[safe/jmp/linux-2.6] / fs / jffs2 / readinode.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright (C) 2001-2003 Red Hat, Inc.
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 * $Id: readinode.c,v 1.129 2005/07/22 10:32:08 dedekind Exp $
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/crc32.h>
#include <linux/pagemap.h>
#include <linux/mtd/mtd.h>
#include <linux/compiler.h>
#include "nodelist.h"

static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *list, struct jffs2_node_frag *newfrag);

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 */
                        D2(printk(KERN_DEBUG "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 {
                        D2(printk(KERN_DEBUG "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);
}

/* Given an inode, probably with existing list of fragments, add the new node
 * to the fragment list.
 */
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;

        D1(printk(KERN_DEBUG "jffs2_add_full_dnode_to_inode(ino #%u, f %p, fn %p)\n", f->inocache->ino, f, fn));

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

        newfrag = jffs2_alloc_node_frag();
        if (unlikely(!newfrag))
                return -ENOMEM;

        D2(printk(KERN_DEBUG "adding node %04x-%04x @0x%08x on flash, newfrag *%p\n",
                  fn->ofs, fn->ofs+fn->size, ref_offset(fn->raw), newfrag));
        
        newfrag->ofs = fn->ofs;
        newfrag->size = fn->size;
        newfrag->node = fn;
        newfrag->node->frags = 1;

        ret = jffs2_add_frag_to_fragtree(c, &f->fragtree, newfrag);
        if (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);
        jffs2_dbg_dump_fragtree_nolock(f);
        return 0;
}

/* Doesn't set inode->i_size */
static int jffs2_add_frag_to_fragtree(struct jffs2_sb_info *c, struct rb_root *list, 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(list, newfrag->node->ofs);

        if (this) {
                D2(printk(KERN_DEBUG "j_a_f_d_t_f: 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 {
                D2(printk(KERN_DEBUG "j_a_f_d_t_f: Lookup gave no frag\n"));
                lastend = 0;
        }
                          
        /* See if we ran off the end of the list */
        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);
                }

                if (lastend < newfrag->node->ofs) {
                        /* ... and we need to put a hole in before the new node */
                        struct jffs2_node_frag *holefrag = jffs2_alloc_node_frag();
                        if (!holefrag) {
                                jffs2_free_node_frag(newfrag);
                                return -ENOMEM;
                        }
                        holefrag->ofs = lastend;
                        holefrag->size = newfrag->node->ofs - lastend;
                        holefrag->node = NULL;
                        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 */
                                D2(printk(KERN_DEBUG "Adding hole frag (%p) on right of node at (%p)\n", holefrag, this));
                                rb_link_node(&holefrag->rb, &this->rb, &this->rb.rb_right);
                        } else {
                                D2(printk(KERN_DEBUG "Adding hole frag (%p) at root of tree\n", holefrag));
                                rb_link_node(&holefrag->rb, NULL, &list->rb_node);
                        }
                        rb_insert_color(&holefrag->rb, list);
                        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 the hole */
                        D2(printk(KERN_DEBUG "Adding new frag (%p) on right of node at (%p)\n", newfrag, this));
                        rb_link_node(&newfrag->rb, &this->rb, &this->rb.rb_right);                      
                } else {
                        D2(printk(KERN_DEBUG "Adding new frag (%p) at root of tree\n", newfrag));
                        rb_link_node(&newfrag->rb, NULL, &list->rb_node);
                }
                rb_insert_color(&newfrag->rb, list);
                return 0;
        }

        D2(printk(KERN_DEBUG "j_a_f_d_t_f: dealing with 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));

        /* 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 = jffs2_alloc_node_frag();
                        if (!newfrag2) {
                                jffs2_free_node_frag(newfrag);
                                return -ENOMEM;
                        }
                        D2(printk(KERN_DEBUG "split old frag 0x%04x-0x%04x -->", this->ofs, this->ofs+this->size);
                        if (this->node)
                                printk("phys 0x%08x\n", ref_offset(this->node->raw));
                        else 
                                printk("hole\n");
                           )
                        
                        /* New second frag pointing to this's node */
                        newfrag2->ofs = newfrag->ofs + newfrag->size;
                        newfrag2->size = (this->ofs+this->size) - newfrag2->ofs;
                        newfrag2->node = this->node;
                        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, list);
                        
                        jffs2_fragtree_insert(newfrag2, newfrag);
                        rb_insert_color(&newfrag2->rb, list);
                        
                        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, list);
        } else {
                /* New frag starts at the same point as 'this' used to. Replace 
                   it in the tree without doing a delete and insertion */
                D2(printk(KERN_DEBUG "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, list);
                
                if (newfrag->ofs + newfrag->size >= this->ofs+this->size) {
                        D2(printk(KERN_DEBUG "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, list);
                        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. */
                D2(printk(KERN_DEBUG "Obsoleting node frag %p (%x-%x) and removing from tree\n", this, this->ofs, this->ofs+this->size));
                rb_erase(&this->rb, list);
                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;
}

void jffs2_truncate_fraglist (struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
{
        struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);

        D1(printk(KERN_DEBUG "Truncating fraglist 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) {
                        D1(printk(KERN_DEBUG "Truncating frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size));
                        frag->size = size - frag->ofs;
                }
                frag = frag_next(frag);
        }
        while (frag && frag->ofs >= size) {
                struct jffs2_node_frag *next = frag_next(frag);

                D1(printk(KERN_DEBUG "Removing frag 0x%08x-0x%08x\n", frag->ofs, frag->ofs+frag->size));
                frag_erase(frag, list);
                jffs2_obsolete_node_frag(c, frag);
                frag = next;
        }
}

/* Scan the list of all nodes present for this ino, build map of versions, etc. */

static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c, 
                                        struct jffs2_inode_info *f,
                                        struct jffs2_raw_inode *latest_node);

int jffs2_do_read_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, 
                        uint32_t ino, struct jffs2_raw_inode *latest_node)
{
        D2(printk(KERN_DEBUG "jffs2_do_read_inode(): getting inocache\n"));

 retry_inocache:
        spin_lock(&c->inocache_lock);
        f->inocache = jffs2_get_ino_cache(c, ino);

        D2(printk(KERN_DEBUG "jffs2_do_read_inode(): Got inocache at %p\n", f->inocache));

        if (f->inocache) {
                /* Check its state. We may need to wait before we can use it */
                switch(f->inocache->state) {
                case INO_STATE_UNCHECKED:
                case INO_STATE_CHECKEDABSENT:
                        f->inocache->state = INO_STATE_READING;
                        break;
                        
                case INO_STATE_CHECKING:
                case INO_STATE_GC:
                        /* If it's in either of these states, we need
                           to wait for whoever's got it to finish and
                           put it back. */
                        D1(printk(KERN_DEBUG "jffs2_get_ino_cache_read waiting for ino #%u in state %d\n",
                                  ino, f->inocache->state));
                        sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
                        goto retry_inocache;

                case INO_STATE_READING:
                case INO_STATE_PRESENT:
                        /* Eep. This should never happen. It can
                        happen if Linux calls read_inode() again
                        before clear_inode() has finished though. */
                        printk(KERN_WARNING "Eep. Trying to read_inode #%u when it's already in state %d!\n", ino, f->inocache->state);
                        /* Fail. That's probably better than allowing it to succeed */
                        f->inocache = NULL;
                        break;

                default:
                        BUG();
                }
        }
        spin_unlock(&c->inocache_lock);

        if (!f->inocache && ino == 1) {
                /* Special case - no root inode on medium */
                f->inocache = jffs2_alloc_inode_cache();
                if (!f->inocache) {
                        printk(KERN_CRIT "jffs2_do_read_inode(): Cannot allocate inocache for root inode\n");
                        return -ENOMEM;
                }
                D1(printk(KERN_DEBUG "jffs2_do_read_inode(): Creating inocache for root inode\n"));
                memset(f->inocache, 0, sizeof(struct jffs2_inode_cache));
                f->inocache->ino = f->inocache->nlink = 1;
                f->inocache->nodes = (struct jffs2_raw_node_ref *)f->inocache;
                f->inocache->state = INO_STATE_READING;
                jffs2_add_ino_cache(c, f->inocache);
        }
        if (!f->inocache) {
                printk(KERN_WARNING "jffs2_do_read_inode() on nonexistent ino %u\n", ino);
                return -ENOENT;
        }

        return jffs2_do_read_inode_internal(c, f, latest_node);
}

int jffs2_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic)
{
        struct jffs2_raw_inode n;
        struct jffs2_inode_info *f = kmalloc(sizeof(*f), GFP_KERNEL);
        int ret;

        if (!f)
                return -ENOMEM;

        memset(f, 0, sizeof(*f));
        init_MUTEX_LOCKED(&f->sem);
        f->inocache = ic;

        ret = jffs2_do_read_inode_internal(c, f, &n);
        if (!ret) {
                up(&f->sem);
                jffs2_do_clear_inode(c, f);
        }
        kfree (f);
        return ret;
}

static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c, 
                                        struct jffs2_inode_info *f,
                                        struct jffs2_raw_inode *latest_node)
{
        struct jffs2_tmp_dnode_info *tn = NULL;
        struct rb_root tn_list;
        struct rb_node *rb, *repl_rb;
        struct jffs2_full_dirent *fd_list;
        struct jffs2_full_dnode *fn = NULL;
        uint32_t crc;
        uint32_t latest_mctime, mctime_ver;
        uint32_t mdata_ver = 0;
        size_t retlen;
        int ret;

        D1(printk(KERN_DEBUG "jffs2_do_read_inode_internal(): ino #%u nlink is %d\n", f->inocache->ino, f->inocache->nlink));

        /* Grab all nodes relevant to this ino */
        ret = jffs2_get_inode_nodes(c, f, &tn_list, &fd_list, &f->highest_version, &latest_mctime, &mctime_ver);

        if (ret) {
                printk(KERN_CRIT "jffs2_get_inode_nodes() for ino %u returned %d\n", f->inocache->ino, ret);
                if (f->inocache->state == INO_STATE_READING)
                        jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
                return ret;
        }
        f->dents = fd_list;

        rb = rb_first(&tn_list);

        while (rb) {
                tn = rb_entry(rb, struct jffs2_tmp_dnode_info, rb);
                fn = tn->fn;

                if (f->metadata) {
                        if (likely(tn->version >= mdata_ver)) {
                                D1(printk(KERN_DEBUG "Obsoleting old metadata at 0x%08x\n", ref_offset(f->metadata->raw)));
                                jffs2_mark_node_obsolete(c, f->metadata->raw);
                                jffs2_free_full_dnode(f->metadata);
                                f->metadata = NULL;
                                
                                mdata_ver = 0;
                        } else {
                                /* This should never happen. */
                                printk(KERN_WARNING "Er. New metadata at 0x%08x with ver %d is actually older than previous ver %d at 0x%08x\n",
                                          ref_offset(fn->raw), tn->version, mdata_ver, ref_offset(f->metadata->raw));
                                jffs2_mark_node_obsolete(c, fn->raw);
                                jffs2_free_full_dnode(fn);
                                /* Fill in latest_node from the metadata, not this one we're about to free... */
                                fn = f->metadata;
                                goto next_tn;
                        }
                }

                if (fn->size) {
                        jffs2_add_full_dnode_to_inode(c, f, fn);
                } else {
                        /* Zero-sized node at end of version list. Just a metadata update */
                        D1(printk(KERN_DEBUG "metadata @%08x: ver %d\n", ref_offset(fn->raw), tn->version));
                        f->metadata = fn;
                        mdata_ver = tn->version;
                }
        next_tn:
                BUG_ON(rb->rb_left);
                if (rb->rb_parent && rb->rb_parent->rb_left == rb) {
                        /* We were then left-hand child of our parent. We need
                           to move our own right-hand child into our place. */
                        repl_rb = rb->rb_right;
                        if (repl_rb)
                                repl_rb->rb_parent = rb->rb_parent;
                } else
                        repl_rb = NULL;

                rb = rb_next(rb);

                /* Remove the spent tn from the tree; don't bother rebalancing
                   but put our right-hand child in our own place. */
                if (tn->rb.rb_parent) {
                        if (tn->rb.rb_parent->rb_left == &tn->rb)
                                tn->rb.rb_parent->rb_left = repl_rb;
                        else if (tn->rb.rb_parent->rb_right == &tn->rb)
                                tn->rb.rb_parent->rb_right = repl_rb;
                        else BUG();
                } else if (tn->rb.rb_right)
                        tn->rb.rb_right->rb_parent = NULL;

                jffs2_free_tmp_dnode_info(tn);
        }
        jffs2_dbg_fragtree_paranoia_check_nolock(f);

        if (!fn) {
                /* No data nodes for this inode. */
                if (f->inocache->ino != 1) {
                        printk(KERN_WARNING "jffs2_do_read_inode(): No data nodes found for ino #%u\n", f->inocache->ino);
                        if (!fd_list) {
                                if (f->inocache->state == INO_STATE_READING)
                                        jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
                                return -EIO;
                        }
                        printk(KERN_WARNING "jffs2_do_read_inode(): But it has children so we fake some modes for it\n");
                }
                latest_node->mode = cpu_to_jemode(S_IFDIR|S_IRUGO|S_IWUSR|S_IXUGO);
                latest_node->version = cpu_to_je32(0);
                latest_node->atime = latest_node->ctime = latest_node->mtime = cpu_to_je32(0);
                latest_node->isize = cpu_to_je32(0);
                latest_node->gid = cpu_to_je16(0);
                latest_node->uid = cpu_to_je16(0);
                if (f->inocache->state == INO_STATE_READING)
                        jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);
                return 0;
        }

        ret = jffs2_flash_read(c, ref_offset(fn->raw), sizeof(*latest_node), &retlen, (void *)latest_node);
        if (ret || retlen != sizeof(*latest_node)) {
                printk(KERN_NOTICE "MTD read in jffs2_do_read_inode() failed: Returned %d, %zd of %zd bytes read\n",
                       ret, retlen, sizeof(*latest_node));
                /* FIXME: If this fails, there seems to be a memory leak. Find it. */
                up(&f->sem);
                jffs2_do_clear_inode(c, f);
                return ret?ret:-EIO;
        }

        crc = crc32(0, latest_node, sizeof(*latest_node)-8);
        if (crc != je32_to_cpu(latest_node->node_crc)) {
                printk(KERN_NOTICE "CRC failed for read_inode of inode %u at physical location 0x%x\n", f->inocache->ino, ref_offset(fn->raw));
                up(&f->sem);
                jffs2_do_clear_inode(c, f);
                return -EIO;
        }

        switch(jemode_to_cpu(latest_node->mode) & S_IFMT) {
        case S_IFDIR:
                if (mctime_ver > je32_to_cpu(latest_node->version)) {
                        /* The times in the latest_node are actually older than
                           mctime in the latest dirent. Cheat. */
                        latest_node->ctime = latest_node->mtime = cpu_to_je32(latest_mctime);
                }
                break;

                        
        case S_IFREG:
                /* If it was a regular file, truncate it to the latest node's isize */
                jffs2_truncate_fraglist(c, &f->fragtree, je32_to_cpu(latest_node->isize));
                break;

        case S_IFLNK:
                /* Hack to work around broken isize in old symlink code.
                   Remove this when dwmw2 comes to his senses and stops
                   symlinks from being an entirely gratuitous special
                   case. */
                if (!je32_to_cpu(latest_node->isize))
                        latest_node->isize = latest_node->dsize;

                if (f->inocache->state != INO_STATE_CHECKING) {
                        /* Symlink's inode data is the target path. Read it and
                         * keep in RAM to facilitate quick follow symlink
                         * operation. */
                        f->target = kmalloc(je32_to_cpu(latest_node->csize) + 1, GFP_KERNEL);
                        if (!f->target) {
                                printk(KERN_WARNING "Can't allocate %d bytes of memory "
                                                "for the symlink target path cache\n",
                                                je32_to_cpu(latest_node->csize));
                                up(&f->sem);
                                jffs2_do_clear_inode(c, f);
                                return -ENOMEM;
                        }
                        
                        ret = jffs2_flash_read(c, ref_offset(fn->raw) + sizeof(*latest_node),
                                                je32_to_cpu(latest_node->csize), &retlen, (char *)f->target);
                        
                        if (ret  || retlen != je32_to_cpu(latest_node->csize)) {
                                if (retlen != je32_to_cpu(latest_node->csize))
                                        ret = -EIO;
                                kfree(f->target);
                                f->target = NULL;
                                up(&f->sem);
                                jffs2_do_clear_inode(c, f);
                                return -ret;
                        }

                        f->target[je32_to_cpu(latest_node->csize)] = '\0';
                        D1(printk(KERN_DEBUG "jffs2_do_read_inode(): symlink's target '%s' cached\n",
                                                f->target));
                }
                
                /* fall through... */

        case S_IFBLK:
        case S_IFCHR:
                /* Certain inode types should have only one data node, and it's
                   kept as the metadata node */
                if (f->metadata) {
                        printk(KERN_WARNING "Argh. Special inode #%u with mode 0%o had metadata node\n",
                               f->inocache->ino, jemode_to_cpu(latest_node->mode));
                        up(&f->sem);
                        jffs2_do_clear_inode(c, f);
                        return -EIO;
                }
                if (!frag_first(&f->fragtree)) {
                        printk(KERN_WARNING "Argh. Special inode #%u with mode 0%o has no fragments\n",
                               f->inocache->ino, jemode_to_cpu(latest_node->mode));
                        up(&f->sem);
                        jffs2_do_clear_inode(c, f);
                        return -EIO;
                }
                /* ASSERT: f->fraglist != NULL */
                if (frag_next(frag_first(&f->fragtree))) {
                        printk(KERN_WARNING "Argh. Special inode #%u with mode 0x%x had more than one node\n",
                               f->inocache->ino, jemode_to_cpu(latest_node->mode));
                        /* FIXME: Deal with it - check crc32, check for duplicate node, check times and discard the older one */
                        up(&f->sem);
                        jffs2_do_clear_inode(c, f);
                        return -EIO;
                }
                /* OK. We're happy */
                f->metadata = frag_first(&f->fragtree)->node;
                jffs2_free_node_frag(frag_first(&f->fragtree));
                f->fragtree = RB_ROOT;
                break;
        }
        if (f->inocache->state == INO_STATE_READING)
                jffs2_set_inocache_state(c, f->inocache, INO_STATE_PRESENT);

        return 0;
}

void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f)
{
        struct jffs2_full_dirent *fd, *fds;
        int deleted;

        down(&f->sem);
        deleted = f->inocache && !f->inocache->nlink;

        if (f->inocache && f->inocache->state != INO_STATE_CHECKING)
                jffs2_set_inocache_state(c, f->inocache, INO_STATE_CLEARING);

        if (f->metadata) {
                if (deleted)
                        jffs2_mark_node_obsolete(c, f->metadata->raw);
                jffs2_free_full_dnode(f->metadata);
        }

        jffs2_kill_fragtree(&f->fragtree, deleted?c:NULL);

        if (f->target) {
                kfree(f->target);
                f->target = NULL;
        }
        
        fds = f->dents;
        while(fds) {
                fd = fds;
                fds = fd->next;
                jffs2_free_full_dirent(fd);
        }

        if (f->inocache && f->inocache->state != INO_STATE_CHECKING) {
                jffs2_set_inocache_state(c, f->inocache, INO_STATE_CHECKEDABSENT);
                if (f->inocache->nodes == (void *)f->inocache)
                        jffs2_del_ino_cache(c, f->inocache);
        }

        up(&f->sem);
}