jffs2: Dynamically choose inocache hash size

When JFFS2 is used for large volumes, the mount times are quite long.
Increasing the hash size provides a significant speed boost on the OLPC
XO-1 laptop.

Add logic that dynamically selects a hash size based on the size of
the medium. A 64mb medium will result in a hash size of 128, and a 512mb
medium will result in a hash size of 1024.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/fs/jffs2/nodelist.c b/fs/jffs2/nodelist.c
index af02bd138469..5e03233c2363 100644
--- a/fs/jffs2/nodelist.c
+++ b/fs/jffs2/nodelist.c
@@ -420,7 +420,7 @@ struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t
 {
         struct jffs2_inode_cache *ret;
 
-        ret = c->inocache_list[ino % INOCACHE_HASHSIZE];
+        ret = c->inocache_list[ino % c->inocache_hashsize];
         while (ret && ret->ino < ino) {
                 ret = ret->next;
         }
@@ -441,7 +441,7 @@ void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new
 
         dbg_inocache("add %p (ino #%u)\n", new, new->ino);
 
-        prev = &c->inocache_list[new->ino % INOCACHE_HASHSIZE];
+        prev = &c->inocache_list[new->ino % c->inocache_hashsize];
 
         while ((*prev) && (*prev)->ino < new->ino) {
                 prev = &(*prev)->next;
@@ -462,7 +462,7 @@ void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old)
         dbg_inocache("del %p (ino #%u)\n", old, old->ino);
         spin_lock(&c->inocache_lock);
 
-        prev = &c->inocache_list[old->ino % INOCACHE_HASHSIZE];
+        prev = &c->inocache_list[old->ino % c->inocache_hashsize];
 
         while ((*prev) && (*prev)->ino < old->ino) {
                 prev = &(*prev)->next;
@@ -487,7 +487,7 @@ void jffs2_free_ino_caches(struct jffs2_sb_info *c)
         int i;
         struct jffs2_inode_cache *this, *next;
 
-        for (i=0; i<INOCACHE_HASHSIZE; i++) {
+        for (i=0; i < c->inocache_hashsize; i++) {
                 this = c->inocache_list[i];
                 while (this) {
                         next = this->next;