vxfs_subr.c

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/*
 * Copyright (c) 2000-2001 Christoph Hellwig.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL").
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Veritas filesystem driver - shared subroutines.
 */
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/kernel.h>
#include <linux/pagemap.h>

#include "vxfs_extern.h"


static int      vxfs_readpage(struct file *, struct page *);
static sector_t     vxfs_bmap(struct address_space *, sector_t);

const struct address_space_operations vxfs_aops = {
    .readpage =     vxfs_readpage,
    .bmap =         vxfs_bmap,
};

inline void
vxfs_put_page(struct page *pp)
{
    kunmap(pp);
    page_cache_release(pp);
}

struct page *
vxfs_get_page(struct address_space *mapping, u_long n)
{
    struct page *           pp;

    pp = read_mapping_page(mapping, n, NULL);

    if (!IS_ERR(pp)) {
        kmap(pp);
        if (PageError(pp))
            goto fail;
    }
    
    return (pp);
         
fail:
    vxfs_put_page(pp);
    return ERR_PTR(-EIO);
}

struct buffer_head *
vxfs_bread(struct inode *ip, int block)
{
    struct buffer_head  *bp;
    daddr_t         pblock;

    pblock = vxfs_bmap1(ip, block);
    bp = sb_bread(ip->i_sb, pblock);

    return (bp);
}

static int
vxfs_getblk(struct inode *ip, sector_t iblock,
        struct buffer_head *bp, int create)
{
    daddr_t         pblock;

    pblock = vxfs_bmap1(ip, iblock);
    if (pblock != 0) {
        map_bh(bp, ip->i_sb, pblock);
        return 0;
    }

    return -EIO;
}

static int
vxfs_readpage(struct file *file, struct page *page)
{
    return block_read_full_page(page, vxfs_getblk);
}
 
static sector_t
vxfs_bmap(struct address_space *mapping, sector_t block)
{
    return generic_block_bmap(mapping, block, vxfs_getblk);
}