/*
   * JFFS2 -- Journalling Flash File System, Version 2.
   *

   * Copyright © 2001-2007 Red Hat, Inc.

   * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>

   *
   * 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/slab.h>

  #include <linux/fs.h>
  #include <linux/crc32.h>
  #include <linux/jffs2.h>

  #include "jffs2_fs_i.h"
  #include "jffs2_fs_sb.h"

  #include <linux/time.h>
  #include "nodelist.h"

  static int jffs2_readdir (struct file *, struct dir_context *);

  static int jffs2_create (struct inode *,struct dentry *,umode_t,

  			 bool);

  static struct dentry *jffs2_lookup (struct inode *,struct dentry *,

  				    unsigned int);

  static int jffs2_link (struct dentry *,struct inode *,struct dentry *);
  static int jffs2_unlink (struct inode *,struct dentry *);
  static int jffs2_symlink (struct inode *,struct dentry *,const char *);

  static int jffs2_mkdir (struct inode *,struct dentry *,umode_t);

  static int jffs2_rmdir (struct inode *,struct dentry *);

  static int jffs2_mknod (struct inode *,struct dentry *,umode_t,dev_t);

  static int jffs2_rename (struct inode *, struct dentry *,

  			 struct inode *, struct dentry *);

  const struct file_operations jffs2_dir_operations =

  {
  	.read =		generic_read_dir,

  	.iterate =	jffs2_readdir,

  	.unlocked_ioctl=jffs2_ioctl,

  	.fsync =	jffs2_fsync,
  	.llseek =	generic_file_llseek,

  };

  const struct inode_operations jffs2_dir_inode_operations =

  {

  	.create =	jffs2_create,
  	.lookup =	jffs2_lookup,

  	.link =		jffs2_link,
  	.unlink =	jffs2_unlink,
  	.symlink =	jffs2_symlink,
  	.mkdir =	jffs2_mkdir,
  	.rmdir =	jffs2_rmdir,
  	.mknod =	jffs2_mknod,
  	.rename =	jffs2_rename,

  	.get_acl =	jffs2_get_acl,

  	.set_acl =	jffs2_set_acl,

  	.setattr =	jffs2_setattr,

  	.setxattr =	jffs2_setxattr,
  	.getxattr =	jffs2_getxattr,
  	.listxattr =	jffs2_listxattr,
  	.removexattr =	jffs2_removexattr

  };
  
  /***********************************************************************/
  
  
  /* We keep the dirent list sorted in increasing order of name hash,

     and we use the same hash function as the dentries. Makes this

     nice and simple
  */
  static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,

  				   unsigned int flags)

  {
  	struct jffs2_inode_info *dir_f;

  	struct jffs2_full_dirent *fd = NULL, *fd_list;
  	uint32_t ino = 0;
  	struct inode *inode = NULL;

  	jffs2_dbg(1, "jffs2_lookup()
  ");

  	if (target->d_name.len > JFFS2_MAX_NAME_LEN)
  		return ERR_PTR(-ENAMETOOLONG);

  	dir_f = JFFS2_INODE_INFO(dir_i);

  	mutex_lock(&dir_f->sem);

  
  	/* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
  	for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= target->d_name.hash; fd_list = fd_list->next) {

  		if (fd_list->nhash == target->d_name.hash &&

  		    (!fd || fd_list->version > fd->version) &&
  		    strlen(fd_list->name) == target->d_name.len &&
  		    !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) {
  			fd = fd_list;
  		}
  	}
  	if (fd)
  		ino = fd->ino;

  	mutex_unlock(&dir_f->sem);

  	if (ino) {

  		inode = jffs2_iget(dir_i->i_sb, ino);

  		if (IS_ERR(inode))

  			pr_warn("iget() failed for ino #%u
  ", ino);

  	}

  	return d_splice_alias(inode, target);

  }
  
  /***********************************************************************/

  static int jffs2_readdir(struct file *file, struct dir_context *ctx)

  {

  	struct inode *inode = file_inode(file);
  	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);

  	struct jffs2_full_dirent *fd;

  	unsigned long curofs = 1;

  	jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu
  ", inode->i_ino);

  	if (!dir_emit_dots(file, ctx))
  		return 0;

  	mutex_lock(&f->sem);

  	for (fd = f->dents; fd; fd = fd->next) {

  		curofs++;

  		/* First loop: curofs = 2; pos = 2 */
  		if (curofs < ctx->pos) {

  			jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld
  ",

  				  fd->name, fd->ino, fd->type, curofs, (unsigned long)ctx->pos);

  			continue;
  		}
  		if (!fd->ino) {

  			jffs2_dbg(2, "Skipping deletion dirent \"%s\"
  ",
  				  fd->name);

  			ctx->pos++;

  			continue;
  		}

  		jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d
  ",

  			  (unsigned long)ctx->pos, fd->name, fd->ino, fd->type);
  		if (!dir_emit(ctx, fd->name, strlen(fd->name), fd->ino, fd->type))

  			break;

  		ctx->pos++;

  	}

  	mutex_unlock(&f->sem);

  	return 0;
  }
  
  /***********************************************************************/

  static int jffs2_create(struct inode *dir_i, struct dentry *dentry,

  			umode_t mode, bool excl)

  {
  	struct jffs2_raw_inode *ri;
  	struct jffs2_inode_info *f, *dir_f;
  	struct jffs2_sb_info *c;
  	struct inode *inode;
  	int ret;
  
  	ri = jffs2_alloc_raw_inode();
  	if (!ri)
  		return -ENOMEM;

  	c = JFFS2_SB_INFO(dir_i->i_sb);

  	jffs2_dbg(1, "%s()
  ", __func__);

  	inode = jffs2_new_inode(dir_i, mode, ri);

  
  	if (IS_ERR(inode)) {

  		jffs2_dbg(1, "jffs2_new_inode() failed
  ");

  		jffs2_free_raw_inode(ri);
  		return PTR_ERR(inode);
  	}
  
  	inode->i_op = &jffs2_file_inode_operations;
  	inode->i_fop = &jffs2_file_operations;
  	inode->i_mapping->a_ops = &jffs2_file_address_operations;
  	inode->i_mapping->nrpages = 0;
  
  	f = JFFS2_INODE_INFO(inode);
  	dir_f = JFFS2_INODE_INFO(dir_i);

  	/* jffs2_do_create() will want to lock it, _after_ reserving
  	   space and taking c-alloc_sem. If we keep it locked here,
  	   lockdep gets unhappy (although it's a false positive;
  	   nothing else will be looking at this inode yet so there's
  	   no chance of AB-BA deadlock involving its f->sem). */
  	mutex_unlock(&f->sem);

  	ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);

  	if (ret)
  		goto fail;

  
  	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
  
  	jffs2_free_raw_inode(ri);

  	jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld
  ",
  		  __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
  		  f->inocache->pino_nlink, inode->i_mapping->nrpages);

  	unlock_new_inode(inode);

  	d_instantiate(dentry, inode);

  	return 0;

  
   fail:

  	iget_failed(inode);

  	jffs2_free_raw_inode(ri);
  	return ret;

  }
  
  /***********************************************************************/
  
  
  static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
  {
  	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
  	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);

  	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode(dentry));

  	int ret;

  	uint32_t now = get_seconds();

  	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,

  			      dentry->d_name.len, dead_f, now);

  	if (dead_f->inocache)

  		set_nlink(d_inode(dentry), dead_f->inocache->pino_nlink);

  	if (!ret)
  		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);

  	return ret;
  }
  /***********************************************************************/
  
  
  static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
  {

  	struct jffs2_sb_info *c = JFFS2_SB_INFO(d_inode(old_dentry)->i_sb);
  	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));

  	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
  	int ret;
  	uint8_t type;

  	uint32_t now;

  
  	/* Don't let people make hard links to bad inodes. */
  	if (!f->inocache)
  		return -EIO;

  	if (d_is_dir(old_dentry))

  		return -EPERM;
  
  	/* XXX: This is ugly */

  	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;

  	if (!type) type = DT_REG;

  	now = get_seconds();
  	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);

  
  	if (!ret) {

  		mutex_lock(&f->sem);

  		set_nlink(d_inode(old_dentry), ++f->inocache->pino_nlink);

  		mutex_unlock(&f->sem);

  		d_instantiate(dentry, d_inode(old_dentry));

  		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);

  		ihold(d_inode(old_dentry));

  	}
  	return ret;
  }
  
  /***********************************************************************/
  
  static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
  {
  	struct jffs2_inode_info *f, *dir_f;
  	struct jffs2_sb_info *c;
  	struct inode *inode;
  	struct jffs2_raw_inode *ri;
  	struct jffs2_raw_dirent *rd;
  	struct jffs2_full_dnode *fn;
  	struct jffs2_full_dirent *fd;
  	int namelen;

  	uint32_t alloclen;

  	int ret, targetlen = strlen(target);

  
  	/* FIXME: If you care. We'd need to use frags for the target
  	   if it grows much more than this */

  	if (targetlen > 254)

  		return -ENAMETOOLONG;

  
  	ri = jffs2_alloc_raw_inode();
  
  	if (!ri)
  		return -ENOMEM;

  	c = JFFS2_SB_INFO(dir_i->i_sb);

  
  	/* Try to reserve enough space for both node and dirent.
  	 * Just the node will do for now, though

  	 */
  	namelen = dentry->d_name.len;

  	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
  				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);

  
  	if (ret) {
  		jffs2_free_raw_inode(ri);
  		return ret;
  	}

  	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);

  
  	if (IS_ERR(inode)) {
  		jffs2_free_raw_inode(ri);
  		jffs2_complete_reservation(c);
  		return PTR_ERR(inode);
  	}
  
  	inode->i_op = &jffs2_symlink_inode_operations;
  
  	f = JFFS2_INODE_INFO(inode);

  	inode->i_size = targetlen;

  	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
  	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
  	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
  
  	ri->compr = JFFS2_COMPR_NONE;

  	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));

  	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));

  	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);

  
  	jffs2_free_raw_inode(ri);
  
  	if (IS_ERR(fn)) {
  		/* Eeek. Wave bye bye */

  		mutex_unlock(&f->sem);

  		jffs2_complete_reservation(c);

  		ret = PTR_ERR(fn);
  		goto fail;

  	}

  	/* We use f->target field to store the target path. */

  	f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);

  	if (!f->target) {

  		pr_warn("Can't allocate %d bytes of memory
  ", targetlen + 1);

  		mutex_unlock(&f->sem);

  		jffs2_complete_reservation(c);

  		ret = -ENOMEM;
  		goto fail;

  	}

  	inode->i_link = f->target;

  	jffs2_dbg(1, "%s(): symlink's target '%s' cached
  ",
  		  __func__, (char *)f->target);

  	/* No data here. Only a metadata node, which will be

  	   obsoleted by the first data write
  	*/
  	f->metadata = fn;

  	mutex_unlock(&f->sem);

  
  	jffs2_complete_reservation(c);

  	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);

  	if (ret)
  		goto fail;

  	ret = jffs2_init_acl_post(inode);

  	if (ret)
  		goto fail;

  	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
  				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));

  	if (ret)
  		goto fail;

  
  	rd = jffs2_alloc_raw_dirent();
  	if (!rd) {
  		/* Argh. Now we treat it like a normal delete */
  		jffs2_complete_reservation(c);

  		ret = -ENOMEM;
  		goto fail;

  	}
  
  	dir_f = JFFS2_INODE_INFO(dir_i);

  	mutex_lock(&dir_f->sem);

  
  	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
  	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
  	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
  	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
  
  	rd->pino = cpu_to_je32(dir_i->i_ino);
  	rd->version = cpu_to_je32(++dir_f->highest_version);
  	rd->ino = cpu_to_je32(inode->i_ino);
  	rd->mctime = cpu_to_je32(get_seconds());
  	rd->nsize = namelen;
  	rd->type = DT_LNK;
  	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
  	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));

  	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);

  
  	if (IS_ERR(fd)) {

  		/* dirent failed to write. Delete the inode normally

  		   as if it were the final unlink() */
  		jffs2_complete_reservation(c);
  		jffs2_free_raw_dirent(rd);

  		mutex_unlock(&dir_f->sem);

  		ret = PTR_ERR(fd);
  		goto fail;

  	}
  
  	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
  
  	jffs2_free_raw_dirent(rd);
  
  	/* Link the fd into the inode's list, obsoleting an old
  	   one if necessary. */
  	jffs2_add_fd_to_list(c, fd, &dir_f->dents);

  	mutex_unlock(&dir_f->sem);

  	jffs2_complete_reservation(c);

  	unlock_new_inode(inode);

  	d_instantiate(dentry, inode);

  	return 0;

  
   fail:

  	iget_failed(inode);

  	return ret;

  }

  static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)

  {
  	struct jffs2_inode_info *f, *dir_f;
  	struct jffs2_sb_info *c;
  	struct inode *inode;
  	struct jffs2_raw_inode *ri;
  	struct jffs2_raw_dirent *rd;
  	struct jffs2_full_dnode *fn;
  	struct jffs2_full_dirent *fd;
  	int namelen;

  	uint32_t alloclen;

  	int ret;
  
  	mode |= S_IFDIR;
  
  	ri = jffs2_alloc_raw_inode();
  	if (!ri)
  		return -ENOMEM;

  	c = JFFS2_SB_INFO(dir_i->i_sb);

  	/* Try to reserve enough space for both node and dirent.
  	 * Just the node will do for now, though

  	 */
  	namelen = dentry->d_name.len;

  	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
  				  JFFS2_SUMMARY_INODE_SIZE);

  
  	if (ret) {
  		jffs2_free_raw_inode(ri);
  		return ret;
  	}

  	inode = jffs2_new_inode(dir_i, mode, ri);

  
  	if (IS_ERR(inode)) {
  		jffs2_free_raw_inode(ri);
  		jffs2_complete_reservation(c);
  		return PTR_ERR(inode);
  	}
  
  	inode->i_op = &jffs2_dir_inode_operations;
  	inode->i_fop = &jffs2_dir_operations;

  
  	f = JFFS2_INODE_INFO(inode);

  	/* Directories get nlink 2 at start */

  	set_nlink(inode, 2);

  	/* but ic->pino_nlink is the parent ino# */
  	f->inocache->pino_nlink = dir_i->i_ino;

  	ri->data_crc = cpu_to_je32(0);
  	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));

  	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);

  
  	jffs2_free_raw_inode(ri);
  
  	if (IS_ERR(fn)) {
  		/* Eeek. Wave bye bye */

  		mutex_unlock(&f->sem);

  		jffs2_complete_reservation(c);

  		ret = PTR_ERR(fn);
  		goto fail;

  	}

  	/* No data here. Only a metadata node, which will be

  	   obsoleted by the first data write
  	*/
  	f->metadata = fn;

  	mutex_unlock(&f->sem);

  
  	jffs2_complete_reservation(c);

  	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);

  	if (ret)
  		goto fail;

  	ret = jffs2_init_acl_post(inode);

  	if (ret)
  		goto fail;

  	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
  				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));

  	if (ret)
  		goto fail;

  	rd = jffs2_alloc_raw_dirent();
  	if (!rd) {
  		/* Argh. Now we treat it like a normal delete */
  		jffs2_complete_reservation(c);

  		ret = -ENOMEM;
  		goto fail;

  	}
  
  	dir_f = JFFS2_INODE_INFO(dir_i);

  	mutex_lock(&dir_f->sem);

  
  	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
  	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
  	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
  	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
  
  	rd->pino = cpu_to_je32(dir_i->i_ino);
  	rd->version = cpu_to_je32(++dir_f->highest_version);
  	rd->ino = cpu_to_je32(inode->i_ino);
  	rd->mctime = cpu_to_je32(get_seconds());
  	rd->nsize = namelen;
  	rd->type = DT_DIR;
  	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
  	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));

  	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);

  	if (IS_ERR(fd)) {

  		/* dirent failed to write. Delete the inode normally

  		   as if it were the final unlink() */
  		jffs2_complete_reservation(c);
  		jffs2_free_raw_dirent(rd);

  		mutex_unlock(&dir_f->sem);

  		ret = PTR_ERR(fd);
  		goto fail;

  	}
  
  	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));

  	inc_nlink(dir_i);

  
  	jffs2_free_raw_dirent(rd);
  
  	/* Link the fd into the inode's list, obsoleting an old
  	   one if necessary. */
  	jffs2_add_fd_to_list(c, fd, &dir_f->dents);

  	mutex_unlock(&dir_f->sem);

  	jffs2_complete_reservation(c);

  	unlock_new_inode(inode);

  	d_instantiate(dentry, inode);

  	return 0;

  
   fail:

  	iget_failed(inode);

  	return ret;

  }
  
  static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
  {

  	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
  	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);

  	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));

  	struct jffs2_full_dirent *fd;
  	int ret;

  	uint32_t now = get_seconds();

  
  	for (fd = f->dents ; fd; fd = fd->next) {
  		if (fd->ino)
  			return -ENOTEMPTY;
  	}

  
  	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
  			      dentry->d_name.len, f, now);
  	if (!ret) {
  		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);

  		clear_nlink(d_inode(dentry));

  		drop_nlink(dir_i);

  	}

  	return ret;
  }

  static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)

  {
  	struct jffs2_inode_info *f, *dir_f;
  	struct jffs2_sb_info *c;
  	struct inode *inode;
  	struct jffs2_raw_inode *ri;
  	struct jffs2_raw_dirent *rd;
  	struct jffs2_full_dnode *fn;
  	struct jffs2_full_dirent *fd;
  	int namelen;

  	union jffs2_device_node dev;

  	int devlen = 0;

  	uint32_t alloclen;

  	int ret;

  	ri = jffs2_alloc_raw_inode();
  	if (!ri)
  		return -ENOMEM;

  	c = JFFS2_SB_INFO(dir_i->i_sb);

  	if (S_ISBLK(mode) || S_ISCHR(mode))
  		devlen = jffs2_encode_dev(&dev, rdev);

  
  	/* Try to reserve enough space for both node and dirent.
  	 * Just the node will do for now, though

  	 */
  	namelen = dentry->d_name.len;

  	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,

  				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);

  
  	if (ret) {
  		jffs2_free_raw_inode(ri);
  		return ret;
  	}

  	inode = jffs2_new_inode(dir_i, mode, ri);

  
  	if (IS_ERR(inode)) {
  		jffs2_free_raw_inode(ri);
  		jffs2_complete_reservation(c);
  		return PTR_ERR(inode);
  	}
  	inode->i_op = &jffs2_file_inode_operations;
  	init_special_inode(inode, inode->i_mode, rdev);
  
  	f = JFFS2_INODE_INFO(inode);
  
  	ri->dsize = ri->csize = cpu_to_je32(devlen);
  	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
  	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
  
  	ri->compr = JFFS2_COMPR_NONE;
  	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
  	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));

  	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);

  
  	jffs2_free_raw_inode(ri);
  
  	if (IS_ERR(fn)) {
  		/* Eeek. Wave bye bye */

  		mutex_unlock(&f->sem);

  		jffs2_complete_reservation(c);

  		ret = PTR_ERR(fn);
  		goto fail;

  	}

  	/* No data here. Only a metadata node, which will be

  	   obsoleted by the first data write
  	*/
  	f->metadata = fn;

  	mutex_unlock(&f->sem);

  
  	jffs2_complete_reservation(c);

  	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);

  	if (ret)
  		goto fail;

  	ret = jffs2_init_acl_post(inode);

  	if (ret)
  		goto fail;

  	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
  				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));

  	if (ret)
  		goto fail;

  
  	rd = jffs2_alloc_raw_dirent();
  	if (!rd) {
  		/* Argh. Now we treat it like a normal delete */
  		jffs2_complete_reservation(c);

  		ret = -ENOMEM;
  		goto fail;

  	}
  
  	dir_f = JFFS2_INODE_INFO(dir_i);

  	mutex_lock(&dir_f->sem);

  
  	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
  	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
  	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
  	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
  
  	rd->pino = cpu_to_je32(dir_i->i_ino);
  	rd->version = cpu_to_je32(++dir_f->highest_version);
  	rd->ino = cpu_to_je32(inode->i_ino);
  	rd->mctime = cpu_to_je32(get_seconds());
  	rd->nsize = namelen;
  
  	/* XXX: This is ugly. */
  	rd->type = (mode & S_IFMT) >> 12;
  
  	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
  	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));

  	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);

  	if (IS_ERR(fd)) {

  		/* dirent failed to write. Delete the inode normally

  		   as if it were the final unlink() */
  		jffs2_complete_reservation(c);
  		jffs2_free_raw_dirent(rd);

  		mutex_unlock(&dir_f->sem);

  		ret = PTR_ERR(fd);
  		goto fail;

  	}
  
  	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
  
  	jffs2_free_raw_dirent(rd);
  
  	/* Link the fd into the inode's list, obsoleting an old
  	   one if necessary. */
  	jffs2_add_fd_to_list(c, fd, &dir_f->dents);

  	mutex_unlock(&dir_f->sem);

  	jffs2_complete_reservation(c);

  	unlock_new_inode(inode);

  	d_instantiate(dentry, inode);

  	return 0;

  
   fail:

  	iget_failed(inode);

  	return ret;

  }
  
  static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,

  			 struct inode *new_dir_i, struct dentry *new_dentry)

  {
  	int ret;
  	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
  	struct jffs2_inode_info *victim_f = NULL;
  	uint8_t type;

  	uint32_t now;

  	/* The VFS will check for us and prevent trying to rename a

  	 * file over a directory and vice versa, but if it's a directory,
  	 * the VFS can't check whether the victim is empty. The filesystem
  	 * needs to do that for itself.
  	 */

  	if (d_really_is_positive(new_dentry)) {
  		victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));

  		if (d_is_dir(new_dentry)) {

  			struct jffs2_full_dirent *fd;

  			mutex_lock(&victim_f->sem);

  			for (fd = victim_f->dents; fd; fd = fd->next) {
  				if (fd->ino) {

  					mutex_unlock(&victim_f->sem);

  					return -ENOTEMPTY;
  				}
  			}

  			mutex_unlock(&victim_f->sem);

  		}
  	}
  
  	/* XXX: We probably ought to alloc enough space for

  	   both nodes at the same time. Writing the new link,

  	   then getting -ENOSPC, is quite bad :)
  	*/
  
  	/* Make a hard link */

  	/* XXX: This is ugly */

  	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;

  	if (!type) type = DT_REG;

  	now = get_seconds();

  	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),

  			    d_inode(old_dentry)->i_ino, type,

  			    new_dentry->d_name.name, new_dentry->d_name.len, now);

  
  	if (ret)
  		return ret;
  
  	if (victim_f) {
  		/* There was a victim. Kill it off nicely */

  		if (d_is_dir(new_dentry))

  			clear_nlink(d_inode(new_dentry));

  		else

  			drop_nlink(d_inode(new_dentry));

  		/* Don't oops if the victim was a dirent pointing to an
  		   inode which didn't exist. */
  		if (victim_f->inocache) {

  			mutex_lock(&victim_f->sem);

  			if (d_is_dir(new_dentry))

  				victim_f->inocache->pino_nlink = 0;
  			else
  				victim_f->inocache->pino_nlink--;

  			mutex_unlock(&victim_f->sem);

  		}
  	}

  	/* If it was a directory we moved, and there was no victim,

  	   increase i_nlink on its new parent */

  	if (d_is_dir(old_dentry) && !victim_f)

  		inc_nlink(new_dir_i);

  
  	/* Unlink the original */

  	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),

  			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);

  
  	/* We don't touch inode->i_nlink */
  
  	if (ret) {
  		/* Oh shit. We really ought to make a single node which can do both atomically */

  		struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));

  		mutex_lock(&f->sem);

  		inc_nlink(d_inode(old_dentry));

  		if (f->inocache && !d_is_dir(old_dentry))

  			f->inocache->pino_nlink++;

  		mutex_unlock(&f->sem);

  		pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link
  ",
  			  __func__, ret);

  		/*
  		 * We can't keep the target in dcache after that.
  		 * For one thing, we can't afford dentry aliases for directories.
  		 * For another, if there was a victim, we _can't_ set new inode
  		 * for that sucker and we have to trigger mount eviction - the
  		 * caller won't do it on its own since we are returning an error.
  		 */
  		d_invalidate(new_dentry);

  		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);

  		return ret;
  	}

  	if (d_is_dir(old_dentry))

  		drop_nlink(old_dir_i);

  	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);

  	return 0;
  }