| Message ID | bdbb9d79839f3149db9cf2ff11a2cc04977e0a64.1507817548.git.pkrempa@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am 12.10.2017 um 16:14 hat Peter Krempa geschrieben: > When refering to a backing file of an image via node name > bdrv_open_backing_file would add the 'driver' option to the option list > filling it with the backing format driver. This breaks construction of > the backing chain via -blockdev, as bdrv_open_inherit reports an error > if both 'reference' and 'options' are provided. > > Signed-off-by: Peter Krempa <pkrempa@redhat.com> If you don't mind, I'd add a specific example to the commit message: $ qemu-img create -f raw /tmp/backing.raw 64M $ qemu-img create -f qcow2 -F raw -b /tmp/backing.raw /tmp/test.qcow2 $ qemu-system-x86_64 \ -blockdev driver=file,filename=/tmp/backing.raw,node-name=backing \ -blockdev driver=qcow2,file.driver=file,file.filename=/tmp/test.qcow2,node-name=root,backing=backing qemu-system-x86_64: -blockdev driver=qcow2,file.driver=file,file.filename=/tmp/test.qcow2,node-name=root,backing=backing: Could not open backing file: Cannot reference an existing block device with additional options or a new filename > diff --git a/block.c b/block.c > index 46eb1728da..684cb018da 100644 > --- a/block.c > +++ b/block.c > @@ -2245,7 +2245,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, > goto free_exit; > } > > - if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { > + if (!reference && > + bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { > qdict_put_str(options, "driver", bs->backing_format); > } Looks good to me. Kevin
On Tue, Oct 17, 2017 at 16:41:00 +0200, Kevin Wolf wrote: > Am 12.10.2017 um 16:14 hat Peter Krempa geschrieben: > > When refering to a backing file of an image via node name > > bdrv_open_backing_file would add the 'driver' option to the option list > > filling it with the backing format driver. This breaks construction of > > the backing chain via -blockdev, as bdrv_open_inherit reports an error > > if both 'reference' and 'options' are provided. > > > > Signed-off-by: Peter Krempa <pkrempa@redhat.com> > > If you don't mind, I'd add a specific example to the commit message: I certainly don't mind. I was frustrated after some attempts to find bugs in my code using it before looking into qemu so I forgot to add the info. (Also it would take me some time to figure out that I have the backing format specified in the overlay image). > > $ qemu-img create -f raw /tmp/backing.raw 64M > $ qemu-img create -f qcow2 -F raw -b /tmp/backing.raw /tmp/test.qcow2 > $ qemu-system-x86_64 \ > -blockdev driver=file,filename=/tmp/backing.raw,node-name=backing \ > -blockdev driver=qcow2,file.driver=file,file.filename=/tmp/test.qcow2,node-name=root,backing=backing > qemu-system-x86_64: -blockdev driver=qcow2,file.driver=file,file.filename=/tmp/test.qcow2,node-name=root,backing=backing: Could not open backing file: Cannot reference an existing block device with additional options or a new filename > > > diff --git a/block.c b/block.c > > index 46eb1728da..684cb018da 100644 > > --- a/block.c > > +++ b/block.c > > @@ -2245,7 +2245,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, > > goto free_exit; > > } > > > > - if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { > > + if (!reference && > > + bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { > > qdict_put_str(options, "driver", bs->backing_format); > > } > > Looks good to me. Thanks.
On 10/12/2017 09:14 AM, Peter Krempa wrote: > When refering to a backing file of an image via node name s/refering/referring/ (here and in the subject) > bdrv_open_backing_file would add the 'driver' option to the option list > filling it with the backing format driver. This breaks construction of > the backing chain via -blockdev, as bdrv_open_inherit reports an error > if both 'reference' and 'options' are provided. > > Signed-off-by: Peter Krempa <pkrempa@redhat.com> > --- > block.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block.c b/block.c index 46eb1728da..684cb018da 100644 --- a/block.c +++ b/block.c @@ -2245,7 +2245,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, goto free_exit; } - if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { + if (!reference && + bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { qdict_put_str(options, "driver", bs->backing_format); }
When refering to a backing file of an image via node name bdrv_open_backing_file would add the 'driver' option to the option list filling it with the backing format driver. This breaks construction of the backing chain via -blockdev, as bdrv_open_inherit reports an error if both 'reference' and 'options' are provided. Signed-off-by: Peter Krempa <pkrempa@redhat.com> --- block.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)