From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: [PATCH 11/22] HWPOISON: Refactor truncate to allow direct truncating of page v3 Date: Mon, 15 Jun 2009 10:45:31 +0800 Message-ID: <20090615031253.870957338@intel.com> References: <20090615024520.786814520@intel.com> Return-path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 273E76B0095 for ; Sun, 14 Jun 2009 23:14:41 -0400 (EDT) Content-Disposition: inline; filename=truncate-refactor Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: LKML , Nick Piggin , Andi Kleen , Ingo Molnar , Mel Gorman , "Wu, Fengguang" , Thomas Gleixner , "H. Peter Anvin" , Peter Zijlstra , Hugh Dickins , Andi Kleen , "riel@redhat.com" , "chris.mason@oracle.com" , "linux-mm@kvack.org" List-Id: linux-mm.kvack.org From: Nick Piggin Extract out truncate_inode_page() out of the truncate path so that it can be used by memory-failure.c [AK: description, headers, fix typos] v2: Some white space changes from Fengguang Wu v3: add comments Signed-off-by: Nick Piggin Signed-off-by: Andi Kleen --- include/linux/mm.h | 2 ++ mm/truncate.c | 34 ++++++++++++++++++++++------------ 2 files changed, 24 insertions(+), 12 deletions(-) --- sound-2.6.orig/mm/truncate.c +++ sound-2.6/mm/truncate.c @@ -135,6 +135,26 @@ invalidate_complete_page(struct address_ return ret; } +/* + * Remove one page from its pagecache mapping. The page must be locked. + * This does not truncate the file on disk, it performs the pagecache + * side of the truncate operation. Dirty data will be discarded, and + * concurrent page references are ignored. + * + * Generic mm/fs code cannot call this on filesystem metadata mappings + * because those can assume that a page reference is enough to pin the + * page to its mapping. + */ +void truncate_inode_page(struct address_space *mapping, struct page *page) +{ + if (page_mapped(page)) { + unmap_mapping_range(mapping, + (loff_t)page->index << PAGE_CACHE_SHIFT, + PAGE_CACHE_SIZE, 0); + } + truncate_complete_page(mapping, page); +} + /** * truncate_inode_pages - truncate range of pages specified by start & end byte offsets * @mapping: mapping to truncate @@ -196,12 +216,7 @@ void truncate_inode_pages_range(struct a unlock_page(page); continue; } - if (page_mapped(page)) { - unmap_mapping_range(mapping, - (loff_t)page_index<index<index > next) next = page->index; next++; - truncate_complete_page(mapping, page); unlock_page(page); } pagevec_release(&pvec); --- sound-2.6.orig/include/linux/mm.h +++ sound-2.6/include/linux/mm.h @@ -814,6 +814,8 @@ static inline void unmap_shared_mapping_ extern int vmtruncate(struct inode * inode, loff_t offset); extern int vmtruncate_range(struct inode * inode, loff_t offset, loff_t end); +void truncate_inode_page(struct address_space *mapping, struct page *page); + #ifdef CONFIG_MMU extern int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, int write_access); -- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org