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TOMOYO Linux Cross Reference
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 #include <linux/fs.h>
 11 #include <linux/dlm.h>
 12 #include <linux/slab.h>
 13 #include <linux/types.h>
 14 #include <linux/delay.h>
 15 #include <linux/gfs2_ondisk.h>
 16 
 17 #include "incore.h"
 18 #include "glock.h"
 19 #include "util.h"
 20 #include "sys.h"
 21 #include "trace_gfs2.h"
 22 
 23 extern struct workqueue_struct *gfs2_control_wq;
 24 
 25 /**
 26  * gfs2_update_stats - Update time based stats
 27  * @mv: Pointer to mean/variance structure to update
 28  * @sample: New data to include
 29  *
 30  * @delta is the difference between the current rtt sample and the
 31  * running average srtt. We add 1/8 of that to the srtt in order to
 32  * update the current srtt estimate. The varience estimate is a bit
 33  * more complicated. We subtract the abs value of the @delta from
 34  * the current variance estimate and add 1/4 of that to the running
 35  * total.
 36  *
 37  * Note that the index points at the array entry containing the smoothed
 38  * mean value, and the variance is always in the following entry
 39  *
 40  * Reference: TCP/IP Illustrated, vol 2, p. 831,832
 41  * All times are in units of integer nanoseconds. Unlike the TCP/IP case,
 42  * they are not scaled fixed point.
 43  */
 44 
 45 static inline void gfs2_update_stats(struct gfs2_lkstats *s, unsigned index,
 46                                      s64 sample)
 47 {
 48         s64 delta = sample - s->stats[index];
 49         s->stats[index] += (delta >> 3);
 50         index++;
 51         s->stats[index] += ((abs64(delta) - s->stats[index]) >> 2);
 52 }
 53 
 54 /**
 55  * gfs2_update_reply_times - Update locking statistics
 56  * @gl: The glock to update
 57  *
 58  * This assumes that gl->gl_dstamp has been set earlier.
 59  *
 60  * The rtt (lock round trip time) is an estimate of the time
 61  * taken to perform a dlm lock request. We update it on each
 62  * reply from the dlm.
 63  *
 64  * The blocking flag is set on the glock for all dlm requests
 65  * which may potentially block due to lock requests from other nodes.
 66  * DLM requests where the current lock state is exclusive, the
 67  * requested state is null (or unlocked) or where the TRY or
 68  * TRY_1CB flags are set are classified as non-blocking. All
 69  * other DLM requests are counted as (potentially) blocking.
 70  */
 71 static inline void gfs2_update_reply_times(struct gfs2_glock *gl)
 72 {
 73         struct gfs2_pcpu_lkstats *lks;
 74         const unsigned gltype = gl->gl_name.ln_type;
 75         unsigned index = test_bit(GLF_BLOCKING, &gl->gl_flags) ?
 76                          GFS2_LKS_SRTTB : GFS2_LKS_SRTT;
 77         s64 rtt;
 78 
 79         preempt_disable();
 80         rtt = ktime_to_ns(ktime_sub(ktime_get_real(), gl->gl_dstamp));
 81         lks = this_cpu_ptr(gl->gl_sbd->sd_lkstats);
 82         gfs2_update_stats(&gl->gl_stats, index, rtt);           /* Local */
 83         gfs2_update_stats(&lks->lkstats[gltype], index, rtt);   /* Global */
 84         preempt_enable();
 85 
 86         trace_gfs2_glock_lock_time(gl, rtt);
 87 }
 88 
 89 /**
 90  * gfs2_update_request_times - Update locking statistics
 91  * @gl: The glock to update
 92  *
 93  * The irt (lock inter-request times) measures the average time
 94  * between requests to the dlm. It is updated immediately before
 95  * each dlm call.
 96  */
 97 
 98 static inline void gfs2_update_request_times(struct gfs2_glock *gl)
 99 {
100         struct gfs2_pcpu_lkstats *lks;
101         const unsigned gltype = gl->gl_name.ln_type;
102         ktime_t dstamp;
103         s64 irt;
104 
105         preempt_disable();
106         dstamp = gl->gl_dstamp;
107         gl->gl_dstamp = ktime_get_real();
108         irt = ktime_to_ns(ktime_sub(gl->gl_dstamp, dstamp));
109         lks = this_cpu_ptr(gl->gl_sbd->sd_lkstats);
110         gfs2_update_stats(&gl->gl_stats, GFS2_LKS_SIRT, irt);           /* Local */
111         gfs2_update_stats(&lks->lkstats[gltype], GFS2_LKS_SIRT, irt);   /* Global */
112         preempt_enable();
113 }
114  
115 static void gdlm_ast(void *arg)
116 {
117         struct gfs2_glock *gl = arg;
118         unsigned ret = gl->gl_state;
119 
120         gfs2_update_reply_times(gl);
121         BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);
122 
123         if ((gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID) && gl->gl_lksb.sb_lvbptr)
124                 memset(gl->gl_lksb.sb_lvbptr, 0, GDLM_LVB_SIZE);
125 
126         switch (gl->gl_lksb.sb_status) {
127         case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */
128                 gfs2_glock_free(gl);
129                 return;
130         case -DLM_ECANCEL: /* Cancel while getting lock */
131                 ret |= LM_OUT_CANCELED;
132                 goto out;
133         case -EAGAIN: /* Try lock fails */
134         case -EDEADLK: /* Deadlock detected */
135                 goto out;
136         case -ETIMEDOUT: /* Canceled due to timeout */
137                 ret |= LM_OUT_ERROR;
138                 goto out;
139         case 0: /* Success */
140                 break;
141         default: /* Something unexpected */
142                 BUG();
143         }
144 
145         ret = gl->gl_req;
146         if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) {
147                 if (gl->gl_req == LM_ST_SHARED)
148                         ret = LM_ST_DEFERRED;
149                 else if (gl->gl_req == LM_ST_DEFERRED)
150                         ret = LM_ST_SHARED;
151                 else
152                         BUG();
153         }
154 
155         set_bit(GLF_INITIAL, &gl->gl_flags);
156         gfs2_glock_complete(gl, ret);
157         return;
158 out:
159         if (!test_bit(GLF_INITIAL, &gl->gl_flags))
160                 gl->gl_lksb.sb_lkid = 0;
161         gfs2_glock_complete(gl, ret);
162 }
163 
164 static void gdlm_bast(void *arg, int mode)
165 {
166         struct gfs2_glock *gl = arg;
167 
168         switch (mode) {
169         case DLM_LOCK_EX:
170                 gfs2_glock_cb(gl, LM_ST_UNLOCKED);
171                 break;
172         case DLM_LOCK_CW:
173                 gfs2_glock_cb(gl, LM_ST_DEFERRED);
174                 break;
175         case DLM_LOCK_PR:
176                 gfs2_glock_cb(gl, LM_ST_SHARED);
177                 break;
178         default:
179                 printk(KERN_ERR "unknown bast mode %d", mode);
180                 BUG();
181         }
182 }
183 
184 /* convert gfs lock-state to dlm lock-mode */
185 
186 static int make_mode(const unsigned int lmstate)
187 {
188         switch (lmstate) {
189         case LM_ST_UNLOCKED:
190                 return DLM_LOCK_NL;
191         case LM_ST_EXCLUSIVE:
192                 return DLM_LOCK_EX;
193         case LM_ST_DEFERRED:
194                 return DLM_LOCK_CW;
195         case LM_ST_SHARED:
196                 return DLM_LOCK_PR;
197         }
198         printk(KERN_ERR "unknown LM state %d", lmstate);
199         BUG();
200         return -1;
201 }
202 
203 static u32 make_flags(struct gfs2_glock *gl, const unsigned int gfs_flags,
204                       const int req)
205 {
206         u32 lkf = 0;
207 
208         if (gl->gl_lksb.sb_lvbptr)
209                 lkf |= DLM_LKF_VALBLK;
210 
211         if (gfs_flags & LM_FLAG_TRY)
212                 lkf |= DLM_LKF_NOQUEUE;
213 
214         if (gfs_flags & LM_FLAG_TRY_1CB) {
215                 lkf |= DLM_LKF_NOQUEUE;
216                 lkf |= DLM_LKF_NOQUEUEBAST;
217         }
218 
219         if (gfs_flags & LM_FLAG_PRIORITY) {
220                 lkf |= DLM_LKF_NOORDER;
221                 lkf |= DLM_LKF_HEADQUE;
222         }
223 
224         if (gfs_flags & LM_FLAG_ANY) {
225                 if (req == DLM_LOCK_PR)
226                         lkf |= DLM_LKF_ALTCW;
227                 else if (req == DLM_LOCK_CW)
228                         lkf |= DLM_LKF_ALTPR;
229                 else
230                         BUG();
231         }
232 
233         if (gl->gl_lksb.sb_lkid != 0) {
234                 lkf |= DLM_LKF_CONVERT;
235                 if (test_bit(GLF_BLOCKING, &gl->gl_flags))
236                         lkf |= DLM_LKF_QUECVT;
237         }
238 
239         return lkf;
240 }
241 
242 static void gfs2_reverse_hex(char *c, u64 value)
243 {
244         *c = '';
245         while (value) {
246                 *c-- = hex_asc[value & 0x0f];
247                 value >>= 4;
248         }
249 }
250 
251 static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state,
252                      unsigned int flags)
253 {
254         struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
255         int req;
256         u32 lkf;
257         char strname[GDLM_STRNAME_BYTES] = "";
258 
259         req = make_mode(req_state);
260         lkf = make_flags(gl, flags, req);
261         gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
262         gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
263         if (gl->gl_lksb.sb_lkid) {
264                 gfs2_update_request_times(gl);
265         } else {
266                 memset(strname, ' ', GDLM_STRNAME_BYTES - 1);
267                 strname[GDLM_STRNAME_BYTES - 1] = '\0';
268                 gfs2_reverse_hex(strname + 7, gl->gl_name.ln_type);
269                 gfs2_reverse_hex(strname + 23, gl->gl_name.ln_number);
270                 gl->gl_dstamp = ktime_get_real();
271         }
272         /*
273          * Submit the actual lock request.
274          */
275 
276         return dlm_lock(ls->ls_dlm, req, &gl->gl_lksb, lkf, strname,
277                         GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast);
278 }
279 
280 static void gdlm_put_lock(struct gfs2_glock *gl)
281 {
282         struct gfs2_sbd *sdp = gl->gl_sbd;
283         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
284         int lvb_needs_unlock = 0;
285         int error;
286 
287         if (gl->gl_lksb.sb_lkid == 0) {
288                 gfs2_glock_free(gl);
289                 return;
290         }
291 
292         clear_bit(GLF_BLOCKING, &gl->gl_flags);
293         gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
294         gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
295         gfs2_update_request_times(gl);
296 
297         /* don't want to skip dlm_unlock writing the lvb when lock is ex */
298 
299         if (gl->gl_lksb.sb_lvbptr && (gl->gl_state == LM_ST_EXCLUSIVE))
300                 lvb_needs_unlock = 1;
301 
302         if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) &&
303             !lvb_needs_unlock) {
304                 gfs2_glock_free(gl);
305                 return;
306         }
307 
308         error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK,
309                            NULL, gl);
310         if (error) {
311                 printk(KERN_ERR "gdlm_unlock %x,%llx err=%d\n",
312                        gl->gl_name.ln_type,
313                        (unsigned long long)gl->gl_name.ln_number, error);
314                 return;
315         }
316 }
317 
318 static void gdlm_cancel(struct gfs2_glock *gl)
319 {
320         struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct;
321         dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl);
322 }
323 
324 /*
325  * dlm/gfs2 recovery coordination using dlm_recover callbacks
326  *
327  *  1. dlm_controld sees lockspace members change
328  *  2. dlm_controld blocks dlm-kernel locking activity
329  *  3. dlm_controld within dlm-kernel notifies gfs2 (recover_prep)
330  *  4. dlm_controld starts and finishes its own user level recovery
331  *  5. dlm_controld starts dlm-kernel dlm_recoverd to do kernel recovery
332  *  6. dlm_recoverd notifies gfs2 of failed nodes (recover_slot)
333  *  7. dlm_recoverd does its own lock recovery
334  *  8. dlm_recoverd unblocks dlm-kernel locking activity
335  *  9. dlm_recoverd notifies gfs2 when done (recover_done with new generation)
336  * 10. gfs2_control updates control_lock lvb with new generation and jid bits
337  * 11. gfs2_control enqueues journals for gfs2_recover to recover (maybe none)
338  * 12. gfs2_recover dequeues and recovers journals of failed nodes
339  * 13. gfs2_recover provides recovery results to gfs2_control (recovery_result)
340  * 14. gfs2_control updates control_lock lvb jid bits for recovered journals
341  * 15. gfs2_control unblocks normal locking when all journals are recovered
342  *
343  * - failures during recovery
344  *
345  * recover_prep() may set BLOCK_LOCKS (step 3) again before gfs2_control
346  * clears BLOCK_LOCKS (step 15), e.g. another node fails while still
347  * recovering for a prior failure.  gfs2_control needs a way to detect
348  * this so it can leave BLOCK_LOCKS set in step 15.  This is managed using
349  * the recover_block and recover_start values.
350  *
351  * recover_done() provides a new lockspace generation number each time it
352  * is called (step 9).  This generation number is saved as recover_start.
353  * When recover_prep() is called, it sets BLOCK_LOCKS and sets
354  * recover_block = recover_start.  So, while recover_block is equal to
355  * recover_start, BLOCK_LOCKS should remain set.  (recover_spin must
356  * be held around the BLOCK_LOCKS/recover_block/recover_start logic.)
357  *
358  * - more specific gfs2 steps in sequence above
359  *
360  *  3. recover_prep sets BLOCK_LOCKS and sets recover_block = recover_start
361  *  6. recover_slot records any failed jids (maybe none)
362  *  9. recover_done sets recover_start = new generation number
363  * 10. gfs2_control sets control_lock lvb = new gen + bits for failed jids
364  * 12. gfs2_recover does journal recoveries for failed jids identified above
365  * 14. gfs2_control clears control_lock lvb bits for recovered jids
366  * 15. gfs2_control checks if recover_block == recover_start (step 3 occured
367  *     again) then do nothing, otherwise if recover_start > recover_block
368  *     then clear BLOCK_LOCKS.
369  *
370  * - parallel recovery steps across all nodes
371  *
372  * All nodes attempt to update the control_lock lvb with the new generation
373  * number and jid bits, but only the first to get the control_lock EX will
374  * do so; others will see that it's already done (lvb already contains new
375  * generation number.)
376  *
377  * . All nodes get the same recover_prep/recover_slot/recover_done callbacks
378  * . All nodes attempt to set control_lock lvb gen + bits for the new gen
379  * . One node gets control_lock first and writes the lvb, others see it's done
380  * . All nodes attempt to recover jids for which they see control_lock bits set
381  * . One node succeeds for a jid, and that one clears the jid bit in the lvb
382  * . All nodes will eventually see all lvb bits clear and unblock locks
383  *
384  * - is there a problem with clearing an lvb bit that should be set
385  *   and missing a journal recovery?
386  *
387  * 1. jid fails
388  * 2. lvb bit set for step 1
389  * 3. jid recovered for step 1
390  * 4. jid taken again (new mount)
391  * 5. jid fails (for step 4)
392  * 6. lvb bit set for step 5 (will already be set)
393  * 7. lvb bit cleared for step 3
394  *
395  * This is not a problem because the failure in step 5 does not
396  * require recovery, because the mount in step 4 could not have
397  * progressed far enough to unblock locks and access the fs.  The
398  * control_mount() function waits for all recoveries to be complete
399  * for the latest lockspace generation before ever unblocking locks
400  * and returning.  The mount in step 4 waits until the recovery in
401  * step 1 is done.
402  *
403  * - special case of first mounter: first node to mount the fs
404  *
405  * The first node to mount a gfs2 fs needs to check all the journals
406  * and recover any that need recovery before other nodes are allowed
407  * to mount the fs.  (Others may begin mounting, but they must wait
408  * for the first mounter to be done before taking locks on the fs
409  * or accessing the fs.)  This has two parts:
410  *
411  * 1. The mounted_lock tells a node it's the first to mount the fs.
412  * Each node holds the mounted_lock in PR while it's mounted.
413  * Each node tries to acquire the mounted_lock in EX when it mounts.
414  * If a node is granted the mounted_lock EX it means there are no
415  * other mounted nodes (no PR locks exist), and it is the first mounter.
416  * The mounted_lock is demoted to PR when first recovery is done, so
417  * others will fail to get an EX lock, but will get a PR lock.
418  *
419  * 2. The control_lock blocks others in control_mount() while the first
420  * mounter is doing first mount recovery of all journals.
421  * A mounting node needs to acquire control_lock in EX mode before
422  * it can proceed.  The first mounter holds control_lock in EX while doing
423  * the first mount recovery, blocking mounts from other nodes, then demotes
424  * control_lock to NL when it's done (others_may_mount/first_done),
425  * allowing other nodes to continue mounting.
426  *
427  * first mounter:
428  * control_lock EX/NOQUEUE success
429  * mounted_lock EX/NOQUEUE success (no other PR, so no other mounters)
430  * set first=1
431  * do first mounter recovery
432  * mounted_lock EX->PR
433  * control_lock EX->NL, write lvb generation
434  *
435  * other mounter:
436  * control_lock EX/NOQUEUE success (if fail -EAGAIN, retry)
437  * mounted_lock EX/NOQUEUE fail -EAGAIN (expected due to other mounters PR)
438  * mounted_lock PR/NOQUEUE success
439  * read lvb generation
440  * control_lock EX->NL
441  * set first=0
442  *
443  * - mount during recovery
444  *
445  * If a node mounts while others are doing recovery (not first mounter),
446  * the mounting node will get its initial recover_done() callback without
447  * having seen any previous failures/callbacks.
448  *
449  * It must wait for all recoveries preceding its mount to be finished
450  * before it unblocks locks.  It does this by repeating the "other mounter"
451  * steps above until the lvb generation number is >= its mount generation
452  * number (from initial recover_done) and all lvb bits are clear.
453  *
454  * - control_lock lvb format
455  *
456  * 4 bytes generation number: the latest dlm lockspace generation number
457  * from recover_done callback.  Indicates the jid bitmap has been updated
458  * to reflect all slot failures through that generation.
459  * 4 bytes unused.
460  * GDLM_LVB_SIZE-8 bytes of jid bit map. If bit N is set, it indicates
461  * that jid N needs recovery.
462  */
463 
464 #define JID_BITMAP_OFFSET 8 /* 4 byte generation number + 4 byte unused */
465 
466 static void control_lvb_read(struct lm_lockstruct *ls, uint32_t *lvb_gen,
467                              char *lvb_bits)
468 {
469         uint32_t gen;
470         memcpy(lvb_bits, ls->ls_control_lvb, GDLM_LVB_SIZE);
471         memcpy(&gen, lvb_bits, sizeof(uint32_t));
472         *lvb_gen = le32_to_cpu(gen);
473 }
474 
475 static void control_lvb_write(struct lm_lockstruct *ls, uint32_t lvb_gen,
476                               char *lvb_bits)
477 {
478         uint32_t gen;
479         memcpy(ls->ls_control_lvb, lvb_bits, GDLM_LVB_SIZE);
480         gen = cpu_to_le32(lvb_gen);
481         memcpy(ls->ls_control_lvb, &gen, sizeof(uint32_t));
482 }
483 
484 static int all_jid_bits_clear(char *lvb)
485 {
486         return !memchr_inv(lvb + JID_BITMAP_OFFSET, 0,
487                         GDLM_LVB_SIZE - JID_BITMAP_OFFSET);
488 }
489 
490 static void sync_wait_cb(void *arg)
491 {
492         struct lm_lockstruct *ls = arg;
493         complete(&ls->ls_sync_wait);
494 }
495 
496 static int sync_unlock(struct gfs2_sbd *sdp, struct dlm_lksb *lksb, char *name)
497 {
498         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
499         int error;
500 
501         error = dlm_unlock(ls->ls_dlm, lksb->sb_lkid, 0, lksb, ls);
502         if (error) {
503                 fs_err(sdp, "%s lkid %x error %d\n",
504                        name, lksb->sb_lkid, error);
505                 return error;
506         }
507 
508         wait_for_completion(&ls->ls_sync_wait);
509 
510         if (lksb->sb_status != -DLM_EUNLOCK) {
511                 fs_err(sdp, "%s lkid %x status %d\n",
512                        name, lksb->sb_lkid, lksb->sb_status);
513                 return -1;
514         }
515         return 0;
516 }
517 
518 static int sync_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags,
519                      unsigned int num, struct dlm_lksb *lksb, char *name)
520 {
521         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
522         char strname[GDLM_STRNAME_BYTES];
523         int error, status;
524 
525         memset(strname, 0, GDLM_STRNAME_BYTES);
526         snprintf(strname, GDLM_STRNAME_BYTES, "%8x%16x", LM_TYPE_NONDISK, num);
527 
528         error = dlm_lock(ls->ls_dlm, mode, lksb, flags,
529                          strname, GDLM_STRNAME_BYTES - 1,
530                          0, sync_wait_cb, ls, NULL);
531         if (error) {
532                 fs_err(sdp, "%s lkid %x flags %x mode %d error %d\n",
533                        name, lksb->sb_lkid, flags, mode, error);
534                 return error;
535         }
536 
537         wait_for_completion(&ls->ls_sync_wait);
538 
539         status = lksb->sb_status;
540 
541         if (status && status != -EAGAIN) {
542                 fs_err(sdp, "%s lkid %x flags %x mode %d status %d\n",
543                        name, lksb->sb_lkid, flags, mode, status);
544         }
545 
546         return status;
547 }
548 
549 static int mounted_unlock(struct gfs2_sbd *sdp)
550 {
551         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
552         return sync_unlock(sdp, &ls->ls_mounted_lksb, "mounted_lock");
553 }
554 
555 static int mounted_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
556 {
557         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
558         return sync_lock(sdp, mode, flags, GFS2_MOUNTED_LOCK,
559                          &ls->ls_mounted_lksb, "mounted_lock");
560 }
561 
562 static int control_unlock(struct gfs2_sbd *sdp)
563 {
564         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
565         return sync_unlock(sdp, &ls->ls_control_lksb, "control_lock");
566 }
567 
568 static int control_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
569 {
570         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
571         return sync_lock(sdp, mode, flags, GFS2_CONTROL_LOCK,
572                          &ls->ls_control_lksb, "control_lock");
573 }
574 
575 static void gfs2_control_func(struct work_struct *work)
576 {
577         struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work);
578         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
579         uint32_t block_gen, start_gen, lvb_gen, flags;
580         int recover_set = 0;
581         int write_lvb = 0;
582         int recover_size;
583         int i, error;
584 
585         spin_lock(&ls->ls_recover_spin);
586         /*
587          * No MOUNT_DONE means we're still mounting; control_mount()
588          * will set this flag, after which this thread will take over
589          * all further clearing of BLOCK_LOCKS.
590          *
591          * FIRST_MOUNT means this node is doing first mounter recovery,
592          * for which recovery control is handled by
593          * control_mount()/control_first_done(), not this thread.
594          */
595         if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
596              test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
597                 spin_unlock(&ls->ls_recover_spin);
598                 return;
599         }
600         block_gen = ls->ls_recover_block;
601         start_gen = ls->ls_recover_start;
602         spin_unlock(&ls->ls_recover_spin);
603 
604         /*
605          * Equal block_gen and start_gen implies we are between
606          * recover_prep and recover_done callbacks, which means
607          * dlm recovery is in progress and dlm locking is blocked.
608          * There's no point trying to do any work until recover_done.
609          */
610 
611         if (block_gen == start_gen)
612                 return;
613 
614         /*
615          * Propagate recover_submit[] and recover_result[] to lvb:
616          * dlm_recoverd adds to recover_submit[] jids needing recovery
617          * gfs2_recover adds to recover_result[] journal recovery results
618          *
619          * set lvb bit for jids in recover_submit[] if the lvb has not
620          * yet been updated for the generation of the failure
621          *
622          * clear lvb bit for jids in recover_result[] if the result of
623          * the journal recovery is SUCCESS
624          */
625 
626         error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
627         if (error) {
628                 fs_err(sdp, "control lock EX error %d\n", error);
629                 return;
630         }
631 
632         control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
633 
634         spin_lock(&ls->ls_recover_spin);
635         if (block_gen != ls->ls_recover_block ||
636             start_gen != ls->ls_recover_start) {
637                 fs_info(sdp, "recover generation %u block1 %u %u\n",
638                         start_gen, block_gen, ls->ls_recover_block);
639                 spin_unlock(&ls->ls_recover_spin);
640                 control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
641                 return;
642         }
643 
644         recover_size = ls->ls_recover_size;
645 
646         if (lvb_gen <= start_gen) {
647                 /*
648                  * Clear lvb bits for jids we've successfully recovered.
649                  * Because all nodes attempt to recover failed journals,
650                  * a journal can be recovered multiple times successfully
651                  * in succession.  Only the first will really do recovery,
652                  * the others find it clean, but still report a successful
653                  * recovery.  So, another node may have already recovered
654                  * the jid and cleared the lvb bit for it.
655                  */
656                 for (i = 0; i < recover_size; i++) {
657                         if (ls->ls_recover_result[i] != LM_RD_SUCCESS)
658                                 continue;
659 
660                         ls->ls_recover_result[i] = 0;
661 
662                         if (!test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET))
663                                 continue;
664 
665                         __clear_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
666                         write_lvb = 1;
667                 }
668         }
669 
670         if (lvb_gen == start_gen) {
671                 /*
672                  * Failed slots before start_gen are already set in lvb.
673                  */
674                 for (i = 0; i < recover_size; i++) {
675                         if (!ls->ls_recover_submit[i])
676                                 continue;
677                         if (ls->ls_recover_submit[i] < lvb_gen)
678                                 ls->ls_recover_submit[i] = 0;
679                 }
680         } else if (lvb_gen < start_gen) {
681                 /*
682                  * Failed slots before start_gen are not yet set in lvb.
683                  */
684                 for (i = 0; i < recover_size; i++) {
685                         if (!ls->ls_recover_submit[i])
686                                 continue;
687                         if (ls->ls_recover_submit[i] < start_gen) {
688                                 ls->ls_recover_submit[i] = 0;
689                                 __set_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
690                         }
691                 }
692                 /* even if there are no bits to set, we need to write the
693                    latest generation to the lvb */
694                 write_lvb = 1;
695         } else {
696                 /*
697                  * we should be getting a recover_done() for lvb_gen soon
698                  */
699         }
700         spin_unlock(&ls->ls_recover_spin);
701 
702         if (write_lvb) {
703                 control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
704                 flags = DLM_LKF_CONVERT | DLM_LKF_VALBLK;
705         } else {
706                 flags = DLM_LKF_CONVERT;
707         }
708 
709         error = control_lock(sdp, DLM_LOCK_NL, flags);
710         if (error) {
711                 fs_err(sdp, "control lock NL error %d\n", error);
712                 return;
713         }
714 
715         /*
716          * Everyone will see jid bits set in the lvb, run gfs2_recover_set(),
717          * and clear a jid bit in the lvb if the recovery is a success.
718          * Eventually all journals will be recovered, all jid bits will
719          * be cleared in the lvb, and everyone will clear BLOCK_LOCKS.
720          */
721 
722         for (i = 0; i < recover_size; i++) {
723                 if (test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET)) {
724                         fs_info(sdp, "recover generation %u jid %d\n",
725                                 start_gen, i);
726                         gfs2_recover_set(sdp, i);
727                         recover_set++;
728                 }
729         }
730         if (recover_set)
731                 return;
732 
733         /*
734          * No more jid bits set in lvb, all recovery is done, unblock locks
735          * (unless a new recover_prep callback has occured blocking locks
736          * again while working above)
737          */
738 
739         spin_lock(&ls->ls_recover_spin);
740         if (ls->ls_recover_block == block_gen &&
741             ls->ls_recover_start == start_gen) {
742                 clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
743                 spin_unlock(&ls->ls_recover_spin);
744                 fs_info(sdp, "recover generation %u done\n", start_gen);
745                 gfs2_glock_thaw(sdp);
746         } else {
747                 fs_info(sdp, "recover generation %u block2 %u %u\n",
748                         start_gen, block_gen, ls->ls_recover_block);
749                 spin_unlock(&ls->ls_recover_spin);
750         }
751 }
752 
753 static int control_mount(struct gfs2_sbd *sdp)
754 {
755         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
756         uint32_t start_gen, block_gen, mount_gen, lvb_gen;
757         int mounted_mode;
758         int retries = 0;
759         int error;
760 
761         memset(&ls->ls_mounted_lksb, 0, sizeof(struct dlm_lksb));
762         memset(&ls->ls_control_lksb, 0, sizeof(struct dlm_lksb));
763         memset(&ls->ls_control_lvb, 0, GDLM_LVB_SIZE);
764         ls->ls_control_lksb.sb_lvbptr = ls->ls_control_lvb;
765         init_completion(&ls->ls_sync_wait);
766 
767         set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
768 
769         error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_VALBLK);
770         if (error) {
771                 fs_err(sdp, "control_mount control_lock NL error %d\n", error);
772                 return error;
773         }
774 
775         error = mounted_lock(sdp, DLM_LOCK_NL, 0);
776         if (error) {
777                 fs_err(sdp, "control_mount mounted_lock NL error %d\n", error);
778                 control_unlock(sdp);
779                 return error;
780         }
781         mounted_mode = DLM_LOCK_NL;
782 
783 restart:
784         if (retries++ && signal_pending(current)) {
785                 error = -EINTR;
786                 goto fail;
787         }
788 
789         /*
790          * We always start with both locks in NL. control_lock is
791          * demoted to NL below so we don't need to do it here.
792          */
793 
794         if (mounted_mode != DLM_LOCK_NL) {
795                 error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
796                 if (error)
797                         goto fail;
798                 mounted_mode = DLM_LOCK_NL;
799         }
800 
801         /*
802          * Other nodes need to do some work in dlm recovery and gfs2_control
803          * before the recover_done and control_lock will be ready for us below.
804          * A delay here is not required but often avoids having to retry.
805          */
806 
807         msleep_interruptible(500);
808 
809         /*
810          * Acquire control_lock in EX and mounted_lock in either EX or PR.
811          * control_lock lvb keeps track of any pending journal recoveries.
812          * mounted_lock indicates if any other nodes have the fs mounted.
813          */
814 
815         error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE|DLM_LKF_VALBLK);
816         if (error == -EAGAIN) {
817                 goto restart;
818         } else if (error) {
819                 fs_err(sdp, "control_mount control_lock EX error %d\n", error);
820                 goto fail;
821         }
822 
823         error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
824         if (!error) {
825                 mounted_mode = DLM_LOCK_EX;
826                 goto locks_done;
827         } else if (error != -EAGAIN) {
828                 fs_err(sdp, "control_mount mounted_lock EX error %d\n", error);
829                 goto fail;
830         }
831 
832         error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
833         if (!error) {
834                 mounted_mode = DLM_LOCK_PR;
835                 goto locks_done;
836         } else {
837                 /* not even -EAGAIN should happen here */
838                 fs_err(sdp, "control_mount mounted_lock PR error %d\n", error);
839                 goto fail;
840         }
841 
842 locks_done:
843         /*
844          * If we got both locks above in EX, then we're the first mounter.
845          * If not, then we need to wait for the control_lock lvb to be
846          * updated by other mounted nodes to reflect our mount generation.
847          *
848          * In simple first mounter cases, first mounter will see zero lvb_gen,
849          * but in cases where all existing nodes leave/fail before mounting
850          * nodes finish control_mount, then all nodes will be mounting and
851          * lvb_gen will be non-zero.
852          */
853 
854         control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
855 
856         if (lvb_gen == 0xFFFFFFFF) {
857                 /* special value to force mount attempts to fail */
858                 fs_err(sdp, "control_mount control_lock disabled\n");
859                 error = -EINVAL;
860                 goto fail;
861         }
862 
863         if (mounted_mode == DLM_LOCK_EX) {
864                 /* first mounter, keep both EX while doing first recovery */
865                 spin_lock(&ls->ls_recover_spin);
866                 clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
867                 set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
868                 set_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
869                 spin_unlock(&ls->ls_recover_spin);
870                 fs_info(sdp, "first mounter control generation %u\n", lvb_gen);
871                 return 0;
872         }
873 
874         error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
875         if (error)
876                 goto fail;
877 
878         /*
879          * We are not first mounter, now we need to wait for the control_lock
880          * lvb generation to be >= the generation from our first recover_done
881          * and all lvb bits to be clear (no pending journal recoveries.)
882          */
883 
884         if (!all_jid_bits_clear(ls->ls_lvb_bits)) {
885                 /* journals need recovery, wait until all are clear */
886                 fs_info(sdp, "control_mount wait for journal recovery\n");
887                 goto restart;
888         }
889 
890         spin_lock(&ls->ls_recover_spin);
891         block_gen = ls->ls_recover_block;
892         start_gen = ls->ls_recover_start;
893         mount_gen = ls->ls_recover_mount;
894 
895         if (lvb_gen < mount_gen) {
896                 /* wait for mounted nodes to update control_lock lvb to our
897                    generation, which might include new recovery bits set */
898                 fs_info(sdp, "control_mount wait1 block %u start %u mount %u "
899                         "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
900                         lvb_gen, ls->ls_recover_flags);
901                 spin_unlock(&ls->ls_recover_spin);
902                 goto restart;
903         }
904 
905         if (lvb_gen != start_gen) {
906                 /* wait for mounted nodes to update control_lock lvb to the
907                    latest recovery generation */
908                 fs_info(sdp, "control_mount wait2 block %u start %u mount %u "
909                         "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
910                         lvb_gen, ls->ls_recover_flags);
911                 spin_unlock(&ls->ls_recover_spin);
912                 goto restart;
913         }
914 
915         if (block_gen == start_gen) {
916                 /* dlm recovery in progress, wait for it to finish */
917                 fs_info(sdp, "control_mount wait3 block %u start %u mount %u "
918                         "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
919                         lvb_gen, ls->ls_recover_flags);
920                 spin_unlock(&ls->ls_recover_spin);
921                 goto restart;
922         }
923 
924         clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
925         set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
926         memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
927         memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
928         spin_unlock(&ls->ls_recover_spin);
929         return 0;
930 
931 fail:
932         mounted_unlock(sdp);
933         control_unlock(sdp);
934         return error;
935 }
936 
937 static int dlm_recovery_wait(void *word)
938 {
939         schedule();
940         return 0;
941 }
942 
943 static int control_first_done(struct gfs2_sbd *sdp)
944 {
945         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
946         uint32_t start_gen, block_gen;
947         int error;
948 
949 restart:
950         spin_lock(&ls->ls_recover_spin);
951         start_gen = ls->ls_recover_start;
952         block_gen = ls->ls_recover_block;
953 
954         if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags) ||
955             !test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
956             !test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
957                 /* sanity check, should not happen */
958                 fs_err(sdp, "control_first_done start %u block %u flags %lx\n",
959                        start_gen, block_gen, ls->ls_recover_flags);
960                 spin_unlock(&ls->ls_recover_spin);
961                 control_unlock(sdp);
962                 return -1;
963         }
964 
965         if (start_gen == block_gen) {
966                 /*
967                  * Wait for the end of a dlm recovery cycle to switch from
968                  * first mounter recovery.  We can ignore any recover_slot
969                  * callbacks between the recover_prep and next recover_done
970                  * because we are still the first mounter and any failed nodes
971                  * have not fully mounted, so they don't need recovery.
972                  */
973                 spin_unlock(&ls->ls_recover_spin);
974                 fs_info(sdp, "control_first_done wait gen %u\n", start_gen);
975 
976                 wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY,
977                             dlm_recovery_wait, TASK_UNINTERRUPTIBLE);
978                 goto restart;
979         }
980 
981         clear_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
982         set_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags);
983         memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
984         memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
985         spin_unlock(&ls->ls_recover_spin);
986 
987         memset(ls->ls_lvb_bits, 0, GDLM_LVB_SIZE);
988         control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
989 
990         error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT);
991         if (error)
992                 fs_err(sdp, "control_first_done mounted PR error %d\n", error);
993 
994         error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
995         if (error)
996                 fs_err(sdp, "control_first_done control NL error %d\n", error);
997 
998         return error;
999 }
1000 
1001 /*
1002  * Expand static jid arrays if necessary (by increments of RECOVER_SIZE_INC)
1003  * to accomodate the largest slot number.  (NB dlm slot numbers start at 1,
1004  * gfs2 jids start at 0, so jid = slot - 1)
1005  */
1006 
1007 #define RECOVER_SIZE_INC 16
1008 
1009 static int set_recover_size(struct gfs2_sbd *sdp, struct dlm_slot *slots,
1010                             int num_slots)
1011 {
1012         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1013         uint32_t *submit = NULL;
1014         uint32_t *result = NULL;
1015         uint32_t old_size, new_size;
1016         int i, max_jid;
1017 
1018         if (!ls->ls_lvb_bits) {
1019                 ls->ls_lvb_bits = kzalloc(GDLM_LVB_SIZE, GFP_NOFS);
1020                 if (!ls->ls_lvb_bits)
1021                         return -ENOMEM;
1022         }
1023 
1024         max_jid = 0;
1025         for (i = 0; i < num_slots; i++) {
1026                 if (max_jid < slots[i].slot - 1)
1027                         max_jid = slots[i].slot - 1;
1028         }
1029 
1030         old_size = ls->ls_recover_size;
1031 
1032         if (old_size >= max_jid + 1)
1033                 return 0;
1034 
1035         new_size = old_size + RECOVER_SIZE_INC;
1036 
1037         submit = kzalloc(new_size * sizeof(uint32_t), GFP_NOFS);
1038         result = kzalloc(new_size * sizeof(uint32_t), GFP_NOFS);
1039         if (!submit || !result) {
1040                 kfree(submit);
1041                 kfree(result);
1042                 return -ENOMEM;
1043         }
1044 
1045         spin_lock(&ls->ls_recover_spin);
1046         memcpy(submit, ls->ls_recover_submit, old_size * sizeof(uint32_t));
1047         memcpy(result, ls->ls_recover_result, old_size * sizeof(uint32_t));
1048         kfree(ls->ls_recover_submit);
1049         kfree(ls->ls_recover_result);
1050         ls->ls_recover_submit = submit;
1051         ls->ls_recover_result = result;
1052         ls->ls_recover_size = new_size;
1053         spin_unlock(&ls->ls_recover_spin);
1054         return 0;
1055 }
1056 
1057 static void free_recover_size(struct lm_lockstruct *ls)
1058 {
1059         kfree(ls->ls_lvb_bits);
1060         kfree(ls->ls_recover_submit);
1061         kfree(ls->ls_recover_result);
1062         ls->ls_recover_submit = NULL;
1063         ls->ls_recover_result = NULL;
1064         ls->ls_recover_size = 0;
1065 }
1066 
1067 /* dlm calls before it does lock recovery */
1068 
1069 static void gdlm_recover_prep(void *arg)
1070 {
1071         struct gfs2_sbd *sdp = arg;
1072         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1073 
1074         spin_lock(&ls->ls_recover_spin);
1075         ls->ls_recover_block = ls->ls_recover_start;
1076         set_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
1077 
1078         if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
1079              test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
1080                 spin_unlock(&ls->ls_recover_spin);
1081                 return;
1082         }
1083         set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
1084         spin_unlock(&ls->ls_recover_spin);
1085 }
1086 
1087 /* dlm calls after recover_prep has been completed on all lockspace members;
1088    identifies slot/jid of failed member */
1089 
1090 static void gdlm_recover_slot(void *arg, struct dlm_slot *slot)
1091 {
1092         struct gfs2_sbd *sdp = arg;
1093         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1094         int jid = slot->slot - 1;
1095 
1096         spin_lock(&ls->ls_recover_spin);
1097         if (ls->ls_recover_size < jid + 1) {
1098                 fs_err(sdp, "recover_slot jid %d gen %u short size %d",
1099                        jid, ls->ls_recover_block, ls->ls_recover_size);
1100                 spin_unlock(&ls->ls_recover_spin);
1101                 return;
1102         }
1103 
1104         if (ls->ls_recover_submit[jid]) {
1105                 fs_info(sdp, "recover_slot jid %d gen %u prev %u",
1106                         jid, ls->ls_recover_block, ls->ls_recover_submit[jid]);
1107         }
1108         ls->ls_recover_submit[jid] = ls->ls_recover_block;
1109         spin_unlock(&ls->ls_recover_spin);
1110 }
1111 
1112 /* dlm calls after recover_slot and after it completes lock recovery */
1113 
1114 static void gdlm_recover_done(void *arg, struct dlm_slot *slots, int num_slots,
1115                               int our_slot, uint32_t generation)
1116 {
1117         struct gfs2_sbd *sdp = arg;
1118         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1119 
1120         /* ensure the ls jid arrays are large enough */
1121         set_recover_size(sdp, slots, num_slots);
1122 
1123         spin_lock(&ls->ls_recover_spin);
1124         ls->ls_recover_start = generation;
1125 
1126         if (!ls->ls_recover_mount) {
1127                 ls->ls_recover_mount = generation;
1128                 ls->ls_jid = our_slot - 1;
1129         }
1130 
1131         if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
1132                 queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work, 0);
1133 
1134         clear_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
1135         smp_mb__after_clear_bit();
1136         wake_up_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY);
1137         spin_unlock(&ls->ls_recover_spin);
1138 }
1139 
1140 /* gfs2_recover thread has a journal recovery result */
1141 
1142 static void gdlm_recovery_result(struct gfs2_sbd *sdp, unsigned int jid,
1143                                  unsigned int result)
1144 {
1145         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1146 
1147         if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1148                 return;
1149 
1150         /* don't care about the recovery of own journal during mount */
1151         if (jid == ls->ls_jid)
1152                 return;
1153 
1154         spin_lock(&ls->ls_recover_spin);
1155         if (test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
1156                 spin_unlock(&ls->ls_recover_spin);
1157                 return;
1158         }
1159         if (ls->ls_recover_size < jid + 1) {
1160                 fs_err(sdp, "recovery_result jid %d short size %d",
1161                        jid, ls->ls_recover_size);
1162                 spin_unlock(&ls->ls_recover_spin);
1163                 return;
1164         }
1165 
1166         fs_info(sdp, "recover jid %d result %s\n", jid,
1167                 result == LM_RD_GAVEUP ? "busy" : "success");
1168 
1169         ls->ls_recover_result[jid] = result;
1170 
1171         /* GAVEUP means another node is recovering the journal; delay our
1172            next attempt to recover it, to give the other node a chance to
1173            finish before trying again */
1174 
1175         if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
1176                 queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work,
1177                                    result == LM_RD_GAVEUP ? HZ : 0);
1178         spin_unlock(&ls->ls_recover_spin);
1179 }
1180 
1181 const struct dlm_lockspace_ops gdlm_lockspace_ops = {
1182         .recover_prep = gdlm_recover_prep,
1183         .recover_slot = gdlm_recover_slot,
1184         .recover_done = gdlm_recover_done,
1185 };
1186 
1187 static int gdlm_mount(struct gfs2_sbd *sdp, const char *table)
1188 {
1189         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1190         char cluster[GFS2_LOCKNAME_LEN];
1191         const char *fsname;
1192         uint32_t flags;
1193         int error, ops_result;
1194 
1195         /*
1196          * initialize everything
1197          */
1198 
1199         INIT_DELAYED_WORK(&sdp->sd_control_work, gfs2_control_func);
1200         spin_lock_init(&ls->ls_recover_spin);
1201         ls->ls_recover_flags = 0;
1202         ls->ls_recover_mount = 0;
1203         ls->ls_recover_start = 0;
1204         ls->ls_recover_block = 0;
1205         ls->ls_recover_size = 0;
1206         ls->ls_recover_submit = NULL;
1207         ls->ls_recover_result = NULL;
1208         ls->ls_lvb_bits = NULL;
1209 
1210         error = set_recover_size(sdp, NULL, 0);
1211         if (error)
1212                 goto fail;
1213 
1214         /*
1215          * prepare dlm_new_lockspace args
1216          */
1217 
1218         fsname = strchr(table, ':');
1219         if (!fsname) {
1220                 fs_info(sdp, "no fsname found\n");
1221                 error = -EINVAL;
1222                 goto fail_free;
1223         }
1224         memset(cluster, 0, sizeof(cluster));
1225         memcpy(cluster, table, strlen(table) - strlen(fsname));
1226         fsname++;
1227 
1228         flags = DLM_LSFL_FS | DLM_LSFL_NEWEXCL;
1229 
1230         /*
1231          * create/join lockspace
1232          */
1233 
1234         error = dlm_new_lockspace(fsname, cluster, flags, GDLM_LVB_SIZE,
1235                                   &gdlm_lockspace_ops, sdp, &ops_result,
1236                                   &ls->ls_dlm);
1237         if (error) {
1238                 fs_err(sdp, "dlm_new_lockspace error %d\n", error);
1239                 goto fail_free;
1240         }
1241 
1242         if (ops_result < 0) {
1243                 /*
1244                  * dlm does not support ops callbacks,
1245                  * old dlm_controld/gfs_controld are used, try without ops.
1246                  */
1247                 fs_info(sdp, "dlm lockspace ops not used\n");
1248                 free_recover_size(ls);
1249                 set_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags);
1250                 return 0;
1251         }
1252 
1253         if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags)) {
1254                 fs_err(sdp, "dlm lockspace ops disallow jid preset\n");
1255                 error = -EINVAL;
1256                 goto fail_release;
1257         }
1258 
1259         /*
1260          * control_mount() uses control_lock to determine first mounter,
1261          * and for later mounts, waits for any recoveries to be cleared.
1262          */
1263 
1264         error = control_mount(sdp);
1265         if (error) {
1266                 fs_err(sdp, "mount control error %d\n", error);
1267                 goto fail_release;
1268         }
1269 
1270         ls->ls_first = !!test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
1271         clear_bit(SDF_NOJOURNALID, &sdp->sd_flags);
1272         smp_mb__after_clear_bit();
1273         wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID);
1274         return 0;
1275 
1276 fail_release:
1277         dlm_release_lockspace(ls->ls_dlm, 2);
1278 fail_free:
1279         free_recover_size(ls);
1280 fail:
1281         return error;
1282 }
1283 
1284 static void gdlm_first_done(struct gfs2_sbd *sdp)
1285 {
1286         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1287         int error;
1288 
1289         if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1290                 return;
1291 
1292         error = control_first_done(sdp);
1293         if (error)
1294                 fs_err(sdp, "mount first_done error %d\n", error);
1295 }
1296 
1297 static void gdlm_unmount(struct gfs2_sbd *sdp)
1298 {
1299         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1300 
1301         if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1302                 goto release;
1303 
1304         /* wait for gfs2_control_wq to be done with this mount */
1305 
1306         spin_lock(&ls->ls_recover_spin);
1307         set_bit(DFL_UNMOUNT, &ls->ls_recover_flags);
1308         spin_unlock(&ls->ls_recover_spin);
1309         flush_delayed_work(&sdp->sd_control_work);
1310 
1311         /* mounted_lock and control_lock will be purged in dlm recovery */
1312 release:
1313         if (ls->ls_dlm) {
1314                 dlm_release_lockspace(ls->ls_dlm, 2);
1315                 ls->ls_dlm = NULL;
1316         }
1317 
1318         free_recover_size(ls);
1319 }
1320 
1321 static const match_table_t dlm_tokens = {
1322         { Opt_jid, "jid=%d"},
1323         { Opt_id, "id=%d"},
1324         { Opt_first, "first=%d"},
1325         { Opt_nodir, "nodir=%d"},
1326         { Opt_err, NULL },
1327 };
1328 
1329 const struct lm_lockops gfs2_dlm_ops = {
1330         .lm_proto_name = "lock_dlm",
1331         .lm_mount = gdlm_mount,
1332         .lm_first_done = gdlm_first_done,
1333         .lm_recovery_result = gdlm_recovery_result,
1334         .lm_unmount = gdlm_unmount,
1335         .lm_put_lock = gdlm_put_lock,
1336         .lm_lock = gdlm_lock,
1337         .lm_cancel = gdlm_cancel,
1338         .lm_tokens = &dlm_tokens,
1339 };
1340 
1341 

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