symlink.c

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/*
 * symlink.c
 *
 * Copyright (c) 1999 Al Smith
 *
 * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
 */

#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include "efs.h"

static int efs_symlink_readpage(struct file *file, struct page *page)
{
    char *link = kmap(page);
    struct buffer_head * bh;
    struct inode * inode = page->mapping->host;
    efs_block_t size = inode->i_size;
    int err;
  
    err = -ENAMETOOLONG;
    if (size > 2 * EFS_BLOCKSIZE)
        goto fail;
  
    /* read first 512 bytes of link target */
    err = -EIO;
    bh = sb_bread(inode->i_sb, efs_bmap(inode, 0));
    if (!bh)
        goto fail;
    memcpy(link, bh->b_data, (size > EFS_BLOCKSIZE) ? EFS_BLOCKSIZE : size);
    brelse(bh);
    if (size > EFS_BLOCKSIZE) {
        bh = sb_bread(inode->i_sb, efs_bmap(inode, 1));
        if (!bh)
            goto fail;
        memcpy(link + EFS_BLOCKSIZE, bh->b_data, size - EFS_BLOCKSIZE);
        brelse(bh);
    }
    link[size] = '\0';
    SetPageUptodate(page);
    kunmap(page);
    unlock_page(page);
    return 0;
fail:
    SetPageError(page);
    kunmap(page);
    unlock_page(page);
    return err;
}

const struct address_space_operations efs_symlink_aops = {
    .readpage   = efs_symlink_readpage
};