[GitHub/mt8127/android_kernel_alcatel_ttab.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
	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
cb00ea35 CG	36	static void udf_pc_to_char(struct super_block sb, char from, int fromlen,
cb00ea35 CG	37	char *to)
1da177e4 LT	38	{
	39	struct pathComponent *pc;
	40	int elen = 0;
	41	char *p = to;
	42
cb00ea35	43	while (elen < fromlen) {
1da177e4	44	pc = (struct pathComponent *)(from + elen);
cb00ea35 CG	45	switch (pc->componentType) {
	46	case 1:
	47	if (pc->lengthComponentIdent == 0) {
	48	p = to;
1da177e4	49	*p++ = '/';
cb00ea35 CG	50	}
	51	break;
	52	case 3:
	53	memcpy(p, "../", 3);
	54	p += 3;
	55	break;
	56	case 4:
	57	memcpy(p, "./", 2);
	58	p += 2;
	59	/* that would be . - just ignore */
	60	break;
	61	case 5:
	62	p += udf_get_filename(sb, pc->componentIdent, p,
	63	pc->lengthComponentIdent);
	64	*p++ = '/';
	65	break;
1da177e4 LT	66	}
	67	elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
	68	}
cb00ea35	69	if (p > to + 1)
1da177e4 LT	70	p[-1] = '\0';
	71	else
	72	p[0] = '\0';
	73	}
	74
	75	static int udf_symlink_filler(struct file file, struct page page)
	76	{
	77	struct inode *inode = page->mapping->host;
	78	struct buffer_head *bh = NULL;
	79	char *symlink;
	80	int err = -EIO;
	81	char *p = kmap(page);
	82
	83	lock_kernel();
	84	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
	85	symlink = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);
cb00ea35	86	else {
1da177e4 LT	87	bh = sb_bread(inode->i_sb, udf_block_map(inode, 0));
	88
	89	if (!bh)
	90	goto out;
	91
	92	symlink = bh->b_data;
	93	}
	94
	95	udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
3bf25cb4	96	brelse(bh);
1da177e4 LT	97
	98	unlock_kernel();
	99	SetPageUptodate(page);
	100	kunmap(page);
	101	unlock_page(page);
	102	return 0;
cb00ea35	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 = {
cb00ea35	115	.readpage = udf_symlink_filler,
1da177e4	116	};