gfs2: Switch to rhashtable_lookup_get_insert_fast
Switch from rhashtable_lookup_insert_fast + rhashtable_lookup_fast to
rhashtable_lookup_get_insert_fast, which is cleaner and avoids an extra
rhashtable lookup.
At the same time, turn the retry loop in gfs2_glock_get into an infinite
loop. The lookup or insert will eventually succeed, usually very fast,
but there is no reason to give up trying at a fixed number of
iterations.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 35f3b0a..9e81219 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -655,10 +655,10 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
struct lm_lockname name = { .ln_number = number,
.ln_type = glops->go_type,
.ln_sbd = sdp };
- struct gfs2_glock *gl, *tmp = NULL;
+ struct gfs2_glock *gl, *tmp;
struct address_space *mapping;
struct kmem_cache *cachep;
- int ret, tries = 0;
+ int ret = 0;
rcu_read_lock();
gl = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms);
@@ -723,35 +723,32 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
}
again:
- ret = rhashtable_lookup_insert_fast(&gl_hash_table, &gl->gl_node,
- ht_parms);
- if (ret == 0) {
+ rcu_read_lock();
+ tmp = rhashtable_lookup_get_insert_fast(&gl_hash_table, &gl->gl_node,
+ ht_parms);
+ if (!tmp) {
*glp = gl;
- return 0;
+ goto out;
}
+ if (IS_ERR(tmp)) {
+ ret = PTR_ERR(tmp);
+ goto out_free;
+ }
+ if (lockref_get_not_dead(&tmp->gl_lockref)) {
+ *glp = tmp;
+ goto out_free;
+ }
+ rcu_read_unlock();
+ cond_resched();
+ goto again;
- if (ret == -EEXIST) {
- ret = 0;
- rcu_read_lock();
- tmp = rhashtable_lookup_fast(&gl_hash_table, &name, ht_parms);
- if (tmp == NULL || !lockref_get_not_dead(&tmp->gl_lockref)) {
- if (++tries < 100) {
- rcu_read_unlock();
- cond_resched();
- goto again;
- }
- tmp = NULL;
- ret = -ENOMEM;
- }
- rcu_read_unlock();
- } else {
- WARN_ON_ONCE(ret);
- }
+out_free:
kfree(gl->gl_lksb.sb_lvbptr);
kmem_cache_free(cachep, gl);
atomic_dec(&sdp->sd_glock_disposal);
- *glp = tmp;
+out:
+ rcu_read_unlock();
return ret;
}