summaryrefslogtreecommitdiffstats
path: root/fs/cifs/cifsglob.h
blob: 87453a6bcaf838ca15c892fba91bd4a8c780514e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
/*
 *   fs/cifs/cifsglob.h
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2006
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 * 
 */
#include <linux/in.h>
#include <linux/in6.h>
#include "cifs_fs_sb.h"
/*
 * The sizes of various internal tables and strings
 */
#define MAX_UID_INFO 16
#define MAX_SES_INFO 2
#define MAX_TCON_INFO 4

#define MAX_TREE_SIZE 2 + MAX_SERVER_SIZE + 1 + MAX_SHARE_SIZE + 1
#define MAX_SERVER_SIZE 15
#define MAX_SHARE_SIZE  64	/* used to be 20 - this should still be enough */
#define MAX_USERNAME_SIZE 32	/* 32 is to allow for 15 char names + null
				   termination then *2 for unicode versions */
#define MAX_PASSWORD_SIZE 16

#define CIFS_MIN_RCV_POOL 4

/*
 * MAX_REQ is the maximum number of requests that WE will send
 * on one socket concurently. It also matches the most common
 * value of max multiplex returned by servers.  We may 
 * eventually want to use the negotiated value (in case
 * future servers can handle more) when we are more confident that
 * we will not have problems oveloading the socket with pending
 * write data.
 */
#define CIFS_MAX_REQ 50 

#define SERVER_NAME_LENGTH 15
#define SERVER_NAME_LEN_WITH_NULL     (SERVER_NAME_LENGTH + 1)

/* used to define string lengths for reversing unicode strings */
/*         (256+1)*2 = 514                                     */
/*           (max path length + 1 for null) * 2 for unicode    */
#define MAX_NAME 514

#include "cifspdu.h"

#ifndef FALSE
#define FALSE 0
#endif

#ifndef TRUE
#define TRUE 1
#endif

#ifndef XATTR_DOS_ATTRIB
#define XATTR_DOS_ATTRIB "user.DOSATTRIB"
#endif

/*
 * This information is kept on every Server we know about.
 *
 * Some things to note:
 *
 */
#define SERVER_NAME_LEN_WITH_NULL	(SERVER_NAME_LENGTH + 1)

/*
 * CIFS vfs client Status information (based on what we know.)
 */

 /* associated with each tcp and smb session */
enum statusEnum {
	CifsNew = 0,
	CifsGood,
	CifsExiting,
	CifsNeedReconnect
};

enum securityEnum {
	LANMAN = 0,             /* Legacy LANMAN auth */
	NTLM,			/* Legacy NTLM012 auth with NTLM hash */
	NTLMv2,			/* Legacy NTLM auth with NTLMv2 hash */
	RawNTLMSSP,		/* NTLMSSP without SPNEGO */
	NTLMSSP,		/* NTLMSSP via SPNEGO */
	Kerberos		/* Kerberos via SPNEGO */
};

enum protocolEnum {
	IPV4 = 0,
	IPV6,
	SCTP
	/* Netbios frames protocol not supported at this time */
};

/*
 *****************************************************************
 * Except the CIFS PDUs themselves all the
 * globally interesting structs should go here
 *****************************************************************
 */

struct TCP_Server_Info {
	/* 15 character server name + 0x20 16th byte indicating type = srv */
	char server_RFC1001_name[SERVER_NAME_LEN_WITH_NULL];
	char unicode_server_Name[SERVER_NAME_LEN_WITH_NULL * 2];
	struct socket *ssocket;
	union {
		struct sockaddr_in sockAddr;
		struct sockaddr_in6 sockAddr6;
	} addr;
	wait_queue_head_t response_q; 
	wait_queue_head_t request_q; /* if more than maxmpx to srvr must block*/
	struct list_head pending_mid_q;
	void *Server_NlsInfo;	/* BB - placeholder for future NLS info  */
	unsigned short server_codepage;	/* codepage for the server    */
	unsigned long ip_address;	/* IP addr for the server if known */
	enum protocolEnum protocolType;	
	char versionMajor;
	char versionMinor;
	unsigned svlocal:1;	/* local server or remote */
	atomic_t socketUseCount; /* number of open cifs sessions on socket */
	atomic_t inFlight;  /* number of requests on the wire to server */
#ifdef CONFIG_CIFS_STATS2
	atomic_t inSend; /* requests trying to send */
	atomic_t num_waiters;   /* blocked waiting to get in sendrecv */
#endif
	enum statusEnum tcpStatus; /* what we think the status is */
	struct semaphore tcpSem;
	struct task_struct *tsk;
	char server_GUID[16];
	char secMode;
	enum securityEnum secType;
	unsigned int maxReq;	/* Clients should submit no more */
	/* than maxReq distinct unanswered SMBs to the server when using  */
	/* multiplexed reads or writes */
	unsigned int maxBuf;	/* maxBuf specifies the maximum */
	/* message size the server can send or receive for non-raw SMBs */
	unsigned int maxRw;	/* maxRw specifies the maximum */
	/* message size the server can send or receive for */
	/* SMB_COM_WRITE_RAW or SMB_COM_READ_RAW. */
	char sessid[4];		/* unique token id for this session */
	/* (returned on Negotiate */
	int capabilities; /* allow selective disabling of caps by smb sess */
	__u16 timeZone;
	__u16 CurrentMid;         /* multiplex id - rotating counter */
	char cryptKey[CIFS_CRYPTO_KEY_SIZE];
	/* 16th byte of RFC1001 workstation name is always null */
	char workstation_RFC1001_name[SERVER_NAME_LEN_WITH_NULL];
	__u32 sequence_number; /* needed for CIFS PDU signature */
	char mac_signing_key[CIFS_SESS_KEY_SIZE + 16]; 
};

/*
 * The following is our shortcut to user information.  We surface the uid,
 * and name. We always get the password on the fly in case it
 * has changed. We also hang a list of sessions owned by this user off here. 
 */
struct cifsUidInfo {
	struct list_head userList;
	struct list_head sessionList; /* SMB sessions for this user */
	uid_t linux_uid;
	char user[MAX_USERNAME_SIZE + 1];	/* ascii name of user */
	/* BB may need ptr or callback for PAM or WinBind info */
};

/*
 * Session structure.  One of these for each uid session with a particular host
 */
struct cifsSesInfo {
	struct list_head cifsSessionList;
	struct semaphore sesSem;
#if 0
	struct cifsUidInfo *uidInfo;	/* pointer to user info */
#endif
	struct TCP_Server_Info *server;	/* pointer to server info */
	atomic_t inUse; /* # of mounts (tree connections) on this ses */
	enum statusEnum status;
	__u16 ipc_tid;		/* special tid for connection to IPC share */
	__u16 flags;
	char *serverOS;		/* name of operating system underlying server */
	char *serverNOS;	/* name of network operating system of server */
	char *serverDomain;	/* security realm of server */
	int Suid;		/* remote smb uid  */
	uid_t linux_uid;        /* local Linux uid */
	int capabilities;
	char serverName[SERVER_NAME_LEN_WITH_NULL * 2];	/* BB make bigger for 
				TCP names - will ipv6 and sctp addresses fit? */
	char userName[MAX_USERNAME_SIZE + 1];
	char * domainName;
	char * password;
};
/* session flags */
#define CIFS_SES_NT4 1

/*
 * there is one of these for each connection to a resource on a particular
 * session 
 */
struct cifsTconInfo {
	struct list_head cifsConnectionList;
	struct list_head openFileList;
	struct semaphore tconSem;
	struct cifsSesInfo *ses;	/* pointer to session associated with */
	char treeName[MAX_TREE_SIZE + 1]; /* UNC name of resource in ASCII */
	char *nativeFileSystem;
	__u16 tid;		/* The 2 byte tree id */
	__u16 Flags;		/* optional support bits */
	enum statusEnum tidStatus;
	atomic_t useCount;	/* how many explicit/implicit mounts to share */
#ifdef CONFIG_CIFS_STATS
	atomic_t num_smbs_sent;
	atomic_t num_writes;
	atomic_t num_reads;
	atomic_t num_oplock_brks;
	atomic_t num_opens;
	atomic_t num_closes;
	atomic_t num_deletes;
	atomic_t num_mkdirs;
	atomic_t num_rmdirs;
	atomic_t num_renames;
	atomic_t num_t2renames;
	atomic_t num_ffirst;
	atomic_t num_fnext;
	atomic_t num_fclose;
	atomic_t num_hardlinks;
	atomic_t num_symlinks;
	atomic_t num_locks;
	atomic_t num_acl_get;
	atomic_t num_acl_set;
#ifdef CONFIG_CIFS_STATS2
	unsigned long long time_writes;
	unsigned long long time_reads;
	unsigned long long time_opens;
	unsigned long long time_deletes;
	unsigned long long time_closes;
	unsigned long long time_mkdirs;
	unsigned long long time_rmdirs;
	unsigned long long time_renames;
	unsigned long long time_t2renames;
	unsigned long long time_ffirst;
	unsigned long long time_fnext;
	unsigned long long time_fclose;
#endif /* CONFIG_CIFS_STATS2 */
	__u64    bytes_read;
	__u64    bytes_written;
	spinlock_t stat_lock;
#endif /* CONFIG_CIFS_STATS */
	FILE_SYSTEM_DEVICE_INFO fsDevInfo;
	FILE_SYSTEM_ATTRIBUTE_INFO fsAttrInfo; /* ok if fs name truncated */
	FILE_SYSTEM_UNIX_INFO fsUnixInfo;
	unsigned retry:1;
	unsigned nocase:1;
	/* BB add field for back pointer to sb struct? */
};

/*
 * This info hangs off the cifsFileInfo structure.  This is used to track
 * byte stream locks on the file
 */
struct cifsLockInfo {
	struct cifsLockInfo *next;
	int start;
	int length;
	int type;
};

/*
 * One of these for each open instance of a file
 */
struct cifs_search_info {
	loff_t index_of_last_entry;
	__u16 entries_in_buffer;
	__u16 info_level;
	__u32 resume_key;
	char * ntwrk_buf_start;
	char * srch_entries_start;
	char * presume_name;
	unsigned int resume_name_len;
	unsigned endOfSearch:1;
	unsigned emptyDir:1;
	unsigned unicode:1;
	unsigned smallBuf:1; /* so we know which buf_release function to call */
};

struct cifsFileInfo {
	struct list_head tlist;	/* pointer to next fid owned by tcon */
	struct list_head flist;	/* next fid (file instance) for this inode */
	unsigned int uid;	/* allows finding which FileInfo structure */
	__u32 pid;		/* process id who opened file */
	__u16 netfid;		/* file id from remote */
	/* BB add lock scope info here if needed */ ;
	/* lock scope id (0 if none) */
	struct file * pfile; /* needed for writepage */
	struct inode * pInode; /* needed for oplock break */
	unsigned closePend:1;	/* file is marked to close */
	unsigned invalidHandle:1;  /* file closed via session abend */
	atomic_t wrtPending;   /* handle in use - defer close */
	struct semaphore fh_sem; /* prevents reopen race after dead ses*/
	char * search_resume_name; /* BB removeme BB */
	struct cifs_search_info srch_inf;
};

/*
 * One of these for each file inode
 */

struct cifsInodeInfo {
	struct list_head lockList;
	/* BB add in lists for dirty pages - i.e. write caching info for oplock */
	struct list_head openFileList;
	int write_behind_rc;
	__u32 cifsAttrs; /* e.g. DOS archive bit, sparse, compressed, system */
	atomic_t inUse;	 /* num concurrent users (local openers cifs) of file*/
	unsigned long time;	/* jiffies of last update/check of inode */
	unsigned clientCanCacheRead:1; /* read oplock */
	unsigned clientCanCacheAll:1;  /* read and writebehind oplock */
	unsigned oplockPending:1;
	struct inode vfs_inode;
};

static inline struct cifsInodeInfo *
CIFS_I(struct inode *inode)
{
	return container_of(inode, struct cifsInodeInfo, vfs_inode);
}

static inline struct cifs_sb_info *
CIFS_SB(struct super_block *sb)
{
	return sb->s_fs_info;
}

static inline char CIFS_DIR_SEP(const struct cifs_sb_info *cifs_sb)
{
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
		return '/';
	else
		return '\\';
}

#ifdef CONFIG_CIFS_STATS
#define cifs_stats_inc atomic_inc

static inline void cifs_stats_bytes_written(struct cifsTconInfo *tcon,
					    unsigned int bytes)
{
	if (bytes) {
		spin_lock(&tcon->stat_lock);
		tcon->bytes_written += bytes;
		spin_unlock(&tcon->stat_lock);
	}
}

static inline void cifs_stats_bytes_read(struct cifsTconInfo *tcon,
					 unsigned int bytes)
{
	spin_lock(&tcon->stat_lock);
	tcon->bytes_read += bytes;
	spin_unlock(&tcon->stat_lock);
}
#else

#define  cifs_stats_inc(field) do {} while(0)
#define  cifs_stats_bytes_written(tcon, bytes) do {} while(0)
#define  cifs_stats_bytes_read(tcon, bytes) do {} while(0)

#endif

/* one of these for every pending CIFS request to the server */
struct mid_q_entry {
	struct list_head qhead;	/* mids waiting on reply from this server */
	__u16 mid;		/* multiplex id */
	__u16 pid;		/* process id */
	__u32 sequence_number;  /* for CIFS signing */
	unsigned long when_alloc;  /* when mid was created */
#ifdef CONFIG_CIFS_STATS2
	unsigned long when_sent; /* time when smb send finished */
	unsigned long when_received; /* when demux complete (taken off wire) */
#endif
	struct cifsSesInfo *ses;	/* smb was sent to this server */
	struct task_struct *tsk;	/* task waiting for response */
	struct smb_hdr *resp_buf;	/* response buffer */
	int midState;	/* wish this were enum but can not pass to wait_event */
	__u8 command;	/* smb command code */
	unsigned largeBuf:1;    /* if valid response, is pointer to large buf */
	unsigned multiRsp:1;   /* multiple trans2 responses for one request  */
	unsigned multiEnd:1; /* both received */
};

struct oplock_q_entry {
	struct list_head qhead;
	struct inode * pinode;
	struct cifsTconInfo * tcon; 
	__u16 netfid;
};

/* for pending dnotify requests */
struct dir_notify_req {
       struct list_head lhead;
       __le16 Pid;
       __le16 PidHigh;
       __u16 Mid;
       __u16 Tid;
       __u16 Uid;
       __u16 netfid;
       __u32 filter; /* CompletionFilter (for multishot) */
       int multishot;
       struct file * pfile;
};

#define   MID_FREE 0
#define   MID_REQUEST_ALLOCATED 1
#define   MID_REQUEST_SUBMITTED 2
#define   MID_RESPONSE_RECEIVED 4
#define   MID_RETRY_NEEDED      8 /* session closed while this request out */
#define   MID_NO_RESP_NEEDED 0x10

/* Types of response buffer returned from SendReceive2 */
#define   CIFS_NO_BUFFER        0    /* Response buffer not returned */
#define   CIFS_SMALL_BUFFER     1
#define   CIFS_LARGE_BUFFER     2
#define   CIFS_IOVEC            4    /* array of response buffers */

/* Security Flags: indicate type of session setup needed */
#define   CIFSSEC_MAY_SIGN	0x00001
#define   CIFSSEC_MAY_NTLM	0x00002
#define   CIFSSEC_MAY_NTLMV2	0x00004
#define   CIFSSEC_MAY_KRB5	0x00008
#ifdef CONFIG_CIFS_WEAK_PW_HASH
#define   CIFSSEC_MAY_LANMAN	0x00010
#define   CIFSSEC_MAY_PLNTXT	0x00020
#endif /* weak passwords */
#define   CIFSSEC_MAY_SEAL	0x00040 /* not supported yet */

#define   CIFSSEC_MUST_SIGN	0x01001
/* note that only one of the following can be set so the
result of setting MUST flags more than once will be to
require use of the stronger protocol */
#define   CIFSSEC_MUST_NTLM	0x02002
#define   CIFSSEC_MUST_NTLMV2	0x04004
#define   CIFSSEC_MUST_KRB5	0x08008
#ifdef CONFIG_CIFS_WEAK_PW_HASH
#define   CIFSSEC_MUST_LANMAN	0x10010
#define   CIFSSEC_MUST_PLNTXT	0x20020
#define   CIFSSEC_MASK          0x37037 /* current flags supported if weak */
#else	  
#define	  CIFSSEC_MASK          0x07007 /* flags supported if no weak config */
#endif /* WEAK_PW_HASH */
#define   CIFSSEC_MUST_SEAL	0x40040 /* not supported yet */

#define   CIFSSEC_DEF  CIFSSEC_MAY_SIGN | CIFSSEC_MAY_NTLM | CIFSSEC_MAY_NTLMV2
#define   CIFSSEC_MAX  CIFSSEC_MUST_SIGN | CIFSSEC_MUST_NTLMV2
/*
 *****************************************************************
 * All constants go here
 *****************************************************************
 */

#define UID_HASH (16)

/*
 * Note that ONE module should define _DECLARE_GLOBALS_HERE to cause the
 * following to be declared.
 */

/****************************************************************************
 *  Locking notes.  All updates to global variables and lists should be
 *                  protected by spinlocks or semaphores.
 *
 *  Spinlocks
 *  ---------
 *  GlobalMid_Lock protects:
 *	list operations on pending_mid_q and oplockQ
 *      updates to XID counters, multiplex id  and SMB sequence numbers
 *  GlobalSMBSesLock protects:
 *	list operations on tcp and SMB session lists and tCon lists
 *  f_owner.lock protects certain per file struct operations
 *  mapping->page_lock protects certain per page operations
 *
 *  Semaphores
 *  ----------
 *  sesSem     operations on smb session
 *  tconSem    operations on tree connection
 *  fh_sem      file handle reconnection operations 
 *
 ****************************************************************************/

#ifdef DECLARE_GLOBALS_HERE
#define GLOBAL_EXTERN
#else
#define GLOBAL_EXTERN extern
#endif

/*
 * The list of servers that did not respond with NT LM 0.12.
 * This list helps improve performance and eliminate the messages indicating
 * that we had a communications error talking to the server in this list. 
 */
GLOBAL_EXTERN struct servers_not_supported *NotSuppList;	/*@z4a */

/*
 * The following is a hash table of all the users we know about.
 */
GLOBAL_EXTERN struct smbUidInfo *GlobalUidList[UID_HASH];

GLOBAL_EXTERN struct list_head GlobalServerList; /* BB not implemented yet */
GLOBAL_EXTERN struct list_head GlobalSMBSessionList;
GLOBAL_EXTERN struct list_head GlobalTreeConnectionList;
GLOBAL_EXTERN rwlock_t GlobalSMBSeslock;  /* protects list inserts on 3 above */

GLOBAL_EXTERN struct list_head GlobalOplock_Q;

GLOBAL_EXTERN struct list_head GlobalDnotifyReqList; /* Outstanding dir notify requests */
GLOBAL_EXTERN struct list_head GlobalDnotifyRsp_Q;/* DirNotify response queue */

/*
 * Global transaction id (XID) information
 */
GLOBAL_EXTERN unsigned int GlobalCurrentXid;	/* protected by GlobalMid_Sem */
GLOBAL_EXTERN unsigned int GlobalTotalActiveXid; /* prot by GlobalMid_Sem */
GLOBAL_EXTERN unsigned int GlobalMaxActiveXid;	/* prot by GlobalMid_Sem */
GLOBAL_EXTERN spinlock_t GlobalMid_Lock;  /* protects above & list operations */
					  /* on midQ entries */
GLOBAL_EXTERN char Local_System_Name[15];

/*
 *  Global counters, updated atomically
 */
GLOBAL_EXTERN atomic_t sesInfoAllocCount;
GLOBAL_EXTERN atomic_t tconInfoAllocCount;
GLOBAL_EXTERN atomic_t tcpSesAllocCount;
GLOBAL_EXTERN atomic_t tcpSesReconnectCount;
GLOBAL_EXTERN atomic_t tconInfoReconnectCount;

/* Various Debug counters to remove someday (BB) */
GLOBAL_EXTERN atomic_t bufAllocCount;    /* current number allocated  */
#ifdef CONFIG_CIFS_STATS2
GLOBAL_EXTERN atomic_t totBufAllocCount; /* total allocated over all time */
GLOBAL_EXTERN atomic_t totSmBufAllocCount;
#endif
GLOBAL_EXTERN atomic_t smBufAllocCount;
GLOBAL_EXTERN atomic_t midCount;

/* Misc globals */
GLOBAL_EXTERN unsigned int multiuser_mount; /* if enabled allows new sessions
				to be established on existing mount if we
				have the uid/password or Kerberos credential 
				or equivalent for current user */
GLOBAL_EXTERN unsigned int oplockEnabled;
GLOBAL_EXTERN unsigned int experimEnabled;
GLOBAL_EXTERN unsigned int lookupCacheEnabled;
GLOBAL_EXTERN unsigned int extended_security;	/* if on, session setup sent 
				with more secure ntlmssp2 challenge/resp */
GLOBAL_EXTERN unsigned int sign_CIFS_PDUs;  /* enable smb packet signing */
GLOBAL_EXTERN unsigned int secFlags;
GLOBAL_EXTERN unsigned int linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
GLOBAL_EXTERN unsigned int CIFSMaxBufSize;  /* max size not including hdr */
GLOBAL_EXTERN unsigned int cifs_min_rcv;    /* min size of big ntwrk buf pool */
GLOBAL_EXTERN unsigned int cifs_min_small;  /* min size of small buf pool */
GLOBAL_EXTERN unsigned int cifs_max_pending; /* MAX requests at once to server*/

OpenPOWER on IntegriCloud