xref: /openbmc/linux/fs/gfs2/lock_dlm.c (revision 9d749629)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright 2004-2011 Red Hat, Inc.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 #include <linux/fs.h>
11 #include <linux/dlm.h>
12 #include <linux/slab.h>
13 #include <linux/types.h>
14 #include <linux/delay.h>
15 #include <linux/gfs2_ondisk.h>
16 
17 #include "incore.h"
18 #include "glock.h"
19 #include "util.h"
20 #include "sys.h"
21 #include "trace_gfs2.h"
22 
23 extern struct workqueue_struct *gfs2_control_wq;
24 
25 /**
26  * gfs2_update_stats - Update time based stats
27  * @mv: Pointer to mean/variance structure to update
28  * @sample: New data to include
29  *
30  * @delta is the difference between the current rtt sample and the
31  * running average srtt. We add 1/8 of that to the srtt in order to
32  * update the current srtt estimate. The varience estimate is a bit
33  * more complicated. We subtract the abs value of the @delta from
34  * the current variance estimate and add 1/4 of that to the running
35  * total.
36  *
37  * Note that the index points at the array entry containing the smoothed
38  * mean value, and the variance is always in the following entry
39  *
40  * Reference: TCP/IP Illustrated, vol 2, p. 831,832
41  * All times are in units of integer nanoseconds. Unlike the TCP/IP case,
42  * they are not scaled fixed point.
43  */
44 
45 static inline void gfs2_update_stats(struct gfs2_lkstats *s, unsigned index,
46 				     s64 sample)
47 {
48 	s64 delta = sample - s->stats[index];
49 	s->stats[index] += (delta >> 3);
50 	index++;
51 	s->stats[index] += ((abs64(delta) - s->stats[index]) >> 2);
52 }
53 
54 /**
55  * gfs2_update_reply_times - Update locking statistics
56  * @gl: The glock to update
57  *
58  * This assumes that gl->gl_dstamp has been set earlier.
59  *
60  * The rtt (lock round trip time) is an estimate of the time
61  * taken to perform a dlm lock request. We update it on each
62  * reply from the dlm.
63  *
64  * The blocking flag is set on the glock for all dlm requests
65  * which may potentially block due to lock requests from other nodes.
66  * DLM requests where the current lock state is exclusive, the
67  * requested state is null (or unlocked) or where the TRY or
68  * TRY_1CB flags are set are classified as non-blocking. All
69  * other DLM requests are counted as (potentially) blocking.
70  */
71 static inline void gfs2_update_reply_times(struct gfs2_glock *gl)
72 {
73 	struct gfs2_pcpu_lkstats *lks;
74 	const unsigned gltype = gl->gl_name.ln_type;
75 	unsigned index = test_bit(GLF_BLOCKING, &gl->gl_flags) ?
76 			 GFS2_LKS_SRTTB : GFS2_LKS_SRTT;
77 	s64 rtt;
78 
79 	preempt_disable();
80 	rtt = ktime_to_ns(ktime_sub(ktime_get_real(), gl->gl_dstamp));
81 	lks = this_cpu_ptr(gl->gl_sbd->sd_lkstats);
82 	gfs2_update_stats(&gl->gl_stats, index, rtt);		/* Local */
83 	gfs2_update_stats(&lks->lkstats[gltype], index, rtt);	/* Global */
84 	preempt_enable();
85 
86 	trace_gfs2_glock_lock_time(gl, rtt);
87 }
88 
89 /**
90  * gfs2_update_request_times - Update locking statistics
91  * @gl: The glock to update
92  *
93  * The irt (lock inter-request times) measures the average time
94  * between requests to the dlm. It is updated immediately before
95  * each dlm call.
96  */
97 
98 static inline void gfs2_update_request_times(struct gfs2_glock *gl)
99 {
100 	struct gfs2_pcpu_lkstats *lks;
101 	const unsigned gltype = gl->gl_name.ln_type;
102 	ktime_t dstamp;
103 	s64 irt;
104 
105 	preempt_disable();
106 	dstamp = gl->gl_dstamp;
107 	gl->gl_dstamp = ktime_get_real();
108 	irt = ktime_to_ns(ktime_sub(gl->gl_dstamp, dstamp));
109 	lks = this_cpu_ptr(gl->gl_sbd->sd_lkstats);
110 	gfs2_update_stats(&gl->gl_stats, GFS2_LKS_SIRT, irt);		/* Local */
111 	gfs2_update_stats(&lks->lkstats[gltype], GFS2_LKS_SIRT, irt);	/* Global */
112 	preempt_enable();
113 }
114 
115 static void gdlm_ast(void *arg)
116 {
117 	struct gfs2_glock *gl = arg;
118 	unsigned ret = gl->gl_state;
119 
120 	gfs2_update_reply_times(gl);
121 	BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);
122 
123 	if ((gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID) && gl->gl_lksb.sb_lvbptr)
124 		memset(gl->gl_lksb.sb_lvbptr, 0, GDLM_LVB_SIZE);
125 
126 	switch (gl->gl_lksb.sb_status) {
127 	case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */
128 		gfs2_glock_free(gl);
129 		return;
130 	case -DLM_ECANCEL: /* Cancel while getting lock */
131 		ret |= LM_OUT_CANCELED;
132 		goto out;
133 	case -EAGAIN: /* Try lock fails */
134 	case -EDEADLK: /* Deadlock detected */
135 		goto out;
136 	case -ETIMEDOUT: /* Canceled due to timeout */
137 		ret |= LM_OUT_ERROR;
138 		goto out;
139 	case 0: /* Success */
140 		break;
141 	default: /* Something unexpected */
142 		BUG();
143 	}
144 
145 	ret = gl->gl_req;
146 	if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) {
147 		if (gl->gl_req == LM_ST_SHARED)
148 			ret = LM_ST_DEFERRED;
149 		else if (gl->gl_req == LM_ST_DEFERRED)
150 			ret = LM_ST_SHARED;
151 		else
152 			BUG();
153 	}
154 
155 	set_bit(GLF_INITIAL, &gl->gl_flags);
156 	gfs2_glock_complete(gl, ret);
157 	return;
158 out:
159 	if (!test_bit(GLF_INITIAL, &gl->gl_flags))
160 		gl->gl_lksb.sb_lkid = 0;
161 	gfs2_glock_complete(gl, ret);
162 }
163 
164 static void gdlm_bast(void *arg, int mode)
165 {
166 	struct gfs2_glock *gl = arg;
167 
168 	switch (mode) {
169 	case DLM_LOCK_EX:
170 		gfs2_glock_cb(gl, LM_ST_UNLOCKED);
171 		break;
172 	case DLM_LOCK_CW:
173 		gfs2_glock_cb(gl, LM_ST_DEFERRED);
174 		break;
175 	case DLM_LOCK_PR:
176 		gfs2_glock_cb(gl, LM_ST_SHARED);
177 		break;
178 	default:
179 		printk(KERN_ERR "unknown bast mode %d", mode);
180 		BUG();
181 	}
182 }
183 
184 /* convert gfs lock-state to dlm lock-mode */
185 
186 static int make_mode(const unsigned int lmstate)
187 {
188 	switch (lmstate) {
189 	case LM_ST_UNLOCKED:
190 		return DLM_LOCK_NL;
191 	case LM_ST_EXCLUSIVE:
192 		return DLM_LOCK_EX;
193 	case LM_ST_DEFERRED:
194 		return DLM_LOCK_CW;
195 	case LM_ST_SHARED:
196 		return DLM_LOCK_PR;
197 	}
198 	printk(KERN_ERR "unknown LM state %d", lmstate);
199 	BUG();
200 	return -1;
201 }
202 
203 static u32 make_flags(struct gfs2_glock *gl, const unsigned int gfs_flags,
204 		      const int req)
205 {
206 	u32 lkf = 0;
207 
208 	if (gl->gl_lksb.sb_lvbptr)
209 		lkf |= DLM_LKF_VALBLK;
210 
211 	if (gfs_flags & LM_FLAG_TRY)
212 		lkf |= DLM_LKF_NOQUEUE;
213 
214 	if (gfs_flags & LM_FLAG_TRY_1CB) {
215 		lkf |= DLM_LKF_NOQUEUE;
216 		lkf |= DLM_LKF_NOQUEUEBAST;
217 	}
218 
219 	if (gfs_flags & LM_FLAG_PRIORITY) {
220 		lkf |= DLM_LKF_NOORDER;
221 		lkf |= DLM_LKF_HEADQUE;
222 	}
223 
224 	if (gfs_flags & LM_FLAG_ANY) {
225 		if (req == DLM_LOCK_PR)
226 			lkf |= DLM_LKF_ALTCW;
227 		else if (req == DLM_LOCK_CW)
228 			lkf |= DLM_LKF_ALTPR;
229 		else
230 			BUG();
231 	}
232 
233 	if (gl->gl_lksb.sb_lkid != 0) {
234 		lkf |= DLM_LKF_CONVERT;
235 		if (test_bit(GLF_BLOCKING, &gl->gl_flags))
236 			lkf |= DLM_LKF_QUECVT;
237 	}
238 
239 	return lkf;
240 }
241 
242 static void gfs2_reverse_hex(char *c, u64 value)
243 {
244 	*c = '0';
245 	while (value) {
246 		*c-- = hex_asc[value & 0x0f];
247 		value >>= 4;
248 	}
249 }
250 
251 static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state,
252 		     unsigned int flags)
253 {
254 	struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
255 	int req;
256 	u32 lkf;
257 	char strname[GDLM_STRNAME_BYTES] = "";
258 
259 	req = make_mode(req_state);
260 	lkf = make_flags(gl, flags, req);
261 	gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
262 	gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
263 	if (gl->gl_lksb.sb_lkid) {
264 		gfs2_update_request_times(gl);
265 	} else {
266 		memset(strname, ' ', GDLM_STRNAME_BYTES - 1);
267 		strname[GDLM_STRNAME_BYTES - 1] = '\0';
268 		gfs2_reverse_hex(strname + 7, gl->gl_name.ln_type);
269 		gfs2_reverse_hex(strname + 23, gl->gl_name.ln_number);
270 		gl->gl_dstamp = ktime_get_real();
271 	}
272 	/*
273 	 * Submit the actual lock request.
274 	 */
275 
276 	return dlm_lock(ls->ls_dlm, req, &gl->gl_lksb, lkf, strname,
277 			GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast);
278 }
279 
280 static void gdlm_put_lock(struct gfs2_glock *gl)
281 {
282 	struct gfs2_sbd *sdp = gl->gl_sbd;
283 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
284 	int lvb_needs_unlock = 0;
285 	int error;
286 
287 	if (gl->gl_lksb.sb_lkid == 0) {
288 		gfs2_glock_free(gl);
289 		return;
290 	}
291 
292 	clear_bit(GLF_BLOCKING, &gl->gl_flags);
293 	gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
294 	gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
295 	gfs2_update_request_times(gl);
296 
297 	/* don't want to skip dlm_unlock writing the lvb when lock is ex */
298 
299 	if (gl->gl_lksb.sb_lvbptr && (gl->gl_state == LM_ST_EXCLUSIVE))
300 		lvb_needs_unlock = 1;
301 
302 	if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) &&
303 	    !lvb_needs_unlock) {
304 		gfs2_glock_free(gl);
305 		return;
306 	}
307 
308 	error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK,
309 			   NULL, gl);
310 	if (error) {
311 		printk(KERN_ERR "gdlm_unlock %x,%llx err=%d\n",
312 		       gl->gl_name.ln_type,
313 		       (unsigned long long)gl->gl_name.ln_number, error);
314 		return;
315 	}
316 }
317 
318 static void gdlm_cancel(struct gfs2_glock *gl)
319 {
320 	struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
321 	dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl);
322 }
323 
324 /*
325  * dlm/gfs2 recovery coordination using dlm_recover callbacks
326  *
327  *  1. dlm_controld sees lockspace members change
328  *  2. dlm_controld blocks dlm-kernel locking activity
329  *  3. dlm_controld within dlm-kernel notifies gfs2 (recover_prep)
330  *  4. dlm_controld starts and finishes its own user level recovery
331  *  5. dlm_controld starts dlm-kernel dlm_recoverd to do kernel recovery
332  *  6. dlm_recoverd notifies gfs2 of failed nodes (recover_slot)
333  *  7. dlm_recoverd does its own lock recovery
334  *  8. dlm_recoverd unblocks dlm-kernel locking activity
335  *  9. dlm_recoverd notifies gfs2 when done (recover_done with new generation)
336  * 10. gfs2_control updates control_lock lvb with new generation and jid bits
337  * 11. gfs2_control enqueues journals for gfs2_recover to recover (maybe none)
338  * 12. gfs2_recover dequeues and recovers journals of failed nodes
339  * 13. gfs2_recover provides recovery results to gfs2_control (recovery_result)
340  * 14. gfs2_control updates control_lock lvb jid bits for recovered journals
341  * 15. gfs2_control unblocks normal locking when all journals are recovered
342  *
343  * - failures during recovery
344  *
345  * recover_prep() may set BLOCK_LOCKS (step 3) again before gfs2_control
346  * clears BLOCK_LOCKS (step 15), e.g. another node fails while still
347  * recovering for a prior failure.  gfs2_control needs a way to detect
348  * this so it can leave BLOCK_LOCKS set in step 15.  This is managed using
349  * the recover_block and recover_start values.
350  *
351  * recover_done() provides a new lockspace generation number each time it
352  * is called (step 9).  This generation number is saved as recover_start.
353  * When recover_prep() is called, it sets BLOCK_LOCKS and sets
354  * recover_block = recover_start.  So, while recover_block is equal to
355  * recover_start, BLOCK_LOCKS should remain set.  (recover_spin must
356  * be held around the BLOCK_LOCKS/recover_block/recover_start logic.)
357  *
358  * - more specific gfs2 steps in sequence above
359  *
360  *  3. recover_prep sets BLOCK_LOCKS and sets recover_block = recover_start
361  *  6. recover_slot records any failed jids (maybe none)
362  *  9. recover_done sets recover_start = new generation number
363  * 10. gfs2_control sets control_lock lvb = new gen + bits for failed jids
364  * 12. gfs2_recover does journal recoveries for failed jids identified above
365  * 14. gfs2_control clears control_lock lvb bits for recovered jids
366  * 15. gfs2_control checks if recover_block == recover_start (step 3 occured
367  *     again) then do nothing, otherwise if recover_start > recover_block
368  *     then clear BLOCK_LOCKS.
369  *
370  * - parallel recovery steps across all nodes
371  *
372  * All nodes attempt to update the control_lock lvb with the new generation
373  * number and jid bits, but only the first to get the control_lock EX will
374  * do so; others will see that it's already done (lvb already contains new
375  * generation number.)
376  *
377  * . All nodes get the same recover_prep/recover_slot/recover_done callbacks
378  * . All nodes attempt to set control_lock lvb gen + bits for the new gen
379  * . One node gets control_lock first and writes the lvb, others see it's done
380  * . All nodes attempt to recover jids for which they see control_lock bits set
381  * . One node succeeds for a jid, and that one clears the jid bit in the lvb
382  * . All nodes will eventually see all lvb bits clear and unblock locks
383  *
384  * - is there a problem with clearing an lvb bit that should be set
385  *   and missing a journal recovery?
386  *
387  * 1. jid fails
388  * 2. lvb bit set for step 1
389  * 3. jid recovered for step 1
390  * 4. jid taken again (new mount)
391  * 5. jid fails (for step 4)
392  * 6. lvb bit set for step 5 (will already be set)
393  * 7. lvb bit cleared for step 3
394  *
395  * This is not a problem because the failure in step 5 does not
396  * require recovery, because the mount in step 4 could not have
397  * progressed far enough to unblock locks and access the fs.  The
398  * control_mount() function waits for all recoveries to be complete
399  * for the latest lockspace generation before ever unblocking locks
400  * and returning.  The mount in step 4 waits until the recovery in
401  * step 1 is done.
402  *
403  * - special case of first mounter: first node to mount the fs
404  *
405  * The first node to mount a gfs2 fs needs to check all the journals
406  * and recover any that need recovery before other nodes are allowed
407  * to mount the fs.  (Others may begin mounting, but they must wait
408  * for the first mounter to be done before taking locks on the fs
409  * or accessing the fs.)  This has two parts:
410  *
411  * 1. The mounted_lock tells a node it's the first to mount the fs.
412  * Each node holds the mounted_lock in PR while it's mounted.
413  * Each node tries to acquire the mounted_lock in EX when it mounts.
414  * If a node is granted the mounted_lock EX it means there are no
415  * other mounted nodes (no PR locks exist), and it is the first mounter.
416  * The mounted_lock is demoted to PR when first recovery is done, so
417  * others will fail to get an EX lock, but will get a PR lock.
418  *
419  * 2. The control_lock blocks others in control_mount() while the first
420  * mounter is doing first mount recovery of all journals.
421  * A mounting node needs to acquire control_lock in EX mode before
422  * it can proceed.  The first mounter holds control_lock in EX while doing
423  * the first mount recovery, blocking mounts from other nodes, then demotes
424  * control_lock to NL when it's done (others_may_mount/first_done),
425  * allowing other nodes to continue mounting.
426  *
427  * first mounter:
428  * control_lock EX/NOQUEUE success
429  * mounted_lock EX/NOQUEUE success (no other PR, so no other mounters)
430  * set first=1
431  * do first mounter recovery
432  * mounted_lock EX->PR
433  * control_lock EX->NL, write lvb generation
434  *
435  * other mounter:
436  * control_lock EX/NOQUEUE success (if fail -EAGAIN, retry)
437  * mounted_lock EX/NOQUEUE fail -EAGAIN (expected due to other mounters PR)
438  * mounted_lock PR/NOQUEUE success
439  * read lvb generation
440  * control_lock EX->NL
441  * set first=0
442  *
443  * - mount during recovery
444  *
445  * If a node mounts while others are doing recovery (not first mounter),
446  * the mounting node will get its initial recover_done() callback without
447  * having seen any previous failures/callbacks.
448  *
449  * It must wait for all recoveries preceding its mount to be finished
450  * before it unblocks locks.  It does this by repeating the "other mounter"
451  * steps above until the lvb generation number is >= its mount generation
452  * number (from initial recover_done) and all lvb bits are clear.
453  *
454  * - control_lock lvb format
455  *
456  * 4 bytes generation number: the latest dlm lockspace generation number
457  * from recover_done callback.  Indicates the jid bitmap has been updated
458  * to reflect all slot failures through that generation.
459  * 4 bytes unused.
460  * GDLM_LVB_SIZE-8 bytes of jid bit map. If bit N is set, it indicates
461  * that jid N needs recovery.
462  */
463 
464 #define JID_BITMAP_OFFSET 8 /* 4 byte generation number + 4 byte unused */
465 
466 static void control_lvb_read(struct lm_lockstruct *ls, uint32_t *lvb_gen,
467 			     char *lvb_bits)
468 {
469 	uint32_t gen;
470 	memcpy(lvb_bits, ls->ls_control_lvb, GDLM_LVB_SIZE);
471 	memcpy(&gen, lvb_bits, sizeof(uint32_t));
472 	*lvb_gen = le32_to_cpu(gen);
473 }
474 
475 static void control_lvb_write(struct lm_lockstruct *ls, uint32_t lvb_gen,
476 			      char *lvb_bits)
477 {
478 	uint32_t gen;
479 	memcpy(ls->ls_control_lvb, lvb_bits, GDLM_LVB_SIZE);
480 	gen = cpu_to_le32(lvb_gen);
481 	memcpy(ls->ls_control_lvb, &gen, sizeof(uint32_t));
482 }
483 
484 static int all_jid_bits_clear(char *lvb)
485 {
486 	int i;
487 	for (i = JID_BITMAP_OFFSET; i < GDLM_LVB_SIZE; i++) {
488 		if (lvb[i])
489 			return 0;
490 	}
491 	return 1;
492 }
493 
494 static void sync_wait_cb(void *arg)
495 {
496 	struct lm_lockstruct *ls = arg;
497 	complete(&ls->ls_sync_wait);
498 }
499 
500 static int sync_unlock(struct gfs2_sbd *sdp, struct dlm_lksb *lksb, char *name)
501 {
502 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
503 	int error;
504 
505 	error = dlm_unlock(ls->ls_dlm, lksb->sb_lkid, 0, lksb, ls);
506 	if (error) {
507 		fs_err(sdp, "%s lkid %x error %d\n",
508 		       name, lksb->sb_lkid, error);
509 		return error;
510 	}
511 
512 	wait_for_completion(&ls->ls_sync_wait);
513 
514 	if (lksb->sb_status != -DLM_EUNLOCK) {
515 		fs_err(sdp, "%s lkid %x status %d\n",
516 		       name, lksb->sb_lkid, lksb->sb_status);
517 		return -1;
518 	}
519 	return 0;
520 }
521 
522 static int sync_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags,
523 		     unsigned int num, struct dlm_lksb *lksb, char *name)
524 {
525 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
526 	char strname[GDLM_STRNAME_BYTES];
527 	int error, status;
528 
529 	memset(strname, 0, GDLM_STRNAME_BYTES);
530 	snprintf(strname, GDLM_STRNAME_BYTES, "%8x%16x", LM_TYPE_NONDISK, num);
531 
532 	error = dlm_lock(ls->ls_dlm, mode, lksb, flags,
533 			 strname, GDLM_STRNAME_BYTES - 1,
534 			 0, sync_wait_cb, ls, NULL);
535 	if (error) {
536 		fs_err(sdp, "%s lkid %x flags %x mode %d error %d\n",
537 		       name, lksb->sb_lkid, flags, mode, error);
538 		return error;
539 	}
540 
541 	wait_for_completion(&ls->ls_sync_wait);
542 
543 	status = lksb->sb_status;
544 
545 	if (status && status != -EAGAIN) {
546 		fs_err(sdp, "%s lkid %x flags %x mode %d status %d\n",
547 		       name, lksb->sb_lkid, flags, mode, status);
548 	}
549 
550 	return status;
551 }
552 
553 static int mounted_unlock(struct gfs2_sbd *sdp)
554 {
555 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
556 	return sync_unlock(sdp, &ls->ls_mounted_lksb, "mounted_lock");
557 }
558 
559 static int mounted_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
560 {
561 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
562 	return sync_lock(sdp, mode, flags, GFS2_MOUNTED_LOCK,
563 			 &ls->ls_mounted_lksb, "mounted_lock");
564 }
565 
566 static int control_unlock(struct gfs2_sbd *sdp)
567 {
568 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
569 	return sync_unlock(sdp, &ls->ls_control_lksb, "control_lock");
570 }
571 
572 static int control_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
573 {
574 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
575 	return sync_lock(sdp, mode, flags, GFS2_CONTROL_LOCK,
576 			 &ls->ls_control_lksb, "control_lock");
577 }
578 
579 static void gfs2_control_func(struct work_struct *work)
580 {
581 	struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work);
582 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
583 	char lvb_bits[GDLM_LVB_SIZE];
584 	uint32_t block_gen, start_gen, lvb_gen, flags;
585 	int recover_set = 0;
586 	int write_lvb = 0;
587 	int recover_size;
588 	int i, error;
589 
590 	spin_lock(&ls->ls_recover_spin);
591 	/*
592 	 * No MOUNT_DONE means we're still mounting; control_mount()
593 	 * will set this flag, after which this thread will take over
594 	 * all further clearing of BLOCK_LOCKS.
595 	 *
596 	 * FIRST_MOUNT means this node is doing first mounter recovery,
597 	 * for which recovery control is handled by
598 	 * control_mount()/control_first_done(), not this thread.
599 	 */
600 	if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
601 	     test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
602 		spin_unlock(&ls->ls_recover_spin);
603 		return;
604 	}
605 	block_gen = ls->ls_recover_block;
606 	start_gen = ls->ls_recover_start;
607 	spin_unlock(&ls->ls_recover_spin);
608 
609 	/*
610 	 * Equal block_gen and start_gen implies we are between
611 	 * recover_prep and recover_done callbacks, which means
612 	 * dlm recovery is in progress and dlm locking is blocked.
613 	 * There's no point trying to do any work until recover_done.
614 	 */
615 
616 	if (block_gen == start_gen)
617 		return;
618 
619 	/*
620 	 * Propagate recover_submit[] and recover_result[] to lvb:
621 	 * dlm_recoverd adds to recover_submit[] jids needing recovery
622 	 * gfs2_recover adds to recover_result[] journal recovery results
623 	 *
624 	 * set lvb bit for jids in recover_submit[] if the lvb has not
625 	 * yet been updated for the generation of the failure
626 	 *
627 	 * clear lvb bit for jids in recover_result[] if the result of
628 	 * the journal recovery is SUCCESS
629 	 */
630 
631 	error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
632 	if (error) {
633 		fs_err(sdp, "control lock EX error %d\n", error);
634 		return;
635 	}
636 
637 	control_lvb_read(ls, &lvb_gen, lvb_bits);
638 
639 	spin_lock(&ls->ls_recover_spin);
640 	if (block_gen != ls->ls_recover_block ||
641 	    start_gen != ls->ls_recover_start) {
642 		fs_info(sdp, "recover generation %u block1 %u %u\n",
643 			start_gen, block_gen, ls->ls_recover_block);
644 		spin_unlock(&ls->ls_recover_spin);
645 		control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
646 		return;
647 	}
648 
649 	recover_size = ls->ls_recover_size;
650 
651 	if (lvb_gen <= start_gen) {
652 		/*
653 		 * Clear lvb bits for jids we've successfully recovered.
654 		 * Because all nodes attempt to recover failed journals,
655 		 * a journal can be recovered multiple times successfully
656 		 * in succession.  Only the first will really do recovery,
657 		 * the others find it clean, but still report a successful
658 		 * recovery.  So, another node may have already recovered
659 		 * the jid and cleared the lvb bit for it.
660 		 */
661 		for (i = 0; i < recover_size; i++) {
662 			if (ls->ls_recover_result[i] != LM_RD_SUCCESS)
663 				continue;
664 
665 			ls->ls_recover_result[i] = 0;
666 
667 			if (!test_bit_le(i, lvb_bits + JID_BITMAP_OFFSET))
668 				continue;
669 
670 			__clear_bit_le(i, lvb_bits + JID_BITMAP_OFFSET);
671 			write_lvb = 1;
672 		}
673 	}
674 
675 	if (lvb_gen == start_gen) {
676 		/*
677 		 * Failed slots before start_gen are already set in lvb.
678 		 */
679 		for (i = 0; i < recover_size; i++) {
680 			if (!ls->ls_recover_submit[i])
681 				continue;
682 			if (ls->ls_recover_submit[i] < lvb_gen)
683 				ls->ls_recover_submit[i] = 0;
684 		}
685 	} else if (lvb_gen < start_gen) {
686 		/*
687 		 * Failed slots before start_gen are not yet set in lvb.
688 		 */
689 		for (i = 0; i < recover_size; i++) {
690 			if (!ls->ls_recover_submit[i])
691 				continue;
692 			if (ls->ls_recover_submit[i] < start_gen) {
693 				ls->ls_recover_submit[i] = 0;
694 				__set_bit_le(i, lvb_bits + JID_BITMAP_OFFSET);
695 			}
696 		}
697 		/* even if there are no bits to set, we need to write the
698 		   latest generation to the lvb */
699 		write_lvb = 1;
700 	} else {
701 		/*
702 		 * we should be getting a recover_done() for lvb_gen soon
703 		 */
704 	}
705 	spin_unlock(&ls->ls_recover_spin);
706 
707 	if (write_lvb) {
708 		control_lvb_write(ls, start_gen, lvb_bits);
709 		flags = DLM_LKF_CONVERT | DLM_LKF_VALBLK;
710 	} else {
711 		flags = DLM_LKF_CONVERT;
712 	}
713 
714 	error = control_lock(sdp, DLM_LOCK_NL, flags);
715 	if (error) {
716 		fs_err(sdp, "control lock NL error %d\n", error);
717 		return;
718 	}
719 
720 	/*
721 	 * Everyone will see jid bits set in the lvb, run gfs2_recover_set(),
722 	 * and clear a jid bit in the lvb if the recovery is a success.
723 	 * Eventually all journals will be recovered, all jid bits will
724 	 * be cleared in the lvb, and everyone will clear BLOCK_LOCKS.
725 	 */
726 
727 	for (i = 0; i < recover_size; i++) {
728 		if (test_bit_le(i, lvb_bits + JID_BITMAP_OFFSET)) {
729 			fs_info(sdp, "recover generation %u jid %d\n",
730 				start_gen, i);
731 			gfs2_recover_set(sdp, i);
732 			recover_set++;
733 		}
734 	}
735 	if (recover_set)
736 		return;
737 
738 	/*
739 	 * No more jid bits set in lvb, all recovery is done, unblock locks
740 	 * (unless a new recover_prep callback has occured blocking locks
741 	 * again while working above)
742 	 */
743 
744 	spin_lock(&ls->ls_recover_spin);
745 	if (ls->ls_recover_block == block_gen &&
746 	    ls->ls_recover_start == start_gen) {
747 		clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
748 		spin_unlock(&ls->ls_recover_spin);
749 		fs_info(sdp, "recover generation %u done\n", start_gen);
750 		gfs2_glock_thaw(sdp);
751 	} else {
752 		fs_info(sdp, "recover generation %u block2 %u %u\n",
753 			start_gen, block_gen, ls->ls_recover_block);
754 		spin_unlock(&ls->ls_recover_spin);
755 	}
756 }
757 
758 static int control_mount(struct gfs2_sbd *sdp)
759 {
760 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
761 	char lvb_bits[GDLM_LVB_SIZE];
762 	uint32_t start_gen, block_gen, mount_gen, lvb_gen;
763 	int mounted_mode;
764 	int retries = 0;
765 	int error;
766 
767 	memset(&ls->ls_mounted_lksb, 0, sizeof(struct dlm_lksb));
768 	memset(&ls->ls_control_lksb, 0, sizeof(struct dlm_lksb));
769 	memset(&ls->ls_control_lvb, 0, GDLM_LVB_SIZE);
770 	ls->ls_control_lksb.sb_lvbptr = ls->ls_control_lvb;
771 	init_completion(&ls->ls_sync_wait);
772 
773 	set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
774 
775 	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_VALBLK);
776 	if (error) {
777 		fs_err(sdp, "control_mount control_lock NL error %d\n", error);
778 		return error;
779 	}
780 
781 	error = mounted_lock(sdp, DLM_LOCK_NL, 0);
782 	if (error) {
783 		fs_err(sdp, "control_mount mounted_lock NL error %d\n", error);
784 		control_unlock(sdp);
785 		return error;
786 	}
787 	mounted_mode = DLM_LOCK_NL;
788 
789 restart:
790 	if (retries++ && signal_pending(current)) {
791 		error = -EINTR;
792 		goto fail;
793 	}
794 
795 	/*
796 	 * We always start with both locks in NL. control_lock is
797 	 * demoted to NL below so we don't need to do it here.
798 	 */
799 
800 	if (mounted_mode != DLM_LOCK_NL) {
801 		error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
802 		if (error)
803 			goto fail;
804 		mounted_mode = DLM_LOCK_NL;
805 	}
806 
807 	/*
808 	 * Other nodes need to do some work in dlm recovery and gfs2_control
809 	 * before the recover_done and control_lock will be ready for us below.
810 	 * A delay here is not required but often avoids having to retry.
811 	 */
812 
813 	msleep_interruptible(500);
814 
815 	/*
816 	 * Acquire control_lock in EX and mounted_lock in either EX or PR.
817 	 * control_lock lvb keeps track of any pending journal recoveries.
818 	 * mounted_lock indicates if any other nodes have the fs mounted.
819 	 */
820 
821 	error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE|DLM_LKF_VALBLK);
822 	if (error == -EAGAIN) {
823 		goto restart;
824 	} else if (error) {
825 		fs_err(sdp, "control_mount control_lock EX error %d\n", error);
826 		goto fail;
827 	}
828 
829 	error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
830 	if (!error) {
831 		mounted_mode = DLM_LOCK_EX;
832 		goto locks_done;
833 	} else if (error != -EAGAIN) {
834 		fs_err(sdp, "control_mount mounted_lock EX error %d\n", error);
835 		goto fail;
836 	}
837 
838 	error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
839 	if (!error) {
840 		mounted_mode = DLM_LOCK_PR;
841 		goto locks_done;
842 	} else {
843 		/* not even -EAGAIN should happen here */
844 		fs_err(sdp, "control_mount mounted_lock PR error %d\n", error);
845 		goto fail;
846 	}
847 
848 locks_done:
849 	/*
850 	 * If we got both locks above in EX, then we're the first mounter.
851 	 * If not, then we need to wait for the control_lock lvb to be
852 	 * updated by other mounted nodes to reflect our mount generation.
853 	 *
854 	 * In simple first mounter cases, first mounter will see zero lvb_gen,
855 	 * but in cases where all existing nodes leave/fail before mounting
856 	 * nodes finish control_mount, then all nodes will be mounting and
857 	 * lvb_gen will be non-zero.
858 	 */
859 
860 	control_lvb_read(ls, &lvb_gen, lvb_bits);
861 
862 	if (lvb_gen == 0xFFFFFFFF) {
863 		/* special value to force mount attempts to fail */
864 		fs_err(sdp, "control_mount control_lock disabled\n");
865 		error = -EINVAL;
866 		goto fail;
867 	}
868 
869 	if (mounted_mode == DLM_LOCK_EX) {
870 		/* first mounter, keep both EX while doing first recovery */
871 		spin_lock(&ls->ls_recover_spin);
872 		clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
873 		set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
874 		set_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
875 		spin_unlock(&ls->ls_recover_spin);
876 		fs_info(sdp, "first mounter control generation %u\n", lvb_gen);
877 		return 0;
878 	}
879 
880 	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
881 	if (error)
882 		goto fail;
883 
884 	/*
885 	 * We are not first mounter, now we need to wait for the control_lock
886 	 * lvb generation to be >= the generation from our first recover_done
887 	 * and all lvb bits to be clear (no pending journal recoveries.)
888 	 */
889 
890 	if (!all_jid_bits_clear(lvb_bits)) {
891 		/* journals need recovery, wait until all are clear */
892 		fs_info(sdp, "control_mount wait for journal recovery\n");
893 		goto restart;
894 	}
895 
896 	spin_lock(&ls->ls_recover_spin);
897 	block_gen = ls->ls_recover_block;
898 	start_gen = ls->ls_recover_start;
899 	mount_gen = ls->ls_recover_mount;
900 
901 	if (lvb_gen < mount_gen) {
902 		/* wait for mounted nodes to update control_lock lvb to our
903 		   generation, which might include new recovery bits set */
904 		fs_info(sdp, "control_mount wait1 block %u start %u mount %u "
905 			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
906 			lvb_gen, ls->ls_recover_flags);
907 		spin_unlock(&ls->ls_recover_spin);
908 		goto restart;
909 	}
910 
911 	if (lvb_gen != start_gen) {
912 		/* wait for mounted nodes to update control_lock lvb to the
913 		   latest recovery generation */
914 		fs_info(sdp, "control_mount wait2 block %u start %u mount %u "
915 			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
916 			lvb_gen, ls->ls_recover_flags);
917 		spin_unlock(&ls->ls_recover_spin);
918 		goto restart;
919 	}
920 
921 	if (block_gen == start_gen) {
922 		/* dlm recovery in progress, wait for it to finish */
923 		fs_info(sdp, "control_mount wait3 block %u start %u mount %u "
924 			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
925 			lvb_gen, ls->ls_recover_flags);
926 		spin_unlock(&ls->ls_recover_spin);
927 		goto restart;
928 	}
929 
930 	clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
931 	set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
932 	memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
933 	memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
934 	spin_unlock(&ls->ls_recover_spin);
935 	return 0;
936 
937 fail:
938 	mounted_unlock(sdp);
939 	control_unlock(sdp);
940 	return error;
941 }
942 
943 static int dlm_recovery_wait(void *word)
944 {
945 	schedule();
946 	return 0;
947 }
948 
949 static int control_first_done(struct gfs2_sbd *sdp)
950 {
951 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
952 	char lvb_bits[GDLM_LVB_SIZE];
953 	uint32_t start_gen, block_gen;
954 	int error;
955 
956 restart:
957 	spin_lock(&ls->ls_recover_spin);
958 	start_gen = ls->ls_recover_start;
959 	block_gen = ls->ls_recover_block;
960 
961 	if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags) ||
962 	    !test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
963 	    !test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
964 		/* sanity check, should not happen */
965 		fs_err(sdp, "control_first_done start %u block %u flags %lx\n",
966 		       start_gen, block_gen, ls->ls_recover_flags);
967 		spin_unlock(&ls->ls_recover_spin);
968 		control_unlock(sdp);
969 		return -1;
970 	}
971 
972 	if (start_gen == block_gen) {
973 		/*
974 		 * Wait for the end of a dlm recovery cycle to switch from
975 		 * first mounter recovery.  We can ignore any recover_slot
976 		 * callbacks between the recover_prep and next recover_done
977 		 * because we are still the first mounter and any failed nodes
978 		 * have not fully mounted, so they don't need recovery.
979 		 */
980 		spin_unlock(&ls->ls_recover_spin);
981 		fs_info(sdp, "control_first_done wait gen %u\n", start_gen);
982 
983 		wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY,
984 			    dlm_recovery_wait, TASK_UNINTERRUPTIBLE);
985 		goto restart;
986 	}
987 
988 	clear_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
989 	set_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags);
990 	memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
991 	memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
992 	spin_unlock(&ls->ls_recover_spin);
993 
994 	memset(lvb_bits, 0, sizeof(lvb_bits));
995 	control_lvb_write(ls, start_gen, lvb_bits);
996 
997 	error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT);
998 	if (error)
999 		fs_err(sdp, "control_first_done mounted PR error %d\n", error);
1000 
1001 	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
1002 	if (error)
1003 		fs_err(sdp, "control_first_done control NL error %d\n", error);
1004 
1005 	return error;
1006 }
1007 
1008 /*
1009  * Expand static jid arrays if necessary (by increments of RECOVER_SIZE_INC)
1010  * to accomodate the largest slot number.  (NB dlm slot numbers start at 1,
1011  * gfs2 jids start at 0, so jid = slot - 1)
1012  */
1013 
1014 #define RECOVER_SIZE_INC 16
1015 
1016 static int set_recover_size(struct gfs2_sbd *sdp, struct dlm_slot *slots,
1017 			    int num_slots)
1018 {
1019 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1020 	uint32_t *submit = NULL;
1021 	uint32_t *result = NULL;
1022 	uint32_t old_size, new_size;
1023 	int i, max_jid;
1024 
1025 	max_jid = 0;
1026 	for (i = 0; i < num_slots; i++) {
1027 		if (max_jid < slots[i].slot - 1)
1028 			max_jid = slots[i].slot - 1;
1029 	}
1030 
1031 	old_size = ls->ls_recover_size;
1032 
1033 	if (old_size >= max_jid + 1)
1034 		return 0;
1035 
1036 	new_size = old_size + RECOVER_SIZE_INC;
1037 
1038 	submit = kzalloc(new_size * sizeof(uint32_t), GFP_NOFS);
1039 	result = kzalloc(new_size * sizeof(uint32_t), GFP_NOFS);
1040 	if (!submit || !result) {
1041 		kfree(submit);
1042 		kfree(result);
1043 		return -ENOMEM;
1044 	}
1045 
1046 	spin_lock(&ls->ls_recover_spin);
1047 	memcpy(submit, ls->ls_recover_submit, old_size * sizeof(uint32_t));
1048 	memcpy(result, ls->ls_recover_result, old_size * sizeof(uint32_t));
1049 	kfree(ls->ls_recover_submit);
1050 	kfree(ls->ls_recover_result);
1051 	ls->ls_recover_submit = submit;
1052 	ls->ls_recover_result = result;
1053 	ls->ls_recover_size = new_size;
1054 	spin_unlock(&ls->ls_recover_spin);
1055 	return 0;
1056 }
1057 
1058 static void free_recover_size(struct lm_lockstruct *ls)
1059 {
1060 	kfree(ls->ls_recover_submit);
1061 	kfree(ls->ls_recover_result);
1062 	ls->ls_recover_submit = NULL;
1063 	ls->ls_recover_result = NULL;
1064 	ls->ls_recover_size = 0;
1065 }
1066 
1067 /* dlm calls before it does lock recovery */
1068 
1069 static void gdlm_recover_prep(void *arg)
1070 {
1071 	struct gfs2_sbd *sdp = arg;
1072 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1073 
1074 	spin_lock(&ls->ls_recover_spin);
1075 	ls->ls_recover_block = ls->ls_recover_start;
1076 	set_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
1077 
1078 	if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
1079 	     test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
1080 		spin_unlock(&ls->ls_recover_spin);
1081 		return;
1082 	}
1083 	set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
1084 	spin_unlock(&ls->ls_recover_spin);
1085 }
1086 
1087 /* dlm calls after recover_prep has been completed on all lockspace members;
1088    identifies slot/jid of failed member */
1089 
1090 static void gdlm_recover_slot(void *arg, struct dlm_slot *slot)
1091 {
1092 	struct gfs2_sbd *sdp = arg;
1093 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1094 	int jid = slot->slot - 1;
1095 
1096 	spin_lock(&ls->ls_recover_spin);
1097 	if (ls->ls_recover_size < jid + 1) {
1098 		fs_err(sdp, "recover_slot jid %d gen %u short size %d",
1099 		       jid, ls->ls_recover_block, ls->ls_recover_size);
1100 		spin_unlock(&ls->ls_recover_spin);
1101 		return;
1102 	}
1103 
1104 	if (ls->ls_recover_submit[jid]) {
1105 		fs_info(sdp, "recover_slot jid %d gen %u prev %u",
1106 			jid, ls->ls_recover_block, ls->ls_recover_submit[jid]);
1107 	}
1108 	ls->ls_recover_submit[jid] = ls->ls_recover_block;
1109 	spin_unlock(&ls->ls_recover_spin);
1110 }
1111 
1112 /* dlm calls after recover_slot and after it completes lock recovery */
1113 
1114 static void gdlm_recover_done(void *arg, struct dlm_slot *slots, int num_slots,
1115 			      int our_slot, uint32_t generation)
1116 {
1117 	struct gfs2_sbd *sdp = arg;
1118 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1119 
1120 	/* ensure the ls jid arrays are large enough */
1121 	set_recover_size(sdp, slots, num_slots);
1122 
1123 	spin_lock(&ls->ls_recover_spin);
1124 	ls->ls_recover_start = generation;
1125 
1126 	if (!ls->ls_recover_mount) {
1127 		ls->ls_recover_mount = generation;
1128 		ls->ls_jid = our_slot - 1;
1129 	}
1130 
1131 	if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
1132 		queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work, 0);
1133 
1134 	clear_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
1135 	smp_mb__after_clear_bit();
1136 	wake_up_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY);
1137 	spin_unlock(&ls->ls_recover_spin);
1138 }
1139 
1140 /* gfs2_recover thread has a journal recovery result */
1141 
1142 static void gdlm_recovery_result(struct gfs2_sbd *sdp, unsigned int jid,
1143 				 unsigned int result)
1144 {
1145 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1146 
1147 	if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1148 		return;
1149 
1150 	/* don't care about the recovery of own journal during mount */
1151 	if (jid == ls->ls_jid)
1152 		return;
1153 
1154 	spin_lock(&ls->ls_recover_spin);
1155 	if (test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
1156 		spin_unlock(&ls->ls_recover_spin);
1157 		return;
1158 	}
1159 	if (ls->ls_recover_size < jid + 1) {
1160 		fs_err(sdp, "recovery_result jid %d short size %d",
1161 		       jid, ls->ls_recover_size);
1162 		spin_unlock(&ls->ls_recover_spin);
1163 		return;
1164 	}
1165 
1166 	fs_info(sdp, "recover jid %d result %s\n", jid,
1167 		result == LM_RD_GAVEUP ? "busy" : "success");
1168 
1169 	ls->ls_recover_result[jid] = result;
1170 
1171 	/* GAVEUP means another node is recovering the journal; delay our
1172 	   next attempt to recover it, to give the other node a chance to
1173 	   finish before trying again */
1174 
1175 	if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
1176 		queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work,
1177 				   result == LM_RD_GAVEUP ? HZ : 0);
1178 	spin_unlock(&ls->ls_recover_spin);
1179 }
1180 
1181 const struct dlm_lockspace_ops gdlm_lockspace_ops = {
1182 	.recover_prep = gdlm_recover_prep,
1183 	.recover_slot = gdlm_recover_slot,
1184 	.recover_done = gdlm_recover_done,
1185 };
1186 
1187 static int gdlm_mount(struct gfs2_sbd *sdp, const char *table)
1188 {
1189 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1190 	char cluster[GFS2_LOCKNAME_LEN];
1191 	const char *fsname;
1192 	uint32_t flags;
1193 	int error, ops_result;
1194 
1195 	/*
1196 	 * initialize everything
1197 	 */
1198 
1199 	INIT_DELAYED_WORK(&sdp->sd_control_work, gfs2_control_func);
1200 	spin_lock_init(&ls->ls_recover_spin);
1201 	ls->ls_recover_flags = 0;
1202 	ls->ls_recover_mount = 0;
1203 	ls->ls_recover_start = 0;
1204 	ls->ls_recover_block = 0;
1205 	ls->ls_recover_size = 0;
1206 	ls->ls_recover_submit = NULL;
1207 	ls->ls_recover_result = NULL;
1208 
1209 	error = set_recover_size(sdp, NULL, 0);
1210 	if (error)
1211 		goto fail;
1212 
1213 	/*
1214 	 * prepare dlm_new_lockspace args
1215 	 */
1216 
1217 	fsname = strchr(table, ':');
1218 	if (!fsname) {
1219 		fs_info(sdp, "no fsname found\n");
1220 		error = -EINVAL;
1221 		goto fail_free;
1222 	}
1223 	memset(cluster, 0, sizeof(cluster));
1224 	memcpy(cluster, table, strlen(table) - strlen(fsname));
1225 	fsname++;
1226 
1227 	flags = DLM_LSFL_FS | DLM_LSFL_NEWEXCL;
1228 
1229 	/*
1230 	 * create/join lockspace
1231 	 */
1232 
1233 	error = dlm_new_lockspace(fsname, cluster, flags, GDLM_LVB_SIZE,
1234 				  &gdlm_lockspace_ops, sdp, &ops_result,
1235 				  &ls->ls_dlm);
1236 	if (error) {
1237 		fs_err(sdp, "dlm_new_lockspace error %d\n", error);
1238 		goto fail_free;
1239 	}
1240 
1241 	if (ops_result < 0) {
1242 		/*
1243 		 * dlm does not support ops callbacks,
1244 		 * old dlm_controld/gfs_controld are used, try without ops.
1245 		 */
1246 		fs_info(sdp, "dlm lockspace ops not used\n");
1247 		free_recover_size(ls);
1248 		set_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags);
1249 		return 0;
1250 	}
1251 
1252 	if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags)) {
1253 		fs_err(sdp, "dlm lockspace ops disallow jid preset\n");
1254 		error = -EINVAL;
1255 		goto fail_release;
1256 	}
1257 
1258 	/*
1259 	 * control_mount() uses control_lock to determine first mounter,
1260 	 * and for later mounts, waits for any recoveries to be cleared.
1261 	 */
1262 
1263 	error = control_mount(sdp);
1264 	if (error) {
1265 		fs_err(sdp, "mount control error %d\n", error);
1266 		goto fail_release;
1267 	}
1268 
1269 	ls->ls_first = !!test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
1270 	clear_bit(SDF_NOJOURNALID, &sdp->sd_flags);
1271 	smp_mb__after_clear_bit();
1272 	wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID);
1273 	return 0;
1274 
1275 fail_release:
1276 	dlm_release_lockspace(ls->ls_dlm, 2);
1277 fail_free:
1278 	free_recover_size(ls);
1279 fail:
1280 	return error;
1281 }
1282 
1283 static void gdlm_first_done(struct gfs2_sbd *sdp)
1284 {
1285 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1286 	int error;
1287 
1288 	if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1289 		return;
1290 
1291 	error = control_first_done(sdp);
1292 	if (error)
1293 		fs_err(sdp, "mount first_done error %d\n", error);
1294 }
1295 
1296 static void gdlm_unmount(struct gfs2_sbd *sdp)
1297 {
1298 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1299 
1300 	if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1301 		goto release;
1302 
1303 	/* wait for gfs2_control_wq to be done with this mount */
1304 
1305 	spin_lock(&ls->ls_recover_spin);
1306 	set_bit(DFL_UNMOUNT, &ls->ls_recover_flags);
1307 	spin_unlock(&ls->ls_recover_spin);
1308 	flush_delayed_work(&sdp->sd_control_work);
1309 
1310 	/* mounted_lock and control_lock will be purged in dlm recovery */
1311 release:
1312 	if (ls->ls_dlm) {
1313 		dlm_release_lockspace(ls->ls_dlm, 2);
1314 		ls->ls_dlm = NULL;
1315 	}
1316 
1317 	free_recover_size(ls);
1318 }
1319 
1320 static const match_table_t dlm_tokens = {
1321 	{ Opt_jid, "jid=%d"},
1322 	{ Opt_id, "id=%d"},
1323 	{ Opt_first, "first=%d"},
1324 	{ Opt_nodir, "nodir=%d"},
1325 	{ Opt_err, NULL },
1326 };
1327 
1328 const struct lm_lockops gfs2_dlm_ops = {
1329 	.lm_proto_name = "lock_dlm",
1330 	.lm_mount = gdlm_mount,
1331 	.lm_first_done = gdlm_first_done,
1332 	.lm_recovery_result = gdlm_recovery_result,
1333 	.lm_unmount = gdlm_unmount,
1334 	.lm_put_lock = gdlm_put_lock,
1335 	.lm_lock = gdlm_lock,
1336 	.lm_cancel = gdlm_cancel,
1337 	.lm_tokens = &dlm_tokens,
1338 };
1339 
1340