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From: "J. Bruce Fields" <bfields@fieldses.org>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
	Jeff Layton <jlayton@primarydata.com>,
	xfs@oss.sgi.com
Subject: Re: [PATCH 10/20] nfsd: implement pNFS operations
Date: Mon, 2 Feb 2015 09:28:32 -0500	[thread overview]
Message-ID: <20150202142832.GC22301@fieldses.org> (raw)
In-Reply-To: <20150202124349.GA15598@lst.de>

On Mon, Feb 02, 2015 at 01:43:49PM +0100, Christoph Hellwig wrote:
> On Thu, Jan 29, 2015 at 03:33:46PM -0500, J. Bruce Fields wrote:
> > Is there no old_stateid case for layout stateids?  And is there any
> > chance of wraparound?  (I was comparing to check_stateid_generation and
> > expecting the only difference to be the handling of the generation-zero
> > case.)
> 
> 12.5.3. explicitly mentions that LAYOUTGET and LAYOUTRETURN might be
> outstading and processed in parallel, and sais that pNFS operations
> use special stateid rules.  It does not explicitly say that old stateids
> are ok, but the model described in there very much requires the server
> to not reject them.
> 
> > > +static inline u64
> > > +layout_end(struct nfsd4_layout_seg *seg)
> > > +{
> > > +	u64 end = seg->offset + seg->length;
> > > +	return end >= seg->offset ? seg->length : NFS4_MAX_UINT64;
> > 
> > Shouldn't that be
> > 
> > 	return end >= seg->offset ? end : NFS_MAX_UINT64;
> > 
> > ?
> 
> Yes.  This is an interesting one that sneaked in, and it turns out
> besides dislabling layout merging it didn't have adverse effects.
> 
> > > +}
> > > +
> > > +static void
> > > +layout_update_len(struct nfsd4_layout_seg *lo, u64 end)
> > > +{
> > > +	if (end == NFS4_MAX_UINT64)
> > > +		lo->length = NFS4_MAX_UINT64;
> > 
> > Is this case necessary?
> > 
> > > +	else
> > > +		lo->length = end - lo->offset;
> 
> 
> We use NFS4_MAX_UINT64 as a magic value for layouts until the
> field end, as specified in the standard.  But because we do all
> kinds of calculations using the end value we need to propagate
> that magic from and to it.
> 
> > Should any of these have OP_MODIFIES_SOMETHING set?  (Basically: would
> > we be in trouble if we succesfully completed one of these operations and
> > then weren't able to encode the result?)
> 
> All but GETDEVICEINFO should get it.
> 
> I've implemented all your suggested changes and will send out and update
> after doing a little more testing.

Thanks!

I didn't notice anything that looked like a big problem to me, so absent
any objections I'll commit the revised versions for 3.20 once we figure
out how to handle the xfs stuff.

--b.

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  reply	other threads:[~2015-02-02 14:28 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-22 11:09 a simple and scalable pNFS block layout server V2 Christoph Hellwig
2015-01-22 11:09 ` [PATCH 04/20] nfsd: factor out a helper to decode nfstime4 values Christoph Hellwig
     [not found]   ` <1421925006-24231-5-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-01-22 20:15     ` J. Bruce Fields
2015-01-22 11:09 ` [PATCH 05/20] nfsd: move nfsd_fh_match to nfsfh.h Christoph Hellwig
2015-01-22 11:09 ` [PATCH 09/20] nfsd: make find_any_file available outside nfs4state.c Christoph Hellwig
2015-01-22 11:09 ` [PATCH 12/20] nfsd: update documentation for pNFS support Christoph Hellwig
2015-01-22 11:09 ` [PATCH 13/20] nfsd: add trace events Christoph Hellwig
2015-01-22 11:10 ` [PATCH 15/20] nfsd: pNFS block layout driver Christoph Hellwig
2015-01-22 11:10 ` [PATCH 18/20] xfs: factor out a xfs_update_prealloc_flags() helper Christoph Hellwig
     [not found]   ` <1421925006-24231-19-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-02-01 23:06     ` Dave Chinner
2015-01-22 16:04 ` a simple and scalable pNFS block layout server V2 Chuck Lever
2015-01-22 16:21   ` Christoph Hellwig
     [not found] ` <1421925006-24231-1-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-01-22 11:09   ` [PATCH 01/20] nfs: add LAYOUT_TYPE_MAX enum value Christoph Hellwig
2015-01-22 11:09   ` [PATCH 02/20] fs: track fl_owner for leases Christoph Hellwig
2015-01-22 11:09   ` [PATCH 03/20] fs: add FL_LAYOUT lease type Christoph Hellwig
2015-01-22 15:45     ` Jeff Layton
     [not found]     ` <1421925006-24231-4-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-01-22 20:14       ` J. Bruce Fields
     [not found]         ` <20150122201442.GJ898-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2015-01-22 20:18           ` Christoph Hellwig
2015-01-22 11:09   ` [PATCH 06/20] nfsd: add fh_fsid_match helper Christoph Hellwig
2015-01-22 11:09   ` [PATCH 07/20] nfsd: make lookup/alloc/unhash_stid available outside nfs4state.c Christoph Hellwig
2015-01-22 11:09   ` [PATCH 08/20] nfsd: make find/get/put file " Christoph Hellwig
2015-01-22 11:09   ` [PATCH 10/20] nfsd: implement pNFS operations Christoph Hellwig
     [not found]     ` <1421925006-24231-11-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-01-29 20:33       ` J. Bruce Fields
     [not found]         ` <20150129203346.GA11064-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2015-02-02 12:43           ` Christoph Hellwig
2015-02-02 14:28             ` J. Bruce Fields [this message]
     [not found]               ` <20150202142832.GC22301-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2015-02-02 14:56                 ` Christoph Hellwig
     [not found]                   ` <20150202145619.GA18387-jcswGhMUV9g@public.gmane.org>
2015-02-02 15:00                     ` J. Bruce Fields
     [not found]                       ` <20150202150032.GD22301-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2015-02-02 18:56                         ` Christoph Hellwig
     [not found]                           ` <20150202185638.GB23319-jcswGhMUV9g@public.gmane.org>
2015-02-03 16:08                             ` J. Bruce Fields
2015-01-22 11:09   ` [PATCH 11/20] nfsd: implement pNFS layout recalls Christoph Hellwig
2015-01-22 11:10   ` [PATCH 14/20] exportfs: add methods for block layout exports Christoph Hellwig
2015-01-22 11:10   ` [PATCH 16/20] xfs: pass a 64-bit count argument to xfs_iomap_write_unwritten Christoph Hellwig
2015-01-29 20:52     ` J. Bruce Fields
2015-02-02  7:30       ` Christoph Hellwig
2015-02-02 19:24         ` Dave Chinner
2015-02-02 19:43           ` Dave Chinner
2015-02-02 19:48             ` J. Bruce Fields
2015-02-03 18:35               ` Christoph Hellwig
     [not found]                 ` <20150203183533.GA16929-jcswGhMUV9g@public.gmane.org>
2015-02-11 22:35                   ` J. Bruce Fields
2015-02-11 22:54                     ` J. Bruce Fields
2015-02-04  7:57             ` Christoph Hellwig
     [not found]               ` <20150204075756.GA763-jcswGhMUV9g@public.gmane.org>
2015-02-04 20:02                 ` Dave Chinner
2015-01-22 11:10   ` [PATCH 17/20] xfs: update the superblock using a synchronous transaction in growfs Christoph Hellwig
2015-01-22 11:10   ` [PATCH 19/20] xfs: implement pNFS export operations Christoph Hellwig
     [not found]     ` <1421925006-24231-20-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-02-05  0:47       ` Dave Chinner
2015-02-05  7:08         ` Christoph Hellwig
     [not found]           ` <20150205070858.GA593-jcswGhMUV9g@public.gmane.org>
2015-02-05 13:57             ` Christoph Hellwig
     [not found]               ` <20150205135756.GA6386-jcswGhMUV9g@public.gmane.org>
2015-02-06 22:20                 ` Dave Chinner
2015-02-06 22:42                   ` J. Bruce Fields
2015-02-08 13:34                     ` Christoph Hellwig
     [not found]                       ` <20150208133435.GA27081-jcswGhMUV9g@public.gmane.org>
2015-02-08 14:09                         ` Jeff Layton
     [not found]                           ` <20150208090942.51e99687-9yPaYZwiELC+kQycOl6kW4xkIHaj4LzF@public.gmane.org>
2015-02-09 20:11                             ` J. Bruce Fields
     [not found]                               ` <20150209201154.GA27746-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2015-02-10  0:04                                 ` Dave Chinner
2015-02-13  1:11                                   ` J. Bruce Fields
2015-02-13  1:54                                     ` Dave Chinner
2015-02-13  2:38                                       ` Stephen Rothwell
2015-02-15 23:25                                         ` Dave Chinner
2015-01-22 11:10   ` [PATCH 20/20] xfs: recall pNFS layouts on conflicting access Christoph Hellwig
     [not found]     ` <1421925006-24231-21-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-02-05  0:51       ` Dave Chinner
2015-01-22 20:01   ` a simple and scalable pNFS block layout server V2 J. Bruce Fields
2015-01-22 20:06   ` J. Bruce Fields
2015-01-22 20:20     ` Christoph Hellwig
     [not found]     ` <20150122200618.GI898-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2015-01-22 20:20       ` Jeff Layton

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