[JFFS2] Reduce visibility of raw_node_ref to upper layers of JFFS2 code.

As the first step towards eliminating the ref->next_phys member and saving
memory by using an _array_ of struct jffs2_raw_node_ref per eraseblock,
stop the write functions from allocating their own refs; have them just
_reserve_ the appropriate number instead. Then jffs2_link_node_ref() can
just fill them in.

Use a linked list of pre-allocated refs in the superblock, for now. Once
we switch to an array, it'll just be a case of extending that array.

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

1 files changed, 33 insertions, 18 deletions

diff --git a/fs/jffs2/nodelist.c b/fs/jffs2/nodelist.c
index d25d4919ca97..1e6eabd730f2 100644
--- a/fs/jffs2/nodelist.c
+++ b/fs/jffs2/nodelist.c
@@ -953,13 +953,19 @@ void jffs2_free_raw_node_refs(struct jffs2_sb_info *c)
 
         for (i=0; i<c->nr_blocks; i++) {
                 this = c->blocks[i].first_node;
-                while(this) {
+                while (this) {
                         next = this->next_phys;
-                        jffs2_free_raw_node_ref(this);
+                        __jffs2_free_raw_node_ref(this);
                         this = next;
                 }
                 c->blocks[i].first_node = c->blocks[i].last_node = NULL;
         }
+        this = c->refs;
+        while (this) {
+                next = this->next_in_ino;
+                __jffs2_free_raw_node_ref(this);
+                this = next;
+        }
 }
 
 struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset)
@@ -1047,10 +1053,27 @@ void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c)
         }
 }
 
-void jffs2_link_node_ref(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
-                         struct jffs2_raw_node_ref *ref, uint32_t len,
-                         struct jffs2_inode_cache *ic)
+struct jffs2_raw_node_ref *jffs2_link_node_ref(struct jffs2_sb_info *c,
+                                               struct jffs2_eraseblock *jeb,
+                                               uint32_t ofs, uint32_t len,
+                                               struct jffs2_inode_cache *ic)
 {
+        struct jffs2_raw_node_ref *ref;
+
+        /* These will be preallocated _very_ shortly. */
+        ref = c->refs;
+        if (!c->refs) {
+                JFFS2_WARNING("Using non-preallocated refs!\n");
+                ref = __jffs2_alloc_raw_node_ref();
+                BUG_ON(!ref);
+                WARN_ON(1);
+        } else {
+                c->refs = ref->next_in_ino;
+        }
+
+        ref->next_phys = NULL;
+        ref->flash_offset = ofs;
+
         if (!jeb->first_node)
                 jeb->first_node = ref;
         if (jeb->last_node) {
@@ -1093,15 +1116,15 @@ void jffs2_link_node_ref(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
         c->free_size -= len;
         jeb->free_size -= len;
 
-        ref->next_phys = NULL;
 #ifdef TEST_TOTLEN
         /* Set (and test) __totlen field... for now */
         ref->__totlen = len;
         ref_totlen(c, jeb, ref);
 #endif
+        return ref;
 }
 
-/* No locking. Do not use on a live file system */
+/* No locking, no reservation of 'ref'. Do not use on a live file system */
 int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
                            uint32_t size)
 {
@@ -1121,18 +1144,10 @@ int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb
                 jeb->dirty_size += size;
                 jeb->free_size -= size;
         } else {
-                struct jffs2_raw_node_ref *ref;
-                ref = jffs2_alloc_raw_node_ref();
-                if (!ref)
-                        return -ENOMEM;
-
-                ref->flash_offset = jeb->offset + c->sector_size - jeb->free_size;
-                ref->flash_offset |= REF_OBSOLETE;
-#ifdef TEST_TOTLEN
-                ref->__totlen = size;
-#endif
+                uint32_t ofs = jeb->offset + c->sector_size - jeb->free_size;
+                ofs |= REF_OBSOLETE;
 
-                jffs2_link_node_ref(c, jeb, ref, size, NULL);
+                jffs2_link_node_ref(c, jeb, ofs, size, NULL);
         }
 
         return 0;