/*
 * 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 <linux/uaccess.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/stat.h>
#include <linux/pagemap.h>
#include "udf_i.h"

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

	/* Reserve one byte for terminating \0 */
	tolen--;
	while (elen < fromlen) {
		pc = (struct pathComponent *)(from + elen);
		elen += sizeof(struct pathComponent);
		switch (pc->componentType) {
		case 1:
			/*
			 * Symlink points to some place which should be agreed
 			 * upon between originator and receiver of the media. Ignore.
			 */
			if (pc->lengthComponentIdent > 0) {
				elen += pc->lengthComponentIdent;
				break;
			}
			/* Fall through */
		case 2:
			if (tolen == 0)
				return -ENAMETOOLONG;
			p = to;
			*p++ = '/';
			tolen--;
			break;
		case 3:
			if (tolen < 3)
				return -ENAMETOOLONG;
			memcpy(p, "../", 3);
			p += 3;
			tolen -= 3;
			break;
		case 4:
			if (tolen < 2)
				return -ENAMETOOLONG;
			memcpy(p, "./", 2);
			p += 2;
			tolen -= 2;
			/* that would be . - just ignore */
			break;
		case 5:
			elen += pc->lengthComponentIdent;
			if (elen > fromlen)
				return -EIO;
			comp_len = udf_get_filename(sb, pc->componentIdent,
						    pc->lengthComponentIdent,
						    p, tolen);
			if (comp_len < 0)
				return comp_len;

			p += comp_len;
			tolen -= comp_len;
			if (tolen == 0)
				return -ENAMETOOLONG;
			*p++ = '/';
			tolen--;
			break;
		}
	}
	if (p > to + 1)
		p[-1] = '\0';
	else
		p[0] = '\0';
	return 0;
}

static int udf_symlink_filler(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	struct buffer_head *bh = NULL;
	unsigned char *symlink;
	int err;
	unsigned char *p = page_address(page);
	struct udf_inode_info *iinfo;
	uint32_t pos;

	/* We don't support symlinks longer than one block */
	if (inode->i_size > inode->i_sb->s_blocksize) {
		err = -ENAMETOOLONG;
		goto out_unmap;
	}

	iinfo = UDF_I(inode);
	pos = udf_block_map(inode, 0);

	down_read(&iinfo->i_data_sem);
	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
		symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
	} else {
		bh = sb_bread(inode->i_sb, pos);

		if (!bh) {
			err = -EIO;
			goto out_unlock_inode;
		}

		symlink = bh->b_data;
	}

	err = udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p, PAGE_SIZE);
	brelse(bh);
	if (err)
		goto out_unlock_inode;

	up_read(&iinfo->i_data_sem);
	SetPageUptodate(page);
	unlock_page(page);
	return 0;

out_unlock_inode:
	up_read(&iinfo->i_data_sem);
	SetPageError(page);
out_unmap:
	unlock_page(page);
	return err;
}

/*
 * symlinks can't do much...
 */
const struct address_space_operations udf_symlink_aops = {
	.readpage		= udf_symlink_filler,
};
='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Arnd Bergmann &lt;arnd@arndb.de&gt;</td><td class='right'>2017-02-07 09:59:21 -0800</td></tr>
<tr><th>committer</th><td>Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;</td><td class='right'>2017-02-07 14:31:45 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/mon?id=413d37326700aaf708730b940b04192c36e13ef4'>413d37326700aaf708730b940b04192c36e13ef4</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/mon?id=413d37326700aaf708730b940b04192c36e13ef4'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=413d37326700aaf708730b940b04192c36e13ef4'>b31f87b933d437d7f1754dfb983f3b33b7296a2e</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/mon?id=413d37326700aaf708730b940b04192c36e13ef4'>drivers/usb/mon</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/mon?id=601bbbe0517303c9f8eb3d75e11d64efed1293c9'>601bbbe0517303c9f8eb3d75e11d64efed1293c9</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/mon?id=413d37326700aaf708730b940b04192c36e13ef4&amp;id2=601bbbe0517303c9f8eb3d75e11d64efed1293c9'>diff</a>)</td></tr></table>
<div class='commit-subject'>Input: synaptics-rmi4 - select 'SERIO' when needed</div><div class='commit-msg'>With CONFIG_SERIO=m, we get a build error for the rmi4-f03 driver,
added in linux-4.10:

warning: (HID_RMI) selects RMI4_F03 which has unmet direct dependencies (!UML &amp;&amp; INPUT &amp;&amp; RMI4_CORE &amp;&amp; (SERIO=y || RMI4_CORE=SERIO))
drivers/input/built-in.o: In function `rmi_f03_attention':
rmi_f03.c:(.text+0xcfe0): undefined reference to `serio_interrupt'
rmi_f03.c:(.text+0xd055): undefined reference to `serio_interrupt'
drivers/input/built-in.o: In function `rmi_f03_remove':
rmi_f03.c:(.text+0xd115): undefined reference to `serio_unregister_port'
drivers/input/built-in.o: In function `rmi_f03_probe':
rmi_f03.c:(.text+0xd209): undefined reference to `__serio_register_port'

An earlier patch tried to fix this, but missed the HID_RMI driver that
does a 'select' on the F03 backend.

This adds a hidden Kconfig symbol that enforces 'serio' to be enabled
when RMI4-F03 is, which covers all cases.

Fixes: d7ddad0acc4a ("Input: synaptics-rmi4 - fix F03 build error when serio is module")
Fixes: c5e8848fc98e ("Input: synaptics-rmi4 - add support for F03")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=413d37326700aaf708730b940b04192c36e13ef4'>Diffstat</a> (limited to 'drivers/usb/mon')</div><table summary='diffstat' class='diffstat'>