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Diffstat (limited to 'block/qcow2.c')
-rw-r--r--block/qcow2.c94
1 files changed, 93 insertions, 1 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index c20141b4e7..f32ddda2a7 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -398,6 +398,21 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset,
#endif
break;
+ case QCOW2_EXT_MAGIC_DATA_FILE:
+ {
+ s->image_data_file = g_malloc0(ext.len + 1);
+ ret = bdrv_pread(bs->file, offset, s->image_data_file, ext.len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "ERROR: Could not read data file name");
+ return ret;
+ }
+#ifdef DEBUG_EXT
+ printf("Qcow2: Got external data file %s\n", s->image_data_file);
+#endif
+ break;
+ }
+
default:
/* unknown magic - save it in case we need to rewrite the header */
/* If you add a new feature, make sure to also update the fast
@@ -1463,6 +1478,15 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
}
if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) {
+ if (!s->data_file && s->image_data_file) {
+ s->data_file = bdrv_open_child(s->image_data_file, options,
+ "data-file", bs, &child_file,
+ false, errp);
+ if (!s->data_file) {
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
if (!s->data_file) {
error_setg(errp, "'data-file' is required for this image");
ret = -EINVAL;
@@ -1650,6 +1674,7 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
return ret;
fail:
+ g_free(s->image_data_file);
if (has_data_file(bs)) {
bdrv_unref_child(bs, s->data_file);
}
@@ -2269,6 +2294,7 @@ static void qcow2_close(BlockDriverState *bs)
g_free(s->unknown_header_fields);
cleanup_unknown_header_ext(bs);
+ g_free(s->image_data_file);
g_free(s->image_backing_file);
g_free(s->image_backing_format);
@@ -2445,6 +2471,19 @@ int qcow2_update_header(BlockDriverState *bs)
buflen -= ret;
}
+ /* External data file header extension */
+ if (has_data_file(bs) && s->image_data_file) {
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE,
+ s->image_data_file, strlen(s->image_data_file),
+ buflen);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ buf += ret;
+ buflen -= ret;
+ }
+
/* Full disk encryption header pointer extension */
if (s->crypto_header.offset != 0) {
s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset);
@@ -3086,6 +3125,12 @@ qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
abort();
}
+ /* Set the external data file if necessary */
+ if (data_bs) {
+ BDRVQcow2State *s = blk_bs(blk)->opaque;
+ s->image_data_file = g_strdup(data_bs->filename);
+ }
+
/* Create a full header (including things like feature table) */
ret = qcow2_update_header(blk_bs(blk));
if (ret < 0) {
@@ -3165,6 +3210,7 @@ static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opt
QDict *qdict;
Visitor *v;
BlockDriverState *bs = NULL;
+ BlockDriverState *data_bs = NULL;
Error *local_err = NULL;
const char *val;
int ret;
@@ -3228,6 +3274,26 @@ static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opt
goto finish;
}
+ /* Create and open an external data file (protocol layer) */
+ val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE);
+ if (val) {
+ ret = bdrv_create_file(val, opts, errp);
+ if (ret < 0) {
+ goto finish;
+ }
+
+ data_bs = bdrv_open(val, NULL, NULL,
+ BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+ errp);
+ if (data_bs == NULL) {
+ ret = -EIO;
+ goto finish;
+ }
+
+ qdict_del(qdict, BLOCK_OPT_DATA_FILE);
+ qdict_put_str(qdict, "data-file", data_bs->node_name);
+ }
+
/* Set 'driver' and 'node' options */
qdict_put_str(qdict, "driver", "qcow2");
qdict_put_str(qdict, "file", bs->node_name);
@@ -3262,6 +3328,7 @@ static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opt
finish:
qobject_unref(qdict);
bdrv_unref(bs);
+ bdrv_unref(data_bs);
qapi_free_BlockdevCreateOptions(create_options);
return ret;
}
@@ -4552,6 +4619,8 @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs,
.refcount_bits = s->refcount_bits,
.has_bitmaps = !!bitmaps,
.bitmaps = bitmaps,
+ .has_data_file = !!s->image_data_file,
+ .data_file = g_strdup(s->image_data_file),
};
} else {
/* if this assertion fails, this probably means a new version was
@@ -4754,7 +4823,7 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
BDRVQcow2State *s = bs->opaque;
int old_version = s->qcow_version, new_version = old_version;
uint64_t new_size = 0;
- const char *backing_file = NULL, *backing_format = NULL;
+ const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL;
bool lazy_refcounts = s->use_lazy_refcounts;
const char *compat = NULL;
uint64_t cluster_size = s->cluster_size;
@@ -4836,6 +4905,13 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
"may not exceed 64 bits");
return -EINVAL;
}
+ } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) {
+ data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE);
+ if (data_file && !has_data_file(bs)) {
+ error_setg(errp, "data-file can only be set for images that "
+ "use an external data file");
+ return -EINVAL;
+ }
} else {
/* if this point is reached, this probably means a new option was
* added without having it covered here */
@@ -4882,6 +4958,17 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
}
}
+ if (data_file) {
+ g_free(s->image_data_file);
+ s->image_data_file = *data_file ? g_strdup(data_file) : NULL;
+ }
+
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to update the image header");
+ return ret;
+ }
+
if (backing_file || backing_format) {
ret = qcow2_change_backing_file(bs,
backing_file ?: s->image_backing_file,
@@ -5030,6 +5117,11 @@ static QemuOptsList qcow2_create_opts = {
.help = "Image format of the base image"
},
{
+ .name = BLOCK_OPT_DATA_FILE,
+ .type = QEMU_OPT_STRING,
+ .help = "File name of an external data file"
+ },
+ {
.name = BLOCK_OPT_ENCRYPT,
.type = QEMU_OPT_BOOL,
.help = "Encrypt the image with format 'aes'. (Deprecated "