Linux 5.8-rc4

[linux/fpc-iii.git] / fs / jffs2 / nodelist.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * 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_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_SHIFT == newfrag->ofs >> PAGE_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_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_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, *next;

        dbg_fragtree("killing\n");
        rbtree_postorder_for_each_entry_safe(frag, next, root, rb) {
                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);
                }

                jffs2_free_node_frag(frag);
                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;
}