cifs: remove the kmap size limit from wsize
[cascardo/linux.git] / fs / cifs / smb2ops.c
1 /*
2  *  SMB2 version specific operations
3  *
4  *  Copyright (c) 2012, Jeff Layton <jlayton@redhat.com>
5  *
6  *  This library is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License v2 as published
8  *  by the Free Software Foundation.
9  *
10  *  This library is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *  the GNU Lesser General Public License for more details.
14  *
15  *  You should have received a copy of the GNU Lesser General Public License
16  *  along with this library; if not, write to the Free Software
17  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19
20 #include <linux/pagemap.h>
21 #include <linux/vfs.h>
22 #include "cifsglob.h"
23 #include "smb2pdu.h"
24 #include "smb2proto.h"
25 #include "cifsproto.h"
26 #include "cifs_debug.h"
27 #include "smb2status.h"
28 #include "smb2glob.h"
29
30 static int
31 change_conf(struct TCP_Server_Info *server)
32 {
33         server->credits += server->echo_credits + server->oplock_credits;
34         server->oplock_credits = server->echo_credits = 0;
35         switch (server->credits) {
36         case 0:
37                 return -1;
38         case 1:
39                 server->echoes = false;
40                 server->oplocks = false;
41                 cERROR(1, "disabling echoes and oplocks");
42                 break;
43         case 2:
44                 server->echoes = true;
45                 server->oplocks = false;
46                 server->echo_credits = 1;
47                 cFYI(1, "disabling oplocks");
48                 break;
49         default:
50                 server->echoes = true;
51                 server->oplocks = true;
52                 server->echo_credits = 1;
53                 server->oplock_credits = 1;
54         }
55         server->credits -= server->echo_credits + server->oplock_credits;
56         return 0;
57 }
58
59 static void
60 smb2_add_credits(struct TCP_Server_Info *server, const unsigned int add,
61                  const int optype)
62 {
63         int *val, rc = 0;
64         spin_lock(&server->req_lock);
65         val = server->ops->get_credits_field(server, optype);
66         *val += add;
67         server->in_flight--;
68         if (server->in_flight == 0 && (optype & CIFS_OP_MASK) != CIFS_NEG_OP)
69                 rc = change_conf(server);
70         /*
71          * Sometimes server returns 0 credits on oplock break ack - we need to
72          * rebalance credits in this case.
73          */
74         else if (server->in_flight > 0 && server->oplock_credits == 0 &&
75                  server->oplocks) {
76                 if (server->credits > 1) {
77                         server->credits--;
78                         server->oplock_credits++;
79                 }
80         }
81         spin_unlock(&server->req_lock);
82         wake_up(&server->request_q);
83         if (rc)
84                 cifs_reconnect(server);
85 }
86
87 static void
88 smb2_set_credits(struct TCP_Server_Info *server, const int val)
89 {
90         spin_lock(&server->req_lock);
91         server->credits = val;
92         spin_unlock(&server->req_lock);
93 }
94
95 static int *
96 smb2_get_credits_field(struct TCP_Server_Info *server, const int optype)
97 {
98         switch (optype) {
99         case CIFS_ECHO_OP:
100                 return &server->echo_credits;
101         case CIFS_OBREAK_OP:
102                 return &server->oplock_credits;
103         default:
104                 return &server->credits;
105         }
106 }
107
108 static unsigned int
109 smb2_get_credits(struct mid_q_entry *mid)
110 {
111         return le16_to_cpu(((struct smb2_hdr *)mid->resp_buf)->CreditRequest);
112 }
113
114 static __u64
115 smb2_get_next_mid(struct TCP_Server_Info *server)
116 {
117         __u64 mid;
118         /* for SMB2 we need the current value */
119         spin_lock(&GlobalMid_Lock);
120         mid = server->CurrentMid++;
121         spin_unlock(&GlobalMid_Lock);
122         return mid;
123 }
124
125 static struct mid_q_entry *
126 smb2_find_mid(struct TCP_Server_Info *server, char *buf)
127 {
128         struct mid_q_entry *mid;
129         struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
130
131         spin_lock(&GlobalMid_Lock);
132         list_for_each_entry(mid, &server->pending_mid_q, qhead) {
133                 if ((mid->mid == hdr->MessageId) &&
134                     (mid->mid_state == MID_REQUEST_SUBMITTED) &&
135                     (mid->command == hdr->Command)) {
136                         spin_unlock(&GlobalMid_Lock);
137                         return mid;
138                 }
139         }
140         spin_unlock(&GlobalMid_Lock);
141         return NULL;
142 }
143
144 static void
145 smb2_dump_detail(void *buf)
146 {
147 #ifdef CONFIG_CIFS_DEBUG2
148         struct smb2_hdr *smb = (struct smb2_hdr *)buf;
149
150         cERROR(1, "Cmd: %d Err: 0x%x Flags: 0x%x Mid: %llu Pid: %d",
151                   smb->Command, smb->Status, smb->Flags, smb->MessageId,
152                   smb->ProcessId);
153         cERROR(1, "smb buf %p len %u", smb, smb2_calc_size(smb));
154 #endif
155 }
156
157 static bool
158 smb2_need_neg(struct TCP_Server_Info *server)
159 {
160         return server->max_read == 0;
161 }
162
163 static int
164 smb2_negotiate(const unsigned int xid, struct cifs_ses *ses)
165 {
166         int rc;
167         ses->server->CurrentMid = 0;
168         rc = SMB2_negotiate(xid, ses);
169         /* BB we probably don't need to retry with modern servers */
170         if (rc == -EAGAIN)
171                 rc = -EHOSTDOWN;
172         return rc;
173 }
174
175 static unsigned int
176 smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
177 {
178         struct TCP_Server_Info *server = tcon->ses->server;
179         unsigned int wsize;
180
181         /* start with specified wsize, or default */
182         wsize = volume_info->wsize ? volume_info->wsize : CIFS_DEFAULT_IOSIZE;
183         wsize = min_t(unsigned int, wsize, server->max_write);
184         /*
185          * limit write size to 2 ** 16, because we don't support multicredit
186          * requests now.
187          */
188         wsize = min_t(unsigned int, wsize, 2 << 15);
189
190         return wsize;
191 }
192
193 static unsigned int
194 smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
195 {
196         struct TCP_Server_Info *server = tcon->ses->server;
197         unsigned int rsize;
198
199         /* start with specified rsize, or default */
200         rsize = volume_info->rsize ? volume_info->rsize : CIFS_DEFAULT_IOSIZE;
201         rsize = min_t(unsigned int, rsize, server->max_read);
202         /*
203          * limit write size to 2 ** 16, because we don't support multicredit
204          * requests now.
205          */
206         rsize = min_t(unsigned int, rsize, 2 << 15);
207
208         /* limit to the amount that we can kmap at once */
209         rsize = min_t(unsigned int, rsize, CIFS_KMAP_SIZE_LIMIT);
210
211         return rsize;
212 }
213
214 static int
215 smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon,
216                         struct cifs_sb_info *cifs_sb, const char *full_path)
217 {
218         int rc;
219         __u64 persistent_fid, volatile_fid;
220         __le16 *utf16_path;
221         __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
222
223         utf16_path = cifs_convert_path_to_utf16(full_path, cifs_sb);
224         if (!utf16_path)
225                 return -ENOMEM;
226
227         rc = SMB2_open(xid, tcon, utf16_path, &persistent_fid, &volatile_fid,
228                        FILE_READ_ATTRIBUTES, FILE_OPEN, 0, 0, &oplock, NULL);
229         if (rc) {
230                 kfree(utf16_path);
231                 return rc;
232         }
233
234         rc = SMB2_close(xid, tcon, persistent_fid, volatile_fid);
235         kfree(utf16_path);
236         return rc;
237 }
238
239 static int
240 smb2_get_srv_inum(const unsigned int xid, struct cifs_tcon *tcon,
241                   struct cifs_sb_info *cifs_sb, const char *full_path,
242                   u64 *uniqueid, FILE_ALL_INFO *data)
243 {
244         *uniqueid = le64_to_cpu(data->IndexNumber);
245         return 0;
246 }
247
248 static int
249 smb2_query_file_info(const unsigned int xid, struct cifs_tcon *tcon,
250                      struct cifs_fid *fid, FILE_ALL_INFO *data)
251 {
252         int rc;
253         struct smb2_file_all_info *smb2_data;
254
255         smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + MAX_NAME * 2,
256                             GFP_KERNEL);
257         if (smb2_data == NULL)
258                 return -ENOMEM;
259
260         rc = SMB2_query_info(xid, tcon, fid->persistent_fid, fid->volatile_fid,
261                              smb2_data);
262         if (!rc)
263                 move_smb2_info_to_cifs(data, smb2_data);
264         kfree(smb2_data);
265         return rc;
266 }
267
268 static char *
269 smb2_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
270                         struct cifs_tcon *tcon)
271 {
272         int pplen = vol->prepath ? strlen(vol->prepath) : 0;
273         char *full_path = NULL;
274
275         /* if no prefix path, simply set path to the root of share to "" */
276         if (pplen == 0) {
277                 full_path = kzalloc(2, GFP_KERNEL);
278                 return full_path;
279         }
280
281         cERROR(1, "prefixpath is not supported for SMB2 now");
282         return NULL;
283 }
284
285 static bool
286 smb2_can_echo(struct TCP_Server_Info *server)
287 {
288         return server->echoes;
289 }
290
291 static void
292 smb2_clear_stats(struct cifs_tcon *tcon)
293 {
294 #ifdef CONFIG_CIFS_STATS
295         int i;
296         for (i = 0; i < NUMBER_OF_SMB2_COMMANDS; i++) {
297                 atomic_set(&tcon->stats.smb2_stats.smb2_com_sent[i], 0);
298                 atomic_set(&tcon->stats.smb2_stats.smb2_com_failed[i], 0);
299         }
300 #endif
301 }
302
303 static void
304 smb2_print_stats(struct seq_file *m, struct cifs_tcon *tcon)
305 {
306 #ifdef CONFIG_CIFS_STATS
307         atomic_t *sent = tcon->stats.smb2_stats.smb2_com_sent;
308         atomic_t *failed = tcon->stats.smb2_stats.smb2_com_failed;
309         seq_printf(m, "\nNegotiates: %d sent %d failed",
310                    atomic_read(&sent[SMB2_NEGOTIATE_HE]),
311                    atomic_read(&failed[SMB2_NEGOTIATE_HE]));
312         seq_printf(m, "\nSessionSetups: %d sent %d failed",
313                    atomic_read(&sent[SMB2_SESSION_SETUP_HE]),
314                    atomic_read(&failed[SMB2_SESSION_SETUP_HE]));
315 #define SMB2LOGOFF              0x0002 /* trivial request/resp */
316         seq_printf(m, "\nLogoffs: %d sent %d failed",
317                    atomic_read(&sent[SMB2_LOGOFF_HE]),
318                    atomic_read(&failed[SMB2_LOGOFF_HE]));
319         seq_printf(m, "\nTreeConnects: %d sent %d failed",
320                    atomic_read(&sent[SMB2_TREE_CONNECT_HE]),
321                    atomic_read(&failed[SMB2_TREE_CONNECT_HE]));
322         seq_printf(m, "\nTreeDisconnects: %d sent %d failed",
323                    atomic_read(&sent[SMB2_TREE_DISCONNECT_HE]),
324                    atomic_read(&failed[SMB2_TREE_DISCONNECT_HE]));
325         seq_printf(m, "\nCreates: %d sent %d failed",
326                    atomic_read(&sent[SMB2_CREATE_HE]),
327                    atomic_read(&failed[SMB2_CREATE_HE]));
328         seq_printf(m, "\nCloses: %d sent %d failed",
329                    atomic_read(&sent[SMB2_CLOSE_HE]),
330                    atomic_read(&failed[SMB2_CLOSE_HE]));
331         seq_printf(m, "\nFlushes: %d sent %d failed",
332                    atomic_read(&sent[SMB2_FLUSH_HE]),
333                    atomic_read(&failed[SMB2_FLUSH_HE]));
334         seq_printf(m, "\nReads: %d sent %d failed",
335                    atomic_read(&sent[SMB2_READ_HE]),
336                    atomic_read(&failed[SMB2_READ_HE]));
337         seq_printf(m, "\nWrites: %d sent %d failed",
338                    atomic_read(&sent[SMB2_WRITE_HE]),
339                    atomic_read(&failed[SMB2_WRITE_HE]));
340         seq_printf(m, "\nLocks: %d sent %d failed",
341                    atomic_read(&sent[SMB2_LOCK_HE]),
342                    atomic_read(&failed[SMB2_LOCK_HE]));
343         seq_printf(m, "\nIOCTLs: %d sent %d failed",
344                    atomic_read(&sent[SMB2_IOCTL_HE]),
345                    atomic_read(&failed[SMB2_IOCTL_HE]));
346         seq_printf(m, "\nCancels: %d sent %d failed",
347                    atomic_read(&sent[SMB2_CANCEL_HE]),
348                    atomic_read(&failed[SMB2_CANCEL_HE]));
349         seq_printf(m, "\nEchos: %d sent %d failed",
350                    atomic_read(&sent[SMB2_ECHO_HE]),
351                    atomic_read(&failed[SMB2_ECHO_HE]));
352         seq_printf(m, "\nQueryDirectories: %d sent %d failed",
353                    atomic_read(&sent[SMB2_QUERY_DIRECTORY_HE]),
354                    atomic_read(&failed[SMB2_QUERY_DIRECTORY_HE]));
355         seq_printf(m, "\nChangeNotifies: %d sent %d failed",
356                    atomic_read(&sent[SMB2_CHANGE_NOTIFY_HE]),
357                    atomic_read(&failed[SMB2_CHANGE_NOTIFY_HE]));
358         seq_printf(m, "\nQueryInfos: %d sent %d failed",
359                    atomic_read(&sent[SMB2_QUERY_INFO_HE]),
360                    atomic_read(&failed[SMB2_QUERY_INFO_HE]));
361         seq_printf(m, "\nSetInfos: %d sent %d failed",
362                    atomic_read(&sent[SMB2_SET_INFO_HE]),
363                    atomic_read(&failed[SMB2_SET_INFO_HE]));
364         seq_printf(m, "\nOplockBreaks: %d sent %d failed",
365                    atomic_read(&sent[SMB2_OPLOCK_BREAK_HE]),
366                    atomic_read(&failed[SMB2_OPLOCK_BREAK_HE]));
367 #endif
368 }
369
370 static void
371 smb2_set_fid(struct cifsFileInfo *cfile, struct cifs_fid *fid, __u32 oplock)
372 {
373         struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
374         cfile->fid.persistent_fid = fid->persistent_fid;
375         cfile->fid.volatile_fid = fid->volatile_fid;
376         smb2_set_oplock_level(cinode, oplock);
377         /* cinode->can_cache_brlcks = cinode->clientCanCacheAll; */
378 }
379
380 static int
381 smb2_close_file(const unsigned int xid, struct cifs_tcon *tcon,
382                 struct cifs_fid *fid)
383 {
384         return SMB2_close(xid, tcon, fid->persistent_fid, fid->volatile_fid);
385 }
386
387 static int
388 smb2_flush_file(const unsigned int xid, struct cifs_tcon *tcon,
389                 struct cifs_fid *fid)
390 {
391         return SMB2_flush(xid, tcon, fid->persistent_fid, fid->volatile_fid);
392 }
393
394 static unsigned int
395 smb2_read_data_offset(char *buf)
396 {
397         struct smb2_read_rsp *rsp = (struct smb2_read_rsp *)buf;
398         return rsp->DataOffset;
399 }
400
401 static unsigned int
402 smb2_read_data_length(char *buf)
403 {
404         struct smb2_read_rsp *rsp = (struct smb2_read_rsp *)buf;
405         return le32_to_cpu(rsp->DataLength);
406 }
407
408
409 static int
410 smb2_sync_read(const unsigned int xid, struct cifsFileInfo *cfile,
411                struct cifs_io_parms *parms, unsigned int *bytes_read,
412                char **buf, int *buf_type)
413 {
414         parms->persistent_fid = cfile->fid.persistent_fid;
415         parms->volatile_fid = cfile->fid.volatile_fid;
416         return SMB2_read(xid, parms, bytes_read, buf, buf_type);
417 }
418
419 static int
420 smb2_sync_write(const unsigned int xid, struct cifsFileInfo *cfile,
421                 struct cifs_io_parms *parms, unsigned int *written,
422                 struct kvec *iov, unsigned long nr_segs)
423 {
424
425         parms->persistent_fid = cfile->fid.persistent_fid;
426         parms->volatile_fid = cfile->fid.volatile_fid;
427         return SMB2_write(xid, parms, written, iov, nr_segs);
428 }
429
430 static int
431 smb2_set_file_size(const unsigned int xid, struct cifs_tcon *tcon,
432                    struct cifsFileInfo *cfile, __u64 size, bool set_alloc)
433 {
434         __le64 eof = cpu_to_le64(size);
435         return SMB2_set_eof(xid, tcon, cfile->fid.persistent_fid,
436                             cfile->fid.volatile_fid, cfile->pid, &eof);
437 }
438
439 static int
440 smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon,
441                      const char *path, struct cifs_sb_info *cifs_sb,
442                      struct cifs_fid *fid, __u16 search_flags,
443                      struct cifs_search_info *srch_inf)
444 {
445         __le16 *utf16_path;
446         int rc;
447         __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
448         __u64 persistent_fid, volatile_fid;
449
450         utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
451         if (!utf16_path)
452                 return -ENOMEM;
453
454         rc = SMB2_open(xid, tcon, utf16_path, &persistent_fid, &volatile_fid,
455                        FILE_READ_ATTRIBUTES | FILE_READ_DATA, FILE_OPEN, 0, 0,
456                        &oplock, NULL);
457         kfree(utf16_path);
458         if (rc) {
459                 cERROR(1, "open dir failed");
460                 return rc;
461         }
462
463         srch_inf->entries_in_buffer = 0;
464         srch_inf->index_of_last_entry = 0;
465         fid->persistent_fid = persistent_fid;
466         fid->volatile_fid = volatile_fid;
467
468         rc = SMB2_query_directory(xid, tcon, persistent_fid, volatile_fid, 0,
469                                   srch_inf);
470         if (rc) {
471                 cERROR(1, "query directory failed");
472                 SMB2_close(xid, tcon, persistent_fid, volatile_fid);
473         }
474         return rc;
475 }
476
477 static int
478 smb2_query_dir_next(const unsigned int xid, struct cifs_tcon *tcon,
479                     struct cifs_fid *fid, __u16 search_flags,
480                     struct cifs_search_info *srch_inf)
481 {
482         return SMB2_query_directory(xid, tcon, fid->persistent_fid,
483                                     fid->volatile_fid, 0, srch_inf);
484 }
485
486 static int
487 smb2_close_dir(const unsigned int xid, struct cifs_tcon *tcon,
488                struct cifs_fid *fid)
489 {
490         return SMB2_close(xid, tcon, fid->persistent_fid, fid->volatile_fid);
491 }
492
493 /*
494 * If we negotiate SMB2 protocol and get STATUS_PENDING - update
495 * the number of credits and return true. Otherwise - return false.
496 */
497 static bool
498 smb2_is_status_pending(char *buf, struct TCP_Server_Info *server, int length)
499 {
500         struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
501
502         if (le32_to_cpu(hdr->Status) != STATUS_PENDING)
503                 return false;
504
505         if (!length) {
506                 spin_lock(&server->req_lock);
507                 server->credits += le16_to_cpu(hdr->CreditRequest);
508                 spin_unlock(&server->req_lock);
509                 wake_up(&server->request_q);
510         }
511
512         return true;
513 }
514
515 static int
516 smb2_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid,
517                      struct cifsInodeInfo *cinode)
518 {
519         return SMB2_oplock_break(0, tcon, fid->persistent_fid,
520                                  fid->volatile_fid,
521                                  cinode->clientCanCacheRead ? 1 : 0);
522 }
523
524 static int
525 smb2_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
526              struct kstatfs *buf)
527 {
528         int rc;
529         u64 persistent_fid, volatile_fid;
530         __le16 srch_path = 0; /* Null - open root of share */
531         u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
532
533         rc = SMB2_open(xid, tcon, &srch_path, &persistent_fid, &volatile_fid,
534                        FILE_READ_ATTRIBUTES, FILE_OPEN, 0, 0, &oplock, NULL);
535         if (rc)
536                 return rc;
537         buf->f_type = SMB2_MAGIC_NUMBER;
538         rc = SMB2_QFS_info(xid, tcon, persistent_fid, volatile_fid, buf);
539         SMB2_close(xid, tcon, persistent_fid, volatile_fid);
540         return rc;
541 }
542
543 struct smb_version_operations smb21_operations = {
544         .setup_request = smb2_setup_request,
545         .setup_async_request = smb2_setup_async_request,
546         .check_receive = smb2_check_receive,
547         .add_credits = smb2_add_credits,
548         .set_credits = smb2_set_credits,
549         .get_credits_field = smb2_get_credits_field,
550         .get_credits = smb2_get_credits,
551         .get_next_mid = smb2_get_next_mid,
552         .read_data_offset = smb2_read_data_offset,
553         .read_data_length = smb2_read_data_length,
554         .map_error = map_smb2_to_linux_error,
555         .find_mid = smb2_find_mid,
556         .check_message = smb2_check_message,
557         .dump_detail = smb2_dump_detail,
558         .clear_stats = smb2_clear_stats,
559         .print_stats = smb2_print_stats,
560         .is_oplock_break = smb2_is_valid_oplock_break,
561         .need_neg = smb2_need_neg,
562         .negotiate = smb2_negotiate,
563         .negotiate_wsize = smb2_negotiate_wsize,
564         .negotiate_rsize = smb2_negotiate_rsize,
565         .sess_setup = SMB2_sess_setup,
566         .logoff = SMB2_logoff,
567         .tree_connect = SMB2_tcon,
568         .tree_disconnect = SMB2_tdis,
569         .is_path_accessible = smb2_is_path_accessible,
570         .can_echo = smb2_can_echo,
571         .echo = SMB2_echo,
572         .query_path_info = smb2_query_path_info,
573         .get_srv_inum = smb2_get_srv_inum,
574         .query_file_info = smb2_query_file_info,
575         .set_path_size = smb2_set_path_size,
576         .set_file_size = smb2_set_file_size,
577         .set_file_info = smb2_set_file_info,
578         .build_path_to_root = smb2_build_path_to_root,
579         .mkdir = smb2_mkdir,
580         .mkdir_setinfo = smb2_mkdir_setinfo,
581         .rmdir = smb2_rmdir,
582         .unlink = smb2_unlink,
583         .rename = smb2_rename_path,
584         .create_hardlink = smb2_create_hardlink,
585         .open = smb2_open_file,
586         .set_fid = smb2_set_fid,
587         .close = smb2_close_file,
588         .flush = smb2_flush_file,
589         .async_readv = smb2_async_readv,
590         .async_writev = smb2_async_writev,
591         .sync_read = smb2_sync_read,
592         .sync_write = smb2_sync_write,
593         .query_dir_first = smb2_query_dir_first,
594         .query_dir_next = smb2_query_dir_next,
595         .close_dir = smb2_close_dir,
596         .calc_smb_size = smb2_calc_size,
597         .is_status_pending = smb2_is_status_pending,
598         .oplock_response = smb2_oplock_response,
599         .queryfs = smb2_queryfs,
600 };
601
602 struct smb_version_values smb21_values = {
603         .version_string = SMB21_VERSION_STRING,
604         .header_size = sizeof(struct smb2_hdr),
605         .max_header_size = MAX_SMB2_HDR_SIZE,
606         .read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
607         .lock_cmd = SMB2_LOCK,
608         .cap_unix = 0,
609         .cap_nt_find = SMB2_NT_FIND,
610         .cap_large_files = SMB2_LARGE_FILES,
611 };