1 files changed, 29 insertions, 22 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 1afd7d4420bd..1379d86f7b4f 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -275,9 +275,11 @@ opaque_hashval(const void *ptr, int nbytes)
         return x;
 }
 
-static void nfsd4_free_file(struct nfs4_file *f)
+static void nfsd4_free_file_rcu(struct rcu_head *rcu)
 {
-        kmem_cache_free(file_slab, f);
+        struct nfs4_file *fp = container_of(rcu, struct nfs4_file, fi_rcu);
+
+        kmem_cache_free(file_slab, fp);
 }
 
 static inline void
@@ -286,9 +288,10 @@ put_nfs4_file(struct nfs4_file *fi)
         might_lock(&state_lock);
 
         if (atomic_dec_and_lock(&fi->fi_ref, &state_lock)) {
-                hlist_del(&fi->fi_hash);
+                hlist_del_rcu(&fi->fi_hash);
                 spin_unlock(&state_lock);
-                nfsd4_free_file(fi);
+                WARN_ON_ONCE(!list_empty(&fi->fi_delegations));
+                call_rcu(&fi->fi_rcu, nfsd4_free_file_rcu);
         }
 }
 
@@ -3057,10 +3060,9 @@ static struct nfs4_file *nfsd4_alloc_file(void)
 }
 
 /* OPEN Share state helper functions */
-static void nfsd4_init_file(struct nfs4_file *fp, struct knfsd_fh *fh)
+static void nfsd4_init_file(struct knfsd_fh *fh, unsigned int hashval,
+                                struct nfs4_file *fp)
 {
-        unsigned int hashval = file_hashval(fh);
-
         lockdep_assert_held(&state_lock);
 
         atomic_set(&fp->fi_ref, 1);
@@ -3073,7 +3075,7 @@ static void nfsd4_init_file(struct nfs4_file *fp, struct knfsd_fh *fh)
         fp->fi_share_deny = 0;
         memset(fp->fi_fds, 0, sizeof(fp->fi_fds));
         memset(fp->fi_access, 0, sizeof(fp->fi_access));
-        hlist_add_head(&fp->fi_hash, &file_hashtbl[hashval]);
+        hlist_add_head_rcu(&fp->fi_hash, &file_hashtbl[hashval]);
 }
 
 void
@@ -3294,17 +3296,14 @@ move_to_close_lru(struct nfs4_ol_stateid *s, struct net *net)
 
 /* search file_hashtbl[] for file */
 static struct nfs4_file *
-find_file_locked(struct knfsd_fh *fh)
+find_file_locked(struct knfsd_fh *fh, unsigned int hashval)
 {
-        unsigned int hashval = file_hashval(fh);
         struct nfs4_file *fp;
 
-        lockdep_assert_held(&state_lock);
-
-        hlist_for_each_entry(fp, &file_hashtbl[hashval], fi_hash) {
+        hlist_for_each_entry_rcu(fp, &file_hashtbl[hashval], fi_hash) {
                 if (nfsd_fh_match(&fp->fi_fhandle, fh)) {
-                        get_nfs4_file(fp);
-                        return fp;
+                        if (atomic_inc_not_zero(&fp->fi_ref))
+                                return fp;
                 }
         }
         return NULL;
@@ -3314,10 +3313,11 @@ static struct nfs4_file *
 find_file(struct knfsd_fh *fh)
 {
         struct nfs4_file *fp;
+        unsigned int hashval = file_hashval(fh);
 
-        spin_lock(&state_lock);
-        fp = find_file_locked(fh);
-        spin_unlock(&state_lock);
+        rcu_read_lock();
+        fp = find_file_locked(fh, hashval);
+        rcu_read_unlock();
         return fp;
 }
 
@@ -3325,11 +3325,18 @@ static struct nfs4_file *
 find_or_add_file(struct nfs4_file *new, struct knfsd_fh *fh)
 {
         struct nfs4_file *fp;
+        unsigned int hashval = file_hashval(fh);
+
+        rcu_read_lock();
+        fp = find_file_locked(fh, hashval);
+        rcu_read_unlock();
+        if (fp)
+                return fp;
 
         spin_lock(&state_lock);
-        fp = find_file_locked(fh);
-        if (fp == NULL) {
-                nfsd4_init_file(new, fh);
+        fp = find_file_locked(fh, hashval);
+        if (likely(fp == NULL)) {
+                nfsd4_init_file(fh, hashval, new);
                 fp = new;
         }
         spin_unlock(&state_lock);
@@ -4127,7 +4134,7 @@ void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
                 nfs4_put_stateowner(so);
         }
         if (open->op_file)
-                nfsd4_free_file(open->op_file);
+                kmem_cache_free(file_slab, open->op_file);
         if (open->op_stp)
                 nfs4_put_stid(&open->op_stp->st_stid);
 }