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 bytes)
  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 + bytes - 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 bytes)
  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 + bytes))
  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         if (vma->vm_flags & VM_SEQ_READ)
 127                 io->ci_seq_read = 1;
 128         else if (vma->vm_flags & VM_RAND_READ)
 129                 io->ci_rand_read = 1;
 130
 131         rc = cl_io_init(env, io, CIT_FAULT, io->ci_obj);
 132         if (rc == 0) {
 133                 struct vvp_io *vio = vvp_env_io(env);
 134                 struct ll_file_data *fd = file->private_data;
 135
 136                 LASSERT(vio->vui_cl.cis_io == io);
 137
 138                 /* mmap lock must be MANDATORY it has to cache
 139                  * pages. */
 140                 io->ci_lockreq = CILR_MANDATORY;
 141                 vio->vui_fd = fd;
 142         } else {
 143                 cl_io_fini(env, io);
 144                 if (io->ci_need_restart)
 145                         goto restart;
 146
 147                 io = ERR_PTR(rc);
 148         }
 149
 150         RETURN(io);
 151 }
 152
 153 /* Sharing code of page_mkwrite method for rhel5 and rhel6 */
 154 static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
 155                             bool *retry)
 156 {
 157         struct lu_env           *env;
 158         struct cl_io            *io;
 159         struct vvp_io           *vio;
 160         int                      result;
 161         __u16                    refcheck;
 162         sigset_t old, new;
 163         struct inode             *inode = NULL;
 164         struct ll_inode_info     *lli;
 165         ENTRY;
 166
 167         LASSERT(vmpage != NULL);
 168         env = cl_env_get(&refcheck);
 169         if (IS_ERR(env))
 170                 RETURN(PTR_ERR(env));
 171
 172         io = ll_fault_io_init(env, vma, vmpage->index, true);
 173         if (IS_ERR(io))
 174                 GOTO(out, result = PTR_ERR(io));
 175
 176         result = io->ci_result;
 177         if (result < 0)
 178                 GOTO(out_io, result);
 179
 180         vio = vvp_env_io(env);
 181         vio->u.fault.ft_vma    = vma;
 182         vio->u.fault.ft_vmpage = vmpage;
 183
 184         siginitsetinv(&new, sigmask(SIGKILL) | sigmask(SIGTERM));
 185         sigprocmask(SIG_BLOCK, &new, &old);
 186
 187         inode = vvp_object_inode(io->ci_obj);
 188         lli = ll_i2info(inode);
 189
 190         result = cl_io_loop(env, io);
 191
 192         sigprocmask(SIG_SETMASK, &old, NULL);
 193
 194         if (result == 0) {
 195                 lock_page(vmpage);
 196                 if (vmpage->mapping == NULL) {
 197                         unlock_page(vmpage);
 198
 199                         /* page was truncated and lock was cancelled, return
 200                          * ENODATA so that VM_FAULT_NOPAGE will be returned
 201                          * to handle_mm_fault(). */
 202                         if (result == 0)
 203                                 result = -ENODATA;
 204                 } else if (!PageDirty(vmpage)) {
 205                         /* race, the page has been cleaned by ptlrpcd after
 206                          * it was unlocked, it has to be added into dirty
 207                          * cache again otherwise this soon-to-dirty page won't
 208                          * consume any grants, even worse if this page is being
 209                          * transferred because it will break RPC checksum.
 210                          */
 211                         unlock_page(vmpage);
 212
 213                         CDEBUG(D_MMAP, "Race on page_mkwrite %p/%lu, page has "
 214                                "been written out, retry.\n",
 215                                vmpage, vmpage->index);
 216
 217                         *retry = true;
 218                         result = -EAGAIN;
 219                 }
 220
 221                 if (result == 0)
 222                         set_bit(LLIF_DATA_MODIFIED, &lli->lli_flags);
 223         }
 224         EXIT;
 225
 226 out_io:
 227         cl_io_fini(env, io);
 228 out:
 229         cl_env_put(env, &refcheck);
 230         CDEBUG(D_MMAP, "%s mkwrite with %d\n", current->comm, result);
 231         LASSERT(ergo(result == 0, PageLocked(vmpage)));
 232
 233         /* if page has been unmapped, presumably due to lock reclaim for
 234          * concurrent usage, add some delay before retrying to prevent
 235          * entering live-lock situation with competitors
 236          */
 237         if (result == -ENODATA && inode != NULL) {
 238                 CDEBUG(D_MMAP, "delaying new page-fault for inode %p to "
 239                                "prevent live-lock\n", inode);
 240                 msleep(10);
 241         }
 242
 243         return result;
 244 }
 245
 246 static inline int to_fault_error(int result)
 247 {
 248         switch(result) {
 249         case 0:
 250                 result = VM_FAULT_LOCKED;
 251                 break;
 252         case -ENOMEM:
 253                 result = VM_FAULT_OOM;
 254                 break;
 255         default:
 256                 result = VM_FAULT_SIGBUS;
 257                 break;
 258         }
 259         return result;
 260 }
 261
 262 int ll_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 263 {
 264         struct inode *inode = file_inode(vma->vm_file);
 265         int ret;
 266         unsigned int seq;
 267
 268         /* this seqlock lets us notice if a page has been deleted on this inode
 269          * during the fault process, allowing us to catch an erroneous SIGBUS
 270          * See LU-16160
 271          */
 272         do {
 273                 seq = read_seqbegin(&ll_i2info(inode)->lli_page_inv_lock);
 274                 ret = __ll_filemap_fault(vma, vmf);
 275         } while (read_seqretry(&ll_i2info(inode)->lli_page_inv_lock, seq) &&
 276                  (ret & VM_FAULT_SIGBUS));
 277
 278         return ret;
 279 }
 280
 281 /**
 282  * Lustre implementation of a vm_operations_struct::fault() method, called by
 283  * VM to server page fault (both in kernel and user space).
 284  *
 285  * \param vma - is virtiual area struct related to page fault
 286  * \param vmf - structure which describe type and address where hit fault
 287  *
 288  * \return allocated and filled _locked_ page for address
 289  * \retval VM_FAULT_ERROR on general error
 290  * \retval NOPAGE_OOM not have memory for allocate new page
 291  */
 292 static vm_fault_t ll_fault0(struct vm_area_struct *vma, struct vm_fault *vmf)
 293 {
 294         struct inode *inode = file_inode(vma->vm_file);
 295         struct lu_env           *env;
 296         struct cl_io            *io;
 297         struct vvp_io           *vio = NULL;
 298         struct page             *vmpage;
 299         int                      result = 0;
 300         int                      fault_ret = 0;
 301         __u16                    refcheck;
 302         ENTRY;
 303
 304         env = cl_env_get(&refcheck);
 305         if (IS_ERR(env))
 306                 RETURN(PTR_ERR(env));
 307
 308         if (ll_sbi_has_fast_read(ll_i2sbi(inode))) {
 309                 /* do fast fault */
 310                 bool allow_retry = vmf->flags & FAULT_FLAG_ALLOW_RETRY;
 311                 bool has_retry = vmf->flags & FAULT_FLAG_RETRY_NOWAIT;
 312
 313                 /* To avoid loops, instruct downstream to not drop mmap_sem */
 314                 /**
 315                  * only need FAULT_FLAG_ALLOW_RETRY prior to Linux 5.1
 316                  * (6b4c9f4469819), where FAULT_FLAG_RETRY_NOWAIT is enough
 317                  * to not drop mmap_sem when failed to lock the page.
 318                  */
 319                 vmf->flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT;
 320                 ll_cl_add(inode, env, NULL, LCC_MMAP);
 321                 fault_ret = ll_filemap_fault(vma, vmf);
 322                 ll_cl_remove(inode, env);
 323                 if (!has_retry)
 324                         vmf->flags &= ~FAULT_FLAG_RETRY_NOWAIT;
 325                 if (!allow_retry)
 326                         vmf->flags &= ~FAULT_FLAG_ALLOW_RETRY;
 327
 328                 /* - If there is no error, then the page was found in cache and
 329                  *   uptodate;
 330                  * - If VM_FAULT_RETRY is set, the page existed but failed to
 331                  *   lock. We will try slow path to avoid loops.
 332                  * - Otherwise, it should try normal fault under DLM lock. */
 333                 if (!(fault_ret & VM_FAULT_RETRY) &&
 334                     !(fault_ret & VM_FAULT_ERROR))
 335                         GOTO(out, result = 0);
 336
 337                 fault_ret = 0;
 338         }
 339
 340         io = ll_fault_io_init(env, vma, vmf->pgoff, false);
 341         if (IS_ERR(io))
 342                 GOTO(out, result = PTR_ERR(io));
 343
 344         result = io->ci_result;
 345         if (result == 0) {
 346                 vio = vvp_env_io(env);
 347                 vio->u.fault.ft_vma       = vma;
 348                 vio->u.fault.ft_vmpage    = NULL;
 349                 vio->u.fault.ft_vmf = vmf;
 350                 vio->u.fault.ft_flags = 0;
 351                 vio->u.fault.ft_flags_valid = 0;
 352
 353                 /* May call ll_readpage() */
 354                 ll_cl_add(inode, env, io, LCC_MMAP);
 355
 356                 result = cl_io_loop(env, io);
 357
 358                 ll_cl_remove(inode, env);
 359
 360                 /* ft_flags are only valid if we reached
 361                  * the call to filemap_fault */
 362                 if (vio->u.fault.ft_flags_valid)
 363                         fault_ret = vio->u.fault.ft_flags;
 364
 365                 vmpage = vio->u.fault.ft_vmpage;
 366                 if (result != 0 && vmpage != NULL) {
 367                         put_page(vmpage);
 368                         vmf->page = NULL;
 369                 }
 370         }
 371         cl_io_fini(env, io);
 372
 373 out:
 374         cl_env_put(env, &refcheck);
 375         if (result != 0 && !(fault_ret & VM_FAULT_RETRY))
 376                 fault_ret |= to_fault_error(result);
 377
 378         CDEBUG(D_MMAP, "%s fault %d/%d\n", current->comm, fault_ret, result);
 379         RETURN(fault_ret);
 380 }
 381
 382 #ifdef HAVE_VM_OPS_USE_VM_FAULT_ONLY
 383 static vm_fault_t ll_fault(struct vm_fault *vmf)
 384 {
 385         struct vm_area_struct *vma = vmf->vma;
 386 #else
 387 static vm_fault_t ll_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 388 {
 389 #endif
 390         int count = 0;
 391         bool printed = false;
 392         bool cached;
 393         vm_fault_t result;
 394         ktime_t kstart = ktime_get();
 395         sigset_t old, new;
 396
 397         result = pcc_fault(vma, vmf, &cached);
 398         if (cached)
 399                 goto out;
 400
 401         CDEBUG(D_MMAP|D_IOTRACE,
 402                "START file %s:"DFID", vma=%p start=%#lx end=%#lx vm_flags=%#lx idx=%lu\n",
 403                file_dentry(vma->vm_file)->d_name.name,
 404                PFID(&ll_i2info(file_inode(vma->vm_file))->lli_fid),
 405                vma, vma->vm_start, vma->vm_end, vma->vm_flags, vmf->pgoff);
 406
 407         /* Only SIGKILL and SIGTERM is allowed for fault/nopage/mkwrite
 408          * so that it can be killed by admin but not cause segfault by
 409          * other signals.
 410          */
 411         siginitsetinv(&new, sigmask(SIGKILL) | sigmask(SIGTERM));
 412         sigprocmask(SIG_BLOCK, &new, &old);
 413
 414         /* make sure offset is not a negative number */
 415         if (vmf->pgoff > (MAX_LFS_FILESIZE >> PAGE_SHIFT))
 416                 return VM_FAULT_SIGBUS;
 417
 418 restart:
 419         result = ll_fault0(vma, vmf);
 420         if (vmf->page &&
 421             !(result & (VM_FAULT_RETRY | VM_FAULT_ERROR | VM_FAULT_LOCKED))) {
 422                 struct page *vmpage = vmf->page;
 423
 424                 /* lock the page, then check if this page has been truncated
 425                  * or deleted from Lustre and retry if so
 426                  */
 427                 lock_page(vmpage);
 428                 if (unlikely(vmpage->mapping == NULL) ||
 429                     vmpage->private == 0) { /* unlucky */
 430                         unlock_page(vmpage);
 431                         put_page(vmpage);
 432                         vmf->page = NULL;
 433
 434                         if (!printed && ++count > 16) {
 435                                 struct inode *inode = file_inode(vma->vm_file);
 436
 437                                 CWARN("%s: FID "DFID" under heavy mmap contention by '%s', consider revising IO pattern\n",
 438                                       ll_i2sbi(inode)->ll_fsname,
 439                                       PFID(&ll_i2info(inode)->lli_fid),
 440                                       current->comm);
 441                                 printed = true;
 442                         }
 443
 444                         goto restart;
 445                 }
 446
 447                 result |= VM_FAULT_LOCKED;
 448         }
 449         sigprocmask(SIG_SETMASK, &old, NULL);
 450
 451 out:
 452         if (vmf->page && result == VM_FAULT_LOCKED) {
 453                 ll_rw_stats_tally(ll_i2sbi(file_inode(vma->vm_file)),
 454                                   current->pid, vma->vm_file->private_data,
 455                                   vmf->page->index << PAGE_SHIFT, PAGE_SIZE,
 456                                   READ);
 457                 ll_stats_ops_tally(ll_i2sbi(file_inode(vma->vm_file)),
 458                                    LPROC_LL_FAULT,
 459                                    ktime_us_delta(ktime_get(), kstart));
 460         }
 461
 462         CDEBUG(D_IOTRACE,
 463                "COMPLETED: "DFID": vma=%p start=%#lx end=%#lx vm_flags=%#lx idx=%lu, rc %d\n",
 464                PFID(&ll_i2info(file_inode(vma->vm_file))->lli_fid),
 465                vma, vma->vm_start, vma->vm_end, vma->vm_flags, vmf->pgoff,
 466                result);
 467
 468         return result;
 469 }
 470
 471 #ifdef HAVE_VM_OPS_USE_VM_FAULT_ONLY
 472 static vm_fault_t ll_page_mkwrite(struct vm_fault *vmf)
 473 {
 474         struct vm_area_struct *vma = vmf->vma;
 475 #else
 476 static vm_fault_t ll_page_mkwrite(struct vm_area_struct *vma,
 477                                   struct vm_fault *vmf)
 478 {
 479 #endif
 480         int count = 0;
 481         bool printed = false;
 482         bool retry;
 483         bool cached;
 484         ktime_t kstart = ktime_get();
 485         vm_fault_t result;
 486
 487         CDEBUG(D_MMAP|D_IOTRACE,
 488                "START file %s:"DFID", vma=%p start=%#lx end=%#lx vm_flags=%#lx idx=%lu\n",
 489                file_dentry(vma->vm_file)->d_name.name,
 490                PFID(&ll_i2info(file_inode(vma->vm_file))->lli_fid),
 491                vma, vma->vm_start, vma->vm_end, vma->vm_flags, vmf->page->index);
 492
 493         result = pcc_page_mkwrite(vma, vmf, &cached);
 494         if (cached)
 495                 goto out;
 496
 497         file_update_time(vma->vm_file);
 498         do {
 499                 retry = false;
 500                 result = ll_page_mkwrite0(vma, vmf->page, &retry);
 501
 502                 if (!printed && ++count > 16) {
 503                         const struct dentry *de = file_dentry(vma->vm_file);
 504
 505                         CWARN("app(%s): the page %lu of file "DFID" is under heavy contention\n",
 506                               current->comm, vmf->pgoff,
 507                               PFID(ll_inode2fid(de->d_inode)));
 508                         printed = true;
 509                 }
 510         } while (retry);
 511
 512         switch (result) {
 513         case 0:
 514                 LASSERT(PageLocked(vmf->page));
 515                 result = VM_FAULT_LOCKED;
 516                 break;
 517         case -ENODATA:
 518         case -EFAULT:
 519                 result = VM_FAULT_NOPAGE;
 520                 break;
 521         case -ENOMEM:
 522                 result = VM_FAULT_OOM;
 523                 break;
 524         case -EAGAIN:
 525                 result = VM_FAULT_RETRY;
 526                 break;
 527         default:
 528                 result = VM_FAULT_SIGBUS;
 529                 break;
 530         }
 531
 532 out:
 533         if (result == VM_FAULT_LOCKED) {
 534                 ll_rw_stats_tally(ll_i2sbi(file_inode(vma->vm_file)),
 535                                   current->pid, vma->vm_file->private_data,
 536                                   vmf->page->index << PAGE_SHIFT, PAGE_SIZE,
 537                                   WRITE);
 538                 ll_stats_ops_tally(ll_i2sbi(file_inode(vma->vm_file)),
 539                                    LPROC_LL_MKWRITE,
 540                                    ktime_us_delta(ktime_get(), kstart));
 541         }
 542
 543         CDEBUG(D_IOTRACE,
 544                "COMPLETED: "DFID": vma=%p start=%#lx end=%#lx vm_flags=%#lx idx=%lu, rc %d\n",
 545                PFID(&ll_i2info(file_inode(vma->vm_file))->lli_fid),
 546                vma, vma->vm_start, vma->vm_end, vma->vm_flags,
 547                vmf->page->index, result);
 548         return result;
 549 }
 550
 551 /**
 552  *  To avoid cancel the locks covering mmapped region for lock cache pressure,
 553  *  we track the mapped vma count in vvp_object::vob_mmap_cnt.
 554  */
 555 static void ll_vm_open(struct vm_area_struct * vma)
 556 {
 557         struct inode *inode    = file_inode(vma->vm_file);
 558         struct vvp_object *vob = cl_inode2vvp(inode);
 559
 560         ENTRY;
 561         LASSERT(atomic_read(&vob->vob_mmap_cnt) >= 0);
 562         atomic_inc(&vob->vob_mmap_cnt);
 563         pcc_vm_open(vma);
 564         EXIT;
 565 }
 566
 567 /**
 568  * Dual to ll_vm_open().
 569  */
 570 static void ll_vm_close(struct vm_area_struct *vma)
 571 {
 572         struct inode      *inode = file_inode(vma->vm_file);
 573         struct vvp_object *vob   = cl_inode2vvp(inode);
 574
 575         ENTRY;
 576         atomic_dec(&vob->vob_mmap_cnt);
 577         LASSERT(atomic_read(&vob->vob_mmap_cnt) >= 0);
 578         pcc_vm_close(vma);
 579         EXIT;
 580 }
 581
 582 static const struct vm_operations_struct ll_file_vm_ops = {
 583         .fault                  = ll_fault,
 584         .page_mkwrite           = ll_page_mkwrite,
 585         .open                   = ll_vm_open,
 586         .close                  = ll_vm_close,
 587 };
 588
 589 int ll_file_mmap(struct file *file, struct vm_area_struct * vma)
 590 {
 591         struct inode *inode = file_inode(file);
 592         ktime_t kstart = ktime_get();
 593         bool cached;
 594         int rc;
 595
 596         ENTRY;
 597         CDEBUG(D_VFSTRACE | D_MMAP,
 598                "VFS_Op: fid="DFID" vma=%p start=%#lx end=%#lx vm_flags=%#lx\n",
 599                PFID(&ll_i2info(inode)->lli_fid),
 600                vma, vma->vm_start, vma->vm_end, vma->vm_flags);
 601
 602         if (ll_file_nolock(file))
 603                 RETURN(-EOPNOTSUPP);
 604
 605         rc = pcc_file_mmap(file, vma, &cached);
 606         if (cached && rc != 0)
 607                 RETURN(rc);
 608
 609         rc = generic_file_mmap(file, vma);
 610         if (rc == 0) {
 611                 vma->vm_ops = &ll_file_vm_ops;
 612                 vma->vm_ops->open(vma);
 613                 /* update the inode's size and mtime */
 614                 if (!cached)
 615                         rc = ll_glimpse_size(inode);
 616         }
 617
 618         if (!rc)
 619                 ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_MMAP,
 620                                    ktime_us_delta(ktime_get(), kstart));
 621
 622         RETURN(rc);
 623 }