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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
  * Copyright 2004-2011 Red Hat, Inc.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/fs.h>
 #include <linux/dlm.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/delay.h>
 #include <linux/gfs2_ondisk.h>
 #include <linux/sched/signal.h>
 
 #include "incore.h"
 #include "glock.h"
 #include "glops.h"
 #include "recovery.h"
 #include "util.h"
 #include "sys.h"
 #include "trace_gfs2.h"
 
 /**
  * gfs2_update_stats - Update time based stats
  * @s: The stats to update (local or global)
  * @index: The index inside @s
  * @sample: New data to include
  */
 static inline void gfs2_update_stats(struct gfs2_lkstats *s, unsigned index,
                      s64 sample)
 {
     /*
      * @delta is the difference between the current rtt sample and the
      * running average srtt. We add 1/8 of that to the srtt in order to
      * update the current srtt estimate. The variance estimate is a bit
      * more complicated. We subtract the current variance estimate from
      * the abs value of the @delta and add 1/4 of that to the running
      * total.  That's equivalent to 3/4 of the current variance
      * estimate plus 1/4 of the abs of @delta.
      *
      * Note that the index points at the array entry containing the
      * smoothed mean value, and the variance is always in the following
      * entry
      *
      * Reference: TCP/IP Illustrated, vol 2, p. 831,832
      * All times are in units of integer nanoseconds. Unlike the TCP/IP
      * case, they are not scaled fixed point.
      */
 
     s64 delta = sample - s->stats[index];
     s->stats[index] += (delta >> 3);
     index++;
     s->stats[index] += (s64)(abs(delta) - s->stats[index]) >> 2;
 }
 
 /**
  * gfs2_update_reply_times - Update locking statistics
  * @gl: The glock to update
  *
  * This assumes that gl->gl_dstamp has been set earlier.
  *
  * The rtt (lock round trip time) is an estimate of the time
  * taken to perform a dlm lock request. We update it on each
  * reply from the dlm.
  *
  * The blocking flag is set on the glock for all dlm requests
  * which may potentially block due to lock requests from other nodes.
  * DLM requests where the current lock state is exclusive, the
  * requested state is null (or unlocked) or where the TRY or
  * TRY_1CB flags are set are classified as non-blocking. All
  * other DLM requests are counted as (potentially) blocking.
  */
 static inline void gfs2_update_reply_times(struct gfs2_glock *gl)
 {
     struct gfs2_pcpu_lkstats *lks;
     const unsigned gltype = gl->gl_name.ln_type;
     unsigned index = test_bit(GLF_BLOCKING, &gl->gl_flags) ?
              GFS2_LKS_SRTTB : GFS2_LKS_SRTT;
     s64 rtt;
 
     preempt_disable();
     rtt = ktime_to_ns(ktime_sub(ktime_get_real(), gl->gl_dstamp));
     lks = this_cpu_ptr(gl->gl_name.ln_sbd->sd_lkstats);
     gfs2_update_stats(&gl->gl_stats, index, rtt);       /* Local */
     gfs2_update_stats(&lks->lkstats[gltype], index, rtt);   /* Global */
     preempt_enable();
 
     trace_gfs2_glock_lock_time(gl, rtt);
 }
 
 /**
  * gfs2_update_request_times - Update locking statistics
  * @gl: The glock to update
  *
  * The irt (lock inter-request times) measures the average time
  * between requests to the dlm. It is updated immediately before
  * each dlm call.
  */
 
 static inline void gfs2_update_request_times(struct gfs2_glock *gl)
 {
     struct gfs2_pcpu_lkstats *lks;
     const unsigned gltype = gl->gl_name.ln_type;
     ktime_t dstamp;
     s64 irt;
 
     preempt_disable();
     dstamp = gl->gl_dstamp;
     gl->gl_dstamp = ktime_get_real();
     irt = ktime_to_ns(ktime_sub(gl->gl_dstamp, dstamp));
     lks = this_cpu_ptr(gl->gl_name.ln_sbd->sd_lkstats);
     gfs2_update_stats(&gl->gl_stats, GFS2_LKS_SIRT, irt);       /* Local */
     gfs2_update_stats(&lks->lkstats[gltype], GFS2_LKS_SIRT, irt);   /* Global */
     preempt_enable();
 }
  
 static void gdlm_ast(void *arg)
 {
     struct gfs2_glock *gl = arg;
     unsigned ret = gl->gl_state;
 
     gfs2_update_reply_times(gl);
     BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED);
 
     if ((gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID) && gl->gl_lksb.sb_lvbptr)
         memset(gl->gl_lksb.sb_lvbptr, 0, GDLM_LVB_SIZE);
 
     switch (gl->gl_lksb.sb_status) {
     case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */
         if (gl->gl_ops->go_free)
             gl->gl_ops->go_free(gl);
         gfs2_glock_free(gl);
         return;
     case -DLM_ECANCEL: /* Cancel while getting lock */
         ret |= LM_OUT_CANCELED;
         goto out;
     case -EAGAIN: /* Try lock fails */
     case -EDEADLK: /* Deadlock detected */
         goto out;
     case -ETIMEDOUT: /* Canceled due to timeout */
         ret |= LM_OUT_ERROR;
         goto out;
     case 0: /* Success */
         break;
     default: /* Something unexpected */
         BUG();
     }
 
     ret = gl->gl_req;
     if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) {
         if (gl->gl_req == LM_ST_SHARED)
             ret = LM_ST_DEFERRED;
         else if (gl->gl_req == LM_ST_DEFERRED)
             ret = LM_ST_SHARED;
         else
             BUG();
     }
 
     set_bit(GLF_INITIAL, &gl->gl_flags);
     gfs2_glock_complete(gl, ret);
     return;
 out:
     if (!test_bit(GLF_INITIAL, &gl->gl_flags))
         gl->gl_lksb.sb_lkid = 0;
     gfs2_glock_complete(gl, ret);
 }
 
 static void gdlm_bast(void *arg, int mode)
 {
     struct gfs2_glock *gl = arg;
 
     switch (mode) {
     case DLM_LOCK_EX:
         gfs2_glock_cb(gl, LM_ST_UNLOCKED);
         break;
     case DLM_LOCK_CW:
         gfs2_glock_cb(gl, LM_ST_DEFERRED);
         break;
     case DLM_LOCK_PR:
         gfs2_glock_cb(gl, LM_ST_SHARED);
         break;
     default:
         fs_err(gl->gl_name.ln_sbd, "unknown bast mode %d\n", mode);
         BUG();
     }
 }
 
 /* convert gfs lock-state to dlm lock-mode */
 
 static int make_mode(struct gfs2_sbd *sdp, const unsigned int lmstate)
 {
     switch (lmstate) {
     case LM_ST_UNLOCKED:
         return DLM_LOCK_NL;
     case LM_ST_EXCLUSIVE:
         return DLM_LOCK_EX;
     case LM_ST_DEFERRED:
         return DLM_LOCK_CW;
     case LM_ST_SHARED:
         return DLM_LOCK_PR;
     }
     fs_err(sdp, "unknown LM state %d\n", lmstate);
     BUG();
     return -1;
 }
 
 static u32 make_flags(struct gfs2_glock *gl, const unsigned int gfs_flags,
               const int req)
 {
     u32 lkf = 0;
 
     if (gl->gl_lksb.sb_lvbptr)
         lkf |= DLM_LKF_VALBLK;
 
     if (gfs_flags & LM_FLAG_TRY)
         lkf |= DLM_LKF_NOQUEUE;
 
     if (gfs_flags & LM_FLAG_TRY_1CB) {
         lkf |= DLM_LKF_NOQUEUE;
         lkf |= DLM_LKF_NOQUEUEBAST;
     }
 
     if (gfs_flags & LM_FLAG_PRIORITY) {
         lkf |= DLM_LKF_NOORDER;
         lkf |= DLM_LKF_HEADQUE;
     }
 
     if (gfs_flags & LM_FLAG_ANY) {
         if (req == DLM_LOCK_PR)
             lkf |= DLM_LKF_ALTCW;
         else if (req == DLM_LOCK_CW)
             lkf |= DLM_LKF_ALTPR;
         else
             BUG();
     }
 
     if (gl->gl_lksb.sb_lkid != 0) {
         lkf |= DLM_LKF_CONVERT;
         if (test_bit(GLF_BLOCKING, &gl->gl_flags))
             lkf |= DLM_LKF_QUECVT;
     }
 
     return lkf;
 }
 
 static void gfs2_reverse_hex(char *c, u64 value)
 {
     *c = '0';
     while (value) {
         *c-- = hex_asc[value & 0x0f];
         value >>= 4;
     }
 }
 
 static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state,
              unsigned int flags)
 {
     struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
     int req;
     u32 lkf;
     char strname[GDLM_STRNAME_BYTES] = "";
     int error;
 
     req = make_mode(gl->gl_name.ln_sbd, req_state);
     lkf = make_flags(gl, flags, req);
     gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
     gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
     if (gl->gl_lksb.sb_lkid) {
         gfs2_update_request_times(gl);
     } else {
         memset(strname, ' ', GDLM_STRNAME_BYTES - 1);
         strname[GDLM_STRNAME_BYTES - 1] = '\0';
         gfs2_reverse_hex(strname + 7, gl->gl_name.ln_type);
         gfs2_reverse_hex(strname + 23, gl->gl_name.ln_number);
         gl->gl_dstamp = ktime_get_real();
     }
     /*
      * Submit the actual lock request.
      */
 
 again:
     error = dlm_lock(ls->ls_dlm, req, &gl->gl_lksb, lkf, strname,
             GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast);
     if (error == -EBUSY) {
         msleep(20);
         goto again;
     }
     return error;
 }
 
 static void gdlm_put_lock(struct gfs2_glock *gl)
 {
     struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     int error;
 
     if (gl->gl_lksb.sb_lkid == 0) {
         gfs2_glock_free(gl);
         return;
     }
 
     clear_bit(GLF_BLOCKING, &gl->gl_flags);
     gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
     gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
     gfs2_update_request_times(gl);
 
     /* don't want to call dlm if we've unmounted the lock protocol */
     if (test_bit(DFL_UNMOUNT, &ls->ls_recover_flags)) {
         gfs2_glock_free(gl);
         return;
     }
     /* don't want to skip dlm_unlock writing the lvb when lock has one */
 
     if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) &&
         !gl->gl_lksb.sb_lvbptr) {
         gfs2_glock_free(gl);
         return;
     }
 
 again:
     error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK,
                NULL, gl);
     if (error == -EBUSY) {
         msleep(20);
         goto again;
     }
 
     if (error) {
         fs_err(sdp, "gdlm_unlock %x,%llx err=%d\n",
                gl->gl_name.ln_type,
                (unsigned long long)gl->gl_name.ln_number, error);
         return;
     }
 }
 
 static void gdlm_cancel(struct gfs2_glock *gl)
 {
     struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;
     dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl);
 }
 
 /*
  * dlm/gfs2 recovery coordination using dlm_recover callbacks
  *
  *  0. gfs2 checks for another cluster node withdraw, needing journal replay
  *  1. dlm_controld sees lockspace members change
  *  2. dlm_controld blocks dlm-kernel locking activity
  *  3. dlm_controld within dlm-kernel notifies gfs2 (recover_prep)
  *  4. dlm_controld starts and finishes its own user level recovery
  *  5. dlm_controld starts dlm-kernel dlm_recoverd to do kernel recovery
  *  6. dlm_recoverd notifies gfs2 of failed nodes (recover_slot)
  *  7. dlm_recoverd does its own lock recovery
  *  8. dlm_recoverd unblocks dlm-kernel locking activity
  *  9. dlm_recoverd notifies gfs2 when done (recover_done with new generation)
  * 10. gfs2_control updates control_lock lvb with new generation and jid bits
  * 11. gfs2_control enqueues journals for gfs2_recover to recover (maybe none)
  * 12. gfs2_recover dequeues and recovers journals of failed nodes
  * 13. gfs2_recover provides recovery results to gfs2_control (recovery_result)
  * 14. gfs2_control updates control_lock lvb jid bits for recovered journals
  * 15. gfs2_control unblocks normal locking when all journals are recovered
  *
  * - failures during recovery
  *
  * recover_prep() may set BLOCK_LOCKS (step 3) again before gfs2_control
  * clears BLOCK_LOCKS (step 15), e.g. another node fails while still
  * recovering for a prior failure.  gfs2_control needs a way to detect
  * this so it can leave BLOCK_LOCKS set in step 15.  This is managed using
  * the recover_block and recover_start values.
  *
  * recover_done() provides a new lockspace generation number each time it
  * is called (step 9).  This generation number is saved as recover_start.
  * When recover_prep() is called, it sets BLOCK_LOCKS and sets
  * recover_block = recover_start.  So, while recover_block is equal to
  * recover_start, BLOCK_LOCKS should remain set.  (recover_spin must
  * be held around the BLOCK_LOCKS/recover_block/recover_start logic.)
  *
  * - more specific gfs2 steps in sequence above
  *
  *  3. recover_prep sets BLOCK_LOCKS and sets recover_block = recover_start
  *  6. recover_slot records any failed jids (maybe none)
  *  9. recover_done sets recover_start = new generation number
  * 10. gfs2_control sets control_lock lvb = new gen + bits for failed jids
  * 12. gfs2_recover does journal recoveries for failed jids identified above
  * 14. gfs2_control clears control_lock lvb bits for recovered jids
  * 15. gfs2_control checks if recover_block == recover_start (step 3 occured
  *     again) then do nothing, otherwise if recover_start > recover_block
  *     then clear BLOCK_LOCKS.
  *
  * - parallel recovery steps across all nodes
  *
  * All nodes attempt to update the control_lock lvb with the new generation
  * number and jid bits, but only the first to get the control_lock EX will
  * do so; others will see that it's already done (lvb already contains new
  * generation number.)
  *
  * . All nodes get the same recover_prep/recover_slot/recover_done callbacks
  * . All nodes attempt to set control_lock lvb gen + bits for the new gen
  * . One node gets control_lock first and writes the lvb, others see it's done
  * . All nodes attempt to recover jids for which they see control_lock bits set
  * . One node succeeds for a jid, and that one clears the jid bit in the lvb
  * . All nodes will eventually see all lvb bits clear and unblock locks
  *
  * - is there a problem with clearing an lvb bit that should be set
  *   and missing a journal recovery?
  *
  * 1. jid fails
  * 2. lvb bit set for step 1
  * 3. jid recovered for step 1
  * 4. jid taken again (new mount)
  * 5. jid fails (for step 4)
  * 6. lvb bit set for step 5 (will already be set)
  * 7. lvb bit cleared for step 3
  *
  * This is not a problem because the failure in step 5 does not
  * require recovery, because the mount in step 4 could not have
  * progressed far enough to unblock locks and access the fs.  The
  * control_mount() function waits for all recoveries to be complete
  * for the latest lockspace generation before ever unblocking locks
  * and returning.  The mount in step 4 waits until the recovery in
  * step 1 is done.
  *
  * - special case of first mounter: first node to mount the fs
  *
  * The first node to mount a gfs2 fs needs to check all the journals
  * and recover any that need recovery before other nodes are allowed
  * to mount the fs.  (Others may begin mounting, but they must wait
  * for the first mounter to be done before taking locks on the fs
  * or accessing the fs.)  This has two parts:
  *
  * 1. The mounted_lock tells a node it's the first to mount the fs.
  * Each node holds the mounted_lock in PR while it's mounted.
  * Each node tries to acquire the mounted_lock in EX when it mounts.
  * If a node is granted the mounted_lock EX it means there are no
  * other mounted nodes (no PR locks exist), and it is the first mounter.
  * The mounted_lock is demoted to PR when first recovery is done, so
  * others will fail to get an EX lock, but will get a PR lock.
  *
  * 2. The control_lock blocks others in control_mount() while the first
  * mounter is doing first mount recovery of all journals.
  * A mounting node needs to acquire control_lock in EX mode before
  * it can proceed.  The first mounter holds control_lock in EX while doing
  * the first mount recovery, blocking mounts from other nodes, then demotes
  * control_lock to NL when it's done (others_may_mount/first_done),
  * allowing other nodes to continue mounting.
  *
  * first mounter:
  * control_lock EX/NOQUEUE success
  * mounted_lock EX/NOQUEUE success (no other PR, so no other mounters)
  * set first=1
  * do first mounter recovery
  * mounted_lock EX->PR
  * control_lock EX->NL, write lvb generation
  *
  * other mounter:
  * control_lock EX/NOQUEUE success (if fail -EAGAIN, retry)
  * mounted_lock EX/NOQUEUE fail -EAGAIN (expected due to other mounters PR)
  * mounted_lock PR/NOQUEUE success
  * read lvb generation
  * control_lock EX->NL
  * set first=0
  *
  * - mount during recovery
  *
  * If a node mounts while others are doing recovery (not first mounter),
  * the mounting node will get its initial recover_done() callback without
  * having seen any previous failures/callbacks.
  *
  * It must wait for all recoveries preceding its mount to be finished
  * before it unblocks locks.  It does this by repeating the "other mounter"
  * steps above until the lvb generation number is >= its mount generation
  * number (from initial recover_done) and all lvb bits are clear.
  *
  * - control_lock lvb format
  *
  * 4 bytes generation number: the latest dlm lockspace generation number
  * from recover_done callback.  Indicates the jid bitmap has been updated
  * to reflect all slot failures through that generation.
  * 4 bytes unused.
  * GDLM_LVB_SIZE-8 bytes of jid bit map. If bit N is set, it indicates
  * that jid N needs recovery.
  */
 
 #define JID_BITMAP_OFFSET 8 /* 4 byte generation number + 4 byte unused */
 
 static void control_lvb_read(struct lm_lockstruct *ls, uint32_t *lvb_gen,
                  char *lvb_bits)
 {
     __le32 gen;
     memcpy(lvb_bits, ls->ls_control_lvb, GDLM_LVB_SIZE);
     memcpy(&gen, lvb_bits, sizeof(__le32));
     *lvb_gen = le32_to_cpu(gen);
 }
 
 static void control_lvb_write(struct lm_lockstruct *ls, uint32_t lvb_gen,
                   char *lvb_bits)
 {
     __le32 gen;
     memcpy(ls->ls_control_lvb, lvb_bits, GDLM_LVB_SIZE);
     gen = cpu_to_le32(lvb_gen);
     memcpy(ls->ls_control_lvb, &gen, sizeof(__le32));
 }
 
 static int all_jid_bits_clear(char *lvb)
 {
     return !memchr_inv(lvb + JID_BITMAP_OFFSET, 0,
             GDLM_LVB_SIZE - JID_BITMAP_OFFSET);
 }
 
 static void sync_wait_cb(void *arg)
 {
     struct lm_lockstruct *ls = arg;
     complete(&ls->ls_sync_wait);
 }
 
 static int sync_unlock(struct gfs2_sbd *sdp, struct dlm_lksb *lksb, char *name)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     int error;
 
     error = dlm_unlock(ls->ls_dlm, lksb->sb_lkid, 0, lksb, ls);
     if (error) {
         fs_err(sdp, "%s lkid %x error %d\n",
                name, lksb->sb_lkid, error);
         return error;
     }
 
     wait_for_completion(&ls->ls_sync_wait);
 
     if (lksb->sb_status != -DLM_EUNLOCK) {
         fs_err(sdp, "%s lkid %x status %d\n",
                name, lksb->sb_lkid, lksb->sb_status);
         return -1;
     }
     return 0;
 }
 
 static int sync_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags,
              unsigned int num, struct dlm_lksb *lksb, char *name)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     char strname[GDLM_STRNAME_BYTES];
     int error, status;
 
     memset(strname, 0, GDLM_STRNAME_BYTES);
     snprintf(strname, GDLM_STRNAME_BYTES, "%8x%16x", LM_TYPE_NONDISK, num);
 
     error = dlm_lock(ls->ls_dlm, mode, lksb, flags,
              strname, GDLM_STRNAME_BYTES - 1,
              0, sync_wait_cb, ls, NULL);
     if (error) {
         fs_err(sdp, "%s lkid %x flags %x mode %d error %d\n",
                name, lksb->sb_lkid, flags, mode, error);
         return error;
     }
 
     wait_for_completion(&ls->ls_sync_wait);
 
     status = lksb->sb_status;
 
     if (status && status != -EAGAIN) {
         fs_err(sdp, "%s lkid %x flags %x mode %d status %d\n",
                name, lksb->sb_lkid, flags, mode, status);
     }
 
     return status;
 }
 
 static int mounted_unlock(struct gfs2_sbd *sdp)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     return sync_unlock(sdp, &ls->ls_mounted_lksb, "mounted_lock");
 }
 
 static int mounted_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     return sync_lock(sdp, mode, flags, GFS2_MOUNTED_LOCK,
              &ls->ls_mounted_lksb, "mounted_lock");
 }
 
 static int control_unlock(struct gfs2_sbd *sdp)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     return sync_unlock(sdp, &ls->ls_control_lksb, "control_lock");
 }
 
 static int control_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     return sync_lock(sdp, mode, flags, GFS2_CONTROL_LOCK,
              &ls->ls_control_lksb, "control_lock");
 }
 
 /**
  * remote_withdraw - react to a node withdrawing from the file system
  * @sdp: The superblock
  */
 static void remote_withdraw(struct gfs2_sbd *sdp)
 {
     struct gfs2_jdesc *jd;
     int ret = 0, count = 0;
 
     list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
         if (jd->jd_jid == sdp->sd_lockstruct.ls_jid)
             continue;
         ret = gfs2_recover_journal(jd, true);
         if (ret)
             break;
         count++;
     }
 
     /* Now drop the additional reference we acquired */
     fs_err(sdp, "Journals checked: %d, ret = %d.\n", count, ret);
 }
 
 static void gfs2_control_func(struct work_struct *work)
 {
     struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work);
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     uint32_t block_gen, start_gen, lvb_gen, flags;
     int recover_set = 0;
     int write_lvb = 0;
     int recover_size;
     int i, error;
 
     /* First check for other nodes that may have done a withdraw. */
     if (test_bit(SDF_REMOTE_WITHDRAW, &sdp->sd_flags)) {
         remote_withdraw(sdp);
         clear_bit(SDF_REMOTE_WITHDRAW, &sdp->sd_flags);
         return;
     }
 
     spin_lock(&ls->ls_recover_spin);
     /*
      * No MOUNT_DONE means we're still mounting; control_mount()
      * will set this flag, after which this thread will take over
      * all further clearing of BLOCK_LOCKS.
      *
      * FIRST_MOUNT means this node is doing first mounter recovery,
      * for which recovery control is handled by
      * control_mount()/control_first_done(), not this thread.
      */
     if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
          test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
         spin_unlock(&ls->ls_recover_spin);
         return;
     }
     block_gen = ls->ls_recover_block;
     start_gen = ls->ls_recover_start;
     spin_unlock(&ls->ls_recover_spin);
 
     /*
      * Equal block_gen and start_gen implies we are between
      * recover_prep and recover_done callbacks, which means
      * dlm recovery is in progress and dlm locking is blocked.
      * There's no point trying to do any work until recover_done.
      */
 
     if (block_gen == start_gen)
         return;
 
     /*
      * Propagate recover_submit[] and recover_result[] to lvb:
      * dlm_recoverd adds to recover_submit[] jids needing recovery
      * gfs2_recover adds to recover_result[] journal recovery results
      *
      * set lvb bit for jids in recover_submit[] if the lvb has not
      * yet been updated for the generation of the failure
      *
      * clear lvb bit for jids in recover_result[] if the result of
      * the journal recovery is SUCCESS
      */
 
     error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
     if (error) {
         fs_err(sdp, "control lock EX error %d\n", error);
         return;
     }
 
     control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
 
     spin_lock(&ls->ls_recover_spin);
     if (block_gen != ls->ls_recover_block ||
         start_gen != ls->ls_recover_start) {
         fs_info(sdp, "recover generation %u block1 %u %u\n",
             start_gen, block_gen, ls->ls_recover_block);
         spin_unlock(&ls->ls_recover_spin);
         control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
         return;
     }
 
     recover_size = ls->ls_recover_size;
 
     if (lvb_gen <= start_gen) {
         /*
          * Clear lvb bits for jids we've successfully recovered.
          * Because all nodes attempt to recover failed journals,
          * a journal can be recovered multiple times successfully
          * in succession.  Only the first will really do recovery,
          * the others find it clean, but still report a successful
          * recovery.  So, another node may have already recovered
          * the jid and cleared the lvb bit for it.
          */
         for (i = 0; i < recover_size; i++) {
             if (ls->ls_recover_result[i] != LM_RD_SUCCESS)
                 continue;
 
             ls->ls_recover_result[i] = 0;
 
             if (!test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET))
                 continue;
 
             __clear_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
             write_lvb = 1;
         }
     }
 
     if (lvb_gen == start_gen) {
         /*
          * Failed slots before start_gen are already set in lvb.
          */
         for (i = 0; i < recover_size; i++) {
             if (!ls->ls_recover_submit[i])
                 continue;
             if (ls->ls_recover_submit[i] < lvb_gen)
                 ls->ls_recover_submit[i] = 0;
         }
     } else if (lvb_gen < start_gen) {
         /*
          * Failed slots before start_gen are not yet set in lvb.
          */
         for (i = 0; i < recover_size; i++) {
             if (!ls->ls_recover_submit[i])
                 continue;
             if (ls->ls_recover_submit[i] < start_gen) {
                 ls->ls_recover_submit[i] = 0;
                 __set_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
             }
         }
         /* even if there are no bits to set, we need to write the
            latest generation to the lvb */
         write_lvb = 1;
     } else {
         /*
          * we should be getting a recover_done() for lvb_gen soon
          */
     }
     spin_unlock(&ls->ls_recover_spin);
 
     if (write_lvb) {
         control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
         flags = DLM_LKF_CONVERT | DLM_LKF_VALBLK;
     } else {
         flags = DLM_LKF_CONVERT;
     }
 
     error = control_lock(sdp, DLM_LOCK_NL, flags);
     if (error) {
         fs_err(sdp, "control lock NL error %d\n", error);
         return;
     }
 
     /*
      * Everyone will see jid bits set in the lvb, run gfs2_recover_set(),
      * and clear a jid bit in the lvb if the recovery is a success.
      * Eventually all journals will be recovered, all jid bits will
      * be cleared in the lvb, and everyone will clear BLOCK_LOCKS.
      */
 
     for (i = 0; i < recover_size; i++) {
         if (test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET)) {
             fs_info(sdp, "recover generation %u jid %d\n",
                 start_gen, i);
             gfs2_recover_set(sdp, i);
             recover_set++;
         }
     }
     if (recover_set)
         return;
 
     /*
      * No more jid bits set in lvb, all recovery is done, unblock locks
      * (unless a new recover_prep callback has occured blocking locks
      * again while working above)
      */
 
     spin_lock(&ls->ls_recover_spin);
     if (ls->ls_recover_block == block_gen &&
         ls->ls_recover_start == start_gen) {
         clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
         spin_unlock(&ls->ls_recover_spin);
         fs_info(sdp, "recover generation %u done\n", start_gen);
         gfs2_glock_thaw(sdp);
     } else {
         fs_info(sdp, "recover generation %u block2 %u %u\n",
             start_gen, block_gen, ls->ls_recover_block);
         spin_unlock(&ls->ls_recover_spin);
     }
 }
 
 static int control_mount(struct gfs2_sbd *sdp)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     uint32_t start_gen, block_gen, mount_gen, lvb_gen;
     int mounted_mode;
     int retries = 0;
     int error;
 
     memset(&ls->ls_mounted_lksb, 0, sizeof(struct dlm_lksb));
     memset(&ls->ls_control_lksb, 0, sizeof(struct dlm_lksb));
     memset(&ls->ls_control_lvb, 0, GDLM_LVB_SIZE);
     ls->ls_control_lksb.sb_lvbptr = ls->ls_control_lvb;
     init_completion(&ls->ls_sync_wait);
 
     set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
 
     error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_VALBLK);
     if (error) {
         fs_err(sdp, "control_mount control_lock NL error %d\n", error);
         return error;
     }
 
     error = mounted_lock(sdp, DLM_LOCK_NL, 0);
     if (error) {
         fs_err(sdp, "control_mount mounted_lock NL error %d\n", error);
         control_unlock(sdp);
         return error;
     }
     mounted_mode = DLM_LOCK_NL;
 
 restart:
     if (retries++ && signal_pending(current)) {
         error = -EINTR;
         goto fail;
     }
 
     /*
      * We always start with both locks in NL. control_lock is
      * demoted to NL below so we don't need to do it here.
      */
 
     if (mounted_mode != DLM_LOCK_NL) {
         error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
         if (error)
             goto fail;
         mounted_mode = DLM_LOCK_NL;
     }
 
     /*
      * Other nodes need to do some work in dlm recovery and gfs2_control
      * before the recover_done and control_lock will be ready for us below.
      * A delay here is not required but often avoids having to retry.
      */
 
     msleep_interruptible(500);
 
     /*
      * Acquire control_lock in EX and mounted_lock in either EX or PR.
      * control_lock lvb keeps track of any pending journal recoveries.
      * mounted_lock indicates if any other nodes have the fs mounted.
      */
 
     error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE|DLM_LKF_VALBLK);
     if (error == -EAGAIN) {
         goto restart;
     } else if (error) {
         fs_err(sdp, "control_mount control_lock EX error %d\n", error);
         goto fail;
     }
 
     /**
      * If we're a spectator, we don't want to take the lock in EX because
      * we cannot do the first-mount responsibility it implies: recovery.
      */
     if (sdp->sd_args.ar_spectator)
         goto locks_done;
 
     error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
     if (!error) {
         mounted_mode = DLM_LOCK_EX;
         goto locks_done;
     } else if (error != -EAGAIN) {
         fs_err(sdp, "control_mount mounted_lock EX error %d\n", error);
         goto fail;
     }
 
     error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
     if (!error) {
         mounted_mode = DLM_LOCK_PR;
         goto locks_done;
     } else {
         /* not even -EAGAIN should happen here */
         fs_err(sdp, "control_mount mounted_lock PR error %d\n", error);
         goto fail;
     }
 
 locks_done:
     /*
      * If we got both locks above in EX, then we're the first mounter.
      * If not, then we need to wait for the control_lock lvb to be
      * updated by other mounted nodes to reflect our mount generation.
      *
      * In simple first mounter cases, first mounter will see zero lvb_gen,
      * but in cases where all existing nodes leave/fail before mounting
      * nodes finish control_mount, then all nodes will be mounting and
      * lvb_gen will be non-zero.
      */
 
     control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);
 
     if (lvb_gen == 0xFFFFFFFF) {
         /* special value to force mount attempts to fail */
         fs_err(sdp, "control_mount control_lock disabled\n");
         error = -EINVAL;
         goto fail;
     }
 
     if (mounted_mode == DLM_LOCK_EX) {
         /* first mounter, keep both EX while doing first recovery */
         spin_lock(&ls->ls_recover_spin);
         clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
         set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
         set_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
         spin_unlock(&ls->ls_recover_spin);
         fs_info(sdp, "first mounter control generation %u\n", lvb_gen);
         return 0;
     }
 
     error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
     if (error)
         goto fail;
 
     /*
      * We are not first mounter, now we need to wait for the control_lock
      * lvb generation to be >= the generation from our first recover_done
      * and all lvb bits to be clear (no pending journal recoveries.)
      */
 
     if (!all_jid_bits_clear(ls->ls_lvb_bits)) {
         /* journals need recovery, wait until all are clear */
         fs_info(sdp, "control_mount wait for journal recovery\n");
         goto restart;
     }
 
     spin_lock(&ls->ls_recover_spin);
     block_gen = ls->ls_recover_block;
     start_gen = ls->ls_recover_start;
     mount_gen = ls->ls_recover_mount;
 
     if (lvb_gen < mount_gen) {
         /* wait for mounted nodes to update control_lock lvb to our
            generation, which might include new recovery bits set */
         if (sdp->sd_args.ar_spectator) {
             fs_info(sdp, "Recovery is required. Waiting for a "
                 "non-spectator to mount.\n");
             msleep_interruptible(1000);
         } else {
             fs_info(sdp, "control_mount wait1 block %u start %u "
                 "mount %u lvb %u flags %lx\n", block_gen,
                 start_gen, mount_gen, lvb_gen,
                 ls->ls_recover_flags);
         }
         spin_unlock(&ls->ls_recover_spin);
         goto restart;
     }
 
     if (lvb_gen != start_gen) {
         /* wait for mounted nodes to update control_lock lvb to the
            latest recovery generation */
         fs_info(sdp, "control_mount wait2 block %u start %u mount %u "
             "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
             lvb_gen, ls->ls_recover_flags);
         spin_unlock(&ls->ls_recover_spin);
         goto restart;
     }
 
     if (block_gen == start_gen) {
         /* dlm recovery in progress, wait for it to finish */
         fs_info(sdp, "control_mount wait3 block %u start %u mount %u "
             "lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
             lvb_gen, ls->ls_recover_flags);
         spin_unlock(&ls->ls_recover_spin);
         goto restart;
     }
 
     clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
     set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
     memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
     memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
     spin_unlock(&ls->ls_recover_spin);
     return 0;
 
 fail:
     mounted_unlock(sdp);
     control_unlock(sdp);
     return error;
 }
 
 static int control_first_done(struct gfs2_sbd *sdp)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     uint32_t start_gen, block_gen;
     int error;
 
 restart:
     spin_lock(&ls->ls_recover_spin);
     start_gen = ls->ls_recover_start;
     block_gen = ls->ls_recover_block;
 
     if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags) ||
         !test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
         !test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
         /* sanity check, should not happen */
         fs_err(sdp, "control_first_done start %u block %u flags %lx\n",
                start_gen, block_gen, ls->ls_recover_flags);
         spin_unlock(&ls->ls_recover_spin);
         control_unlock(sdp);
         return -1;
     }
 
     if (start_gen == block_gen) {
         /*
          * Wait for the end of a dlm recovery cycle to switch from
          * first mounter recovery.  We can ignore any recover_slot
          * callbacks between the recover_prep and next recover_done
          * because we are still the first mounter and any failed nodes
          * have not fully mounted, so they don't need recovery.
          */
         spin_unlock(&ls->ls_recover_spin);
         fs_info(sdp, "control_first_done wait gen %u\n", start_gen);
 
         wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY,
                 TASK_UNINTERRUPTIBLE);
         goto restart;
     }
 
     clear_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
     set_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags);
     memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
     memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
     spin_unlock(&ls->ls_recover_spin);
 
     memset(ls->ls_lvb_bits, 0, GDLM_LVB_SIZE);
     control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
 
     error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT);
     if (error)
         fs_err(sdp, "control_first_done mounted PR error %d\n", error);
 
     error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
     if (error)
         fs_err(sdp, "control_first_done control NL error %d\n", error);
 
     return error;
 }
 
 /*
  * Expand static jid arrays if necessary (by increments of RECOVER_SIZE_INC)
  * to accommodate the largest slot number.  (NB dlm slot numbers start at 1,
  * gfs2 jids start at 0, so jid = slot - 1)
  */
 
 #define RECOVER_SIZE_INC 16
 
 static int set_recover_size(struct gfs2_sbd *sdp, struct dlm_slot *slots,
                 int num_slots)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     uint32_t *submit = NULL;
     uint32_t *result = NULL;
     uint32_t old_size, new_size;
     int i, max_jid;
 
     if (!ls->ls_lvb_bits) {
         ls->ls_lvb_bits = kzalloc(GDLM_LVB_SIZE, GFP_NOFS);
         if (!ls->ls_lvb_bits)
             return -ENOMEM;
     }
 
     max_jid = 0;
     for (i = 0; i < num_slots; i++) {
         if (max_jid < slots[i].slot - 1)
             max_jid = slots[i].slot - 1;
     }
 
     old_size = ls->ls_recover_size;
     new_size = old_size;
     while (new_size < max_jid + 1)
         new_size += RECOVER_SIZE_INC;
     if (new_size == old_size)
         return 0;
 
     submit = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS);
     result = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS);
     if (!submit || !result) {
         kfree(submit);
         kfree(result);
         return -ENOMEM;
     }
 
     spin_lock(&ls->ls_recover_spin);
     memcpy(submit, ls->ls_recover_submit, old_size * sizeof(uint32_t));
     memcpy(result, ls->ls_recover_result, old_size * sizeof(uint32_t));
     kfree(ls->ls_recover_submit);
     kfree(ls->ls_recover_result);
     ls->ls_recover_submit = submit;
     ls->ls_recover_result = result;
     ls->ls_recover_size = new_size;
     spin_unlock(&ls->ls_recover_spin);
     return 0;
 }
 
 static void free_recover_size(struct lm_lockstruct *ls)
 {
     kfree(ls->ls_lvb_bits);
     kfree(ls->ls_recover_submit);
     kfree(ls->ls_recover_result);
     ls->ls_recover_submit = NULL;
     ls->ls_recover_result = NULL;
     ls->ls_recover_size = 0;
     ls->ls_lvb_bits = NULL;
 }
 
 /* dlm calls before it does lock recovery */
 
 static void gdlm_recover_prep(void *arg)
 {
     struct gfs2_sbd *sdp = arg;
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 
     if (gfs2_withdrawn(sdp)) {
         fs_err(sdp, "recover_prep ignored due to withdraw.\n");
         return;
     }
     spin_lock(&ls->ls_recover_spin);
     ls->ls_recover_block = ls->ls_recover_start;
     set_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
 
     if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
          test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
         spin_unlock(&ls->ls_recover_spin);
         return;
     }
     set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
     spin_unlock(&ls->ls_recover_spin);
 }
 
 /* dlm calls after recover_prep has been completed on all lockspace members;
    identifies slot/jid of failed member */
 
 static void gdlm_recover_slot(void *arg, struct dlm_slot *slot)
 {
     struct gfs2_sbd *sdp = arg;
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     int jid = slot->slot - 1;
 
     if (gfs2_withdrawn(sdp)) {
         fs_err(sdp, "recover_slot jid %d ignored due to withdraw.\n",
                jid);
         return;
     }
     spin_lock(&ls->ls_recover_spin);
     if (ls->ls_recover_size < jid + 1) {
         fs_err(sdp, "recover_slot jid %d gen %u short size %d\n",
                jid, ls->ls_recover_block, ls->ls_recover_size);
         spin_unlock(&ls->ls_recover_spin);
         return;
     }
 
     if (ls->ls_recover_submit[jid]) {
         fs_info(sdp, "recover_slot jid %d gen %u prev %u\n",
             jid, ls->ls_recover_block, ls->ls_recover_submit[jid]);
     }
     ls->ls_recover_submit[jid] = ls->ls_recover_block;
     spin_unlock(&ls->ls_recover_spin);
 }
 
 /* dlm calls after recover_slot and after it completes lock recovery */
 
 static void gdlm_recover_done(void *arg, struct dlm_slot *slots, int num_slots,
                   int our_slot, uint32_t generation)
 {
     struct gfs2_sbd *sdp = arg;
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 
     if (gfs2_withdrawn(sdp)) {
         fs_err(sdp, "recover_done ignored due to withdraw.\n");
         return;
     }
     /* ensure the ls jid arrays are large enough */
     set_recover_size(sdp, slots, num_slots);
 
     spin_lock(&ls->ls_recover_spin);
     ls->ls_recover_start = generation;
 
     if (!ls->ls_recover_mount) {
         ls->ls_recover_mount = generation;
         ls->ls_jid = our_slot - 1;
     }
 
     if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
         queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work, 0);
 
     clear_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags);
     smp_mb__after_atomic();
     wake_up_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY);
     spin_unlock(&ls->ls_recover_spin);
 }
 
 /* gfs2_recover thread has a journal recovery result */
 
 static void gdlm_recovery_result(struct gfs2_sbd *sdp, unsigned int jid,
                  unsigned int result)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 
     if (gfs2_withdrawn(sdp)) {
         fs_err(sdp, "recovery_result jid %d ignored due to withdraw.\n",
                jid);
         return;
     }
     if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
         return;
 
     /* don't care about the recovery of own journal during mount */
     if (jid == ls->ls_jid)
         return;
 
     spin_lock(&ls->ls_recover_spin);
     if (test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
         spin_unlock(&ls->ls_recover_spin);
         return;
     }
     if (ls->ls_recover_size < jid + 1) {
         fs_err(sdp, "recovery_result jid %d short size %d\n",
                jid, ls->ls_recover_size);
         spin_unlock(&ls->ls_recover_spin);
         return;
     }
 
     fs_info(sdp, "recover jid %d result %s\n", jid,
         result == LM_RD_GAVEUP ? "busy" : "success");
 
     ls->ls_recover_result[jid] = result;
 
     /* GAVEUP means another node is recovering the journal; delay our
        next attempt to recover it, to give the other node a chance to
        finish before trying again */
 
     if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags))
         queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work,
                    result == LM_RD_GAVEUP ? HZ : 0);
     spin_unlock(&ls->ls_recover_spin);
 }
 
 static const struct dlm_lockspace_ops gdlm_lockspace_ops = {
     .recover_prep = gdlm_recover_prep,
     .recover_slot = gdlm_recover_slot,
     .recover_done = gdlm_recover_done,
 };
 
 static int gdlm_mount(struct gfs2_sbd *sdp, const char *table)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     char cluster[GFS2_LOCKNAME_LEN];
     const char *fsname;
     uint32_t flags;
     int error, ops_result;
 
     /*
      * initialize everything
      */
 
     INIT_DELAYED_WORK(&sdp->sd_control_work, gfs2_control_func);
     spin_lock_init(&ls->ls_recover_spin);
     ls->ls_recover_flags = 0;
     ls->ls_recover_mount = 0;
     ls->ls_recover_start = 0;
     ls->ls_recover_block = 0;
     ls->ls_recover_size = 0;
     ls->ls_recover_submit = NULL;
     ls->ls_recover_result = NULL;
     ls->ls_lvb_bits = NULL;
 
     error = set_recover_size(sdp, NULL, 0);
     if (error)
         goto fail;
 
     /*
      * prepare dlm_new_lockspace args
      */
 
     fsname = strchr(table, ':');
     if (!fsname) {
         fs_info(sdp, "no fsname found\n");
         error = -EINVAL;
         goto fail_free;
     }
     memset(cluster, 0, sizeof(cluster));
     memcpy(cluster, table, strlen(table) - strlen(fsname));
     fsname++;
 
     flags = DLM_LSFL_FS | DLM_LSFL_NEWEXCL;
 
     /*
      * create/join lockspace
      */
 
     error = dlm_new_lockspace(fsname, cluster, flags, GDLM_LVB_SIZE,
                   &gdlm_lockspace_ops, sdp, &ops_result,
                   &ls->ls_dlm);
     if (error) {
         fs_err(sdp, "dlm_new_lockspace error %d\n", error);
         goto fail_free;
     }
 
     if (ops_result < 0) {
         /*
          * dlm does not support ops callbacks,
          * old dlm_controld/gfs_controld are used, try without ops.
          */
         fs_info(sdp, "dlm lockspace ops not used\n");
         free_recover_size(ls);
         set_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags);
         return 0;
     }
 
     if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags)) {
         fs_err(sdp, "dlm lockspace ops disallow jid preset\n");
         error = -EINVAL;
         goto fail_release;
     }
 
     /*
      * control_mount() uses control_lock to determine first mounter,
      * and for later mounts, waits for any recoveries to be cleared.
      */
 
     error = control_mount(sdp);
     if (error) {
         fs_err(sdp, "mount control error %d\n", error);
         goto fail_release;
     }
 
     ls->ls_first = !!test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
     clear_bit(SDF_NOJOURNALID, &sdp->sd_flags);
     smp_mb__after_atomic();
     wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID);
     return 0;
 
 fail_release:
     dlm_release_lockspace(ls->ls_dlm, 2);
 fail_free:
     free_recover_size(ls);
 fail:
     return error;
 }
 
 static void gdlm_first_done(struct gfs2_sbd *sdp)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
     int error;
 
     if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
         return;
 
     error = control_first_done(sdp);
     if (error)
         fs_err(sdp, "mount first_done error %d\n", error);
 }
 
 static void gdlm_unmount(struct gfs2_sbd *sdp)
 {
     struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 
     if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags))
         goto release;
 
     /* wait for gfs2_control_wq to be done with this mount */
 
     spin_lock(&ls->ls_recover_spin);
     set_bit(DFL_UNMOUNT, &ls->ls_recover_flags);
     spin_unlock(&ls->ls_recover_spin);
     flush_delayed_work(&sdp->sd_control_work);
 
     /* mounted_lock and control_lock will be purged in dlm recovery */
 release:
     if (ls->ls_dlm) {
         dlm_release_lockspace(ls->ls_dlm, 2);
         ls->ls_dlm = NULL;
     }
 
     free_recover_size(ls);
 }
 
 static const match_table_t dlm_tokens = {
     { Opt_jid, "jid=%d"},
     { Opt_id, "id=%d"},
     { Opt_first, "first=%d"},
     { Opt_nodir, "nodir=%d"},
     { Opt_err, NULL },
 };
 
 const struct lm_lockops gfs2_dlm_ops = {
     .lm_proto_name = "lock_dlm",
     .lm_mount = gdlm_mount,
     .lm_first_done = gdlm_first_done,
     .lm_recovery_result = gdlm_recovery_result,
     .lm_unmount = gdlm_unmount,
     .lm_put_lock = gdlm_put_lock,
     .lm_lock = gdlm_lock,
     .lm_cancel = gdlm_cancel,
     .lm_tokens = &dlm_tokens,
 };
 

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