diff options
Diffstat (limited to 'include/linux/pagemap.h')
| -rw-r--r-- | include/linux/pagemap.h | 84 |
1 files changed, 24 insertions, 60 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 92395a0a7dc5..97354102794d 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -86,31 +86,16 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask) (__force unsigned long)mask; } -/* - * The page cache can be done in larger chunks than - * one page, because it allows for more efficient - * throughput (it can then be mapped into user - * space in smaller chunks for same flexibility). - * - * Or rather, it _will_ be done in larger chunks. - */ -#define PAGE_CACHE_SHIFT PAGE_SHIFT -#define PAGE_CACHE_SIZE PAGE_SIZE -#define PAGE_CACHE_MASK PAGE_MASK -#define PAGE_CACHE_ALIGN(addr) (((addr)+PAGE_CACHE_SIZE-1)&PAGE_CACHE_MASK) - -#define page_cache_get(page) get_page(page) -#define page_cache_release(page) put_page(page) void release_pages(struct page **pages, int nr, bool cold); /* * speculatively take a reference to a page. - * If the page is free (_count == 0), then _count is untouched, and 0 - * is returned. Otherwise, _count is incremented by 1 and 1 is returned. + * If the page is free (_refcount == 0), then _refcount is untouched, and 0 + * is returned. Otherwise, _refcount is incremented by 1 and 1 is returned. * * This function must be called inside the same rcu_read_lock() section as has * been used to lookup the page in the pagecache radix-tree (or page table): - * this allows allocators to use a synchronize_rcu() to stabilize _count. + * this allows allocators to use a synchronize_rcu() to stabilize _refcount. * * Unless an RCU grace period has passed, the count of all pages coming out * of the allocator must be considered unstable. page_count may return higher @@ -126,7 +111,7 @@ void release_pages(struct page **pages, int nr, bool cold); * 2. conditionally increment refcount * 3. check the page is still in pagecache (if no, goto 1) * - * Remove-side that cares about stability of _count (eg. reclaim) has the + * Remove-side that cares about stability of _refcount (eg. reclaim) has the * following (with tree_lock held for write): * A. atomically check refcount is correct and set it to 0 (atomic_cmpxchg) * B. remove page from pagecache @@ -165,7 +150,7 @@ static inline int page_cache_get_speculative(struct page *page) * SMP requires. */ VM_BUG_ON_PAGE(page_count(page) == 0, page); - atomic_inc(&page->_count); + page_ref_inc(page); #else if (unlikely(!get_page_unless_zero(page))) { @@ -194,10 +179,10 @@ static inline int page_cache_add_speculative(struct page *page, int count) VM_BUG_ON(!in_atomic()); # endif VM_BUG_ON_PAGE(page_count(page) == 0, page); - atomic_add(count, &page->_count); + page_ref_add(page, count); #else - if (unlikely(!atomic_add_unless(&page->_count, count, 0))) + if (unlikely(!page_ref_add_unless(page, count, 0))) return 0; #endif VM_BUG_ON_PAGE(PageCompound(page) && page != compound_head(page), page); @@ -205,19 +190,6 @@ static inline int page_cache_add_speculative(struct page *page, int count) return 1; } -static inline int page_freeze_refs(struct page *page, int count) -{ - return likely(atomic_cmpxchg(&page->_count, count, 0) == count); -} - -static inline void page_unfreeze_refs(struct page *page, int count) -{ - VM_BUG_ON_PAGE(page_count(page) != 0, page); - VM_BUG_ON(count == 0); - - atomic_set(&page->_count, count); -} - #ifdef CONFIG_NUMA extern struct page *__page_cache_alloc(gfp_t gfp); #else @@ -403,13 +375,13 @@ static inline pgoff_t page_to_pgoff(struct page *page) return page->index << compound_order(page); if (likely(!PageTransTail(page))) - return page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); + return page->index; /* * We don't initialize ->index for tail pages: calculate based on * head page */ - pgoff = compound_head(page)->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); + pgoff = compound_head(page)->index; pgoff += page - compound_head(page); return pgoff; } @@ -419,12 +391,12 @@ static inline pgoff_t page_to_pgoff(struct page *page) */ static inline loff_t page_offset(struct page *page) { - return ((loff_t)page->index) << PAGE_CACHE_SHIFT; + return ((loff_t)page->index) << PAGE_SHIFT; } static inline loff_t page_file_offset(struct page *page) { - return ((loff_t)page_file_index(page)) << PAGE_CACHE_SHIFT; + return ((loff_t)page_file_index(page)) << PAGE_SHIFT; } extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma, @@ -438,7 +410,7 @@ static inline pgoff_t linear_page_index(struct vm_area_struct *vma, return linear_hugepage_index(vma, address); pgoff = (address - vma->vm_start) >> PAGE_SHIFT; pgoff += vma->vm_pgoff; - return pgoff >> (PAGE_CACHE_SHIFT - PAGE_SHIFT); + return pgoff; } extern void __lock_page(struct page *page); @@ -546,34 +518,27 @@ void page_endio(struct page *page, int rw, int err); extern void add_page_wait_queue(struct page *page, wait_queue_t *waiter); /* - * Fault a userspace page into pagetables. Return non-zero on a fault. - * - * This assumes that two userspace pages are always sufficient. That's - * not true if PAGE_CACHE_SIZE > PAGE_SIZE. + * Fault one or two userspace pages into pagetables. + * Return -EINVAL if more than two pages would be needed. + * Return non-zero on a fault. */ static inline int fault_in_pages_writeable(char __user *uaddr, int size) { - int ret; + int span, ret; if (unlikely(size == 0)) return 0; + span = offset_in_page(uaddr) + size; + if (span > 2 * PAGE_SIZE) + return -EINVAL; /* * Writing zeroes into userspace here is OK, because we know that if * the zero gets there, we'll be overwriting it. */ ret = __put_user(0, uaddr); - if (ret == 0) { - char __user *end = uaddr + size - 1; - - /* - * If the page was already mapped, this will get a cache miss - * for sure, so try to avoid doing it. - */ - if (((unsigned long)uaddr & PAGE_MASK) != - ((unsigned long)end & PAGE_MASK)) - ret = __put_user(0, end); - } + if (ret == 0 && span > PAGE_SIZE) + ret = __put_user(0, uaddr + size - 1); return ret; } @@ -663,8 +628,7 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping, int add_to_page_cache_lru(struct page *page, struct address_space *mapping, pgoff_t index, gfp_t gfp_mask); extern void delete_from_page_cache(struct page *page); -extern void __delete_from_page_cache(struct page *page, void *shadow, - struct mem_cgroup *memcg); +extern void __delete_from_page_cache(struct page *page, void *shadow); int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask); /* @@ -685,8 +649,8 @@ static inline int add_to_page_cache(struct page *page, static inline unsigned long dir_pages(struct inode *inode) { - return (unsigned long)(inode->i_size + PAGE_CACHE_SIZE - 1) >> - PAGE_CACHE_SHIFT; + return (unsigned long)(inode->i_size + PAGE_SIZE - 1) >> + PAGE_SHIFT; } #endif /* _LINUX_PAGEMAP_H */ |