xref: /openbmc/linux/fs/gfs2/lock_dlm.c (revision 6da2ec56)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 
12 #include <linux/fs.h>
13 #include <linux/dlm.h>
14 #include <linux/slab.h>
15 #include <linux/types.h>
16 #include <linux/delay.h>
17 #include <linux/gfs2_ondisk.h>
18 #include <linux/sched/signal.h>
19 
20 #include "incore.h"
21 #include "glock.h"
22 #include "util.h"
23 #include "sys.h"
24 #include "trace_gfs2.h"
25 
26 /**
27  * gfs2_update_stats - Update time based stats
28  * @mv: Pointer to mean/variance structure to update
29  * @sample: New data to include
30  *
31  * @delta is the difference between the current rtt sample and the
32  * running average srtt. We add 1/8 of that to the srtt in order to
33  * update the current srtt estimate. The variance estimate is a bit
34  * more complicated. We subtract the abs value of the @delta from
35  * the current variance estimate and add 1/4 of that to the running
36  * total.
37  *
38  * Note that the index points at the array entry containing the smoothed
39  * mean value, and the variance is always in the following entry
40  *
41  * Reference: TCP/IP Illustrated, vol 2, p. 831,832
42  * All times are in units of integer nanoseconds. Unlike the TCP/IP case,
43  * they are not scaled fixed point.
44  */
45 
46 static inline void gfs2_update_stats(struct gfs2_lkstats *s, unsigned index,
47 				     s64 sample)
48 {
49 	s64 delta = sample - s->stats[index];
50 	s->stats[index] += (delta >> 3);
51 	index++;
52 	s->stats[index] += ((abs(delta) - s->stats[index]) >> 2);
53 }
54 
55 /**
56  * gfs2_update_reply_times - Update locking statistics
57  * @gl: The glock to update
58  *
59  * This assumes that gl->gl_dstamp has been set earlier.
60  *
61  * The rtt (lock round trip time) is an estimate of the time
62  * taken to perform a dlm lock request. We update it on each
63  * reply from the dlm.
64  *
65  * The blocking flag is set on the glock for all dlm requests
66  * which may potentially block due to lock requests from other nodes.
67  * DLM requests where the current lock state is exclusive, the
68  * requested state is null (or unlocked) or where the TRY or
69  * TRY_1CB flags are set are classified as non-blocking. All
70  * other DLM requests are counted as (potentially) blocking.
71  */
72 static inline void gfs2_update_reply_times(struct gfs2_glock *gl)
73 {
74 	struct gfs2_pcpu_lkstats *lks;
75 	const unsigned gltype = gl->gl_name.ln_type;
76 	unsigned index = test_bit(GLF_BLOCKING, &gl->gl_flags) ?
77 			 GFS2_LKS_SRTTB : GFS2_LKS_SRTT;
78 	s64 rtt;
79 
80 	preempt_disable();
81 	rtt = ktime_to_ns(ktime_sub(ktime_get_real(), gl->gl_dstamp));
82 	lks = this_cpu_ptr(gl->gl_name.ln_sbd->sd_lkstats);
83 	gfs2_update_stats(&gl->gl_stats, index, rtt);		/* Local */
84 	gfs2_update_stats(&lks->lkstats[gltype], index, rtt);	/* Global */
85 	preempt_enable();
86 
87 	trace_gfs2_glock_lock_time(gl, rtt);
88 }
89 
90 /**
91  * gfs2_update_request_times - Update locking statistics
92  * @gl: The glock to update
93  *
94  * The irt (lock inter-request times) measures the average time
95  * between requests to the dlm. It is updated immediately before
96  * each dlm call.
97  */
98 
99 static inline void gfs2_update_request_times(struct gfs2_glock *gl)
100 {
101 	struct gfs2_pcpu_lkstats *lks;
102 	const unsigned gltype = gl->gl_name.ln_type;
103 	ktime_t dstamp;
104 	s64 irt;
105 
106 	preempt_disable();
107 	dstamp = gl->gl_dstamp;
108 	gl->gl_dstamp = ktime_get_real();
109 	irt = ktime_to_ns(ktime_sub(gl->gl_dstamp, dstamp));
110 	lks = this_cpu_ptr(gl->gl_name.ln_sbd->sd_lkstats);
111 	gfs2_update_stats(&gl->gl_stats, GFS2_LKS_SIRT, irt);		/* Local */
112 	gfs2_update_stats(&lks->lkstats[gltype], GFS2_LKS_SIRT, irt);	/* Global */
113 	preempt_enable();
114 }
115 
116 static void gdlm_ast(void *arg)
117 {
118 	struct gfs2_glock *gl = arg;
119 	unsigned ret = gl->gl_state;
120 
121 	gfs2_update_reply_times(gl);
122 	BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);
123 
124 	if ((gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID) && gl->gl_lksb.sb_lvbptr)
125 		memset(gl->gl_lksb.sb_lvbptr, 0, GDLM_LVB_SIZE);
126 
127 	switch (gl->gl_lksb.sb_status) {
128 	case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */
129 		gfs2_glock_free(gl);
130 		return;
131 	case -DLM_ECANCEL: /* Cancel while getting lock */
132 		ret |= LM_OUT_CANCELED;
133 		goto out;
134 	case -EAGAIN: /* Try lock fails */
135 	case -EDEADLK: /* Deadlock detected */
136 		goto out;
137 	case -ETIMEDOUT: /* Canceled due to timeout */
138 		ret |= LM_OUT_ERROR;
139 		goto out;
140 	case 0: /* Success */
141 		break;
142 	default: /* Something unexpected */
143 		BUG();
144 	}
145 
146 	ret = gl->gl_req;
147 	if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) {
148 		if (gl->gl_req == LM_ST_SHARED)
149 			ret = LM_ST_DEFERRED;
150 		else if (gl->gl_req == LM_ST_DEFERRED)
151 			ret = LM_ST_SHARED;
152 		else
153 			BUG();
154 	}
155 
156 	set_bit(GLF_INITIAL, &gl->gl_flags);
157 	gfs2_glock_complete(gl, ret);
158 	return;
159 out:
160 	if (!test_bit(GLF_INITIAL, &gl->gl_flags))
161 		gl->gl_lksb.sb_lkid = 0;
162 	gfs2_glock_complete(gl, ret);
163 }
164 
165 static void gdlm_bast(void *arg, int mode)
166 {
167 	struct gfs2_glock *gl = arg;
168 
169 	switch (mode) {
170 	case DLM_LOCK_EX:
171 		gfs2_glock_cb(gl, LM_ST_UNLOCKED);
172 		break;
173 	case DLM_LOCK_CW:
174 		gfs2_glock_cb(gl, LM_ST_DEFERRED);
175 		break;
176 	case DLM_LOCK_PR:
177 		gfs2_glock_cb(gl, LM_ST_SHARED);
178 		break;
179 	default:
180 		pr_err("unknown bast mode %d\n", mode);
181 		BUG();
182 	}
183 }
184 
185 /* convert gfs lock-state to dlm lock-mode */
186 
187 static int make_mode(const unsigned int lmstate)
188 {
189 	switch (lmstate) {
190 	case LM_ST_UNLOCKED:
191 		return DLM_LOCK_NL;
192 	case LM_ST_EXCLUSIVE:
193 		return DLM_LOCK_EX;
194 	case LM_ST_DEFERRED:
195 		return DLM_LOCK_CW;
196 	case LM_ST_SHARED:
197 		return DLM_LOCK_PR;
198 	}
199 	pr_err("unknown LM state %d\n", lmstate);
200 	BUG();
201 	return -1;
202 }
203 
204 static u32 make_flags(struct gfs2_glock *gl, const unsigned int gfs_flags,
205 		      const int req)
206 {
207 	u32 lkf = 0;
208 
209 	if (gl->gl_lksb.sb_lvbptr)
210 		lkf |= DLM_LKF_VALBLK;
211 
212 	if (gfs_flags & LM_FLAG_TRY)
213 		lkf |= DLM_LKF_NOQUEUE;
214 
215 	if (gfs_flags & LM_FLAG_TRY_1CB) {
216 		lkf |= DLM_LKF_NOQUEUE;
217 		lkf |= DLM_LKF_NOQUEUEBAST;
218 	}
219 
220 	if (gfs_flags & LM_FLAG_PRIORITY) {
221 		lkf |= DLM_LKF_NOORDER;
222 		lkf |= DLM_LKF_HEADQUE;
223 	}
224 
225 	if (gfs_flags & LM_FLAG_ANY) {
226 		if (req == DLM_LOCK_PR)
227 			lkf |= DLM_LKF_ALTCW;
228 		else if (req == DLM_LOCK_CW)
229 			lkf |= DLM_LKF_ALTPR;
230 		else
231 			BUG();
232 	}
233 
234 	if (gl->gl_lksb.sb_lkid != 0) {
235 		lkf |= DLM_LKF_CONVERT;
236 		if (test_bit(GLF_BLOCKING, &gl->gl_flags))
237 			lkf |= DLM_LKF_QUECVT;
238 	}
239 
240 	return lkf;
241 }
242 
243 static void gfs2_reverse_hex(char *c, u64 value)
244 {
245 	*c = '0';
246 	while (value) {
247 		*c-- = hex_asc[value & 0x0f];
248 		value >>= 4;
249 	}
250 }
251 
252 static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state,
253 		     unsigned int flags)
254 {
255 	struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
256 	int req;
257 	u32 lkf;
258 	char strname[GDLM_STRNAME_BYTES] = "";
259 
260 	req = make_mode(req_state);
261 	lkf = make_flags(gl, flags, req);
262 	gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
263 	gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
264 	if (gl->gl_lksb.sb_lkid) {
265 		gfs2_update_request_times(gl);
266 	} else {
267 		memset(strname, ' ', GDLM_STRNAME_BYTES - 1);
268 		strname[GDLM_STRNAME_BYTES - 1] = '\0';
269 		gfs2_reverse_hex(strname + 7, gl->gl_name.ln_type);
270 		gfs2_reverse_hex(strname + 23, gl->gl_name.ln_number);
271 		gl->gl_dstamp = ktime_get_real();
272 	}
273 	/*
274 	 * Submit the actual lock request.
275 	 */
276 
277 	return dlm_lock(ls->ls_dlm, req, &gl->gl_lksb, lkf, strname,
278 			GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast);
279 }
280 
281 static void gdlm_put_lock(struct gfs2_glock *gl)
282 {
283 	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
284 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
285 	int lvb_needs_unlock = 0;
286 	int error;
287 
288 	if (gl->gl_lksb.sb_lkid == 0) {
289 		gfs2_glock_free(gl);
290 		return;
291 	}
292 
293 	clear_bit(GLF_BLOCKING, &gl->gl_flags);
294 	gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
295 	gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
296 	gfs2_update_request_times(gl);
297 
298 	/* don't want to skip dlm_unlock writing the lvb when lock is ex */
299 
300 	if (gl->gl_lksb.sb_lvbptr && (gl->gl_state == LM_ST_EXCLUSIVE))
301 		lvb_needs_unlock = 1;
302 
303 	if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) &&
304 	    !lvb_needs_unlock) {
305 		gfs2_glock_free(gl);
306 		return;
307 	}
308 
309 	error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK,
310 			   NULL, gl);
311 	if (error) {
312 		pr_err("gdlm_unlock %x,%llx err=%d\n",
313 		       gl->gl_name.ln_type,
314 		       (unsigned long long)gl->gl_name.ln_number, error);
315 		return;
316 	}
317 }
318 
319 static void gdlm_cancel(struct gfs2_glock *gl)
320 {
321 	struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
322 	dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl);
323 }
324 
325 /*
326  * dlm/gfs2 recovery coordination using dlm_recover callbacks
327  *
328  *  1. dlm_controld sees lockspace members change
329  *  2. dlm_controld blocks dlm-kernel locking activity
330  *  3. dlm_controld within dlm-kernel notifies gfs2 (recover_prep)
331  *  4. dlm_controld starts and finishes its own user level recovery
332  *  5. dlm_controld starts dlm-kernel dlm_recoverd to do kernel recovery
333  *  6. dlm_recoverd notifies gfs2 of failed nodes (recover_slot)
334  *  7. dlm_recoverd does its own lock recovery
335  *  8. dlm_recoverd unblocks dlm-kernel locking activity
336  *  9. dlm_recoverd notifies gfs2 when done (recover_done with new generation)
337  * 10. gfs2_control updates control_lock lvb with new generation and jid bits
338  * 11. gfs2_control enqueues journals for gfs2_recover to recover (maybe none)
339  * 12. gfs2_recover dequeues and recovers journals of failed nodes
340  * 13. gfs2_recover provides recovery results to gfs2_control (recovery_result)
341  * 14. gfs2_control updates control_lock lvb jid bits for recovered journals
342  * 15. gfs2_control unblocks normal locking when all journals are recovered
343  *
344  * - failures during recovery
345  *
346  * recover_prep() may set BLOCK_LOCKS (step 3) again before gfs2_control
347  * clears BLOCK_LOCKS (step 15), e.g. another node fails while still
348  * recovering for a prior failure.  gfs2_control needs a way to detect
349  * this so it can leave BLOCK_LOCKS set in step 15.  This is managed using
350  * the recover_block and recover_start values.
351  *
352  * recover_done() provides a new lockspace generation number each time it
353  * is called (step 9).  This generation number is saved as recover_start.
354  * When recover_prep() is called, it sets BLOCK_LOCKS and sets
355  * recover_block = recover_start.  So, while recover_block is equal to
356  * recover_start, BLOCK_LOCKS should remain set.  (recover_spin must
357  * be held around the BLOCK_LOCKS/recover_block/recover_start logic.)
358  *
359  * - more specific gfs2 steps in sequence above
360  *
361  *  3. recover_prep sets BLOCK_LOCKS and sets recover_block = recover_start
362  *  6. recover_slot records any failed jids (maybe none)
363  *  9. recover_done sets recover_start = new generation number
364  * 10. gfs2_control sets control_lock lvb = new gen + bits for failed jids
365  * 12. gfs2_recover does journal recoveries for failed jids identified above
366  * 14. gfs2_control clears control_lock lvb bits for recovered jids
367  * 15. gfs2_control checks if recover_block == recover_start (step 3 occured
368  *     again) then do nothing, otherwise if recover_start > recover_block
369  *     then clear BLOCK_LOCKS.
370  *
371  * - parallel recovery steps across all nodes
372  *
373  * All nodes attempt to update the control_lock lvb with the new generation
374  * number and jid bits, but only the first to get the control_lock EX will
375  * do so; others will see that it's already done (lvb already contains new
376  * generation number.)
377  *
378  * . All nodes get the same recover_prep/recover_slot/recover_done callbacks
379  * . All nodes attempt to set control_lock lvb gen + bits for the new gen
380  * . One node gets control_lock first and writes the lvb, others see it's done
381  * . All nodes attempt to recover jids for which they see control_lock bits set
382  * . One node succeeds for a jid, and that one clears the jid bit in the lvb
383  * . All nodes will eventually see all lvb bits clear and unblock locks
384  *
385  * - is there a problem with clearing an lvb bit that should be set
386  *   and missing a journal recovery?
387  *
388  * 1. jid fails
389  * 2. lvb bit set for step 1
390  * 3. jid recovered for step 1
391  * 4. jid taken again (new mount)
392  * 5. jid fails (for step 4)
393  * 6. lvb bit set for step 5 (will already be set)
394  * 7. lvb bit cleared for step 3
395  *
396  * This is not a problem because the failure in step 5 does not
397  * require recovery, because the mount in step 4 could not have
398  * progressed far enough to unblock locks and access the fs.  The
399  * control_mount() function waits for all recoveries to be complete
400  * for the latest lockspace generation before ever unblocking locks
401  * and returning.  The mount in step 4 waits until the recovery in
402  * step 1 is done.
403  *
404  * - special case of first mounter: first node to mount the fs
405  *
406  * The first node to mount a gfs2 fs needs to check all the journals
407  * and recover any that need recovery before other nodes are allowed
408  * to mount the fs.  (Others may begin mounting, but they must wait
409  * for the first mounter to be done before taking locks on the fs
410  * or accessing the fs.)  This has two parts:
411  *
412  * 1. The mounted_lock tells a node it's the first to mount the fs.
413  * Each node holds the mounted_lock in PR while it's mounted.
414  * Each node tries to acquire the mounted_lock in EX when it mounts.
415  * If a node is granted the mounted_lock EX it means there are no
416  * other mounted nodes (no PR locks exist), and it is the first mounter.
417  * The mounted_lock is demoted to PR when first recovery is done, so
418  * others will fail to get an EX lock, but will get a PR lock.
419  *
420  * 2. The control_lock blocks others in control_mount() while the first
421  * mounter is doing first mount recovery of all journals.
422  * A mounting node needs to acquire control_lock in EX mode before
423  * it can proceed.  The first mounter holds control_lock in EX while doing
424  * the first mount recovery, blocking mounts from other nodes, then demotes
425  * control_lock to NL when it's done (others_may_mount/first_done),
426  * allowing other nodes to continue mounting.
427  *
428  * first mounter:
429  * control_lock EX/NOQUEUE success
430  * mounted_lock EX/NOQUEUE success (no other PR, so no other mounters)
431  * set first=1
432  * do first mounter recovery
433  * mounted_lock EX->PR
434  * control_lock EX->NL, write lvb generation
435  *
436  * other mounter:
437  * control_lock EX/NOQUEUE success (if fail -EAGAIN, retry)
438  * mounted_lock EX/NOQUEUE fail -EAGAIN (expected due to other mounters PR)
439  * mounted_lock PR/NOQUEUE success
440  * read lvb generation
441  * control_lock EX->NL
442  * set first=0
443  *
444  * - mount during recovery
445  *
446  * If a node mounts while others are doing recovery (not first mounter),
447  * the mounting node will get its initial recover_done() callback without
448  * having seen any previous failures/callbacks.
449  *
450  * It must wait for all recoveries preceding its mount to be finished
451  * before it unblocks locks.  It does this by repeating the "other mounter"
452  * steps above until the lvb generation number is >= its mount generation
453  * number (from initial recover_done) and all lvb bits are clear.
454  *
455  * - control_lock lvb format
456  *
457  * 4 bytes generation number: the latest dlm lockspace generation number
458  * from recover_done callback.  Indicates the jid bitmap has been updated
459  * to reflect all slot failures through that generation.
460  * 4 bytes unused.
461  * GDLM_LVB_SIZE-8 bytes of jid bit map. If bit N is set, it indicates
462  * that jid N needs recovery.
463  */
464 
465 #define JID_BITMAP_OFFSET 8 /* 4 byte generation number + 4 byte unused */
466 
467 static void control_lvb_read(struct lm_lockstruct *ls, uint32_t *lvb_gen,
468 			     char *lvb_bits)
469 {
470 	__le32 gen;
471 	memcpy(lvb_bits, ls->ls_control_lvb, GDLM_LVB_SIZE);
472 	memcpy(&gen, lvb_bits, sizeof(__le32));
473 	*lvb_gen = le32_to_cpu(gen);
474 }
475 
476 static void control_lvb_write(struct lm_lockstruct *ls, uint32_t lvb_gen,
477 			      char *lvb_bits)
478 {
479 	__le32 gen;
480 	memcpy(ls->ls_control_lvb, lvb_bits, GDLM_LVB_SIZE);
481 	gen = cpu_to_le32(lvb_gen);
482 	memcpy(ls->ls_control_lvb, &gen, sizeof(__le32));
483 }
484 
485 static int all_jid_bits_clear(char *lvb)
486 {
487 	return !memchr_inv(lvb + JID_BITMAP_OFFSET, 0,
488 			GDLM_LVB_SIZE - JID_BITMAP_OFFSET);
489 }
490 
491 static void sync_wait_cb(void *arg)
492 {
493 	struct lm_lockstruct *ls = arg;
494 	complete(&ls->ls_sync_wait);
495 }
496 
497 static int sync_unlock(struct gfs2_sbd *sdp, struct dlm_lksb *lksb, char *name)
498 {
499 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
500 	int error;
501 
502 	error = dlm_unlock(ls->ls_dlm, lksb->sb_lkid, 0, lksb, ls);
503 	if (error) {
504 		fs_err(sdp, "%s lkid %x error %d\n",
505 		       name, lksb->sb_lkid, error);
506 		return error;
507 	}
508 
509 	wait_for_completion(&ls->ls_sync_wait);
510 
511 	if (lksb->sb_status != -DLM_EUNLOCK) {
512 		fs_err(sdp, "%s lkid %x status %d\n",
513 		       name, lksb->sb_lkid, lksb->sb_status);
514 		return -1;
515 	}
516 	return 0;
517 }
518 
519 static int sync_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags,
520 		     unsigned int num, struct dlm_lksb *lksb, char *name)
521 {
522 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
523 	char strname[GDLM_STRNAME_BYTES];
524 	int error, status;
525 
526 	memset(strname, 0, GDLM_STRNAME_BYTES);
527 	snprintf(strname, GDLM_STRNAME_BYTES, "%8x%16x", LM_TYPE_NONDISK, num);
528 
529 	error = dlm_lock(ls->ls_dlm, mode, lksb, flags,
530 			 strname, GDLM_STRNAME_BYTES - 1,
531 			 0, sync_wait_cb, ls, NULL);
532 	if (error) {
533 		fs_err(sdp, "%s lkid %x flags %x mode %d error %d\n",
534 		       name, lksb->sb_lkid, flags, mode, error);
535 		return error;
536 	}
537 
538 	wait_for_completion(&ls->ls_sync_wait);
539 
540 	status = lksb->sb_status;
541 
542 	if (status && status != -EAGAIN) {
543 		fs_err(sdp, "%s lkid %x flags %x mode %d status %d\n",
544 		       name, lksb->sb_lkid, flags, mode, status);
545 	}
546 
547 	return status;
548 }
549 
550 static int mounted_unlock(struct gfs2_sbd *sdp)
551 {
552 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
553 	return sync_unlock(sdp, &ls->ls_mounted_lksb, "mounted_lock");
554 }
555 
556 static int mounted_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
557 {
558 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
559 	return sync_lock(sdp, mode, flags, GFS2_MOUNTED_LOCK,
560 			 &ls->ls_mounted_lksb, "mounted_lock");
561 }
562 
563 static int control_unlock(struct gfs2_sbd *sdp)
564 {
565 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
566 	return sync_unlock(sdp, &ls->ls_control_lksb, "control_lock");
567 }
568 
569 static int control_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
570 {
571 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
572 	return sync_lock(sdp, mode, flags, GFS2_CONTROL_LOCK,
573 			 &ls->ls_control_lksb, "control_lock");
574 }
575 
576 static void gfs2_control_func(struct work_struct *work)
577 {
578 	struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work);
579 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
580 	uint32_t block_gen, start_gen, lvb_gen, flags;
581 	int recover_set = 0;
582 	int write_lvb = 0;
583 	int recover_size;
584 	int i, error;
585 
586 	spin_lock(&ls->ls_recover_spin);
587 	/*
588 	 * No MOUNT_DONE means we're still mounting; control_mount()
589 	 * will set this flag, after which this thread will take over
590 	 * all further clearing of BLOCK_LOCKS.
591 	 *
592 	 * FIRST_MOUNT means this node is doing first mounter recovery,
593 	 * for which recovery control is handled by
594 	 * control_mount()/control_first_done(), not this thread.
595 	 */
596 	if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
597 	     test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
598 		spin_unlock(&ls->ls_recover_spin);
599 		return;
600 	}
601 	block_gen = ls->ls_recover_block;
602 	start_gen = ls->ls_recover_start;
603 	spin_unlock(&ls->ls_recover_spin);
604 
605 	/*
606 	 * Equal block_gen and start_gen implies we are between
607 	 * recover_prep and recover_done callbacks, which means
608 	 * dlm recovery is in progress and dlm locking is blocked.
609 	 * There's no point trying to do any work until recover_done.
610 	 */
611 
612 	if (block_gen == start_gen)
613 		return;
614 
615 	/*
616 	 * Propagate recover_submit[] and recover_result[] to lvb:
617 	 * dlm_recoverd adds to recover_submit[] jids needing recovery
618 	 * gfs2_recover adds to recover_result[] journal recovery results
619 	 *
620 	 * set lvb bit for jids in recover_submit[] if the lvb has not
621 	 * yet been updated for the generation of the failure
622 	 *
623 	 * clear lvb bit for jids in recover_result[] if the result of
624 	 * the journal recovery is SUCCESS
625 	 */
626 
627 	error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
628 	if (error) {
629 		fs_err(sdp, "control lock EX error %d\n", error);
630 		return;
631 	}
632 
633 	control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
634 
635 	spin_lock(&ls->ls_recover_spin);
636 	if (block_gen != ls->ls_recover_block ||
637 	    start_gen != ls->ls_recover_start) {
638 		fs_info(sdp, "recover generation %u block1 %u %u\n",
639 			start_gen, block_gen, ls->ls_recover_block);
640 		spin_unlock(&ls->ls_recover_spin);
641 		control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
642 		return;
643 	}
644 
645 	recover_size = ls->ls_recover_size;
646 
647 	if (lvb_gen <= start_gen) {
648 		/*
649 		 * Clear lvb bits for jids we've successfully recovered.
650 		 * Because all nodes attempt to recover failed journals,
651 		 * a journal can be recovered multiple times successfully
652 		 * in succession.  Only the first will really do recovery,
653 		 * the others find it clean, but still report a successful
654 		 * recovery.  So, another node may have already recovered
655 		 * the jid and cleared the lvb bit for it.
656 		 */
657 		for (i = 0; i < recover_size; i++) {
658 			if (ls->ls_recover_result[i] != LM_RD_SUCCESS)
659 				continue;
660 
661 			ls->ls_recover_result[i] = 0;
662 
663 			if (!test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET))
664 				continue;
665 
666 			__clear_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
667 			write_lvb = 1;
668 		}
669 	}
670 
671 	if (lvb_gen == start_gen) {
672 		/*
673 		 * Failed slots before start_gen are already set in lvb.
674 		 */
675 		for (i = 0; i < recover_size; i++) {
676 			if (!ls->ls_recover_submit[i])
677 				continue;
678 			if (ls->ls_recover_submit[i] < lvb_gen)
679 				ls->ls_recover_submit[i] = 0;
680 		}
681 	} else if (lvb_gen < start_gen) {
682 		/*
683 		 * Failed slots before start_gen are not yet set in lvb.
684 		 */
685 		for (i = 0; i < recover_size; i++) {
686 			if (!ls->ls_recover_submit[i])
687 				continue;
688 			if (ls->ls_recover_submit[i] < start_gen) {
689 				ls->ls_recover_submit[i] = 0;
690 				__set_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
691 			}
692 		}
693 		/* even if there are no bits to set, we need to write the
694 		   latest generation to the lvb */
695 		write_lvb = 1;
696 	} else {
697 		/*
698 		 * we should be getting a recover_done() for lvb_gen soon
699 		 */
700 	}
701 	spin_unlock(&ls->ls_recover_spin);
702 
703 	if (write_lvb) {
704 		control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
705 		flags = DLM_LKF_CONVERT | DLM_LKF_VALBLK;
706 	} else {
707 		flags = DLM_LKF_CONVERT;
708 	}
709 
710 	error = control_lock(sdp, DLM_LOCK_NL, flags);
711 	if (error) {
712 		fs_err(sdp, "control lock NL error %d\n", error);
713 		return;
714 	}
715 
716 	/*
717 	 * Everyone will see jid bits set in the lvb, run gfs2_recover_set(),
718 	 * and clear a jid bit in the lvb if the recovery is a success.
719 	 * Eventually all journals will be recovered, all jid bits will
720 	 * be cleared in the lvb, and everyone will clear BLOCK_LOCKS.
721 	 */
722 
723 	for (i = 0; i < recover_size; i++) {
724 		if (test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET)) {
725 			fs_info(sdp, "recover generation %u jid %d\n",
726 				start_gen, i);
727 			gfs2_recover_set(sdp, i);
728 			recover_set++;
729 		}
730 	}
731 	if (recover_set)
732 		return;
733 
734 	/*
735 	 * No more jid bits set in lvb, all recovery is done, unblock locks
736 	 * (unless a new recover_prep callback has occured blocking locks
737 	 * again while working above)
738 	 */
739 
740 	spin_lock(&ls->ls_recover_spin);
741 	if (ls->ls_recover_block == block_gen &&
742 	    ls->ls_recover_start == start_gen) {
743 		clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
744 		spin_unlock(&ls->ls_recover_spin);
745 		fs_info(sdp, "recover generation %u done\n", start_gen);
746 		gfs2_glock_thaw(sdp);
747 	} else {
748 		fs_info(sdp, "recover generation %u block2 %u %u\n",
749 			start_gen, block_gen, ls->ls_recover_block);
750 		spin_unlock(&ls->ls_recover_spin);
751 	}
752 }
753 
754 static int control_mount(struct gfs2_sbd *sdp)
755 {
756 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
757 	uint32_t start_gen, block_gen, mount_gen, lvb_gen;
758 	int mounted_mode;
759 	int retries = 0;
760 	int error;
761 
762 	memset(&ls->ls_mounted_lksb, 0, sizeof(struct dlm_lksb));
763 	memset(&ls->ls_control_lksb, 0, sizeof(struct dlm_lksb));
764 	memset(&ls->ls_control_lvb, 0, GDLM_LVB_SIZE);
765 	ls->ls_control_lksb.sb_lvbptr = ls->ls_control_lvb;
766 	init_completion(&ls->ls_sync_wait);
767 
768 	set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
769 
770 	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_VALBLK);
771 	if (error) {
772 		fs_err(sdp, "control_mount control_lock NL error %d\n", error);
773 		return error;
774 	}
775 
776 	error = mounted_lock(sdp, DLM_LOCK_NL, 0);
777 	if (error) {
778 		fs_err(sdp, "control_mount mounted_lock NL error %d\n", error);
779 		control_unlock(sdp);
780 		return error;
781 	}
782 	mounted_mode = DLM_LOCK_NL;
783 
784 restart:
785 	if (retries++ && signal_pending(current)) {
786 		error = -EINTR;
787 		goto fail;
788 	}
789 
790 	/*
791 	 * We always start with both locks in NL. control_lock is
792 	 * demoted to NL below so we don't need to do it here.
793 	 */
794 
795 	if (mounted_mode != DLM_LOCK_NL) {
796 		error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
797 		if (error)
798 			goto fail;
799 		mounted_mode = DLM_LOCK_NL;
800 	}
801 
802 	/*
803 	 * Other nodes need to do some work in dlm recovery and gfs2_control
804 	 * before the recover_done and control_lock will be ready for us below.
805 	 * A delay here is not required but often avoids having to retry.
806 	 */
807 
808 	msleep_interruptible(500);
809 
810 	/*
811 	 * Acquire control_lock in EX and mounted_lock in either EX or PR.
812 	 * control_lock lvb keeps track of any pending journal recoveries.
813 	 * mounted_lock indicates if any other nodes have the fs mounted.
814 	 */
815 
816 	error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE|DLM_LKF_VALBLK);
817 	if (error == -EAGAIN) {
818 		goto restart;
819 	} else if (error) {
820 		fs_err(sdp, "control_mount control_lock EX error %d\n", error);
821 		goto fail;
822 	}
823 
824 	error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
825 	if (!error) {
826 		mounted_mode = DLM_LOCK_EX;
827 		goto locks_done;
828 	} else if (error != -EAGAIN) {
829 		fs_err(sdp, "control_mount mounted_lock EX error %d\n", error);
830 		goto fail;
831 	}
832 
833 	error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
834 	if (!error) {
835 		mounted_mode = DLM_LOCK_PR;
836 		goto locks_done;
837 	} else {
838 		/* not even -EAGAIN should happen here */
839 		fs_err(sdp, "control_mount mounted_lock PR error %d\n", error);
840 		goto fail;
841 	}
842 
843 locks_done:
844 	/*
845 	 * If we got both locks above in EX, then we're the first mounter.
846 	 * If not, then we need to wait for the control_lock lvb to be
847 	 * updated by other mounted nodes to reflect our mount generation.
848 	 *
849 	 * In simple first mounter cases, first mounter will see zero lvb_gen,
850 	 * but in cases where all existing nodes leave/fail before mounting
851 	 * nodes finish control_mount, then all nodes will be mounting and
852 	 * lvb_gen will be non-zero.
853 	 */
854 
855 	control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
856 
857 	if (lvb_gen == 0xFFFFFFFF) {
858 		/* special value to force mount attempts to fail */
859 		fs_err(sdp, "control_mount control_lock disabled\n");
860 		error = -EINVAL;
861 		goto fail;
862 	}
863 
864 	if (mounted_mode == DLM_LOCK_EX) {
865 		/* first mounter, keep both EX while doing first recovery */
866 		spin_lock(&ls->ls_recover_spin);
867 		clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
868 		set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
869 		set_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
870 		spin_unlock(&ls->ls_recover_spin);
871 		fs_info(sdp, "first mounter control generation %u\n", lvb_gen);
872 		return 0;
873 	}
874 
875 	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
876 	if (error)
877 		goto fail;
878 
879 	/*
880 	 * We are not first mounter, now we need to wait for the control_lock
881 	 * lvb generation to be >= the generation from our first recover_done
882 	 * and all lvb bits to be clear (no pending journal recoveries.)
883 	 */
884 
885 	if (!all_jid_bits_clear(ls->ls_lvb_bits)) {
886 		/* journals need recovery, wait until all are clear */
887 		fs_info(sdp, "control_mount wait for journal recovery\n");
888 		goto restart;
889 	}
890 
891 	spin_lock(&ls->ls_recover_spin);
892 	block_gen = ls->ls_recover_block;
893 	start_gen = ls->ls_recover_start;
894 	mount_gen = ls->ls_recover_mount;
895 
896 	if (lvb_gen < mount_gen) {
897 		/* wait for mounted nodes to update control_lock lvb to our
898 		   generation, which might include new recovery bits set */
899 		fs_info(sdp, "control_mount wait1 block %u start %u mount %u "
900 			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
901 			lvb_gen, ls->ls_recover_flags);
902 		spin_unlock(&ls->ls_recover_spin);
903 		goto restart;
904 	}
905 
906 	if (lvb_gen != start_gen) {
907 		/* wait for mounted nodes to update control_lock lvb to the
908 		   latest recovery generation */
909 		fs_info(sdp, "control_mount wait2 block %u start %u mount %u "
910 			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
911 			lvb_gen, ls->ls_recover_flags);
912 		spin_unlock(&ls->ls_recover_spin);
913 		goto restart;
914 	}
915 
916 	if (block_gen == start_gen) {
917 		/* dlm recovery in progress, wait for it to finish */
918 		fs_info(sdp, "control_mount wait3 block %u start %u mount %u "
919 			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
920 			lvb_gen, ls->ls_recover_flags);
921 		spin_unlock(&ls->ls_recover_spin);
922 		goto restart;
923 	}
924 
925 	clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
926 	set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
927 	memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
928 	memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
929 	spin_unlock(&ls->ls_recover_spin);
930 	return 0;
931 
932 fail:
933 	mounted_unlock(sdp);
934 	control_unlock(sdp);
935 	return error;
936 }
937 
938 static int control_first_done(struct gfs2_sbd *sdp)
939 {
940 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
941 	uint32_t start_gen, block_gen;
942 	int error;
943 
944 restart:
945 	spin_lock(&ls->ls_recover_spin);
946 	start_gen = ls->ls_recover_start;
947 	block_gen = ls->ls_recover_block;
948 
949 	if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags) ||
950 	    !test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
951 	    !test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
952 		/* sanity check, should not happen */
953 		fs_err(sdp, "control_first_done start %u block %u flags %lx\n",
954 		       start_gen, block_gen, ls->ls_recover_flags);
955 		spin_unlock(&ls->ls_recover_spin);
956 		control_unlock(sdp);
957 		return -1;
958 	}
959 
960 	if (start_gen == block_gen) {
961 		/*
962 		 * Wait for the end of a dlm recovery cycle to switch from
963 		 * first mounter recovery.  We can ignore any recover_slot
964 		 * callbacks between the recover_prep and next recover_done
965 		 * because we are still the first mounter and any failed nodes
966 		 * have not fully mounted, so they don't need recovery.
967 		 */
968 		spin_unlock(&ls->ls_recover_spin);
969 		fs_info(sdp, "control_first_done wait gen %u\n", start_gen);
970 
971 		wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY,
972 			    TASK_UNINTERRUPTIBLE);
973 		goto restart;
974 	}
975 
976 	clear_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
977 	set_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags);
978 	memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
979 	memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
980 	spin_unlock(&ls->ls_recover_spin);
981 
982 	memset(ls->ls_lvb_bits, 0, GDLM_LVB_SIZE);
983 	control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
984 
985 	error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT);
986 	if (error)
987 		fs_err(sdp, "control_first_done mounted PR error %d\n", error);
988 
989 	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
990 	if (error)
991 		fs_err(sdp, "control_first_done control NL error %d\n", error);
992 
993 	return error;
994 }
995 
996 /*
997  * Expand static jid arrays if necessary (by increments of RECOVER_SIZE_INC)
998  * to accomodate the largest slot number.  (NB dlm slot numbers start at 1,
999  * gfs2 jids start at 0, so jid = slot - 1)
1000  */
1001 
1002 #define RECOVER_SIZE_INC 16
1003 
1004 static int set_recover_size(struct gfs2_sbd *sdp, struct dlm_slot *slots,
1005 			    int num_slots)
1006 {
1007 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1008 	uint32_t *submit = NULL;
1009 	uint32_t *result = NULL;
1010 	uint32_t old_size, new_size;
1011 	int i, max_jid;
1012 
1013 	if (!ls->ls_lvb_bits) {
1014 		ls->ls_lvb_bits = kzalloc(GDLM_LVB_SIZE, GFP_NOFS);
1015 		if (!ls->ls_lvb_bits)
1016 			return -ENOMEM;
1017 	}
1018 
1019 	max_jid = 0;
1020 	for (i = 0; i < num_slots; i++) {
1021 		if (max_jid < slots[i].slot - 1)
1022 			max_jid = slots[i].slot - 1;
1023 	}
1024 
1025 	old_size = ls->ls_recover_size;
1026 
1027 	if (old_size >= max_jid + 1)
1028 		return 0;
1029 
1030 	new_size = old_size + RECOVER_SIZE_INC;
1031 
1032 	submit = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS);
1033 	result = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS);
1034 	if (!submit || !result) {
1035 		kfree(submit);
1036 		kfree(result);
1037 		return -ENOMEM;
1038 	}
1039 
1040 	spin_lock(&ls->ls_recover_spin);
1041 	memcpy(submit, ls->ls_recover_submit, old_size * sizeof(uint32_t));
1042 	memcpy(result, ls->ls_recover_result, old_size * sizeof(uint32_t));
1043 	kfree(ls->ls_recover_submit);
1044 	kfree(ls->ls_recover_result);
1045 	ls->ls_recover_submit = submit;
1046 	ls->ls_recover_result = result;
1047 	ls->ls_recover_size = new_size;
1048 	spin_unlock(&ls->ls_recover_spin);
1049 	return 0;
1050 }
1051 
1052 static void free_recover_size(struct lm_lockstruct *ls)
1053 {
1054 	kfree(ls->ls_lvb_bits);
1055 	kfree(ls->ls_recover_submit);
1056 	kfree(ls->ls_recover_result);
1057 	ls->ls_recover_submit = NULL;
1058 	ls->ls_recover_result = NULL;
1059 	ls->ls_recover_size = 0;
1060 	ls->ls_lvb_bits = NULL;
1061 }
1062 
1063 /* dlm calls before it does lock recovery */
1064 
1065 static void gdlm_recover_prep(void *arg)
1066 {
1067 	struct gfs2_sbd *sdp = arg;
1068 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1069 
1070 	spin_lock(&ls->ls_recover_spin);
1071 	ls->ls_recover_block = ls->ls_recover_start;
1072 	set_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
1073 
1074 	if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
1075 	     test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
1076 		spin_unlock(&ls->ls_recover_spin);
1077 		return;
1078 	}
1079 	set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
1080 	spin_unlock(&ls->ls_recover_spin);
1081 }
1082 
1083 /* dlm calls after recover_prep has been completed on all lockspace members;
1084    identifies slot/jid of failed member */
1085 
1086 static void gdlm_recover_slot(void *arg, struct dlm_slot *slot)
1087 {
1088 	struct gfs2_sbd *sdp = arg;
1089 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1090 	int jid = slot->slot - 1;
1091 
1092 	spin_lock(&ls->ls_recover_spin);
1093 	if (ls->ls_recover_size < jid + 1) {
1094 		fs_err(sdp, "recover_slot jid %d gen %u short size %d\n",
1095 		       jid, ls->ls_recover_block, ls->ls_recover_size);
1096 		spin_unlock(&ls->ls_recover_spin);
1097 		return;
1098 	}
1099 
1100 	if (ls->ls_recover_submit[jid]) {
1101 		fs_info(sdp, "recover_slot jid %d gen %u prev %u\n",
1102 			jid, ls->ls_recover_block, ls->ls_recover_submit[jid]);
1103 	}
1104 	ls->ls_recover_submit[jid] = ls->ls_recover_block;
1105 	spin_unlock(&ls->ls_recover_spin);
1106 }
1107 
1108 /* dlm calls after recover_slot and after it completes lock recovery */
1109 
1110 static void gdlm_recover_done(void *arg, struct dlm_slot *slots, int num_slots,
1111 			      int our_slot, uint32_t generation)
1112 {
1113 	struct gfs2_sbd *sdp = arg;
1114 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1115 
1116 	/* ensure the ls jid arrays are large enough */
1117 	set_recover_size(sdp, slots, num_slots);
1118 
1119 	spin_lock(&ls->ls_recover_spin);
1120 	ls->ls_recover_start = generation;
1121 
1122 	if (!ls->ls_recover_mount) {
1123 		ls->ls_recover_mount = generation;
1124 		ls->ls_jid = our_slot - 1;
1125 	}
1126 
1127 	if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
1128 		queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work, 0);
1129 
1130 	clear_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
1131 	smp_mb__after_atomic();
1132 	wake_up_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY);
1133 	spin_unlock(&ls->ls_recover_spin);
1134 }
1135 
1136 /* gfs2_recover thread has a journal recovery result */
1137 
1138 static void gdlm_recovery_result(struct gfs2_sbd *sdp, unsigned int jid,
1139 				 unsigned int result)
1140 {
1141 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1142 
1143 	if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1144 		return;
1145 
1146 	/* don't care about the recovery of own journal during mount */
1147 	if (jid == ls->ls_jid)
1148 		return;
1149 
1150 	spin_lock(&ls->ls_recover_spin);
1151 	if (test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
1152 		spin_unlock(&ls->ls_recover_spin);
1153 		return;
1154 	}
1155 	if (ls->ls_recover_size < jid + 1) {
1156 		fs_err(sdp, "recovery_result jid %d short size %d\n",
1157 		       jid, ls->ls_recover_size);
1158 		spin_unlock(&ls->ls_recover_spin);
1159 		return;
1160 	}
1161 
1162 	fs_info(sdp, "recover jid %d result %s\n", jid,
1163 		result == LM_RD_GAVEUP ? "busy" : "success");
1164 
1165 	ls->ls_recover_result[jid] = result;
1166 
1167 	/* GAVEUP means another node is recovering the journal; delay our
1168 	   next attempt to recover it, to give the other node a chance to
1169 	   finish before trying again */
1170 
1171 	if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
1172 		queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work,
1173 				   result == LM_RD_GAVEUP ? HZ : 0);
1174 	spin_unlock(&ls->ls_recover_spin);
1175 }
1176 
1177 static const struct dlm_lockspace_ops gdlm_lockspace_ops = {
1178 	.recover_prep = gdlm_recover_prep,
1179 	.recover_slot = gdlm_recover_slot,
1180 	.recover_done = gdlm_recover_done,
1181 };
1182 
1183 static int gdlm_mount(struct gfs2_sbd *sdp, const char *table)
1184 {
1185 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1186 	char cluster[GFS2_LOCKNAME_LEN];
1187 	const char *fsname;
1188 	uint32_t flags;
1189 	int error, ops_result;
1190 
1191 	/*
1192 	 * initialize everything
1193 	 */
1194 
1195 	INIT_DELAYED_WORK(&sdp->sd_control_work, gfs2_control_func);
1196 	spin_lock_init(&ls->ls_recover_spin);
1197 	ls->ls_recover_flags = 0;
1198 	ls->ls_recover_mount = 0;
1199 	ls->ls_recover_start = 0;
1200 	ls->ls_recover_block = 0;
1201 	ls->ls_recover_size = 0;
1202 	ls->ls_recover_submit = NULL;
1203 	ls->ls_recover_result = NULL;
1204 	ls->ls_lvb_bits = NULL;
1205 
1206 	error = set_recover_size(sdp, NULL, 0);
1207 	if (error)
1208 		goto fail;
1209 
1210 	/*
1211 	 * prepare dlm_new_lockspace args
1212 	 */
1213 
1214 	fsname = strchr(table, ':');
1215 	if (!fsname) {
1216 		fs_info(sdp, "no fsname found\n");
1217 		error = -EINVAL;
1218 		goto fail_free;
1219 	}
1220 	memset(cluster, 0, sizeof(cluster));
1221 	memcpy(cluster, table, strlen(table) - strlen(fsname));
1222 	fsname++;
1223 
1224 	flags = DLM_LSFL_FS | DLM_LSFL_NEWEXCL;
1225 
1226 	/*
1227 	 * create/join lockspace
1228 	 */
1229 
1230 	error = dlm_new_lockspace(fsname, cluster, flags, GDLM_LVB_SIZE,
1231 				  &gdlm_lockspace_ops, sdp, &ops_result,
1232 				  &ls->ls_dlm);
1233 	if (error) {
1234 		fs_err(sdp, "dlm_new_lockspace error %d\n", error);
1235 		goto fail_free;
1236 	}
1237 
1238 	if (ops_result < 0) {
1239 		/*
1240 		 * dlm does not support ops callbacks,
1241 		 * old dlm_controld/gfs_controld are used, try without ops.
1242 		 */
1243 		fs_info(sdp, "dlm lockspace ops not used\n");
1244 		free_recover_size(ls);
1245 		set_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags);
1246 		return 0;
1247 	}
1248 
1249 	if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags)) {
1250 		fs_err(sdp, "dlm lockspace ops disallow jid preset\n");
1251 		error = -EINVAL;
1252 		goto fail_release;
1253 	}
1254 
1255 	/*
1256 	 * control_mount() uses control_lock to determine first mounter,
1257 	 * and for later mounts, waits for any recoveries to be cleared.
1258 	 */
1259 
1260 	error = control_mount(sdp);
1261 	if (error) {
1262 		fs_err(sdp, "mount control error %d\n", error);
1263 		goto fail_release;
1264 	}
1265 
1266 	ls->ls_first = !!test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
1267 	clear_bit(SDF_NOJOURNALID, &sdp->sd_flags);
1268 	smp_mb__after_atomic();
1269 	wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID);
1270 	return 0;
1271 
1272 fail_release:
1273 	dlm_release_lockspace(ls->ls_dlm, 2);
1274 fail_free:
1275 	free_recover_size(ls);
1276 fail:
1277 	return error;
1278 }
1279 
1280 static void gdlm_first_done(struct gfs2_sbd *sdp)
1281 {
1282 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1283 	int error;
1284 
1285 	if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1286 		return;
1287 
1288 	error = control_first_done(sdp);
1289 	if (error)
1290 		fs_err(sdp, "mount first_done error %d\n", error);
1291 }
1292 
1293 static void gdlm_unmount(struct gfs2_sbd *sdp)
1294 {
1295 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1296 
1297 	if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1298 		goto release;
1299 
1300 	/* wait for gfs2_control_wq to be done with this mount */
1301 
1302 	spin_lock(&ls->ls_recover_spin);
1303 	set_bit(DFL_UNMOUNT, &ls->ls_recover_flags);
1304 	spin_unlock(&ls->ls_recover_spin);
1305 	flush_delayed_work(&sdp->sd_control_work);
1306 
1307 	/* mounted_lock and control_lock will be purged in dlm recovery */
1308 release:
1309 	if (ls->ls_dlm) {
1310 		dlm_release_lockspace(ls->ls_dlm, 2);
1311 		ls->ls_dlm = NULL;
1312 	}
1313 
1314 	free_recover_size(ls);
1315 }
1316 
1317 static const match_table_t dlm_tokens = {
1318 	{ Opt_jid, "jid=%d"},
1319 	{ Opt_id, "id=%d"},
1320 	{ Opt_first, "first=%d"},
1321 	{ Opt_nodir, "nodir=%d"},
1322 	{ Opt_err, NULL },
1323 };
1324 
1325 const struct lm_lockops gfs2_dlm_ops = {
1326 	.lm_proto_name = "lock_dlm",
1327 	.lm_mount = gdlm_mount,
1328 	.lm_first_done = gdlm_first_done,
1329 	.lm_recovery_result = gdlm_recovery_result,
1330 	.lm_unmount = gdlm_unmount,
1331 	.lm_put_lock = gdlm_put_lock,
1332 	.lm_lock = gdlm_lock,
1333 	.lm_cancel = gdlm_cancel,
1334 	.lm_tokens = &dlm_tokens,
1335 };
1336 
1337