[linux.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);
	udf_release_data(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
	14	* (C) 1999 Stelias Computing Inc
	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
	36	static void udf_pc_to_char(struct super_block sb, char from, int fromlen, char *to)
	37	{
	38	struct pathComponent *pc;
	39	int elen = 0;
	40	char *p = to;
	41
	42	while (elen < fromlen)
	43	{
	44	pc = (struct pathComponent *)(from + elen);
	45	switch (pc->componentType)
	46	{
	47	case 1:
	48	if (pc->lengthComponentIdent == 0)
	49	{
	50	p = to;
	51	*p++ = '/';
	52	}
	53	break;
	54	case 3:
	55	memcpy(p, "../", 3);
	56	p += 3;
	57	break;
	58	case 4:
	59	memcpy(p, "./", 2);
	60	p += 2;
	61	/* that would be . - just ignore */
	62	break;
	63	case 5:
	64	p += udf_get_filename(sb, pc->componentIdent, p, pc->lengthComponentIdent);
	65	*p++ = '/';
	66	break;
	67	}
	68	elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
	69	}
	70	if (p > to+1)
71	p[-1] = '\0';
72	else
73	p[0] = '\0';
74	}
75
76	static int udf_symlink_filler(struct file file, struct page page)
77	{
78	struct inode *inode = page->mapping->host;
79	struct buffer_head *bh = NULL;
80	char *symlink;
81	int err = -EIO;
82	char *p = kmap(page);
83
84	lock_kernel();
85	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
86	symlink = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);
87	else
88	{
89	bh = sb_bread(inode->i_sb, udf_block_map(inode, 0));
90
91	if (!bh)
92	goto out;
93
94	symlink = bh->b_data;
95	}
96
97	udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
98	udf_release_data(bh);
99
100	unlock_kernel();
101	SetPageUptodate(page);
102	kunmap(page);
103	unlock_page(page);
104	return 0;
105	out:
106	unlock_kernel();
107	SetPageError(page);
108	kunmap(page);
109	unlock_page(page);
110	return err;
111	}
112
113	/*
114	* symlinks can't do much...
115	*/
f5e54d6e	116	const struct address_space_operations udf_symlink_aops = {
1da177e4 LT	117	.readpage = udf_symlink_filler,
1da177e4 LT	118	};