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| author | Mel Gorman <mgorman@suse.de> | 2012-07-31 16:44:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-31 18:42:47 -0700 |
| commit | f981c5950fa85916ba49bea5d9a7a5078f47e569 (patch) | |
| tree | e742598755e57e1bbed06dc90b05fe6e13091236 /include/linux/swap.h | |
| parent | 6290c2c439732727899405f39fb76c2f5585b707 (diff) | |
| download | linux-f981c5950fa85916ba49bea5d9a7a5078f47e569.tar.gz linux-f981c5950fa85916ba49bea5d9a7a5078f47e569.tar.bz2 linux-f981c5950fa85916ba49bea5d9a7a5078f47e569.zip | |
mm: methods for teaching filesystems about PG_swapcache pages
In order to teach filesystems to handle swap cache pages, three new page
functions are introduced:
pgoff_t page_file_index(struct page *);
loff_t page_file_offset(struct page *);
struct address_space *page_file_mapping(struct page *);
page_file_index() - gives the offset of this page in the file in
PAGE_CACHE_SIZE blocks. Like page->index is for mapped pages, this
function also gives the correct index for PG_swapcache pages.
page_file_offset() - uses page_file_index(), so that it will give the
expected result, even for PG_swapcache pages.
page_file_mapping() - gives the mapping backing the actual page; that is
for swap cache pages it will give swap_file->f_mapping.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/swap.h')
| -rw-r--r-- | include/linux/swap.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index 9a16bb1cefd1..e62425ded2ed 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; |