block: Format/protocol split

118 lines not on this page · raw message

index 05ad572..f58edf1 100644
@@ -57,6 +57,7 @@ BlockDriver *bdrv_find_format(const char *format_name);
 BlockDriver *bdrv_find_whitelisted_format(const char *format_name);
 int bdrv_create(BlockDriver *drv, const char* filename,
     QEMUOptionParameter *options);
+int bdrv_create_file(const char* filename, QEMUOptionParameter *options);
 BlockDriverState *bdrv_new(const char *device_name);
 void bdrv_delete(BlockDriverState *bs);
 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags);

index 4cda9c1..8f57ab0 100644
@@ -768,8 +768,9 @@ static QEMUOptionParameter raw_create_options[] = {
     { NULL }
 };
 
-static BlockDriver bdrv_raw = {
-    .format_name = "raw",
+static BlockDriver bdrv_file = {
+    .format_name = "file",
+    .protocol_name = "file",
     .instance_size = sizeof(BDRVRawState),
     .bdrv_probe = NULL, /* no probe for protocols */
     .bdrv_open = raw_open,

@@ -1026,6 +1027,7 @@ static int hdev_create(const char *filename, QEMUOptionParameter *options)
 
 static BlockDriver bdrv_host_device = {
     .format_name        = "host_device",
+    .protocol_name        = "host_device",
     .instance_size      = sizeof(BDRVRawState),
     .bdrv_probe_device  = hdev_probe_device,
     .bdrv_open          = hdev_open,

@@ -1140,6 +1142,7 @@ static int floppy_eject(BlockDriverState *bs, int eject_flag)
 
 static BlockDriver bdrv_host_floppy = {
     .format_name        = "host_floppy",
+    .protocol_name      = "host_floppy",
     .instance_size      = sizeof(BDRVRawState),
     .bdrv_probe_device	= floppy_probe_device,
     .bdrv_open          = floppy_open,

@@ -1239,6 +1242,7 @@ static int cdrom_set_locked(BlockDriverState *bs, int locked)
 
 static BlockDriver bdrv_host_cdrom = {
     .format_name        = "host_cdrom",
+    .protocol_name      = "host_cdrom",
     .instance_size      = sizeof(BDRVRawState),
     .bdrv_probe_device	= cdrom_probe_device,
     .bdrv_open          = cdrom_open,

@@ -1361,6 +1365,7 @@ static int cdrom_set_locked(BlockDriverState *bs, int locked)
 
 static BlockDriver bdrv_host_cdrom = {
     .format_name        = "host_cdrom",
+    .protocol_name      = "host_cdrom",
     .instance_size      = sizeof(BDRVRawState),
     .bdrv_probe_device	= cdrom_probe_device,
     .bdrv_open          = cdrom_open,

@@ -1385,13 +1390,13 @@ static BlockDriver bdrv_host_cdrom = {
 };
 #endif /* __FreeBSD__ */
 
-static void bdrv_raw_init(void)
+static void bdrv_file_init(void)
 {
     /*
      * Register all the drivers.  Note that order is important, the driver
      * registered last will get probed first.
      */
-    bdrv_register(&bdrv_raw);
+    bdrv_register(&bdrv_file);
     bdrv_register(&bdrv_host_device);
 #ifdef __linux__
     bdrv_register(&bdrv_host_floppy);

@@ -1402,4 +1407,4 @@ static void bdrv_raw_init(void)
 #endif
 }
 
-block_init(bdrv_raw_init);
+block_init(bdrv_file_init);

index 526764f..eadebeb 100644
@@ -238,8 +238,9 @@ static QEMUOptionParameter raw_create_options[] = {
     { NULL }
 };
 
-static BlockDriver bdrv_raw = {
-    .format_name	= "raw",
+static BlockDriver bdrv_file = {
+    .format_name	= "file",
+    .protocol_name	= "file",
     .instance_size	= sizeof(BDRVRawState),
     .bdrv_open		= raw_open,
     .bdrv_close		= raw_close,

@@ -395,6 +396,7 @@ static int raw_set_locked(BlockDriverState *bs, int locked)
 
 static BlockDriver bdrv_host_device = {
     .format_name	= "host_device",
+    .protocol_name	= "host_device",
     .instance_size	= sizeof(BDRVRawState),
     .bdrv_probe_device	= hdev_probe_device,
     .bdrv_open		= hdev_open,

@@ -406,10 +408,10 @@ static BlockDriver bdrv_host_device = {
     .bdrv_getlength	= raw_getlength,
 };
 
-static void bdrv_raw_init(void)
+static void bdrv_file_init(void)
 {
-    bdrv_register(&bdrv_raw);
+    bdrv_register(&bdrv_file);
     bdrv_register(&bdrv_host_device);
 }
 
-block_init(bdrv_raw_init);
+block_init(bdrv_file_init);

171 lines not on this page · raw message

index 715c30e..e04f80d 100644
@@ -42,6 +42,9 @@
 #include <windows.h>
 #endif
 
+static int bdrv_open_common(BlockDriverState *bs, const char *filename,
+    int flags, BlockDriver *drv);
+
 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque);

@@ -350,6 +353,9 @@ static BlockDriver *find_image_format(const char *filename)
     return drv;
 }
 
+/*
+ * Opens a file using a protocol (file, host_device, nbd, ...)
+ */
 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
 {
     BlockDriverState *bs;

@@ -362,7 +368,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
     }
 
     bs = bdrv_new("");
-    ret = bdrv_open(bs, filename, flags, drv);
+    ret = bdrv_open_common(bs, filename, flags, drv);
     if (ret < 0) {
         bdrv_delete(bs);
         return ret;

@@ -372,19 +378,13 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
     return 0;
 }
 
+/*
+ * Opens a disk image (raw, qcow2, vmdk, ...)
+ */
 int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
               BlockDriver *drv)
 {
-    int ret, open_flags;
-    char tmp_filename[PATH_MAX];
-    char backing_filename[PATH_MAX];
-
-    bs->is_temporary = 0;
-    bs->encrypted = 0;
-    bs->valid_key = 0;
-    bs->open_flags = flags;
-    /* buffer_alignment defaulted to 512, drivers can change this value */
-    bs->buffer_alignment = 512;
+    int ret;
 
     if (flags & BDRV_O_SNAPSHOT) {
         BlockDriverState *bs1;

@@ -392,6 +392,8 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         int is_protocol = 0;
         BlockDriver *bdrv_qcow2;
         QEMUOptionParameter *options;
+        char tmp_filename[PATH_MAX];
+        char backing_filename[PATH_MAX];
 
         /* if snapshot, we create a temporary backing file and open it
            instead of opening 'filename' directly */

@@ -439,8 +441,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         bs->is_temporary = 1;
     }
 
-    pstrcpy(bs->filename, sizeof(bs->filename), filename);
-
+    /* Find the right image format driver */
     if (!drv) {
         drv = find_image_format(filename);
     }

@@ -449,11 +450,81 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         ret = -ENOENT;
         goto unlink_and_fail;
     }
-    if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
-        ret = -ENOTSUP;
+
+    /* Open the image */
+    ret = bdrv_open_common(bs, filename, flags, drv);
+    if (ret < 0) {
         goto unlink_and_fail;
     }
 
+    /* If there is a backing file, use it */
+    if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
+        char backing_filename[PATH_MAX];
+        int back_flags;
+        BlockDriver *back_drv = NULL;
+
+        bs->backing_hd = bdrv_new("");
+        path_combine(backing_filename, sizeof(backing_filename),
+                     filename, bs->backing_file);
+        if (bs->backing_format[0] != '\0')
+            back_drv = bdrv_find_format(bs->backing_format);
+
+        /* backing files always opened read-only */
+        back_flags =
+            flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
+
+        ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv);
+        if (ret < 0) {
+            bdrv_close(bs);
+            return ret;
+        }
+        if (bs->is_temporary) {
+            bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
+        } else {
+            /* base image inherits from "parent" */
+            bs->backing_hd->keep_read_only = bs->keep_read_only;
+        }
+    }
+
+    if (!bdrv_key_required(bs)) {
+        /* call the change callback */
+        bs->media_changed = 1;
+        if (bs->change_cb)
+            bs->change_cb(bs->change_opaque);
+    }
+
+    return 0;
+
+unlink_and_fail:
+    if (bs->is_temporary) {
+        unlink(filename);
+    }
+    return ret;
+}
+
+/*
+ * Common part for opening disk images and files
+ */
+static int bdrv_open_common(BlockDriverState *bs, const char *filename,
+    int flags, BlockDriver *drv)
+{
+    int ret, open_flags;
+
+    assert(drv != NULL);
+
+    bs->is_temporary = 0;
+    bs->encrypted = 0;
+    bs->valid_key = 0;
+    bs->open_flags = flags;
+    /* buffer_alignment defaulted to 512, drivers can change this value */
+    bs->buffer_alignment = 512;
+
+    pstrcpy(bs->filename, sizeof(bs->filename), filename);
+
+    if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
+        return -ENOTSUP;
+    }
+
     bs->drv = drv;
     bs->opaque = qemu_mallocz(drv->instance_size);
 

@@ -493,46 +564,12 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         unlink(filename);
     }
 #endif
-    if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
-        /* if there is a backing file, use it */
-        BlockDriver *back_drv = NULL;
-        bs->backing_hd = bdrv_new("");
-        path_combine(backing_filename, sizeof(backing_filename),
-                     filename, bs->backing_file);
-        if (bs->backing_format[0] != '\0')
-            back_drv = bdrv_find_format(bs->backing_format);
-
-        /* backing files always opened read-only */
-        open_flags &= ~BDRV_O_RDWR;
-
-        ret = bdrv_open(bs->backing_hd, backing_filename, open_flags, back_drv);
-        if (ret < 0) {
-            bdrv_close(bs);
-            return ret;
-        }
-        if (bs->is_temporary) {
-            bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR);
-        } else {
-            /* base image inherits from "parent" */
-            bs->backing_hd->keep_read_only = bs->keep_read_only;
-        }
-    }
-
-    if (!bdrv_key_required(bs)) {
-        /* call the change callback */
-        bs->media_changed = 1;
-        if (bs->change_cb)
-            bs->change_cb(bs->change_opaque);
-    }
     return 0;
 
 free_and_fail:
     qemu_free(bs->opaque);
     bs->opaque = NULL;
     bs->drv = NULL;
-unlink_and_fail:
-    if (bs->is_temporary)
-        unlink(filename);
     return ret;
 }
 

index e04f80d..fd70d64 100644
@@ -42,9 +42,6 @@
 #include <windows.h>
 #endif
 
-static int bdrv_open_common(BlockDriverState *bs, const char *filename,
-    int flags, BlockDriver *drv);
-
 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque);

@@ -354,6 +351,77 @@ static BlockDriver *find_image_format(const char *filename)
 }
 
 /*
+ * Common part for opening disk images and files
+ */
+static int bdrv_open_common(BlockDriverState *bs, const char *filename,
+    int flags, BlockDriver *drv)
+{
+    int ret, open_flags;
+
+    assert(drv != NULL);
+
+    bs->is_temporary = 0;
+    bs->encrypted = 0;
+    bs->valid_key = 0;
+    bs->open_flags = flags;
+    /* buffer_alignment defaulted to 512, drivers can change this value */
+    bs->buffer_alignment = 512;
+
+    pstrcpy(bs->filename, sizeof(bs->filename), filename);
+
+    if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
+        return -ENOTSUP;
+    }
+
+    bs->drv = drv;
+    bs->opaque = qemu_mallocz(drv->instance_size);
+
+    /*
+     * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
+     * write cache to the guest.  We do need the fdatasync to flush
+     * out transactions for block allocations, and we maybe have a
+     * volatile write cache in our backing device to deal with.
+     */
+    if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
+        bs->enable_write_cache = 1;
+
+    /*
+     * Clear flags that are internal to the block layer before opening the
+     * image.
+     */
+    open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
+
+    /*
+     * Snapshots should be writeable.
+     */
+    if (bs->is_temporary) {
+        open_flags |= BDRV_O_RDWR;
+    }
+
+    ret = drv->bdrv_open(bs, filename, open_flags);
+    if (ret < 0) {
+        goto free_and_fail;
+    }
+
+    bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
+    if (drv->bdrv_getlength) {
+        bs->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
+    }
+#ifndef _WIN32
+    if (bs->is_temporary) {
+        unlink(filename);
+    }
+#endif
+    return 0;
+
+free_and_fail:
+    qemu_free(bs->opaque);
+    bs->opaque = NULL;
+    bs->drv = NULL;
+    return ret;
+}
+
+/*
  * Opens a file using a protocol (file, host_device, nbd, ...)
  */
 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)

@@ -502,77 +570,6 @@ unlink_and_fail:
     return ret;
 }
 
-/*
- * Common part for opening disk images and files
- */
-static int bdrv_open_common(BlockDriverState *bs, const char *filename,
-    int flags, BlockDriver *drv)
-{
-    int ret, open_flags;
-
-    assert(drv != NULL);
-
-    bs->is_temporary = 0;
-    bs->encrypted = 0;
-    bs->valid_key = 0;
-    bs->open_flags = flags;
-    /* buffer_alignment defaulted to 512, drivers can change this value */
-    bs->buffer_alignment = 512;
-
-    pstrcpy(bs->filename, sizeof(bs->filename), filename);
-
-    if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) {
-        return -ENOTSUP;
-    }
-
-    bs->drv = drv;
-    bs->opaque = qemu_mallocz(drv->instance_size);
-
-    /*
-     * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
-     * write cache to the guest.  We do need the fdatasync to flush
-     * out transactions for block allocations, and we maybe have a
-     * volatile write cache in our backing device to deal with.
-     */
-    if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
-        bs->enable_write_cache = 1;
-
-    /*
-     * Clear flags that are internal to the block layer before opening the
-     * image.
-     */
-    open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
-
-    /*
-     * Snapshots should be writeable.
-     */
-    if (bs->is_temporary) {
-        open_flags |= BDRV_O_RDWR;
-    }
-
-    ret = drv->bdrv_open(bs, filename, open_flags);
-    if (ret < 0) {
-        goto free_and_fail;
-    }
-
-    bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR);
-    if (drv->bdrv_getlength) {
-        bs->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
-    }
-#ifndef _WIN32
-    if (bs->is_temporary) {
-        unlink(filename);
-    }
-#endif
-    return 0;
-
-free_and_fail:
-    qemu_free(bs->opaque);
-    bs->opaque = NULL;
-    bs->drv = NULL;
-    return ret;
-}
-
 void bdrv_close(BlockDriverState *bs)
 {
     if (bs->drv) {

index fd70d64..6c66974 100644
@@ -288,6 +288,8 @@ static BlockDriver *find_protocol(const char *filename)
     int len;
     const char *p;
 
+    /* TODO Drivers without bdrv_file_open must be specified explicitly */
+
 #ifdef _WIN32
     if (is_windows_drive(filename) ||
         is_windows_drive_prefix(filename))

@@ -398,7 +400,16 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
         open_flags |= BDRV_O_RDWR;
     }
 
-    ret = drv->bdrv_open(bs, filename, open_flags);
+    /* Open the image, either directly or using a protocol */
+    if (drv->bdrv_file_open) {
+        ret = drv->bdrv_file_open(bs, filename, open_flags);
+    } else {
+        ret = bdrv_file_open(&bs->file, filename, open_flags);
+        if (ret >= 0) {
+            ret = drv->bdrv_open(bs, open_flags);
+        }
+    }
+
     if (ret < 0) {
         goto free_and_fail;
     }

@@ -415,6 +426,10 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename,
     return 0;
 
 free_and_fail:
+    if (bs->file) {
+        bdrv_delete(bs->file);
+        bs->file = NULL;
+    }
     qemu_free(bs->opaque);
     bs->opaque = NULL;
     bs->drv = NULL;

@@ -585,6 +600,10 @@ void bdrv_close(BlockDriverState *bs)
         bs->opaque = NULL;
         bs->drv = NULL;
 
+        if (bs->file != NULL) {
+            bdrv_close(bs->file);
+        }
+
         /* call the change callback */
         bs->media_changed = 1;
         if (bs->change_cb)

@@ -600,6 +619,10 @@ void bdrv_delete(BlockDriverState *bs)
     }
 
     bdrv_close(bs);
+    if (bs->file != NULL) {
+        bdrv_delete(bs->file);
+    }
+
     qemu_free(bs);
 }
 

index 643c397..bb4a91a 100644
@@ -44,7 +44,6 @@ typedef struct BlkdebugVars {
 } BlkdebugVars;
 
 typedef struct BDRVBlkdebugState {
-    BlockDriverState *hd;
     BlkdebugVars vars;
     QLIST_HEAD(list, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
 } BDRVBlkdebugState;

@@ -303,7 +302,7 @@ static int blkdebug_open(BlockDriverState *bs, const char *filename, int flags)
     filename = c + 1;
 
     /* Open the backing file */
-    ret = bdrv_file_open(&s->hd, filename, flags);
+    ret = bdrv_file_open(&bs->file, filename, flags);
     if (ret < 0) {
         return ret;
     }

@@ -362,7 +361,7 @@ static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
     }
 
     BlockDriverAIOCB *acb =
-        bdrv_aio_readv(s->hd, sector_num, qiov, nb_sectors, cb, opaque);
+        bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
     return acb;
 }
 

@@ -377,7 +376,7 @@ static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
     }
 
     BlockDriverAIOCB *acb =
-        bdrv_aio_writev(s->hd, sector_num, qiov, nb_sectors, cb, opaque);
+        bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
     return acb;
 }
 

@@ -393,21 +392,17 @@ static void blkdebug_close(BlockDriverState *bs)
             qemu_free(rule);
         }
     }
-
-    bdrv_delete(s->hd);
 }
 
 static void blkdebug_flush(BlockDriverState *bs)
 {
-    BDRVBlkdebugState *s = bs->opaque;
-    bdrv_flush(s->hd);
+    bdrv_flush(bs->file);
 }
 
 static BlockDriverAIOCB *blkdebug_aio_flush(BlockDriverState *bs,
     BlockDriverCompletionFunc *cb, void *opaque)
 {
-    BDRVBlkdebugState *s = bs->opaque;
-    return bdrv_aio_flush(s->hd, cb, opaque);
+    return bdrv_aio_flush(bs->file, cb, opaque);
 }
 
 static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,

@@ -456,7 +451,7 @@ static BlockDriver bdrv_blkdebug = {
 
     .instance_size      = sizeof(BDRVBlkdebugState),
 
-    .bdrv_open          = blkdebug_open,
+    .bdrv_file_open     = blkdebug_open,
     .bdrv_close         = blkdebug_close,
     .bdrv_flush         = blkdebug_flush,
 

index 843008f..c8f921f 100644
@@ -254,7 +254,7 @@ static BlockDriver bdrv_bochs = {
     .format_name	= "bochs",
     .instance_size	= sizeof(BDRVBochsState),
     .bdrv_probe		= bochs_probe,
-    .bdrv_open		= bochs_open,
+    .bdrv_file_open	= bochs_open,
     .bdrv_read		= bochs_read,
     .bdrv_close		= bochs_close,
 };

index bf1b9b4..96cbb89 100644
@@ -161,7 +161,7 @@ static BlockDriver bdrv_cloop = {
     .format_name	= "cloop",
     .instance_size	= sizeof(BDRVCloopState),
     .bdrv_probe		= cloop_probe,
-    .bdrv_open		= cloop_open,
+    .bdrv_file_open	= cloop_open,
     .bdrv_read		= cloop_read,
     .bdrv_close		= cloop_close,
 };

index 97e9745..fde066e 100644
@@ -291,7 +291,7 @@ static BlockDriver bdrv_cow = {
     .format_name	= "cow",
     .instance_size	= sizeof(BDRVCowState),
     .bdrv_probe		= cow_probe,
-    .bdrv_open		= cow_open,
+    .bdrv_file_open	= cow_open,
     .bdrv_read		= cow_read,
     .bdrv_write		= cow_write,
     .bdrv_close		= cow_close,

index 2cf72cb..b944740 100644
@@ -495,7 +495,7 @@ static BlockDriver bdrv_http = {
     .protocol_name   = "http",
 
     .instance_size   = sizeof(BDRVCURLState),
-    .bdrv_open       = curl_open,
+    .bdrv_file_open  = curl_open,
     .bdrv_close      = curl_close,
     .bdrv_getlength  = curl_getlength,
 

@@ -507,7 +507,7 @@ static BlockDriver bdrv_https = {
     .protocol_name   = "https",
 
     .instance_size   = sizeof(BDRVCURLState),
-    .bdrv_open       = curl_open,
+    .bdrv_file_open  = curl_open,
     .bdrv_close      = curl_close,
     .bdrv_getlength  = curl_getlength,
 

@@ -519,7 +519,7 @@ static BlockDriver bdrv_ftp = {
     .protocol_name   = "ftp",
 
     .instance_size   = sizeof(BDRVCURLState),
-    .bdrv_open       = curl_open,
+    .bdrv_file_open  = curl_open,
     .bdrv_close      = curl_close,
     .bdrv_getlength  = curl_getlength,
 

@@ -531,7 +531,7 @@ static BlockDriver bdrv_ftps = {
     .protocol_name   = "ftps",
 
     .instance_size   = sizeof(BDRVCURLState),
-    .bdrv_open       = curl_open,
+    .bdrv_file_open  = curl_open,
     .bdrv_close      = curl_close,
     .bdrv_getlength  = curl_getlength,
 

@@ -543,7 +543,7 @@ static BlockDriver bdrv_tftp = {
     .protocol_name   = "tftp",
 
     .instance_size   = sizeof(BDRVCURLState),
-    .bdrv_open       = curl_open,
+    .bdrv_file_open  = curl_open,
     .bdrv_close      = curl_close,
     .bdrv_getlength  = curl_getlength,
 

index dbb4eda..f65b5f5 100644
@@ -291,7 +291,7 @@ static BlockDriver bdrv_dmg = {
     .format_name	= "dmg",
     .instance_size	= sizeof(BDRVDMGState),
     .bdrv_probe		= dmg_probe,
-    .bdrv_open		= dmg_open,
+    .bdrv_file_open	= dmg_open,
     .bdrv_read		= dmg_read,
     .bdrv_close		= dmg_close,
 };

index 7bac38d..a1ec123 100644
@@ -177,7 +177,7 @@ static int64_t nbd_getlength(BlockDriverState *bs)
 static BlockDriver bdrv_nbd = {
     .format_name	= "nbd",
     .instance_size	= sizeof(BDRVNBDState),
-    .bdrv_open		= nbd_open,
+    .bdrv_file_open	= nbd_open,
     .bdrv_read		= nbd_read,
     .bdrv_write		= nbd_write,
     .bdrv_close		= nbd_close,

index b6312a6..3d04965 100644
@@ -169,7 +169,7 @@ static BlockDriver bdrv_parallels = {
     .format_name	= "parallels",
     .instance_size	= sizeof(BDRVParallelsState),
     .bdrv_probe		= parallels_probe,
-    .bdrv_open		= parallels_open,
+    .bdrv_file_open	= parallels_open,
     .bdrv_read		= parallels_read,
     .bdrv_close		= parallels_close,
 };

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258 lines not on this page · raw message

index 8ddaea2..2a21c17 100644
@@ -79,7 +79,7 @@ int qcow2_read_snapshots(BlockDriverState *bs)
     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))
+        if (bdrv_pread(bs->file, offset, &h, sizeof(h)) != sizeof(h))
             goto fail;
         offset += sizeof(h);
         sn = s->snapshots + i;

@@ -97,13 +97,13 @@ int qcow2_read_snapshots(BlockDriverState *bs)
         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)
+        if (bdrv_pread(bs->file, 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)
+        if (bdrv_pread(bs->file, offset, sn->name, name_size) != name_size)
             goto fail;
         offset += name_size;
         sn->name[name_size] = '\0';

@@ -158,24 +158,24 @@ static int qcow_write_snapshots(BlockDriverState *bs)
         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))
+        if (bdrv_pwrite(bs->file, 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)
+        if (bdrv_pwrite(bs->file, 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)
+        if (bdrv_pwrite(bs->file, 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),
+    if (bdrv_pwrite(bs->file, 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),
+    if (bdrv_pwrite(bs->file, offsetof(QCowHeader, nb_snapshots),
                     &data32, sizeof(data32)) != sizeof(data32))
         goto fail;
 

@@ -284,7 +284,7 @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
     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,
+    if (bdrv_pwrite(bs->file, sn->l1_table_offset,
                     l1_table, s->l1_size * sizeof(uint64_t)) !=
         (s->l1_size * sizeof(uint64_t)))
         goto fail;

@@ -332,10 +332,10 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id)
     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,
+    if (bdrv_pread(bs->file, sn->l1_table_offset,
                    s->l1_table, l1_size2) != l1_size2)
         goto fail;
-    if (bdrv_pwrite(s->hd, s->l1_table_offset,
+    if (bdrv_pwrite(bs->file, s->l1_table_offset,
                     s->l1_table, l1_size2) != l1_size2)
         goto fail;
     for(i = 0;i < s->l1_size; i++) {

222 lines not on this page · raw message

index de9397a..5bd08db 100644
@@ -184,7 +184,7 @@ int qcow2_check_refcounts(BlockDriverState *bs);
 /* qcow2-cluster.c functions */
 int qcow2_grow_l1_table(BlockDriverState *bs, int min_size);
 void qcow2_l2_cache_reset(BlockDriverState *bs);
-int qcow2_decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset);
+int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
 void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
                      uint8_t *out_buf, const uint8_t *in_buf,
                      int nb_sectors, int enc,

index 8f57ab0..598ea19 100644
@@ -773,7 +773,7 @@ static BlockDriver bdrv_file = {
     .protocol_name = "file",
     .instance_size = sizeof(BDRVRawState),
     .bdrv_probe = NULL, /* no probe for protocols */
-    .bdrv_open = raw_open,
+    .bdrv_file_open = raw_open,
     .bdrv_read = raw_read,
     .bdrv_write = raw_write,
     .bdrv_close = raw_close,

@@ -1030,7 +1030,7 @@ static BlockDriver bdrv_host_device = {
     .protocol_name        = "host_device",
     .instance_size      = sizeof(BDRVRawState),
     .bdrv_probe_device  = hdev_probe_device,
-    .bdrv_open          = hdev_open,
+    .bdrv_file_open     = hdev_open,
     .bdrv_close         = raw_close,
     .bdrv_create        = hdev_create,
     .create_options     = raw_create_options,

@@ -1145,7 +1145,7 @@ static BlockDriver bdrv_host_floppy = {
     .protocol_name      = "host_floppy",
     .instance_size      = sizeof(BDRVRawState),
     .bdrv_probe_device	= floppy_probe_device,
-    .bdrv_open          = floppy_open,
+    .bdrv_file_open     = floppy_open,
     .bdrv_close         = raw_close,
     .bdrv_create        = hdev_create,
     .create_options     = raw_create_options,

@@ -1245,7 +1245,7 @@ static BlockDriver bdrv_host_cdrom = {
     .protocol_name      = "host_cdrom",
     .instance_size      = sizeof(BDRVRawState),
     .bdrv_probe_device	= cdrom_probe_device,
-    .bdrv_open          = cdrom_open,
+    .bdrv_file_open     = cdrom_open,
     .bdrv_close         = raw_close,
     .bdrv_create        = hdev_create,
     .create_options     = raw_create_options,

@@ -1368,7 +1368,7 @@ static BlockDriver bdrv_host_cdrom = {
     .protocol_name      = "host_cdrom",
     .instance_size      = sizeof(BDRVRawState),
     .bdrv_probe_device	= cdrom_probe_device,
-    .bdrv_open          = cdrom_open,
+    .bdrv_file_open     = cdrom_open,
     .bdrv_close         = raw_close,
     .bdrv_create        = hdev_create,
     .create_options     = raw_create_options,

index eadebeb..745bbde 100644
@@ -242,7 +242,7 @@ static BlockDriver bdrv_file = {
     .format_name	= "file",
     .protocol_name	= "file",
     .instance_size	= sizeof(BDRVRawState),
-    .bdrv_open		= raw_open,
+    .bdrv_file_open	= raw_open,
     .bdrv_close		= raw_close,
     .bdrv_create	= raw_create,
     .bdrv_flush		= raw_flush,

@@ -399,7 +399,7 @@ static BlockDriver bdrv_host_device = {
     .protocol_name	= "host_device",
     .instance_size	= sizeof(BDRVRawState),
     .bdrv_probe_device	= hdev_probe_device,
-    .bdrv_open		= hdev_open,
+    .bdrv_file_open	= hdev_open,
     .bdrv_close		= raw_close,
     .bdrv_flush		= raw_flush,
 

144 lines not on this page · raw message

index c91961a..8b85339 100644
@@ -376,21 +376,15 @@ static int vdi_probe(const uint8_t *buf, int buf_size, const char *filename)
     return result;
 }
 
-static int vdi_open(BlockDriverState *bs, const char *filename, int flags)
+static int vdi_open(BlockDriverState *bs, int flags)
 {
     BDRVVdiState *s = bs->opaque;
     VdiHeader header;
     size_t bmap_size;
-    int ret;
 
     logout("\n");
 
-    ret = bdrv_file_open(&s->hd, filename, flags);
-    if (ret < 0) {
-        return ret;
-    }
-
-    if (bdrv_read(s->hd, 0, (uint8_t *)&header, 1) < 0) {
+    if (bdrv_read(bs->file, 0, (uint8_t *)&header, 1) < 0) {
         goto fail;
     }
 

@@ -442,7 +436,7 @@ static int vdi_open(BlockDriverState *bs, const char *filename, int flags)
     bmap_size = header.blocks_in_image * sizeof(uint32_t);
     bmap_size = (bmap_size + SECTOR_SIZE - 1) / SECTOR_SIZE;
     s->bmap = qemu_malloc(bmap_size * SECTOR_SIZE);
-    if (bdrv_read(s->hd, s->bmap_sector, (uint8_t *)s->bmap, bmap_size) < 0) {
+    if (bdrv_read(bs->file, s->bmap_sector, (uint8_t *)s->bmap, bmap_size) < 0) {
         goto fail_free_bmap;
     }
 

@@ -452,7 +446,7 @@ static int vdi_open(BlockDriverState *bs, const char *filename, int flags)
     qemu_free(s->bmap);
 
  fail:
-    bdrv_delete(s->hd);
+    bdrv_delete(bs->file);
     return -1;
 }
 

@@ -607,7 +601,7 @@ static void vdi_aio_read_cb(void *opaque, int ret)
         acb->hd_iov.iov_base = (void *)acb->buf;
         acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE;
         qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
-        acb->hd_aiocb = bdrv_aio_readv(s->hd, offset, &acb->hd_qiov,
+        acb->hd_aiocb = bdrv_aio_readv(bs->file, offset, &acb->hd_qiov,
                                        n_sectors, vdi_aio_read_cb, acb);
         if (acb->hd_aiocb == NULL) {
             goto done;

@@ -670,7 +664,7 @@ static void vdi_aio_write_cb(void *opaque, int ret)
             acb->hd_iov.iov_base = acb->block_buffer;
             acb->hd_iov.iov_len = SECTOR_SIZE;
             qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
-            acb->hd_aiocb = bdrv_aio_writev(s->hd, 0, &acb->hd_qiov, 1,
+            acb->hd_aiocb = bdrv_aio_writev(bs->file, 0, &acb->hd_qiov, 1,
                                             vdi_aio_write_cb, acb);
             if (acb->hd_aiocb == NULL) {
                 goto done;

@@ -699,7 +693,7 @@ static void vdi_aio_write_cb(void *opaque, int ret)
             qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
             logout("will write %u block map sectors starting from entry %u\n",
                    n_sectors, bmap_first);
-            acb->hd_aiocb = bdrv_aio_writev(s->hd, offset, &acb->hd_qiov,
+            acb->hd_aiocb = bdrv_aio_writev(bs->file, offset, &acb->hd_qiov,
                                             n_sectors, vdi_aio_write_cb, acb);
             if (acb->hd_aiocb == NULL) {
                 goto done;

@@ -748,7 +742,7 @@ static void vdi_aio_write_cb(void *opaque, int ret)
         acb->hd_iov.iov_base = (void *)block;
         acb->hd_iov.iov_len = s->block_size;
         qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
-        acb->hd_aiocb = bdrv_aio_writev(s->hd, offset,
+        acb->hd_aiocb = bdrv_aio_writev(bs->file, offset,
                                         &acb->hd_qiov, s->block_sectors,
                                         vdi_aio_write_cb, acb);
         if (acb->hd_aiocb == NULL) {

@@ -761,7 +755,7 @@ static void vdi_aio_write_cb(void *opaque, int ret)
         acb->hd_iov.iov_base = (void *)acb->buf;
         acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE;
         qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
-        acb->hd_aiocb = bdrv_aio_writev(s->hd, offset, &acb->hd_qiov,
+        acb->hd_aiocb = bdrv_aio_writev(bs->file, offset, &acb->hd_qiov,
                                         n_sectors, vdi_aio_write_cb, acb);
         if (acb->hd_aiocb == NULL) {
             goto done;

@@ -891,16 +885,12 @@ static int vdi_create(const char *filename, QEMUOptionParameter *options)
 
 static void vdi_close(BlockDriverState *bs)
 {
-    BDRVVdiState *s = bs->opaque;
-    logout("\n");
-    bdrv_delete(s->hd);
 }
 
 static void vdi_flush(BlockDriverState *bs)
 {
-    BDRVVdiState *s = bs->opaque;
     logout("\n");
-    bdrv_flush(s->hd);
+    bdrv_flush(bs->file);
 }
 
 

index 6fdea1d..5ef4375 100644
@@ -914,7 +914,7 @@ static BlockDriver bdrv_vmdk = {
     .format_name	= "vmdk",
     .instance_size	= sizeof(BDRVVmdkState),
     .bdrv_probe		= vmdk_probe,
-    .bdrv_open		= vmdk_open,
+    .bdrv_file_open	= vmdk_open,
     .bdrv_read		= vmdk_read,
     .bdrv_write		= vmdk_write,
     .bdrv_close		= vmdk_close,

index 950ad58..1d1ae09 100644
@@ -150,20 +150,16 @@ static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename)
     return 0;
 }
 
-static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
+static int vpc_open(BlockDriverState *bs, int flags)
 {
     BDRVVPCState *s = bs->opaque;
-    int ret, i;
+    int i;
     struct vhd_footer* footer;
     struct vhd_dyndisk_header* dyndisk_header;
     uint8_t buf[HEADER_SIZE];
     uint32_t checksum;
 
-    ret = bdrv_file_open(&s->hd, filename, flags);
-    if (ret < 0)
-        return ret;
-
-    if (bdrv_pread(s->hd, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE)
+    if (bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE)
         goto fail;
 
     footer = (struct vhd_footer*) s->footer_buf;

@@ -174,7 +170,7 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
     footer->checksum = 0;
     if (vpc_checksum(s->footer_buf, HEADER_SIZE) != checksum)
         fprintf(stderr, "block-vpc: The header checksum of '%s' is "
-            "incorrect.\n", filename);
+            "incorrect.\n", bs->filename);
 
     // The visible size of a image in Virtual PC depends on the geometry
     // rather than on the size stored in the footer (the size in the footer

@@ -182,7 +178,7 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
     bs->total_sectors = (int64_t)
         be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl;
 
-    if (bdrv_pread(s->hd, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE)
+    if (bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE)
             != HEADER_SIZE)
         goto fail;
 

@@ -199,7 +195,7 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
     s->pagetable = qemu_malloc(s->max_table_entries * 4);
 
     s->bat_offset = be64_to_cpu(dyndisk_header->table_offset);
-    if (bdrv_pread(s->hd, s->bat_offset, s->pagetable,
+    if (bdrv_pread(bs->file, s->bat_offset, s->pagetable,
             s->max_table_entries * 4) != s->max_table_entries * 4)
 	    goto fail;
 

@@ -228,7 +224,7 @@ static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
 
     return 0;
  fail:
-    bdrv_delete(s->hd);
+    bdrv_delete(bs->file);
     return -1;
 }
 

@@ -266,7 +262,7 @@ static inline int64_t get_sector_offset(BlockDriverState *bs,
 
         s->last_bitmap_offset = bitmap_offset;
         memset(bitmap, 0xff, s->bitmap_size);
-        bdrv_pwrite(s->hd, bitmap_offset, bitmap, s->bitmap_size);
+        bdrv_pwrite(bs->file, bitmap_offset, bitmap, s->bitmap_size);
     }
 
 //    printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n",

@@ -316,7 +312,7 @@ static int rewrite_footer(BlockDriverState* bs)
     BDRVVPCState *s = bs->opaque;
     int64_t offset = s->free_data_block_offset;
 
-    ret = bdrv_pwrite(s->hd, offset, s->footer_buf, HEADER_SIZE);
+    ret = bdrv_pwrite(bs->file, offset, s->footer_buf, HEADER_SIZE);
     if (ret < 0)
         return ret;
 

@@ -351,7 +347,7 @@ static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num)
 
     // Initialize the block's bitmap
     memset(bitmap, 0xff, s->bitmap_size);
-    bdrv_pwrite(s->hd, s->free_data_block_offset, bitmap, s->bitmap_size);
+    bdrv_pwrite(bs->file, s->free_data_block_offset, bitmap, s->bitmap_size);
 
     // Write new footer (the old one will be overwritten)
     s->free_data_block_offset += s->block_size + s->bitmap_size;

@@ -362,7 +358,7 @@ static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num)
     // Write BAT entry to disk
     bat_offset = s->bat_offset + (4 * index);
     bat_value = be32_to_cpu(s->pagetable[index]);
-    ret = bdrv_pwrite(s->hd, bat_offset, &bat_value, 4);
+    ret = bdrv_pwrite(bs->file, bat_offset, &bat_value, 4);
     if (ret < 0)
         goto fail;
 

@@ -376,7 +372,6 @@ fail:
 static int vpc_read(BlockDriverState *bs, int64_t sector_num,
                     uint8_t *buf, int nb_sectors)
 {
-    BDRVVPCState *s = bs->opaque;
     int ret;
     int64_t offset;
 

@@ -386,7 +381,7 @@ static int vpc_read(BlockDriverState *bs, int64_t sector_num,
         if (offset == -1) {
             memset(buf, 0, 512);
         } else {
-            ret = bdrv_pread(s->hd, offset, buf, 512);
+            ret = bdrv_pread(bs->file, offset, buf, 512);
             if (ret != 512)
                 return -1;
         }

@@ -401,7 +396,6 @@ static int vpc_read(BlockDriverState *bs, int64_t sector_num,
 static int vpc_write(BlockDriverState *bs, int64_t sector_num,
     const uint8_t *buf, int nb_sectors)
 {
-    BDRVVPCState *s = bs->opaque;
     int64_t offset;
     int ret;
 

@@ -414,7 +408,7 @@ static int vpc_write(BlockDriverState *bs, int64_t sector_num,
                 return -1;
         }
 
-        ret = bdrv_pwrite(s->hd, offset, buf, 512);
+        ret = bdrv_pwrite(bs->file, offset, buf, 512);
         if (ret != 512)
             return -1;
 

@@ -590,7 +584,7 @@ static void vpc_close(BlockDriverState *bs)
 #ifdef CACHE
     qemu_free(s->pageentry_u8);
 #endif
-    bdrv_delete(s->hd);
+    bdrv_delete(bs->file);
 }
 
 static QEMUOptionParameter vpc_create_options[] = {

index 0701df4..5adbe84 100644
@@ -2827,7 +2827,7 @@ static void vvfat_close(BlockDriverState *bs)
 static BlockDriver bdrv_vvfat = {
     .format_name	= "vvfat",
     .instance_size	= sizeof(BDRVVVFATState),
-    .bdrv_open		= vvfat_open,
+    .bdrv_file_open	= vvfat_open,
     .bdrv_read		= vvfat_read,
     .bdrv_write		= vvfat_write,
     .bdrv_close		= vvfat_close,

index d4067ff..a3afe63 100644
@@ -51,7 +51,8 @@ struct BlockDriver {
     int instance_size;
     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
     int (*bdrv_probe_device)(const char *filename);
-    int (*bdrv_open)(BlockDriverState *bs, const char *filename, int flags);
+    int (*bdrv_open)(BlockDriverState *bs, int flags);
+    int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
                      uint8_t *buf, int nb_sectors);
     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,

@@ -155,6 +156,8 @@ struct BlockDriverState {
     int media_changed;
 
     BlockDriverState *backing_hd;
+    BlockDriverState *file;
+
     /* async read/write emulation */
 
     void *sync_aiocb;

index 6c66974..cf75f97 100644
@@ -1281,6 +1281,19 @@ void bdrv_flush_all(void)
     }
 }
 
+int bdrv_has_zero_init(BlockDriverState *bs)
+{
+    assert(bs->drv);
+
+    if (bs->drv->no_zero_init) {
+        return 0;
+    } else if (bs->file) {
+        return bdrv_has_zero_init(bs->file);
+    }
+
+    return 1;
+}
+
 /*
  * Returns true iff the specified sector is present in the disk image. Drivers
  * not implementing the functionality are assumed to not support backing files,

index f58edf1..f87d24e 100644
@@ -122,6 +122,7 @@ BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
 void bdrv_flush(BlockDriverState *bs);
 void bdrv_flush_all(void);
 
+int bdrv_has_zero_init(BlockDriverState *bs);
 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
 	int *pnum);
 

index 7203b8b..74311a5 100644
@@ -732,6 +732,8 @@ static int img_convert(int argc, char **argv)
         /* signal EOF to align */
         bdrv_write_compressed(out_bs, 0, NULL, 0);
     } else {
+        int has_zero_init = bdrv_has_zero_init(out_bs);
+
         sector_num = 0; // total number of sectors converted so far
         for(;;) {
             nb_sectors = total_sectors - sector_num;

@@ -755,7 +757,7 @@ static int img_convert(int argc, char **argv)
             if (n > bs_offset + bs_sectors - sector_num)
                 n = bs_offset + bs_sectors - sector_num;
 
-            if (!drv->no_zero_init) {
+            if (has_zero_init) {
                 /* If the output image is being created as a copy on write image,
                    assume that sectors which are unallocated in the input image
                    are present in both the output's and input's base images (no

@@ -788,7 +790,7 @@ static int img_convert(int argc, char **argv)
                    If the output is to a host device, we also write out
                    sectors that are entirely 0, since whatever data was
                    already there is garbage, not 0s. */
-                if (drv->no_zero_init || out_baseimg ||
+                if (!has_zero_init || out_baseimg ||
                     is_allocated_sectors(buf1, n, &n1)) {
                     if (bdrv_write(out_bs, sector_num, buf1, n1) < 0)
                         error("error while writing");