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
 13static struct dentry *topdir;
 14static struct dentry *rpc_fault_dir;
 15static struct dentry *rpc_clnt_dir;
 16static struct dentry *rpc_xprt_dir;
 17
 18unsigned int rpc_inject_disconnect;
 19
 20static int
 21tasks_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
 42static void *
 43tasks_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
 57static void *
 58tasks_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
 72static void
 73tasks_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
 80static 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
 87static 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
103static int
104tasks_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
113static 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
121void
122rpc_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;
164out_err:
165	debugfs_remove_recursive(clnt->cl_debugfs);
166	clnt->cl_debugfs = NULL;
167}
168
169void
170rpc_clnt_debugfs_unregister(struct rpc_clnt *clnt)
171{
172	debugfs_remove_recursive(clnt->cl_debugfs);
173	clnt->cl_debugfs = NULL;
174}
175
176static int
177xprt_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
188static int
189xprt_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
205static int
206xprt_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
214static 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
222void
223rpc_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
253void
254rpc_xprt_debugfs_unregister(struct rpc_xprt *xprt)
255{
256	debugfs_remove_recursive(xprt->debugfs);
257	xprt->debugfs = NULL;
258}
259
260static int
261fault_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
269static int
270fault_release(struct inode *inode, struct file *filp)
271{
272	kfree(filp->private_data);
273	return 0;
274}
275
276static ssize_t
277fault_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
287static ssize_t
288fault_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
303static 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
311static struct dentry *
312inject_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
327void __exit
328sunrpc_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
337void __init
338sunrpc_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;
357out_remove:
358	debugfs_remove_recursive(topdir);
359	topdir = NULL;
360	rpc_fault_dir = NULL;
361	rpc_clnt_dir = NULL;
362}