Re: [pnfs] [PATCH v2 06/47] nfsd41: Add Kconfig symbols for NFSv4.1

["J. Bruce Fields" <bfields@fieldses.org>]

On Thu, Apr 02, 2009 at 12:18:46PM +0300, Benny Halevy wrote:
> On Apr. 01, 2009, 18:32 +0300, Benny Halevy <bhalevy@panasas.com> wrote:
> > On Apr. 01, 2009, 17:07 +0300, Benny Halevy <bhalevy@panasas.com> wrote:
> >> On Apr. 01, 2009, 16:10 +0300, "J. Bruce Fields" <bfields@fieldses.org> wrote:
> >>> On Wed, Apr 01, 2009 at 11:31:21AM +0300, Benny Halevy wrote:
> >>>> On Apr. 01, 2009, 7:33 +0300, "J. Bruce Fields" <bfields@fieldses.org> wrote:
> >>>>> On Sat, Mar 28, 2009 at 11:31:09AM +0300, Benny Halevy wrote:
> >>>>>> Added CONFIG_NFSD_V4_1 and made it depend upon NFSD_V4 and EXPERIMENTAL
> >>>>>> Indicate that CONFIG_NFS_V4_1 is for NFS developers at the moment
> >>>>> Stupid question: do we need CONFIG_NFSD_V4_1 at all?  How many people
> >>>>> will want to build a kernel with v4.0 but not v4.1?
> 
> Bruce,  with the patch below in place, would it be reasonable to
> remove CONFIG_NFSD_V4_1?

It would be fine with me, but perhaps queuing that up as a separate
patch for 2.6.31 would be better than doing it at the last moment.

(Did you figure out what the problem was?)

--b.

> 
> Benny
> 
> >>>> That's a good question.  I'd love to get rid of it
> >>>> and it seems like like distros, at least RH are going to have it
> >>>> configured-in anyway.
> >>>>
> >>>> If the main reason to turn 4.1 support off is bugs affecting 4.0
> >>>> then I'd much rather fix these bugs rather than hide them.
> >>>>
> >>>>> (And: do we have an interface that allows turning off 4.1 at run-time?
> >>>>> That's more important than the config option.)
> >>>> No, it's still on our todo list.  We haven't thought this completely
> >>>> through, though.  Where would be the best place to implement that?
> >>>> Should this be an export option or an nfsd tunable?
> >>> Imitating (or extending, if possible) nfsd/versions would be one way.
> >>> See fs/nfsd/nfsctl.c:write_versions.  Cc'ing Steved, as I think that was
> >>> originally his work.
> >>>
> >>> --b.
> >>
> >> Sounds great.
> >> Here's a crude untested patch.  Does that what you mean?
> >>
> > 
> > The following works better.
> > 
> > But I still see a problem with it.
> > This all works nicely when the nfs service is stopped (on Fedora 9)
> > but when I restart it all version return to their defaults.
> > I'm probably doing something wrong...
> > 
> > Benny
> > 
> > git diff --stat -p
> >  fs/nfsd/nfs4proc.c        |    2 +-
> >  fs/nfsd/nfsctl.c          |   26 +++++++++++++++++++++++---
> >  fs/nfsd/nfssvc.c          |   24 ++++++++++++++++++++++++
> >  include/linux/nfsd/nfsd.h |    2 ++
> >  4 files changed, 50 insertions(+), 4 deletions(-)
> > 
> > diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> > index a393d38..7619970 100644
> > --- a/fs/nfsd/nfs4proc.c
> > +++ b/fs/nfsd/nfs4proc.c
> > @@ -943,7 +943,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
> >  	 * According to RFC3010, this takes precedence over all other errors.
> >  	 */
> >  	status = nfserr_minor_vers_mismatch;
> > -	if (args->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
> > +	if (args->minorversion > nfsd_supported_minorversion)
> >  		goto out;
> >  
> >  	if (!nfs41_op_ordering_ok(args)) {
> > diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> > index 4d63010..af16849 100644
> > --- a/fs/nfsd/nfsctl.c
> > +++ b/fs/nfsd/nfsctl.c
> > @@ -792,8 +792,9 @@ out_free:
> >  static ssize_t __write_versions(struct file *file, char *buf, size_t size)
> >  {
> >  	char *mesg = buf;
> > -	char *vers, sign;
> > +	char *vers, *minorp, sign;
> >  	int len, num;
> > +	unsigned minor;
> >  	ssize_t tlen = 0;
> >  	char *sep;
> >  
> > @@ -814,9 +815,20 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
> >  		do {
> >  			sign = *vers;
> >  			if (sign == '+' || sign == '-')
> > -				num = simple_strtol((vers+1), NULL, 0);
> > +				num = simple_strtol((vers+1), &minorp, 0);
> >  			else
> > -				num = simple_strtol(vers, NULL, 0);
> > +				num = simple_strtol(vers, &minorp, 0);
> > +			if (*minorp == '.') {
> > +				if (num < 4)
> > +					return -EINVAL;
> > +				minor = simple_strtoul(minorp+1, NULL, 0);
> > +				if (minor == 0)
> > +					return -EINVAL;
> > +				if (nfsd_minorversion(minor, sign == '-' ?
> > +						     NFSD_CLEAR : NFSD_SET) < 0)
> > +					return -EINVAL;
> > +				goto next;
> > +			}
> >  			switch(num) {
> >  			case 2:
> >  			case 3:
> > @@ -826,6 +838,7 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
> >  			default:
> >  				return -EINVAL;
> >  			}
> > +		next:
> >  			vers += len + 1;
> >  			tlen += len;
> >  		} while ((len = qword_get(&mesg, vers, size)) > 0);
> > @@ -844,6 +857,13 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
> >  				       num);
> >  			sep = " ";
> >  		}
> > +	if (nfsd_vers(4, NFSD_AVAIL))
> > +		for (minor = 1; minor <= NFSD_SUPPORTED_MINOR_VERSION; minor++)
> > +			len += sprintf(buf+len, " %c4.%u",
> > +					(nfsd_vers(4, NFSD_TEST) &&
> > +					 nfsd_minorversion(minor, NFSD_TEST)) ?
> > +						'+' : '-',
> > +					minor);
> >  	len += sprintf(buf+len, "\n");
> >  	return len;
> >  }
> > diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
> > index 6ec29c7..5f4cecb 100644
> > --- a/fs/nfsd/nfssvc.c
> > +++ b/fs/nfsd/nfssvc.c
> > @@ -121,6 +121,8 @@ struct svc_program		nfsd_program = {
> >  
> >  };
> >  
> > +u32 nfsd_supported_minorversion = NFSD_SUPPORTED_MINOR_VERSION;
> > +
> >  int nfsd_vers(int vers, enum vers_op change)
> >  {
> >  	if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
> > @@ -147,6 +149,28 @@ int nfsd_vers(int vers, enum vers_op change)
> >  	}
> >  	return 0;
> >  }
> > +
> > +int nfsd_minorversion(u32 minorversion, enum vers_op change)
> > +{
> > +	if (minorversion > NFSD_SUPPORTED_MINOR_VERSION)
> > +		return -1;
> > +	switch(change) {
> > +	case NFSD_SET:
> > +		nfsd_supported_minorversion = minorversion;
> > +		break;
> > +	case NFSD_CLEAR:
> > +		if (minorversion == 0)
> > +			return -1;
> > +		nfsd_supported_minorversion = minorversion - 1;
> > +		break;
> > +	case NFSD_TEST:
> > +		return minorversion <= nfsd_supported_minorversion;
> > +	case NFSD_AVAIL:
> > +		return minorversion <= NFSD_SUPPORTED_MINOR_VERSION;
> > +	}
> > +	return 0;
> > +}
> > +
> >  /*
> >   * Maximum number of nfsd processes
> >   */
> > diff --git a/include/linux/nfsd/nfsd.h b/include/linux/nfsd/nfsd.h
> > index b9e6682..27b9cf5 100644
> > --- a/include/linux/nfsd/nfsd.h
> > +++ b/include/linux/nfsd/nfsd.h
> > @@ -57,6 +57,7 @@ typedef int (*nfsd_dirop_t)(struct inode *, struct dentry *, int, int);
> >  extern struct svc_program	nfsd_program;
> >  extern struct svc_version	nfsd_version2, nfsd_version3,
> >  				nfsd_version4;
> > +extern u32			nfsd_supported_minorversion;
> >  extern struct mutex		nfsd_mutex;
> >  extern struct svc_serv		*nfsd_serv;
> >  
> > @@ -153,6 +154,7 @@ int nfsd_set_posix_acl(struct svc_fh *, int, struct posix_acl *);
> >  
> >  enum vers_op {NFSD_SET, NFSD_CLEAR, NFSD_TEST, NFSD_AVAIL };
> >  int nfsd_vers(int vers, enum vers_op change);
> > +int nfsd_minorversion(u32 minorversion, enum vers_op change);
> >  void nfsd_reset_versions(void);
> >  int nfsd_create_serv(void);
> >  
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