* Re: two odstate optimizations
2015-04-28 12:50 ` two odstate optimizations Jeff Layton
@ 2015-04-28 16:31 ` J. Bruce Fields
[not found] ` <CANMZn7___SXopxOB-dO0fBj3keVrkXOTwLaYPazzVLHGtgLvPw@mail.gmail.com>
1 sibling, 0 replies; 6+ messages in thread
From: J. Bruce Fields @ 2015-04-28 16:31 UTC (permalink / raw)
To: Jeff Layton; +Cc: Christoph Hellwig, Jeff Layton, Sachin Bhamare, linux-nfs
On Tue, Apr 28, 2015 at 08:50:06AM -0400, Jeff Layton wrote:
> On Tue, 28 Apr 2015 14:00:47 +0200
> Christoph Hellwig <hch@lst.de> wrote:
>
> > Two small optimizations for the odstate handling. Feel free to squash them
> > into "nfsd: fix pNFS return on close semantics" if you need to rebase anyway.
> >
>
> Both look good to me!
>
> Acked-by: Jeff Layton <jeff.layton@primarydata.com>
Thanks, I've currently got the following.--b.
commit 31f354f575ac
Author: Sachin Bhamare <sachin.bhamare@primarydata.com>
Date: Mon Apr 27 14:50:14 2015 +0200
nfsd: fix pNFS return on close semantics
For the sake of forgetful clients, the server should return the layouts
to the file system on 'last close' of a file (assuming that there are no
delegations outstanding to that particular client) or on delegreturn
(assuming that there are no opens on a file from that particular
client).
In theory the information is all there in current data structures, but
it's not efficiently available; nfs4_file->fi_ref includes references on
the file across all clients, but we need a per-(client, file) count.
Walking through lots of stateid's to calculate this on each close or
delegreturn would be painful.
This patch introduces infrastructure to maintain per-client opens and
delegation counters on a per-file basis.
[hch: ported to the mainline pNFS support, merged various fixes from Jeff]
Signed-off-by: Sachin Bhamare <sachin.bhamare@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 38f2d7abe3a7..907296476846 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -94,6 +94,7 @@ static struct kmem_cache *lockowner_slab;
static struct kmem_cache *file_slab;
static struct kmem_cache *stateid_slab;
static struct kmem_cache *deleg_slab;
+static struct kmem_cache *odstate_slab;
static void free_session(struct nfsd4_session *);
@@ -281,6 +282,7 @@ put_nfs4_file(struct nfs4_file *fi)
if (atomic_dec_and_lock(&fi->fi_ref, &state_lock)) {
hlist_del_rcu(&fi->fi_hash);
spin_unlock(&state_lock);
+ WARN_ON_ONCE(!list_empty(&fi->fi_clnt_odstate));
WARN_ON_ONCE(!list_empty(&fi->fi_delegations));
call_rcu(&fi->fi_rcu, nfsd4_free_file_rcu);
}
@@ -471,6 +473,86 @@ static void nfs4_file_put_access(struct nfs4_file *fp, u32 access)
__nfs4_file_put_access(fp, O_RDONLY);
}
+/*
+ * Allocate a new open/delegation state counter. This is needed for
+ * pNFS for proper return on close semantics.
+ *
+ * Note that we only allocate it for pNFS-enabled exports, otherwise
+ * all pointers to struct nfs4_clnt_odstate are always NULL.
+ */
+static struct nfs4_clnt_odstate *
+alloc_clnt_odstate(struct nfs4_client *clp)
+{
+ struct nfs4_clnt_odstate *co;
+
+ co = kmem_cache_zalloc(odstate_slab, GFP_KERNEL);
+ if (co) {
+ co->co_client = clp;
+ atomic_set(&co->co_odcount, 1);
+ }
+ return co;
+}
+
+static void
+hash_clnt_odstate_locked(struct nfs4_clnt_odstate *co)
+{
+ struct nfs4_file *fp = co->co_file;
+
+ lockdep_assert_held(&fp->fi_lock);
+ list_add(&co->co_perfile, &fp->fi_clnt_odstate);
+}
+
+static inline void
+get_clnt_odstate(struct nfs4_clnt_odstate *co)
+{
+ if (co)
+ atomic_inc(&co->co_odcount);
+}
+
+static void
+put_clnt_odstate(struct nfs4_clnt_odstate *co)
+{
+ struct nfs4_file *fp;
+
+ if (!co)
+ return;
+
+ fp = co->co_file;
+ if (atomic_dec_and_lock(&co->co_odcount, &fp->fi_lock)) {
+ list_del(&co->co_perfile);
+ spin_unlock(&fp->fi_lock);
+
+ nfsd4_return_all_file_layouts(co->co_client, fp);
+ kmem_cache_free(odstate_slab, co);
+ }
+}
+
+static struct nfs4_clnt_odstate *
+find_or_hash_clnt_odstate(struct nfs4_file *fp, struct nfs4_clnt_odstate *new)
+{
+ struct nfs4_clnt_odstate *co;
+ struct nfs4_client *cl;
+
+ if (!new)
+ return NULL;
+
+ cl = new->co_client;
+
+ spin_lock(&fp->fi_lock);
+ list_for_each_entry(co, &fp->fi_clnt_odstate, co_perfile) {
+ if (co->co_client == cl) {
+ get_clnt_odstate(co);
+ goto out;
+ }
+ }
+ co = new;
+ co->co_file = fp;
+ hash_clnt_odstate_locked(new);
+out:
+ spin_unlock(&fp->fi_lock);
+ return co;
+}
+
struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl,
struct kmem_cache *slab)
{
@@ -606,7 +688,8 @@ static void block_delegations(struct knfsd_fh *fh)
}
static struct nfs4_delegation *
-alloc_init_deleg(struct nfs4_client *clp, struct svc_fh *current_fh)
+alloc_init_deleg(struct nfs4_client *clp, struct svc_fh *current_fh,
+ struct nfs4_clnt_odstate *odstate)
{
struct nfs4_delegation *dp;
long n;
@@ -631,6 +714,8 @@ alloc_init_deleg(struct nfs4_client *clp, struct svc_fh *current_fh)
INIT_LIST_HEAD(&dp->dl_perfile);
INIT_LIST_HEAD(&dp->dl_perclnt);
INIT_LIST_HEAD(&dp->dl_recall_lru);
+ dp->dl_clnt_odstate = odstate;
+ get_clnt_odstate(odstate);
dp->dl_type = NFS4_OPEN_DELEGATE_READ;
dp->dl_retries = 1;
nfsd4_init_cb(&dp->dl_recall, dp->dl_stid.sc_client,
@@ -714,6 +799,7 @@ static void destroy_delegation(struct nfs4_delegation *dp)
spin_lock(&state_lock);
unhash_delegation_locked(dp);
spin_unlock(&state_lock);
+ put_clnt_odstate(dp->dl_clnt_odstate);
nfs4_put_deleg_lease(dp->dl_stid.sc_file);
nfs4_put_stid(&dp->dl_stid);
}
@@ -724,6 +810,7 @@ static void revoke_delegation(struct nfs4_delegation *dp)
WARN_ON(!list_empty(&dp->dl_recall_lru));
+ put_clnt_odstate(dp->dl_clnt_odstate);
nfs4_put_deleg_lease(dp->dl_stid.sc_file);
if (clp->cl_minorversion == 0)
@@ -933,6 +1020,7 @@ static void nfs4_free_ol_stateid(struct nfs4_stid *stid)
{
struct nfs4_ol_stateid *stp = openlockstateid(stid);
+ put_clnt_odstate(stp->st_clnt_odstate);
release_all_access(stp);
if (stp->st_stateowner)
nfs4_put_stateowner(stp->st_stateowner);
@@ -1634,6 +1722,7 @@ __destroy_client(struct nfs4_client *clp)
while (!list_empty(&reaplist)) {
dp = list_entry(reaplist.next, struct nfs4_delegation, dl_recall_lru);
list_del_init(&dp->dl_recall_lru);
+ put_clnt_odstate(dp->dl_clnt_odstate);
nfs4_put_deleg_lease(dp->dl_stid.sc_file);
nfs4_put_stid(&dp->dl_stid);
}
@@ -3057,6 +3146,7 @@ static void nfsd4_init_file(struct knfsd_fh *fh, unsigned int hashval,
spin_lock_init(&fp->fi_lock);
INIT_LIST_HEAD(&fp->fi_stateids);
INIT_LIST_HEAD(&fp->fi_delegations);
+ INIT_LIST_HEAD(&fp->fi_clnt_odstate);
fh_copy_shallow(&fp->fi_fhandle, fh);
fp->fi_deleg_file = NULL;
fp->fi_had_conflict = false;
@@ -3073,6 +3163,7 @@ static void nfsd4_init_file(struct knfsd_fh *fh, unsigned int hashval,
void
nfsd4_free_slabs(void)
{
+ kmem_cache_destroy(odstate_slab);
kmem_cache_destroy(openowner_slab);
kmem_cache_destroy(lockowner_slab);
kmem_cache_destroy(file_slab);
@@ -3103,8 +3194,14 @@ nfsd4_init_slabs(void)
sizeof(struct nfs4_delegation), 0, 0, NULL);
if (deleg_slab == NULL)
goto out_free_stateid_slab;
+ odstate_slab = kmem_cache_create("nfsd4_odstate",
+ sizeof(struct nfs4_clnt_odstate), 0, 0, NULL);
+ if (odstate_slab == NULL)
+ goto out_free_deleg_slab;
return 0;
+out_free_deleg_slab:
+ kmem_cache_destroy(deleg_slab);
out_free_stateid_slab:
kmem_cache_destroy(stateid_slab);
out_free_file_slab:
@@ -3581,6 +3678,14 @@ alloc_stateid:
open->op_stp = nfs4_alloc_open_stateid(clp);
if (!open->op_stp)
return nfserr_jukebox;
+
+ if (nfsd4_has_session(cstate) &&
+ (cstate->current_fh.fh_export->ex_flags & NFSEXP_PNFS)) {
+ open->op_odstate = alloc_clnt_odstate(clp);
+ if (!open->op_odstate)
+ return nfserr_jukebox;
+ }
+
return nfs_ok;
}
@@ -3869,7 +3974,7 @@ out_fput:
static struct nfs4_delegation *
nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh,
- struct nfs4_file *fp)
+ struct nfs4_file *fp, struct nfs4_clnt_odstate *odstate)
{
int status;
struct nfs4_delegation *dp;
@@ -3877,7 +3982,7 @@ nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh,
if (fp->fi_had_conflict)
return ERR_PTR(-EAGAIN);
- dp = alloc_init_deleg(clp, fh);
+ dp = alloc_init_deleg(clp, fh, odstate);
if (!dp)
return ERR_PTR(-ENOMEM);
@@ -3903,6 +4008,7 @@ out_unlock:
spin_unlock(&state_lock);
out:
if (status) {
+ put_clnt_odstate(dp->dl_clnt_odstate);
nfs4_put_stid(&dp->dl_stid);
return ERR_PTR(status);
}
@@ -3980,7 +4086,7 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open,
default:
goto out_no_deleg;
}
- dp = nfs4_set_delegation(clp, fh, stp->st_stid.sc_file);
+ dp = nfs4_set_delegation(clp, fh, stp->st_stid.sc_file, stp->st_clnt_odstate);
if (IS_ERR(dp))
goto out_no_deleg;
@@ -4069,6 +4175,11 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
release_open_stateid(stp);
goto out;
}
+
+ stp->st_clnt_odstate = find_or_hash_clnt_odstate(fp,
+ open->op_odstate);
+ if (stp->st_clnt_odstate == open->op_odstate)
+ open->op_odstate = NULL;
}
update_stateid(&stp->st_stid.sc_stateid);
memcpy(&open->op_stateid, &stp->st_stid.sc_stateid, sizeof(stateid_t));
@@ -4129,6 +4240,8 @@ void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
kmem_cache_free(file_slab, open->op_file);
if (open->op_stp)
nfs4_put_stid(&open->op_stp->st_stid);
+ if (open->op_odstate)
+ kmem_cache_free(odstate_slab, open->op_odstate);
}
__be32
@@ -4852,9 +4965,6 @@ nfsd4_close(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
update_stateid(&stp->st_stid.sc_stateid);
memcpy(&close->cl_stateid, &stp->st_stid.sc_stateid, sizeof(stateid_t));
- nfsd4_return_all_file_layouts(stp->st_stateowner->so_client,
- stp->st_stid.sc_file);
-
nfsd4_close_open_stateid(stp);
/* put reference from nfs4_preprocess_seqid_op */
@@ -6488,6 +6598,7 @@ nfs4_state_shutdown_net(struct net *net)
list_for_each_safe(pos, next, &reaplist) {
dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
list_del_init(&dp->dl_recall_lru);
+ put_clnt_odstate(dp->dl_clnt_odstate);
nfs4_put_deleg_lease(dp->dl_stid.sc_file);
nfs4_put_stid(&dp->dl_stid);
}
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 4f3bfeb11766..bde45d90b746 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -126,6 +126,7 @@ struct nfs4_delegation {
struct list_head dl_perfile;
struct list_head dl_perclnt;
struct list_head dl_recall_lru; /* delegation recalled */
+ struct nfs4_clnt_odstate *dl_clnt_odstate;
u32 dl_type;
time_t dl_time;
/* For recall: */
@@ -465,6 +466,17 @@ static inline struct nfs4_lockowner * lockowner(struct nfs4_stateowner *so)
}
/*
+ * Per-client state indicating no. of opens and outstanding delegations
+ * on a file from a particular client.'od' stands for 'open & delegation'
+ */
+struct nfs4_clnt_odstate {
+ struct nfs4_client *co_client;
+ struct nfs4_file *co_file;
+ struct list_head co_perfile;
+ atomic_t co_odcount;
+};
+
+/*
* nfs4_file: a file opened by some number of (open) nfs4_stateowners.
*
* These objects are global. nfsd keeps one instance of a nfs4_file per
@@ -485,6 +497,7 @@ struct nfs4_file {
struct list_head fi_delegations;
struct rcu_head fi_rcu;
};
+ struct list_head fi_clnt_odstate;
/* One each for O_RDONLY, O_WRONLY, O_RDWR: */
struct file * fi_fds[3];
/*
@@ -526,6 +539,7 @@ struct nfs4_ol_stateid {
struct list_head st_perstateowner;
struct list_head st_locks;
struct nfs4_stateowner * st_stateowner;
+ struct nfs4_clnt_odstate * st_clnt_odstate;
unsigned char st_access_bmap;
unsigned char st_deny_bmap;
struct nfs4_ol_stateid * st_openstp;
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index f982ae84f0cd..2f8c092be2b3 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -247,6 +247,7 @@ struct nfsd4_open {
struct nfs4_openowner *op_openowner; /* used during processing */
struct nfs4_file *op_file; /* used during processing */
struct nfs4_ol_stateid *op_stp; /* used during processing */
+ struct nfs4_clnt_odstate *op_odstate; /* used during processing */
struct nfs4_acl *op_acl;
struct xdr_netobj op_label;
};
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