index]);
- nb_clusters = size_to_clusters(s, nb_needed << 9);
+ assert((acb->cluster_offset & 511) == 0);
- if (!cluster_offset) {
- /* how many empty clusters ? */
- c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]);
+ if (s->crypt_method) {
+ if (!acb->cluster_data) {
+ acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS *
+ s->cluster_size);
+ }
+ qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
+ acb->cur_nr_sectors, 1, &s->aes_encrypt_key);
+ src_buf = acb->cluster_data;
} else {
- /* how many allocated clusters ? */
- c = count_contiguous_clusters(nb_clusters, s->cluster_size,
- &l2_table[l2_index], 0, QCOW_OFLAG_COPIED);
+ src_buf = acb->buf;
+ }
+ acb->hd_iov.iov_base = (void *)src_buf;
+ acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
+ qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
+ BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
+ acb->hd_aiocb = bdrv_aio_writev(bs->file,
+ (acb->cluster_offset >> 9) + index_in_cluster,
+ &acb->hd_qiov, acb->cur_nr_sectors,
+ qcow_aio_write_cb, acb);
+ if (acb->hd_aiocb == NULL) {
+ ret = -EIO;
+ goto fail;
}
- nb_available = (c * s->cluster_sectors);
-out:
- if (nb_available > nb_needed)
- nb_available = nb_needed;
-
- *num = nb_available - index_in_cluster;
+ return;
- return cluster_offset & ~QCOW_OFLAG_COPIED;
+fail:
+ if (acb->l2meta.nb_clusters != 0) {
+ QLIST_REMOVE(&acb->l2meta, next_in_flight);
+ }
+done:
+ if (acb->qiov->niov > 1)
+ qemu_vfree(acb->orig_buf);
+ acb->common.cb(acb->common.opaque, ret);
+ qemu_aio_release(acb);
}
-/*
- * free_any_clusters
- *
- * free clusters according to its type: compressed or not
- *
- */
-
-static void free_any_clusters(BlockDriverState *bs,
- uint64_t cluster_offset, int nb_clusters)
+static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVQcowState *s = bs->opaque;
+ QCowAIOCB *acb;
- /* free the cluster */
-
- if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
- int nb_csectors;
- nb_csectors = ((cluster_offset >> s->csize_shift) &
- s->csize_mask) + 1;
- free_clusters(bs, (cluster_offset & s->cluster_offset_mask) & ~511,
- nb_csectors * 512);
- return;
- }
+ s->cluster_cache_offset = -1; /* disable compressed cache */
- free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits);
+ acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
+ if (!acb)
+ return NULL;
- return;
+ qcow_aio_write_cb(acb, 0);
+ return &acb->common;
}
-/*
- * get_cluster_table
- *
- * for a given disk offset, load (and allocate if needed)
- * the l2 table.
- *
- * the l2 table offset in the qcow2 file and the cluster index
- * in the l2 table are given to the caller.
- *
- */
-
-static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
- uint64_t **new_l2_table,
- uint64_t *new_l2_offset,
- int *new_l2_index)
+static void qcow_close(BlockDriverState *bs)
{
BDRVQcowState *s = bs->opaque;
- int l1_index, l2_index, ret;
- uint64_t l2_offset, *l2_table;
-
- /* seek the the l2 offset in the l1 table */
-
- l1_index = offset >> (s->l2_bits + s->cluster_bits);
- if (l1_index >= s->l1_size) {
- ret = grow_l1_table(bs, l1_index + 1);
- if (ret < 0)
- return 0;
- }
- l2_offset = s->l1_table[l1_index];
-
- /* seek the l2 table of the given l2 offset */
-
- if (l2_offset & QCOW_OFLAG_COPIED) {
- /* load the l2 table in memory */
- l2_offset &= ~QCOW_OFLAG_COPIED;
- l2_table = l2_load(bs, l2_offset);
- if (l2_table == NULL)
- return 0;
- } else {
- if (l2_offset)
- free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t));
- l2_table = l2_allocate(bs, l1_index);
- if (l2_table == NULL)
- return 0;
- l2_offset = s->l1_table[l1_index] & ~QCOW_OFLAG_COPIED;
- }
-
- /* find the cluster offset for the given disk offset */
-
- l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
-
- *new_l2_table = l2_table;
- *new_l2_offset = l2_offset;
- *new_l2_index = l2_index;
-
- return 1;
+ qemu_free(s->l1_table);
+ qemu_free(s->l2_cache);
+ qemu_free(s->cluster_cache);
+ qemu_free(s->cluster_data);
+ qcow2_refcount_close(bs);
}
/*
- * alloc_compressed_cluster_offset
- *
- * For a given offset of the disk image, return cluster offset in
- * qcow2 file.
- *
- * If the offset is not found, allocate a new compressed cluster.
- *
- * Return the cluster offset if successful,
- * Return 0, otherwise.
+ * Updates the variable length parts of the qcow2 header, i.e. the backing file
+ * name and all extensions. qcow2 was not designed to allow such changes, so if
+ * we run out of space (we can only use the first cluster) this function may
+ * fail.
*
+ * Returns 0 on success, -errno in error cases.
*/
-
-static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs,
- uint64_t offset,
- int compressed_size)
+static int qcow2_update_ext_header(BlockDriverState *bs,
+ const char *backing_file, const char *backing_fmt)
{
+ size_t backing_file_len = 0;
+ size_t backing_fmt_len = 0;
BDRVQcowState *s = bs->opaque;
- int l2_index, ret;
- uint64_t l2_offset, *l2_table, cluster_offset;
- int nb_csectors;
+ QCowExtension ext_backing_fmt = {0, 0};
+ int ret;
- ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index);
- if (ret == 0)
- return 0;
+ /* Backing file format doesn't make sense without a backing file */
+ if (backing_fmt && !backing_file) {
+ return -EINVAL;
+ }
- cluster_offset = be64_to_cpu(l2_table[l2_index]);
- if (cluster_offset & QCOW_OFLAG_COPIED)
- return cluster_offset & ~QCOW_OFLAG_COPIED;
+ /* Prepare the backing file format extension if needed */
+ if (backing_fmt) {
+ ext_backing_fmt.len = cpu_to_be32(strlen(backing_fmt));
+ ext_backing_fmt.magic = cpu_to_be32(QCOW_EXT_MAGIC_BACKING_FORMAT);
+ backing_fmt_len = ((sizeof(ext_backing_fmt)
+ + strlen(backing_fmt) + 7) & ~7);
+ }
- if (cluster_offset)
- free_any_clusters(bs, cluster_offset, 1);
+ /* Check if we can fit the new header into the first cluster */
+ if (backing_file) {
+ backing_file_len = strlen(backing_file);
+ }
- cluster_offset = alloc_bytes(bs, compressed_size);
- nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) -
- (cluster_offset >> 9);
+ size_t header_size = sizeof(QCowHeader) + backing_file_len
+ + backing_fmt_len;
- cluster_offset |= QCOW_OFLAG_COMPRESSED |
- ((uint64_t)nb_csectors << s->csize_shift);
+ if (header_size > s->cluster_size) {
+ return -ENOSPC;
+ }
- /* update L2 table */
+ /* Rewrite backing file name and qcow2 extensions */
+ size_t ext_size = header_size - sizeof(QCowHeader);
+ uint8_t buf[ext_size];
+ size_t offset = 0;
+ size_t backing_file_offset = 0;
- /* compressed clusters never have the copied flag */
+ if (backing_file) {
+ if (backing_fmt) {
+ int padding = backing_fmt_len -
+ (sizeof(ext_backing_fmt) + strlen(backing_fmt));
- l2_table[l2_index] = cpu_to_be64(cluster_offset);
- if (bdrv_pwrite(s->hd,
- l2_offset + l2_index * sizeof(uint64_t),
- l2_table + l2_index,
- sizeof(uint64_t)) != sizeof(uint64_t))
- return 0;
+ memcpy(buf + offset, &ext_backing_fmt, sizeof(ext_backing_fmt));
+ offset += sizeof(ext_backing_fmt);
- return cluster_offset;
-}
+ memcpy(buf + offset, backing_fmt, strlen(backing_fmt));
+ offset += strlen(backing_fmt);
-typedef struct QCowL2Meta
-{
- uint64_t offset;
- int n_start;
- int nb_available;
- int nb_clusters;
-} QCowL2Meta;
+ memset(buf + offset, 0, padding);
+ offset += padding;
+ }
-static int alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset,
- QCowL2Meta *m)
-{
- BDRVQcowState *s = bs->opaque;
- int i, j = 0, l2_index, ret;
- uint64_t *old_cluster, start_sect, l2_offset, *l2_table;
+ memcpy(buf + offset, backing_file, backing_file_len);
+ backing_file_offset = sizeof(QCowHeader) + offset;
+ }
- if (m->nb_clusters == 0)
- return 0;
+ ret = bdrv_pwrite_sync(bs->file, sizeof(QCowHeader), buf, ext_size);
+ if (ret < 0) {
+ goto fail;
+ }
- old_cluster = qemu_malloc(m->nb_clusters * sizeof(uint64_t));
+ /* Update header fields */
+ uint64_t be_backing_file_offset = cpu_to_be64(backing_file_offset);
+ uint32_t be_backing_file_size = cpu_to_be32(backing_file_len);
- /* copy content of unmodified sectors */
- start_sect = (m->offset & ~(s->cluster_size - 1)) >> 9;
- if (m->n_start) {
- ret = copy_sectors(bs, start_sect, cluster_offset, 0, m->n_start);
- if (ret < 0)
- goto err;
+ ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_offset),
+ &be_backing_file_offset, sizeof(uint64_t));
+ if (ret < 0) {
+ goto fail;
}
- if (m->nb_available & (s->cluster_sectors - 1)) {
- uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1);
- ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9),
- m->nb_available - end, s->cluster_sectors);
- if (ret < 0)
- goto err;
+ ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_size),
+ &be_backing_file_size, sizeof(uint32_t));
+ if (ret < 0) {
+ goto fail;
}
- ret = -EIO;
- /* update L2 table */
- if (!get_cluster_table(bs, m->offset, &l2_table, &l2_offset, &l2_index))
- goto err;
-
- for (i = 0; i < m->nb_clusters; i++) {
- /* if two concurrent writes happen to the same unallocated cluster
- * each write allocates separate cluster and writes data concurrently.
- * The first one to complete updates l2 table with pointer to its
- * cluster the second one has to do RMW (which is done above by
- * copy_sectors()), update l2 table with its cluster pointer and free
- * old cluster. This is what this loop does */
- if(l2_table[l2_index + i] != 0)
- old_cluster[j++] = l2_table[l2_index + i];
-
- l2_table[l2_index + i] = cpu_to_be64((cluster_offset +
- (i << s->cluster_bits)) | QCOW_OFLAG_COPIED);
- }
-
- if (bdrv_pwrite(s->hd, l2_offset + l2_index * sizeof(uint64_t),
- l2_table + l2_index, m->nb_clusters * sizeof(uint64_t)) !=
- m->nb_clusters * sizeof(uint64_t))
- goto err;
-
- for (i = 0; i < j; i++)
- free_any_clusters(bs, be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED,
- 1);
-
ret = 0;
-err:
- qemu_free(old_cluster);
+fail:
return ret;
- }
-
-/*
- * alloc_cluster_offset
- *
- * For a given offset of the disk image, return cluster offset in
- * qcow2 file.
- *
- * If the offset is not found, allocate a new cluster.
- *
- * Return the cluster offset if successful,
- * Return 0, otherwise.
- *
- */
+}
-static uint64_t alloc_cluster_offset(BlockDriverState *bs,
- uint64_t offset,
- int n_start, int n_end,
- int *num, QCowL2Meta *m)
+static int qcow2_change_backing_file(BlockDriverState *bs,
+ const char *backing_file, const char *backing_fmt)
{
- BDRVQcowState *s = bs->opaque;
- int l2_index, ret;
- uint64_t l2_offset, *l2_table, cluster_offset;
- int nb_clusters, i = 0;
-
- ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index);
- if (ret == 0)
- return 0;
-
- nb_clusters = size_to_clusters(s, n_end << 9);
-
- nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
-
- cluster_offset = be64_to_cpu(l2_table[l2_index]);
-
- /* We keep all QCOW_OFLAG_COPIED clusters */
-
- if (cluster_offset & QCOW_OFLAG_COPIED) {
- nb_clusters = count_contiguous_clusters(nb_clusters, s->cluster_size,
- &l2_table[l2_index], 0, 0);
+ return qcow2_update_ext_header(bs, backing_file, backing_fmt);
+}
- cluster_offset &= ~QCOW_OFLAG_COPIED;
- m->nb_clusters = 0;
+static int get_bits_from_size(size_t size)
+{
+ int res = 0;
- goto out;
+ if (size == 0) {
+ return -1;
}
- /* for the moment, multiple compressed clusters are not managed */
-
- if (cluster_offset & QCOW_OFLAG_COMPRESSED)
- nb_clusters = 1;
-
- /* how many available clusters ? */
-
- while (i < nb_clusters) {
- i += count_contiguous_clusters(nb_clusters - i, s->cluster_size,
- &l2_table[l2_index], i, 0);
-
- if(be64_to_cpu(l2_table[l2_index + i]))
- break;
-
- i += count_contiguous_free_clusters(nb_clusters - i,
- &l2_table[l2_index + i]);
-
- cluster_offset = be64_to_cpu(l2_table[l2_index + i]);
+ while (size != 1) {
+ /* Not a power of two */
+ if (size & 1) {
+ return -1;
+ }
- if ((cluster_offset & QCOW_OFLAG_COPIED) ||
- (cluster_offset & QCOW_OFLAG_COMPRESSED))
- break;
+ size >>= 1;
+ res++;
}
- nb_clusters = i;
-
- /* allocate a new cluster */
-
- cluster_offset = alloc_clusters(bs, nb_clusters * s->cluster_size);
-
- /* save info needed for meta data update */
- m->offset = offset;
- m->n_start = n_start;
- m->nb_clusters = nb_clusters;
-out:
- m->nb_available = MIN(nb_clusters << (s->cluster_bits - 9), n_end);
-
- *num = m->nb_available - n_start;
-
- return cluster_offset;
+ return res;
}
-static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
- int nb_sectors, int *pnum)
+
+static int preallocate(BlockDriverState *bs)
{
- uint64_t cluster_offset;
+ uint64_t nb_sectors;
+ uint64_t offset;
+ int num;
+ int ret;
+ QCowL2Meta meta;
- *pnum = nb_sectors;
- cluster_offset = get_cluster_offset(bs, sector_num << 9, pnum);
+ nb_sectors = bdrv_getlength(bs) >> 9;
+ offset = 0;
+ QLIST_INIT(&meta.dependent_requests);
+ meta.cluster_offset = 0;
- return (cluster_offset != 0);
-}
+ while (nb_sectors) {
+ num = MIN(nb_sectors, INT_MAX >> 9);
+ ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta);
+ if (ret < 0) {
+ return ret;
+ }
-static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
- const uint8_t *buf, int buf_size)
-{
- z_stream strm1, *strm = &strm1;
- int ret, out_len;
+ ret = qcow2_alloc_cluster_link_l2(bs, &meta);
+ if (ret < 0) {
+ qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters);
+ return ret;
+ }
- memset(strm, 0, sizeof(*strm));
+ /* There are no dependent requests, but we need to remove our request
+ * from the list of in-flight requests */
+ run_dependent_requests(&meta);
- strm->next_in = (uint8_t *)buf;
- strm->avail_in = buf_size;
- strm->next_out = out_buf;
- strm->avail_out = out_buf_size;
+ /* TODO Preallocate data if requested */
- ret = inflateInit2(strm, -12);
- if (ret != Z_OK)
- return -1;
- ret = inflate(strm, Z_FINISH);
- out_len = strm->next_out - out_buf;
- if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
- out_len != out_buf_size) {
- inflateEnd(strm);
- return -1;
+ nb_sectors -= num;
+ offset += num << 9;
}
- inflateEnd(strm);
- return 0;
-}
-static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset)
-{
- int ret, csize, nb_csectors, sector_offset;
- uint64_t coffset;
-
- coffset = cluster_offset & s->cluster_offset_mask;
- if (s->cluster_cache_offset != coffset) {
- nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
- sector_offset = coffset & 511;
- csize = nb_csectors * 512 - sector_offset;
- ret = bdrv_read(s->hd, coffset >> 9, s->cluster_data, nb_csectors);
+ /*
+ * It is expected that the image file is large enough to actually contain
+ * all of the allocated clusters (otherwise we get failing reads after
+ * EOF). Extend the image to the last allocated sector.
+ */
+ if (meta.cluster_offset != 0) {
+ uint8_t buf[512];
+ memset(buf, 0, 512);
+ ret = bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1);
if (ret < 0) {
- return -1;
- }
- if (decompress_buffer(s->cluster_cache, s->cluster_size,
- s->cluster_data + sector_offset, csize) < 0) {
- return -1;
+ return ret;
}
- s->cluster_cache_offset = coffset;
}
+
return 0;
}
-/* handle reading after the end of the backing file */
-static int backing_read1(BlockDriverState *bs,
- int64_t sector_num, uint8_t *buf, int nb_sectors)
+static int qcow_create2(const char *filename, int64_t total_size,
+ const char *backing_file, const char *backing_format,
+ int flags, size_t cluster_size, int prealloc)
{
- int n1;
- if ((sector_num + nb_sectors) <= bs->total_sectors)
- return nb_sectors;
- if (sector_num >= bs->total_sectors)
- n1 = 0;
- else
- n1 = bs->total_sectors - sector_num;
- memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1));
- return n1;
-}
-static int qcow_read(BlockDriverState *bs, int64_t sector_num,
- uint8_t *buf, int nb_sectors)
-{
- BDRVQcowState *s = bs->opaque;
- int ret, index_in_cluster, n, n1;
- uint64_t cluster_offset;
+ int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
+ int ref_clusters, reftable_clusters, backing_format_len = 0;
+ int rounded_ext_bf_len = 0;
+ QCowHeader header;
+ uint64_t tmp, offset;
+ uint64_t old_ref_clusters;
+ QCowCreateState s1, *s = &s1;
+ QCowExtension ext_bf = {0, 0};
+ int ret;
- while (nb_sectors > 0) {
- n = nb_sectors;
- cluster_offset = get_cluster_offset(bs, sector_num << 9, &n);
- index_in_cluster = sector_num & (s->cluster_sectors - 1);
- if (!cluster_offset) {
- if (bs->backing_hd) {
- /* read from the base image */
- n1 = backing_read1(bs->backing_hd, sector_num, buf, n);
- if (n1 > 0) {
- ret = bdrv_read(bs->backing_hd, sector_num, buf, n1);
- if (ret < 0)
- return -1;
- }
- } else {
- memset(buf, 0, 512 * n);
- }
- } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
- if (decompress_cluster(s, cluster_offset) < 0)
- return -1;
- memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n);
- } else {
- ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512);
- if (ret != n * 512)
- return -1;
- if (s->crypt_method) {
- encrypt_sectors(s, sector_num, buf, buf, n, 0,
- &s->aes_decrypt_key);
- }
+ memset(s, 0, sizeof(*s));
+
+ fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
+ if (fd < 0)
+ return -errno;
+ memset(&header, 0, sizeof(header));
+ header.magic = cpu_to_be32(QCOW_MAGIC);
+ header.version = cpu_to_be32(QCOW_VERSION);
+ header.size = cpu_to_be64(total_size * 512);
+ header_size = sizeof(header);
+ backing_filename_len = 0;
+ if (backing_file) {
+ if (backing_format) {
+ ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT;
+ backing_format_len = strlen(backing_format);
+ ext_bf.len = backing_format_len;
+ rounded_ext_bf_len = (sizeof(ext_bf) + ext_bf.len + 7) & ~7;
+ header_size += rounded_ext_bf_len;
}
- nb_sectors -= n;
- sector_num += n;
- buf += n * 512;
+ header.backing_file_offset = cpu_to_be64(header_size);
+ backing_filename_len = strlen(backing_file);
+ header.backing_file_size = cpu_to_be32(backing_filename_len);
+ header_size += backing_filename_len;
}
- return 0;
-}
-typedef struct QCowAIOCB {
- BlockDriverAIOCB common;
- int64_t sector_num;
- QEMUIOVector *qiov;
- uint8_t *buf;
- void *orig_buf;
- int nb_sectors;
- int n;
- uint64_t cluster_offset;
- uint8_t *cluster_data;
- BlockDriverAIOCB *hd_aiocb;
- struct iovec hd_iov;
- QEMUIOVector hd_qiov;
- QEMUBH *bh;
- QCowL2Meta l2meta;
-} QCowAIOCB;
-
-static void qcow_aio_read_cb(void *opaque, int ret);
-static void qcow_aio_read_bh(void *opaque)
-{
- QCowAIOCB *acb = opaque;
- qemu_bh_delete(acb->bh);
- acb->bh = NULL;
- qcow_aio_read_cb(opaque, 0);
-}
-
-static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb)
-{
- if (acb->bh)
- return -EIO;
-
- acb->bh = qemu_bh_new(cb, acb);
- if (!acb->bh)
- return -EIO;
-
- qemu_bh_schedule(acb->bh);
-
- return 0;
-}
-
-static void qcow_aio_read_cb(void *opaque, int ret)
-{
- QCowAIOCB *acb = opaque;
- BlockDriverState *bs = acb->common.bs;
- BDRVQcowState *s = bs->opaque;
- int index_in_cluster, n1;
-
- acb->hd_aiocb = NULL;
- if (ret < 0)
- goto done;
-
- /* post process the read buffer */
- if (!acb->cluster_offset) {
- /* nothing to do */
- } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
- /* nothing to do */
- } else {
- if (s->crypt_method) {
- encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
- acb->n, 0,
- &s->aes_decrypt_key);
- }
- }
-
- acb->nb_sectors -= acb->n;
- acb->sector_num += acb->n;
- acb->buf += acb->n * 512;
-
- if (acb->nb_sectors == 0) {
- /* request completed */
- ret = 0;
- goto done;
- }
-
- /* prepare next AIO request */
- acb->n = acb->nb_sectors;
- acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, &acb->n);
- index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
-
- if (!acb->cluster_offset) {
- if (bs->backing_hd) {
- /* read from the base image */
- n1 = backing_read1(bs->backing_hd, acb->sector_num,
- acb->buf, acb->n);
- if (n1 > 0) {
- acb->hd_iov.iov_base = (void *)acb->buf;
- acb->hd_iov.iov_len = acb->n * 512;
- qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
- acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
- &acb->hd_qiov, acb->n,
- qcow_aio_read_cb, acb);
- if (acb->hd_aiocb == NULL)
- goto done;
- } else {
- ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
- if (ret < 0)
- goto done;
- }
- } else {
- /* Note: in this case, no need to wait */
- memset(acb->buf, 0, 512 * acb->n);
- ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
- if (ret < 0)
- goto done;
- }
- } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
- /* add AIO support for compressed blocks ? */
- if (decompress_cluster(s, acb->cluster_offset) < 0)
- goto done;
- memcpy(acb->buf,
- s->cluster_cache + index_in_cluster * 512, 512 * acb->n);
- ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
- if (ret < 0)
- goto done;
- } else {
- if ((acb->cluster_offset & 511) != 0) {
- ret = -EIO;
- goto done;
- }
-
- acb->hd_iov.iov_base = (void *)acb->buf;
- acb->hd_iov.iov_len = acb->n * 512;
- qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
- acb->hd_aiocb = bdrv_aio_readv(s->hd,
- (acb->cluster_offset >> 9) + index_in_cluster,
- &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
- if (acb->hd_aiocb == NULL)
- goto done;
- }
-
- return;
-done:
- if (acb->qiov->niov > 1) {
- qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
- qemu_vfree(acb->orig_buf);
- }
- acb->common.cb(acb->common.opaque, ret);
- qemu_aio_release(acb);
-}
-
-static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockDriverCompletionFunc *cb, void *opaque, int is_write)
-{
- QCowAIOCB *acb;
-
- acb = qemu_aio_get(bs, cb, opaque);
- if (!acb)
- return NULL;
- acb->hd_aiocb = NULL;
- acb->sector_num = sector_num;
- acb->qiov = qiov;
- if (qiov->niov > 1) {
- acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
- if (is_write)
- qemu_iovec_to_buffer(qiov, acb->buf);
- } else {
- acb->buf = (uint8_t *)qiov->iov->iov_base;
- }
- acb->nb_sectors = nb_sectors;
- acb->n = 0;
- acb->cluster_offset = 0;
- acb->l2meta.nb_clusters = 0;
- return acb;
-}
-
-static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockDriverCompletionFunc *cb, void *opaque)
-{
- QCowAIOCB *acb;
-
- acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
- if (!acb)
- return NULL;
-
- qcow_aio_read_cb(acb, 0);
- return &acb->common;
-}
-
-static void qcow_aio_write_cb(void *opaque, int ret)
-{
- QCowAIOCB *acb = opaque;
- BlockDriverState *bs = acb->common.bs;
- BDRVQcowState *s = bs->opaque;
- int index_in_cluster;
- const uint8_t *src_buf;
- int n_end;
-
- acb->hd_aiocb = NULL;
-
- if (ret < 0)
- goto done;
-
- if (alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta) < 0) {
- free_any_clusters(bs, acb->cluster_offset, acb->l2meta.nb_clusters);
- goto done;
- }
-
- acb->nb_sectors -= acb->n;
- acb->sector_num += acb->n;
- acb->buf += acb->n * 512;
-
- if (acb->nb_sectors == 0) {
- /* request completed */
- ret = 0;
- goto done;
- }
-
- index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
- n_end = index_in_cluster + acb->nb_sectors;
- if (s->crypt_method &&
- n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors)
- n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
-
- acb->cluster_offset = alloc_cluster_offset(bs, acb->sector_num << 9,
- index_in_cluster,
- n_end, &acb->n, &acb->l2meta);
- if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) {
- ret = -EIO;
- goto done;
- }
- if (s->crypt_method) {
- if (!acb->cluster_data) {
- acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS *
- s->cluster_size);
- }
- encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
- acb->n, 1, &s->aes_encrypt_key);
- src_buf = acb->cluster_data;
- } else {
- src_buf = acb->buf;
- }
- acb->hd_iov.iov_base = (void *)src_buf;
- acb->hd_iov.iov_len = acb->n * 512;
- qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
- acb->hd_aiocb = bdrv_aio_writev(s->hd,
- (acb->cluster_offset >> 9) + index_in_cluster,
- &acb->hd_qiov, acb->n,
- qcow_aio_write_cb, acb);
- if (acb->hd_aiocb == NULL)
- goto done;
-
- return;
-
-done:
- if (acb->qiov->niov > 1)
- qemu_vfree(acb->orig_buf);
- acb->common.cb(acb->common.opaque, ret);
- qemu_aio_release(acb);
-}
-
-static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
- int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
- BlockDriverCompletionFunc *cb, void *opaque)
-{
- BDRVQcowState *s = bs->opaque;
- QCowAIOCB *acb;
-
- s->cluster_cache_offset = -1; /* disable compressed cache */
-
- acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
- if (!acb)
- return NULL;
-
- qcow_aio_write_cb(acb, 0);
- return &acb->common;
-}
-
-static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
-{
- QCowAIOCB *acb = (QCowAIOCB *)blockacb;
- if (acb->hd_aiocb)
- bdrv_aio_cancel(acb->hd_aiocb);
- qemu_aio_release(acb);
-}
-
-static void qcow_close(BlockDriverState *bs)
-{
- BDRVQcowState *s = bs->opaque;
- qemu_free(s->l1_table);
- qemu_free(s->l2_cache);
- qemu_free(s->cluster_cache);
- qemu_free(s->cluster_data);
- refcount_close(bs);
- bdrv_delete(s->hd);
-}
-
-/* XXX: use std qcow open function ? */
-typedef struct QCowCreateState {
- int cluster_size;
- int cluster_bits;
- uint16_t *refcount_block;
- uint64_t *refcount_table;
- int64_t l1_table_offset;
- int64_t refcount_table_offset;
- int64_t refcount_block_offset;
-} QCowCreateState;
-
-static void create_refcount_update(QCowCreateState *s,
- int64_t offset, int64_t size)
-{
- int refcount;
- int64_t start, last, cluster_offset;
- uint16_t *p;
-
- start = offset & ~(s->cluster_size - 1);
- last = (offset + size - 1) & ~(s->cluster_size - 1);
- for(cluster_offset = start; cluster_offset <= last;
- cluster_offset += s->cluster_size) {
- p = &s->refcount_block[cluster_offset >> s->cluster_bits];
- refcount = be16_to_cpu(*p);
- refcount++;
- *p = cpu_to_be16(refcount);
- }
-}
-
-static int get_bits_from_size(size_t size)
-{
- int res = 0;
-
- if (size == 0) {
- return -1;
- }
-
- while (size != 1) {
- /* Not a power of two */
- if (size & 1) {
- return -1;
- }
-
- size >>= 1;
- res++;
- }
-
- return res;
-}
-
-static int qcow_create2(const char *filename, int64_t total_size,
- const char *backing_file, const char *backing_format,
- int flags, size_t cluster_size)
-{
-
- int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
- int ref_clusters, backing_format_len = 0;
- QCowHeader header;
- uint64_t tmp, offset;
- QCowCreateState s1, *s = &s1;
- QCowExtension ext_bf = {0, 0};
-
-
- memset(s, 0, sizeof(*s));
-
- fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
- if (fd < 0)
- return -1;
- memset(&header, 0, sizeof(header));
- header.magic = cpu_to_be32(QCOW_MAGIC);
- header.version = cpu_to_be32(QCOW_VERSION);
- header.size = cpu_to_be64(total_size * 512);
- header_size = sizeof(header);
- backing_filename_len = 0;
- if (backing_file) {
- if (backing_format) {
- ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT;
- backing_format_len = strlen(backing_format);
- ext_bf.len = (backing_format_len + 7) & ~7;
- header_size += ((sizeof(ext_bf) + ext_bf.len + 7) & ~7);
- }
- header.backing_file_offset = cpu_to_be64(header_size);
- backing_filename_len = strlen(backing_file);
- header.backing_file_size = cpu_to_be32(backing_filename_len);
- header_size += backing_filename_len;
- }
-
- /* Cluster size */
- s->cluster_bits = get_bits_from_size(cluster_size);
- if (s->cluster_bits < MIN_CLUSTER_BITS ||
- s->cluster_bits > MAX_CLUSTER_BITS)
- {
- fprintf(stderr, "Cluster size must be a power of two between "
- "%d and %dk\n",
- 1 << MIN_CLUSTER_BITS,
- 1 << (MAX_CLUSTER_BITS - 10));
- return -EINVAL;
- }
- s->cluster_size = 1 << s->cluster_bits;
-
- header.cluster_bits = cpu_to_be32(s->cluster_bits);
- header_size = (header_size + 7) & ~7;
- if (flags & BLOCK_FLAG_ENCRYPT) {
- header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
- } else {
- header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
- }
- l2_bits = s->cluster_bits - 3;
- shift = s->cluster_bits + l2_bits;
- l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift);
- offset = align_offset(header_size, s->cluster_size);
- s->l1_table_offset = offset;
- header.l1_table_offset = cpu_to_be64(s->l1_table_offset);
- header.l1_size = cpu_to_be32(l1_size);
- offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
-
- s->refcount_table = qemu_mallocz(s->cluster_size);
-
- s->refcount_table_offset = offset;
- header.refcount_table_offset = cpu_to_be64(offset);
- header.refcount_table_clusters = cpu_to_be32(1);
- offset += s->cluster_size;
- s->refcount_block_offset = offset;
-
- /* count how many refcount blocks needed */
- tmp = offset >> s->cluster_bits;
- ref_clusters = (tmp >> (s->cluster_bits - REFCOUNT_SHIFT)) + 1;
- for (i=0; i < ref_clusters; i++) {
- s->refcount_table[i] = cpu_to_be64(offset);
- offset += s->cluster_size;
- }
-
- s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size);
-
- /* update refcounts */
- create_refcount_update(s, 0, header_size);
- create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t));
- create_refcount_update(s, s->refcount_table_offset, s->cluster_size);
- create_refcount_update(s, s->refcount_block_offset, ref_clusters * s->cluster_size);
-
- /* write all the data */
- write(fd, &header, sizeof(header));
- if (backing_file) {
- if (backing_format_len) {
- char zero[16];
- int d = ext_bf.len - backing_format_len;
-
- memset(zero, 0, sizeof(zero));
- cpu_to_be32s(&ext_bf.magic);
- cpu_to_be32s(&ext_bf.len);
- write(fd, &ext_bf, sizeof(ext_bf));
- write(fd, backing_format, backing_format_len);
- if (d>0) {
- write(fd, zero, d);
- }
- }
- write(fd, backing_file, backing_filename_len);
- }
- lseek(fd, s->l1_table_offset, SEEK_SET);
- tmp = 0;
- for(i = 0;i < l1_size; i++) {
- write(fd, &tmp, sizeof(tmp));
- }
- lseek(fd, s->refcount_table_offset, SEEK_SET);
- write(fd, s->refcount_table, s->cluster_size);
-
- lseek(fd, s->refcount_block_offset, SEEK_SET);
- write(fd, s->refcount_block, ref_clusters * s->cluster_size);
-
- qemu_free(s->refcount_table);
- qemu_free(s->refcount_block);
- close(fd);
- return 0;
-}
-
-static int qcow_create(const char *filename, QEMUOptionParameter *options)
-{
- const char *backing_file = NULL;
- const char *backing_fmt = NULL;
- uint64_t sectors = 0;
- int flags = 0;
- size_t cluster_size = 4096;
-
- /* Read out options */
- while (options && options->name) {
- if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
- sectors = options->value.n / 512;
- } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
- backing_file = options->value.s;
- } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) {
- backing_fmt = options->value.s;
- } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
- flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
- } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
- if (options->value.n) {
- cluster_size = options->value.n;
- }
- }
- options++;
- }
-
- return qcow_create2(filename, sectors, backing_file, backing_fmt, flags,
- cluster_size);
-}
-
-static int qcow_make_empty(BlockDriverState *bs)
-{
-#if 0
- /* XXX: not correct */
- BDRVQcowState *s = bs->opaque;
- uint32_t l1_length = s->l1_size * sizeof(uint64_t);
- int ret;
-
- memset(s->l1_table, 0, l1_length);
- if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0)
- return -1;
- ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length);
- if (ret < 0)
- return ret;
-
- l2_cache_reset(bs);
-#endif
- return 0;
-}
-
-/* XXX: put compressed sectors first, then all the cluster aligned
- tables to avoid losing bytes in alignment */
-static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
- const uint8_t *buf, int nb_sectors)
-{
- BDRVQcowState *s = bs->opaque;
- z_stream strm;
- int ret, out_len;
- uint8_t *out_buf;
- uint64_t cluster_offset;
-
- if (nb_sectors == 0) {
- /* align end of file to a sector boundary to ease reading with
- sector based I/Os */
- cluster_offset = bdrv_getlength(s->hd);
- cluster_offset = (cluster_offset + 511) & ~511;
- bdrv_truncate(s->hd, cluster_offset);
- return 0;
- }
-
- if (nb_sectors != s->cluster_sectors)
+ /* Cluster size */
+ s->cluster_bits = get_bits_from_size(cluster_size);
+ if (s->cluster_bits < MIN_CLUSTER_BITS ||
+ s->cluster_bits > MAX_CLUSTER_BITS)
+ {
+ fprintf(stderr, "Cluster size must be a power of two between "
+ "%d and %dk\n",
+ 1 << MIN_CLUSTER_BITS,
+ 1 << (MAX_CLUSTER_BITS - 10));
return -EINVAL;
-
- out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
-
- /* best compression, small window, no zlib header */
- memset(&strm, 0, sizeof(strm));
- ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
- Z_DEFLATED, -12,
- 9, Z_DEFAULT_STRATEGY);
- if (ret != 0) {
- qemu_free(out_buf);
- return -1;
- }
-
- strm.avail_in = s->cluster_size;
- strm.next_in = (uint8_t *)buf;
- strm.avail_out = s->cluster_size;
- strm.next_out = out_buf;
-
- ret = deflate(&strm, Z_FINISH);
- if (ret != Z_STREAM_END && ret != Z_OK) {
- qemu_free(out_buf);
- deflateEnd(&strm);
- return -1;
- }
- out_len = strm.next_out - out_buf;
-
- deflateEnd(&strm);
-
- if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
- /* could not compress: write normal cluster */
- bdrv_write(bs, sector_num, buf, s->cluster_sectors);
- } else {
- cluster_offset = alloc_compressed_cluster_offset(bs, sector_num << 9,
- out_len);
- if (!cluster_offset)
- return -1;
- cluster_offset &= s->cluster_offset_mask;
- if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
- qemu_free(out_buf);
- return -1;
- }
}
+ s->cluster_size = 1 << s->cluster_bits;
- qemu_free(out_buf);
- return 0;
-}
-
-static void qcow_flush(BlockDriverState *bs)
-{
- BDRVQcowState *s = bs->opaque;
- bdrv_flush(s->hd);
-}
-
-static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
-{
- BDRVQcowState *s = bs->opaque;
- bdi->cluster_size = s->cluster_size;
- bdi->vm_state_offset = (int64_t)s->l1_vm_state_index <<
- (s->cluster_bits + s->l2_bits);
- return 0;
-}
-
-/*********************************************************/
-/* snapshot support */
-
-/* update the refcounts of snapshots and the copied flag */
-static int update_snapshot_refcount(BlockDriverState *bs,
- int64_t l1_table_offset,
- int l1_size,
- int addend)
-{
- BDRVQcowState *s = bs->opaque;
- uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated;
- int64_t old_offset, old_l2_offset;
- int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount;
-
- l2_cache_reset(bs);
-
- l2_table = NULL;
- l1_table = NULL;
- l1_size2 = l1_size * sizeof(uint64_t);
- l1_allocated = 0;
- if (l1_table_offset != s->l1_table_offset) {
- l1_table = qemu_malloc(l1_size2);
- l1_allocated = 1;
- if (bdrv_pread(s->hd, l1_table_offset,
- l1_table, l1_size2) != l1_size2)
- goto fail;
- for(i = 0;i < l1_size; i++)
- be64_to_cpus(&l1_table[i]);
+ header.cluster_bits = cpu_to_be32(s->cluster_bits);
+ header_size = (header_size + 7) & ~7;
+ if (flags & BLOCK_FLAG_ENCRYPT) {
+ header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
} else {
- assert(l1_size == s->l1_size);
- l1_table = s->l1_table;
- l1_allocated = 0;
- }
-
- l2_size = s->l2_size * sizeof(uint64_t);
- l2_table = qemu_malloc(l2_size);
- l1_modified = 0;
- for(i = 0; i < l1_size; i++) {
- l2_offset = l1_table[i];
- if (l2_offset) {
- old_l2_offset = l2_offset;
- l2_offset &= ~QCOW_OFLAG_COPIED;
- l2_modified = 0;
- if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
- goto fail;
- for(j = 0; j < s->l2_size; j++) {
- offset = be64_to_cpu(l2_table[j]);
- if (offset != 0) {
- old_offset = offset;
- offset &= ~QCOW_OFLAG_COPIED;
- if (offset & QCOW_OFLAG_COMPRESSED) {
- nb_csectors = ((offset >> s->csize_shift) &
- s->csize_mask) + 1;
- if (addend != 0)
- update_refcount(bs, (offset & s->cluster_offset_mask) & ~511,
- nb_csectors * 512, addend);
- /* compressed clusters are never modified */
- refcount = 2;
- } else {
- if (addend != 0) {
- refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend);
- } else {
- refcount = get_refcount(bs, offset >> s->cluster_bits);
- }
- }
-
- if (refcount == 1) {
- offset |= QCOW_OFLAG_COPIED;
- }
- if (offset != old_offset) {
- l2_table[j] = cpu_to_be64(offset);
- l2_modified = 1;
- }
- }
- }
- if (l2_modified) {
- if (bdrv_pwrite(s->hd,
- l2_offset, l2_table, l2_size) != l2_size)
- goto fail;
- }
-
- if (addend != 0) {
- refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend);
- } else {
- refcount = get_refcount(bs, l2_offset >> s->cluster_bits);
- }
- if (refcount == 1) {
- l2_offset |= QCOW_OFLAG_COPIED;
- }
- if (l2_offset != old_l2_offset) {
- l1_table[i] = l2_offset;
- l1_modified = 1;
- }
- }
- }
- if (l1_modified) {
- for(i = 0; i < l1_size; i++)
- cpu_to_be64s(&l1_table[i]);
- if (bdrv_pwrite(s->hd, l1_table_offset, l1_table,
- l1_size2) != l1_size2)
- goto fail;
- for(i = 0; i < l1_size; i++)
- be64_to_cpus(&l1_table[i]);
- }
- if (l1_allocated)
- qemu_free(l1_table);
- qemu_free(l2_table);
- return 0;
- fail:
- if (l1_allocated)
- qemu_free(l1_table);
- qemu_free(l2_table);
- return -EIO;
-}
-
-static void qcow_free_snapshots(BlockDriverState *bs)
-{
- BDRVQcowState *s = bs->opaque;
- int i;
-
- for(i = 0; i < s->nb_snapshots; i++) {
- qemu_free(s->snapshots[i].name);
- qemu_free(s->snapshots[i].id_str);
- }
- qemu_free(s->snapshots);
- s->snapshots = NULL;
- s->nb_snapshots = 0;
-}
-
-static int qcow_read_snapshots(BlockDriverState *bs)
-{
- BDRVQcowState *s = bs->opaque;
- QCowSnapshotHeader h;
- QCowSnapshot *sn;
- int i, id_str_size, name_size;
- int64_t offset;
- uint32_t extra_data_size;
-
- if (!s->nb_snapshots) {
- s->snapshots = NULL;
- s->snapshots_size = 0;
- return 0;
- }
-
- offset = s->snapshots_offset;
- s->snapshots = qemu_mallocz(s->nb_snapshots * sizeof(QCowSnapshot));
- for(i = 0; i < s->nb_snapshots; i++) {
- offset = align_offset(offset, 8);
- if (bdrv_pread(s->hd, offset, &h, sizeof(h)) != sizeof(h))
- goto fail;
- offset += sizeof(h);
- sn = s->snapshots + i;
- sn->l1_table_offset = be64_to_cpu(h.l1_table_offset);
- sn->l1_size = be32_to_cpu(h.l1_size);
- sn->vm_state_size = be32_to_cpu(h.vm_state_size);
- sn->date_sec = be32_to_cpu(h.date_sec);
- sn->date_nsec = be32_to_cpu(h.date_nsec);
- sn->vm_clock_nsec = be64_to_cpu(h.vm_clock_nsec);
- extra_data_size = be32_to_cpu(h.extra_data_size);
-
- id_str_size = be16_to_cpu(h.id_str_size);
- name_size = be16_to_cpu(h.name_size);
-
- offset += extra_data_size;
-
- sn->id_str = qemu_malloc(id_str_size + 1);
- if (bdrv_pread(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
- goto fail;
- offset += id_str_size;
- sn->id_str[id_str_size] = '\0';
-
- sn->name = qemu_malloc(name_size + 1);
- if (bdrv_pread(s->hd, offset, sn->name, name_size) != name_size)
- goto fail;
- offset += name_size;
- sn->name[name_size] = '\0';
- }
- s->snapshots_size = offset - s->snapshots_offset;
- return 0;
- fail:
- qcow_free_snapshots(bs);
- return -1;
-}
-
-/* add at the end of the file a new list of snapshots */
-static int qcow_write_snapshots(BlockDriverState *bs)
-{
- BDRVQcowState *s = bs->opaque;
- QCowSnapshot *sn;
- QCowSnapshotHeader h;
- int i, name_size, id_str_size, snapshots_size;
- uint64_t data64;
- uint32_t data32;
- int64_t offset, snapshots_offset;
-
- /* compute the size of the snapshots */
- offset = 0;
- for(i = 0; i < s->nb_snapshots; i++) {
- sn = s->snapshots + i;
- offset = align_offset(offset, 8);
- offset += sizeof(h);
- offset += strlen(sn->id_str);
- offset += strlen(sn->name);
- }
- snapshots_size = offset;
-
- snapshots_offset = alloc_clusters(bs, snapshots_size);
- offset = snapshots_offset;
-
- for(i = 0; i < s->nb_snapshots; i++) {
- sn = s->snapshots + i;
- memset(&h, 0, sizeof(h));
- h.l1_table_offset = cpu_to_be64(sn->l1_table_offset);
- h.l1_size = cpu_to_be32(sn->l1_size);
- h.vm_state_size = cpu_to_be32(sn->vm_state_size);
- h.date_sec = cpu_to_be32(sn->date_sec);
- h.date_nsec = cpu_to_be32(sn->date_nsec);
- h.vm_clock_nsec = cpu_to_be64(sn->vm_clock_nsec);
-
- id_str_size = strlen(sn->id_str);
- name_size = strlen(sn->name);
- h.id_str_size = cpu_to_be16(id_str_size);
- h.name_size = cpu_to_be16(name_size);
- offset = align_offset(offset, 8);
- if (bdrv_pwrite(s->hd, offset, &h, sizeof(h)) != sizeof(h))
- goto fail;
- offset += sizeof(h);
- if (bdrv_pwrite(s->hd, offset, sn->id_str, id_str_size) != id_str_size)
- goto fail;
- offset += id_str_size;
- if (bdrv_pwrite(s->hd, offset, sn->name, name_size) != name_size)
- goto fail;
- offset += name_size;
- }
-
- /* update the various header fields */
- data64 = cpu_to_be64(snapshots_offset);
- if (bdrv_pwrite(s->hd, offsetof(QCowHeader, snapshots_offset),
- &data64, sizeof(data64)) != sizeof(data64))
- goto fail;
- data32 = cpu_to_be32(s->nb_snapshots);
- if (bdrv_pwrite(s->hd, offsetof(QCowHeader, nb_snapshots),
- &data32, sizeof(data32)) != sizeof(data32))
- goto fail;
-
- /* free the old snapshot table */
- free_clusters(bs, s->snapshots_offset, s->snapshots_size);
- s->snapshots_offset = snapshots_offset;
- s->snapshots_size = snapshots_size;
- return 0;
- fail:
- return -1;
-}
-
-static void find_new_snapshot_id(BlockDriverState *bs,
- char *id_str, int id_str_size)
-{
- BDRVQcowState *s = bs->opaque;
- QCowSnapshot *sn;
- int i, id, id_max = 0;
-
- for(i = 0; i < s->nb_snapshots; i++) {
- sn = s->snapshots + i;
- id = strtoul(sn->id_str, NULL, 10);
- if (id > id_max)
- id_max = id;
- }
- snprintf(id_str, id_str_size, "%d", id_max + 1);
-}
-
-static int find_snapshot_by_id(BlockDriverState *bs, const char *id_str)
-{
- BDRVQcowState *s = bs->opaque;
- int i;
-
- for(i = 0; i < s->nb_snapshots; i++) {
- if (!strcmp(s->snapshots[i].id_str, id_str))
- return i;
- }
- return -1;
-}
-
-static int find_snapshot_by_id_or_name(BlockDriverState *bs, const char *name)
-{
- BDRVQcowState *s = bs->opaque;
- int i, ret;
-
- ret = find_snapshot_by_id(bs, name);
- if (ret >= 0)
- return ret;
- for(i = 0; i < s->nb_snapshots; i++) {
- if (!strcmp(s->snapshots[i].name, name))
- return i;
- }
- return -1;
-}
-
-/* if no id is provided, a new one is constructed */
-static int qcow_snapshot_create(BlockDriverState *bs,
- QEMUSnapshotInfo *sn_info)
-{
- BDRVQcowState *s = bs->opaque;
- QCowSnapshot *snapshots1, sn1, *sn = &sn1;
- int i, ret;
- uint64_t *l1_table = NULL;
-
- memset(sn, 0, sizeof(*sn));
-
- if (sn_info->id_str[0] == '\0') {
- /* compute a new id */
- find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
- }
-
- /* check that the ID is unique */
- if (find_snapshot_by_id(bs, sn_info->id_str) >= 0)
- return -ENOENT;
-
- sn->id_str = qemu_strdup(sn_info->id_str);
- if (!sn->id_str)
- goto fail;
- sn->name = qemu_strdup(sn_info->name);
- if (!sn->name)
- goto fail;
- sn->vm_state_size = sn_info->vm_state_size;
- sn->date_sec = sn_info->date_sec;
- sn->date_nsec = sn_info->date_nsec;
- sn->vm_clock_nsec = sn_info->vm_clock_nsec;
-
- ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1);
- if (ret < 0)
- goto fail;
-
- /* create the L1 table of the snapshot */
- sn->l1_table_offset = alloc_clusters(bs, s->l1_size * sizeof(uint64_t));
- sn->l1_size = s->l1_size;
-
- l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
- for(i = 0; i < s->l1_size; i++) {
- l1_table[i] = cpu_to_be64(s->l1_table[i]);
- }
- if (bdrv_pwrite(s->hd, sn->l1_table_offset,
- l1_table, s->l1_size * sizeof(uint64_t)) !=
- (s->l1_size * sizeof(uint64_t)))
- goto fail;
- qemu_free(l1_table);
- l1_table = NULL;
-
- snapshots1 = qemu_malloc((s->nb_snapshots + 1) * sizeof(QCowSnapshot));
- if (s->snapshots) {
- memcpy(snapshots1, s->snapshots, s->nb_snapshots * sizeof(QCowSnapshot));
- qemu_free(s->snapshots);
- }
- s->snapshots = snapshots1;
- s->snapshots[s->nb_snapshots++] = *sn;
-
- if (qcow_write_snapshots(bs) < 0)
- goto fail;
-#ifdef DEBUG_ALLOC
- check_refcounts(bs);
-#endif
- return 0;
- fail:
- qemu_free(sn->name);
- qemu_free(l1_table);
- return -1;
-}
-
-/* copy the snapshot 'snapshot_name' into the current disk image */
-static int qcow_snapshot_goto(BlockDriverState *bs,
- const char *snapshot_id)
-{
- BDRVQcowState *s = bs->opaque;
- QCowSnapshot *sn;
- int i, snapshot_index, l1_size2;
-
- snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
- if (snapshot_index < 0)
- return -ENOENT;
- sn = &s->snapshots[snapshot_index];
-
- if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, -1) < 0)
- goto fail;
-
- if (grow_l1_table(bs, sn->l1_size) < 0)
- goto fail;
-
- s->l1_size = sn->l1_size;
- l1_size2 = s->l1_size * sizeof(uint64_t);
- /* copy the snapshot l1 table to the current l1 table */
- if (bdrv_pread(s->hd, sn->l1_table_offset,
- s->l1_table, l1_size2) != l1_size2)
- goto fail;
- if (bdrv_pwrite(s->hd, s->l1_table_offset,
- s->l1_table, l1_size2) != l1_size2)
- goto fail;
- for(i = 0;i < s->l1_size; i++) {
- be64_to_cpus(&s->l1_table[i]);
- }
-
- if (update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 1) < 0)
- goto fail;
-
-#ifdef DEBUG_ALLOC
- check_refcounts(bs);
-#endif
- return 0;
- fail:
- return -EIO;
-}
-
-static int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
-{
- BDRVQcowState *s = bs->opaque;
- QCowSnapshot *sn;
- int snapshot_index, ret;
-
- snapshot_index = find_snapshot_by_id_or_name(bs, snapshot_id);
- if (snapshot_index < 0)
- return -ENOENT;
- sn = &s->snapshots[snapshot_index];
-
- ret = update_snapshot_refcount(bs, sn->l1_table_offset, sn->l1_size, -1);
- if (ret < 0)
- return ret;
- /* must update the copied flag on the current cluster offsets */
- ret = update_snapshot_refcount(bs, s->l1_table_offset, s->l1_size, 0);
- if (ret < 0)
- return ret;
- free_clusters(bs, sn->l1_table_offset, sn->l1_size * sizeof(uint64_t));
-
- qemu_free(sn->id_str);
- qemu_free(sn->name);
- memmove(sn, sn + 1, (s->nb_snapshots - snapshot_index - 1) * sizeof(*sn));
- s->nb_snapshots--;
- ret = qcow_write_snapshots(bs);
- if (ret < 0) {
- /* XXX: restore snapshot if error ? */
- return ret;
- }
-#ifdef DEBUG_ALLOC
- check_refcounts(bs);
-#endif
- return 0;
-}
-
-static int qcow_snapshot_list(BlockDriverState *bs,
- QEMUSnapshotInfo **psn_tab)
-{
- BDRVQcowState *s = bs->opaque;
- QEMUSnapshotInfo *sn_tab, *sn_info;
- QCowSnapshot *sn;
- int i;
-
- if (!s->nb_snapshots) {
- *psn_tab = NULL;
- return s->nb_snapshots;
- }
-
- sn_tab = qemu_mallocz(s->nb_snapshots * sizeof(QEMUSnapshotInfo));
- for(i = 0; i < s->nb_snapshots; i++) {
- sn_info = sn_tab + i;
- sn = s->snapshots + i;
- pstrcpy(sn_info->id_str, sizeof(sn_info->id_str),
- sn->id_str);
- pstrcpy(sn_info->name, sizeof(sn_info->name),
- sn->name);
- sn_info->vm_state_size = sn->vm_state_size;
- sn_info->date_sec = sn->date_sec;
- sn_info->date_nsec = sn->date_nsec;
- sn_info->vm_clock_nsec = sn->vm_clock_nsec;
- }
- *psn_tab = sn_tab;
- return s->nb_snapshots;
-}
-
-/*********************************************************/
-/* refcount handling */
-
-static int refcount_init(BlockDriverState *bs)
-{
- BDRVQcowState *s = bs->opaque;
- int ret, refcount_table_size2, i;
-
- s->refcount_block_cache = qemu_malloc(s->cluster_size);
- refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
- s->refcount_table = qemu_malloc(refcount_table_size2);
- if (s->refcount_table_size > 0) {
- ret = bdrv_pread(s->hd, s->refcount_table_offset,
- s->refcount_table, refcount_table_size2);
- if (ret != refcount_table_size2)
- goto fail;
- for(i = 0; i < s->refcount_table_size; i++)
- be64_to_cpus(&s->refcount_table[i]);
+ header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
}
- return 0;
- fail:
- return -ENOMEM;
-}
+ l2_bits = s->cluster_bits - 3;
+ shift = s->cluster_bits + l2_bits;
+ l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift);
+ offset = align_offset(header_size, s->cluster_size);
+ s->l1_table_offset = offset;
+ header.l1_table_offset = cpu_to_be64(s->l1_table_offset);
+ header.l1_size = cpu_to_be32(l1_size);
+ offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
-static void refcount_close(BlockDriverState *bs)
-{
- BDRVQcowState *s = bs->opaque;
- qemu_free(s->refcount_block_cache);
- qemu_free(s->refcount_table);
-}
+ /* count how many refcount blocks needed */
+#define NUM_CLUSTERS(bytes) \
+ (((bytes) + (s->cluster_size) - 1) / (s->cluster_size))
-static int load_refcount_block(BlockDriverState *bs,
- int64_t refcount_block_offset)
-{
- BDRVQcowState *s = bs->opaque;
- int ret;
- ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache,
- s->cluster_size);
- if (ret != s->cluster_size)
- return -EIO;
- s->refcount_block_cache_offset = refcount_block_offset;
- return 0;
-}
+ ref_clusters = NUM_CLUSTERS(NUM_CLUSTERS(offset) * sizeof(uint16_t));
-static int get_refcount(BlockDriverState *bs, int64_t cluster_index)
-{
- BDRVQcowState *s = bs->opaque;
- int refcount_table_index, block_index;
- int64_t refcount_block_offset;
+ do {
+ uint64_t image_clusters;
+ old_ref_clusters = ref_clusters;
- refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
- if (refcount_table_index >= s->refcount_table_size)
- return 0;
- refcount_block_offset = s->refcount_table[refcount_table_index];
- if (!refcount_block_offset)
- return 0;
- if (refcount_block_offset != s->refcount_block_cache_offset) {
- /* better than nothing: return allocated if read error */
- if (load_refcount_block(bs, refcount_block_offset) < 0)
- return 1;
- }
- block_index = cluster_index &
- ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
- return be16_to_cpu(s->refcount_block_cache[block_index]);
-}
+ /* Number of clusters used for the refcount table */
+ reftable_clusters = NUM_CLUSTERS(ref_clusters * sizeof(uint64_t));
-/* return < 0 if error */
-static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
-{
- BDRVQcowState *s = bs->opaque;
- int i, nb_clusters;
+ /* Number of clusters that the whole image will have */
+ image_clusters = NUM_CLUSTERS(offset) + ref_clusters
+ + reftable_clusters;
- nb_clusters = size_to_clusters(s, size);
-retry:
- for(i = 0; i < nb_clusters; i++) {
- int64_t i = s->free_cluster_index++;
- if (get_refcount(bs, i) != 0)
- goto retry;
+ /* Number of refcount blocks needed for the image */
+ ref_clusters = NUM_CLUSTERS(image_clusters * sizeof(uint16_t));
+
+ } while (ref_clusters != old_ref_clusters);
+
+ s->refcount_table = qemu_mallocz(reftable_clusters * s->cluster_size);
+
+ s->refcount_table_offset = offset;
+ header.refcount_table_offset = cpu_to_be64(offset);
+ header.refcount_table_clusters = cpu_to_be32(reftable_clusters);
+ offset += (reftable_clusters * s->cluster_size);
+ s->refcount_block_offset = offset;
+
+ for (i=0; i < ref_clusters; i++) {
+ s->refcount_table[i] = cpu_to_be64(offset);
+ offset += s->cluster_size;
}
-#ifdef DEBUG_ALLOC2
- printf("alloc_clusters: size=%lld -> %lld\n",
- size,
- (s->free_cluster_index - nb_clusters) << s->cluster_bits);
-#endif
- return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
-}
-static int64_t alloc_clusters(BlockDriverState *bs, int64_t size)
-{
- int64_t offset;
+ s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size);
- offset = alloc_clusters_noref(bs, size);
- update_refcount(bs, offset, size, 1);
- return offset;
-}
+ /* update refcounts */
+ qcow2_create_refcount_update(s, 0, header_size);
+ qcow2_create_refcount_update(s, s->l1_table_offset,
+ l1_size * sizeof(uint64_t));
+ qcow2_create_refcount_update(s, s->refcount_table_offset,
+ reftable_clusters * s->cluster_size);
+ qcow2_create_refcount_update(s, s->refcount_block_offset,
+ ref_clusters * s->cluster_size);
-/* only used to allocate compressed sectors. We try to allocate
- contiguous sectors. size must be <= cluster_size */
-static int64_t alloc_bytes(BlockDriverState *bs, int size)
-{
- BDRVQcowState *s = bs->opaque;
- int64_t offset, cluster_offset;
- int free_in_cluster;
+ /* write all the data */
+ ret = qemu_write_full(fd, &header, sizeof(header));
+ if (ret != sizeof(header)) {
+ ret = -errno;
+ goto exit;
+ }
+ if (backing_file) {
+ if (backing_format_len) {
+ char zero[16];
+ int padding = rounded_ext_bf_len - (ext_bf.len + sizeof(ext_bf));
- assert(size > 0 && size <= s->cluster_size);
- if (s->free_byte_offset == 0) {
- s->free_byte_offset = alloc_clusters(bs, s->cluster_size);
+ memset(zero, 0, sizeof(zero));
+ cpu_to_be32s(&ext_bf.magic);
+ cpu_to_be32s(&ext_bf.len);
+ ret = qemu_write_full(fd, &ext_bf, sizeof(ext_bf));
+ if (ret != sizeof(ext_bf)) {
+ ret = -errno;
+ goto exit;
+ }
+ ret = qemu_write_full(fd, backing_format, backing_format_len);
+ if (ret != backing_format_len) {
+ ret = -errno;
+ goto exit;
+ }
+ if (padding > 0) {
+ ret = qemu_write_full(fd, zero, padding);
+ if (ret != padding) {
+ ret = -errno;
+ goto exit;
+ }
+ }
+ }
+ ret = qemu_write_full(fd, backing_file, backing_filename_len);
+ if (ret != backing_filename_len) {
+ ret = -errno;
+ goto exit;
+ }
}
- redo:
- free_in_cluster = s->cluster_size -
- (s->free_byte_offset & (s->cluster_size - 1));
- if (size <= free_in_cluster) {
- /* enough space in current cluster */
- offset = s->free_byte_offset;
- s->free_byte_offset += size;
- free_in_cluster -= size;
- if (free_in_cluster == 0)
- s->free_byte_offset = 0;
- if ((offset & (s->cluster_size - 1)) != 0)
- update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
- } else {
- offset = alloc_clusters(bs, s->cluster_size);
- cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1);
- if ((cluster_offset + s->cluster_size) == offset) {
- /* we are lucky: contiguous data */
- offset = s->free_byte_offset;
- update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
- s->free_byte_offset += size;
- } else {
- s->free_byte_offset = offset;
- goto redo;
+ lseek(fd, s->l1_table_offset, SEEK_SET);
+ tmp = 0;
+ for(i = 0;i < l1_size; i++) {
+ ret = qemu_write_full(fd, &tmp, sizeof(tmp));
+ if (ret != sizeof(tmp)) {
+ ret = -errno;
+ goto exit;
}
}
- return offset;
-}
-
-static void free_clusters(BlockDriverState *bs,
- int64_t offset, int64_t size)
-{
- update_refcount(bs, offset, size, -1);
-}
+ lseek(fd, s->refcount_table_offset, SEEK_SET);
+ ret = qemu_write_full(fd, s->refcount_table,
+ reftable_clusters * s->cluster_size);
+ if (ret != reftable_clusters * s->cluster_size) {
+ ret = -errno;
+ goto exit;
+ }
-static int grow_refcount_table(BlockDriverState *bs, int min_size)
-{
- BDRVQcowState *s = bs->opaque;
- int new_table_size, new_table_size2, refcount_table_clusters, i, ret;
- uint64_t *new_table;
- int64_t table_offset;
- uint8_t data[12];
- int old_table_size;
- int64_t old_table_offset;
-
- if (min_size <= s->refcount_table_size)
- return 0;
- /* compute new table size */
- refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
- for(;;) {
- if (refcount_table_clusters == 0) {
- refcount_table_clusters = 1;
- } else {
- refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2;
- }
- new_table_size = refcount_table_clusters << (s->cluster_bits - 3);
- if (min_size <= new_table_size)
- break;
+ lseek(fd, s->refcount_block_offset, SEEK_SET);
+ ret = qemu_write_full(fd, s->refcount_block,
+ ref_clusters * s->cluster_size);
+ if (ret != ref_clusters * s->cluster_size) {
+ ret = -errno;
+ goto exit;
}
-#ifdef DEBUG_ALLOC2
- printf("grow_refcount_table from %d to %d\n",
- s->refcount_table_size,
- new_table_size);
-#endif
- new_table_size2 = new_table_size * sizeof(uint64_t);
- new_table = qemu_mallocz(new_table_size2);
- memcpy(new_table, s->refcount_table,
- s->refcount_table_size * sizeof(uint64_t));
- for(i = 0; i < s->refcount_table_size; i++)
- cpu_to_be64s(&new_table[i]);
- /* Note: we cannot update the refcount now to avoid recursion */
- table_offset = alloc_clusters_noref(bs, new_table_size2);
- ret = bdrv_pwrite(s->hd, table_offset, new_table, new_table_size2);
- if (ret != new_table_size2)
- goto fail;
- for(i = 0; i < s->refcount_table_size; i++)
- be64_to_cpus(&new_table[i]);
- cpu_to_be64w((uint64_t*)data, table_offset);
- cpu_to_be32w((uint32_t*)(data + 8), refcount_table_clusters);
- if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset),
- data, sizeof(data)) != sizeof(data))
- goto fail;
+ ret = 0;
+exit:
qemu_free(s->refcount_table);
- old_table_offset = s->refcount_table_offset;
- old_table_size = s->refcount_table_size;
- s->refcount_table = new_table;
- s->refcount_table_size = new_table_size;
- s->refcount_table_offset = table_offset;
-
- update_refcount(bs, table_offset, new_table_size2, 1);
- free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t));
- return 0;
- fail:
- free_clusters(bs, table_offset, new_table_size2);
- qemu_free(new_table);
- return -EIO;
-}
+ qemu_free(s->refcount_block);
+ close(fd);
+
+ /* Preallocate metadata */
+ if (ret == 0 && prealloc) {
+ BlockDriverState *bs;
+ BlockDriver *drv = bdrv_find_format("qcow2");
+ bs = bdrv_new("");
+ bdrv_open(bs, filename, BDRV_O_CACHE_WB | BDRV_O_RDWR, drv);
+ ret = preallocate(bs);
+ bdrv_close(bs);
+ }
+ return ret;
+}
-static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
+static int qcow_create(const char *filename, QEMUOptionParameter *options)
{
- BDRVQcowState *s = bs->opaque;
- int64_t offset, refcount_block_offset;
- int ret, refcount_table_index;
- uint64_t data64;
-
- /* Find L1 index and grow refcount table if needed */
- refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
- if (refcount_table_index >= s->refcount_table_size) {
- ret = grow_refcount_table(bs, refcount_table_index + 1);
- if (ret < 0)
- return ret;
- }
+ const char *backing_file = NULL;
+ const char *backing_fmt = NULL;
+ uint64_t sectors = 0;
+ int flags = 0;
+ size_t cluster_size = 65536;
+ int prealloc = 0;
- /* Load or allocate the refcount block */
- refcount_block_offset = s->refcount_table[refcount_table_index];
- if (!refcount_block_offset) {
- /* create a new refcount block */
- /* Note: we cannot update the refcount now to avoid recursion */
- offset = alloc_clusters_noref(bs, s->cluster_size);
- memset(s->refcount_block_cache, 0, s->cluster_size);
- ret = bdrv_pwrite(s->hd, offset, s->refcount_block_cache, s->cluster_size);
- if (ret != s->cluster_size)
- return -EINVAL;
- s->refcount_table[refcount_table_index] = offset;
- data64 = cpu_to_be64(offset);
- ret = bdrv_pwrite(s->hd, s->refcount_table_offset +
- refcount_table_index * sizeof(uint64_t),
- &data64, sizeof(data64));
- if (ret != sizeof(data64))
- return -EINVAL;
-
- refcount_block_offset = offset;
- s->refcount_block_cache_offset = offset;
- update_refcount(bs, offset, s->cluster_size, 1);
- } else {
- if (refcount_block_offset != s->refcount_block_cache_offset) {
- if (load_refcount_block(bs, refcount_block_offset) < 0)
- return -EIO;
+ /* Read out options */
+ while (options && options->name) {
+ if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
+ sectors = options->value.n / 512;
+ } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
+ backing_file = options->value.s;
+ } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) {
+ backing_fmt = options->value.s;
+ } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
+ flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
+ } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
+ if (options->value.n) {
+ cluster_size = options->value.n;
+ }
+ } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) {
+ if (!options->value.s || !strcmp(options->value.s, "off")) {
+ prealloc = 0;
+ } else if (!strcmp(options->value.s, "metadata")) {
+ prealloc = 1;
+ } else {
+ fprintf(stderr, "Invalid preallocation mode: '%s'\n",
+ options->value.s);
+ return -EINVAL;
+ }
}
+ options++;
}
- return refcount_block_offset;
+ if (backing_file && prealloc) {
+ fprintf(stderr, "Backing file and preallocation cannot be used at "
+ "the same time\n");
+ return -EINVAL;
+ }
+
+ return qcow_create2(filename, sectors, backing_file, backing_fmt, flags,
+ cluster_size, prealloc);
}
-/* addend must be 1 or -1 */
-static int update_cluster_refcount(BlockDriverState *bs,
- int64_t cluster_index,
- int addend)
+static int qcow_make_empty(BlockDriverState *bs)
{
+#if 0
+ /* XXX: not correct */
BDRVQcowState *s = bs->opaque;
+ uint32_t l1_length = s->l1_size * sizeof(uint64_t);
int ret;
- ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend);
- if (ret < 0) {
+ memset(s->l1_table, 0, l1_length);
+ if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
+ return -1;
+ ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
+ if (ret < 0)
return ret;
- }
- return get_refcount(bs, cluster_index);
+ l2_cache_reset(bs);
+#endif
+ return 0;
}
-/* XXX: cache several refcount block clusters ? */
-static int update_refcount(BlockDriverState *bs,
- int64_t offset, int64_t length,
- int addend)
+static int qcow2_truncate(BlockDriverState *bs, int64_t offset)
{
BDRVQcowState *s = bs->opaque;
- int64_t start, last, cluster_offset;
+ int ret, new_l1_size;
-#ifdef DEBUG_ALLOC2
- printf("update_refcount: offset=%lld size=%lld addend=%d\n",
- offset, length, addend);
-#endif
- if (length <= 0)
+ if (offset & 511) {
return -EINVAL;
- start = offset & ~(s->cluster_size - 1);
- last = (offset + length - 1) & ~(s->cluster_size - 1);
- for(cluster_offset = start; cluster_offset <= last;
- cluster_offset += s->cluster_size)
- {
- int64_t refcount_block_offset;
- int block_index, refcount;
- int64_t cluster_index = cluster_offset >> s->cluster_bits;
-
- /* Load the refcount block and allocate it if needed */
- refcount_block_offset = alloc_refcount_block(bs, cluster_index);
- if (refcount_block_offset < 0) {
- return refcount_block_offset;
- }
+ }
- /* we can update the count and save it */
- block_index = cluster_index &
- ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
- refcount = be16_to_cpu(s->refcount_block_cache[block_index]);
- refcount += addend;
- if (refcount < 0 || refcount > 0xffff)
- return -EINVAL;
- if (refcount == 0 && cluster_index < s->free_cluster_index) {
- s->free_cluster_index = cluster_index;
- }
- s->refcount_block_cache[block_index] = cpu_to_be16(refcount);
- if (bdrv_pwrite(s->hd,
- refcount_block_offset + (block_index << REFCOUNT_SHIFT),
- &s->refcount_block_cache[block_index], 2) != 2)
- return -EIO;
+ /* cannot proceed if image has snapshots */
+ if (s->nb_snapshots) {
+ return -ENOTSUP;
+ }
+
+ /* shrinking is currently not supported */
+ if (offset < bs->total_sectors * 512) {
+ return -ENOTSUP;
+ }
+
+ new_l1_size = size_to_l1(s, offset);
+ ret = qcow2_grow_l1_table(bs, new_l1_size);
+ if (ret < 0) {
+ return ret;
+ }
+ /* write updated header.size */
+ offset = cpu_to_be64(offset);
+ ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size),
+ &offset, sizeof(uint64_t));
+ if (ret < 0) {
+ return ret;
}
+
+ s->l1_vm_state_index = new_l1_size;
return 0;
}
-/*
- * Increases the refcount for a range of clusters in a given refcount table.
- * This is used to construct a temporary refcount table out of L1 and L2 tables
- * which can be compared the the refcount table saved in the image.
- *
- * Returns the number of errors in the image that were found
- */
-static int inc_refcounts(BlockDriverState *bs,
- uint16_t *refcount_table,
- int refcount_table_size,
- int64_t offset, int64_t size)
+/* XXX: put compressed sectors first, then all the cluster aligned
+ tables to avoid losing bytes in alignment */
+static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
+ const uint8_t *buf, int nb_sectors)
{
BDRVQcowState *s = bs->opaque;
- int64_t start, last, cluster_offset;
- int k;
- int errors = 0;
+ z_stream strm;
+ int ret, out_len;
+ uint8_t *out_buf;
+ uint64_t cluster_offset;
- if (size <= 0)
+ if (nb_sectors == 0) {
+ /* align end of file to a sector boundary to ease reading with
+ sector based I/Os */
+ cluster_offset = bdrv_getlength(bs->file);
+ cluster_offset = (cluster_offset + 511) & ~511;
+ bdrv_truncate(bs->file, cluster_offset);
return 0;
-
- start = offset & ~(s->cluster_size - 1);
- last = (offset + size - 1) & ~(s->cluster_size - 1);
- for(cluster_offset = start; cluster_offset <= last;
- cluster_offset += s->cluster_size) {
- k = cluster_offset >> s->cluster_bits;
- if (k < 0 || k >= refcount_table_size) {
- fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n",
- cluster_offset);
- errors++;
- } else {
- if (++refcount_table[k] == 0) {
- fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64
- "\n", cluster_offset);
- errors++;
- }
- }
}
- return errors;
-}
+ if (nb_sectors != s->cluster_sectors)
+ return -EINVAL;
-/*
- * Increases the refcount in the given refcount table for the all clusters
- * referenced in the L2 table. While doing so, performs some checks on L2
- * entries.
- *
- * Returns the number of errors found by the checks or -errno if an internal
- * error occurred.
- */
-static int check_refcounts_l2(BlockDriverState *bs,
- uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset,
- int check_copied)
-{
- BDRVQcowState *s = bs->opaque;
- uint64_t *l2_table, offset;
- int i, l2_size, nb_csectors, refcount;
- int errors = 0;
+ out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
- /* Read L2 table from disk */
- l2_size = s->l2_size * sizeof(uint64_t);
- l2_table = qemu_malloc(l2_size);
+ /* best compression, small window, no zlib header */
+ memset(&strm, 0, sizeof(strm));
+ ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
+ Z_DEFLATED, -12,
+ 9, Z_DEFAULT_STRATEGY);
+ if (ret != 0) {
+ qemu_free(out_buf);
+ return -1;
+ }
- if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size)
- goto fail;
+ strm.avail_in = s->cluster_size;
+ strm.next_in = (uint8_t *)buf;
+ strm.avail_out = s->cluster_size;
+ strm.next_out = out_buf;
- /* Do the actual checks */
- for(i = 0; i < s->l2_size; i++) {
- offset = be64_to_cpu(l2_table[i]);
- if (offset != 0) {
- if (offset & QCOW_OFLAG_COMPRESSED) {
- /* Compressed clusters don't have QCOW_OFLAG_COPIED */
- if (offset & QCOW_OFLAG_COPIED) {
- fprintf(stderr, "ERROR: cluster %" PRId64 ": "
- "copied flag must never be set for compressed "
- "clusters\n", offset >> s->cluster_bits);
- offset &= ~QCOW_OFLAG_COPIED;
- errors++;
- }
+ ret = deflate(&strm, Z_FINISH);
+ if (ret != Z_STREAM_END && ret != Z_OK) {
+ qemu_free(out_buf);
+ deflateEnd(&strm);
+ return -1;
+ }
+ out_len = strm.next_out - out_buf;
- /* Mark cluster as used */
- nb_csectors = ((offset >> s->csize_shift) &
- s->csize_mask) + 1;
- offset &= s->cluster_offset_mask;
- errors += inc_refcounts(bs, refcount_table,
- refcount_table_size,
- offset & ~511, nb_csectors * 512);
- } else {
- /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
- if (check_copied) {
- uint64_t entry = offset;
- offset &= ~QCOW_OFLAG_COPIED;
- refcount = get_refcount(bs, offset >> s->cluster_bits);
- if ((refcount == 1) != ((entry & QCOW_OFLAG_COPIED) != 0)) {
- fprintf(stderr, "ERROR OFLAG_COPIED: offset=%"
- PRIx64 " refcount=%d\n", entry, refcount);
- errors++;
- }
- }
+ deflateEnd(&strm);
- /* Mark cluster as used */
- offset &= ~QCOW_OFLAG_COPIED;
- errors += inc_refcounts(bs, refcount_table,
- refcount_table_size,
- offset, s->cluster_size);
-
- /* Correct offsets are cluster aligned */
- if (offset & (s->cluster_size - 1)) {
- fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not "
- "properly aligned; L2 entry corrupted.\n", offset);
- errors++;
- }
- }
+ if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
+ /* could not compress: write normal cluster */
+ bdrv_write(bs, sector_num, buf, s->cluster_sectors);
+ } else {
+ cluster_offset = qcow2_alloc_compressed_cluster_offset(bs,
+ sector_num << 9, out_len);
+ if (!cluster_offset)
+ return -1;
+ cluster_offset &= s->cluster_offset_mask;
+ BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
+ if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
+ qemu_free(out_buf);
+ return -1;
}
}
- qemu_free(l2_table);
- return errors;
-
-fail:
- fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
- qemu_free(l2_table);
- return -EIO;
+ qemu_free(out_buf);
+ return 0;
}
-/*
- * Increases the refcount for the L1 table, its L2 tables and all referenced
- * clusters in the given refcount table. While doing so, performs some checks
- * on L1 and L2 entries.
- *
- * Returns the number of errors found by the checks or -errno if an internal
- * error occurred.
- */
-static int check_refcounts_l1(BlockDriverState *bs,
- uint16_t *refcount_table,
- int refcount_table_size,
- int64_t l1_table_offset, int l1_size,
- int check_copied)
+static void qcow_flush(BlockDriverState *bs)
{
- BDRVQcowState *s = bs->opaque;
- uint64_t *l1_table, l2_offset, l1_size2;
- int i, refcount, ret;
- int errors = 0;
-
- l1_size2 = l1_size * sizeof(uint64_t);
-
- /* Mark L1 table as used */
- errors += inc_refcounts(bs, refcount_table, refcount_table_size,
- l1_table_offset, l1_size2);
-
- /* Read L1 table entries from disk */
- l1_table = qemu_malloc(l1_size2);
- if (bdrv_pread(s->hd, l1_table_offset,
- l1_table, l1_size2) != l1_size2)
- goto fail;
- for(i = 0;i < l1_size; i++)
- be64_to_cpus(&l1_table[i]);
-
- /* Do the actual checks */
- for(i = 0; i < l1_size; i++) {
- l2_offset = l1_table[i];
- if (l2_offset) {
- /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
- if (check_copied) {
- refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED)
- >> s->cluster_bits);
- if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) {
- fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64
- " refcount=%d\n", l2_offset, refcount);
- errors++;
- }
- }
-
- /* Mark L2 table as used */
- l2_offset &= ~QCOW_OFLAG_COPIED;
- errors += inc_refcounts(bs, refcount_table,
- refcount_table_size,
- l2_offset,
- s->cluster_size);
-
- /* L2 tables are cluster aligned */
- if (l2_offset & (s->cluster_size - 1)) {
- fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not "
- "cluster aligned; L1 entry corrupted\n", l2_offset);
- errors++;
- }
+ bdrv_flush(bs->file);
+}
- /* Process and check L2 entries */
- ret = check_refcounts_l2(bs, refcount_table, refcount_table_size,
- l2_offset, check_copied);
- if (ret < 0) {
- goto fail;
- }
- errors += ret;
- }
- }
- qemu_free(l1_table);
- return errors;
+static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
+ BlockDriverCompletionFunc *cb, void *opaque)
+{
+ return bdrv_aio_flush(bs->file, cb, opaque);
+}
-fail:
- fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
- qemu_free(l1_table);
- return -EIO;
+static int64_t qcow_vm_state_offset(BDRVQcowState *s)
+{
+ return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
}
-/*
- * Checks an image for refcount consistency.
- *
- * Returns 0 if no errors are found, the number of errors in case the image is
- * detected as corrupted, and -errno when an internal error occured.
- */
-static int check_refcounts(BlockDriverState *bs)
+static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
BDRVQcowState *s = bs->opaque;
- int64_t size;
- int nb_clusters, refcount1, refcount2, i;
- QCowSnapshot *sn;
- uint16_t *refcount_table;
- int ret, errors = 0;
-
- size = bdrv_getlength(s->hd);
- nb_clusters = size_to_clusters(s, size);
- refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t));
-
- /* header */
- errors += inc_refcounts(bs, refcount_table, nb_clusters,
- 0, s->cluster_size);
-
- /* current L1 table */
- ret = check_refcounts_l1(bs, refcount_table, nb_clusters,
- s->l1_table_offset, s->l1_size, 1);
- if (ret < 0) {
- return ret;
- }
- errors += ret;
-
- /* snapshots */
- for(i = 0; i < s->nb_snapshots; i++) {
- sn = s->snapshots + i;
- check_refcounts_l1(bs, refcount_table, nb_clusters,
- sn->l1_table_offset, sn->l1_size, 0);
- }
- errors += inc_refcounts(bs, refcount_table, nb_clusters,
- s->snapshots_offset, s->snapshots_size);
-
- /* refcount data */
- errors += inc_refcounts(bs, refcount_table, nb_clusters,
- s->refcount_table_offset,
- s->refcount_table_size * sizeof(uint64_t));
- for(i = 0; i < s->refcount_table_size; i++) {
- int64_t offset;
- offset = s->refcount_table[i];
- if (offset != 0) {
- errors += inc_refcounts(bs, refcount_table, nb_clusters,
- offset, s->cluster_size);
- }
- }
-
- /* compare ref counts */
- for(i = 0; i < nb_clusters; i++) {
- refcount1 = get_refcount(bs, i);
- refcount2 = refcount_table[i];
- if (refcount1 != refcount2) {
- fprintf(stderr, "ERROR cluster %d refcount=%d reference=%d\n",
- i, refcount1, refcount2);
- errors++;
- }
- }
-
- qemu_free(refcount_table);
-
- return errors;
+ bdi->cluster_size = s->cluster_size;
+ bdi->vm_state_offset = qcow_vm_state_offset(s);
+ return 0;
}
-static int qcow_check(BlockDriverState *bs)
+
+static int qcow_check(BlockDriverState *bs, BdrvCheckResult *result)
{
- return check_refcounts(bs);
+ return qcow2_check_refcounts(bs, result);
}
#if 0
int64_t nb_clusters, k, k1, size;
int refcount;
- size = bdrv_getlength(s->hd);
+ size = bdrv_getlength(bs->file);
nb_clusters = size_to_clusters(s, size);
for(k = 0; k < nb_clusters;) {
k1 = k;
k++;
while (k < nb_clusters && get_refcount(bs, k) == refcount)
k++;
- printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1);
+ printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
+ k - k1);
}
}
#endif
-static int qcow_put_buffer(BlockDriverState *bs, const uint8_t *buf,
+static int qcow_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
int64_t pos, int size)
{
+ BDRVQcowState *s = bs->opaque;
int growable = bs->growable;
+ int ret;
+ BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
bs->growable = 1;
- bdrv_pwrite(bs, pos, buf, size);
+ ret = bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size);
bs->growable = growable;
- return size;
+ return ret;
}
-static int qcow_get_buffer(BlockDriverState *bs, uint8_t *buf,
+static int qcow_load_vmstate(BlockDriverState *bs, uint8_t *buf,
int64_t pos, int size)
{
+ BDRVQcowState *s = bs->opaque;
int growable = bs->growable;
int ret;
+ BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
bs->growable = 1;
- ret = bdrv_pread(bs, pos, buf, size);
+ ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size);
bs->growable = growable;
return ret;
}
static QEMUOptionParameter qcow_create_options[] = {
- { BLOCK_OPT_SIZE, OPT_SIZE },
- { BLOCK_OPT_BACKING_FILE, OPT_STRING },
- { BLOCK_OPT_BACKING_FMT, OPT_STRING },
- { BLOCK_OPT_ENCRYPT, OPT_FLAG },
- { BLOCK_OPT_CLUSTER_SIZE, OPT_SIZE },
+ {
+ .name = BLOCK_OPT_SIZE,
+ .type = OPT_SIZE,
+ .help = "Virtual disk size"
+ },
+ {
+ .name = BLOCK_OPT_BACKING_FILE,
+ .type = OPT_STRING,
+ .help = "File name of a base image"
+ },
+ {
+ .name = BLOCK_OPT_BACKING_FMT,
+ .type = OPT_STRING,
+ .help = "Image format of the base image"
+ },
+ {
+ .name = BLOCK_OPT_ENCRYPT,
+ .type = OPT_FLAG,
+ .help = "Encrypt the image"
+ },
+ {
+ .name = BLOCK_OPT_CLUSTER_SIZE,
+ .type = OPT_SIZE,
+ .help = "qcow2 cluster size"
+ },
+ {
+ .name = BLOCK_OPT_PREALLOC,
+ .type = OPT_STRING,
+ .help = "Preallocation mode (allowed values: off, metadata)"
+ },
{ NULL }
};
.bdrv_aio_readv = qcow_aio_readv,
.bdrv_aio_writev = qcow_aio_writev,
- .bdrv_aio_cancel = qcow_aio_cancel,
- .aiocb_size = sizeof(QCowAIOCB),
- .bdrv_write_compressed = qcow_write_compressed,
-
- .bdrv_snapshot_create = qcow_snapshot_create,
- .bdrv_snapshot_goto = qcow_snapshot_goto,
- .bdrv_snapshot_delete = qcow_snapshot_delete,
- .bdrv_snapshot_list = qcow_snapshot_list,
+ .bdrv_aio_flush = qcow_aio_flush,
+
+ .bdrv_truncate = qcow2_truncate,
+ .bdrv_write_compressed = qcow_write_compressed,
+
+ .bdrv_snapshot_create = qcow2_snapshot_create,
+ .bdrv_snapshot_goto = qcow2_snapshot_goto,
+ .bdrv_snapshot_delete = qcow2_snapshot_delete,
+ .bdrv_snapshot_list = qcow2_snapshot_list,
.bdrv_get_info = qcow_get_info,
- .bdrv_put_buffer = qcow_put_buffer,
- .bdrv_get_buffer = qcow_get_buffer,
+ .bdrv_save_vmstate = qcow_save_vmstate,
+ .bdrv_load_vmstate = qcow_load_vmstate,
+
+ .bdrv_change_backing_file = qcow2_change_backing_file,
.create_options = qcow_create_options,
.bdrv_check = qcow_check,
projects / qemu.git / blobdiff