path: root/fs/cifs/readdir.c

/*
 *   fs/cifs/readdir.c
 *
 *   Directory search handling
 *
 *   Copyright (C) International Business Machines  Corp., 2004, 2008
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/stat.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "cifsfs.h"

/*
 * To be safe - for UCS to UTF-8 with strings loaded with the rare long
 * characters alloc more to account for such multibyte target UTF-8
 * characters.
 */
#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)

#ifdef CONFIG_CIFS_DEBUG2
static void dump_cifs_file_struct(struct file *file, char *label)
{
	struct cifsFileInfo *cf;

	if (file) {
		cf = file->private_data;
		if (cf == NULL) {
			cFYI(1, ("empty cifs private file data"));
			return;
		}
		if (cf->invalidHandle)
			cFYI(1, ("invalid handle"));
		if (cf->srch_inf.endOfSearch)
			cFYI(1, ("end of search"));
		if (cf->srch_inf.emptyDir)
			cFYI(1, ("empty dir"));
	}
}
#else
static inline void dump_cifs_file_struct(struct file *file, char *label)
{
}
#endif /* DEBUG2 */

/*
 * Find the dentry that matches "name". If there isn't one, create one. If it's
 * a negative dentry or the uniqueid changed, then drop it and recreate it.
 */
static struct dentry *
cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
		    struct cifs_fattr *fattr)
{
	struct dentry *dentry, *alias;
	struct inode *inode;
	struct super_block *sb = parent->d_inode->i_sb;

	cFYI(1, ("For %s", name->name));

	dentry = d_lookup(parent, name);
	if (dentry) {
		/* FIXME: check for inode number changes? */
		if (dentry->d_inode != NULL)
			return dentry;
		d_drop(dentry);
		dput(dentry);
	}

	dentry = d_alloc(parent, name);
	if (dentry == NULL)
		return NULL;

	inode = cifs_iget(sb, fattr);
	if (!inode) {
		dput(dentry);
		return NULL;
	}

	if (CIFS_SB(sb)->tcon->nocase)
		dentry->d_op = &cifs_ci_dentry_ops;
	else
		dentry->d_op = &cifs_dentry_ops;

	alias = d_materialise_unique(dentry, inode);
	if (alias != NULL) {
		dput(dentry);
		if (IS_ERR(alias))
			return NULL;
		dentry = alias;
	}

	return dentry;
}

/* Returns 1 if new inode created, 2 if both dentry and inode were */
/* Might check in the future if inode number changed so we can rehash inode */
static int
construct_dentry(struct qstr *qstring, struct file *file,
		 struct inode **ptmp_inode, struct dentry **pnew_dentry,
		 __u64 *inum)
{
	struct dentry *tmp_dentry = NULL;
	struct super_block *sb = file->f_path.dentry->d_sb;
	int rc = 0;

	cFYI(1, ("For %s", qstring->name));

	tmp_dentry = d_lookup(file->f_path.dentry, qstring);
	if (tmp_dentry) {
		/* BB: overwrite old name? i.e. tmp_dentry->d_name and
		 * tmp_dentry->d_name.len??
		 */
		cFYI(0, ("existing dentry with inode 0x%p",
			 tmp_dentry->d_inode));
		*ptmp_inode = tmp_dentry->d_inode;
		if (*ptmp_inode == NULL) {
			*ptmp_inode = cifs_new_inode(sb, inum);
			if (*ptmp_inode == NULL)
				return rc;
			rc = 1;
		}
	} else {
		tmp_dentry = d_alloc(file->f_path.dentry, qstring);