1 files changed, 147 insertions, 2 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index ed14572e739c..c41b4aa7c8bd 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -695,7 +695,8 @@ struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *sla
 
 	idr_preload(GFP_KERNEL);
 	spin_lock(&cl->cl_lock);
-	new_id = idr_alloc_cyclic(&cl->cl_stateids, stid, 0, 0, GFP_NOWAIT);
+	/* Reserving 0 for start of file in nfsdfs "states" file: */
+	new_id = idr_alloc_cyclic(&cl->cl_stateids, stid, 1, 0, GFP_NOWAIT);
 	spin_unlock(&cl->cl_lock);
 	idr_preload_end();
 	if (new_id < 0)
@@ -2256,9 +2257,153 @@ static const struct file_operations client_info_fops = {
 	.release	= single_release,
 };
 
+static void *states_start(struct seq_file *s, loff_t *pos)
+	__acquires(&clp->cl_lock)
+{
+	struct nfs4_client *clp = s->private;
+	unsigned long id = *pos;
+	void *ret;
+
+	spin_lock(&clp->cl_lock);
+	ret = idr_get_next_ul(&clp->cl_stateids, &id);
+	*pos = id;
+	return ret;
+}
+
+static void *states_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	struct nfs4_client *clp = s->private;
+	unsigned long id = *pos;
+	void *ret;
+
+	id = *pos;
+	id++;
+	ret = idr_get_next_ul(&clp->cl_stateids, &id);
+	*pos = id;
+	return ret;
+}
+
+static void states_stop(struct seq_file *s, void *v)
+	__releases(&clp->cl_lock)
+{
+	struct nfs4_client *clp = s->private;
+
+	spin_unlock(&clp->cl_lock);
+}
+
+static void nfs4_show_superblock(struct seq_file *s, struct file *f)
+{
+	struct inode *inode = file_inode(f);
+
+	seq_printf(s, "superblock: \"%02x:%02x:%ld\"",
+					MAJOR(inode->i_sb->s_dev),
+					 MINOR(inode->i_sb->s_dev),
+					 inode->i_ino);
+}
+
+static void nfs4_show_owner(struct seq_file *s, struct nfs4_stateowner *oo)
+{
+	seq_printf(s, "owner: ");
+	seq_quote_mem(s, oo->so_owner.data, oo->so_owner.len);
+}
+
+static int nfs4_show_open(struct seq_file *s, struct nfs4_stid *st)
+{
+	struct nfs4_ol_stateid *ols;
+	struct nfs4_file *nf;
+	struct file *file;
+	struct nfs4_stateowner *oo;
+	unsigned int access, deny;
+
+	if (st->sc_type != NFS4_OPEN_STID && st->sc_type != NFS4_LOCK_STID)
+		return 0; /* XXX: or SEQ_SKIP? */
+	ols = openlockstateid(st);
+	oo = ols->st_stateowner;
+	nf = st->sc_file;
+	file = find_any_file(nf);
+
+	seq_printf(s, "- 0x%16phN: { type: open, ", &st->sc_stateid);
+
+	access = bmap_to_share_mode(ols->st_access_bmap);
+	deny   = bmap_to_share_mode(ols->st_deny_bmap);
+
+	seq_printf(s, "access: \%s\%s, ",
+		access & NFS4_SHARE_ACCESS_READ ? "r" : "-",
+		access & NFS4_SHARE_ACCESS_WRITE ? "w" : "-");
+	seq_printf(s, "deny: \%s\%s, ",
+		deny & NFS4_SHARE_ACCESS_READ ? "r" : "-",
+		deny & NFS4_SHARE_ACCESS_WRITE ? "w" : "-");
+
+	nfs4_show_superblock(s, file);
+	seq_printf(s, ", ");
+	nfs4_show_owner(s, oo);
+	seq_printf(s, " }\n");
+
+	fput(file);
+
+	return 0;
+}
+
+static int states_show(struct seq_file *s, void *v)
+{
+	struct nfs4_stid *st = v;
+
+	switch (st->sc_type) {
+	case NFS4_OPEN_STID:
+		return nfs4_show_open(s, st);
+	default:
+		return 0; /* XXX: or SEQ_SKIP? */
+	}
+}
+
+static struct seq_operations states_seq_ops = {
+	.start = states_start,
+	.next = states_next,
+	.stop = states_stop,
+	.show = states_show
+};
+
+static int client_states_open(struct inode *inode, struct file *file)
+{
+	struct nfsdfs_client *nc;
+	struct seq_file *s;
+	struct nfs4_client *clp;
+	int ret;
+
+	nc = get_nfsdfs_client(inode);
+	if (!nc)
+		return -ENXIO;
+	clp = container_of(nc, struct nfs4_client, cl_nfsdfs);
+
+	ret = seq_open(file, &states_seq_ops);
+	if (ret)
+		return ret;
+	s = file->private_data;
+	s->private = clp;
+	return 0;
+}
+
+static int client_opens_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *m = file->private_data;
+	struct nfs4_client *clp = m->private;
+
+	/* XXX: alternatively, we could get/drop in seq start/stop */
+	drop_client(clp);
+	return 0;
+}
+
+static const struct file_operations client_states_fops = {
+	.open		= client_states_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= client_opens_release,
+};
+
 static const struct tree_descr client_files[] = {
 	[0] = {"info", &client_info_fops, S_IRUSR},
-	[1] = {""},
+	[1] = {"states", &client_states_fops, S_IRUSR},
+	[3] = {""},
 };
 
 static struct nfs4_client *create_client(struct xdr_netobj name,