xref: /openbmc/linux/drivers/md/md-cluster.c (revision 7eb8ff02)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2015, SUSE
4  */
5 
6 
7 #include <linux/module.h>
8 #include <linux/kthread.h>
9 #include <linux/dlm.h>
10 #include <linux/sched.h>
11 #include <linux/raid/md_p.h>
12 #include "md.h"
13 #include "md-bitmap.h"
14 #include "md-cluster.h"
15 
16 #define LVB_SIZE	64
17 #define NEW_DEV_TIMEOUT 5000
18 
19 struct dlm_lock_resource {
20 	dlm_lockspace_t *ls;
21 	struct dlm_lksb lksb;
22 	char *name; /* lock name. */
23 	uint32_t flags; /* flags to pass to dlm_lock() */
24 	wait_queue_head_t sync_locking; /* wait queue for synchronized locking */
25 	bool sync_locking_done;
26 	void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
27 	struct mddev *mddev; /* pointing back to mddev. */
28 	int mode;
29 };
30 
31 struct resync_info {
32 	__le64 lo;
33 	__le64 hi;
34 };
35 
36 /* md_cluster_info flags */
37 #define		MD_CLUSTER_WAITING_FOR_NEWDISK		1
38 #define		MD_CLUSTER_SUSPEND_READ_BALANCING	2
39 #define		MD_CLUSTER_BEGIN_JOIN_CLUSTER		3
40 
41 /* Lock the send communication. This is done through
42  * bit manipulation as opposed to a mutex in order to
43  * accommodate lock and hold. See next comment.
44  */
45 #define		MD_CLUSTER_SEND_LOCK			4
46 /* If cluster operations (such as adding a disk) must lock the
47  * communication channel, so as to perform extra operations
48  * (update metadata) and no other operation is allowed on the
49  * MD. Token needs to be locked and held until the operation
50  * completes witha md_update_sb(), which would eventually release
51  * the lock.
52  */
53 #define		MD_CLUSTER_SEND_LOCKED_ALREADY		5
54 /* We should receive message after node joined cluster and
55  * set up all the related infos such as bitmap and personality */
56 #define		MD_CLUSTER_ALREADY_IN_CLUSTER		6
57 #define		MD_CLUSTER_PENDING_RECV_EVENT		7
58 #define 	MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD		8
59 
60 struct md_cluster_info {
61 	struct mddev *mddev; /* the md device which md_cluster_info belongs to */
62 	/* dlm lock space and resources for clustered raid. */
63 	dlm_lockspace_t *lockspace;
64 	int slot_number;
65 	struct completion completion;
66 	struct mutex recv_mutex;
67 	struct dlm_lock_resource *bitmap_lockres;
68 	struct dlm_lock_resource **other_bitmap_lockres;
69 	struct dlm_lock_resource *resync_lockres;
70 	struct list_head suspend_list;
71 
72 	spinlock_t suspend_lock;
73 	/* record the region which write should be suspended */
74 	sector_t suspend_lo;
75 	sector_t suspend_hi;
76 	int suspend_from; /* the slot which broadcast suspend_lo/hi */
77 
78 	struct md_thread __rcu *recovery_thread;
79 	unsigned long recovery_map;
80 	/* communication loc resources */
81 	struct dlm_lock_resource *ack_lockres;
82 	struct dlm_lock_resource *message_lockres;
83 	struct dlm_lock_resource *token_lockres;
84 	struct dlm_lock_resource *no_new_dev_lockres;
85 	struct md_thread __rcu *recv_thread;
86 	struct completion newdisk_completion;
87 	wait_queue_head_t wait;
88 	unsigned long state;
89 	/* record the region in RESYNCING message */
90 	sector_t sync_low;
91 	sector_t sync_hi;
92 };
93 
94 enum msg_type {
95 	METADATA_UPDATED = 0,
96 	RESYNCING,
97 	NEWDISK,
98 	REMOVE,
99 	RE_ADD,
100 	BITMAP_NEEDS_SYNC,
101 	CHANGE_CAPACITY,
102 	BITMAP_RESIZE,
103 };
104 
105 struct cluster_msg {
106 	__le32 type;
107 	__le32 slot;
108 	/* TODO: Unionize this for smaller footprint */
109 	__le64 low;
110 	__le64 high;
111 	char uuid[16];
112 	__le32 raid_slot;
113 };
114 
sync_ast(void * arg)115 static void sync_ast(void *arg)
116 {
117 	struct dlm_lock_resource *res;
118 
119 	res = arg;
120 	res->sync_locking_done = true;
121 	wake_up(&res->sync_locking);
122 }
123 
dlm_lock_sync(struct dlm_lock_resource * res,int mode)124 static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
125 {
126 	int ret = 0;
127 
128 	ret = dlm_lock(res->ls, mode, &res->lksb,
129 			res->flags, res->name, strlen(res->name),
130 			0, sync_ast, res, res->bast);
131 	if (ret)
132 		return ret;
133 	wait_event(res->sync_locking, res->sync_locking_done);
134 	res->sync_locking_done = false;
135 	if (res->lksb.sb_status == 0)
136 		res->mode = mode;
137 	return res->lksb.sb_status;
138 }
139 
dlm_unlock_sync(struct dlm_lock_resource * res)140 static int dlm_unlock_sync(struct dlm_lock_resource *res)
141 {
142 	return dlm_lock_sync(res, DLM_LOCK_NL);
143 }
144 
145 /*
146  * An variation of dlm_lock_sync, which make lock request could
147  * be interrupted
148  */
dlm_lock_sync_interruptible(struct dlm_lock_resource * res,int mode,struct mddev * mddev)149 static int dlm_lock_sync_interruptible(struct dlm_lock_resource *res, int mode,
150 				       struct mddev *mddev)
151 {
152 	int ret = 0;
153 
154 	ret = dlm_lock(res->ls, mode, &res->lksb,
155 			res->flags, res->name, strlen(res->name),
156 			0, sync_ast, res, res->bast);
157 	if (ret)
158 		return ret;
159 
160 	wait_event(res->sync_locking, res->sync_locking_done
161 				      || kthread_should_stop()
162 				      || test_bit(MD_CLOSING, &mddev->flags));
163 	if (!res->sync_locking_done) {
164 		/*
165 		 * the convert queue contains the lock request when request is
166 		 * interrupted, and sync_ast could still be run, so need to
167 		 * cancel the request and reset completion
168 		 */
169 		ret = dlm_unlock(res->ls, res->lksb.sb_lkid, DLM_LKF_CANCEL,
170 			&res->lksb, res);
171 		res->sync_locking_done = false;
172 		if (unlikely(ret != 0))
173 			pr_info("failed to cancel previous lock request "
174 				 "%s return %d\n", res->name, ret);
175 		return -EPERM;
176 	} else
177 		res->sync_locking_done = false;
178 	if (res->lksb.sb_status == 0)
179 		res->mode = mode;
180 	return res->lksb.sb_status;
181 }
182 
lockres_init(struct mddev * mddev,char * name,void (* bastfn)(void * arg,int mode),int with_lvb)183 static struct dlm_lock_resource *lockres_init(struct mddev *mddev,
184 		char *name, void (*bastfn)(void *arg, int mode), int with_lvb)
185 {
186 	struct dlm_lock_resource *res = NULL;
187 	int ret, namelen;
188 	struct md_cluster_info *cinfo = mddev->cluster_info;
189 
190 	res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
191 	if (!res)
192 		return NULL;
193 	init_waitqueue_head(&res->sync_locking);
194 	res->sync_locking_done = false;
195 	res->ls = cinfo->lockspace;
196 	res->mddev = mddev;
197 	res->mode = DLM_LOCK_IV;
198 	namelen = strlen(name);
199 	res->name = kzalloc(namelen + 1, GFP_KERNEL);
200 	if (!res->name) {
201 		pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name);
202 		goto out_err;
203 	}
204 	strscpy(res->name, name, namelen + 1);
205 	if (with_lvb) {
206 		res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL);
207 		if (!res->lksb.sb_lvbptr) {
208 			pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name);
209 			goto out_err;
210 		}
211 		res->flags = DLM_LKF_VALBLK;
212 	}
213 
214 	if (bastfn)
215 		res->bast = bastfn;
216 
217 	res->flags |= DLM_LKF_EXPEDITE;
218 
219 	ret = dlm_lock_sync(res, DLM_LOCK_NL);
220 	if (ret) {
221 		pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name);
222 		goto out_err;
223 	}
224 	res->flags &= ~DLM_LKF_EXPEDITE;
225 	res->flags |= DLM_LKF_CONVERT;
226 
227 	return res;
228 out_err:
229 	kfree(res->lksb.sb_lvbptr);
230 	kfree(res->name);
231 	kfree(res);
232 	return NULL;
233 }
234 
lockres_free(struct dlm_lock_resource * res)235 static void lockres_free(struct dlm_lock_resource *res)
236 {
237 	int ret = 0;
238 
239 	if (!res)
240 		return;
241 
242 	/*
243 	 * use FORCEUNLOCK flag, so we can unlock even the lock is on the
244 	 * waiting or convert queue
245 	 */
246 	ret = dlm_unlock(res->ls, res->lksb.sb_lkid, DLM_LKF_FORCEUNLOCK,
247 		&res->lksb, res);
248 	if (unlikely(ret != 0))
249 		pr_err("failed to unlock %s return %d\n", res->name, ret);
250 	else
251 		wait_event(res->sync_locking, res->sync_locking_done);
252 
253 	kfree(res->name);
254 	kfree(res->lksb.sb_lvbptr);
255 	kfree(res);
256 }
257 
add_resync_info(struct dlm_lock_resource * lockres,sector_t lo,sector_t hi)258 static void add_resync_info(struct dlm_lock_resource *lockres,
259 			    sector_t lo, sector_t hi)
260 {
261 	struct resync_info *ri;
262 
263 	ri = (struct resync_info *)lockres->lksb.sb_lvbptr;
264 	ri->lo = cpu_to_le64(lo);
265 	ri->hi = cpu_to_le64(hi);
266 }
267 
read_resync_info(struct mddev * mddev,struct dlm_lock_resource * lockres)268 static int read_resync_info(struct mddev *mddev,
269 			    struct dlm_lock_resource *lockres)
270 {
271 	struct resync_info ri;
272 	struct md_cluster_info *cinfo = mddev->cluster_info;
273 	int ret = 0;
274 
275 	dlm_lock_sync(lockres, DLM_LOCK_CR);
276 	memcpy(&ri, lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
277 	if (le64_to_cpu(ri.hi) > 0) {
278 		cinfo->suspend_hi = le64_to_cpu(ri.hi);
279 		cinfo->suspend_lo = le64_to_cpu(ri.lo);
280 		ret = 1;
281 	}
282 	dlm_unlock_sync(lockres);
283 	return ret;
284 }
285 
recover_bitmaps(struct md_thread * thread)286 static void recover_bitmaps(struct md_thread *thread)
287 {
288 	struct mddev *mddev = thread->mddev;
289 	struct md_cluster_info *cinfo = mddev->cluster_info;
290 	struct dlm_lock_resource *bm_lockres;
291 	char str[64];
292 	int slot, ret;
293 	sector_t lo, hi;
294 
295 	while (cinfo->recovery_map) {
296 		slot = fls64((u64)cinfo->recovery_map) - 1;
297 
298 		snprintf(str, 64, "bitmap%04d", slot);
299 		bm_lockres = lockres_init(mddev, str, NULL, 1);
300 		if (!bm_lockres) {
301 			pr_err("md-cluster: Cannot initialize bitmaps\n");
302 			goto clear_bit;
303 		}
304 
305 		ret = dlm_lock_sync_interruptible(bm_lockres, DLM_LOCK_PW, mddev);
306 		if (ret) {
307 			pr_err("md-cluster: Could not DLM lock %s: %d\n",
308 					str, ret);
309 			goto clear_bit;
310 		}
311 		ret = md_bitmap_copy_from_slot(mddev, slot, &lo, &hi, true);
312 		if (ret) {
313 			pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
314 			goto clear_bit;
315 		}
316 
317 		/* Clear suspend_area associated with the bitmap */
318 		spin_lock_irq(&cinfo->suspend_lock);
319 		cinfo->suspend_hi = 0;
320 		cinfo->suspend_lo = 0;
321 		cinfo->suspend_from = -1;
322 		spin_unlock_irq(&cinfo->suspend_lock);
323 
324 		/* Kick off a reshape if needed */
325 		if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
326 		    test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
327 		    mddev->reshape_position != MaxSector)
328 			md_wakeup_thread(mddev->sync_thread);
329 
330 		if (hi > 0) {
331 			if (lo < mddev->recovery_cp)
332 				mddev->recovery_cp = lo;
333 			/* wake up thread to continue resync in case resync
334 			 * is not finished */
335 			if (mddev->recovery_cp != MaxSector) {
336 				/*
337 				 * clear the REMOTE flag since we will launch
338 				 * resync thread in current node.
339 				 */
340 				clear_bit(MD_RESYNCING_REMOTE,
341 					  &mddev->recovery);
342 				set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
343 				md_wakeup_thread(mddev->thread);
344 			}
345 		}
346 clear_bit:
347 		lockres_free(bm_lockres);
348 		clear_bit(slot, &cinfo->recovery_map);
349 	}
350 }
351 
recover_prep(void * arg)352 static void recover_prep(void *arg)
353 {
354 	struct mddev *mddev = arg;
355 	struct md_cluster_info *cinfo = mddev->cluster_info;
356 	set_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
357 }
358 
__recover_slot(struct mddev * mddev,int slot)359 static void __recover_slot(struct mddev *mddev, int slot)
360 {
361 	struct md_cluster_info *cinfo = mddev->cluster_info;
362 
363 	set_bit(slot, &cinfo->recovery_map);
364 	if (!cinfo->recovery_thread) {
365 		rcu_assign_pointer(cinfo->recovery_thread,
366 			md_register_thread(recover_bitmaps, mddev, "recover"));
367 		if (!cinfo->recovery_thread) {
368 			pr_warn("md-cluster: Could not create recovery thread\n");
369 			return;
370 		}
371 	}
372 	md_wakeup_thread(cinfo->recovery_thread);
373 }
374 
recover_slot(void * arg,struct dlm_slot * slot)375 static void recover_slot(void *arg, struct dlm_slot *slot)
376 {
377 	struct mddev *mddev = arg;
378 	struct md_cluster_info *cinfo = mddev->cluster_info;
379 
380 	pr_info("md-cluster: %s Node %d/%d down. My slot: %d. Initiating recovery.\n",
381 			mddev->bitmap_info.cluster_name,
382 			slot->nodeid, slot->slot,
383 			cinfo->slot_number);
384 	/* deduct one since dlm slot starts from one while the num of
385 	 * cluster-md begins with 0 */
386 	__recover_slot(mddev, slot->slot - 1);
387 }
388 
recover_done(void * arg,struct dlm_slot * slots,int num_slots,int our_slot,uint32_t generation)389 static void recover_done(void *arg, struct dlm_slot *slots,
390 		int num_slots, int our_slot,
391 		uint32_t generation)
392 {
393 	struct mddev *mddev = arg;
394 	struct md_cluster_info *cinfo = mddev->cluster_info;
395 
396 	cinfo->slot_number = our_slot;
397 	/* completion is only need to be complete when node join cluster,
398 	 * it doesn't need to run during another node's failure */
399 	if (test_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state)) {
400 		complete(&cinfo->completion);
401 		clear_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
402 	}
403 	clear_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
404 }
405 
406 /* the ops is called when node join the cluster, and do lock recovery
407  * if node failure occurs */
408 static const struct dlm_lockspace_ops md_ls_ops = {
409 	.recover_prep = recover_prep,
410 	.recover_slot = recover_slot,
411 	.recover_done = recover_done,
412 };
413 
414 /*
415  * The BAST function for the ack lock resource
416  * This function wakes up the receive thread in
417  * order to receive and process the message.
418  */
ack_bast(void * arg,int mode)419 static void ack_bast(void *arg, int mode)
420 {
421 	struct dlm_lock_resource *res = arg;
422 	struct md_cluster_info *cinfo = res->mddev->cluster_info;
423 
424 	if (mode == DLM_LOCK_EX) {
425 		if (test_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state))
426 			md_wakeup_thread(cinfo->recv_thread);
427 		else
428 			set_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state);
429 	}
430 }
431 
remove_suspend_info(struct mddev * mddev,int slot)432 static void remove_suspend_info(struct mddev *mddev, int slot)
433 {
434 	struct md_cluster_info *cinfo = mddev->cluster_info;
435 	mddev->pers->quiesce(mddev, 1);
436 	spin_lock_irq(&cinfo->suspend_lock);
437 	cinfo->suspend_hi = 0;
438 	cinfo->suspend_lo = 0;
439 	spin_unlock_irq(&cinfo->suspend_lock);
440 	mddev->pers->quiesce(mddev, 0);
441 }
442 
process_suspend_info(struct mddev * mddev,int slot,sector_t lo,sector_t hi)443 static void process_suspend_info(struct mddev *mddev,
444 		int slot, sector_t lo, sector_t hi)
445 {
446 	struct md_cluster_info *cinfo = mddev->cluster_info;
447 	struct mdp_superblock_1 *sb = NULL;
448 	struct md_rdev *rdev;
449 
450 	if (!hi) {
451 		/*
452 		 * clear the REMOTE flag since resync or recovery is finished
453 		 * in remote node.
454 		 */
455 		clear_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
456 		remove_suspend_info(mddev, slot);
457 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
458 		md_wakeup_thread(mddev->thread);
459 		return;
460 	}
461 
462 	rdev_for_each(rdev, mddev)
463 		if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
464 			sb = page_address(rdev->sb_page);
465 			break;
466 		}
467 
468 	/*
469 	 * The bitmaps are not same for different nodes
470 	 * if RESYNCING is happening in one node, then
471 	 * the node which received the RESYNCING message
472 	 * probably will perform resync with the region
473 	 * [lo, hi] again, so we could reduce resync time
474 	 * a lot if we can ensure that the bitmaps among
475 	 * different nodes are match up well.
476 	 *
477 	 * sync_low/hi is used to record the region which
478 	 * arrived in the previous RESYNCING message,
479 	 *
480 	 * Call md_bitmap_sync_with_cluster to clear NEEDED_MASK
481 	 * and set RESYNC_MASK since  resync thread is running
482 	 * in another node, so we don't need to do the resync
483 	 * again with the same section.
484 	 *
485 	 * Skip md_bitmap_sync_with_cluster in case reshape
486 	 * happening, because reshaping region is small and
487 	 * we don't want to trigger lots of WARN.
488 	 */
489 	if (sb && !(le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE))
490 		md_bitmap_sync_with_cluster(mddev, cinfo->sync_low,
491 					    cinfo->sync_hi, lo, hi);
492 	cinfo->sync_low = lo;
493 	cinfo->sync_hi = hi;
494 
495 	mddev->pers->quiesce(mddev, 1);
496 	spin_lock_irq(&cinfo->suspend_lock);
497 	cinfo->suspend_from = slot;
498 	cinfo->suspend_lo = lo;
499 	cinfo->suspend_hi = hi;
500 	spin_unlock_irq(&cinfo->suspend_lock);
501 	mddev->pers->quiesce(mddev, 0);
502 }
503 
process_add_new_disk(struct mddev * mddev,struct cluster_msg * cmsg)504 static void process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)
505 {
506 	char disk_uuid[64];
507 	struct md_cluster_info *cinfo = mddev->cluster_info;
508 	char event_name[] = "EVENT=ADD_DEVICE";
509 	char raid_slot[16];
510 	char *envp[] = {event_name, disk_uuid, raid_slot, NULL};
511 	int len;
512 
513 	len = snprintf(disk_uuid, 64, "DEVICE_UUID=");
514 	sprintf(disk_uuid + len, "%pU", cmsg->uuid);
515 	snprintf(raid_slot, 16, "RAID_DISK=%d", le32_to_cpu(cmsg->raid_slot));
516 	pr_info("%s:%d Sending kobject change with %s and %s\n", __func__, __LINE__, disk_uuid, raid_slot);
517 	init_completion(&cinfo->newdisk_completion);
518 	set_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
519 	kobject_uevent_env(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE, envp);
520 	wait_for_completion_timeout(&cinfo->newdisk_completion,
521 			NEW_DEV_TIMEOUT);
522 	clear_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
523 }
524 
525 
process_metadata_update(struct mddev * mddev,struct cluster_msg * msg)526 static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg)
527 {
528 	int got_lock = 0;
529 	struct md_thread *thread;
530 	struct md_cluster_info *cinfo = mddev->cluster_info;
531 	mddev->good_device_nr = le32_to_cpu(msg->raid_slot);
532 
533 	dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
534 
535 	/* daemaon thread must exist */
536 	thread = rcu_dereference_protected(mddev->thread, true);
537 	wait_event(thread->wqueue,
538 		   (got_lock = mddev_trylock(mddev)) ||
539 		    test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state));
540 	md_reload_sb(mddev, mddev->good_device_nr);
541 	if (got_lock)
542 		mddev_unlock(mddev);
543 }
544 
process_remove_disk(struct mddev * mddev,struct cluster_msg * msg)545 static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
546 {
547 	struct md_rdev *rdev;
548 
549 	rcu_read_lock();
550 	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
551 	if (rdev) {
552 		set_bit(ClusterRemove, &rdev->flags);
553 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
554 		md_wakeup_thread(mddev->thread);
555 	}
556 	else
557 		pr_warn("%s: %d Could not find disk(%d) to REMOVE\n",
558 			__func__, __LINE__, le32_to_cpu(msg->raid_slot));
559 	rcu_read_unlock();
560 }
561 
process_readd_disk(struct mddev * mddev,struct cluster_msg * msg)562 static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
563 {
564 	struct md_rdev *rdev;
565 
566 	rcu_read_lock();
567 	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
568 	if (rdev && test_bit(Faulty, &rdev->flags))
569 		clear_bit(Faulty, &rdev->flags);
570 	else
571 		pr_warn("%s: %d Could not find disk(%d) which is faulty",
572 			__func__, __LINE__, le32_to_cpu(msg->raid_slot));
573 	rcu_read_unlock();
574 }
575 
process_recvd_msg(struct mddev * mddev,struct cluster_msg * msg)576 static int process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
577 {
578 	int ret = 0;
579 
580 	if (WARN(mddev->cluster_info->slot_number - 1 == le32_to_cpu(msg->slot),
581 		"node %d received its own msg\n", le32_to_cpu(msg->slot)))
582 		return -1;
583 	switch (le32_to_cpu(msg->type)) {
584 	case METADATA_UPDATED:
585 		process_metadata_update(mddev, msg);
586 		break;
587 	case CHANGE_CAPACITY:
588 		set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
589 		break;
590 	case RESYNCING:
591 		set_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
592 		process_suspend_info(mddev, le32_to_cpu(msg->slot),
593 				     le64_to_cpu(msg->low),
594 				     le64_to_cpu(msg->high));
595 		break;
596 	case NEWDISK:
597 		process_add_new_disk(mddev, msg);
598 		break;
599 	case REMOVE:
600 		process_remove_disk(mddev, msg);
601 		break;
602 	case RE_ADD:
603 		process_readd_disk(mddev, msg);
604 		break;
605 	case BITMAP_NEEDS_SYNC:
606 		__recover_slot(mddev, le32_to_cpu(msg->slot));
607 		break;
608 	case BITMAP_RESIZE:
609 		if (le64_to_cpu(msg->high) != mddev->pers->size(mddev, 0, 0))
610 			ret = md_bitmap_resize(mddev->bitmap,
611 					    le64_to_cpu(msg->high), 0, 0);
612 		break;
613 	default:
614 		ret = -1;
615 		pr_warn("%s:%d Received unknown message from %d\n",
616 			__func__, __LINE__, msg->slot);
617 	}
618 	return ret;
619 }
620 
621 /*
622  * thread for receiving message
623  */
recv_daemon(struct md_thread * thread)624 static void recv_daemon(struct md_thread *thread)
625 {
626 	struct md_cluster_info *cinfo = thread->mddev->cluster_info;
627 	struct dlm_lock_resource *ack_lockres = cinfo->ack_lockres;
628 	struct dlm_lock_resource *message_lockres = cinfo->message_lockres;
629 	struct cluster_msg msg;
630 	int ret;
631 
632 	mutex_lock(&cinfo->recv_mutex);
633 	/*get CR on Message*/
634 	if (dlm_lock_sync(message_lockres, DLM_LOCK_CR)) {
635 		pr_err("md/raid1:failed to get CR on MESSAGE\n");
636 		mutex_unlock(&cinfo->recv_mutex);
637 		return;
638 	}
639 
640 	/* read lvb and wake up thread to process this message_lockres */
641 	memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
642 	ret = process_recvd_msg(thread->mddev, &msg);
643 	if (ret)
644 		goto out;
645 
646 	/*release CR on ack_lockres*/
647 	ret = dlm_unlock_sync(ack_lockres);
648 	if (unlikely(ret != 0))
649 		pr_info("unlock ack failed return %d\n", ret);
650 	/*up-convert to PR on message_lockres*/
651 	ret = dlm_lock_sync(message_lockres, DLM_LOCK_PR);
652 	if (unlikely(ret != 0))
653 		pr_info("lock PR on msg failed return %d\n", ret);
654 	/*get CR on ack_lockres again*/
655 	ret = dlm_lock_sync(ack_lockres, DLM_LOCK_CR);
656 	if (unlikely(ret != 0))
657 		pr_info("lock CR on ack failed return %d\n", ret);
658 out:
659 	/*release CR on message_lockres*/
660 	ret = dlm_unlock_sync(message_lockres);
661 	if (unlikely(ret != 0))
662 		pr_info("unlock msg failed return %d\n", ret);
663 	mutex_unlock(&cinfo->recv_mutex);
664 }
665 
666 /* lock_token()
667  * Takes the lock on the TOKEN lock resource so no other
668  * node can communicate while the operation is underway.
669  */
lock_token(struct md_cluster_info * cinfo)670 static int lock_token(struct md_cluster_info *cinfo)
671 {
672 	int error;
673 
674 	error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
675 	if (error) {
676 		pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
677 				__func__, __LINE__, error);
678 	} else {
679 		/* Lock the receive sequence */
680 		mutex_lock(&cinfo->recv_mutex);
681 	}
682 	return error;
683 }
684 
685 /* lock_comm()
686  * Sets the MD_CLUSTER_SEND_LOCK bit to lock the send channel.
687  */
lock_comm(struct md_cluster_info * cinfo,bool mddev_locked)688 static int lock_comm(struct md_cluster_info *cinfo, bool mddev_locked)
689 {
690 	int rv, set_bit = 0;
691 	struct mddev *mddev = cinfo->mddev;
692 
693 	/*
694 	 * If resync thread run after raid1d thread, then process_metadata_update
695 	 * could not continue if raid1d held reconfig_mutex (and raid1d is blocked
696 	 * since another node already got EX on Token and waiting the EX of Ack),
697 	 * so let resync wake up thread in case flag is set.
698 	 */
699 	if (mddev_locked && !test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
700 				      &cinfo->state)) {
701 		rv = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
702 					      &cinfo->state);
703 		WARN_ON_ONCE(rv);
704 		md_wakeup_thread(mddev->thread);
705 		set_bit = 1;
706 	}
707 
708 	wait_event(cinfo->wait,
709 		   !test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state));
710 	rv = lock_token(cinfo);
711 	if (set_bit)
712 		clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
713 	return rv;
714 }
715 
unlock_comm(struct md_cluster_info * cinfo)716 static void unlock_comm(struct md_cluster_info *cinfo)
717 {
718 	WARN_ON(cinfo->token_lockres->mode != DLM_LOCK_EX);
719 	mutex_unlock(&cinfo->recv_mutex);
720 	dlm_unlock_sync(cinfo->token_lockres);
721 	clear_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state);
722 	wake_up(&cinfo->wait);
723 }
724 
725 /* __sendmsg()
726  * This function performs the actual sending of the message. This function is
727  * usually called after performing the encompassing operation
728  * The function:
729  * 1. Grabs the message lockresource in EX mode
730  * 2. Copies the message to the message LVB
731  * 3. Downconverts message lockresource to CW
732  * 4. Upconverts ack lock resource from CR to EX. This forces the BAST on other nodes
733  *    and the other nodes read the message. The thread will wait here until all other
734  *    nodes have released ack lock resource.
735  * 5. Downconvert ack lockresource to CR
736  */
__sendmsg(struct md_cluster_info * cinfo,struct cluster_msg * cmsg)737 static int __sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
738 {
739 	int error;
740 	int slot = cinfo->slot_number - 1;
741 
742 	cmsg->slot = cpu_to_le32(slot);
743 	/*get EX on Message*/
744 	error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_EX);
745 	if (error) {
746 		pr_err("md-cluster: failed to get EX on MESSAGE (%d)\n", error);
747 		goto failed_message;
748 	}
749 
750 	memcpy(cinfo->message_lockres->lksb.sb_lvbptr, (void *)cmsg,
751 			sizeof(struct cluster_msg));
752 	/*down-convert EX to CW on Message*/
753 	error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_CW);
754 	if (error) {
755 		pr_err("md-cluster: failed to convert EX to CW on MESSAGE(%d)\n",
756 				error);
757 		goto failed_ack;
758 	}
759 
760 	/*up-convert CR to EX on Ack*/
761 	error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_EX);
762 	if (error) {
763 		pr_err("md-cluster: failed to convert CR to EX on ACK(%d)\n",
764 				error);
765 		goto failed_ack;
766 	}
767 
768 	/*down-convert EX to CR on Ack*/
769 	error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR);
770 	if (error) {
771 		pr_err("md-cluster: failed to convert EX to CR on ACK(%d)\n",
772 				error);
773 		goto failed_ack;
774 	}
775 
776 failed_ack:
777 	error = dlm_unlock_sync(cinfo->message_lockres);
778 	if (unlikely(error != 0)) {
779 		pr_err("md-cluster: failed convert to NL on MESSAGE(%d)\n",
780 			error);
781 		/* in case the message can't be released due to some reason */
782 		goto failed_ack;
783 	}
784 failed_message:
785 	return error;
786 }
787 
sendmsg(struct md_cluster_info * cinfo,struct cluster_msg * cmsg,bool mddev_locked)788 static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg,
789 		   bool mddev_locked)
790 {
791 	int ret;
792 
793 	ret = lock_comm(cinfo, mddev_locked);
794 	if (!ret) {
795 		ret = __sendmsg(cinfo, cmsg);
796 		unlock_comm(cinfo);
797 	}
798 	return ret;
799 }
800 
gather_all_resync_info(struct mddev * mddev,int total_slots)801 static int gather_all_resync_info(struct mddev *mddev, int total_slots)
802 {
803 	struct md_cluster_info *cinfo = mddev->cluster_info;
804 	int i, ret = 0;
805 	struct dlm_lock_resource *bm_lockres;
806 	char str[64];
807 	sector_t lo, hi;
808 
809 
810 	for (i = 0; i < total_slots; i++) {
811 		memset(str, '\0', 64);
812 		snprintf(str, 64, "bitmap%04d", i);
813 		bm_lockres = lockres_init(mddev, str, NULL, 1);
814 		if (!bm_lockres)
815 			return -ENOMEM;
816 		if (i == (cinfo->slot_number - 1)) {
817 			lockres_free(bm_lockres);
818 			continue;
819 		}
820 
821 		bm_lockres->flags |= DLM_LKF_NOQUEUE;
822 		ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
823 		if (ret == -EAGAIN) {
824 			if (read_resync_info(mddev, bm_lockres)) {
825 				pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
826 						__func__, __LINE__,
827 					(unsigned long long) cinfo->suspend_lo,
828 					(unsigned long long) cinfo->suspend_hi,
829 					i);
830 				cinfo->suspend_from = i;
831 			}
832 			ret = 0;
833 			lockres_free(bm_lockres);
834 			continue;
835 		}
836 		if (ret) {
837 			lockres_free(bm_lockres);
838 			goto out;
839 		}
840 
841 		/* Read the disk bitmap sb and check if it needs recovery */
842 		ret = md_bitmap_copy_from_slot(mddev, i, &lo, &hi, false);
843 		if (ret) {
844 			pr_warn("md-cluster: Could not gather bitmaps from slot %d", i);
845 			lockres_free(bm_lockres);
846 			continue;
847 		}
848 		if ((hi > 0) && (lo < mddev->recovery_cp)) {
849 			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
850 			mddev->recovery_cp = lo;
851 			md_check_recovery(mddev);
852 		}
853 
854 		lockres_free(bm_lockres);
855 	}
856 out:
857 	return ret;
858 }
859 
join(struct mddev * mddev,int nodes)860 static int join(struct mddev *mddev, int nodes)
861 {
862 	struct md_cluster_info *cinfo;
863 	int ret, ops_rv;
864 	char str[64];
865 
866 	cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
867 	if (!cinfo)
868 		return -ENOMEM;
869 
870 	INIT_LIST_HEAD(&cinfo->suspend_list);
871 	spin_lock_init(&cinfo->suspend_lock);
872 	init_completion(&cinfo->completion);
873 	set_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
874 	init_waitqueue_head(&cinfo->wait);
875 	mutex_init(&cinfo->recv_mutex);
876 
877 	mddev->cluster_info = cinfo;
878 	cinfo->mddev = mddev;
879 
880 	memset(str, 0, 64);
881 	sprintf(str, "%pU", mddev->uuid);
882 	ret = dlm_new_lockspace(str, mddev->bitmap_info.cluster_name,
883 				0, LVB_SIZE, &md_ls_ops, mddev,
884 				&ops_rv, &cinfo->lockspace);
885 	if (ret)
886 		goto err;
887 	wait_for_completion(&cinfo->completion);
888 	if (nodes < cinfo->slot_number) {
889 		pr_err("md-cluster: Slot allotted(%d) is greater than available slots(%d).",
890 			cinfo->slot_number, nodes);
891 		ret = -ERANGE;
892 		goto err;
893 	}
894 	/* Initiate the communication resources */
895 	ret = -ENOMEM;
896 	rcu_assign_pointer(cinfo->recv_thread,
897 			md_register_thread(recv_daemon, mddev, "cluster_recv"));
898 	if (!cinfo->recv_thread) {
899 		pr_err("md-cluster: cannot allocate memory for recv_thread!\n");
900 		goto err;
901 	}
902 	cinfo->message_lockres = lockres_init(mddev, "message", NULL, 1);
903 	if (!cinfo->message_lockres)
904 		goto err;
905 	cinfo->token_lockres = lockres_init(mddev, "token", NULL, 0);
906 	if (!cinfo->token_lockres)
907 		goto err;
908 	cinfo->no_new_dev_lockres = lockres_init(mddev, "no-new-dev", NULL, 0);
909 	if (!cinfo->no_new_dev_lockres)
910 		goto err;
911 
912 	ret = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
913 	if (ret) {
914 		ret = -EAGAIN;
915 		pr_err("md-cluster: can't join cluster to avoid lock issue\n");
916 		goto err;
917 	}
918 	cinfo->ack_lockres = lockres_init(mddev, "ack", ack_bast, 0);
919 	if (!cinfo->ack_lockres) {
920 		ret = -ENOMEM;
921 		goto err;
922 	}
923 	/* get sync CR lock on ACK. */
924 	if (dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR))
925 		pr_err("md-cluster: failed to get a sync CR lock on ACK!(%d)\n",
926 				ret);
927 	dlm_unlock_sync(cinfo->token_lockres);
928 	/* get sync CR lock on no-new-dev. */
929 	if (dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR))
930 		pr_err("md-cluster: failed to get a sync CR lock on no-new-dev!(%d)\n", ret);
931 
932 
933 	pr_info("md-cluster: Joined cluster %s slot %d\n", str, cinfo->slot_number);
934 	snprintf(str, 64, "bitmap%04d", cinfo->slot_number - 1);
935 	cinfo->bitmap_lockres = lockres_init(mddev, str, NULL, 1);
936 	if (!cinfo->bitmap_lockres) {
937 		ret = -ENOMEM;
938 		goto err;
939 	}
940 	if (dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW)) {
941 		pr_err("Failed to get bitmap lock\n");
942 		ret = -EINVAL;
943 		goto err;
944 	}
945 
946 	cinfo->resync_lockres = lockres_init(mddev, "resync", NULL, 0);
947 	if (!cinfo->resync_lockres) {
948 		ret = -ENOMEM;
949 		goto err;
950 	}
951 
952 	return 0;
953 err:
954 	set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
955 	md_unregister_thread(mddev, &cinfo->recovery_thread);
956 	md_unregister_thread(mddev, &cinfo->recv_thread);
957 	lockres_free(cinfo->message_lockres);
958 	lockres_free(cinfo->token_lockres);
959 	lockres_free(cinfo->ack_lockres);
960 	lockres_free(cinfo->no_new_dev_lockres);
961 	lockres_free(cinfo->resync_lockres);
962 	lockres_free(cinfo->bitmap_lockres);
963 	if (cinfo->lockspace)
964 		dlm_release_lockspace(cinfo->lockspace, 2);
965 	mddev->cluster_info = NULL;
966 	kfree(cinfo);
967 	return ret;
968 }
969 
load_bitmaps(struct mddev * mddev,int total_slots)970 static void load_bitmaps(struct mddev *mddev, int total_slots)
971 {
972 	struct md_cluster_info *cinfo = mddev->cluster_info;
973 
974 	/* load all the node's bitmap info for resync */
975 	if (gather_all_resync_info(mddev, total_slots))
976 		pr_err("md-cluster: failed to gather all resyn infos\n");
977 	set_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state);
978 	/* wake up recv thread in case something need to be handled */
979 	if (test_and_clear_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state))
980 		md_wakeup_thread(cinfo->recv_thread);
981 }
982 
resync_bitmap(struct mddev * mddev)983 static void resync_bitmap(struct mddev *mddev)
984 {
985 	struct md_cluster_info *cinfo = mddev->cluster_info;
986 	struct cluster_msg cmsg = {0};
987 	int err;
988 
989 	cmsg.type = cpu_to_le32(BITMAP_NEEDS_SYNC);
990 	err = sendmsg(cinfo, &cmsg, 1);
991 	if (err)
992 		pr_err("%s:%d: failed to send BITMAP_NEEDS_SYNC message (%d)\n",
993 			__func__, __LINE__, err);
994 }
995 
996 static void unlock_all_bitmaps(struct mddev *mddev);
leave(struct mddev * mddev)997 static int leave(struct mddev *mddev)
998 {
999 	struct md_cluster_info *cinfo = mddev->cluster_info;
1000 
1001 	if (!cinfo)
1002 		return 0;
1003 
1004 	/*
1005 	 * BITMAP_NEEDS_SYNC message should be sent when node
1006 	 * is leaving the cluster with dirty bitmap, also we
1007 	 * can only deliver it when dlm connection is available.
1008 	 *
1009 	 * Also, we should send BITMAP_NEEDS_SYNC message in
1010 	 * case reshaping is interrupted.
1011 	 */
1012 	if ((cinfo->slot_number > 0 && mddev->recovery_cp != MaxSector) ||
1013 	    (mddev->reshape_position != MaxSector &&
1014 	     test_bit(MD_CLOSING, &mddev->flags)))
1015 		resync_bitmap(mddev);
1016 
1017 	set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1018 	md_unregister_thread(mddev, &cinfo->recovery_thread);
1019 	md_unregister_thread(mddev, &cinfo->recv_thread);
1020 	lockres_free(cinfo->message_lockres);
1021 	lockres_free(cinfo->token_lockres);
1022 	lockres_free(cinfo->ack_lockres);
1023 	lockres_free(cinfo->no_new_dev_lockres);
1024 	lockres_free(cinfo->resync_lockres);
1025 	lockres_free(cinfo->bitmap_lockres);
1026 	unlock_all_bitmaps(mddev);
1027 	dlm_release_lockspace(cinfo->lockspace, 2);
1028 	kfree(cinfo);
1029 	return 0;
1030 }
1031 
1032 /* slot_number(): Returns the MD slot number to use
1033  * DLM starts the slot numbers from 1, wheras cluster-md
1034  * wants the number to be from zero, so we deduct one
1035  */
slot_number(struct mddev * mddev)1036 static int slot_number(struct mddev *mddev)
1037 {
1038 	struct md_cluster_info *cinfo = mddev->cluster_info;
1039 
1040 	return cinfo->slot_number - 1;
1041 }
1042 
1043 /*
1044  * Check if the communication is already locked, else lock the communication
1045  * channel.
1046  * If it is already locked, token is in EX mode, and hence lock_token()
1047  * should not be called.
1048  */
metadata_update_start(struct mddev * mddev)1049 static int metadata_update_start(struct mddev *mddev)
1050 {
1051 	struct md_cluster_info *cinfo = mddev->cluster_info;
1052 	int ret;
1053 
1054 	/*
1055 	 * metadata_update_start is always called with the protection of
1056 	 * reconfig_mutex, so set WAITING_FOR_TOKEN here.
1057 	 */
1058 	ret = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
1059 				    &cinfo->state);
1060 	WARN_ON_ONCE(ret);
1061 	md_wakeup_thread(mddev->thread);
1062 
1063 	wait_event(cinfo->wait,
1064 		   !test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state) ||
1065 		   test_and_clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state));
1066 
1067 	/* If token is already locked, return 0 */
1068 	if (cinfo->token_lockres->mode == DLM_LOCK_EX) {
1069 		clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1070 		return 0;
1071 	}
1072 
1073 	ret = lock_token(cinfo);
1074 	clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1075 	return ret;
1076 }
1077 
metadata_update_finish(struct mddev * mddev)1078 static int metadata_update_finish(struct mddev *mddev)
1079 {
1080 	struct md_cluster_info *cinfo = mddev->cluster_info;
1081 	struct cluster_msg cmsg;
1082 	struct md_rdev *rdev;
1083 	int ret = 0;
1084 	int raid_slot = -1;
1085 
1086 	memset(&cmsg, 0, sizeof(cmsg));
1087 	cmsg.type = cpu_to_le32(METADATA_UPDATED);
1088 	/* Pick up a good active device number to send.
1089 	 */
1090 	rdev_for_each(rdev, mddev)
1091 		if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
1092 			raid_slot = rdev->desc_nr;
1093 			break;
1094 		}
1095 	if (raid_slot >= 0) {
1096 		cmsg.raid_slot = cpu_to_le32(raid_slot);
1097 		ret = __sendmsg(cinfo, &cmsg);
1098 	} else
1099 		pr_warn("md-cluster: No good device id found to send\n");
1100 	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1101 	unlock_comm(cinfo);
1102 	return ret;
1103 }
1104 
metadata_update_cancel(struct mddev * mddev)1105 static void metadata_update_cancel(struct mddev *mddev)
1106 {
1107 	struct md_cluster_info *cinfo = mddev->cluster_info;
1108 	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1109 	unlock_comm(cinfo);
1110 }
1111 
update_bitmap_size(struct mddev * mddev,sector_t size)1112 static int update_bitmap_size(struct mddev *mddev, sector_t size)
1113 {
1114 	struct md_cluster_info *cinfo = mddev->cluster_info;
1115 	struct cluster_msg cmsg = {0};
1116 	int ret;
1117 
1118 	cmsg.type = cpu_to_le32(BITMAP_RESIZE);
1119 	cmsg.high = cpu_to_le64(size);
1120 	ret = sendmsg(cinfo, &cmsg, 0);
1121 	if (ret)
1122 		pr_err("%s:%d: failed to send BITMAP_RESIZE message (%d)\n",
1123 			__func__, __LINE__, ret);
1124 	return ret;
1125 }
1126 
resize_bitmaps(struct mddev * mddev,sector_t newsize,sector_t oldsize)1127 static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsize)
1128 {
1129 	struct bitmap_counts *counts;
1130 	char str[64];
1131 	struct dlm_lock_resource *bm_lockres;
1132 	struct bitmap *bitmap = mddev->bitmap;
1133 	unsigned long my_pages = bitmap->counts.pages;
1134 	int i, rv;
1135 
1136 	/*
1137 	 * We need to ensure all the nodes can grow to a larger
1138 	 * bitmap size before make the reshaping.
1139 	 */
1140 	rv = update_bitmap_size(mddev, newsize);
1141 	if (rv)
1142 		return rv;
1143 
1144 	for (i = 0; i < mddev->bitmap_info.nodes; i++) {
1145 		if (i == md_cluster_ops->slot_number(mddev))
1146 			continue;
1147 
1148 		bitmap = get_bitmap_from_slot(mddev, i);
1149 		if (IS_ERR(bitmap)) {
1150 			pr_err("can't get bitmap from slot %d\n", i);
1151 			bitmap = NULL;
1152 			goto out;
1153 		}
1154 		counts = &bitmap->counts;
1155 
1156 		/*
1157 		 * If we can hold the bitmap lock of one node then
1158 		 * the slot is not occupied, update the pages.
1159 		 */
1160 		snprintf(str, 64, "bitmap%04d", i);
1161 		bm_lockres = lockres_init(mddev, str, NULL, 1);
1162 		if (!bm_lockres) {
1163 			pr_err("Cannot initialize %s lock\n", str);
1164 			goto out;
1165 		}
1166 		bm_lockres->flags |= DLM_LKF_NOQUEUE;
1167 		rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
1168 		if (!rv)
1169 			counts->pages = my_pages;
1170 		lockres_free(bm_lockres);
1171 
1172 		if (my_pages != counts->pages)
1173 			/*
1174 			 * Let's revert the bitmap size if one node
1175 			 * can't resize bitmap
1176 			 */
1177 			goto out;
1178 		md_bitmap_free(bitmap);
1179 	}
1180 
1181 	return 0;
1182 out:
1183 	md_bitmap_free(bitmap);
1184 	update_bitmap_size(mddev, oldsize);
1185 	return -1;
1186 }
1187 
1188 /*
1189  * return 0 if all the bitmaps have the same sync_size
1190  */
cluster_check_sync_size(struct mddev * mddev)1191 static int cluster_check_sync_size(struct mddev *mddev)
1192 {
1193 	int i, rv;
1194 	bitmap_super_t *sb;
1195 	unsigned long my_sync_size, sync_size = 0;
1196 	int node_num = mddev->bitmap_info.nodes;
1197 	int current_slot = md_cluster_ops->slot_number(mddev);
1198 	struct bitmap *bitmap = mddev->bitmap;
1199 	char str[64];
1200 	struct dlm_lock_resource *bm_lockres;
1201 
1202 	sb = kmap_atomic(bitmap->storage.sb_page);
1203 	my_sync_size = sb->sync_size;
1204 	kunmap_atomic(sb);
1205 
1206 	for (i = 0; i < node_num; i++) {
1207 		if (i == current_slot)
1208 			continue;
1209 
1210 		bitmap = get_bitmap_from_slot(mddev, i);
1211 		if (IS_ERR(bitmap)) {
1212 			pr_err("can't get bitmap from slot %d\n", i);
1213 			return -1;
1214 		}
1215 
1216 		/*
1217 		 * If we can hold the bitmap lock of one node then
1218 		 * the slot is not occupied, update the sb.
1219 		 */
1220 		snprintf(str, 64, "bitmap%04d", i);
1221 		bm_lockres = lockres_init(mddev, str, NULL, 1);
1222 		if (!bm_lockres) {
1223 			pr_err("md-cluster: Cannot initialize %s\n", str);
1224 			md_bitmap_free(bitmap);
1225 			return -1;
1226 		}
1227 		bm_lockres->flags |= DLM_LKF_NOQUEUE;
1228 		rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
1229 		if (!rv)
1230 			md_bitmap_update_sb(bitmap);
1231 		lockres_free(bm_lockres);
1232 
1233 		sb = kmap_atomic(bitmap->storage.sb_page);
1234 		if (sync_size == 0)
1235 			sync_size = sb->sync_size;
1236 		else if (sync_size != sb->sync_size) {
1237 			kunmap_atomic(sb);
1238 			md_bitmap_free(bitmap);
1239 			return -1;
1240 		}
1241 		kunmap_atomic(sb);
1242 		md_bitmap_free(bitmap);
1243 	}
1244 
1245 	return (my_sync_size == sync_size) ? 0 : -1;
1246 }
1247 
1248 /*
1249  * Update the size for cluster raid is a little more complex, we perform it
1250  * by the steps:
1251  * 1. hold token lock and update superblock in initiator node.
1252  * 2. send METADATA_UPDATED msg to other nodes.
1253  * 3. The initiator node continues to check each bitmap's sync_size, if all
1254  *    bitmaps have the same value of sync_size, then we can set capacity and
1255  *    let other nodes to perform it. If one node can't update sync_size
1256  *    accordingly, we need to revert to previous value.
1257  */
update_size(struct mddev * mddev,sector_t old_dev_sectors)1258 static void update_size(struct mddev *mddev, sector_t old_dev_sectors)
1259 {
1260 	struct md_cluster_info *cinfo = mddev->cluster_info;
1261 	struct cluster_msg cmsg;
1262 	struct md_rdev *rdev;
1263 	int ret = 0;
1264 	int raid_slot = -1;
1265 
1266 	md_update_sb(mddev, 1);
1267 	if (lock_comm(cinfo, 1)) {
1268 		pr_err("%s: lock_comm failed\n", __func__);
1269 		return;
1270 	}
1271 
1272 	memset(&cmsg, 0, sizeof(cmsg));
1273 	cmsg.type = cpu_to_le32(METADATA_UPDATED);
1274 	rdev_for_each(rdev, mddev)
1275 		if (rdev->raid_disk >= 0 && !test_bit(Faulty, &rdev->flags)) {
1276 			raid_slot = rdev->desc_nr;
1277 			break;
1278 		}
1279 	if (raid_slot >= 0) {
1280 		cmsg.raid_slot = cpu_to_le32(raid_slot);
1281 		/*
1282 		 * We can only change capiticy after all the nodes can do it,
1283 		 * so need to wait after other nodes already received the msg
1284 		 * and handled the change
1285 		 */
1286 		ret = __sendmsg(cinfo, &cmsg);
1287 		if (ret) {
1288 			pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
1289 			       __func__, __LINE__);
1290 			unlock_comm(cinfo);
1291 			return;
1292 		}
1293 	} else {
1294 		pr_err("md-cluster: No good device id found to send\n");
1295 		unlock_comm(cinfo);
1296 		return;
1297 	}
1298 
1299 	/*
1300 	 * check the sync_size from other node's bitmap, if sync_size
1301 	 * have already updated in other nodes as expected, send an
1302 	 * empty metadata msg to permit the change of capacity
1303 	 */
1304 	if (cluster_check_sync_size(mddev) == 0) {
1305 		memset(&cmsg, 0, sizeof(cmsg));
1306 		cmsg.type = cpu_to_le32(CHANGE_CAPACITY);
1307 		ret = __sendmsg(cinfo, &cmsg);
1308 		if (ret)
1309 			pr_err("%s:%d: failed to send CHANGE_CAPACITY msg\n",
1310 			       __func__, __LINE__);
1311 		set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
1312 	} else {
1313 		/* revert to previous sectors */
1314 		ret = mddev->pers->resize(mddev, old_dev_sectors);
1315 		ret = __sendmsg(cinfo, &cmsg);
1316 		if (ret)
1317 			pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
1318 			       __func__, __LINE__);
1319 	}
1320 	unlock_comm(cinfo);
1321 }
1322 
resync_start(struct mddev * mddev)1323 static int resync_start(struct mddev *mddev)
1324 {
1325 	struct md_cluster_info *cinfo = mddev->cluster_info;
1326 	return dlm_lock_sync_interruptible(cinfo->resync_lockres, DLM_LOCK_EX, mddev);
1327 }
1328 
resync_info_get(struct mddev * mddev,sector_t * lo,sector_t * hi)1329 static void resync_info_get(struct mddev *mddev, sector_t *lo, sector_t *hi)
1330 {
1331 	struct md_cluster_info *cinfo = mddev->cluster_info;
1332 
1333 	spin_lock_irq(&cinfo->suspend_lock);
1334 	*lo = cinfo->suspend_lo;
1335 	*hi = cinfo->suspend_hi;
1336 	spin_unlock_irq(&cinfo->suspend_lock);
1337 }
1338 
resync_info_update(struct mddev * mddev,sector_t lo,sector_t hi)1339 static int resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi)
1340 {
1341 	struct md_cluster_info *cinfo = mddev->cluster_info;
1342 	struct resync_info ri;
1343 	struct cluster_msg cmsg = {0};
1344 
1345 	/* do not send zero again, if we have sent before */
1346 	if (hi == 0) {
1347 		memcpy(&ri, cinfo->bitmap_lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
1348 		if (le64_to_cpu(ri.hi) == 0)
1349 			return 0;
1350 	}
1351 
1352 	add_resync_info(cinfo->bitmap_lockres, lo, hi);
1353 	/* Re-acquire the lock to refresh LVB */
1354 	dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW);
1355 	cmsg.type = cpu_to_le32(RESYNCING);
1356 	cmsg.low = cpu_to_le64(lo);
1357 	cmsg.high = cpu_to_le64(hi);
1358 
1359 	/*
1360 	 * mddev_lock is held if resync_info_update is called from
1361 	 * resync_finish (md_reap_sync_thread -> resync_finish)
1362 	 */
1363 	if (lo == 0 && hi == 0)
1364 		return sendmsg(cinfo, &cmsg, 1);
1365 	else
1366 		return sendmsg(cinfo, &cmsg, 0);
1367 }
1368 
resync_finish(struct mddev * mddev)1369 static int resync_finish(struct mddev *mddev)
1370 {
1371 	struct md_cluster_info *cinfo = mddev->cluster_info;
1372 	int ret = 0;
1373 
1374 	clear_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
1375 
1376 	/*
1377 	 * If resync thread is interrupted so we can't say resync is finished,
1378 	 * another node will launch resync thread to continue.
1379 	 */
1380 	if (!test_bit(MD_CLOSING, &mddev->flags))
1381 		ret = resync_info_update(mddev, 0, 0);
1382 	dlm_unlock_sync(cinfo->resync_lockres);
1383 	return ret;
1384 }
1385 
area_resyncing(struct mddev * mddev,int direction,sector_t lo,sector_t hi)1386 static int area_resyncing(struct mddev *mddev, int direction,
1387 		sector_t lo, sector_t hi)
1388 {
1389 	struct md_cluster_info *cinfo = mddev->cluster_info;
1390 	int ret = 0;
1391 
1392 	if ((direction == READ) &&
1393 		test_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state))
1394 		return 1;
1395 
1396 	spin_lock_irq(&cinfo->suspend_lock);
1397 	if (hi > cinfo->suspend_lo && lo < cinfo->suspend_hi)
1398 		ret = 1;
1399 	spin_unlock_irq(&cinfo->suspend_lock);
1400 	return ret;
1401 }
1402 
1403 /* add_new_disk() - initiates a disk add
1404  * However, if this fails before writing md_update_sb(),
1405  * add_new_disk_cancel() must be called to release token lock
1406  */
add_new_disk(struct mddev * mddev,struct md_rdev * rdev)1407 static int add_new_disk(struct mddev *mddev, struct md_rdev *rdev)
1408 {
1409 	struct md_cluster_info *cinfo = mddev->cluster_info;
1410 	struct cluster_msg cmsg;
1411 	int ret = 0;
1412 	struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1413 	char *uuid = sb->device_uuid;
1414 
1415 	memset(&cmsg, 0, sizeof(cmsg));
1416 	cmsg.type = cpu_to_le32(NEWDISK);
1417 	memcpy(cmsg.uuid, uuid, 16);
1418 	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1419 	if (lock_comm(cinfo, 1))
1420 		return -EAGAIN;
1421 	ret = __sendmsg(cinfo, &cmsg);
1422 	if (ret) {
1423 		unlock_comm(cinfo);
1424 		return ret;
1425 	}
1426 	cinfo->no_new_dev_lockres->flags |= DLM_LKF_NOQUEUE;
1427 	ret = dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_EX);
1428 	cinfo->no_new_dev_lockres->flags &= ~DLM_LKF_NOQUEUE;
1429 	/* Some node does not "see" the device */
1430 	if (ret == -EAGAIN)
1431 		ret = -ENOENT;
1432 	if (ret)
1433 		unlock_comm(cinfo);
1434 	else {
1435 		dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
1436 		/* Since MD_CHANGE_DEVS will be set in add_bound_rdev which
1437 		 * will run soon after add_new_disk, the below path will be
1438 		 * invoked:
1439 		 *   md_wakeup_thread(mddev->thread)
1440 		 *	-> conf->thread (raid1d)
1441 		 *	-> md_check_recovery -> md_update_sb
1442 		 *	-> metadata_update_start/finish
1443 		 * MD_CLUSTER_SEND_LOCKED_ALREADY will be cleared eventually.
1444 		 *
1445 		 * For other failure cases, metadata_update_cancel and
1446 		 * add_new_disk_cancel also clear below bit as well.
1447 		 * */
1448 		set_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1449 		wake_up(&cinfo->wait);
1450 	}
1451 	return ret;
1452 }
1453 
add_new_disk_cancel(struct mddev * mddev)1454 static void add_new_disk_cancel(struct mddev *mddev)
1455 {
1456 	struct md_cluster_info *cinfo = mddev->cluster_info;
1457 	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1458 	unlock_comm(cinfo);
1459 }
1460 
new_disk_ack(struct mddev * mddev,bool ack)1461 static int new_disk_ack(struct mddev *mddev, bool ack)
1462 {
1463 	struct md_cluster_info *cinfo = mddev->cluster_info;
1464 
1465 	if (!test_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state)) {
1466 		pr_warn("md-cluster(%s): Spurious cluster confirmation\n", mdname(mddev));
1467 		return -EINVAL;
1468 	}
1469 
1470 	if (ack)
1471 		dlm_unlock_sync(cinfo->no_new_dev_lockres);
1472 	complete(&cinfo->newdisk_completion);
1473 	return 0;
1474 }
1475 
remove_disk(struct mddev * mddev,struct md_rdev * rdev)1476 static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1477 {
1478 	struct cluster_msg cmsg = {0};
1479 	struct md_cluster_info *cinfo = mddev->cluster_info;
1480 	cmsg.type = cpu_to_le32(REMOVE);
1481 	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1482 	return sendmsg(cinfo, &cmsg, 1);
1483 }
1484 
lock_all_bitmaps(struct mddev * mddev)1485 static int lock_all_bitmaps(struct mddev *mddev)
1486 {
1487 	int slot, my_slot, ret, held = 1, i = 0;
1488 	char str[64];
1489 	struct md_cluster_info *cinfo = mddev->cluster_info;
1490 
1491 	cinfo->other_bitmap_lockres =
1492 		kcalloc(mddev->bitmap_info.nodes - 1,
1493 			sizeof(struct dlm_lock_resource *), GFP_KERNEL);
1494 	if (!cinfo->other_bitmap_lockres) {
1495 		pr_err("md: can't alloc mem for other bitmap locks\n");
1496 		return 0;
1497 	}
1498 
1499 	my_slot = slot_number(mddev);
1500 	for (slot = 0; slot < mddev->bitmap_info.nodes; slot++) {
1501 		if (slot == my_slot)
1502 			continue;
1503 
1504 		memset(str, '\0', 64);
1505 		snprintf(str, 64, "bitmap%04d", slot);
1506 		cinfo->other_bitmap_lockres[i] = lockres_init(mddev, str, NULL, 1);
1507 		if (!cinfo->other_bitmap_lockres[i])
1508 			return -ENOMEM;
1509 
1510 		cinfo->other_bitmap_lockres[i]->flags |= DLM_LKF_NOQUEUE;
1511 		ret = dlm_lock_sync(cinfo->other_bitmap_lockres[i], DLM_LOCK_PW);
1512 		if (ret)
1513 			held = -1;
1514 		i++;
1515 	}
1516 
1517 	return held;
1518 }
1519 
unlock_all_bitmaps(struct mddev * mddev)1520 static void unlock_all_bitmaps(struct mddev *mddev)
1521 {
1522 	struct md_cluster_info *cinfo = mddev->cluster_info;
1523 	int i;
1524 
1525 	/* release other node's bitmap lock if they are existed */
1526 	if (cinfo->other_bitmap_lockres) {
1527 		for (i = 0; i < mddev->bitmap_info.nodes - 1; i++) {
1528 			if (cinfo->other_bitmap_lockres[i]) {
1529 				lockres_free(cinfo->other_bitmap_lockres[i]);
1530 			}
1531 		}
1532 		kfree(cinfo->other_bitmap_lockres);
1533 		cinfo->other_bitmap_lockres = NULL;
1534 	}
1535 }
1536 
gather_bitmaps(struct md_rdev * rdev)1537 static int gather_bitmaps(struct md_rdev *rdev)
1538 {
1539 	int sn, err;
1540 	sector_t lo, hi;
1541 	struct cluster_msg cmsg = {0};
1542 	struct mddev *mddev = rdev->mddev;
1543 	struct md_cluster_info *cinfo = mddev->cluster_info;
1544 
1545 	cmsg.type = cpu_to_le32(RE_ADD);
1546 	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1547 	err = sendmsg(cinfo, &cmsg, 1);
1548 	if (err)
1549 		goto out;
1550 
1551 	for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
1552 		if (sn == (cinfo->slot_number - 1))
1553 			continue;
1554 		err = md_bitmap_copy_from_slot(mddev, sn, &lo, &hi, false);
1555 		if (err) {
1556 			pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
1557 			goto out;
1558 		}
1559 		if ((hi > 0) && (lo < mddev->recovery_cp))
1560 			mddev->recovery_cp = lo;
1561 	}
1562 out:
1563 	return err;
1564 }
1565 
1566 static struct md_cluster_operations cluster_ops = {
1567 	.join   = join,
1568 	.leave  = leave,
1569 	.slot_number = slot_number,
1570 	.resync_start = resync_start,
1571 	.resync_finish = resync_finish,
1572 	.resync_info_update = resync_info_update,
1573 	.resync_info_get = resync_info_get,
1574 	.metadata_update_start = metadata_update_start,
1575 	.metadata_update_finish = metadata_update_finish,
1576 	.metadata_update_cancel = metadata_update_cancel,
1577 	.area_resyncing = area_resyncing,
1578 	.add_new_disk = add_new_disk,
1579 	.add_new_disk_cancel = add_new_disk_cancel,
1580 	.new_disk_ack = new_disk_ack,
1581 	.remove_disk = remove_disk,
1582 	.load_bitmaps = load_bitmaps,
1583 	.gather_bitmaps = gather_bitmaps,
1584 	.resize_bitmaps = resize_bitmaps,
1585 	.lock_all_bitmaps = lock_all_bitmaps,
1586 	.unlock_all_bitmaps = unlock_all_bitmaps,
1587 	.update_size = update_size,
1588 };
1589 
cluster_init(void)1590 static int __init cluster_init(void)
1591 {
1592 	pr_warn("md-cluster: support raid1 and raid10 (limited support)\n");
1593 	pr_info("Registering Cluster MD functions\n");
1594 	register_md_cluster_operations(&cluster_ops, THIS_MODULE);
1595 	return 0;
1596 }
1597 
cluster_exit(void)1598 static void cluster_exit(void)
1599 {
1600 	unregister_md_cluster_operations();
1601 }
1602 
1603 module_init(cluster_init);
1604 module_exit(cluster_exit);
1605 MODULE_AUTHOR("SUSE");
1606 MODULE_LICENSE("GPL");
1607 MODULE_DESCRIPTION("Clustering support for MD");
1608