dlm: change rsbtbl rwlock to spinlock

The rwlock is almost always used in write mode, so there's no reason
to not use a spinlock instead.

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

5 files changed, 32 insertions, 32 deletions

diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c
index bc4af3ef65a3..1d1d27442235 100644
--- a/fs/dlm/debug_fs.c
+++ b/fs/dlm/debug_fs.c
@@ -416,7 +416,7 @@ static void *table_seq_start(struct seq_file *seq, loff_t *pos)
         if (seq->op == &format3_seq_ops)
                 ri->format = 3;
 
-        read_lock(&ls->ls_rsbtbl[bucket].lock);
+        spin_lock(&ls->ls_rsbtbl[bucket].lock);
         if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
                 list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list,
                                     res_hashchain) {
@@ -424,12 +424,12 @@ static void *table_seq_start(struct seq_file *seq, loff_t *pos)
                                 dlm_hold_rsb(r);
                                 ri->rsb = r;
                                 ri->bucket = bucket;
-                                read_unlock(&ls->ls_rsbtbl[bucket].lock);
+                                spin_unlock(&ls->ls_rsbtbl[bucket].lock);
                                 return ri;
                         }
                 }
         }
-        read_unlock(&ls->ls_rsbtbl[bucket].lock);
+        spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 
         /*
          * move to the first rsb in the next non-empty bucket
@@ -447,18 +447,18 @@ static void *table_seq_start(struct seq_file *seq, loff_t *pos)
                         return NULL;
                 }
 
-                read_lock(&ls->ls_rsbtbl[bucket].lock);
+                spin_lock(&ls->ls_rsbtbl[bucket].lock);
                 if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
                         r = list_first_entry(&ls->ls_rsbtbl[bucket].list,
                                              struct dlm_rsb, res_hashchain);
                         dlm_hold_rsb(r);
                         ri->rsb = r;
                         ri->bucket = bucket;
-                        read_unlock(&ls->ls_rsbtbl[bucket].lock);
+                        spin_unlock(&ls->ls_rsbtbl[bucket].lock);
                         *pos = n;
                         return ri;
                 }
-                read_unlock(&ls->ls_rsbtbl[bucket].lock);
+                spin_unlock(&ls->ls_rsbtbl[bucket].lock);
         }
 }
 
@@ -477,7 +477,7 @@ static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
          * move to the next rsb in the same bucket
          */
 
-        read_lock(&ls->ls_rsbtbl[bucket].lock);
+        spin_lock(&ls->ls_rsbtbl[bucket].lock);
         rp = ri->rsb;
         next = rp->res_hashchain.next;
 
@@ -485,12 +485,12 @@ static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
                 r = list_entry(next, struct dlm_rsb, res_hashchain);
                 dlm_hold_rsb(r);
                 ri->rsb = r;
-                read_unlock(&ls->ls_rsbtbl[bucket].lock);
+                spin_unlock(&ls->ls_rsbtbl[bucket].lock);
                 dlm_put_rsb(rp);
                 ++*pos;
                 return ri;
         }
-        read_unlock(&ls->ls_rsbtbl[bucket].lock);
+        spin_unlock(&ls->ls_rsbtbl[bucket].lock);
         dlm_put_rsb(rp);
 
         /*
@@ -509,18 +509,18 @@ static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
                         return NULL;
                 }
 
-                read_lock(&ls->ls_rsbtbl[bucket].lock);
+                spin_lock(&ls->ls_rsbtbl[bucket].lock);
                 if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
                         r = list_first_entry(&ls->ls_rsbtbl[bucket].list,
                                              struct dlm_rsb, res_hashchain);
                         dlm_hold_rsb(r);
                         ri->rsb = r;
                         ri->bucket = bucket;
-                        read_unlock(&ls->ls_rsbtbl[bucket].lock);
+                        spin_unlock(&ls->ls_rsbtbl[bucket].lock);
                         *pos = n;
                         return ri;
                 }
-                read_unlock(&ls->ls_rsbtbl[bucket].lock);
+                spin_unlock(&ls->ls_rsbtbl[bucket].lock);
         }
 }
 
diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index ef2f1e353966..076e86f38bc8 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -105,7 +105,7 @@ struct dlm_dirtable {
 struct dlm_rsbtable {
         struct list_head        list;
         struct list_head        toss;
-        rwlock_t                lock;
+        spinlock_t              lock;
 };
 
 struct dlm_lkbtable {
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 6cfe65bbf4a2..01e7d39c5fba 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -412,9 +412,9 @@ static int search_rsb(struct dlm_ls *ls, char *name, int len, int b,
                       unsigned int flags, struct dlm_rsb **r_ret)
 {
         int error;
-        write_lock(&ls->ls_rsbtbl[b].lock);
+        spin_lock(&ls->ls_rsbtbl[b].lock);
         error = _search_rsb(ls, name, len, b, flags, r_ret);
-        write_unlock(&ls->ls_rsbtbl[b].lock);
+        spin_unlock(&ls->ls_rsbtbl[b].lock);
         return error;
 }
 
@@ -478,16 +478,16 @@ static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
                 r->res_nodeid = nodeid;
         }
 
-        write_lock(&ls->ls_rsbtbl[bucket].lock);
+        spin_lock(&ls->ls_rsbtbl[bucket].lock);
         error = _search_rsb(ls, name, namelen, bucket, 0, &tmp);
         if (!error) {
-                write_unlock(&ls->ls_rsbtbl[bucket].lock);
+                spin_unlock(&ls->ls_rsbtbl[bucket].lock);
                 dlm_free_rsb(r);
                 r = tmp;
                 goto out;
         }
         list_add(&r->res_hashchain, &ls->ls_rsbtbl[bucket].list);
-        write_unlock(&ls->ls_rsbtbl[bucket].lock);
+        spin_unlock(&ls->ls_rsbtbl[bucket].lock);
         error = 0;
  out:
         *r_ret = r;
@@ -530,9 +530,9 @@ static void put_rsb(struct dlm_rsb *r)
         struct dlm_ls *ls = r->res_ls;
         uint32_t bucket = r->res_bucket;
 
-        write_lock(&ls->ls_rsbtbl[bucket].lock);
+        spin_lock(&ls->ls_rsbtbl[bucket].lock);
         kref_put(&r->res_ref, toss_rsb);
-        write_unlock(&ls->ls_rsbtbl[bucket].lock);
+        spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 }
 
 void dlm_put_rsb(struct dlm_rsb *r)
@@ -967,7 +967,7 @@ static int shrink_bucket(struct dlm_ls *ls, int b)
 
         for (;;) {
                 found = 0;
-                write_lock(&ls->ls_rsbtbl[b].lock);
+                spin_lock(&ls->ls_rsbtbl[b].lock);
                 list_for_each_entry_reverse(r, &ls->ls_rsbtbl[b].toss,
                                             res_hashchain) {
                         if (!time_after_eq(jiffies, r->res_toss_time +
@@ -978,20 +978,20 @@ static int shrink_bucket(struct dlm_ls *ls, int b)
                 }
 
                 if (!found) {
-                        write_unlock(&ls->ls_rsbtbl[b].lock);
+                        spin_unlock(&ls->ls_rsbtbl[b].lock);
                         break;
                 }
 
                 if (kref_put(&r->res_ref, kill_rsb)) {
                         list_del(&r->res_hashchain);
-                        write_unlock(&ls->ls_rsbtbl[b].lock);
+                        spin_unlock(&ls->ls_rsbtbl[b].lock);
 
                         if (is_master(r))
                                 dir_remove(r);
                         dlm_free_rsb(r);
                         count++;
                 } else {
-                        write_unlock(&ls->ls_rsbtbl[b].lock);
+                        spin_unlock(&ls->ls_rsbtbl[b].lock);
                         log_error(ls, "tossed rsb in use %s", r->res_name);
                 }
         }
@@ -4224,7 +4224,7 @@ static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
 {
         struct dlm_rsb *r, *r_ret = NULL;
 
-        read_lock(&ls->ls_rsbtbl[bucket].lock);
+        spin_lock(&ls->ls_rsbtbl[bucket].lock);
         list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list, res_hashchain) {
                 if (!rsb_flag(r, RSB_LOCKS_PURGED))
                         continue;
@@ -4233,7 +4233,7 @@ static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
                 r_ret = r;
                 break;
         }
-        read_unlock(&ls->ls_rsbtbl[bucket].lock);
+        spin_unlock(&ls->ls_rsbtbl[bucket].lock);
         return r_ret;
 }
 
diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 8d86b7960f0d..aa32e5f02493 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -464,7 +464,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace,
         for (i = 0; i < size; i++) {
                 INIT_LIST_HEAD(&ls->ls_rsbtbl[i].list);
                 INIT_LIST_HEAD(&ls->ls_rsbtbl[i].toss);
-                rwlock_init(&ls->ls_rsbtbl[i].lock);
+                spin_lock_init(&ls->ls_rsbtbl[i].lock);
         }
 
         size = dlm_config.ci_lkbtbl_size;
diff --git a/fs/dlm/recover.c b/fs/dlm/recover.c
index 80aba5bdd4a4..eda43f362616 100644
--- a/fs/dlm/recover.c
+++ b/fs/dlm/recover.c
@@ -726,7 +726,7 @@ int dlm_create_root_list(struct dlm_ls *ls)
         }
 
         for (i = 0; i < ls->ls_rsbtbl_size; i++) {
-                read_lock(&ls->ls_rsbtbl[i].lock);
+                spin_lock(&ls->ls_rsbtbl[i].lock);
                 list_for_each_entry(r, &ls->ls_rsbtbl[i].list, res_hashchain) {
                         list_add(&r->res_root_list, &ls->ls_root_list);
                         dlm_hold_rsb(r);
@@ -737,7 +737,7 @@ int dlm_create_root_list(struct dlm_ls *ls)
                    but no other recovery steps should do anything with them. */
 
                 if (dlm_no_directory(ls)) {
-                        read_unlock(&ls->ls_rsbtbl[i].lock);
+                        spin_unlock(&ls->ls_rsbtbl[i].lock);
                         continue;
                 }
 
@@ -745,7 +745,7 @@ int dlm_create_root_list(struct dlm_ls *ls)
                         list_add(&r->res_root_list, &ls->ls_root_list);
                         dlm_hold_rsb(r);
                 }
-                read_unlock(&ls->ls_rsbtbl[i].lock);
+                spin_unlock(&ls->ls_rsbtbl[i].lock);
         }
  out:
         up_write(&ls->ls_root_sem);
@@ -775,7 +775,7 @@ void dlm_clear_toss_list(struct dlm_ls *ls)
         int i;
 
         for (i = 0; i < ls->ls_rsbtbl_size; i++) {
-                write_lock(&ls->ls_rsbtbl[i].lock);
+                spin_lock(&ls->ls_rsbtbl[i].lock);
                 list_for_each_entry_safe(r, safe, &ls->ls_rsbtbl[i].toss,
                                          res_hashchain) {
                         if (dlm_no_directory(ls) || !is_master(r)) {
@@ -783,7 +783,7 @@ void dlm_clear_toss_list(struct dlm_ls *ls)
                                 dlm_free_rsb(r);
                         }
                 }
-                write_unlock(&ls->ls_rsbtbl[i].lock);
+                spin_unlock(&ls->ls_rsbtbl[i].lock);
         }
 }