]> git.proxmox.com Git - qemu.git/blobdiff - block/qcow2.c
qcow2/vdi: Change check to distinguish error cases
[qemu.git] / block / qcow2.c
index 8fc8f8cc3732f7d32799a37ee71503bf8ac77cd7..a53014dbdaad00fc4e8a00419d2fdf0ea9cbbefe 100644 (file)
@@ -52,8 +52,6 @@ typedef struct {
 #define  QCOW_EXT_MAGIC_END 0
 #define  QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
 
-
-
 static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
 {
     const QCowHeader *cow_header = (const void *)buf;
@@ -77,7 +75,6 @@ static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
 static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset,
                                 uint64_t end_offset)
 {
-    BDRVQcowState *s = bs->opaque;
     QCowExtension ext;
     uint64_t offset;
 
@@ -95,9 +92,10 @@ static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_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);
@@ -117,7 +115,7 @@ static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset,
                         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';
@@ -138,17 +136,14 @@ static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset,
 }
 
 
-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;
 
-    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);
@@ -192,8 +187,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags)
 
     /* 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)
@@ -202,7 +196,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags)
     if (s->l1_size > 0) {
         s->l1_table = qemu_mallocz(
             align_offset(s->l1_size * sizeof(uint64_t), 512));
-        if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) !=
+        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++) {
@@ -235,7 +229,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags)
         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';
     }
@@ -254,7 +248,6 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags)
     qemu_free(s->l2_cache);
     qemu_free(s->cluster_cache);
     qemu_free(s->cluster_data);
-    bdrv_delete(s->hd);
     return -1;
 }
 
@@ -304,9 +297,15 @@ static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
                              int nb_sectors, int *pnum)
 {
     uint64_t cluster_offset;
+    int ret;
 
     *pnum = nb_sectors;
-    cluster_offset = qcow2_get_cluster_offset(bs, sector_num << 9, pnum);
+    /* 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;
+    }
 
     return (cluster_offset != 0);
 }
@@ -332,8 +331,8 @@ typedef struct QCowAIOCB {
     QEMUIOVector *qiov;
     uint8_t *buf;
     void *orig_buf;
-    int nb_sectors;
-    int n;
+    int remaining_sectors;
+    int cur_nr_sectors;        /* number of sectors in current iteration */
     uint64_t cluster_offset;
     uint8_t *cluster_data;
     BlockDriverAIOCB *hd_aiocb;
@@ -346,7 +345,7 @@ typedef struct QCowAIOCB {
 
 static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
 {
-    QCowAIOCB *acb = (QCowAIOCB *)blockacb;
+    QCowAIOCB *acb = container_of(blockacb, QCowAIOCB, common);
     if (acb->hd_aiocb)
         bdrv_aio_cancel(acb->hd_aiocb);
     qemu_aio_release(acb);
@@ -399,38 +398,43 @@ static void qcow_aio_read_cb(void *opaque, int ret)
     } else {
         if (s->crypt_method) {
             qcow2_encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
-                            acb->n, 0,
+                            acb->cur_nr_sectors, 0,
                             &s->aes_decrypt_key);
         }
     }
 
-    acb->nb_sectors -= acb->n;
-    acb->sector_num += acb->n;
-    acb->buf += acb->n * 512;
+    acb->remaining_sectors -= acb->cur_nr_sectors;
+    acb->sector_num += acb->cur_nr_sectors;
+    acb->buf += acb->cur_nr_sectors * 512;
 
-    if (acb->nb_sectors == 0) {
+    if (acb->remaining_sectors == 0) {
         /* request completed */
         ret = 0;
         goto done;
     }
 
     /* prepare next AIO request */
-    acb->n = acb->nb_sectors;
-    acb->cluster_offset =
-        qcow2_get_cluster_offset(bs, acb->sector_num << 9, &acb->n);
+    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;
+    }
+
     index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
 
     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->n);
+                               acb->buf, acb->cur_nr_sectors);
             if (n1 > 0) {
                 acb->hd_iov.iov_base = (void *)acb->buf;
-                acb->hd_iov.iov_len = acb->n * 512;
+                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->n,
+                                    &acb->hd_qiov, acb->cur_nr_sectors,
                                    qcow_aio_read_cb, acb);
                 if (acb->hd_aiocb == NULL)
                     goto done;
@@ -441,17 +445,17 @@ static void qcow_aio_read_cb(void *opaque, int ret)
             }
         } else {
             /* Note: in this case, no need to wait */
-            memset(acb->buf, 0, 512 * acb->n);
+            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(s, acb->cluster_offset) < 0)
+        if (qcow2_decompress_cluster(bs, acb->cluster_offset) < 0)
             goto done;
-        memcpy(acb->buf,
-               s->cluster_cache + index_in_cluster * 512, 512 * acb->n);
+        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;
@@ -462,13 +466,17 @@ static void qcow_aio_read_cb(void *opaque, int ret)
         }
 
         acb->hd_iov.iov_base = (void *)acb->buf;
-        acb->hd_iov.iov_len = acb->n * 512;
+        acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
         qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
-        acb->hd_aiocb = bdrv_aio_readv(s->hd,
+        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->n, qcow_aio_read_cb, acb);
-        if (acb->hd_aiocb == NULL)
+                            &acb->hd_qiov, acb->cur_nr_sectors,
+                            qcow_aio_read_cb, acb);
+        if (acb->hd_aiocb == NULL) {
+            ret = -EIO;
             goto done;
+        }
     }
 
     return;
@@ -500,8 +508,8 @@ static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
     } else {
         acb->buf = (uint8_t *)qiov->iov->iov_base;
     }
-    acb->nb_sectors = nb_sectors;
-    acb->n = 0;
+    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);
@@ -534,14 +542,8 @@ static void run_dependent_requests(QCowL2Meta *m)
         QLIST_REMOVE(m, next_in_flight);
     }
 
-    /*
-     * Restart all dependent requests.
-     * Can't use QLIST_FOREACH here - the next link might not be the same
-     * any more after the callback  (request could depend on a different
-     * request now)
-     */
-    for (req = m->dependent_requests.lh_first; req != NULL; req = next) {
-        next = req->next_depend.le_next;
+    /* Restart all dependent requests */
+    QLIST_FOREACH_SAFE(req, &m->dependent_requests, next_depend, next) {
         qcow_aio_write_cb(req, 0);
     }
 
@@ -569,24 +571,24 @@ static void qcow_aio_write_cb(void *opaque, int ret)
     if (ret < 0)
         goto done;
 
-    acb->nb_sectors -= acb->n;
-    acb->sector_num += acb->n;
-    acb->buf += acb->n * 512;
+    acb->remaining_sectors -= acb->cur_nr_sectors;
+    acb->sector_num += acb->cur_nr_sectors;
+    acb->buf += acb->cur_nr_sectors * 512;
 
-    if (acb->nb_sectors == 0) {
+    if (acb->remaining_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;
+    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;
 
     ret = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9,
-        index_in_cluster, n_end, &acb->n, &acb->l2meta);
+        index_in_cluster, n_end, &acb->cur_nr_sectors, &acb->l2meta);
     if (ret < 0) {
         goto done;
     }
@@ -608,23 +610,30 @@ static void qcow_aio_write_cb(void *opaque, int ret)
                                              s->cluster_size);
         }
         qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
-                        acb->n, 1, &s->aes_encrypt_key);
+                        acb->cur_nr_sectors, 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;
+    acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
     qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
-    acb->hd_aiocb = bdrv_aio_writev(s->hd,
+    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->n,
+                                    &acb->hd_qiov, acb->cur_nr_sectors,
                                     qcow_aio_write_cb, acb);
-    if (acb->hd_aiocb == NULL)
-        goto done;
+    if (acb->hd_aiocb == NULL) {
+        ret = -EIO;
+        goto fail;
+    }
 
     return;
 
+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);
@@ -657,7 +666,6 @@ static void qcow_close(BlockDriverState *bs)
     qemu_free(s->cluster_cache);
     qemu_free(s->cluster_data);
     qcow2_refcount_close(bs);
-    bdrv_delete(s->hd);
 }
 
 /*
@@ -727,7 +735,7 @@ static int qcow2_update_ext_header(BlockDriverState *bs,
         backing_file_offset = sizeof(QCowHeader) + offset;
     }
 
-    ret = bdrv_pwrite(s->hd, sizeof(QCowHeader), buf, ext_size);
+    ret = bdrv_pwrite_sync(bs->file, sizeof(QCowHeader), buf, ext_size);
     if (ret < 0) {
         goto fail;
     }
@@ -736,13 +744,13 @@ static int qcow2_update_ext_header(BlockDriverState *bs,
     uint64_t be_backing_file_offset = cpu_to_be64(backing_file_offset);
     uint32_t be_backing_file_size = cpu_to_be32(backing_file_len);
 
-    ret = bdrv_pwrite(s->hd, offsetof(QCowHeader, backing_file_offset),
+    ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_offset),
         &be_backing_file_offset, sizeof(uint64_t));
     if (ret < 0) {
         goto fail;
     }
 
-    ret = bdrv_pwrite(s->hd, offsetof(QCowHeader, backing_file_size),
+    ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, backing_file_size),
         &be_backing_file_size, sizeof(uint32_t));
     if (ret < 0) {
         goto fail;
@@ -783,7 +791,6 @@ static int get_bits_from_size(size_t size)
 
 static int preallocate(BlockDriverState *bs)
 {
-    BDRVQcowState *s = bs->opaque;
     uint64_t nb_sectors;
     uint64_t offset;
     int num;
@@ -798,14 +805,14 @@ static int preallocate(BlockDriverState *bs)
     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 -1;
+            return ret;
         }
 
-        if (qcow2_alloc_cluster_link_l2(bs, &meta) < 0) {
+        ret = qcow2_alloc_cluster_link_l2(bs, &meta);
+        if (ret < 0) {
             qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters);
-            return -1;
+            return ret;
         }
 
         /* There are no dependent requests, but we need to remove our request
@@ -826,7 +833,10 @@ static int preallocate(BlockDriverState *bs)
     if (meta.cluster_offset != 0) {
         uint8_t buf[512];
         memset(buf, 0, 512);
-        bdrv_write(s->hd, (meta.cluster_offset >> 9) + num - 1, buf, 1);
+        ret = bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1);
+        if (ret < 0) {
+            return ret;
+        }
     }
 
     return 0;
@@ -838,10 +848,11 @@ static int qcow_create2(const char *filename, int64_t total_size,
 {
 
     int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
-    int ref_clusters, backing_format_len = 0;
+    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;
@@ -850,7 +861,7 @@ static int qcow_create2(const char *filename, int64_t total_size,
 
     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
     if (fd < 0)
-        return -1;
+        return -errno;
     memset(&header, 0, sizeof(header));
     header.magic = cpu_to_be32(QCOW_MAGIC);
     header.version = cpu_to_be32(QCOW_VERSION);
@@ -900,17 +911,37 @@ static int qcow_create2(const char *filename, int64_t total_size,
     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);
+    /* count how many refcount blocks needed */
+
+#define NUM_CLUSTERS(bytes) \
+    (((bytes) + (s->cluster_size) - 1) / (s->cluster_size))
+
+    ref_clusters = NUM_CLUSTERS(NUM_CLUSTERS(offset) * sizeof(uint16_t));
+
+    do {
+        uint64_t image_clusters;
+        old_ref_clusters = ref_clusters;
+
+        /* Number of clusters used for the refcount table */
+        reftable_clusters = NUM_CLUSTERS(ref_clusters * sizeof(uint64_t));
+
+        /* Number of clusters that the whole image will have */
+        image_clusters = NUM_CLUSTERS(offset) + ref_clusters
+            + reftable_clusters;
+
+        /* 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(1);
-    offset += s->cluster_size;
+    header.refcount_table_clusters = cpu_to_be32(reftable_clusters);
+    offset += (reftable_clusters * 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;
@@ -922,14 +953,15 @@ static int qcow_create2(const char *filename, int64_t total_size,
     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, s->cluster_size);
+    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);
 
     /* write all the data */
     ret = qemu_write_full(fd, &header, sizeof(header));
     if (ret != sizeof(header)) {
-        ret = -1;
+        ret = -errno;
         goto exit;
     }
     if (backing_file) {
@@ -942,25 +974,25 @@ static int qcow_create2(const char *filename, int64_t total_size,
             cpu_to_be32s(&ext_bf.len);
             ret = qemu_write_full(fd, &ext_bf, sizeof(ext_bf));
             if (ret != sizeof(ext_bf)) {
-                ret = -1;
+                ret = -errno;
                 goto exit;
             }
             ret = qemu_write_full(fd, backing_format, backing_format_len);
             if (ret != backing_format_len) {
-                ret = -1;
+                ret = -errno;
                 goto exit;
             }
             if (padding > 0) {
                 ret = qemu_write_full(fd, zero, padding);
                 if (ret != padding) {
-                    ret = -1;
+                    ret = -errno;
                     goto exit;
                 }
             }
         }
         ret = qemu_write_full(fd, backing_file, backing_filename_len);
         if (ret != backing_filename_len) {
-            ret = -1;
+            ret = -errno;
             goto exit;
         }
     }
@@ -969,22 +1001,23 @@ static int qcow_create2(const char *filename, int64_t total_size,
     for(i = 0;i < l1_size; i++) {
         ret = qemu_write_full(fd, &tmp, sizeof(tmp));
         if (ret != sizeof(tmp)) {
-            ret = -1;
+            ret = -errno;
             goto exit;
         }
     }
     lseek(fd, s->refcount_table_offset, SEEK_SET);
-    ret = qemu_write_full(fd, s->refcount_table, s->cluster_size);
-    if (ret != s->cluster_size) {
-        ret = -1;
+    ret = qemu_write_full(fd, s->refcount_table,
+        reftable_clusters * s->cluster_size);
+    if (ret != reftable_clusters * s->cluster_size) {
+        ret = -errno;
         goto exit;
     }
 
     lseek(fd, s->refcount_block_offset, SEEK_SET);
     ret = qemu_write_full(fd, s->refcount_block,
                    ref_clusters * s->cluster_size);
-    if (ret != s->cluster_size) {
-        ret = -1;
+    if (ret != ref_clusters * s->cluster_size) {
+        ret = -errno;
         goto exit;
     }
 
@@ -995,11 +1028,12 @@ exit:
     close(fd);
 
     /* Preallocate metadata */
-    if (prealloc) {
+    if (ret == 0 && prealloc) {
         BlockDriverState *bs;
+        BlockDriver *drv = bdrv_find_format("qcow2");
         bs = bdrv_new("");
-        bdrv_open(bs, filename, BDRV_O_CACHE_WB);
-        preallocate(bs);
+        bdrv_open(bs, filename, BDRV_O_CACHE_WB | BDRV_O_RDWR, drv);
+        ret = preallocate(bs);
         bdrv_close(bs);
     }
 
@@ -1062,9 +1096,9 @@ static int qcow_make_empty(BlockDriverState *bs)
     int ret;
 
     memset(s->l1_table, 0, l1_length);
-    if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0)
+    if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
         return -1;
-    ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length);
+    ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
     if (ret < 0)
         return ret;
 
@@ -1073,6 +1107,43 @@ static int qcow_make_empty(BlockDriverState *bs)
     return 0;
 }
 
+static int qcow2_truncate(BlockDriverState *bs, int64_t offset)
+{
+    BDRVQcowState *s = bs->opaque;
+    int ret, new_l1_size;
+
+    if (offset & 511) {
+        return -EINVAL;
+    }
+
+    /* 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;
+}
+
 /* 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,
@@ -1087,9 +1158,9 @@ static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
     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 = bdrv_getlength(bs->file);
         cluster_offset = (cluster_offset + 511) & ~511;
-        bdrv_truncate(s->hd, cluster_offset);
+        bdrv_truncate(bs->file, cluster_offset);
         return 0;
     }
 
@@ -1132,7 +1203,8 @@ static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
         if (!cluster_offset)
             return -1;
         cluster_offset &= s->cluster_offset_mask;
-        if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
+        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;
         }
@@ -1144,16 +1216,13 @@ static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
 
 static void qcow_flush(BlockDriverState *bs)
 {
-    BDRVQcowState *s = bs->opaque;
-    bdrv_flush(s->hd);
+    bdrv_flush(bs->file);
 }
 
 static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
          BlockDriverCompletionFunc *cb, void *opaque)
 {
-     BDRVQcowState *s = bs->opaque;
-
-     return bdrv_aio_flush(s->hd, cb, opaque);
+    return bdrv_aio_flush(bs->file, cb, opaque);
 }
 
 static int64_t qcow_vm_state_offset(BDRVQcowState *s)
@@ -1170,9 +1239,9 @@ static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 }
 
 
-static int qcow_check(BlockDriverState *bs)
+static int qcow_check(BlockDriverState *bs, BdrvCheckResult *result)
 {
-    return qcow2_check_refcounts(bs);
+    return qcow2_check_refcounts(bs, result);
 }
 
 #if 0
@@ -1182,7 +1251,7 @@ static void dump_refcounts(BlockDriverState *bs)
     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;
@@ -1190,7 +1259,8 @@ static void dump_refcounts(BlockDriverState *bs)
         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
@@ -1202,6 +1272,7 @@ static int qcow_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
     int growable = bs->growable;
     int ret;
 
+    BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
     bs->growable = 1;
     ret = bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size);
     bs->growable = growable;
@@ -1216,6 +1287,7 @@ static int qcow_load_vmstate(BlockDriverState *bs, uint8_t *buf,
     int growable = bs->growable;
     int ret;
 
+    BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
     bs->growable = 1;
     ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size);
     bs->growable = growable;
@@ -1272,7 +1344,9 @@ static BlockDriver bdrv_qcow2 = {
     .bdrv_aio_readv    = qcow_aio_readv,
     .bdrv_aio_writev   = qcow_aio_writev,
     .bdrv_aio_flush    = qcow_aio_flush,
-    .bdrv_write_compressed = qcow_write_compressed,
+
+    .bdrv_truncate          = qcow2_truncate,
+    .bdrv_write_compressed  = qcow_write_compressed,
 
     .bdrv_snapshot_create   = qcow2_snapshot_create,
     .bdrv_snapshot_goto     = qcow2_snapshot_goto,