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	#define WAIT_DLM_LOCK_TIMEOUT (30 * HZ)
19
20	struct dlm_lock_resource {
21	dlm_lockspace_t *ls;
22	struct dlm_lksb lksb;
23	char *name; /* lock name. */
24	uint32_t flags; /* flags to pass to dlm_lock() */
25	wait_queue_head_t sync_locking; /* wait queue for synchronized locking */
26	bool sync_locking_done;
27	void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
28	struct mddev *mddev; /* pointing back to mddev. */
29	int mode;
30	};
31
32	struct resync_info {
33	__le64 lo;
34	__le64 hi;
35	};
36
37	/* md_cluster_info flags */
38	#define MD_CLUSTER_WAITING_FOR_NEWDISK 1
39	#define MD_CLUSTER_SUSPEND_READ_BALANCING 2
40	#define MD_CLUSTER_BEGIN_JOIN_CLUSTER 3
41
42	/* Lock the send communication. This is done through
43	* bit manipulation as opposed to a mutex in order to
44	* accommodate lock and hold. See next comment.
45	*/
46	#define MD_CLUSTER_SEND_LOCK 4
47	/* If cluster operations (such as adding a disk) must lock the
48	* communication channel, so as to perform extra operations
49	* (update metadata) and no other operation is allowed on the
50	* MD. Token needs to be locked and held until the operation
51	* completes witha md_update_sb(), which would eventually release
52	* the lock.
53	*/
54	#define MD_CLUSTER_SEND_LOCKED_ALREADY 5
55	/* We should receive message after node joined cluster and
56	* set up all the related infos such as bitmap and personality */
57	#define MD_CLUSTER_ALREADY_IN_CLUSTER 6
58	#define MD_CLUSTER_PENDING_RECV_EVENT 7
59	#define MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD 8
60	#define MD_CLUSTER_WAITING_FOR_SYNC 9
61
62	struct md_cluster_info {
63	struct mddev *mddev; /* the md device which md_cluster_info belongs to */
64	/* dlm lock space and resources for clustered raid. */
65	dlm_lockspace_t *lockspace;
66	int slot_number;
67	struct completion completion;
68	struct mutex recv_mutex;
69	struct dlm_lock_resource *bitmap_lockres;
70	struct dlm_lock_resource **other_bitmap_lockres;
71	struct dlm_lock_resource *resync_lockres;
72	struct list_head suspend_list;
73
74	spinlock_t suspend_lock;
75	/* record the region which write should be suspended */
76	sector_t suspend_lo;
77	sector_t suspend_hi;
78	int suspend_from; /* the slot which broadcast suspend_lo/hi */
79
80	struct md_thread __rcu *recovery_thread;
81	unsigned long recovery_map;
82	/* communication loc resources */
83	struct dlm_lock_resource *ack_lockres;
84	struct dlm_lock_resource *message_lockres;
85	struct dlm_lock_resource *token_lockres;
86	struct dlm_lock_resource *no_new_dev_lockres;
87	struct md_thread __rcu *recv_thread;
88	struct completion newdisk_completion;
89	wait_queue_head_t wait;
90	unsigned long state;
91	/* record the region in RESYNCING message */
92	sector_t sync_low;
93	sector_t sync_hi;
94	};
95
96	/* For compatibility, add the new msg_type at the end. */
97	enum msg_type {
98	METADATA_UPDATED = 0,
99	RESYNCING,
100	NEWDISK,
101	REMOVE,
102	RE_ADD,
103	BITMAP_NEEDS_SYNC,
104	CHANGE_CAPACITY,
105	BITMAP_RESIZE,
106	RESYNCING_START,
107	};
108
109	struct cluster_msg {
110	__le32 type;
111	__le32 slot;
112	/* TODO: Unionize this for smaller footprint */
113	__le64 low;
114	__le64 high;
115	char uuid[16];
116	__le32 raid_slot;
117	};
118
119	static void sync_ast(void *arg)
120	{
121	struct dlm_lock_resource *res;
122
123	res = arg;
124	res->sync_locking_done = true;
125	wake_up(&res->sync_locking);
126	}
127
128	static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
129	{
130	int ret = 0;
131
132	ret = dlm_lock(lockspace: res->ls, mode, lksb: &res->lksb,
133	flags: res->flags, name: res->name, strlen(res->name),
134	parent_lkid: 0, lockast: sync_ast, astarg: res, bast: res->bast);
135	if (ret)
136	return ret;
137	ret = wait_event_timeout(res->sync_locking, res->sync_locking_done,
138	WAIT_DLM_LOCK_TIMEOUT);
139	res->sync_locking_done = false;
140	if (!ret) {
141	pr_err("locking DLM '%s' timeout!\n", res->name);
142	return -EBUSY;
143	}
144	if (res->lksb.sb_status == 0)
145	res->mode = mode;
146	return res->lksb.sb_status;
147	}
148
149	static int dlm_unlock_sync(struct dlm_lock_resource *res)
150	{
151	return dlm_lock_sync(res, DLM_LOCK_NL);
152	}
153
154	/*
155	* An variation of dlm_lock_sync, which make lock request could
156	* be interrupted
157	*/
158	static int dlm_lock_sync_interruptible(struct dlm_lock_resource *res, int mode,
159	struct mddev *mddev)
160	{
161	int ret = 0;
162
163	ret = dlm_lock(lockspace: res->ls, mode, lksb: &res->lksb,
164	flags: res->flags, name: res->name, strlen(res->name),
165	parent_lkid: 0, lockast: sync_ast, astarg: res, bast: res->bast);
166	if (ret)
167	return ret;
168
169	wait_event(res->sync_locking, res->sync_locking_done
170	|| kthread_should_stop()
171	|| test_bit(MD_CLOSING, &mddev->flags));
172	if (!res->sync_locking_done) {
173	/*
174	* the convert queue contains the lock request when request is
175	* interrupted, and sync_ast could still be run, so need to
176	* cancel the request and reset completion
177	*/
178	ret = dlm_unlock(lockspace: res->ls, lkid: res->lksb.sb_lkid, DLM_LKF_CANCEL,
179	lksb: &res->lksb, astarg: res);
180	res->sync_locking_done = false;
181	if (unlikely(ret != 0))
182	pr_info("failed to cancel previous lock request "
183	"%s return %d\n", res->name, ret);
184	return -EPERM;
185	} else
186	res->sync_locking_done = false;
187	if (res->lksb.sb_status == 0)
188	res->mode = mode;
189	return res->lksb.sb_status;
190	}
191
192	static struct dlm_lock_resource *lockres_init(struct mddev *mddev,
193	char *name, void (*bastfn)(void *arg, int mode), int with_lvb)
194	{
195	struct dlm_lock_resource *res = NULL;
196	int ret, namelen;
197	struct md_cluster_info *cinfo = mddev->cluster_info;
198
199	res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
200	if (!res)
201	return NULL;
202	init_waitqueue_head(&res->sync_locking);
203	res->sync_locking_done = false;
204	res->ls = cinfo->lockspace;
205	res->mddev = mddev;
206	res->mode = DLM_LOCK_IV;
207	namelen = strlen(name);
208	res->name = kzalloc(namelen + 1, GFP_KERNEL);
209	if (!res->name) {
210	pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name);
211	goto out_err;
212	}
213	strscpy(res->name, name, namelen + 1);
214	if (with_lvb) {
215	res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL);
216	if (!res->lksb.sb_lvbptr) {
217	pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name);
218	goto out_err;
219	}
220	res->flags = DLM_LKF_VALBLK;
221	}
222
223	if (bastfn)
224	res->bast = bastfn;
225
226	res->flags |= DLM_LKF_EXPEDITE;
227
228	ret = dlm_lock_sync(res, DLM_LOCK_NL);
229	if (ret) {
230	pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name);
231	goto out_err;
232	}
233	res->flags &= ~DLM_LKF_EXPEDITE;
234	res->flags |= DLM_LKF_CONVERT;
235
236	return res;
237	out_err:
238	kfree(objp: res->lksb.sb_lvbptr);
239	kfree(objp: res->name);
240	kfree(objp: res);
241	return NULL;
242	}
243
244	static void lockres_free(struct dlm_lock_resource *res)
245	{
246	int ret = 0;
247
248	if (!res)
249	return;
250
251	/*
252	* use FORCEUNLOCK flag, so we can unlock even the lock is on the
253	* waiting or convert queue
254	*/
255	ret = dlm_unlock(lockspace: res->ls, lkid: res->lksb.sb_lkid, DLM_LKF_FORCEUNLOCK,
256	lksb: &res->lksb, astarg: res);
257	if (unlikely(ret != 0))
258	pr_err("failed to unlock %s return %d\n", res->name, ret);
259	else
260	wait_event(res->sync_locking, res->sync_locking_done);
261
262	kfree(objp: res->name);
263	kfree(objp: res->lksb.sb_lvbptr);
264	kfree(objp: res);
265	}
266
267	static void add_resync_info(struct dlm_lock_resource *lockres,
268	sector_t lo, sector_t hi)
269	{
270	struct resync_info *ri;
271
272	ri = (struct resync_info *)lockres->lksb.sb_lvbptr;
273	ri->lo = cpu_to_le64(lo);
274	ri->hi = cpu_to_le64(hi);
275	}
276
277	static int read_resync_info(struct mddev *mddev,
278	struct dlm_lock_resource *lockres)
279	{
280	struct resync_info ri;
281	struct md_cluster_info *cinfo = mddev->cluster_info;
282	int ret = 0;
283
284	dlm_lock_sync(res: lockres, DLM_LOCK_CR);
285	memcpy(&ri, lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
286	if (le64_to_cpu(ri.hi) > 0) {
287	cinfo->suspend_hi = le64_to_cpu(ri.hi);
288	cinfo->suspend_lo = le64_to_cpu(ri.lo);
289	ret = 1;
290	}
291	dlm_unlock_sync(res: lockres);
292	return ret;
293	}
294
295	static void recover_bitmaps(struct md_thread *thread)
296	{
297	struct mddev *mddev = thread->mddev;
298	struct md_cluster_info *cinfo = mddev->cluster_info;
299	struct dlm_lock_resource *bm_lockres;
300	char str[64];
301	int slot, ret;
302	sector_t lo, hi;
303
304	while (cinfo->recovery_map) {
305	slot = fls64(x: (u64)cinfo->recovery_map) - 1;
306
307	snprintf(buf: str, size: 64, fmt: "bitmap%04d", slot);
308	bm_lockres = lockres_init(mddev, name: str, NULL, with_lvb: 1);
309	if (!bm_lockres) {
310	pr_err("md-cluster: Cannot initialize bitmaps\n");
311	goto clear_bit;
312	}
313
314	ret = dlm_lock_sync_interruptible(res: bm_lockres, DLM_LOCK_PW, mddev);
315	if (ret) {
316	pr_err("md-cluster: Could not DLM lock %s: %d\n",
317	str, ret);
318	goto clear_bit;
319	}
320	ret = mddev->bitmap_ops->copy_from_slot(mddev, slot, &lo, &hi, true);
321	if (ret) {
322	pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
323	goto clear_bit;
324	}
325
326	/* Clear suspend_area associated with the bitmap */
327	spin_lock_irq(lock: &cinfo->suspend_lock);
328	cinfo->suspend_hi = 0;
329	cinfo->suspend_lo = 0;
330	cinfo->suspend_from = -1;
331	spin_unlock_irq(lock: &cinfo->suspend_lock);
332
333	/* Kick off a reshape if needed */
334	if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
335	test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
336	mddev->reshape_position != MaxSector)
337	md_wakeup_thread(thread: mddev->sync_thread);
338
339	if (hi > 0) {
340	if (lo < mddev->recovery_cp)
341	mddev->recovery_cp = lo;
342	/* wake up thread to continue resync in case resync
343	* is not finished */
344	if (mddev->recovery_cp != MaxSector) {
345	/*
346	* clear the REMOTE flag since we will launch
347	* resync thread in current node.
348	*/
349	clear_bit(nr: MD_RESYNCING_REMOTE,
350	addr: &mddev->recovery);
351	set_bit(nr: MD_RECOVERY_NEEDED, addr: &mddev->recovery);
352	md_wakeup_thread(thread: mddev->thread);
353	}
354	}
355	clear_bit:
356	lockres_free(res: bm_lockres);
357	clear_bit(nr: slot, addr: &cinfo->recovery_map);
358	}
359	}
360
361	static void recover_prep(void *arg)
362	{
363	struct mddev *mddev = arg;
364	struct md_cluster_info *cinfo = mddev->cluster_info;
365	set_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, addr: &cinfo->state);
366	}
367
368	static void __recover_slot(struct mddev *mddev, int slot)
369	{
370	struct md_cluster_info *cinfo = mddev->cluster_info;
371
372	set_bit(nr: slot, addr: &cinfo->recovery_map);
373	if (!cinfo->recovery_thread) {
374	rcu_assign_pointer(cinfo->recovery_thread,
375	md_register_thread(recover_bitmaps, mddev, "recover"));
376	if (!cinfo->recovery_thread) {
377	pr_warn("md-cluster: Could not create recovery thread\n");
378	return;
379	}
380	}
381	md_wakeup_thread(thread: cinfo->recovery_thread);
382	}
383
384	static void recover_slot(void *arg, struct dlm_slot *slot)
385	{
386	struct mddev *mddev = arg;
387	struct md_cluster_info *cinfo = mddev->cluster_info;
388
389	pr_info("md-cluster: %s Node %d/%d down. My slot: %d. Initiating recovery.\n",
390	mddev->bitmap_info.cluster_name,
391	slot->nodeid, slot->slot,
392	cinfo->slot_number);
393	/* deduct one since dlm slot starts from one while the num of
394	* cluster-md begins with 0 */
395	__recover_slot(mddev, slot: slot->slot - 1);
396	}
397
398	static void recover_done(void *arg, struct dlm_slot *slots,
399	int num_slots, int our_slot,
400	uint32_t generation)
401	{
402	struct mddev *mddev = arg;
403	struct md_cluster_info *cinfo = mddev->cluster_info;
404
405	cinfo->slot_number = our_slot;
406	/* completion is only need to be complete when node join cluster,
407	* it doesn't need to run during another node's failure */
408	if (test_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state)) {
409	complete(&cinfo->completion);
410	clear_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, addr: &cinfo->state);
411	}
412	clear_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, addr: &cinfo->state);
413	}
414
415	/* the ops is called when node join the cluster, and do lock recovery
416	* if node failure occurs */
417	static const struct dlm_lockspace_ops md_ls_ops = {
418	.recover_prep = recover_prep,
419	.recover_slot = recover_slot,
420	.recover_done = recover_done,
421	};
422
423	/*
424	* The BAST function for the ack lock resource
425	* This function wakes up the receive thread in
426	* order to receive and process the message.
427	*/
428	static void ack_bast(void *arg, int mode)
429	{
430	struct dlm_lock_resource *res = arg;
431	struct md_cluster_info *cinfo = res->mddev->cluster_info;
432
433	if (mode == DLM_LOCK_EX) {
434	if (test_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state))
435	md_wakeup_thread(thread: cinfo->recv_thread);
436	else
437	set_bit(MD_CLUSTER_PENDING_RECV_EVENT, addr: &cinfo->state);
438	}
439	}
440
441	static void remove_suspend_info(struct mddev *mddev, int slot)
442	{
443	struct md_cluster_info *cinfo = mddev->cluster_info;
444	mddev->pers->quiesce(mddev, 1);
445	spin_lock_irq(lock: &cinfo->suspend_lock);
446	cinfo->suspend_hi = 0;
447	cinfo->suspend_lo = 0;
448	spin_unlock_irq(lock: &cinfo->suspend_lock);
449	mddev->pers->quiesce(mddev, 0);
450	}
451
452	static void process_suspend_info(struct mddev *mddev,
453	int slot, sector_t lo, sector_t hi)
454	{
455	struct md_cluster_info *cinfo = mddev->cluster_info;
456	struct mdp_superblock_1 *sb = NULL;
457	struct md_rdev *rdev;
458
459	if (!hi) {
460	/*
461	* clear the REMOTE flag since resync or recovery is finished
462	* in remote node.
463	*/
464	clear_bit(nr: MD_RESYNCING_REMOTE, addr: &mddev->recovery);
465	remove_suspend_info(mddev, slot);
466	set_bit(nr: MD_RECOVERY_NEEDED, addr: &mddev->recovery);
467	clear_bit(MD_CLUSTER_WAITING_FOR_SYNC, addr: &cinfo->state);
468	md_wakeup_thread(thread: mddev->thread);
469	return;
470	}
471
472	rdev_for_each(rdev, mddev)
473	if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
474	sb = page_address(rdev->sb_page);
475	break;
476	}
477
478	/*
479	* The bitmaps are not same for different nodes
480	* if RESYNCING is happening in one node, then
481	* the node which received the RESYNCING message
482	* probably will perform resync with the region
483	* [lo, hi] again, so we could reduce resync time
484	* a lot if we can ensure that the bitmaps among
485	* different nodes are match up well.
486	*
487	* sync_low/hi is used to record the region which
488	* arrived in the previous RESYNCING message,
489	*
490	* Call md_bitmap_sync_with_cluster to clear NEEDED_MASK
491	* and set RESYNC_MASK since resync thread is running
492	* in another node, so we don't need to do the resync
493	* again with the same section.
494	*
495	* Skip md_bitmap_sync_with_cluster in case reshape
496	* happening, because reshaping region is small and
497	* we don't want to trigger lots of WARN.
498	*/
499	if (sb && !(le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE))
500	mddev->bitmap_ops->sync_with_cluster(mddev, cinfo->sync_low,
501	cinfo->sync_hi, lo, hi);
502	cinfo->sync_low = lo;
503	cinfo->sync_hi = hi;
504
505	mddev->pers->quiesce(mddev, 1);
506	spin_lock_irq(lock: &cinfo->suspend_lock);
507	cinfo->suspend_from = slot;
508	cinfo->suspend_lo = lo;
509	cinfo->suspend_hi = hi;
510	spin_unlock_irq(lock: &cinfo->suspend_lock);
511	mddev->pers->quiesce(mddev, 0);
512	}
513
514	static int process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)
515	{
516	char disk_uuid[64];
517	struct md_cluster_info *cinfo = mddev->cluster_info;
518	char event_name[] = "EVENT=ADD_DEVICE";
519	char raid_slot[16];
520	char *envp[] = {event_name, disk_uuid, raid_slot, NULL};
521	int len;
522	int res = 0;
523
524	len = snprintf(buf: disk_uuid, size: 64, fmt: "DEVICE_UUID=");
525	sprintf(buf: disk_uuid + len, fmt: "%pU", cmsg->uuid);
526	snprintf(buf: raid_slot, size: 16, fmt: "RAID_DISK=%d", le32_to_cpu(cmsg->raid_slot));
527	pr_info("%s:%d Sending kobject change with %s and %s\n", __func__, __LINE__, disk_uuid, raid_slot);
528	init_completion(x: &cinfo->newdisk_completion);
529	set_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, addr: &cinfo->state);
530	kobject_uevent_env(kobj: &disk_to_dev(mddev->gendisk)->kobj, action: KOBJ_CHANGE, envp);
531	if (!wait_for_completion_timeout(x: &cinfo->newdisk_completion,
532	NEW_DEV_TIMEOUT)) {
533	pr_err("md-cluster(%s:%d): timeout on a new disk adding\n",
534	__func__, __LINE__);
535	res = -1;
536	}
537	clear_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, addr: &cinfo->state);
538	set_bit(MD_CLUSTER_WAITING_FOR_SYNC, addr: &cinfo->state);
539	return res;
540	}
541
542
543	static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg)
544	{
545	int got_lock = 0;
546	struct md_thread *thread;
547	struct md_cluster_info *cinfo = mddev->cluster_info;
548	mddev->good_device_nr = le32_to_cpu(msg->raid_slot);
549
550	dlm_lock_sync(res: cinfo->no_new_dev_lockres, DLM_LOCK_CR);
551
552	/* daemaon thread must exist */
553	thread = rcu_dereference_protected(mddev->thread, true);
554	wait_event(thread->wqueue,
555	(got_lock = mddev_trylock(mddev)) ||
556	test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state));
557	md_reload_sb(mddev, raid_disk: mddev->good_device_nr);
558	if (got_lock)
559	mddev_unlock(mddev);
560	}
561
562	static void process_remove_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) {
569	set_bit(nr: ClusterRemove, addr: &rdev->flags);
570	set_bit(nr: MD_RECOVERY_NEEDED, addr: &mddev->recovery);
571	md_wakeup_thread(thread: mddev->thread);
572	}
573	else
574	pr_warn("%s: %d Could not find disk(%d) to REMOVE\n",
575	__func__, __LINE__, le32_to_cpu(msg->raid_slot));
576	rcu_read_unlock();
577	}
578
579	static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
580	{
581	struct md_rdev *rdev;
582
583	rcu_read_lock();
584	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
585	if (rdev && test_bit(Faulty, &rdev->flags))
586	clear_bit(nr: Faulty, addr: &rdev->flags);
587	else
588	pr_warn("%s: %d Could not find disk(%d) which is faulty",
589	__func__, __LINE__, le32_to_cpu(msg->raid_slot));
590	rcu_read_unlock();
591	}
592
593	static int process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
594	{
595	int ret = 0;
596
597	if (WARN(mddev->cluster_info->slot_number - 1 == le32_to_cpu(msg->slot),
598	"node %d received its own msg\n", le32_to_cpu(msg->slot)))
599	return -1;
600	switch (le32_to_cpu(msg->type)) {
601	case METADATA_UPDATED:
602	process_metadata_update(mddev, msg);
603	break;
604	case CHANGE_CAPACITY:
605	set_capacity_and_notify(disk: mddev->gendisk, size: mddev->array_sectors);
606	break;
607	case RESYNCING_START:
608	clear_bit(MD_CLUSTER_WAITING_FOR_SYNC, addr: &mddev->cluster_info->state);
609	break;
610	case RESYNCING:
611	set_bit(nr: MD_RESYNCING_REMOTE, addr: &mddev->recovery);
612	process_suspend_info(mddev, le32_to_cpu(msg->slot),
613	le64_to_cpu(msg->low),
614	le64_to_cpu(msg->high));
615	break;
616	case NEWDISK:
617	if (process_add_new_disk(mddev, cmsg: msg))
618	ret = -1;
619	break;
620	case REMOVE:
621	process_remove_disk(mddev, msg);
622	break;
623	case RE_ADD:
624	process_readd_disk(mddev, msg);
625	break;
626	case BITMAP_NEEDS_SYNC:
627	__recover_slot(mddev, le32_to_cpu(msg->slot));
628	break;
629	case BITMAP_RESIZE:
630	if (le64_to_cpu(msg->high) != mddev->pers->size(mddev, 0, 0))
631	ret = mddev->bitmap_ops->resize(mddev,
632	le64_to_cpu(msg->high),
633	0, false);
634	break;
635	default:
636	ret = -1;
637	pr_warn("%s:%d Received unknown message from %d\n",
638	__func__, __LINE__, msg->slot);
639	}
640	return ret;
641	}
642
643	/*
644	* thread for receiving message
645	*/
646	static void recv_daemon(struct md_thread *thread)
647	{
648	struct md_cluster_info *cinfo = thread->mddev->cluster_info;
649	struct dlm_lock_resource *ack_lockres = cinfo->ack_lockres;
650	struct dlm_lock_resource *message_lockres = cinfo->message_lockres;
651	struct cluster_msg msg;
652	int ret;
653
654	mutex_lock(&cinfo->recv_mutex);
655	/*get CR on Message*/
656	if (dlm_lock_sync(res: message_lockres, DLM_LOCK_CR)) {
657	pr_err("md/raid1:failed to get CR on MESSAGE\n");
658	mutex_unlock(lock: &cinfo->recv_mutex);
659	return;
660	}
661
662	/* read lvb and wake up thread to process this message_lockres */
663	memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
664	ret = process_recvd_msg(mddev: thread->mddev, msg: &msg);
665	if (ret)
666	goto out;
667
668	/*release CR on ack_lockres*/
669	ret = dlm_unlock_sync(res: ack_lockres);
670	if (unlikely(ret != 0))
671	pr_info("unlock ack failed return %d\n", ret);
672	/*up-convert to PR on message_lockres*/
673	ret = dlm_lock_sync(res: message_lockres, DLM_LOCK_PR);
674	if (unlikely(ret != 0))
675	pr_info("lock PR on msg failed return %d\n", ret);
676	/*get CR on ack_lockres again*/
677	ret = dlm_lock_sync(res: ack_lockres, DLM_LOCK_CR);
678	if (unlikely(ret != 0))
679	pr_info("lock CR on ack failed return %d\n", ret);
680	out:
681	/*release CR on message_lockres*/
682	ret = dlm_unlock_sync(res: message_lockres);
683	if (unlikely(ret != 0))
684	pr_info("unlock msg failed return %d\n", ret);
685	mutex_unlock(lock: &cinfo->recv_mutex);
686	}
687
688	/* lock_token()
689	* Takes the lock on the TOKEN lock resource so no other
690	* node can communicate while the operation is underway.
691	*/
692	static int lock_token(struct md_cluster_info *cinfo)
693	{
694	int error;
695
696	error = dlm_lock_sync(res: cinfo->token_lockres, DLM_LOCK_EX);
697	if (error) {
698	pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
699	__func__, __LINE__, error);
700	} else {
701	/* Lock the receive sequence */
702	mutex_lock(&cinfo->recv_mutex);
703	}
704	return error;
705	}
706
707	/* lock_comm()
708	* Sets the MD_CLUSTER_SEND_LOCK bit to lock the send channel.
709	*/
710	static int lock_comm(struct md_cluster_info *cinfo, bool mddev_locked)
711	{
712	int rv, set_bit = 0;
713	struct mddev *mddev = cinfo->mddev;
714
715	/*
716	* If resync thread run after raid1d thread, then process_metadata_update
717	* could not continue if raid1d held reconfig_mutex (and raid1d is blocked
718	* since another node already got EX on Token and waiting the EX of Ack),
719	* so let resync wake up thread in case flag is set.
720	*/
721	if (mddev_locked && !test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
722	&cinfo->state)) {
723	rv = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
724	addr: &cinfo->state);
725	WARN_ON_ONCE(rv);
726	md_wakeup_thread(thread: mddev->thread);
727	set_bit = 1;
728	}
729
730	wait_event(cinfo->wait,
731	!test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state));
732	rv = lock_token(cinfo);
733	if (set_bit)
734	clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, addr: &cinfo->state);
735	return rv;
736	}
737
738	static void unlock_comm(struct md_cluster_info *cinfo)
739	{
740	WARN_ON(cinfo->token_lockres->mode != DLM_LOCK_EX);
741	mutex_unlock(lock: &cinfo->recv_mutex);
742	dlm_unlock_sync(res: cinfo->token_lockres);
743	clear_bit(MD_CLUSTER_SEND_LOCK, addr: &cinfo->state);
744	wake_up(&cinfo->wait);
745	}
746
747	/* __sendmsg()
748	* This function performs the actual sending of the message. This function is
749	* usually called after performing the encompassing operation
750	* The function:
751	* 1. Grabs the message lockresource in EX mode
752	* 2. Copies the message to the message LVB
753	* 3. Downconverts message lockresource to CW
754	* 4. Upconverts ack lock resource from CR to EX. This forces the BAST on other nodes
755	* and the other nodes read the message. The thread will wait here until all other
756	* nodes have released ack lock resource.
757	* 5. Downconvert ack lockresource to CR
758	*/
759	static int __sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
760	{
761	int error, unlock_error;
762	int slot = cinfo->slot_number - 1;
763
764	cmsg->slot = cpu_to_le32(slot);
765	/*get EX on Message*/
766	error = dlm_lock_sync(res: cinfo->message_lockres, DLM_LOCK_EX);
767	if (error) {
768	pr_err("md-cluster: failed to get EX on MESSAGE (%d)\n", error);
769	return error;
770	}
771
772	memcpy(cinfo->message_lockres->lksb.sb_lvbptr, (void *)cmsg,
773	sizeof(struct cluster_msg));
774	/*down-convert EX to CW on Message*/
775	error = dlm_lock_sync(res: cinfo->message_lockres, DLM_LOCK_CW);
776	if (error) {
777	pr_err("md-cluster: failed to convert EX to CW on MESSAGE(%d)\n",
778	error);
779	goto failed_ack;
780	}
781
782	/*up-convert CR to EX on Ack*/
783	error = dlm_lock_sync(res: cinfo->ack_lockres, DLM_LOCK_EX);
784	if (error) {
785	pr_err("md-cluster: failed to convert CR to EX on ACK(%d)\n",
786	error);
787	goto failed_ack;
788	}
789
790	/*down-convert EX to CR on Ack*/
791	error = dlm_lock_sync(res: cinfo->ack_lockres, DLM_LOCK_CR);
792	if (error) {
793	pr_err("md-cluster: failed to convert EX to CR on ACK(%d)\n",
794	error);
795	goto failed_ack;
796	}
797
798	failed_ack:
799	while ((unlock_error = dlm_unlock_sync(res: cinfo->message_lockres)))
800	pr_err("md-cluster: failed convert to NL on MESSAGE(%d)\n",
801	unlock_error);
802
803	return error;
804	}
805
806	static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg,
807	bool mddev_locked)
808	{
809	int ret;
810
811	ret = lock_comm(cinfo, mddev_locked);
812	if (!ret) {
813	ret = __sendmsg(cinfo, cmsg);
814	unlock_comm(cinfo);
815	}
816	return ret;
817	}
818
819	static int gather_all_resync_info(struct mddev *mddev, int total_slots)
820	{
821	struct md_cluster_info *cinfo = mddev->cluster_info;
822	int i, ret = 0;
823	struct dlm_lock_resource *bm_lockres;
824	char str[64];
825	sector_t lo, hi;
826
827
828	for (i = 0; i < total_slots; i++) {
829	memset(str, '\0', 64);
830	snprintf(buf: str, size: 64, fmt: "bitmap%04d", i);
831	bm_lockres = lockres_init(mddev, name: str, NULL, with_lvb: 1);
832	if (!bm_lockres)
833	return -ENOMEM;
834	if (i == (cinfo->slot_number - 1)) {
835	lockres_free(res: bm_lockres);
836	continue;
837	}
838
839	bm_lockres->flags |= DLM_LKF_NOQUEUE;
840	ret = dlm_lock_sync(res: bm_lockres, DLM_LOCK_PW);
841	if (ret == -EAGAIN) {
842	if (read_resync_info(mddev, lockres: bm_lockres)) {
843	pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
844	__func__, __LINE__,
845	(unsigned long long) cinfo->suspend_lo,
846	(unsigned long long) cinfo->suspend_hi,
847	i);
848	cinfo->suspend_from = i;
849	}
850	ret = 0;
851	lockres_free(res: bm_lockres);
852	continue;
853	}
854	if (ret) {
855	lockres_free(res: bm_lockres);
856	goto out;
857	}
858
859	/* Read the disk bitmap sb and check if it needs recovery */
860	ret = mddev->bitmap_ops->copy_from_slot(mddev, i, &lo, &hi, false);
861	if (ret) {
862	pr_warn("md-cluster: Could not gather bitmaps from slot %d", i);
863	lockres_free(res: bm_lockres);
864	continue;
865	}
866	if ((hi > 0) && (lo < mddev->recovery_cp)) {
867	set_bit(nr: MD_RECOVERY_NEEDED, addr: &mddev->recovery);
868	mddev->recovery_cp = lo;
869	md_check_recovery(mddev);
870	}
871
872	lockres_free(res: bm_lockres);
873	}
874	out:
875	return ret;
876	}
877
878	static int join(struct mddev *mddev, int nodes)
879	{
880	struct md_cluster_info *cinfo;
881	int ret, ops_rv;
882	char str[64];
883
884	cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
885	if (!cinfo)
886	return -ENOMEM;
887
888	INIT_LIST_HEAD(list: &cinfo->suspend_list);
889	spin_lock_init(&cinfo->suspend_lock);
890	init_completion(x: &cinfo->completion);
891	set_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, addr: &cinfo->state);
892	init_waitqueue_head(&cinfo->wait);
893	mutex_init(&cinfo->recv_mutex);
894
895	mddev->cluster_info = cinfo;
896	cinfo->mddev = mddev;
897
898	memset(str, 0, 64);
899	sprintf(buf: str, fmt: "%pU", mddev->uuid);
900	ret = dlm_new_lockspace(name: str, cluster: mddev->bitmap_info.cluster_name,
901	DLM_LSFL_SOFTIRQ, LVB_SIZE, ops: &md_ls_ops, ops_arg: mddev,
902	ops_result: &ops_rv, lockspace: &cinfo->lockspace);
903	if (ret)
904	goto err;
905	wait_for_completion(&cinfo->completion);
906	if (nodes < cinfo->slot_number) {
907	pr_err("md-cluster: Slot allotted(%d) is greater than available slots(%d).",
908	cinfo->slot_number, nodes);
909	ret = -ERANGE;
910	goto err;
911	}
912	/* Initiate the communication resources */
913	ret = -ENOMEM;
914	rcu_assign_pointer(cinfo->recv_thread,
915	md_register_thread(recv_daemon, mddev, "cluster_recv"));
916	if (!cinfo->recv_thread) {
917	pr_err("md-cluster: cannot allocate memory for recv_thread!\n");
918	goto err;
919	}
920	cinfo->message_lockres = lockres_init(mddev, name: "message", NULL, with_lvb: 1);
921	if (!cinfo->message_lockres)
922	goto err;
923	cinfo->token_lockres = lockres_init(mddev, name: "token", NULL, with_lvb: 0);
924	if (!cinfo->token_lockres)
925	goto err;
926	cinfo->no_new_dev_lockres = lockres_init(mddev, name: "no-new-dev", NULL, with_lvb: 0);
927	if (!cinfo->no_new_dev_lockres)
928	goto err;
929
930	ret = dlm_lock_sync(res: cinfo->token_lockres, DLM_LOCK_EX);
931	if (ret) {
932	ret = -EAGAIN;
933	pr_err("md-cluster: can't join cluster to avoid lock issue\n");
934	goto err;
935	}
936	cinfo->ack_lockres = lockres_init(mddev, name: "ack", bastfn: ack_bast, with_lvb: 0);
937	if (!cinfo->ack_lockres) {
938	ret = -ENOMEM;
939	goto err;
940	}
941	/* get sync CR lock on ACK. */
942	if (dlm_lock_sync(res: cinfo->ack_lockres, DLM_LOCK_CR))
943	pr_err("md-cluster: failed to get a sync CR lock on ACK!(%d)\n",
944	ret);
945	dlm_unlock_sync(res: cinfo->token_lockres);
946	/* get sync CR lock on no-new-dev. */
947	if (dlm_lock_sync(res: cinfo->no_new_dev_lockres, DLM_LOCK_CR))
948	pr_err("md-cluster: failed to get a sync CR lock on no-new-dev!(%d)\n", ret);
949
950
951	pr_info("md-cluster: Joined cluster %s slot %d\n", str, cinfo->slot_number);
952	snprintf(buf: str, size: 64, fmt: "bitmap%04d", cinfo->slot_number - 1);
953	cinfo->bitmap_lockres = lockres_init(mddev, name: str, NULL, with_lvb: 1);
954	if (!cinfo->bitmap_lockres) {
955	ret = -ENOMEM;
956	goto err;
957	}
958	if (dlm_lock_sync(res: cinfo->bitmap_lockres, DLM_LOCK_PW)) {
959	pr_err("Failed to get bitmap lock\n");
960	ret = -EINVAL;
961	goto err;
962	}
963
964	cinfo->resync_lockres = lockres_init(mddev, name: "resync", NULL, with_lvb: 0);
965	if (!cinfo->resync_lockres) {
966	ret = -ENOMEM;
967	goto err;
968	}
969
970	return 0;
971	err:
972	set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, addr: &cinfo->state);
973	md_unregister_thread(mddev, threadp: &cinfo->recovery_thread);
974	md_unregister_thread(mddev, threadp: &cinfo->recv_thread);
975	lockres_free(res: cinfo->message_lockres);
976	lockres_free(res: cinfo->token_lockres);
977	lockres_free(res: cinfo->ack_lockres);
978	lockres_free(res: cinfo->no_new_dev_lockres);
979	lockres_free(res: cinfo->resync_lockres);
980	lockres_free(res: cinfo->bitmap_lockres);
981	if (cinfo->lockspace)
982	dlm_release_lockspace(lockspace: cinfo->lockspace, force: 2);
983	mddev->cluster_info = NULL;
984	kfree(objp: cinfo);
985	return ret;
986	}
987
988	static void load_bitmaps(struct mddev *mddev, int total_slots)
989	{
990	struct md_cluster_info *cinfo = mddev->cluster_info;
991
992	/* load all the node's bitmap info for resync */
993	if (gather_all_resync_info(mddev, total_slots))
994	pr_err("md-cluster: failed to gather all resyn infos\n");
995	set_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, addr: &cinfo->state);
996	/* wake up recv thread in case something need to be handled */
997	if (test_and_clear_bit(MD_CLUSTER_PENDING_RECV_EVENT, addr: &cinfo->state))
998	md_wakeup_thread(thread: cinfo->recv_thread);
999	}
1000
1001	static void resync_bitmap(struct mddev *mddev)
1002	{
1003	struct md_cluster_info *cinfo = mddev->cluster_info;
1004	struct cluster_msg cmsg = {0};
1005	int err;
1006
1007	cmsg.type = cpu_to_le32(BITMAP_NEEDS_SYNC);
1008	err = sendmsg(cinfo, cmsg: &cmsg, mddev_locked: 1);
1009	if (err)
1010	pr_err("%s:%d: failed to send BITMAP_NEEDS_SYNC message (%d)\n",
1011	__func__, __LINE__, err);
1012	}
1013
1014	static void unlock_all_bitmaps(struct mddev *mddev);
1015	static int leave(struct mddev *mddev)
1016	{
1017	struct md_cluster_info *cinfo = mddev->cluster_info;
1018
1019	if (!cinfo)
1020	return 0;
1021
1022	/*
1023	* BITMAP_NEEDS_SYNC message should be sent when node
1024	* is leaving the cluster with dirty bitmap, also we
1025	* can only deliver it when dlm connection is available.
1026	*
1027	* Also, we should send BITMAP_NEEDS_SYNC message in
1028	* case reshaping is interrupted.
1029	*/
1030	if ((cinfo->slot_number > 0 && mddev->recovery_cp != MaxSector) ||
1031	(mddev->reshape_position != MaxSector &&
1032	test_bit(MD_CLOSING, &mddev->flags)))
1033	resync_bitmap(mddev);
1034
1035	set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, addr: &cinfo->state);
1036	md_unregister_thread(mddev, threadp: &cinfo->recovery_thread);
1037	md_unregister_thread(mddev, threadp: &cinfo->recv_thread);
1038	lockres_free(res: cinfo->message_lockres);
1039	lockres_free(res: cinfo->token_lockres);
1040	lockres_free(res: cinfo->ack_lockres);
1041	lockres_free(res: cinfo->no_new_dev_lockres);
1042	lockres_free(res: cinfo->resync_lockres);
1043	lockres_free(res: cinfo->bitmap_lockres);
1044	unlock_all_bitmaps(mddev);
1045	dlm_release_lockspace(lockspace: cinfo->lockspace, force: 2);
1046	kfree(objp: cinfo);
1047	return 0;
1048	}
1049
1050	/* slot_number(): Returns the MD slot number to use
1051	* DLM starts the slot numbers from 1, wheras cluster-md
1052	* wants the number to be from zero, so we deduct one
1053	*/
1054	static int slot_number(struct mddev *mddev)
1055	{
1056	struct md_cluster_info *cinfo = mddev->cluster_info;
1057
1058	return cinfo->slot_number - 1;
1059	}
1060
1061	/*
1062	* Check if the communication is already locked, else lock the communication
1063	* channel.
1064	* If it is already locked, token is in EX mode, and hence lock_token()
1065	* should not be called.
1066	*/
1067	static int metadata_update_start(struct mddev *mddev)
1068	{
1069	struct md_cluster_info *cinfo = mddev->cluster_info;
1070	int ret;
1071
1072	/*
1073	* metadata_update_start is always called with the protection of
1074	* reconfig_mutex, so set WAITING_FOR_TOKEN here.
1075	*/
1076	ret = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
1077	addr: &cinfo->state);
1078	WARN_ON_ONCE(ret);
1079	md_wakeup_thread(thread: mddev->thread);
1080
1081	wait_event(cinfo->wait,
1082	!test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state) ||
1083	test_and_clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state));
1084
1085	/* If token is already locked, return 0 */
1086	if (cinfo->token_lockres->mode == DLM_LOCK_EX) {
1087	clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, addr: &cinfo->state);
1088	return 0;
1089	}
1090
1091	ret = lock_token(cinfo);
1092	clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, addr: &cinfo->state);
1093	return ret;
1094	}
1095
1096	static int metadata_update_finish(struct mddev *mddev)
1097	{
1098	struct md_cluster_info *cinfo = mddev->cluster_info;
1099	struct cluster_msg cmsg;
1100	struct md_rdev *rdev;
1101	int ret = 0;
1102	int raid_slot = -1;
1103
1104	memset(&cmsg, 0, sizeof(cmsg));
1105	cmsg.type = cpu_to_le32(METADATA_UPDATED);
1106	/* Pick up a good active device number to send.
1107	*/
1108	rdev_for_each(rdev, mddev)
1109	if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
1110	raid_slot = rdev->desc_nr;
1111	break;
1112	}
1113	if (raid_slot >= 0) {
1114	cmsg.raid_slot = cpu_to_le32(raid_slot);
1115	ret = __sendmsg(cinfo, cmsg: &cmsg);
1116	} else
1117	pr_warn("md-cluster: No good device id found to send\n");
1118	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, addr: &cinfo->state);
1119	unlock_comm(cinfo);
1120	return ret;
1121	}
1122
1123	static void metadata_update_cancel(struct mddev *mddev)
1124	{
1125	struct md_cluster_info *cinfo = mddev->cluster_info;
1126	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, addr: &cinfo->state);
1127	unlock_comm(cinfo);
1128	}
1129
1130	static int update_bitmap_size(struct mddev *mddev, sector_t size)
1131	{
1132	struct md_cluster_info *cinfo = mddev->cluster_info;
1133	struct cluster_msg cmsg = {0};
1134	int ret;
1135
1136	cmsg.type = cpu_to_le32(BITMAP_RESIZE);
1137	cmsg.high = cpu_to_le64(size);
1138	ret = sendmsg(cinfo, cmsg: &cmsg, mddev_locked: 0);
1139	if (ret)
1140	pr_err("%s:%d: failed to send BITMAP_RESIZE message (%d)\n",
1141	__func__, __LINE__, ret);
1142	return ret;
1143	}
1144
1145	static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsize)
1146	{
1147	void *bitmap = mddev->bitmap;
1148	struct md_bitmap_stats stats;
1149	unsigned long my_pages;
1150	int i, rv;
1151
1152	rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
1153	if (rv)
1154	return rv;
1155
1156	my_pages = stats.pages;
1157	/*
1158	* We need to ensure all the nodes can grow to a larger
1159	* bitmap size before make the reshaping.
1160	*/
1161	rv = update_bitmap_size(mddev, size: newsize);
1162	if (rv)
1163	return rv;
1164
1165	for (i = 0; i < mddev->bitmap_info.nodes; i++) {
1166	struct dlm_lock_resource *bm_lockres;
1167	char str[64];
1168
1169	if (i == slot_number(mddev))
1170	continue;
1171
1172	bitmap = mddev->bitmap_ops->get_from_slot(mddev, i);
1173	if (IS_ERR(ptr: bitmap)) {
1174	pr_err("can't get bitmap from slot %d\n", i);
1175	bitmap = NULL;
1176	goto out;
1177	}
1178
1179	rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
1180	if (rv)
1181	goto out;
1182	/*
1183	* If we can hold the bitmap lock of one node then
1184	* the slot is not occupied, update the pages.
1185	*/
1186	snprintf(buf: str, size: 64, fmt: "bitmap%04d", i);
1187	bm_lockres = lockres_init(mddev, name: str, NULL, with_lvb: 1);
1188	if (!bm_lockres) {
1189	pr_err("Cannot initialize %s lock\n", str);
1190	goto out;
1191	}
1192	bm_lockres->flags |= DLM_LKF_NOQUEUE;
1193	rv = dlm_lock_sync(res: bm_lockres, DLM_LOCK_PW);
1194	if (!rv)
1195	mddev->bitmap_ops->set_pages(bitmap, my_pages);
1196	lockres_free(res: bm_lockres);
1197
1198	if (my_pages != stats.pages)
1199	/*
1200	* Let's revert the bitmap size if one node
1201	* can't resize bitmap
1202	*/
1203	goto out;
1204	mddev->bitmap_ops->free(bitmap);
1205	}
1206
1207	return 0;
1208	out:
1209	mddev->bitmap_ops->free(bitmap);
1210	update_bitmap_size(mddev, size: oldsize);
1211	return -1;
1212	}
1213
1214	/*
1215	* return 0 if all the bitmaps have the same sync_size
1216	*/
1217	static int cluster_check_sync_size(struct mddev *mddev)
1218	{
1219	int current_slot = slot_number(mddev);
1220	int node_num = mddev->bitmap_info.nodes;
1221	struct dlm_lock_resource *bm_lockres;
1222	struct md_bitmap_stats stats;
1223	void *bitmap = mddev->bitmap;
1224	unsigned long sync_size = 0;
1225	unsigned long my_sync_size;
1226	char str[64];
1227	int i, rv;
1228
1229	rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
1230	if (rv)
1231	return rv;
1232
1233	my_sync_size = stats.sync_size;
1234
1235	for (i = 0; i < node_num; i++) {
1236	if (i == current_slot)
1237	continue;
1238
1239	bitmap = mddev->bitmap_ops->get_from_slot(mddev, i);
1240	if (IS_ERR(ptr: bitmap)) {
1241	pr_err("can't get bitmap from slot %d\n", i);
1242	return -1;
1243	}
1244
1245	/*
1246	* If we can hold the bitmap lock of one node then
1247	* the slot is not occupied, update the sb.
1248	*/
1249	snprintf(buf: str, size: 64, fmt: "bitmap%04d", i);
1250	bm_lockres = lockres_init(mddev, name: str, NULL, with_lvb: 1);
1251	if (!bm_lockres) {
1252	pr_err("md-cluster: Cannot initialize %s\n", str);
1253	mddev->bitmap_ops->free(bitmap);
1254	return -1;
1255	}
1256	bm_lockres->flags |= DLM_LKF_NOQUEUE;
1257	rv = dlm_lock_sync(res: bm_lockres, DLM_LOCK_PW);
1258	if (!rv)
1259	mddev->bitmap_ops->update_sb(bitmap);
1260	lockres_free(res: bm_lockres);
1261
1262	rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
1263	if (rv) {
1264	mddev->bitmap_ops->free(bitmap);
1265	return rv;
1266	}
1267
1268	if (sync_size == 0) {
1269	sync_size = stats.sync_size;
1270	} else if (sync_size != stats.sync_size) {
1271	mddev->bitmap_ops->free(bitmap);
1272	return -1;
1273	}
1274	mddev->bitmap_ops->free(bitmap);
1275	}
1276
1277	return (my_sync_size == sync_size) ? 0 : -1;
1278	}
1279
1280	/*
1281	* Update the size for cluster raid is a little more complex, we perform it
1282	* by the steps:
1283	* 1. hold token lock and update superblock in initiator node.
1284	* 2. send METADATA_UPDATED msg to other nodes.
1285	* 3. The initiator node continues to check each bitmap's sync_size, if all
1286	* bitmaps have the same value of sync_size, then we can set capacity and
1287	* let other nodes to perform it. If one node can't update sync_size
1288	* accordingly, we need to revert to previous value.
1289	*/
1290	static void update_size(struct mddev *mddev, sector_t old_dev_sectors)
1291	{
1292	struct md_cluster_info *cinfo = mddev->cluster_info;
1293	struct cluster_msg cmsg;
1294	struct md_rdev *rdev;
1295	int ret = 0;
1296	int raid_slot = -1;
1297
1298	md_update_sb(mddev, force: 1);
1299	if (lock_comm(cinfo, mddev_locked: 1)) {
1300	pr_err("%s: lock_comm failed\n", __func__);
1301	return;
1302	}
1303
1304	memset(&cmsg, 0, sizeof(cmsg));
1305	cmsg.type = cpu_to_le32(METADATA_UPDATED);
1306	rdev_for_each(rdev, mddev)
1307	if (rdev->raid_disk >= 0 && !test_bit(Faulty, &rdev->flags)) {
1308	raid_slot = rdev->desc_nr;
1309	break;
1310	}
1311	if (raid_slot >= 0) {
1312	cmsg.raid_slot = cpu_to_le32(raid_slot);
1313	/*
1314	* We can only change capiticy after all the nodes can do it,
1315	* so need to wait after other nodes already received the msg
1316	* and handled the change
1317	*/
1318	ret = __sendmsg(cinfo, cmsg: &cmsg);
1319	if (ret) {
1320	pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
1321	__func__, __LINE__);
1322	unlock_comm(cinfo);
1323	return;
1324	}
1325	} else {
1326	pr_err("md-cluster: No good device id found to send\n");
1327	unlock_comm(cinfo);
1328	return;
1329	}
1330
1331	/*
1332	* check the sync_size from other node's bitmap, if sync_size
1333	* have already updated in other nodes as expected, send an
1334	* empty metadata msg to permit the change of capacity
1335	*/
1336	if (cluster_check_sync_size(mddev) == 0) {
1337	memset(&cmsg, 0, sizeof(cmsg));
1338	cmsg.type = cpu_to_le32(CHANGE_CAPACITY);
1339	ret = __sendmsg(cinfo, cmsg: &cmsg);
1340	if (ret)
1341	pr_err("%s:%d: failed to send CHANGE_CAPACITY msg\n",
1342	__func__, __LINE__);
1343	set_capacity_and_notify(disk: mddev->gendisk, size: mddev->array_sectors);
1344	} else {
1345	/* revert to previous sectors */
1346	ret = mddev->pers->resize(mddev, old_dev_sectors);
1347	ret = __sendmsg(cinfo, cmsg: &cmsg);
1348	if (ret)
1349	pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
1350	__func__, __LINE__);
1351	}
1352	unlock_comm(cinfo);
1353	}
1354
1355	static int resync_start(struct mddev *mddev)
1356	{
1357	struct md_cluster_info *cinfo = mddev->cluster_info;
1358	return dlm_lock_sync_interruptible(res: cinfo->resync_lockres, DLM_LOCK_EX, mddev);
1359	}
1360
1361	static void resync_info_get(struct mddev *mddev, sector_t *lo, sector_t *hi)
1362	{
1363	struct md_cluster_info *cinfo = mddev->cluster_info;
1364
1365	spin_lock_irq(lock: &cinfo->suspend_lock);
1366	*lo = cinfo->suspend_lo;
1367	*hi = cinfo->suspend_hi;
1368	spin_unlock_irq(lock: &cinfo->suspend_lock);
1369	}
1370
1371	static int resync_status_get(struct mddev *mddev)
1372	{
1373	struct md_cluster_info *cinfo = mddev->cluster_info;
1374
1375	return test_bit(MD_CLUSTER_WAITING_FOR_SYNC, &cinfo->state);
1376	}
1377
1378	static int resync_start_notify(struct mddev *mddev)
1379	{
1380	struct md_cluster_info *cinfo = mddev->cluster_info;
1381	struct cluster_msg cmsg = {0};
1382
1383	cmsg.type = cpu_to_le32(RESYNCING_START);
1384
1385	return sendmsg(cinfo, cmsg: &cmsg, mddev_locked: 0);
1386	}
1387
1388	static int resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi)
1389	{
1390	struct md_cluster_info *cinfo = mddev->cluster_info;
1391	struct resync_info ri;
1392	struct cluster_msg cmsg = {0};
1393
1394	/* do not send zero again, if we have sent before */
1395	if (hi == 0) {
1396	memcpy(&ri, cinfo->bitmap_lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
1397	if (le64_to_cpu(ri.hi) == 0)
1398	return 0;
1399	}
1400
1401	add_resync_info(lockres: cinfo->bitmap_lockres, lo, hi);
1402	/* Re-acquire the lock to refresh LVB */
1403	dlm_lock_sync(res: cinfo->bitmap_lockres, DLM_LOCK_PW);
1404	cmsg.type = cpu_to_le32(RESYNCING);
1405	cmsg.low = cpu_to_le64(lo);
1406	cmsg.high = cpu_to_le64(hi);
1407
1408	/*
1409	* mddev_lock is held if resync_info_update is called from
1410	* resync_finish (md_reap_sync_thread -> resync_finish)
1411	*/
1412	if (lo == 0 && hi == 0)
1413	return sendmsg(cinfo, cmsg: &cmsg, mddev_locked: 1);
1414	else
1415	return sendmsg(cinfo, cmsg: &cmsg, mddev_locked: 0);
1416	}
1417
1418	static int resync_finish(struct mddev *mddev)
1419	{
1420	struct md_cluster_info *cinfo = mddev->cluster_info;
1421	int ret = 0;
1422
1423	clear_bit(nr: MD_RESYNCING_REMOTE, addr: &mddev->recovery);
1424
1425	/*
1426	* If resync thread is interrupted so we can't say resync is finished,
1427	* another node will launch resync thread to continue.
1428	*/
1429	if (!test_bit(MD_CLOSING, &mddev->flags))
1430	ret = resync_info_update(mddev, lo: 0, hi: 0);
1431	dlm_unlock_sync(res: cinfo->resync_lockres);
1432	return ret;
1433	}
1434
1435	static int area_resyncing(struct mddev *mddev, int direction,
1436	sector_t lo, sector_t hi)
1437	{
1438	struct md_cluster_info *cinfo = mddev->cluster_info;
1439	int ret = 0;
1440
1441	if ((direction == READ) &&
1442	test_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state))
1443	return 1;
1444
1445	spin_lock_irq(lock: &cinfo->suspend_lock);
1446	if (hi > cinfo->suspend_lo && lo < cinfo->suspend_hi)
1447	ret = 1;
1448	spin_unlock_irq(lock: &cinfo->suspend_lock);
1449	return ret;
1450	}
1451
1452	/* add_new_disk() - initiates a disk add
1453	* However, if this fails before writing md_update_sb(),
1454	* add_new_disk_cancel() must be called to release token lock
1455	*/
1456	static int add_new_disk(struct mddev *mddev, struct md_rdev *rdev)
1457	{
1458	struct md_cluster_info *cinfo = mddev->cluster_info;
1459	struct cluster_msg cmsg;
1460	int ret = 0;
1461	struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1462	char *uuid = sb->device_uuid;
1463
1464	memset(&cmsg, 0, sizeof(cmsg));
1465	cmsg.type = cpu_to_le32(NEWDISK);
1466	memcpy(cmsg.uuid, uuid, 16);
1467	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1468	if (lock_comm(cinfo, mddev_locked: 1))
1469	return -EAGAIN;
1470	ret = __sendmsg(cinfo, cmsg: &cmsg);
1471	if (ret) {
1472	unlock_comm(cinfo);
1473	return ret;
1474	}
1475	cinfo->no_new_dev_lockres->flags |= DLM_LKF_NOQUEUE;
1476	ret = dlm_lock_sync(res: cinfo->no_new_dev_lockres, DLM_LOCK_EX);
1477	cinfo->no_new_dev_lockres->flags &= ~DLM_LKF_NOQUEUE;
1478	/* Some node does not "see" the device */
1479	if (ret == -EAGAIN)
1480	ret = -ENOENT;
1481	if (ret)
1482	unlock_comm(cinfo);
1483	else {
1484	dlm_lock_sync(res: cinfo->no_new_dev_lockres, DLM_LOCK_CR);
1485	/* Since MD_CHANGE_DEVS will be set in add_bound_rdev which
1486	* will run soon after add_new_disk, the below path will be
1487	* invoked:
1488	* md_wakeup_thread(mddev->thread)
1489	* -> conf->thread (raid1d)
1490	* -> md_check_recovery -> md_update_sb
1491	* -> metadata_update_start/finish
1492	* MD_CLUSTER_SEND_LOCKED_ALREADY will be cleared eventually.
1493	*
1494	* For other failure cases, metadata_update_cancel and
1495	* add_new_disk_cancel also clear below bit as well.
1496	* */
1497	set_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, addr: &cinfo->state);
1498	wake_up(&cinfo->wait);
1499	}
1500	return ret;
1501	}
1502
1503	static void add_new_disk_cancel(struct mddev *mddev)
1504	{
1505	struct md_cluster_info *cinfo = mddev->cluster_info;
1506	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, addr: &cinfo->state);
1507	unlock_comm(cinfo);
1508	}
1509
1510	static int new_disk_ack(struct mddev *mddev, bool ack)
1511	{
1512	struct md_cluster_info *cinfo = mddev->cluster_info;
1513
1514	if (!test_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state)) {
1515	pr_warn("md-cluster(%s): Spurious cluster confirmation\n", mdname(mddev));
1516	return -EINVAL;
1517	}
1518
1519	if (ack)
1520	dlm_unlock_sync(res: cinfo->no_new_dev_lockres);
1521	complete(&cinfo->newdisk_completion);
1522	return 0;
1523	}
1524
1525	static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1526	{
1527	struct cluster_msg cmsg = {0};
1528	struct md_cluster_info *cinfo = mddev->cluster_info;
1529	cmsg.type = cpu_to_le32(REMOVE);
1530	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1531	return sendmsg(cinfo, cmsg: &cmsg, mddev_locked: 1);
1532	}
1533
1534	static int lock_all_bitmaps(struct mddev *mddev)
1535	{
1536	int slot, my_slot, ret, held = 1, i = 0;
1537	char str[64];
1538	struct md_cluster_info *cinfo = mddev->cluster_info;
1539
1540	cinfo->other_bitmap_lockres =
1541	kcalloc(mddev->bitmap_info.nodes - 1,
1542	sizeof(struct dlm_lock_resource *), GFP_KERNEL);
1543	if (!cinfo->other_bitmap_lockres) {
1544	pr_err("md: can't alloc mem for other bitmap locks\n");
1545	return 0;
1546	}
1547
1548	my_slot = slot_number(mddev);
1549	for (slot = 0; slot < mddev->bitmap_info.nodes; slot++) {
1550	if (slot == my_slot)
1551	continue;
1552
1553	memset(str, '\0', 64);
1554	snprintf(buf: str, size: 64, fmt: "bitmap%04d", slot);
1555	cinfo->other_bitmap_lockres[i] = lockres_init(mddev, name: str, NULL, with_lvb: 1);
1556	if (!cinfo->other_bitmap_lockres[i])
1557	return -ENOMEM;
1558
1559	cinfo->other_bitmap_lockres[i]->flags |= DLM_LKF_NOQUEUE;
1560	ret = dlm_lock_sync(res: cinfo->other_bitmap_lockres[i], DLM_LOCK_PW);
1561	if (ret)
1562	held = -1;
1563	i++;
1564	}
1565
1566	return held;
1567	}
1568
1569	static void unlock_all_bitmaps(struct mddev *mddev)
1570	{
1571	struct md_cluster_info *cinfo = mddev->cluster_info;
1572	int i;
1573
1574	/* release other node's bitmap lock if they are existed */
1575	if (cinfo->other_bitmap_lockres) {
1576	for (i = 0; i < mddev->bitmap_info.nodes - 1; i++) {
1577	if (cinfo->other_bitmap_lockres[i]) {
1578	lockres_free(res: cinfo->other_bitmap_lockres[i]);
1579	}
1580	}
1581	kfree(objp: cinfo->other_bitmap_lockres);
1582	cinfo->other_bitmap_lockres = NULL;
1583	}
1584	}
1585
1586	static int gather_bitmaps(struct md_rdev *rdev)
1587	{
1588	int sn, err;
1589	sector_t lo, hi;
1590	struct cluster_msg cmsg = {0};
1591	struct mddev *mddev = rdev->mddev;
1592	struct md_cluster_info *cinfo = mddev->cluster_info;
1593
1594	cmsg.type = cpu_to_le32(RE_ADD);
1595	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1596	err = sendmsg(cinfo, cmsg: &cmsg, mddev_locked: 1);
1597	if (err)
1598	goto out;
1599
1600	for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
1601	if (sn == (cinfo->slot_number - 1))
1602	continue;
1603	err = mddev->bitmap_ops->copy_from_slot(mddev, sn, &lo, &hi, false);
1604	if (err) {
1605	pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
1606	goto out;
1607	}
1608	if ((hi > 0) && (lo < mddev->recovery_cp))
1609	mddev->recovery_cp = lo;
1610	}
1611	out:
1612	return err;
1613	}
1614
1615	static struct md_cluster_operations cluster_ops = {
1616	.head = {
1617	.type = MD_CLUSTER,
1618	.id = ID_CLUSTER,
1619	.name = "cluster",
1620	.owner = THIS_MODULE,
1621	},
1622
1623	.join = join,
1624	.leave = leave,
1625	.slot_number = slot_number,
1626	.resync_start = resync_start,
1627	.resync_finish = resync_finish,
1628	.resync_info_update = resync_info_update,
1629	.resync_start_notify = resync_start_notify,
1630	.resync_status_get = resync_status_get,
1631	.resync_info_get = resync_info_get,
1632	.metadata_update_start = metadata_update_start,
1633	.metadata_update_finish = metadata_update_finish,
1634	.metadata_update_cancel = metadata_update_cancel,
1635	.area_resyncing = area_resyncing,
1636	.add_new_disk = add_new_disk,
1637	.add_new_disk_cancel = add_new_disk_cancel,
1638	.new_disk_ack = new_disk_ack,
1639	.remove_disk = remove_disk,
1640	.load_bitmaps = load_bitmaps,
1641	.gather_bitmaps = gather_bitmaps,
1642	.resize_bitmaps = resize_bitmaps,
1643	.lock_all_bitmaps = lock_all_bitmaps,
1644	.unlock_all_bitmaps = unlock_all_bitmaps,
1645	.update_size = update_size,
1646	};
1647
1648	static int __init cluster_init(void)
1649	{
1650	pr_warn("md-cluster: support raid1 and raid10 (limited support)\n");
1651	pr_info("Registering Cluster MD functions\n");
1652	return register_md_submodule(msh: &cluster_ops.head);
1653	}
1654
1655	static void cluster_exit(void)
1656	{
1657	unregister_md_submodule(msh: &cluster_ops.head);
1658	}
1659
1660	module_init(cluster_init);
1661	module_exit(cluster_exit);
1662	MODULE_AUTHOR("SUSE");
1663	MODULE_LICENSE("GPL");
1664	MODULE_DESCRIPTION("Clustering support for MD");
1665