Return-Path: Received: from fieldses.org ([173.255.197.46]:39828 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750822AbcFAMvI (ORCPT ); Wed, 1 Jun 2016 08:51:08 -0400 Date: Wed, 1 Jun 2016 08:51:07 -0400 To: "Mkrtchyan, Tigran" Cc: Jeff Layton , Weston Andros Adamson , linux-nfs list , Tom Haynes , Christoph Hellwig Subject: Re: [RFC PATCH] nfsd: allow nfsd to advertise multiple layout types Message-ID: <20160601125107.GB3387@fieldses.org> References: <1464555567-16055-1-git-send-email-jlayton@poochiereds.net> <643433762.15123359.1464623258309.JavaMail.zimbra@desy.de> <1464627098.8117.6.camel@poochiereds.net> <1373800959.15136324.1464627888132.JavaMail.zimbra@desy.de> <1464631520.13639.12.camel@poochiereds.net> <1457806307.15151735.1464633767657.JavaMail.zimbra@desy.de> <1464659250.8117.25.camel@poochiereds.net> <703205520.15241153.1464699640808.JavaMail.zimbra@desy.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <703205520.15241153.1464699640808.JavaMail.zimbra@desy.de> From: bfields@fieldses.org (J. Bruce Fields) Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, May 31, 2016 at 03:00:40PM +0200, Mkrtchyan, Tigran wrote: > Hi Jeff, > > I have tested the patch. Works as expected. > I am able to use flexfiles with latest kernel > while older client use nfs4_file_layout. So Please just add a comment documenting the issue with older clients and what we're doing to keep them working, so that we don't accidentally break that. --b. > > Teset-by: > > Unrelated to you patch (as it now fails with my as well), > flex file layout hangs on write with 4.7-rc1 (and 4.6.0). > The same test works with nfs4_files. I will recompile with > an older version, where I tested in the past (4.5-rc3?). > > I will start a new email with my discoveries. > > Tigran. > > ----- Original Message ----- > > From: "Jeff Layton" > > To: "Weston Andros Adamson" , "Tigran Mkrtchyan" > > Cc: "linux-nfs list" , "Tom Haynes" , "Christoph Hellwig" > > > > Sent: Tuesday, May 31, 2016 3:47:30 AM > > Subject: Re: [RFC PATCH] nfsd: allow nfsd to advertise multiple layout types > > > On Mon, 2016-05-30 at 21:10 -0400, Weston Andros Adamson wrote: > >> > > >> > On May 30, 2016, at 2:42 PM, Mkrtchyan, Tigran wrote: > >> > > >> > > >> > > >> > You have explicit order in set_pnfs_layoutdriver function. > >> > Your patch looks like ot to me. I will try it with our > >> > server and will let you know. > >> > > >> > Tigran. > >> > > >> > ----- Original Message ----- > >> > > From: "Jeff Layton" > >> > > To: "Mkrtchyan, Tigran" > >> > > Cc: linux-nfs@vger.kernel.org, "Tom Haynes" , "Christoph Hellwig" > >> > > Sent: Monday, May 30, 2016 8:05:20 PM > >> > > Subject: Re: [RFC PATCH] nfsd: allow nfsd to advertise multiple layout types > >> > > >> > > On Mon, 2016-05-30 at 19:04 +0200, Mkrtchyan, Tigran wrote: > >> > > > > >> > > > ----- Original Message ----- > >> > > > > > >> > > > > From: "Jeff Layton" > >> > > > > To: "Mkrtchyan, Tigran" > >> > > > > Cc: linux-nfs@vger.kernel.org, "Tom Haynes" , "Christoph Hellwig" > >> > > > > Sent: Monday, May 30, 2016 6:51:38 PM > >> > > > > Subject: Re: [RFC PATCH] nfsd: allow nfsd to advertise multiple layout types > >> > > > > > >> > > > > On Mon, 2016-05-30 at 17:47 +0200, Mkrtchyan, Tigran wrote: > >> > > > > > > >> > > > > > > >> > > > > > ----- Original Message ----- > >> > > > > > > > >> > > > > > > From: "Jeff Layton" > >> > > > > > > To: linux-nfs@vger.kernel.org > >> > > > > > > Cc: "Tom Haynes" , "Christoph Hellwig" > >> > > > > > > > >> > > > > > > Sent: Sunday, May 29, 2016 11:06:14 PM > >> > > > > > > Subject: Re: [RFC PATCH] nfsd: allow nfsd to advertise multiple layout types > >> > > > > > > > >> > > > > > > On Sun, 2016-05-29 at 16:59 -0400, Jeff Layton wrote: > >> > > > > > > > > >> > > > > > > > If the underlying filesystem supports multiple layout types, then there > >> > > > > > > > is little reason not to advertise that fact to clients and let them > >> > > > > > > > choose what type to use. > >> > > > > > > > > >> > > > > > > > Turn the ex_layout_type field into a bitfield. For each supported > >> > > > > > > > layout type, we set a bit in that field. When the client requests a > >> > > > > > > > layout, ensure that the bit for that layout type is set. When the > >> > > > > > > > client requests attributes, send back a list of supported types. > >> > > > > > > > > >> > > > > > > > Signed-off-by: Jeff Layton > >> > > > > > > > --- > >> > > > > > > >  fs/nfsd/export.c      |  4 ++-- > >> > > > > > > >  fs/nfsd/export.h      |  2 +- > >> > > > > > > >  fs/nfsd/nfs4layouts.c |  6 +++--- > >> > > > > > > >  fs/nfsd/nfs4proc.c    |  4 ++-- > >> > > > > > > >  fs/nfsd/nfs4xdr.c     | 30 ++++++++++++++---------------- > >> > > > > > > >  5 files changed, 22 insertions(+), 24 deletions(-) > >> > > > > > > > > >> > > > > > > > diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c > >> > > > > > > > index b4d84b579f20..f97ba49d5e66 100644 > >> > > > > > > > --- a/fs/nfsd/export.c > >> > > > > > > > +++ b/fs/nfsd/export.c > >> > > > > > > > @@ -706,7 +706,7 @@ static void svc_export_init(struct cache_head *cnew, struct > >> > > > > > > > cache_head *citem) > >> > > > > > > >   new->ex_fslocs.locations = NULL; > >> > > > > > > >   new->ex_fslocs.locations_count = 0; > >> > > > > > > >   new->ex_fslocs.migrated = 0; > >> > > > > > > > - new->ex_layout_type = 0; > >> > > > > > > > + new->ex_layout_types = 0; > >> > > > > > > >   new->ex_uuid = NULL; > >> > > > > > > >   new->cd = item->cd; > >> > > > > > > >  } > >> > > > > > > > @@ -731,7 +731,7 @@ static void export_update(struct cache_head *cnew, struct > >> > > > > > > > cache_head *citem) > >> > > > > > > >   item->ex_fslocs.locations_count = 0; > >> > > > > > > >   new->ex_fslocs.migrated = item->ex_fslocs.migrated; > >> > > > > > > >   item->ex_fslocs.migrated = 0; > >> > > > > > > > - new->ex_layout_type = item->ex_layout_type; > >> > > > > > > > + new->ex_layout_types = item->ex_layout_types; > >> > > > > > > >   new->ex_nflavors = item->ex_nflavors; > >> > > > > > > >   for (i = 0; i < MAX_SECINFO_LIST; i++) { > >> > > > > > > >   new->ex_flavors[i] = item->ex_flavors[i]; > >> > > > > > > > diff --git a/fs/nfsd/export.h b/fs/nfsd/export.h > >> > > > > > > > index 2e315072bf3f..730f15eeb7ed 100644 > >> > > > > > > > --- a/fs/nfsd/export.h > >> > > > > > > > +++ b/fs/nfsd/export.h > >> > > > > > > > @@ -57,7 +57,7 @@ struct svc_export { > >> > > > > > > >   struct nfsd4_fs_locations ex_fslocs; > >> > > > > > > >   uint32_t ex_nflavors; > >> > > > > > > >   struct exp_flavor_info ex_flavors[MAX_SECINFO_LIST]; > >> > > > > > > > - enum pnfs_layouttype ex_layout_type; > >> > > > > > > > + u32 ex_layout_types; > >> > > > > > > >   struct nfsd4_deviceid_map *ex_devid_map; > >> > > > > > > >   struct cache_detail *cd; > >> > > > > > > >  }; > >> > > > > > > > diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c > >> > > > > > > > index 6d98d16b3354..2be9602b0221 100644 > >> > > > > > > > --- a/fs/nfsd/nfs4layouts.c > >> > > > > > > > +++ b/fs/nfsd/nfs4layouts.c > >> > > > > > > > @@ -139,21 +139,21 @@ void nfsd4_setup_layout_type(struct svc_export *exp) > >> > > > > > > >    * otherwise advertise the block layout. > >> > > > > > > >    */ > >> > > > > > > >  #ifdef CONFIG_NFSD_FLEXFILELAYOUT > >> > > > > > > > - exp->ex_layout_type = LAYOUT_FLEX_FILES; > >> > > > > > > > + exp->ex_layout_types |= 1 << LAYOUT_FLEX_FILES; > >> > > > > > > >  #endif > >> > > > > > > >  #ifdef CONFIG_NFSD_BLOCKLAYOUT > >> > > > > > > >   /* overwrite flex file layout selection if needed */ > >> > > > > > > >   if (sb->s_export_op->get_uuid && > >> > > > > > > >       sb->s_export_op->map_blocks && > >> > > > > > > >       sb->s_export_op->commit_blocks) > >> > > > > > > > - exp->ex_layout_type = LAYOUT_BLOCK_VOLUME; > >> > > > > > > > + exp->ex_layout_types |= 1 << LAYOUT_BLOCK_VOLUME; > >> > > > > > > >  #endif > >> > > > > > > >  #ifdef CONFIG_NFSD_SCSILAYOUT > >> > > > > > > >   /* overwrite block layout selection if needed */ > >> > > > > > > >   if (sb->s_export_op->map_blocks && > >> > > > > > > >       sb->s_export_op->commit_blocks && > >> > > > > > > >       sb->s_bdev && sb->s_bdev->bd_disk->fops->pr_ops) > >> > > > > > > > - exp->ex_layout_type = LAYOUT_SCSI; > >> > > > > > > > + exp->ex_layout_types |= 1 << LAYOUT_SCSI; > >> > > > > > > >  #endif > >> > > > > > > >  } > >> > > > > > > >   > >> > > > > > > > diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c > >> > > > > > > > index 2ee2dc170327..719c620753e2 100644 > >> > > > > > > > --- a/fs/nfsd/nfs4proc.c > >> > > > > > > > +++ b/fs/nfsd/nfs4proc.c > >> > > > > > > > @@ -1219,12 +1219,12 @@ nfsd4_verify(struct svc_rqst *rqstp, struct > >> > > > > > > > nfsd4_compound_state *cstate, > >> > > > > > > >  static const struct nfsd4_layout_ops * > >> > > > > > > >  nfsd4_layout_verify(struct svc_export *exp, unsigned int layout_type) > >> > > > > > > >  { > >> > > > > > > > - if (!exp->ex_layout_type) { > >> > > > > > > > + if (!exp->ex_layout_types) { > >> > > > > > > >   dprintk("%s: export does not support pNFS\n", __func__); > >> > > > > > > >   return NULL; > >> > > > > > > >   } > >> > > > > > > >   > >> > > > > > > > - if (exp->ex_layout_type != layout_type) { > >> > > > > > > > + if (!(exp->ex_layout_types & (1 << layout_type))) { > >> > > > > > > >   dprintk("%s: layout type %d not supported\n", > >> > > > > > > >   __func__, layout_type); > >> > > > > > > >   return NULL; > >> > > > > > > > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c > >> > > > > > > > index 9df898ba648f..4d3ae75ad4c8 100644 > >> > > > > > > > --- a/fs/nfsd/nfs4xdr.c > >> > > > > > > > +++ b/fs/nfsd/nfs4xdr.c > >> > > > > > > > @@ -2164,22 +2164,20 @@ nfsd4_encode_aclname(struct xdr_stream *xdr, struct > >> > > > > > > > svc_rqst *rqstp, > >> > > > > > > >  } > >> > > > > > > >   > >> > > > > > > >  static inline __be32 > >> > > > > > > > -nfsd4_encode_layout_type(struct xdr_stream *xdr, enum pnfs_layouttype > >> > > > > > > > layout_type) > >> > > > > > > > +nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types) > >> > > > > > > >  { > >> > > > > > > > - __be32 *p; > >> > > > > > > > + __be32 *p; > >> > > > > > > > + unsigned long i = hweight_long(layout_types); > >> > > > > > > >   > >> > > > > > > > - if (layout_type) { > >> > > > > > > > - p = xdr_reserve_space(xdr, 8); > >> > > > > > > > - if (!p) > >> > > > > > > > - return nfserr_resource; > >> > > > > > > > - *p++ = cpu_to_be32(1); > >> > > > > > > > - *p++ = cpu_to_be32(layout_type); > >> > > > > > > > - } else { > >> > > > > > > > - p = xdr_reserve_space(xdr, 4); > >> > > > > > > > - if (!p) > >> > > > > > > > - return nfserr_resource; > >> > > > > > > > - *p++ = cpu_to_be32(0); > >> > > > > > > > - } > >> > > > > > > > + p = xdr_reserve_space(xdr, 4 + 4 * i); > >> > > > > > > > + if (!p) > >> > > > > > > > + return nfserr_resource; > >> > > > > > > > + > >> > > > > > > > + *p++ = cpu_to_be32(i); > >> > > > > > > > + > >> > > > > > > > + for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i) > >> > > > > > > > + if (layout_types & (1 << i)) > >> > > > > > > > + *p++ = cpu_to_be32(i); > >> > > > > > > >   > >> > > > > > > >   return 0; > >> > > > > > > >  } > >> > > > > > > > @@ -2754,13 +2752,13 @@ out_acl: > >> > > > > > > >   } > >> > > > > > > >  #ifdef CONFIG_NFSD_PNFS > >> > > > > > > >   if (bmval1 & FATTR4_WORD1_FS_LAYOUT_TYPES) { > >> > > > > > > > - status = nfsd4_encode_layout_type(xdr, exp->ex_layout_type); > >> > > > > > > > + status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types); > >> > > > > > > >   if (status) > >> > > > > > > >   goto out; > >> > > > > > > >   } > >> > > > > > > >   > >> > > > > > > >   if (bmval2 & FATTR4_WORD2_LAYOUT_TYPES) { > >> > > > > > > > - status = nfsd4_encode_layout_type(xdr, exp->ex_layout_type); > >> > > > > > > > + status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types); > >> > > > > > > >   if (status) > >> > > > > > > >   goto out; > >> > > > > > > >   } > >> > > > > > > > >> > > > > > > Just a (lightly-tested) RFC patch for now. > >> > > > > > > > >> > > > > > > This seems to do the right thing WRT to GETATTR response that requests > >> > > > > > > a layout types list. The current client code spews this into the ring > >> > > > > > > buffer though: > >> > > > > > > > >> > > > > > >     NFS: decode_first_pnfs_layout_type: Warning: Multiple pNFS layout drivers per > >> > > > > > >     filesystem not supported > >> > > > > > > > >> > > > > > > ...so that would need a little work. Wireshark also seems to not parse > >> > > > > > > the layout types list correctly. > >> > > > > > Hi Jeff, > >> > > > > > > >> > > > > > I had an attempt to add multi-layout support into the client: > >> > > > > > > >> > > > > > https://github.com/0day-ci/linux/commit/e2d792dc32b82ffc511b009c0a8db5313126888e > >> > > > > > > >> > > > > > I can't find it in the list archive. This explains why Trond never > >> > > > > > respond to it. > >> > > > > > > >> > > > > > Tigran. > >> > > > > > > >> > > > > Thanks. I had already rolled one up that does a different approach of a > >> > > > > hardcoded selection order in the client code and sent it as an RFC. > >> > > > > > >> > > > > So...yours assumes that the server will send the "default" one first in > >> > > > > the list, but AFAICT, the spec doesn't say anything about the > >> > > > > fs_layout_type list being ordered in any way. I don't think we can make > >> > > > > that assumption. Am I wrong there? > >> > > > Imagine a muti-layout server in a deployment, where some client are old (RHEL6) > >> > > > and some clients are new. RHEL6 will always take only the first one and fail, if > >> > > > it wasn't nfs4_file_layout. But, if we always return 'well-known' as a first > >> > > > one, > >> > > > then, then RHEL6 clients will be able to coexists with newer clients. > >> > > > > >> > > > Our server can provide flexfile layouts, but 99% of our clients are > >> > > > RHEL6-clones. > >> > > > This stops us from enable flexfile support, unless we add per-client based > >> > > > control > >> > > > of layout type. > >> > > > > >> > > > Tigran. > >> > > > > >> > > > >> > > Ahh ok, I see what you mean... > >> > > > >> > > So yeah, I don't think the spec places any significance on the order of > >> > > the list, but we some de-facto precedence due to legacy clients. Not > >> > > much we can do about that. I guess all you can do for those clients is > >> > > just ensure that the first entry is the one most likely to be usable by > >> > > those clients. > >> > > > >> > > This patch just orders the list by numerical value of the layout type > >> > > constants. If someone can offer up a sane argument for ordering the > >> > > list in a different fashion, then I'm OK with doing that. > >> > > > >> > > -- > >> > > Jeff Layton > >> > > >> > >> Jeff, this patch looks good to me. > >> > >> As for backward compatibility, we could do some complicated client > >> support detection (implementation ID based or fallback if layout is rejected), > >> but that’s probably going overboard for now. > >> > > > > Yeah, this is a step in the right direction I think, but we may need to > > do something more elaborate eventually. > > > >> Maybe we should just hardcode this array instead of building it in the > >> order of the numerical value of each layout type. We could add them in > >> the order that the client supported them. > >> I think that would fix Tigran’s > >> problem. Maybe it’s already in this order as client support quickly followed > >> layout type number allocation? > >> > > > > Hmm...knfsd only supports block, scsi and flexfiles (as of Tom's > > patches). We might want to re-sort the list so that scsi comes first, > > actually? OTOH...block was there first so maybe it ought to be first? > > Hard to know without knowing exactly what sort of clients you have. > > > > Either way, the order of the array that the server sends and the > > preference of the client for various layouts can both definitely be > > changed. > > > > Perhaps this isn't a one-size-fits-all situation and it needs to be > > configurable somehow at the client and/or server? > > -- > > Jeff Layton > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html