summaryrefslogtreecommitdiffstats
path: root/fs/cifs/dir.c
blob: 12ba81d7b07f6d1baefc380a43fb24261a583991 (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
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
/*
 *   fs/cifs/dir.c
 *
 *   vfs operations that deal with dentries
 * 
 *   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/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"

void
renew_parental_timestamps(struct dentry *direntry)
{
	/* BB check if there is a way to get the kernel to do this or if we really need this */
	do {
		direntry->d_time = jiffies;
		direntry = direntry->d_parent;
	} while (!IS_ROOT(direntry));	
}

/* Note: caller must free return buffer */
char *
build_path_from_dentry(struct dentry *direntry)
{
	struct dentry *temp;
	int namelen = 0;
	char *full_path;

	if(direntry == NULL)
		return NULL;  /* not much we can do if dentry is freed and
		we need to reopen the file after it was closed implicitly
		when the server crashed */

cifs_bp_rename_retry:
	for (temp = direntry; !IS_ROOT(temp);) {
		namelen += (1 + temp->d_name.len);
		temp = temp->d_parent;
		if(temp == NULL) {
			cERROR(1,("corrupt dentry"));
			return NULL;
		}
	}

	full_path = kmalloc(namelen+1, GFP_KERNEL);
	if(full_path == NULL)
		return full_path;
	full_path[namelen] = 0;	/* trailing null */

	for (temp = direntry; !IS_ROOT(temp);) {
		namelen -= 1 + temp->d_name.len;
		if (namelen < 0) {
			break;
		} else {
			full_path[namelen] = '\\';
			strncpy(full_path + namelen + 1, temp->d_name.name,
				temp->d_name.len);
			cFYI(0, (" name: %s ", full_path + namelen));
		}
		temp = temp->d_parent;
		if(temp == NULL) {
			cERROR(1,("corrupt dentry"));
			kfree(full_path);
			return NULL;
		}
	}
	if (namelen != 0) {
		cERROR(1,
		       ("We did not end path lookup where we expected namelen is %d",
			namelen));
		/* presumably this is only possible if we were racing with a rename 
		of one of the parent directories  (we can not lock the dentries
		above us to prevent this, but retrying should be harmless) */
		kfree(full_path);
		namelen = 0;
		goto cifs_bp_rename_retry;
	}

	return full_path;
}

/* Note: caller must free return buffer */
char *
build_wildcard_path_from_dentry(struct dentry *direntry)
{
	struct dentry *temp;
	int namelen = 0;
	char *full_path;

	if(direntry == NULL)
		return NULL;  /* not much we can do if dentry is freed and
		we need to reopen the file after it was closed implicitly
		when the server crashed */

cifs_bwp_rename_retry:
	for (temp = direntry; !IS_ROOT(temp);) {
		namelen += (1 + temp->d_name.len);
		temp = temp->d_parent;
		if(temp == NULL) {
			cERROR(1,("corrupt dentry"));
			return NULL;
		}
	}

	full_path = kmalloc(namelen+3, GFP_KERNEL);
	if(full_path == NULL)
		return full_path;

	full_path[namelen] = '\\';
	full_path[namelen+1] = '*';
	full_path[namelen+2] = 0;  /* trailing null */

	for (temp = direntry; !IS_ROOT(temp);) {
		namelen -= 1 + temp->d_name.len;
		if (namelen < 0) {
			break;
		} else {
			full_path[namelen] = '\\';
			strncpy(full_path + namelen + 1, temp->d_name.name,
				temp->d_name.len);
			cFYI(0, (" name: %s ", full_path + namelen));
		}
		temp = temp->d_parent;
		if(temp == NULL) {
			cERROR(1,("corrupt dentry"));
			kfree(full_path);
			return NULL;
		}
	}
	if (namelen != 0) {
		cERROR(1,
		       ("We did not end path lookup where we expected namelen is %d",
			namelen));
		/* presumably this is only possible if we were racing with a rename 
		of one of the parent directories  (we can not lock the dentries
		above us to prevent this, but retrying should be harmless) */
		kfree(full_path);
		namelen = 0;
		goto cifs_bwp_rename_retry;
	}

	return full_path;
}

/* Inode operations in similar order to how they appear in the Linux file fs.h */

int
cifs_create(struct inode *inode, struct dentry *direntry, int mode,
		struct nameidata *nd)
{
	int rc = -ENOENT;
	int xid;
	int oplock = 0;
	int desiredAccess = GENERIC_READ | GENERIC_WRITE;
	__u16 fileHandle;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	FILE_ALL_INFO * buf = NULL;
	struct inode *newinode = NULL;
	struct cifsFileInfo * pCifsFile = NULL;
	struct cifsInodeInfo * pCifsInode;
	int disposition = FILE_OVERWRITE_IF;
	int write_only = FALSE;

	xid = GetXid();

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

	down(&direntry->d_sb->s_vfs_rename_sem);
	full_path = build_path_from_dentry(direntry);
	up(&direntry->d_sb->s_vfs_rename_sem);
	if(full_path == NULL) {
		FreeXid(xid);
		return -ENOMEM;
	}

	if(nd) {
		if ((nd->intent.open.flags & O_ACCMODE) == O_RDONLY)
			desiredAccess = GENERIC_READ;
		else if ((nd->intent.open.flags & O_ACCMODE) == O_WRONLY) {
			desiredAccess = GENERIC_WRITE;
			write_only = TRUE;
		} else if ((nd->intent.open.flags & O_ACCMODE) == O_RDWR) {
			/* GENERIC_ALL is too much permission to request */
			/* can cause unnecessary access denied on create */
			/* desiredAccess = GENERIC_ALL; */
			desiredAccess = GENERIC_READ | GENERIC_WRITE;
		}

		if((nd->intent.open.flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
			disposition = FILE_CREATE;
		else if((nd->intent.open.flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
			disposition = FILE_OVERWRITE_IF;
		else if((nd->intent.open.flags & O_CREAT) == O_CREAT)
			disposition = FILE_OPEN_IF;
		else {
			cFYI(1,("Create flag not set in create function"));
		}
	}

	/* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
	if (oplockEnabled)
		oplock = REQ_OPLOCK;

	buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
	if(buf == NULL) {
		kfree(full_path);
		FreeXid(xid);
		return -ENOMEM;
	}

	rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
			 desiredAccess, CREATE_NOT_DIR,
			 &fileHandle, &oplock, buf, cifs_sb->local_nls);
	if (rc) {
		cFYI(1, ("cifs_create returned 0x%x ", rc));
	} else {
		/* If Open reported that we actually created a file
		then we now have to set the mode if possible */
		if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
			(oplock & CIFS_CREATE_ACTION))
			if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
				CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
					(__u64)current->euid,
					(__u64)current->egid,
					0 /* dev */,
					cifs_sb->local_nls);
			} else {
				CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
					(__u64)-1,
					(__u64)-1,
					0 /* dev */,
					cifs_sb->local_nls);
			}
		else {
			/* BB implement via Windows security descriptors */
			/* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
			/* could set r/o dos attribute if mode & 0222 == 0 */
		}

	/* BB server might mask mode so we have to query for Unix case*/
		if (pTcon->ses->capabilities & CAP_UNIX)
			rc = cifs_get_inode_info_unix(&newinode, full_path,
						 inode->i_sb,xid);
		else {
			rc = cifs_get_inode_info(&newinode, full_path,
						 buf, inode->i_sb,xid);
			if(newinode)
				newinode->i_mode = mode;
		}

		if (rc != 0) {
			cFYI(1,("Create worked but get_inode_info failed with rc = %d",
			      rc));
		} else {
			direntry->d_op = &cifs_dentry_ops;
			d_instantiate(direntry, newinode);
		}
		if((nd->flags & LOOKUP_OPEN) == FALSE) {
			/* mknod case - do not leave file open */
			CIFSSMBClose(xid, pTcon, fileHandle);
		} else if(newinode) {
			pCifsFile =
			   kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
			
			if(pCifsFile == NULL)
				goto cifs_create_out;
			memset((char *)pCifsFile, 0,
			       sizeof (struct cifsFileInfo));
			pCifsFile->netfid = fileHandle;
			pCifsFile->pid = current->tgid;
			pCifsFile->pInode = newinode;
			pCifsFile->invalidHandle = FALSE;
			pCifsFile->closePend     = FALSE;
			init_MUTEX(&pCifsFile->fh_sem);
			/* set the following in open now 
				pCifsFile->pfile = file; */
			write_lock(&GlobalSMBSeslock);
			list_add(&pCifsFile->tlist,&pTcon->openFileList);
			pCifsInode = CIFS_I(newinode);
			if(pCifsInode) {
				/* if readable file instance put first in list*/
				if (write_only == TRUE) {
                                       	list_add_tail(&pCifsFile->flist,
						&pCifsInode->openFileList);
				} else {
					list_add(&pCifsFile->flist,
						&pCifsInode->openFileList);
				}
				if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
					pCifsInode->clientCanCacheAll = TRUE;
					pCifsInode->clientCanCacheRead = TRUE;
					cFYI(1,("Exclusive Oplock for inode %p",
						newinode));
				} else if((oplock & 0xF) == OPLOCK_READ)
					pCifsInode->clientCanCacheRead = TRUE;
			}
			write_unlock(&GlobalSMBSeslock);
		}
	} 
cifs_create_out:
	kfree(buf);
	kfree(full_path);
	FreeXid(xid);
	return rc;
}

int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number) 
{
	int rc = -EPERM;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	struct inode * newinode = NULL;

	if (!old_valid_dev(device_number))
		return -EINVAL;

	xid = GetXid();

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

	down(&direntry->d_sb->s_vfs_rename_sem);
	full_path = build_path_from_dentry(direntry);
	up(&direntry->d_sb->s_vfs_rename_sem);
	if(full_path == NULL)
		rc = -ENOMEM;
	
	if (full_path && (pTcon->ses->capabilities & CAP_UNIX)) {
		if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
			rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
				mode,(__u64)current->euid,(__u64)current->egid,
				device_number, cifs_sb->local_nls);
		} else {
			rc = CIFSSMBUnixSetPerms(xid, pTcon,
				full_path, mode, (__u64)-1, (__u64)-1,
				device_number, cifs_sb->local_nls);
		}

		if(!rc) {
			rc = cifs_get_inode_info_unix(&newinode, full_path,
						inode->i_sb,xid);
			direntry->d_op = &cifs_dentry_ops;
			if(rc == 0)
				d_instantiate(direntry, newinode);
		}
	}

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


struct dentry *
cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
{
	int xid;
	int rc = 0; /* to get around spurious gcc warning, set to zero here */
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct inode *newInode = NULL;
	char *full_path = NULL;

	xid = GetXid();

	cFYI(1,
	     (" parent inode = 0x%p name is: %s and dentry = 0x%p",
	      parent_dir_inode, direntry->d_name.name, direntry));

	/* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */

	/* check whether path exists */

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

	/* can not grab the rename sem here since it would
	deadlock in the cases (beginning of sys_rename itself)
	in which we already have the sb rename sem */
	full_path = build_path_from_dentry(direntry);
	if(full_path == NULL) {
		FreeXid(xid);
		return ERR_PTR(-ENOMEM);
	}

	if (direntry->d_inode != NULL) {
		cFYI(1, (" non-NULL inode in lookup"));
	} else {
		cFYI(1, (" NULL inode in lookup"));
	}
	cFYI(1,
	     (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));

	if (pTcon->ses->capabilities & CAP_UNIX)
		rc = cifs_get_inode_info_unix(&newInode, full_path,
					      parent_dir_inode->i_sb,xid);
	else
		rc = cifs_get_inode_info(&newInode, full_path, NULL,
					 parent_dir_inode->i_sb,xid);

	if ((rc == 0) && (newInode != NULL)) {
		direntry->d_op = &cifs_dentry_ops;
		d_add(direntry, newInode);

		/* since paths are not looked up by component - the parent directories are presumed to be good here */
		renew_parental_timestamps(direntry);

	} else if (rc == -ENOENT) {
		rc = 0;
		d_add(direntry, NULL);
	} else {
		cERROR(1,("Error 0x%x or on cifs_get_inode_info in lookup",rc));
		/* BB special case check for Access Denied - watch security 
		exposure of returning dir info implicitly via different rc 
		if file exists or not but no access BB */
	}

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

int
cifs_dir_open(struct inode *inode, struct file *file)
{				/* NB: currently unused since searches are opened in readdir */
	int rc = 0;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;

	xid = GetXid();

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

	if(file->f_dentry) {
		down(&file->f_dentry->d_sb->s_vfs_rename_sem);
		full_path = build_wildcard_path_from_dentry(file->f_dentry);
		up(&file->f_dentry->d_sb->s_vfs_rename_sem);
	} else {
		FreeXid(xid);
		return -EIO;
	}

	cFYI(1, ("inode = 0x%p and full path is %s", inode, full_path));

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

static int
cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
{
	int isValid = 1;

/*	lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */

	if (direntry->d_inode) {
		if (cifs_revalidate(direntry)) {
			/* unlock_kernel(); */
			return 0;
		}
	} else {
		cFYI(1,
		     ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
		      direntry->d_name.name, direntry));
	}

/*    unlock_kernel(); */

	return isValid;
}

/* static int cifs_d_delete(struct dentry *direntry)
{
	int rc = 0;

	cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));

	return rc;
}     */

struct dentry_operations cifs_dentry_ops = {
	.d_revalidate = cifs_d_revalidate,
/* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
	/* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
};
OpenPOWER on IntegriCloud