[net-next-2.6.git] / fs / udf / symlink.c

/*
 * symlink.c
 *
 * PURPOSE
 *	Symlink handling routines for the OSTA-UDF(tm) filesystem.
 *
 * COPYRIGHT
 *	This file is distributed under the terms of the GNU General Public
 *	License (GPL). Copies of the GPL can be obtained from:
 *		ftp://prep.ai.mit.edu/pub/gnu/GPL
 *	Each contributing author retains all rights to their own work.
 *
 *  (C) 1998-2001 Ben Fennema
 *  (C) 1999 Stelias Computing Inc
 *
 * HISTORY
 *
 *  04/16/99 blf  Created.
 *
 */

#include "udfdecl.h"
#include <asm/uaccess.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/udf_fs.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include "udf_i.h"

static void udf_pc_to_char(struct super_block *sb, char *from, int fromlen, char *to)
{
	struct pathComponent *pc;
	int elen = 0;
	char *p = to;

	while (elen < fromlen) {
		pc = (struct pathComponent *)(from + elen);
		switch (pc->componentType) {
		case 1:
			if (pc->lengthComponentIdent == 0) {
				p = to;
				*p++ = '/';
			}
			break;
		case 3:
			memcpy(p, "../", 3);
			p += 3;
			break;
		case 4:
			memcpy(p, "./", 2);
			p += 2;
			/* that would be . - just ignore */
			break;
		case 5:
			p += udf_get_filename(sb, pc->componentIdent, p,
					      pc->lengthComponentIdent);
			*p++ = '/';
			break;
		}
		elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
	}
	if (p > to + 1)
		p[-1] = '\0';
	else
		p[0] = '\0';
}

static int udf_symlink_filler(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	struct buffer_head *bh = NULL;
	char *symlink;
	int err = -EIO;
	char *p = kmap(page);

	lock_kernel();
	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB) {
		symlink = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);
	} else {
		bh = sb_bread(inode->i_sb, udf_block_map(inode, 0));

		if (!bh)
			goto out;

		symlink = bh->b_data;
	}

	udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
	brelse(bh);

	unlock_kernel();
	SetPageUptodate(page);
	kunmap(page);
	unlock_page(page);
	return 0;

out:
	unlock_kernel();
	SetPageError(page);
	kunmap(page);
	unlock_page(page);
	return err;
}

/*
 * symlinks can't do much...
 */
const struct address_space_operations udf_symlink_aops = {
	.readpage		= udf_symlink_filler,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* symlink.c
	3	*
	4	* PURPOSE
	5	* Symlink handling routines for the OSTA-UDF(tm) filesystem.
	6	*
1da177e4 LT	7	* COPYRIGHT
	8	* This file is distributed under the terms of the GNU General Public
	9	* License (GPL). Copies of the GPL can be obtained from:
	10	* ftp://prep.ai.mit.edu/pub/gnu/GPL
	11	* Each contributing author retains all rights to their own work.
	12	*
	13	* (C) 1998-2001 Ben Fennema
28de7948	14	* (C) 1999 Stelias Computing Inc
1da177e4 LT	15	*
	16	* HISTORY
	17	*
	18	* 04/16/99 blf Created.
	19	*
	20	*/
	21
	22	#include "udfdecl.h"
	23	#include <asm/uaccess.h>
	24	#include <linux/errno.h>
	25	#include <linux/fs.h>
	26	#include <linux/udf_fs.h>
	27	#include <linux/time.h>
	28	#include <linux/mm.h>
	29	#include <linux/stat.h>
	30	#include <linux/slab.h>
	31	#include <linux/pagemap.h>
	32	#include <linux/smp_lock.h>
	33	#include <linux/buffer_head.h>
	34	#include "udf_i.h"
	35
28de7948	36	static void udf_pc_to_char(struct super_block sb, char from, int fromlen, char *to)
1da177e4 LT	37	{
	38	struct pathComponent *pc;
	39	int elen = 0;
	40	char *p = to;
	41
cb00ea35	42	while (elen < fromlen) {
1da177e4	43	pc = (struct pathComponent *)(from + elen);
cb00ea35 CG	44	switch (pc->componentType) {
	45	case 1:
	46	if (pc->lengthComponentIdent == 0) {
	47	p = to;
1da177e4	48	*p++ = '/';
cb00ea35 CG	49	}
	50	break;
	51	case 3:
	52	memcpy(p, "../", 3);
	53	p += 3;
	54	break;
	55	case 4:
	56	memcpy(p, "./", 2);
	57	p += 2;
	58	/* that would be . - just ignore */
	59	break;
	60	case 5:
	61	p += udf_get_filename(sb, pc->componentIdent, p,
	62	pc->lengthComponentIdent);
	63	*p++ = '/';
	64	break;
1da177e4 LT	65	}
	66	elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
	67	}
cb00ea35	68	if (p > to + 1)
1da177e4 LT	69	p[-1] = '\0';
	70	else
	71	p[0] = '\0';
	72	}
	73
	74	static int udf_symlink_filler(struct file file, struct page page)
	75	{
	76	struct inode *inode = page->mapping->host;
	77	struct buffer_head *bh = NULL;
	78	char *symlink;
	79	int err = -EIO;
	80	char *p = kmap(page);
	81
	82	lock_kernel();
28de7948	83	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB) {
1da177e4	84	symlink = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);
28de7948	85	} else {
1da177e4 LT	86	bh = sb_bread(inode->i_sb, udf_block_map(inode, 0));
	87
	88	if (!bh)
	89	goto out;
	90
	91	symlink = bh->b_data;
	92	}
	93
	94	udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
3bf25cb4	95	brelse(bh);
1da177e4 LT	96
	97	unlock_kernel();
	98	SetPageUptodate(page);
	99	kunmap(page);
	100	unlock_page(page);
	101	return 0;
28de7948 CG	102
28de7948 CG	103	out:
1da177e4 LT	104	unlock_kernel();
	105	SetPageError(page);
	106	kunmap(page);
	107	unlock_page(page);
	108	return err;
	109	}
	110
	111	/*
	112	* symlinks can't do much...
	113	*/
f5e54d6e	114	const struct address_space_operations udf_symlink_aops = {
28de7948	115	.readpage = udf_symlink_filler,
1da177e4	116	};