xref: /openbmc/linux/net/sunrpc/debugfs.c (revision 174cd4b1)
1 /**
2  * debugfs interface for sunrpc
3  *
4  * (c) 2014 Jeff Layton <jlayton@primarydata.com>
5  */
6 
7 #include <linux/debugfs.h>
8 #include <linux/sunrpc/sched.h>
9 #include <linux/sunrpc/clnt.h>
10 #include "netns.h"
11 
12 static struct dentry *topdir;
13 static struct dentry *rpc_fault_dir;
14 static struct dentry *rpc_clnt_dir;
15 static struct dentry *rpc_xprt_dir;
16 
17 unsigned int rpc_inject_disconnect;
18 
19 static int
20 tasks_show(struct seq_file *f, void *v)
21 {
22 	u32 xid = 0;
23 	struct rpc_task *task = v;
24 	struct rpc_clnt *clnt = task->tk_client;
25 	const char *rpc_waitq = "none";
26 
27 	if (RPC_IS_QUEUED(task))
28 		rpc_waitq = rpc_qname(task->tk_waitqueue);
29 
30 	if (task->tk_rqstp)
31 		xid = be32_to_cpu(task->tk_rqstp->rq_xid);
32 
33 	seq_printf(f, "%5u %04x %6d 0x%x 0x%x %8ld %ps %sv%u %s a:%ps q:%s\n",
34 		task->tk_pid, task->tk_flags, task->tk_status,
35 		clnt->cl_clid, xid, task->tk_timeout, task->tk_ops,
36 		clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
37 		task->tk_action, rpc_waitq);
38 	return 0;
39 }
40 
41 static void *
42 tasks_start(struct seq_file *f, loff_t *ppos)
43 	__acquires(&clnt->cl_lock)
44 {
45 	struct rpc_clnt *clnt = f->private;
46 	loff_t pos = *ppos;
47 	struct rpc_task *task;
48 
49 	spin_lock(&clnt->cl_lock);
50 	list_for_each_entry(task, &clnt->cl_tasks, tk_task)
51 		if (pos-- == 0)
52 			return task;
53 	return NULL;
54 }
55 
56 static void *
57 tasks_next(struct seq_file *f, void *v, loff_t *pos)
58 {
59 	struct rpc_clnt *clnt = f->private;
60 	struct rpc_task *task = v;
61 	struct list_head *next = task->tk_task.next;
62 
63 	++*pos;
64 
65 	/* If there's another task on list, return it */
66 	if (next == &clnt->cl_tasks)
67 		return NULL;
68 	return list_entry(next, struct rpc_task, tk_task);
69 }
70 
71 static void
72 tasks_stop(struct seq_file *f, void *v)
73 	__releases(&clnt->cl_lock)
74 {
75 	struct rpc_clnt *clnt = f->private;
76 	spin_unlock(&clnt->cl_lock);
77 }
78 
79 static const struct seq_operations tasks_seq_operations = {
80 	.start	= tasks_start,
81 	.next	= tasks_next,
82 	.stop	= tasks_stop,
83 	.show	= tasks_show,
84 };
85 
86 static int tasks_open(struct inode *inode, struct file *filp)
87 {
88 	int ret = seq_open(filp, &tasks_seq_operations);
89 	if (!ret) {
90 		struct seq_file *seq = filp->private_data;
91 		struct rpc_clnt *clnt = seq->private = inode->i_private;
92 
93 		if (!atomic_inc_not_zero(&clnt->cl_count)) {
94 			seq_release(inode, filp);
95 			ret = -EINVAL;
96 		}
97 	}
98 
99 	return ret;
100 }
101 
102 static int
103 tasks_release(struct inode *inode, struct file *filp)
104 {
105 	struct seq_file *seq = filp->private_data;
106 	struct rpc_clnt *clnt = seq->private;
107 
108 	rpc_release_client(clnt);
109 	return seq_release(inode, filp);
110 }
111 
112 static const struct file_operations tasks_fops = {
113 	.owner		= THIS_MODULE,
114 	.open		= tasks_open,
115 	.read		= seq_read,
116 	.llseek		= seq_lseek,
117 	.release	= tasks_release,
118 };
119 
120 void
121 rpc_clnt_debugfs_register(struct rpc_clnt *clnt)
122 {
123 	int len;
124 	char name[24]; /* enough for "../../rpc_xprt/ + 8 hex digits + NULL */
125 	struct rpc_xprt *xprt;
126 
127 	/* Already registered? */
128 	if (clnt->cl_debugfs || !rpc_clnt_dir)
129 		return;
130 
131 	len = snprintf(name, sizeof(name), "%x", clnt->cl_clid);
132 	if (len >= sizeof(name))
133 		return;
134 
135 	/* make the per-client dir */
136 	clnt->cl_debugfs = debugfs_create_dir(name, rpc_clnt_dir);
137 	if (!clnt->cl_debugfs)
138 		return;
139 
140 	/* make tasks file */
141 	if (!debugfs_create_file("tasks", S_IFREG | S_IRUSR, clnt->cl_debugfs,
142 				 clnt, &tasks_fops))
143 		goto out_err;
144 
145 	rcu_read_lock();
146 	xprt = rcu_dereference(clnt->cl_xprt);
147 	/* no "debugfs" dentry? Don't bother with the symlink. */
148 	if (!xprt->debugfs) {
149 		rcu_read_unlock();
150 		return;
151 	}
152 	len = snprintf(name, sizeof(name), "../../rpc_xprt/%s",
153 			xprt->debugfs->d_name.name);
154 	rcu_read_unlock();
155 
156 	if (len >= sizeof(name))
157 		goto out_err;
158 
159 	if (!debugfs_create_symlink("xprt", clnt->cl_debugfs, name))
160 		goto out_err;
161 
162 	return;
163 out_err:
164 	debugfs_remove_recursive(clnt->cl_debugfs);
165 	clnt->cl_debugfs = NULL;
166 }
167 
168 void
169 rpc_clnt_debugfs_unregister(struct rpc_clnt *clnt)
170 {
171 	debugfs_remove_recursive(clnt->cl_debugfs);
172 	clnt->cl_debugfs = NULL;
173 }
174 
175 static int
176 xprt_info_show(struct seq_file *f, void *v)
177 {
178 	struct rpc_xprt *xprt = f->private;
179 
180 	seq_printf(f, "netid: %s\n", xprt->address_strings[RPC_DISPLAY_NETID]);
181 	seq_printf(f, "addr:  %s\n", xprt->address_strings[RPC_DISPLAY_ADDR]);
182 	seq_printf(f, "port:  %s\n", xprt->address_strings[RPC_DISPLAY_PORT]);
183 	seq_printf(f, "state: 0x%lx\n", xprt->state);
184 	return 0;
185 }
186 
187 static int
188 xprt_info_open(struct inode *inode, struct file *filp)
189 {
190 	int ret;
191 	struct rpc_xprt *xprt = inode->i_private;
192 
193 	ret = single_open(filp, xprt_info_show, xprt);
194 
195 	if (!ret) {
196 		if (!xprt_get(xprt)) {
197 			single_release(inode, filp);
198 			ret = -EINVAL;
199 		}
200 	}
201 	return ret;
202 }
203 
204 static int
205 xprt_info_release(struct inode *inode, struct file *filp)
206 {
207 	struct rpc_xprt *xprt = inode->i_private;
208 
209 	xprt_put(xprt);
210 	return single_release(inode, filp);
211 }
212 
213 static const struct file_operations xprt_info_fops = {
214 	.owner		= THIS_MODULE,
215 	.open		= xprt_info_open,
216 	.read		= seq_read,
217 	.llseek		= seq_lseek,
218 	.release	= xprt_info_release,
219 };
220 
221 void
222 rpc_xprt_debugfs_register(struct rpc_xprt *xprt)
223 {
224 	int len, id;
225 	static atomic_t	cur_id;
226 	char		name[9]; /* 8 hex digits + NULL term */
227 
228 	if (!rpc_xprt_dir)
229 		return;
230 
231 	id = (unsigned int)atomic_inc_return(&cur_id);
232 
233 	len = snprintf(name, sizeof(name), "%x", id);
234 	if (len >= sizeof(name))
235 		return;
236 
237 	/* make the per-client dir */
238 	xprt->debugfs = debugfs_create_dir(name, rpc_xprt_dir);
239 	if (!xprt->debugfs)
240 		return;
241 
242 	/* make tasks file */
243 	if (!debugfs_create_file("info", S_IFREG | S_IRUSR, xprt->debugfs,
244 				 xprt, &xprt_info_fops)) {
245 		debugfs_remove_recursive(xprt->debugfs);
246 		xprt->debugfs = NULL;
247 	}
248 
249 	atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
250 }
251 
252 void
253 rpc_xprt_debugfs_unregister(struct rpc_xprt *xprt)
254 {
255 	debugfs_remove_recursive(xprt->debugfs);
256 	xprt->debugfs = NULL;
257 }
258 
259 static int
260 fault_open(struct inode *inode, struct file *filp)
261 {
262 	filp->private_data = kmalloc(128, GFP_KERNEL);
263 	if (!filp->private_data)
264 		return -ENOMEM;
265 	return 0;
266 }
267 
268 static int
269 fault_release(struct inode *inode, struct file *filp)
270 {
271 	kfree(filp->private_data);
272 	return 0;
273 }
274 
275 static ssize_t
276 fault_disconnect_read(struct file *filp, char __user *user_buf,
277 		      size_t len, loff_t *offset)
278 {
279 	char *buffer = (char *)filp->private_data;
280 	size_t size;
281 
282 	size = sprintf(buffer, "%u\n", rpc_inject_disconnect);
283 	return simple_read_from_buffer(user_buf, len, offset, buffer, size);
284 }
285 
286 static ssize_t
287 fault_disconnect_write(struct file *filp, const char __user *user_buf,
288 		       size_t len, loff_t *offset)
289 {
290 	char buffer[16];
291 
292 	if (len >= sizeof(buffer))
293 		len = sizeof(buffer) - 1;
294 	if (copy_from_user(buffer, user_buf, len))
295 		return -EFAULT;
296 	buffer[len] = '\0';
297 	if (kstrtouint(buffer, 10, &rpc_inject_disconnect))
298 		return -EINVAL;
299 	return len;
300 }
301 
302 static const struct file_operations fault_disconnect_fops = {
303 	.owner		= THIS_MODULE,
304 	.open		= fault_open,
305 	.read		= fault_disconnect_read,
306 	.write		= fault_disconnect_write,
307 	.release	= fault_release,
308 };
309 
310 static struct dentry *
311 inject_fault_dir(struct dentry *topdir)
312 {
313 	struct dentry *faultdir;
314 
315 	faultdir = debugfs_create_dir("inject_fault", topdir);
316 	if (!faultdir)
317 		return NULL;
318 
319 	if (!debugfs_create_file("disconnect", S_IFREG | S_IRUSR, faultdir,
320 				 NULL, &fault_disconnect_fops))
321 		return NULL;
322 
323 	return faultdir;
324 }
325 
326 void __exit
327 sunrpc_debugfs_exit(void)
328 {
329 	debugfs_remove_recursive(topdir);
330 	topdir = NULL;
331 	rpc_fault_dir = NULL;
332 	rpc_clnt_dir = NULL;
333 	rpc_xprt_dir = NULL;
334 }
335 
336 void __init
337 sunrpc_debugfs_init(void)
338 {
339 	topdir = debugfs_create_dir("sunrpc", NULL);
340 	if (!topdir)
341 		return;
342 
343 	rpc_fault_dir = inject_fault_dir(topdir);
344 	if (!rpc_fault_dir)
345 		goto out_remove;
346 
347 	rpc_clnt_dir = debugfs_create_dir("rpc_clnt", topdir);
348 	if (!rpc_clnt_dir)
349 		goto out_remove;
350 
351 	rpc_xprt_dir = debugfs_create_dir("rpc_xprt", topdir);
352 	if (!rpc_xprt_dir)
353 		goto out_remove;
354 
355 	return;
356 out_remove:
357 	debugfs_remove_recursive(topdir);
358 	topdir = NULL;
359 	rpc_fault_dir = NULL;
360 	rpc_clnt_dir = NULL;
361 }
362