// SPDX-License-Identifier: GPL-2.0
/*
 * 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_read_folio(struct file *file, struct folio *folio)
{
        char *link = folio_address(folio);
        struct buffer_head *bh;
        struct inode *inode = folio->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';
        err = 0;
fail:
        folio_end_read(folio, err == 0);
        return err;
}

const struct address_space_operations efs_symlink_aops = {
        .read_folio     = efs_symlink_read_folio
};