[libvirt] [PATCH 5/6] util: refactor storage file checks to allow error reporting

[Daniel P. Berrangé]

On Thu, Apr 26, 2018 at 11:15:42AM +0200, Peter Krempa wrote:
> On Wed, Apr 25, 2018 at 16:52:42 +0100, Daniel Berrange wrote:
> > The virStorageFileSupportsSecurityDriver and
> > virStorageFileSupportsAccess currently just return a boolean
> > value. This is ok because they don't have any failure scenarios
> > but a subsequent patch is going to introduce potential failure
> > scenario. This changes their return type from a boolean to an
> > int with values -1, 0, 1.
> > 
> > Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
> > ---
> >  src/qemu/qemu_domain.c    | 21 +++++++++------
> >  src/qemu/qemu_driver.c    |  6 +++--
> >  src/util/virstoragefile.c | 66 +++++++++++++++++++++++++++++++----------------
> >  src/util/virstoragefile.h |  4 +--
> >  4 files changed, 63 insertions(+), 34 deletions(-)
> 
> [...]
> 
> > index f09035cd4a..da13d51d32 100644
> > --- a/src/util/virstoragefile.c
> > +++ b/src/util/virstoragefile.c
> > @@ -4098,34 +4098,46 @@ virStorageFileIsInitialized(const virStorageSource *src)
> 
> [...]
> 
> > -static bool
> > +static int
> >  virStorageFileSupportsBackingChainTraversal(virStorageSourcePtr src)
> >  {
> >      virStorageFileBackendPtr backend;
> > +    int ret;
> 
> Hmm, isn't 'rv' better in the case when this variable actually is not
> returned?

Sure will change it.

> 
> >  
> > -    if (!(backend = virStorageFileGetBackendForSupportCheck(src)))
> > -        return false;
> > +    ret = virStorageFileGetBackendForSupportCheck(src, &backend);
> > +    if (ret < 0)
> > +        return -1;
> > +
> > +    if (!backend)
> > +        return 0;
> >  
> >      return backend->storageFileGetUniqueIdentifier &&
> > -           backend->storageFileRead &&
> > -           backend->storageFileAccess;
> > +        backend->storageFileRead &&
> > +        backend->storageFileAccess ? 1 : 0;
> 
> Alignment looks off

Depends on your POV - this is standard indentation after a new
line - it would only line up following lines if there was a
opening round bracket on first line. That said I'll change it
to avoid affecting pre-existing code alignment.

> 
> >  }
> >  
> >  
> > @@ -4137,15 +4149,19 @@ virStorageFileSupportsBackingChainTraversal(virStorageSourcePtr src)
> >   * Check if a storage file supports operations needed by the security
> >   * driver to perform labelling
> >   */
> > -bool
> > +int
> >  virStorageFileSupportsSecurityDriver(const virStorageSource *src)
> >  {
> >      virStorageFileBackendPtr backend;
> > +    int ret;
> 
> As in above hunk.
> 
> >  
> > -    if (!(backend = virStorageFileGetBackendForSupportCheck(src)))
> > -        return false;
> > +    ret = virStorageFileGetBackendForSupportCheck(src, &backend);
> > +    if (ret < 0)
> > +        return -1;
> > +    if (backend == NULL)
> > +        return 0;
> >  
> > -    return !!backend->storageFileChown;
> > +    return backend->storageFileChown ? 1 : 0;
> 
> ACK



Regards,
Daniel
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