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/*

 *  linux/fs/affs/symlink.c

 *

 *  1995  Hans-Joachim Widmaier - Modified for affs.

 *

 *  Copyright (C) 1991, 1992  Linus Torvalds

 *

 *  affs symlink handling code

 */

#include <linux/errno.h>

#include <linux/sched.h>

#include <linux/malloc.h>

#include <linux/fs.h>

#include <linux/stat.h>

#include <linux/affs_fs.h>

#include <linux/amigaffs.h>

#include <asm/segment.h>

#define MIN(a,b) (((a) < (b)) ? (a) : (b))

static int affs_readlink(struct inode *, char *, int);

static int affs_follow_link(struct inode *, struct inode *, int, int, struct inode **);

struct inode_operations affs_symlink_inode_operations = {

        NULL,                   /* no file-operations */

        NULL,                   /* create */

        NULL,                   /* lookup */

        NULL,                   /* link */

        NULL,                   /* unlink */

        NULL,                   /* symlink */

        NULL,                   /* mkdir */

        NULL,                   /* rmdir */

        NULL,                   /* mknod */

        NULL,                   /* rename */

        affs_readlink,          /* readlink */

        affs_follow_link,       /* follow_link */

        NULL,                   /* bmap */

        NULL,                   /* truncate */

        NULL                    /* permission */

};

static int

affs_follow_link(struct inode *dir, struct inode *inode, int flag, int mode,

                 struct inode **res_inode)

{

        struct buffer_head      *bh;

        struct slink_front      *lf;

        char                    *buffer;

        int                      error;

        int                      i, j;

        char                     c;

        char                     lc;

        pr_debug("AFFS: follow_link(ino=%lu)\n",inode->i_ino);

        *res_inode = NULL;

        if (!dir) {

                dir = current->fs->root;

                dir->i_count++;

        }

        if (!inode) {

                iput(dir);

                return -ENOENT;

        }

        if (!S_ISLNK(inode->i_mode)) {

                iput(dir);

                *res_inode = inode;

                return 0;

        }

        if (current->link_count > 5) {

                iput(inode);

                iput(dir);

                return -ELOOP;

        }

        if (!(buffer = kmalloc(1024,GFP_KERNEL))) {

                iput(inode);

                iput(dir);

                return -ENOSPC;

        }

        bh = affs_bread(inode->i_dev,inode->i_ino,AFFS_I2BSIZE(inode));

        i  = 0;

        j  = 0;

        if (!bh) {

                printk("AFFS: unable to read i-node block %lu\n",inode->i_ino);

                kfree(buffer);

                iput(inode);

                iput(dir);

                return -EIO;

        }

        lf = (struct slink_front *)bh->b_data;

        lc = 0;

        if (strchr(lf->symname,':')) {          /* Handle assign or volume name */

                while (i < 1023 && (c = inode->i_sb->u.affs_sb.s_prefix[i]))

                        buffer[i++] = c;

                while (i < 1023 && lf->symname[j] != ':')

                        buffer[i++] = lf->symname[j++];

                if (i < 1023)

                         buffer[i++] = '/';

                j++;

                lc = '/';

        }

        while (i < 1023 && (c = lf->symname[j])) {

                if (c == '/' && lc == '/' && i < 1020) {        /* parent dir */

                        buffer[i++] = '.';

                        buffer[i++] = '.';

                }

                buffer[i++] = c;

                lc = c;

                j++;

        }

        buffer[i] = '\0';

        affs_brelse(bh);

        iput(inode);

        current->link_count++;

        error = open_namei(buffer,flag,mode,res_inode,dir);

        current->link_count--;

        kfree(buffer);

        return error;

}

static int

affs_readlink(struct inode *inode, char *buffer, int buflen)

{

        struct buffer_head      *bh;

        struct slink_front      *lf;

        int                      i, j;

        char                     c;

        char                     lc;

        pr_debug("AFFS: readlink(ino=%lu,buflen=%d)\n",inode->i_ino,buflen);

        if (!S_ISLNK(inode->i_mode)) {

                iput(inode);

                return -EINVAL;

        }

        bh = affs_bread(inode->i_dev,inode->i_ino,AFFS_I2BSIZE(inode));

        i  = 0;

        j  = 0;

        if (!bh) {

                printk("AFFS: unable to read i-node block %lu\n",inode->i_ino);

                goto symlink_end;

        }

        lf = (struct slink_front *)bh->b_data;

        lc = 0;

        if (strchr(lf->symname,':')) {          /* Handle assign or volume name */

                while (i < buflen && (c = inode->i_sb->u.affs_sb.s_prefix[i])) {

                        put_user(c,buffer++);

                        i++;

                }

                while (i < buflen && (c = lf->symname[j]) != ':') {

                        put_user(c,buffer++);

                        i++, j++;

                }

                if (i < buflen) {

                        put_user('/',buffer++);

                        i++, j++;

                }

                lc = '/';

        }

        while (i < buflen && (c = lf->symname[j])) {

                if (c == '/' && lc == '/' && (i + 3 < buflen)) {        /* parent dir */

                        put_user('.',buffer++);

                        put_user('.',buffer++);

                        i += 2;

                }

                put_user(c,buffer++);

                lc = c;

                i++, j++;

        }

symlink_end:

        iput(inode);

        affs_brelse(bh);

        return i;

}