linux/fs/gfs2/lock_dlm.c
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   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 "glops.h"
  20#include "recovery.h"
  21#include "util.h"
  22#include "sys.h"
  23#include "trace_gfs2.h"
  24
  25/**
  26 * gfs2_update_stats - Update time based stats
  27 * @s: The stats to update (local or global)
  28 * @index: The index inside @s
  29 * @sample: New data to include
  30 */
  31static inline void gfs2_update_stats(struct gfs2_lkstats *s, unsigned index,
  32                                     s64 sample)
  33{
  34        /*
  35         * @delta is the difference between the current rtt sample and the
  36         * running average srtt. We add 1/8 of that to the srtt in order to
  37         * update the current srtt estimate. The variance estimate is a bit
  38         * more complicated. We subtract the current variance estimate from
  39         * the abs value of the @delta and add 1/4 of that to the running
  40         * total.  That's equivalent to 3/4 of the current variance
  41         * estimate plus 1/4 of the abs of @delta.
  42         *
  43         * Note that the index points at the array entry containing the
  44         * smoothed mean value, and the variance is always in the following
  45         * entry
  46         *
  47         * Reference: TCP/IP Illustrated, vol 2, p. 831,832
  48         * All times are in units of integer nanoseconds. Unlike the TCP/IP
  49         * case, they are not scaled fixed point.
  50         */
  51
  52        s64 delta = sample - s->stats[index];
  53        s->stats[index] += (delta >> 3);
  54        index++;
  55        s->stats[index] += (s64)(abs(delta) - s->stats[index]) >> 2;
  56}
  57
  58/**
  59 * gfs2_update_reply_times - Update locking statistics
  60 * @gl: The glock to update
  61 *
  62 * This assumes that gl->gl_dstamp has been set earlier.
  63 *
  64 * The rtt (lock round trip time) is an estimate of the time
  65 * taken to perform a dlm lock request. We update it on each
  66 * reply from the dlm.
  67 *
  68 * The blocking flag is set on the glock for all dlm requests
  69 * which may potentially block due to lock requests from other nodes.
  70 * DLM requests where the current lock state is exclusive, the
  71 * requested state is null (or unlocked) or where the TRY or
  72 * TRY_1CB flags are set are classified as non-blocking. All
  73 * other DLM requests are counted as (potentially) blocking.
  74 */
  75static inline void gfs2_update_reply_times(struct gfs2_glock *gl)
  76{
  77        struct gfs2_pcpu_lkstats *lks;
  78        const unsigned gltype = gl->gl_name.ln_type;
  79        unsigned index = test_bit(GLF_BLOCKING, &gl->gl_flags) ?
  80                         GFS2_LKS_SRTTB : GFS2_LKS_SRTT;
  81        s64 rtt;
  82
  83        preempt_disable();
  84        rtt = ktime_to_ns(ktime_sub(ktime_get_real(), gl->gl_dstamp));
  85        lks = this_cpu_ptr(gl->gl_name.ln_sbd->sd_lkstats);
  86        gfs2_update_stats(&gl->gl_stats, index, rtt);           /* Local */
  87        gfs2_update_stats(&lks->lkstats[gltype], index, rtt);   /* Global */
  88        preempt_enable();
  89
  90        trace_gfs2_glock_lock_time(gl, rtt);
  91}
  92
  93/**
  94 * gfs2_update_request_times - Update locking statistics
  95 * @gl: The glock to update
  96 *
  97 * The irt (lock inter-request times) measures the average time
  98 * between requests to the dlm. It is updated immediately before
  99 * each dlm call.
 100 */
 101
 102static inline void gfs2_update_request_times(struct gfs2_glock *gl)
 103{
 104        struct gfs2_pcpu_lkstats *lks;
 105        const unsigned gltype = gl->gl_name.ln_type;
 106        ktime_t dstamp;
 107        s64 irt;
 108
 109        preempt_disable();
 110        dstamp = gl->gl_dstamp;
 111        gl->gl_dstamp = ktime_get_real();
 112        irt = ktime_to_ns(ktime_sub(gl->gl_dstamp, dstamp));
 113        lks = this_cpu_ptr(gl->gl_name.ln_sbd->sd_lkstats);
 114        gfs2_update_stats(&gl->gl_stats, GFS2_LKS_SIRT, irt);           /* Local */
 115        gfs2_update_stats(&lks->lkstats[gltype], GFS2_LKS_SIRT, irt);   /* Global */
 116        preempt_enable();
 117}
 118 
 119static void gdlm_ast(void *arg)
 120{
 121        struct gfs2_glock *gl = arg;
 122        unsigned ret = gl->gl_state;
 123
 124        gfs2_update_reply_times(gl);
 125        BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);
 126
 127        if ((gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID) && gl->gl_lksb.sb_lvbptr)
 128                memset(gl->gl_lksb.sb_lvbptr, 0, GDLM_LVB_SIZE);
 129
 130        switch (gl->gl_lksb.sb_status) {
 131        case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */
 132                if (gl->gl_ops->go_free)
 133                        gl->gl_ops->go_free(gl);
 134                gfs2_glock_free(gl);
 135                return;
 136        case -DLM_ECANCEL: /* Cancel while getting lock */
 137                ret |= LM_OUT_CANCELED;
 138                goto out;
 139        case -EAGAIN: /* Try lock fails */
 140        case -EDEADLK: /* Deadlock detected */
 141                goto out;
 142        case -ETIMEDOUT: /* Canceled due to timeout */
 143                ret |= LM_OUT_ERROR;
 144                goto out;
 145        case 0: /* Success */
 146                break;
 147        default: /* Something unexpected */
 148                BUG();
 149        }
 150
 151        ret = gl->gl_req;
 152        if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) {
 153                if (gl->gl_req == LM_ST_SHARED)
 154                        ret = LM_ST_DEFERRED;
 155                else if (gl->gl_req == LM_ST_DEFERRED)
 156                        ret = LM_ST_SHARED;
 157                else
 158                        BUG();
 159        }
 160
 161        set_bit(GLF_INITIAL, &gl->gl_flags);
 162        gfs2_glock_complete(gl, ret);
 163        return;
 164out:
 165        if (!test_bit(GLF_INITIAL, &gl->gl_flags))
 166                gl->gl_lksb.sb_lkid = 0;
 167        gfs2_glock_complete(gl, ret);
 168}
 169
 170static void gdlm_bast(void *arg, int mode)
 171{
 172        struct gfs2_glock *gl = arg;
 173
 174        switch (mode) {
 175        case DLM_LOCK_EX:
 176                gfs2_glock_cb(gl, LM_ST_UNLOCKED);
 177                break;
 178        case DLM_LOCK_CW:
 179                gfs2_glock_cb(gl, LM_ST_DEFERRED);
 180                break;
 181        case DLM_LOCK_PR:
 182                gfs2_glock_cb(gl, LM_ST_SHARED);
 183                break;
 184        default:
 185                fs_err(gl->gl_name.ln_sbd, "unknown bast mode %d\n", mode);
 186                BUG();
 187        }
 188}
 189
 190/* convert gfs lock-state to dlm lock-mode */
 191
 192static int make_mode(struct gfs2_sbd *sdp, const unsigned int lmstate)
 193{
 194        switch (lmstate) {
 195        case LM_ST_UNLOCKED:
 196                return DLM_LOCK_NL;
 197        case LM_ST_EXCLUSIVE:
 198                return DLM_LOCK_EX;
 199        case LM_ST_DEFERRED:
 200                return DLM_LOCK_CW;
 201        case LM_ST_SHARED:
 202                return DLM_LOCK_PR;
 203        }
 204        fs_err(sdp, "unknown LM state %d\n", lmstate);
 205        BUG();
 206        return -1;
 207}
 208
 209static u32 make_flags(struct gfs2_glock *gl, const unsigned int gfs_flags,
 210                      const int req)
 211{
 212        u32 lkf = 0;
 213
 214        if (gl->gl_lksb.sb_lvbptr)
 215                lkf |= DLM_LKF_VALBLK;
 216
 217        if (gfs_flags & LM_FLAG_TRY)
 218                lkf |= DLM_LKF_NOQUEUE;
 219
 220        if (gfs_flags & LM_FLAG_TRY_1CB) {
 221                lkf |= DLM_LKF_NOQUEUE;
 222                lkf |= DLM_LKF_NOQUEUEBAST;
 223        }
 224
 225        if (gfs_flags & LM_FLAG_PRIORITY) {
 226                lkf |= DLM_LKF_NOORDER;
 227                lkf |= DLM_LKF_HEADQUE;
 228        }
 229
 230        if (gfs_flags & LM_FLAG_ANY) {
 231                if (req == DLM_LOCK_PR)
 232                        lkf |= DLM_LKF_ALTCW;
 233                else if (req == DLM_LOCK_CW)
 234                        lkf |= DLM_LKF_ALTPR;
 235                else
 236                        BUG();
 237        }
 238
 239        if (gl->gl_lksb.sb_lkid != 0) {
 240                lkf |= DLM_LKF_CONVERT;
 241                if (test_bit(GLF_BLOCKING, &gl->gl_flags))
 242                        lkf |= DLM_LKF_QUECVT;
 243        }
 244
 245        return lkf;
 246}
 247
 248static void gfs2_reverse_hex(char *c, u64 value)
 249{
 250        *c = '0';
 251        while (value) {
 252                *c-- = hex_asc[value & 0x0f];
 253                value >>= 4;
 254        }
 255}
 256
 257static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state,
 258                     unsigned int flags)
 259{
 260        struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
 261        int req;
 262        u32 lkf;
 263        char strname[GDLM_STRNAME_BYTES] = "";
 264
 265        req = make_mode(gl->gl_name.ln_sbd, req_state);
 266        lkf = make_flags(gl, flags, req);
 267        gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
 268        gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
 269        if (gl->gl_lksb.sb_lkid) {
 270                gfs2_update_request_times(gl);
 271        } else {
 272                memset(strname, ' ', GDLM_STRNAME_BYTES - 1);
 273                strname[GDLM_STRNAME_BYTES - 1] = '\0';
 274                gfs2_reverse_hex(strname + 7, gl->gl_name.ln_type);
 275                gfs2_reverse_hex(strname + 23, gl->gl_name.ln_number);
 276                gl->gl_dstamp = ktime_get_real();
 277        }
 278        /*
 279         * Submit the actual lock request.
 280         */
 281
 282        return dlm_lock(ls->ls_dlm, req, &gl->gl_lksb, lkf, strname,
 283                        GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast);
 284}
 285
 286static void gdlm_put_lock(struct gfs2_glock *gl)
 287{
 288        struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 289        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 290        int error;
 291
 292        if (gl->gl_lksb.sb_lkid == 0) {
 293                gfs2_glock_free(gl);
 294                return;
 295        }
 296
 297        clear_bit(GLF_BLOCKING, &gl->gl_flags);
 298        gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
 299        gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
 300        gfs2_update_request_times(gl);
 301
 302        /* don't want to skip dlm_unlock writing the lvb when lock has one */
 303
 304        if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) &&
 305            !gl->gl_lksb.sb_lvbptr) {
 306                gfs2_glock_free(gl);
 307                return;
 308        }
 309
 310        error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK,
 311                           NULL, gl);
 312        if (error) {
 313                fs_err(sdp, "gdlm_unlock %x,%llx err=%d\n",
 314                       gl->gl_name.ln_type,
 315                       (unsigned long long)gl->gl_name.ln_number, error);
 316                return;
 317        }
 318}
 319
 320static void gdlm_cancel(struct gfs2_glock *gl)
 321{
 322        struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
 323        dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl);
 324}
 325
 326/*
 327 * dlm/gfs2 recovery coordination using dlm_recover callbacks
 328 *
 329 *  0. gfs2 checks for another cluster node withdraw, needing journal replay
 330 *  1. dlm_controld sees lockspace members change
 331 *  2. dlm_controld blocks dlm-kernel locking activity
 332 *  3. dlm_controld within dlm-kernel notifies gfs2 (recover_prep)
 333 *  4. dlm_controld starts and finishes its own user level recovery
 334 *  5. dlm_controld starts dlm-kernel dlm_recoverd to do kernel recovery
 335 *  6. dlm_recoverd notifies gfs2 of failed nodes (recover_slot)
 336 *  7. dlm_recoverd does its own lock recovery
 337 *  8. dlm_recoverd unblocks dlm-kernel locking activity
 338 *  9. dlm_recoverd notifies gfs2 when done (recover_done with new generation)
 339 * 10. gfs2_control updates control_lock lvb with new generation and jid bits
 340 * 11. gfs2_control enqueues journals for gfs2_recover to recover (maybe none)
 341 * 12. gfs2_recover dequeues and recovers journals of failed nodes
 342 * 13. gfs2_recover provides recovery results to gfs2_control (recovery_result)
 343 * 14. gfs2_control updates control_lock lvb jid bits for recovered journals
 344 * 15. gfs2_control unblocks normal locking when all journals are recovered
 345 *
 346 * - failures during recovery
 347 *
 348 * recover_prep() may set BLOCK_LOCKS (step 3) again before gfs2_control
 349 * clears BLOCK_LOCKS (step 15), e.g. another node fails while still
 350 * recovering for a prior failure.  gfs2_control needs a way to detect
 351 * this so it can leave BLOCK_LOCKS set in step 15.  This is managed using
 352 * the recover_block and recover_start values.
 353 *
 354 * recover_done() provides a new lockspace generation number each time it
 355 * is called (step 9).  This generation number is saved as recover_start.
 356 * When recover_prep() is called, it sets BLOCK_LOCKS and sets
 357 * recover_block = recover_start.  So, while recover_block is equal to
 358 * recover_start, BLOCK_LOCKS should remain set.  (recover_spin must
 359 * be held around the BLOCK_LOCKS/recover_block/recover_start logic.)
 360 *
 361 * - more specific gfs2 steps in sequence above
 362 *
 363 *  3. recover_prep sets BLOCK_LOCKS and sets recover_block = recover_start
 364 *  6. recover_slot records any failed jids (maybe none)
 365 *  9. recover_done sets recover_start = new generation number
 366 * 10. gfs2_control sets control_lock lvb = new gen + bits for failed jids
 367 * 12. gfs2_recover does journal recoveries for failed jids identified above
 368 * 14. gfs2_control clears control_lock lvb bits for recovered jids
 369 * 15. gfs2_control checks if recover_block == recover_start (step 3 occured
 370 *     again) then do nothing, otherwise if recover_start > recover_block
 371 *     then clear BLOCK_LOCKS.
 372 *
 373 * - parallel recovery steps across all nodes
 374 *
 375 * All nodes attempt to update the control_lock lvb with the new generation
 376 * number and jid bits, but only the first to get the control_lock EX will
 377 * do so; others will see that it's already done (lvb already contains new
 378 * generation number.)
 379 *
 380 * . All nodes get the same recover_prep/recover_slot/recover_done callbacks
 381 * . All nodes attempt to set control_lock lvb gen + bits for the new gen
 382 * . One node gets control_lock first and writes the lvb, others see it's done
 383 * . All nodes attempt to recover jids for which they see control_lock bits set
 384 * . One node succeeds for a jid, and that one clears the jid bit in the lvb
 385 * . All nodes will eventually see all lvb bits clear and unblock locks
 386 *
 387 * - is there a problem with clearing an lvb bit that should be set
 388 *   and missing a journal recovery?
 389 *
 390 * 1. jid fails
 391 * 2. lvb bit set for step 1
 392 * 3. jid recovered for step 1
 393 * 4. jid taken again (new mount)
 394 * 5. jid fails (for step 4)
 395 * 6. lvb bit set for step 5 (will already be set)
 396 * 7. lvb bit cleared for step 3
 397 *
 398 * This is not a problem because the failure in step 5 does not
 399 * require recovery, because the mount in step 4 could not have
 400 * progressed far enough to unblock locks and access the fs.  The
 401 * control_mount() function waits for all recoveries to be complete
 402 * for the latest lockspace generation before ever unblocking locks
 403 * and returning.  The mount in step 4 waits until the recovery in
 404 * step 1 is done.
 405 *
 406 * - special case of first mounter: first node to mount the fs
 407 *
 408 * The first node to mount a gfs2 fs needs to check all the journals
 409 * and recover any that need recovery before other nodes are allowed
 410 * to mount the fs.  (Others may begin mounting, but they must wait
 411 * for the first mounter to be done before taking locks on the fs
 412 * or accessing the fs.)  This has two parts:
 413 *
 414 * 1. The mounted_lock tells a node it's the first to mount the fs.
 415 * Each node holds the mounted_lock in PR while it's mounted.
 416 * Each node tries to acquire the mounted_lock in EX when it mounts.
 417 * If a node is granted the mounted_lock EX it means there are no
 418 * other mounted nodes (no PR locks exist), and it is the first mounter.
 419 * The mounted_lock is demoted to PR when first recovery is done, so
 420 * others will fail to get an EX lock, but will get a PR lock.
 421 *
 422 * 2. The control_lock blocks others in control_mount() while the first
 423 * mounter is doing first mount recovery of all journals.
 424 * A mounting node needs to acquire control_lock in EX mode before
 425 * it can proceed.  The first mounter holds control_lock in EX while doing
 426 * the first mount recovery, blocking mounts from other nodes, then demotes
 427 * control_lock to NL when it's done (others_may_mount/first_done),
 428 * allowing other nodes to continue mounting.
 429 *
 430 * first mounter:
 431 * control_lock EX/NOQUEUE success
 432 * mounted_lock EX/NOQUEUE success (no other PR, so no other mounters)
 433 * set first=1
 434 * do first mounter recovery
 435 * mounted_lock EX->PR
 436 * control_lock EX->NL, write lvb generation
 437 *
 438 * other mounter:
 439 * control_lock EX/NOQUEUE success (if fail -EAGAIN, retry)
 440 * mounted_lock EX/NOQUEUE fail -EAGAIN (expected due to other mounters PR)
 441 * mounted_lock PR/NOQUEUE success
 442 * read lvb generation
 443 * control_lock EX->NL
 444 * set first=0
 445 *
 446 * - mount during recovery
 447 *
 448 * If a node mounts while others are doing recovery (not first mounter),
 449 * the mounting node will get its initial recover_done() callback without
 450 * having seen any previous failures/callbacks.
 451 *
 452 * It must wait for all recoveries preceding its mount to be finished
 453 * before it unblocks locks.  It does this by repeating the "other mounter"
 454 * steps above until the lvb generation number is >= its mount generation
 455 * number (from initial recover_done) and all lvb bits are clear.
 456 *
 457 * - control_lock lvb format
 458 *
 459 * 4 bytes generation number: the latest dlm lockspace generation number
 460 * from recover_done callback.  Indicates the jid bitmap has been updated
 461 * to reflect all slot failures through that generation.
 462 * 4 bytes unused.
 463 * GDLM_LVB_SIZE-8 bytes of jid bit map. If bit N is set, it indicates
 464 * that jid N needs recovery.
 465 */
 466
 467#define JID_BITMAP_OFFSET 8 /* 4 byte generation number + 4 byte unused */
 468
 469static void control_lvb_read(struct lm_lockstruct *ls, uint32_t *lvb_gen,
 470                             char *lvb_bits)
 471{
 472        __le32 gen;
 473        memcpy(lvb_bits, ls->ls_control_lvb, GDLM_LVB_SIZE);
 474        memcpy(&gen, lvb_bits, sizeof(__le32));
 475        *lvb_gen = le32_to_cpu(gen);
 476}
 477
 478static void control_lvb_write(struct lm_lockstruct *ls, uint32_t lvb_gen,
 479                              char *lvb_bits)
 480{
 481        __le32 gen;
 482        memcpy(ls->ls_control_lvb, lvb_bits, GDLM_LVB_SIZE);
 483        gen = cpu_to_le32(lvb_gen);
 484        memcpy(ls->ls_control_lvb, &gen, sizeof(__le32));
 485}
 486
 487static int all_jid_bits_clear(char *lvb)
 488{
 489        return !memchr_inv(lvb + JID_BITMAP_OFFSET, 0,
 490                        GDLM_LVB_SIZE - JID_BITMAP_OFFSET);
 491}
 492
 493static void sync_wait_cb(void *arg)
 494{
 495        struct lm_lockstruct *ls = arg;
 496        complete(&ls->ls_sync_wait);
 497}
 498
 499static int sync_unlock(struct gfs2_sbd *sdp, struct dlm_lksb *lksb, char *name)
 500{
 501        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 502        int error;
 503
 504        error = dlm_unlock(ls->ls_dlm, lksb->sb_lkid, 0, lksb, ls);
 505        if (error) {
 506                fs_err(sdp, "%s lkid %x error %d\n",
 507                       name, lksb->sb_lkid, error);
 508                return error;
 509        }
 510
 511        wait_for_completion(&ls->ls_sync_wait);
 512
 513        if (lksb->sb_status != -DLM_EUNLOCK) {
 514                fs_err(sdp, "%s lkid %x status %d\n",
 515                       name, lksb->sb_lkid, lksb->sb_status);
 516                return -1;
 517        }
 518        return 0;
 519}
 520
 521static int sync_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags,
 522                     unsigned int num, struct dlm_lksb *lksb, char *name)
 523{
 524        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 525        char strname[GDLM_STRNAME_BYTES];
 526        int error, status;
 527
 528        memset(strname, 0, GDLM_STRNAME_BYTES);
 529        snprintf(strname, GDLM_STRNAME_BYTES, "%8x%16x", LM_TYPE_NONDISK, num);
 530
 531        error = dlm_lock(ls->ls_dlm, mode, lksb, flags,
 532                         strname, GDLM_STRNAME_BYTES - 1,
 533                         0, sync_wait_cb, ls, NULL);
 534        if (error) {
 535                fs_err(sdp, "%s lkid %x flags %x mode %d error %d\n",
 536                       name, lksb->sb_lkid, flags, mode, error);
 537                return error;
 538        }
 539
 540        wait_for_completion(&ls->ls_sync_wait);
 541
 542        status = lksb->sb_status;
 543
 544        if (status && status != -EAGAIN) {
 545                fs_err(sdp, "%s lkid %x flags %x mode %d status %d\n",
 546                       name, lksb->sb_lkid, flags, mode, status);
 547        }
 548
 549        return status;
 550}
 551
 552static int mounted_unlock(struct gfs2_sbd *sdp)
 553{
 554        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 555        return sync_unlock(sdp, &ls->ls_mounted_lksb, "mounted_lock");
 556}
 557
 558static int mounted_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
 559{
 560        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 561        return sync_lock(sdp, mode, flags, GFS2_MOUNTED_LOCK,
 562                         &ls->ls_mounted_lksb, "mounted_lock");
 563}
 564
 565static int control_unlock(struct gfs2_sbd *sdp)
 566{
 567        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 568        return sync_unlock(sdp, &ls->ls_control_lksb, "control_lock");
 569}
 570
 571static int control_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
 572{
 573        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 574        return sync_lock(sdp, mode, flags, GFS2_CONTROL_LOCK,
 575                         &ls->ls_control_lksb, "control_lock");
 576}
 577
 578/**
 579 * remote_withdraw - react to a node withdrawing from the file system
 580 * @sdp: The superblock
 581 */
 582static void remote_withdraw(struct gfs2_sbd *sdp)
 583{
 584        struct gfs2_jdesc *jd;
 585        int ret = 0, count = 0;
 586
 587        list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
 588                if (jd->jd_jid == sdp->sd_lockstruct.ls_jid)
 589                        continue;
 590                ret = gfs2_recover_journal(jd, true);
 591                if (ret)
 592                        break;
 593                count++;
 594        }
 595
 596        /* Now drop the additional reference we acquired */
 597        fs_err(sdp, "Journals checked: %d, ret = %d.\n", count, ret);
 598}
 599
 600static void gfs2_control_func(struct work_struct *work)
 601{
 602        struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work);
 603        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 604        uint32_t block_gen, start_gen, lvb_gen, flags;
 605        int recover_set = 0;
 606        int write_lvb = 0;
 607        int recover_size;
 608        int i, error;
 609
 610        /* First check for other nodes that may have done a withdraw. */
 611        if (test_bit(SDF_REMOTE_WITHDRAW, &sdp->sd_flags)) {
 612                remote_withdraw(sdp);
 613                clear_bit(SDF_REMOTE_WITHDRAW, &sdp->sd_flags);
 614                return;
 615        }
 616
 617        spin_lock(&ls->ls_recover_spin);
 618        /*
 619         * No MOUNT_DONE means we're still mounting; control_mount()
 620         * will set this flag, after which this thread will take over
 621         * all further clearing of BLOCK_LOCKS.
 622         *
 623         * FIRST_MOUNT means this node is doing first mounter recovery,
 624         * for which recovery control is handled by
 625         * control_mount()/control_first_done(), not this thread.
 626         */
 627        if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
 628             test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
 629                spin_unlock(&ls->ls_recover_spin);
 630                return;
 631        }
 632        block_gen = ls->ls_recover_block;
 633        start_gen = ls->ls_recover_start;
 634        spin_unlock(&ls->ls_recover_spin);
 635
 636        /*
 637         * Equal block_gen and start_gen implies we are between
 638         * recover_prep and recover_done callbacks, which means
 639         * dlm recovery is in progress and dlm locking is blocked.
 640         * There's no point trying to do any work until recover_done.
 641         */
 642
 643        if (block_gen == start_gen)
 644                return;
 645
 646        /*
 647         * Propagate recover_submit[] and recover_result[] to lvb:
 648         * dlm_recoverd adds to recover_submit[] jids needing recovery
 649         * gfs2_recover adds to recover_result[] journal recovery results
 650         *
 651         * set lvb bit for jids in recover_submit[] if the lvb has not
 652         * yet been updated for the generation of the failure
 653         *
 654         * clear lvb bit for jids in recover_result[] if the result of
 655         * the journal recovery is SUCCESS
 656         */
 657
 658        error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
 659        if (error) {
 660                fs_err(sdp, "control lock EX error %d\n", error);
 661                return;
 662        }
 663
 664        control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
 665
 666        spin_lock(&ls->ls_recover_spin);
 667        if (block_gen != ls->ls_recover_block ||
 668            start_gen != ls->ls_recover_start) {
 669                fs_info(sdp, "recover generation %u block1 %u %u\n",
 670                        start_gen, block_gen, ls->ls_recover_block);
 671                spin_unlock(&ls->ls_recover_spin);
 672                control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
 673                return;
 674        }
 675
 676        recover_size = ls->ls_recover_size;
 677
 678        if (lvb_gen <= start_gen) {
 679                /*
 680                 * Clear lvb bits for jids we've successfully recovered.
 681                 * Because all nodes attempt to recover failed journals,
 682                 * a journal can be recovered multiple times successfully
 683                 * in succession.  Only the first will really do recovery,
 684                 * the others find it clean, but still report a successful
 685                 * recovery.  So, another node may have already recovered
 686                 * the jid and cleared the lvb bit for it.
 687                 */
 688                for (i = 0; i < recover_size; i++) {
 689                        if (ls->ls_recover_result[i] != LM_RD_SUCCESS)
 690                                continue;
 691
 692                        ls->ls_recover_result[i] = 0;
 693
 694                        if (!test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET))
 695                                continue;
 696
 697                        __clear_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
 698                        write_lvb = 1;
 699                }
 700        }
 701
 702        if (lvb_gen == start_gen) {
 703                /*
 704                 * Failed slots before start_gen are already set in lvb.
 705                 */
 706                for (i = 0; i < recover_size; i++) {
 707                        if (!ls->ls_recover_submit[i])
 708                                continue;
 709                        if (ls->ls_recover_submit[i] < lvb_gen)
 710                                ls->ls_recover_submit[i] = 0;
 711                }
 712        } else if (lvb_gen < start_gen) {
 713                /*
 714                 * Failed slots before start_gen are not yet set in lvb.
 715                 */
 716                for (i = 0; i < recover_size; i++) {
 717                        if (!ls->ls_recover_submit[i])
 718                                continue;
 719                        if (ls->ls_recover_submit[i] < start_gen) {
 720                                ls->ls_recover_submit[i] = 0;
 721                                __set_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
 722                        }
 723                }
 724                /* even if there are no bits to set, we need to write the
 725                   latest generation to the lvb */
 726                write_lvb = 1;
 727        } else {
 728                /*
 729                 * we should be getting a recover_done() for lvb_gen soon
 730                 */
 731        }
 732        spin_unlock(&ls->ls_recover_spin);
 733
 734        if (write_lvb) {
 735                control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
 736                flags = DLM_LKF_CONVERT | DLM_LKF_VALBLK;
 737        } else {
 738                flags = DLM_LKF_CONVERT;
 739        }
 740
 741        error = control_lock(sdp, DLM_LOCK_NL, flags);
 742        if (error) {
 743                fs_err(sdp, "control lock NL error %d\n", error);
 744                return;
 745        }
 746
 747        /*
 748         * Everyone will see jid bits set in the lvb, run gfs2_recover_set(),
 749         * and clear a jid bit in the lvb if the recovery is a success.
 750         * Eventually all journals will be recovered, all jid bits will
 751         * be cleared in the lvb, and everyone will clear BLOCK_LOCKS.
 752         */
 753
 754        for (i = 0; i < recover_size; i++) {
 755                if (test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET)) {
 756                        fs_info(sdp, "recover generation %u jid %d\n",
 757                                start_gen, i);
 758                        gfs2_recover_set(sdp, i);
 759                        recover_set++;
 760                }
 761        }
 762        if (recover_set)
 763                return;
 764
 765        /*
 766         * No more jid bits set in lvb, all recovery is done, unblock locks
 767         * (unless a new recover_prep callback has occured blocking locks
 768         * again while working above)
 769         */
 770
 771        spin_lock(&ls->ls_recover_spin);
 772        if (ls->ls_recover_block == block_gen &&
 773            ls->ls_recover_start == start_gen) {
 774                clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
 775                spin_unlock(&ls->ls_recover_spin);
 776                fs_info(sdp, "recover generation %u done\n", start_gen);
 777                gfs2_glock_thaw(sdp);
 778        } else {
 779                fs_info(sdp, "recover generation %u block2 %u %u\n",
 780                        start_gen, block_gen, ls->ls_recover_block);
 781                spin_unlock(&ls->ls_recover_spin);
 782        }
 783}
 784
 785static int control_mount(struct gfs2_sbd *sdp)
 786{
 787        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 788        uint32_t start_gen, block_gen, mount_gen, lvb_gen;
 789        int mounted_mode;
 790        int retries = 0;
 791        int error;
 792
 793        memset(&ls->ls_mounted_lksb, 0, sizeof(struct dlm_lksb));
 794        memset(&ls->ls_control_lksb, 0, sizeof(struct dlm_lksb));
 795        memset(&ls->ls_control_lvb, 0, GDLM_LVB_SIZE);
 796        ls->ls_control_lksb.sb_lvbptr = ls->ls_control_lvb;
 797        init_completion(&ls->ls_sync_wait);
 798
 799        set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
 800
 801        error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_VALBLK);
 802        if (error) {
 803                fs_err(sdp, "control_mount control_lock NL error %d\n", error);
 804                return error;
 805        }
 806
 807        error = mounted_lock(sdp, DLM_LOCK_NL, 0);
 808        if (error) {
 809                fs_err(sdp, "control_mount mounted_lock NL error %d\n", error);
 810                control_unlock(sdp);
 811                return error;
 812        }
 813        mounted_mode = DLM_LOCK_NL;
 814
 815restart:
 816        if (retries++ && signal_pending(current)) {
 817                error = -EINTR;
 818                goto fail;
 819        }
 820
 821        /*
 822         * We always start with both locks in NL. control_lock is
 823         * demoted to NL below so we don't need to do it here.
 824         */
 825
 826        if (mounted_mode != DLM_LOCK_NL) {
 827                error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
 828                if (error)
 829                        goto fail;
 830                mounted_mode = DLM_LOCK_NL;
 831        }
 832
 833        /*
 834         * Other nodes need to do some work in dlm recovery and gfs2_control
 835         * before the recover_done and control_lock will be ready for us below.
 836         * A delay here is not required but often avoids having to retry.
 837         */
 838
 839        msleep_interruptible(500);
 840
 841        /*
 842         * Acquire control_lock in EX and mounted_lock in either EX or PR.
 843         * control_lock lvb keeps track of any pending journal recoveries.
 844         * mounted_lock indicates if any other nodes have the fs mounted.
 845         */
 846
 847        error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE|DLM_LKF_VALBLK);
 848        if (error == -EAGAIN) {
 849                goto restart;
 850        } else if (error) {
 851                fs_err(sdp, "control_mount control_lock EX error %d\n", error);
 852                goto fail;
 853        }
 854
 855        /**
 856         * If we're a spectator, we don't want to take the lock in EX because
 857         * we cannot do the first-mount responsibility it implies: recovery.
 858         */
 859        if (sdp->sd_args.ar_spectator)
 860                goto locks_done;
 861
 862        error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
 863        if (!error) {
 864                mounted_mode = DLM_LOCK_EX;
 865                goto locks_done;
 866        } else if (error != -EAGAIN) {
 867                fs_err(sdp, "control_mount mounted_lock EX error %d\n", error);
 868                goto fail;
 869        }
 870
 871        error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
 872        if (!error) {
 873                mounted_mode = DLM_LOCK_PR;
 874                goto locks_done;
 875        } else {
 876                /* not even -EAGAIN should happen here */
 877                fs_err(sdp, "control_mount mounted_lock PR error %d\n", error);
 878                goto fail;
 879        }
 880
 881locks_done:
 882        /*
 883         * If we got both locks above in EX, then we're the first mounter.
 884         * If not, then we need to wait for the control_lock lvb to be
 885         * updated by other mounted nodes to reflect our mount generation.
 886         *
 887         * In simple first mounter cases, first mounter will see zero lvb_gen,
 888         * but in cases where all existing nodes leave/fail before mounting
 889         * nodes finish control_mount, then all nodes will be mounting and
 890         * lvb_gen will be non-zero.
 891         */
 892
 893        control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
 894
 895        if (lvb_gen == 0xFFFFFFFF) {
 896                /* special value to force mount attempts to fail */
 897                fs_err(sdp, "control_mount control_lock disabled\n");
 898                error = -EINVAL;
 899                goto fail;
 900        }
 901
 902        if (mounted_mode == DLM_LOCK_EX) {
 903                /* first mounter, keep both EX while doing first recovery */
 904                spin_lock(&ls->ls_recover_spin);
 905                clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
 906                set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
 907                set_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
 908                spin_unlock(&ls->ls_recover_spin);
 909                fs_info(sdp, "first mounter control generation %u\n", lvb_gen);
 910                return 0;
 911        }
 912
 913        error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
 914        if (error)
 915                goto fail;
 916
 917        /*
 918         * We are not first mounter, now we need to wait for the control_lock
 919         * lvb generation to be >= the generation from our first recover_done
 920         * and all lvb bits to be clear (no pending journal recoveries.)
 921         */
 922
 923        if (!all_jid_bits_clear(ls->ls_lvb_bits)) {
 924                /* journals need recovery, wait until all are clear */
 925                fs_info(sdp, "control_mount wait for journal recovery\n");
 926                goto restart;
 927        }
 928
 929        spin_lock(&ls->ls_recover_spin);
 930        block_gen = ls->ls_recover_block;
 931        start_gen = ls->ls_recover_start;
 932        mount_gen = ls->ls_recover_mount;
 933
 934        if (lvb_gen < mount_gen) {
 935                /* wait for mounted nodes to update control_lock lvb to our
 936                   generation, which might include new recovery bits set */
 937                if (sdp->sd_args.ar_spectator) {
 938                        fs_info(sdp, "Recovery is required. Waiting for a "
 939                                "non-spectator to mount.\n");
 940                        msleep_interruptible(1000);
 941                } else {
 942                        fs_info(sdp, "control_mount wait1 block %u start %u "
 943                                "mount %u lvb %u flags %lx\n", block_gen,
 944                                start_gen, mount_gen, lvb_gen,
 945                                ls->ls_recover_flags);
 946                }
 947                spin_unlock(&ls->ls_recover_spin);
 948                goto restart;
 949        }
 950
 951        if (lvb_gen != start_gen) {
 952                /* wait for mounted nodes to update control_lock lvb to the
 953                   latest recovery generation */
 954                fs_info(sdp, "control_mount wait2 block %u start %u mount %u "
 955                        "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
 956                        lvb_gen, ls->ls_recover_flags);
 957                spin_unlock(&ls->ls_recover_spin);
 958                goto restart;
 959        }
 960
 961        if (block_gen == start_gen) {
 962                /* dlm recovery in progress, wait for it to finish */
 963                fs_info(sdp, "control_mount wait3 block %u start %u mount %u "
 964                        "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
 965                        lvb_gen, ls->ls_recover_flags);
 966                spin_unlock(&ls->ls_recover_spin);
 967                goto restart;
 968        }
 969
 970        clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
 971        set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
 972        memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
 973        memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
 974        spin_unlock(&ls->ls_recover_spin);
 975        return 0;
 976
 977fail:
 978        mounted_unlock(sdp);
 979        control_unlock(sdp);
 980        return error;
 981}
 982
 983static int control_first_done(struct gfs2_sbd *sdp)
 984{
 985        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 986        uint32_t start_gen, block_gen;
 987        int error;
 988
 989restart:
 990        spin_lock(&ls->ls_recover_spin);
 991        start_gen = ls->ls_recover_start;
 992        block_gen = ls->ls_recover_block;
 993
 994        if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags) ||
 995            !test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
 996            !test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
 997                /* sanity check, should not happen */
 998                fs_err(sdp, "control_first_done start %u block %u flags %lx\n",
 999                       start_gen, block_gen, ls->ls_recover_flags);
1000                spin_unlock(&ls->ls_recover_spin);
1001                control_unlock(sdp);
1002                return -1;
1003        }
1004
1005        if (start_gen == block_gen) {
1006                /*
1007                 * Wait for the end of a dlm recovery cycle to switch from
1008                 * first mounter recovery.  We can ignore any recover_slot
1009                 * callbacks between the recover_prep and next recover_done
1010                 * because we are still the first mounter and any failed nodes
1011                 * have not fully mounted, so they don't need recovery.
1012                 */
1013                spin_unlock(&ls->ls_recover_spin);
1014                fs_info(sdp, "control_first_done wait gen %u\n", start_gen);
1015
1016                wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY,
1017                            TASK_UNINTERRUPTIBLE);
1018                goto restart;
1019        }
1020
1021        clear_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
1022        set_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags);
1023        memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
1024        memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
1025        spin_unlock(&ls->ls_recover_spin);
1026
1027        memset(ls->ls_lvb_bits, 0, GDLM_LVB_SIZE);
1028        control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
1029
1030        error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT);
1031        if (error)
1032                fs_err(sdp, "control_first_done mounted PR error %d\n", error);
1033
1034        error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
1035        if (error)
1036                fs_err(sdp, "control_first_done control NL error %d\n", error);
1037
1038        return error;
1039}
1040
1041/*
1042 * Expand static jid arrays if necessary (by increments of RECOVER_SIZE_INC)
1043 * to accomodate the largest slot number.  (NB dlm slot numbers start at 1,
1044 * gfs2 jids start at 0, so jid = slot - 1)
1045 */
1046
1047#define RECOVER_SIZE_INC 16
1048
1049static int set_recover_size(struct gfs2_sbd *sdp, struct dlm_slot *slots,
1050                            int num_slots)
1051{
1052        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1053        uint32_t *submit = NULL;
1054        uint32_t *result = NULL;
1055        uint32_t old_size, new_size;
1056        int i, max_jid;
1057
1058        if (!ls->ls_lvb_bits) {
1059                ls->ls_lvb_bits = kzalloc(GDLM_LVB_SIZE, GFP_NOFS);
1060                if (!ls->ls_lvb_bits)
1061                        return -ENOMEM;
1062        }
1063
1064        max_jid = 0;
1065        for (i = 0; i < num_slots; i++) {
1066                if (max_jid < slots[i].slot - 1)
1067                        max_jid = slots[i].slot - 1;
1068        }
1069
1070        old_size = ls->ls_recover_size;
1071        new_size = old_size;
1072        while (new_size < max_jid + 1)
1073                new_size += RECOVER_SIZE_INC;
1074        if (new_size == old_size)
1075                return 0;
1076
1077        submit = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS);
1078        result = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS);
1079        if (!submit || !result) {
1080                kfree(submit);
1081                kfree(result);
1082                return -ENOMEM;
1083        }
1084
1085        spin_lock(&ls->ls_recover_spin);
1086        memcpy(submit, ls->ls_recover_submit, old_size * sizeof(uint32_t));
1087        memcpy(result, ls->ls_recover_result, old_size * sizeof(uint32_t));
1088        kfree(ls->ls_recover_submit);
1089        kfree(ls->ls_recover_result);
1090        ls->ls_recover_submit = submit;
1091        ls->ls_recover_result = result;
1092        ls->ls_recover_size = new_size;
1093        spin_unlock(&ls->ls_recover_spin);
1094        return 0;
1095}
1096
1097static void free_recover_size(struct lm_lockstruct *ls)
1098{
1099        kfree(ls->ls_lvb_bits);
1100        kfree(ls->ls_recover_submit);
1101        kfree(ls->ls_recover_result);
1102        ls->ls_recover_submit = NULL;
1103        ls->ls_recover_result = NULL;
1104        ls->ls_recover_size = 0;
1105        ls->ls_lvb_bits = NULL;
1106}
1107
1108/* dlm calls before it does lock recovery */
1109
1110static void gdlm_recover_prep(void *arg)
1111{
1112        struct gfs2_sbd *sdp = arg;
1113        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1114
1115        if (gfs2_withdrawn(sdp)) {
1116                fs_err(sdp, "recover_prep ignored due to withdraw.\n");
1117                return;
1118        }
1119        spin_lock(&ls->ls_recover_spin);
1120        ls->ls_recover_block = ls->ls_recover_start;
1121        set_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
1122
1123        if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
1124             test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
1125                spin_unlock(&ls->ls_recover_spin);
1126                return;
1127        }
1128        set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
1129        spin_unlock(&ls->ls_recover_spin);
1130}
1131
1132/* dlm calls after recover_prep has been completed on all lockspace members;
1133   identifies slot/jid of failed member */
1134
1135static void gdlm_recover_slot(void *arg, struct dlm_slot *slot)
1136{
1137        struct gfs2_sbd *sdp = arg;
1138        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1139        int jid = slot->slot - 1;
1140
1141        if (gfs2_withdrawn(sdp)) {
1142                fs_err(sdp, "recover_slot jid %d ignored due to withdraw.\n",
1143                       jid);
1144                return;
1145        }
1146        spin_lock(&ls->ls_recover_spin);
1147        if (ls->ls_recover_size < jid + 1) {
1148                fs_err(sdp, "recover_slot jid %d gen %u short size %d\n",
1149                       jid, ls->ls_recover_block, ls->ls_recover_size);
1150                spin_unlock(&ls->ls_recover_spin);
1151                return;
1152        }
1153
1154        if (ls->ls_recover_submit[jid]) {
1155                fs_info(sdp, "recover_slot jid %d gen %u prev %u\n",
1156                        jid, ls->ls_recover_block, ls->ls_recover_submit[jid]);
1157        }
1158        ls->ls_recover_submit[jid] = ls->ls_recover_block;
1159        spin_unlock(&ls->ls_recover_spin);
1160}
1161
1162/* dlm calls after recover_slot and after it completes lock recovery */
1163
1164static void gdlm_recover_done(void *arg, struct dlm_slot *slots, int num_slots,
1165                              int our_slot, uint32_t generation)
1166{
1167        struct gfs2_sbd *sdp = arg;
1168        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1169
1170        if (gfs2_withdrawn(sdp)) {
1171                fs_err(sdp, "recover_done ignored due to withdraw.\n");
1172                return;
1173        }
1174        /* ensure the ls jid arrays are large enough */
1175        set_recover_size(sdp, slots, num_slots);
1176
1177        spin_lock(&ls->ls_recover_spin);
1178        ls->ls_recover_start = generation;
1179
1180        if (!ls->ls_recover_mount) {
1181                ls->ls_recover_mount = generation;
1182                ls->ls_jid = our_slot - 1;
1183        }
1184
1185        if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
1186                queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work, 0);
1187
1188        clear_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
1189        smp_mb__after_atomic();
1190        wake_up_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY);
1191        spin_unlock(&ls->ls_recover_spin);
1192}
1193
1194/* gfs2_recover thread has a journal recovery result */
1195
1196static void gdlm_recovery_result(struct gfs2_sbd *sdp, unsigned int jid,
1197                                 unsigned int result)
1198{
1199        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1200
1201        if (gfs2_withdrawn(sdp)) {
1202                fs_err(sdp, "recovery_result jid %d ignored due to withdraw.\n",
1203                       jid);
1204                return;
1205        }
1206        if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1207                return;
1208
1209        /* don't care about the recovery of own journal during mount */
1210        if (jid == ls->ls_jid)
1211                return;
1212
1213        spin_lock(&ls->ls_recover_spin);
1214        if (test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
1215                spin_unlock(&ls->ls_recover_spin);
1216                return;
1217        }
1218        if (ls->ls_recover_size < jid + 1) {
1219                fs_err(sdp, "recovery_result jid %d short size %d\n",
1220                       jid, ls->ls_recover_size);
1221                spin_unlock(&ls->ls_recover_spin);
1222                return;
1223        }
1224
1225        fs_info(sdp, "recover jid %d result %s\n", jid,
1226                result == LM_RD_GAVEUP ? "busy" : "success");
1227
1228        ls->ls_recover_result[jid] = result;
1229
1230        /* GAVEUP means another node is recovering the journal; delay our
1231           next attempt to recover it, to give the other node a chance to
1232           finish before trying again */
1233
1234        if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
1235                queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work,
1236                                   result == LM_RD_GAVEUP ? HZ : 0);
1237        spin_unlock(&ls->ls_recover_spin);
1238}
1239
1240static const struct dlm_lockspace_ops gdlm_lockspace_ops = {
1241        .recover_prep = gdlm_recover_prep,
1242        .recover_slot = gdlm_recover_slot,
1243        .recover_done = gdlm_recover_done,
1244};
1245
1246static int gdlm_mount(struct gfs2_sbd *sdp, const char *table)
1247{
1248        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1249        char cluster[GFS2_LOCKNAME_LEN];
1250        const char *fsname;
1251        uint32_t flags;
1252        int error, ops_result;
1253
1254        /*
1255         * initialize everything
1256         */
1257
1258        INIT_DELAYED_WORK(&sdp->sd_control_work, gfs2_control_func);
1259        spin_lock_init(&ls->ls_recover_spin);
1260        ls->ls_recover_flags = 0;
1261        ls->ls_recover_mount = 0;
1262        ls->ls_recover_start = 0;
1263        ls->ls_recover_block = 0;
1264        ls->ls_recover_size = 0;
1265        ls->ls_recover_submit = NULL;
1266        ls->ls_recover_result = NULL;
1267        ls->ls_lvb_bits = NULL;
1268
1269        error = set_recover_size(sdp, NULL, 0);
1270        if (error)
1271                goto fail;
1272
1273        /*
1274         * prepare dlm_new_lockspace args
1275         */
1276
1277        fsname = strchr(table, ':');
1278        if (!fsname) {
1279                fs_info(sdp, "no fsname found\n");
1280                error = -EINVAL;
1281                goto fail_free;
1282        }
1283        memset(cluster, 0, sizeof(cluster));
1284        memcpy(cluster, table, strlen(table) - strlen(fsname));
1285        fsname++;
1286
1287        flags = DLM_LSFL_FS | DLM_LSFL_NEWEXCL;
1288
1289        /*
1290         * create/join lockspace
1291         */
1292
1293        error = dlm_new_lockspace(fsname, cluster, flags, GDLM_LVB_SIZE,
1294                                  &gdlm_lockspace_ops, sdp, &ops_result,
1295                                  &ls->ls_dlm);
1296        if (error) {
1297                fs_err(sdp, "dlm_new_lockspace error %d\n", error);
1298                goto fail_free;
1299        }
1300
1301        if (ops_result < 0) {
1302                /*
1303                 * dlm does not support ops callbacks,
1304                 * old dlm_controld/gfs_controld are used, try without ops.
1305                 */
1306                fs_info(sdp, "dlm lockspace ops not used\n");
1307                free_recover_size(ls);
1308                set_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags);
1309                return 0;
1310        }
1311
1312        if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags)) {
1313                fs_err(sdp, "dlm lockspace ops disallow jid preset\n");
1314                error = -EINVAL;
1315                goto fail_release;
1316        }
1317
1318        /*
1319         * control_mount() uses control_lock to determine first mounter,
1320         * and for later mounts, waits for any recoveries to be cleared.
1321         */
1322
1323        error = control_mount(sdp);
1324        if (error) {
1325                fs_err(sdp, "mount control error %d\n", error);
1326                goto fail_release;
1327        }
1328
1329        ls->ls_first = !!test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
1330        clear_bit(SDF_NOJOURNALID, &sdp->sd_flags);
1331        smp_mb__after_atomic();
1332        wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID);
1333        return 0;
1334
1335fail_release:
1336        dlm_release_lockspace(ls->ls_dlm, 2);
1337fail_free:
1338        free_recover_size(ls);
1339fail:
1340        return error;
1341}
1342
1343static void gdlm_first_done(struct gfs2_sbd *sdp)
1344{
1345        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1346        int error;
1347
1348        if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1349                return;
1350
1351        error = control_first_done(sdp);
1352        if (error)
1353                fs_err(sdp, "mount first_done error %d\n", error);
1354}
1355
1356static void gdlm_unmount(struct gfs2_sbd *sdp)
1357{
1358        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1359
1360        if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
1361                goto release;
1362
1363        /* wait for gfs2_control_wq to be done with this mount */
1364
1365        spin_lock(&ls->ls_recover_spin);
1366        set_bit(DFL_UNMOUNT, &ls->ls_recover_flags);
1367        spin_unlock(&ls->ls_recover_spin);
1368        flush_delayed_work(&sdp->sd_control_work);
1369
1370        /* mounted_lock and control_lock will be purged in dlm recovery */
1371release:
1372        if (ls->ls_dlm) {
1373                dlm_release_lockspace(ls->ls_dlm, 2);
1374                ls->ls_dlm = NULL;
1375        }
1376
1377        free_recover_size(ls);
1378}
1379
1380static const match_table_t dlm_tokens = {
1381        { Opt_jid, "jid=%d"},
1382        { Opt_id, "id=%d"},
1383        { Opt_first, "first=%d"},
1384        { Opt_nodir, "nodir=%d"},
1385        { Opt_err, NULL },
1386};
1387
1388const struct lm_lockops gfs2_dlm_ops = {
1389        .lm_proto_name = "lock_dlm",
1390        .lm_mount = gdlm_mount,
1391        .lm_first_done = gdlm_first_done,
1392        .lm_recovery_result = gdlm_recovery_result,
1393        .lm_unmount = gdlm_unmount,
1394        .lm_put_lock = gdlm_put_lock,
1395        .lm_lock = gdlm_lock,
1396        .lm_cancel = gdlm_cancel,
1397        .lm_tokens = &dlm_tokens,
1398};
1399
1400
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