From 4770d722014b99e5438c0d1dc44db31ac4547af1 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 29 Jul 2014 21:34:10 -0400 Subject: [PATCH] nfsd4: use cl_lock to synchronize all stateid idr calls Currently, this is serialized by the client_mutex, which is slated for removal. Add finer-grained locking here. Also, do some cleanup around find_stateid to prepare for taking references. Signed-off-by: Trond Myklebust Signed-off-by: Benny Halevy Signed-off-by: Jeff Layton Reviewed-by: Christoph Hellwig Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 41 ++++++++++++++++++++++++++++++----------- 1 file changed, 30 insertions(+), 11 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 344cd1ac3f67..bb37cc4dd573 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -467,7 +467,6 @@ static void nfs4_file_put_access(struct nfs4_file *fp, u32 access) static struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *slab) { - struct idr *stateids = &cl->cl_stateids; struct nfs4_stid *stid; int new_id; @@ -475,7 +474,11 @@ static struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, if (!stid) return NULL; - new_id = idr_alloc_cyclic(stateids, stid, 0, 0, GFP_KERNEL); + idr_preload(GFP_KERNEL); + spin_lock(&cl->cl_lock); + new_id = idr_alloc_cyclic(&cl->cl_stateids, stid, 0, 0, GFP_NOWAIT); + spin_unlock(&cl->cl_lock); + idr_preload_end(); if (new_id < 0) goto out_free; stid->sc_client = cl; @@ -635,9 +638,12 @@ nfs4_put_stid(struct nfs4_stid *s) struct nfs4_file *fp = s->sc_file; struct nfs4_client *clp = s->sc_client; - if (!atomic_dec_and_test(&s->sc_count)) + might_lock(&clp->cl_lock); + + if (!atomic_dec_and_lock(&s->sc_count, &clp->cl_lock)) return; idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id); + spin_unlock(&clp->cl_lock); s->sc_free(s); if (fp) put_nfs4_file(fp); @@ -1652,7 +1658,8 @@ static void gen_confirm(struct nfs4_client *clp) memcpy(clp->cl_confirm.data, verf, sizeof(clp->cl_confirm.data)); } -static struct nfs4_stid *find_stateid(struct nfs4_client *cl, stateid_t *t) +static struct nfs4_stid * +find_stateid_locked(struct nfs4_client *cl, stateid_t *t) { struct nfs4_stid *ret; @@ -1662,16 +1669,28 @@ static struct nfs4_stid *find_stateid(struct nfs4_client *cl, stateid_t *t) return ret; } -static struct nfs4_stid *find_stateid_by_type(struct nfs4_client *cl, stateid_t *t, char typemask) +static struct nfs4_stid * +find_stateid(struct nfs4_client *cl, stateid_t *t) +{ + struct nfs4_stid *ret; + + spin_lock(&cl->cl_lock); + ret = find_stateid_locked(cl, t); + spin_unlock(&cl->cl_lock); + return ret; +} + +static struct nfs4_stid * +find_stateid_by_type(struct nfs4_client *cl, stateid_t *t, char typemask) { struct nfs4_stid *s; - s = find_stateid(cl, t); - if (!s) - return NULL; - if (typemask & s->sc_type) - return s; - return NULL; + spin_lock(&cl->cl_lock); + s = find_stateid_locked(cl, t); + if (s != NULL && !(typemask & s->sc_type)) + s = NULL; + spin_unlock(&cl->cl_lock); + return s; } static struct nfs4_client *create_client(struct xdr_netobj name, -- 2.34.1