ifile.c

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/*
 * 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 <[email protected]>.
 * Revised by Ryusuke Konishi <[email protected]>.
 *
 */

#include <linux/types.h>
#include <linux/buffer_head.h>
#include "nilfs.h"
#include "mdt.h"
#include "alloc.h"
#include "ifile.h"

struct nilfs_ifile_info {
    struct nilfs_mdt_info mi;
    struct nilfs_palloc_cache palloc_cache;
};

static inline struct nilfs_ifile_info *NILFS_IFILE_I(struct inode *ifile)
{
    return (struct nilfs_ifile_info *)NILFS_MDT(ifile);
}

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);
    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;
}

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);
    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);

    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))
        nilfs_warning(sb, __func__, "unable to read inode: %lu",
                  (unsigned long) ino);
    return err;
}

int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,
             size_t inode_size, struct nilfs_inode *raw_inode,
             struct inode **inodep)
{
    struct inode *ifile;
    int err;

    ifile = nilfs_iget_locked(sb, root, NILFS_IFILE_INO);
    if (unlikely(!ifile))
        return -ENOMEM;
    if (!(ifile->i_state & I_NEW))
        goto out;

    err = nilfs_mdt_init(ifile, NILFS_MDT_GFP,
                 sizeof(struct nilfs_ifile_info));
    if (err)
        goto failed;

    err = nilfs_palloc_init_blockgroup(ifile, inode_size);
    if (err)
        goto failed;

    nilfs_palloc_setup_cache(ifile, &NILFS_IFILE_I(ifile)->palloc_cache);

    err = nilfs_read_inode_common(ifile, raw_inode);
    if (err)
        goto failed;

    unlock_new_inode(ifile);
 out:
    *inodep = ifile;
    return 0;
 failed:
    iget_failed(ifile);
    return err;
}