lustre/llite/llite_mmap.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2016, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  */
  31
  32 #include <linux/errno.h>
  33 #include <linux/delay.h>
  34 #include <linux/kernel.h>
  35 #include <linux/mm.h>
  36 #include <linux/file.h>
  37
  38 #define DEBUG_SUBSYSTEM S_LLITE
  39
  40 #include "llite_internal.h"
  41 #include <lustre_compat.h>
  42
  43 static const struct vm_operations_struct ll_file_vm_ops;
  44
  45 void policy_from_vma(union ldlm_policy_data *policy, struct vm_area_struct *vma,
  46                      unsigned long addr, size_t count)
  47 {
  48         policy->l_extent.start = ((addr - vma->vm_start) & PAGE_MASK) +
  49                                  (vma->vm_pgoff << PAGE_SHIFT);
  50         policy->l_extent.end = (policy->l_extent.start + count - 1) |
  51                                ~PAGE_MASK;
  52 }
  53
  54 /*
  55  * Linux commit v6.0-rc3-225-gf39af05949a4
  56  * mm: add VMA iterator
  57  */
  58 #ifndef VMA_ITERATOR
  59 #define vma_iterator vm_area_struct *
  60 #define vma_iter_init(vmip, mm, addr) *(vmip) = find_vma(mm, addr)
  61 #define for_each_vma(vmi, vma) \
  62         for (vma = vmi; vma != NULL; vma = vma->vm_next)
  63 #endif
  64
  65 struct vm_area_struct *our_vma(struct mm_struct *mm, unsigned long addr,
  66                                size_t count)
  67 {
  68         struct vm_area_struct *vma, *ret = NULL;
  69         struct vma_iterator vmi;
  70
  71         ENTRY;
  72
  73         /* mmap_lock must have been held by caller. */
  74         LASSERT(!mmap_write_trylock(mm));
  75
  76         vma_iter_init(&vmi, mm, addr);
  77         for_each_vma(vmi, vma) {
  78                 if (vma->vm_start < (addr + count))
  79                         break;
  80                 if (vma->vm_ops && vma->vm_ops == &ll_file_vm_ops &&
  81                     vma->vm_flags & VM_SHARED) {
  82                         ret = vma;
  83                         break;
  84                 }
  85         }
  86         RETURN(ret);
  87 }
  88
  89 /**
  90  * API independent part for page fault initialization.
  91  * \param env - corespondent lu_env to processing
  92  * \param vma - virtual memory area addressed to page fault
  93  * \param index - page index corespondent to fault.
  94  * \param mkwrite - whether it is mmap write.
  95  *
  96  * \return error codes from cl_io_init.
  97  */
  98 static struct cl_io *
  99 ll_fault_io_init(struct lu_env *env, struct vm_area_struct *vma,
 100                 pgoff_t index, bool mkwrite)
 101 {
 102         struct file            *file = vma->vm_file;
 103         struct inode           *inode = file_inode(file);
 104         struct cl_io           *io;
 105         struct cl_fault_io     *fio;
 106         int                     rc;
 107         ENTRY;
 108
 109         if (ll_file_nolock(file))
 110                 RETURN(ERR_PTR(-EOPNOTSUPP));
 111
 112 restart:
 113         io = vvp_env_thread_io(env);
 114         io->ci_obj = ll_i2info(inode)->lli_clob;
 115         LASSERT(io->ci_obj != NULL);
 116
 117         fio = &io->u.ci_fault;
 118         fio->ft_index = index;
 119         fio->ft_executable = vma->vm_flags & VM_EXEC;
 120
 121         if (mkwrite) {
 122                 fio->ft_mkwrite = 1;
 123                 fio->ft_writable = 1;
 124         }
 125
 126         CDEBUG(D_MMAP,
 127                DFID": vma=%p start=%#lx end=%#lx vm_flags=%#lx idx=%lu\n",
 128                PFID(&ll_i2info(inode)->lli_fid), vma, vma->vm_start,
 129                vma->vm_end, vma->vm_flags, fio->ft_index);
 130
 131         if (vma->vm_flags & VM_SEQ_READ)
 132                 io->ci_seq_read = 1;
 133         else if (vma->vm_flags & VM_RAND_READ)
 134                 io->ci_rand_read = 1;
 135
 136         rc = cl_io_init(env, io, CIT_FAULT, io->ci_obj);
 137         if (rc == 0) {
 138                 struct vvp_io *vio = vvp_env_io(env);
 139                 struct ll_file_data *fd = file->private_data;
 140
 141                 LASSERT(vio->vui_cl.cis_io == io);
 142
 143                 /* mmap lock must be MANDATORY it has to cache
 144                  * pages. */
 145                 io->ci_lockreq = CILR_MANDATORY;
 146                 vio->vui_fd = fd;
 147         } else {
 148                 cl_io_fini(env, io);
 149                 if (io->ci_need_restart)
 150                         goto restart;
 151
 152                 io = ERR_PTR(rc);
 153         }
 154
 155         RETURN(io);
 156 }
 157
 158 /* Sharing code of page_mkwrite method for rhel5 and rhel6 */
 159 static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
 160                             bool *retry)
 161 {
 162         struct lu_env           *env;
 163         struct cl_io            *io;
 164         struct vvp_io           *vio;
 165         int                      result;
 166         __u16                    refcheck;
 167         sigset_t old, new;
 168         struct inode             *inode = NULL;
 169         struct ll_inode_info     *lli;
 170         ENTRY;
 171
 172         LASSERT(vmpage != NULL);
 173         env = cl_env_get(&refcheck);
 174         if (IS_ERR(env))
 175                 RETURN(PTR_ERR(env));
 176
 177         io = ll_fault_io_init(env, vma, vmpage->index, true);
 178         if (IS_ERR(io))
 179                 GOTO(out, result = PTR_ERR(io));
 180
 181         result = io->ci_result;
 182         if (result < 0)
 183                 GOTO(out_io, result);
 184
 185         vio = vvp_env_io(env);
 186         vio->u.fault.ft_vma    = vma;
 187         vio->u.fault.ft_vmpage = vmpage;
 188
 189         siginitsetinv(&new, sigmask(SIGKILL) | sigmask(SIGTERM));
 190         sigprocmask(SIG_BLOCK, &new, &old);
 191
 192         inode = vvp_object_inode(io->ci_obj);
 193         lli = ll_i2info(inode);
 194
 195         result = cl_io_loop(env, io);
 196
 197         sigprocmask(SIG_SETMASK, &old, NULL);
 198
 199         if (result == 0) {
 200                 lock_page(vmpage);
 201                 if (vmpage->mapping == NULL) {
 202                         unlock_page(vmpage);
 203
 204                         /* page was truncated and lock was cancelled, return
 205                          * ENODATA so that VM_FAULT_NOPAGE will be returned
 206                          * to handle_mm_fault(). */
 207                         if (result == 0)
 208                                 result = -ENODATA;
 209                 } else if (!PageDirty(vmpage)) {
 210                         /* race, the page has been cleaned by ptlrpcd after
 211                          * it was unlocked, it has to be added into dirty
 212                          * cache again otherwise this soon-to-dirty page won't
 213                          * consume any grants, even worse if this page is being
 214                          * transferred because it will break RPC checksum.
 215                          */
 216                         unlock_page(vmpage);
 217
 218                         CDEBUG(D_MMAP, "Race on page_mkwrite %p/%lu, page has "
 219                                "been written out, retry.\n",
 220                                vmpage, vmpage->index);
 221
 222                         *retry = true;
 223                         result = -EAGAIN;
 224                 }
 225
 226                 if (result == 0)
 227                         set_bit(LLIF_DATA_MODIFIED, &lli->lli_flags);
 228         }
 229         EXIT;
 230
 231 out_io:
 232         cl_io_fini(env, io);
 233 out:
 234         cl_env_put(env, &refcheck);
 235         CDEBUG(D_MMAP, "%s mkwrite with %d\n", current->comm, result);
 236         LASSERT(ergo(result == 0, PageLocked(vmpage)));
 237
 238         /* if page has been unmapped, presumably due to lock reclaim for
 239          * concurrent usage, add some delay before retrying to prevent
 240          * entering live-lock situation with competitors
 241          */
 242         if (result == -ENODATA && inode != NULL) {
 243                 CDEBUG(D_MMAP, "delaying new page-fault for inode %p to "
 244                                "prevent live-lock\n", inode);
 245                 msleep(10);
 246         }
 247
 248         return result;
 249 }
 250
 251 static inline int to_fault_error(int result)
 252 {
 253         switch(result) {
 254         case 0:
 255                 result = VM_FAULT_LOCKED;
 256                 break;
 257         case -ENOMEM:
 258                 result = VM_FAULT_OOM;
 259                 break;
 260         default:
 261                 result = VM_FAULT_SIGBUS;
 262                 break;
 263         }
 264         return result;
 265 }
 266
 267 int ll_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 268 {
 269         struct inode *inode = file_inode(vma->vm_file);
 270         int ret;
 271         unsigned int seq;
 272
 273         /* this seqlock lets us notice if a page has been deleted on this inode
 274          * during the fault process, allowing us to catch an erroneous SIGBUS
 275          * See LU-16160
 276          */
 277         do {
 278                 seq = read_seqbegin(&ll_i2info(inode)->lli_page_inv_lock);
 279                 ret = __ll_filemap_fault(vma, vmf);
 280         } while (read_seqretry(&ll_i2info(inode)->lli_page_inv_lock, seq) &&
 281                  (ret & VM_FAULT_SIGBUS));
 282
 283         return ret;
 284 }
 285
 286 /**
 287  * Lustre implementation of a vm_operations_struct::fault() method, called by
 288  * VM to server page fault (both in kernel and user space).
 289  *
 290  * \param vma - is virtiual area struct related to page fault
 291  * \param vmf - structure which describe type and address where hit fault
 292  *
 293  * \return allocated and filled _locked_ page for address
 294  * \retval VM_FAULT_ERROR on general error
 295  * \retval NOPAGE_OOM not have memory for allocate new page
 296  */
 297 static vm_fault_t ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)
 298 {
 299         struct inode *inode = file_inode(vma->vm_file);
 300         struct lu_env           *env;
 301         struct cl_io            *io;
 302         struct vvp_io           *vio = NULL;
 303         struct page             *vmpage;
 304         int                      result = 0;
 305         int                      fault_ret = 0;
 306         __u16                    refcheck;
 307         ENTRY;
 308
 309         env = cl_env_get(&refcheck);
 310         if (IS_ERR(env))
 311                 RETURN(PTR_ERR(env));
 312
 313         if (ll_sbi_has_fast_read(ll_i2sbi(inode))) {
 314                 /* do fast fault */
 315                 bool allow_retry = vmf->flags & FAULT_FLAG_ALLOW_RETRY;
 316                 bool has_retry = vmf->flags & FAULT_FLAG_RETRY_NOWAIT;
 317
 318                 /* To avoid loops, instruct downstream to not drop mmap_sem */
 319                 /**
 320                  * only need FAULT_FLAG_ALLOW_RETRY prior to Linux 5.1
 321                  * (6b4c9f4469819), where FAULT_FLAG_RETRY_NOWAIT is enough
 322                  * to not drop mmap_sem when failed to lock the page.
 323                  */
 324                 vmf->flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT;
 325                 ll_cl_add(inode, env, NULL, LCC_MMAP);
 326                 fault_ret = ll_filemap_fault(vma, vmf);
 327                 ll_cl_remove(inode, env);
 328                 if (!has_retry)
 329                         vmf->flags &= ~FAULT_FLAG_RETRY_NOWAIT;
 330                 if (!allow_retry)
 331                         vmf->flags &= ~FAULT_FLAG_ALLOW_RETRY;
 332
 333                 /* - If there is no error, then the page was found in cache and
 334                  *   uptodate;
 335                  * - If VM_FAULT_RETRY is set, the page existed but failed to
 336                  *   lock. We will try slow path to avoid loops.
 337                  * - Otherwise, it should try normal fault under DLM lock. */
 338                 if (!(fault_ret & VM_FAULT_RETRY) &&
 339                     !(fault_ret & VM_FAULT_ERROR))
 340                         GOTO(out, result = 0);
 341
 342                 fault_ret = 0;
 343         }
 344
 345         io = ll_fault_io_init(env, vma, vmf->pgoff, false);
 346         if (IS_ERR(io))
 347                 GOTO(out, result = PTR_ERR(io));
 348
 349         result = io->ci_result;
 350         if (result == 0) {
 351                 vio = vvp_env_io(env);
 352                 vio->u.fault.ft_vma       = vma;
 353                 vio->u.fault.ft_vmpage    = NULL;
 354                 vio->u.fault.ft_vmf = vmf;
 355                 vio->u.fault.ft_flags = 0;
 356                 vio->u.fault.ft_flags_valid = 0;
 357
 358                 /* May call ll_readpage() */
 359                 ll_cl_add(inode, env, io, LCC_MMAP);
 360
 361                 result = cl_io_loop(env, io);
 362
 363                 ll_cl_remove(inode, env);
 364
 365                 /* ft_flags are only valid if we reached
 366                  * the call to filemap_fault */
 367                 if (vio->u.fault.ft_flags_valid)
 368                         fault_ret = vio->u.fault.ft_flags;
 369
 370                 vmpage = vio->u.fault.ft_vmpage;
 371                 if (result != 0 && vmpage != NULL) {
 372                         put_page(vmpage);
 373                         vmf->page = NULL;
 374                 }
 375         }
 376         cl_io_fini(env, io);
 377
 378 out:
 379         cl_env_put(env, &refcheck);
 380         if (result != 0 && !(fault_ret & VM_FAULT_RETRY))
 381                 fault_ret |= to_fault_error(result);
 382
 383         CDEBUG(D_MMAP, "%s fault %d/%d\n", current->comm, fault_ret, result);
 384         RETURN(fault_ret);
 385 }
 386
 387 #ifdef HAVE_VM_OPS_USE_VM_FAULT_ONLY
 388 static vm_fault_t ll_fault(struct vm_fault *vmf)
 389 {
 390         struct vm_area_struct *vma = vmf->vma;
 391 #else
 392 static vm_fault_t ll_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 393 {
 394 #endif
 395         int count = 0;
 396         bool printed = false;
 397         bool cached;
 398         vm_fault_t result;
 399         ktime_t kstart = ktime_get();
 400         sigset_t old, new;
 401
 402         result = pcc_fault(vma, vmf, &cached);
 403         if (cached)
 404                 goto out;
 405
 406         CDEBUG(D_MMAP|D_IOTRACE,
 407                DFID": vma=%p start=%#lx end=%#lx vm_flags=%#lx idx=%lu\n",
 408                PFID(&ll_i2info(file_inode(vma->vm_file))->lli_fid),
 409                vma, vma->vm_start, vma->vm_end, vma->vm_flags, vmf->pgoff);
 410
 411         /* Only SIGKILL and SIGTERM is allowed for fault/nopage/mkwrite
 412          * so that it can be killed by admin but not cause segfault by
 413          * other signals.
 414          */
 415         siginitsetinv(&new, sigmask(SIGKILL) | sigmask(SIGTERM));
 416         sigprocmask(SIG_BLOCK, &new, &old);
 417
 418         /* make sure offset is not a negative number */
 419         if (vmf->pgoff > (MAX_LFS_FILESIZE >> PAGE_SHIFT))
 420                 return VM_FAULT_SIGBUS;
 421
 422 restart:
 423         result = ll_fault0(vma, vmf);
 424         if (vmf->page &&
 425             !(result & (VM_FAULT_RETRY | VM_FAULT_ERROR | VM_FAULT_LOCKED))) {
 426                 struct page *vmpage = vmf->page;
 427
 428                 /* lock the page, then check if this page has been truncated
 429                  * or deleted from Lustre and retry if so
 430                  */
 431                 lock_page(vmpage);
 432                 if (unlikely(vmpage->mapping == NULL) ||
 433                     vmpage->private == 0) { /* unlucky */
 434                         unlock_page(vmpage);
 435                         put_page(vmpage);
 436                         vmf->page = NULL;
 437
 438                         if (!printed && ++count > 16) {
 439                                 struct inode *inode = file_inode(vma->vm_file);
 440
 441                                 CWARN("%s: FID "DFID" under heavy mmap contention by '%s', consider revising IO pattern\n",
 442                                       ll_i2sbi(inode)->ll_fsname,
 443                                       PFID(&ll_i2info(inode)->lli_fid),
 444                                       current->comm);
 445                                 printed = true;
 446                         }
 447
 448                         goto restart;
 449                 }
 450
 451                 result |= VM_FAULT_LOCKED;
 452         }
 453         sigprocmask(SIG_SETMASK, &old, NULL);
 454
 455 out:
 456         if (vmf->page && result == VM_FAULT_LOCKED) {
 457                 ll_rw_stats_tally(ll_i2sbi(file_inode(vma->vm_file)),
 458                                   current->pid, vma->vm_file->private_data,
 459                                   vmf->page->index << PAGE_SHIFT, PAGE_SIZE,
 460                                   READ);
 461                 ll_stats_ops_tally(ll_i2sbi(file_inode(vma->vm_file)),
 462                                    LPROC_LL_FAULT,
 463                                    ktime_us_delta(ktime_get(), kstart));
 464         }
 465
 466         CDEBUG(D_IOTRACE,
 467                "COMPLETED: "DFID": vma=%p start=%#lx end=%#lx vm_flags=%#lx idx=%lu\n",
 468                PFID(&ll_i2info(file_inode(vma->vm_file))->lli_fid),
 469                vma, vma->vm_start, vma->vm_end, vma->vm_flags, vmf->pgoff);
 470
 471         return result;
 472 }
 473
 474 #ifdef HAVE_VM_OPS_USE_VM_FAULT_ONLY
 475 static vm_fault_t ll_page_mkwrite(struct vm_fault *vmf)
 476 {
 477         struct vm_area_struct *vma = vmf->vma;
 478 #else
 479 static vm_fault_t ll_page_mkwrite(struct vm_area_struct *vma,
 480                                   struct vm_fault *vmf)
 481 {
 482 #endif
 483         int count = 0;
 484         bool printed = false;
 485         bool retry;
 486         bool cached;
 487         ktime_t kstart = ktime_get();
 488         vm_fault_t result;
 489
 490         CDEBUG(D_MMAP|D_IOTRACE,
 491                DFID": vma=%p start=%#lx end=%#lx vm_flags=%#lx idx=%lu\n",
 492                PFID(&ll_i2info(file_inode(vma->vm_file))->lli_fid),
 493                vma, vma->vm_start, vma->vm_end, vma->vm_flags,
 494                vmf->page->index);
 495
 496         result = pcc_page_mkwrite(vma, vmf, &cached);
 497         if (cached)
 498                 goto out;
 499
 500         file_update_time(vma->vm_file);
 501         do {
 502                 retry = false;
 503                 result = ll_page_mkwrite0(vma, vmf->page, &retry);
 504
 505                 if (!printed && ++count > 16) {
 506                         const struct dentry *de = file_dentry(vma->vm_file);
 507
 508                         CWARN("app(%s): the page %lu of file "DFID" is under heavy contention\n",
 509                               current->comm, vmf->pgoff,
 510                               PFID(ll_inode2fid(de->d_inode)));
 511                         printed = true;
 512                 }
 513         } while (retry);
 514
 515         switch (result) {
 516         case 0:
 517                 LASSERT(PageLocked(vmf->page));
 518                 result = VM_FAULT_LOCKED;
 519                 break;
 520         case -ENODATA:
 521         case -EFAULT:
 522                 result = VM_FAULT_NOPAGE;
 523                 break;
 524         case -ENOMEM:
 525                 result = VM_FAULT_OOM;
 526                 break;
 527         case -EAGAIN:
 528                 result = VM_FAULT_RETRY;
 529                 break;
 530         default:
 531                 result = VM_FAULT_SIGBUS;
 532                 break;
 533         }
 534
 535 out:
 536         if (result == VM_FAULT_LOCKED) {
 537                 ll_rw_stats_tally(ll_i2sbi(file_inode(vma->vm_file)),
 538                                   current->pid, vma->vm_file->private_data,
 539                                   vmf->page->index << PAGE_SHIFT, PAGE_SIZE,
 540                                   WRITE);
 541                 ll_stats_ops_tally(ll_i2sbi(file_inode(vma->vm_file)),
 542                                    LPROC_LL_MKWRITE,
 543                                    ktime_us_delta(ktime_get(), kstart));
 544         }
 545
 546         CDEBUG(D_IOTRACE,
 547                "COMPLETED: "DFID": vma=%p start=%#lx end=%#lx vm_flags=%#lx idx=%lu\n",
 548                PFID(&ll_i2info(file_inode(vma->vm_file))->lli_fid),
 549                vma, vma->vm_start, vma->vm_end, vma->vm_flags,
 550                vmf->page->index);
 551         return result;
 552 }
 553
 554 /**
 555  *  To avoid cancel the locks covering mmapped region for lock cache pressure,
 556  *  we track the mapped vma count in vvp_object::vob_mmap_cnt.
 557  */
 558 static void ll_vm_open(struct vm_area_struct * vma)
 559 {
 560         struct inode *inode    = file_inode(vma->vm_file);
 561         struct vvp_object *vob = cl_inode2vvp(inode);
 562
 563         ENTRY;
 564         LASSERT(atomic_read(&vob->vob_mmap_cnt) >= 0);
 565         atomic_inc(&vob->vob_mmap_cnt);
 566         pcc_vm_open(vma);
 567         EXIT;
 568 }
 569
 570 /**
 571  * Dual to ll_vm_open().
 572  */
 573 static void ll_vm_close(struct vm_area_struct *vma)
 574 {
 575         struct inode      *inode = file_inode(vma->vm_file);
 576         struct vvp_object *vob   = cl_inode2vvp(inode);
 577
 578         ENTRY;
 579         atomic_dec(&vob->vob_mmap_cnt);
 580         LASSERT(atomic_read(&vob->vob_mmap_cnt) >= 0);
 581         pcc_vm_close(vma);
 582         EXIT;
 583 }
 584
 585 static const struct vm_operations_struct ll_file_vm_ops = {
 586         .fault                  = ll_fault,
 587         .page_mkwrite           = ll_page_mkwrite,
 588         .open                   = ll_vm_open,
 589         .close                  = ll_vm_close,
 590 };
 591
 592 int ll_file_mmap(struct file *file, struct vm_area_struct * vma)
 593 {
 594         struct inode *inode = file_inode(file);
 595         ktime_t kstart = ktime_get();
 596         bool cached;
 597         int rc;
 598
 599         ENTRY;
 600         CDEBUG(D_VFSTRACE | D_MMAP,
 601                "VFS_Op: fid="DFID" vma=%p start=%#lx end=%#lx vm_flags=%#lx\n",
 602                PFID(&ll_i2info(inode)->lli_fid),
 603                vma, vma->vm_start, vma->vm_end, vma->vm_flags);
 604
 605         if (ll_file_nolock(file))
 606                 RETURN(-EOPNOTSUPP);
 607
 608         rc = pcc_file_mmap(file, vma, &cached);
 609         if (cached && rc != 0)
 610                 RETURN(rc);
 611
 612         rc = generic_file_mmap(file, vma);
 613         if (rc == 0) {
 614                 vma->vm_ops = &ll_file_vm_ops;
 615                 vma->vm_ops->open(vma);
 616                 /* update the inode's size and mtime */
 617                 if (!cached)
 618                         rc = ll_glimpse_size(inode);
 619         }
 620
 621         if (!rc)
 622                 ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_MMAP,
 623                                    ktime_us_delta(ktime_get(), kstart));
 624
 625         RETURN(rc);
 626 }