root/include/linux/pagemap.h

INCLUDED FROM

DEFINITIONS

1. mapping_set_error
2. mapping_set_unevictable
3. mapping_clear_unevictable
4. mapping_unevictable
5. mapping_set_exiting
6. mapping_exiting
7. mapping_set_no_writeback_tags
8. mapping_use_writeback_tags
9. mapping_gfp_mask
10. mapping_gfp_constraint
11. mapping_set_gfp_mask
12. __page_cache_add_speculative
13. page_cache_get_speculative
14. page_cache_add_speculative
15. __page_cache_alloc
16. page_cache_alloc
17. readahead_gfp_mask
18. find_get_page
19. find_get_page_flags
20. find_lock_page
21. find_or_create_page
22. grab_cache_page_nowait
23. find_subpage
24. find_get_pages
25. find_get_pages_tag
26. grab_cache_page
27. read_mapping_page
28. page_to_index
29. page_to_pgoff
30. page_offset
31. page_file_offset
32. linear_page_index
33. trylock_page
34. lock_page
35. lock_page_killable
36. lock_page_or_retry
37. wait_on_page_locked
38. wait_on_page_locked_killable
39. fault_in_pages_writeable
40. fault_in_pages_readable
41. add_to_page_cache
42. dir_pages

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_PAGEMAP_H
   3 #define _LINUX_PAGEMAP_H
   4 
   5 /*
   6  * Copyright 1995 Linus Torvalds
   7  */
   8 #include <linux/mm.h>
   9 #include <linux/fs.h>
  10 #include <linux/list.h>
  11 #include <linux/highmem.h>
  12 #include <linux/compiler.h>
  13 #include <linux/uaccess.h>
  14 #include <linux/gfp.h>
  15 #include <linux/bitops.h>
  16 #include <linux/hardirq.h> /* for in_interrupt() */
  17 #include <linux/hugetlb_inline.h>
  18 
  19 struct pagevec;
  20 
  21 /*
  22  * Bits in mapping->flags.
  23  */
  24 enum mapping_flags {
  25         AS_EIO          = 0,    /* IO error on async write */
  26         AS_ENOSPC       = 1,    /* ENOSPC on async write */
  27         AS_MM_ALL_LOCKS = 2,    /* under mm_take_all_locks() */
  28         AS_UNEVICTABLE  = 3,    /* e.g., ramdisk, SHM_LOCK */
  29         AS_EXITING      = 4,    /* final truncate in progress */
  30         /* writeback related tags are not used */
  31         AS_NO_WRITEBACK_TAGS = 5,
  32 };
  33 
  34 /**
  35  * mapping_set_error - record a writeback error in the address_space
  36  * @mapping - the mapping in which an error should be set
  37  * @error - the error to set in the mapping
  38  *
  39  * When writeback fails in some way, we must record that error so that
  40  * userspace can be informed when fsync and the like are called.  We endeavor
  41  * to report errors on any file that was open at the time of the error.  Some
  42  * internal callers also need to know when writeback errors have occurred.
  43  *
  44  * When a writeback error occurs, most filesystems will want to call
  45  * mapping_set_error to record the error in the mapping so that it can be
  46  * reported when the application calls fsync(2).
  47  */
  48 static inline void mapping_set_error(struct address_space *mapping, int error)
  49 {
  50         if (likely(!error))
  51                 return;
  52 
  53         /* Record in wb_err for checkers using errseq_t based tracking */
  54         filemap_set_wb_err(mapping, error);
  55 
  56         /* Record it in flags for now, for legacy callers */
  57         if (error == -ENOSPC)
  58                 set_bit(AS_ENOSPC, &mapping->flags);
  59         else
  60                 set_bit(AS_EIO, &mapping->flags);
  61 }
  62 
  63 static inline void mapping_set_unevictable(struct address_space *mapping)
  64 {
  65         set_bit(AS_UNEVICTABLE, &mapping->flags);
  66 }
  67 
  68 static inline void mapping_clear_unevictable(struct address_space *mapping)
  69 {
  70         clear_bit(AS_UNEVICTABLE, &mapping->flags);
  71 }
  72 
  73 static inline int mapping_unevictable(struct address_space *mapping)
  74 {
  75         if (mapping)
  76                 return test_bit(AS_UNEVICTABLE, &mapping->flags);
  77         return !!mapping;
  78 }
  79 
  80 static inline void mapping_set_exiting(struct address_space *mapping)
  81 {
  82         set_bit(AS_EXITING, &mapping->flags);
  83 }
  84 
  85 static inline int mapping_exiting(struct address_space *mapping)
  86 {
  87         return test_bit(AS_EXITING, &mapping->flags);
  88 }
  89 
  90 static inline void mapping_set_no_writeback_tags(struct address_space *mapping)
  91 {
  92         set_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags);
  93 }
  94 
  95 static inline int mapping_use_writeback_tags(struct address_space *mapping)
  96 {
  97         return !test_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags);
  98 }
  99 
 100 static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
 101 {
 102         return mapping->gfp_mask;
 103 }
 104 
 105 /* Restricts the given gfp_mask to what the mapping allows. */
 106 static inline gfp_t mapping_gfp_constraint(struct address_space *mapping,
 107                 gfp_t gfp_mask)
 108 {
 109         return mapping_gfp_mask(mapping) & gfp_mask;
 110 }
 111 
 112 /*
 113  * This is non-atomic.  Only to be used before the mapping is activated.
 114  * Probably needs a barrier...
 115  */
 116 static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask)
 117 {
 118         m->gfp_mask = mask;
 119 }
 120 
 121 void release_pages(struct page **pages, int nr);
 122 
 123 /*
 124  * speculatively take a reference to a page.
 125  * If the page is free (_refcount == 0), then _refcount is untouched, and 0
 126  * is returned. Otherwise, _refcount is incremented by 1 and 1 is returned.
 127  *
 128  * This function must be called inside the same rcu_read_lock() section as has
 129  * been used to lookup the page in the pagecache radix-tree (or page table):
 130  * this allows allocators to use a synchronize_rcu() to stabilize _refcount.
 131  *
 132  * Unless an RCU grace period has passed, the count of all pages coming out
 133  * of the allocator must be considered unstable. page_count may return higher
 134  * than expected, and put_page must be able to do the right thing when the
 135  * page has been finished with, no matter what it is subsequently allocated
 136  * for (because put_page is what is used here to drop an invalid speculative
 137  * reference).
 138  *
 139  * This is the interesting part of the lockless pagecache (and lockless
 140  * get_user_pages) locking protocol, where the lookup-side (eg. find_get_page)
 141  * has the following pattern:
 142  * 1. find page in radix tree
 143  * 2. conditionally increment refcount
 144  * 3. check the page is still in pagecache (if no, goto 1)
 145  *
 146  * Remove-side that cares about stability of _refcount (eg. reclaim) has the
 147  * following (with the i_pages lock held):
 148  * A. atomically check refcount is correct and set it to 0 (atomic_cmpxchg)
 149  * B. remove page from pagecache
 150  * C. free the page
 151  *
 152  * There are 2 critical interleavings that matter:
 153  * - 2 runs before A: in this case, A sees elevated refcount and bails out
 154  * - A runs before 2: in this case, 2 sees zero refcount and retries;
 155  *   subsequently, B will complete and 1 will find no page, causing the
 156  *   lookup to return NULL.
 157  *
 158  * It is possible that between 1 and 2, the page is removed then the exact same
 159  * page is inserted into the same position in pagecache. That's OK: the
 160  * old find_get_page using a lock could equally have run before or after
 161  * such a re-insertion, depending on order that locks are granted.
 162  *
 163  * Lookups racing against pagecache insertion isn't a big problem: either 1
 164  * will find the page or it will not. Likewise, the old find_get_page could run
 165  * either before the insertion or afterwards, depending on timing.
 166  */
 167 static inline int __page_cache_add_speculative(struct page *page, int count)
 168 {
 169 #ifdef CONFIG_TINY_RCU
 170 # ifdef CONFIG_PREEMPT_COUNT
 171         VM_BUG_ON(!in_atomic() && !irqs_disabled());
 172 # endif
 173         /*
 174          * Preempt must be disabled here - we rely on rcu_read_lock doing
 175          * this for us.
 176          *
 177          * Pagecache won't be truncated from interrupt context, so if we have
 178          * found a page in the radix tree here, we have pinned its refcount by
 179          * disabling preempt, and hence no need for the "speculative get" that
 180          * SMP requires.
 181          */
 182         VM_BUG_ON_PAGE(page_count(page) == 0, page);
 183         page_ref_add(page, count);
 184 
 185 #else
 186         if (unlikely(!page_ref_add_unless(page, count, 0))) {
 187                 /*
 188                  * Either the page has been freed, or will be freed.
 189                  * In either case, retry here and the caller should
 190                  * do the right thing (see comments above).
 191                  */
 192                 return 0;
 193         }
 194 #endif
 195         VM_BUG_ON_PAGE(PageTail(page), page);
 196 
 197         return 1;
 198 }
 199 
 200 static inline int page_cache_get_speculative(struct page *page)
 201 {
 202         return __page_cache_add_speculative(page, 1);
 203 }
 204 
 205 static inline int page_cache_add_speculative(struct page *page, int count)
 206 {
 207         return __page_cache_add_speculative(page, count);
 208 }
 209 
 210 #ifdef CONFIG_NUMA
 211 extern struct page *__page_cache_alloc(gfp_t gfp);
 212 #else
 213 static inline struct page *__page_cache_alloc(gfp_t gfp)
 214 {
 215         return alloc_pages(gfp, 0);
 216 }
 217 #endif
 218 
 219 static inline struct page *page_cache_alloc(struct address_space *x)
 220 {
 221         return __page_cache_alloc(mapping_gfp_mask(x));
 222 }
 223 
 224 static inline gfp_t readahead_gfp_mask(struct address_space *x)
 225 {
 226         return mapping_gfp_mask(x) | __GFP_NORETRY | __GFP_NOWARN;
 227 }
 228 
 229 typedef int filler_t(void *, struct page *);
 230 
 231 pgoff_t page_cache_next_miss(struct address_space *mapping,
 232                              pgoff_t index, unsigned long max_scan);
 233 pgoff_t page_cache_prev_miss(struct address_space *mapping,
 234                              pgoff_t index, unsigned long max_scan);
 235 
 236 #define FGP_ACCESSED            0x00000001
 237 #define FGP_LOCK                0x00000002
 238 #define FGP_CREAT               0x00000004
 239 #define FGP_WRITE               0x00000008
 240 #define FGP_NOFS                0x00000010
 241 #define FGP_NOWAIT              0x00000020
 242 #define FGP_FOR_MMAP            0x00000040
 243 
 244 struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
 245                 int fgp_flags, gfp_t cache_gfp_mask);
 246 
 247 /**
 248  * find_get_page - find and get a page reference
 249  * @mapping: the address_space to search
 250  * @offset: the page index
 251  *
 252  * Looks up the page cache slot at @mapping & @offset.  If there is a
 253  * page cache page, it is returned with an increased refcount.
 254  *
 255  * Otherwise, %NULL is returned.
 256  */
 257 static inline struct page *find_get_page(struct address_space *mapping,
 258                                         pgoff_t offset)
 259 {
 260         return pagecache_get_page(mapping, offset, 0, 0);
 261 }
 262 
 263 static inline struct page *find_get_page_flags(struct address_space *mapping,
 264                                         pgoff_t offset, int fgp_flags)
 265 {
 266         return pagecache_get_page(mapping, offset, fgp_flags, 0);
 267 }
 268 
 269 /**
 270  * find_lock_page - locate, pin and lock a pagecache page
 271  * @mapping: the address_space to search
 272  * @offset: the page index
 273  *
 274  * Looks up the page cache slot at @mapping & @offset.  If there is a
 275  * page cache page, it is returned locked and with an increased
 276  * refcount.
 277  *
 278  * Otherwise, %NULL is returned.
 279  *
 280  * find_lock_page() may sleep.
 281  */
 282 static inline struct page *find_lock_page(struct address_space *mapping,
 283                                         pgoff_t offset)
 284 {
 285         return pagecache_get_page(mapping, offset, FGP_LOCK, 0);
 286 }
 287 
 288 /**
 289  * find_or_create_page - locate or add a pagecache page
 290  * @mapping: the page's address_space
 291  * @index: the page's index into the mapping
 292  * @gfp_mask: page allocation mode
 293  *
 294  * Looks up the page cache slot at @mapping & @offset.  If there is a
 295  * page cache page, it is returned locked and with an increased
 296  * refcount.
 297  *
 298  * If the page is not present, a new page is allocated using @gfp_mask
 299  * and added to the page cache and the VM's LRU list.  The page is
 300  * returned locked and with an increased refcount.
 301  *
 302  * On memory exhaustion, %NULL is returned.
 303  *
 304  * find_or_create_page() may sleep, even if @gfp_flags specifies an
 305  * atomic allocation!
 306  */
 307 static inline struct page *find_or_create_page(struct address_space *mapping,
 308                                         pgoff_t offset, gfp_t gfp_mask)
 309 {
 310         return pagecache_get_page(mapping, offset,
 311                                         FGP_LOCK|FGP_ACCESSED|FGP_CREAT,
 312                                         gfp_mask);
 313 }
 314 
 315 /**
 316  * grab_cache_page_nowait - returns locked page at given index in given cache
 317  * @mapping: target address_space
 318  * @index: the page index
 319  *
 320  * Same as grab_cache_page(), but do not wait if the page is unavailable.
 321  * This is intended for speculative data generators, where the data can
 322  * be regenerated if the page couldn't be grabbed.  This routine should
 323  * be safe to call while holding the lock for another page.
 324  *
 325  * Clear __GFP_FS when allocating the page to avoid recursion into the fs
 326  * and deadlock against the caller's locked page.
 327  */
 328 static inline struct page *grab_cache_page_nowait(struct address_space *mapping,
 329                                 pgoff_t index)
 330 {
 331         return pagecache_get_page(mapping, index,
 332                         FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT,
 333                         mapping_gfp_mask(mapping));
 334 }
 335 
 336 static inline struct page *find_subpage(struct page *page, pgoff_t offset)
 337 {
 338         if (PageHuge(page))
 339                 return page;
 340 
 341         VM_BUG_ON_PAGE(PageTail(page), page);
 342 
 343         return page + (offset & (compound_nr(page) - 1));
 344 }
 345 
 346 struct page *find_get_entry(struct address_space *mapping, pgoff_t offset);
 347 struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset);
 348 unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
 349                           unsigned int nr_entries, struct page **entries,
 350                           pgoff_t *indices);
 351 unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
 352                         pgoff_t end, unsigned int nr_pages,
 353                         struct page **pages);
 354 static inline unsigned find_get_pages(struct address_space *mapping,
 355                         pgoff_t *start, unsigned int nr_pages,
 356                         struct page **pages)
 357 {
 358         return find_get_pages_range(mapping, start, (pgoff_t)-1, nr_pages,
 359                                     pages);
 360 }
 361 unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
 362                                unsigned int nr_pages, struct page **pages);
 363 unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
 364                         pgoff_t end, xa_mark_t tag, unsigned int nr_pages,
 365                         struct page **pages);
 366 static inline unsigned find_get_pages_tag(struct address_space *mapping,
 367                         pgoff_t *index, xa_mark_t tag, unsigned int nr_pages,
 368                         struct page **pages)
 369 {
 370         return find_get_pages_range_tag(mapping, index, (pgoff_t)-1, tag,
 371                                         nr_pages, pages);
 372 }
 373 
 374 struct page *grab_cache_page_write_begin(struct address_space *mapping,
 375                         pgoff_t index, unsigned flags);
 376 
 377 /*
 378  * Returns locked page at given index in given cache, creating it if needed.
 379  */
 380 static inline struct page *grab_cache_page(struct address_space *mapping,
 381                                                                 pgoff_t index)
 382 {
 383         return find_or_create_page(mapping, index, mapping_gfp_mask(mapping));
 384 }
 385 
 386 extern struct page * read_cache_page(struct address_space *mapping,
 387                                 pgoff_t index, filler_t *filler, void *data);
 388 extern struct page * read_cache_page_gfp(struct address_space *mapping,
 389                                 pgoff_t index, gfp_t gfp_mask);
 390 extern int read_cache_pages(struct address_space *mapping,
 391                 struct list_head *pages, filler_t *filler, void *data);
 392 
 393 static inline struct page *read_mapping_page(struct address_space *mapping,
 394                                 pgoff_t index, void *data)
 395 {
 396         return read_cache_page(mapping, index, NULL, data);
 397 }
 398 
 399 /*
 400  * Get index of the page with in radix-tree
 401  * (TODO: remove once hugetlb pages will have ->index in PAGE_SIZE)
 402  */
 403 static inline pgoff_t page_to_index(struct page *page)
 404 {
 405         pgoff_t pgoff;
 406 
 407         if (likely(!PageTransTail(page)))
 408                 return page->index;
 409 
 410         /*
 411          *  We don't initialize ->index for tail pages: calculate based on
 412          *  head page
 413          */
 414         pgoff = compound_head(page)->index;
 415         pgoff += page - compound_head(page);
 416         return pgoff;
 417 }
 418 
 419 /*
 420  * Get the offset in PAGE_SIZE.
 421  * (TODO: hugepage should have ->index in PAGE_SIZE)
 422  */
 423 static inline pgoff_t page_to_pgoff(struct page *page)
 424 {
 425         if (unlikely(PageHeadHuge(page)))
 426                 return page->index << compound_order(page);
 427 
 428         return page_to_index(page);
 429 }
 430 
 431 /*
 432  * Return byte-offset into filesystem object for page.
 433  */
 434 static inline loff_t page_offset(struct page *page)
 435 {
 436         return ((loff_t)page->index) << PAGE_SHIFT;
 437 }
 438 
 439 static inline loff_t page_file_offset(struct page *page)
 440 {
 441         return ((loff_t)page_index(page)) << PAGE_SHIFT;
 442 }
 443 
 444 extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
 445                                      unsigned long address);
 446 
 447 static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
 448                                         unsigned long address)
 449 {
 450         pgoff_t pgoff;
 451         if (unlikely(is_vm_hugetlb_page(vma)))
 452                 return linear_hugepage_index(vma, address);
 453         pgoff = (address - vma->vm_start) >> PAGE_SHIFT;
 454         pgoff += vma->vm_pgoff;
 455         return pgoff;
 456 }
 457 
 458 extern void __lock_page(struct page *page);
 459 extern int __lock_page_killable(struct page *page);
 460 extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
 461                                 unsigned int flags);
 462 extern void unlock_page(struct page *page);
 463 
 464 /*
 465  * Return true if the page was successfully locked
 466  */
 467 static inline int trylock_page(struct page *page)
 468 {
 469         page = compound_head(page);
 470         return (likely(!test_and_set_bit_lock(PG_locked, &page->flags)));
 471 }
 472 
 473 /*
 474  * lock_page may only be called if we have the page's inode pinned.
 475  */
 476 static inline void lock_page(struct page *page)
 477 {
 478         might_sleep();
 479         if (!trylock_page(page))
 480                 __lock_page(page);
 481 }
 482 
 483 /*
 484  * lock_page_killable is like lock_page but can be interrupted by fatal
 485  * signals.  It returns 0 if it locked the page and -EINTR if it was
 486  * killed while waiting.
 487  */
 488 static inline int lock_page_killable(struct page *page)
 489 {
 490         might_sleep();
 491         if (!trylock_page(page))
 492                 return __lock_page_killable(page);
 493         return 0;
 494 }
 495 
 496 /*
 497  * lock_page_or_retry - Lock the page, unless this would block and the
 498  * caller indicated that it can handle a retry.
 499  *
 500  * Return value and mmap_sem implications depend on flags; see
 501  * __lock_page_or_retry().
 502  */
 503 static inline int lock_page_or_retry(struct page *page, struct mm_struct *mm,
 504                                      unsigned int flags)
 505 {
 506         might_sleep();
 507         return trylock_page(page) || __lock_page_or_retry(page, mm, flags);
 508 }
 509 
 510 /*
 511  * This is exported only for wait_on_page_locked/wait_on_page_writeback, etc.,
 512  * and should not be used directly.
 513  */
 514 extern void wait_on_page_bit(struct page *page, int bit_nr);
 515 extern int wait_on_page_bit_killable(struct page *page, int bit_nr);
 516 
 517 /* 
 518  * Wait for a page to be unlocked.
 519  *
 520  * This must be called with the caller "holding" the page,
 521  * ie with increased "page->count" so that the page won't
 522  * go away during the wait..
 523  */
 524 static inline void wait_on_page_locked(struct page *page)
 525 {
 526         if (PageLocked(page))
 527                 wait_on_page_bit(compound_head(page), PG_locked);
 528 }
 529 
 530 static inline int wait_on_page_locked_killable(struct page *page)
 531 {
 532         if (!PageLocked(page))
 533                 return 0;
 534         return wait_on_page_bit_killable(compound_head(page), PG_locked);
 535 }
 536 
 537 extern void put_and_wait_on_page_locked(struct page *page);
 538 
 539 void wait_on_page_writeback(struct page *page);
 540 extern void end_page_writeback(struct page *page);
 541 void wait_for_stable_page(struct page *page);
 542 
 543 void page_endio(struct page *page, bool is_write, int err);
 544 
 545 /*
 546  * Add an arbitrary waiter to a page's wait queue
 547  */
 548 extern void add_page_wait_queue(struct page *page, wait_queue_entry_t *waiter);
 549 
 550 /*
 551  * Fault everything in given userspace address range in.
 552  */
 553 static inline int fault_in_pages_writeable(char __user *uaddr, int size)
 554 {
 555         char __user *end = uaddr + size - 1;
 556 
 557         if (unlikely(size == 0))
 558                 return 0;
 559 
 560         if (unlikely(uaddr > end))
 561                 return -EFAULT;
 562         /*
 563          * Writing zeroes into userspace here is OK, because we know that if
 564          * the zero gets there, we'll be overwriting it.
 565          */
 566         do {
 567                 if (unlikely(__put_user(0, uaddr) != 0))
 568                         return -EFAULT;
 569                 uaddr += PAGE_SIZE;
 570         } while (uaddr <= end);
 571 
 572         /* Check whether the range spilled into the next page. */
 573         if (((unsigned long)uaddr & PAGE_MASK) ==
 574                         ((unsigned long)end & PAGE_MASK))
 575                 return __put_user(0, end);
 576 
 577         return 0;
 578 }
 579 
 580 static inline int fault_in_pages_readable(const char __user *uaddr, int size)
 581 {
 582         volatile char c;
 583         const char __user *end = uaddr + size - 1;
 584 
 585         if (unlikely(size == 0))
 586                 return 0;
 587 
 588         if (unlikely(uaddr > end))
 589                 return -EFAULT;
 590 
 591         do {
 592                 if (unlikely(__get_user(c, uaddr) != 0))
 593                         return -EFAULT;
 594                 uaddr += PAGE_SIZE;
 595         } while (uaddr <= end);
 596 
 597         /* Check whether the range spilled into the next page. */
 598         if (((unsigned long)uaddr & PAGE_MASK) ==
 599                         ((unsigned long)end & PAGE_MASK)) {
 600                 return __get_user(c, end);
 601         }
 602 
 603         (void)c;
 604         return 0;
 605 }
 606 
 607 int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
 608                                 pgoff_t index, gfp_t gfp_mask);
 609 int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
 610                                 pgoff_t index, gfp_t gfp_mask);
 611 extern void delete_from_page_cache(struct page *page);
 612 extern void __delete_from_page_cache(struct page *page, void *shadow);
 613 int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask);
 614 void delete_from_page_cache_batch(struct address_space *mapping,
 615                                   struct pagevec *pvec);
 616 
 617 /*
 618  * Like add_to_page_cache_locked, but used to add newly allocated pages:
 619  * the page is new, so we can just run __SetPageLocked() against it.
 620  */
 621 static inline int add_to_page_cache(struct page *page,
 622                 struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask)
 623 {
 624         int error;
 625 
 626         __SetPageLocked(page);
 627         error = add_to_page_cache_locked(page, mapping, offset, gfp_mask);
 628         if (unlikely(error))
 629                 __ClearPageLocked(page);
 630         return error;
 631 }
 632 
 633 static inline unsigned long dir_pages(struct inode *inode)
 634 {
 635         return (unsigned long)(inode->i_size + PAGE_SIZE - 1) >>
 636                                PAGE_SHIFT;
 637 }
 638 
 639 #endif /* _LINUX_PAGEMAP_H */