[JFFS2] Finally eliminate __totlen field from struct jffs2_raw_node_ref
Well, almost. We'll actually keep a 'TEST_TOTLEN' macro set for now, and keep
doing some paranoia checks to make sure it's all working correctly. But if
TEST_TOTLEN is unset, the size of struct jffs2_raw_node_ref drops from 16
bytes to 12 on 32-bit machines. That's a saving of about half a megabyte of
memory on the OLPC prototype board, with 125K or so nodes in its 512MiB of
flash.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/fs/jffs2/nodelist.c b/fs/jffs2/nodelist.c
index 0050685..9a6ced0 100644
--- a/fs/jffs2/nodelist.c
+++ b/fs/jffs2/nodelist.c
@@ -1052,8 +1052,17 @@
{
if (!jeb->first_node)
jeb->first_node = ref;
- if (jeb->last_node)
+ if (jeb->last_node) {
jeb->last_node->next_phys = ref;
+#ifdef TEST_TOTLEN
+ if (ref_offset(jeb->last_node) + jeb->last_node->__totlen != ref_offset(ref)) {
+ printk(KERN_CRIT "Adding new ref %p at (0x%08x-0x%08x) not immediately after previous (0x%08x-0x%08x)\n",
+ ref, ref_offset(ref), ref_offset(ref)+ref->__totlen,
+ ref_offset(jeb->last_node), ref_offset(jeb->last_node)+jeb->last_node->__totlen);
+ WARN_ON(1);
+ }
+#endif
+ }
jeb->last_node = ref;
switch(ref_flags(ref)) {
@@ -1076,18 +1085,110 @@
c->free_size -= len;
jeb->free_size -= len;
- /* Set __totlen field... for now */
- ref->__totlen = len;
ref->next_phys = NULL;
+#ifdef TEST_TOTLEN
+ /* Set (and test) __totlen field... for now */
+ ref->__totlen = len;
+ ref_totlen(c, jeb, ref);
+#endif
}
+/* No locking. 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)
{
- c->dirty_size += size;
- c->free_size -= size;
- jeb->dirty_size += size;
- jeb->free_size -= size;
+ if (!size)
+ return 0;
+ if (size > c->sector_size - jeb->used_size) {
+ printk(KERN_CRIT "Dirty space 0x%x larger then used_size 0x%x (wasted 0x%x)\n",
+ size, jeb->used_size, jeb->wasted_size);
+ BUG();
+ }
+ if (jeb->last_node && ref_obsolete(jeb->last_node)) {
+#ifdef TEST_TOTLEN
+ jeb->last_node->__totlen += size;
+#endif
+ c->dirty_size += size;
+ c->free_size -= size;
+ 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;
+ ref->next_in_ino = 0;
+#ifdef TEST_TOTLEN
+ ref->__totlen = size;
+#endif
+
+ jffs2_link_node_ref(c, jeb, ref, size);
+ }
return 0;
}
+
+/* Calculate totlen from surrounding nodes or eraseblock */
+static inline uint32_t __ref_totlen(struct jffs2_sb_info *c,
+ struct jffs2_eraseblock *jeb,
+ struct jffs2_raw_node_ref *ref)
+{
+ uint32_t ref_end;
+
+ if (ref->next_phys)
+ ref_end = ref_offset(ref->next_phys);
+ else {
+ if (!jeb)
+ jeb = &c->blocks[ref->flash_offset / c->sector_size];
+
+ /* Last node in block. Use free_space */
+ if (ref != jeb->last_node) {
+ printk(KERN_CRIT "ref %p @0x%08x is not jeb->last_node (%p @0x%08x)\n",
+ ref, ref_offset(ref), jeb->last_node, jeb->last_node?ref_offset(jeb->last_node):0);
+ BUG();
+ }
+ ref_end = jeb->offset + c->sector_size - jeb->free_size;
+ }
+ return ref_end - ref_offset(ref);
+}
+
+uint32_t __jffs2_ref_totlen(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
+ struct jffs2_raw_node_ref *ref)
+{
+ uint32_t ret;
+
+#if CONFIG_JFFS2_FS_DEBUG > 0
+ if (jeb && jeb != &c->blocks[ref->flash_offset / c->sector_size]) {
+ printk(KERN_CRIT "ref_totlen called with wrong block -- at 0x%08x instead of 0x%08x; ref 0x%08x\n",
+ jeb->offset, c->blocks[ref->flash_offset / c->sector_size].offset, ref_offset(ref));
+ BUG();
+ }
+#endif
+
+ ret = __ref_totlen(c, jeb, ref);
+#ifdef TEST_TOTLEN
+ if (ret != ref->__totlen) {
+ printk(KERN_CRIT "Totlen for ref at %p (0x%08x-0x%08x) miscalculated as 0x%x instead of %x\n",
+ ref, ref_offset(ref), ref_offset(ref)+ref->__totlen,
+ ret, ref->__totlen);
+ if (ref->next_phys) {
+ printk(KERN_CRIT "next_phys %p (0x%08x-0x%08x)\n", ref->next_phys, ref_offset(ref->next_phys),
+ ref_offset(ref->next_phys)+ref->__totlen);
+ } else
+ printk(KERN_CRIT "No next_phys. jeb->last_node is %p\n", jeb->last_node);
+
+ printk(KERN_CRIT "jeb->wasted_size %x, dirty_size %x, used_size %x, free_size %x\n", jeb->wasted_size, jeb->dirty_size, jeb->used_size, jeb->free_size);
+ ret = ref->__totlen;
+ if (!jeb)
+ jeb = &c->blocks[ref->flash_offset / c->sector_size];
+#if defined(JFFS2_DBG_DUMPS) || defined(JFFS2_DBG_PARANOIA_CHECKS)
+ __jffs2_dbg_dump_node_refs_nolock(c, jeb);
+#endif
+ WARN_ON(1);
+ }
+#endif /* TEST_TOTLEN */
+ return ret;
+}