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Linux/fs/gfs2/lock_dlm.c

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  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 
 19 #include "incore.h"
 20 #include "glock.h"
 21 #include "util.h"
 22 #include "sys.h"
 23 #include "trace_gfs2.h"
 24 
 25 extern struct workqueue_struct *gfs2_control_wq;
 26 
 27 /**
 28  * gfs2_update_stats - Update time based stats
 29  * @mv: Pointer to mean/variance structure to update
 30  * @sample: New data to include
 31  *
 32  * @delta is the difference between the current rtt sample and the
 33  * running average srtt. We add 1/8 of that to the srtt in order to
 34  * update the current srtt estimate. The varience estimate is a bit
 35  * more complicated. We subtract the abs value of the @delta from
 36  * the current variance estimate and add 1/4 of that to the running
 37  * total.
 38  *
 39  * Note that the index points at the array entry containing the smoothed
 40  * mean value, and the variance is always in the following entry
 41  *
 42  * Reference: TCP/IP Illustrated, vol 2, p. 831,832
 43  * All times are in units of integer nanoseconds. Unlike the TCP/IP case,
 44  * they are not scaled fixed point.
 45  */
 46 
 47 static inline void gfs2_update_stats(struct gfs2_lkstats *s, unsigned index,
 48                                      s64 sample)
 49 {
 50         s64 delta = sample - s->stats[index];
 51         s->stats[index] += (delta >> 3);
 52         index++;
 53         s->stats[index] += ((abs64(delta) - s->stats[index]) >> 2);
 54 }
 55 
 56 /**
 57  * gfs2_update_reply_times - Update locking statistics
 58  * @gl: The glock to update
 59  *
 60  * This assumes that gl->gl_dstamp has been set earlier.
 61  *
 62  * The rtt (lock round trip time) is an estimate of the time
 63  * taken to perform a dlm lock request. We update it on each
 64  * reply from the dlm.
 65  *
 66  * The blocking flag is set on the glock for all dlm requests
 67  * which may potentially block due to lock requests from other nodes.
 68  * DLM requests where the current lock state is exclusive, the
 69  * requested state is null (or unlocked) or where the TRY or
 70  * TRY_1CB flags are set are classified as non-blocking. All
 71  * other DLM requests are counted as (potentially) blocking.
 72  */
 73 static inline void gfs2_update_reply_times(struct gfs2_glock *gl)
 74 {
 75         struct gfs2_pcpu_lkstats *lks;
 76         const unsigned gltype = gl->gl_name.ln_type;
 77         unsigned index = test_bit(GLF_BLOCKING, &gl->gl_flags) ?
 78                          GFS2_LKS_SRTTB : GFS2_LKS_SRTT;
 79         s64 rtt;
 80 
 81         preempt_disable();
 82         rtt = ktime_to_ns(ktime_sub(ktime_get_real(), gl->gl_dstamp));
 83         lks = this_cpu_ptr(gl->gl_sbd->sd_lkstats);
 84         gfs2_update_stats(&gl->gl_stats, index, rtt);           /* Local */
 85         gfs2_update_stats(&lks->lkstats[gltype], index, rtt);   /* Global */
 86         preempt_enable();
 87 
 88         trace_gfs2_glock_lock_time(gl, rtt);
 89 }
 90 
 91 /**
 92  * gfs2_update_request_times - Update locking statistics
 93  * @gl: The glock to update
 94  *
 95  * The irt (lock inter-request times) measures the average time
 96  * between requests to the dlm. It is updated immediately before
 97  * each dlm call.
 98  */
 99 
100 static inline void gfs2_update_request_times(struct gfs2_glock *gl)
101 {
102         struct gfs2_pcpu_lkstats *lks;
103         const unsigned gltype = gl->gl_name.ln_type;
104         ktime_t dstamp;
105         s64 irt;
106 
107         preempt_disable();
108         dstamp = gl->gl_dstamp;
109         gl->gl_dstamp = ktime_get_real();
110         irt = ktime_to_ns(ktime_sub(gl->gl_dstamp, dstamp));
111         lks = this_cpu_ptr(gl->gl_sbd->sd_lkstats);
112         gfs2_update_stats(&gl->gl_stats, GFS2_LKS_SIRT, irt);           /* Local */
113         gfs2_update_stats(&lks->lkstats[gltype], GFS2_LKS_SIRT, irt);   /* Global */
114         preempt_enable();
115 }
116  
117 static void gdlm_ast(void *arg)
118 {
119         struct gfs2_glock *gl = arg;
120         unsigned ret = gl->gl_state;
121 
122         gfs2_update_reply_times(gl);
123         BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);
124 
125         if ((gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID) && gl->gl_lksb.sb_lvbptr)
126                 memset(gl->gl_lksb.sb_lvbptr, 0, GDLM_LVB_SIZE);
127 
128         switch (gl->gl_lksb.sb_status) {
129         case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */
130                 gfs2_glock_free(gl);
131                 return;
132         case -DLM_ECANCEL: /* Cancel while getting lock */
133                 ret |= LM_OUT_CANCELED;
134                 goto out;
135         case -EAGAIN: /* Try lock fails */
136         case -EDEADLK: /* Deadlock detected */
137                 goto out;
138         case -ETIMEDOUT: /* Canceled due to timeout */
139                 ret |= LM_OUT_ERROR;
140                 goto out;
141         case 0: /* Success */
142                 break;
143         default: /* Something unexpected */
144                 BUG();
145         }
146 
147         ret = gl->gl_req;
148         if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) {
149                 if (gl->gl_req == LM_ST_SHARED)
150                         ret = LM_ST_DEFERRED;
151                 else if (gl->gl_req == LM_ST_DEFERRED)
152                         ret = LM_ST_SHARED;
153                 else
154                         BUG();
155         }
156 
157         set_bit(GLF_INITIAL, &gl->gl_flags);
158         gfs2_glock_complete(gl, ret);
159         return;
160 out:
161         if (!test_bit(GLF_INITIAL, &gl->gl_flags))
162                 gl->gl_lksb.sb_lkid = 0;
163         gfs2_glock_complete(gl, ret);
164 }
165 
166 static void gdlm_bast(void *arg, int mode)
167 {
168         struct gfs2_glock *gl = arg;
169 
170         switch (mode) {
171         case DLM_LOCK_EX:
172                 gfs2_glock_cb(gl, LM_ST_UNLOCKED);
173                 break;
174         case DLM_LOCK_CW:
175                 gfs2_glock_cb(gl, LM_ST_DEFERRED);
176                 break;
177         case DLM_LOCK_PR:
178                 gfs2_glock_cb(gl, LM_ST_SHARED);
179                 break;
180         default:
181                 pr_err("unknown bast mode %d\n", mode);
182                 BUG();
183         }
184 }
185 
186 /* convert gfs lock-state to dlm lock-mode */
187 
188 static int make_mode(const unsigned int lmstate)
189 {
190         switch (lmstate) {
191         case LM_ST_UNLOCKED:
192                 return DLM_LOCK_NL;
193         case LM_ST_EXCLUSIVE:
194                 return DLM_LOCK_EX;
195         case LM_ST_DEFERRED:
196                 return DLM_LOCK_CW;
197         case LM_ST_SHARED:
198                 return DLM_LOCK_PR;
199         }
200         pr_err("unknown LM state %d\n", lmstate);
201         BUG();
202         return -1;
203 }
204 
205 static u32 make_flags(struct gfs2_glock *gl, const unsigned int gfs_flags,
206                       const int req)
207 {
208         u32 lkf = 0;
209 
210         if (gl->gl_lksb.sb_lvbptr)
211                 lkf |= DLM_LKF_VALBLK;
212 
213         if (gfs_flags & LM_FLAG_TRY)
214                 lkf |= DLM_LKF_NOQUEUE;
215 
216         if (gfs_flags & LM_FLAG_TRY_1CB) {
217                 lkf |= DLM_LKF_NOQUEUE;
218                 lkf |= DLM_LKF_NOQUEUEBAST;
219         }
220 
221         if (gfs_flags & LM_FLAG_PRIORITY) {
222                 lkf |= DLM_LKF_NOORDER;
223                 lkf |= DLM_LKF_HEADQUE;
224         }
225 
226         if (gfs_flags & LM_FLAG_ANY) {
227                 if (req == DLM_LOCK_PR)
228                         lkf |= DLM_LKF_ALTCW;
229                 else if (req == DLM_LOCK_CW)
230                         lkf |= DLM_LKF_ALTPR;
231                 else
232                         BUG();
233         }
234 
235         if (gl->gl_lksb.sb_lkid != 0) {
236                 lkf |= DLM_LKF_CONVERT;
237                 if (test_bit(GLF_BLOCKING, &gl->gl_flags))
238                         lkf |= DLM_LKF_QUECVT;
239         }
240 
241         return lkf;
242 }
243 
244 static void gfs2_reverse_hex(char *c, u64 value)
245 {
246         *c = '';
247         while (value) {
248                 *c-- = hex_asc[value & 0x0f];
249                 value >>= 4;
250         }
251 }
252 
253 static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state,
254                      unsigned int flags)
255 {
256         struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
257         int req;
258         u32 lkf;
259         char strname[GDLM_STRNAME_BYTES] = "";
260 
261         req = make_mode(req_state);
262         lkf = make_flags(gl, flags, req);
263         gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
264         gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
265         if (gl->gl_lksb.sb_lkid) {
266                 gfs2_update_request_times(gl);
267         } else {
268                 memset(strname, ' ', GDLM_STRNAME_BYTES - 1);
269                 strname[GDLM_STRNAME_BYTES - 1] = '\0';
270                 gfs2_reverse_hex(strname + 7, gl->gl_name.ln_type);
271                 gfs2_reverse_hex(strname + 23, gl->gl_name.ln_number);
272                 gl->gl_dstamp = ktime_get_real();
273         }
274         /*
275          * Submit the actual lock request.
276          */
277 
278         return dlm_lock(ls->ls_dlm, req, &gl->gl_lksb, lkf, strname,
279                         GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast);
280 }
281 
282 static void gdlm_put_lock(struct gfs2_glock *gl)
283 {
284         struct gfs2_sbd *sdp = gl->gl_sbd;
285         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
286         int lvb_needs_unlock = 0;
287         int error;
288 
289         if (gl->gl_lksb.sb_lkid == 0) {
290                 gfs2_glock_free(gl);
291                 return;
292         }
293 
294         clear_bit(GLF_BLOCKING, &gl->gl_flags);
295         gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
296         gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
297         gfs2_update_request_times(gl);
298 
299         /* don't want to skip dlm_unlock writing the lvb when lock is ex */
300 
301         if (gl->gl_lksb.sb_lvbptr && (gl->gl_state == LM_ST_EXCLUSIVE))
302                 lvb_needs_unlock = 1;
303 
304         if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) &&
305             !lvb_needs_unlock) {
306                 gfs2_glock_free(gl);
307                 return;
308         }
309 
310         error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK,
311                            NULL, gl);
312         if (error) {
313                 pr_err("gdlm_unlock %x,%llx err=%d\n",
314                        gl->gl_name.ln_type,
315                        (unsigned long long)gl->gl_name.ln_number, error);
316                 return;
317         }
318 }
319 
320 static void gdlm_cancel(struct gfs2_glock *gl)
321 {
322         struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
323         dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl);
324 }
325 
326 /*
327  * dlm/gfs2 recovery coordination using dlm_recover callbacks
328  *
329  *  1. dlm_controld sees lockspace members change
330  *  2. dlm_controld blocks dlm-kernel locking activity
331  *  3. dlm_controld within dlm-kernel notifies gfs2 (recover_prep)
332  *  4. dlm_controld starts and finishes its own user level recovery
333  *  5. dlm_controld starts dlm-kernel dlm_recoverd to do kernel recovery
334  *  6. dlm_recoverd notifies gfs2 of failed nodes (recover_slot)
335  *  7. dlm_recoverd does its own lock recovery
336  *  8. dlm_recoverd unblocks dlm-kernel locking activity
337  *  9. dlm_recoverd notifies gfs2 when done (recover_done with new generation)
338  * 10. gfs2_control updates control_lock lvb with new generation and jid bits
339  * 11. gfs2_control enqueues journals for gfs2_recover to recover (maybe none)
340  * 12. gfs2_recover dequeues and recovers journals of failed nodes
341  * 13. gfs2_recover provides recovery results to gfs2_control (recovery_result)
342  * 14. gfs2_control updates control_lock lvb jid bits for recovered journals
343  * 15. gfs2_control unblocks normal locking when all journals are recovered
344  *
345  * - failures during recovery
346  *
347  * recover_prep() may set BLOCK_LOCKS (step 3) again before gfs2_control
348  * clears BLOCK_LOCKS (step 15), e.g. another node fails while still
349  * recovering for a prior failure.  gfs2_control needs a way to detect
350  * this so it can leave BLOCK_LOCKS set in step 15.  This is managed using
351  * the recover_block and recover_start values.
352  *
353  * recover_done() provides a new lockspace generation number each time it
354  * is called (step 9).  This generation number is saved as recover_start.
355  * When recover_prep() is called, it sets BLOCK_LOCKS and sets
356  * recover_block = recover_start.  So, while recover_block is equal to
357  * recover_start, BLOCK_LOCKS should remain set.  (recover_spin must
358  * be held around the BLOCK_LOCKS/recover_block/recover_start logic.)
359  *
360  * - more specific gfs2 steps in sequence above
361  *
362  *  3. recover_prep sets BLOCK_LOCKS and sets recover_block = recover_start
363  *  6. recover_slot records any failed jids (maybe none)
364  *  9. recover_done sets recover_start = new generation number
365  * 10. gfs2_control sets control_lock lvb = new gen + bits for failed jids
366  * 12. gfs2_recover does journal recoveries for failed jids identified above
367  * 14. gfs2_control clears control_lock lvb bits for recovered jids
368  * 15. gfs2_control checks if recover_block == recover_start (step 3 occured
369  *     again) then do nothing, otherwise if recover_start > recover_block
370  *     then clear BLOCK_LOCKS.
371  *
372  * - parallel recovery steps across all nodes
373  *
374  * All nodes attempt to update the control_lock lvb with the new generation
375  * number and jid bits, but only the first to get the control_lock EX will
376  * do so; others will see that it's already done (lvb already contains new
377  * generation number.)
378  *
379  * . All nodes get the same recover_prep/recover_slot/recover_done callbacks
380  * . All nodes attempt to set control_lock lvb gen + bits for the new gen
381  * . One node gets control_lock first and writes the lvb, others see it's done
382  * . All nodes attempt to recover jids for which they see control_lock bits set
383  * . One node succeeds for a jid, and that one clears the jid bit in the lvb
384  * . All nodes will eventually see all lvb bits clear and unblock locks
385  *
386  * - is there a problem with clearing an lvb bit that should be set
387  *   and missing a journal recovery?
388  *
389  * 1. jid fails
390  * 2. lvb bit set for step 1
391  * 3. jid recovered for step 1
392  * 4. jid taken again (new mount)
393  * 5. jid fails (for step 4)
394  * 6. lvb bit set for step 5 (will already be set)
395  * 7. lvb bit cleared for step 3
396  *
397  * This is not a problem because the failure in step 5 does not
398  * require recovery, because the mount in step 4 could not have
399  * progressed far enough to unblock locks and access the fs.  The
400  * control_mount() function waits for all recoveries to be complete
401  * for the latest lockspace generation before ever unblocking locks
402  * and returning.  The mount in step 4 waits until the recovery in
403  * step 1 is done.
404  *
405  * - special case of first mounter: first node to mount the fs
406  *
407  * The first node to mount a gfs2 fs needs to check all the journals
408  * and recover any that need recovery before other nodes are allowed
409  * to mount the fs.  (Others may begin mounting, but they must wait
410  * for the first mounter to be done before taking locks on the fs
411  * or accessing the fs.)  This has two parts:
412  *
413  * 1. The mounted_lock tells a node it's the first to mount the fs.
414  * Each node holds the mounted_lock in PR while it's mounted.
415  * Each node tries to acquire the mounted_lock in EX when it mounts.
416  * If a node is granted the mounted_lock EX it means there are no
417  * other mounted nodes (no PR locks exist), and it is the first mounter.
418  * The mounted_lock is demoted to PR when first recovery is done, so
419  * others will fail to get an EX lock, but will get a PR lock.
420  *
421  * 2. The control_lock blocks others in control_mount() while the first
422  * mounter is doing first mount recovery of all journals.
423  * A mounting node needs to acquire control_lock in EX mode before
424  * it can proceed.  The first mounter holds control_lock in EX while doing
425  * the first mount recovery, blocking mounts from other nodes, then demotes
426  * control_lock to NL when it's done (others_may_mount/first_done),
427  * allowing other nodes to continue mounting.
428  *
429  * first mounter:
430  * control_lock EX/NOQUEUE success
431  * mounted_lock EX/NOQUEUE success (no other PR, so no other mounters)
432  * set first=1
433  * do first mounter recovery
434  * mounted_lock EX->PR
435  * control_lock EX->NL, write lvb generation
436  *
437  * other mounter:
438  * control_lock EX/NOQUEUE success (if fail -EAGAIN, retry)
439  * mounted_lock EX/NOQUEUE fail -EAGAIN (expected due to other mounters PR)
440  * mounted_lock PR/NOQUEUE success
441  * read lvb generation
442  * control_lock EX->NL
443  * set first=0
444  *
445  * - mount during recovery
446  *
447  * If a node mounts while others are doing recovery (not first mounter),
448  * the mounting node will get its initial recover_done() callback without
449  * having seen any previous failures/callbacks.
450  *
451  * It must wait for all recoveries preceding its mount to be finished
452  * before it unblocks locks.  It does this by repeating the "other mounter"
453  * steps above until the lvb generation number is >= its mount generation
454  * number (from initial recover_done) and all lvb bits are clear.
455  *
456  * - control_lock lvb format
457  *
458  * 4 bytes generation number: the latest dlm lockspace generation number
459  * from recover_done callback.  Indicates the jid bitmap has been updated
460  * to reflect all slot failures through that generation.
461  * 4 bytes unused.
462  * GDLM_LVB_SIZE-8 bytes of jid bit map. If bit N is set, it indicates
463  * that jid N needs recovery.
464  */
465 
466 #define JID_BITMAP_OFFSET 8 /* 4 byte generation number + 4 byte unused */
467 
468 static void control_lvb_read(struct lm_lockstruct *ls, uint32_t *lvb_gen,
469                              char *lvb_bits)
470 {
471         __le32 gen;
472         memcpy(lvb_bits, ls->ls_control_lvb, GDLM_LVB_SIZE);
473         memcpy(&gen, lvb_bits, sizeof(__le32));
474         *lvb_gen = le32_to_cpu(gen);
475 }
476 
477 static void control_lvb_write(struct lm_lockstruct *ls, uint32_t lvb_gen,
478                               char *lvb_bits)
479 {
480         __le32 gen;
481         memcpy(ls->ls_control_lvb, lvb_bits, GDLM_LVB_SIZE);
482         gen = cpu_to_le32(lvb_gen);
483         memcpy(ls->ls_control_lvb, &gen, sizeof(__le32));
484 }
485 
486 static int all_jid_bits_clear(char *lvb)
487 {
488         return !memchr_inv(lvb + JID_BITMAP_OFFSET, 0,
489                         GDLM_LVB_SIZE - JID_BITMAP_OFFSET);
490 }
491 
492 static void sync_wait_cb(void *arg)
493 {
494         struct lm_lockstruct *ls = arg;
495         complete(&ls->ls_sync_wait);
496 }
497 
498 static int sync_unlock(struct gfs2_sbd *sdp, struct dlm_lksb *lksb, char *name)
499 {
500         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
501         int error;
502 
503         error = dlm_unlock(ls->ls_dlm, lksb->sb_lkid, 0, lksb, ls);
504         if (error) {
505                 fs_err(sdp, "%s lkid %x error %d\n",
506                        name, lksb->sb_lkid, error);
507                 return error;
508         }
509 
510         wait_for_completion(&ls->ls_sync_wait);
511 
512         if (lksb->sb_status != -DLM_EUNLOCK) {
513                 fs_err(sdp, "%s lkid %x status %d\n",
514                        name, lksb->sb_lkid, lksb->sb_status);
515                 return -1;
516         }
517         return 0;
518 }
519 
520 static int sync_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags,
521                      unsigned int num, struct dlm_lksb *lksb, char *name)
522 {
523         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
524         char strname[GDLM_STRNAME_BYTES];
525         int error, status;
526 
527         memset(strname, 0, GDLM_STRNAME_BYTES);
528         snprintf(strname, GDLM_STRNAME_BYTES, "%8x%16x", LM_TYPE_NONDISK, num);
529 
530         error = dlm_lock(ls->ls_dlm, mode, lksb, flags,
531                          strname, GDLM_STRNAME_BYTES - 1,
532                          0, sync_wait_cb, ls, NULL);
533         if (error) {
534                 fs_err(sdp, "%s lkid %x flags %x mode %d error %d\n",
535                        name, lksb->sb_lkid, flags, mode, error);
536                 return error;
537         }
538 
539         wait_for_completion(&ls->ls_sync_wait);
540 
541         status = lksb->sb_status;
542 
543         if (status && status != -EAGAIN) {
544                 fs_err(sdp, "%s lkid %x flags %x mode %d status %d\n",
545                        name, lksb->sb_lkid, flags, mode, status);
546         }
547 
548         return status;
549 }
550 
551 static int mounted_unlock(struct gfs2_sbd *sdp)
552 {
553         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
554         return sync_unlock(sdp, &ls->ls_mounted_lksb, "mounted_lock");
555 }
556 
557 static int mounted_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
558 {
559         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
560         return sync_lock(sdp, mode, flags, GFS2_MOUNTED_LOCK,
561                          &ls->ls_mounted_lksb, "mounted_lock");
562 }
563 
564 static int control_unlock(struct gfs2_sbd *sdp)
565 {
566         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
567         return sync_unlock(sdp, &ls->ls_control_lksb, "control_lock");
568 }
569 
570 static int control_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
571 {
572         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
573         return sync_lock(sdp, mode, flags, GFS2_CONTROL_LOCK,
574                          &ls->ls_control_lksb, "control_lock");
575 }
576 
577 static void gfs2_control_func(struct work_struct *work)
578 {
579         struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work);
580         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
581         uint32_t block_gen, start_gen, lvb_gen, flags;
582         int recover_set = 0;
583         int write_lvb = 0;
584         int recover_size;
585         int i, error;
586 
587         spin_lock(&ls->ls_recover_spin);
588         /*
589          * No MOUNT_DONE means we're still mounting; control_mount()
590          * will set this flag, after which this thread will take over
591          * all further clearing of BLOCK_LOCKS.
592          *
593          * FIRST_MOUNT means this node is doing first mounter recovery,
594          * for which recovery control is handled by
595          * control_mount()/control_first_done(), not this thread.
596          */
597         if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
598              test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
599                 spin_unlock(&ls->ls_recover_spin);
600                 return;
601         }
602         block_gen = ls->ls_recover_block;
603         start_gen = ls->ls_recover_start;
604         spin_unlock(&ls->ls_recover_spin);
605 
606         /*
607          * Equal block_gen and start_gen implies we are between
608          * recover_prep and recover_done callbacks, which means
609          * dlm recovery is in progress and dlm locking is blocked.
610          * There's no point trying to do any work until recover_done.
611          */
612 
613         if (block_gen == start_gen)
614                 return;
615 
616         /*
617          * Propagate recover_submit[] and recover_result[] to lvb:
618          * dlm_recoverd adds to recover_submit[] jids needing recovery
619          * gfs2_recover adds to recover_result[] journal recovery results
620          *
621          * set lvb bit for jids in recover_submit[] if the lvb has not
622          * yet been updated for the generation of the failure
623          *
624          * clear lvb bit for jids in recover_result[] if the result of
625          * the journal recovery is SUCCESS
626          */
627 
628         error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
629         if (error) {
630                 fs_err(sdp, "control lock EX error %d\n", error);
631                 return;
632         }
633 
634         control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
635 
636         spin_lock(&ls->ls_recover_spin);
637         if (block_gen != ls->ls_recover_block ||
638             start_gen != ls->ls_recover_start) {
639                 fs_info(sdp, "recover generation %u block1 %u %u\n",
640                         start_gen, block_gen, ls->ls_recover_block);
641                 spin_unlock(&ls->ls_recover_spin);
642                 control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
643                 return;
644         }
645 
646         recover_size = ls->ls_recover_size;
647 
648         if (lvb_gen <= start_gen) {
649                 /*
650                  * Clear lvb bits for jids we've successfully recovered.
651                  * Because all nodes attempt to recover failed journals,
652                  * a journal can be recovered multiple times successfully
653                  * in succession.  Only the first will really do recovery,
654                  * the others find it clean, but still report a successful
655                  * recovery.  So, another node may have already recovered
656                  * the jid and cleared the lvb bit for it.
657                  */
658                 for (i = 0; i < recover_size; i++) {
659                         if (ls->ls_recover_result[i] != LM_RD_SUCCESS)
660                                 continue;
661 
662                         ls->ls_recover_result[i] = 0;
663 
664                         if (!test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET))
665                                 continue;
666 
667                         __clear_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
668                         write_lvb = 1;
669                 }
670         }
671 
672         if (lvb_gen == start_gen) {
673                 /*
674                  * Failed slots before start_gen are already set in lvb.
675                  */
676                 for (i = 0; i < recover_size; i++) {
677                         if (!ls->ls_recover_submit[i])
678                                 continue;
679                         if (ls->ls_recover_submit[i] < lvb_gen)
680                                 ls->ls_recover_submit[i] = 0;
681                 }
682         } else if (lvb_gen < start_gen) {
683                 /*
684                  * Failed slots before start_gen are not yet set in lvb.
685                  */
686                 for (i = 0; i < recover_size; i++) {
687                         if (!ls->ls_recover_submit[i])
688                                 continue;
689                         if (ls->ls_recover_submit[i] < start_gen) {
690                                 ls->ls_recover_submit[i] = 0;
691                                 __set_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
692                         }
693                 }
694                 /* even if there are no bits to set, we need to write the
695                    latest generation to the lvb */
696                 write_lvb = 1;
697         } else {
698                 /*
699                  * we should be getting a recover_done() for lvb_gen soon
700                  */
701         }
702         spin_unlock(&ls->ls_recover_spin);
703 
704         if (write_lvb) {
705                 control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
706                 flags = DLM_LKF_CONVERT | DLM_LKF_VALBLK;
707         } else {
708                 flags = DLM_LKF_CONVERT;
709         }
710 
711         error = control_lock(sdp, DLM_LOCK_NL, flags);
712         if (error) {
713                 fs_err(sdp, "control lock NL error %d\n", error);
714                 return;
715         }
716 
717         /*
718          * Everyone will see jid bits set in the lvb, run gfs2_recover_set(),
719          * and clear a jid bit in the lvb if the recovery is a success.
720          * Eventually all journals will be recovered, all jid bits will
721          * be cleared in the lvb, and everyone will clear BLOCK_LOCKS.
722          */
723 
724         for (i = 0; i < recover_size; i++) {
725                 if (test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET)) {
726                         fs_info(sdp, "recover generation %u jid %d\n",
727                                 start_gen, i);
728                         gfs2_recover_set(sdp, i);
729                         recover_set++;
730                 }
731         }
732         if (recover_set)
733                 return;
734 
735         /*
736          * No more jid bits set in lvb, all recovery is done, unblock locks
737          * (unless a new recover_prep callback has occured blocking locks
738          * again while working above)
739          */
740 
741         spin_lock(&ls->ls_recover_spin);
742         if (ls->ls_recover_block == block_gen &&
743             ls->ls_recover_start == start_gen) {
744                 clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
745                 spin_unlock(&ls->ls_recover_spin);
746                 fs_info(sdp, "recover generation %u done\n", start_gen);
747                 gfs2_glock_thaw(sdp);
748         } else {
749                 fs_info(sdp, "recover generation %u block2 %u %u\n",
750                         start_gen, block_gen, ls->ls_recover_block);
751                 spin_unlock(&ls->ls_recover_spin);
752         }
753 }
754 
755 static int control_mount(struct gfs2_sbd *sdp)
756 {
757         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
758         uint32_t start_gen, block_gen, mount_gen, lvb_gen;
759         int mounted_mode;
760         int retries = 0;
761         int error;
762 
763         memset(&ls->ls_mounted_lksb, 0, sizeof(struct dlm_lksb));
764         memset(&ls->ls_control_lksb, 0, sizeof(struct dlm_lksb));
765         memset(&ls->ls_control_lvb, 0, GDLM_LVB_SIZE);
766         ls->ls_control_lksb.sb_lvbptr = ls->ls_control_lvb;
767         init_completion(&ls->ls_sync_wait);
768 
769         set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
770 
771         error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_VALBLK);
772         if (error) {
773                 fs_err(sdp, "control_mount control_lock NL error %d\n", error);
774                 return error;
775         }
776 
777         error = mounted_lock(sdp, DLM_LOCK_NL, 0);
778         if (error) {
779                 fs_err(sdp, "control_mount mounted_lock NL error %d\n", error);
780                 control_unlock(sdp);
781                 return error;
782         }
783         mounted_mode = DLM_LOCK_NL;
784 
785 restart:
786         if (retries++ && signal_pending(current)) {
787                 error = -EINTR;
788                 goto fail;
789         }
790 
791         /*
792          * We always start with both locks in NL. control_lock is
793          * demoted to NL below so we don't need to do it here.
794          */
795 
796         if (mounted_mode != DLM_LOCK_NL) {
797                 error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
798                 if (error)
799                         goto fail;
800                 mounted_mode = DLM_LOCK_NL;
801         }
802 
803         /*
804          * Other nodes need to do some work in dlm recovery and gfs2_control
805          * before the recover_done and control_lock will be ready for us below.
806          * A delay here is not required but often avoids having to retry.
807          */
808 
809         msleep_interruptible(500);
810 
811         /*
812          * Acquire control_lock in EX and mounted_lock in either EX or PR.
813          * control_lock lvb keeps track of any pending journal recoveries.
814          * mounted_lock indicates if any other nodes have the fs mounted.
815          */
816 
817         error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE|DLM_LKF_VALBLK);
818         if (error == -EAGAIN) {
819                 goto restart;
820         } else if (error) {
821                 fs_err(sdp, "control_mount control_lock EX error %d\n", error);
822                 goto fail;
823         }
824 
825         error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
826         if (!error) {
827                 mounted_mode = DLM_LOCK_EX;
828                 goto locks_done;
829         } else if (error != -EAGAIN) {
830                 fs_err(sdp, "control_mount mounted_lock EX error %d\n", error);
831                 goto fail;
832         }
833 
834         error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
835         if (!error) {
836                 mounted_mode = DLM_LOCK_PR;
837                 goto locks_done;
838         } else {
839                 /* not even -EAGAIN should happen here */
840                 fs_err(sdp, "control_mount mounted_lock PR error %d\n", error);
841                 goto fail;
842         }
843 
844 locks_done:
845         /*
846          * If we got both locks above in EX, then we're the first mounter.
847          * If not, then we need to wait for the control_lock lvb to be
848          * updated by other mounted nodes to reflect our mount generation.
849          *
850          * In simple first mounter cases, first mounter will see zero lvb_gen,
851          * but in cases where all existing nodes leave/fail before mounting
852          * nodes finish control_mount, then all nodes will be mounting and
853          * lvb_gen will be non-zero.
854          */
855 
856         control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
857 
858         if (lvb_gen == 0xFFFFFFFF) {
859                 /* special value to force mount attempts to fail */
860                 fs_err(sdp, "control_mount control_lock disabled\n");
861                 error = -EINVAL;
862                 goto fail;
863         }
864 
865         if (mounted_mode == DLM_LOCK_EX) {
866                 /* first mounter, keep both EX while doing first recovery */
867                 spin_lock(&ls->ls_recover_spin);
868                 clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
869                 set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
870                 set_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
871                 spin_unlock(&ls->ls_recover_spin);
872                 fs_info(sdp, "first mounter control generation %u\n", lvb_gen);
873                 return 0;
874         }
875 
876         error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
877         if (error)
878                 goto fail;
879 
880         /*
881          * We are not first mounter, now we need to wait for the control_lock
882          * lvb generation to be >= the generation from our first recover_done
883          * and all lvb bits to be clear (no pending journal recoveries.)
884          */
885 
886         if (!all_jid_bits_clear(ls->ls_lvb_bits)) {
887                 /* journals need recovery, wait until all are clear */
888                 fs_info(sdp, "control_mount wait for journal recovery\n");
889                 goto restart;
890         }
891 
892         spin_lock(&ls->ls_recover_spin);
893         block_gen = ls->ls_recover_block;
894         start_gen = ls->ls_recover_start;
895         mount_gen = ls->ls_recover_mount;
896 
897         if (lvb_gen < mount_gen) {
898                 /* wait for mounted nodes to update control_lock lvb to our
899                    generation, which might include new recovery bits set */
900                 fs_info(sdp, "control_mount wait1 block %u start %u mount %u "
901                         "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
902                         lvb_gen, ls->ls_recover_flags);
903                 spin_unlock(&ls->ls_recover_spin);
904                 goto restart;
905         }
906 
907         if (lvb_gen != start_gen) {
908                 /* wait for mounted nodes to update control_lock lvb to the
909                    latest recovery generation */
910                 fs_info(sdp, "control_mount wait2 block %u start %u mount %u "
911                         "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
912                         lvb_gen, ls->ls_recover_flags);
913                 spin_unlock(&ls->ls_recover_spin);
914                 goto restart;
915         }
916 
917         if (block_gen == start_gen) {
918                 /* dlm recovery in progress, wait for it to finish */
919                 fs_info(sdp, "control_mount wait3 block %u start %u mount %u "
920                         "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
921                         lvb_gen, ls->ls_recover_flags);
922                 spin_unlock(&ls->ls_recover_spin);
923                 goto restart;
924         }
925 
926         clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
927         set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
928         memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
929         memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
930         spin_unlock(&ls->ls_recover_spin);
931         return 0;
932 
933 fail:
934         mounted_unlock(sdp);
935         control_unlock(sdp);
936         return error;
937 }
938 
939 static int control_first_done(struct gfs2_sbd *sdp)
940 {
941         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
942         uint32_t start_gen, block_gen;
943         int error;
944 
945 restart:
946         spin_lock(&ls->ls_recover_spin);
947         start_gen = ls->ls_recover_start;
948         block_gen = ls->ls_recover_block;
949 
950         if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags) ||
951             !test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
952             !test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
953                 /* sanity check, should not happen */
954                 fs_err(sdp, "control_first_done start %u block %u flags %lx\n",
955                        start_gen, block_gen, ls->ls_recover_flags);
956                 spin_unlock(&ls->ls_recover_spin);
957                 control_unlock(sdp);
958                 return -1;
959         }
960 
961         if (start_gen == block_gen) {
962                 /*
963                  * Wait for the end of a dlm recovery cycle to switch from
964                  * first mounter recovery.  We can ignore any recover_slot
965                  * callbacks between the recover_prep and next recover_done
966                  * because we are still the first mounter and any failed nodes
967                  * have not fully mounted, so they don't need recovery.
968                  */
969                 spin_unlock(&ls->ls_recover_spin);
970                 fs_info(sdp, "control_first_done wait gen %u\n", start_gen);
971 
972                 wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY,
973                             TASK_UNINTERRUPTIBLE);
974                 goto restart;
975         }
976 
977         clear_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
978         set_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags);
979         memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
980         memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
981         spin_unlock(&ls->ls_recover_spin);
982 
983         memset(ls->ls_lvb_bits, 0, GDLM_LVB_SIZE);
984         control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
985 
986         error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT);
987         if (error)
988                 fs_err(sdp, "control_first_done mounted PR error %d\n", error);
989 
990         error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
991         if (error)
992                 fs_err(sdp, "control_first_done control NL error %d\n", error);
993 
994         return error;
995 }
996 
997 /*
998  * Expand static jid arrays if necessary (by increments of RECOVER_SIZE_INC)
999  * to accomodate the largest slot number.  (NB dlm slot numbers start at 1,
1000  * gfs2 jids start at 0, so jid = slot - 1)
1001  */
1002 
1003 #define RECOVER_SIZE_INC 16
1004 
1005 static int set_recover_size(struct gfs2_sbd *sdp, struct dlm_slot *slots,
1006                             int num_slots)
1007 {
1008         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1009         uint32_t *submit = NULL;
1010         uint32_t *result = NULL;
1011         uint32_t old_size, new_size;
1012         int i, max_jid;
1013 
1014         if (!ls->ls_lvb_bits) {
1015                 ls->ls_lvb_bits = kzalloc(GDLM_LVB_SIZE, GFP_NOFS);
1016                 if (!ls->ls_lvb_bits)
1017                         return -ENOMEM;
1018         }
1019 
1020         max_jid = 0;
1021         for (i = 0; i < num_slots; i++) {
1022                 if (max_jid < slots[i].slot - 1)
1023                         max_jid = slots[i].slot - 1;
1024         }
1025 
1026         old_size = ls->ls_recover_size;
1027 
1028         if (old_size >= max_jid + 1)
1029                 return 0;
1030 
1031         new_size = old_size + RECOVER_SIZE_INC;
1032 
1033         submit = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS);
1034         result = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS);
1035         if (!submit || !result) {
1036                 kfree(submit);
1037                 kfree(result);
1038                 return -ENOMEM;
1039         }
1040 
1041         spin_lock(&ls->ls_recover_spin);
1042         memcpy(submit, ls->ls_recover_submit, old_size * sizeof(uint32_t));
1043         memcpy(result, ls->ls_recover_result, old_size * sizeof(uint32_t));
1044         kfree(ls->ls_recover_submit);
1045         kfree(ls->ls_recover_result);
1046         ls->ls_recover_submit = submit;
1047         ls->ls_recover_result = result;
1048         ls->ls_recover_size = new_size;
1049         spin_unlock(&ls->ls_recover_spin);
1050         return 0;
1051 }
1052 
1053 static void free_recover_size(struct lm_lockstruct *ls)
1054 {
1055         kfree(ls->ls_lvb_bits);
1056         kfree(ls->ls_recover_submit);
1057         kfree(ls->ls_recover_result);
1058         ls->ls_recover_submit = NULL;
1059         ls->ls_recover_result = NULL;
1060         ls->ls_recover_size = 0;
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",
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",
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 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 

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