xref: /linux/fs/smb/client/fs_context.c (revision 0678df8271820bcf8fb4f877129f05d68a237de4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) 2020, Microsoft Corporation.
4  *
5  *   Author(s): Steve French <stfrench@microsoft.com>
6  *              David Howells <dhowells@redhat.com>
7  */
8 
9 /*
10 #include <linux/module.h>
11 #include <linux/nsproxy.h>
12 #include <linux/slab.h>
13 #include <linux/magic.h>
14 #include <linux/security.h>
15 #include <net/net_namespace.h>
16 #ifdef CONFIG_CIFS_DFS_UPCALL
17 #include "dfs_cache.h"
18 #endif
19 */
20 
21 #include <linux/ctype.h>
22 #include <linux/fs_context.h>
23 #include <linux/fs_parser.h>
24 #include <linux/fs.h>
25 #include <linux/mount.h>
26 #include <linux/parser.h>
27 #include <linux/utsname.h>
28 #include "cifsfs.h"
29 #include "cifspdu.h"
30 #include "cifsglob.h"
31 #include "cifsproto.h"
32 #include "cifs_unicode.h"
33 #include "cifs_debug.h"
34 #include "cifs_fs_sb.h"
35 #include "ntlmssp.h"
36 #include "nterr.h"
37 #include "rfc1002pdu.h"
38 #include "fs_context.h"
39 
40 static DEFINE_MUTEX(cifs_mount_mutex);
41 
42 static const match_table_t cifs_smb_version_tokens = {
43 	{ Smb_1, SMB1_VERSION_STRING },
44 	{ Smb_20, SMB20_VERSION_STRING},
45 	{ Smb_21, SMB21_VERSION_STRING },
46 	{ Smb_30, SMB30_VERSION_STRING },
47 	{ Smb_302, SMB302_VERSION_STRING },
48 	{ Smb_302, ALT_SMB302_VERSION_STRING },
49 	{ Smb_311, SMB311_VERSION_STRING },
50 	{ Smb_311, ALT_SMB311_VERSION_STRING },
51 	{ Smb_3any, SMB3ANY_VERSION_STRING },
52 	{ Smb_default, SMBDEFAULT_VERSION_STRING },
53 	{ Smb_version_err, NULL }
54 };
55 
56 static const match_table_t cifs_secflavor_tokens = {
57 	{ Opt_sec_krb5, "krb5" },
58 	{ Opt_sec_krb5i, "krb5i" },
59 	{ Opt_sec_krb5p, "krb5p" },
60 	{ Opt_sec_ntlmsspi, "ntlmsspi" },
61 	{ Opt_sec_ntlmssp, "ntlmssp" },
62 	{ Opt_sec_ntlmv2, "nontlm" },
63 	{ Opt_sec_ntlmv2, "ntlmv2" },
64 	{ Opt_sec_ntlmv2i, "ntlmv2i" },
65 	{ Opt_sec_none, "none" },
66 
67 	{ Opt_sec_err, NULL }
68 };
69 
70 const struct fs_parameter_spec smb3_fs_parameters[] = {
71 	/* Mount options that take no arguments */
72 	fsparam_flag_no("user_xattr", Opt_user_xattr),
73 	fsparam_flag_no("forceuid", Opt_forceuid),
74 	fsparam_flag_no("multichannel", Opt_multichannel),
75 	fsparam_flag_no("forcegid", Opt_forcegid),
76 	fsparam_flag("noblocksend", Opt_noblocksend),
77 	fsparam_flag("noautotune", Opt_noautotune),
78 	fsparam_flag("nolease", Opt_nolease),
79 	fsparam_flag_no("hard", Opt_hard),
80 	fsparam_flag_no("soft", Opt_soft),
81 	fsparam_flag_no("perm", Opt_perm),
82 	fsparam_flag("nodelete", Opt_nodelete),
83 	fsparam_flag_no("mapposix", Opt_mapposix),
84 	fsparam_flag("mapchars", Opt_mapchars),
85 	fsparam_flag("nomapchars", Opt_nomapchars),
86 	fsparam_flag_no("sfu", Opt_sfu),
87 	fsparam_flag("nodfs", Opt_nodfs),
88 	fsparam_flag_no("posixpaths", Opt_posixpaths),
89 	fsparam_flag_no("unix", Opt_unix),
90 	fsparam_flag_no("linux", Opt_unix),
91 	fsparam_flag_no("posix", Opt_unix),
92 	fsparam_flag("nocase", Opt_nocase),
93 	fsparam_flag("ignorecase", Opt_nocase),
94 	fsparam_flag_no("brl", Opt_brl),
95 	fsparam_flag_no("handlecache", Opt_handlecache),
96 	fsparam_flag("forcemandatorylock", Opt_forcemandatorylock),
97 	fsparam_flag("forcemand", Opt_forcemandatorylock),
98 	fsparam_flag("setuidfromacl", Opt_setuidfromacl),
99 	fsparam_flag("idsfromsid", Opt_setuidfromacl),
100 	fsparam_flag_no("setuids", Opt_setuids),
101 	fsparam_flag_no("dynperm", Opt_dynperm),
102 	fsparam_flag_no("intr", Opt_intr),
103 	fsparam_flag_no("strictsync", Opt_strictsync),
104 	fsparam_flag_no("serverino", Opt_serverino),
105 	fsparam_flag("rwpidforward", Opt_rwpidforward),
106 	fsparam_flag("cifsacl", Opt_cifsacl),
107 	fsparam_flag_no("acl", Opt_acl),
108 	fsparam_flag("locallease", Opt_locallease),
109 	fsparam_flag("sign", Opt_sign),
110 	fsparam_flag("ignore_signature", Opt_ignore_signature),
111 	fsparam_flag("signloosely", Opt_ignore_signature),
112 	fsparam_flag("seal", Opt_seal),
113 	fsparam_flag("noac", Opt_noac),
114 	fsparam_flag("fsc", Opt_fsc),
115 	fsparam_flag("mfsymlinks", Opt_mfsymlinks),
116 	fsparam_flag("multiuser", Opt_multiuser),
117 	fsparam_flag("sloppy", Opt_sloppy),
118 	fsparam_flag("nosharesock", Opt_nosharesock),
119 	fsparam_flag_no("persistenthandles", Opt_persistent),
120 	fsparam_flag_no("resilienthandles", Opt_resilient),
121 	fsparam_flag_no("tcpnodelay", Opt_tcp_nodelay),
122 	fsparam_flag("nosparse", Opt_nosparse),
123 	fsparam_flag("domainauto", Opt_domainauto),
124 	fsparam_flag("rdma", Opt_rdma),
125 	fsparam_flag("modesid", Opt_modesid),
126 	fsparam_flag("modefromsid", Opt_modesid),
127 	fsparam_flag("rootfs", Opt_rootfs),
128 	fsparam_flag("compress", Opt_compress),
129 	fsparam_flag("witness", Opt_witness),
130 
131 	/* Mount options which take numeric value */
132 	fsparam_u32("backupuid", Opt_backupuid),
133 	fsparam_u32("backupgid", Opt_backupgid),
134 	fsparam_u32("uid", Opt_uid),
135 	fsparam_u32("cruid", Opt_cruid),
136 	fsparam_u32("gid", Opt_gid),
137 	fsparam_u32("file_mode", Opt_file_mode),
138 	fsparam_u32("dirmode", Opt_dirmode),
139 	fsparam_u32("dir_mode", Opt_dirmode),
140 	fsparam_u32("port", Opt_port),
141 	fsparam_u32("min_enc_offload", Opt_min_enc_offload),
142 	fsparam_u32("esize", Opt_min_enc_offload),
143 	fsparam_u32("bsize", Opt_blocksize),
144 	fsparam_u32("rasize", Opt_rasize),
145 	fsparam_u32("rsize", Opt_rsize),
146 	fsparam_u32("wsize", Opt_wsize),
147 	fsparam_u32("actimeo", Opt_actimeo),
148 	fsparam_u32("acdirmax", Opt_acdirmax),
149 	fsparam_u32("acregmax", Opt_acregmax),
150 	fsparam_u32("closetimeo", Opt_closetimeo),
151 	fsparam_u32("echo_interval", Opt_echo_interval),
152 	fsparam_u32("max_credits", Opt_max_credits),
153 	fsparam_u32("max_cached_dirs", Opt_max_cached_dirs),
154 	fsparam_u32("handletimeout", Opt_handletimeout),
155 	fsparam_u64("snapshot", Opt_snapshot),
156 	fsparam_u32("max_channels", Opt_max_channels),
157 
158 	/* Mount options which take string value */
159 	fsparam_string("source", Opt_source),
160 	fsparam_string("user", Opt_user),
161 	fsparam_string("username", Opt_user),
162 	fsparam_string("pass", Opt_pass),
163 	fsparam_string("password", Opt_pass),
164 	fsparam_string("ip", Opt_ip),
165 	fsparam_string("addr", Opt_ip),
166 	fsparam_string("domain", Opt_domain),
167 	fsparam_string("dom", Opt_domain),
168 	fsparam_string("srcaddr", Opt_srcaddr),
169 	fsparam_string("iocharset", Opt_iocharset),
170 	fsparam_string("netbiosname", Opt_netbiosname),
171 	fsparam_string("servern", Opt_servern),
172 	fsparam_string("ver", Opt_ver),
173 	fsparam_string("vers", Opt_vers),
174 	fsparam_string("sec", Opt_sec),
175 	fsparam_string("cache", Opt_cache),
176 
177 	/* Arguments that should be ignored */
178 	fsparam_flag("guest", Opt_ignore),
179 	fsparam_flag("noatime", Opt_ignore),
180 	fsparam_flag("relatime", Opt_ignore),
181 	fsparam_flag("_netdev", Opt_ignore),
182 	fsparam_flag_no("suid", Opt_ignore),
183 	fsparam_flag_no("exec", Opt_ignore),
184 	fsparam_flag_no("dev", Opt_ignore),
185 	fsparam_flag_no("mand", Opt_ignore),
186 	fsparam_flag_no("auto", Opt_ignore),
187 	fsparam_string("cred", Opt_ignore),
188 	fsparam_string("credentials", Opt_ignore),
189 	/*
190 	 * UNC and prefixpath is now extracted from Opt_source
191 	 * in the new mount API so we can just ignore them going forward.
192 	 */
193 	fsparam_string("unc", Opt_ignore),
194 	fsparam_string("prefixpath", Opt_ignore),
195 	{}
196 };
197 
198 static int
199 cifs_parse_security_flavors(struct fs_context *fc, char *value, struct smb3_fs_context *ctx)
200 {
201 
202 	substring_t args[MAX_OPT_ARGS];
203 
204 	/*
205 	 * With mount options, the last one should win. Reset any existing
206 	 * settings back to default.
207 	 */
208 	ctx->sectype = Unspecified;
209 	ctx->sign = false;
210 
211 	switch (match_token(value, cifs_secflavor_tokens, args)) {
212 	case Opt_sec_krb5p:
213 		cifs_errorf(fc, "sec=krb5p is not supported!\n");
214 		return 1;
215 	case Opt_sec_krb5i:
216 		ctx->sign = true;
217 		fallthrough;
218 	case Opt_sec_krb5:
219 		ctx->sectype = Kerberos;
220 		break;
221 	case Opt_sec_ntlmsspi:
222 		ctx->sign = true;
223 		fallthrough;
224 	case Opt_sec_ntlmssp:
225 		ctx->sectype = RawNTLMSSP;
226 		break;
227 	case Opt_sec_ntlmv2i:
228 		ctx->sign = true;
229 		fallthrough;
230 	case Opt_sec_ntlmv2:
231 		ctx->sectype = NTLMv2;
232 		break;
233 	case Opt_sec_none:
234 		ctx->nullauth = 1;
235 		kfree(ctx->username);
236 		ctx->username = NULL;
237 		break;
238 	default:
239 		cifs_errorf(fc, "bad security option: %s\n", value);
240 		return 1;
241 	}
242 
243 	return 0;
244 }
245 
246 static const match_table_t cifs_cacheflavor_tokens = {
247 	{ Opt_cache_loose, "loose" },
248 	{ Opt_cache_strict, "strict" },
249 	{ Opt_cache_none, "none" },
250 	{ Opt_cache_ro, "ro" },
251 	{ Opt_cache_rw, "singleclient" },
252 	{ Opt_cache_err, NULL }
253 };
254 
255 static int
256 cifs_parse_cache_flavor(struct fs_context *fc, char *value, struct smb3_fs_context *ctx)
257 {
258 	substring_t args[MAX_OPT_ARGS];
259 
260 	switch (match_token(value, cifs_cacheflavor_tokens, args)) {
261 	case Opt_cache_loose:
262 		ctx->direct_io = false;
263 		ctx->strict_io = false;
264 		ctx->cache_ro = false;
265 		ctx->cache_rw = false;
266 		break;
267 	case Opt_cache_strict:
268 		ctx->direct_io = false;
269 		ctx->strict_io = true;
270 		ctx->cache_ro = false;
271 		ctx->cache_rw = false;
272 		break;
273 	case Opt_cache_none:
274 		ctx->direct_io = true;
275 		ctx->strict_io = false;
276 		ctx->cache_ro = false;
277 		ctx->cache_rw = false;
278 		break;
279 	case Opt_cache_ro:
280 		ctx->direct_io = false;
281 		ctx->strict_io = false;
282 		ctx->cache_ro = true;
283 		ctx->cache_rw = false;
284 		break;
285 	case Opt_cache_rw:
286 		ctx->direct_io = false;
287 		ctx->strict_io = false;
288 		ctx->cache_ro = false;
289 		ctx->cache_rw = true;
290 		break;
291 	default:
292 		cifs_errorf(fc, "bad cache= option: %s\n", value);
293 		return 1;
294 	}
295 	return 0;
296 }
297 
298 #define DUP_CTX_STR(field)						\
299 do {									\
300 	if (ctx->field) {						\
301 		new_ctx->field = kstrdup(ctx->field, GFP_ATOMIC);	\
302 		if (new_ctx->field == NULL) {				\
303 			smb3_cleanup_fs_context_contents(new_ctx);	\
304 			return -ENOMEM;					\
305 		}							\
306 	}								\
307 } while (0)
308 
309 int
310 smb3_fs_context_dup(struct smb3_fs_context *new_ctx, struct smb3_fs_context *ctx)
311 {
312 	memcpy(new_ctx, ctx, sizeof(*ctx));
313 	new_ctx->prepath = NULL;
314 	new_ctx->nodename = NULL;
315 	new_ctx->username = NULL;
316 	new_ctx->password = NULL;
317 	new_ctx->server_hostname = NULL;
318 	new_ctx->domainname = NULL;
319 	new_ctx->UNC = NULL;
320 	new_ctx->source = NULL;
321 	new_ctx->iocharset = NULL;
322 	new_ctx->leaf_fullpath = NULL;
323 	/*
324 	 * Make sure to stay in sync with smb3_cleanup_fs_context_contents()
325 	 */
326 	DUP_CTX_STR(prepath);
327 	DUP_CTX_STR(username);
328 	DUP_CTX_STR(password);
329 	DUP_CTX_STR(server_hostname);
330 	DUP_CTX_STR(UNC);
331 	DUP_CTX_STR(source);
332 	DUP_CTX_STR(domainname);
333 	DUP_CTX_STR(nodename);
334 	DUP_CTX_STR(iocharset);
335 	DUP_CTX_STR(leaf_fullpath);
336 
337 	return 0;
338 }
339 
340 static int
341 cifs_parse_smb_version(struct fs_context *fc, char *value, struct smb3_fs_context *ctx, bool is_smb3)
342 {
343 	substring_t args[MAX_OPT_ARGS];
344 
345 	switch (match_token(value, cifs_smb_version_tokens, args)) {
346 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
347 	case Smb_1:
348 		if (disable_legacy_dialects) {
349 			cifs_errorf(fc, "mount with legacy dialect disabled\n");
350 			return 1;
351 		}
352 		if (is_smb3) {
353 			cifs_errorf(fc, "vers=1.0 (cifs) not permitted when mounting with smb3\n");
354 			return 1;
355 		}
356 		cifs_errorf(fc, "Use of the less secure dialect vers=1.0 is not recommended unless required for access to very old servers\n");
357 		ctx->ops = &smb1_operations;
358 		ctx->vals = &smb1_values;
359 		break;
360 	case Smb_20:
361 		if (disable_legacy_dialects) {
362 			cifs_errorf(fc, "mount with legacy dialect disabled\n");
363 			return 1;
364 		}
365 		if (is_smb3) {
366 			cifs_errorf(fc, "vers=2.0 not permitted when mounting with smb3\n");
367 			return 1;
368 		}
369 		ctx->ops = &smb20_operations;
370 		ctx->vals = &smb20_values;
371 		break;
372 #else
373 	case Smb_1:
374 		cifs_errorf(fc, "vers=1.0 (cifs) mount not permitted when legacy dialects disabled\n");
375 		return 1;
376 	case Smb_20:
377 		cifs_errorf(fc, "vers=2.0 mount not permitted when legacy dialects disabled\n");
378 		return 1;
379 #endif /* CIFS_ALLOW_INSECURE_LEGACY */
380 	case Smb_21:
381 		ctx->ops = &smb21_operations;
382 		ctx->vals = &smb21_values;
383 		break;
384 	case Smb_30:
385 		ctx->ops = &smb30_operations;
386 		ctx->vals = &smb30_values;
387 		break;
388 	case Smb_302:
389 		ctx->ops = &smb30_operations; /* currently identical with 3.0 */
390 		ctx->vals = &smb302_values;
391 		break;
392 	case Smb_311:
393 		ctx->ops = &smb311_operations;
394 		ctx->vals = &smb311_values;
395 		break;
396 	case Smb_3any:
397 		ctx->ops = &smb30_operations; /* currently identical with 3.0 */
398 		ctx->vals = &smb3any_values;
399 		break;
400 	case Smb_default:
401 		ctx->ops = &smb30_operations;
402 		ctx->vals = &smbdefault_values;
403 		break;
404 	default:
405 		cifs_errorf(fc, "Unknown vers= option specified: %s\n", value);
406 		return 1;
407 	}
408 	return 0;
409 }
410 
411 int smb3_parse_opt(const char *options, const char *key, char **val)
412 {
413 	int rc = -ENOENT;
414 	char *opts, *orig, *p;
415 
416 	orig = opts = kstrdup(options, GFP_KERNEL);
417 	if (!opts)
418 		return -ENOMEM;
419 
420 	while ((p = strsep(&opts, ","))) {
421 		char *nval;
422 
423 		if (!*p)
424 			continue;
425 		if (strncasecmp(p, key, strlen(key)))
426 			continue;
427 		nval = strchr(p, '=');
428 		if (nval) {
429 			if (nval == p)
430 				continue;
431 			*nval++ = 0;
432 			*val = kstrdup(nval, GFP_KERNEL);
433 			rc = !*val ? -ENOMEM : 0;
434 			goto out;
435 		}
436 	}
437 out:
438 	kfree(orig);
439 	return rc;
440 }
441 
442 /*
443  * Remove duplicate path delimiters. Windows is supposed to do that
444  * but there are some bugs that prevent rename from working if there are
445  * multiple delimiters.
446  *
447  * Return a sanitized duplicate of @path or NULL for empty prefix paths.
448  * Otherwise, return ERR_PTR.
449  *
450  * @gfp indicates the GFP_* flags for kstrdup.
451  * The caller is responsible for freeing the original.
452  */
453 #define IS_DELIM(c) ((c) == '/' || (c) == '\\')
454 char *cifs_sanitize_prepath(char *prepath, gfp_t gfp)
455 {
456 	char *cursor1 = prepath, *cursor2 = prepath;
457 	char *s;
458 
459 	/* skip all prepended delimiters */
460 	while (IS_DELIM(*cursor1))
461 		cursor1++;
462 
463 	/* copy the first letter */
464 	*cursor2 = *cursor1;
465 
466 	/* copy the remainder... */
467 	while (*(cursor1++)) {
468 		/* ... skipping all duplicated delimiters */
469 		if (IS_DELIM(*cursor1) && IS_DELIM(*cursor2))
470 			continue;
471 		*(++cursor2) = *cursor1;
472 	}
473 
474 	/* if the last character is a delimiter, skip it */
475 	if (IS_DELIM(*(cursor2 - 1)))
476 		cursor2--;
477 
478 	*cursor2 = '\0';
479 	if (!*prepath)
480 		return NULL;
481 	s = kstrdup(prepath, gfp);
482 	if (!s)
483 		return ERR_PTR(-ENOMEM);
484 	return s;
485 }
486 
487 /*
488  * Return full path based on the values of @ctx->{UNC,prepath}.
489  *
490  * It is assumed that both values were already parsed by smb3_parse_devname().
491  */
492 char *smb3_fs_context_fullpath(const struct smb3_fs_context *ctx, char dirsep)
493 {
494 	size_t ulen, plen;
495 	char *s;
496 
497 	ulen = strlen(ctx->UNC);
498 	plen = ctx->prepath ? strlen(ctx->prepath) + 1 : 0;
499 
500 	s = kmalloc(ulen + plen + 1, GFP_KERNEL);
501 	if (!s)
502 		return ERR_PTR(-ENOMEM);
503 	memcpy(s, ctx->UNC, ulen);
504 	if (plen) {
505 		s[ulen] = dirsep;
506 		memcpy(s + ulen + 1, ctx->prepath, plen);
507 	}
508 	s[ulen + plen] = '\0';
509 	convert_delimiter(s, dirsep);
510 	return s;
511 }
512 
513 /*
514  * Parse a devname into substrings and populate the ctx->UNC and ctx->prepath
515  * fields with the result. Returns 0 on success and an error otherwise
516  * (e.g. ENOMEM or EINVAL)
517  */
518 int
519 smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx)
520 {
521 	char *pos;
522 	const char *delims = "/\\";
523 	size_t len;
524 	int rc;
525 
526 	if (unlikely(!devname || !*devname)) {
527 		cifs_dbg(VFS, "Device name not specified\n");
528 		return -EINVAL;
529 	}
530 
531 	/* make sure we have a valid UNC double delimiter prefix */
532 	len = strspn(devname, delims);
533 	if (len != 2)
534 		return -EINVAL;
535 
536 	/* find delimiter between host and sharename */
537 	pos = strpbrk(devname + 2, delims);
538 	if (!pos)
539 		return -EINVAL;
540 
541 	/* record the server hostname */
542 	kfree(ctx->server_hostname);
543 	ctx->server_hostname = kstrndup(devname + 2, pos - devname - 2, GFP_KERNEL);
544 	if (!ctx->server_hostname)
545 		return -ENOMEM;
546 
547 	/* skip past delimiter */
548 	++pos;
549 
550 	/* now go until next delimiter or end of string */
551 	len = strcspn(pos, delims);
552 	if (!len)
553 		return -EINVAL;
554 
555 	/* move "pos" up to delimiter or NULL */
556 	pos += len;
557 	kfree(ctx->UNC);
558 	ctx->UNC = kstrndup(devname, pos - devname, GFP_KERNEL);
559 	if (!ctx->UNC)
560 		return -ENOMEM;
561 
562 	convert_delimiter(ctx->UNC, '\\');
563 
564 	/* skip any delimiter */
565 	if (*pos == '/' || *pos == '\\')
566 		pos++;
567 
568 	kfree(ctx->prepath);
569 	ctx->prepath = NULL;
570 
571 	/* If pos is NULL then no prepath */
572 	if (!*pos)
573 		return 0;
574 
575 	ctx->prepath = cifs_sanitize_prepath(pos, GFP_KERNEL);
576 	if (IS_ERR(ctx->prepath)) {
577 		rc = PTR_ERR(ctx->prepath);
578 		ctx->prepath = NULL;
579 		return rc;
580 	}
581 
582 	return 0;
583 }
584 
585 static void smb3_fs_context_free(struct fs_context *fc);
586 static int smb3_fs_context_parse_param(struct fs_context *fc,
587 				       struct fs_parameter *param);
588 static int smb3_fs_context_parse_monolithic(struct fs_context *fc,
589 					    void *data);
590 static int smb3_get_tree(struct fs_context *fc);
591 static int smb3_reconfigure(struct fs_context *fc);
592 
593 static const struct fs_context_operations smb3_fs_context_ops = {
594 	.free			= smb3_fs_context_free,
595 	.parse_param		= smb3_fs_context_parse_param,
596 	.parse_monolithic	= smb3_fs_context_parse_monolithic,
597 	.get_tree		= smb3_get_tree,
598 	.reconfigure		= smb3_reconfigure,
599 };
600 
601 /*
602  * Parse a monolithic block of data from sys_mount().
603  * smb3_fs_context_parse_monolithic - Parse key[=val][,key[=val]]* mount data
604  * @ctx: The superblock configuration to fill in.
605  * @data: The data to parse
606  *
607  * Parse a blob of data that's in key[=val][,key[=val]]* form.  This can be
608  * called from the ->monolithic_mount_data() fs_context operation.
609  *
610  * Returns 0 on success or the error returned by the ->parse_option() fs_context
611  * operation on failure.
612  */
613 static int smb3_fs_context_parse_monolithic(struct fs_context *fc,
614 					   void *data)
615 {
616 	char *options = data, *key;
617 	int ret = 0;
618 
619 	if (!options)
620 		return 0;
621 
622 	ret = security_sb_eat_lsm_opts(options, &fc->security);
623 	if (ret)
624 		return ret;
625 
626 	/* BB Need to add support for sep= here TBD */
627 	while ((key = strsep(&options, ",")) != NULL) {
628 		size_t len;
629 		char *value;
630 
631 		if (*key == 0)
632 			break;
633 
634 		/* Check if following character is the deliminator If yes,
635 		 * we have encountered a double deliminator reset the NULL
636 		 * character to the deliminator
637 		 */
638 		while (options && options[0] == ',') {
639 			len = strlen(key);
640 			strcpy(key + len, options);
641 			options = strchr(options, ',');
642 			if (options)
643 				*options++ = 0;
644 		}
645 
646 
647 		len = 0;
648 		value = strchr(key, '=');
649 		if (value) {
650 			if (value == key)
651 				continue;
652 			*value++ = 0;
653 			len = strlen(value);
654 		}
655 
656 		ret = vfs_parse_fs_string(fc, key, value, len);
657 		if (ret < 0)
658 			break;
659 	}
660 
661 	return ret;
662 }
663 
664 /*
665  * Validate the preparsed information in the config.
666  */
667 static int smb3_fs_context_validate(struct fs_context *fc)
668 {
669 	struct smb3_fs_context *ctx = smb3_fc2context(fc);
670 
671 	if (ctx->rdma && ctx->vals->protocol_id < SMB30_PROT_ID) {
672 		cifs_errorf(fc, "SMB Direct requires Version >=3.0\n");
673 		return -EOPNOTSUPP;
674 	}
675 
676 #ifndef CONFIG_KEYS
677 	/* Muliuser mounts require CONFIG_KEYS support */
678 	if (ctx->multiuser) {
679 		cifs_errorf(fc, "Multiuser mounts require kernels with CONFIG_KEYS enabled\n");
680 		return -1;
681 	}
682 #endif
683 
684 	if (ctx->got_version == false)
685 		pr_warn_once("No dialect specified on mount. Default has changed to a more secure dialect, SMB2.1 or later (e.g. SMB3.1.1), from CIFS (SMB1). To use the less secure SMB1 dialect to access old servers which do not support SMB3.1.1 (or even SMB3 or SMB2.1) specify vers=1.0 on mount.\n");
686 
687 
688 	if (!ctx->UNC) {
689 		cifs_errorf(fc, "CIFS mount error: No usable UNC path provided in device string!\n");
690 		return -1;
691 	}
692 
693 	/* make sure UNC has a share name */
694 	if (strlen(ctx->UNC) < 3 || !strchr(ctx->UNC + 3, '\\')) {
695 		cifs_errorf(fc, "Malformed UNC. Unable to find share name.\n");
696 		return -ENOENT;
697 	}
698 
699 	if (!ctx->got_ip) {
700 		int len;
701 		const char *slash;
702 
703 		/* No ip= option specified? Try to get it from UNC */
704 		/* Use the address part of the UNC. */
705 		slash = strchr(&ctx->UNC[2], '\\');
706 		len = slash - &ctx->UNC[2];
707 		if (!cifs_convert_address((struct sockaddr *)&ctx->dstaddr,
708 					  &ctx->UNC[2], len)) {
709 			pr_err("Unable to determine destination address\n");
710 			return -EHOSTUNREACH;
711 		}
712 	}
713 
714 	/* set the port that we got earlier */
715 	cifs_set_port((struct sockaddr *)&ctx->dstaddr, ctx->port);
716 
717 	if (ctx->override_uid && !ctx->uid_specified) {
718 		ctx->override_uid = 0;
719 		pr_notice("ignoring forceuid mount option specified with no uid= option\n");
720 	}
721 
722 	if (ctx->override_gid && !ctx->gid_specified) {
723 		ctx->override_gid = 0;
724 		pr_notice("ignoring forcegid mount option specified with no gid= option\n");
725 	}
726 
727 	return 0;
728 }
729 
730 static int smb3_get_tree_common(struct fs_context *fc)
731 {
732 	struct smb3_fs_context *ctx = smb3_fc2context(fc);
733 	struct dentry *root;
734 	int rc = 0;
735 
736 	root = cifs_smb3_do_mount(fc->fs_type, 0, ctx);
737 	if (IS_ERR(root))
738 		return PTR_ERR(root);
739 
740 	fc->root = root;
741 
742 	return rc;
743 }
744 
745 /*
746  * Create an SMB3 superblock from the parameters passed.
747  */
748 static int smb3_get_tree(struct fs_context *fc)
749 {
750 	int err = smb3_fs_context_validate(fc);
751 	int ret;
752 
753 	if (err)
754 		return err;
755 	mutex_lock(&cifs_mount_mutex);
756 	ret = smb3_get_tree_common(fc);
757 	mutex_unlock(&cifs_mount_mutex);
758 	return ret;
759 }
760 
761 static void smb3_fs_context_free(struct fs_context *fc)
762 {
763 	struct smb3_fs_context *ctx = smb3_fc2context(fc);
764 
765 	smb3_cleanup_fs_context(ctx);
766 }
767 
768 /*
769  * Compare the old and new proposed context during reconfigure
770  * and check if the changes are compatible.
771  */
772 static int smb3_verify_reconfigure_ctx(struct fs_context *fc,
773 				       struct smb3_fs_context *new_ctx,
774 				       struct smb3_fs_context *old_ctx)
775 {
776 	if (new_ctx->posix_paths != old_ctx->posix_paths) {
777 		cifs_errorf(fc, "can not change posixpaths during remount\n");
778 		return -EINVAL;
779 	}
780 	if (new_ctx->sectype != old_ctx->sectype) {
781 		cifs_errorf(fc, "can not change sec during remount\n");
782 		return -EINVAL;
783 	}
784 	if (new_ctx->multiuser != old_ctx->multiuser) {
785 		cifs_errorf(fc, "can not change multiuser during remount\n");
786 		return -EINVAL;
787 	}
788 	if (new_ctx->UNC &&
789 	    (!old_ctx->UNC || strcmp(new_ctx->UNC, old_ctx->UNC))) {
790 		cifs_errorf(fc, "can not change UNC during remount\n");
791 		return -EINVAL;
792 	}
793 	if (new_ctx->username &&
794 	    (!old_ctx->username || strcmp(new_ctx->username, old_ctx->username))) {
795 		cifs_errorf(fc, "can not change username during remount\n");
796 		return -EINVAL;
797 	}
798 	if (new_ctx->password &&
799 	    (!old_ctx->password || strcmp(new_ctx->password, old_ctx->password))) {
800 		cifs_errorf(fc, "can not change password during remount\n");
801 		return -EINVAL;
802 	}
803 	if (new_ctx->domainname &&
804 	    (!old_ctx->domainname || strcmp(new_ctx->domainname, old_ctx->domainname))) {
805 		cifs_errorf(fc, "can not change domainname during remount\n");
806 		return -EINVAL;
807 	}
808 	if (strcmp(new_ctx->workstation_name, old_ctx->workstation_name)) {
809 		cifs_errorf(fc, "can not change workstation_name during remount\n");
810 		return -EINVAL;
811 	}
812 	if (new_ctx->nodename &&
813 	    (!old_ctx->nodename || strcmp(new_ctx->nodename, old_ctx->nodename))) {
814 		cifs_errorf(fc, "can not change nodename during remount\n");
815 		return -EINVAL;
816 	}
817 	if (new_ctx->iocharset &&
818 	    (!old_ctx->iocharset || strcmp(new_ctx->iocharset, old_ctx->iocharset))) {
819 		cifs_errorf(fc, "can not change iocharset during remount\n");
820 		return -EINVAL;
821 	}
822 
823 	return 0;
824 }
825 
826 #define STEAL_STRING(cifs_sb, ctx, field)				\
827 do {									\
828 	kfree(ctx->field);						\
829 	ctx->field = cifs_sb->ctx->field;				\
830 	cifs_sb->ctx->field = NULL;					\
831 } while (0)
832 
833 #define STEAL_STRING_SENSITIVE(cifs_sb, ctx, field)			\
834 do {									\
835 	kfree_sensitive(ctx->field);					\
836 	ctx->field = cifs_sb->ctx->field;				\
837 	cifs_sb->ctx->field = NULL;					\
838 } while (0)
839 
840 static int smb3_reconfigure(struct fs_context *fc)
841 {
842 	struct smb3_fs_context *ctx = smb3_fc2context(fc);
843 	struct dentry *root = fc->root;
844 	struct cifs_sb_info *cifs_sb = CIFS_SB(root->d_sb);
845 	int rc;
846 
847 	rc = smb3_verify_reconfigure_ctx(fc, ctx, cifs_sb->ctx);
848 	if (rc)
849 		return rc;
850 
851 	/*
852 	 * We can not change UNC/username/password/domainname/
853 	 * workstation_name/nodename/iocharset
854 	 * during reconnect so ignore what we have in the new context and
855 	 * just use what we already have in cifs_sb->ctx.
856 	 */
857 	STEAL_STRING(cifs_sb, ctx, UNC);
858 	STEAL_STRING(cifs_sb, ctx, source);
859 	STEAL_STRING(cifs_sb, ctx, username);
860 	STEAL_STRING_SENSITIVE(cifs_sb, ctx, password);
861 	STEAL_STRING(cifs_sb, ctx, domainname);
862 	STEAL_STRING(cifs_sb, ctx, nodename);
863 	STEAL_STRING(cifs_sb, ctx, iocharset);
864 
865 	/* if rsize or wsize not passed in on remount, use previous values */
866 	if (ctx->rsize == 0)
867 		ctx->rsize = cifs_sb->ctx->rsize;
868 	if (ctx->wsize == 0)
869 		ctx->wsize = cifs_sb->ctx->wsize;
870 
871 
872 	smb3_cleanup_fs_context_contents(cifs_sb->ctx);
873 	rc = smb3_fs_context_dup(cifs_sb->ctx, ctx);
874 	smb3_update_mnt_flags(cifs_sb);
875 #ifdef CONFIG_CIFS_DFS_UPCALL
876 	if (!rc)
877 		rc = dfs_cache_remount_fs(cifs_sb);
878 #endif
879 
880 	return rc;
881 }
882 
883 static int smb3_fs_context_parse_param(struct fs_context *fc,
884 				      struct fs_parameter *param)
885 {
886 	struct fs_parse_result result;
887 	struct smb3_fs_context *ctx = smb3_fc2context(fc);
888 	int i, opt;
889 	bool is_smb3 = !strcmp(fc->fs_type->name, "smb3");
890 	bool skip_parsing = false;
891 	kuid_t uid;
892 	kgid_t gid;
893 
894 	cifs_dbg(FYI, "CIFS: parsing cifs mount option '%s'\n", param->key);
895 
896 	/*
897 	 * fs_parse can not handle string options with an empty value so
898 	 * we will need special handling of them.
899 	 */
900 	if (param->type == fs_value_is_string && param->string[0] == 0) {
901 		if (!strcmp("pass", param->key) || !strcmp("password", param->key)) {
902 			skip_parsing = true;
903 			opt = Opt_pass;
904 		} else if (!strcmp("user", param->key) || !strcmp("username", param->key)) {
905 			skip_parsing = true;
906 			opt = Opt_user;
907 		}
908 	}
909 
910 	if (!skip_parsing) {
911 		opt = fs_parse(fc, smb3_fs_parameters, param, &result);
912 		if (opt < 0)
913 			return ctx->sloppy ? 1 : opt;
914 	}
915 
916 	switch (opt) {
917 	case Opt_compress:
918 		ctx->compression = UNKNOWN_TYPE;
919 		cifs_dbg(VFS,
920 			"SMB3 compression support is experimental\n");
921 		break;
922 	case Opt_nodfs:
923 		ctx->nodfs = 1;
924 		break;
925 	case Opt_hard:
926 		if (result.negated) {
927 			if (ctx->retry == 1)
928 				cifs_dbg(VFS, "conflicting hard vs. soft mount options\n");
929 			ctx->retry = 0;
930 		} else
931 			ctx->retry = 1;
932 		break;
933 	case Opt_soft:
934 		if (result.negated)
935 			ctx->retry = 1;
936 		else {
937 			if (ctx->retry == 1)
938 				cifs_dbg(VFS, "conflicting hard vs soft mount options\n");
939 			ctx->retry = 0;
940 		}
941 		break;
942 	case Opt_mapposix:
943 		if (result.negated)
944 			ctx->remap = false;
945 		else {
946 			ctx->remap = true;
947 			ctx->sfu_remap = false; /* disable SFU mapping */
948 		}
949 		break;
950 	case Opt_mapchars:
951 		if (result.negated)
952 			ctx->sfu_remap = false;
953 		else {
954 			ctx->sfu_remap = true;
955 			ctx->remap = false; /* disable SFM (mapposix) mapping */
956 		}
957 		break;
958 	case Opt_user_xattr:
959 		if (result.negated)
960 			ctx->no_xattr = 1;
961 		else
962 			ctx->no_xattr = 0;
963 		break;
964 	case Opt_forceuid:
965 		if (result.negated)
966 			ctx->override_uid = 0;
967 		else
968 			ctx->override_uid = 1;
969 		break;
970 	case Opt_forcegid:
971 		if (result.negated)
972 			ctx->override_gid = 0;
973 		else
974 			ctx->override_gid = 1;
975 		break;
976 	case Opt_perm:
977 		if (result.negated)
978 			ctx->noperm = 1;
979 		else
980 			ctx->noperm = 0;
981 		break;
982 	case Opt_dynperm:
983 		if (result.negated)
984 			ctx->dynperm = 0;
985 		else
986 			ctx->dynperm = 1;
987 		break;
988 	case Opt_sfu:
989 		if (result.negated)
990 			ctx->sfu_emul = 0;
991 		else
992 			ctx->sfu_emul = 1;
993 		break;
994 	case Opt_noblocksend:
995 		ctx->noblocksnd = 1;
996 		break;
997 	case Opt_noautotune:
998 		ctx->noautotune = 1;
999 		break;
1000 	case Opt_nolease:
1001 		ctx->no_lease = 1;
1002 		break;
1003 	case Opt_nosparse:
1004 		ctx->no_sparse = 1;
1005 		break;
1006 	case Opt_nodelete:
1007 		ctx->nodelete = 1;
1008 		break;
1009 	case Opt_multichannel:
1010 		if (result.negated) {
1011 			ctx->multichannel = false;
1012 			ctx->max_channels = 1;
1013 		} else {
1014 			ctx->multichannel = true;
1015 			/* if number of channels not specified, default to 2 */
1016 			if (ctx->max_channels < 2)
1017 				ctx->max_channels = 2;
1018 		}
1019 		break;
1020 	case Opt_uid:
1021 		uid = make_kuid(current_user_ns(), result.uint_32);
1022 		if (!uid_valid(uid))
1023 			goto cifs_parse_mount_err;
1024 		ctx->linux_uid = uid;
1025 		ctx->uid_specified = true;
1026 		break;
1027 	case Opt_cruid:
1028 		uid = make_kuid(current_user_ns(), result.uint_32);
1029 		if (!uid_valid(uid))
1030 			goto cifs_parse_mount_err;
1031 		ctx->cred_uid = uid;
1032 		ctx->cruid_specified = true;
1033 		break;
1034 	case Opt_backupuid:
1035 		uid = make_kuid(current_user_ns(), result.uint_32);
1036 		if (!uid_valid(uid))
1037 			goto cifs_parse_mount_err;
1038 		ctx->backupuid = uid;
1039 		ctx->backupuid_specified = true;
1040 		break;
1041 	case Opt_backupgid:
1042 		gid = make_kgid(current_user_ns(), result.uint_32);
1043 		if (!gid_valid(gid))
1044 			goto cifs_parse_mount_err;
1045 		ctx->backupgid = gid;
1046 		ctx->backupgid_specified = true;
1047 		break;
1048 	case Opt_gid:
1049 		gid = make_kgid(current_user_ns(), result.uint_32);
1050 		if (!gid_valid(gid))
1051 			goto cifs_parse_mount_err;
1052 		ctx->linux_gid = gid;
1053 		ctx->gid_specified = true;
1054 		break;
1055 	case Opt_port:
1056 		ctx->port = result.uint_32;
1057 		break;
1058 	case Opt_file_mode:
1059 		ctx->file_mode = result.uint_32;
1060 		break;
1061 	case Opt_dirmode:
1062 		ctx->dir_mode = result.uint_32;
1063 		break;
1064 	case Opt_min_enc_offload:
1065 		ctx->min_offload = result.uint_32;
1066 		break;
1067 	case Opt_blocksize:
1068 		/*
1069 		 * inode blocksize realistically should never need to be
1070 		 * less than 16K or greater than 16M and default is 1MB.
1071 		 * Note that small inode block sizes (e.g. 64K) can lead
1072 		 * to very poor performance of common tools like cp and scp
1073 		 */
1074 		if ((result.uint_32 < CIFS_MAX_MSGSIZE) ||
1075 		   (result.uint_32 > (4 * SMB3_DEFAULT_IOSIZE))) {
1076 			cifs_errorf(fc, "%s: Invalid blocksize\n",
1077 				__func__);
1078 			goto cifs_parse_mount_err;
1079 		}
1080 		ctx->bsize = result.uint_32;
1081 		ctx->got_bsize = true;
1082 		break;
1083 	case Opt_rasize:
1084 		/*
1085 		 * readahead size realistically should never need to be
1086 		 * less than 1M (CIFS_DEFAULT_IOSIZE) or greater than 32M
1087 		 * (perhaps an exception should be considered in the
1088 		 * for the case of a large number of channels
1089 		 * when multichannel is negotiated) since that would lead
1090 		 * to plenty of parallel I/O in flight to the server.
1091 		 * Note that smaller read ahead sizes would
1092 		 * hurt performance of common tools like cp and scp
1093 		 * which often trigger sequential i/o with read ahead
1094 		 */
1095 		if ((result.uint_32 > (8 * SMB3_DEFAULT_IOSIZE)) ||
1096 		    (result.uint_32 < CIFS_DEFAULT_IOSIZE)) {
1097 			cifs_errorf(fc, "%s: Invalid rasize %d vs. %d\n",
1098 				__func__, result.uint_32, SMB3_DEFAULT_IOSIZE);
1099 			goto cifs_parse_mount_err;
1100 		}
1101 		ctx->rasize = result.uint_32;
1102 		break;
1103 	case Opt_rsize:
1104 		ctx->rsize = result.uint_32;
1105 		ctx->got_rsize = true;
1106 		break;
1107 	case Opt_wsize:
1108 		ctx->wsize = result.uint_32;
1109 		ctx->got_wsize = true;
1110 		break;
1111 	case Opt_acregmax:
1112 		ctx->acregmax = HZ * result.uint_32;
1113 		if (ctx->acregmax > CIFS_MAX_ACTIMEO) {
1114 			cifs_errorf(fc, "acregmax too large\n");
1115 			goto cifs_parse_mount_err;
1116 		}
1117 		break;
1118 	case Opt_acdirmax:
1119 		ctx->acdirmax = HZ * result.uint_32;
1120 		if (ctx->acdirmax > CIFS_MAX_ACTIMEO) {
1121 			cifs_errorf(fc, "acdirmax too large\n");
1122 			goto cifs_parse_mount_err;
1123 		}
1124 		break;
1125 	case Opt_actimeo:
1126 		if (HZ * result.uint_32 > CIFS_MAX_ACTIMEO) {
1127 			cifs_errorf(fc, "timeout too large\n");
1128 			goto cifs_parse_mount_err;
1129 		}
1130 		if ((ctx->acdirmax != CIFS_DEF_ACTIMEO) ||
1131 		    (ctx->acregmax != CIFS_DEF_ACTIMEO)) {
1132 			cifs_errorf(fc, "actimeo ignored since acregmax or acdirmax specified\n");
1133 			break;
1134 		}
1135 		ctx->acdirmax = ctx->acregmax = HZ * result.uint_32;
1136 		break;
1137 	case Opt_closetimeo:
1138 		ctx->closetimeo = HZ * result.uint_32;
1139 		if (ctx->closetimeo > SMB3_MAX_DCLOSETIMEO) {
1140 			cifs_errorf(fc, "closetimeo too large\n");
1141 			goto cifs_parse_mount_err;
1142 		}
1143 		break;
1144 	case Opt_echo_interval:
1145 		ctx->echo_interval = result.uint_32;
1146 		break;
1147 	case Opt_snapshot:
1148 		ctx->snapshot_time = result.uint_64;
1149 		break;
1150 	case Opt_max_credits:
1151 		if (result.uint_32 < 20 || result.uint_32 > 60000) {
1152 			cifs_errorf(fc, "%s: Invalid max_credits value\n",
1153 				 __func__);
1154 			goto cifs_parse_mount_err;
1155 		}
1156 		ctx->max_credits = result.uint_32;
1157 		break;
1158 	case Opt_max_channels:
1159 		if (result.uint_32 < 1 || result.uint_32 > CIFS_MAX_CHANNELS) {
1160 			cifs_errorf(fc, "%s: Invalid max_channels value, needs to be 1-%d\n",
1161 				 __func__, CIFS_MAX_CHANNELS);
1162 			goto cifs_parse_mount_err;
1163 		}
1164 		ctx->max_channels = result.uint_32;
1165 		/* If more than one channel requested ... they want multichan */
1166 		if (result.uint_32 > 1)
1167 			ctx->multichannel = true;
1168 		break;
1169 	case Opt_max_cached_dirs:
1170 		if (result.uint_32 < 1) {
1171 			cifs_errorf(fc, "%s: Invalid max_cached_dirs, needs to be 1 or more\n",
1172 				    __func__);
1173 			goto cifs_parse_mount_err;
1174 		}
1175 		ctx->max_cached_dirs = result.uint_32;
1176 		break;
1177 	case Opt_handletimeout:
1178 		ctx->handle_timeout = result.uint_32;
1179 		if (ctx->handle_timeout > SMB3_MAX_HANDLE_TIMEOUT) {
1180 			cifs_errorf(fc, "Invalid handle cache timeout, longer than 16 minutes\n");
1181 			goto cifs_parse_mount_err;
1182 		}
1183 		break;
1184 	case Opt_source:
1185 		kfree(ctx->UNC);
1186 		ctx->UNC = NULL;
1187 		switch (smb3_parse_devname(param->string, ctx)) {
1188 		case 0:
1189 			break;
1190 		case -ENOMEM:
1191 			cifs_errorf(fc, "Unable to allocate memory for devname\n");
1192 			goto cifs_parse_mount_err;
1193 		case -EINVAL:
1194 			cifs_errorf(fc, "Malformed UNC in devname\n");
1195 			goto cifs_parse_mount_err;
1196 		default:
1197 			cifs_errorf(fc, "Unknown error parsing devname\n");
1198 			goto cifs_parse_mount_err;
1199 		}
1200 		ctx->source = smb3_fs_context_fullpath(ctx, '/');
1201 		if (IS_ERR(ctx->source)) {
1202 			ctx->source = NULL;
1203 			cifs_errorf(fc, "OOM when copying UNC string\n");
1204 			goto cifs_parse_mount_err;
1205 		}
1206 		fc->source = kstrdup(ctx->source, GFP_KERNEL);
1207 		if (fc->source == NULL) {
1208 			cifs_errorf(fc, "OOM when copying UNC string\n");
1209 			goto cifs_parse_mount_err;
1210 		}
1211 		break;
1212 	case Opt_user:
1213 		kfree(ctx->username);
1214 		ctx->username = NULL;
1215 		if (ctx->nullauth)
1216 			break;
1217 		if (strlen(param->string) == 0) {
1218 			/* null user, ie. anonymous authentication */
1219 			ctx->nullauth = 1;
1220 			break;
1221 		}
1222 
1223 		if (strnlen(param->string, CIFS_MAX_USERNAME_LEN) >
1224 		    CIFS_MAX_USERNAME_LEN) {
1225 			pr_warn("username too long\n");
1226 			goto cifs_parse_mount_err;
1227 		}
1228 		ctx->username = kstrdup(param->string, GFP_KERNEL);
1229 		if (ctx->username == NULL) {
1230 			cifs_errorf(fc, "OOM when copying username string\n");
1231 			goto cifs_parse_mount_err;
1232 		}
1233 		break;
1234 	case Opt_pass:
1235 		kfree_sensitive(ctx->password);
1236 		ctx->password = NULL;
1237 		if (strlen(param->string) == 0)
1238 			break;
1239 
1240 		ctx->password = kstrdup(param->string, GFP_KERNEL);
1241 		if (ctx->password == NULL) {
1242 			cifs_errorf(fc, "OOM when copying password string\n");
1243 			goto cifs_parse_mount_err;
1244 		}
1245 		break;
1246 	case Opt_ip:
1247 		if (strlen(param->string) == 0) {
1248 			ctx->got_ip = false;
1249 			break;
1250 		}
1251 		if (!cifs_convert_address((struct sockaddr *)&ctx->dstaddr,
1252 					  param->string,
1253 					  strlen(param->string))) {
1254 			pr_err("bad ip= option (%s)\n", param->string);
1255 			goto cifs_parse_mount_err;
1256 		}
1257 		ctx->got_ip = true;
1258 		break;
1259 	case Opt_domain:
1260 		if (strnlen(param->string, CIFS_MAX_DOMAINNAME_LEN)
1261 				== CIFS_MAX_DOMAINNAME_LEN) {
1262 			pr_warn("domain name too long\n");
1263 			goto cifs_parse_mount_err;
1264 		}
1265 
1266 		kfree(ctx->domainname);
1267 		ctx->domainname = kstrdup(param->string, GFP_KERNEL);
1268 		if (ctx->domainname == NULL) {
1269 			cifs_errorf(fc, "OOM when copying domainname string\n");
1270 			goto cifs_parse_mount_err;
1271 		}
1272 		cifs_dbg(FYI, "Domain name set\n");
1273 		break;
1274 	case Opt_srcaddr:
1275 		if (!cifs_convert_address(
1276 				(struct sockaddr *)&ctx->srcaddr,
1277 				param->string, strlen(param->string))) {
1278 			pr_warn("Could not parse srcaddr: %s\n",
1279 				param->string);
1280 			goto cifs_parse_mount_err;
1281 		}
1282 		break;
1283 	case Opt_iocharset:
1284 		if (strnlen(param->string, 1024) >= 65) {
1285 			pr_warn("iocharset name too long\n");
1286 			goto cifs_parse_mount_err;
1287 		}
1288 
1289 		if (strncasecmp(param->string, "default", 7) != 0) {
1290 			kfree(ctx->iocharset);
1291 			ctx->iocharset = kstrdup(param->string, GFP_KERNEL);
1292 			if (ctx->iocharset == NULL) {
1293 				cifs_errorf(fc, "OOM when copying iocharset string\n");
1294 				goto cifs_parse_mount_err;
1295 			}
1296 		}
1297 		/* if iocharset not set then load_nls_default
1298 		 * is used by caller
1299 		 */
1300 		cifs_dbg(FYI, "iocharset set to %s\n", ctx->iocharset);
1301 		break;
1302 	case Opt_netbiosname:
1303 		memset(ctx->source_rfc1001_name, 0x20,
1304 			RFC1001_NAME_LEN);
1305 		/*
1306 		 * FIXME: are there cases in which a comma can
1307 		 * be valid in workstation netbios name (and
1308 		 * need special handling)?
1309 		 */
1310 		for (i = 0; i < RFC1001_NAME_LEN; i++) {
1311 			/* don't ucase netbiosname for user */
1312 			if (param->string[i] == 0)
1313 				break;
1314 			ctx->source_rfc1001_name[i] = param->string[i];
1315 		}
1316 		/* The string has 16th byte zero still from
1317 		 * set at top of the function
1318 		 */
1319 		if (i == RFC1001_NAME_LEN && param->string[i] != 0)
1320 			pr_warn("netbiosname longer than 15 truncated\n");
1321 		break;
1322 	case Opt_servern:
1323 		/* last byte, type, is 0x20 for servr type */
1324 		memset(ctx->target_rfc1001_name, 0x20,
1325 			RFC1001_NAME_LEN_WITH_NULL);
1326 		/*
1327 		 * BB are there cases in which a comma can be valid in this
1328 		 * workstation netbios name (and need special handling)?
1329 		 */
1330 
1331 		/* user or mount helper must uppercase the netbios name */
1332 		for (i = 0; i < 15; i++) {
1333 			if (param->string[i] == 0)
1334 				break;
1335 			ctx->target_rfc1001_name[i] = param->string[i];
1336 		}
1337 
1338 		/* The string has 16th byte zero still from set at top of function */
1339 		if (i == RFC1001_NAME_LEN && param->string[i] != 0)
1340 			pr_warn("server netbiosname longer than 15 truncated\n");
1341 		break;
1342 	case Opt_ver:
1343 		/* version of mount userspace tools, not dialect */
1344 		/* If interface changes in mount.cifs bump to new ver */
1345 		if (strncasecmp(param->string, "1", 1) == 0) {
1346 			if (strlen(param->string) > 1) {
1347 				pr_warn("Bad mount helper ver=%s. Did you want SMB1 (CIFS) dialect and mean to type vers=1.0 instead?\n",
1348 					param->string);
1349 				goto cifs_parse_mount_err;
1350 			}
1351 			/* This is the default */
1352 			break;
1353 		}
1354 		/* For all other value, error */
1355 		pr_warn("Invalid mount helper version specified\n");
1356 		goto cifs_parse_mount_err;
1357 	case Opt_vers:
1358 		/* protocol version (dialect) */
1359 		if (cifs_parse_smb_version(fc, param->string, ctx, is_smb3) != 0)
1360 			goto cifs_parse_mount_err;
1361 		ctx->got_version = true;
1362 		break;
1363 	case Opt_sec:
1364 		if (cifs_parse_security_flavors(fc, param->string, ctx) != 0)
1365 			goto cifs_parse_mount_err;
1366 		break;
1367 	case Opt_cache:
1368 		if (cifs_parse_cache_flavor(fc, param->string, ctx) != 0)
1369 			goto cifs_parse_mount_err;
1370 		break;
1371 	case Opt_witness:
1372 #ifndef CONFIG_CIFS_SWN_UPCALL
1373 		cifs_errorf(fc, "Witness support needs CONFIG_CIFS_SWN_UPCALL config option\n");
1374 			goto cifs_parse_mount_err;
1375 #endif
1376 		ctx->witness = true;
1377 		pr_warn_once("Witness protocol support is experimental\n");
1378 		break;
1379 	case Opt_rootfs:
1380 #ifndef CONFIG_CIFS_ROOT
1381 		cifs_dbg(VFS, "rootfs support requires CONFIG_CIFS_ROOT config option\n");
1382 		goto cifs_parse_mount_err;
1383 #endif
1384 		ctx->rootfs = true;
1385 		break;
1386 	case Opt_posixpaths:
1387 		if (result.negated)
1388 			ctx->posix_paths = 0;
1389 		else
1390 			ctx->posix_paths = 1;
1391 		break;
1392 	case Opt_unix:
1393 		if (result.negated) {
1394 			if (ctx->linux_ext == 1)
1395 				pr_warn_once("conflicting posix mount options specified\n");
1396 			ctx->linux_ext = 0;
1397 			ctx->no_linux_ext = 1;
1398 		} else {
1399 			if (ctx->no_linux_ext == 1)
1400 				pr_warn_once("conflicting posix mount options specified\n");
1401 			ctx->linux_ext = 1;
1402 			ctx->no_linux_ext = 0;
1403 		}
1404 		break;
1405 	case Opt_nocase:
1406 		ctx->nocase = 1;
1407 		break;
1408 	case Opt_brl:
1409 		if (result.negated) {
1410 			/*
1411 			 * turn off mandatory locking in mode
1412 			 * if remote locking is turned off since the
1413 			 * local vfs will do advisory
1414 			 */
1415 			if (ctx->file_mode ==
1416 				(S_IALLUGO & ~(S_ISUID | S_IXGRP)))
1417 				ctx->file_mode = S_IALLUGO;
1418 			ctx->nobrl =  1;
1419 		} else
1420 			ctx->nobrl =  0;
1421 		break;
1422 	case Opt_handlecache:
1423 		if (result.negated)
1424 			ctx->nohandlecache = 1;
1425 		else
1426 			ctx->nohandlecache = 0;
1427 		break;
1428 	case Opt_forcemandatorylock:
1429 		ctx->mand_lock = 1;
1430 		break;
1431 	case Opt_setuids:
1432 		ctx->setuids = result.negated;
1433 		break;
1434 	case Opt_intr:
1435 		ctx->intr = !result.negated;
1436 		break;
1437 	case Opt_setuidfromacl:
1438 		ctx->setuidfromacl = 1;
1439 		break;
1440 	case Opt_strictsync:
1441 		ctx->nostrictsync = result.negated;
1442 		break;
1443 	case Opt_serverino:
1444 		ctx->server_ino = !result.negated;
1445 		break;
1446 	case Opt_rwpidforward:
1447 		ctx->rwpidforward = 1;
1448 		break;
1449 	case Opt_modesid:
1450 		ctx->mode_ace = 1;
1451 		break;
1452 	case Opt_cifsacl:
1453 		ctx->cifs_acl = !result.negated;
1454 		break;
1455 	case Opt_acl:
1456 		ctx->no_psx_acl = result.negated;
1457 		break;
1458 	case Opt_locallease:
1459 		ctx->local_lease = 1;
1460 		break;
1461 	case Opt_sign:
1462 		ctx->sign = true;
1463 		break;
1464 	case Opt_ignore_signature:
1465 		ctx->sign = true;
1466 		ctx->ignore_signature = true;
1467 		break;
1468 	case Opt_seal:
1469 		/* we do not do the following in secFlags because seal
1470 		 * is a per tree connection (mount) not a per socket
1471 		 * or per-smb connection option in the protocol
1472 		 * vol->secFlg |= CIFSSEC_MUST_SEAL;
1473 		 */
1474 		ctx->seal = 1;
1475 		break;
1476 	case Opt_noac:
1477 		pr_warn("Mount option noac not supported. Instead set /proc/fs/cifs/LookupCacheEnabled to 0\n");
1478 		break;
1479 	case Opt_fsc:
1480 #ifndef CONFIG_CIFS_FSCACHE
1481 		cifs_errorf(fc, "FS-Cache support needs CONFIG_CIFS_FSCACHE kernel config option set\n");
1482 		goto cifs_parse_mount_err;
1483 #endif
1484 		ctx->fsc = true;
1485 		break;
1486 	case Opt_mfsymlinks:
1487 		ctx->mfsymlinks = true;
1488 		break;
1489 	case Opt_multiuser:
1490 		ctx->multiuser = true;
1491 		break;
1492 	case Opt_sloppy:
1493 		ctx->sloppy = true;
1494 		break;
1495 	case Opt_nosharesock:
1496 		ctx->nosharesock = true;
1497 		break;
1498 	case Opt_persistent:
1499 		if (result.negated) {
1500 			ctx->nopersistent = true;
1501 			if (ctx->persistent) {
1502 				cifs_errorf(fc, "persistenthandles mount options conflict\n");
1503 				goto cifs_parse_mount_err;
1504 			}
1505 		} else {
1506 			ctx->persistent = true;
1507 			if ((ctx->nopersistent) || (ctx->resilient)) {
1508 				cifs_errorf(fc, "persistenthandles mount options conflict\n");
1509 				goto cifs_parse_mount_err;
1510 			}
1511 		}
1512 		break;
1513 	case Opt_resilient:
1514 		if (result.negated) {
1515 			ctx->resilient = false; /* already the default */
1516 		} else {
1517 			ctx->resilient = true;
1518 			if (ctx->persistent) {
1519 				cifs_errorf(fc, "persistenthandles mount options conflict\n");
1520 				goto cifs_parse_mount_err;
1521 			}
1522 		}
1523 		break;
1524 	case Opt_tcp_nodelay:
1525 		/* tcp nodelay should not usually be needed since we CORK/UNCORK the socket */
1526 		if (result.negated)
1527 			ctx->sockopt_tcp_nodelay = false;
1528 		else
1529 			ctx->sockopt_tcp_nodelay = true;
1530 		break;
1531 	case Opt_domainauto:
1532 		ctx->domainauto = true;
1533 		break;
1534 	case Opt_rdma:
1535 		ctx->rdma = true;
1536 		break;
1537 	}
1538 	/* case Opt_ignore: - is ignored as expected ... */
1539 
1540 	return 0;
1541 
1542  cifs_parse_mount_err:
1543 	kfree_sensitive(ctx->password);
1544 	ctx->password = NULL;
1545 	return -EINVAL;
1546 }
1547 
1548 int smb3_init_fs_context(struct fs_context *fc)
1549 {
1550 	struct smb3_fs_context *ctx;
1551 	char *nodename = utsname()->nodename;
1552 	int i;
1553 
1554 	ctx = kzalloc(sizeof(struct smb3_fs_context), GFP_KERNEL);
1555 	if (unlikely(!ctx))
1556 		return -ENOMEM;
1557 
1558 	strscpy(ctx->workstation_name, nodename, sizeof(ctx->workstation_name));
1559 
1560 	/*
1561 	 * does not have to be perfect mapping since field is
1562 	 * informational, only used for servers that do not support
1563 	 * port 445 and it can be overridden at mount time
1564 	 */
1565 	memset(ctx->source_rfc1001_name, 0x20, RFC1001_NAME_LEN);
1566 	for (i = 0; i < strnlen(nodename, RFC1001_NAME_LEN); i++)
1567 		ctx->source_rfc1001_name[i] = toupper(nodename[i]);
1568 
1569 	ctx->source_rfc1001_name[RFC1001_NAME_LEN] = 0;
1570 	/*
1571 	 * null target name indicates to use *SMBSERVR default called name
1572 	 *  if we end up sending RFC1001 session initialize
1573 	 */
1574 	ctx->target_rfc1001_name[0] = 0;
1575 	ctx->cred_uid = current_uid();
1576 	ctx->linux_uid = current_uid();
1577 	ctx->linux_gid = current_gid();
1578 	/* By default 4MB read ahead size, 1MB block size */
1579 	ctx->bsize = CIFS_DEFAULT_IOSIZE; /* can improve cp performance significantly */
1580 	ctx->rasize = 0; /* 0 = use default (ie negotiated rsize) for read ahead pages */
1581 
1582 	/*
1583 	 * default to SFM style remapping of seven reserved characters
1584 	 * unless user overrides it or we negotiate CIFS POSIX where
1585 	 * it is unnecessary.  Can not simultaneously use more than one mapping
1586 	 * since then readdir could list files that open could not open
1587 	 */
1588 	ctx->remap = true;
1589 
1590 	/* default to only allowing write access to owner of the mount */
1591 	ctx->dir_mode = ctx->file_mode = S_IRUGO | S_IXUGO | S_IWUSR;
1592 
1593 	/* ctx->retry default is 0 (i.e. "soft" limited retry not hard retry) */
1594 	/* default is always to request posix paths. */
1595 	ctx->posix_paths = 1;
1596 	/* default to using server inode numbers where available */
1597 	ctx->server_ino = 1;
1598 
1599 	/* default is to use strict cifs caching semantics */
1600 	ctx->strict_io = true;
1601 
1602 	ctx->acregmax = CIFS_DEF_ACTIMEO;
1603 	ctx->acdirmax = CIFS_DEF_ACTIMEO;
1604 	ctx->closetimeo = SMB3_DEF_DCLOSETIMEO;
1605 	ctx->max_cached_dirs = MAX_CACHED_FIDS;
1606 	/* Most clients set timeout to 0, allows server to use its default */
1607 	ctx->handle_timeout = 0; /* See MS-SMB2 spec section 2.2.14.2.12 */
1608 
1609 	/* offer SMB2.1 and later (SMB3 etc). Secure and widely accepted */
1610 	ctx->ops = &smb30_operations;
1611 	ctx->vals = &smbdefault_values;
1612 
1613 	ctx->echo_interval = SMB_ECHO_INTERVAL_DEFAULT;
1614 
1615 	/* default to no multichannel (single server connection) */
1616 	ctx->multichannel = false;
1617 	ctx->max_channels = 1;
1618 
1619 	ctx->backupuid_specified = false; /* no backup intent for a user */
1620 	ctx->backupgid_specified = false; /* no backup intent for a group */
1621 
1622 /*
1623  *	short int override_uid = -1;
1624  *	short int override_gid = -1;
1625  *	char *nodename = strdup(utsname()->nodename);
1626  *	struct sockaddr *dstaddr = (struct sockaddr *)&vol->dstaddr;
1627  */
1628 
1629 	fc->fs_private = ctx;
1630 	fc->ops = &smb3_fs_context_ops;
1631 	return 0;
1632 }
1633 
1634 void
1635 smb3_cleanup_fs_context_contents(struct smb3_fs_context *ctx)
1636 {
1637 	if (ctx == NULL)
1638 		return;
1639 
1640 	/*
1641 	 * Make sure this stays in sync with smb3_fs_context_dup()
1642 	 */
1643 	kfree(ctx->username);
1644 	ctx->username = NULL;
1645 	kfree_sensitive(ctx->password);
1646 	ctx->password = NULL;
1647 	kfree(ctx->server_hostname);
1648 	ctx->server_hostname = NULL;
1649 	kfree(ctx->UNC);
1650 	ctx->UNC = NULL;
1651 	kfree(ctx->source);
1652 	ctx->source = NULL;
1653 	kfree(ctx->domainname);
1654 	ctx->domainname = NULL;
1655 	kfree(ctx->nodename);
1656 	ctx->nodename = NULL;
1657 	kfree(ctx->iocharset);
1658 	ctx->iocharset = NULL;
1659 	kfree(ctx->prepath);
1660 	ctx->prepath = NULL;
1661 	kfree(ctx->leaf_fullpath);
1662 	ctx->leaf_fullpath = NULL;
1663 }
1664 
1665 void
1666 smb3_cleanup_fs_context(struct smb3_fs_context *ctx)
1667 {
1668 	if (!ctx)
1669 		return;
1670 	smb3_cleanup_fs_context_contents(ctx);
1671 	kfree(ctx);
1672 }
1673 
1674 void smb3_update_mnt_flags(struct cifs_sb_info *cifs_sb)
1675 {
1676 	struct smb3_fs_context *ctx = cifs_sb->ctx;
1677 
1678 	if (ctx->nodfs)
1679 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_DFS;
1680 	else
1681 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_NO_DFS;
1682 
1683 	if (ctx->noperm)
1684 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_PERM;
1685 	else
1686 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_NO_PERM;
1687 
1688 	if (ctx->setuids)
1689 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_SET_UID;
1690 	else
1691 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SET_UID;
1692 
1693 	if (ctx->setuidfromacl)
1694 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_UID_FROM_ACL;
1695 	else
1696 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_UID_FROM_ACL;
1697 
1698 	if (ctx->server_ino)
1699 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_SERVER_INUM;
1700 	else
1701 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
1702 
1703 	if (ctx->remap)
1704 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_MAP_SFM_CHR;
1705 	else
1706 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_MAP_SFM_CHR;
1707 
1708 	if (ctx->sfu_remap)
1709 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_MAP_SPECIAL_CHR;
1710 	else
1711 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_MAP_SPECIAL_CHR;
1712 
1713 	if (ctx->no_xattr)
1714 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_XATTR;
1715 	else
1716 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_NO_XATTR;
1717 
1718 	if (ctx->sfu_emul)
1719 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_UNX_EMUL;
1720 	else
1721 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_UNX_EMUL;
1722 
1723 	if (ctx->nobrl)
1724 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_BRL;
1725 	else
1726 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_NO_BRL;
1727 
1728 	if (ctx->nohandlecache)
1729 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_HANDLE_CACHE;
1730 	else
1731 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_NO_HANDLE_CACHE;
1732 
1733 	if (ctx->nostrictsync)
1734 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NOSSYNC;
1735 	else
1736 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_NOSSYNC;
1737 
1738 	if (ctx->mand_lock)
1739 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NOPOSIXBRL;
1740 	else
1741 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_NOPOSIXBRL;
1742 
1743 	if (ctx->rwpidforward)
1744 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RWPIDFORWARD;
1745 	else
1746 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_RWPIDFORWARD;
1747 
1748 	if (ctx->mode_ace)
1749 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_MODE_FROM_SID;
1750 	else
1751 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_MODE_FROM_SID;
1752 
1753 	if (ctx->cifs_acl)
1754 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_CIFS_ACL;
1755 	else
1756 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_CIFS_ACL;
1757 
1758 	if (ctx->backupuid_specified)
1759 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_CIFS_BACKUPUID;
1760 	else
1761 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_CIFS_BACKUPUID;
1762 
1763 	if (ctx->backupgid_specified)
1764 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_CIFS_BACKUPGID;
1765 	else
1766 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_CIFS_BACKUPGID;
1767 
1768 	if (ctx->override_uid)
1769 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_OVERR_UID;
1770 	else
1771 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_OVERR_UID;
1772 
1773 	if (ctx->override_gid)
1774 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_OVERR_GID;
1775 	else
1776 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_OVERR_GID;
1777 
1778 	if (ctx->dynperm)
1779 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_DYNPERM;
1780 	else
1781 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_DYNPERM;
1782 
1783 	if (ctx->fsc)
1784 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_FSCACHE;
1785 	else
1786 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_FSCACHE;
1787 
1788 	if (ctx->multiuser)
1789 		cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_MULTIUSER |
1790 					    CIFS_MOUNT_NO_PERM);
1791 	else
1792 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_MULTIUSER;
1793 
1794 
1795 	if (ctx->strict_io)
1796 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_STRICT_IO;
1797 	else
1798 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_STRICT_IO;
1799 
1800 	if (ctx->direct_io)
1801 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_DIRECT_IO;
1802 	else
1803 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_DIRECT_IO;
1804 
1805 	if (ctx->mfsymlinks)
1806 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_MF_SYMLINKS;
1807 	else
1808 		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_MF_SYMLINKS;
1809 	if (ctx->mfsymlinks) {
1810 		if (ctx->sfu_emul) {
1811 			/*
1812 			 * Our SFU ("Services for Unix" emulation does not allow
1813 			 * creating symlinks but does allow reading existing SFU
1814 			 * symlinks (it does allow both creating and reading SFU
1815 			 * style mknod and FIFOs though). When "mfsymlinks" and
1816 			 * "sfu" are both enabled at the same time, it allows
1817 			 * reading both types of symlinks, but will only create
1818 			 * them with mfsymlinks format. This allows better
1819 			 * Apple compatibility (probably better for Samba too)
1820 			 * while still recognizing old Windows style symlinks.
1821 			 */
1822 			cifs_dbg(VFS, "mount options mfsymlinks and sfu both enabled\n");
1823 		}
1824 	}
1825 	cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SHUTDOWN;
1826 
1827 	return;
1828 }
1829