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authorArnd Bergmann <arnd@arndb.de>2012-11-12 22:54:08 +0100
committerArnd Bergmann <arnd@arndb.de>2012-11-12 22:54:08 +0100
commit8a6ff8a0a2bc51b29681aab093b349c9eb32acf5 (patch)
tree7ee7315a4aa9b33cba73cf46e59187157a00866a /mm/rmap.c
parent65829ef5a0b9bdffa34b35479853d24e547cfde8 (diff)
parent75984df05d86956541795f01e62d7dc67bc522fd (diff)
Merge tag 'for-3.8-at91_header_clean' of git://github.com/at91linux/linux-at91 into next/headers
From Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>: arm: at91: mach header cleanup This first patch serie start the cleanup of the header in mach by moving all the platform data to include/linux/platform_data and move the board header and drivers header next to them * tag 'for-3.8-at91_header_clean' of git://github.com/at91linux/linux-at91: arm: at91: move at91rm9200 rtc header in drivers/rtc arm: at91: move reset controller header to arm/arm/mach-at91 arm: at91: move pit define to the driver arm: at91: move at91_shdwc.h to arch/arm/mach-at91 arm: at91: move board header to arch/arm/mach-at91 arn: at91: move at91_tc.h to arch/arm/mach-at91 arm: at91 move at91_aic.h to arch/arm/mach-at91 arm: at91 move board.h to arch/arm/mach-at91 arm: at91: move platfarm_data to include/linux/platform_data/atmel.h arm: at91: drop machine defconfig Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 7df7984d476..2ee1ef0f317 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -56,6 +56,7 @@
#include <linux/mmu_notifier.h>
#include <linux/migrate.h>
#include <linux/hugetlb.h>
+#include <linux/backing-dev.h>
#include <asm/tlbflush.h>
@@ -926,11 +927,8 @@ int page_mkclean(struct page *page)
if (page_mapped(page)) {
struct address_space *mapping = page_mapping(page);
- if (mapping) {
+ if (mapping)
ret = page_mkclean_file(mapping, page);
- if (page_test_and_clear_dirty(page_to_pfn(page), 1))
- ret = 1;
- }
}
return ret;
@@ -1116,6 +1114,7 @@ void page_add_file_rmap(struct page *page)
*/
void page_remove_rmap(struct page *page)
{
+ struct address_space *mapping = page_mapping(page);
bool anon = PageAnon(page);
bool locked;
unsigned long flags;
@@ -1138,8 +1137,19 @@ void page_remove_rmap(struct page *page)
* this if the page is anon, so about to be freed; but perhaps
* not if it's in swapcache - there might be another pte slot
* containing the swap entry, but page not yet written to swap.
+ *
+ * And we can skip it on file pages, so long as the filesystem
+ * participates in dirty tracking; but need to catch shm and tmpfs
+ * and ramfs pages which have been modified since creation by read
+ * fault.
+ *
+ * Note that mapping must be decided above, before decrementing
+ * mapcount (which luckily provides a barrier): once page is unmapped,
+ * it could be truncated and page->mapping reset to NULL at any moment.
+ * Note also that we are relying on page_mapping(page) to set mapping
+ * to &swapper_space when PageSwapCache(page).
*/
- if ((!anon || PageSwapCache(page)) &&
+ if (mapping && !mapping_cap_account_dirty(mapping) &&
page_test_and_clear_dirty(page_to_pfn(page), 1))
set_page_dirty(page);
/*