1 #define pr_fmt(fmt) "drbd debugfs: " fmt
2 #include <linux/kernel.h>
3 #include <linux/module.h>
4 #include <linux/debugfs.h>
5 #include <linux/seq_file.h>
6 #include <linux/stat.h>
7 #include <linux/jiffies.h>
8 #include <linux/list.h>
9 
10 #include "drbd_int.h"
11 #include "drbd_req.h"
12 #include "drbd_debugfs.h"
13 
14 
15 /**********************************************************************
16  * Whenever you change the file format, remember to bump the version. *
17  **********************************************************************/
18 
19 static struct dentry *drbd_debugfs_root;
20 static struct dentry *drbd_debugfs_version;
21 static struct dentry *drbd_debugfs_resources;
22 static struct dentry *drbd_debugfs_minors;
23 
24 static void seq_print_age_or_dash(struct seq_file *m, bool valid, unsigned long dt)
25 {
26 	if (valid)
27 		seq_printf(m, "\t%d", jiffies_to_msecs(dt));
28 	else
29 		seq_printf(m, "\t-");
30 }
31 
32 static void __seq_print_rq_state_bit(struct seq_file *m,
33 	bool is_set, char *sep, const char *set_name, const char *unset_name)
34 {
35 	if (is_set && set_name) {
36 		seq_putc(m, *sep);
37 		seq_puts(m, set_name);
38 		*sep = '|';
39 	} else if (!is_set && unset_name) {
40 		seq_putc(m, *sep);
41 		seq_puts(m, unset_name);
42 		*sep = '|';
43 	}
44 }
45 
46 static void seq_print_rq_state_bit(struct seq_file *m,
47 	bool is_set, char *sep, const char *set_name)
48 {
49 	__seq_print_rq_state_bit(m, is_set, sep, set_name, NULL);
50 }
51 
52 /* pretty print enum drbd_req_state_bits req->rq_state */
53 static void seq_print_request_state(struct seq_file *m, struct drbd_request *req)
54 {
55 	unsigned int s = req->rq_state;
56 	char sep = ' ';
57 	seq_printf(m, "\t0x%08x", s);
58 	seq_printf(m, "\tmaster: %s", req->master_bio ? "pending" : "completed");
59 
60 	/* RQ_WRITE ignored, already reported */
61 	seq_puts(m, "\tlocal:");
62 	seq_print_rq_state_bit(m, s & RQ_IN_ACT_LOG, &sep, "in-AL");
63 	seq_print_rq_state_bit(m, s & RQ_POSTPONED, &sep, "postponed");
64 	seq_print_rq_state_bit(m, s & RQ_COMPLETION_SUSP, &sep, "suspended");
65 	sep = ' ';
66 	seq_print_rq_state_bit(m, s & RQ_LOCAL_PENDING, &sep, "pending");
67 	seq_print_rq_state_bit(m, s & RQ_LOCAL_COMPLETED, &sep, "completed");
68 	seq_print_rq_state_bit(m, s & RQ_LOCAL_ABORTED, &sep, "aborted");
69 	seq_print_rq_state_bit(m, s & RQ_LOCAL_OK, &sep, "ok");
70 	if (sep == ' ')
71 		seq_puts(m, " -");
72 
73 	/* for_each_connection ... */
74 	seq_printf(m, "\tnet:");
75 	sep = ' ';
76 	seq_print_rq_state_bit(m, s & RQ_NET_PENDING, &sep, "pending");
77 	seq_print_rq_state_bit(m, s & RQ_NET_QUEUED, &sep, "queued");
78 	seq_print_rq_state_bit(m, s & RQ_NET_SENT, &sep, "sent");
79 	seq_print_rq_state_bit(m, s & RQ_NET_DONE, &sep, "done");
80 	seq_print_rq_state_bit(m, s & RQ_NET_SIS, &sep, "sis");
81 	seq_print_rq_state_bit(m, s & RQ_NET_OK, &sep, "ok");
82 	if (sep == ' ')
83 		seq_puts(m, " -");
84 
85 	seq_printf(m, " :");
86 	sep = ' ';
87 	seq_print_rq_state_bit(m, s & RQ_EXP_RECEIVE_ACK, &sep, "B");
88 	seq_print_rq_state_bit(m, s & RQ_EXP_WRITE_ACK, &sep, "C");
89 	seq_print_rq_state_bit(m, s & RQ_EXP_BARR_ACK, &sep, "barr");
90 	if (sep == ' ')
91 		seq_puts(m, " -");
92 	seq_printf(m, "\n");
93 }
94 
95 static void seq_print_one_request(struct seq_file *m, struct drbd_request *req, unsigned long now)
96 {
97 	/* change anything here, fixup header below! */
98 	unsigned int s = req->rq_state;
99 
100 #define RQ_HDR_1 "epoch\tsector\tsize\trw"
101 	seq_printf(m, "0x%x\t%llu\t%u\t%s",
102 		req->epoch,
103 		(unsigned long long)req->i.sector, req->i.size >> 9,
104 		(s & RQ_WRITE) ? "W" : "R");
105 
106 #define RQ_HDR_2 "\tstart\tin AL\tsubmit"
107 	seq_printf(m, "\t%d", jiffies_to_msecs(now - req->start_jif));
108 	seq_print_age_or_dash(m, s & RQ_IN_ACT_LOG, now - req->in_actlog_jif);
109 	seq_print_age_or_dash(m, s & RQ_LOCAL_PENDING, now - req->pre_submit_jif);
110 
111 #define RQ_HDR_3 "\tsent\tacked\tdone"
112 	seq_print_age_or_dash(m, s & RQ_NET_SENT, now - req->pre_send_jif);
113 	seq_print_age_or_dash(m, (s & RQ_NET_SENT) && !(s & RQ_NET_PENDING), now - req->acked_jif);
114 	seq_print_age_or_dash(m, s & RQ_NET_DONE, now - req->net_done_jif);
115 
116 #define RQ_HDR_4 "\tstate\n"
117 	seq_print_request_state(m, req);
118 }
119 #define RQ_HDR RQ_HDR_1 RQ_HDR_2 RQ_HDR_3 RQ_HDR_4
120 
121 static void seq_print_minor_vnr_req(struct seq_file *m, struct drbd_request *req, unsigned long now)
122 {
123 	seq_printf(m, "%u\t%u\t", req->device->minor, req->device->vnr);
124 	seq_print_one_request(m, req, now);
125 }
126 
127 static void seq_print_resource_pending_meta_io(struct seq_file *m, struct drbd_resource *resource, unsigned long now)
128 {
129 	struct drbd_device *device;
130 	unsigned int i;
131 
132 	seq_puts(m, "minor\tvnr\tstart\tsubmit\tintent\n");
133 	rcu_read_lock();
134 	idr_for_each_entry(&resource->devices, device, i) {
135 		struct drbd_md_io tmp;
136 		/* In theory this is racy,
137 		 * in the sense that there could have been a
138 		 * drbd_md_put_buffer(); drbd_md_get_buffer();
139 		 * between accessing these members here.  */
140 		tmp = device->md_io;
141 		if (atomic_read(&tmp.in_use)) {
142 			seq_printf(m, "%u\t%u\t%d\t",
143 				device->minor, device->vnr,
144 				jiffies_to_msecs(now - tmp.start_jif));
145 			if (time_before(tmp.submit_jif, tmp.start_jif))
146 				seq_puts(m, "-\t");
147 			else
148 				seq_printf(m, "%d\t", jiffies_to_msecs(now - tmp.submit_jif));
149 			seq_printf(m, "%s\n", tmp.current_use);
150 		}
151 	}
152 	rcu_read_unlock();
153 }
154 
155 static void seq_print_waiting_for_AL(struct seq_file *m, struct drbd_resource *resource, unsigned long now)
156 {
157 	struct drbd_device *device;
158 	unsigned int i;
159 
160 	seq_puts(m, "minor\tvnr\tage\t#waiting\n");
161 	rcu_read_lock();
162 	idr_for_each_entry(&resource->devices, device, i) {
163 		unsigned long jif;
164 		struct drbd_request *req;
165 		int n = atomic_read(&device->ap_actlog_cnt);
166 		if (n) {
167 			spin_lock_irq(&device->resource->req_lock);
168 			req = list_first_entry_or_null(&device->pending_master_completion[1],
169 				struct drbd_request, req_pending_master_completion);
170 			/* if the oldest request does not wait for the activity log
171 			 * it is not interesting for us here */
172 			if (req && !(req->rq_state & RQ_IN_ACT_LOG))
173 				jif = req->start_jif;
174 			else
175 				req = NULL;
176 			spin_unlock_irq(&device->resource->req_lock);
177 		}
178 		if (n) {
179 			seq_printf(m, "%u\t%u\t", device->minor, device->vnr);
180 			if (req)
181 				seq_printf(m, "%u\t", jiffies_to_msecs(now - jif));
182 			else
183 				seq_puts(m, "-\t");
184 			seq_printf(m, "%u\n", n);
185 		}
186 	}
187 	rcu_read_unlock();
188 }
189 
190 static void seq_print_device_bitmap_io(struct seq_file *m, struct drbd_device *device, unsigned long now)
191 {
192 	struct drbd_bm_aio_ctx *ctx;
193 	unsigned long start_jif;
194 	unsigned int in_flight;
195 	unsigned int flags;
196 	spin_lock_irq(&device->resource->req_lock);
197 	ctx = list_first_entry_or_null(&device->pending_bitmap_io, struct drbd_bm_aio_ctx, list);
198 	if (ctx && ctx->done)
199 		ctx = NULL;
200 	if (ctx) {
201 		start_jif = ctx->start_jif;
202 		in_flight = atomic_read(&ctx->in_flight);
203 		flags = ctx->flags;
204 	}
205 	spin_unlock_irq(&device->resource->req_lock);
206 	if (ctx) {
207 		seq_printf(m, "%u\t%u\t%c\t%u\t%u\n",
208 			device->minor, device->vnr,
209 			(flags & BM_AIO_READ) ? 'R' : 'W',
210 			jiffies_to_msecs(now - start_jif),
211 			in_flight);
212 	}
213 }
214 
215 static void seq_print_resource_pending_bitmap_io(struct seq_file *m, struct drbd_resource *resource, unsigned long now)
216 {
217 	struct drbd_device *device;
218 	unsigned int i;
219 
220 	seq_puts(m, "minor\tvnr\trw\tage\t#in-flight\n");
221 	rcu_read_lock();
222 	idr_for_each_entry(&resource->devices, device, i) {
223 		seq_print_device_bitmap_io(m, device, now);
224 	}
225 	rcu_read_unlock();
226 }
227 
228 /* pretty print enum peer_req->flags */
229 static void seq_print_peer_request_flags(struct seq_file *m, struct drbd_peer_request *peer_req)
230 {
231 	unsigned long f = peer_req->flags;
232 	char sep = ' ';
233 
234 	__seq_print_rq_state_bit(m, f & EE_SUBMITTED, &sep, "submitted", "preparing");
235 	__seq_print_rq_state_bit(m, f & EE_APPLICATION, &sep, "application", "internal");
236 	seq_print_rq_state_bit(m, f & EE_CALL_AL_COMPLETE_IO, &sep, "in-AL");
237 	seq_print_rq_state_bit(m, f & EE_SEND_WRITE_ACK, &sep, "C");
238 	seq_print_rq_state_bit(m, f & EE_MAY_SET_IN_SYNC, &sep, "set-in-sync");
239 
240 	if (f & EE_IS_TRIM)
241 		__seq_print_rq_state_bit(m, f & EE_IS_TRIM_USE_ZEROOUT, &sep, "zero-out", "trim");
242 	seq_print_rq_state_bit(m, f & EE_WRITE_SAME, &sep, "write-same");
243 	seq_putc(m, '\n');
244 }
245 
246 static void seq_print_peer_request(struct seq_file *m,
247 	struct drbd_device *device, struct list_head *lh,
248 	unsigned long now)
249 {
250 	bool reported_preparing = false;
251 	struct drbd_peer_request *peer_req;
252 	list_for_each_entry(peer_req, lh, w.list) {
253 		if (reported_preparing && !(peer_req->flags & EE_SUBMITTED))
254 			continue;
255 
256 		if (device)
257 			seq_printf(m, "%u\t%u\t", device->minor, device->vnr);
258 
259 		seq_printf(m, "%llu\t%u\t%c\t%u\t",
260 			(unsigned long long)peer_req->i.sector, peer_req->i.size >> 9,
261 			(peer_req->flags & EE_WRITE) ? 'W' : 'R',
262 			jiffies_to_msecs(now - peer_req->submit_jif));
263 		seq_print_peer_request_flags(m, peer_req);
264 		if (peer_req->flags & EE_SUBMITTED)
265 			break;
266 		else
267 			reported_preparing = true;
268 	}
269 }
270 
271 static void seq_print_device_peer_requests(struct seq_file *m,
272 	struct drbd_device *device, unsigned long now)
273 {
274 	seq_puts(m, "minor\tvnr\tsector\tsize\trw\tage\tflags\n");
275 	spin_lock_irq(&device->resource->req_lock);
276 	seq_print_peer_request(m, device, &device->active_ee, now);
277 	seq_print_peer_request(m, device, &device->read_ee, now);
278 	seq_print_peer_request(m, device, &device->sync_ee, now);
279 	spin_unlock_irq(&device->resource->req_lock);
280 	if (test_bit(FLUSH_PENDING, &device->flags)) {
281 		seq_printf(m, "%u\t%u\t-\t-\tF\t%u\tflush\n",
282 			device->minor, device->vnr,
283 			jiffies_to_msecs(now - device->flush_jif));
284 	}
285 }
286 
287 static void seq_print_resource_pending_peer_requests(struct seq_file *m,
288 	struct drbd_resource *resource, unsigned long now)
289 {
290 	struct drbd_device *device;
291 	unsigned int i;
292 
293 	rcu_read_lock();
294 	idr_for_each_entry(&resource->devices, device, i) {
295 		seq_print_device_peer_requests(m, device, now);
296 	}
297 	rcu_read_unlock();
298 }
299 
300 static void seq_print_resource_transfer_log_summary(struct seq_file *m,
301 	struct drbd_resource *resource,
302 	struct drbd_connection *connection,
303 	unsigned long now)
304 {
305 	struct drbd_request *req;
306 	unsigned int count = 0;
307 	unsigned int show_state = 0;
308 
309 	seq_puts(m, "n\tdevice\tvnr\t" RQ_HDR);
310 	spin_lock_irq(&resource->req_lock);
311 	list_for_each_entry(req, &connection->transfer_log, tl_requests) {
312 		unsigned int tmp = 0;
313 		unsigned int s;
314 		++count;
315 
316 		/* don't disable irq "forever" */
317 		if (!(count & 0x1ff)) {
318 			struct drbd_request *req_next;
319 			kref_get(&req->kref);
320 			spin_unlock_irq(&resource->req_lock);
321 			cond_resched();
322 			spin_lock_irq(&resource->req_lock);
323 			req_next = list_next_entry(req, tl_requests);
324 			if (kref_put(&req->kref, drbd_req_destroy))
325 				req = req_next;
326 			if (&req->tl_requests == &connection->transfer_log)
327 				break;
328 		}
329 
330 		s = req->rq_state;
331 
332 		/* This is meant to summarize timing issues, to be able to tell
333 		 * local disk problems from network problems.
334 		 * Skip requests, if we have shown an even older request with
335 		 * similar aspects already.  */
336 		if (req->master_bio == NULL)
337 			tmp |= 1;
338 		if ((s & RQ_LOCAL_MASK) && (s & RQ_LOCAL_PENDING))
339 			tmp |= 2;
340 		if (s & RQ_NET_MASK) {
341 			if (!(s & RQ_NET_SENT))
342 				tmp |= 4;
343 			if (s & RQ_NET_PENDING)
344 				tmp |= 8;
345 			if (!(s & RQ_NET_DONE))
346 				tmp |= 16;
347 		}
348 		if ((tmp & show_state) == tmp)
349 			continue;
350 		show_state |= tmp;
351 		seq_printf(m, "%u\t", count);
352 		seq_print_minor_vnr_req(m, req, now);
353 		if (show_state == 0x1f)
354 			break;
355 	}
356 	spin_unlock_irq(&resource->req_lock);
357 }
358 
359 /* TODO: transfer_log and friends should be moved to resource */
360 static int in_flight_summary_show(struct seq_file *m, void *pos)
361 {
362 	struct drbd_resource *resource = m->private;
363 	struct drbd_connection *connection;
364 	unsigned long jif = jiffies;
365 
366 	connection = first_connection(resource);
367 	/* This does not happen, actually.
368 	 * But be robust and prepare for future code changes. */
369 	if (!connection || !kref_get_unless_zero(&connection->kref))
370 		return -ESTALE;
371 
372 	/* BUMP me if you change the file format/content/presentation */
373 	seq_printf(m, "v: %u\n\n", 0);
374 
375 	seq_puts(m, "oldest bitmap IO\n");
376 	seq_print_resource_pending_bitmap_io(m, resource, jif);
377 	seq_putc(m, '\n');
378 
379 	seq_puts(m, "meta data IO\n");
380 	seq_print_resource_pending_meta_io(m, resource, jif);
381 	seq_putc(m, '\n');
382 
383 	seq_puts(m, "socket buffer stats\n");
384 	/* for each connection ... once we have more than one */
385 	rcu_read_lock();
386 	if (connection->data.socket) {
387 		/* open coded SIOCINQ, the "relevant" part */
388 		struct tcp_sock *tp = tcp_sk(connection->data.socket->sk);
389 		int answ = tp->rcv_nxt - tp->copied_seq;
390 		seq_printf(m, "unread receive buffer: %u Byte\n", answ);
391 		/* open coded SIOCOUTQ, the "relevant" part */
392 		answ = tp->write_seq - tp->snd_una;
393 		seq_printf(m, "unacked send buffer: %u Byte\n", answ);
394 	}
395 	rcu_read_unlock();
396 	seq_putc(m, '\n');
397 
398 	seq_puts(m, "oldest peer requests\n");
399 	seq_print_resource_pending_peer_requests(m, resource, jif);
400 	seq_putc(m, '\n');
401 
402 	seq_puts(m, "application requests waiting for activity log\n");
403 	seq_print_waiting_for_AL(m, resource, jif);
404 	seq_putc(m, '\n');
405 
406 	seq_puts(m, "oldest application requests\n");
407 	seq_print_resource_transfer_log_summary(m, resource, connection, jif);
408 	seq_putc(m, '\n');
409 
410 	jif = jiffies - jif;
411 	if (jif)
412 		seq_printf(m, "generated in %d ms\n", jiffies_to_msecs(jif));
413 	kref_put(&connection->kref, drbd_destroy_connection);
414 	return 0;
415 }
416 
417 /* make sure at *open* time that the respective object won't go away. */
418 static int drbd_single_open(struct file *file, int (*show)(struct seq_file *, void *),
419 		                void *data, struct kref *kref,
420 				void (*release)(struct kref *))
421 {
422 	struct dentry *parent;
423 	int ret = -ESTALE;
424 
425 	/* Are we still linked,
426 	 * or has debugfs_remove() already been called? */
427 	parent = file->f_path.dentry->d_parent;
428 	/* serialize with d_delete() */
429 	inode_lock(d_inode(parent));
430 	/* Make sure the object is still alive */
431 	if (simple_positive(file->f_path.dentry)
432 	&& kref_get_unless_zero(kref))
433 		ret = 0;
434 	inode_unlock(d_inode(parent));
435 	if (!ret) {
436 		ret = single_open(file, show, data);
437 		if (ret)
438 			kref_put(kref, release);
439 	}
440 	return ret;
441 }
442 
443 static int in_flight_summary_open(struct inode *inode, struct file *file)
444 {
445 	struct drbd_resource *resource = inode->i_private;
446 	return drbd_single_open(file, in_flight_summary_show, resource,
447 				&resource->kref, drbd_destroy_resource);
448 }
449 
450 static int in_flight_summary_release(struct inode *inode, struct file *file)
451 {
452 	struct drbd_resource *resource = inode->i_private;
453 	kref_put(&resource->kref, drbd_destroy_resource);
454 	return single_release(inode, file);
455 }
456 
457 static const struct file_operations in_flight_summary_fops = {
458 	.owner		= THIS_MODULE,
459 	.open		= in_flight_summary_open,
460 	.read		= seq_read,
461 	.llseek		= seq_lseek,
462 	.release	= in_flight_summary_release,
463 };
464 
465 void drbd_debugfs_resource_add(struct drbd_resource *resource)
466 {
467 	struct dentry *dentry;
468 	if (!drbd_debugfs_resources)
469 		return;
470 
471 	dentry = debugfs_create_dir(resource->name, drbd_debugfs_resources);
472 	if (IS_ERR_OR_NULL(dentry))
473 		goto fail;
474 	resource->debugfs_res = dentry;
475 
476 	dentry = debugfs_create_dir("volumes", resource->debugfs_res);
477 	if (IS_ERR_OR_NULL(dentry))
478 		goto fail;
479 	resource->debugfs_res_volumes = dentry;
480 
481 	dentry = debugfs_create_dir("connections", resource->debugfs_res);
482 	if (IS_ERR_OR_NULL(dentry))
483 		goto fail;
484 	resource->debugfs_res_connections = dentry;
485 
486 	dentry = debugfs_create_file("in_flight_summary", S_IRUSR|S_IRGRP,
487 			resource->debugfs_res, resource,
488 			&in_flight_summary_fops);
489 	if (IS_ERR_OR_NULL(dentry))
490 		goto fail;
491 	resource->debugfs_res_in_flight_summary = dentry;
492 	return;
493 
494 fail:
495 	drbd_debugfs_resource_cleanup(resource);
496 	drbd_err(resource, "failed to create debugfs dentry\n");
497 }
498 
499 static void drbd_debugfs_remove(struct dentry **dp)
500 {
501 	debugfs_remove(*dp);
502 	*dp = NULL;
503 }
504 
505 void drbd_debugfs_resource_cleanup(struct drbd_resource *resource)
506 {
507 	/* it is ok to call debugfs_remove(NULL) */
508 	drbd_debugfs_remove(&resource->debugfs_res_in_flight_summary);
509 	drbd_debugfs_remove(&resource->debugfs_res_connections);
510 	drbd_debugfs_remove(&resource->debugfs_res_volumes);
511 	drbd_debugfs_remove(&resource->debugfs_res);
512 }
513 
514 static void seq_print_one_timing_detail(struct seq_file *m,
515 	const struct drbd_thread_timing_details *tdp,
516 	unsigned long now)
517 {
518 	struct drbd_thread_timing_details td;
519 	/* No locking...
520 	 * use temporary assignment to get at consistent data. */
521 	do {
522 		td = *tdp;
523 	} while (td.cb_nr != tdp->cb_nr);
524 	if (!td.cb_addr)
525 		return;
526 	seq_printf(m, "%u\t%d\t%s:%u\t%ps\n",
527 			td.cb_nr,
528 			jiffies_to_msecs(now - td.start_jif),
529 			td.caller_fn, td.line,
530 			td.cb_addr);
531 }
532 
533 static void seq_print_timing_details(struct seq_file *m,
534 		const char *title,
535 		unsigned int cb_nr, struct drbd_thread_timing_details *tdp, unsigned long now)
536 {
537 	unsigned int start_idx;
538 	unsigned int i;
539 
540 	seq_printf(m, "%s\n", title);
541 	/* If not much is going on, this will result in natural ordering.
542 	 * If it is very busy, we will possibly skip events, or even see wrap
543 	 * arounds, which could only be avoided with locking.
544 	 */
545 	start_idx = cb_nr % DRBD_THREAD_DETAILS_HIST;
546 	for (i = start_idx; i < DRBD_THREAD_DETAILS_HIST; i++)
547 		seq_print_one_timing_detail(m, tdp+i, now);
548 	for (i = 0; i < start_idx; i++)
549 		seq_print_one_timing_detail(m, tdp+i, now);
550 }
551 
552 static int callback_history_show(struct seq_file *m, void *ignored)
553 {
554 	struct drbd_connection *connection = m->private;
555 	unsigned long jif = jiffies;
556 
557 	/* BUMP me if you change the file format/content/presentation */
558 	seq_printf(m, "v: %u\n\n", 0);
559 
560 	seq_puts(m, "n\tage\tcallsite\tfn\n");
561 	seq_print_timing_details(m, "worker", connection->w_cb_nr, connection->w_timing_details, jif);
562 	seq_print_timing_details(m, "receiver", connection->r_cb_nr, connection->r_timing_details, jif);
563 	return 0;
564 }
565 
566 static int callback_history_open(struct inode *inode, struct file *file)
567 {
568 	struct drbd_connection *connection = inode->i_private;
569 	return drbd_single_open(file, callback_history_show, connection,
570 				&connection->kref, drbd_destroy_connection);
571 }
572 
573 static int callback_history_release(struct inode *inode, struct file *file)
574 {
575 	struct drbd_connection *connection = inode->i_private;
576 	kref_put(&connection->kref, drbd_destroy_connection);
577 	return single_release(inode, file);
578 }
579 
580 static const struct file_operations connection_callback_history_fops = {
581 	.owner		= THIS_MODULE,
582 	.open		= callback_history_open,
583 	.read		= seq_read,
584 	.llseek		= seq_lseek,
585 	.release	= callback_history_release,
586 };
587 
588 static int connection_oldest_requests_show(struct seq_file *m, void *ignored)
589 {
590 	struct drbd_connection *connection = m->private;
591 	unsigned long now = jiffies;
592 	struct drbd_request *r1, *r2;
593 
594 	/* BUMP me if you change the file format/content/presentation */
595 	seq_printf(m, "v: %u\n\n", 0);
596 
597 	spin_lock_irq(&connection->resource->req_lock);
598 	r1 = connection->req_next;
599 	if (r1)
600 		seq_print_minor_vnr_req(m, r1, now);
601 	r2 = connection->req_ack_pending;
602 	if (r2 && r2 != r1) {
603 		r1 = r2;
604 		seq_print_minor_vnr_req(m, r1, now);
605 	}
606 	r2 = connection->req_not_net_done;
607 	if (r2 && r2 != r1)
608 		seq_print_minor_vnr_req(m, r2, now);
609 	spin_unlock_irq(&connection->resource->req_lock);
610 	return 0;
611 }
612 
613 static int connection_oldest_requests_open(struct inode *inode, struct file *file)
614 {
615 	struct drbd_connection *connection = inode->i_private;
616 	return drbd_single_open(file, connection_oldest_requests_show, connection,
617 				&connection->kref, drbd_destroy_connection);
618 }
619 
620 static int connection_oldest_requests_release(struct inode *inode, struct file *file)
621 {
622 	struct drbd_connection *connection = inode->i_private;
623 	kref_put(&connection->kref, drbd_destroy_connection);
624 	return single_release(inode, file);
625 }
626 
627 static const struct file_operations connection_oldest_requests_fops = {
628 	.owner		= THIS_MODULE,
629 	.open		= connection_oldest_requests_open,
630 	.read		= seq_read,
631 	.llseek		= seq_lseek,
632 	.release	= connection_oldest_requests_release,
633 };
634 
635 void drbd_debugfs_connection_add(struct drbd_connection *connection)
636 {
637 	struct dentry *conns_dir = connection->resource->debugfs_res_connections;
638 	struct dentry *dentry;
639 	if (!conns_dir)
640 		return;
641 
642 	/* Once we enable mutliple peers,
643 	 * these connections will have descriptive names.
644 	 * For now, it is just the one connection to the (only) "peer". */
645 	dentry = debugfs_create_dir("peer", conns_dir);
646 	if (IS_ERR_OR_NULL(dentry))
647 		goto fail;
648 	connection->debugfs_conn = dentry;
649 
650 	dentry = debugfs_create_file("callback_history", S_IRUSR|S_IRGRP,
651 			connection->debugfs_conn, connection,
652 			&connection_callback_history_fops);
653 	if (IS_ERR_OR_NULL(dentry))
654 		goto fail;
655 	connection->debugfs_conn_callback_history = dentry;
656 
657 	dentry = debugfs_create_file("oldest_requests", S_IRUSR|S_IRGRP,
658 			connection->debugfs_conn, connection,
659 			&connection_oldest_requests_fops);
660 	if (IS_ERR_OR_NULL(dentry))
661 		goto fail;
662 	connection->debugfs_conn_oldest_requests = dentry;
663 	return;
664 
665 fail:
666 	drbd_debugfs_connection_cleanup(connection);
667 	drbd_err(connection, "failed to create debugfs dentry\n");
668 }
669 
670 void drbd_debugfs_connection_cleanup(struct drbd_connection *connection)
671 {
672 	drbd_debugfs_remove(&connection->debugfs_conn_callback_history);
673 	drbd_debugfs_remove(&connection->debugfs_conn_oldest_requests);
674 	drbd_debugfs_remove(&connection->debugfs_conn);
675 }
676 
677 static void resync_dump_detail(struct seq_file *m, struct lc_element *e)
678 {
679        struct bm_extent *bme = lc_entry(e, struct bm_extent, lce);
680 
681        seq_printf(m, "%5d %s %s %s", bme->rs_left,
682 		  test_bit(BME_NO_WRITES, &bme->flags) ? "NO_WRITES" : "---------",
683 		  test_bit(BME_LOCKED, &bme->flags) ? "LOCKED" : "------",
684 		  test_bit(BME_PRIORITY, &bme->flags) ? "PRIORITY" : "--------"
685 		  );
686 }
687 
688 static int device_resync_extents_show(struct seq_file *m, void *ignored)
689 {
690 	struct drbd_device *device = m->private;
691 
692 	/* BUMP me if you change the file format/content/presentation */
693 	seq_printf(m, "v: %u\n\n", 0);
694 
695 	if (get_ldev_if_state(device, D_FAILED)) {
696 		lc_seq_printf_stats(m, device->resync);
697 		lc_seq_dump_details(m, device->resync, "rs_left flags", resync_dump_detail);
698 		put_ldev(device);
699 	}
700 	return 0;
701 }
702 
703 static int device_act_log_extents_show(struct seq_file *m, void *ignored)
704 {
705 	struct drbd_device *device = m->private;
706 
707 	/* BUMP me if you change the file format/content/presentation */
708 	seq_printf(m, "v: %u\n\n", 0);
709 
710 	if (get_ldev_if_state(device, D_FAILED)) {
711 		lc_seq_printf_stats(m, device->act_log);
712 		lc_seq_dump_details(m, device->act_log, "", NULL);
713 		put_ldev(device);
714 	}
715 	return 0;
716 }
717 
718 static int device_oldest_requests_show(struct seq_file *m, void *ignored)
719 {
720 	struct drbd_device *device = m->private;
721 	struct drbd_resource *resource = device->resource;
722 	unsigned long now = jiffies;
723 	struct drbd_request *r1, *r2;
724 	int i;
725 
726 	/* BUMP me if you change the file format/content/presentation */
727 	seq_printf(m, "v: %u\n\n", 0);
728 
729 	seq_puts(m, RQ_HDR);
730 	spin_lock_irq(&resource->req_lock);
731 	/* WRITE, then READ */
732 	for (i = 1; i >= 0; --i) {
733 		r1 = list_first_entry_or_null(&device->pending_master_completion[i],
734 			struct drbd_request, req_pending_master_completion);
735 		r2 = list_first_entry_or_null(&device->pending_completion[i],
736 			struct drbd_request, req_pending_local);
737 		if (r1)
738 			seq_print_one_request(m, r1, now);
739 		if (r2 && r2 != r1)
740 			seq_print_one_request(m, r2, now);
741 	}
742 	spin_unlock_irq(&resource->req_lock);
743 	return 0;
744 }
745 
746 static int device_data_gen_id_show(struct seq_file *m, void *ignored)
747 {
748 	struct drbd_device *device = m->private;
749 	struct drbd_md *md;
750 	enum drbd_uuid_index idx;
751 
752 	if (!get_ldev_if_state(device, D_FAILED))
753 		return -ENODEV;
754 
755 	md = &device->ldev->md;
756 	spin_lock_irq(&md->uuid_lock);
757 	for (idx = UI_CURRENT; idx <= UI_HISTORY_END; idx++) {
758 		seq_printf(m, "0x%016llX\n", md->uuid[idx]);
759 	}
760 	spin_unlock_irq(&md->uuid_lock);
761 	put_ldev(device);
762 	return 0;
763 }
764 
765 static int device_ed_gen_id_show(struct seq_file *m, void *ignored)
766 {
767 	struct drbd_device *device = m->private;
768 	seq_printf(m, "0x%016llX\n", (unsigned long long)device->ed_uuid);
769 	return 0;
770 }
771 
772 #define drbd_debugfs_device_attr(name)						\
773 static int device_ ## name ## _open(struct inode *inode, struct file *file)	\
774 {										\
775 	struct drbd_device *device = inode->i_private;				\
776 	return drbd_single_open(file, device_ ## name ## _show, device,		\
777 				&device->kref, drbd_destroy_device);		\
778 }										\
779 static int device_ ## name ## _release(struct inode *inode, struct file *file)	\
780 {										\
781 	struct drbd_device *device = inode->i_private;				\
782 	kref_put(&device->kref, drbd_destroy_device);				\
783 	return single_release(inode, file);					\
784 }										\
785 static const struct file_operations device_ ## name ## _fops = {		\
786 	.owner		= THIS_MODULE,						\
787 	.open		= device_ ## name ## _open,				\
788 	.read		= seq_read,						\
789 	.llseek		= seq_lseek,						\
790 	.release	= device_ ## name ## _release,				\
791 };
792 
793 drbd_debugfs_device_attr(oldest_requests)
794 drbd_debugfs_device_attr(act_log_extents)
795 drbd_debugfs_device_attr(resync_extents)
796 drbd_debugfs_device_attr(data_gen_id)
797 drbd_debugfs_device_attr(ed_gen_id)
798 
799 void drbd_debugfs_device_add(struct drbd_device *device)
800 {
801 	struct dentry *vols_dir = device->resource->debugfs_res_volumes;
802 	char minor_buf[8]; /* MINORMASK, MINORBITS == 20; */
803 	char vnr_buf[8];   /* volume number vnr is even 16 bit only; */
804 	char *slink_name = NULL;
805 
806 	struct dentry *dentry;
807 	if (!vols_dir || !drbd_debugfs_minors)
808 		return;
809 
810 	snprintf(vnr_buf, sizeof(vnr_buf), "%u", device->vnr);
811 	dentry = debugfs_create_dir(vnr_buf, vols_dir);
812 	if (IS_ERR_OR_NULL(dentry))
813 		goto fail;
814 	device->debugfs_vol = dentry;
815 
816 	snprintf(minor_buf, sizeof(minor_buf), "%u", device->minor);
817 	slink_name = kasprintf(GFP_KERNEL, "../resources/%s/volumes/%u",
818 			device->resource->name, device->vnr);
819 	if (!slink_name)
820 		goto fail;
821 	dentry = debugfs_create_symlink(minor_buf, drbd_debugfs_minors, slink_name);
822 	kfree(slink_name);
823 	slink_name = NULL;
824 	if (IS_ERR_OR_NULL(dentry))
825 		goto fail;
826 	device->debugfs_minor = dentry;
827 
828 #define DCF(name)	do {					\
829 	dentry = debugfs_create_file(#name, S_IRUSR|S_IRGRP,	\
830 			device->debugfs_vol, device,		\
831 			&device_ ## name ## _fops);		\
832 	if (IS_ERR_OR_NULL(dentry))				\
833 		goto fail;					\
834 	device->debugfs_vol_ ## name = dentry;			\
835 	} while (0)
836 
837 	DCF(oldest_requests);
838 	DCF(act_log_extents);
839 	DCF(resync_extents);
840 	DCF(data_gen_id);
841 	DCF(ed_gen_id);
842 #undef DCF
843 	return;
844 
845 fail:
846 	drbd_debugfs_device_cleanup(device);
847 	drbd_err(device, "failed to create debugfs entries\n");
848 }
849 
850 void drbd_debugfs_device_cleanup(struct drbd_device *device)
851 {
852 	drbd_debugfs_remove(&device->debugfs_minor);
853 	drbd_debugfs_remove(&device->debugfs_vol_oldest_requests);
854 	drbd_debugfs_remove(&device->debugfs_vol_act_log_extents);
855 	drbd_debugfs_remove(&device->debugfs_vol_resync_extents);
856 	drbd_debugfs_remove(&device->debugfs_vol_data_gen_id);
857 	drbd_debugfs_remove(&device->debugfs_vol_ed_gen_id);
858 	drbd_debugfs_remove(&device->debugfs_vol);
859 }
860 
861 void drbd_debugfs_peer_device_add(struct drbd_peer_device *peer_device)
862 {
863 	struct dentry *conn_dir = peer_device->connection->debugfs_conn;
864 	struct dentry *dentry;
865 	char vnr_buf[8];
866 
867 	if (!conn_dir)
868 		return;
869 
870 	snprintf(vnr_buf, sizeof(vnr_buf), "%u", peer_device->device->vnr);
871 	dentry = debugfs_create_dir(vnr_buf, conn_dir);
872 	if (IS_ERR_OR_NULL(dentry))
873 		goto fail;
874 	peer_device->debugfs_peer_dev = dentry;
875 	return;
876 
877 fail:
878 	drbd_debugfs_peer_device_cleanup(peer_device);
879 	drbd_err(peer_device, "failed to create debugfs entries\n");
880 }
881 
882 void drbd_debugfs_peer_device_cleanup(struct drbd_peer_device *peer_device)
883 {
884 	drbd_debugfs_remove(&peer_device->debugfs_peer_dev);
885 }
886 
887 static int drbd_version_show(struct seq_file *m, void *ignored)
888 {
889 	seq_printf(m, "# %s\n", drbd_buildtag());
890 	seq_printf(m, "VERSION=%s\n", REL_VERSION);
891 	seq_printf(m, "API_VERSION=%u\n", API_VERSION);
892 	seq_printf(m, "PRO_VERSION_MIN=%u\n", PRO_VERSION_MIN);
893 	seq_printf(m, "PRO_VERSION_MAX=%u\n", PRO_VERSION_MAX);
894 	return 0;
895 }
896 
897 static int drbd_version_open(struct inode *inode, struct file *file)
898 {
899 	return single_open(file, drbd_version_show, NULL);
900 }
901 
902 static const struct file_operations drbd_version_fops = {
903 	.owner = THIS_MODULE,
904 	.open = drbd_version_open,
905 	.llseek = seq_lseek,
906 	.read = seq_read,
907 	.release = single_release,
908 };
909 
910 /* not __exit, may be indirectly called
911  * from the module-load-failure path as well. */
912 void drbd_debugfs_cleanup(void)
913 {
914 	drbd_debugfs_remove(&drbd_debugfs_resources);
915 	drbd_debugfs_remove(&drbd_debugfs_minors);
916 	drbd_debugfs_remove(&drbd_debugfs_version);
917 	drbd_debugfs_remove(&drbd_debugfs_root);
918 }
919 
920 int __init drbd_debugfs_init(void)
921 {
922 	struct dentry *dentry;
923 
924 	dentry = debugfs_create_dir("drbd", NULL);
925 	if (IS_ERR_OR_NULL(dentry))
926 		goto fail;
927 	drbd_debugfs_root = dentry;
928 
929 	dentry = debugfs_create_file("version", 0444, drbd_debugfs_root, NULL, &drbd_version_fops);
930 	if (IS_ERR_OR_NULL(dentry))
931 		goto fail;
932 	drbd_debugfs_version = dentry;
933 
934 	dentry = debugfs_create_dir("resources", drbd_debugfs_root);
935 	if (IS_ERR_OR_NULL(dentry))
936 		goto fail;
937 	drbd_debugfs_resources = dentry;
938 
939 	dentry = debugfs_create_dir("minors", drbd_debugfs_root);
940 	if (IS_ERR_OR_NULL(dentry))
941 		goto fail;
942 	drbd_debugfs_minors = dentry;
943 	return 0;
944 
945 fail:
946 	drbd_debugfs_cleanup();
947 	if (dentry)
948 		return PTR_ERR(dentry);
949 	else
950 		return -EINVAL;
951 }
952