[mirror_ubuntu-zesty-kernel.git] / fs / cifs / cifs_dfs_ref.c

/*
 *   Contains the CIFS DFS referral mounting routines used for handling
 *   traversal via DFS junction point
 *
 *   Copyright (c) 2007 Igor Mammedov
 *   Copyright (C) International Business Machines  Corp., 2008
 *   Author(s): Igor Mammedov (niallain@gmail.com)
 *		Steve French (sfrench@us.ibm.com)
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation; either version
 *   2 of the License, or (at your option) any later version.
 */

#include <linux/dcache.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/vfs.h>
#include <linux/fs.h>
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifsfs.h"
#include "dns_resolve.h"
#include "cifs_debug.h"

LIST_HEAD(cifs_dfs_automount_list);

/*
 * DFS functions
*/

void dfs_shrink_umount_helper(struct vfsmount *vfsmnt)
{
	mark_mounts_for_expiry(&cifs_dfs_automount_list);
	mark_mounts_for_expiry(&cifs_dfs_automount_list);
	shrink_submounts(vfsmnt, &cifs_dfs_automount_list);
}

/**
 * cifs_get_share_name	-	extracts share name from UNC
 * @node_name:	pointer to UNC string
 *
 * Extracts sharename form full UNC.
 * i.e. strips from UNC trailing path that is not part of share
 * name and fixup missing '\' in the begining of DFS node refferal
 * if neccessary.
 * Returns pointer to share name on success or NULL on error.
 * Caller is responsible for freeing returned string.
 */
static char *cifs_get_share_name(const char *node_name)
{
	int len;
	char *UNC;
	char *pSep;

	len = strlen(node_name);
	UNC = kmalloc(len+2 /*for term null and additional \ if it's missed */,
			 GFP_KERNEL);
	if (!UNC)
		return NULL;

	/* get share name and server name */
	if (node_name[1] != '\\') {
		UNC[0] = '\\';
		strncpy(UNC+1, node_name, len);
		len++;
		UNC[len] = 0;
	} else {
		strncpy(UNC, node_name, len);
		UNC[len] = 0;
	}

	/* find server name end */
	pSep = memchr(UNC+2, '\\', len-2);
	if (!pSep) {
		cERROR(1, ("%s: no server name end in node name: %s",
			__FUNCTION__, node_name));
		kfree(UNC);
		return NULL;
	}

	/* find sharename end */
	pSep++;
	pSep = memchr(UNC+(pSep-UNC), '\\', len-(pSep-UNC));
	if (!pSep) {
		cERROR(1, ("%s:2 cant find share name in node name: %s",
			__FUNCTION__, node_name));
		kfree(UNC);
		return NULL;
	}
	/* trim path up to sharename end
	 *          * now we have share name in UNC */
	*pSep = 0;

	return UNC;
}


/**
 * compose_mount_options	-	creates mount options for refferral
 * @sb_mountdata:	parent/root DFS mount options (template)
 * @ref_unc:		refferral server UNC
 * @devname:		pointer for saving device name
 *
 * creates mount options for submount based on template options sb_mountdata
 * and replacing unc,ip,prefixpath options with ones we've got form ref_unc.
 *
 * Returns: pointer to new mount options or ERR_PTR.
 * Caller is responcible for freeing retunrned value if it is not error.
 */
static char *compose_mount_options(const char *sb_mountdata,
				   const char *ref_unc,
				   char **devname)
{
	int rc;
	char *mountdata;
	int md_len;
	char *tkn_e;
	char *srvIP = NULL;
	char sep = ',';
	int off, noff;

	if (sb_mountdata == NULL)
		return ERR_PTR(-EINVAL);

	*devname = cifs_get_share_name(ref_unc);
	rc = dns_resolve_server_name_to_ip(*devname, &srvIP);
	if (rc != 0) {
		cERROR(1, ("%s: Failed to resolve server part of %s to IP",
			  __FUNCTION__, *devname));
		mountdata = ERR_PTR(rc);
		goto compose_mount_options_out;
	}
	md_len = strlen(sb_mountdata) + strlen(srvIP) + strlen(ref_unc) + 3;
	mountdata = kzalloc(md_len+1, GFP_KERNEL);
	if (mountdata == NULL) {
		mountdata = ERR_PTR(-ENOMEM);
		goto compose_mount_options_out;
	}

	/* copy all options except of unc,ip,prefixpath */
	off = 0;
	if (strncmp(sb_mountdata, "sep=", 4) == 0) {
			sep = sb_mountdata[4];
			strncpy(mountdata, sb_mountdata, 5);
			off += 5;
	}
	while ((tkn_e = strchr(sb_mountdata+off, sep))) {
		noff = (tkn_e - (sb_mountdata+off)) + 1;
		if (strnicmp(sb_mountdata+off, "unc=", 4) == 0) {
			off += noff;
			continue;
		}
		if (strnicmp(sb_mountdata+off, "ip=", 3) == 0) {
			off += noff;
			continue;
		}
		if (strnicmp(sb_mountdata+off, "prefixpath=", 3) == 0) {
			off += noff;
			continue;
		}
		strncat(mountdata, sb_mountdata+off, noff);
		off += noff;
	}
	strcat(mountdata, sb_mountdata+off);
	mountdata[md_len] = '\0';

	/* copy new IP and ref share name */
	strcat(mountdata, ",ip=");
	strcat(mountdata, srvIP);
	strcat(mountdata, ",unc=");
	strcat(mountdata, *devname);

	/* find & copy prefixpath */
	tkn_e = strchr(ref_unc+2, '\\');
	if (tkn_e) {
		tkn_e = strchr(tkn_e+1, '\\');
		if (tkn_e) {
			strcat(mountdata, ",prefixpath=");
			strcat(mountdata, tkn_e);
		}
	}

	/*cFYI(1,("%s: parent mountdata: %s", __FUNCTION__,sb_mountdata));*/
	/*cFYI(1, ("%s: submount mountdata: %s", __FUNCTION__, mountdata ));*/

compose_mount_options_out:
	kfree(srvIP);
	return mountdata;
}


static struct vfsmount *cifs_dfs_do_refmount(const struct vfsmount *mnt_parent,
		struct dentry *dentry, char *ref_unc)
{
	struct cifs_sb_info *cifs_sb;
	struct vfsmount *mnt;
	char *mountdata;
	char *devname = NULL;

	cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
	mountdata = compose_mount_options(cifs_sb->mountdata,
						ref_unc, &devname);

	if (IS_ERR(mountdata))
		return (struct vfsmount *)mountdata;

	mnt = vfs_kern_mount(&cifs_fs_type, 0, devname, mountdata);
	kfree(mountdata);
	kfree(devname);
	return mnt;

}

static char *build_full_dfs_path_from_dentry(struct dentry *dentry)
{
	char *full_path = NULL;
	char *search_path;
	char *tmp_path;
	size_t l_max_len;
	struct cifs_sb_info *cifs_sb;

	if (dentry->d_inode == NULL)
		return NULL;

	cifs_sb = CIFS_SB(dentry->d_inode->i_sb);

	if (cifs_sb->tcon == NULL)
		return NULL;

	search_path = build_path_from_dentry(dentry);
	if (search_path == NULL)
		return NULL;

	if (cifs_sb->tcon->Flags & SMB_SHARE_IS_IN_DFS) {
		/* we should use full path name to correct working with DFS */
		l_max_len = strnlen(cifs_sb->tcon->treeName, MAX_TREE_SIZE+1) +
					strnlen(search_path, MAX_PATHCONF) + 1;
		tmp_path = kmalloc(l_max_len, GFP_KERNEL);
		if (tmp_path == NULL) {
			kfree(search_path);
			return NULL;
		}
		strncpy(tmp_path, cifs_sb->tcon->treeName, l_max_len);
		strcat(tmp_path, search_path);
		tmp_path[l_max_len-1] = 0;
		full_path = tmp_path;
		kfree(search_path);
	} else {
		full_path = search_path;
	}
	return full_path;
}

static int add_mount_helper(struct vfsmount *newmnt, struct nameidata *nd,
				struct list_head *mntlist)
{
	/* stolen from afs code */
	int err;

	mntget(newmnt);
	err = do_add_mount(newmnt, nd, nd->mnt->mnt_flags, mntlist);
	switch (err) {
	case 0:
		dput(nd->dentry);
		mntput(nd->mnt);
		nd->mnt = newmnt;
		nd->dentry = dget(newmnt->mnt_root);
		break;
	case -EBUSY:
		/* someone else made a mount here whilst we were busy */
		while (d_mountpoint(nd->dentry) &&
		       follow_down(&nd->mnt, &nd->dentry))
			;
		err = 0;
	default:
		mntput(newmnt);
		break;
	}
	return err;
}

static void dump_referral(const struct dfs_info3_param *ref)
{
	cFYI(1, ("DFS: ref path: %s", ref->path_name));
	cFYI(1, ("DFS: node path: %s", ref->node_name));
	cFYI(1, ("DFS: fl: %hd, srv_type: %hd", ref->flags, ref->server_type));
	cFYI(1, ("DFS: ref_flags: %hd, path_consumed: %hd", ref->ref_flag,
				ref->PathConsumed));
}


static void*
cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
{
	struct dfs_info3_param *referrals = NULL;
	unsigned int num_referrals = 0;
	struct cifs_sb_info *cifs_sb;
	struct cifsSesInfo *ses;
	char *full_path = NULL;
	int xid, i;
	int rc = 0;
	struct vfsmount *mnt = ERR_PTR(-ENOENT);

	cFYI(1, ("in %s", __FUNCTION__));
	BUG_ON(IS_ROOT(dentry));

	xid = GetXid();

	dput(nd->dentry);
	nd->dentry = dget(dentry);

	cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
	ses = cifs_sb->tcon->ses;

	if (!ses) {
		rc = -EINVAL;
		goto out_err;
	}

	full_path = build_full_dfs_path_from_dentry(dentry);
	if (full_path == NULL) {
		rc = -ENOMEM;
		goto out_err;
	}

	rc = get_dfs_path(xid, ses , full_path, cifs_sb->local_nls,
		&num_referrals, &referrals,
		cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);

	for (i = 0; i < num_referrals; i++) {
		dump_referral(referrals+i);
		/* connect to a storage node */
		if (referrals[i].flags & DFSREF_STORAGE_SERVER) {
			int len;
			len = strlen(referrals[i].node_name);
			if (len < 2) {
				cERROR(1, ("%s: Net Address path too short: %s",
					__FUNCTION__, referrals[i].node_name));
				rc = -EINVAL;
				goto out_err;
			}
			mnt = cifs_dfs_do_refmount(nd->mnt, nd->dentry,
						referrals[i].node_name);
			cFYI(1, ("%s: cifs_dfs_do_refmount:%s , mnt:%p",
					 __FUNCTION__,
					referrals[i].node_name, mnt));

			/* complete mount procedure if we accured submount */
			if (!IS_ERR(mnt))
				break;
		}
	}

	/* we need it cause for() above could exit without valid submount */
	rc = PTR_ERR(mnt);
	if (IS_ERR(mnt))
		goto out_err;

	nd->mnt->mnt_flags |= MNT_SHRINKABLE;
	rc = add_mount_helper(mnt, nd, &cifs_dfs_automount_list);

out:
	FreeXid(xid);
	free_dfs_info_array(referrals, num_referrals);
	kfree(full_path);
	cFYI(1, ("leaving %s" , __FUNCTION__));
	return ERR_PTR(rc);
out_err:
	path_release(nd);
	goto out;
}

struct inode_operations cifs_dfs_referral_inode_operations = {
	.follow_link = cifs_dfs_follow_mountpoint,
};
Commit	Line	Data
6d5ae0de IM	1	/*
	2	* Contains the CIFS DFS referral mounting routines used for handling
	3	* traversal via DFS junction point
	4	*
	5	* Copyright (c) 2007 Igor Mammedov
366781c1	6	* Copyright (C) International Business Machines Corp., 2008
6d5ae0de	7	* Author(s): Igor Mammedov (niallain@gmail.com)
366781c1	8	* Steve French (sfrench@us.ibm.com)
6d5ae0de IM	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*/
	14
	15	#include <linux/dcache.h>
	16	#include <linux/mount.h>
	17	#include <linux/namei.h>
	18	#include <linux/vfs.h>
	19	#include <linux/fs.h>
	20	#include "cifsglob.h"
	21	#include "cifsproto.h"
	22	#include "cifsfs.h"
	23	#include "dns_resolve.h"
	24	#include "cifs_debug.h"
	25
	26	LIST_HEAD(cifs_dfs_automount_list);
	27
	28	/*
	29	* DFS functions
	30	*/
	31
	32	void dfs_shrink_umount_helper(struct vfsmount *vfsmnt)
	33	{
	34	mark_mounts_for_expiry(&cifs_dfs_automount_list);
	35	mark_mounts_for_expiry(&cifs_dfs_automount_list);
	36	shrink_submounts(vfsmnt, &cifs_dfs_automount_list);
	37	}
	38
	39	/**
	40	* cifs_get_share_name - extracts share name from UNC
	41	* @node_name: pointer to UNC string
	42	*
	43	* Extracts sharename form full UNC.
	44	* i.e. strips from UNC trailing path that is not part of share
	45	* name and fixup missing '\' in the begining of DFS node refferal
	46	* if neccessary.
	47	* Returns pointer to share name on success or NULL on error.
	48	* Caller is responsible for freeing returned string.
	49	*/
	50	static char cifs_get_share_name(const char node_name)
	51	{
	52	int len;
	53	char *UNC;
	54	char *pSep;
	55
	56	len = strlen(node_name);
	57	UNC = kmalloc(len+2 /for term null and additional \ if it's missed /,
	58	GFP_KERNEL);
	59	if (!UNC)
	60	return NULL;
	61
	62	/* get share name and server name */
	63	if (node_name[1] != '\\') {
	64	UNC[0] = '\\';
	65	strncpy(UNC+1, node_name, len);
	66	len++;
	67	UNC[len] = 0;
	68	} else {
	69	strncpy(UNC, node_name, len);
	70	UNC[len] = 0;
	71	}
	72
73	/* find server name end */
74	pSep = memchr(UNC+2, '\\', len-2);
75	if (!pSep) {
76	cERROR(1, ("%s: no server name end in node name: %s",
77	__FUNCTION__, node_name));
78	kfree(UNC);
79	return NULL;
80	}
81
82	/* find sharename end */
83	pSep++;
84	pSep = memchr(UNC+(pSep-UNC), '\\', len-(pSep-UNC));
85	if (!pSep) {
86	cERROR(1, ("%s:2 cant find share name in node name: %s",
87	__FUNCTION__, node_name));
88	kfree(UNC);
89	return NULL;
90	}
91	/* trim path up to sharename end
92	* * now we have share name in UNC */
93	*pSep = 0;
94
95	return UNC;
96	}
97
98
99	/**
100	* compose_mount_options - creates mount options for refferral
101	* @sb_mountdata: parent/root DFS mount options (template)
102	* @ref_unc: refferral server UNC
103	* @devname: pointer for saving device name
104	*
105	* creates mount options for submount based on template options sb_mountdata
106	* and replacing unc,ip,prefixpath options with ones we've got form ref_unc.
107	*
108	* Returns: pointer to new mount options or ERR_PTR.
109	* Caller is responcible for freeing retunrned value if it is not error.
110	*/
366781c1 SF	111	static char compose_mount_options(const char sb_mountdata,
	112	const char *ref_unc,
	113	char **devname)
6d5ae0de IM	114	{
	115	int rc;
	116	char *mountdata;
	117	int md_len;
	118	char *tkn_e;
	119	char *srvIP = NULL;
	120	char sep = ',';
	121	int off, noff;
	122
	123	if (sb_mountdata == NULL)
	124	return ERR_PTR(-EINVAL);
	125
	126	*devname = cifs_get_share_name(ref_unc);
	127	rc = dns_resolve_server_name_to_ip(*devname, &srvIP);
	128	if (rc != 0) {
	129	cERROR(1, ("%s: Failed to resolve server part of %s to IP",
	130	__FUNCTION__, *devname));
	131	mountdata = ERR_PTR(rc);
	132	goto compose_mount_options_out;
	133	}
	134	md_len = strlen(sb_mountdata) + strlen(srvIP) + strlen(ref_unc) + 3;
	135	mountdata = kzalloc(md_len+1, GFP_KERNEL);
	136	if (mountdata == NULL) {
	137	mountdata = ERR_PTR(-ENOMEM);
	138	goto compose_mount_options_out;
	139	}
	140
	141	/* copy all options except of unc,ip,prefixpath */
	142	off = 0;
	143	if (strncmp(sb_mountdata, "sep=", 4) == 0) {
	144	sep = sb_mountdata[4];
	145	strncpy(mountdata, sb_mountdata, 5);
	146	off += 5;
	147	}
	148	while ((tkn_e = strchr(sb_mountdata+off, sep))) {
	149	noff = (tkn_e - (sb_mountdata+off)) + 1;
	150	if (strnicmp(sb_mountdata+off, "unc=", 4) == 0) {
	151	off += noff;
	152	continue;
	153	}
	154	if (strnicmp(sb_mountdata+off, "ip=", 3) == 0) {
	155	off += noff;
	156	continue;
	157	}
	158	if (strnicmp(sb_mountdata+off, "prefixpath=", 3) == 0) {
	159	off += noff;
	160	continue;
	161	}
	162	strncat(mountdata, sb_mountdata+off, noff);
	163	off += noff;
	164	}
	165	strcat(mountdata, sb_mountdata+off);
	166	mountdata[md_len] = '\0';
	167
	168	/* copy new IP and ref share name */
	169	strcat(mountdata, ",ip=");
	170	strcat(mountdata, srvIP);
	171	strcat(mountdata, ",unc=");
	172	strcat(mountdata, *devname);
	173
	174	/* find & copy prefixpath */
	175	tkn_e = strchr(ref_unc+2, '\\');
	176	if (tkn_e) {
	177	tkn_e = strchr(tkn_e+1, '\\');
178	if (tkn_e) {
179	strcat(mountdata, ",prefixpath=");
180	strcat(mountdata, tkn_e);
181	}
182	}
183
184	/cFYI(1,("%s: parent mountdata: %s", __FUNCTION__,sb_mountdata));/
185	/cFYI(1, ("%s: submount mountdata: %s", __FUNCTION__, mountdata ));/
186
187	compose_mount_options_out:
188	kfree(srvIP);
189	return mountdata;
190	}
191
192
366781c1	193	static struct vfsmount cifs_dfs_do_refmount(const struct vfsmount mnt_parent,
6d5ae0de IM	194	struct dentry dentry, char ref_unc)
	195	{
	196	struct cifs_sb_info *cifs_sb;
	197	struct vfsmount *mnt;
	198	char *mountdata;
366781c1	199	char *devname = NULL;
6d5ae0de IM	200
	201	cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
	202	mountdata = compose_mount_options(cifs_sb->mountdata,
	203	ref_unc, &devname);
	204
	205	if (IS_ERR(mountdata))
	206	return (struct vfsmount *)mountdata;
	207
	208	mnt = vfs_kern_mount(&cifs_fs_type, 0, devname, mountdata);
	209	kfree(mountdata);
	210	kfree(devname);
	211	return mnt;
	212
	213	}
	214
	215	static char build_full_dfs_path_from_dentry(struct dentry dentry)
	216	{
	217	char *full_path = NULL;
	218	char *search_path;
	219	char *tmp_path;
	220	size_t l_max_len;
	221	struct cifs_sb_info *cifs_sb;
	222
	223	if (dentry->d_inode == NULL)
	224	return NULL;
	225
	226	cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
	227
	228	if (cifs_sb->tcon == NULL)
	229	return NULL;
	230
	231	search_path = build_path_from_dentry(dentry);
	232	if (search_path == NULL)
	233	return NULL;
	234
	235	if (cifs_sb->tcon->Flags & SMB_SHARE_IS_IN_DFS) {
	236	/* we should use full path name to correct working with DFS */
	237	l_max_len = strnlen(cifs_sb->tcon->treeName, MAX_TREE_SIZE+1) +
	238	strnlen(search_path, MAX_PATHCONF) + 1;
	239	tmp_path = kmalloc(l_max_len, GFP_KERNEL);
	240	if (tmp_path == NULL) {
	241	kfree(search_path);
	242	return NULL;
	243	}
	244	strncpy(tmp_path, cifs_sb->tcon->treeName, l_max_len);
	245	strcat(tmp_path, search_path);
	246	tmp_path[l_max_len-1] = 0;
	247	full_path = tmp_path;
	248	kfree(search_path);
	249	} else {
	250	full_path = search_path;
	251	}
	252	return full_path;
	253	}
	254
	255	static int add_mount_helper(struct vfsmount newmnt, struct nameidata nd,
	256	struct list_head *mntlist)
	257	{
	258	/* stolen from afs code */
	259	int err;
	260
	261	mntget(newmnt);
	262	err = do_add_mount(newmnt, nd, nd->mnt->mnt_flags, mntlist);
	263	switch (err) {
264	case 0:
265	dput(nd->dentry);
266	mntput(nd->mnt);
267	nd->mnt = newmnt;
268	nd->dentry = dget(newmnt->mnt_root);
269	break;
270	case -EBUSY:
271	/* someone else made a mount here whilst we were busy */
272	while (d_mountpoint(nd->dentry) &&
273	follow_down(&nd->mnt, &nd->dentry))
274	;
275	err = 0;
276	default:
277	mntput(newmnt);
278	break;
279	}
280	return err;
281	}
282
366781c1	283	static void dump_referral(const struct dfs_info3_param *ref)
6d5ae0de IM	284	{
	285	cFYI(1, ("DFS: ref path: %s", ref->path_name));
	286	cFYI(1, ("DFS: node path: %s", ref->node_name));
	287	cFYI(1, ("DFS: fl: %hd, srv_type: %hd", ref->flags, ref->server_type));
	288	cFYI(1, ("DFS: ref_flags: %hd, path_consumed: %hd", ref->ref_flag,
	289	ref->PathConsumed));
	290	}
	291
	292
	293	static void*
	294	cifs_dfs_follow_mountpoint(struct dentry dentry, struct nameidata nd)
	295	{
	296	struct dfs_info3_param *referrals = NULL;
	297	unsigned int num_referrals = 0;
	298	struct cifs_sb_info *cifs_sb;
	299	struct cifsSesInfo *ses;
	300	char *full_path = NULL;
	301	int xid, i;
	302	int rc = 0;
	303	struct vfsmount *mnt = ERR_PTR(-ENOENT);
	304
	305	cFYI(1, ("in %s", __FUNCTION__));
	306	BUG_ON(IS_ROOT(dentry));
	307
	308	xid = GetXid();
	309
	310	dput(nd->dentry);
	311	nd->dentry = dget(dentry);
	312
	313	cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
	314	ses = cifs_sb->tcon->ses;
	315
	316	if (!ses) {
	317	rc = -EINVAL;
	318	goto out_err;
	319	}
	320
	321	full_path = build_full_dfs_path_from_dentry(dentry);
	322	if (full_path == NULL) {
	323	rc = -ENOMEM;
	324	goto out_err;
	325	}
	326
	327	rc = get_dfs_path(xid, ses , full_path, cifs_sb->local_nls,
	328	&num_referrals, &referrals,
	329	cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
	330
	331	for (i = 0; i < num_referrals; i++) {
	332	dump_referral(referrals+i);
	333	/* connect to a storage node */
	334	if (referrals[i].flags & DFSREF_STORAGE_SERVER) {
	335	int len;
	336	len = strlen(referrals[i].node_name);
	337	if (len < 2) {
	338	cERROR(1, ("%s: Net Address path too short: %s",
	339	__FUNCTION__, referrals[i].node_name));
	340	rc = -EINVAL;
	341	goto out_err;
	342	}
	343	mnt = cifs_dfs_do_refmount(nd->mnt, nd->dentry,
	344	referrals[i].node_name);
	345	cFYI(1, ("%s: cifs_dfs_do_refmount:%s , mnt:%p",
	346	__FUNCTION__,
	347	referrals[i].node_name, mnt));
348
349	/* complete mount procedure if we accured submount */
350	if (!IS_ERR(mnt))
351	break;
352	}
353	}
354
355	/* we need it cause for() above could exit without valid submount */
356	rc = PTR_ERR(mnt);
357	if (IS_ERR(mnt))
358	goto out_err;
359
360	nd->mnt->mnt_flags \|= MNT_SHRINKABLE;
361	rc = add_mount_helper(mnt, nd, &cifs_dfs_automount_list);
362
363	out:
364	FreeXid(xid);
365	free_dfs_info_array(referrals, num_referrals);
366	kfree(full_path);
367	cFYI(1, ("leaving %s" , __FUNCTION__));
368	return ERR_PTR(rc);
369	out_err:
370	path_release(nd);
371	goto out;
372	}
373
374	struct inode_operations cifs_dfs_referral_inode_operations = {
375	.follow_link = cifs_dfs_follow_mountpoint,
376	};
377