Re: [PATCH v2 4/5] firmware: generalize reading file contents as a helper

[Luis R. Rodriguez]

On Thu, Oct 08, 2015 at 01:36:53PM -0400, Josh Boyer wrote:
> On Thu, Oct 1, 2015 at 1:44 PM, Luis R. Rodriguez
> <mcgrof@xxxxxxxxxxxxxxxx> wrote:
> > From: David Howells <dhowells@xxxxxxxxxx>
> >
> > We'll want to reuse this same code later in order to
> > read two separate types of file contents. This generalizes
> > fw_read_file() for reading a file rebrands it as fw_read_file().
> 
> Er, maybe that should read "...fw_read_file_contents() for reading a
> file and rebrands it as fw_read_file()." ?

Thanks, corrected.

> > This caller lets us pegs arbitrary data onto the target
> > buffer and size if the file is found.
> 
> This sentence is somewhat confusing.  The data isn't arbitrary. It is
> what the caller wants you to read from path.  What is arbitrary, at
> least in the context of this function, is the path passed to it.
> Maybe rewrite this as:
> 
> "The new function allows us to read file contents from arbitrary paths
> and return the data and size of the files read."

The path is arbitrary but what I meant by arbitrary data is that
the data need no longer be firmware, whereas fw_read_file_contents()
*did* require passing firmware_class data structures. What this does
is it make the possibility of eventually making a more core system
data file reader more obvious, so for instance the goal is to later
share a reader with:

    - firmware_class: fw_read_file()
    - module: kernel_read()
    - kexec: copy_file_fd()

I will clarify this in the commit log and also clarify the path is
arbitrary as well as you note.

> > While at it this cleans up the exit paths on fw_read_file().
> >
> > Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> > Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxx>
> 
> The code changes themselves look fine.

Thank you for the review. Can I peg your Acked-by or Reviewed-by?
How about this for a change in the commit log:

firmware: generalize reading file contents as a helper                          
                                                                                
We'll want to reuse this same code later in order to read                       
two separate types of file contents. This generalizes                            
fw_read_file_contents() for reading a file and rebrands it                      
as fw_read_file(). This new caller is now generic and that                      
path can be arbitrary, the caller is also agnostic to the                       
firmware_class code now, which begs the possibility of code                     
re-use with other similar callers in the kernel. For instance                   
in the future we may want to share a solution with:                             
                                                                                
    - firmware_class: fw_read_file()                                            
    - module: kernel_read()                                                     
    - kexec: copy_file_fd()                                                     
                                                                                
While at it this also cleans up the exit paths on fw_read_file().               

  Luis
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