nfsd: lock owners are not per open stateid

In the NFSv4 spec, lock stateids are per-file objects. Lockowners are not.
This patch replaces the current list of lock owners in the open stateids
with a list of lock stateids.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4state.c

@@ -695,10 +695,11 @@ static void free_generic_stateid(struct nfs4_ol_stateid *stp)
 	nfs4_free_stid(stateid_slab, &stp->st_stid);
 }
 
-static void release_lock_stateid(struct nfs4_ol_stateid *stp)
+static void __release_lock_stateid(struct nfs4_ol_stateid *stp)
 {
 	struct file *file;
 
+	list_del(&stp->st_locks);
 	unhash_generic_stateid(stp);
 	unhash_stid(&stp->st_stid);
 	file = find_any_file(stp->st_file);
@@ -713,12 +714,11 @@ static void unhash_lockowner(struct nfs4_lockowner *lo)
 	struct nfs4_ol_stateid *stp;
 
 	list_del(&lo->lo_owner.so_strhash);
-	list_del(&lo->lo_perstateid);
 	list_del(&lo->lo_owner_ino_hash);
 	while (!list_empty(&lo->lo_owner.so_stateids)) {
 		stp = list_first_entry(&lo->lo_owner.so_stateids,
 				struct nfs4_ol_stateid, st_perstateowner);
-		release_lock_stateid(stp);
+		__release_lock_stateid(stp);
 	}
 }
 
@@ -734,22 +734,36 @@ static void release_lockowner(struct nfs4_lockowner *lo)
 	nfs4_free_lockowner(lo);
 }
 
-static void
-release_stateid_lockowners(struct nfs4_ol_stateid *open_stp)
+static void release_lockowner_if_empty(struct nfs4_lockowner *lo)
+{
+	if (list_empty(&lo->lo_owner.so_stateids))
+		release_lockowner(lo);
+}
+
+static void release_lock_stateid(struct nfs4_ol_stateid *stp)
 {
 	struct nfs4_lockowner *lo;
 
-	while (!list_empty(&open_stp->st_lockowners)) {
-		lo = list_entry(open_stp->st_lockowners.next,
-				struct nfs4_lockowner, lo_perstateid);
-		release_lockowner(lo);
+	lo = lockowner(stp->st_stateowner);
+	__release_lock_stateid(stp);
+	release_lockowner_if_empty(lo);
+}
+
+static void release_open_stateid_locks(struct nfs4_ol_stateid *open_stp)
+{
+	struct nfs4_ol_stateid *stp;
+
+	while (!list_empty(&open_stp->st_locks)) {
+		stp = list_entry(open_stp->st_locks.next,
+				struct nfs4_ol_stateid, st_locks);
+		release_lock_stateid(stp);
 	}
 }
 
 static void unhash_open_stateid(struct nfs4_ol_stateid *stp)
 {
 	unhash_generic_stateid(stp);
-	release_stateid_lockowners(stp);
+	release_open_stateid_locks(stp);
 	close_generic_stateid(stp);
 }
 
@@ -2744,7 +2758,7 @@ static void init_open_stateid(struct nfs4_ol_stateid *stp, struct nfs4_file *fp,
 	struct nfs4_openowner *oo = open->op_openowner;
 
 	stp->st_stid.sc_type = NFS4_OPEN_STID;
-	INIT_LIST_HEAD(&stp->st_lockowners);
+	INIT_LIST_HEAD(&stp->st_locks);
 	list_add(&stp->st_perstateowner, &oo->oo_owner.so_stateids);
 	list_add(&stp->st_perfile, &fp->fi_stateids);
 	stp->st_stateowner = &oo->oo_owner;
@@ -4335,7 +4349,6 @@ static void hash_lockowner(struct nfs4_lockowner *lo, unsigned int strhashval, s
 
 	list_add(&lo->lo_owner.so_strhash, &nn->ownerstr_hashtbl[strhashval]);
 	list_add(&lo->lo_owner_ino_hash, &nn->lockowner_ino_hashtbl[inohash]);
-	list_add(&lo->lo_perstateid, &open_stp->st_lockowners);
 }
 
 /*
@@ -4380,6 +4393,7 @@ alloc_init_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp, struct
 	stp->st_access_bmap = 0;
 	stp->st_deny_bmap = open_stp->st_deny_bmap;
 	stp->st_openstp = open_stp;
+	list_add(&stp->st_locks, &open_stp->st_locks);
 	return stp;
 }
 
@@ -4967,18 +4981,21 @@ static void nfsd_print_count(struct nfs4_client *clp, unsigned int count,
 	printk(KERN_INFO "NFS Client: %s has %u %s\n", buf, count, type);
 }
 
-static u64 nfsd_foreach_client_lock(struct nfs4_client *clp, u64 max, void (*func)(struct nfs4_lockowner *))
+static u64 nfsd_foreach_client_lock(struct nfs4_client *clp, u64 max,
+				    void (*func)(struct nfs4_ol_stateid *))
 {
 	struct nfs4_openowner *oop;
-	struct nfs4_lockowner *lop, *lo_next;
 	struct nfs4_ol_stateid *stp, *st_next;
+	struct nfs4_ol_stateid *lst, *lst_next;
 	u64 count = 0;
 
 	list_for_each_entry(oop, &clp->cl_openowners, oo_perclient) {
-		list_for_each_entry_safe(stp, st_next, &oop->oo_owner.so_stateids, st_perstateowner) {
-			list_for_each_entry_safe(lop, lo_next, &stp->st_lockowners, lo_perstateid) {
+		list_for_each_entry_safe(stp, st_next,
+				&oop->oo_owner.so_stateids, st_perstateowner) {
+			list_for_each_entry_safe(lst, lst_next,
+					&stp->st_locks, st_locks) {
 				if (func)
-					func(lop);
+					func(lst);
 				if (++count == max)
 					return count;
 			}
@@ -4990,7 +5007,7 @@ static u64 nfsd_foreach_client_lock(struct nfs4_client *clp, u64 max, void (*fun
 
 u64 nfsd_forget_client_locks(struct nfs4_client *clp, u64 max)
 {
-	return nfsd_foreach_client_lock(clp, max, release_lockowner);
+	return nfsd_foreach_client_lock(clp, max, release_lock_stateid);
 }
 
 u64 nfsd_print_client_locks(struct nfs4_client *clp, u64 max)

fs/nfsd/state.h

@@ -365,7 +365,6 @@ struct nfs4_openowner {
 struct nfs4_lockowner {
 	struct nfs4_stateowner	lo_owner; /* must be first element */
 	struct list_head	lo_owner_ino_hash; /* hash by owner,file */
-	struct list_head        lo_perstateid;
 	struct list_head	lo_list; /* for temporary uses */
 };
 
@@ -433,7 +432,7 @@ struct nfs4_ol_stateid {
 	struct nfs4_stid    st_stid; /* must be first field */
 	struct list_head              st_perfile;
 	struct list_head              st_perstateowner;
-	struct list_head              st_lockowners;
+	struct list_head              st_locks;
 	struct nfs4_stateowner      * st_stateowner;
 	struct nfs4_file            * st_file;
 	unsigned long                 st_access_bmap;