Re: [PATCH 2/4] NFSD: Rervert "knfsd: locks: flag NFSv4-owned locks"

[Jeff Layton <jeff.layton@primarydata.com>]

On Mon, 07 Jul 2014 22:12:21 +0800
Kinglong Mee <kinglongmee@gmail.com> wrote:

> Commit d5b9026a67 ([PATCH] knfsd: locks: flag NFSv4-owned locks) using
> fl_lmops field in file_lock for checking nfsd4 lockowner.
> 
> But, commit 1a747ee0cc (locks: don't call ->copy_lock methods on return of conflicting locks) causes the fl_lmops of conflock for nfsd4_lock always be NULL.
> 
> Also, commit 0996905f93 (lockd: posix_test_lock() should not call locks_copy_lock()) caused the fl_lmops of conflock for nfsd4_lockt always be NULL too.
> 
> So that, using fl_lmops cannot checking nfsd4 lockowner for it always be NULL.
> 
> This patch save the strhashval in nfs4_lockowner for searching lockownerlike before.
> 
> Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
> ---
>  fs/nfsd/nfs4state.c | 35 +++++++++++++++++++++++------------
>  fs/nfsd/state.h     |  1 +
>  2 files changed, 24 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 9b9474c..1b5afc1 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -4282,18 +4282,30 @@ nfs4_transform_lock_offset(struct file_lock *lock)
>  		lock->fl_end = OFFSET_MAX;
>  }
>  
> -/* Hack!: For now, we're defining this just so we can use a pointer to it
> - * as a unique cookie to identify our (NFSv4's) posix locks. */
> -static const struct lock_manager_operations nfsd_posix_mng_ops  = {
> -};
> +static bool
> +nfs4_verify_lock_stateowner(struct nfs4_lockowner *lo, struct nfsd_net *nn)
> +{
> +	struct nfs4_stateowner *local = NULL;
> +	unsigned hashval = lo->lo_hashval;
> +
> +	if (hashval >= OWNER_HASH_SIZE)
> +		return false;
> +

^^^^
Maybe a WARN_ON_ONCE or something here would be appropriate?

> +	list_for_each_entry(local, &nn->ownerstr_hashtbl[hashval], so_strhash) {
> +		if (local == &lo->lo_owner)
> +			return true;
> +	}
> +
> +	return false;
> +}
>  
>  static inline void
> -nfs4_set_lock_denied(struct file_lock *fl, struct nfsd4_lock_denied *deny)
> +nfs4_set_lock_denied(struct file_lock *fl, struct nfsd4_lock_denied *deny,
> +			struct nfsd_net *nn)
>  {
> -	struct nfs4_lockowner *lo;
> +	struct nfs4_lockowner *lo = (struct nfs4_lockowner *) fl->fl_owner;
>  
> -	if (fl->fl_lmops == &nfsd_posix_mng_ops) {
> -		lo = (struct nfs4_lockowner *) fl->fl_owner;
> +	if (nfs4_verify_lock_stateowner(lo, nn)) {
>  		deny->ld_owner.data = kmemdup(lo->lo_owner.so_owner.data,
>  					lo->lo_owner.so_owner.len, GFP_KERNEL);
>  		if (!deny->ld_owner.data)
> @@ -4350,6 +4362,7 @@ alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp, str
>  	if (!lo)
>  		return NULL;
>  	INIT_LIST_HEAD(&lo->lo_owner.so_stateids);
> +	lo->lo_hashval = strhashval;
>  	lo->lo_owner.so_is_open_owner = 0;
>  	/* It is the openowner seqid that will be incremented in encode in the
>  	 * case of new lockowners; so increment the lock seqid manually: */
> @@ -4564,7 +4577,6 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  	file_lock->fl_pid = current->tgid;
>  	file_lock->fl_file = filp;
>  	file_lock->fl_flags = FL_POSIX;
> -	file_lock->fl_lmops = &nfsd_posix_mng_ops;
>  	file_lock->fl_start = lock->lk_offset;
>  	file_lock->fl_end = last_byte_offset(lock->lk_offset, lock->lk_length);
>  	nfs4_transform_lock_offset(file_lock);
> @@ -4587,7 +4599,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  	case (EAGAIN):		/* conflock holds conflicting lock */
>  		status = nfserr_denied;
>  		dprintk("NFSD: nfsd4_lock: conflicting lock found!\n");
> -		nfs4_set_lock_denied(conflock, &lock->lk_denied);
> +		nfs4_set_lock_denied(conflock, &lock->lk_denied, nn);
>  		break;
>  	case (EDEADLK):
>  		status = nfserr_deadlock;
> @@ -4695,7 +4707,7 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  
>  	if (file_lock->fl_type != F_UNLCK) {
>  		status = nfserr_denied;
> -		nfs4_set_lock_denied(file_lock, &lockt->lt_denied);
> +		nfs4_set_lock_denied(file_lock, &lockt->lt_denied, nn);
>  	}
>  out:
>  	nfs4_unlock_state();
> @@ -4746,7 +4758,6 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  	file_lock->fl_pid = current->tgid;
>  	file_lock->fl_file = filp;
>  	file_lock->fl_flags = FL_POSIX;
> -	file_lock->fl_lmops = &nfsd_posix_mng_ops;
>  	file_lock->fl_start = locku->lu_offset;
>  
>  	file_lock->fl_end = last_byte_offset(locku->lu_offset,
> diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> index 1848fed..9ecae58 100644
> --- a/fs/nfsd/state.h
> +++ b/fs/nfsd/state.h
> @@ -362,6 +362,7 @@ struct nfs4_openowner {
>  
>  struct nfs4_lockowner {
>  	struct nfs4_stateowner	lo_owner; /* must be first element */
> +	unsigned int		lo_hashval;
>  };
>  
>  static inline struct nfs4_openowner * openowner(struct nfs4_stateowner *so)

Looks fine other than the comment about the warning. I do have some
patches that change the ownerstr_hashtbl to be a per-client entity.
I'll need to respin them to account for this change, but that shouldn't
be too onerous.

Acked-by: Jeff Layton <jlayton@primarydata.com>