xref: /linux/fs/smb/client/misc.c (revision e5ac3ff6c6e7ea3bd0859edb80b9241135fe10c0)
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 "cifsglob.h"
14 #include "cifsproto.h"
15 #include "cifs_debug.h"
16 #include "smberr.h"
17 #include "nterr.h"
18 #include "cifs_unicode.h"
19 #include "smb2pdu.h"
20 #include "smb2proto.h"
21 #include "smb1proto.h"
22 #include "cifsfs.h"
23 #ifdef CONFIG_CIFS_DFS_UPCALL
24 #include "dns_resolve.h"
25 #include "dfs_cache.h"
26 #include "dfs.h"
27 #endif
28 #include "fs_context.h"
29 #include "cached_dir.h"
30 
31 /* The xid serves as a useful identifier for each incoming vfs request,
32    in a similar way to the mid which is useful to track each sent smb,
33    and CurrentXid can also provide a running counter (although it
34    will eventually wrap past zero) of the total vfs operations handled
35    since the cifs fs was mounted */
36 
37 unsigned int
38 _get_xid(void)
39 {
40 	unsigned int xid;
41 
42 	spin_lock(&GlobalMid_Lock);
43 	GlobalTotalActiveXid++;
44 
45 	/* keep high water mark for number of simultaneous ops in filesystem */
46 	if (GlobalTotalActiveXid > GlobalMaxActiveXid)
47 		GlobalMaxActiveXid = GlobalTotalActiveXid;
48 	if (GlobalTotalActiveXid > 65000)
49 		cifs_dbg(FYI, "warning: more than 65000 requests active\n");
50 	xid = GlobalCurrentXid++;
51 	spin_unlock(&GlobalMid_Lock);
52 	return xid;
53 }
54 
55 void
56 _free_xid(unsigned int xid)
57 {
58 	spin_lock(&GlobalMid_Lock);
59 	/* if (GlobalTotalActiveXid == 0)
60 		BUG(); */
61 	GlobalTotalActiveXid--;
62 	spin_unlock(&GlobalMid_Lock);
63 }
64 
65 struct cifs_ses *
66 sesInfoAlloc(void)
67 {
68 	struct cifs_ses *ret_buf;
69 
70 	ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
71 	if (ret_buf) {
72 		atomic_inc(&sesInfoAllocCount);
73 		spin_lock_init(&ret_buf->ses_lock);
74 		ret_buf->ses_status = SES_NEW;
75 		++ret_buf->ses_count;
76 		INIT_LIST_HEAD(&ret_buf->smb_ses_list);
77 		INIT_LIST_HEAD(&ret_buf->tcon_list);
78 		mutex_init(&ret_buf->session_mutex);
79 		spin_lock_init(&ret_buf->iface_lock);
80 		INIT_LIST_HEAD(&ret_buf->iface_list);
81 		spin_lock_init(&ret_buf->chan_lock);
82 	}
83 	return ret_buf;
84 }
85 
86 void
87 sesInfoFree(struct cifs_ses *buf_to_free)
88 {
89 	struct cifs_server_iface *iface = NULL, *niface = NULL;
90 
91 	if (buf_to_free == NULL) {
92 		cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
93 		return;
94 	}
95 
96 	unload_nls(buf_to_free->local_nls);
97 	atomic_dec(&sesInfoAllocCount);
98 	kfree(buf_to_free->serverOS);
99 	kfree(buf_to_free->serverDomain);
100 	kfree(buf_to_free->serverNOS);
101 	kfree_sensitive(buf_to_free->password);
102 	kfree_sensitive(buf_to_free->password2);
103 	kfree(buf_to_free->user_name);
104 	kfree(buf_to_free->domainName);
105 	kfree(buf_to_free->dns_dom);
106 	kfree_sensitive(buf_to_free->auth_key.response);
107 	spin_lock(&buf_to_free->iface_lock);
108 	list_for_each_entry_safe(iface, niface, &buf_to_free->iface_list,
109 				 iface_head)
110 		kref_put(&iface->refcount, release_iface);
111 	spin_unlock(&buf_to_free->iface_lock);
112 	kfree_sensitive(buf_to_free);
113 }
114 
115 struct cifs_tcon *
116 tcon_info_alloc(bool dir_leases_enabled, enum smb3_tcon_ref_trace trace)
117 {
118 	struct cifs_tcon *ret_buf;
119 	static atomic_t tcon_debug_id;
120 
121 	ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
122 	if (!ret_buf)
123 		return NULL;
124 
125 	if (dir_leases_enabled == true) {
126 		ret_buf->cfids = init_cached_dirs();
127 		if (!ret_buf->cfids) {
128 			kfree(ret_buf);
129 			return NULL;
130 		}
131 	}
132 	/* else ret_buf->cfids is already set to NULL above */
133 
134 	atomic_inc(&tconInfoAllocCount);
135 	ret_buf->status = TID_NEW;
136 	ret_buf->debug_id = atomic_inc_return(&tcon_debug_id);
137 	ret_buf->tc_count = 1;
138 	spin_lock_init(&ret_buf->tc_lock);
139 	INIT_LIST_HEAD(&ret_buf->openFileList);
140 	INIT_LIST_HEAD(&ret_buf->tcon_list);
141 	INIT_LIST_HEAD(&ret_buf->cifs_sb_list);
142 	spin_lock_init(&ret_buf->open_file_lock);
143 	spin_lock_init(&ret_buf->stat_lock);
144 	spin_lock_init(&ret_buf->sb_list_lock);
145 	atomic_set(&ret_buf->num_local_opens, 0);
146 	atomic_set(&ret_buf->num_remote_opens, 0);
147 	ret_buf->stats_from_time = ktime_get_real_seconds();
148 #ifdef CONFIG_CIFS_FSCACHE
149 	mutex_init(&ret_buf->fscache_lock);
150 #endif
151 	trace_smb3_tcon_ref(ret_buf->debug_id, ret_buf->tc_count, trace);
152 #ifdef CONFIG_CIFS_DFS_UPCALL
153 	INIT_LIST_HEAD(&ret_buf->dfs_ses_list);
154 #endif
155 	INIT_LIST_HEAD(&ret_buf->pending_opens);
156 	INIT_DELAYED_WORK(&ret_buf->query_interfaces,
157 			  smb2_query_server_interfaces);
158 #ifdef CONFIG_CIFS_DFS_UPCALL
159 	INIT_DELAYED_WORK(&ret_buf->dfs_cache_work, dfs_cache_refresh);
160 #endif
161 
162 	return ret_buf;
163 }
164 
165 void
166 tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
167 {
168 	if (tcon == NULL) {
169 		cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
170 		return;
171 	}
172 	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, trace);
173 	free_cached_dirs(tcon->cfids);
174 	atomic_dec(&tconInfoAllocCount);
175 	kfree(tcon->nativeFileSystem);
176 	kfree_sensitive(tcon->password);
177 	kfree(tcon->origin_fullpath);
178 	kfree(tcon);
179 }
180 
181 void *
182 cifs_buf_get(void)
183 {
184 	void *ret_buf = NULL;
185 	/*
186 	 * SMB2 header is bigger than CIFS one - no problems to clean some
187 	 * more bytes for CIFS.
188 	 */
189 	size_t buf_size = sizeof(struct smb2_hdr);
190 
191 	/*
192 	 * We could use negotiated size instead of max_msgsize -
193 	 * but it may be more efficient to always alloc same size
194 	 * albeit slightly larger than necessary and maxbuffersize
195 	 * defaults to this and can not be bigger.
196 	 */
197 	ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
198 
199 	/* clear the first few header bytes */
200 	/* for most paths, more is cleared in header_assemble */
201 	memset(ret_buf, 0, buf_size + 3);
202 	atomic_inc(&buf_alloc_count);
203 #ifdef CONFIG_CIFS_STATS2
204 	atomic_inc(&total_buf_alloc_count);
205 #endif /* CONFIG_CIFS_STATS2 */
206 
207 	return ret_buf;
208 }
209 
210 void
211 cifs_buf_release(void *buf_to_free)
212 {
213 	if (buf_to_free == NULL) {
214 		/* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
215 		return;
216 	}
217 	mempool_free(buf_to_free, cifs_req_poolp);
218 
219 	atomic_dec(&buf_alloc_count);
220 	return;
221 }
222 
223 void *
224 cifs_small_buf_get(void)
225 {
226 	void *ret_buf = NULL;
227 
228 /* We could use negotiated size instead of max_msgsize -
229    but it may be more efficient to always alloc same size
230    albeit slightly larger than necessary and maxbuffersize
231    defaults to this and can not be bigger */
232 	ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
233 	/* No need to clear memory here, cleared in header assemble */
234 	atomic_inc(&small_buf_alloc_count);
235 #ifdef CONFIG_CIFS_STATS2
236 	atomic_inc(&total_small_buf_alloc_count);
237 #endif /* CONFIG_CIFS_STATS2 */
238 
239 	return ret_buf;
240 }
241 
242 void
243 cifs_small_buf_release(void *buf_to_free)
244 {
245 
246 	if (buf_to_free == NULL) {
247 		cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
248 		return;
249 	}
250 	mempool_free(buf_to_free, cifs_sm_req_poolp);
251 
252 	atomic_dec(&small_buf_alloc_count);
253 	return;
254 }
255 
256 void
257 free_rsp_buf(int resp_buftype, void *rsp)
258 {
259 	if (resp_buftype == CIFS_SMALL_BUFFER)
260 		cifs_small_buf_release(rsp);
261 	else if (resp_buftype == CIFS_LARGE_BUFFER)
262 		cifs_buf_release(rsp);
263 }
264 
265 /* NB: MID can not be set if treeCon not passed in, in that
266    case it is responsibility of caller to set the mid */
267 unsigned int
268 header_assemble(struct smb_hdr *buffer, char smb_command,
269 		const struct cifs_tcon *treeCon, int word_count
270 		/* length of fixed section (word count) in two byte units  */)
271 {
272 	unsigned int in_len;
273 	char *temp = (char *) buffer;
274 
275 	memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
276 
277 	in_len = (2 * word_count) + sizeof(struct smb_hdr) +
278 		2 /* for bcc field itself */;
279 
280 	buffer->Protocol[0] = 0xFF;
281 	buffer->Protocol[1] = 'S';
282 	buffer->Protocol[2] = 'M';
283 	buffer->Protocol[3] = 'B';
284 	buffer->Command = smb_command;
285 	buffer->Flags = 0x00;	/* case sensitive */
286 	buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
287 	buffer->Pid = cpu_to_le16((__u16)current->tgid);
288 	buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
289 	if (treeCon) {
290 		buffer->Tid = treeCon->tid;
291 		if (treeCon->ses) {
292 			if (treeCon->ses->capabilities & CAP_UNICODE)
293 				buffer->Flags2 |= SMBFLG2_UNICODE;
294 			if (treeCon->ses->capabilities & CAP_STATUS32)
295 				buffer->Flags2 |= SMBFLG2_ERR_STATUS;
296 
297 			/* Uid is not converted */
298 			buffer->Uid = treeCon->ses->Suid;
299 			if (treeCon->ses->server)
300 				buffer->Mid = get_next_mid(treeCon->ses->server);
301 		}
302 		if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
303 			buffer->Flags2 |= SMBFLG2_DFS;
304 		if (treeCon->nocase)
305 			buffer->Flags  |= SMBFLG_CASELESS;
306 		if ((treeCon->ses) && (treeCon->ses->server))
307 			if (treeCon->ses->server->sign)
308 				buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
309 	}
310 
311 /*  endian conversion of flags is now done just before sending */
312 	buffer->WordCount = (char) word_count;
313 	return in_len;
314 }
315 
316 bool
317 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
318 {
319 	struct smb_hdr *buf = (struct smb_hdr *)buffer;
320 	struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
321 	struct TCP_Server_Info *pserver;
322 	struct cifs_ses *ses;
323 	struct cifs_tcon *tcon;
324 	struct cifsInodeInfo *pCifsInode;
325 	struct cifsFileInfo *netfile;
326 
327 	cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
328 	if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
329 	   (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
330 		struct smb_com_transaction_change_notify_rsp *pSMBr =
331 			(struct smb_com_transaction_change_notify_rsp *)buf;
332 		struct file_notify_information *pnotify;
333 		__u32 data_offset = 0;
334 		size_t len = srv->total_read - srv->pdu_size;
335 
336 		if (get_bcc(buf) > sizeof(struct file_notify_information)) {
337 			data_offset = le32_to_cpu(pSMBr->DataOffset);
338 
339 			if (data_offset >
340 			    len - sizeof(struct file_notify_information)) {
341 				cifs_dbg(FYI, "Invalid data_offset %u\n",
342 					 data_offset);
343 				return true;
344 			}
345 			pnotify = (struct file_notify_information *)
346 				((char *)&pSMBr->hdr.Protocol + data_offset);
347 			cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
348 				 pnotify->FileName, pnotify->Action);
349 			/*   cifs_dump_mem("Rcvd notify Data: ",buf,
350 				sizeof(struct smb_hdr)+60); */
351 			return true;
352 		}
353 		if (pSMBr->hdr.Status.CifsError) {
354 			cifs_dbg(FYI, "notify err 0x%x\n",
355 				 pSMBr->hdr.Status.CifsError);
356 			return true;
357 		}
358 		return false;
359 	}
360 	if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
361 		return false;
362 	if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
363 		/* no sense logging error on invalid handle on oplock
364 		   break - harmless race between close request and oplock
365 		   break response is expected from time to time writing out
366 		   large dirty files cached on the client */
367 		if ((NT_STATUS_INVALID_HANDLE) ==
368 		   le32_to_cpu(pSMB->hdr.Status.CifsError)) {
369 			cifs_dbg(FYI, "Invalid handle on oplock break\n");
370 			return true;
371 		} else if (ERRbadfid ==
372 		   le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
373 			return true;
374 		} else {
375 			return false; /* on valid oplock brk we get "request" */
376 		}
377 	}
378 	if (pSMB->hdr.WordCount != 8)
379 		return false;
380 
381 	cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
382 		 pSMB->LockType, pSMB->OplockLevel);
383 	if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
384 		return false;
385 
386 	/* If server is a channel, select the primary channel */
387 	pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv;
388 
389 	/* look up tcon based on tid & uid */
390 	spin_lock(&cifs_tcp_ses_lock);
391 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
392 		if (cifs_ses_exiting(ses))
393 			continue;
394 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
395 			if (tcon->tid != buf->Tid)
396 				continue;
397 
398 			cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
399 			spin_lock(&tcon->open_file_lock);
400 			list_for_each_entry(netfile, &tcon->openFileList, tlist) {
401 				if (pSMB->Fid != netfile->fid.netfid)
402 					continue;
403 
404 				cifs_dbg(FYI, "file id match, oplock break\n");
405 				pCifsInode = CIFS_I(d_inode(netfile->dentry));
406 
407 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
408 					&pCifsInode->flags);
409 
410 				netfile->oplock_epoch = 0;
411 				netfile->oplock_level = pSMB->OplockLevel;
412 				netfile->oplock_break_cancelled = false;
413 				cifs_queue_oplock_break(netfile);
414 
415 				spin_unlock(&tcon->open_file_lock);
416 				spin_unlock(&cifs_tcp_ses_lock);
417 				return true;
418 			}
419 			spin_unlock(&tcon->open_file_lock);
420 			spin_unlock(&cifs_tcp_ses_lock);
421 			cifs_dbg(FYI, "No matching file for oplock break\n");
422 			return true;
423 		}
424 	}
425 	spin_unlock(&cifs_tcp_ses_lock);
426 	cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
427 	return true;
428 }
429 
430 void
431 dump_smb(void *buf, int smb_buf_length)
432 {
433 	if (traceSMB == 0)
434 		return;
435 
436 	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
437 		       smb_buf_length, true);
438 }
439 
440 void
441 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
442 {
443 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
444 		struct cifs_tcon *tcon = NULL;
445 
446 		if (cifs_sb->master_tlink)
447 			tcon = cifs_sb_master_tcon(cifs_sb);
448 
449 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
450 		cifs_sb->mnt_cifs_serverino_autodisabled = true;
451 		cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n",
452 			 tcon ? tcon->tree_name : "new server");
453 		cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n");
454 		cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
455 
456 	}
457 }
458 
459 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
460 {
461 	oplock &= 0xF;
462 
463 	if (oplock == OPLOCK_EXCLUSIVE) {
464 		cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
465 		cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
466 			 &cinode->netfs.inode);
467 	} else if (oplock == OPLOCK_READ) {
468 		cinode->oplock = CIFS_CACHE_READ_FLG;
469 		cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
470 			 &cinode->netfs.inode);
471 	} else
472 		cinode->oplock = 0;
473 }
474 
475 /*
476  * We wait for oplock breaks to be processed before we attempt to perform
477  * writes.
478  */
479 int cifs_get_writer(struct cifsInodeInfo *cinode)
480 {
481 	int rc;
482 
483 start:
484 	rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
485 			 TASK_KILLABLE);
486 	if (rc)
487 		return rc;
488 
489 	spin_lock(&cinode->writers_lock);
490 	if (!cinode->writers)
491 		set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
492 	cinode->writers++;
493 	/* Check to see if we have started servicing an oplock break */
494 	if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
495 		cinode->writers--;
496 		if (cinode->writers == 0) {
497 			clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
498 			wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
499 		}
500 		spin_unlock(&cinode->writers_lock);
501 		goto start;
502 	}
503 	spin_unlock(&cinode->writers_lock);
504 	return 0;
505 }
506 
507 void cifs_put_writer(struct cifsInodeInfo *cinode)
508 {
509 	spin_lock(&cinode->writers_lock);
510 	cinode->writers--;
511 	if (cinode->writers == 0) {
512 		clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
513 		wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
514 	}
515 	spin_unlock(&cinode->writers_lock);
516 }
517 
518 /**
519  * cifs_queue_oplock_break - queue the oplock break handler for cfile
520  * @cfile: The file to break the oplock on
521  *
522  * This function is called from the demultiplex thread when it
523  * receives an oplock break for @cfile.
524  *
525  * Assumes the tcon->open_file_lock is held.
526  * Assumes cfile->file_info_lock is NOT held.
527  */
528 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
529 {
530 	/*
531 	 * Bump the handle refcount now while we hold the
532 	 * open_file_lock to enforce the validity of it for the oplock
533 	 * break handler. The matching put is done at the end of the
534 	 * handler.
535 	 */
536 	cifsFileInfo_get(cfile);
537 
538 	queue_work(cifsoplockd_wq, &cfile->oplock_break);
539 }
540 
541 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
542 {
543 	clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
544 	wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
545 }
546 
547 bool
548 backup_cred(struct cifs_sb_info *cifs_sb)
549 {
550 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
551 		if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid()))
552 			return true;
553 	}
554 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
555 		if (in_group_p(cifs_sb->ctx->backupgid))
556 			return true;
557 	}
558 
559 	return false;
560 }
561 
562 void
563 cifs_del_pending_open(struct cifs_pending_open *open)
564 {
565 	spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
566 	list_del(&open->olist);
567 	spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
568 }
569 
570 void
571 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
572 			     struct cifs_pending_open *open)
573 {
574 	memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
575 	open->oplock = CIFS_OPLOCK_NO_CHANGE;
576 	open->tlink = tlink;
577 	fid->pending_open = open;
578 	list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
579 }
580 
581 void
582 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
583 		      struct cifs_pending_open *open)
584 {
585 	spin_lock(&tlink_tcon(tlink)->open_file_lock);
586 	cifs_add_pending_open_locked(fid, tlink, open);
587 	spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
588 }
589 
590 /*
591  * Critical section which runs after acquiring deferred_lock.
592  * As there is no reference count on cifs_deferred_close, pdclose
593  * should not be used outside deferred_lock.
594  */
595 bool
596 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose)
597 {
598 	struct cifs_deferred_close *dclose;
599 
600 	list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) {
601 		if ((dclose->netfid == cfile->fid.netfid) &&
602 			(dclose->persistent_fid == cfile->fid.persistent_fid) &&
603 			(dclose->volatile_fid == cfile->fid.volatile_fid)) {
604 			*pdclose = dclose;
605 			return true;
606 		}
607 	}
608 	return false;
609 }
610 
611 /*
612  * Critical section which runs after acquiring deferred_lock.
613  */
614 void
615 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose)
616 {
617 	bool is_deferred = false;
618 	struct cifs_deferred_close *pdclose;
619 
620 	is_deferred = cifs_is_deferred_close(cfile, &pdclose);
621 	if (is_deferred) {
622 		kfree(dclose);
623 		return;
624 	}
625 
626 	dclose->tlink = cfile->tlink;
627 	dclose->netfid = cfile->fid.netfid;
628 	dclose->persistent_fid = cfile->fid.persistent_fid;
629 	dclose->volatile_fid = cfile->fid.volatile_fid;
630 	list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes);
631 }
632 
633 /*
634  * Critical section which runs after acquiring deferred_lock.
635  */
636 void
637 cifs_del_deferred_close(struct cifsFileInfo *cfile)
638 {
639 	bool is_deferred = false;
640 	struct cifs_deferred_close *dclose;
641 
642 	is_deferred = cifs_is_deferred_close(cfile, &dclose);
643 	if (!is_deferred)
644 		return;
645 	list_del(&dclose->dlist);
646 	kfree(dclose);
647 }
648 
649 void
650 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode)
651 {
652 	struct cifsFileInfo *cfile = NULL;
653 	struct file_list *tmp_list, *tmp_next_list;
654 	LIST_HEAD(file_head);
655 
656 	if (cifs_inode == NULL)
657 		return;
658 
659 	spin_lock(&cifs_inode->open_file_lock);
660 	list_for_each_entry(cfile, &cifs_inode->openFileList, flist) {
661 		if (delayed_work_pending(&cfile->deferred)) {
662 			if (cancel_delayed_work(&cfile->deferred)) {
663 				spin_lock(&cifs_inode->deferred_lock);
664 				cifs_del_deferred_close(cfile);
665 				spin_unlock(&cifs_inode->deferred_lock);
666 
667 				tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
668 				if (tmp_list == NULL)
669 					break;
670 				tmp_list->cfile = cfile;
671 				list_add_tail(&tmp_list->list, &file_head);
672 			}
673 		}
674 	}
675 	spin_unlock(&cifs_inode->open_file_lock);
676 
677 	list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
678 		_cifsFileInfo_put(tmp_list->cfile, false, false);
679 		list_del(&tmp_list->list);
680 		kfree(tmp_list);
681 	}
682 }
683 
684 void
685 cifs_close_all_deferred_files(struct cifs_tcon *tcon)
686 {
687 	struct cifsFileInfo *cfile;
688 	struct file_list *tmp_list, *tmp_next_list;
689 	LIST_HEAD(file_head);
690 
691 	spin_lock(&tcon->open_file_lock);
692 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
693 		if (delayed_work_pending(&cfile->deferred)) {
694 			if (cancel_delayed_work(&cfile->deferred)) {
695 				spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
696 				cifs_del_deferred_close(cfile);
697 				spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
698 
699 				tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
700 				if (tmp_list == NULL)
701 					break;
702 				tmp_list->cfile = cfile;
703 				list_add_tail(&tmp_list->list, &file_head);
704 			}
705 		}
706 	}
707 	spin_unlock(&tcon->open_file_lock);
708 
709 	list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
710 		_cifsFileInfo_put(tmp_list->cfile, true, false);
711 		list_del(&tmp_list->list);
712 		kfree(tmp_list);
713 	}
714 }
715 
716 void cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon,
717 					   struct dentry *dentry)
718 {
719 	struct file_list *tmp_list, *tmp_next_list;
720 	struct cifsFileInfo *cfile;
721 	LIST_HEAD(file_head);
722 
723 	spin_lock(&tcon->open_file_lock);
724 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
725 		if ((cfile->dentry == dentry) &&
726 		    delayed_work_pending(&cfile->deferred) &&
727 		    cancel_delayed_work(&cfile->deferred)) {
728 			spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
729 			cifs_del_deferred_close(cfile);
730 			spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
731 
732 			tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
733 			if (tmp_list == NULL)
734 				break;
735 			tmp_list->cfile = cfile;
736 			list_add_tail(&tmp_list->list, &file_head);
737 		}
738 	}
739 	spin_unlock(&tcon->open_file_lock);
740 
741 	list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
742 		_cifsFileInfo_put(tmp_list->cfile, true, false);
743 		list_del(&tmp_list->list);
744 		kfree(tmp_list);
745 	}
746 }
747 
748 /*
749  * If a dentry has been deleted, all corresponding open handles should know that
750  * so that we do not defer close them.
751  */
752 void cifs_mark_open_handles_for_deleted_file(struct inode *inode,
753 					     const char *path)
754 {
755 	struct cifsFileInfo *cfile;
756 	void *page;
757 	const char *full_path;
758 	struct cifsInodeInfo *cinode = CIFS_I(inode);
759 
760 	page = alloc_dentry_path();
761 	spin_lock(&cinode->open_file_lock);
762 
763 	/*
764 	 * note: we need to construct path from dentry and compare only if the
765 	 * inode has any hardlinks. When number of hardlinks is 1, we can just
766 	 * mark all open handles since they are going to be from the same file.
767 	 */
768 	if (inode->i_nlink > 1) {
769 		list_for_each_entry(cfile, &cinode->openFileList, flist) {
770 			full_path = build_path_from_dentry(cfile->dentry, page);
771 			if (!IS_ERR(full_path) && strcmp(full_path, path) == 0)
772 				cfile->status_file_deleted = true;
773 		}
774 	} else {
775 		list_for_each_entry(cfile, &cinode->openFileList, flist)
776 			cfile->status_file_deleted = true;
777 	}
778 	spin_unlock(&cinode->open_file_lock);
779 	free_dentry_path(page);
780 }
781 
782 /* parses DFS referral V3 structure
783  * caller is responsible for freeing target_nodes
784  * returns:
785  * - on success - 0
786  * - on failure - errno
787  */
788 int
789 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
790 		    unsigned int *num_of_nodes,
791 		    struct dfs_info3_param **target_nodes,
792 		    const struct nls_table *nls_codepage, int remap,
793 		    const char *searchName, bool is_unicode)
794 {
795 	int i, rc = 0;
796 	char *data_end;
797 	struct dfs_referral_level_3 *ref;
798 
799 	if (rsp_size < sizeof(*rsp)) {
800 		cifs_dbg(VFS | ONCE,
801 			 "%s: header is malformed (size is %u, must be %zu)\n",
802 			 __func__, rsp_size, sizeof(*rsp));
803 		rc = -EINVAL;
804 		goto parse_DFS_referrals_exit;
805 	}
806 
807 	*num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
808 
809 	if (*num_of_nodes < 1) {
810 		cifs_dbg(VFS | ONCE, "%s: [path=%s] num_referrals must be at least > 0, but we got %d\n",
811 			 __func__, searchName, *num_of_nodes);
812 		rc = -ENOENT;
813 		goto parse_DFS_referrals_exit;
814 	}
815 
816 	if (sizeof(*rsp) + *num_of_nodes * sizeof(REFERRAL3) > rsp_size) {
817 		cifs_dbg(VFS | ONCE,
818 			 "%s: malformed buffer (size is %u, must be at least %zu)\n",
819 			 __func__, rsp_size,
820 			 sizeof(*rsp) + *num_of_nodes * sizeof(REFERRAL3));
821 		rc = -EINVAL;
822 		goto parse_DFS_referrals_exit;
823 	}
824 
825 	ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
826 	if (ref->VersionNumber != cpu_to_le16(3)) {
827 		cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
828 			 le16_to_cpu(ref->VersionNumber));
829 		rc = -EINVAL;
830 		goto parse_DFS_referrals_exit;
831 	}
832 
833 	/* get the upper boundary of the resp buffer */
834 	data_end = (char *)rsp + rsp_size;
835 
836 	cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
837 		 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
838 
839 	*target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
840 				GFP_KERNEL);
841 	if (*target_nodes == NULL) {
842 		rc = -ENOMEM;
843 		goto parse_DFS_referrals_exit;
844 	}
845 
846 	/* collect necessary data from referrals */
847 	for (i = 0; i < *num_of_nodes; i++) {
848 		char *temp;
849 		int max_len;
850 		struct dfs_info3_param *node = (*target_nodes)+i;
851 
852 		node->flags = le32_to_cpu(rsp->DFSFlags);
853 		if (is_unicode) {
854 			__le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
855 						GFP_KERNEL);
856 			if (tmp == NULL) {
857 				rc = -ENOMEM;
858 				goto parse_DFS_referrals_exit;
859 			}
860 			cifsConvertToUTF16((__le16 *) tmp, searchName,
861 					   PATH_MAX, nls_codepage, remap);
862 			node->path_consumed = cifs_utf16_bytes(tmp,
863 					le16_to_cpu(rsp->PathConsumed),
864 					nls_codepage);
865 			kfree(tmp);
866 		} else
867 			node->path_consumed = le16_to_cpu(rsp->PathConsumed);
868 
869 		node->server_type = le16_to_cpu(ref->ServerType);
870 		node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
871 
872 		/* copy DfsPath */
873 		temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
874 		max_len = data_end - temp;
875 		node->path_name = cifs_strndup_from_utf16(temp, max_len,
876 						is_unicode, nls_codepage);
877 		if (!node->path_name) {
878 			rc = -ENOMEM;
879 			goto parse_DFS_referrals_exit;
880 		}
881 
882 		/* copy link target UNC */
883 		temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
884 		max_len = data_end - temp;
885 		node->node_name = cifs_strndup_from_utf16(temp, max_len,
886 						is_unicode, nls_codepage);
887 		if (!node->node_name) {
888 			rc = -ENOMEM;
889 			goto parse_DFS_referrals_exit;
890 		}
891 
892 		node->ttl = le32_to_cpu(ref->TimeToLive);
893 
894 		ref++;
895 	}
896 
897 parse_DFS_referrals_exit:
898 	if (rc) {
899 		free_dfs_info_array(*target_nodes, *num_of_nodes);
900 		*target_nodes = NULL;
901 		*num_of_nodes = 0;
902 	}
903 	return rc;
904 }
905 
906 /**
907  * cifs_alloc_hash - allocate hash and hash context together
908  * @name: The name of the crypto hash algo
909  * @sdesc: SHASH descriptor where to put the pointer to the hash TFM
910  *
911  * The caller has to make sure @sdesc is initialized to either NULL or
912  * a valid context. It can be freed via cifs_free_hash().
913  */
914 int
915 cifs_alloc_hash(const char *name, struct shash_desc **sdesc)
916 {
917 	int rc = 0;
918 	struct crypto_shash *alg = NULL;
919 
920 	if (*sdesc)
921 		return 0;
922 
923 	alg = crypto_alloc_shash(name, 0, 0);
924 	if (IS_ERR(alg)) {
925 		cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name);
926 		rc = PTR_ERR(alg);
927 		*sdesc = NULL;
928 		return rc;
929 	}
930 
931 	*sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL);
932 	if (*sdesc == NULL) {
933 		cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name);
934 		crypto_free_shash(alg);
935 		return -ENOMEM;
936 	}
937 
938 	(*sdesc)->tfm = alg;
939 	return 0;
940 }
941 
942 /**
943  * cifs_free_hash - free hash and hash context together
944  * @sdesc: Where to find the pointer to the hash TFM
945  *
946  * Freeing a NULL descriptor is safe.
947  */
948 void
949 cifs_free_hash(struct shash_desc **sdesc)
950 {
951 	if (unlikely(!sdesc) || !*sdesc)
952 		return;
953 
954 	if ((*sdesc)->tfm) {
955 		crypto_free_shash((*sdesc)->tfm);
956 		(*sdesc)->tfm = NULL;
957 	}
958 
959 	kfree_sensitive(*sdesc);
960 	*sdesc = NULL;
961 }
962 
963 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
964 {
965 	const char *end;
966 
967 	/* skip initial slashes */
968 	while (*unc && (*unc == '\\' || *unc == '/'))
969 		unc++;
970 
971 	end = unc;
972 
973 	while (*end && !(*end == '\\' || *end == '/'))
974 		end++;
975 
976 	*h = unc;
977 	*len = end - unc;
978 }
979 
980 /**
981  * copy_path_name - copy src path to dst, possibly truncating
982  * @dst: The destination buffer
983  * @src: The source name
984  *
985  * returns number of bytes written (including trailing nul)
986  */
987 int copy_path_name(char *dst, const char *src)
988 {
989 	int name_len;
990 
991 	/*
992 	 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
993 	 * will truncate and strlen(dst) will be PATH_MAX-1
994 	 */
995 	name_len = strscpy(dst, src, PATH_MAX);
996 	if (WARN_ON_ONCE(name_len < 0))
997 		name_len = PATH_MAX-1;
998 
999 	/* we count the trailing nul */
1000 	name_len++;
1001 	return name_len;
1002 }
1003 
1004 struct super_cb_data {
1005 	void *data;
1006 	struct super_block *sb;
1007 };
1008 
1009 static void tcon_super_cb(struct super_block *sb, void *arg)
1010 {
1011 	struct super_cb_data *sd = arg;
1012 	struct cifs_sb_info *cifs_sb;
1013 	struct cifs_tcon *t1 = sd->data, *t2;
1014 
1015 	if (sd->sb)
1016 		return;
1017 
1018 	cifs_sb = CIFS_SB(sb);
1019 	t2 = cifs_sb_master_tcon(cifs_sb);
1020 
1021 	spin_lock(&t2->tc_lock);
1022 	if ((t1->ses == t2->ses ||
1023 	     t1->ses->dfs_root_ses == t2->ses->dfs_root_ses) &&
1024 	    t1->ses->server == t2->ses->server &&
1025 	    t2->origin_fullpath &&
1026 	    dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath))
1027 		sd->sb = sb;
1028 	spin_unlock(&t2->tc_lock);
1029 }
1030 
1031 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),
1032 					    void *data)
1033 {
1034 	struct super_cb_data sd = {
1035 		.data = data,
1036 		.sb = NULL,
1037 	};
1038 	struct file_system_type **fs_type = (struct file_system_type *[]) {
1039 		&cifs_fs_type, &smb3_fs_type, NULL,
1040 	};
1041 
1042 	for (; *fs_type; fs_type++) {
1043 		iterate_supers_type(*fs_type, f, &sd);
1044 		if (sd.sb) {
1045 			/*
1046 			 * Grab an active reference in order to prevent automounts (DFS links)
1047 			 * of expiring and then freeing up our cifs superblock pointer while
1048 			 * we're doing failover.
1049 			 */
1050 			cifs_sb_active(sd.sb);
1051 			return sd.sb;
1052 		}
1053 	}
1054 	pr_warn_once("%s: could not find dfs superblock\n", __func__);
1055 	return ERR_PTR(-EINVAL);
1056 }
1057 
1058 static void __cifs_put_super(struct super_block *sb)
1059 {
1060 	if (!IS_ERR_OR_NULL(sb))
1061 		cifs_sb_deactive(sb);
1062 }
1063 
1064 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon)
1065 {
1066 	spin_lock(&tcon->tc_lock);
1067 	if (!tcon->origin_fullpath) {
1068 		spin_unlock(&tcon->tc_lock);
1069 		return ERR_PTR(-ENOENT);
1070 	}
1071 	spin_unlock(&tcon->tc_lock);
1072 	return __cifs_get_super(tcon_super_cb, tcon);
1073 }
1074 
1075 void cifs_put_tcp_super(struct super_block *sb)
1076 {
1077 	__cifs_put_super(sb);
1078 }
1079 
1080 #ifdef CONFIG_CIFS_DFS_UPCALL
1081 int match_target_ip(struct TCP_Server_Info *server,
1082 		    const char *host, size_t hostlen,
1083 		    bool *result)
1084 {
1085 	struct sockaddr_storage ss;
1086 	int rc;
1087 
1088 	cifs_dbg(FYI, "%s: hostname=%.*s\n", __func__, (int)hostlen, host);
1089 
1090 	*result = false;
1091 
1092 	rc = dns_resolve_name(server->dns_dom, host, hostlen,
1093 			      (struct sockaddr *)&ss);
1094 	if (rc < 0)
1095 		return rc;
1096 
1097 	spin_lock(&server->srv_lock);
1098 	*result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);
1099 	spin_unlock(&server->srv_lock);
1100 	cifs_dbg(FYI, "%s: ip addresses matched: %s\n", __func__, str_yes_no(*result));
1101 	return 0;
1102 }
1103 
1104 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix)
1105 {
1106 	int rc;
1107 
1108 	kfree(cifs_sb->prepath);
1109 	cifs_sb->prepath = NULL;
1110 
1111 	if (prefix && *prefix) {
1112 		cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC);
1113 		if (IS_ERR(cifs_sb->prepath)) {
1114 			rc = PTR_ERR(cifs_sb->prepath);
1115 			cifs_sb->prepath = NULL;
1116 			return rc;
1117 		}
1118 		if (cifs_sb->prepath)
1119 			convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
1120 	}
1121 
1122 	cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
1123 	return 0;
1124 }
1125 
1126 /*
1127  * Handle weird Windows SMB server behaviour. It responds with
1128  * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for
1129  * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains
1130  * non-ASCII unicode symbols.
1131  */
1132 int cifs_inval_name_dfs_link_error(const unsigned int xid,
1133 				   struct cifs_tcon *tcon,
1134 				   struct cifs_sb_info *cifs_sb,
1135 				   const char *full_path,
1136 				   bool *islink)
1137 {
1138 	struct TCP_Server_Info *server = tcon->ses->server;
1139 	struct cifs_ses *ses = tcon->ses;
1140 	size_t len;
1141 	char *path;
1142 	char *ref_path;
1143 
1144 	*islink = false;
1145 
1146 	/*
1147 	 * Fast path - skip check when @full_path doesn't have a prefix path to
1148 	 * look up or tcon is not DFS.
1149 	 */
1150 	if (strlen(full_path) < 2 || !cifs_sb ||
1151 	    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
1152 	    !is_tcon_dfs(tcon))
1153 		return 0;
1154 
1155 	spin_lock(&server->srv_lock);
1156 	if (!server->leaf_fullpath) {
1157 		spin_unlock(&server->srv_lock);
1158 		return 0;
1159 	}
1160 	spin_unlock(&server->srv_lock);
1161 
1162 	/*
1163 	 * Slow path - tcon is DFS and @full_path has prefix path, so attempt
1164 	 * to get a referral to figure out whether it is an DFS link.
1165 	 */
1166 	len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1;
1167 	path = kmalloc(len, GFP_KERNEL);
1168 	if (!path)
1169 		return -ENOMEM;
1170 
1171 	scnprintf(path, len, "%s%s", tcon->tree_name, full_path);
1172 	ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls,
1173 					    cifs_remap(cifs_sb));
1174 	kfree(path);
1175 
1176 	if (IS_ERR(ref_path)) {
1177 		if (PTR_ERR(ref_path) != -EINVAL)
1178 			return PTR_ERR(ref_path);
1179 	} else {
1180 		struct dfs_info3_param *refs = NULL;
1181 		int num_refs = 0;
1182 
1183 		/*
1184 		 * XXX: we are not using dfs_cache_find() here because we might
1185 		 * end up filling all the DFS cache and thus potentially
1186 		 * removing cached DFS targets that the client would eventually
1187 		 * need during failover.
1188 		 */
1189 		ses = CIFS_DFS_ROOT_SES(ses);
1190 		if (ses->server->ops->get_dfs_refer &&
1191 		    !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs,
1192 						     &num_refs, cifs_sb->local_nls,
1193 						     cifs_remap(cifs_sb)))
1194 			*islink = refs[0].server_type == DFS_TYPE_LINK;
1195 		free_dfs_info_array(refs, num_refs);
1196 		kfree(ref_path);
1197 	}
1198 	return 0;
1199 }
1200 #endif
1201 
1202 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry)
1203 {
1204 	int timeout = 10;
1205 	int rc;
1206 
1207 	spin_lock(&server->srv_lock);
1208 	if (server->tcpStatus != CifsNeedReconnect) {
1209 		spin_unlock(&server->srv_lock);
1210 		return 0;
1211 	}
1212 	timeout *= server->nr_targets;
1213 	spin_unlock(&server->srv_lock);
1214 
1215 	/*
1216 	 * Give demultiplex thread up to 10 seconds to each target available for
1217 	 * reconnect -- should be greater than cifs socket timeout which is 7
1218 	 * seconds.
1219 	 *
1220 	 * On "soft" mounts we wait once. Hard mounts keep retrying until
1221 	 * process is killed or server comes back on-line.
1222 	 */
1223 	do {
1224 		rc = wait_event_interruptible_timeout(server->response_q,
1225 						      (server->tcpStatus != CifsNeedReconnect),
1226 						      timeout * HZ);
1227 		if (rc < 0) {
1228 			cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n",
1229 				 __func__);
1230 			return -ERESTARTSYS;
1231 		}
1232 
1233 		/* are we still trying to reconnect? */
1234 		spin_lock(&server->srv_lock);
1235 		if (server->tcpStatus != CifsNeedReconnect) {
1236 			spin_unlock(&server->srv_lock);
1237 			return 0;
1238 		}
1239 		spin_unlock(&server->srv_lock);
1240 	} while (retry);
1241 
1242 	cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__);
1243 	return -EHOSTDOWN;
1244 }
1245