SUNRPC: rework cache upcall logic
[linux-3.10.git] / fs / nfsd / fault_inject.c
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
18 struct nfsd_fault_inject_op {
19         char *file;
20         u64 (*forget)(struct nfs4_client *, u64);
21         u64 (*print)(struct nfs4_client *, u64);
22 };
23
24 static struct nfsd_fault_inject_op inject_ops[] = {
25         {
26                 .file   = "forget_clients",
27                 .forget = nfsd_forget_client,
28                 .print  = nfsd_print_client,
29         },
30         {
31                 .file   = "forget_locks",
32                 .forget = nfsd_forget_client_locks,
33                 .print  = nfsd_print_client_locks,
34         },
35         {
36                 .file   = "forget_openowners",
37                 .forget = nfsd_forget_client_openowners,
38                 .print  = nfsd_print_client_openowners,
39         },
40         {
41                 .file   = "forget_delegations",
42                 .forget = nfsd_forget_client_delegations,
43                 .print  = nfsd_print_client_delegations,
44         },
45         {
46                 .file   = "recall_delegations",
47                 .forget = nfsd_recall_client_delegations,
48                 .print  = nfsd_print_client_delegations,
49         },
50 };
51
52 static long int NUM_INJECT_OPS = sizeof(inject_ops) / sizeof(struct nfsd_fault_inject_op);
53 static struct dentry *debug_dir;
54
55 static void nfsd_inject_set(struct nfsd_fault_inject_op *op, u64 val)
56 {
57         u64 count = 0;
58
59         if (val == 0)
60                 printk(KERN_INFO "NFSD Fault Injection: %s (all)", op->file);
61         else
62                 printk(KERN_INFO "NFSD Fault Injection: %s (n = %llu)", op->file, val);
63
64         nfs4_lock_state();
65         count = nfsd_for_n_state(val, op->forget);
66         nfs4_unlock_state();
67         printk(KERN_INFO "NFSD: %s: found %llu", op->file, count);
68 }
69
70 static void nfsd_inject_set_client(struct nfsd_fault_inject_op *op,
71                                    struct sockaddr_storage *addr,
72                                    size_t addr_size)
73 {
74         char buf[INET6_ADDRSTRLEN];
75         struct nfs4_client *clp;
76         u64 count;
77
78         nfs4_lock_state();
79         clp = nfsd_find_client(addr, addr_size);
80         if (clp) {
81                 count = op->forget(clp, 0);
82                 rpc_ntop((struct sockaddr *)&clp->cl_addr, buf, sizeof(buf));
83                 printk(KERN_INFO "NFSD [%s]: Client %s had %llu state object(s)\n", op->file, buf, count);
84         }
85         nfs4_unlock_state();
86 }
87
88 static void nfsd_inject_get(struct nfsd_fault_inject_op *op, u64 *val)
89 {
90         nfs4_lock_state();
91         *val = nfsd_for_n_state(0, op->print);
92         nfs4_unlock_state();
93 }
94
95 static ssize_t fault_inject_read(struct file *file, char __user *buf,
96                                  size_t len, loff_t *ppos)
97 {
98         static u64 val;
99         char read_buf[25];
100         size_t size, ret;
101         loff_t pos = *ppos;
102
103         if (!pos)
104                 nfsd_inject_get(file->f_dentry->d_inode->i_private, &val);
105         size = scnprintf(read_buf, sizeof(read_buf), "%llu\n", val);
106
107         if (pos < 0)
108                 return -EINVAL;
109         if (pos >= size || !len)
110                 return 0;
111         if (len > size - pos)
112                 len = size - pos;
113         ret = copy_to_user(buf, read_buf + pos, len);
114         if (ret == len)
115                 return -EFAULT;
116         len -= ret;
117         *ppos = pos + len;
118         return len;
119 }
120
121 static ssize_t fault_inject_write(struct file *file, const char __user *buf,
122                                   size_t len, loff_t *ppos)
123 {
124         char write_buf[INET6_ADDRSTRLEN];
125         size_t size = min(sizeof(write_buf) - 1, len);
126         struct net *net = current->nsproxy->net_ns;
127         struct sockaddr_storage sa;
128         u64 val;
129
130         if (copy_from_user(write_buf, buf, size))
131                 return -EFAULT;
132         write_buf[size] = '\0';
133
134         size = rpc_pton(net, write_buf, size, (struct sockaddr *)&sa, sizeof(sa));
135         if (size > 0)
136                 nfsd_inject_set_client(file->f_dentry->d_inode->i_private, &sa, size);
137         else {
138                 val = simple_strtoll(write_buf, NULL, 0);
139                 nfsd_inject_set(file->f_dentry->d_inode->i_private, val);
140         }
141         return len; /* on success, claim we got the whole input */
142 }
143
144 static const struct file_operations fops_nfsd = {
145         .owner   = THIS_MODULE,
146         .read    = fault_inject_read,
147         .write   = fault_inject_write,
148 };
149
150 void nfsd_fault_inject_cleanup(void)
151 {
152         debugfs_remove_recursive(debug_dir);
153 }
154
155 int nfsd_fault_inject_init(void)
156 {
157         unsigned int i;
158         struct nfsd_fault_inject_op *op;
159         umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
160
161         debug_dir = debugfs_create_dir("nfsd", NULL);
162         if (!debug_dir)
163                 goto fail;
164
165         for (i = 0; i < NUM_INJECT_OPS; i++) {
166                 op = &inject_ops[i];
167                 if (!debugfs_create_file(op->file, mode, debug_dir, op, &fops_nfsd))
168                         goto fail;
169         }
170         return 0;
171
172 fail:
173         nfsd_fault_inject_cleanup();
174         return -ENOMEM;
175 }