Re: [Xen-devel] [PATCH V3 2/6] libxl_read_file_contents: fix reading sysfs file

["Chun Yan Liu" <cyliu@xxxxxxxx>]

>>> On 5/18/2015 at 10:30 PM, in message
<20150518143008.GE9503@xxxxxxxxxxxxxxxxxxxxx>, Wei Liu <wei.liu2@xxxxxxxxxx>
wrote: 
> On Mon, May 18, 2015 at 03:23:38PM +0100, Ian Jackson wrote: 
> > Chunyan Liu writes ("[PATCH V3 2/6] libxl_read_file_contents: fix reading  
> sysfs file"): 
> > > Sysfs file has size=4096 but actual file content is less than that. 
> >  
> > Wow. 
> >  
> > Is there any danger that the actual size might be >4096 ? 
> >  
> >  
> > > Current libxl_read_file_contents will treat it as error when file size 
> > > and actual file content differs, so reading sysfs file content with 
> > > this function always fails. Fix it so that we can reuse this function 
> > > to get sysfs file content in later pvusb work. 
> >  
> > I'm uncomfortable with removing an error check from this function for 
> > all its call sites. 
> >  
> > I think, sadly, that we are going to need a new function - at least, a 
> > new entrypoint. 
> >  
> >  
> > We don't want to repeat the whole of libxl__read_file_contents. 
> >  
> > Perhaps the bulk should be made into libxl__read_file_contents_core 
> > which takes a boolean instructing whether to tolerate magically 
> > shrinking files ? 
> >  
> > Setting that boolean probably ought to arrange to insist that the 
> > function gets eof, in case the file is actually bigger rather than 
> > smaller than the size. 
> >  
> >  
> > Ian, Wei ? 
> >  
>  
> Yes, we need a new entry point. 

Will update. Thanks!

>  
> Wei. 
>  
> > Ian. 
>  
>  



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel