root/fs/efs/symlink.c

DEFINITIONS

1. efs_symlink_readpage

/*
 * 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 <linux/smp_lock.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_notlocked;
  
        lock_kernel();
        /* 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';
        unlock_kernel();
        SetPageUptodate(page);
        kunmap(page);
        unlock_page(page);
        return 0;
fail:
        unlock_kernel();
fail_notlocked:
        SetPageError(page);
        kunmap(page);
        unlock_page(page);
        return err;
}

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