qemu: copy: Accept 'format' parameter when copying to a non-existing img

We have the following matrix of possible arguments handled by the logic
statement touched by this patch:
       | flags & _REUSE_EXT | !(flags & _REUSE_EXT)
-------+--------------------+----------------------
 format| (1)                | (2)
-------+--------------------+----------------------
!format| (3)                | (4)
-------+--------------------+----------------------

In cases 1 and 2 the user provided a format, in cases 3 and 4 not. The
user requests to use a pre-existing image in 1 and 3 and libvirt will
create a new image in 2 and 4.

The difference between cases 3 and 4 is that for 3 the format is probed
from the user-provided image, whereas in 4 we just use the existing disk
format.

The current code would treat cases 1,3 and 4 correctly but in case 2 the
format provided by the user would be ignored.

The particular piece of code was broken in commit 35c7701c64
but since it was introduced a few commits before that it was never
released as working.

(cherry picked from commit 42619ed05d)
Signed-off-by: Eric Blake <eblake@redhat.com>

Conflicts:
	src/qemu/qemu_driver.c - no refactoring of commits 7b7bf001, 4f20226
This commit is contained in:
Peter Krempa 2014-07-01 13:52:51 +02:00 committed by Eric Blake
parent 9ed3607121
commit 53bde6b7b4

View File

@ -14229,29 +14229,34 @@ qemuDomainBlockCopy(virDomainObjPtr vm,
goto endjob;
}
if (format) {
if ((mirrorFormat = virStorageFileFormatTypeFromString(format)) <= 0) {
virReportError(VIR_ERR_INVALID_ARG, _("unrecognized format '%s'"),
format);
goto endjob;
}
} else {
if (!(flags & VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT)) {
mirrorFormat = disk->format;
} else {
/* If the user passed the REUSE_EXT flag, then either they
* also passed the RAW flag (and format is non-NULL), or it is
* safe for us to probe the format from the file that we will
* be using. */
mirrorFormat = virStorageFileProbeFormat(dest, cfg->user,
cfg->group);
}
}
/* pre-create the image file */
if (!(flags & VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT)) {
int fd = qemuOpenFile(driver, vm, dest, O_WRONLY | O_TRUNC | O_CREAT,
&need_unlink, NULL);
if (fd < 0)
goto endjob;
VIR_FORCE_CLOSE(fd);
if (!format)
mirrorFormat = disk->format;
} else if (format) {
mirrorFormat = virStorageFileFormatTypeFromString(format);
if (mirrorFormat <= 0) {
virReportError(VIR_ERR_INVALID_ARG, _("unrecognized format '%s'"),
format);
goto endjob;
}
} else {
/* If the user passed the REUSE_EXT flag, then either they
* also passed the RAW flag (and format is non-NULL), or it is
* safe for us to probe the format from the file that we will
* be using. */
mirrorFormat = virStorageFileProbeFormat(dest, cfg->user,
cfg->group);
}
if (!format && mirrorFormat > 0)
format = virStorageFileFormatTypeToString(mirrorFormat);
if (VIR_STRDUP(mirror, dest) < 0)