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                 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
 402
 403                 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
 404                         data_offset = le32_to_cpu(pSMBr->DataOffset);
 405
 406                         if (data_offset >
 407                             len - sizeof(struct file_notify_information)) {
 408                                 cifs_dbg(FYI, "invalid data_offset %u\n",
 409                                          data_offset);
 410                                 return true;
 411                         }
 412                         pnotify = (struct file_notify_information *)
 413                                 ((char *)&pSMBr->hdr.Protocol + data_offset);
 414                         cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
 415                                  pnotify->FileName, pnotify->Action);
 416                         /*   cifs_dump_mem("Rcvd notify Data: ",buf,
 417                                 sizeof(struct smb_hdr)+60); */
 418                         return true;
 419                 }
 420                 if (pSMBr->hdr.Status.CifsError) {
 421                         cifs_dbg(FYI, "notify err 0x%x\n",
 422                                  pSMBr->hdr.Status.CifsError);
 423                         return true;
 424                 }
 425                 return false;
 426         }
 427         if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
 428                 return false;
 429         if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
 430                 /* no sense logging error on invalid handle on oplock
 431                    break - harmless race between close request and oplock
 432                    break response is expected from time to time writing out
 433                    large dirty files cached on the client */
 434                 if ((NT_STATUS_INVALID_HANDLE) ==
 435                    le32_to_cpu(pSMB->hdr.Status.CifsError)) {
 436                         cifs_dbg(FYI, "invalid handle on oplock break\n");
 437                         return true;
 438                 } else if (ERRbadfid ==
 439                    le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
 440                         return true;
 441                 } else {
 442                         return false; /* on valid oplock brk we get "request" */
 443                 }
 444         }
 445         if (pSMB->hdr.WordCount != 8)
 446                 return false;
 447
 448         cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
 449                  pSMB->LockType, pSMB->OplockLevel);
 450         if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
 451                 return false;
 452
 453         /* look up tcon based on tid & uid */
 454         spin_lock(&cifs_tcp_ses_lock);
 455         list_for_each(tmp, &srv->smb_ses_list) {
 456                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
 457                 list_for_each(tmp1, &ses->tcon_list) {
 458                         tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
 459                         if (tcon->tid != buf->Tid)
 460                                 continue;
 461
 462                         cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
 463                         spin_lock(&tcon->open_file_lock);
 464                         list_for_each(tmp2, &tcon->openFileList) {
 465                                 netfile = list_entry(tmp2, struct cifsFileInfo,
 466                                                      tlist);
 467                                 if (pSMB->Fid != netfile->fid.netfid)
 468                                         continue;
 469
 470                                 cifs_dbg(FYI, "file id match, oplock break\n");
 471                                 pCifsInode = CIFS_I(d_inode(netfile->dentry));
 472
 473                                 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
 474                                         &pCifsInode->flags);
 475
 476                                 netfile->oplock_epoch = 0;
 477                                 netfile->oplock_level = pSMB->OplockLevel;
 478                                 netfile->oplock_break_cancelled = false;
 479                                 cifs_queue_oplock_break(netfile);
 480
 481                                 spin_unlock(&tcon->open_file_lock);
 482                                 spin_unlock(&cifs_tcp_ses_lock);
 483                                 return true;
 484                         }
 485                         spin_unlock(&tcon->open_file_lock);
 486                         spin_unlock(&cifs_tcp_ses_lock);
 487                         cifs_dbg(FYI, "No matching file for oplock break\n");
 488                         return true;
 489                 }
 490         }
 491         spin_unlock(&cifs_tcp_ses_lock);
 492         cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
 493         return true;
 494 }
 495
 496 void
 497 dump_smb(void *buf, int smb_buf_length)
 498 {
 499         if (traceSMB == 0)
 500                 return;
 501
 502         print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
 503                        smb_buf_length, true);
 504 }
 505
 506 void
 507 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
 508 {
 509         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 510                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 511                 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",
 512                          cifs_sb_master_tcon(cifs_sb)->treeName);
 513         }
 514 }
 515
 516 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
 517 {
 518         oplock &= 0xF;
 519
 520         if (oplock == OPLOCK_EXCLUSIVE) {
 521                 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
 522                 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
 523                          &cinode->vfs_inode);
 524         } else if (oplock == OPLOCK_READ) {
 525                 cinode->oplock = CIFS_CACHE_READ_FLG;
 526                 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
 527                          &cinode->vfs_inode);
 528         } else
 529                 cinode->oplock = 0;
 530 }
 531
 532 /*
 533  * We wait for oplock breaks to be processed before we attempt to perform
 534  * writes.
 535  */
 536 int cifs_get_writer(struct cifsInodeInfo *cinode)
 537 {
 538         int rc;
 539
 540 start:
 541         rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
 542                          TASK_KILLABLE);
 543         if (rc)
 544                 return rc;
 545
 546         spin_lock(&cinode->writers_lock);
 547         if (!cinode->writers)
 548                 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
 549         cinode->writers++;
 550         /* Check to see if we have started servicing an oplock break */
 551         if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
 552                 cinode->writers--;
 553                 if (cinode->writers == 0) {
 554                         clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
 555                         wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
 556                 }
 557                 spin_unlock(&cinode->writers_lock);
 558                 goto start;
 559         }
 560         spin_unlock(&cinode->writers_lock);
 561         return 0;
 562 }
 563
 564 void cifs_put_writer(struct cifsInodeInfo *cinode)
 565 {
 566         spin_lock(&cinode->writers_lock);
 567         cinode->writers--;
 568         if (cinode->writers == 0) {
 569                 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
 570                 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
 571         }
 572         spin_unlock(&cinode->writers_lock);
 573 }
 574
 575 /**
 576  * cifs_queue_oplock_break - queue the oplock break handler for cfile
 577  *
 578  * This function is called from the demultiplex thread when it
 579  * receives an oplock break for @cfile.
 580  *
 581  * Assumes the tcon->open_file_lock is held.
 582  * Assumes cfile->file_info_lock is NOT held.
 583  */
 584 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
 585 {
 586         /*
 587          * Bump the handle refcount now while we hold the
 588          * open_file_lock to enforce the validity of it for the oplock
 589          * break handler. The matching put is done at the end of the
 590          * handler.
 591          */
 592         cifsFileInfo_get(cfile);
 593
 594         queue_work(cifsoplockd_wq, &cfile->oplock_break);
 595 }
 596
 597 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
 598 {
 599         clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
 600         wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
 601 }
 602
 603 bool
 604 backup_cred(struct cifs_sb_info *cifs_sb)
 605 {
 606         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
 607                 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
 608                         return true;
 609         }
 610         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
 611                 if (in_group_p(cifs_sb->mnt_backupgid))
 612                         return true;
 613         }
 614
 615         return false;
 616 }
 617
 618 void
 619 cifs_del_pending_open(struct cifs_pending_open *open)
 620 {
 621         spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
 622         list_del(&open->olist);
 623         spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
 624 }
 625
 626 void
 627 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
 628                              struct cifs_pending_open *open)
 629 {
 630         memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
 631         open->oplock = CIFS_OPLOCK_NO_CHANGE;
 632         open->tlink = tlink;
 633         fid->pending_open = open;
 634         list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
 635 }
 636
 637 void
 638 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
 639                       struct cifs_pending_open *open)
 640 {
 641         spin_lock(&tlink_tcon(tlink)->open_file_lock);
 642         cifs_add_pending_open_locked(fid, tlink, open);
 643         spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
 644 }
 645
 646 /* parses DFS refferal V3 structure
 647  * caller is responsible for freeing target_nodes
 648  * returns:
 649  * - on success - 0
 650  * - on failure - errno
 651  */
 652 int
 653 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
 654                     unsigned int *num_of_nodes,
 655                     struct dfs_info3_param **target_nodes,
 656                     const struct nls_table *nls_codepage, int remap,
 657                     const char *searchName, bool is_unicode)
 658 {
 659         int i, rc = 0;
 660         char *data_end;
 661         struct dfs_referral_level_3 *ref;
 662
 663         *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
 664
 665         if (*num_of_nodes < 1) {
 666                 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
 667                          *num_of_nodes);
 668                 rc = -EINVAL;
 669                 goto parse_DFS_referrals_exit;
 670         }
 671
 672         ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
 673         if (ref->VersionNumber != cpu_to_le16(3)) {
 674                 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
 675                          le16_to_cpu(ref->VersionNumber));
 676                 rc = -EINVAL;
 677                 goto parse_DFS_referrals_exit;
 678         }
 679
 680         /* get the upper boundary of the resp buffer */
 681         data_end = (char *)rsp + rsp_size;
 682
 683         cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
 684                  *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
 685
 686         *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
 687                                 GFP_KERNEL);
 688         if (*target_nodes == NULL) {
 689                 rc = -ENOMEM;
 690                 goto parse_DFS_referrals_exit;
 691         }
 692
 693         /* collect necessary data from referrals */
 694         for (i = 0; i < *num_of_nodes; i++) {
 695                 char *temp;
 696                 int max_len;
 697                 struct dfs_info3_param *node = (*target_nodes)+i;
 698
 699                 node->flags = le32_to_cpu(rsp->DFSFlags);
 700                 if (is_unicode) {
 701                         __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
 702                                                 GFP_KERNEL);
 703                         if (tmp == NULL) {
 704                                 rc = -ENOMEM;
 705                                 goto parse_DFS_referrals_exit;
 706                         }
 707                         cifsConvertToUTF16((__le16 *) tmp, searchName,
 708                                            PATH_MAX, nls_codepage, remap);
 709                         node->path_consumed = cifs_utf16_bytes(tmp,
 710                                         le16_to_cpu(rsp->PathConsumed),
 711                                         nls_codepage);
 712                         kfree(tmp);
 713                 } else
 714                         node->path_consumed = le16_to_cpu(rsp->PathConsumed);
 715
 716                 node->server_type = le16_to_cpu(ref->ServerType);
 717                 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
 718
 719                 /* copy DfsPath */
 720                 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
 721                 max_len = data_end - temp;
 722                 node->path_name = cifs_strndup_from_utf16(temp, max_len,
 723                                                 is_unicode, nls_codepage);
 724                 if (!node->path_name) {
 725                         rc = -ENOMEM;
 726                         goto parse_DFS_referrals_exit;
 727                 }
 728
 729                 /* copy link target UNC */
 730                 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
 731                 max_len = data_end - temp;
 732                 node->node_name = cifs_strndup_from_utf16(temp, max_len,
 733                                                 is_unicode, nls_codepage);
 734                 if (!node->node_name) {
 735                         rc = -ENOMEM;
 736                         goto parse_DFS_referrals_exit;
 737                 }
 738
 739                 ref++;
 740         }
 741
 742 parse_DFS_referrals_exit:
 743         if (rc) {
 744                 free_dfs_info_array(*target_nodes, *num_of_nodes);
 745                 *target_nodes = NULL;
 746                 *num_of_nodes = 0;
 747         }
 748         return rc;
 749 }
 750
 751 struct cifs_aio_ctx *
 752 cifs_aio_ctx_alloc(void)
 753 {
 754         struct cifs_aio_ctx *ctx;
 755
 756         ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
 757         if (!ctx)
 758                 return NULL;
 759
 760         INIT_LIST_HEAD(&ctx->list);
 761         mutex_init(&ctx->aio_mutex);
 762         init_completion(&ctx->done);
 763         kref_init(&ctx->refcount);
 764         return ctx;
 765 }
 766
 767 void
 768 cifs_aio_ctx_release(struct kref *refcount)
 769 {
 770         struct cifs_aio_ctx *ctx = container_of(refcount,
 771                                         struct cifs_aio_ctx, refcount);
 772
 773         cifsFileInfo_put(ctx->cfile);
 774         kvfree(ctx->bv);
 775         kfree(ctx);
 776 }
 777
 778 #define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
 779
 780 int
 781 setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
 782 {
 783         ssize_t rc;
 784         unsigned int cur_npages;
 785         unsigned int npages = 0;
 786         unsigned int i;
 787         size_t len;
 788         size_t count = iov_iter_count(iter);
 789         unsigned int saved_len;
 790         size_t start;
 791         unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
 792         struct page **pages = NULL;
 793         struct bio_vec *bv = NULL;
 794
 795         if (iter->type & ITER_KVEC) {
 796                 memcpy(&ctx->iter, iter, sizeof(struct iov_iter));
 797                 ctx->len = count;
 798                 iov_iter_advance(iter, count);
 799                 return 0;
 800         }
 801
 802         if (max_pages * sizeof(struct bio_vec) <= CIFS_AIO_KMALLOC_LIMIT)
 803                 bv = kmalloc_array(max_pages, sizeof(struct bio_vec),
 804                                    GFP_KERNEL);
 805
 806         if (!bv) {
 807                 bv = vmalloc(max_pages * sizeof(struct bio_vec));
 808                 if (!bv)
 809                         return -ENOMEM;
 810         }
 811
 812         if (max_pages * sizeof(struct page *) <= CIFS_AIO_KMALLOC_LIMIT)
 813                 pages = kmalloc_array(max_pages, sizeof(struct page *),
 814                                       GFP_KERNEL);
 815
 816         if (!pages) {
 817                 pages = vmalloc(max_pages * sizeof(struct page *));
 818                 if (!pages) {
 819                         kvfree(bv);
 820                         return -ENOMEM;
 821                 }
 822         }
 823
 824         saved_len = count;
 825
 826         while (count && npages < max_pages) {
 827                 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
 828                 if (rc < 0) {
 829                         cifs_dbg(VFS, "couldn't get user pages (rc=%zd)\n", rc);
 830                         break;
 831                 }
 832
 833                 if (rc > count) {
 834                         cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
 835                                  count);
 836                         break;
 837                 }
 838
 839                 iov_iter_advance(iter, rc);
 840                 count -= rc;
 841                 rc += start;
 842                 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
 843
 844                 if (npages + cur_npages > max_pages) {
 845                         cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
 846                                  npages + cur_npages, max_pages);
 847                         break;
 848                 }
 849
 850                 for (i = 0; i < cur_npages; i++) {
 851                         len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
 852                         bv[npages + i].bv_page = pages[i];
 853                         bv[npages + i].bv_offset = start;
 854                         bv[npages + i].bv_len = len - start;
 855                         rc -= len;
 856                         start = 0;
 857                 }
 858
 859                 npages += cur_npages;
 860         }
 861
 862         kvfree(pages);
 863         ctx->bv = bv;
 864         ctx->len = saved_len - count;
 865         ctx->npages = npages;
 866         iov_iter_bvec(&ctx->iter, ITER_BVEC | rw, ctx->bv, npages, ctx->len);
 867         return 0;
 868 }
 869
 870 /**
 871  * cifs_alloc_hash - allocate hash and hash context together
 872  *
 873  * The caller has to make sure @sdesc is initialized to either NULL or
 874  * a valid context. Both can be freed via cifs_free_hash().
 875  */
 876 int
 877 cifs_alloc_hash(const char *name,
 878                 struct crypto_shash **shash, struct sdesc **sdesc)
 879 {
 880         int rc = 0;
 881         size_t size;
 882
 883         if (*sdesc != NULL)
 884                 return 0;
 885
 886         *shash = crypto_alloc_shash(name, 0, 0);
 887         if (IS_ERR(*shash)) {
 888                 cifs_dbg(VFS, "could not allocate crypto %s\n", name);
 889                 rc = PTR_ERR(*shash);
 890                 *shash = NULL;
 891                 *sdesc = NULL;
 892                 return rc;
 893         }
 894
 895         size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
 896         *sdesc = kmalloc(size, GFP_KERNEL);
 897         if (*sdesc == NULL) {
 898                 cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
 899                 crypto_free_shash(*shash);
 900                 *shash = NULL;
 901                 return -ENOMEM;
 902         }
 903
 904         (*sdesc)->shash.tfm = *shash;
 905         (*sdesc)->shash.flags = 0x0;
 906         return 0;
 907 }
 908
 909 /**
 910  * cifs_free_hash - free hash and hash context together
 911  *
 912  * Freeing a NULL hash or context is safe.
 913  */
 914 void
 915 cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
 916 {
 917         kfree(*sdesc);
 918         *sdesc = NULL;
 919         if (*shash)
 920                 crypto_free_shash(*shash);
 921         *shash = NULL;
 922 }