[net-next-2.6.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);
}

/**
 * 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",
			__func__, 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",
			__func__, 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",
			  __func__, *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", __func__,sb_mountdata));*/
	/*cFYI(1, ("%s: submount mountdata: %s", __func__, 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->path.mnt->mnt_flags, mntlist);
	switch (err) {
	case 0:
		dput(nd->path.dentry);
		mntput(nd->path.mnt);
		nd->path.mnt = newmnt;
		nd->path.dentry = dget(newmnt->mnt_root);
		break;
	case -EBUSY:
		/* someone else made a mount here whilst we were busy */
		while (d_mountpoint(nd->path.dentry) &&
		       follow_down(&nd->path.mnt, &nd->path.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->path_consumed));
}


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", __func__));
	BUG_ON(IS_ROOT(dentry));

	xid = GetXid();

	dput(nd->path.dentry);
	nd->path.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",
					__func__, referrals[i].node_name));
				rc = -EINVAL;
				goto out_err;
			}
			mnt = cifs_dfs_do_refmount(nd->path.mnt,
						nd->path.dentry,
						referrals[i].node_name);
			cFYI(1, ("%s: cifs_dfs_do_refmount:%s , mnt:%p",
					 __func__,
					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->path.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" , __func__));
	return ERR_PTR(rc);
out_err:
	path_put(&nd->path);
	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);
6d5ae0de IM	36	}
	37
	38	/**
	39	* cifs_get_share_name - extracts share name from UNC
	40	* @node_name: pointer to UNC string
	41	*
	42	* Extracts sharename form full UNC.
	43	* i.e. strips from UNC trailing path that is not part of share
	44	* name and fixup missing '\' in the begining of DFS node refferal
	45	* if neccessary.
	46	* Returns pointer to share name on success or NULL on error.
	47	* Caller is responsible for freeing returned string.
	48	*/
	49	static char cifs_get_share_name(const char node_name)
	50	{
	51	int len;
	52	char *UNC;
	53	char *pSep;
	54
	55	len = strlen(node_name);
	56	UNC = kmalloc(len+2 /for term null and additional \ if it's missed /,
	57	GFP_KERNEL);
	58	if (!UNC)
	59	return NULL;
	60
	61	/* get share name and server name */
	62	if (node_name[1] != '\\') {
	63	UNC[0] = '\\';
	64	strncpy(UNC+1, node_name, len);
	65	len++;
	66	UNC[len] = 0;
	67	} else {
	68	strncpy(UNC, node_name, len);
	69	UNC[len] = 0;
	70	}
	71
	72	/* find server name end */
	73	pSep = memchr(UNC+2, '\\', len-2);
	74	if (!pSep) {
	75	cERROR(1, ("%s: no server name end in node name: %s",
55f78e17	76	__func__, node_name));
6d5ae0de IM	77	kfree(UNC);
	78	return NULL;
	79	}
	80
	81	/* find sharename end */
	82	pSep++;
	83	pSep = memchr(UNC+(pSep-UNC), '\\', len-(pSep-UNC));
	84	if (!pSep) {
	85	cERROR(1, ("%s:2 cant find share name in node name: %s",
55f78e17	86	__func__, node_name));
6d5ae0de IM	87	kfree(UNC);
	88	return NULL;
	89	}
	90	/* trim path up to sharename end
	91	* * now we have share name in UNC */
	92	*pSep = 0;
	93
	94	return UNC;
	95	}
	96
	97
	98	/**
	99	* compose_mount_options - creates mount options for refferral
	100	* @sb_mountdata: parent/root DFS mount options (template)
	101	* @ref_unc: refferral server UNC
	102	* @devname: pointer for saving device name
	103	*
	104	* creates mount options for submount based on template options sb_mountdata
	105	* and replacing unc,ip,prefixpath options with ones we've got form ref_unc.
	106	*
	107	* Returns: pointer to new mount options or ERR_PTR.
	108	* Caller is responcible for freeing retunrned value if it is not error.
	109	*/
366781c1 SF	110	static char compose_mount_options(const char sb_mountdata,
	111	const char *ref_unc,
	112	char **devname)
6d5ae0de IM	113	{
	114	int rc;
	115	char *mountdata;
	116	int md_len;
	117	char *tkn_e;
	118	char *srvIP = NULL;
	119	char sep = ',';
	120	int off, noff;
	121
	122	if (sb_mountdata == NULL)
	123	return ERR_PTR(-EINVAL);
	124
	125	*devname = cifs_get_share_name(ref_unc);
	126	rc = dns_resolve_server_name_to_ip(*devname, &srvIP);
	127	if (rc != 0) {
	128	cERROR(1, ("%s: Failed to resolve server part of %s to IP",
55f78e17	129	__func__, *devname));
6d5ae0de IM	130	mountdata = ERR_PTR(rc);
	131	goto compose_mount_options_out;
	132	}
	133	md_len = strlen(sb_mountdata) + strlen(srvIP) + strlen(ref_unc) + 3;
	134	mountdata = kzalloc(md_len+1, GFP_KERNEL);
	135	if (mountdata == NULL) {
	136	mountdata = ERR_PTR(-ENOMEM);
	137	goto compose_mount_options_out;
	138	}
	139
	140	/* copy all options except of unc,ip,prefixpath */
	141	off = 0;
	142	if (strncmp(sb_mountdata, "sep=", 4) == 0) {
	143	sep = sb_mountdata[4];
	144	strncpy(mountdata, sb_mountdata, 5);
	145	off += 5;
	146	}
	147	while ((tkn_e = strchr(sb_mountdata+off, sep))) {
	148	noff = (tkn_e - (sb_mountdata+off)) + 1;
	149	if (strnicmp(sb_mountdata+off, "unc=", 4) == 0) {
	150	off += noff;
	151	continue;
	152	}
	153	if (strnicmp(sb_mountdata+off, "ip=", 3) == 0) {
	154	off += noff;
	155	continue;
	156	}
	157	if (strnicmp(sb_mountdata+off, "prefixpath=", 3) == 0) {
	158	off += noff;
	159	continue;
	160	}
	161	strncat(mountdata, sb_mountdata+off, noff);
	162	off += noff;
	163	}
	164	strcat(mountdata, sb_mountdata+off);
	165	mountdata[md_len] = '\0';
	166
	167	/* copy new IP and ref share name */
	168	strcat(mountdata, ",ip=");
	169	strcat(mountdata, srvIP);
	170	strcat(mountdata, ",unc=");
	171	strcat(mountdata, *devname);
	172
	173	/* find & copy prefixpath */
	174	tkn_e = strchr(ref_unc+2, '\\');
	175	if (tkn_e) {
	176	tkn_e = strchr(tkn_e+1, '\\');
	177	if (tkn_e) {
	178	strcat(mountdata, ",prefixpath=");
	179	strcat(mountdata, tkn_e);
	180	}
	181	}
	182
55f78e17 HH	183	/cFYI(1,("%s: parent mountdata: %s", __func__,sb_mountdata));/
55f78e17 HH	184	/cFYI(1, ("%s: submount mountdata: %s", __func__, mountdata ));/
6d5ae0de IM	185
	186	compose_mount_options_out:
	187	kfree(srvIP);
	188	return mountdata;
	189	}
	190
	191
366781c1	192	static struct vfsmount cifs_dfs_do_refmount(const struct vfsmount mnt_parent,
6d5ae0de IM	193	struct dentry dentry, char ref_unc)
	194	{
	195	struct cifs_sb_info *cifs_sb;
	196	struct vfsmount *mnt;
	197	char *mountdata;
366781c1	198	char *devname = NULL;
6d5ae0de IM	199
	200	cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
	201	mountdata = compose_mount_options(cifs_sb->mountdata,
	202	ref_unc, &devname);
	203
	204	if (IS_ERR(mountdata))
	205	return (struct vfsmount *)mountdata;
	206
	207	mnt = vfs_kern_mount(&cifs_fs_type, 0, devname, mountdata);
	208	kfree(mountdata);
	209	kfree(devname);
	210	return mnt;
	211
	212	}
	213
	214	static char build_full_dfs_path_from_dentry(struct dentry dentry)
	215	{
	216	char *full_path = NULL;
	217	char *search_path;
	218	char *tmp_path;
	219	size_t l_max_len;
	220	struct cifs_sb_info *cifs_sb;
	221
	222	if (dentry->d_inode == NULL)
	223	return NULL;
	224
	225	cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
	226
	227	if (cifs_sb->tcon == NULL)
	228	return NULL;
	229
	230	search_path = build_path_from_dentry(dentry);
	231	if (search_path == NULL)
	232	return NULL;
	233
	234	if (cifs_sb->tcon->Flags & SMB_SHARE_IS_IN_DFS) {
	235	/* we should use full path name to correct working with DFS */
	236	l_max_len = strnlen(cifs_sb->tcon->treeName, MAX_TREE_SIZE+1) +
	237	strnlen(search_path, MAX_PATHCONF) + 1;
	238	tmp_path = kmalloc(l_max_len, GFP_KERNEL);
	239	if (tmp_path == NULL) {
	240	kfree(search_path);
	241	return NULL;
	242	}
	243	strncpy(tmp_path, cifs_sb->tcon->treeName, l_max_len);
	244	strcat(tmp_path, search_path);
	245	tmp_path[l_max_len-1] = 0;
	246	full_path = tmp_path;
	247	kfree(search_path);
	248	} else {
	249	full_path = search_path;
	250	}
	251	return full_path;
	252	}
	253
	254	static int add_mount_helper(struct vfsmount newmnt, struct nameidata nd,
	255	struct list_head *mntlist)
	256	{
	257	/* stolen from afs code */
	258	int err;
	259
	260	mntget(newmnt);
4ac91378	261	err = do_add_mount(newmnt, nd, nd->path.mnt->mnt_flags, mntlist);
6d5ae0de IM	262	switch (err) {
6d5ae0de IM	263	case 0:
4ac91378 JB	264	dput(nd->path.dentry);
	265	mntput(nd->path.mnt);
	266	nd->path.mnt = newmnt;
	267	nd->path.dentry = dget(newmnt->mnt_root);
6d5ae0de IM	268	break;
	269	case -EBUSY:
	270	/* someone else made a mount here whilst we were busy */
4ac91378 JB	271	while (d_mountpoint(nd->path.dentry) &&
4ac91378 JB	272	follow_down(&nd->path.mnt, &nd->path.dentry))
6d5ae0de IM	273	;
	274	err = 0;
	275	default:
	276	mntput(newmnt);
	277	break;
	278	}
	279	return err;
	280	}
	281
366781c1	282	static void dump_referral(const struct dfs_info3_param *ref)
6d5ae0de IM	283	{
	284	cFYI(1, ("DFS: ref path: %s", ref->path_name));
	285	cFYI(1, ("DFS: node path: %s", ref->node_name));
	286	cFYI(1, ("DFS: fl: %hd, srv_type: %hd", ref->flags, ref->server_type));
	287	cFYI(1, ("DFS: ref_flags: %hd, path_consumed: %hd", ref->ref_flag,
8aad018b	288	ref->path_consumed));
6d5ae0de IM	289	}
	290
	291
	292	static void*
	293	cifs_dfs_follow_mountpoint(struct dentry dentry, struct nameidata nd)
	294	{
	295	struct dfs_info3_param *referrals = NULL;
	296	unsigned int num_referrals = 0;
	297	struct cifs_sb_info *cifs_sb;
	298	struct cifsSesInfo *ses;
	299	char *full_path = NULL;
	300	int xid, i;
	301	int rc = 0;
	302	struct vfsmount *mnt = ERR_PTR(-ENOENT);
	303
55f78e17	304	cFYI(1, ("in %s", __func__));
6d5ae0de IM	305	BUG_ON(IS_ROOT(dentry));
	306
	307	xid = GetXid();
	308
4ac91378 JB	309	dput(nd->path.dentry);
4ac91378 JB	310	nd->path.dentry = dget(dentry);
6d5ae0de IM	311
	312	cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
	313	ses = cifs_sb->tcon->ses;
	314
	315	if (!ses) {
	316	rc = -EINVAL;
	317	goto out_err;
	318	}
	319
	320	full_path = build_full_dfs_path_from_dentry(dentry);
	321	if (full_path == NULL) {
	322	rc = -ENOMEM;
	323	goto out_err;
	324	}
	325
	326	rc = get_dfs_path(xid, ses , full_path, cifs_sb->local_nls,
	327	&num_referrals, &referrals,
	328	cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
	329
	330	for (i = 0; i < num_referrals; i++) {
	331	dump_referral(referrals+i);
	332	/* connect to a storage node */
	333	if (referrals[i].flags & DFSREF_STORAGE_SERVER) {
	334	int len;
	335	len = strlen(referrals[i].node_name);
	336	if (len < 2) {
	337	cERROR(1, ("%s: Net Address path too short: %s",
55f78e17	338	__func__, referrals[i].node_name));
6d5ae0de IM	339	rc = -EINVAL;
	340	goto out_err;
	341	}
4ac91378 JB	342	mnt = cifs_dfs_do_refmount(nd->path.mnt,
4ac91378 JB	343	nd->path.dentry,
6d5ae0de IM	344	referrals[i].node_name);
6d5ae0de IM	345	cFYI(1, ("%s: cifs_dfs_do_refmount:%s , mnt:%p",
55f78e17	346	__func__,
6d5ae0de IM	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
4ac91378	360	nd->path.mnt->mnt_flags \|= MNT_SHRINKABLE;
6d5ae0de IM	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);
55f78e17	367	cFYI(1, ("leaving %s" , __func__));
6d5ae0de IM	368	return ERR_PTR(rc);
6d5ae0de IM	369	out_err:
1d957f9b	370	path_put(&nd->path);
6d5ae0de IM	371	goto out;
	372	}
	373
	374	struct inode_operations cifs_dfs_referral_inode_operations = {
	375	.follow_link = cifs_dfs_follow_mountpoint,
	376	};
	377