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>

diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c
index bc4af3ef65a32d7219218fd3167cc2cdf10991c3..1d1d27442235b9487c3db8a8490a6a0da7c6122c 100644 (file)
--- 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 ef2f1e353966d85ef15d9a9dd0cf8b273df51f4b..076e86f38bc84a4a6e247b7fb184658592e7f732 100644 (file)
--- 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 6cfe65bbf4a2e16daaf1aec41638430174b407db..01e7d39c5fba8d55a4fa1a4bd8f64e13d4c32a95 100644 (file)
--- 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 8d86b7960f0df7527fed5494230676b137b4f63b..aa32e5f02493656ef461099a024337793437e245 100644 (file)
--- 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 80aba5bdd4a4b72b0949fe4f0516c02f7d7f25ad..eda43f3626169ec9b08ad03fdecfd9b5aef7e821 100644 (file)
--- 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);
        }
 }