1 files changed, 2 insertions, 765 deletions

diff --git a/block/qcow2.c b/block/qcow2.c
index 91903fe596..9f8b9379bd 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -78,9 +78,6 @@ typedef struct __attribute__((packed)) QCowSnapshotHeader {
 } QCowSnapshotHeader;
 
 
-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);
 
@@ -334,679 +331,12 @@ static int qcow_set_key(BlockDriverState *bs, const char *key)
     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)
-{
-    BDRVQcowState *s = bs->opaque;
-    int n, 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);
-    }
-    ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start,
-                     s->cluster_data, n);
-    if (ret < 0)
-        return ret;
-    return 0;
-}
-
-void l2_cache_reset(BlockDriverState *bs)
-{
-    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));
-}
-
-static inline int l2_cache_new_entry(BlockDriverState *bs)
-{
-    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;
-}
-
 static int64_t align_offset(int64_t offset, int n)
 {
     offset = (offset + n - 1) & ~(n - 1);
     return offset;
 }
 
-static int grow_l1_table(BlockDriverState *bs, int min_size)
-{
-    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
-
-    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));
-
-    /* write new table (align to cluster) */
-    new_l1_table_offset = alloc_clusters(bs, new_l1_size2);
-
-    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)
-{
-    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);
-        }
-    }
-    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.
- */
-
-static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
-{
-    BDRVQcowState *s = bs->opaque;
-    int min_index;
-    uint64_t *l2_table;
-
-    /* seek if the table for the given offset is in the cache */
-
-    l2_table = seek_l2_table(s, l2_offset);
-    if (l2_table != NULL)
-        return l2_table;
-
-    /* not found: load a new entry in the least used one */
-
-    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;
-
-    return l2_table;
-}
-
-/*
- * 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)
-{
-    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;
-
-    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))
-        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));
-    } 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;
-    }
-    /* 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;
-
-    /* update the l2 cache entry */
-
-    s->l2_cache_offsets[min_index] = l2_offset;
-    s->l2_cache_counts[min_index] = 1;
-
-    return l2_table;
-}
-
-static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size,
-        uint64_t *l2_table, uint64_t start, uint64_t mask)
-{
-    int i;
-    uint64_t offset = be64_to_cpu(l2_table[0]) & ~mask;
-
-    if (!offset)
-        return 0;
-
-    for (i = start; i < start + nb_clusters; i++)
-        if (offset + i * cluster_size != (be64_to_cpu(l2_table[i]) & ~mask))
-            break;
-
-	return (i - start);
-}
-
-static int count_contiguous_free_clusters(uint64_t nb_clusters, uint64_t *l2_table)
-{
-    int i = 0;
-
-    while(nb_clusters-- && l2_table[i] == 0)
-        i++;
-
-    return i;
-}
-
-/*
- * 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.
- *
- */
-
-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 */
-
-    nb_available = (nb_available >> 9) + index_in_cluster;
-
-    if (nb_needed > nb_available) {
-        nb_needed = nb_available;
-    }
-
-    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;
-
-    /* load the l2 table in memory */
-
-    l2_offset &= ~QCOW_OFLAG_COPIED;
-    l2_table = l2_load(bs, l2_offset);
-    if (l2_table == NULL)
-        return 0;
-
-    /* find the cluster offset for the given disk offset */
-
-    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);
-
-    if (!cluster_offset) {
-        /* how many empty clusters ? */
-        c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]);
-    } else {
-        /* how many allocated clusters ? */
-        c = count_contiguous_clusters(nb_clusters, s->cluster_size,
-                &l2_table[l2_index], 0, QCOW_OFLAG_COPIED);
-    }
-
-   nb_available = (c * s->cluster_sectors);
-out:
-    if (nb_available > nb_needed)
-        nb_available = nb_needed;
-
-    *num = nb_available - index_in_cluster;
-
-    return cluster_offset & ~QCOW_OFLAG_COPIED;
-}
-
-/*
- * 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)
-{
-    BDRVQcowState *s = bs->opaque;
-
-    /* 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;
-    }
-
-    free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits);
-
-    return;
-}
-
-/*
- * 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)
-{
-    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;
-}
-
-/*
- * 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.
- *
- */
-
-static uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs,
-                                                uint64_t offset,
-                                                int compressed_size)
-{
-    BDRVQcowState *s = bs->opaque;
-    int l2_index, ret;
-    uint64_t l2_offset, *l2_table, cluster_offset;
-    int nb_csectors;
-
-    ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index);
-    if (ret == 0)
-        return 0;
-
-    cluster_offset = be64_to_cpu(l2_table[l2_index]);
-    if (cluster_offset & QCOW_OFLAG_COPIED)
-        return cluster_offset & ~QCOW_OFLAG_COPIED;
-
-    if (cluster_offset)
-        free_any_clusters(bs, cluster_offset, 1);
-
-    cluster_offset = alloc_bytes(bs, compressed_size);
-    nb_csectors = ((cluster_offset + compressed_size - 1) >> 9) -
-                  (cluster_offset >> 9);
-
-    cluster_offset |= QCOW_OFLAG_COMPRESSED |
-                      ((uint64_t)nb_csectors << s->csize_shift);
-
-    /* update L2 table */
-
-    /* compressed clusters never have the copied flag */
-
-    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;
-
-    return cluster_offset;
-}
-
-typedef struct QCowL2Meta
-{
-    uint64_t offset;
-    int n_start;
-    int nb_available;
-    int nb_clusters;
-} QCowL2Meta;
-
-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;
-
-    if (m->nb_clusters == 0)
-        return 0;
-
-    old_cluster = qemu_malloc(m->nb_clusters * sizeof(uint64_t));
-
-    /* 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;
-    }
-
-    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 = -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);
-    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)
-{
-    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);
-
-        cluster_offset &= ~QCOW_OFLAG_COPIED;
-        m->nb_clusters = 0;
-
-        goto out;
-    }
-
-    /* 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]);
-
-        if ((cluster_offset & QCOW_OFLAG_COPIED) ||
-                (cluster_offset & QCOW_OFLAG_COMPRESSED))
-            break;
-    }
-    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;
-}
-
 static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
                              int nb_sectors, int *pnum)
 {
@@ -1018,59 +348,9 @@ static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
     return (cluster_offset != 0);
 }
 
-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;
-
-    memset(strm, 0, sizeof(*strm));
-
-    strm->next_in = (uint8_t *)buf;
-    strm->avail_in = buf_size;
-    strm->next_out = out_buf;
-    strm->avail_out = out_buf_size;
-
-    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;
-    }
-    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);
-        if (ret < 0) {
-            return -1;
-        }
-        if (decompress_buffer(s->cluster_cache, s->cluster_size,
-                              s->cluster_data + sector_offset, csize) < 0) {
-            return -1;
-        }
-        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)
+int backing_read1(BlockDriverState *bs,
+                  int64_t sector_num, uint8_t *buf, int nb_sectors)
 {
     int n1;
     if ((sector_num + nb_sectors) <= bs->total_sectors)
@@ -1083,49 +363,6 @@ static int backing_read1(BlockDriverState *bs,
     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;
-
-    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);
-            }
-        }
-        nb_sectors -= n;
-        sector_num += n;
-        buf += n * 512;
-    }
-    return 0;
-}
-
 typedef struct QCowAIOCB {
     BlockDriverAIOCB common;
     int64_t sector_num;