1/*
  2 * Copyright (c) 2011 Bryan Schumaker <bjschuma@netapp.com>
  3 *
  4 * Uses debugfs to create fault injection points for client testing
  5 */
  6
  7#include <linux/types.h>
  8#include <linux/fs.h>
  9#include <linux/debugfs.h>
 10#include <linux/module.h>
 11#include <linux/nsproxy.h>
 12#include <linux/sunrpc/addr.h>
 13#include <asm/uaccess.h>
 14
 15#include "state.h"
 16#include "netns.h"
 17
 18struct nfsd_fault_inject_op {
 19	char *file;
 20	u64 (*get)(void);
 21	u64 (*set_val)(u64);
 22	u64 (*set_clnt)(struct sockaddr_storage *, size_t);
 23};
 24
 25static struct dentry *debug_dir;
 26
 27static ssize_t fault_inject_read(struct file *file, char __user *buf,
 28				 size_t len, loff_t *ppos)
 29{
 30	static u64 val;
 31	char read_buf[25];
 32	size_t size;
 33	loff_t pos = *ppos;
 34	struct nfsd_fault_inject_op *op = file_inode(file)->i_private;
 35
 36	if (!pos)
 37		val = op->get();
 38	size = scnprintf(read_buf, sizeof(read_buf), "%llu\n", val);
 39
 40	return simple_read_from_buffer(buf, len, ppos, read_buf, size);
 41}
 42
 43static ssize_t fault_inject_write(struct file *file, const char __user *buf,
 44				  size_t len, loff_t *ppos)
 45{
 46	char write_buf[INET6_ADDRSTRLEN];
 47	size_t size = min(sizeof(write_buf) - 1, len);
 48	struct net *net = current->nsproxy->net_ns;
 49	struct sockaddr_storage sa;
 50	struct nfsd_fault_inject_op *op = file_inode(file)->i_private;
 51	u64 val;
 52	char *nl;
 53
 54	if (copy_from_user(write_buf, buf, size))
 55		return -EFAULT;
 56	write_buf[size] = '\0';
 57
 58	/* Deal with any embedded newlines in the string */
 59	nl = strchr(write_buf, '\n');
 60	if (nl) {
 61		size = nl - write_buf;
 62		*nl = '\0';
 63	}
 64
 65	size = rpc_pton(net, write_buf, size, (struct sockaddr *)&sa, sizeof(sa));
 66	if (size > 0) {
 67		val = op->set_clnt(&sa, size);
 68		if (val)
 69			pr_info("NFSD [%s]: Client %s had %llu state object(s)\n",
 70				op->file, write_buf, val);
 71	} else {
 72		val = simple_strtoll(write_buf, NULL, 0);
 73		if (val == 0)
 74			pr_info("NFSD Fault Injection: %s (all)", op->file);
 75		else
 76			pr_info("NFSD Fault Injection: %s (n = %llu)",
 77				op->file, val);
 78		val = op->set_val(val);
 79		pr_info("NFSD: %s: found %llu", op->file, val);
 80	}
 81	return len; /* on success, claim we got the whole input */
 82}
 83
 84static const struct file_operations fops_nfsd = {
 85	.owner   = THIS_MODULE,
 86	.read    = fault_inject_read,
 87	.write   = fault_inject_write,
 88};
 89
 90void nfsd_fault_inject_cleanup(void)
 91{
 92	debugfs_remove_recursive(debug_dir);
 93}
 94
 95static struct nfsd_fault_inject_op inject_ops[] = {
 96	{
 97		.file     = "forget_clients",
 98		.get	  = nfsd_inject_print_clients,
 99		.set_val  = nfsd_inject_forget_clients,
100		.set_clnt = nfsd_inject_forget_client,
101	},
102	{
103		.file     = "forget_locks",
104		.get	  = nfsd_inject_print_locks,
105		.set_val  = nfsd_inject_forget_locks,
106		.set_clnt = nfsd_inject_forget_client_locks,
107	},
108	{
109		.file     = "forget_openowners",
110		.get	  = nfsd_inject_print_openowners,
111		.set_val  = nfsd_inject_forget_openowners,
112		.set_clnt = nfsd_inject_forget_client_openowners,
113	},
114	{
115		.file     = "forget_delegations",
116		.get	  = nfsd_inject_print_delegations,
117		.set_val  = nfsd_inject_forget_delegations,
118		.set_clnt = nfsd_inject_forget_client_delegations,
119	},
120	{
121		.file     = "recall_delegations",
122		.get	  = nfsd_inject_print_delegations,
123		.set_val  = nfsd_inject_recall_delegations,
124		.set_clnt = nfsd_inject_recall_client_delegations,
125	},
126};
127
128#define NUM_INJECT_OPS (sizeof(inject_ops)/sizeof(struct nfsd_fault_inject_op))
129
130int nfsd_fault_inject_init(void)
131{
132	unsigned int i;
133	struct nfsd_fault_inject_op *op;
134	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
135
136	debug_dir = debugfs_create_dir("nfsd", NULL);
137	if (!debug_dir)
138		goto fail;
139
140	for (i = 0; i < NUM_INJECT_OPS; i++) {
141		op = &inject_ops[i];
142		if (!debugfs_create_file(op->file, mode, debug_dir, op, &fops_nfsd))
143			goto fail;
144	}
145	return 0;
146
147fail:
148	nfsd_fault_inject_cleanup();
149	return -ENOMEM;
150}