block: Allow reference for bdrv_file_open()

Allow specifying a reference to an existing block device (by name) for
bdrv_file_open() instead of a filename and/or options.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Max Reitz 2013-12-20 19:28:08 +01:00 committed by Kevin Wolf
parent 89f2b21e36
commit 72daa72eee
12 changed files with 41 additions and 19 deletions

25
block.c
View File

@ -858,9 +858,10 @@ free_and_fail:
* dictionary, it needs to use QINCREF() before calling bdrv_file_open.
*/
int bdrv_file_open(BlockDriverState **pbs, const char *filename,
QDict *options, int flags, Error **errp)
const char *reference, QDict *options, int flags,
Error **errp)
{
BlockDriverState *bs;
BlockDriverState *bs = NULL;
BlockDriver *drv;
const char *drvname;
bool allow_protocol_prefix = false;
@ -872,6 +873,24 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
options = qdict_new();
}
if (reference) {
if (filename || qdict_size(options)) {
error_setg(errp, "Cannot reference an existing block device with "
"additional options or a new filename");
return -EINVAL;
}
QDECREF(options);
bs = bdrv_find(reference);
if (!bs) {
error_setg(errp, "Cannot find block device '%s'", reference);
return -ENODEV;
}
bdrv_ref(bs);
*pbs = bs;
return 0;
}
bs = bdrv_new("");
bs->options = options;
options = qdict_clone_shallow(options);
@ -1124,7 +1143,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
qdict_extract_subqdict(options, &file_options, "file.");
ret = bdrv_file_open(&file, filename, file_options,
ret = bdrv_file_open(&file, filename, NULL, file_options,
bdrv_open_flags(bs, flags | BDRV_O_UNMAP), &local_err);
if (ret < 0) {
goto fail;

View File

@ -403,7 +403,7 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
goto fail;
}
ret = bdrv_file_open(&bs->file, filename, NULL, flags, &local_err);
ret = bdrv_file_open(&bs->file, filename, NULL, NULL, flags, &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
goto fail;

View File

@ -141,7 +141,7 @@ static int blkverify_open(BlockDriverState *bs, QDict *options, int flags,
goto fail;
}
ret = bdrv_file_open(&bs->file, raw, NULL, flags, &local_err);
ret = bdrv_file_open(&bs->file, raw, NULL, NULL, flags, &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
goto fail;

View File

@ -351,7 +351,8 @@ static int cow_create(const char *filename, QEMUOptionParameter *options,
return ret;
}
ret = bdrv_file_open(&cow_bs, filename, NULL, BDRV_O_RDWR, &local_err);
ret = bdrv_file_open(&cow_bs, filename, NULL, NULL, BDRV_O_RDWR,
&local_err);
if (ret < 0) {
qerror_report_err(local_err);
error_free(local_err);

View File

@ -691,7 +691,8 @@ static int qcow_create(const char *filename, QEMUOptionParameter *options,
return ret;
}
ret = bdrv_file_open(&qcow_bs, filename, NULL, BDRV_O_RDWR, &local_err);
ret = bdrv_file_open(&qcow_bs, filename, NULL, NULL, BDRV_O_RDWR,
&local_err);
if (ret < 0) {
qerror_report_err(local_err);
error_free(local_err);

View File

@ -1483,7 +1483,7 @@ static int qcow2_create2(const char *filename, int64_t total_size,
return ret;
}
ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR, &local_err);
ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
return ret;

View File

@ -563,8 +563,8 @@ static int qed_create(const char *filename, uint32_t cluster_size,
return ret;
}
ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR | BDRV_O_CACHE_WB,
&local_err);
ret = bdrv_file_open(&bs, filename, NULL, NULL,
BDRV_O_RDWR | BDRV_O_CACHE_WB, &local_err);
if (ret < 0) {
qerror_report_err(local_err);
error_free(local_err);

View File

@ -1534,7 +1534,7 @@ static int sd_prealloc(const char *filename)
Error *local_err = NULL;
int ret;
ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR, &local_err);
ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err);
if (ret < 0) {
qerror_report_err(local_err);
error_free(local_err);
@ -1695,7 +1695,7 @@ static int sd_create(const char *filename, QEMUOptionParameter *options,
goto out;
}
ret = bdrv_file_open(&bs, backing_file, NULL, 0, &local_err);
ret = bdrv_file_open(&bs, backing_file, NULL, NULL, 0, &local_err);
if (ret < 0) {
qerror_report_err(local_err);
error_free(local_err);

View File

@ -1797,7 +1797,7 @@ static int vhdx_create(const char *filename, QEMUOptionParameter *options,
goto exit;
}
ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR, &local_err);
ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
goto exit;

View File

@ -769,8 +769,8 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
path_combine(extent_path, sizeof(extent_path),
desc_file_path, fname);
ret = bdrv_file_open(&extent_file, extent_path, NULL, bs->open_flags,
errp);
ret = bdrv_file_open(&extent_file, extent_path, NULL, NULL,
bs->open_flags, errp);
if (ret) {
return ret;
}
@ -1469,7 +1469,7 @@ static int vmdk_create_extent(const char *filename, int64_t filesize,
goto exit;
}
ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR, &local_err);
ret = bdrv_file_open(&bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err);
if (ret < 0) {
error_propagate(errp, local_err);
goto exit;
@ -1807,7 +1807,7 @@ static int vmdk_create(const char *filename, QEMUOptionParameter *options,
goto exit;
}
}
ret = bdrv_file_open(&new_bs, filename, NULL, BDRV_O_RDWR, &local_err);
ret = bdrv_file_open(&new_bs, filename, NULL, NULL, BDRV_O_RDWR, &local_err);
if (ret < 0) {
error_setg_errno(errp, -ret, "Could not write description");
goto exit;

View File

@ -184,7 +184,8 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top);
int bdrv_parse_cache_flags(const char *mode, int *flags);
int bdrv_parse_discard_flags(const char *mode, int *flags);
int bdrv_file_open(BlockDriverState **pbs, const char *filename,
QDict *options, int flags, Error **errp);
const char *reference, QDict *options, int flags,
Error **errp);
int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp);
int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
int flags, BlockDriver *drv, Error **errp);

View File

@ -59,7 +59,7 @@ static int openfile(char *name, int flags, int growable, QDict *opts)
}
if (growable) {
if (bdrv_file_open(&qemuio_bs, name, opts, flags, &local_err)) {
if (bdrv_file_open(&qemuio_bs, name, NULL, opts, flags, &local_err)) {
fprintf(stderr, "%s: can't open device %s: %s\n", progname, name,
error_get_pretty(local_err));
error_free(local_err);