dlm: fix slow rsb search in dir recovery

The function used to find an rsb during directory
recovery was searching the single linear list of
rsb's.  This wasted a lot of time compared to
using the standard hash table to find the rsb.

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

3 files changed, 24 insertions, 4 deletions

diff --git a/fs/dlm/dir.c b/fs/dlm/dir.c
index 83641574b016..dc5eb598b81f 100644
--- a/fs/dlm/dir.c
+++ b/fs/dlm/dir.c
@@ -351,11 +351,28 @@ int dlm_dir_lookup(struct dlm_ls *ls, int nodeid, char *name, int namelen,
 static struct dlm_rsb *find_rsb_root(struct dlm_ls *ls, char *name, int len)
 {
         struct dlm_rsb *r;
+        uint32_t hash, bucket;
+        int rv;
+
+        hash = jhash(name, len, 0);
+        bucket = hash & (ls->ls_rsbtbl_size - 1);
+
+        spin_lock(&ls->ls_rsbtbl[bucket].lock);
+        rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].keep, name, len, 0, &r);
+        if (rv)
+                rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[bucket].toss,
+                                         name, len, 0, &r);
+        spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+
+        if (!rv)
+                return r;
 
         down_read(&ls->ls_root_sem);
         list_for_each_entry(r, &ls->ls_root_list, res_root_list) {
                 if (len == r->res_length && !memcmp(name, r->res_name, len)) {
                         up_read(&ls->ls_root_sem);
+                        log_error(ls, "find_rsb_root revert to root_list %s",
+                                  r->res_name);
                         return r;
                 }
         }
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index d47183043c59..fa5c07d51dcc 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -411,8 +411,8 @@ static int rsb_cmp(struct dlm_rsb *r, const char *name, int nlen)
         return memcmp(r->res_name, maxname, DLM_RESNAME_MAXLEN);
 }
 
-static int search_rsb_tree(struct rb_root *tree, char *name, int len,
-                           unsigned int flags, struct dlm_rsb **r_ret)
+int dlm_search_rsb_tree(struct rb_root *tree, char *name, int len,
+                        unsigned int flags, struct dlm_rsb **r_ret)
 {
         struct rb_node *node = tree->rb_node;
         struct dlm_rsb *r;
@@ -474,12 +474,12 @@ static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b,
         struct dlm_rsb *r;
         int error;
 
-        error = search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, flags, &r);
+        error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, flags, &r);
         if (!error) {
                 kref_get(&r->res_ref);
                 goto out;
         }
-        error = search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
+        error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
         if (error)
                 goto out;
 
diff --git a/fs/dlm/lock.h b/fs/dlm/lock.h
index 265017a7c3e7..1a255307f6ff 100644
--- a/fs/dlm/lock.h
+++ b/fs/dlm/lock.h
@@ -28,6 +28,9 @@ void dlm_scan_waiters(struct dlm_ls *ls);
 void dlm_scan_timeout(struct dlm_ls *ls);
 void dlm_adjust_timeouts(struct dlm_ls *ls);
 
+int dlm_search_rsb_tree(struct rb_root *tree, char *name, int len,
+                        unsigned int flags, struct dlm_rsb **r_ret);
+
 int dlm_purge_locks(struct dlm_ls *ls);
 void dlm_purge_mstcpy_locks(struct dlm_rsb *r);
 void dlm_grant_after_purge(struct dlm_ls *ls);