1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3 *
4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 */
8
9 #include <linux/slab.h>
10 #include <linux/ctype.h>
11 #include <linux/mempool.h>
12 #include <linux/vmalloc.h>
13 #include "cifspdu.h"
14 #include "cifsglob.h"
15 #include "cifsproto.h"
16 #include "cifs_debug.h"
17 #include "smberr.h"
18 #include "nterr.h"
19 #include "cifs_unicode.h"
20 #include "smb2pdu.h"
21 #include "cifsfs.h"
22 #ifdef CONFIG_CIFS_DFS_UPCALL
23 #include "dns_resolve.h"
24 #include "dfs_cache.h"
25 #include "dfs.h"
26 #endif
27 #include "fs_context.h"
28 #include "cached_dir.h"
29
30 /* The xid serves as a useful identifier for each incoming vfs request,
31 in a similar way to the mid which is useful to track each sent smb,
32 and CurrentXid can also provide a running counter (although it
33 will eventually wrap past zero) of the total vfs operations handled
34 since the cifs fs was mounted */
35
36 unsigned int
37 _get_xid(void)
38 {
39 unsigned int xid;
40
41 spin_lock(&GlobalMid_Lock);
42 GlobalTotalActiveXid++;
43
44 /* keep high water mark for number of simultaneous ops in filesystem */
45 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
46 GlobalMaxActiveXid = GlobalTotalActiveXid;
47 if (GlobalTotalActiveXid > 65000)
48 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
49 xid = GlobalCurrentXid++;
50 spin_unlock(&GlobalMid_Lock);
51 return xid;
52 }
53
54 void
55 _free_xid(unsigned int xid)
56 {
57 spin_lock(&GlobalMid_Lock);
58 /* if (GlobalTotalActiveXid == 0)
59 BUG(); */
60 GlobalTotalActiveXid--;
61 spin_unlock(&GlobalMid_Lock);
62 }
63
64 struct cifs_ses *
65 sesInfoAlloc(void)
66 {
67 struct cifs_ses *ret_buf;
68
69 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
70 if (ret_buf) {
71 atomic_inc(&sesInfoAllocCount);
72 spin_lock_init(&ret_buf->ses_lock);
73 ret_buf->ses_status = SES_NEW;
74 ++ret_buf->ses_count;
75 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
76 INIT_LIST_HEAD(&ret_buf->tcon_list);
77 mutex_init(&ret_buf->session_mutex);
78 spin_lock_init(&ret_buf->iface_lock);
79 INIT_LIST_HEAD(&ret_buf->iface_list);
80 spin_lock_init(&ret_buf->chan_lock);
81 }
82 return ret_buf;
83 }
84
85 void
86 sesInfoFree(struct cifs_ses *buf_to_free)
87 {
88 struct cifs_server_iface *iface = NULL, *niface = NULL;
89
90 if (buf_to_free == NULL) {
91 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
92 return;
93 }
94
95 unload_nls(buf_to_free->local_nls);
96 atomic_dec(&sesInfoAllocCount);
97 kfree(buf_to_free->serverOS);
98 kfree(buf_to_free->serverDomain);
99 kfree(buf_to_free->serverNOS);
100 kfree_sensitive(buf_to_free->password);
101 kfree_sensitive(buf_to_free->password2);
102 kfree(buf_to_free->user_name);
103 kfree(buf_to_free->domainName);
104 kfree_sensitive(buf_to_free->auth_key.response);
105 spin_lock(&buf_to_free->iface_lock);
106 list_for_each_entry_safe(iface, niface, &buf_to_free->iface_list,
107 iface_head)
108 kref_put(&iface->refcount, release_iface);
109 spin_unlock(&buf_to_free->iface_lock);
110 kfree_sensitive(buf_to_free);
111 }
112
113 struct cifs_tcon *
114 tcon_info_alloc(bool dir_leases_enabled, enum smb3_tcon_ref_trace trace)
115 {
116 struct cifs_tcon *ret_buf;
117 static atomic_t tcon_debug_id;
118
119 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
120 if (!ret_buf)
121 return NULL;
122
123 if (dir_leases_enabled == true) {
124 ret_buf->cfids = init_cached_dirs();
125 if (!ret_buf->cfids) {
126 kfree(ret_buf);
127 return NULL;
128 }
129 }
130 /* else ret_buf->cfids is already set to NULL above */
131
132 atomic_inc(&tconInfoAllocCount);
133 ret_buf->status = TID_NEW;
134 ret_buf->debug_id = atomic_inc_return(&tcon_debug_id);
135 ret_buf->tc_count = 1;
136 spin_lock_init(&ret_buf->tc_lock);
137 INIT_LIST_HEAD(&ret_buf->openFileList);
138 INIT_LIST_HEAD(&ret_buf->tcon_list);
139 spin_lock_init(&ret_buf->open_file_lock);
140 spin_lock_init(&ret_buf->stat_lock);
141 atomic_set(&ret_buf->num_local_opens, 0);
142 atomic_set(&ret_buf->num_remote_opens, 0);
143 ret_buf->stats_from_time = ktime_get_real_seconds();
144 #ifdef CONFIG_CIFS_FSCACHE
145 mutex_init(&ret_buf->fscache_lock);
146 #endif
147 trace_smb3_tcon_ref(ret_buf->debug_id, ret_buf->tc_count, trace);
148
149 return ret_buf;
150 }
151
152 void
153 tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
154 {
155 if (tcon == NULL) {
156 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
157 return;
158 }
159 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, trace);
160 free_cached_dirs(tcon->cfids);
161 atomic_dec(&tconInfoAllocCount);
162 kfree(tcon->nativeFileSystem);
163 kfree_sensitive(tcon->password);
164 kfree(tcon->origin_fullpath);
165 kfree(tcon);
166 }
167
168 struct smb_hdr *
169 cifs_buf_get(void)
170 {
171 struct smb_hdr *ret_buf = NULL;
172 /*
173 * SMB2 header is bigger than CIFS one - no problems to clean some
174 * more bytes for CIFS.
175 */
176 size_t buf_size = sizeof(struct smb2_hdr);
177
178 /*
179 * We could use negotiated size instead of max_msgsize -
180 * but it may be more efficient to always alloc same size
181 * albeit slightly larger than necessary and maxbuffersize
182 * defaults to this and can not be bigger.
183 */
184 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
185
186 /* clear the first few header bytes */
187 /* for most paths, more is cleared in header_assemble */
188 memset(ret_buf, 0, buf_size + 3);
189 atomic_inc(&buf_alloc_count);
190 #ifdef CONFIG_CIFS_STATS2
191 atomic_inc(&total_buf_alloc_count);
192 #endif /* CONFIG_CIFS_STATS2 */
193
194 return ret_buf;
195 }
196
197 void
198 cifs_buf_release(void *buf_to_free)
199 {
200 if (buf_to_free == NULL) {
201 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
202 return;
203 }
204 mempool_free(buf_to_free, cifs_req_poolp);
205
206 atomic_dec(&buf_alloc_count);
207 return;
208 }
209
210 struct smb_hdr *
211 cifs_small_buf_get(void)
212 {
213 struct smb_hdr *ret_buf = NULL;
214
215 /* We could use negotiated size instead of max_msgsize -
216 but it may be more efficient to always alloc same size
217 albeit slightly larger than necessary and maxbuffersize
218 defaults to this and can not be bigger */
219 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
220 /* No need to clear memory here, cleared in header assemble */
221 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
222 atomic_inc(&small_buf_alloc_count);
223 #ifdef CONFIG_CIFS_STATS2
224 atomic_inc(&total_small_buf_alloc_count);
225 #endif /* CONFIG_CIFS_STATS2 */
226
227 return ret_buf;
228 }
229
230 void
231 cifs_small_buf_release(void *buf_to_free)
232 {
233
234 if (buf_to_free == NULL) {
235 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
236 return;
237 }
238 mempool_free(buf_to_free, cifs_sm_req_poolp);
239
240 atomic_dec(&small_buf_alloc_count);
241 return;
242 }
243
244 void
245 free_rsp_buf(int resp_buftype, void *rsp)
246 {
247 if (resp_buftype == CIFS_SMALL_BUFFER)
248 cifs_small_buf_release(rsp);
249 else if (resp_buftype == CIFS_LARGE_BUFFER)
250 cifs_buf_release(rsp);
251 }
252
253 /* NB: MID can not be set if treeCon not passed in, in that
254 case it is responsbility of caller to set the mid */
255 void
256 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
257 const struct cifs_tcon *treeCon, int word_count
258 /* length of fixed section (word count) in two byte units */)
259 {
260 char *temp = (char *) buffer;
261
262 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
263
264 buffer->smb_buf_length = cpu_to_be32(
265 (2 * word_count) + sizeof(struct smb_hdr) -
266 4 /* RFC 1001 length field does not count */ +
267 2 /* for bcc field itself */) ;
268
269 buffer->Protocol[0] = 0xFF;
270 buffer->Protocol[1] = 'S';
271 buffer->Protocol[2] = 'M';
272 buffer->Protocol[3] = 'B';
273 buffer->Command = smb_command;
274 buffer->Flags = 0x00; /* case sensitive */
275 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
276 buffer->Pid = cpu_to_le16((__u16)current->tgid);
277 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
278 if (treeCon) {
279 buffer->Tid = treeCon->tid;
280 if (treeCon->ses) {
281 if (treeCon->ses->capabilities & CAP_UNICODE)
282 buffer->Flags2 |= SMBFLG2_UNICODE;
283 if (treeCon->ses->capabilities & CAP_STATUS32)
284 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
285
286 /* Uid is not converted */
287 buffer->Uid = treeCon->ses->Suid;
288 if (treeCon->ses->server)
289 buffer->Mid = get_next_mid(treeCon->ses->server);
290 }
291 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
292 buffer->Flags2 |= SMBFLG2_DFS;
293 if (treeCon->nocase)
294 buffer->Flags |= SMBFLG_CASELESS;
295 if ((treeCon->ses) && (treeCon->ses->server))
296 if (treeCon->ses->server->sign)
297 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
298 }
299
300 /* endian conversion of flags is now done just before sending */
301 buffer->WordCount = (char) word_count;
302 return;
303 }
304
305 static int
306 check_smb_hdr(struct smb_hdr *smb)
307 {
308 /* does it have the right SMB "signature" ? */
309 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
310 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
311 *(unsigned int *)smb->Protocol);
312 return 1;
313 }
314
315 /* if it's a response then accept */
316 if (smb->Flags & SMBFLG_RESPONSE)
317 return 0;
318
319 /* only one valid case where server sends us request */
320 if (smb->Command == SMB_COM_LOCKING_ANDX)
321 return 0;
322
323 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
324 get_mid(smb));
325 return 1;
326 }
327
328 int
329 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
330 {
331 struct smb_hdr *smb = (struct smb_hdr *)buf;
332 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
333 __u32 clc_len; /* calculated length */
334 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
335 total_read, rfclen);
336
337 /* is this frame too small to even get to a BCC? */
338 if (total_read < 2 + sizeof(struct smb_hdr)) {
339 if ((total_read >= sizeof(struct smb_hdr) - 1)
340 && (smb->Status.CifsError != 0)) {
341 /* it's an error return */
342 smb->WordCount = 0;
343 /* some error cases do not return wct and bcc */
344 return 0;
345 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
346 (smb->WordCount == 0)) {
347 char *tmp = (char *)smb;
348 /* Need to work around a bug in two servers here */
349 /* First, check if the part of bcc they sent was zero */
350 if (tmp[sizeof(struct smb_hdr)] == 0) {
351 /* some servers return only half of bcc
352 * on simple responses (wct, bcc both zero)
353 * in particular have seen this on
354 * ulogoffX and FindClose. This leaves
355 * one byte of bcc potentially uninitialized
356 */
357 /* zero rest of bcc */
358 tmp[sizeof(struct smb_hdr)+1] = 0;
359 return 0;
360 }
361 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
362 } else {
363 cifs_dbg(VFS, "Length less than smb header size\n");
364 }
365 return -EIO;
366 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) {
367 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n",
368 __func__, smb->WordCount);
369 return -EIO;
370 }
371
372 /* otherwise, there is enough to get to the BCC */
373 if (check_smb_hdr(smb))
374 return -EIO;
375 clc_len = smbCalcSize(smb);
376
377 if (4 + rfclen != total_read) {
378 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
379 rfclen);
380 return -EIO;
381 }
382
383 if (4 + rfclen != clc_len) {
384 __u16 mid = get_mid(smb);
385 /* check if bcc wrapped around for large read responses */
386 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
387 /* check if lengths match mod 64K */
388 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
389 return 0; /* bcc wrapped */
390 }
391 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
392 clc_len, 4 + rfclen, mid);
393
394 if (4 + rfclen < clc_len) {
395 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
396 rfclen, mid);
397 return -EIO;
398 } else if (rfclen > clc_len + 512) {
399 /*
400 * Some servers (Windows XP in particular) send more
401 * data than the lengths in the SMB packet would
402 * indicate on certain calls (byte range locks and
403 * trans2 find first calls in particular). While the
404 * client can handle such a frame by ignoring the
405 * trailing data, we choose limit the amount of extra
406 * data to 512 bytes.
407 */
408 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
409 rfclen, mid);
410 return -EIO;
411 }
412 }
413 return 0;
414 }
415
416 bool
417 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
418 {
419 struct smb_hdr *buf = (struct smb_hdr *)buffer;
420 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
421 struct TCP_Server_Info *pserver;
422 struct cifs_ses *ses;
423 struct cifs_tcon *tcon;
424 struct cifsInodeInfo *pCifsInode;
425 struct cifsFileInfo *netfile;
426
427 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
428 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
429 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
430 struct smb_com_transaction_change_notify_rsp *pSMBr =
431 (struct smb_com_transaction_change_notify_rsp *)buf;
432 struct file_notify_information *pnotify;
433 __u32 data_offset = 0;
434 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
435
436 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
437 data_offset = le32_to_cpu(pSMBr->DataOffset);
438
439 if (data_offset >
440 len - sizeof(struct file_notify_information)) {
441 cifs_dbg(FYI, "Invalid data_offset %u\n",
442 data_offset);
443 return true;
444 }
445 pnotify = (struct file_notify_information *)
446 ((char *)&pSMBr->hdr.Protocol + data_offset);
447 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
448 pnotify->FileName, pnotify->Action);
449 /* cifs_dump_mem("Rcvd notify Data: ",buf,
450 sizeof(struct smb_hdr)+60); */
451 return true;
452 }
453 if (pSMBr->hdr.Status.CifsError) {
454 cifs_dbg(FYI, "notify err 0x%x\n",
455 pSMBr->hdr.Status.CifsError);
456 return true;
457 }
458 return false;
459 }
460 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
461 return false;
462 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
463 /* no sense logging error on invalid handle on oplock
464 break - harmless race between close request and oplock
465 break response is expected from time to time writing out
466 large dirty files cached on the client */
467 if ((NT_STATUS_INVALID_HANDLE) ==
468 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
469 cifs_dbg(FYI, "Invalid handle on oplock break\n");
470 return true;
471 } else if (ERRbadfid ==
472 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
473 return true;
474 } else {
475 return false; /* on valid oplock brk we get "request" */
476 }
477 }
478 if (pSMB->hdr.WordCount != 8)
479 return false;
480
481 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
482 pSMB->LockType, pSMB->OplockLevel);
483 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
484 return false;
485
486 /* If server is a channel, select the primary channel */
487 pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv;
488
489 /* look up tcon based on tid & uid */
490 spin_lock(&cifs_tcp_ses_lock);
491 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
492 if (cifs_ses_exiting(ses))
493 continue;
494 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
495 if (tcon->tid != buf->Tid)
496 continue;
497
498 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
499 spin_lock(&tcon->open_file_lock);
500 list_for_each_entry(netfile, &tcon->openFileList, tlist) {
501 if (pSMB->Fid != netfile->fid.netfid)
502 continue;
503
504 cifs_dbg(FYI, "file id match, oplock break\n");
505 pCifsInode = CIFS_I(d_inode(netfile->dentry));
506
507 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
508 &pCifsInode->flags);
509
510 netfile->oplock_epoch = 0;
511 netfile->oplock_level = pSMB->OplockLevel;
512 netfile->oplock_break_cancelled = false;
513 cifs_queue_oplock_break(netfile);
514
515 spin_unlock(&tcon->open_file_lock);
516 spin_unlock(&cifs_tcp_ses_lock);
517 return true;
518 }
519 spin_unlock(&tcon->open_file_lock);
520 spin_unlock(&cifs_tcp_ses_lock);
521 cifs_dbg(FYI, "No matching file for oplock break\n");
522 return true;
523 }
524 }
525 spin_unlock(&cifs_tcp_ses_lock);
526 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
527 return true;
528 }
529
530 void
531 dump_smb(void *buf, int smb_buf_length)
532 {
533 if (traceSMB == 0)
534 return;
535
536 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
537 smb_buf_length, true);
538 }
539
540 void
541 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
542 {
543 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
544 struct cifs_tcon *tcon = NULL;
545
546 if (cifs_sb->master_tlink)
547 tcon = cifs_sb_master_tcon(cifs_sb);
548
549 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
550 cifs_sb->mnt_cifs_serverino_autodisabled = true;
551 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n",
552 tcon ? tcon->tree_name : "new server");
553 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n");
554 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
555
556 }
557 }
558
559 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
560 {
561 oplock &= 0xF;
562
563 if (oplock == OPLOCK_EXCLUSIVE) {
564 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
565 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
566 &cinode->netfs.inode);
567 } else if (oplock == OPLOCK_READ) {
568 cinode->oplock = CIFS_CACHE_READ_FLG;
569 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
570 &cinode->netfs.inode);
571 } else
572 cinode->oplock = 0;
573 }
574
575 /*
576 * We wait for oplock breaks to be processed before we attempt to perform
577 * writes.
578 */
579 int cifs_get_writer(struct cifsInodeInfo *cinode)
580 {
581 int rc;
582
583 start:
584 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
585 TASK_KILLABLE);
586 if (rc)
587 return rc;
588
589 spin_lock(&cinode->writers_lock);
590 if (!cinode->writers)
591 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
592 cinode->writers++;
593 /* Check to see if we have started servicing an oplock break */
594 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
595 cinode->writers--;
596 if (cinode->writers == 0) {
597 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
598 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
599 }
600 spin_unlock(&cinode->writers_lock);
601 goto start;
602 }
603 spin_unlock(&cinode->writers_lock);
604 return 0;
605 }
606
607 void cifs_put_writer(struct cifsInodeInfo *cinode)
608 {
609 spin_lock(&cinode->writers_lock);
610 cinode->writers--;
611 if (cinode->writers == 0) {
612 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
613 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
614 }
615 spin_unlock(&cinode->writers_lock);
616 }
617
618 /**
619 * cifs_queue_oplock_break - queue the oplock break handler for cfile
620 * @cfile: The file to break the oplock on
621 *
622 * This function is called from the demultiplex thread when it
623 * receives an oplock break for @cfile.
624 *
625 * Assumes the tcon->open_file_lock is held.
626 * Assumes cfile->file_info_lock is NOT held.
627 */
628 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
629 {
630 /*
631 * Bump the handle refcount now while we hold the
632 * open_file_lock to enforce the validity of it for the oplock
633 * break handler. The matching put is done at the end of the
634 * handler.
635 */
636 cifsFileInfo_get(cfile);
637
638 queue_work(cifsoplockd_wq, &cfile->oplock_break);
639 }
640
641 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
642 {
643 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
644 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
645 }
646
647 bool
648 backup_cred(struct cifs_sb_info *cifs_sb)
649 {
650 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
651 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid()))
652 return true;
653 }
654 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
655 if (in_group_p(cifs_sb->ctx->backupgid))
656 return true;
657 }
658
659 return false;
660 }
661
662 void
663 cifs_del_pending_open(struct cifs_pending_open *open)
664 {
665 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
666 list_del(&open->olist);
667 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
668 }
669
670 void
671 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
672 struct cifs_pending_open *open)
673 {
674 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
675 open->oplock = CIFS_OPLOCK_NO_CHANGE;
676 open->tlink = tlink;
677 fid->pending_open = open;
678 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
679 }
680
681 void
682 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
683 struct cifs_pending_open *open)
684 {
685 spin_lock(&tlink_tcon(tlink)->open_file_lock);
686 cifs_add_pending_open_locked(fid, tlink, open);
687 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
688 }
689
690 /*
691 * Critical section which runs after acquiring deferred_lock.
692 * As there is no reference count on cifs_deferred_close, pdclose
693 * should not be used outside deferred_lock.
694 */
695 bool
696 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose)
697 {
698 struct cifs_deferred_close *dclose;
699
700 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) {
701 if ((dclose->netfid == cfile->fid.netfid) &&
702 (dclose->persistent_fid == cfile->fid.persistent_fid) &&
703 (dclose->volatile_fid == cfile->fid.volatile_fid)) {
704 *pdclose = dclose;
705 return true;
706 }
707 }
708 return false;
709 }
710
711 /*
712 * Critical section which runs after acquiring deferred_lock.
713 */
714 void
715 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose)
716 {
717 bool is_deferred = false;
718 struct cifs_deferred_close *pdclose;
719
720 is_deferred = cifs_is_deferred_close(cfile, &pdclose);
721 if (is_deferred) {
722 kfree(dclose);
723 return;
724 }
725
726 dclose->tlink = cfile->tlink;
727 dclose->netfid = cfile->fid.netfid;
728 dclose->persistent_fid = cfile->fid.persistent_fid;
729 dclose->volatile_fid = cfile->fid.volatile_fid;
730 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes);
731 }
732
733 /*
734 * Critical section which runs after acquiring deferred_lock.
735 */
736 void
737 cifs_del_deferred_close(struct cifsFileInfo *cfile)
738 {
739 bool is_deferred = false;
740 struct cifs_deferred_close *dclose;
741
742 is_deferred = cifs_is_deferred_close(cfile, &dclose);
743 if (!is_deferred)
744 return;
745 list_del(&dclose->dlist);
746 kfree(dclose);
747 }
748
749 void
750 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode)
751 {
752 struct cifsFileInfo *cfile = NULL;
753 struct file_list *tmp_list, *tmp_next_list;
754 struct list_head file_head;
755
756 if (cifs_inode == NULL)
757 return;
758
759 INIT_LIST_HEAD(&file_head);
760 spin_lock(&cifs_inode->open_file_lock);
761 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) {
762 if (delayed_work_pending(&cfile->deferred)) {
763 if (cancel_delayed_work(&cfile->deferred)) {
764 spin_lock(&cifs_inode->deferred_lock);
765 cifs_del_deferred_close(cfile);
766 spin_unlock(&cifs_inode->deferred_lock);
767
768 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
769 if (tmp_list == NULL)
770 break;
771 tmp_list->cfile = cfile;
772 list_add_tail(&tmp_list->list, &file_head);
773 }
774 }
775 }
776 spin_unlock(&cifs_inode->open_file_lock);
777
778 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
779 _cifsFileInfo_put(tmp_list->cfile, false, false);
780 list_del(&tmp_list->list);
781 kfree(tmp_list);
782 }
783 }
784
785 void
786 cifs_close_all_deferred_files(struct cifs_tcon *tcon)
787 {
788 struct cifsFileInfo *cfile;
789 struct file_list *tmp_list, *tmp_next_list;
790 struct list_head file_head;
791
792 INIT_LIST_HEAD(&file_head);
793 spin_lock(&tcon->open_file_lock);
794 list_for_each_entry(cfile, &tcon->openFileList, tlist) {
795 if (delayed_work_pending(&cfile->deferred)) {
796 if (cancel_delayed_work(&cfile->deferred)) {
797 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
798 cifs_del_deferred_close(cfile);
799 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
800
801 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
802 if (tmp_list == NULL)
803 break;
804 tmp_list->cfile = cfile;
805 list_add_tail(&tmp_list->list, &file_head);
806 }
807 }
808 }
809 spin_unlock(&tcon->open_file_lock);
810
811 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
812 _cifsFileInfo_put(tmp_list->cfile, true, false);
813 list_del(&tmp_list->list);
814 kfree(tmp_list);
815 }
816 }
817 void
818 cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path)
819 {
820 struct cifsFileInfo *cfile;
821 struct file_list *tmp_list, *tmp_next_list;
822 struct list_head file_head;
823 void *page;
824 const char *full_path;
825
826 INIT_LIST_HEAD(&file_head);
827 page = alloc_dentry_path();
828 spin_lock(&tcon->open_file_lock);
829 list_for_each_entry(cfile, &tcon->openFileList, tlist) {
830 full_path = build_path_from_dentry(cfile->dentry, page);
831 if (strstr(full_path, path)) {
832 if (delayed_work_pending(&cfile->deferred)) {
833 if (cancel_delayed_work(&cfile->deferred)) {
834 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
835 cifs_del_deferred_close(cfile);
836 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
837
838 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
839 if (tmp_list == NULL)
840 break;
841 tmp_list->cfile = cfile;
842 list_add_tail(&tmp_list->list, &file_head);
843 }
844 }
845 }
846 }
847 spin_unlock(&tcon->open_file_lock);
848
849 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
850 _cifsFileInfo_put(tmp_list->cfile, true, false);
851 list_del(&tmp_list->list);
852 kfree(tmp_list);
853 }
854 free_dentry_path(page);
855 }
856
857 /*
858 * If a dentry has been deleted, all corresponding open handles should know that
859 * so that we do not defer close them.
860 */
861 void cifs_mark_open_handles_for_deleted_file(struct inode *inode,
862 const char *path)
863 {
864 struct cifsFileInfo *cfile;
865 void *page;
866 const char *full_path;
867 struct cifsInodeInfo *cinode = CIFS_I(inode);
868
869 page = alloc_dentry_path();
870 spin_lock(&cinode->open_file_lock);
871
872 /*
873 * note: we need to construct path from dentry and compare only if the
874 * inode has any hardlinks. When number of hardlinks is 1, we can just
875 * mark all open handles since they are going to be from the same file.
876 */
877 if (inode->i_nlink > 1) {
878 list_for_each_entry(cfile, &cinode->openFileList, flist) {
879 full_path = build_path_from_dentry(cfile->dentry, page);
880 if (!IS_ERR(full_path) && strcmp(full_path, path) == 0)
881 cfile->status_file_deleted = true;
882 }
883 } else {
884 list_for_each_entry(cfile, &cinode->openFileList, flist)
885 cfile->status_file_deleted = true;
886 }
887 spin_unlock(&cinode->open_file_lock);
888 free_dentry_path(page);
889 }
890
891 /* parses DFS referral V3 structure
892 * caller is responsible for freeing target_nodes
893 * returns:
894 * - on success - 0
895 * - on failure - errno
896 */
897 int
898 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
899 unsigned int *num_of_nodes,
900 struct dfs_info3_param **target_nodes,
901 const struct nls_table *nls_codepage, int remap,
902 const char *searchName, bool is_unicode)
903 {
904 int i, rc = 0;
905 char *data_end;
906 struct dfs_referral_level_3 *ref;
907
908 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
909
910 if (*num_of_nodes < 1) {
911 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
912 *num_of_nodes);
913 rc = -EINVAL;
914 goto parse_DFS_referrals_exit;
915 }
916
917 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
918 if (ref->VersionNumber != cpu_to_le16(3)) {
919 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
920 le16_to_cpu(ref->VersionNumber));
921 rc = -EINVAL;
922 goto parse_DFS_referrals_exit;
923 }
924
925 /* get the upper boundary of the resp buffer */
926 data_end = (char *)rsp + rsp_size;
927
928 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
929 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
930
931 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
932 GFP_KERNEL);
933 if (*target_nodes == NULL) {
934 rc = -ENOMEM;
935 goto parse_DFS_referrals_exit;
936 }
937
938 /* collect necessary data from referrals */
939 for (i = 0; i < *num_of_nodes; i++) {
940 char *temp;
941 int max_len;
942 struct dfs_info3_param *node = (*target_nodes)+i;
943
944 node->flags = le32_to_cpu(rsp->DFSFlags);
945 if (is_unicode) {
946 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
947 GFP_KERNEL);
948 if (tmp == NULL) {
949 rc = -ENOMEM;
950 goto parse_DFS_referrals_exit;
951 }
952 cifsConvertToUTF16((__le16 *) tmp, searchName,
953 PATH_MAX, nls_codepage, remap);
954 node->path_consumed = cifs_utf16_bytes(tmp,
955 le16_to_cpu(rsp->PathConsumed),
956 nls_codepage);
957 kfree(tmp);
958 } else
959 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
960
961 node->server_type = le16_to_cpu(ref->ServerType);
962 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
963
964 /* copy DfsPath */
965 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
966 max_len = data_end - temp;
967 node->path_name = cifs_strndup_from_utf16(temp, max_len,
968 is_unicode, nls_codepage);
969 if (!node->path_name) {
970 rc = -ENOMEM;
971 goto parse_DFS_referrals_exit;
972 }
973
974 /* copy link target UNC */
975 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
976 max_len = data_end - temp;
977 node->node_name = cifs_strndup_from_utf16(temp, max_len,
978 is_unicode, nls_codepage);
979 if (!node->node_name) {
980 rc = -ENOMEM;
981 goto parse_DFS_referrals_exit;
982 }
983
984 node->ttl = le32_to_cpu(ref->TimeToLive);
985
986 ref++;
987 }
988
989 parse_DFS_referrals_exit:
990 if (rc) {
991 free_dfs_info_array(*target_nodes, *num_of_nodes);
992 *target_nodes = NULL;
993 *num_of_nodes = 0;
994 }
995 return rc;
996 }
997
998 /**
999 * cifs_alloc_hash - allocate hash and hash context together
1000 * @name: The name of the crypto hash algo
1001 * @sdesc: SHASH descriptor where to put the pointer to the hash TFM
1002 *
1003 * The caller has to make sure @sdesc is initialized to either NULL or
1004 * a valid context. It can be freed via cifs_free_hash().
1005 */
1006 int
1007 cifs_alloc_hash(const char *name, struct shash_desc **sdesc)
1008 {
1009 int rc = 0;
1010 struct crypto_shash *alg = NULL;
1011
1012 if (*sdesc)
1013 return 0;
1014
1015 alg = crypto_alloc_shash(name, 0, 0);
1016 if (IS_ERR(alg)) {
1017 cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name);
1018 rc = PTR_ERR(alg);
1019 *sdesc = NULL;
1020 return rc;
1021 }
1022
1023 *sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL);
1024 if (*sdesc == NULL) {
1025 cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name);
1026 crypto_free_shash(alg);
1027 return -ENOMEM;
1028 }
1029
1030 (*sdesc)->tfm = alg;
1031 return 0;
1032 }
1033
1034 /**
1035 * cifs_free_hash - free hash and hash context together
1036 * @sdesc: Where to find the pointer to the hash TFM
1037 *
1038 * Freeing a NULL descriptor is safe.
1039 */
1040 void
1041 cifs_free_hash(struct shash_desc **sdesc)
1042 {
1043 if (unlikely(!sdesc) || !*sdesc)
1044 return;
1045
1046 if ((*sdesc)->tfm) {
1047 crypto_free_shash((*sdesc)->tfm);
1048 (*sdesc)->tfm = NULL;
1049 }
1050
1051 kfree_sensitive(*sdesc);
1052 *sdesc = NULL;
1053 }
1054
1055 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
1056 {
1057 const char *end;
1058
1059 /* skip initial slashes */
1060 while (*unc && (*unc == '\\' || *unc == '/'))
1061 unc++;
1062
1063 end = unc;
1064
1065 while (*end && !(*end == '\\' || *end == '/'))
1066 end++;
1067
1068 *h = unc;
1069 *len = end - unc;
1070 }
1071
1072 /**
1073 * copy_path_name - copy src path to dst, possibly truncating
1074 * @dst: The destination buffer
1075 * @src: The source name
1076 *
1077 * returns number of bytes written (including trailing nul)
1078 */
1079 int copy_path_name(char *dst, const char *src)
1080 {
1081 int name_len;
1082
1083 /*
1084 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1085 * will truncate and strlen(dst) will be PATH_MAX-1
1086 */
1087 name_len = strscpy(dst, src, PATH_MAX);
1088 if (WARN_ON_ONCE(name_len < 0))
1089 name_len = PATH_MAX-1;
1090
1091 /* we count the trailing nul */
1092 name_len++;
1093 return name_len;
1094 }
1095
1096 struct super_cb_data {
1097 void *data;
1098 struct super_block *sb;
1099 };
1100
1101 static void tcon_super_cb(struct super_block *sb, void *arg)
1102 {
1103 struct super_cb_data *sd = arg;
1104 struct cifs_sb_info *cifs_sb;
1105 struct cifs_tcon *t1 = sd->data, *t2;
1106
1107 if (sd->sb)
1108 return;
1109
1110 cifs_sb = CIFS_SB(sb);
1111 t2 = cifs_sb_master_tcon(cifs_sb);
1112
1113 spin_lock(&t2->tc_lock);
1114 if (t1->ses == t2->ses &&
1115 t1->ses->server == t2->ses->server &&
1116 t2->origin_fullpath &&
1117 dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath))
1118 sd->sb = sb;
1119 spin_unlock(&t2->tc_lock);
1120 }
1121
1122 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),
1123 void *data)
1124 {
1125 struct super_cb_data sd = {
1126 .data = data,
1127 .sb = NULL,
1128 };
1129 struct file_system_type **fs_type = (struct file_system_type *[]) {
1130 &cifs_fs_type, &smb3_fs_type, NULL,
1131 };
1132
1133 for (; *fs_type; fs_type++) {
1134 iterate_supers_type(*fs_type, f, &sd);
1135 if (sd.sb) {
1136 /*
1137 * Grab an active reference in order to prevent automounts (DFS links)
1138 * of expiring and then freeing up our cifs superblock pointer while
1139 * we're doing failover.
1140 */
1141 cifs_sb_active(sd.sb);
1142 return sd.sb;
1143 }
1144 }
1145 pr_warn_once("%s: could not find dfs superblock\n", __func__);
1146 return ERR_PTR(-EINVAL);
1147 }
1148
1149 static void __cifs_put_super(struct super_block *sb)
1150 {
1151 if (!IS_ERR_OR_NULL(sb))
1152 cifs_sb_deactive(sb);
1153 }
1154
1155 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon)
1156 {
1157 spin_lock(&tcon->tc_lock);
1158 if (!tcon->origin_fullpath) {
1159 spin_unlock(&tcon->tc_lock);
1160 return ERR_PTR(-ENOENT);
1161 }
1162 spin_unlock(&tcon->tc_lock);
1163 return __cifs_get_super(tcon_super_cb, tcon);
1164 }
1165
1166 void cifs_put_tcp_super(struct super_block *sb)
1167 {
1168 __cifs_put_super(sb);
1169 }
1170
1171 #ifdef CONFIG_CIFS_DFS_UPCALL
1172 int match_target_ip(struct TCP_Server_Info *server,
1173 const char *share, size_t share_len,
1174 bool *result)
1175 {
1176 int rc;
1177 char *target;
1178 struct sockaddr_storage ss;
1179
1180 *result = false;
1181
1182 target = kzalloc(share_len + 3, GFP_KERNEL);
1183 if (!target)
1184 return -ENOMEM;
1185
1186 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share);
1187
1188 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2);
1189
1190 rc = dns_resolve_server_name_to_ip(target, (struct sockaddr *)&ss, NULL);
1191 kfree(target);
1192
1193 if (rc < 0)
1194 return rc;
1195
1196 spin_lock(&server->srv_lock);
1197 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);
1198 spin_unlock(&server->srv_lock);
1199 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
1200 return 0;
1201 }
1202
1203 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix)
1204 {
1205 int rc;
1206
1207 kfree(cifs_sb->prepath);
1208 cifs_sb->prepath = NULL;
1209
1210 if (prefix && *prefix) {
1211 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC);
1212 if (IS_ERR(cifs_sb->prepath)) {
1213 rc = PTR_ERR(cifs_sb->prepath);
1214 cifs_sb->prepath = NULL;
1215 return rc;
1216 }
1217 if (cifs_sb->prepath)
1218 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
1219 }
1220
1221 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
1222 return 0;
1223 }
1224
1225 /*
1226 * Handle weird Windows SMB server behaviour. It responds with
1227 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for
1228 * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains
1229 * non-ASCII unicode symbols.
1230 */
1231 int cifs_inval_name_dfs_link_error(const unsigned int xid,
1232 struct cifs_tcon *tcon,
1233 struct cifs_sb_info *cifs_sb,
1234 const char *full_path,
1235 bool *islink)
1236 {
1237 struct TCP_Server_Info *server = tcon->ses->server;
1238 struct cifs_ses *ses = tcon->ses;
1239 size_t len;
1240 char *path;
1241 char *ref_path;
1242
1243 *islink = false;
1244
1245 /*
1246 * Fast path - skip check when @full_path doesn't have a prefix path to
1247 * look up or tcon is not DFS.
1248 */
1249 if (strlen(full_path) < 2 || !cifs_sb ||
1250 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
1251 !is_tcon_dfs(tcon))
1252 return 0;
1253
1254 spin_lock(&server->srv_lock);
1255 if (!server->leaf_fullpath) {
1256 spin_unlock(&server->srv_lock);
1257 return 0;
1258 }
1259 spin_unlock(&server->srv_lock);
1260
1261 /*
1262 * Slow path - tcon is DFS and @full_path has prefix path, so attempt
1263 * to get a referral to figure out whether it is an DFS link.
1264 */
1265 len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1;
1266 path = kmalloc(len, GFP_KERNEL);
1267 if (!path)
1268 return -ENOMEM;
1269
1270 scnprintf(path, len, "%s%s", tcon->tree_name, full_path);
1271 ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls,
1272 cifs_remap(cifs_sb));
1273 kfree(path);
1274
1275 if (IS_ERR(ref_path)) {
1276 if (PTR_ERR(ref_path) != -EINVAL)
1277 return PTR_ERR(ref_path);
1278 } else {
1279 struct dfs_info3_param *refs = NULL;
1280 int num_refs = 0;
1281
1282 /*
1283 * XXX: we are not using dfs_cache_find() here because we might
1284 * end up filling all the DFS cache and thus potentially
1285 * removing cached DFS targets that the client would eventually
1286 * need during failover.
1287 */
1288 ses = CIFS_DFS_ROOT_SES(ses);
1289 if (ses->server->ops->get_dfs_refer &&
1290 !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs,
1291 &num_refs, cifs_sb->local_nls,
1292 cifs_remap(cifs_sb)))
1293 *islink = refs[0].server_type == DFS_TYPE_LINK;
1294 free_dfs_info_array(refs, num_refs);
1295 kfree(ref_path);
1296 }
1297 return 0;
1298 }
1299 #endif
1300
1301 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry)
1302 {
1303 int timeout = 10;
1304 int rc;
1305
1306 spin_lock(&server->srv_lock);
1307 if (server->tcpStatus != CifsNeedReconnect) {
1308 spin_unlock(&server->srv_lock);
1309 return 0;
1310 }
1311 timeout *= server->nr_targets;
1312 spin_unlock(&server->srv_lock);
1313
1314 /*
1315 * Give demultiplex thread up to 10 seconds to each target available for
1316 * reconnect -- should be greater than cifs socket timeout which is 7
1317 * seconds.
1318 *
1319 * On "soft" mounts we wait once. Hard mounts keep retrying until
1320 * process is killed or server comes back on-line.
1321 */
1322 do {
1323 rc = wait_event_interruptible_timeout(server->response_q,
1324 (server->tcpStatus != CifsNeedReconnect),
1325 timeout * HZ);
1326 if (rc < 0) {
1327 cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n",
1328 __func__);
1329 return -ERESTARTSYS;
1330 }
1331
1332 /* are we still trying to reconnect? */
1333 spin_lock(&server->srv_lock);
1334 if (server->tcpStatus != CifsNeedReconnect) {
1335 spin_unlock(&server->srv_lock);
1336 return 0;
1337 }
1338 spin_unlock(&server->srv_lock);
1339 } while (retry);
1340
1341 cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__);
1342 return -EHOSTDOWN;
1343 }
1344
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