nodelist.c

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/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 *
 * Created by David Woodhouse <[email protected]>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/mtd/mtd.h>
#include <linux/rbtree.h>
#include <linux/crc32.h>
#include <linux/pagemap.h>
#include "nodelist.h"

static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c,
                     struct jffs2_node_frag *this);

void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list)
{
    struct jffs2_full_dirent **prev = list;

    dbg_dentlist("add dirent \"%s\", ino #%u\n", new->name, new->ino);

    while ((*prev) && (*prev)->nhash <= new->nhash) {
        if ((*prev)->nhash == new->nhash && !strcmp((*prev)->name, new->name)) {
            /* Duplicate. Free one */
            if (new->version < (*prev)->version) {
                dbg_dentlist("Eep! Marking new dirent node obsolete, old is \"%s\", ino #%u\n",
                    (*prev)->name, (*prev)->ino);
                jffs2_mark_node_obsolete(c, new->raw);
                jffs2_free_full_dirent(new);
            } else {
                dbg_dentlist("marking old dirent \"%s\", ino #%u obsolete\n",
                    (*prev)->name, (*prev)->ino);
                new->next = (*prev)->next;
                /* It may have been a 'placeholder' deletion dirent, 
                   if jffs2_can_mark_obsolete() (see jffs2_do_unlink()) */
                if ((*prev)->raw)
                    jffs2_mark_node_obsolete(c, ((*prev)->raw));
                jffs2_free_full_dirent(*prev);
                *prev = new;
            }
            return;
        }
        prev = &((*prev)->next);
    }
    new->next = *prev;
    *prev = new;
}

uint32_t jffs2_truncate_fragtree(struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
{
    struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);

    dbg_fragtree("truncating fragtree to 0x%08x bytes\n", size);

    /* We know frag->ofs <= size. That's what lookup does for us */
    if (frag && frag->ofs != size) {
        if (frag->ofs+frag->size > size) {
            frag->size = size - frag->ofs;
        }
        frag = frag_next(frag);
    }
    while (frag && frag->ofs >= size) {
        struct jffs2_node_frag *next = frag_next(frag);

        frag_erase(frag, list);
        jffs2_obsolete_node_frag(c, frag);
        frag = next;
    }

    if (size == 0)
        return 0;

    frag = frag_last(list);

    /* Sanity check for truncation to longer than we started with... */
    if (!frag)
        return 0;
    if (frag->ofs + frag->size < size)
        return frag->ofs + frag->size;

    /* If the last fragment starts at the RAM page boundary, it is
     * REF_PRISTINE irrespective of its size. */
    if (frag->node && (frag->ofs & (PAGE_CACHE_SIZE - 1)) == 0) {
        dbg_fragtree2("marking the last fragment 0x%08x-0x%08x REF_PRISTINE.\n",
            frag->ofs, frag->ofs + frag->size);
        frag->node->raw->flash_offset = ref_offset(frag->node->raw) | REF_PRISTINE;
    }
    return size;
}

static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c,
                     struct jffs2_node_frag *this)
{
    if (this->node) {
        this->node->frags--;
        if (!this->node->frags) {
            /* The node has no valid frags left. It's totally obsoleted */
            dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) obsolete\n",
                ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size);
            jffs2_mark_node_obsolete(c, this->node->raw);
            jffs2_free_full_dnode(this->node);
        } else {
            dbg_fragtree2("marking old node @0x%08x (0x%04x-0x%04x) REF_NORMAL. frags is %d\n",
                ref_offset(this->node->raw), this->node->ofs, this->node->ofs+this->node->size, this->node->frags);
            mark_ref_normal(this->node->raw);
        }

    }
    jffs2_free_node_frag(this);
}

static void jffs2_fragtree_insert(struct jffs2_node_frag *newfrag, struct jffs2_node_frag *base)
{
    struct rb_node *parent = &base->rb;
    struct rb_node **link = &parent;

    dbg_fragtree2("insert frag (0x%04x-0x%04x)\n", newfrag->ofs, newfrag->ofs + newfrag->size);

    while (*link) {
        parent = *link;
        base = rb_entry(parent, struct jffs2_node_frag, rb);

        if (newfrag->ofs > base->ofs)
            link = &base->rb.rb_right;
        else if (newfrag->ofs < base->ofs)
            link = &base->rb.rb_left;
        else {
            JFFS2_ERROR("duplicate frag at %08x (%p,%p)\n", newfrag->ofs, newfrag, base);
            BUG();
        }
    }

    rb_link_node(&newfrag->rb, &base->rb, link);
}

/*
 * Allocate and initializes a new fragment.
 */
static struct jffs2_node_frag * new_fragment(struct jffs2_full_dnode *fn, uint32_t ofs, uint32_t size)
{
    struct jffs2_node_frag *newfrag;

    newfrag = jffs2_alloc_node_frag();
    if (likely(newfrag)) {
        newfrag->ofs = ofs;
        newfrag->size = size;
        newfrag->node = fn;
    } else {
        JFFS2_ERROR("cannot allocate a jffs2_node_frag object\n");
    }

    return newfrag;
}

/*
 * Called when there is no overlapping fragment exist. Inserts a hole before the new
 * fragment and inserts the new fragment to the fragtree.
 */
static int no_overlapping_node(struct jffs2_sb_info *c, struct rb_root *root,
                   struct jffs2_node_frag *newfrag,
                   struct jffs2_node_frag *this, uint32_t lastend)
{
    if (lastend < newfrag->node->ofs) {
        /* put a hole in before the new fragment */
        struct jffs2_node_frag *holefrag;

        holefrag= new_fragment(NULL, lastend, newfrag->node->ofs - lastend);
        if (unlikely(!holefrag)) {
            jffs2_free_node_frag(newfrag);
            return -ENOMEM;
        }

        if (this) {
            /* By definition, the 'this' node has no right-hand child,
               because there are no frags with offset greater than it.
               So that's where we want to put the hole */
            dbg_fragtree2("add hole frag %#04x-%#04x on the right of the new frag.\n",
                holefrag->ofs, holefrag->ofs + holefrag->size);
            rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
        } else {
            dbg_fragtree2("Add hole frag %#04x-%#04x to the root of the tree.\n",
                holefrag->ofs, holefrag->ofs + holefrag->size);
            rb_link_node(&holefrag->rb, NULL, &root->rb_node);
        }
        rb_insert_color(&holefrag->rb, root);
        this = holefrag;
    }

    if (this) {
        /* By definition, the 'this' node has no right-hand child,
           because there are no frags with offset greater than it.
           So that's where we want to put new fragment */
        dbg_fragtree2("add the new node at the right\n");
        rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);
    } else {
        dbg_fragtree2("insert the new node at the root of the tree\n");
        rb_link_node(&newfrag->rb, NULL, &root->rb_node);
    }
    rb_insert_color(&newfrag->rb, root);

    return 0;
}

/* Doesn't set inode->i_size */
static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *root, struct jffs2_node_frag *newfrag)
{
    struct jffs2_node_frag *this;
    uint32_t lastend;

    /* Skip all the nodes which are completed before this one starts */
    this = jffs2_lookup_node_frag(root, newfrag->node->ofs);

    if (this) {
        dbg_fragtree2("lookup gave frag 0x%04x-0x%04x; phys 0x%08x (*%p)\n",
              this->ofs, this->ofs+this->size, this->node?(ref_offset(this->node->raw)):0xffffffff, this);
        lastend = this->ofs + this->size;
    } else {
        dbg_fragtree2("lookup gave no frag\n");
        lastend = 0;
    }

    /* See if we ran off the end of the fragtree */
    if (lastend <= newfrag->ofs) {
        /* We did */

        /* Check if 'this' node was on the same page as the new node.
           If so, both 'this' and the new node get marked REF_NORMAL so
           the GC can take a look.
        */
        if (lastend && (lastend-1) >> PAGE_CACHE_SHIFT == newfrag->ofs >> PAGE_CACHE_SHIFT) {
            if (this->node)
                mark_ref_normal(this->node->raw);
            mark_ref_normal(newfrag->node->raw);
        }

        return no_overlapping_node(c, root, newfrag, this, lastend);
    }

    if (this->node)
        dbg_fragtree2("dealing with frag %u-%u, phys %#08x(%d).\n",
        this->ofs, this->ofs + this->size,
        ref_offset(this->node->raw), ref_flags(this->node->raw));
    else
        dbg_fragtree2("dealing with hole frag %u-%u.\n",
        this->ofs, this->ofs + this->size);

    /* OK. 'this' is pointing at the first frag that newfrag->ofs at least partially obsoletes,
     * - i.e. newfrag->ofs < this->ofs+this->size && newfrag->ofs >= this->ofs
     */
    if (newfrag->ofs > this->ofs) {
        /* This node isn't completely obsoleted. The start of it remains valid */

        /* Mark the new node and the partially covered node REF_NORMAL -- let
           the GC take a look at them */
        mark_ref_normal(newfrag->node->raw);
        if (this->node)
            mark_ref_normal(this->node->raw);

        if (this->ofs + this->size > newfrag->ofs + newfrag->size) {
            /* The new node splits 'this' frag into two */
            struct jffs2_node_frag *newfrag2;

            if (this->node)
                dbg_fragtree2("split old frag 0x%04x-0x%04x, phys 0x%08x\n",
                    this->ofs, this->ofs+this->size, ref_offset(this->node->raw));
            else
                dbg_fragtree2("split old hole frag 0x%04x-0x%04x\n",
                    this->ofs, this->ofs+this->size);

            /* New second frag pointing to this's node */
            newfrag2 = new_fragment(this->node, newfrag->ofs + newfrag->size,
                        this->ofs + this->size - newfrag->ofs - newfrag->size);
            if (unlikely(!newfrag2))
                return -ENOMEM;
            if (this->node)
                this->node->frags++;

            /* Adjust size of original 'this' */
            this->size = newfrag->ofs - this->ofs;

            /* Now, we know there's no node with offset
               greater than this->ofs but smaller than
               newfrag2->ofs or newfrag->ofs, for obvious
               reasons. So we can do a tree insert from
               'this' to insert newfrag, and a tree insert
               from newfrag to insert newfrag2. */
            jffs2_fragtree_insert(newfrag, this);
            rb_insert_color(&newfrag->rb, root);

            jffs2_fragtree_insert(newfrag2, newfrag);
            rb_insert_color(&newfrag2->rb, root);

            return 0;
        }
        /* New node just reduces 'this' frag in size, doesn't split it */
        this->size = newfrag->ofs - this->ofs;

        /* Again, we know it lives down here in the tree */
        jffs2_fragtree_insert(newfrag, this);
        rb_insert_color(&newfrag->rb, root);
    } else {
        /* New frag starts at the same point as 'this' used to. Replace
           it in the tree without doing a delete and insertion */
        dbg_fragtree2("inserting newfrag (*%p),%d-%d in before 'this' (*%p),%d-%d\n",
              newfrag, newfrag->ofs, newfrag->ofs+newfrag->size, this, this->ofs, this->ofs+this->size);

        rb_replace_node(&this->rb, &newfrag->rb, root);

        if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
            dbg_fragtree2("obsoleting node frag %p (%x-%x)\n", this, this->ofs, this->ofs+this->size);
            jffs2_obsolete_node_frag(c, this);
        } else {
            this->ofs += newfrag->size;
            this->size -= newfrag->size;

            jffs2_fragtree_insert(this, newfrag);
            rb_insert_color(&this->rb, root);
            return 0;
        }
    }
    /* OK, now we have newfrag added in the correct place in the tree, but
       frag_next(newfrag) may be a fragment which is overlapped by it
    */
    while ((this = frag_next(newfrag)) && newfrag->ofs + newfrag->size >= this->ofs + this->size) {
        /* 'this' frag is obsoleted completely. */
        dbg_fragtree2("obsoleting node frag %p (%x-%x) and removing from tree\n",
            this, this->ofs, this->ofs+this->size);
        rb_erase(&this->rb, root);
        jffs2_obsolete_node_frag(c, this);
    }
    /* Now we're pointing at the first frag which isn't totally obsoleted by
       the new frag */

    if (!this || newfrag->ofs + newfrag->size == this->ofs)
        return 0;

    /* Still some overlap but we don't need to move it in the tree */
    this->size = (this->ofs + this->size) - (newfrag->ofs + newfrag->size);
    this->ofs = newfrag->ofs + newfrag->size;

    /* And mark them REF_NORMAL so the GC takes a look at them */
    if (this->node)
        mark_ref_normal(this->node->raw);
    mark_ref_normal(newfrag->node->raw);

    return 0;
}

/*
 * Given an inode, probably with existing tree of fragments, add the new node
 * to the fragment tree.
 */
int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn)
{
    int ret;
    struct jffs2_node_frag *newfrag;

    if (unlikely(!fn->size))
        return 0;

    newfrag = new_fragment(fn, fn->ofs, fn->size);
    if (unlikely(!newfrag))
        return -ENOMEM;
    newfrag->node->frags = 1;

    dbg_fragtree("adding node %#04x-%#04x @0x%08x on flash, newfrag *%p\n",
          fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag);

    ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
    if (unlikely(ret))
        return ret;

    /* If we now share a page with other nodes, mark either previous
       or next node REF_NORMAL, as appropriate.  */
    if (newfrag->ofs & (PAGE_CACHE_SIZE-1)) {
        struct jffs2_node_frag *prev = frag_prev(newfrag);

        mark_ref_normal(fn->raw);
        /* If we don't start at zero there's _always_ a previous */
        if (prev->node)
            mark_ref_normal(prev->node->raw);
    }

    if ((newfrag->ofs+newfrag->size) & (PAGE_CACHE_SIZE-1)) {
        struct jffs2_node_frag *next = frag_next(newfrag);

        if (next) {
            mark_ref_normal(fn->raw);
            if (next->node)
                mark_ref_normal(next->node->raw);
        }
    }
    jffs2_dbg_fragtree_paranoia_check_nolock(f);

    return 0;
}

void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state)
{
    spin_lock(&c->inocache_lock);
    ic->state = state;
    wake_up(&c->inocache_wq);
    spin_unlock(&c->inocache_lock);
}

/* During mount, this needs no locking. During normal operation, its
   callers want to do other stuff while still holding the inocache_lock.
   Rather than introducing special case get_ino_cache functions or
   callbacks, we just let the caller do the locking itself. */

struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
{
    struct jffs2_inode_cache *ret;

    ret = c->inocache_list[ino % c->inocache_hashsize];
    while (ret && ret->ino < ino) {
        ret = ret->next;
    }

    if (ret && ret->ino != ino)
        ret = NULL;

    return ret;
}

void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new)
{
    struct jffs2_inode_cache **prev;

    spin_lock(&c->inocache_lock);
    if (!new->ino)
        new->ino = ++c->highest_ino;

    dbg_inocache("add %p (ino #%u)\n", new, new->ino);

    prev = &c->inocache_list[new->ino % c->inocache_hashsize];

    while ((*prev) && (*prev)->ino < new->ino) {
        prev = &(*prev)->next;
    }
    new->next = *prev;
    *prev = new;

    spin_unlock(&c->inocache_lock);
}

void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old)
{
    struct jffs2_inode_cache **prev;

#ifdef CONFIG_JFFS2_FS_XATTR
    BUG_ON(old->xref);
#endif
    dbg_inocache("del %p (ino #%u)\n", old, old->ino);
    spin_lock(&c->inocache_lock);

    prev = &c->inocache_list[old->ino % c->inocache_hashsize];

    while ((*prev) && (*prev)->ino < old->ino) {
        prev = &(*prev)->next;
    }
    if ((*prev) == old) {
        *prev = old->next;
    }

    /* Free it now unless it's in READING or CLEARING state, which
       are the transitions upon read_inode() and clear_inode(). The
       rest of the time we know nobody else is looking at it, and
       if it's held by read_inode() or clear_inode() they'll free it
       for themselves. */
    if (old->state != INO_STATE_READING && old->state != INO_STATE_CLEARING)
        jffs2_free_inode_cache(old);

    spin_unlock(&c->inocache_lock);
}

void jffs2_free_ino_caches(struct jffs2_sb_info *c)
{
    int i;
    struct jffs2_inode_cache *this, *next;

    for (i=0; i < c->inocache_hashsize; i++) {
        this = c->inocache_list[i];
        while (this) {
            next = this->next;
            jffs2_xattr_free_inode(c, this);
            jffs2_free_inode_cache(this);
            this = next;
        }
        c->inocache_list[i] = NULL;
    }
}

void jffs2_free_raw_node_refs(struct jffs2_sb_info *c)
{
    int i;
    struct jffs2_raw_node_ref *this, *next;

    for (i=0; i<c->nr_blocks; i++) {
        this = c->blocks[i].first_node;
        while (this) {
            if (this[REFS_PER_BLOCK].flash_offset == REF_LINK_NODE)
                next = this[REFS_PER_BLOCK].next_in_ino;
            else
                next = NULL;

            jffs2_free_refblock(this);
            this = next;
        }
        c->blocks[i].first_node = c->blocks[i].last_node = NULL;
    }
}

struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset)
{
    /* The common case in lookup is that there will be a node
       which precisely matches. So we go looking for that first */
    struct rb_node *next;
    struct jffs2_node_frag *prev = NULL;
    struct jffs2_node_frag *frag = NULL;

    dbg_fragtree2("root %p, offset %d\n", fragtree, offset);

    next = fragtree->rb_node;

    while(next) {
        frag = rb_entry(next, struct jffs2_node_frag, rb);

        if (frag->ofs + frag->size <= offset) {
            /* Remember the closest smaller match on the way down */
            if (!prev || frag->ofs > prev->ofs)
                prev = frag;
            next = frag->rb.rb_right;
        } else if (frag->ofs > offset) {
            next = frag->rb.rb_left;
        } else {
            return frag;
        }
    }

    /* Exact match not found. Go back up looking at each parent,
       and return the closest smaller one */

    if (prev)
        dbg_fragtree2("no match. Returning frag %#04x-%#04x, closest previous\n",
              prev->ofs, prev->ofs+prev->size);
    else
        dbg_fragtree2("returning NULL, empty fragtree\n");

    return prev;
}

/* Pass 'c' argument to indicate that nodes should be marked obsolete as
   they're killed. */
void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c)
{
    struct jffs2_node_frag *frag;
    struct jffs2_node_frag *parent;

    if (!root->rb_node)
        return;

    dbg_fragtree("killing\n");

    frag = (rb_entry(root->rb_node, struct jffs2_node_frag, rb));
    while(frag) {
        if (frag->rb.rb_left) {
            frag = frag_left(frag);
            continue;
        }
        if (frag->rb.rb_right) {
            frag = frag_right(frag);
            continue;
        }

        if (frag->node && !(--frag->node->frags)) {
            /* Not a hole, and it's the final remaining frag
               of this node. Free the node */
            if (c)
                jffs2_mark_node_obsolete(c, frag->node->raw);

            jffs2_free_full_dnode(frag->node);
        }
        parent = frag_parent(frag);
        if (parent) {
            if (frag_left(parent) == frag)
                parent->rb.rb_left = NULL;
            else
                parent->rb.rb_right = NULL;
        }

        jffs2_free_node_frag(frag);
        frag = parent;

        cond_resched();
    }
}

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;

    BUG_ON(!jeb->allocated_refs);
    jeb->allocated_refs--;

    ref = jeb->last_node;

    dbg_noderef("Last node at %p is (%08x,%p)\n", ref, ref->flash_offset,
            ref->next_in_ino);

    while (ref->flash_offset != REF_EMPTY_NODE) {
        if (ref->flash_offset == REF_LINK_NODE)
            ref = ref->next_in_ino;
        else
            ref++;
    }

    dbg_noderef("New ref is %p (%08x becomes %08x,%p) len 0x%x\n", ref, 
            ref->flash_offset, ofs, ref->next_in_ino, len);

    ref->flash_offset = ofs;

    if (!jeb->first_node) {
        jeb->first_node = ref;
        BUG_ON(ref_offset(ref) != jeb->offset);
    } else if (unlikely(ref_offset(ref) != jeb->offset + c->sector_size - jeb->free_size)) {
        uint32_t last_len = ref_totlen(c, jeb, jeb->last_node);

        JFFS2_ERROR("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)+len,
                ref_offset(jeb->last_node), 
                ref_offset(jeb->last_node)+last_len);
        BUG();
    }
    jeb->last_node = ref;

    if (ic) {
        ref->next_in_ino = ic->nodes;
        ic->nodes = ref;
    } else {
        ref->next_in_ino = NULL;
    }

    switch(ref_flags(ref)) {
    case REF_UNCHECKED:
        c->unchecked_size += len;
        jeb->unchecked_size += len;
        break;

    case REF_NORMAL:
    case REF_PRISTINE:
        c->used_size += len;
        jeb->used_size += len;
        break;

    case REF_OBSOLETE:
        c->dirty_size += len;
        jeb->dirty_size += len;
        break;
    }
    c->free_size -= len;
    jeb->free_size -= len;

#ifdef TEST_TOTLEN
    /* Set (and test) __totlen field... for now */
    ref->__totlen = len;
    ref_totlen(c, jeb, ref);
#endif
    return ref;
}

/* 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)
{
    if (!size)
        return 0;
    if (unlikely(size > jeb->free_size)) {
        pr_crit("Dirty space 0x%x larger then free_size 0x%x (wasted 0x%x)\n",
            size, jeb->free_size, jeb->wasted_size);
        BUG();
    }
    /* REF_EMPTY_NODE is !obsolete, so that works OK */
    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 {
        uint32_t ofs = jeb->offset + c->sector_size - jeb->free_size;
        ofs |= REF_OBSOLETE;

        jffs2_link_node_ref(c, jeb, ofs, size, NULL);
    }

    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;
    struct jffs2_raw_node_ref *next_ref = ref_next(ref);

    if (next_ref)
        ref_end = ref_offset(next_ref);
    else {
        if (!jeb)
            jeb = &c->blocks[ref->flash_offset / c->sector_size];

        /* Last node in block. Use free_space */
        if (unlikely(ref != jeb->last_node)) {
            pr_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;

    ret = __ref_totlen(c, jeb, ref);

#ifdef TEST_TOTLEN
    if (unlikely(ret != ref->__totlen)) {
        if (!jeb)
            jeb = &c->blocks[ref->flash_offset / c->sector_size];

        pr_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(ref)) {
            pr_crit("next %p (0x%08x-0x%08x)\n",
                ref_next(ref), ref_offset(ref_next(ref)),
                ref_offset(ref_next(ref)) + ref->__totlen);
        } else 
            pr_crit("No next ref. jeb->last_node is %p\n",
                jeb->last_node);

        pr_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);

#if defined(JFFS2_DBG_DUMPS) || defined(JFFS2_DBG_PARANOIA_CHECKS)
        __jffs2_dbg_dump_node_refs_nolock(c, jeb);
#endif

        WARN_ON(1);

        ret = ref->__totlen;
    }
#endif /* TEST_TOTLEN */
    return ret;
}