Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-pd0-f177.google.com ([209.85.192.177]:60973 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751134AbaHJPrb (ORCPT ); Sun, 10 Aug 2014 11:47:31 -0400 Message-ID: <53E79408.2050901@gmail.com> Date: Sun, 10 Aug 2014 23:47:20 +0800 From: Kinglong Mee MIME-Version: 1.0 To: Jeff Layton CC: "J. Bruce Fields" , Linux NFS Mailing List , Trond Myklebust , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 2/3] NFSD: Increase the reference of lockowner when coping file_lock References: <53BAAAC5.9000106@gmail.com> <53E22EA5.70708@gmail.com> <53E22F2C.8070900@gmail.com> <20140809070818.4d939a6a@tlielax.poochiereds.net> In-Reply-To: <20140809070818.4d939a6a@tlielax.poochiereds.net> Content-Type: text/plain; charset=windows-1252 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 8/9/2014 19:08, Jeff Layton wrote: > On Wed, 06 Aug 2014 21:35:40 +0800 > Kinglong Mee wrote: > >> Signed-off-by: Kinglong Mee >> --- >> fs/nfsd/nfs4state.c | 33 +++++++++++++++++++++++++++++++-- >> 1 file changed, 31 insertions(+), 2 deletions(-) >> >> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c >> index 24168ae..07e4b5c 100644 >> --- a/fs/nfsd/nfs4state.c >> +++ b/fs/nfsd/nfs4state.c >> @@ -4867,6 +4867,29 @@ nfs4_transform_lock_offset(struct file_lock *lock) >> lock->fl_end = OFFSET_MAX; >> } >> >> +static inline struct nfs4_lockowner *get_lockowner(struct nfs4_lockowner *lo) >> +{ >> + atomic_inc(&lo->lo_owner.so_count); >> + return lo; >> +} >> + >> +static void nfsd4_fl_copy_lock(struct file_lock *dst, struct file_lock *src) >> +{ >> + struct nfs4_lockowner *lo = (struct nfs4_lockowner *) src->fl_owner; >> + get_lockowner(lo); >> +} >> + >> +static void nfsd4_fl_release_lock(struct file_lock *fl) >> +{ >> + struct nfs4_lockowner *lo = (struct nfs4_lockowner *) fl->fl_owner; >> + nfs4_put_stateowner(&lo->lo_owner); >> +} >> + >> +static const struct file_lock_operations nfsd4_fl_lock_ops = { >> + .fl_copy_lock = nfsd4_fl_copy_lock, >> + .fl_release_private = nfsd4_fl_release_lock, >> +}; >> + >> static inline void >> nfs4_set_lock_denied(struct file_lock *fl, struct nfsd4_lock_denied *deny) >> { >> @@ -5233,10 +5256,12 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, >> status = nfserr_openmode; >> goto out; >> } >> - file_lock->fl_owner = (fl_owner_t)lock_sop; >> + >> + file_lock->fl_owner = (fl_owner_t)get_lockowner(lock_sop); >> file_lock->fl_pid = current->tgid; >> file_lock->fl_file = filp; >> file_lock->fl_flags = FL_POSIX | FL_NFSD; >> + file_lock->fl_ops = &nfsd4_fl_lock_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); >> @@ -5399,6 +5424,7 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, >> struct nfs4_ol_stateid *stp; >> struct file *filp = NULL; >> struct file_lock *file_lock = NULL; >> + struct nfs4_lockowner *lock_sop = NULL; >> __be32 status; >> int err; >> struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); >> @@ -5420,6 +5446,8 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, >> status = nfserr_lock_range; >> goto put_stateid; >> } >> + >> + lock_sop = lockowner(stp->st_stateowner); >> file_lock = locks_alloc_lock(); >> if (!file_lock) { >> dprintk("NFSD: %s: unable to allocate lock!\n", __func__); >> @@ -5428,10 +5456,11 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, >> } >> locks_init_lock(file_lock); >> file_lock->fl_type = F_UNLCK; >> - file_lock->fl_owner = (fl_owner_t)lockowner(stp->st_stateowner); >> + file_lock->fl_owner = (fl_owner_t)get_lockowner(lock_sop); >> file_lock->fl_pid = current->tgid; >> file_lock->fl_file = filp; >> file_lock->fl_flags = FL_POSIX | FL_NFSD; >> + file_lock->fl_ops = &nfsd4_fl_lock_ops; >> file_lock->fl_start = locku->lu_offset; >> >> file_lock->fl_end = last_byte_offset(locku->lu_offset, > > (Sorry I didn't respond to these before -- I no longer work for Red > Hat, so emails to jlayton@redhat.com don't get to me). > > This looks really wrong. In this case, knfsd is acting as a > (server-side) lock manager, not a filesystem: > > const struct file_lock_operations *fl_ops; /* Callbacks for filesystems */ > const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */ > > So really, taking and putting of lockowner references is really the > purview of the lockmanager. If you had a filesystem that set fl_ops and > was exportable, then this will likely break it. > > The fact that the file locking code uses struct file_lock for lock > requests and for tracking the locks themselves makes for a horribly > confusing interface. If I were designing this from scratch I would have > made those two distinct structures. Maybe we should do that anyway > sometime. > > What you probably ought want to do is to declare some new fl_lmops for > taking and putting lockowner references and add hooks to call them at > the appropriate places. Sorry for my fault, a new resolve as v2 has be send. Please help have a check, thank you very much. thanks, Kinglong Mee