[JFFS2] Switch to using an array of jffs2_raw_node_refs instead of a list.

This allows us to drop another pointer from the struct jffs2_raw_node_ref,
shrinking it to 8 bytes on 32-bit machines (if the TEST_TOTLEN) paranoia
check is turned off, which will be committed soon).

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 51 insertions, 24 deletions

diff --git a/fs/jffs2/malloc.c b/fs/jffs2/malloc.c
index 171483ef0e4d..4889d0700c0e 100644
--- a/fs/jffs2/malloc.c
+++ b/fs/jffs2/malloc.c
@@ -57,8 +57,8 @@ int __init jffs2_create_slab_caches(void)
         if (!tmp_dnode_info_slab)
                 goto err;
 
-        raw_node_ref_slab = kmem_cache_create("jffs2_raw_node_ref",
-                                              sizeof(struct jffs2_raw_node_ref),
+        raw_node_ref_slab = kmem_cache_create("jffs2_refblock",
+                                              sizeof(struct jffs2_raw_node_ref) * (REFS_PER_BLOCK + 1),
                                               0, 0, NULL, NULL);
         if (!raw_node_ref_slab)
                 goto err;
@@ -190,38 +190,65 @@ void jffs2_free_tmp_dnode_info(struct jffs2_tmp_dnode_info *x)
         kmem_cache_free(tmp_dnode_info_slab, x);
 }
 
+struct jffs2_raw_node_ref *jffs2_alloc_refblock(void)
+{
+        struct jffs2_raw_node_ref *ret;
+
+        ret = kmem_cache_alloc(raw_node_ref_slab, GFP_KERNEL);
+        if (ret) {
+                int i = 0;
+                for (i=0; i < REFS_PER_BLOCK; i++) {
+                        ret[i].flash_offset = REF_EMPTY_NODE;
+                        ret[i].next_in_ino = NULL;
+                }
+                ret[i].flash_offset = REF_LINK_NODE;
+                ret[i].next_in_ino = NULL;
+        }
+        return ret;
+}
+
 int jffs2_prealloc_raw_node_refs(struct jffs2_sb_info *c,
                                  struct jffs2_eraseblock *jeb, int nr)
 {
-        struct jffs2_raw_node_ref *p = c->refs;
+        struct jffs2_raw_node_ref **p, *ref;
+        int i = nr;
 
         dbg_memalloc("%d\n", nr);
 
-        while (nr && p) {
-                p = p->next_in_ino;
-                nr--;
-        }
-        while (nr) {
-                p = __jffs2_alloc_raw_node_ref();
-                if (!p)
-                        return -ENOMEM;
-                p->next_in_ino = c->refs;
-                c->refs = p;
-                nr--;
+        p = &jeb->last_node;
+        ref = *p;
+
+        dbg_memalloc("Reserving %d refs for block @0x%08x\n", nr, jeb->offset);
+
+        /* If jeb->last_node is really a valid node then skip over it */
+        if (ref && ref->flash_offset != REF_EMPTY_NODE)
+                ref++;
+
+        while (i) {
+                if (!ref) {
+                        dbg_memalloc("Allocating new refblock linked from %p\n", p);
+                        ref = *p = jffs2_alloc_refblock();
+                        if (!ref)
+                                return -ENOMEM;
+                }
+                if (ref->flash_offset == REF_LINK_NODE) {
+                        p = &ref->next_in_ino;
+                        ref = *p;
+                        continue;
+                }
+                i--;
+                ref++;
         }
-        c->reserved_refs = nr;
-        return 0;
-}
+        jeb->allocated_refs = nr;
 
-struct jffs2_raw_node_ref *__jffs2_alloc_raw_node_ref(void)
-{
-        struct jffs2_raw_node_ref *ret;
-        ret = kmem_cache_alloc(raw_node_ref_slab, GFP_KERNEL);
-        dbg_memalloc("%p\n", ret);
-        return ret;
+        dbg_memalloc("Reserved %d refs for block @0x%08x, last_node is %p (%08x,%p)\n",
+                  nr, jeb->offset, jeb->last_node, jeb->last_node->flash_offset,
+                  jeb->last_node->next_in_ino);
+
+        return 0;
 }
 
-void __jffs2_free_raw_node_ref(struct jffs2_raw_node_ref *x)
+void jffs2_free_refblock(struct jffs2_raw_node_ref *x)
 {
         dbg_memalloc("%p\n", x);
         kmem_cache_free(raw_node_ref_slab, x);