From ca89a517fa577e6f26621463d3aa4f3c3d530b1e Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Sun, 21 May 2006 13:29:11 +0100 Subject: [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 --- fs/jffs2/nodelist.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 108 insertions(+), 7 deletions(-) (limited to 'fs/jffs2/nodelist.c') diff --git a/fs/jffs2/nodelist.c b/fs/jffs2/nodelist.c index 00506857eabc..9a6ced05f894 100644 --- a/fs/jffs2/nodelist.c +++ b/fs/jffs2/nodelist.c @@ -1052,8 +1052,17 @@ void jffs2_link_node_ref(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, { 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 @@ void jffs2_link_node_ref(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, 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; +} -- cgit v1.2.3