aboutsummaryrefslogtreecommitdiff
path: root/fs/cifs/link.c
blob: 473ca8033656fc1c8ab14a7a9d78bafd12722217 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/*
 *   fs/cifs/link.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2008
 *   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/stat.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"

int
cifs_hardlink(struct dentry *old_file, struct inode *inode,
	      struct dentry *direntry)
{
	int rc = -EACCES;
	int xid;
	char *fromName = NULL;
	char *toName = NULL;
	struct cifs_sb_info *cifs_sb_target;
	struct cifsTconInfo *pTcon;
	struct cifsInodeInfo *cifsInode;

	xid = GetXid();

	cifs_sb_target = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb_target->tcon;

/* No need to check for cross device links since server will do that
   BB note DFS case in future though (when we may have to check) */

	fromName = build_path_from_dentry(old_file);
	toName = build_path_from_dentry(direntry);
	if ((fromName == NULL) || (toName == NULL)) {
		rc = -ENOMEM;
		goto cifs_hl_exit;
	}

/*	if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)*/
	if (pTcon->unix_ext)
		rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
					    cifs_sb_target->local_nls,
					    cifs_sb_target->mnt_cifs_flags &
						CIFS_MOUNT_MAP_SPECIAL_CHR);
	else {
		rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
					cifs_sb_target->local_nls,
					cifs_sb_target->mnt_cifs_flags &
						CIFS_MOUNT_MAP_SPECIAL_CHR);
		if ((rc == -EIO) || (rc == -EINVAL))
			rc = -EOPNOTSUPP;
	}

	d_drop(direntry);	/* force new lookup from server of target */

	/* if source file is cached (oplocked) revalidate will not go to server
	   until the file is closed or oplock broken so update nlinks locally */
	if (old_file->d_inode) {
		cifsInode = CIFS_I(old_file->d_inode);
		if (rc == 0) {
			old_file->d_inode->i_nlink++;
/* BB should we make this contingent on superblock flag NOATIME? */
/*			old_file->d_inode->i_ctime = CURRENT_TIME;*/
			/* parent dir timestamps will update from srv
			within a second, would it really be worth it
			to set the parent dir cifs inode time to zero
			to force revalidate (faster) for it too? */
		}
		/* if not oplocked will force revalidate to get info
		   on source file from srv */
		cifsInode->time = 0;

		/* Will update parent dir timestamps from srv within a second.
		   Would it really be worth it to set the parent dir (cifs
		   inode) time field to zero to force revalidate on parent
		   directory faster ie
			CIFS_I(inode)->time = 0;  */
	}

cifs_hl_exit:
	kfree(fromName);
	kfree(toName);
	FreeXid(xid);
	return rc;
}

void *
cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
{
	struct inode *inode = direntry->d_inode;
	int rc = -ENOMEM;
	int xid;
	char *full_path = NULL;
	char *target_path = NULL;
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifsTconInfo *tcon = cifs_sb->tcon;

	xid = GetXid();

	/*
	 * For now, we just handle symlinks with unix extensions enabled.
	 * Eventually we should handle NTFS reparse points, and MacOS
	 * symlink support. For instance...
	 *
	 * rc = CIFSSMBQueryReparseLinkInfo(...)
	 *
	 * For now, just return -EACCES when the server doesn't support posix
	 * extensions. Note that we still allow querying symlinks when posix
	 * extensions are manually disabled. We could disable these as well
	 * but there doesn't seem to be any harm in allowing the client to
	 * read them.
	 */
	if (!(tcon->ses->capabilities & CAP_UNIX)) {
		rc = -EACCES;
		goto out;
	}

	full_path = build_path_from_dentry(direntry);
	if (!full_path)
		goto out;

	cFYI(1, "Full path: %s inode = 0x%p", full_path, inode);

	rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path,
				     cifs_sb->local_nls);
	kfree(full_path);
out:
	if (rc != 0) {
		kfree(target_path);
		target_path = ERR_PTR(rc);
	}

	FreeXid(xid);
	nd_set_link(nd, target_path);
	return NULL;
}

int
cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
{
	int rc = -EOPNOTSUPP;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	struct inode *newinode = NULL;

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	full_path = build_path_from_dentry(direntry);

	if (full_path == NULL) {
		rc = -ENOMEM;
		FreeXid(xid);
		return rc;
	}

	cFYI(1, "Full path: %s", full_path);
	cFYI(1, "symname is %s", symname);

	/* BB what if DFS and this volume is on different share? BB */
	if (pTcon->unix_ext)
		rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
					   cifs_sb->local_nls);
	/* else
	   rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
					cifs_sb_target->local_nls); */

	if (rc == 0) {
		if (pTcon->unix_ext)
			rc = cifs_get_inode_info_unix(&newinode, full_path,
						      inode->i_sb, xid);
		else
			rc = cifs_get_inode_info(&newinode, full_path, NULL,
						 inode->i_sb, xid, NULL);

		if (rc != 0) {
			cFYI(1, "Create symlink ok, getinodeinfo fail rc = %d",
			      rc);
		} else {
			if (pTcon->nocase)
				direntry->d_op = &cifs_ci_dentry_ops;
			else
				direntry->d_op = &cifs_dentry_ops;
			d_instantiate(direntry, newinode);
		}
	}

	kfree(full_path);
	FreeXid(xid);
	return rc;
}

void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
{
	char *p = nd_get_link(nd);
	if (!IS_ERR(p))
		kfree(p);
}