nilfs2: inode map file

/*

 * ifile.c - NILFS inode file

 *

 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 *

 * Written by Amagai Yoshiji <amagai@osrg.net>.

 * Revised by Ryusuke Konishi <ryusuke@osrg.net>.

 *

 */

#include <linux/types.h>

#include <linux/buffer_head.h>

#include "nilfs.h"

#include "mdt.h"

#include "alloc.h"

#include "ifile.h"

/**

 * nilfs_ifile_create_inode - create a new disk inode

 * @ifile: ifile inode

 * @out_ino: pointer to a variable to store inode number

 * @out_bh: buffer_head contains newly allocated disk inode

 *

 * Return Value: On success, 0 is returned and the newly allocated inode

 * number is stored in the place pointed by @ino, and buffer_head pointer

 * that contains newly allocated disk inode structure is stored in the

 * place pointed by @out_bh

 * On error, one of the following negative error codes is returned.

 *

 * %-EIO - I/O error.

 *

 * %-ENOMEM - Insufficient amount of memory available.

 *

 * %-ENOSPC - No inode left.

 */

int nilfs_ifile_create_inode(struct inode *ifile, ino_t *out_ino,

			     struct buffer_head **out_bh)

{

	struct nilfs_palloc_req req;

	int ret;

	req.pr_entry_nr = 0;  /* 0 says find free inode from beginning of

				 a group. dull code!! */

	req.pr_entry_bh = NULL;

	ret = nilfs_palloc_prepare_alloc_entry(ifile, &req);

	if (!ret) {

		ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 1,

						   &req.pr_entry_bh);

		if (ret < 0)

			nilfs_palloc_abort_alloc_entry(ifile, &req);

	}

	if (ret < 0) {

		brelse(req.pr_entry_bh);

		return ret;

	}

	nilfs_palloc_commit_alloc_entry(ifile, &req);

	nilfs_mdt_mark_buffer_dirty(req.pr_entry_bh);

	nilfs_mdt_mark_dirty(ifile);

	*out_ino = (ino_t)req.pr_entry_nr;

	*out_bh = req.pr_entry_bh;

	return 0;

}

/**

 * nilfs_ifile_delete_inode - delete a disk inode

 * @ifile: ifile inode

 * @ino: inode number

 *

 * Return Value: On success, 0 is returned. On error, one of the following

 * negative error codes is returned.

 *

 * %-EIO - I/O error.

 *

 * %-ENOMEM - Insufficient amount of memory available.

 *

 * %-ENOENT - The inode number @ino have not been allocated.

 */

int nilfs_ifile_delete_inode(struct inode *ifile, ino_t ino)

{

	struct nilfs_palloc_req req = {

		.pr_entry_nr = ino, .pr_entry_bh = NULL

	};

	struct nilfs_inode *raw_inode;

	void *kaddr;

	int ret;

	ret = nilfs_palloc_prepare_free_entry(ifile, &req);

	if (!ret) {

		ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 0,

						   &req.pr_entry_bh);

		if (ret < 0)

			nilfs_palloc_abort_free_entry(ifile, &req);

	}

	if (ret < 0) {

		brelse(req.pr_entry_bh);

		return ret;

	}

	kaddr = kmap_atomic(req.pr_entry_bh->b_page, KM_USER0);

	raw_inode = nilfs_palloc_block_get_entry(ifile, req.pr_entry_nr,

						 req.pr_entry_bh, kaddr);

	raw_inode->i_flags = 0;

	kunmap_atomic(kaddr, KM_USER0);

	nilfs_mdt_mark_buffer_dirty(req.pr_entry_bh);

	brelse(req.pr_entry_bh);

	nilfs_palloc_commit_free_entry(ifile, &req);

	return 0;

}

int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,

				struct buffer_head **out_bh)

{

	struct super_block *sb = ifile->i_sb;

	int err;

	if (unlikely(!NILFS_VALID_INODE(sb, ino))) {

		nilfs_error(sb, __func__, "bad inode number: %lu",

			    (unsigned long) ino);

		return -EINVAL;

	}

	err = nilfs_palloc_get_entry_block(ifile, ino, 0, out_bh);

	if (unlikely(err)) {

		if (err == -EINVAL)

			nilfs_error(sb, __func__, "ifile is broken");

		else

			nilfs_warning(sb, __func__,

				      "unable to read inode: %lu",

				      (unsigned long) ino);

	}

	return err;

}

/*

 * ifile.h - NILFS inode file

 *

 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 *

 * Written by Amagai Yoshiji <amagai@osrg.net>

 * Revised by Ryusuke Konishi <ryusuke@osrg.net>

 *

 */

#ifndef _NILFS_IFILE_H

#define _NILFS_IFILE_H

#include <linux/fs.h>

#include <linux/buffer_head.h>

#include <linux/nilfs2_fs.h>

#include "mdt.h"

#include "alloc.h"

#define NILFS_IFILE_GFP  NILFS_MDT_GFP

static inline struct nilfs_inode *

nilfs_ifile_map_inode(struct inode *ifile, ino_t ino, struct buffer_head *ibh)

{

	void *kaddr = kmap(ibh->b_page);

	return nilfs_palloc_block_get_entry(ifile, ino, ibh, kaddr);

}

static inline void nilfs_ifile_unmap_inode(struct inode *ifile, ino_t ino,

					   struct buffer_head *ibh)

{

	kunmap(ibh->b_page);

}

int nilfs_ifile_create_inode(struct inode *, ino_t *, struct buffer_head **);

int nilfs_ifile_delete_inode(struct inode *, ino_t);

int nilfs_ifile_get_inode_block(struct inode *, ino_t, struct buffer_head **);

#endif	/* _NILFS_IFILE_H */