diff options
| -rw-r--r-- | include/linux/mm.h | 25 | ||||
| -rw-r--r-- | include/linux/pagemap.h | 5 | ||||
| -rw-r--r-- | include/linux/swap.h | 1 | ||||
| -rw-r--r-- | mm/swapfile.c | 26 |
4 files changed, 57 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 7c6dfd2faa6..7cdac1676b5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -805,6 +805,17 @@ static inline void *page_rmapping(struct page *page) return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS); } +extern struct address_space *__page_file_mapping(struct page *); + +static inline +struct address_space *page_file_mapping(struct page *page) +{ + if (unlikely(PageSwapCache(page))) + return __page_file_mapping(page); + + return page->mapping; +} + static inline int PageAnon(struct page *page) { return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; @@ -821,6 +832,20 @@ static inline pgoff_t page_index(struct page *page) return page->index; } +extern pgoff_t __page_file_index(struct page *page); + +/* + * Return the file index of the page. Regular pagecache pages use ->index + * whereas swapcache pages use swp_offset(->private) + */ +static inline pgoff_t page_file_index(struct page *page) +{ + if (unlikely(PageSwapCache(page))) + return __page_file_index(page); + + return page->index; +} + /* * Return true if this page is mapped into pagetables. */ diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 7cfad3bbb0c..e42c762f0dc 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -286,6 +286,11 @@ static inline loff_t page_offset(struct page *page) return ((loff_t)page->index) << PAGE_CACHE_SHIFT; } +static inline loff_t page_file_offset(struct page *page) +{ + return ((loff_t)page_file_index(page)) << PAGE_CACHE_SHIFT; +} + extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma, unsigned long address); diff --git a/include/linux/swap.h b/include/linux/swap.h index 9a16bb1cefd..e62425ded2e 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -356,6 +356,7 @@ extern unsigned int count_swap_pages(int, int); extern sector_t map_swap_page(struct page *, struct block_device **); extern sector_t swapdev_block(int, pgoff_t); extern int page_swapcount(struct page *); +extern struct swap_info_struct *page_swap_info(struct page *); extern int reuse_swap_page(struct page *); extern int try_to_free_swap(struct page *); struct backing_dev_info; diff --git a/mm/swapfile.c b/mm/swapfile.c index 71373d03fce..f89af5ba2eb 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -33,6 +33,7 @@ #include <linux/oom.h> #include <linux/frontswap.h> #include <linux/swapfile.h> +#include <linux/export.h> #include <asm/pgtable.h> #include <asm/tlbflush.h> @@ -2285,6 +2286,31 @@ int swapcache_prepare(swp_entry_t entry) return __swap_duplicate(entry, SWAP_HAS_CACHE); } +struct swap_info_struct *page_swap_info(struct page *page) +{ + swp_entry_t swap = { .val = page_private(page) }; + BUG_ON(!PageSwapCache(page)); + return swap_info[swp_type(swap)]; +} + +/* + * out-of-line __page_file_ methods to avoid include hell. + */ +struct address_space *__page_file_mapping(struct page *page) +{ + VM_BUG_ON(!PageSwapCache(page)); + return page_swap_info(page)->swap_file->f_mapping; +} +EXPORT_SYMBOL_GPL(__page_file_mapping); + +pgoff_t __page_file_index(struct page *page) +{ + swp_entry_t swap = { .val = page_private(page) }; + VM_BUG_ON(!PageSwapCache(page)); + return swp_offset(swap); +} +EXPORT_SYMBOL_GPL(__page_file_index); + /* * add_swap_count_continuation - called when a swap count is duplicated * beyond SWAP_MAP_MAX, it allocates a new page and links that to the entry's |