NFSv4: Add nfs4_state_recovery_ops

 We want to reuse the same code to recover the NFSv4 state after a server
 reboot, a network partition, or a failover situation.

 Add a structure to contain those operations will that depend on the recovery
 scenario under consideration.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4proc.c

@@ -263,7 +263,7 @@ static int _nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *st
 	return status;
 }
 
-int nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *state)
+static int nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *state)
 {
 	struct nfs_server *server = NFS_SERVER(state->inode);
 	struct nfs4_exception exception = { };
@@ -2558,7 +2558,7 @@ static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *r
 	return status;
 }
 
-int nfs4_lock_reclaim(struct nfs4_state *state, struct file_lock *request)
+static int nfs4_lock_reclaim(struct nfs4_state *state, struct file_lock *request)
 {
 	return _nfs4_do_setlk(state, F_SETLK, request, 1);
 }
@@ -2632,6 +2632,11 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request)
 	return status;
 }
 
+struct nfs4_state_recovery_ops nfs4_reboot_recovery_ops = {
+	.recover_open	= nfs4_open_reclaim,
+	.recover_lock	= nfs4_lock_reclaim,
+};
+
 struct nfs_rpc_ops	nfs_v4_clientops = {
 	.version	= 4,			/* protocol version */
 	.dentry_ops	= &nfs4_dentry_operations,

fs/nfs/nfs4state.c

@@ -765,7 +765,7 @@ nfs4_schedule_state_recovery(struct nfs4_client *clp)
 		schedule_work(&clp->cl_recoverd);
 }
 
-static int nfs4_reclaim_locks(struct nfs4_state *state)
+static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
 {
 	struct inode *inode = state->inode;
 	struct file_lock *fl;
@@ -776,7 +776,7 @@ static int nfs4_reclaim_locks(struct nfs4_state *state)
 			continue;
 		if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
 			continue;
-		status = nfs4_lock_reclaim(state, fl);
+		status = ops->recover_lock(state, fl);
 		if (status >= 0)
 			continue;
 		switch (status) {
@@ -798,7 +798,7 @@ static int nfs4_reclaim_locks(struct nfs4_state *state)
 	return status;
 }
 
-static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp)
+static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
 {
 	struct nfs4_state *state;
 	struct nfs4_lock_state *lock;
@@ -815,11 +815,11 @@ static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp)
 	list_for_each_entry(state, &sp->so_states, open_states) {
 		if (state->state == 0)
 			continue;
-		status = nfs4_open_reclaim(sp, state);
+		status = ops->recover_open(sp, state);
 		list_for_each_entry(lock, &state->lock_states, ls_locks)
 			lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
 		if (status >= 0) {
-			status = nfs4_reclaim_locks(state);
+			status = nfs4_reclaim_locks(ops, state);
 			if (status < 0)
 				goto out_err;
 			list_for_each_entry(lock, &state->lock_states, ls_locks) {
@@ -860,6 +860,7 @@ static int reclaimer(void *ptr)
 	struct reclaimer_args *args = (struct reclaimer_args *)ptr;
 	struct nfs4_client *clp = args->clp;
 	struct nfs4_state_owner *sp;
+	struct nfs4_state_recovery_ops *ops;
 	int status = 0;
 
 	daemonize("%u.%u.%u.%u-reclaim", NIPQUAD(clp->cl_addr));
@@ -878,6 +879,7 @@ static int reclaimer(void *ptr)
 	status = nfs4_proc_renew(clp);
 	if (status == 0 || status == -NFS4ERR_CB_PATH_DOWN)
 		goto out;
+	ops = &nfs4_reboot_recovery_ops;
 	status = __nfs4_init_client(clp);
 	if (status)
 		goto out_error;
@@ -885,7 +887,7 @@ static int reclaimer(void *ptr)
 	nfs_delegation_mark_reclaim(clp);
 	/* Note: list is protected by exclusive lock on cl->cl_sem */
 	list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
-		status = nfs4_reclaim_open_state(sp);
+		status = nfs4_reclaim_open_state(ops, sp);
 		if (status < 0) {
 			if (status == -NFS4ERR_STALE_CLIENTID)
 				goto restart_loop;

include/linux/nfs_fs.h

@@ -673,6 +673,11 @@ struct nfs4_exception {
 	int retry;
 };
 
+struct nfs4_state_recovery_ops {
+	int (*recover_open)(struct nfs4_state_owner *, struct nfs4_state *);
+	int (*recover_lock)(struct nfs4_state *, struct file_lock *);
+};
+
 extern struct dentry_operations nfs4_dentry_operations;
 extern struct inode_operations nfs4_dir_inode_operations;
 
@@ -680,13 +685,13 @@ extern struct inode_operations nfs4_dir_inode_operations;
 extern int nfs4_map_errors(int err);
 extern int nfs4_proc_setclientid(struct nfs4_client *, u32, unsigned short);
 extern int nfs4_proc_setclientid_confirm(struct nfs4_client *);
-extern int nfs4_open_reclaim(struct nfs4_state_owner *, struct nfs4_state *);
 extern int nfs4_proc_async_renew(struct nfs4_client *);
 extern int nfs4_proc_renew(struct nfs4_client *);
 extern int nfs4_do_close(struct inode *inode, struct nfs4_state *state, mode_t mode);
 extern struct inode *nfs4_atomic_open(struct inode *, struct dentry *, struct nameidata *);
 extern int nfs4_open_revalidate(struct inode *, struct dentry *, int);
-extern int nfs4_lock_reclaim(struct nfs4_state *state, struct file_lock *request);
+
+extern struct nfs4_state_recovery_ops nfs4_reboot_recovery_ops;
 
 /* nfs4renewd.c */
 extern void nfs4_schedule_state_renewal(struct nfs4_client *);