lustre/llite/llite_mmap.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  */
  36
  37 #ifndef AUTOCONF_INCLUDED
  38 #include <linux/config.h>
  39 #endif
  40 #include <linux/kernel.h>
  41 #include <linux/mm.h>
  42 #include <linux/string.h>
  43 #include <linux/stat.h>
  44 #include <linux/errno.h>
  45 #include <linux/smp_lock.h>
  46 #include <linux/unistd.h>
  47 #include <linux/version.h>
  48 #include <asm/system.h>
  49 #include <asm/uaccess.h>
  50
  51 #include <linux/fs.h>
  52 #include <linux/stat.h>
  53 #include <asm/uaccess.h>
  54 #include <linux/mm.h>
  55 #include <linux/pagemap.h>
  56 #include <linux/smp_lock.h>
  57
  58 #define DEBUG_SUBSYSTEM S_LLITE
  59
  60 //#include <lustre_mdc.h>
  61 #include <lustre_lite.h>
  62 #include "llite_internal.h"
  63 #include <linux/lustre_compat25.h>
  64
  65 #define VMA_DEBUG(vma, fmt, arg...)                                     \
  66         CDEBUG(D_MMAP, "vma(%p) start(%ld) end(%ld) pgoff(%ld) inode(%p) "   \
  67                "ino(%lu) iname(%s): " fmt, vma, vma->vm_start, vma->vm_end,  \
  68                vma->vm_pgoff, vma->vm_file->f_dentry->d_inode,               \
  69                vma->vm_file->f_dentry->d_inode->i_ino,                       \
  70                vma->vm_file->f_dentry->d_iname, ## arg);                     \
  71
  72
  73 struct ll_lock_tree_node {
  74         rb_node_t               lt_node;
  75         struct list_head        lt_locked_item;
  76         __u64                   lt_oid;
  77         ldlm_policy_data_t      lt_policy;
  78         struct lustre_handle    lt_lockh;
  79         ldlm_mode_t             lt_mode;
  80         struct inode           *lt_inode;
  81 };
  82
  83 int lt_get_mmap_locks(struct ll_lock_tree *tree,
  84                       unsigned long addr, size_t count);
  85
  86 struct page *ll_nopage(struct vm_area_struct *vma, unsigned long address,
  87                        int *type);
  88
  89 struct ll_lock_tree_node * ll_node_from_inode(struct inode *inode, __u64 start,
  90                                               __u64 end, ldlm_mode_t mode)
  91 {
  92         struct ll_lock_tree_node *node;
  93
  94         OBD_ALLOC(node, sizeof(*node));
  95         if (node == NULL)
  96                 RETURN(ERR_PTR(-ENOMEM));
  97
  98         node->lt_inode = inode;
  99         node->lt_oid = ll_i2info(inode)->lli_smd->lsm_object_id;
 100         node->lt_policy.l_extent.start = start;
 101         node->lt_policy.l_extent.end = end;
 102         memset(&node->lt_lockh, 0, sizeof(node->lt_lockh));
 103         INIT_LIST_HEAD(&node->lt_locked_item);
 104         node->lt_mode = mode;
 105
 106         return node;
 107 }
 108
 109 int lt_compare(struct ll_lock_tree_node *one, struct ll_lock_tree_node *two)
 110 {
 111         /* To avoid multiple fs deadlock */
 112         if (one->lt_inode->i_sb->s_dev < two->lt_inode->i_sb->s_dev)
 113                 return -1;
 114         if (one->lt_inode->i_sb->s_dev > two->lt_inode->i_sb->s_dev)
 115                 return 1;
 116
 117         if (one->lt_oid < two->lt_oid)
 118                 return -1;
 119         if (one->lt_oid > two->lt_oid)
 120                 return 1;
 121
 122         if (one->lt_policy.l_extent.end < two->lt_policy.l_extent.start)
 123                 return -1;
 124         if (one->lt_policy.l_extent.start > two->lt_policy.l_extent.end)
 125                 return 1;
 126
 127         return 0; /* they are the same object and overlap */
 128 }
 129
 130 static void lt_merge(struct ll_lock_tree_node *dst,
 131                      struct ll_lock_tree_node *src)
 132 {
 133         dst->lt_policy.l_extent.start = min(dst->lt_policy.l_extent.start,
 134                                             src->lt_policy.l_extent.start);
 135         dst->lt_policy.l_extent.end = max(dst->lt_policy.l_extent.end,
 136                                           src->lt_policy.l_extent.end);
 137
 138         /* XXX could be a real call to the dlm to find superset modes */
 139         if (src->lt_mode == LCK_PW && dst->lt_mode != LCK_PW)
 140                 dst->lt_mode = LCK_PW;
 141 }
 142
 143 static void lt_insert(struct ll_lock_tree *tree,
 144                       struct ll_lock_tree_node *node)
 145 {
 146         struct ll_lock_tree_node *walk;
 147         rb_node_t **p, *parent;
 148         ENTRY;
 149
 150 restart:
 151         p = &tree->lt_root.rb_node;
 152         parent = NULL;
 153         while (*p) {
 154                 parent = *p;
 155                 walk = rb_entry(parent, struct ll_lock_tree_node, lt_node);
 156                 switch (lt_compare(node, walk)) {
 157                 case -1:
 158                         p = &(*p)->rb_left;
 159                         break;
 160                 case 1:
 161                         p = &(*p)->rb_right;
 162                         break;
 163                 case 0:
 164                         lt_merge(node, walk);
 165                         rb_erase(&walk->lt_node, &tree->lt_root);
 166                         OBD_FREE(walk, sizeof(*walk));
 167                         goto restart;
 168                         break;
 169                 default:
 170                         LBUG();
 171                         break;
 172                 }
 173         }
 174         rb_link_node(&node->lt_node, parent, p);
 175         rb_insert_color(&node->lt_node, &tree->lt_root);
 176         EXIT;
 177 }
 178
 179 static struct ll_lock_tree_node *lt_least_node(struct ll_lock_tree *tree)
 180 {
 181         rb_node_t *rbnode;
 182         struct ll_lock_tree_node *node = NULL;
 183
 184         for ( rbnode = tree->lt_root.rb_node; rbnode != NULL;
 185               rbnode = rbnode->rb_left) {
 186                 if (rbnode->rb_left == NULL) {
 187                         node = rb_entry(rbnode, struct ll_lock_tree_node,
 188                                         lt_node);
 189                         break;
 190                 }
 191         }
 192         RETURN(node);
 193 }
 194
 195 int ll_tree_unlock(struct ll_lock_tree *tree)
 196 {
 197         struct ll_lock_tree_node *node;
 198         struct list_head *pos, *n;
 199         struct inode *inode;
 200         int rc = 0;
 201         ENTRY;
 202
 203         list_for_each_safe(pos, n, &tree->lt_locked_list) {
 204                 node = list_entry(pos, struct ll_lock_tree_node,
 205                                   lt_locked_item);
 206
 207                 inode = node->lt_inode;
 208                 rc = ll_extent_unlock(tree->lt_fd, inode,
 209                                       ll_i2info(inode)->lli_smd, node->lt_mode,
 210                                       &node->lt_lockh);
 211                 if (rc != 0) {
 212                         /* XXX better message */
 213                         CERROR("couldn't unlock %d\n", rc);
 214                 }
 215                 list_del(&node->lt_locked_item);
 216                 OBD_FREE(node, sizeof(*node));
 217         }
 218
 219         while ((node = lt_least_node(tree))) {
 220                 rb_erase(&node->lt_node, &tree->lt_root);
 221                 OBD_FREE(node, sizeof(*node));
 222         }
 223
 224         RETURN(rc);
 225 }
 226
 227 int ll_tree_lock(struct ll_lock_tree *tree,
 228                  struct ll_lock_tree_node *first_node,
 229                  const char *buf, size_t count, int ast_flags)
 230 {
 231         struct ll_lock_tree_node *node;
 232         int rc = 0;
 233         ENTRY;
 234
 235         tree->lt_root.rb_node = NULL;
 236         INIT_LIST_HEAD(&tree->lt_locked_list);
 237         if (first_node != NULL)
 238                 lt_insert(tree, first_node);
 239
 240         /* To avoid such subtle deadlock case: client1 try to read file1 to
 241          * mmapped file2, on the same time, client2 try to read file2 to
 242          * mmapped file1.*/
 243         rc = lt_get_mmap_locks(tree, (unsigned long)buf, count);
 244         if (rc)
 245                 GOTO(out, rc);
 246
 247         while ((node = lt_least_node(tree))) {
 248                 struct inode *inode = node->lt_inode;
 249                 rc = ll_extent_lock(tree->lt_fd, inode,
 250                                     ll_i2info(inode)->lli_smd, node->lt_mode,
 251                                     &node->lt_policy, &node->lt_lockh,
 252                                     ast_flags);
 253                 if (rc != 0)
 254                         GOTO(out, rc);
 255
 256                 rb_erase(&node->lt_node, &tree->lt_root);
 257                 list_add_tail(&node->lt_locked_item, &tree->lt_locked_list);
 258         }
 259         RETURN(rc);
 260 out:
 261         ll_tree_unlock(tree);
 262         RETURN(rc);
 263 }
 264
 265 static ldlm_mode_t mode_from_vma(struct vm_area_struct *vma)
 266 {
 267         /* we only want to hold PW locks if the mmap() can generate
 268          * writes back to the file and that only happens in shared
 269          * writable vmas */
 270         if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE))
 271                 return LCK_PW;
 272         return LCK_PR;
 273 }
 274
 275 static void policy_from_vma(ldlm_policy_data_t *policy,
 276                             struct vm_area_struct *vma, unsigned long addr,
 277                             size_t count)
 278 {
 279         policy->l_extent.start = ((addr - vma->vm_start) & CFS_PAGE_MASK) +
 280                                  (vma->vm_pgoff << CFS_PAGE_SHIFT);
 281         policy->l_extent.end = (policy->l_extent.start + count - 1) |
 282                                ~CFS_PAGE_MASK;
 283 }
 284
 285 static struct vm_area_struct * our_vma(unsigned long addr, size_t count)
 286 {
 287         struct mm_struct *mm = current->mm;
 288         struct vm_area_struct *vma, *ret = NULL;
 289         ENTRY;
 290
 291         /* No MM (e.g. NFS)? No vmas too. */
 292         if (!mm)
 293                 RETURN(NULL);
 294
 295         spin_lock(&mm->page_table_lock);
 296         for(vma = find_vma(mm, addr);
 297             vma != NULL && vma->vm_start < (addr + count); vma = vma->vm_next) {
 298                 if (vma->vm_ops && vma->vm_ops->nopage == ll_nopage &&
 299                     vma->vm_flags & VM_SHARED) {
 300                         ret = vma;
 301                         break;
 302                 }
 303         }
 304         spin_unlock(&mm->page_table_lock);
 305         RETURN(ret);
 306 }
 307
 308 int ll_region_mapped(unsigned long addr, size_t count)
 309 {
 310         return !!our_vma(addr, count);
 311 }
 312
 313 int lt_get_mmap_locks(struct ll_lock_tree *tree,
 314                       unsigned long addr, size_t count)
 315 {
 316         struct vm_area_struct *vma;
 317         struct ll_lock_tree_node *node;
 318         ldlm_policy_data_t policy;
 319         struct inode *inode;
 320         ENTRY;
 321
 322         if (count == 0)
 323                 RETURN(0);
 324
 325         /* we need to look up vmas on page aligned addresses */
 326         count += addr & (~CFS_PAGE_MASK);
 327         addr &= CFS_PAGE_MASK;
 328
 329         while ((vma = our_vma(addr, count)) != NULL) {
 330                 LASSERT(vma->vm_file);
 331
 332                 inode = vma->vm_file->f_dentry->d_inode;
 333                 policy_from_vma(&policy, vma, addr, count);
 334                 node = ll_node_from_inode(inode, policy.l_extent.start,
 335                                           policy.l_extent.end,
 336                                           mode_from_vma(vma));
 337                 if (IS_ERR(node)) {
 338                         CERROR("not enough mem for lock_tree_node!\n");
 339                         RETURN(-ENOMEM);
 340                 }
 341                 lt_insert(tree, node);
 342
 343                 if (vma->vm_end - addr >= count)
 344                         break;
 345                 count -= vma->vm_end - addr;
 346                 addr = vma->vm_end;
 347         }
 348         RETURN(0);
 349 }
 350
 351 /**
 352  * Page fault handler.
 353  *
 354  * \param vma - is virtiual area struct related to page fault
 355  * \param address - address when hit fault
 356  * \param type - of fault
 357  *
 358  * \return allocated and filled page for address
 359  * \retval NOPAGE_SIGBUS if page not exist on this address
 360  * \retval NOPAGE_OOM not have memory for allocate new page
 361  */
 362 struct page *ll_nopage(struct vm_area_struct *vma, unsigned long address,
 363                        int *type)
 364 {
 365         struct file *filp = vma->vm_file;
 366         struct ll_file_data *fd = LUSTRE_FPRIVATE(filp);
 367         struct inode *inode = filp->f_dentry->d_inode;
 368         struct lustre_handle lockh = { 0 };
 369         ldlm_policy_data_t policy;
 370         ldlm_mode_t mode;
 371         struct page *page = NULL;
 372         struct ll_inode_info *lli = ll_i2info(inode);
 373         struct lov_stripe_md *lsm;
 374         struct ost_lvb lvb;
 375         __u64 kms, old_mtime;
 376         unsigned long pgoff, size, rand_read, seq_read;
 377         int rc = 0;
 378         ENTRY;
 379
 380         if (lli->lli_smd == NULL) {
 381                 CERROR("No lsm on fault?\n");
 382                 RETURN(NULL);
 383         }
 384
 385         ll_clear_file_contended(inode);
 386
 387         /* start and end the lock on the first and last bytes in the page */
 388         policy_from_vma(&policy, vma, address, CFS_PAGE_SIZE);
 389
 390         CDEBUG(D_MMAP, "nopage vma %p inode %lu, locking ["LPU64", "LPU64"]\n",
 391                vma, inode->i_ino, policy.l_extent.start, policy.l_extent.end);
 392
 393         mode = mode_from_vma(vma);
 394         old_mtime = LTIME_S(inode->i_mtime);
 395
 396         lsm = lli->lli_smd;
 397         rc = ll_extent_lock(fd, inode, lsm, mode, &policy,
 398                             &lockh, LDLM_FL_CBPENDING | LDLM_FL_NO_LRU);
 399         if (rc != 0)
 400                 RETURN(NULL);
 401
 402         if (vma->vm_flags & VM_EXEC && LTIME_S(inode->i_mtime) != old_mtime)
 403                 CWARN("binary changed. inode %lu\n", inode->i_ino);
 404
 405         lov_stripe_lock(lsm);
 406         inode_init_lvb(inode, &lvb);
 407         obd_merge_lvb(ll_i2dtexp(inode), lsm, &lvb, 1);
 408         kms = lvb.lvb_size;
 409
 410         pgoff = ((address - vma->vm_start) >> CFS_PAGE_SHIFT) + vma->vm_pgoff;
 411         size = (kms + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT;
 412
 413         if (pgoff >= size) {
 414                 lov_stripe_unlock(lsm);
 415                 ll_glimpse_size(inode, LDLM_FL_BLOCK_GRANTED);
 416         } else {
 417                 /* XXX change inode size without ll_inode_size_lock() held!
 418                  *     there is a race condition with truncate path. (see
 419                  *     ll_extent_lock) */
 420                 /* XXX i_size_write() is not used because it is not safe to
 421                  *     take the ll_inode_size_lock() due to a potential lock
 422                  *     inversion (bug 6077).  And since it's not safe to use
 423                  *     i_size_write() without a covering mutex we do the
 424                  *     assignment directly.  It is not critical that the
 425                  *     size be correct. */
 426                 /* region is within kms and, hence, within real file size (A).
 427                  * We need to increase i_size to cover the read region so that
 428                  * generic_file_read() will do its job, but that doesn't mean
 429                  * the kms size is _correct_, it is only the _minimum_ size.
 430                  * If someone does a stat they will get the correct size which
 431                  * will always be >= the kms value here.  b=11081 */
 432                 if (i_size_read(inode) < kms) {
 433                         inode->i_size = kms;
 434                         CDEBUG(D_INODE, "ino=%lu, updating i_size %llu\n",
 435                                inode->i_ino, i_size_read(inode));
 436                 }
 437                 lov_stripe_unlock(lsm);
 438         }
 439
 440         /* If mapping is writeable, adjust kms to cover this page,
 441          * but do not extend kms beyond actual file size.
 442          * policy.l_extent.end is set to the end of the page by policy_from_vma
 443          * bug 10919 */
 444         lov_stripe_lock(lsm);
 445         if (mode == LCK_PW)
 446                 obd_adjust_kms(ll_i2dtexp(inode), lsm,
 447                                min_t(loff_t, policy.l_extent.end + 1,
 448                                i_size_read(inode)), 0);
 449         lov_stripe_unlock(lsm);
 450
 451         /* disable VM_SEQ_READ and use VM_RAND_READ to make sure that
 452          * the kernel will not read other pages not covered by ldlm in
 453          * filemap_nopage. we do our readahead in ll_readpage.
 454          */
 455         rand_read = vma->vm_flags & VM_RAND_READ;
 456         seq_read = vma->vm_flags & VM_SEQ_READ;
 457         vma->vm_flags &= ~ VM_SEQ_READ;
 458         vma->vm_flags |= VM_RAND_READ;
 459
 460         page = filemap_nopage(vma, address, type);
 461         if (page != NOPAGE_SIGBUS && page != NOPAGE_OOM)
 462                 LL_CDEBUG_PAGE(D_PAGE, page, "got addr %lu type %lx\n", address,
 463                                (long)type);
 464         else
 465                 CDEBUG(D_PAGE, "got addr %lu type %lx - SIGBUS\n",  address,
 466                                (long)type);
 467
 468         vma->vm_flags &= ~VM_RAND_READ;
 469         vma->vm_flags |= (rand_read | seq_read);
 470
 471         ll_extent_unlock(fd, inode, ll_i2info(inode)->lli_smd, mode, &lockh);
 472         RETURN(page);
 473 }
 474
 475 /* To avoid cancel the locks covering mmapped region for lock cache pressure,
 476  * we track the mapped vma count by lli_mmap_cnt.
 477  * ll_vm_open():  when first vma is linked, split locks from lru.
 478  * ll_vm_close(): when last vma is unlinked, join all this file's locks to lru.
 479  *
 480  * XXX we don't check the if the region of vma/lock for performance.
 481  */
 482 static void ll_vm_open(struct vm_area_struct * vma)
 483 {
 484         struct inode *inode = vma->vm_file->f_dentry->d_inode;
 485         struct ll_inode_info *lli = ll_i2info(inode);
 486         ENTRY;
 487
 488         LASSERT(vma->vm_file);
 489
 490         spin_lock(&lli->lli_lock);
 491         LASSERT(atomic_read(&lli->lli_mmap_cnt) >= 0);
 492
 493         atomic_inc(&lli->lli_mmap_cnt);
 494         if (atomic_read(&lli->lli_mmap_cnt) == 1) {
 495                 struct lov_stripe_md *lsm = lli->lli_smd;
 496                 struct ll_sb_info *sbi = ll_i2sbi(inode);
 497                 int count;
 498
 499                 spin_unlock(&lli->lli_lock);
 500
 501                 if (!lsm)
 502                         return;
 503                 count = obd_join_lru(sbi->ll_dt_exp, lsm, 0);
 504                 VMA_DEBUG(vma, "split %d unused locks from lru\n", count);
 505         } else {
 506                 spin_unlock(&lli->lli_lock);
 507         }
 508
 509 }
 510
 511 static void ll_vm_close(struct vm_area_struct *vma)
 512 {
 513         struct inode *inode = vma->vm_file->f_dentry->d_inode;
 514         struct ll_inode_info *lli = ll_i2info(inode);
 515         ENTRY;
 516
 517         LASSERT(vma->vm_file);
 518
 519         spin_lock(&lli->lli_lock);
 520         LASSERT(atomic_read(&lli->lli_mmap_cnt) > 0);
 521
 522         atomic_dec(&lli->lli_mmap_cnt);
 523         if (atomic_read(&lli->lli_mmap_cnt) == 0) {
 524                 struct lov_stripe_md *lsm = lli->lli_smd;
 525                 struct ll_sb_info *sbi = ll_i2sbi(inode);
 526                 int count;
 527
 528                 spin_unlock(&lli->lli_lock);
 529
 530                 if (!lsm)
 531                         return;
 532                 count = obd_join_lru(sbi->ll_dt_exp, lsm, 1);
 533                 VMA_DEBUG(vma, "join %d unused locks to lru\n", count);
 534         } else {
 535                 spin_unlock(&lli->lli_lock);
 536         }
 537 }
 538
 539 #ifndef HAVE_FILEMAP_POPULATE
 540 static int (*filemap_populate)(struct vm_area_struct * area, unsigned long address, unsigned long len, pgprot_t prot, unsigned long pgoff, int nonblock);
 541 #endif
 542 static int ll_populate(struct vm_area_struct *area, unsigned long address,
 543                        unsigned long len, pgprot_t prot, unsigned long pgoff,
 544                        int nonblock)
 545 {
 546         int rc = 0;
 547         ENTRY;
 548
 549         /* always set nonblock as true to avoid page read ahead */
 550         rc = filemap_populate(area, address, len, prot, pgoff, 1);
 551         RETURN(rc);
 552 }
 553
 554 /* return the user space pointer that maps to a file offset via a vma */
 555 static inline unsigned long file_to_user(struct vm_area_struct *vma, __u64 byte)
 556 {
 557         return vma->vm_start + (byte - ((__u64)vma->vm_pgoff << CFS_PAGE_SHIFT));
 558
 559 }
 560
 561 /* XXX put nice comment here.  talk about __free_pte -> dirty pages and
 562  * nopage's reference passing to the pte */
 563 int ll_teardown_mmaps(struct address_space *mapping, __u64 first, __u64 last)
 564 {
 565         int rc = -ENOENT;
 566         ENTRY;
 567
 568         LASSERTF(last > first, "last "LPU64" first "LPU64"\n", last, first);
 569         if (mapping_mapped(mapping)) {
 570                 rc = 0;
 571                 unmap_mapping_range(mapping, first + CFS_PAGE_SIZE - 1,
 572                                     last - first + 1, 0);
 573         }
 574
 575         RETURN(rc);
 576 }
 577
 578 static struct vm_operations_struct ll_file_vm_ops = {
 579         .nopage         = ll_nopage,
 580         .open           = ll_vm_open,
 581         .close          = ll_vm_close,
 582         .populate       = ll_populate,
 583 };
 584
 585 int ll_file_mmap(struct file * file, struct vm_area_struct * vma)
 586 {
 587         int rc;
 588         ENTRY;
 589
 590         ll_stats_ops_tally(ll_i2sbi(file->f_dentry->d_inode), LPROC_LL_MAP, 1);
 591         rc = generic_file_mmap(file, vma);
 592         if (rc == 0) {
 593 #if !defined(HAVE_FILEMAP_POPULATE)
 594                 if (!filemap_populate)
 595                         filemap_populate = vma->vm_ops->populate;
 596 #endif
 597                 vma->vm_ops = &ll_file_vm_ops;
 598                 vma->vm_ops->open(vma);
 599                 /* update the inode's size and mtime */
 600                 rc = ll_glimpse_size(file->f_dentry->d_inode, 0);
 601         }
 602
 603         RETURN(rc);
 604 }