summaryrefslogtreecommitdiffstats
path: root/fs/cifs/link.c
blob: 11f265726db780e968e8084359696bc8a4c6446b (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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
/*
 *   fs/cifs/link.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2003
 *   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/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 = -EACCES;
	int xid;
	char *full_path = NULL;
	char *target_path = ERR_PTR(-ENOMEM);
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;

	xid = GetXid();

	full_path = build_path_from_dentry(direntry);

	if (!full_path)
		goto out_no_free;

	cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;
	target_path = kmalloc(PATH_MAX, GFP_KERNEL);
	if (!target_path) {
		target_path = ERR_PTR(-ENOMEM);
		goto out;
	}

	/* We could change this to:
		if (pTcon->unix_ext)
	   but there does not seem any point in refusing to
	   get symlink info if we can, even if unix extensions
	   turned off for this mount */

	if (pTcon->ses->capabilities & CAP_UNIX)
		rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
					     target_path,
					     PATH_MAX-1,
					     cifs_sb->local_nls);
	else {
		/* BB add read reparse point symlink code here */
		/* rc = CIFSSMBQueryReparseLinkInfo */
		/* BB Add code to Query ReparsePoint info */
		/* BB Add MAC style xsymlink check here if enabled */
	}

	if (rc == 0) {

/* BB Add special case check for Samba DFS symlinks */

		target_path[PATH_MAX-1] = 0;
	} else {
		kfree(target_path);
		target_path = ERR_PTR(rc);
	}

out:
	kfree(full_path);
out_no_free:
	FreeXid(xid);
	nd_set_link(nd, target_path);
	return NULL;	/* No cookie */
}

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) {
		FreeXid(xid);
		return -ENOMEM;
	}

	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);

		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;
}

int
cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
{
	struct inode *inode = direntry->d_inode;
	int rc = -EACCES;
	int xid;
	int oplock = FALSE;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	char *tmp_path = NULL;
	char *tmpbuffer;
	unsigned char *referrals = NULL;
	unsigned int num_referrals = 0;
	int len;
	__u16 fid;

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

/* BB would it be safe against deadlock to grab this sem
      even though rename itself grabs the sem and calls lookup? */
/*       mutex_lock(&inode->i_sb->s_vfs_rename_mutex);*/
	full_path = build_path_from_dentry(direntry);
/*       mutex_unlock(&inode->i_sb->s_vfs_rename_mutex);*/

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

	cFYI(1,
	     ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
	      full_path, inode, pBuffer, buflen));
	if (buflen > PATH_MAX)
		len = PATH_MAX;
	else
		len = buflen;
	tmpbuffer = kmalloc(len, GFP_KERNEL);
	if (tmpbuffer == NULL) {
		kfree(full_path);
		FreeXid(xid);
		return -ENOMEM;
	}

/* BB add read reparse point symlink code and
	Unix extensions symlink code here BB */
/* We could disable this based on pTcon->unix_ext flag instead ... but why? */
	if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
		rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
				tmpbuffer,
				len - 1,
				cifs_sb->local_nls);
	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
		cERROR(1, ("SFU style symlinks not implemented yet"));
		/* add open and read as in fs/cifs/inode.c */
	} else {
		rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
				OPEN_REPARSE_POINT, &fid, &oplock, NULL,
				cifs_sb->local_nls,
				cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);
		if (!rc) {
			rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
				tmpbuffer,
				len - 1,
				fid,
				cifs_sb->local_nls);
			if (CIFSSMBClose(xid, pTcon, fid)) {
				cFYI(1, ("Error closing junction point "
					 "(open for ioctl)"));
			}
			if (rc == -EIO) {
				/* Query if DFS Junction */
				tmp_path =
					kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
						GFP_KERNEL);
				if (tmp_path) {
					strncpy(tmp_path, pTcon->treeName,
						MAX_TREE_SIZE);
					strncat(tmp_path, full_path,
						MAX_PATHCONF);
					rc = get_dfs_path(xid, pTcon->ses,
						tmp_path,
						cifs_sb->local_nls,
						&num_referrals, &referrals,
						cifs_sb->mnt_cifs_flags &
						    CIFS_MOUNT_MAP_SPECIAL_CHR);
					cFYI(1, ("Get DFS for %s rc = %d ",
						tmp_path, rc));
					if ((num_referrals == 0) && (rc == 0))
						rc = -EACCES;
					else {
						cFYI(1, ("num referral: %d",
							num_referrals));
						if (referrals) {
							cFYI(1,("referral string: %s", referrals));
							strncpy(tmpbuffer,
								referrals,
								len-1);
						}
					}
					kfree(referrals);
					kfree(tmp_path);
}
				/* BB add code like else decode referrals
				then memcpy to tmpbuffer and free referrals
				string array BB */
			}
		}
	}
	/* BB Anything else to do to handle recursive links? */
	/* BB Should we be using page ops here? */

	/* BB null terminate returned string in pBuffer? BB */
	if (rc == 0) {
		rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
		cFYI(1,
		     ("vfs_readlink called from cifs_readlink returned %d",
		      rc));
	}

	kfree(tmpbuffer);
	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);
}
OpenPOWER on IntegriCloud