Re: [PATCH] Add dax mount option to man xfs(5)

[Carlos Maiolino <cmaiolino@redhat.com>]

On Thu, Apr 01, 2021 at 08:33:33AM -0700, Darrick J. Wong wrote:
> On Mon, Mar 15, 2021 at 04:02:50PM +0100, Carlos Maiolino wrote:
> > Details are already in kernel's documentation, but make dax mount option
> > information accessible through xfs(5) manpage.
> > 
> > Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
> > ---
> >  man/man5/xfs.5 | 18 ++++++++++++++++++
> >  1 file changed, 18 insertions(+)
> > 
> > diff --git a/man/man5/xfs.5 b/man/man5/xfs.5
> > index 7642662f..46b0558a 100644
> > --- a/man/man5/xfs.5
> > +++ b/man/man5/xfs.5
> > @@ -133,6 +133,24 @@ by the filesystem.
> >  CRC enabled filesystems always use the attr2 format, and so
> >  will reject the noattr2 mount option if it is set.
> >  .TP
> > +.BR dax=value
> > +Set DAX behavior for the current filesystem. This mount option accepts the
> 
> It might be worth defining what DAX (the acronym) is...
> 
> "Set CPU direct access (DAX) behavior for regular files in the
> filesystem."
> 
> > +following values:
> > +
> > +"dax=inode" DAX will be enabled only on files with FS_XFLAG_DAX applied.
> 
> "...enabled on regular files..."
> 
> > +
> > +"dax=never" DAX will be disabled by the whole filesystem including files with
> > +FS_XFLAG_DAX applied"
> 
> "DAX will not be enabled for any files.  FS_XFLAG_DAX will be ignored."
> 
> > +
> > +"dax=always" DAX will be enabled to every file in the filesystem inclduing files
> 
> "DAX will be enabled for all regular files, regardless of the
> FS_XFLAG_DAX state."
> 
> > +without FS_XFLAG_DAX applied"
> > +
> > +If no option is used when mounting a pmem device, dax=inode will be used as
> 
> "If no option is used when mounting a filesystem stored on a device
> capable of DAX access modes, dax=inode...."
> 
> (DAX is a possibility with more than just persistent memory now...)
> 

Thanks for the review Darrick. All the changes make sense to me, I'll apply them
and send a V2.

Cheers.

-- 
Carlos