45a033329cd4a7156c41509a255e1ca1d969f2df
[muen/linux.git] / net / sunrpc / debugfs.c
1 // SPDX-License-Identifier: GPL-2.0
2 /**
3  * debugfs interface for sunrpc
4  *
5  * (c) 2014 Jeff Layton <jlayton@primarydata.com>
6  */
7
8 #include <linux/debugfs.h>
9 #include <linux/sunrpc/sched.h>
10 #include <linux/sunrpc/clnt.h>
11 #include "netns.h"
12
13 static struct dentry *topdir;
14 static struct dentry *rpc_fault_dir;
15 static struct dentry *rpc_clnt_dir;
16 static struct dentry *rpc_xprt_dir;
17
18 unsigned int rpc_inject_disconnect;
19
20 static int
21 tasks_show(struct seq_file *f, void *v)
22 {
23         u32 xid = 0;
24         struct rpc_task *task = v;
25         struct rpc_clnt *clnt = task->tk_client;
26         const char *rpc_waitq = "none";
27
28         if (RPC_IS_QUEUED(task))
29                 rpc_waitq = rpc_qname(task->tk_waitqueue);
30
31         if (task->tk_rqstp)
32                 xid = be32_to_cpu(task->tk_rqstp->rq_xid);
33
34         seq_printf(f, "%5u %04x %6d 0x%x 0x%x %8ld %ps %sv%u %s a:%ps q:%s\n",
35                 task->tk_pid, task->tk_flags, task->tk_status,
36                 clnt->cl_clid, xid, task->tk_timeout, task->tk_ops,
37                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
38                 task->tk_action, rpc_waitq);
39         return 0;
40 }
41
42 static void *
43 tasks_start(struct seq_file *f, loff_t *ppos)
44         __acquires(&clnt->cl_lock)
45 {
46         struct rpc_clnt *clnt = f->private;
47         loff_t pos = *ppos;
48         struct rpc_task *task;
49
50         spin_lock(&clnt->cl_lock);
51         list_for_each_entry(task, &clnt->cl_tasks, tk_task)
52                 if (pos-- == 0)
53                         return task;
54         return NULL;
55 }
56
57 static void *
58 tasks_next(struct seq_file *f, void *v, loff_t *pos)
59 {
60         struct rpc_clnt *clnt = f->private;
61         struct rpc_task *task = v;
62         struct list_head *next = task->tk_task.next;
63
64         ++*pos;
65
66         /* If there's another task on list, return it */
67         if (next == &clnt->cl_tasks)
68                 return NULL;
69         return list_entry(next, struct rpc_task, tk_task);
70 }
71
72 static void
73 tasks_stop(struct seq_file *f, void *v)
74         __releases(&clnt->cl_lock)
75 {
76         struct rpc_clnt *clnt = f->private;
77         spin_unlock(&clnt->cl_lock);
78 }
79
80 static const struct seq_operations tasks_seq_operations = {
81         .start  = tasks_start,
82         .next   = tasks_next,
83         .stop   = tasks_stop,
84         .show   = tasks_show,
85 };
86
87 static int tasks_open(struct inode *inode, struct file *filp)
88 {
89         int ret = seq_open(filp, &tasks_seq_operations);
90         if (!ret) {
91                 struct seq_file *seq = filp->private_data;
92                 struct rpc_clnt *clnt = seq->private = inode->i_private;
93
94                 if (!atomic_inc_not_zero(&clnt->cl_count)) {
95                         seq_release(inode, filp);
96                         ret = -EINVAL;
97                 }
98         }
99
100         return ret;
101 }
102
103 static int
104 tasks_release(struct inode *inode, struct file *filp)
105 {
106         struct seq_file *seq = filp->private_data;
107         struct rpc_clnt *clnt = seq->private;
108
109         rpc_release_client(clnt);
110         return seq_release(inode, filp);
111 }
112
113 static const struct file_operations tasks_fops = {
114         .owner          = THIS_MODULE,
115         .open           = tasks_open,
116         .read           = seq_read,
117         .llseek         = seq_lseek,
118         .release        = tasks_release,
119 };
120
121 void
122 rpc_clnt_debugfs_register(struct rpc_clnt *clnt)
123 {
124         int len;
125         char name[24]; /* enough for "../../rpc_xprt/ + 8 hex digits + NULL */
126         struct rpc_xprt *xprt;
127
128         /* Already registered? */
129         if (clnt->cl_debugfs || !rpc_clnt_dir)
130                 return;
131
132         len = snprintf(name, sizeof(name), "%x", clnt->cl_clid);
133         if (len >= sizeof(name))
134                 return;
135
136         /* make the per-client dir */
137         clnt->cl_debugfs = debugfs_create_dir(name, rpc_clnt_dir);
138         if (!clnt->cl_debugfs)
139                 return;
140
141         /* make tasks file */
142         if (!debugfs_create_file("tasks", S_IFREG | 0400, clnt->cl_debugfs,
143                                  clnt, &tasks_fops))
144                 goto out_err;
145
146         rcu_read_lock();
147         xprt = rcu_dereference(clnt->cl_xprt);
148         /* no "debugfs" dentry? Don't bother with the symlink. */
149         if (!xprt->debugfs) {
150                 rcu_read_unlock();
151                 return;
152         }
153         len = snprintf(name, sizeof(name), "../../rpc_xprt/%s",
154                         xprt->debugfs->d_name.name);
155         rcu_read_unlock();
156
157         if (len >= sizeof(name))
158                 goto out_err;
159
160         if (!debugfs_create_symlink("xprt", clnt->cl_debugfs, name))
161                 goto out_err;
162
163         return;
164 out_err:
165         debugfs_remove_recursive(clnt->cl_debugfs);
166         clnt->cl_debugfs = NULL;
167 }
168
169 void
170 rpc_clnt_debugfs_unregister(struct rpc_clnt *clnt)
171 {
172         debugfs_remove_recursive(clnt->cl_debugfs);
173         clnt->cl_debugfs = NULL;
174 }
175
176 static int
177 xprt_info_show(struct seq_file *f, void *v)
178 {
179         struct rpc_xprt *xprt = f->private;
180
181         seq_printf(f, "netid: %s\n", xprt->address_strings[RPC_DISPLAY_NETID]);
182         seq_printf(f, "addr:  %s\n", xprt->address_strings[RPC_DISPLAY_ADDR]);
183         seq_printf(f, "port:  %s\n", xprt->address_strings[RPC_DISPLAY_PORT]);
184         seq_printf(f, "state: 0x%lx\n", xprt->state);
185         return 0;
186 }
187
188 static int
189 xprt_info_open(struct inode *inode, struct file *filp)
190 {
191         int ret;
192         struct rpc_xprt *xprt = inode->i_private;
193
194         ret = single_open(filp, xprt_info_show, xprt);
195
196         if (!ret) {
197                 if (!xprt_get(xprt)) {
198                         single_release(inode, filp);
199                         ret = -EINVAL;
200                 }
201         }
202         return ret;
203 }
204
205 static int
206 xprt_info_release(struct inode *inode, struct file *filp)
207 {
208         struct rpc_xprt *xprt = inode->i_private;
209
210         xprt_put(xprt);
211         return single_release(inode, filp);
212 }
213
214 static const struct file_operations xprt_info_fops = {
215         .owner          = THIS_MODULE,
216         .open           = xprt_info_open,
217         .read           = seq_read,
218         .llseek         = seq_lseek,
219         .release        = xprt_info_release,
220 };
221
222 void
223 rpc_xprt_debugfs_register(struct rpc_xprt *xprt)
224 {
225         int len, id;
226         static atomic_t cur_id;
227         char            name[9]; /* 8 hex digits + NULL term */
228
229         if (!rpc_xprt_dir)
230                 return;
231
232         id = (unsigned int)atomic_inc_return(&cur_id);
233
234         len = snprintf(name, sizeof(name), "%x", id);
235         if (len >= sizeof(name))
236                 return;
237
238         /* make the per-client dir */
239         xprt->debugfs = debugfs_create_dir(name, rpc_xprt_dir);
240         if (!xprt->debugfs)
241                 return;
242
243         /* make tasks file */
244         if (!debugfs_create_file("info", S_IFREG | 0400, xprt->debugfs,
245                                  xprt, &xprt_info_fops)) {
246                 debugfs_remove_recursive(xprt->debugfs);
247                 xprt->debugfs = NULL;
248         }
249
250         atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
251 }
252
253 void
254 rpc_xprt_debugfs_unregister(struct rpc_xprt *xprt)
255 {
256         debugfs_remove_recursive(xprt->debugfs);
257         xprt->debugfs = NULL;
258 }
259
260 static int
261 fault_open(struct inode *inode, struct file *filp)
262 {
263         filp->private_data = kmalloc(128, GFP_KERNEL);
264         if (!filp->private_data)
265                 return -ENOMEM;
266         return 0;
267 }
268
269 static int
270 fault_release(struct inode *inode, struct file *filp)
271 {
272         kfree(filp->private_data);
273         return 0;
274 }
275
276 static ssize_t
277 fault_disconnect_read(struct file *filp, char __user *user_buf,
278                       size_t len, loff_t *offset)
279 {
280         char *buffer = (char *)filp->private_data;
281         size_t size;
282
283         size = sprintf(buffer, "%u\n", rpc_inject_disconnect);
284         return simple_read_from_buffer(user_buf, len, offset, buffer, size);
285 }
286
287 static ssize_t
288 fault_disconnect_write(struct file *filp, const char __user *user_buf,
289                        size_t len, loff_t *offset)
290 {
291         char buffer[16];
292
293         if (len >= sizeof(buffer))
294                 len = sizeof(buffer) - 1;
295         if (copy_from_user(buffer, user_buf, len))
296                 return -EFAULT;
297         buffer[len] = '\0';
298         if (kstrtouint(buffer, 10, &rpc_inject_disconnect))
299                 return -EINVAL;
300         return len;
301 }
302
303 static const struct file_operations fault_disconnect_fops = {
304         .owner          = THIS_MODULE,
305         .open           = fault_open,
306         .read           = fault_disconnect_read,
307         .write          = fault_disconnect_write,
308         .release        = fault_release,
309 };
310
311 static struct dentry *
312 inject_fault_dir(struct dentry *topdir)
313 {
314         struct dentry *faultdir;
315
316         faultdir = debugfs_create_dir("inject_fault", topdir);
317         if (!faultdir)
318                 return NULL;
319
320         if (!debugfs_create_file("disconnect", S_IFREG | 0400, faultdir,
321                                  NULL, &fault_disconnect_fops))
322                 return NULL;
323
324         return faultdir;
325 }
326
327 void __exit
328 sunrpc_debugfs_exit(void)
329 {
330         debugfs_remove_recursive(topdir);
331         topdir = NULL;
332         rpc_fault_dir = NULL;
333         rpc_clnt_dir = NULL;
334         rpc_xprt_dir = NULL;
335 }
336
337 void __init
338 sunrpc_debugfs_init(void)
339 {
340         topdir = debugfs_create_dir("sunrpc", NULL);
341         if (!topdir)
342                 return;
343
344         rpc_fault_dir = inject_fault_dir(topdir);
345         if (!rpc_fault_dir)
346                 goto out_remove;
347
348         rpc_clnt_dir = debugfs_create_dir("rpc_clnt", topdir);
349         if (!rpc_clnt_dir)
350                 goto out_remove;
351
352         rpc_xprt_dir = debugfs_create_dir("rpc_xprt", topdir);
353         if (!rpc_xprt_dir)
354                 goto out_remove;
355
356         return;
357 out_remove:
358         debugfs_remove_recursive(topdir);
359         topdir = NULL;
360         rpc_fault_dir = NULL;
361         rpc_clnt_dir = NULL;
362 }