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TOMOYO Linux Cross Reference
Linux/fs/cifs/misc.c

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  1 /*
  2  *   fs/cifs/misc.c
  3  *
  4  *   Copyright (C) International Business Machines  Corp., 2002,2008
  5  *   Author(s): Steve French (sfrench@us.ibm.com)
  6  *
  7  *   This library is free software; you can redistribute it and/or modify
  8  *   it under the terms of the GNU Lesser General Public License as published
  9  *   by the Free Software Foundation; either version 2.1 of the License, or
 10  *   (at your option) any later version.
 11  *
 12  *   This library is distributed in the hope that it will be useful,
 13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 15  *   the GNU Lesser General Public License for more details.
 16  *
 17  *   You should have received a copy of the GNU Lesser General Public License
 18  *   along with this library; if not, write to the Free Software
 19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 20  */
 21 
 22 #include <linux/slab.h>
 23 #include <linux/ctype.h>
 24 #include <linux/mempool.h>
 25 #include "cifspdu.h"
 26 #include "cifsglob.h"
 27 #include "cifsproto.h"
 28 #include "cifs_debug.h"
 29 #include "smberr.h"
 30 #include "nterr.h"
 31 #include "cifs_unicode.h"
 32 #ifdef CONFIG_CIFS_SMB2
 33 #include "smb2pdu.h"
 34 #endif
 35 
 36 extern mempool_t *cifs_sm_req_poolp;
 37 extern mempool_t *cifs_req_poolp;
 38 
 39 /* The xid serves as a useful identifier for each incoming vfs request,
 40    in a similar way to the mid which is useful to track each sent smb,
 41    and CurrentXid can also provide a running counter (although it
 42    will eventually wrap past zero) of the total vfs operations handled
 43    since the cifs fs was mounted */
 44 
 45 unsigned int
 46 _get_xid(void)
 47 {
 48         unsigned int xid;
 49 
 50         spin_lock(&GlobalMid_Lock);
 51         GlobalTotalActiveXid++;
 52 
 53         /* keep high water mark for number of simultaneous ops in filesystem */
 54         if (GlobalTotalActiveXid > GlobalMaxActiveXid)
 55                 GlobalMaxActiveXid = GlobalTotalActiveXid;
 56         if (GlobalTotalActiveXid > 65000)
 57                 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
 58         xid = GlobalCurrentXid++;
 59         spin_unlock(&GlobalMid_Lock);
 60         return xid;
 61 }
 62 
 63 void
 64 _free_xid(unsigned int xid)
 65 {
 66         spin_lock(&GlobalMid_Lock);
 67         /* if (GlobalTotalActiveXid == 0)
 68                 BUG(); */
 69         GlobalTotalActiveXid--;
 70         spin_unlock(&GlobalMid_Lock);
 71 }
 72 
 73 struct cifs_ses *
 74 sesInfoAlloc(void)
 75 {
 76         struct cifs_ses *ret_buf;
 77 
 78         ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
 79         if (ret_buf) {
 80                 atomic_inc(&sesInfoAllocCount);
 81                 ret_buf->status = CifsNew;
 82                 ++ret_buf->ses_count;
 83                 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
 84                 INIT_LIST_HEAD(&ret_buf->tcon_list);
 85                 mutex_init(&ret_buf->session_mutex);
 86         }
 87         return ret_buf;
 88 }
 89 
 90 void
 91 sesInfoFree(struct cifs_ses *buf_to_free)
 92 {
 93         if (buf_to_free == NULL) {
 94                 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
 95                 return;
 96         }
 97 
 98         atomic_dec(&sesInfoAllocCount);
 99         kfree(buf_to_free->serverOS);
100         kfree(buf_to_free->serverDomain);
101         kfree(buf_to_free->serverNOS);
102         if (buf_to_free->password) {
103                 memset(buf_to_free->password, 0, strlen(buf_to_free->password));
104                 kfree(buf_to_free->password);
105         }
106         kfree(buf_to_free->user_name);
107         kfree(buf_to_free->domainName);
108         kfree(buf_to_free->auth_key.response);
109         kfree(buf_to_free);
110 }
111 
112 struct cifs_tcon *
113 tconInfoAlloc(void)
114 {
115         struct cifs_tcon *ret_buf;
116         ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
117         if (ret_buf) {
118                 atomic_inc(&tconInfoAllocCount);
119                 ret_buf->tidStatus = CifsNew;
120                 ++ret_buf->tc_count;
121                 INIT_LIST_HEAD(&ret_buf->openFileList);
122                 INIT_LIST_HEAD(&ret_buf->tcon_list);
123 #ifdef CONFIG_CIFS_STATS
124                 spin_lock_init(&ret_buf->stat_lock);
125 #endif
126         }
127         return ret_buf;
128 }
129 
130 void
131 tconInfoFree(struct cifs_tcon *buf_to_free)
132 {
133         if (buf_to_free == NULL) {
134                 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
135                 return;
136         }
137         atomic_dec(&tconInfoAllocCount);
138         kfree(buf_to_free->nativeFileSystem);
139         if (buf_to_free->password) {
140                 memset(buf_to_free->password, 0, strlen(buf_to_free->password));
141                 kfree(buf_to_free->password);
142         }
143         kfree(buf_to_free);
144 }
145 
146 struct smb_hdr *
147 cifs_buf_get(void)
148 {
149         struct smb_hdr *ret_buf = NULL;
150         size_t buf_size = sizeof(struct smb_hdr);
151 
152 #ifdef CONFIG_CIFS_SMB2
153         /*
154          * SMB2 header is bigger than CIFS one - no problems to clean some
155          * more bytes for CIFS.
156          */
157         buf_size = sizeof(struct smb2_hdr);
158 #endif
159         /*
160          * We could use negotiated size instead of max_msgsize -
161          * but it may be more efficient to always alloc same size
162          * albeit slightly larger than necessary and maxbuffersize
163          * defaults to this and can not be bigger.
164          */
165         ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
166 
167         /* clear the first few header bytes */
168         /* for most paths, more is cleared in header_assemble */
169         if (ret_buf) {
170                 memset(ret_buf, 0, buf_size + 3);
171                 atomic_inc(&bufAllocCount);
172 #ifdef CONFIG_CIFS_STATS2
173                 atomic_inc(&totBufAllocCount);
174 #endif /* CONFIG_CIFS_STATS2 */
175         }
176 
177         return ret_buf;
178 }
179 
180 void
181 cifs_buf_release(void *buf_to_free)
182 {
183         if (buf_to_free == NULL) {
184                 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
185                 return;
186         }
187         mempool_free(buf_to_free, cifs_req_poolp);
188 
189         atomic_dec(&bufAllocCount);
190         return;
191 }
192 
193 struct smb_hdr *
194 cifs_small_buf_get(void)
195 {
196         struct smb_hdr *ret_buf = NULL;
197 
198 /* We could use negotiated size instead of max_msgsize -
199    but it may be more efficient to always alloc same size
200    albeit slightly larger than necessary and maxbuffersize
201    defaults to this and can not be bigger */
202         ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
203         if (ret_buf) {
204         /* No need to clear memory here, cleared in header assemble */
205         /*      memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
206                 atomic_inc(&smBufAllocCount);
207 #ifdef CONFIG_CIFS_STATS2
208                 atomic_inc(&totSmBufAllocCount);
209 #endif /* CONFIG_CIFS_STATS2 */
210 
211         }
212         return ret_buf;
213 }
214 
215 void
216 cifs_small_buf_release(void *buf_to_free)
217 {
218 
219         if (buf_to_free == NULL) {
220                 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
221                 return;
222         }
223         mempool_free(buf_to_free, cifs_sm_req_poolp);
224 
225         atomic_dec(&smBufAllocCount);
226         return;
227 }
228 
229 /* NB: MID can not be set if treeCon not passed in, in that
230    case it is responsbility of caller to set the mid */
231 void
232 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
233                 const struct cifs_tcon *treeCon, int word_count
234                 /* length of fixed section (word count) in two byte units  */)
235 {
236         char *temp = (char *) buffer;
237 
238         memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
239 
240         buffer->smb_buf_length = cpu_to_be32(
241             (2 * word_count) + sizeof(struct smb_hdr) -
242             4 /*  RFC 1001 length field does not count */  +
243             2 /* for bcc field itself */) ;
244 
245         buffer->Protocol[0] = 0xFF;
246         buffer->Protocol[1] = 'S';
247         buffer->Protocol[2] = 'M';
248         buffer->Protocol[3] = 'B';
249         buffer->Command = smb_command;
250         buffer->Flags = 0x00;   /* case sensitive */
251         buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
252         buffer->Pid = cpu_to_le16((__u16)current->tgid);
253         buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
254         if (treeCon) {
255                 buffer->Tid = treeCon->tid;
256                 if (treeCon->ses) {
257                         if (treeCon->ses->capabilities & CAP_UNICODE)
258                                 buffer->Flags2 |= SMBFLG2_UNICODE;
259                         if (treeCon->ses->capabilities & CAP_STATUS32)
260                                 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
261 
262                         /* Uid is not converted */
263                         buffer->Uid = treeCon->ses->Suid;
264                         buffer->Mid = get_next_mid(treeCon->ses->server);
265                 }
266                 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
267                         buffer->Flags2 |= SMBFLG2_DFS;
268                 if (treeCon->nocase)
269                         buffer->Flags  |= SMBFLG_CASELESS;
270                 if ((treeCon->ses) && (treeCon->ses->server))
271                         if (treeCon->ses->server->sign)
272                                 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
273         }
274 
275 /*  endian conversion of flags is now done just before sending */
276         buffer->WordCount = (char) word_count;
277         return;
278 }
279 
280 static int
281 check_smb_hdr(struct smb_hdr *smb)
282 {
283         /* does it have the right SMB "signature" ? */
284         if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
285                 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
286                          *(unsigned int *)smb->Protocol);
287                 return 1;
288         }
289 
290         /* if it's a response then accept */
291         if (smb->Flags & SMBFLG_RESPONSE)
292                 return 0;
293 
294         /* only one valid case where server sends us request */
295         if (smb->Command == SMB_COM_LOCKING_ANDX)
296                 return 0;
297 
298         cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
299                  get_mid(smb));
300         return 1;
301 }
302 
303 int
304 checkSMB(char *buf, unsigned int total_read)
305 {
306         struct smb_hdr *smb = (struct smb_hdr *)buf;
307         __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
308         __u32 clc_len;  /* calculated length */
309         cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
310                  total_read, rfclen);
311 
312         /* is this frame too small to even get to a BCC? */
313         if (total_read < 2 + sizeof(struct smb_hdr)) {
314                 if ((total_read >= sizeof(struct smb_hdr) - 1)
315                             && (smb->Status.CifsError != 0)) {
316                         /* it's an error return */
317                         smb->WordCount = 0;
318                         /* some error cases do not return wct and bcc */
319                         return 0;
320                 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
321                                 (smb->WordCount == 0)) {
322                         char *tmp = (char *)smb;
323                         /* Need to work around a bug in two servers here */
324                         /* First, check if the part of bcc they sent was zero */
325                         if (tmp[sizeof(struct smb_hdr)] == 0) {
326                                 /* some servers return only half of bcc
327                                  * on simple responses (wct, bcc both zero)
328                                  * in particular have seen this on
329                                  * ulogoffX and FindClose. This leaves
330                                  * one byte of bcc potentially unitialized
331                                  */
332                                 /* zero rest of bcc */
333                                 tmp[sizeof(struct smb_hdr)+1] = 0;
334                                 return 0;
335                         }
336                         cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
337                 } else {
338                         cifs_dbg(VFS, "Length less than smb header size\n");
339                 }
340                 return -EIO;
341         }
342 
343         /* otherwise, there is enough to get to the BCC */
344         if (check_smb_hdr(smb))
345                 return -EIO;
346         clc_len = smbCalcSize(smb);
347 
348         if (4 + rfclen != total_read) {
349                 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
350                          rfclen);
351                 return -EIO;
352         }
353 
354         if (4 + rfclen != clc_len) {
355                 __u16 mid = get_mid(smb);
356                 /* check if bcc wrapped around for large read responses */
357                 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
358                         /* check if lengths match mod 64K */
359                         if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
360                                 return 0; /* bcc wrapped */
361                 }
362                 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
363                          clc_len, 4 + rfclen, mid);
364 
365                 if (4 + rfclen < clc_len) {
366                         cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
367                                  rfclen, mid);
368                         return -EIO;
369                 } else if (rfclen > clc_len + 512) {
370                         /*
371                          * Some servers (Windows XP in particular) send more
372                          * data than the lengths in the SMB packet would
373                          * indicate on certain calls (byte range locks and
374                          * trans2 find first calls in particular). While the
375                          * client can handle such a frame by ignoring the
376                          * trailing data, we choose limit the amount of extra
377                          * data to 512 bytes.
378                          */
379                         cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
380                                  rfclen, mid);
381                         return -EIO;
382                 }
383         }
384         return 0;
385 }
386 
387 bool
388 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
389 {
390         struct smb_hdr *buf = (struct smb_hdr *)buffer;
391         struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
392         struct list_head *tmp, *tmp1, *tmp2;
393         struct cifs_ses *ses;
394         struct cifs_tcon *tcon;
395         struct cifsInodeInfo *pCifsInode;
396         struct cifsFileInfo *netfile;
397 
398         cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
399         if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
400            (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
401                 struct smb_com_transaction_change_notify_rsp *pSMBr =
402                         (struct smb_com_transaction_change_notify_rsp *)buf;
403                 struct file_notify_information *pnotify;
404                 __u32 data_offset = 0;
405                 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
406                         data_offset = le32_to_cpu(pSMBr->DataOffset);
407 
408                         pnotify = (struct file_notify_information *)
409                                 ((char *)&pSMBr->hdr.Protocol + data_offset);
410                         cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
411                                  pnotify->FileName, pnotify->Action);
412                         /*   cifs_dump_mem("Rcvd notify Data: ",buf,
413                                 sizeof(struct smb_hdr)+60); */
414                         return true;
415                 }
416                 if (pSMBr->hdr.Status.CifsError) {
417                         cifs_dbg(FYI, "notify err 0x%d\n",
418                                  pSMBr->hdr.Status.CifsError);
419                         return true;
420                 }
421                 return false;
422         }
423         if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
424                 return false;
425         if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
426                 /* no sense logging error on invalid handle on oplock
427                    break - harmless race between close request and oplock
428                    break response is expected from time to time writing out
429                    large dirty files cached on the client */
430                 if ((NT_STATUS_INVALID_HANDLE) ==
431                    le32_to_cpu(pSMB->hdr.Status.CifsError)) {
432                         cifs_dbg(FYI, "invalid handle on oplock break\n");
433                         return true;
434                 } else if (ERRbadfid ==
435                    le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
436                         return true;
437                 } else {
438                         return false; /* on valid oplock brk we get "request" */
439                 }
440         }
441         if (pSMB->hdr.WordCount != 8)
442                 return false;
443 
444         cifs_dbg(FYI, "oplock type 0x%d level 0x%d\n",
445                  pSMB->LockType, pSMB->OplockLevel);
446         if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
447                 return false;
448 
449         /* look up tcon based on tid & uid */
450         spin_lock(&cifs_tcp_ses_lock);
451         list_for_each(tmp, &srv->smb_ses_list) {
452                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
453                 list_for_each(tmp1, &ses->tcon_list) {
454                         tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
455                         if (tcon->tid != buf->Tid)
456                                 continue;
457 
458                         cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
459                         spin_lock(&cifs_file_list_lock);
460                         list_for_each(tmp2, &tcon->openFileList) {
461                                 netfile = list_entry(tmp2, struct cifsFileInfo,
462                                                      tlist);
463                                 if (pSMB->Fid != netfile->fid.netfid)
464                                         continue;
465 
466                                 cifs_dbg(FYI, "file id match, oplock break\n");
467                                 pCifsInode = CIFS_I(netfile->dentry->d_inode);
468 
469                                 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
470                                         &pCifsInode->flags);
471 
472                                 /*
473                                  * Set flag if the server downgrades the oplock
474                                  * to L2 else clear.
475                                  */
476                                 if (pSMB->OplockLevel)
477                                         set_bit(
478                                            CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
479                                            &pCifsInode->flags);
480                                 else
481                                         clear_bit(
482                                            CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
483                                            &pCifsInode->flags);
484 
485                                 queue_work(cifsiod_wq,
486                                            &netfile->oplock_break);
487                                 netfile->oplock_break_cancelled = false;
488 
489                                 spin_unlock(&cifs_file_list_lock);
490                                 spin_unlock(&cifs_tcp_ses_lock);
491                                 return true;
492                         }
493                         spin_unlock(&cifs_file_list_lock);
494                         spin_unlock(&cifs_tcp_ses_lock);
495                         cifs_dbg(FYI, "No matching file for oplock break\n");
496                         return true;
497                 }
498         }
499         spin_unlock(&cifs_tcp_ses_lock);
500         cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
501         return true;
502 }
503 
504 void
505 dump_smb(void *buf, int smb_buf_length)
506 {
507         int i, j;
508         char debug_line[17];
509         unsigned char *buffer = buf;
510 
511         if (traceSMB == 0)
512                 return;
513 
514         for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
515                 if (i % 8 == 0) {
516                         /* have reached the beginning of line */
517                         printk(KERN_DEBUG "| ");
518                         j = 0;
519                 }
520                 printk("%0#4x ", buffer[i]);
521                 debug_line[2 * j] = ' ';
522                 if (isprint(buffer[i]))
523                         debug_line[1 + (2 * j)] = buffer[i];
524                 else
525                         debug_line[1 + (2 * j)] = '_';
526 
527                 if (i % 8 == 7) {
528                         /* reached end of line, time to print ascii */
529                         debug_line[16] = 0;
530                         printk(" | %s\n", debug_line);
531                 }
532         }
533         for (; j < 8; j++) {
534                 printk("     ");
535                 debug_line[2 * j] = ' ';
536                 debug_line[1 + (2 * j)] = ' ';
537         }
538         printk(" | %s\n", debug_line);
539         return;
540 }
541 
542 void
543 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
544 {
545         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
546                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
547                 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s. This server doesn't seem to support them properly. Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n",
548                          cifs_sb_master_tcon(cifs_sb)->treeName);
549         }
550 }
551 
552 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
553 {
554         oplock &= 0xF;
555 
556         if (oplock == OPLOCK_EXCLUSIVE) {
557                 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
558                 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
559                          &cinode->vfs_inode);
560         } else if (oplock == OPLOCK_READ) {
561                 cinode->oplock = CIFS_CACHE_READ_FLG;
562                 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
563                          &cinode->vfs_inode);
564         } else
565                 cinode->oplock = 0;
566 }
567 
568 static int
569 cifs_oplock_break_wait(void *unused)
570 {
571         schedule();
572         return signal_pending(current) ? -ERESTARTSYS : 0;
573 }
574 
575 /*
576  * We wait for oplock breaks to be processed before we attempt to perform
577  * writes.
578  */
579 int cifs_get_writer(struct cifsInodeInfo *cinode)
580 {
581         int rc;
582 
583 start:
584         rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
585                                    cifs_oplock_break_wait, TASK_KILLABLE);
586         if (rc)
587                 return rc;
588 
589         spin_lock(&cinode->writers_lock);
590         if (!cinode->writers)
591                 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
592         cinode->writers++;
593         /* Check to see if we have started servicing an oplock break */
594         if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
595                 cinode->writers--;
596                 if (cinode->writers == 0) {
597                         clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
598                         wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
599                 }
600                 spin_unlock(&cinode->writers_lock);
601                 goto start;
602         }
603         spin_unlock(&cinode->writers_lock);
604         return 0;
605 }
606 
607 void cifs_put_writer(struct cifsInodeInfo *cinode)
608 {
609         spin_lock(&cinode->writers_lock);
610         cinode->writers--;
611         if (cinode->writers == 0) {
612                 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
613                 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
614         }
615         spin_unlock(&cinode->writers_lock);
616 }
617 
618 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
619 {
620         clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
621         wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
622 }
623 
624 bool
625 backup_cred(struct cifs_sb_info *cifs_sb)
626 {
627         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
628                 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
629                         return true;
630         }
631         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
632                 if (in_group_p(cifs_sb->mnt_backupgid))
633                         return true;
634         }
635 
636         return false;
637 }
638 
639 void
640 cifs_del_pending_open(struct cifs_pending_open *open)
641 {
642         spin_lock(&cifs_file_list_lock);
643         list_del(&open->olist);
644         spin_unlock(&cifs_file_list_lock);
645 }
646 
647 void
648 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
649                              struct cifs_pending_open *open)
650 {
651 #ifdef CONFIG_CIFS_SMB2
652         memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
653 #endif
654         open->oplock = CIFS_OPLOCK_NO_CHANGE;
655         open->tlink = tlink;
656         fid->pending_open = open;
657         list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
658 }
659 
660 void
661 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
662                       struct cifs_pending_open *open)
663 {
664         spin_lock(&cifs_file_list_lock);
665         cifs_add_pending_open_locked(fid, tlink, open);
666         spin_unlock(&cifs_file_list_lock);
667 }
668 

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