• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  *   fs/cifs/smb2misc.c
3  *
4  *   Copyright (C) International Business Machines  Corp., 2002,2011
5  *                 Etersoft, 2012
6  *   Author(s): Steve French (sfrench@us.ibm.com)
7  *              Pavel Shilovsky (pshilovsky@samba.org) 2012
8  *
9  *   This library is free software; you can redistribute it and/or modify
10  *   it under the terms of the GNU Lesser General Public License as published
11  *   by the Free Software Foundation; either version 2.1 of the License, or
12  *   (at your option) any later version.
13  *
14  *   This library is distributed in the hope that it will be useful,
15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
17  *   the GNU Lesser General Public License for more details.
18  *
19  *   You should have received a copy of the GNU Lesser General Public License
20  *   along with this library; if not, write to the Free Software
21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22  */
23 #include <linux/ctype.h>
24 #include "smb2pdu.h"
25 #include "cifsglob.h"
26 #include "cifsproto.h"
27 #include "smb2proto.h"
28 #include "cifs_debug.h"
29 #include "cifs_unicode.h"
30 #include "smb2status.h"
31 
32 static int
check_smb2_hdr(struct smb2_hdr * hdr,__u64 mid)33 check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
34 {
35 	/*
36 	 * Make sure that this really is an SMB, that it is a response,
37 	 * and that the message ids match.
38 	 */
39 	if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
40 	    (mid == hdr->MessageId)) {
41 		if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
42 			return 0;
43 		else {
44 			/* only one valid case where server sends us request */
45 			if (hdr->Command == SMB2_OPLOCK_BREAK)
46 				return 0;
47 			else
48 				cifs_dbg(VFS, "Received Request not response\n");
49 		}
50 	} else { /* bad signature or mid */
51 		if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
52 			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
53 				 *(unsigned int *) hdr->ProtocolId);
54 		if (mid != hdr->MessageId)
55 			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
56 				 mid, hdr->MessageId);
57 	}
58 	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", hdr->MessageId);
59 	return 1;
60 }
61 
62 /*
63  *  The following table defines the expected "StructureSize" of SMB2 responses
64  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
65  *
66  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
67  *  indexed by command in host byte order
68  */
69 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
70 	/* SMB2_NEGOTIATE */ __constant_cpu_to_le16(65),
71 	/* SMB2_SESSION_SETUP */ __constant_cpu_to_le16(9),
72 	/* SMB2_LOGOFF */ __constant_cpu_to_le16(4),
73 	/* SMB2_TREE_CONNECT */ __constant_cpu_to_le16(16),
74 	/* SMB2_TREE_DISCONNECT */ __constant_cpu_to_le16(4),
75 	/* SMB2_CREATE */ __constant_cpu_to_le16(89),
76 	/* SMB2_CLOSE */ __constant_cpu_to_le16(60),
77 	/* SMB2_FLUSH */ __constant_cpu_to_le16(4),
78 	/* SMB2_READ */ __constant_cpu_to_le16(17),
79 	/* SMB2_WRITE */ __constant_cpu_to_le16(17),
80 	/* SMB2_LOCK */ __constant_cpu_to_le16(4),
81 	/* SMB2_IOCTL */ __constant_cpu_to_le16(49),
82 	/* BB CHECK this ... not listed in documentation */
83 	/* SMB2_CANCEL */ __constant_cpu_to_le16(0),
84 	/* SMB2_ECHO */ __constant_cpu_to_le16(4),
85 	/* SMB2_QUERY_DIRECTORY */ __constant_cpu_to_le16(9),
86 	/* SMB2_CHANGE_NOTIFY */ __constant_cpu_to_le16(9),
87 	/* SMB2_QUERY_INFO */ __constant_cpu_to_le16(9),
88 	/* SMB2_SET_INFO */ __constant_cpu_to_le16(2),
89 	/* BB FIXME can also be 44 for lease break */
90 	/* SMB2_OPLOCK_BREAK */ __constant_cpu_to_le16(24)
91 };
92 
93 int
smb2_check_message(char * buf,unsigned int length)94 smb2_check_message(char *buf, unsigned int length)
95 {
96 	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
97 	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
98 	__u64 mid = hdr->MessageId;
99 	__u32 len = get_rfc1002_length(buf);
100 	__u32 clc_len;  /* calculated length */
101 	int command;
102 
103 	/* BB disable following printk later */
104 	cifs_dbg(FYI, "%s length: 0x%x, smb_buf_length: 0x%x\n",
105 		 __func__, length, len);
106 
107 	/*
108 	 * Add function to do table lookup of StructureSize by command
109 	 * ie Validate the wct via smb2_struct_sizes table above
110 	 */
111 
112 	if (length < sizeof(struct smb2_pdu)) {
113 		if ((length >= sizeof(struct smb2_hdr)) && (hdr->Status != 0)) {
114 			pdu->StructureSize2 = 0;
115 			/*
116 			 * As with SMB/CIFS, on some error cases servers may
117 			 * not return wct properly
118 			 */
119 			return 0;
120 		} else {
121 			cifs_dbg(VFS, "Length less than SMB header size\n");
122 		}
123 		return 1;
124 	}
125 	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) {
126 		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
127 			 mid);
128 		return 1;
129 	}
130 
131 	if (check_smb2_hdr(hdr, mid))
132 		return 1;
133 
134 	if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
135 		cifs_dbg(VFS, "Illegal structure size %u\n",
136 			 le16_to_cpu(hdr->StructureSize));
137 		return 1;
138 	}
139 
140 	command = le16_to_cpu(hdr->Command);
141 	if (command >= NUMBER_OF_SMB2_COMMANDS) {
142 		cifs_dbg(VFS, "Illegal SMB2 command %d\n", command);
143 		return 1;
144 	}
145 
146 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
147 		if (command != SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0 ||
148 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
149 			/* error packets have 9 byte structure size */
150 			cifs_dbg(VFS, "Illegal response size %u for command %d\n",
151 				 le16_to_cpu(pdu->StructureSize2), command);
152 			return 1;
153 		} else if (command == SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0)
154 			   && (le16_to_cpu(pdu->StructureSize2) != 44)
155 			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
156 			/* special case for SMB2.1 lease break message */
157 			cifs_dbg(VFS, "Illegal response size %d for oplock break\n",
158 				 le16_to_cpu(pdu->StructureSize2));
159 			return 1;
160 		}
161 	}
162 
163 	if (4 + len != length) {
164 		cifs_dbg(VFS, "Total length %u RFC1002 length %u mismatch mid %llu\n",
165 			 length, 4 + len, mid);
166 		return 1;
167 	}
168 
169 	clc_len = smb2_calc_size(hdr);
170 
171 	if (4 + len != clc_len) {
172 		cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
173 			 clc_len, 4 + len, mid);
174 		/* Windows 7 server returns 24 bytes more */
175 		if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE)
176 			return 0;
177 		/* server can return one byte more */
178 		if (clc_len == 4 + len + 1)
179 			return 0;
180 		return 1;
181 	}
182 	return 0;
183 }
184 
185 /*
186  * The size of the variable area depends on the offset and length fields
187  * located in different fields for various SMB2 responses. SMB2 responses
188  * with no variable length info, show an offset of zero for the offset field.
189  */
190 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
191 	/* SMB2_NEGOTIATE */ true,
192 	/* SMB2_SESSION_SETUP */ true,
193 	/* SMB2_LOGOFF */ false,
194 	/* SMB2_TREE_CONNECT */	false,
195 	/* SMB2_TREE_DISCONNECT */ false,
196 	/* SMB2_CREATE */ true,
197 	/* SMB2_CLOSE */ false,
198 	/* SMB2_FLUSH */ false,
199 	/* SMB2_READ */	true,
200 	/* SMB2_WRITE */ false,
201 	/* SMB2_LOCK */	false,
202 	/* SMB2_IOCTL */ true,
203 	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
204 	/* SMB2_ECHO */ false,
205 	/* SMB2_QUERY_DIRECTORY */ true,
206 	/* SMB2_CHANGE_NOTIFY */ true,
207 	/* SMB2_QUERY_INFO */ true,
208 	/* SMB2_SET_INFO */ false,
209 	/* SMB2_OPLOCK_BREAK */ false
210 };
211 
212 /*
213  * Returns the pointer to the beginning of the data area. Length of the data
214  * area and the offset to it (from the beginning of the smb are also returned.
215  */
216 char *
smb2_get_data_area_len(int * off,int * len,struct smb2_hdr * hdr)217 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr)
218 {
219 	*off = 0;
220 	*len = 0;
221 
222 	/* error responses do not have data area */
223 	if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
224 	    (((struct smb2_err_rsp *)hdr)->StructureSize) ==
225 						SMB2_ERROR_STRUCTURE_SIZE2)
226 		return NULL;
227 
228 	/*
229 	 * Following commands have data areas so we have to get the location
230 	 * of the data buffer offset and data buffer length for the particular
231 	 * command.
232 	 */
233 	switch (hdr->Command) {
234 	case SMB2_NEGOTIATE:
235 		*off = le16_to_cpu(
236 		    ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset);
237 		*len = le16_to_cpu(
238 		    ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength);
239 		break;
240 	case SMB2_SESSION_SETUP:
241 		*off = le16_to_cpu(
242 		    ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset);
243 		*len = le16_to_cpu(
244 		    ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength);
245 		break;
246 	case SMB2_CREATE:
247 		*off = le32_to_cpu(
248 		    ((struct smb2_create_rsp *)hdr)->CreateContextsOffset);
249 		*len = le32_to_cpu(
250 		    ((struct smb2_create_rsp *)hdr)->CreateContextsLength);
251 		break;
252 	case SMB2_QUERY_INFO:
253 		*off = le16_to_cpu(
254 		    ((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset);
255 		*len = le32_to_cpu(
256 		    ((struct smb2_query_info_rsp *)hdr)->OutputBufferLength);
257 		break;
258 	case SMB2_READ:
259 		*off = ((struct smb2_read_rsp *)hdr)->DataOffset;
260 		*len = le32_to_cpu(((struct smb2_read_rsp *)hdr)->DataLength);
261 		break;
262 	case SMB2_QUERY_DIRECTORY:
263 		*off = le16_to_cpu(
264 		  ((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset);
265 		*len = le32_to_cpu(
266 		  ((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength);
267 		break;
268 	case SMB2_IOCTL:
269 	case SMB2_CHANGE_NOTIFY:
270 	default:
271 		/* BB FIXME for unimplemented cases above */
272 		cifs_dbg(VFS, "no length check for command\n");
273 		break;
274 	}
275 
276 	/*
277 	 * Invalid length or offset probably means data area is invalid, but
278 	 * we have little choice but to ignore the data area in this case.
279 	 */
280 	if (*off > 4096) {
281 		cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
282 		*len = 0;
283 		*off = 0;
284 	} else if (*off < 0) {
285 		cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
286 			 *off);
287 		*off = 0;
288 		*len = 0;
289 	} else if (*len < 0) {
290 		cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
291 			 *len);
292 		*len = 0;
293 	} else if (*len > 128 * 1024) {
294 		cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
295 		*len = 0;
296 	}
297 
298 	/* return pointer to beginning of data area, ie offset from SMB start */
299 	if ((*off != 0) && (*len != 0))
300 		return hdr->ProtocolId + *off;
301 	else
302 		return NULL;
303 }
304 
305 /*
306  * Calculate the size of the SMB message based on the fixed header
307  * portion, the number of word parameters and the data portion of the message.
308  */
309 unsigned int
smb2_calc_size(void * buf)310 smb2_calc_size(void *buf)
311 {
312 	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
313 	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
314 	int offset; /* the offset from the beginning of SMB to data area */
315 	int data_length; /* the length of the variable length data area */
316 	/* Structure Size has already been checked to make sure it is 64 */
317 	int len = 4 + le16_to_cpu(pdu->hdr.StructureSize);
318 
319 	/*
320 	 * StructureSize2, ie length of fixed parameter area has already
321 	 * been checked to make sure it is the correct length.
322 	 */
323 	len += le16_to_cpu(pdu->StructureSize2);
324 
325 	if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
326 		goto calc_size_exit;
327 
328 	smb2_get_data_area_len(&offset, &data_length, hdr);
329 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
330 
331 	if (data_length > 0) {
332 		/*
333 		 * Check to make sure that data area begins after fixed area,
334 		 * Note that last byte of the fixed area is part of data area
335 		 * for some commands, typically those with odd StructureSize,
336 		 * so we must add one to the calculation (and 4 to account for
337 		 * the size of the RFC1001 hdr.
338 		 */
339 		if (offset + 4 + 1 < len) {
340 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
341 				 offset + 4 + 1, len);
342 			data_length = 0;
343 		} else {
344 			len = 4 + offset + data_length;
345 		}
346 	}
347 calc_size_exit:
348 	cifs_dbg(FYI, "SMB2 len %d\n", len);
349 	return len;
350 }
351 
352 /* Note: caller must free return buffer */
353 __le16 *
cifs_convert_path_to_utf16(const char * from,struct cifs_sb_info * cifs_sb)354 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
355 {
356 	int len;
357 	const char *start_of_path;
358 	__le16 *to;
359 
360 	/* Windows doesn't allow paths beginning with \ */
361 	if (from[0] == '\\')
362 		start_of_path = from + 1;
363 	else
364 		start_of_path = from;
365 	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
366 				   cifs_sb->local_nls,
367 				   cifs_sb->mnt_cifs_flags &
368 					CIFS_MOUNT_MAP_SPECIAL_CHR);
369 	return to;
370 }
371 
372 __le32
smb2_get_lease_state(struct cifsInodeInfo * cinode)373 smb2_get_lease_state(struct cifsInodeInfo *cinode)
374 {
375 	if (cinode->clientCanCacheAll)
376 		return SMB2_LEASE_WRITE_CACHING | SMB2_LEASE_READ_CACHING;
377 	else if (cinode->clientCanCacheRead)
378 		return SMB2_LEASE_READ_CACHING;
379 	return 0;
380 }
381 
smb2_map_lease_to_oplock(__le32 lease_state)382 __u8 smb2_map_lease_to_oplock(__le32 lease_state)
383 {
384 	if (lease_state & SMB2_LEASE_WRITE_CACHING) {
385 		if (lease_state & SMB2_LEASE_HANDLE_CACHING)
386 			return SMB2_OPLOCK_LEVEL_BATCH;
387 		else
388 			return SMB2_OPLOCK_LEVEL_EXCLUSIVE;
389 	} else if (lease_state & SMB2_LEASE_READ_CACHING)
390 		return SMB2_OPLOCK_LEVEL_II;
391 	return 0;
392 }
393 
394 struct smb2_lease_break_work {
395 	struct work_struct lease_break;
396 	struct tcon_link *tlink;
397 	__u8 lease_key[16];
398 	__le32 lease_state;
399 };
400 
401 static void
cifs_ses_oplock_break(struct work_struct * work)402 cifs_ses_oplock_break(struct work_struct *work)
403 {
404 	struct smb2_lease_break_work *lw = container_of(work,
405 				struct smb2_lease_break_work, lease_break);
406 	int rc;
407 
408 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
409 			      lw->lease_state);
410 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
411 	cifs_put_tlink(lw->tlink);
412 	kfree(lw);
413 }
414 
415 static bool
smb2_is_valid_lease_break(char * buffer,struct TCP_Server_Info * server)416 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
417 {
418 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
419 	struct list_head *tmp, *tmp1, *tmp2;
420 	struct cifs_ses *ses;
421 	struct cifs_tcon *tcon;
422 	struct cifsInodeInfo *cinode;
423 	struct cifsFileInfo *cfile;
424 	struct cifs_pending_open *open;
425 	struct smb2_lease_break_work *lw;
426 	bool found;
427 	int ack_req = le32_to_cpu(rsp->Flags &
428 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
429 
430 	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
431 	if (!lw)
432 		return false;
433 
434 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
435 	lw->lease_state = rsp->NewLeaseState;
436 
437 	cifs_dbg(FYI, "Checking for lease break\n");
438 
439 	/* look up tcon based on tid & uid */
440 	spin_lock(&cifs_tcp_ses_lock);
441 	list_for_each(tmp, &server->smb_ses_list) {
442 		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
443 
444 		spin_lock(&cifs_file_list_lock);
445 		list_for_each(tmp1, &ses->tcon_list) {
446 			tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
447 
448 			cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
449 			list_for_each(tmp2, &tcon->openFileList) {
450 				cfile = list_entry(tmp2, struct cifsFileInfo,
451 						   tlist);
452 				cinode = CIFS_I(cfile->dentry->d_inode);
453 
454 				if (memcmp(cinode->lease_key, rsp->LeaseKey,
455 					   SMB2_LEASE_KEY_SIZE))
456 					continue;
457 
458 				cifs_dbg(FYI, "found in the open list\n");
459 				cifs_dbg(FYI, "lease key match, lease break 0x%d\n",
460 					 le32_to_cpu(rsp->NewLeaseState));
461 
462 				smb2_set_oplock_level(cinode,
463 				  smb2_map_lease_to_oplock(rsp->NewLeaseState));
464 
465 				if (ack_req)
466 					cfile->oplock_break_cancelled = false;
467 				else
468 					cfile->oplock_break_cancelled = true;
469 
470 				queue_work(cifsiod_wq, &cfile->oplock_break);
471 
472 				spin_unlock(&cifs_file_list_lock);
473 				spin_unlock(&cifs_tcp_ses_lock);
474 				return true;
475 			}
476 
477 			found = false;
478 			list_for_each_entry(open, &tcon->pending_opens, olist) {
479 				if (memcmp(open->lease_key, rsp->LeaseKey,
480 					   SMB2_LEASE_KEY_SIZE))
481 					continue;
482 
483 				if (!found && ack_req) {
484 					found = true;
485 					memcpy(lw->lease_key, open->lease_key,
486 					       SMB2_LEASE_KEY_SIZE);
487 					lw->tlink = cifs_get_tlink(open->tlink);
488 					queue_work(cifsiod_wq,
489 						   &lw->lease_break);
490 				}
491 
492 				cifs_dbg(FYI, "found in the pending open list\n");
493 				cifs_dbg(FYI, "lease key match, lease break 0x%d\n",
494 					 le32_to_cpu(rsp->NewLeaseState));
495 
496 				open->oplock =
497 				  smb2_map_lease_to_oplock(rsp->NewLeaseState);
498 			}
499 			if (found) {
500 				spin_unlock(&cifs_file_list_lock);
501 				spin_unlock(&cifs_tcp_ses_lock);
502 				return true;
503 			}
504 		}
505 		spin_unlock(&cifs_file_list_lock);
506 	}
507 	spin_unlock(&cifs_tcp_ses_lock);
508 	kfree(lw);
509 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
510 	return false;
511 }
512 
513 bool
smb2_is_valid_oplock_break(char * buffer,struct TCP_Server_Info * server)514 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
515 {
516 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
517 	struct list_head *tmp, *tmp1, *tmp2;
518 	struct cifs_ses *ses;
519 	struct cifs_tcon *tcon;
520 	struct cifsInodeInfo *cinode;
521 	struct cifsFileInfo *cfile;
522 
523 	cifs_dbg(FYI, "Checking for oplock break\n");
524 
525 	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
526 		return false;
527 
528 	if (rsp->StructureSize !=
529 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
530 		if (le16_to_cpu(rsp->StructureSize) == 44)
531 			return smb2_is_valid_lease_break(buffer, server);
532 		else
533 			return false;
534 	}
535 
536 	cifs_dbg(FYI, "oplock level 0x%d\n", rsp->OplockLevel);
537 
538 	/* look up tcon based on tid & uid */
539 	spin_lock(&cifs_tcp_ses_lock);
540 	list_for_each(tmp, &server->smb_ses_list) {
541 		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
542 		list_for_each(tmp1, &ses->tcon_list) {
543 			tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
544 
545 			cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
546 			spin_lock(&cifs_file_list_lock);
547 			list_for_each(tmp2, &tcon->openFileList) {
548 				cfile = list_entry(tmp2, struct cifsFileInfo,
549 						     tlist);
550 				if (rsp->PersistentFid !=
551 				    cfile->fid.persistent_fid ||
552 				    rsp->VolatileFid !=
553 				    cfile->fid.volatile_fid)
554 					continue;
555 
556 				cifs_dbg(FYI, "file id match, oplock break\n");
557 				cinode = CIFS_I(cfile->dentry->d_inode);
558 
559 				if (!cinode->clientCanCacheAll &&
560 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
561 					cfile->oplock_break_cancelled = true;
562 				else
563 					cfile->oplock_break_cancelled = false;
564 
565 				smb2_set_oplock_level(cinode,
566 				  rsp->OplockLevel ? SMB2_OPLOCK_LEVEL_II : 0);
567 
568 				queue_work(cifsiod_wq, &cfile->oplock_break);
569 
570 				spin_unlock(&cifs_file_list_lock);
571 				spin_unlock(&cifs_tcp_ses_lock);
572 				return true;
573 			}
574 			spin_unlock(&cifs_file_list_lock);
575 			spin_unlock(&cifs_tcp_ses_lock);
576 			cifs_dbg(FYI, "No matching file for oplock break\n");
577 			return true;
578 		}
579 	}
580 	spin_unlock(&cifs_tcp_ses_lock);
581 	cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
582 	return false;
583 }
584