fs/cifs/misc.c

   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 <linux/vmalloc.h>
  26 #include "cifspdu.h"
  27 #include "cifsglob.h"
  28 #include "cifsproto.h"
  29 #include "cifs_debug.h"
  30 #include "smberr.h"
  31 #include "nterr.h"
  32 #include "cifs_unicode.h"
  33 #include "smb2pdu.h"
  34
  35 extern mempool_t *cifs_sm_req_poolp;
  36 extern mempool_t *cifs_req_poolp;
  37
  38 /* The xid serves as a useful identifier for each incoming vfs request,
  39    in a similar way to the mid which is useful to track each sent smb,
  40    and CurrentXid can also provide a running counter (although it
  41    will eventually wrap past zero) of the total vfs operations handled
  42    since the cifs fs was mounted */
  43
  44 unsigned int
  45 _get_xid(void)
  46 {
  47         unsigned int xid;
  48
  49         spin_lock(&GlobalMid_Lock);
  50         GlobalTotalActiveXid++;
  51
  52         /* keep high water mark for number of simultaneous ops in filesystem */
  53         if (GlobalTotalActiveXid > GlobalMaxActiveXid)
  54                 GlobalMaxActiveXid = GlobalTotalActiveXid;
  55         if (GlobalTotalActiveXid > 65000)
  56                 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
  57         xid = GlobalCurrentXid++;
  58         spin_unlock(&GlobalMid_Lock);
  59         return xid;
  60 }
  61
  62 void
  63 _free_xid(unsigned int xid)
  64 {
  65         spin_lock(&GlobalMid_Lock);
  66         /* if (GlobalTotalActiveXid == 0)
  67                 BUG(); */
  68         GlobalTotalActiveXid--;
  69         spin_unlock(&GlobalMid_Lock);
  70 }
  71
  72 struct cifs_ses *
  73 sesInfoAlloc(void)
  74 {
  75         struct cifs_ses *ret_buf;
  76
  77         ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
  78         if (ret_buf) {
  79                 atomic_inc(&sesInfoAllocCount);
  80                 ret_buf->status = CifsNew;
  81                 ++ret_buf->ses_count;
  82                 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
  83                 INIT_LIST_HEAD(&ret_buf->tcon_list);
  84                 mutex_init(&ret_buf->session_mutex);
  85         }
  86         return ret_buf;
  87 }
  88
  89 void
  90 sesInfoFree(struct cifs_ses *buf_to_free)
  91 {
  92         if (buf_to_free == NULL) {
  93                 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
  94                 return;
  95         }
  96
  97         atomic_dec(&sesInfoAllocCount);
  98         kfree(buf_to_free->serverOS);
  99         kfree(buf_to_free->serverDomain);
 100         kfree(buf_to_free->serverNOS);
 101         kzfree(buf_to_free->password);
 102         kfree(buf_to_free->user_name);
 103         kfree(buf_to_free->domainName);
 104         kzfree(buf_to_free->auth_key.response);
 105         kzfree(buf_to_free);
 106 }
 107
 108 struct cifs_tcon *
 109 tconInfoAlloc(void)
 110 {
 111         struct cifs_tcon *ret_buf;
 112         ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
 113         if (ret_buf) {
 114                 atomic_inc(&tconInfoAllocCount);
 115                 ret_buf->tidStatus = CifsNew;
 116                 ++ret_buf->tc_count;
 117                 INIT_LIST_HEAD(&ret_buf->openFileList);
 118                 INIT_LIST_HEAD(&ret_buf->tcon_list);
 119                 spin_lock_init(&ret_buf->open_file_lock);
 120 #ifdef CONFIG_CIFS_STATS
 121                 spin_lock_init(&ret_buf->stat_lock);
 122 #endif
 123         }
 124         return ret_buf;
 125 }
 126
 127 void
 128 tconInfoFree(struct cifs_tcon *buf_to_free)
 129 {
 130         if (buf_to_free == NULL) {
 131                 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
 132                 return;
 133         }
 134         atomic_dec(&tconInfoAllocCount);
 135         kfree(buf_to_free->nativeFileSystem);
 136         kzfree(buf_to_free->password);
 137         kfree(buf_to_free);
 138 }
 139
 140 struct smb_hdr *
 141 cifs_buf_get(void)
 142 {
 143         struct smb_hdr *ret_buf = NULL;
 144         /*
 145          * SMB2 header is bigger than CIFS one - no problems to clean some
 146          * more bytes for CIFS.
 147          */
 148         size_t buf_size = sizeof(struct smb2_hdr);
 149
 150         /*
 151          * We could use negotiated size instead of max_msgsize -
 152          * but it may be more efficient to always alloc same size
 153          * albeit slightly larger than necessary and maxbuffersize
 154          * defaults to this and can not be bigger.
 155          */
 156         ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
 157
 158         /* clear the first few header bytes */
 159         /* for most paths, more is cleared in header_assemble */
 160         memset(ret_buf, 0, buf_size + 3);
 161         atomic_inc(&bufAllocCount);
 162 #ifdef CONFIG_CIFS_STATS2
 163         atomic_inc(&totBufAllocCount);
 164 #endif /* CONFIG_CIFS_STATS2 */
 165
 166         return ret_buf;
 167 }
 168
 169 void
 170 cifs_buf_release(void *buf_to_free)
 171 {
 172         if (buf_to_free == NULL) {
 173                 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
 174                 return;
 175         }
 176         mempool_free(buf_to_free, cifs_req_poolp);
 177
 178         atomic_dec(&bufAllocCount);
 179         return;
 180 }
 181
 182 struct smb_hdr *
 183 cifs_small_buf_get(void)
 184 {
 185         struct smb_hdr *ret_buf = NULL;
 186
 187 /* We could use negotiated size instead of max_msgsize -
 188    but it may be more efficient to always alloc same size
 189    albeit slightly larger than necessary and maxbuffersize
 190    defaults to this and can not be bigger */
 191         ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
 192         /* No need to clear memory here, cleared in header assemble */
 193         /*      memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
 194         atomic_inc(&smBufAllocCount);
 195 #ifdef CONFIG_CIFS_STATS2
 196         atomic_inc(&totSmBufAllocCount);
 197 #endif /* CONFIG_CIFS_STATS2 */
 198
 199         return ret_buf;
 200 }
 201
 202 void
 203 cifs_small_buf_release(void *buf_to_free)
 204 {
 205
 206         if (buf_to_free == NULL) {
 207                 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
 208                 return;
 209         }
 210         mempool_free(buf_to_free, cifs_sm_req_poolp);
 211
 212         atomic_dec(&smBufAllocCount);
 213         return;
 214 }
 215
 216 void
 217 free_rsp_buf(int resp_buftype, void *rsp)
 218 {
 219         if (resp_buftype == CIFS_SMALL_BUFFER)
 220                 cifs_small_buf_release(rsp);
 221         else if (resp_buftype == CIFS_LARGE_BUFFER)
 222                 cifs_buf_release(rsp);
 223 }
 224
 225 /* NB: MID can not be set if treeCon not passed in, in that
 226    case it is responsbility of caller to set the mid */
 227 void
 228 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
 229                 const struct cifs_tcon *treeCon, int word_count
 230                 /* length of fixed section (word count) in two byte units  */)
 231 {
 232         char *temp = (char *) buffer;
 233
 234         memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
 235
 236         buffer->smb_buf_length = cpu_to_be32(
 237             (2 * word_count) + sizeof(struct smb_hdr) -
 238             4 /*  RFC 1001 length field does not count */  +
 239             2 /* for bcc field itself */) ;
 240
 241         buffer->Protocol[0] = 0xFF;
 242         buffer->Protocol[1] = 'S';
 243         buffer->Protocol[2] = 'M';
 244         buffer->Protocol[3] = 'B';
 245         buffer->Command = smb_command;
 246         buffer->Flags = 0x00;   /* case sensitive */
 247         buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
 248         buffer->Pid = cpu_to_le16((__u16)current->tgid);
 249         buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
 250         if (treeCon) {
 251                 buffer->Tid = treeCon->tid;
 252                 if (treeCon->ses) {
 253                         if (treeCon->ses->capabilities & CAP_UNICODE)
 254                                 buffer->Flags2 |= SMBFLG2_UNICODE;
 255                         if (treeCon->ses->capabilities & CAP_STATUS32)
 256                                 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
 257
 258                         /* Uid is not converted */
 259                         buffer->Uid = treeCon->ses->Suid;
 260                         buffer->Mid = get_next_mid(treeCon->ses->server);
 261                 }
 262                 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
 263                         buffer->Flags2 |= SMBFLG2_DFS;
 264                 if (treeCon->nocase)
 265                         buffer->Flags  |= SMBFLG_CASELESS;
 266                 if ((treeCon->ses) && (treeCon->ses->server))
 267                         if (treeCon->ses->server->sign)
 268                                 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
 269         }
 270
 271 /*  endian conversion of flags is now done just before sending */
 272         buffer->WordCount = (char) word_count;
 273         return;
 274 }
 275
 276 static int
 277 check_smb_hdr(struct smb_hdr *smb)
 278 {
 279         /* does it have the right SMB "signature" ? */
 280         if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
 281                 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
 282                          *(unsigned int *)smb->Protocol);
 283                 return 1;
 284         }
 285
 286         /* if it's a response then accept */
 287         if (smb->Flags & SMBFLG_RESPONSE)
 288                 return 0;
 289
 290         /* only one valid case where server sends us request */
 291         if (smb->Command == SMB_COM_LOCKING_ANDX)
 292                 return 0;
 293
 294         cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
 295                  get_mid(smb));
 296         return 1;
 297 }
 298
 299 int
 300 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
 301 {
 302         struct smb_hdr *smb = (struct smb_hdr *)buf;
 303         __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
 304         __u32 clc_len;  /* calculated length */
 305         cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
 306                  total_read, rfclen);
 307
 308         /* is this frame too small to even get to a BCC? */
 309         if (total_read < 2 + sizeof(struct smb_hdr)) {
 310                 if ((total_read >= sizeof(struct smb_hdr) - 1)
 311                             && (smb->Status.CifsError != 0)) {
 312                         /* it's an error return */
 313                         smb->WordCount = 0;
 314                         /* some error cases do not return wct and bcc */
 315                         return 0;
 316                 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
 317                                 (smb->WordCount == 0)) {
 318                         char *tmp = (char *)smb;
 319                         /* Need to work around a bug in two servers here */
 320                         /* First, check if the part of bcc they sent was zero */
 321                         if (tmp[sizeof(struct smb_hdr)] == 0) {
 322                                 /* some servers return only half of bcc
 323                                  * on simple responses (wct, bcc both zero)
 324                                  * in particular have seen this on
 325                                  * ulogoffX and FindClose. This leaves
 326                                  * one byte of bcc potentially unitialized
 327                                  */
 328                                 /* zero rest of bcc */
 329                                 tmp[sizeof(struct smb_hdr)+1] = 0;
 330                                 return 0;
 331                         }
 332                         cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
 333                 } else {
 334                         cifs_dbg(VFS, "Length less than smb header size\n");
 335                 }
 336                 return -EIO;
 337         }
 338
 339         /* otherwise, there is enough to get to the BCC */
 340         if (check_smb_hdr(smb))
 341                 return -EIO;
 342         clc_len = smbCalcSize(smb);
 343
 344         if (4 + rfclen != total_read) {
 345                 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
 346                          rfclen);
 347                 return -EIO;
 348         }
 349
 350         if (4 + rfclen != clc_len) {
 351                 __u16 mid = get_mid(smb);
 352                 /* check if bcc wrapped around for large read responses */
 353                 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
 354                         /* check if lengths match mod 64K */
 355                         if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
 356                                 return 0; /* bcc wrapped */
 357                 }
 358                 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
 359                          clc_len, 4 + rfclen, mid);
 360
 361                 if (4 + rfclen < clc_len) {
 362                         cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
 363                                  rfclen, mid);
 364                         return -EIO;
 365                 } else if (rfclen > clc_len + 512) {
 366                         /*
 367                          * Some servers (Windows XP in particular) send more
 368                          * data than the lengths in the SMB packet would
 369                          * indicate on certain calls (byte range locks and
 370                          * trans2 find first calls in particular). While the
 371                          * client can handle such a frame by ignoring the
 372                          * trailing data, we choose limit the amount of extra
 373                          * data to 512 bytes.
 374                          */
 375                         cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
 376                                  rfclen, mid);
 377                         return -EIO;
 378                 }
 379         }
 380         return 0;
 381 }
 382
 383 bool
 384 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
 385 {
 386         struct smb_hdr *buf = (struct smb_hdr *)buffer;
 387         struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
 388         struct list_head *tmp, *tmp1, *tmp2;
 389         struct cifs_ses *ses;
 390         struct cifs_tcon *tcon;
 391         struct cifsInodeInfo *pCifsInode;
 392         struct cifsFileInfo *netfile;
 393
 394         cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
 395         if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
 396            (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
 397                 struct smb_com_transaction_change_notify_rsp *pSMBr =
 398                         (struct smb_com_transaction_change_notify_rsp *)buf;
 399                 struct file_notify_information *pnotify;
 400                 __u32 data_offset = 0;
 401                 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
 402                         data_offset = le32_to_cpu(pSMBr->DataOffset);
 403
 404                         pnotify = (struct file_notify_information *)
 405                                 ((char *)&pSMBr->hdr.Protocol + data_offset);
 406                         cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
 407                                  pnotify->FileName, pnotify->Action);
 408                         /*   cifs_dump_mem("Rcvd notify Data: ",buf,
 409                                 sizeof(struct smb_hdr)+60); */
 410                         return true;
 411                 }
 412                 if (pSMBr->hdr.Status.CifsError) {
 413                         cifs_dbg(FYI, "notify err 0x%x\n",
 414                                  pSMBr->hdr.Status.CifsError);
 415                         return true;
 416                 }
 417                 return false;
 418         }
 419         if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
 420                 return false;
 421         if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
 422                 /* no sense logging error on invalid handle on oplock
 423                    break - harmless race between close request and oplock
 424                    break response is expected from time to time writing out
 425                    large dirty files cached on the client */
 426                 if ((NT_STATUS_INVALID_HANDLE) ==
 427                    le32_to_cpu(pSMB->hdr.Status.CifsError)) {
 428                         cifs_dbg(FYI, "invalid handle on oplock break\n");
 429                         return true;
 430                 } else if (ERRbadfid ==
 431                    le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
 432                         return true;
 433                 } else {
 434                         return false; /* on valid oplock brk we get "request" */
 435                 }
 436         }
 437         if (pSMB->hdr.WordCount != 8)
 438                 return false;
 439
 440         cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
 441                  pSMB->LockType, pSMB->OplockLevel);
 442         if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
 443                 return false;
 444
 445         /* look up tcon based on tid & uid */
 446         spin_lock(&cifs_tcp_ses_lock);
 447         list_for_each(tmp, &srv->smb_ses_list) {
 448                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
 449                 list_for_each(tmp1, &ses->tcon_list) {
 450                         tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
 451                         if (tcon->tid != buf->Tid)
 452                                 continue;
 453
 454                         cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
 455                         spin_lock(&tcon->open_file_lock);
 456                         list_for_each(tmp2, &tcon->openFileList) {
 457                                 netfile = list_entry(tmp2, struct cifsFileInfo,
 458                                                      tlist);
 459                                 if (pSMB->Fid != netfile->fid.netfid)
 460                                         continue;
 461
 462                                 cifs_dbg(FYI, "file id match, oplock break\n");
 463                                 pCifsInode = CIFS_I(d_inode(netfile->dentry));
 464
 465                                 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
 466                                         &pCifsInode->flags);
 467
 468                                 /*
 469                                  * Set flag if the server downgrades the oplock
 470                                  * to L2 else clear.
 471                                  */
 472                                 if (pSMB->OplockLevel)
 473                                         set_bit(
 474                                            CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
 475                                            &pCifsInode->flags);
 476                                 else
 477                                         clear_bit(
 478                                            CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
 479                                            &pCifsInode->flags);
 480
 481                                 queue_work(cifsoplockd_wq,
 482                                            &netfile->oplock_break);
 483                                 netfile->oplock_break_cancelled = false;
 484
 485                                 spin_unlock(&tcon->open_file_lock);
 486                                 spin_unlock(&cifs_tcp_ses_lock);
 487                                 return true;
 488                         }
 489                         spin_unlock(&tcon->open_file_lock);
 490                         spin_unlock(&cifs_tcp_ses_lock);
 491                         cifs_dbg(FYI, "No matching file for oplock break\n");
 492                         return true;
 493                 }
 494         }
 495         spin_unlock(&cifs_tcp_ses_lock);
 496         cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
 497         return true;
 498 }
 499
 500 void
 501 dump_smb(void *buf, int smb_buf_length)
 502 {
 503         if (traceSMB == 0)
 504                 return;
 505
 506         print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
 507                        smb_buf_length, true);
 508 }
 509
 510 void
 511 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
 512 {
 513         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 514                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 515                 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",
 516                          cifs_sb_master_tcon(cifs_sb)->treeName);
 517         }
 518 }
 519
 520 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
 521 {
 522         oplock &= 0xF;
 523
 524         if (oplock == OPLOCK_EXCLUSIVE) {
 525                 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
 526                 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
 527                          &cinode->vfs_inode);
 528         } else if (oplock == OPLOCK_READ) {
 529                 cinode->oplock = CIFS_CACHE_READ_FLG;
 530                 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
 531                          &cinode->vfs_inode);
 532         } else
 533                 cinode->oplock = 0;
 534 }
 535
 536 /*
 537  * We wait for oplock breaks to be processed before we attempt to perform
 538  * writes.
 539  */
 540 int cifs_get_writer(struct cifsInodeInfo *cinode)
 541 {
 542         int rc;
 543
 544 start:
 545         rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
 546                          TASK_KILLABLE);
 547         if (rc)
 548                 return rc;
 549
 550         spin_lock(&cinode->writers_lock);
 551         if (!cinode->writers)
 552                 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
 553         cinode->writers++;
 554         /* Check to see if we have started servicing an oplock break */
 555         if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
 556                 cinode->writers--;
 557                 if (cinode->writers == 0) {
 558                         clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
 559                         wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
 560                 }
 561                 spin_unlock(&cinode->writers_lock);
 562                 goto start;
 563         }
 564         spin_unlock(&cinode->writers_lock);
 565         return 0;
 566 }
 567
 568 void cifs_put_writer(struct cifsInodeInfo *cinode)
 569 {
 570         spin_lock(&cinode->writers_lock);
 571         cinode->writers--;
 572         if (cinode->writers == 0) {
 573                 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
 574                 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
 575         }
 576         spin_unlock(&cinode->writers_lock);
 577 }
 578
 579 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
 580 {
 581         clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
 582         wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
 583 }
 584
 585 bool
 586 backup_cred(struct cifs_sb_info *cifs_sb)
 587 {
 588         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
 589                 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
 590                         return true;
 591         }
 592         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
 593                 if (in_group_p(cifs_sb->mnt_backupgid))
 594                         return true;
 595         }
 596
 597         return false;
 598 }
 599
 600 void
 601 cifs_del_pending_open(struct cifs_pending_open *open)
 602 {
 603         spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
 604         list_del(&open->olist);
 605         spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
 606 }
 607
 608 void
 609 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
 610                              struct cifs_pending_open *open)
 611 {
 612         memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
 613         open->oplock = CIFS_OPLOCK_NO_CHANGE;
 614         open->tlink = tlink;
 615         fid->pending_open = open;
 616         list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
 617 }
 618
 619 void
 620 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
 621                       struct cifs_pending_open *open)
 622 {
 623         spin_lock(&tlink_tcon(tlink)->open_file_lock);
 624         cifs_add_pending_open_locked(fid, tlink, open);
 625         spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
 626 }
 627
 628 /* parses DFS refferal V3 structure
 629  * caller is responsible for freeing target_nodes
 630  * returns:
 631  * - on success - 0
 632  * - on failure - errno
 633  */
 634 int
 635 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
 636                     unsigned int *num_of_nodes,
 637                     struct dfs_info3_param **target_nodes,
 638                     const struct nls_table *nls_codepage, int remap,
 639                     const char *searchName, bool is_unicode)
 640 {
 641         int i, rc = 0;
 642         char *data_end;
 643         struct dfs_referral_level_3 *ref;
 644
 645         *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
 646
 647         if (*num_of_nodes < 1) {
 648                 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
 649                          *num_of_nodes);
 650                 rc = -EINVAL;
 651                 goto parse_DFS_referrals_exit;
 652         }
 653
 654         ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
 655         if (ref->VersionNumber != cpu_to_le16(3)) {
 656                 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
 657                          le16_to_cpu(ref->VersionNumber));
 658                 rc = -EINVAL;
 659                 goto parse_DFS_referrals_exit;
 660         }
 661
 662         /* get the upper boundary of the resp buffer */
 663         data_end = (char *)rsp + rsp_size;
 664
 665         cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
 666                  *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
 667
 668         *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
 669                                 GFP_KERNEL);
 670         if (*target_nodes == NULL) {
 671                 rc = -ENOMEM;
 672                 goto parse_DFS_referrals_exit;
 673         }
 674
 675         /* collect necessary data from referrals */
 676         for (i = 0; i < *num_of_nodes; i++) {
 677                 char *temp;
 678                 int max_len;
 679                 struct dfs_info3_param *node = (*target_nodes)+i;
 680
 681                 node->flags = le32_to_cpu(rsp->DFSFlags);
 682                 if (is_unicode) {
 683                         __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
 684                                                 GFP_KERNEL);
 685                         if (tmp == NULL) {
 686                                 rc = -ENOMEM;
 687                                 goto parse_DFS_referrals_exit;
 688                         }
 689                         cifsConvertToUTF16((__le16 *) tmp, searchName,
 690                                            PATH_MAX, nls_codepage, remap);
 691                         node->path_consumed = cifs_utf16_bytes(tmp,
 692                                         le16_to_cpu(rsp->PathConsumed),
 693                                         nls_codepage);
 694                         kfree(tmp);
 695                 } else
 696                         node->path_consumed = le16_to_cpu(rsp->PathConsumed);
 697
 698                 node->server_type = le16_to_cpu(ref->ServerType);
 699                 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
 700
 701                 /* copy DfsPath */
 702                 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
 703                 max_len = data_end - temp;
 704                 node->path_name = cifs_strndup_from_utf16(temp, max_len,
 705                                                 is_unicode, nls_codepage);
 706                 if (!node->path_name) {
 707                         rc = -ENOMEM;
 708                         goto parse_DFS_referrals_exit;
 709                 }
 710
 711                 /* copy link target UNC */
 712                 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
 713                 max_len = data_end - temp;
 714                 node->node_name = cifs_strndup_from_utf16(temp, max_len,
 715                                                 is_unicode, nls_codepage);
 716                 if (!node->node_name) {
 717                         rc = -ENOMEM;
 718                         goto parse_DFS_referrals_exit;
 719                 }
 720
 721                 ref++;
 722         }
 723
 724 parse_DFS_referrals_exit:
 725         if (rc) {
 726                 free_dfs_info_array(*target_nodes, *num_of_nodes);
 727                 *target_nodes = NULL;
 728                 *num_of_nodes = 0;
 729         }
 730         return rc;
 731 }
 732
 733 struct cifs_aio_ctx *
 734 cifs_aio_ctx_alloc(void)
 735 {
 736         struct cifs_aio_ctx *ctx;
 737
 738         ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
 739         if (!ctx)
 740                 return NULL;
 741
 742         INIT_LIST_HEAD(&ctx->list);
 743         mutex_init(&ctx->aio_mutex);
 744         init_completion(&ctx->done);
 745         kref_init(&ctx->refcount);
 746         return ctx;
 747 }
 748
 749 void
 750 cifs_aio_ctx_release(struct kref *refcount)
 751 {
 752         struct cifs_aio_ctx *ctx = container_of(refcount,
 753                                         struct cifs_aio_ctx, refcount);
 754
 755         cifsFileInfo_put(ctx->cfile);
 756         kvfree(ctx->bv);
 757         kfree(ctx);
 758 }
 759
 760 #define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
 761
 762 int
 763 setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
 764 {
 765         ssize_t rc;
 766         unsigned int cur_npages;
 767         unsigned int npages = 0;
 768         unsigned int i;
 769         size_t len;
 770         size_t count = iov_iter_count(iter);
 771         unsigned int saved_len;
 772         size_t start;
 773         unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
 774         struct page **pages = NULL;
 775         struct bio_vec *bv = NULL;
 776
 777         if (iter->type & ITER_KVEC) {
 778                 memcpy(&ctx->iter, iter, sizeof(struct iov_iter));
 779                 ctx->len = count;
 780                 iov_iter_advance(iter, count);
 781                 return 0;
 782         }
 783
 784         if (max_pages * sizeof(struct bio_vec) <= CIFS_AIO_KMALLOC_LIMIT)
 785                 bv = kmalloc_array(max_pages, sizeof(struct bio_vec),
 786                                    GFP_KERNEL);
 787
 788         if (!bv) {
 789                 bv = vmalloc(max_pages * sizeof(struct bio_vec));
 790                 if (!bv)
 791                         return -ENOMEM;
 792         }
 793
 794         if (max_pages * sizeof(struct page *) <= CIFS_AIO_KMALLOC_LIMIT)
 795                 pages = kmalloc_array(max_pages, sizeof(struct page *),
 796                                       GFP_KERNEL);
 797
 798         if (!pages) {
 799                 pages = vmalloc(max_pages * sizeof(struct page *));
 800                 if (!pages) {
 801                         kvfree(bv);
 802                         return -ENOMEM;
 803                 }
 804         }
 805
 806         saved_len = count;
 807
 808         while (count && npages < max_pages) {
 809                 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
 810                 if (rc < 0) {
 811                         cifs_dbg(VFS, "couldn't get user pages (rc=%zd)\n", rc);
 812                         break;
 813                 }
 814
 815                 if (rc > count) {
 816                         cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
 817                                  count);
 818                         break;
 819                 }
 820
 821                 iov_iter_advance(iter, rc);
 822                 count -= rc;
 823                 rc += start;
 824                 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
 825
 826                 if (npages + cur_npages > max_pages) {
 827                         cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
 828                                  npages + cur_npages, max_pages);
 829                         break;
 830                 }
 831
 832                 for (i = 0; i < cur_npages; i++) {
 833                         len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
 834                         bv[npages + i].bv_page = pages[i];
 835                         bv[npages + i].bv_offset = start;
 836                         bv[npages + i].bv_len = len - start;
 837                         rc -= len;
 838                         start = 0;
 839                 }
 840
 841                 npages += cur_npages;
 842         }
 843
 844         kvfree(pages);
 845         ctx->bv = bv;
 846         ctx->len = saved_len - count;
 847         ctx->npages = npages;
 848         iov_iter_bvec(&ctx->iter, ITER_BVEC | rw, ctx->bv, npages, ctx->len);
 849         return 0;
 850 }