From: Steve Dickson <SteveD@redhat.com>
Date: Mon, 30 Aug 2010 17:39:41 -0400
Subject: [fs] nfsv4: add support for RELEASE_LOCKOWNER operation
Message-id: <1283189983-10655-4-git-send-email-steved@redhat.com>
Patchwork-id: 27946
O-Subject: [RHEL5.5.z PATCH 3/5] NFSv4: Add support for the RELEASE_LOCKOWNER
	operation
Bugzilla: 620502
RH-Acked-by: Jeff Layton <jlayton@redhat.com>
RH-Acked-by: J. Bruce Fields <bfields@redhat.com>

From: Trond Myklebust <Trond.Myklebust@netapp.com>

This is needed by NFSv4.0 servers in order to keep the number of locking
stateids at a manageable level.

Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 0888827..cd68c23 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -171,6 +171,7 @@ extern int nfs4_open_revalidate(struct inode *, struct dentry *, int, struct nam
 extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
 extern int nfs4_proc_fs_locations(struct inode *dir, struct dentry *dentry,
 		struct nfs4_fs_locations *fs_locations, struct page *page);
+extern void nfs4_release_lockowner(const struct nfs4_lock_state *);
 
 extern struct nfs4_state_recovery_ops nfs4_reboot_recovery_ops;
 extern struct nfs4_state_recovery_ops nfs4_network_partition_recovery_ops;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 67b5ed1..73a0cb2 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3682,6 +3682,32 @@ out:
 	return err;
 }
 
+static void nfs4_release_lockowner_release(void *calldata)
+{
+	kfree(calldata);
+}
+
+const struct rpc_call_ops nfs4_release_lockowner_ops = {
+	.rpc_release = nfs4_release_lockowner_release,
+};
+
+void nfs4_release_lockowner(const struct nfs4_lock_state *lsp)
+{
+	struct nfs_server *server = NFS_SERVER(lsp->ls_state->inode);
+	struct nfs_release_lockowner_args *args;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_RELEASE_LOCKOWNER],
+	};
+
+	args = kmalloc(sizeof(*args), GFP_NOFS);
+	if (!args)
+		return;
+	args->lock_owner.clientid = server->nfs_client->cl_clientid;
+	args->lock_owner.id = lsp->ls_id;
+	msg.rpc_argp = args;
+	rpc_call_async(server->client, &msg, 0, &nfs4_release_lockowner_ops, args);
+}
+
 #define XATTR_NAME_NFSV4_ACL "system.nfs4_acl"
 
 int nfs4_setxattr(struct dentry *dentry, const char *key, const void *buf,
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 34c5268..1fc1ef2 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -452,6 +452,8 @@ void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 	if (list_empty(&state->lock_states))
 		clear_bit(LK_STATE_IN_USE, &state->flags);
 	spin_unlock(&state->state_lock);
+	if (lsp->ls_flags & NFS_LOCK_INITIALIZED)
+		nfs4_release_lockowner(lsp);
 	kfree(lsp);
 }
 
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index cc49973..fdcbda7 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -71,6 +71,7 @@ static int nfs4_stat_to_errno(int);
  * we currently use size 1 (u32) out of (NFS4_OPAQUE_LIMIT  >> 2)
  */
 #define owner_id_maxsz          (1 + 1)
+#define decode_lockowner_maxsz  (1 + XDR_QUADLEN(IDMAP_NAMESZ))
 #define compound_encode_hdr_maxsz	(3 + (NFS4_MAXTAGLEN >> 2))
 #define compound_decode_hdr_maxsz	(3 + (NFS4_MAXTAGLEN >> 2))
 #define op_encode_hdr_maxsz	(1)
@@ -126,6 +127,7 @@ static int nfs4_stat_to_errno(int);
 #define encode_link_maxsz	(op_encode_hdr_maxsz + \
 				nfs4_name_maxsz)
 #define decode_link_maxsz	(op_decode_hdr_maxsz + 5)
+#define encode_lockowner_maxsz  (7)
 #define encode_symlink_maxsz	(op_encode_hdr_maxsz + \
 				1 + nfs4_name_maxsz + \
 				1 + \
@@ -278,6 +280,12 @@ static int nfs4_stat_to_errno(int);
 				decode_putfh_maxsz + \
 				decode_getattr_maxsz + \
 				op_decode_hdr_maxsz + 4)
+#define NFS4_enc_release_lockowner_sz \
+                (compound_encode_hdr_maxsz + \
+                 encode_lockowner_maxsz)
+#define NFS4_dec_release_lockowner_sz \
+                (compound_decode_hdr_maxsz + \
+                 decode_lockowner_maxsz)
 #define NFS4_enc_access_sz	(compound_encode_hdr_maxsz + \
 				encode_putfh_maxsz + \
 				op_encode_hdr_maxsz + 1)
@@ -845,6 +853,14 @@ static int encode_locku(struct xdr_stream *xdr, const struct nfs_locku_args *arg
 
 	return 0;
 }
+static void encode_release_lockowner(struct xdr_stream *xdr, const struct nfs_lowner *lowner)
+{
+	uint32_t *p;
+
+	RESERVE_SPACE(4);
+	WRITE32(OP_RELEASE_LOCKOWNER);
+	encode_lockowner(xdr, lowner);
+}
 
 static int encode_lookup(struct xdr_stream *xdr, const struct qstr *name)
 {
@@ -1693,6 +1709,19 @@ out:
 	return status;
 }
 
+static int nfs4_xdr_enc_release_lockowner(struct rpc_rqst *req, __be32 *p, struct nfs_release_lockowner_args *args)
+{
+	struct xdr_stream xdr;
+	struct compound_hdr hdr = {
+		.nops = 1,
+	};
+
+	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
+	encode_compound_hdr(&xdr, &hdr);
+	encode_release_lockowner(&xdr, &args->lock_owner);
+	return 0;
+}
+
 /*
  * Encode a READLINK request
  */
@@ -3214,6 +3243,11 @@ static int decode_locku(struct xdr_stream *xdr, struct nfs_locku_res *res)
 	return status;
 }
 
+static int decode_release_lockowner(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_RELEASE_LOCKOWNER);
+}
+
 static int decode_lookup(struct xdr_stream *xdr)
 {
 	return decode_op_hdr(xdr, OP_LOOKUP);
@@ -4155,6 +4189,19 @@ out:
 	return status;
 }
 
+static int nfs4_xdr_dec_release_lockowner(struct rpc_rqst *rqstp, __be32 *p, void *dummy)
+{
+	struct xdr_stream xdr;
+	struct compound_hdr hdr;
+	int status;
+
+	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
+	status = decode_compound_hdr(&xdr, &hdr);
+	if (!status)
+		status = decode_release_lockowner(&xdr);
+	return status;
+}
+
 /*
  * Decode READLINK response
  */
@@ -4621,6 +4668,7 @@ struct rpc_procinfo	nfs4_procedures[] = {
   PROC(GETACL,		enc_getacl,	dec_getacl),
   PROC(SETACL,		enc_setacl,	dec_setacl),
   PROC(FS_LOCATIONS,	enc_fs_locations, dec_fs_locations),
+  PROC(RELEASE_LOCKOWNER, enc_release_lockowner, dec_release_lockowner),
 };
 
 struct rpc_version		nfs_version4 = {
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 4397ed9..53bc193 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -391,6 +391,7 @@ enum {
 	NFSPROC4_CLNT_GETACL,
 	NFSPROC4_CLNT_SETACL,
 	NFSPROC4_CLNT_FS_LOCATIONS,
+	NFSPROC4_CLNT_RELEASE_LOCKOWNER,
 };
 
 #endif
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index e05943f..1d7c25f 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -225,6 +225,10 @@ struct nfs_lockt_res {
 	struct file_lock *	denied; /* LOCK, LOCKT failed */
 };
 
+struct nfs_release_lockowner_args {
+	struct nfs_lowner	lock_owner;
+};
+
 struct nfs4_delegreturnargs {
 	const struct nfs_fh *fhandle;
 	const nfs4_stateid *stateid;