fs/gfs2/lock

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This source file includes following definitions.
gfs2_update_stats
gfs2_update_reply_times
gfs2_update_request_times
gdlm_ast
gdlm_bast
make_mode
make_flags
gfs2_reverse_hex
gdlm_lock
gdlm_put_lock
gdlm_cancel
control_lvb_read
control_lvb_write
all_jid_bits_clear
sync_wait_cb
sync_unlock
sync_lock
mounted_unlock
mounted_lock
control_unlock
control_lock
gfs2_control_func
control_mount
control_first_done
set_recover_size
free_recover_size
gdlm_recover_prep
gdlm_recover_slot
gdlm_recover_done
gdlm_recovery_result
gdlm_mount
gdlm_first_done
gdlm_unmount
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   4  * Copyright 2004-2011 Red Hat, Inc.
   5  */
   6 
   7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   8 
   9 #include <linux/fs.h>
  10 #include <linux/dlm.h>
  11 #include <linux/slab.h>
  12 #include <linux/types.h>
  13 #include <linux/delay.h>
  14 #include <linux/gfs2_ondisk.h>
  15 #include <linux/sched/signal.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 /**
  24  * gfs2_update_stats - Update time based stats
  25  * @mv: Pointer to mean/variance structure to update
  26  * @sample: New data to include
  27  *
  28  * @delta is the difference between the current rtt sample and the
  29  * running average srtt. We add 1/8 of that to the srtt in order to
  30  * update the current srtt estimate. The variance estimate is a bit
  31  * more complicated. We subtract the current variance estimate from
  32  * the abs value of the @delta and add 1/4 of that to the running
  33  * total.  That's equivalent to 3/4 of the current variance
  34  * estimate plus 1/4 of the abs of @delta.
  35  *
  36  * Note that the index points at the array entry containing the smoothed
  37  * mean value, and the variance is always in the following entry
  38  *
  39  * Reference: TCP/IP Illustrated, vol 2, p. 831,832
  40  * All times are in units of integer nanoseconds. Unlike the TCP/IP case,
  41  * they are not scaled fixed point.
  42  */
  43 
  44 static inline void gfs2_update_stats(struct gfs2_lkstats *s, unsigned index,
  45                                      s64 sample)
  46 {
  47         s64 delta = sample - s->stats[index];
  48         s->stats[index] += (delta >> 3);
  49         index++;
  50         s->stats[index] += (s64)(abs(delta) - s->stats[index]) >> 2;
  51 }
  52 
  53 /**
  54  * gfs2_update_reply_times - Update locking statistics
  55  * @gl: The glock to update
  56  *
  57  * This assumes that gl->gl_dstamp has been set earlier.
  58  *
  59  * The rtt (lock round trip time) is an estimate of the time
  60  * taken to perform a dlm lock request. We update it on each
  61  * reply from the dlm.
  62  *
  63  * The blocking flag is set on the glock for all dlm requests
  64  * which may potentially block due to lock requests from other nodes.
  65  * DLM requests where the current lock state is exclusive, the
  66  * requested state is null (or unlocked) or where the TRY or
  67  * TRY_1CB flags are set are classified as non-blocking. All
  68  * other DLM requests are counted as (potentially) blocking.
  69  */
  70 static inline void gfs2_update_reply_times(struct gfs2_glock *gl)
  71 {
  72         struct gfs2_pcpu_lkstats *lks;
  73         const unsigned gltype = gl->gl_name.ln_type;
  74         unsigned index = test_bit(GLF_BLOCKING, &gl->gl_flags) ?
  75                          GFS2_LKS_SRTTB : GFS2_LKS_SRTT;
  76         s64 rtt;
  77 
  78         preempt_disable();
  79         rtt = ktime_to_ns(ktime_sub(ktime_get_real(), gl->gl_dstamp));
  80         lks = this_cpu_ptr(gl->gl_name.ln_sbd->sd_lkstats);
  81         gfs2_update_stats(&gl->gl_stats, index, rtt);           /* Local */
  82         gfs2_update_stats(&lks->lkstats[gltype], index, rtt);   /* Global */
  83         preempt_enable();
  84 
  85         trace_gfs2_glock_lock_time(gl, rtt);
  86 }
  87 
  88 /**
  89  * gfs2_update_request_times - Update locking statistics
  90  * @gl: The glock to update
  91  *
  92  * The irt (lock inter-request times) measures the average time
  93  * between requests to the dlm. It is updated immediately before
  94  * each dlm call.
  95  */
  96 
  97 static inline void gfs2_update_request_times(struct gfs2_glock *gl)
  98 {
  99         struct gfs2_pcpu_lkstats *lks;
 100         const unsigned gltype = gl->gl_name.ln_type;
 101         ktime_t dstamp;
 102         s64 irt;
 103 
 104         preempt_disable();
 105         dstamp = gl->gl_dstamp;
 106         gl->gl_dstamp = ktime_get_real();
 107         irt = ktime_to_ns(ktime_sub(gl->gl_dstamp, dstamp));
 108         lks = this_cpu_ptr(gl->gl_name.ln_sbd->sd_lkstats);
 109         gfs2_update_stats(&gl->gl_stats, GFS2_LKS_SIRT, irt);           /* Local */
 110         gfs2_update_stats(&lks->lkstats[gltype], GFS2_LKS_SIRT, irt);   /* Global */
 111         preempt_enable();
 112 }
 113  
 114 static void gdlm_ast(void *arg)
 115 {
 116         struct gfs2_glock *gl = arg;
 117         unsigned ret = gl->gl_state;
 118 
 119         gfs2_update_reply_times(gl);
 120         BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);
 121 
 122         if ((gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID) && gl->gl_lksb.sb_lvbptr)
 123                 memset(gl->gl_lksb.sb_lvbptr, 0, GDLM_LVB_SIZE);
 124 
 125         switch (gl->gl_lksb.sb_status) {
 126         case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */
 127                 gfs2_glock_free(gl);
 128                 return;
 129         case -DLM_ECANCEL: /* Cancel while getting lock */
 130                 ret |= LM_OUT_CANCELED;
 131                 goto out;
 132         case -EAGAIN: /* Try lock fails */
 133         case -EDEADLK: /* Deadlock detected */
 134                 goto out;
 135         case -ETIMEDOUT: /* Canceled due to timeout */
 136                 ret |= LM_OUT_ERROR;
 137                 goto out;
 138         case 0: /* Success */
 139                 break;
 140         default: /* Something unexpected */
 141                 BUG();
 142         }
 143 
 144         ret = gl->gl_req;
 145         if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) {
 146                 if (gl->gl_req == LM_ST_SHARED)
 147                         ret = LM_ST_DEFERRED;
 148                 else if (gl->gl_req == LM_ST_DEFERRED)
 149                         ret = LM_ST_SHARED;
 150                 else
 151                         BUG();
 152         }
 153 
 154         set_bit(GLF_INITIAL, &gl->gl_flags);
 155         gfs2_glock_complete(gl, ret);
 156         return;
 157 out:
 158         if (!test_bit(GLF_INITIAL, &gl->gl_flags))
 159                 gl->gl_lksb.sb_lkid = 0;
 160         gfs2_glock_complete(gl, ret);
 161 }
 162 
 163 static void gdlm_bast(void *arg, int mode)
 164 {
 165         struct gfs2_glock *gl = arg;
 166 
 167         switch (mode) {
 168         case DLM_LOCK_EX:
 169                 gfs2_glock_cb(gl, LM_ST_UNLOCKED);
 170                 break;
 171         case DLM_LOCK_CW:
 172                 gfs2_glock_cb(gl, LM_ST_DEFERRED);
 173                 break;
 174         case DLM_LOCK_PR:
 175                 gfs2_glock_cb(gl, LM_ST_SHARED);
 176                 break;
 177         default:
 178                 fs_err(gl->gl_name.ln_sbd, "unknown bast mode %d\n", mode);
 179                 BUG();
 180         }
 181 }
 182 
 183 /* convert gfs lock-state to dlm lock-mode */
 184 
 185 static int make_mode(struct gfs2_sbd *sdp, const unsigned int lmstate)
 186 {
 187         switch (lmstate) {
 188         case LM_ST_UNLOCKED:
 189                 return DLM_LOCK_NL;
 190         case LM_ST_EXCLUSIVE:
 191                 return DLM_LOCK_EX;
 192         case LM_ST_DEFERRED:
 193                 return DLM_LOCK_CW;
 194         case LM_ST_SHARED:
 195                 return DLM_LOCK_PR;
 196         }
 197         fs_err(sdp, "unknown LM state %d\n", lmstate);
 198         BUG();
 199         return -1;
 200 }
 201 
 202 static u32 make_flags(struct gfs2_glock *gl, const unsigned int gfs_flags,
 203                       const int req)
 204 {
 205         u32 lkf = 0;
 206 
 207         if (gl->gl_lksb.sb_lvbptr)
 208                 lkf |= DLM_LKF_VALBLK;
 209 
 210         if (gfs_flags & LM_FLAG_TRY)
 211                 lkf |= DLM_LKF_NOQUEUE;
 212 
 213         if (gfs_flags & LM_FLAG_TRY_1CB) {
 214                 lkf |= DLM_LKF_NOQUEUE;
 215                 lkf |= DLM_LKF_NOQUEUEBAST;
 216         }
 217 
 218         if (gfs_flags & LM_FLAG_PRIORITY) {
 219                 lkf |= DLM_LKF_NOORDER;
 220                 lkf |= DLM_LKF_HEADQUE;
 221         }
 222 
 223         if (gfs_flags & LM_FLAG_ANY) {
 224                 if (req == DLM_LOCK_PR)
 225                         lkf |= DLM_LKF_ALTCW;
 226                 else if (req == DLM_LOCK_CW)
 227                         lkf |= DLM_LKF_ALTPR;
 228                 else
 229                         BUG();
 230         }
 231 
 232         if (gl->gl_lksb.sb_lkid != 0) {
 233                 lkf |= DLM_LKF_CONVERT;
 234                 if (test_bit(GLF_BLOCKING, &gl->gl_flags))
 235                         lkf |= DLM_LKF_QUECVT;
 236         }
 237 
 238         return lkf;
 239 }
 240 
 241 static void gfs2_reverse_hex(char *c, u64 value)
 242 {
 243         *c = '0';
 244         while (value) {
 245                 *c-- = hex_asc[value & 0x0f];
 246                 value >>= 4;
 247         }
 248 }
 249 
 250 static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state,
 251                      unsigned int flags)
 252 {
 253         struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
 254         int req;
 255         u32 lkf;
 256         char strname[GDLM_STRNAME_BYTES] = "";
 257 
 258         req = make_mode(gl->gl_name.ln_sbd, req_state);
 259         lkf = make_flags(gl, flags, req);
 260         gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
 261         gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
 262         if (gl->gl_lksb.sb_lkid) {
 263                 gfs2_update_request_times(gl);
 264         } else {
 265                 memset(strname, ' ', GDLM_STRNAME_BYTES - 1);
 266                 strname[GDLM_STRNAME_BYTES - 1] = '\0';
 267                 gfs2_reverse_hex(strname + 7, gl->gl_name.ln_type);
 268                 gfs2_reverse_hex(strname + 23, gl->gl_name.ln_number);
 269                 gl->gl_dstamp = ktime_get_real();
 270         }
 271         /*
 272          * Submit the actual lock request.
 273          */
 274 
 275         return dlm_lock(ls->ls_dlm, req, &gl->gl_lksb, lkf, strname,
 276                         GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast);
 277 }
 278 
 279 static void gdlm_put_lock(struct gfs2_glock *gl)
 280 {
 281         struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 282         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 283         int lvb_needs_unlock = 0;
 284         int error;
 285 
 286         if (gl->gl_lksb.sb_lkid == 0) {
 287                 gfs2_glock_free(gl);
 288                 return;
 289         }
 290 
 291         clear_bit(GLF_BLOCKING, &gl->gl_flags);
 292         gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
 293         gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
 294         gfs2_update_request_times(gl);
 295 
 296         /* don't want to skip dlm_unlock writing the lvb when lock is ex */
 297 
 298         if (gl->gl_lksb.sb_lvbptr && (gl->gl_state == LM_ST_EXCLUSIVE))
 299                 lvb_needs_unlock = 1;
 300 
 301         if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) &&
 302             !lvb_needs_unlock) {
 303                 gfs2_glock_free(gl);
 304                 return;
 305         }
 306 
 307         error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK,
 308                            NULL, gl);
 309         if (error) {
 310                 fs_err(sdp, "gdlm_unlock %x,%llx err=%d\n",
 311                        gl->gl_name.ln_type,
 312                        (unsigned long long)gl->gl_name.ln_number, error);
 313                 return;
 314         }
 315 }
 316 
 317 static void gdlm_cancel(struct gfs2_glock *gl)
 318 {
 319         struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
 320         dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl);
 321 }
 322 
 323 /*
 324  * dlm/gfs2 recovery coordination using dlm_recover callbacks
 325  *
 326  *  1. dlm_controld sees lockspace members change
 327  *  2. dlm_controld blocks dlm-kernel locking activity
 328  *  3. dlm_controld within dlm-kernel notifies gfs2 (recover_prep)
 329  *  4. dlm_controld starts and finishes its own user level recovery
 330  *  5. dlm_controld starts dlm-kernel dlm_recoverd to do kernel recovery
 331  *  6. dlm_recoverd notifies gfs2 of failed nodes (recover_slot)
 332  *  7. dlm_recoverd does its own lock recovery
 333  *  8. dlm_recoverd unblocks dlm-kernel locking activity
 334  *  9. dlm_recoverd notifies gfs2 when done (recover_done with new generation)
 335  * 10. gfs2_control updates control_lock lvb with new generation and jid bits
 336  * 11. gfs2_control enqueues journals for gfs2_recover to recover (maybe none)
 337  * 12. gfs2_recover dequeues and recovers journals of failed nodes
 338  * 13. gfs2_recover provides recovery results to gfs2_control (recovery_result)
 339  * 14. gfs2_control updates control_lock lvb jid bits for recovered journals
 340  * 15. gfs2_control unblocks normal locking when all journals are recovered
 341  *
 342  * - failures during recovery
 343  *
 344  * recover_prep() may set BLOCK_LOCKS (step 3) again before gfs2_control
 345  * clears BLOCK_LOCKS (step 15), e.g. another node fails while still
 346  * recovering for a prior failure.  gfs2_control needs a way to detect
 347  * this so it can leave BLOCK_LOCKS set in step 15.  This is managed using
 348  * the recover_block and recover_start values.
 349  *
 350  * recover_done() provides a new lockspace generation number each time it
 351  * is called (step 9).  This generation number is saved as recover_start.
 352  * When recover_prep() is called, it sets BLOCK_LOCKS and sets
 353  * recover_block = recover_start.  So, while recover_block is equal to
 354  * recover_start, BLOCK_LOCKS should remain set.  (recover_spin must
 355  * be held around the BLOCK_LOCKS/recover_block/recover_start logic.)
 356  *
 357  * - more specific gfs2 steps in sequence above
 358  *
 359  *  3. recover_prep sets BLOCK_LOCKS and sets recover_block = recover_start
 360  *  6. recover_slot records any failed jids (maybe none)
 361  *  9. recover_done sets recover_start = new generation number
 362  * 10. gfs2_control sets control_lock lvb = new gen + bits for failed jids
 363  * 12. gfs2_recover does journal recoveries for failed jids identified above
 364  * 14. gfs2_control clears control_lock lvb bits for recovered jids
 365  * 15. gfs2_control checks if recover_block == recover_start (step 3 occured
 366  *     again) then do nothing, otherwise if recover_start > recover_block
 367  *     then clear BLOCK_LOCKS.
 368  *
 369  * - parallel recovery steps across all nodes
 370  *
 371  * All nodes attempt to update the control_lock lvb with the new generation
 372  * number and jid bits, but only the first to get the control_lock EX will
 373  * do so; others will see that it's already done (lvb already contains new
 374  * generation number.)
 375  *
 376  * . All nodes get the same recover_prep/recover_slot/recover_done callbacks
 377  * . All nodes attempt to set control_lock lvb gen + bits for the new gen
 378  * . One node gets control_lock first and writes the lvb, others see it's done
 379  * . All nodes attempt to recover jids for which they see control_lock bits set
 380  * . One node succeeds for a jid, and that one clears the jid bit in the lvb
 381  * . All nodes will eventually see all lvb bits clear and unblock locks
 382  *
 383  * - is there a problem with clearing an lvb bit that should be set
 384  *   and missing a journal recovery?
 385  *
 386  * 1. jid fails
 387  * 2. lvb bit set for step 1
 388  * 3. jid recovered for step 1
 389  * 4. jid taken again (new mount)
 390  * 5. jid fails (for step 4)
 391  * 6. lvb bit set for step 5 (will already be set)
 392  * 7. lvb bit cleared for step 3
 393  *
 394  * This is not a problem because the failure in step 5 does not
 395  * require recovery, because the mount in step 4 could not have
 396  * progressed far enough to unblock locks and access the fs.  The
 397  * control_mount() function waits for all recoveries to be complete
 398  * for the latest lockspace generation before ever unblocking locks
 399  * and returning.  The mount in step 4 waits until the recovery in
 400  * step 1 is done.
 401  *
 402  * - special case of first mounter: first node to mount the fs
 403  *
 404  * The first node to mount a gfs2 fs needs to check all the journals
 405  * and recover any that need recovery before other nodes are allowed
 406  * to mount the fs.  (Others may begin mounting, but they must wait
 407  * for the first mounter to be done before taking locks on the fs
 408  * or accessing the fs.)  This has two parts:
 409  *
 410  * 1. The mounted_lock tells a node it's the first to mount the fs.
 411  * Each node holds the mounted_lock in PR while it's mounted.
 412  * Each node tries to acquire the mounted_lock in EX when it mounts.
 413  * If a node is granted the mounted_lock EX it means there are no
 414  * other mounted nodes (no PR locks exist), and it is the first mounter.
 415  * The mounted_lock is demoted to PR when first recovery is done, so
 416  * others will fail to get an EX lock, but will get a PR lock.
 417  *
 418  * 2. The control_lock blocks others in control_mount() while the first
 419  * mounter is doing first mount recovery of all journals.
 420  * A mounting node needs to acquire control_lock in EX mode before
 421  * it can proceed.  The first mounter holds control_lock in EX while doing
 422  * the first mount recovery, blocking mounts from other nodes, then demotes
 423  * control_lock to NL when it's done (others_may_mount/first_done),
 424  * allowing other nodes to continue mounting.
 425  *
 426  * first mounter:
 427  * control_lock EX/NOQUEUE success
 428  * mounted_lock EX/NOQUEUE success (no other PR, so no other mounters)
 429  * set first=1
 430  * do first mounter recovery
 431  * mounted_lock EX->PR
 432  * control_lock EX->NL, write lvb generation
 433  *
 434  * other mounter:
 435  * control_lock EX/NOQUEUE success (if fail -EAGAIN, retry)
 436  * mounted_lock EX/NOQUEUE fail -EAGAIN (expected due to other mounters PR)
 437  * mounted_lock PR/NOQUEUE success
 438  * read lvb generation
 439  * control_lock EX->NL
 440  * set first=0
 441  *
 442  * - mount during recovery
 443  *
 444  * If a node mounts while others are doing recovery (not first mounter),
 445  * the mounting node will get its initial recover_done() callback without
 446  * having seen any previous failures/callbacks.
 447  *
 448  * It must wait for all recoveries preceding its mount to be finished
 449  * before it unblocks locks.  It does this by repeating the "other mounter"
 450  * steps above until the lvb generation number is >= its mount generation
 451  * number (from initial recover_done) and all lvb bits are clear.
 452  *
 453  * - control_lock lvb format
 454  *
 455  * 4 bytes generation number: the latest dlm lockspace generation number
 456  * from recover_done callback.  Indicates the jid bitmap has been updated
 457  * to reflect all slot failures through that generation.
 458  * 4 bytes unused.
 459  * GDLM_LVB_SIZE-8 bytes of jid bit map. If bit N is set, it indicates
 460  * that jid N needs recovery.
 461  */
 462 
 463 #define JID_BITMAP_OFFSET 8 /* 4 byte generation number + 4 byte unused */
 464 
 465 static void control_lvb_read(struct lm_lockstruct *ls, uint32_t *lvb_gen,
 466                              char *lvb_bits)
 467 {
 468         __le32 gen;
 469         memcpy(lvb_bits, ls->ls_control_lvb, GDLM_LVB_SIZE);
 470         memcpy(&gen, lvb_bits, sizeof(__le32));
 471         *lvb_gen = le32_to_cpu(gen);
 472 }
 473 
 474 static void control_lvb_write(struct lm_lockstruct *ls, uint32_t lvb_gen,
 475                               char *lvb_bits)
 476 {
 477         __le32 gen;
 478         memcpy(ls->ls_control_lvb, lvb_bits, GDLM_LVB_SIZE);
 479         gen = cpu_to_le32(lvb_gen);
 480         memcpy(ls->ls_control_lvb, &gen, sizeof(__le32));
 481 }
 482 
 483 static int all_jid_bits_clear(char *lvb)
 484 {
 485         return !memchr_inv(lvb + JID_BITMAP_OFFSET, 0,
 486                         GDLM_LVB_SIZE - JID_BITMAP_OFFSET);
 487 }
 488 
 489 static void sync_wait_cb(void *arg)
 490 {
 491         struct lm_lockstruct *ls = arg;
 492         complete(&ls->ls_sync_wait);
 493 }
 494 
 495 static int sync_unlock(struct gfs2_sbd *sdp, struct dlm_lksb *lksb, char *name)
 496 {
 497         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 498         int error;
 499 
 500         error = dlm_unlock(ls->ls_dlm, lksb->sb_lkid, 0, lksb, ls);
 501         if (error) {
 502                 fs_err(sdp, "%s lkid %x error %d\n",
 503                        name, lksb->sb_lkid, error);
 504                 return error;
 505         }
 506 
 507         wait_for_completion(&ls->ls_sync_wait);
 508 
 509         if (lksb->sb_status != -DLM_EUNLOCK) {
 510                 fs_err(sdp, "%s lkid %x status %d\n",
 511                        name, lksb->sb_lkid, lksb->sb_status);
 512                 return -1;
 513         }
 514         return 0;
 515 }
 516 
 517 static int sync_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags,
 518                      unsigned int num, struct dlm_lksb *lksb, char *name)
 519 {
 520         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 521         char strname[GDLM_STRNAME_BYTES];
 522         int error, status;
 523 
 524         memset(strname, 0, GDLM_STRNAME_BYTES);
 525         snprintf(strname, GDLM_STRNAME_BYTES, "%8x%16x", LM_TYPE_NONDISK, num);
 526 
 527         error = dlm_lock(ls->ls_dlm, mode, lksb, flags,
 528                          strname, GDLM_STRNAME_BYTES - 1,
 529                          0, sync_wait_cb, ls, NULL);
 530         if (error) {
 531                 fs_err(sdp, "%s lkid %x flags %x mode %d error %d\n",
 532                        name, lksb->sb_lkid, flags, mode, error);
 533                 return error;
 534         }
 535 
 536         wait_for_completion(&ls->ls_sync_wait);
 537 
 538         status = lksb->sb_status;
 539 
 540         if (status && status != -EAGAIN) {
 541                 fs_err(sdp, "%s lkid %x flags %x mode %d status %d\n",
 542                        name, lksb->sb_lkid, flags, mode, status);
 543         }
 544 
 545         return status;
 546 }
 547 
 548 static int mounted_unlock(struct gfs2_sbd *sdp)
 549 {
 550         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 551         return sync_unlock(sdp, &ls->ls_mounted_lksb, "mounted_lock");
 552 }
 553 
 554 static int mounted_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
 555 {
 556         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 557         return sync_lock(sdp, mode, flags, GFS2_MOUNTED_LOCK,
 558                          &ls->ls_mounted_lksb, "mounted_lock");
 559 }
 560 
 561 static int control_unlock(struct gfs2_sbd *sdp)
 562 {
 563         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 564         return sync_unlock(sdp, &ls->ls_control_lksb, "control_lock");
 565 }
 566 
 567 static int control_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
 568 {
 569         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 570         return sync_lock(sdp, mode, flags, GFS2_CONTROL_LOCK,
 571                          &ls->ls_control_lksb, "control_lock");
 572 }
 573 
 574 static void gfs2_control_func(struct work_struct *work)
 575 {
 576         struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work);
 577         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 578         uint32_t block_gen, start_gen, lvb_gen, flags;
 579         int recover_set = 0;
 580         int write_lvb = 0;
 581         int recover_size;
 582         int i, error;
 583 
 584         spin_lock(&ls->ls_recover_spin);
 585         /*
 586          * No MOUNT_DONE means we're still mounting; control_mount()
 587          * will set this flag, after which this thread will take over
 588          * all further clearing of BLOCK_LOCKS.
 589          *
 590          * FIRST_MOUNT means this node is doing first mounter recovery,
 591          * for which recovery control is handled by
 592          * control_mount()/control_first_done(), not this thread.
 593          */
 594         if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
 595              test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
 596                 spin_unlock(&ls->ls_recover_spin);
 597                 return;
 598         }
 599         block_gen = ls->ls_recover_block;
 600         start_gen = ls->ls_recover_start;
 601         spin_unlock(&ls->ls_recover_spin);
 602 
 603         /*
 604          * Equal block_gen and start_gen implies we are between
 605          * recover_prep and recover_done callbacks, which means
 606          * dlm recovery is in progress and dlm locking is blocked.
 607          * There's no point trying to do any work until recover_done.
 608          */
 609 
 610         if (block_gen == start_gen)
 611                 return;
 612 
 613         /*
 614          * Propagate recover_submit[] and recover_result[] to lvb:
 615          * dlm_recoverd adds to recover_submit[] jids needing recovery
 616          * gfs2_recover adds to recover_result[] journal recovery results
 617          *
 618          * set lvb bit for jids in recover_submit[] if the lvb has not
 619          * yet been updated for the generation of the failure
 620          *
 621          * clear lvb bit for jids in recover_result[] if the result of
 622          * the journal recovery is SUCCESS
 623          */
 624 
 625         error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
 626         if (error) {
 627                 fs_err(sdp, "control lock EX error %d\n", error);
 628                 return;
 629         }
 630 
 631         control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
 632 
 633         spin_lock(&ls->ls_recover_spin);
 634         if (block_gen != ls->ls_recover_block ||
 635             start_gen != ls->ls_recover_start) {
 636                 fs_info(sdp, "recover generation %u block1 %u %u\n",
 637                         start_gen, block_gen, ls->ls_recover_block);
 638                 spin_unlock(&ls->ls_recover_spin);
 639                 control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
 640                 return;
 641         }
 642 
 643         recover_size = ls->ls_recover_size;
 644 
 645         if (lvb_gen <= start_gen) {
 646                 /*
 647                  * Clear lvb bits for jids we've successfully recovered.
 648                  * Because all nodes attempt to recover failed journals,
 649                  * a journal can be recovered multiple times successfully
 650                  * in succession.  Only the first will really do recovery,
 651                  * the others find it clean, but still report a successful
 652                  * recovery.  So, another node may have already recovered
 653                  * the jid and cleared the lvb bit for it.
 654                  */
 655                 for (i = 0; i < recover_size; i++) {
 656                         if (ls->ls_recover_result[i] != LM_RD_SUCCESS)
 657                                 continue;
 658 
 659                         ls->ls_recover_result[i] = 0;
 660 
 661                         if (!test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET))
 662                                 continue;
 663 
 664                         __clear_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
 665                         write_lvb = 1;
 666                 }
 667         }
 668 
 669         if (lvb_gen == start_gen) {
 670                 /*
 671                  * Failed slots before start_gen are already set in lvb.
 672                  */
 673                 for (i = 0; i < recover_size; i++) {
 674                         if (!ls->ls_recover_submit[i])
 675                                 continue;
 676                         if (ls->ls_recover_submit[i] < lvb_gen)
 677                                 ls->ls_recover_submit[i] = 0;
 678                 }
 679         } else if (lvb_gen < start_gen) {
 680                 /*
 681                  * Failed slots before start_gen are not yet set in lvb.
 682                  */
 683                 for (i = 0; i < recover_size; i++) {
 684                         if (!ls->ls_recover_submit[i])
 685                                 continue;
 686                         if (ls->ls_recover_submit[i] < start_gen) {
 687                                 ls->ls_recover_submit[i] = 0;
 688                                 __set_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
 689                         }
 690                 }
 691                 /* even if there are no bits to set, we need to write the
 692                    latest generation to the lvb */
 693                 write_lvb = 1;
 694         } else {
 695                 /*
 696                  * we should be getting a recover_done() for lvb_gen soon
 697                  */
 698         }
 699         spin_unlock(&ls->ls_recover_spin);
 700 
 701         if (write_lvb) {
 702                 control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
 703                 flags = DLM_LKF_CONVERT | DLM_LKF_VALBLK;
 704         } else {
 705                 flags = DLM_LKF_CONVERT;
 706         }
 707 
 708         error = control_lock(sdp, DLM_LOCK_NL, flags);
 709         if (error) {
 710                 fs_err(sdp, "control lock NL error %d\n", error);
 711                 return;
 712         }
 713 
 714         /*
 715          * Everyone will see jid bits set in the lvb, run gfs2_recover_set(),
 716          * and clear a jid bit in the lvb if the recovery is a success.
 717          * Eventually all journals will be recovered, all jid bits will
 718          * be cleared in the lvb, and everyone will clear BLOCK_LOCKS.
 719          */
 720 
 721         for (i = 0; i < recover_size; i++) {
 722                 if (test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET)) {
 723                         fs_info(sdp, "recover generation %u jid %d\n",
 724                                 start_gen, i);
 725                         gfs2_recover_set(sdp, i);
 726                         recover_set++;
 727                 }
 728         }
 729         if (recover_set)
 730                 return;
 731 
 732         /*
 733          * No more jid bits set in lvb, all recovery is done, unblock locks
 734          * (unless a new recover_prep callback has occured blocking locks
 735          * again while working above)
 736          */
 737 
 738         spin_lock(&ls->ls_recover_spin);
 739         if (ls->ls_recover_block == block_gen &&
 740             ls->ls_recover_start == start_gen) {
 741                 clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
 742                 spin_unlock(&ls->ls_recover_spin);
 743                 fs_info(sdp, "recover generation %u done\n", start_gen);
 744                 gfs2_glock_thaw(sdp);
 745         } else {
 746                 fs_info(sdp, "recover generation %u block2 %u %u\n",
 747                         start_gen, block_gen, ls->ls_recover_block);
 748                 spin_unlock(&ls->ls_recover_spin);
 749         }
 750 }
 751 
 752 static int control_mount(struct gfs2_sbd *sdp)
 753 {
 754         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 755         uint32_t start_gen, block_gen, mount_gen, lvb_gen;
 756         int mounted_mode;
 757         int retries = 0;
 758         int error;
 759 
 760         memset(&ls->ls_mounted_lksb, 0, sizeof(struct dlm_lksb));
 761         memset(&ls->ls_control_lksb, 0, sizeof(struct dlm_lksb));
 762         memset(&ls->ls_control_lvb, 0, GDLM_LVB_SIZE);
 763         ls->ls_control_lksb.sb_lvbptr = ls->ls_control_lvb;
 764         init_completion(&ls->ls_sync_wait);
 765 
 766         set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
 767 
 768         error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_VALBLK);
 769         if (error) {
 770                 fs_err(sdp, "control_mount control_lock NL error %d\n", error);
 771                 return error;
 772         }
 773 
 774         error = mounted_lock(sdp, DLM_LOCK_NL, 0);
 775         if (error) {
 776                 fs_err(sdp, "control_mount mounted_lock NL error %d\n", error);
 777                 control_unlock(sdp);
 778                 return error;
 779         }
 780         mounted_mode = DLM_LOCK_NL;
 781 
 782 restart:
 783         if (retries++ && signal_pending(current)) {
 784                 error = -EINTR;
 785                 goto fail;
 786         }
 787 
 788         /*
 789          * We always start with both locks in NL. control_lock is
 790          * demoted to NL below so we don't need to do it here.
 791          */
 792 
 793         if (mounted_mode != DLM_LOCK_NL) {
 794                 error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
 795                 if (error)
 796                         goto fail;
 797                 mounted_mode = DLM_LOCK_NL;
 798         }
 799 
 800         /*
 801          * Other nodes need to do some work in dlm recovery and gfs2_control
 802          * before the recover_done and control_lock will be ready for us below.
 803          * A delay here is not required but often avoids having to retry.
 804          */
 805 
 806         msleep_interruptible(500);
 807 
 808         /*
 809          * Acquire control_lock in EX and mounted_lock in either EX or PR.
 810          * control_lock lvb keeps track of any pending journal recoveries.
 811          * mounted_lock indicates if any other nodes have the fs mounted.
 812          */
 813 
 814         error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE|DLM_LKF_VALBLK);
 815         if (error == -EAGAIN) {
 816                 goto restart;
 817         } else if (error) {
 818                 fs_err(sdp, "control_mount control_lock EX error %d\n", error);
 819                 goto fail;
 820         }
 821 
 822         /**
 823          * If we're a spectator, we don't want to take the lock in EX because
 824          * we cannot do the first-mount responsibility it implies: recovery.
 825          */
 826         if (sdp->sd_args.ar_spectator)
 827                 goto locks_done;
 828 
 829         error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
 830         if (!error) {
 831                 mounted_mode = DLM_LOCK_EX;
 832                 goto locks_done;
 833         } else if (error != -EAGAIN) {
 834                 fs_err(sdp, "control_mount mounted_lock EX error %d\n", error);
 835                 goto fail;
 836         }
 837 
 838         error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
 839         if (!error) {
 840                 mounted_mode = DLM_LOCK_PR;
 841                 goto locks_done;
 842         } else {
 843                 /* not even -EAGAIN should happen here */
 844                 fs_err(sdp, "control_mount mounted_lock PR error %d\n", error);
 845                 goto fail;
 846         }
 847 
 848 locks_done:
 849         /*
 850          * If we got both locks above in EX, then we're the first mounter.
 851          * If not, then we need to wait for the control_lock lvb to be
 852          * updated by other mounted nodes to reflect our mount generation.
 853          *
 854          * In simple first mounter cases, first mounter will see zero lvb_gen,
 855          * but in cases where all existing nodes leave/fail before mounting
 856          * nodes finish control_mount, then all nodes will be mounting and
 857          * lvb_gen will be non-zero.
 858          */
 859 
 860         control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
 861 
 862         if (lvb_gen == 0xFFFFFFFF) {
 863                 /* special value to force mount attempts to fail */
 864                 fs_err(sdp, "control_mount control_lock disabled\n");
 865                 error = -EINVAL;
 866                 goto fail;
 867         }
 868 
 869         if (mounted_mode == DLM_LOCK_EX) {
 870                 /* first mounter, keep both EX while doing first recovery */
 871                 spin_lock(&ls->ls_recover_spin);
 872                 clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
 873                 set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
 874                 set_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
 875                 spin_unlock(&ls->ls_recover_spin);
 876                 fs_info(sdp, "first mounter control generation %u\n", lvb_gen);
 877                 return 0;
 878         }
 879 
 880         error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
 881         if (error)
 882                 goto fail;
 883 
 884         /*
 885          * We are not first mounter, now we need to wait for the control_lock
 886          * lvb generation to be >= the generation from our first recover_done
 887          * and all lvb bits to be clear (no pending journal recoveries.)
 888          */
 889 
 890         if (!all_jid_bits_clear(ls->ls_lvb_bits)) {
 891                 /* journals need recovery, wait until all are clear */
 892                 fs_info(sdp, "control_mount wait for journal recovery\n");
 893                 goto restart;
 894         }
 895 
 896         spin_lock(&ls->ls_recover_spin);
 897         block_gen = ls->ls_recover_block;
 898         start_gen = ls->ls_recover_start;
 899         mount_gen = ls->ls_recover_mount;
 900 
 901         if (lvb_gen < mount_gen) {
 902                 /* wait for mounted nodes to update control_lock lvb to our
 903                    generation, which might include new recovery bits set */
 904                 if (sdp->sd_args.ar_spectator) {
 905                         fs_info(sdp, "Recovery is required. Waiting for a "
 906                                 "non-spectator to mount.\n");
 907                         msleep_interruptible(1000);
 908                 } else {
 909                         fs_info(sdp, "control_mount wait1 block %u start %u "
 910                                 "mount %u lvb %u flags %lx\n", block_gen,
 911                                 start_gen, mount_gen, lvb_gen,
 912                                 ls->ls_recover_flags);
 913                 }
 914                 spin_unlock(&ls->ls_recover_spin);
 915                 goto restart;
 916         }
 917 
 918         if (lvb_gen != start_gen) {
 919                 /* wait for mounted nodes to update control_lock lvb to the
 920                    latest recovery generation */
 921                 fs_info(sdp, "control_mount wait2 block %u start %u mount %u "
 922                         "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
 923                         lvb_gen, ls->ls_recover_flags);
 924                 spin_unlock(&ls->ls_recover_spin);
 925                 goto restart;
 926         }
 927 
 928         if (block_gen == start_gen) {
 929                 /* dlm recovery in progress, wait for it to finish */
 930                 fs_info(sdp, "control_mount wait3 block %u start %u mount %u "
 931                         "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
 932                         lvb_gen, ls->ls_recover_flags);
 933                 spin_unlock(&ls->ls_recover_spin);
 934                 goto restart;
 935         }
 936 
 937         clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
 938         set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
 939         memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
 940         memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
 941         spin_unlock(&ls->ls_recover_spin);
 942         return 0;
 943 
 944 fail:
 945         mounted_unlock(sdp);
 946         control_unlock(sdp);
 947         return error;
 948 }
 949 
 950 static int control_first_done(struct gfs2_sbd *sdp)
 951 {
 952         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 953         uint32_t start_gen, block_gen;
 954         int error;
 955 
 956 restart:
 957         spin_lock(&ls->ls_recover_spin);
 958         start_gen = ls->ls_recover_start;
 959         block_gen = ls->ls_recover_block;
 960 
 961         if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags) ||
 962             !test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
 963             !test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
 964                 /* sanity check, should not happen */
 965                 fs_err(sdp, "control_first_done start %u block %u flags %lx\n",
 966                        start_gen, block_gen, ls->ls_recover_flags);
 967                 spin_unlock(&ls->ls_recover_spin);
 968                 control_unlock(sdp);
 969                 return -1;
 970         }
 971 
 972         if (start_gen == block_gen) {
 973                 /*
 974                  * Wait for the end of a dlm recovery cycle to switch from
 975                  * first mounter recovery.  We can ignore any recover_slot
 976                  * callbacks between the recover_prep and next recover_done
 977                  * because we are still the first mounter and any failed nodes
 978                  * have not fully mounted, so they don't need recovery.
 979                  */
 980                 spin_unlock(&ls->ls_recover_spin);
 981                 fs_info(sdp, "control_first_done wait gen %u\n", start_gen);
 982 
 983                 wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY,
 984                             TASK_UNINTERRUPTIBLE);
 985                 goto restart;
 986         }
 987 
 988         clear_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
 989         set_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags);
 990         memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
 991         memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
 992         spin_unlock(&ls->ls_recover_spin);
 993 
 994         memset(ls->ls_lvb_bits, 0, GDLM_LVB_SIZE);
 995         control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
 996 
 997         error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT);
 998         if (error)
 999                 fs_err(sdp, "control_first_done mounted PR error %d\n", error);
1000 
1001         error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
1002         if (error)
1003                 fs_err(sdp, "control_first_done control NL error %d\n", error);
1004 
1005         return error;
1006 }
1007 
1008 /*
1009  * Expand static jid arrays if necessary (by increments of RECOVER_SIZE_INC)
1010  * to accomodate the largest slot number.  (NB dlm slot numbers start at 1,
1011  * gfs2 jids start at 0, so jid = slot - 1)
1012  */
1013 
1014 #define RECOVER_SIZE_INC 16
1015 
1016 static int set_recover_size(struct gfs2_sbd *sdp, struct dlm_slot *slots,
1017                             int num_slots)
1018 {
1019         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1020         uint32_t *submit = NULL;
1021         uint32_t *result = NULL;
1022         uint32_t old_size, new_size;
1023         int i, max_jid;
1024 
1025         if (!ls->ls_lvb_bits) {
1026                 ls->ls_lvb_bits = kzalloc(GDLM_LVB_SIZE, GFP_NOFS);
1027                 if (!ls->ls_lvb_bits)
1028                         return -ENOMEM;
1029         }
1030 
1031         max_jid = 0;
1032         for (i = 0; i < num_slots; i++) {
1033                 if (max_jid < slots[i].slot - 1)
1034                         max_jid = slots[i].slot - 1;
1035         }
1036 
1037         old_size = ls->ls_recover_size;
1038         new_size = old_size;
1039         while (new_size < max_jid + 1)
1040                 new_size += RECOVER_SIZE_INC;
1041         if (new_size == old_size)
1042                 return 0;
1043 
1044         submit = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS);
1045         result = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS);
1046         if (!submit || !result) {
1047                 kfree(submit);
1048                 kfree(result);
1049                 return -ENOMEM;
1050         }
1051 
1052         spin_lock(&ls->ls_recover_spin);
1053         memcpy(submit, ls->ls_recover_submit, old_size * sizeof(uint32_t));
1054         memcpy(result, ls->ls_recover_result, old_size * sizeof(uint32_t));
1055         kfree(ls->ls_recover_submit);
1056         kfree(ls->ls_recover_result);
1057         ls->ls_recover_submit = submit;
1058         ls->ls_recover_result = result;
1059         ls->ls_recover_size = new_size;
1060         spin_unlock(&ls->ls_recover_spin);
1061         return 0;
1062 }
1063 
1064 static void free_recover_size(struct lm_lockstruct *ls)
1065 {
1066         kfree(ls->ls_lvb_bits);
1067         kfree(ls->ls_recover_submit);
1068         kfree(ls->ls_recover_result);
1069         ls->ls_recover_submit = NULL;
1070         ls->ls_recover_result = NULL;
1071         ls->ls_recover_size = 0;
1072         ls->ls_lvb_bits = NULL;
1073 }
1074 
1075 /* dlm calls before it does lock recovery */
1076 
1077 static void gdlm_recover_prep(void *arg)
1078 {
1079         struct gfs2_sbd *sdp = arg;
1080         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1081 
1082         spin_lock(&ls->ls_recover_spin);
1083         ls->ls_recover_block = ls->ls_recover_start;
1084         set_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
1085 
1086         if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
1087              test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
1088                 spin_unlock(&ls->ls_recover_spin);
1089                 return;
1090         }
1091         set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
1092         spin_unlock(&ls->ls_recover_spin);
1093 }
1094 
1095 /* dlm calls after recover_prep has been completed on all lockspace members;
1096    identifies slot/jid of failed member */
1097 
1098 static void gdlm_recover_slot(void *arg, struct dlm_slot *slot)
1099 {
1100         struct gfs2_sbd *sdp = arg;
1101         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1102         int jid = slot->slot - 1;
1103 
1104         spin_lock(&ls->ls_recover_spin);
1105         if (ls->ls_recover_size < jid + 1) {
1106                 fs_err(sdp, "recover_slot jid %d gen %u short size %d\n",
1107                        jid, ls->ls_recover_block, ls->ls_recover_size);
1108                 spin_unlock(&ls->ls_recover_spin);
1109                 return;
1110         }
1111 
1112         if (ls->ls_recover_submit[jid]) {
1113                 fs_info(sdp, "recover_slot jid %d gen %u prev %u\n",
1114                         jid, ls->ls_recover_block, ls->ls_recover_submit[jid]);
1115         }
1116         ls->ls_recover_submit[jid] = ls->ls_recover_block;
1117         spin_unlock(&ls->ls_recover_spin);
1118 }
1119 
1120 /* dlm calls after recover_slot and after it completes lock recovery */
1121 
1122 static void gdlm_recover_done(void *arg, struct dlm_slot *slots, int num_slots,
1123                               int our_slot, uint32_t generation)
1124 {
1125         struct gfs2_sbd *sdp = arg;
1126         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1127 
1128         /* ensure the ls jid arrays are large enough */
1129         set_recover_size(sdp, slots, num_slots);
1130 
1131         spin_lock(&ls->ls_recover_spin);
1132         ls->ls_recover_start = generation;
1133 
1134         if (!ls->ls_recover_mount) {
1135                 ls->ls_recover_mount = generation;
1136                 ls->ls_jid = our_slot - 1;
1137         }
1138 
1139         if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
1140                 queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work, 0);
1141 
1142         clear_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
1143         smp_mb__after_atomic();
1144         wake_up_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY);
1145         spin_unlock(&ls->ls_recover_spin);
1146 }
1147 
1148 /* gfs2_recover thread has a journal recovery result */
1149 
1150 static void gdlm_recovery_result(struct gfs2_sbd *sdp, unsigned int jid,
1151                                  unsigned int result)
1152 {
1153         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1154 
1155         if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1156                 return;
1157 
1158         /* don't care about the recovery of own journal during mount */
1159         if (jid == ls->ls_jid)
1160                 return;
1161 
1162         spin_lock(&ls->ls_recover_spin);
1163         if (test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
1164                 spin_unlock(&ls->ls_recover_spin);
1165                 return;
1166         }
1167         if (ls->ls_recover_size < jid + 1) {
1168                 fs_err(sdp, "recovery_result jid %d short size %d\n",
1169                        jid, ls->ls_recover_size);
1170                 spin_unlock(&ls->ls_recover_spin);
1171                 return;
1172         }
1173 
1174         fs_info(sdp, "recover jid %d result %s\n", jid,
1175                 result == LM_RD_GAVEUP ? "busy" : "success");
1176 
1177         ls->ls_recover_result[jid] = result;
1178 
1179         /* GAVEUP means another node is recovering the journal; delay our
1180            next attempt to recover it, to give the other node a chance to
1181            finish before trying again */
1182 
1183         if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
1184                 queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work,
1185                                    result == LM_RD_GAVEUP ? HZ : 0);
1186         spin_unlock(&ls->ls_recover_spin);
1187 }
1188 
1189 static const struct dlm_lockspace_ops gdlm_lockspace_ops = {
1190         .recover_prep = gdlm_recover_prep,
1191         .recover_slot = gdlm_recover_slot,
1192         .recover_done = gdlm_recover_done,
1193 };
1194 
1195 static int gdlm_mount(struct gfs2_sbd *sdp, const char *table)
1196 {
1197         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1198         char cluster[GFS2_LOCKNAME_LEN];
1199         const char *fsname;
1200         uint32_t flags;
1201         int error, ops_result;
1202 
1203         /*
1204          * initialize everything
1205          */
1206 
1207         INIT_DELAYED_WORK(&sdp->sd_control_work, gfs2_control_func);
1208         spin_lock_init(&ls->ls_recover_spin);
1209         ls->ls_recover_flags = 0;
1210         ls->ls_recover_mount = 0;
1211         ls->ls_recover_start = 0;
1212         ls->ls_recover_block = 0;
1213         ls->ls_recover_size = 0;
1214         ls->ls_recover_submit = NULL;
1215         ls->ls_recover_result = NULL;
1216         ls->ls_lvb_bits = NULL;
1217 
1218         error = set_recover_size(sdp, NULL, 0);
1219         if (error)
1220                 goto fail;
1221 
1222         /*
1223          * prepare dlm_new_lockspace args
1224          */
1225 
1226         fsname = strchr(table, ':');
1227         if (!fsname) {
1228                 fs_info(sdp, "no fsname found\n");
1229                 error = -EINVAL;
1230                 goto fail_free;
1231         }
1232         memset(cluster, 0, sizeof(cluster));
1233         memcpy(cluster, table, strlen(table) - strlen(fsname));
1234         fsname++;
1235 
1236         flags = DLM_LSFL_FS | DLM_LSFL_NEWEXCL;
1237 
1238         /*
1239          * create/join lockspace
1240          */
1241 
1242         error = dlm_new_lockspace(fsname, cluster, flags, GDLM_LVB_SIZE,
1243                                   &gdlm_lockspace_ops, sdp, &ops_result,
1244                                   &ls->ls_dlm);
1245         if (error) {
1246                 fs_err(sdp, "dlm_new_lockspace error %d\n", error);
1247                 goto fail_free;
1248         }
1249 
1250         if (ops_result < 0) {
1251                 /*
1252                  * dlm does not support ops callbacks,
1253                  * old dlm_controld/gfs_controld are used, try without ops.
1254                  */
1255                 fs_info(sdp, "dlm lockspace ops not used\n");
1256                 free_recover_size(ls);
1257                 set_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags);
1258                 return 0;
1259         }
1260 
1261         if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags)) {
1262                 fs_err(sdp, "dlm lockspace ops disallow jid preset\n");
1263                 error = -EINVAL;
1264                 goto fail_release;
1265         }
1266 
1267         /*
1268          * control_mount() uses control_lock to determine first mounter,
1269          * and for later mounts, waits for any recoveries to be cleared.
1270          */
1271 
1272         error = control_mount(sdp);
1273         if (error) {
1274                 fs_err(sdp, "mount control error %d\n", error);
1275                 goto fail_release;
1276         }
1277 
1278         ls->ls_first = !!test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
1279         clear_bit(SDF_NOJOURNALID, &sdp->sd_flags);
1280         smp_mb__after_atomic();
1281         wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID);
1282         return 0;
1283 
1284 fail_release:
1285         dlm_release_lockspace(ls->ls_dlm, 2);
1286 fail_free:
1287         free_recover_size(ls);
1288 fail:
1289         return error;
1290 }
1291 
1292 static void gdlm_first_done(struct gfs2_sbd *sdp)
1293 {
1294         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1295         int error;
1296 
1297         if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1298                 return;
1299 
1300         error = control_first_done(sdp);
1301         if (error)
1302                 fs_err(sdp, "mount first_done error %d\n", error);
1303 }
1304 
1305 static void gdlm_unmount(struct gfs2_sbd *sdp)
1306 {
1307         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1308 
1309         if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1310                 goto release;
1311 
1312         /* wait for gfs2_control_wq to be done with this mount */
1313 
1314         spin_lock(&ls->ls_recover_spin);
1315         set_bit(DFL_UNMOUNT, &ls->ls_recover_flags);
1316         spin_unlock(&ls->ls_recover_spin);
1317         flush_delayed_work(&sdp->sd_control_work);
1318 
1319         /* mounted_lock and control_lock will be purged in dlm recovery */
1320 release:
1321         if (ls->ls_dlm) {
1322                 dlm_release_lockspace(ls->ls_dlm, 2);
1323                 ls->ls_dlm = NULL;
1324         }
1325 
1326         free_recover_size(ls);
1327 }
1328 
1329 static const match_table_t dlm_tokens = {
1330         { Opt_jid, "jid=%d"},
1331         { Opt_id, "id=%d"},
1332         { Opt_first, "first=%d"},
1333         { Opt_nodir, "nodir=%d"},
1334         { Opt_err, NULL },
1335 };
1336 
1337 const struct lm_lockops gfs2_dlm_ops = {
1338         .lm_proto_name = "lock_dlm",
1339         .lm_mount = gdlm_mount,
1340         .lm_first_done = gdlm_first_done,
1341         .lm_recovery_result = gdlm_recovery_result,
1342         .lm_unmount = gdlm_unmount,
1343         .lm_put_lock = gdlm_put_lock,
1344         .lm_lock = gdlm_lock,
1345         .lm_cancel = gdlm_cancel,
1346         .lm_tokens = &dlm_tokens,
1347 };
1348
/* [<][>][^][v][top][bottom][index][help] */
root/fs/gfs2/lock_dlm.c

DEFINITIONS
