dlm: use workqueue for callbacks

Instead of creating our own kthread (dlm_astd) to deliver
callbacks for all lockspaces, use a per-lockspace workqueue
to deliver the callbacks.  This eliminates complications and
slowdowns from many lockspaces sharing the same thread.

Signed-off-by: David Teigland <teigland@redhat.com>

7 files changed, 172 insertions, 205 deletions

diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index abc49f292454..4f29add0e7d1 100644
--- a/fs/dlm/ast.c
+++ b/fs/dlm/ast.c
@@ -14,17 +14,9 @@
 #include "dlm_internal.h"
 #include "lock.h"
 #include "user.h"
-#include "ast.h"
-
-#define WAKE_ASTS  0
-
-static uint64_t                 ast_seq_count;
-static struct list_head         ast_queue;
-static spinlock_t               ast_queue_lock;
-static struct task_struct *     astd_task;
-static unsigned long            astd_wakeflags;
-static struct mutex             astd_running;
 
+static uint64_t                 dlm_cb_seq;
+static spinlock_t               dlm_cb_seq_spin;
 
 static void dlm_dump_lkb_callbacks(struct dlm_lkb *lkb)
 {
@@ -57,21 +49,13 @@ static void dlm_dump_lkb_callbacks(struct dlm_lkb *lkb)
         }
 }
 
-void dlm_del_ast(struct dlm_lkb *lkb)
-{
-        spin_lock(&ast_queue_lock);
-        if (!list_empty(&lkb->lkb_astqueue))
-                list_del_init(&lkb->lkb_astqueue);
-        spin_unlock(&ast_queue_lock);
-}
-
 int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
                          int status, uint32_t sbflags, uint64_t seq)
 {
         struct dlm_ls *ls = lkb->lkb_resource->res_ls;
         uint64_t prev_seq;
         int prev_mode;
-        int i;
+        int i, rv;
 
         for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
                 if (lkb->lkb_callbacks[i].seq)
@@ -100,7 +84,8 @@ int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
                                           mode,
                                           (unsigned long long)prev_seq,
                                           prev_mode);
-                                return 0;
+                                rv = 0;
+                                goto out;
                         }
                 }
 
@@ -109,6 +94,7 @@ int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
                 lkb->lkb_callbacks[i].mode = mode;
                 lkb->lkb_callbacks[i].sb_status = status;
                 lkb->lkb_callbacks[i].sb_flags = (sbflags & 0x000000FF);
+                rv = 0;
                 break;
         }
 
@@ -117,21 +103,24 @@ int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
                           lkb->lkb_id, (unsigned long long)seq,
                           flags, mode, status, sbflags);
                 dlm_dump_lkb_callbacks(lkb);
-                return -1;
+                rv = -1;
+                goto out;
         }
-
-        return 0;
+ out:
+        return rv;
 }
 
 int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb,
                          struct dlm_callback *cb, int *resid)
 {
-        int i;
+        int i, rv;
 
         *resid = 0;
 
-        if (!lkb->lkb_callbacks[0].seq)
-                return -ENOENT;
+        if (!lkb->lkb_callbacks[0].seq) {
+                rv = -ENOENT;
+                goto out;
+        }
 
         /* oldest undelivered cb is callbacks[0] */
 
@@ -163,7 +152,8 @@ int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb,
                                   cb->mode,
                                   (unsigned long long)lkb->lkb_last_cast.seq,
                                   lkb->lkb_last_cast.mode);
-                        return 0;
+                        rv = 0;
+                        goto out;
                 }
         }
 
@@ -176,171 +166,147 @@ int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb,
                 memcpy(&lkb->lkb_last_bast, cb, sizeof(struct dlm_callback));
                 lkb->lkb_last_bast_time = ktime_get();
         }
-
-        return 0;
+        rv = 0;
+ out:
+        return rv;
 }
 
-void dlm_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
-                 uint32_t sbflags)
+void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
+                uint32_t sbflags)
 {
-        uint64_t seq;
+        struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+        uint64_t new_seq, prev_seq;
         int rv;
 
-        spin_lock(&ast_queue_lock);
-
-        seq = ++ast_seq_count;
+        spin_lock(&dlm_cb_seq_spin);
+        new_seq = ++dlm_cb_seq;
+        spin_unlock(&dlm_cb_seq_spin);
 
         if (lkb->lkb_flags & DLM_IFL_USER) {
-                spin_unlock(&ast_queue_lock);
-                dlm_user_add_ast(lkb, flags, mode, status, sbflags, seq);
+                dlm_user_add_ast(lkb, flags, mode, status, sbflags, new_seq);
                 return;
         }
 
-        rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, seq);
-        if (rv < 0) {
-                spin_unlock(&ast_queue_lock);
-                return;
-        }
+        mutex_lock(&lkb->lkb_cb_mutex);
+        prev_seq = lkb->lkb_callbacks[0].seq;
 
-        if (list_empty(&lkb->lkb_astqueue)) {
+        rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, new_seq);
+        if (rv < 0)
+                goto out;
+
+        if (!prev_seq) {
                 kref_get(&lkb->lkb_ref);
-                list_add_tail(&lkb->lkb_astqueue, &ast_queue);
-        }
-        spin_unlock(&ast_queue_lock);
 
-        set_bit(WAKE_ASTS, &astd_wakeflags);
-        wake_up_process(astd_task);
+                if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) {
+                        mutex_lock(&ls->ls_cb_mutex);
+                        list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay);
+                        mutex_unlock(&ls->ls_cb_mutex);
+                } else {
+                        queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
+                }
+        }
+ out:
+        mutex_unlock(&lkb->lkb_cb_mutex);
 }
 
-static void process_asts(void)
+void dlm_callback_work(struct work_struct *work)
 {
-        struct dlm_ls *ls = NULL;
-        struct dlm_rsb *r = NULL;
-        struct dlm_lkb *lkb;
+        struct dlm_lkb *lkb = container_of(work, struct dlm_lkb, lkb_cb_work);
+        struct dlm_ls *ls = lkb->lkb_resource->res_ls;
         void (*castfn) (void *astparam);
         void (*bastfn) (void *astparam, int mode);
         struct dlm_callback callbacks[DLM_CALLBACKS_SIZE];
         int i, rv, resid;
 
-repeat:
-        spin_lock(&ast_queue_lock);
-        list_for_each_entry(lkb, &ast_queue, lkb_astqueue) {
-                r = lkb->lkb_resource;
-                ls = r->res_ls;
+        memset(&callbacks, 0, sizeof(callbacks));
 
-                if (dlm_locking_stopped(ls))
-                        continue;
-
-                /* we remove from astqueue list and remove everything in
-                   lkb_callbacks before releasing the spinlock so empty
-                   lkb_astqueue is always consistent with empty lkb_callbacks */
-
-                list_del_init(&lkb->lkb_astqueue);
-
-                castfn = lkb->lkb_astfn;
-                bastfn = lkb->lkb_bastfn;
+        mutex_lock(&lkb->lkb_cb_mutex);
+        if (!lkb->lkb_callbacks[0].seq) {
+                /* no callback work exists, shouldn't happen */
+                log_error(ls, "dlm_callback_work %x no work", lkb->lkb_id);
+                dlm_print_lkb(lkb);
+                dlm_dump_lkb_callbacks(lkb);
+        }
 
-                memset(&callbacks, 0, sizeof(callbacks));
+        for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
+                rv = dlm_rem_lkb_callback(ls, lkb, &callbacks[i], &resid);
+                if (rv < 0)
+                        break;
+        }
 
-                for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
-                        rv = dlm_rem_lkb_callback(ls, lkb, &callbacks[i], &resid);
-                        if (rv < 0)
-                                break;
-                }
-                spin_unlock(&ast_queue_lock);
+        if (resid) {
+                /* cbs remain, loop should have removed all, shouldn't happen */
+                log_error(ls, "dlm_callback_work %x resid %d", lkb->lkb_id,
+                          resid);
+                dlm_print_lkb(lkb);
+                dlm_dump_lkb_callbacks(lkb);
+        }
+        mutex_unlock(&lkb->lkb_cb_mutex);
 
-                if (resid) {
-                        /* shouldn't happen, for loop should have removed all */
-                        log_error(ls, "callback resid %d lkb %x",
-                                  resid, lkb->lkb_id);
-                }
+        castfn = lkb->lkb_astfn;
+        bastfn = lkb->lkb_bastfn;
 
-                for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
-                        if (!callbacks[i].seq)
-                                break;
-                        if (callbacks[i].flags & DLM_CB_SKIP) {
-                                continue;
-                        } else if (callbacks[i].flags & DLM_CB_BAST) {
-                                bastfn(lkb->lkb_astparam, callbacks[i].mode);
-                        } else if (callbacks[i].flags & DLM_CB_CAST) {
-                                lkb->lkb_lksb->sb_status = callbacks[i].sb_status;
-                                lkb->lkb_lksb->sb_flags = callbacks[i].sb_flags;
-                                castfn(lkb->lkb_astparam);
-                        }
+        for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
+                if (!callbacks[i].seq)
+                        break;
+                if (callbacks[i].flags & DLM_CB_SKIP) {
+                        continue;
+                } else if (callbacks[i].flags & DLM_CB_BAST) {
+                        bastfn(lkb->lkb_astparam, callbacks[i].mode);
+                } else if (callbacks[i].flags & DLM_CB_CAST) {
+                        lkb->lkb_lksb->sb_status = callbacks[i].sb_status;
+                        lkb->lkb_lksb->sb_flags = callbacks[i].sb_flags;
+                        castfn(lkb->lkb_astparam);
                 }
-
-                /* removes ref for ast_queue, may cause lkb to be freed */
-                dlm_put_lkb(lkb);
-
-                cond_resched();
-                goto repeat;
         }
-        spin_unlock(&ast_queue_lock);
-}
-
-static inline int no_asts(void)
-{
-        int ret;
 
-        spin_lock(&ast_queue_lock);
-        ret = list_empty(&ast_queue);
-        spin_unlock(&ast_queue_lock);
-        return ret;
+        /* undo kref_get from dlm_add_callback, may cause lkb to be freed */
+        dlm_put_lkb(lkb);
 }
 
-static int dlm_astd(void *data)
+int dlm_callback_start(struct dlm_ls *ls)
 {
-        while (!kthread_should_stop()) {
-                set_current_state(TASK_INTERRUPTIBLE);
-                if (!test_bit(WAKE_ASTS, &astd_wakeflags))
-                        schedule();
-                set_current_state(TASK_RUNNING);
-
-                mutex_lock(&astd_running);
-                if (test_and_clear_bit(WAKE_ASTS, &astd_wakeflags))
-                        process_asts();
-                mutex_unlock(&astd_running);
+        ls->ls_callback_wq = alloc_workqueue("dlm_callback",
+                                             WQ_UNBOUND | WQ_MEM_RECLAIM, 1);
+        if (!ls->ls_callback_wq) {
+                log_print("can't start dlm_callback workqueue");
+                return -ENOMEM;
         }
         return 0;
 }
 
-void dlm_astd_wake(void)
+void dlm_callback_stop(struct dlm_ls *ls)
 {
-        if (!no_asts()) {
-                set_bit(WAKE_ASTS, &astd_wakeflags);
-                wake_up_process(astd_task);
-        }
+        if (ls->ls_callback_wq)
+                destroy_workqueue(ls->ls_callback_wq);
 }
 
-int dlm_astd_start(void)
+void dlm_callback_suspend(struct dlm_ls *ls)
 {
-        struct task_struct *p;
-        int error = 0;
-
-        INIT_LIST_HEAD(&ast_queue);
-        spin_lock_init(&ast_queue_lock);
-        mutex_init(&astd_running);
-
-        p = kthread_run(dlm_astd, NULL, "dlm_astd");
-        if (IS_ERR(p))
-                error = PTR_ERR(p);
-        else
-                astd_task = p;
-        return error;
-}
+        set_bit(LSFL_CB_DELAY, &ls->ls_flags);
 
-void dlm_astd_stop(void)
-{
-        kthread_stop(astd_task);
+        if (ls->ls_callback_wq)
+                flush_workqueue(ls->ls_callback_wq);
 }
 
-void dlm_astd_suspend(void)
+void dlm_callback_resume(struct dlm_ls *ls)
 {
-        mutex_lock(&astd_running);
-}
+        struct dlm_lkb *lkb, *safe;
+        int count = 0;
 
-void dlm_astd_resume(void)
-{
-        mutex_unlock(&astd_running);
+        clear_bit(LSFL_CB_DELAY, &ls->ls_flags);
+
+        if (!ls->ls_callback_wq)
+                return;
+
+        mutex_lock(&ls->ls_cb_mutex);
+        list_for_each_entry_safe(lkb, safe, &ls->ls_cb_delay, lkb_cb_list) {
+                list_del_init(&lkb->lkb_cb_list);
+                queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
+                count++;
+        }
+        mutex_unlock(&ls->ls_cb_mutex);
+
+        log_debug(ls, "dlm_callback_resume %d", count);
 }
 
diff --git a/fs/dlm/ast.h b/fs/dlm/ast.h
index 8aa89c9b5611..757b551c6820 100644
--- a/fs/dlm/ast.h
+++ b/fs/dlm/ast.h
@@ -18,14 +18,15 @@ int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
                          int status, uint32_t sbflags, uint64_t seq);
 int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb,
                          struct dlm_callback *cb, int *resid);
-void dlm_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
-                 uint32_t sbflags);
+void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
+                uint32_t sbflags);
 
-void dlm_astd_wake(void);
-int dlm_astd_start(void);
-void dlm_astd_stop(void);
-void dlm_astd_suspend(void);
-void dlm_astd_resume(void);
+void dlm_callback_work(struct work_struct *work);
+int dlm_callback_start(struct dlm_ls *ls);
+void dlm_callback_stop(struct dlm_ls *ls);
+void dlm_callback_suspend(struct dlm_ls *ls);
+void dlm_callback_resume(struct dlm_ls *ls);
 
 #endif
 
+
diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 6614f335e25d..fe2860c02449 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -246,13 +246,15 @@ struct dlm_lkb {
         struct list_head        lkb_statequeue; /* rsb g/c/w list */
         struct list_head        lkb_rsb_lookup; /* waiting for rsb lookup */
         struct list_head        lkb_wait_reply; /* waiting for remote reply */
-        struct list_head        lkb_astqueue;   /* need ast to be sent */
         struct list_head        lkb_ownqueue;   /* list of locks for a process */
         struct list_head        lkb_time_list;
         ktime_t                 lkb_timestamp;
         ktime_t                 lkb_wait_time;
         unsigned long           lkb_timeout_cs;
 
+        struct mutex            lkb_cb_mutex;
+        struct work_struct      lkb_cb_work;
+        struct list_head        lkb_cb_list; /* for ls_cb_delay or proc->asts */
         struct dlm_callback     lkb_callbacks[DLM_CALLBACKS_SIZE];
         struct dlm_callback     lkb_last_cast;
         struct dlm_callback     lkb_last_bast;
@@ -504,8 +506,12 @@ struct dlm_ls {
 
         struct miscdevice       ls_device;
 
+        struct workqueue_struct *ls_callback_wq;
+
         /* recovery related */
 
+        struct mutex            ls_cb_mutex;
+        struct list_head        ls_cb_delay; /* save for queue_work later */
         struct timer_list       ls_timer;
         struct task_struct      *ls_recoverd_task;
         struct mutex            ls_recoverd_active;
@@ -542,6 +548,7 @@ struct dlm_ls {
 #define LSFL_RCOM_WAIT          4
 #define LSFL_UEVENT_WAIT        5
 #define LSFL_TIMEWARN           6
+#define LSFL_CB_DELAY           7
 
 /* much of this is just saving user space pointers associated with the
    lock that we pass back to the user lib with an ast */
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 6772e5c5bcd6..83b5e32514e1 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -305,7 +305,7 @@ static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
                 rv = -EDEADLK;
         }
 
-        dlm_add_ast(lkb, DLM_CB_CAST, lkb->lkb_grmode, rv, lkb->lkb_sbflags);
+        dlm_add_cb(lkb, DLM_CB_CAST, lkb->lkb_grmode, rv, lkb->lkb_sbflags);
 }
 
 static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb *lkb)
@@ -319,7 +319,7 @@ static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode)
         if (is_master_copy(lkb)) {
                 send_bast(r, lkb, rqmode);
         } else {
-                dlm_add_ast(lkb, DLM_CB_BAST, rqmode, 0, 0);
+                dlm_add_cb(lkb, DLM_CB_BAST, rqmode, 0, 0);
         }
 }
 
@@ -638,7 +638,9 @@ static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
         INIT_LIST_HEAD(&lkb->lkb_ownqueue);
         INIT_LIST_HEAD(&lkb->lkb_rsb_lookup);
         INIT_LIST_HEAD(&lkb->lkb_time_list);
-        INIT_LIST_HEAD(&lkb->lkb_astqueue);
+        INIT_LIST_HEAD(&lkb->lkb_cb_list);
+        mutex_init(&lkb->lkb_cb_mutex);
+        INIT_WORK(&lkb->lkb_cb_work, dlm_callback_work);
 
  retry:
         rv = idr_pre_get(&ls->ls_lkbidr, GFP_NOFS);
@@ -4010,8 +4012,6 @@ static void _receive_message(struct dlm_ls *ls, struct dlm_message *ms)
         default:
                 log_error(ls, "unknown message type %d", ms->m_type);
         }
-
-        dlm_astd_wake();
 }
 
 /* If the lockspace is in recovery mode (locking stopped), then normal
@@ -4826,7 +4826,7 @@ int dlm_user_unlock(struct dlm_ls *ls, struct dlm_user_args *ua_tmp,
                 goto out_put;
 
         spin_lock(&ua->proc->locks_spin);
-        /* dlm_user_add_ast() may have already taken lkb off the proc list */
+        /* dlm_user_add_cb() may have already taken lkb off the proc list */
         if (!list_empty(&lkb->lkb_ownqueue))
                 list_move(&lkb->lkb_ownqueue, &ua->proc->unlocking);
         spin_unlock(&ua->proc->locks_spin);
@@ -4963,7 +4963,7 @@ static int unlock_proc_lock(struct dlm_ls *ls, struct dlm_lkb *lkb)
 
 /* We have to release clear_proc_locks mutex before calling unlock_proc_lock()
    (which does lock_rsb) due to deadlock with receiving a message that does
-   lock_rsb followed by dlm_user_add_ast() */
+   lock_rsb followed by dlm_user_add_cb() */
 
 static struct dlm_lkb *del_proc_lock(struct dlm_ls *ls,
                                      struct dlm_user_proc *proc)
@@ -4986,7 +4986,7 @@ static struct dlm_lkb *del_proc_lock(struct dlm_ls *ls,
         return lkb;
 }
 
-/* The ls_clear_proc_locks mutex protects against dlm_user_add_asts() which
+/* The ls_clear_proc_locks mutex protects against dlm_user_add_cb() which
    1) references lkb->ua which we free here and 2) adds lkbs to proc->asts,
    which we clear here. */
 
@@ -5028,10 +5028,10 @@ void dlm_clear_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
                 dlm_put_lkb(lkb);
         }
 
-        list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_astqueue) {
+        list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) {
                 memset(&lkb->lkb_callbacks, 0,
                        sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE);
-                list_del_init(&lkb->lkb_astqueue);
+                list_del_init(&lkb->lkb_cb_list);
                 dlm_put_lkb(lkb);
         }
 
@@ -5070,10 +5070,10 @@ static void purge_proc_locks(struct dlm_ls *ls, struct dlm_user_proc *proc)
         spin_unlock(&proc->locks_spin);
 
         spin_lock(&proc->asts_spin);
-        list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_astqueue) {
+        list_for_each_entry_safe(lkb, safe, &proc->asts, lkb_cb_list) {
                 memset(&lkb->lkb_callbacks, 0,
                        sizeof(struct dlm_callback) * DLM_CALLBACKS_SIZE);
-                list_del_init(&lkb->lkb_astqueue);
+                list_del_init(&lkb->lkb_cb_list);
                 dlm_put_lkb(lkb);
         }
         spin_unlock(&proc->asts_spin);
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 98a97762c893..a1d8f1af144b 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -15,7 +15,6 @@
 #include "lockspace.h"
 #include "member.h"
 #include "recoverd.h"
-#include "ast.h"
 #include "dir.h"
 #include "lowcomms.h"
 #include "config.h"
@@ -24,6 +23,7 @@
 #include "recover.h"
 #include "requestqueue.h"
 #include "user.h"
+#include "ast.h"
 
 static int                      ls_count;
 static struct mutex             ls_lock;
@@ -359,17 +359,10 @@ static int threads_start(void)
 {
         int error;
 
-        /* Thread which process lock requests for all lockspace's */
-        error = dlm_astd_start();
-        if (error) {
-                log_print("cannot start dlm_astd thread %d", error);
-                goto fail;
-        }
-
         error = dlm_scand_start();
         if (error) {
                 log_print("cannot start dlm_scand thread %d", error);
-                goto astd_fail;
+                goto fail;
         }
 
         /* Thread for sending/receiving messages for all lockspace's */
@@ -383,8 +376,6 @@ static int threads_start(void)
 
  scand_fail:
         dlm_scand_stop();
- astd_fail:
-        dlm_astd_stop();
  fail:
         return error;
 }
@@ -393,7 +384,6 @@ static void threads_stop(void)
 {
         dlm_scand_stop();
         dlm_lowcomms_stop();
-        dlm_astd_stop();
 }
 
 static int new_lockspace(const char *name, int namelen, void **lockspace,
@@ -514,6 +504,9 @@ static int new_lockspace(const char *name, int namelen, void **lockspace,
         init_completion(&ls->ls_members_done);
         ls->ls_members_result = -1;
 
+        mutex_init(&ls->ls_cb_mutex);
+        INIT_LIST_HEAD(&ls->ls_cb_delay);
+
         ls->ls_recoverd_task = NULL;
         mutex_init(&ls->ls_recoverd_active);
         spin_lock_init(&ls->ls_recover_lock);
@@ -547,18 +540,26 @@ static int new_lockspace(const char *name, int namelen, void **lockspace,
         list_add(&ls->ls_list, &lslist);
         spin_unlock(&lslist_lock);
 
+        if (flags & DLM_LSFL_FS) {
+                error = dlm_callback_start(ls);
+                if (error) {
+                        log_error(ls, "can't start dlm_callback %d", error);
+                        goto out_delist;
+                }
+        }
+
         /* needs to find ls in lslist */
         error = dlm_recoverd_start(ls);
         if (error) {
                 log_error(ls, "can't start dlm_recoverd %d", error);
-                goto out_delist;
+                goto out_callback;
         }
 
         ls->ls_kobj.kset = dlm_kset;
         error = kobject_init_and_add(&ls->ls_kobj, &dlm_ktype, NULL,
                                      "%s", ls->ls_name);
         if (error)
-                goto out_stop;
+                goto out_recoverd;
         kobject_uevent(&ls->ls_kobj, KOBJ_ADD);
 
         /* let kobject handle freeing of ls if there's an error */
@@ -572,7 +573,7 @@ static int new_lockspace(const char *name, int namelen, void **lockspace,
 
         error = do_uevent(ls, 1);
         if (error)
-                goto out_stop;
+                goto out_recoverd;
 
         wait_for_completion(&ls->ls_members_done);
         error = ls->ls_members_result;
@@ -589,8 +590,10 @@ static int new_lockspace(const char *name, int namelen, void **lockspace,
         do_uevent(ls, 0);
         dlm_clear_members(ls);
         kfree(ls->ls_node_array);
- out_stop:
+ out_recoverd:
         dlm_recoverd_stop(ls);
+ out_callback:
+        dlm_callback_stop(ls);
  out_delist:
         spin_lock(&lslist_lock);
         list_del(&ls->ls_list);
@@ -652,8 +655,6 @@ static int lkb_idr_free(int id, void *p, void *data)
 {
         struct dlm_lkb *lkb = p;
 
-        dlm_del_ast(lkb);
-
         if (lkb->lkb_lvbptr && lkb->lkb_flags & DLM_IFL_MSTCPY)
                 dlm_free_lvb(lkb->lkb_lvbptr);
 
@@ -717,12 +718,12 @@ static int release_lockspace(struct dlm_ls *ls, int force)
 
         dlm_recoverd_stop(ls);
 
+        dlm_callback_stop(ls);
+
         remove_lockspace(ls);
 
         dlm_delete_debug_file(ls);
 
-        dlm_astd_suspend();
-
         kfree(ls->ls_recover_buf);
 
         /*
@@ -740,8 +741,6 @@ static int release_lockspace(struct dlm_ls *ls, int force)
         idr_remove_all(&ls->ls_lkbidr);
         idr_destroy(&ls->ls_lkbidr);
 
-        dlm_astd_resume();
-
         /*
          * Free all rsb's on rsbtbl[] lists
          */
diff --git a/fs/dlm/recoverd.c b/fs/dlm/recoverd.c
index fd677c8c3d3b..774da3cf92c6 100644
--- a/fs/dlm/recoverd.c
+++ b/fs/dlm/recoverd.c
@@ -58,13 +58,7 @@ static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
 
         mutex_lock(&ls->ls_recoverd_active);
 
-        /*
-         * Suspending and resuming dlm_astd ensures that no lkb's from this ls
-         * will be processed by dlm_astd during recovery.
-         */
-
-        dlm_astd_suspend();
-        dlm_astd_resume();
+        dlm_callback_suspend(ls);
 
         /*
          * Free non-master tossed rsb's.  Master rsb's are kept on toss
@@ -202,6 +196,8 @@ static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
 
         dlm_adjust_timeouts(ls);
 
+        dlm_callback_resume(ls);
+
         error = enable_locking(ls, rv->seq);
         if (error) {
                 log_debug(ls, "enable_locking failed %d", error);
@@ -222,8 +218,6 @@ static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
 
         dlm_grant_after_purge(ls);
 
-        dlm_astd_wake();
-
         log_debug(ls, "recover %llx done: %u ms",
                   (unsigned long long)rv->seq,
                   jiffies_to_msecs(jiffies - start));
diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index e96bf3e9be88..d8ea60756403 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -213,9 +213,9 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode,
                 goto out;
         }
 
-        if (list_empty(&lkb->lkb_astqueue)) {
+        if (list_empty(&lkb->lkb_cb_list)) {
                 kref_get(&lkb->lkb_ref);
-                list_add_tail(&lkb->lkb_astqueue, &proc->asts);
+                list_add_tail(&lkb->lkb_cb_list, &proc->asts);
                 wake_up_interruptible(&proc->wait);
         }
         spin_unlock(&proc->asts_spin);
@@ -832,24 +832,24 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count,
         }
 
         /* if we empty lkb_callbacks, we don't want to unlock the spinlock
-           without removing lkb_astqueue; so empty lkb_astqueue is always
+           without removing lkb_cb_list; so empty lkb_cb_list is always
            consistent with empty lkb_callbacks */
 
-        lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_astqueue);
+        lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_cb_list);
 
         rv = dlm_rem_lkb_callback(lkb->lkb_resource->res_ls, lkb, &cb, &resid);
         if (rv < 0) {
                 /* this shouldn't happen; lkb should have been removed from
                    list when resid was zero */
                 log_print("dlm_rem_lkb_callback empty %x", lkb->lkb_id);
-                list_del_init(&lkb->lkb_astqueue);
+                list_del_init(&lkb->lkb_cb_list);
                 spin_unlock(&proc->asts_spin);
                 /* removes ref for proc->asts, may cause lkb to be freed */
                 dlm_put_lkb(lkb);
                 goto try_another;
         }
         if (!resid)
-                list_del_init(&lkb->lkb_astqueue);
+                list_del_init(&lkb->lkb_cb_list);
         spin_unlock(&proc->asts_spin);
 
         if (cb.flags & DLM_CB_SKIP) {