Re: [PATCH v7 11/17] xfs: refactor suffix_kstrtoint()

[Ian Kent <raven@themaw.net>]

On Thu, 2019-10-24 at 08:38 -0700, Darrick J. Wong wrote:
> On Thu, Oct 24, 2019 at 03:51:32PM +0800, Ian Kent wrote:
> > The mount-api doesn't have a "human unit" parse type yet so the
> > options
> > that have values like "10k" etc. still need to be converted by the
> > fs.
> 
> Do you have plans to add such a thing to the mount api?  Or port the
> xfs
> helper?  TBH I'd have thought that would show up as one of the vfs
> patches at the start of this series.

I asked David (Howells) about this a while back and he did have some
patches for it but they weren't posted.

I can't remember now but I think there was a reason for holding back
on it.

I expect they will be posted for merge at some point but I don't
know when that will be.

> 
> I guess the patch itself looks fine as temporary support structures
> for
> handling a transition.
> 
> --D
> 
> > But the value comes to the fs as a string (not a substring_t type)
> > so
> > there's a need to change the conversion function to take a
> > character
> > string instead.
> > 
> > When xfs is switched to use the new mount-api match_kstrtoint()
> > will no
> > longer be used and will be removed.
> > 
> > Signed-off-by: Ian Kent <raven@themaw.net>
> > Reviewed-by: Brian Foster <bfoster@redhat.com>
> > ---
> >  fs/xfs/xfs_super.c |   38 +++++++++++++++++++++++++++++---------
> >  1 file changed, 29 insertions(+), 9 deletions(-)
> > 
> > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> > index 97c3f1edb69c..003ec725d4b6 100644
> > --- a/fs/xfs/xfs_super.c
> > +++ b/fs/xfs/xfs_super.c
> > @@ -112,14 +112,17 @@ static const match_table_t tokens = {
> >  };
> >  
> >  
> > -STATIC int
> > -suffix_kstrtoint(const substring_t *s, unsigned int base, int
> > *res)
> > +static int
> > +suffix_kstrtoint(
> > +	const char	*s,
> > +	unsigned int	base,
> > +	int		*res)
> >  {
> > -	int	last, shift_left_factor = 0, _res;
> > -	char	*value;
> > -	int	ret = 0;
> > +	int		last, shift_left_factor = 0, _res;
> > +	char		*value;
> > +	int		ret = 0;
> >  
> > -	value = match_strdup(s);
> > +	value = kstrdup(s, GFP_KERNEL);
> >  	if (!value)
> >  		return -ENOMEM;
> >  
> > @@ -144,6 +147,23 @@ suffix_kstrtoint(const substring_t *s,
> > unsigned int base, int *res)
> >  	return ret;
> >  }
> >  
> > +static int
> > +match_kstrtoint(
> > +	const substring_t	*s,
> > +	unsigned int		base,
> > +	int			*res)
> > +{
> > +	const char		*value;
> > +	int			ret;
> > +
> > +	value = match_strdup(s);
> > +	if (!value)
> > +		return -ENOMEM;
> > +	ret = suffix_kstrtoint(value, base, res);
> > +	kfree(value);
> > +	return ret;
> > +}
> > +
> >  /*
> >   * This function fills in xfs_mount_t fields based on mount args.
> >   * Note: the superblock has _not_ yet been read in.
> > @@ -155,7 +175,7 @@ suffix_kstrtoint(const substring_t *s, unsigned
> > int base, int *res)
> >   * path, and we don't want this to have any side effects at
> > remount time.
> >   * Today this function does not change *sb, but just to future-
> > proof...
> >   */
> > -STATIC int
> > +static int
> >  xfs_parseargs(
> >  	struct xfs_mount	*mp,
> >  	char			*options)
> > @@ -206,7 +226,7 @@ xfs_parseargs(
> >  				return -EINVAL;
> >  			break;
> >  		case Opt_logbsize:
> > -			if (suffix_kstrtoint(args, 10, &mp-
> > >m_logbsize))
> > +			if (match_kstrtoint(args, 10, &mp->m_logbsize))
> >  				return -EINVAL;
> >  			break;
> >  		case Opt_logdev:
> > @@ -222,7 +242,7 @@ xfs_parseargs(
> >  				return -ENOMEM;
> >  			break;
> >  		case Opt_allocsize:
> > -			if (suffix_kstrtoint(args, 10, &iosize))
> > +			if (match_kstrtoint(args, 10, &iosize))
> >  				return -EINVAL;
> >  			iosizelog = ffs(iosize) - 1;
> >  			break;
> >