The patch titled Subject: mm: methods for teaching filesystems about PG_swapcache pages has been added to the -mm tree. Its filename is mm-methods-for-teaching-filesystems-about-pg_swapcache-pages.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Mel Gorman <mgorman@xxxxxxx> Subject: 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@xxxxxxxxx> Signed-off-by: Mel Gorman <mgorman@xxxxxxx> Reviewed-by: Rik van Riel <riel@xxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> Cc: David S. Miller <davem@xxxxxxxxxxxxx> Cc: Eric B Munson <emunson@xxxxxxxxx> Cc: Eric Paris <eparis@xxxxxxxxxx> Cc: James Morris <jmorris@xxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Mike Christie <michaelc@xxxxxxxxxxx> Cc: Neil Brown <neilb@xxxxxxx> Cc: Sebastian Andrzej Siewior <sebastian@xxxxxxxxxxxxx> Cc: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> Cc: Xiaotian Feng <dfeng@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mm.h | 25 +++++++++++++++++++++++++ include/linux/pagemap.h | 5 +++++ mm/swapfile.c | 19 +++++++++++++++++++ 3 files changed, 49 insertions(+) diff -puN include/linux/mm.h~mm-methods-for-teaching-filesystems-about-pg_swapcache-pages include/linux/mm.h --- a/include/linux/mm.h~mm-methods-for-teaching-filesystems-about-pg_swapcache-pages +++ a/include/linux/mm.h @@ -805,6 +805,17 @@ static inline void *page_rmapping(struct 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 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 -puN include/linux/pagemap.h~mm-methods-for-teaching-filesystems-about-pg_swapcache-pages include/linux/pagemap.h --- a/include/linux/pagemap.h~mm-methods-for-teaching-filesystems-about-pg_swapcache-pages +++ a/include/linux/pagemap.h @@ -286,6 +286,11 @@ static inline loff_t page_offset(struct 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 -puN mm/swapfile.c~mm-methods-for-teaching-filesystems-about-pg_swapcache-pages mm/swapfile.c --- a/mm/swapfile.c~mm-methods-for-teaching-filesystems-about-pg_swapcache-pages +++ a/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> @@ -2299,6 +2300,24 @@ int swapcache_prepare(swp_entry_t entry) } /* + * 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 * page of the original vmalloc'ed swap_map, to hold the continuation count _ Subject: Subject: mm: methods for teaching filesystems about PG_swapcache pages Patches currently in -mm which might be from mgorman@xxxxxxx are origin.patch linux-next.patch memcg-prevent-oom-with-too-many-dirty-pages.patch memcg-prevent-oom-with-too-many-dirty-pages-fix.patch mm-do-not-use-page_count-without-a-page-pin.patch mm-clean-up-__count_immobile_pages.patch mm-hotplug-correctly-setup-fallback-zonelists-when-creating-new-pgdat.patch mm-hotplug-correctly-add-new-zone-to-all-other-nodes-zone-lists.patch mm-hotplug-free-zone-pageset-when-a-zone-becomes-empty.patch mm-hotplug-mark-memory-hotplug-code-in-page_allocc-as-__meminit.patch mm-factor-out-memory-isolate-functions.patch mm-bug-fix-free-page-check-in-zone_watermark_ok.patch memory-hotplug-fix-kswapd-looping-forever-problem.patch memory-hotplug-fix-kswapd-looping-forever-problem-fix.patch mm-slb-add-knowledge-of-pfmemalloc-reserve-pages.patch mm-slub-optimise-the-slub-fast-path-to-avoid-pfmemalloc-checks.patch mm-introduce-__gfp_memalloc-to-allow-access-to-emergency-reserves.patch mm-allow-pf_memalloc-from-softirq-context.patch mm-only-set-page-pfmemalloc-when-alloc_no_watermarks-was-used.patch mm-ignore-mempolicies-when-using-alloc_no_watermark.patch net-introduce-sk_gfp_atomic-to-allow-addition-of-gfp-flags-depending-on-the-individual-socket.patch netvm-allow-the-use-of-__gfp_memalloc-by-specific-sockets.patch netvm-allow-skb-allocation-to-use-pfmemalloc-reserves.patch netvm-propagate-page-pfmemalloc-to-skb.patch netvm-propagate-page-pfmemalloc-from-skb_alloc_page-to-skb.patch netvm-set-pf_memalloc-as-appropriate-during-skb-processing.patch mm-micro-optimise-slab-to-avoid-a-function-call.patch nbd-set-sock_memalloc-for-access-to-pfmemalloc-reserves.patch mm-throttle-direct-reclaimers-if-pf_memalloc-reserves-are-low-and-swap-is-backed-by-network-storage.patch mm-account-for-the-number-of-times-direct-reclaimers-get-throttled.patch netvm-prevent-a-stream-specific-deadlock.patch selinux-tag-avc-cache-alloc-as-non-critical.patch mm-methods-for-teaching-filesystems-about-pg_swapcache-pages.patch mm-add-support-for-a-filesystem-to-activate-swap-files-and-use-direct_io-for-writing-swap-pages.patch mm-swap-implement-generic-handler-for-swap_activate.patch mm-add-get_kernel_page-for-pinning-of-kernel-addresses-for-i-o.patch mm-add-support-for-direct_io-to-highmem-pages.patch nfs-teach-the-nfs-client-how-to-treat-pg_swapcache-pages.patch nfs-disable-data-cache-revalidation-for-swapfiles.patch nfs-enable-swap-on-nfs.patch nfs-prevent-page-allocator-recursions-with-swap-over-nfs.patch swapfile-avoid-dereferencing-bd_disk-during-swap_entry_free-for-network-storage.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html