dir.c

jffs2源代码基于2。6内核

		jffs2_free_raw_dirent(rd);
		up(&dir_f->sem);
		jffs2_clear_inode(inode);
		return PTR_ERR(fd);
	}

	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);

	up(&dir_f->sem);
	jffs2_complete_reservation(c);

	d_instantiate(dentry, inode);
	return 0;
}


static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, int 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, phys_ofs;
	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), &phys_ofs, &alloclen, ALLOC_NORMAL);

	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;
	/* Directories get nlink 2 at start */
	inode->i_nlink = 2;

	f = JFFS2_INODE_INFO(inode);

	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, phys_ofs, ALLOC_NORMAL);

	jffs2_free_raw_inode(ri);

	if (IS_ERR(fn)) {
		/* Eeek. Wave bye bye */
		up(&f->sem);
		jffs2_complete_reservation(c);
		jffs2_clear_inode(inode);
		return PTR_ERR(fn);
	}
	/* No data here. Only a metadata node, which will be 
	   obsoleted by the first data write
	*/
	f->metadata = fn;
	up(&f->sem);

	jffs2_complete_reservation(c);
	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &phys_ofs, &alloclen, ALLOC_NORMAL);
	if (ret) {
		/* Eep. */
		jffs2_clear_inode(inode);
		return ret;
	}
	
	rd = jffs2_alloc_raw_dirent();
	if (!rd) {
		/* Argh. Now we treat it like a normal delete */
		jffs2_complete_reservation(c);
		jffs2_clear_inode(inode);
		return -ENOMEM;
	}

	dir_f = JFFS2_INODE_INFO(dir_i);
	down(&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, phys_ofs, 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);
		up(&dir_f->sem);
		jffs2_clear_inode(inode);
		return PTR_ERR(fd);
	}

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

	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);

	up(&dir_f->sem);
	jffs2_complete_reservation(c);

	d_instantiate(dentry, inode);
	return 0;
}

static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
	struct jffs2_full_dirent *fd;
	int ret;

	for (fd = f->dents ; fd; fd = fd->next) {
		if (fd->ino)
			return -ENOTEMPTY;
	}
	ret = jffs2_unlink(dir_i, dentry);
	if (!ret)
		dir_i->i_nlink--;
	return ret;
}

static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, int mode, mknod_arg_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;
	jint16_t dev;
	int devlen = 0;
	uint32_t alloclen, phys_ofs;
	int ret;

	if (!old_valid_dev(rdev))
		return -EINVAL;

	ri = jffs2_alloc_raw_inode();
	if (!ri)
		return -ENOMEM;
	
	c = JFFS2_SB_INFO(dir_i->i_sb);
	
	if (S_ISBLK(mode) || S_ISCHR(mode)) {
		dev = cpu_to_je16(old_encode_dev(rdev));
		devlen = sizeof(dev);
	}
	
	/* 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, &phys_ofs, &alloclen, ALLOC_NORMAL);

	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, phys_ofs, ALLOC_NORMAL);

	jffs2_free_raw_inode(ri);

	if (IS_ERR(fn)) {
		/* Eeek. Wave bye bye */
		up(&f->sem);
		jffs2_complete_reservation(c);
		jffs2_clear_inode(inode);
		return PTR_ERR(fn);
	}
	/* No data here. Only a metadata node, which will be 
	   obsoleted by the first data write
	*/
	f->metadata = fn;
	up(&f->sem);

	jffs2_complete_reservation(c);
	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &phys_ofs, &alloclen, ALLOC_NORMAL);
	if (ret) {
		/* Eep. */
		jffs2_clear_inode(inode);
		return ret;
	}

	rd = jffs2_alloc_raw_dirent();
	if (!rd) {
		/* Argh. Now we treat it like a normal delete */
		jffs2_complete_reservation(c);
		jffs2_clear_inode(inode);
		return -ENOMEM;
	}

	dir_f = JFFS2_INODE_INFO(dir_i);
	down(&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, phys_ofs, 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);
		up(&dir_f->sem);
		jffs2_clear_inode(inode);
		return PTR_ERR(fd);
	}

	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);

	up(&dir_f->sem);
	jffs2_complete_reservation(c);

	d_instantiate(dentry, inode);

	return 0;
}

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;

	/* 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 (new_dentry->d_inode) {
		victim_f = JFFS2_INODE_INFO(new_dentry->d_inode);
		if (S_ISDIR(new_dentry->d_inode->i_mode)) {
			struct jffs2_full_dirent *fd;

			down(&victim_f->sem);
			for (fd = victim_f->dents; fd; fd = fd->next) {
				if (fd->ino) {
					up(&victim_f->sem);
					return -ENOTEMPTY;
				}
			}
			up(&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 = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
	if (!type) type = DT_REG;

	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i), 
			    old_dentry->d_inode->i_ino, type,
			    new_dentry->d_name.name, new_dentry->d_name.len);

	if (ret)
		return ret;

	if (victim_f) {
		/* There was a victim. Kill it off nicely */
		new_dentry->d_inode->i_nlink--;
		/* Don't oops if the victim was a dirent pointing to an
		   inode which didn't exist. */
		if (victim_f->inocache) {
			down(&victim_f->sem);
			victim_f->inocache->nlink--;
			up(&victim_f->sem);
		}
	}

	/* If it was a directory we moved, and there was no victim, 
	   increase i_nlink on its new parent */
	if (S_ISDIR(old_dentry->d_inode->i_mode) && !victim_f)
		new_dir_i->i_nlink++;

	/* 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);

	/* 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(old_dentry->d_inode);
		down(&f->sem);
		old_dentry->d_inode->i_nlink++;
		if (f->inocache)
			f->inocache->nlink++;
		up(&f->sem);

		printk(KERN_NOTICE "jffs2_rename(): Link succeeded, unlink failed (err %d). You now have a hard link\n", ret);
		/* Might as well let the VFS know */
		d_instantiate(new_dentry, old_dentry->d_inode);
		atomic_inc(&old_dentry->d_inode->i_count);
		return ret;
	}

	if (S_ISDIR(old_dentry->d_inode->i_mode))
		old_dir_i->i_nlink--;

	return 0;
}