2016-05-05 10:53:58

by Jeff Layton

[permalink] [raw]
Subject: [PATCH] nfsd: handle seqid wraparound in nfsd4_preprocess_layout_stateid

Move the existing static function to an inline helper, and call it.

Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Jeff Layton <[email protected]>
---
fs/nfsd/nfs4layouts.c | 2 +-
fs/nfsd/nfs4state.c | 8 +-------
fs/nfsd/state.h | 5 +++++
3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
index 825c7bc8d789..953c0755cb37 100644
--- a/fs/nfsd/nfs4layouts.c
+++ b/fs/nfsd/nfs4layouts.c
@@ -289,7 +289,7 @@ nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,

status = nfserr_bad_stateid;
mutex_lock(&ls->ls_mutex);
- if (stateid->si_generation > stid->sc_stateid.si_generation)
+ if (nfsd4_stateid_generation_after(stateid, &stid->sc_stateid))
goto out_unlock_stid;
if (layout_type != ls->ls_layout_type)
goto out_unlock_stid;
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 0462eeddfff9..f5f82e145018 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4651,12 +4651,6 @@ grace_disallows_io(struct net *net, struct inode *inode)
return opens_in_grace(net) && mandatory_lock(inode);
}

-/* Returns true iff a is later than b: */
-static bool stateid_generation_after(stateid_t *a, stateid_t *b)
-{
- return (s32)(a->si_generation - b->si_generation) > 0;
-}
-
static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_session)
{
/*
@@ -4670,7 +4664,7 @@ static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_s
return nfs_ok;

/* If the client sends us a stateid from the future, it's buggy: */
- if (stateid_generation_after(in, ref))
+ if (nfsd4_stateid_generation_after(in, ref))
return nfserr_bad_stateid;
/*
* However, we could see a stateid from the past, even from a
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index c050c53036a6..986e51e5ceac 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -573,6 +573,11 @@ enum nfsd4_cb_op {
NFSPROC4_CLNT_CB_SEQUENCE,
};

+/* Returns true iff a is later than b: */
+static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b)
+{
+ return (s32)(a->si_generation - b->si_generation) > 0;
+}

struct nfsd4_compound_state;
struct nfsd_net;
--
2.5.5



2016-05-05 11:00:22

by Jeff Layton

[permalink] [raw]
Subject: Re: [PATCH] nfsd: handle seqid wraparound in nfsd4_preprocess_layout_stateid

On Thu, 2016-05-05 at 06:53 -0400, Jeff Layton wrote:
> Move the existing static function to an inline helper, and call it.
>
> Cc: Christoph Hellwig <[email protected]>
> Signed-off-by: Jeff Layton <[email protected]>

This is just something I noticed by inspection while ensuring that some
client-side changes that I have queued won't cause a problem. I don't
have a knfsd pnfs test rig though, so I can't test this easily.

As a side note though...should we also be verifying that the seqid is not zero in this function? That's never allowed for layout stateids.

> ---
>  fs/nfsd/nfs4layouts.c | 2 +-
>  fs/nfsd/nfs4state.c   | 8 +-------
>  fs/nfsd/state.h       | 5 +++++
>  3 files changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
> index 825c7bc8d789..953c0755cb37 100644
> --- a/fs/nfsd/nfs4layouts.c
> +++ b/fs/nfsd/nfs4layouts.c
> @@ -289,7 +289,7 @@ nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
>  
>   status = nfserr_bad_stateid;
>   mutex_lock(&ls->ls_mutex);
> - if (stateid->si_generation > stid->sc_stateid.si_generation)
> + if (nfsd4_stateid_generation_after(stateid, &stid->sc_stateid))
>   goto out_unlock_stid;
>   if (layout_type != ls->ls_layout_type)
>   goto out_unlock_stid;
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 0462eeddfff9..f5f82e145018 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -4651,12 +4651,6 @@ grace_disallows_io(struct net *net, struct inode *inode)
>   return opens_in_grace(net) && mandatory_lock(inode);
>  }
>  
> -/* Returns true iff a is later than b: */
> -static bool stateid_generation_after(stateid_t *a, stateid_t *b)
> -{
> - return (s32)(a->si_generation - b->si_generation) > 0;
> -}
> -
>  static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_session)
>  {
>   /*
> @@ -4670,7 +4664,7 @@ static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_s
>   return nfs_ok;
>  
>   /* If the client sends us a stateid from the future, it's buggy: */
> - if (stateid_generation_after(in, ref))
> + if (nfsd4_stateid_generation_after(in, ref))
>   return nfserr_bad_stateid;
>   /*
>    * However, we could see a stateid from the past, even from a
> diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> index c050c53036a6..986e51e5ceac 100644
> --- a/fs/nfsd/state.h
> +++ b/fs/nfsd/state.h
> @@ -573,6 +573,11 @@ enum nfsd4_cb_op {
>   NFSPROC4_CLNT_CB_SEQUENCE,
>  };
>  
> +/* Returns true iff a is later than b: */
> +static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b)
> +{
> + return (s32)(a->si_generation - b->si_generation) > 0;
> +}
>  
>  struct nfsd4_compound_state;
>  struct nfsd_net;
--
Jeff Layton <[email protected]>

2016-05-13 19:43:24

by J. Bruce Fields

[permalink] [raw]
Subject: Re: [PATCH] nfsd: handle seqid wraparound in nfsd4_preprocess_layout_stateid

On Thu, May 05, 2016 at 07:00:17AM -0400, Jeff Layton wrote:
> On Thu, 2016-05-05 at 06:53 -0400, Jeff Layton wrote:
> > Move the existing static function to an inline helper, and call it.
> >
> > Cc: Christoph Hellwig <[email protected]>
> > Signed-off-by: Jeff Layton <[email protected]>
>
> This is just something I noticed by inspection while ensuring that some
> client-side changes that I have queued won't cause a problem. I don't
> have a knfsd pnfs test rig though, so I can't test this easily.
>
> As a side note though...should we also be verifying that the seqid is not zero in this function? That's never allowed for layout stateids.

In nfsd4_preprocess_layout_stateid()? Sure. I guess it's just a
courtesy to help debug out-of-spec clients, but, may as well.

--b.

>
> > ---
> >  fs/nfsd/nfs4layouts.c | 2 +-
> >  fs/nfsd/nfs4state.c   | 8 +-------
> >  fs/nfsd/state.h       | 5 +++++
> >  3 files changed, 7 insertions(+), 8 deletions(-)
> >
> > diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
> > index 825c7bc8d789..953c0755cb37 100644
> > --- a/fs/nfsd/nfs4layouts.c
> > +++ b/fs/nfsd/nfs4layouts.c
> > @@ -289,7 +289,7 @@ nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
> >  
> >   status = nfserr_bad_stateid;
> >   mutex_lock(&ls->ls_mutex);
> > - if (stateid->si_generation > stid->sc_stateid.si_generation)
> > + if (nfsd4_stateid_generation_after(stateid, &stid->sc_stateid))
> >   goto out_unlock_stid;
> >   if (layout_type != ls->ls_layout_type)
> >   goto out_unlock_stid;
> > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> > index 0462eeddfff9..f5f82e145018 100644
> > --- a/fs/nfsd/nfs4state.c
> > +++ b/fs/nfsd/nfs4state.c
> > @@ -4651,12 +4651,6 @@ grace_disallows_io(struct net *net, struct inode *inode)
> >   return opens_in_grace(net) && mandatory_lock(inode);
> >  }
> >  
> > -/* Returns true iff a is later than b: */
> > -static bool stateid_generation_after(stateid_t *a, stateid_t *b)
> > -{
> > - return (s32)(a->si_generation - b->si_generation) > 0;
> > -}
> > -
> >  static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_session)
> >  {
> >   /*
> > @@ -4670,7 +4664,7 @@ static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_s
> >   return nfs_ok;
> >  
> >   /* If the client sends us a stateid from the future, it's buggy: */
> > - if (stateid_generation_after(in, ref))
> > + if (nfsd4_stateid_generation_after(in, ref))
> >   return nfserr_bad_stateid;
> >   /*
> >    * However, we could see a stateid from the past, even from a
> > diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> > index c050c53036a6..986e51e5ceac 100644
> > --- a/fs/nfsd/state.h
> > +++ b/fs/nfsd/state.h
> > @@ -573,6 +573,11 @@ enum nfsd4_cb_op {
> >   NFSPROC4_CLNT_CB_SEQUENCE,
> >  };
> >  
> > +/* Returns true iff a is later than b: */
> > +static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b)
> > +{
> > + return (s32)(a->si_generation - b->si_generation) > 0;
> > +}
> >  
> >  struct nfsd4_compound_state;
> >  struct nfsd_net;
> --
> Jeff Layton <[email protected]>