From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 240986B005D for ; Wed, 5 Aug 2009 08:38:00 -0400 (EDT) Date: Wed, 5 Aug 2009 20:37:49 +0800 From: Wu Fengguang Subject: Re: [PATCH] [11/19] HWPOISON: Refactor truncate to allow direct truncating of page v2 Message-ID: <20090805123749.GA9443@localhost> References: <200908051136.682859934@firstfloor.org> <20090805093638.D3754B15D8@basil.firstfloor.org> <20090805102008.GB17190@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090805102008.GB17190@wotan.suse.de> Sender: owner-linux-mm@kvack.org To: Nick Piggin Cc: Andi Kleen , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "hidehiro.kawai.ez@hitachi.com" List-ID: On Wed, Aug 05, 2009 at 06:20:08PM +0800, Nick Piggin wrote: > On Wed, Aug 05, 2009 at 11:36:38AM +0200, Andi Kleen wrote: > > > > 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 > > > > Signed-off-by: Andi Kleen > > > > --- > > include/linux/mm.h | 2 ++ > > mm/truncate.c | 29 +++++++++++++++-------------- > > 2 files changed, 17 insertions(+), 14 deletions(-) > > > > Index: linux/mm/truncate.c > > =================================================================== > > --- linux.orig/mm/truncate.c > > +++ linux/mm/truncate.c > > @@ -93,11 +93,11 @@ EXPORT_SYMBOL(cancel_dirty_page); > > * its lock, b) when a concurrent invalidate_mapping_pages got there first and > > * c) when tmpfs swizzles a page between a tmpfs inode and swapper_space. > > */ > > -static void > > +static int > > truncate_complete_page(struct address_space *mapping, struct page *page) > > { > > if (page->mapping != mapping) > > - return; > > + return -EIO; > > Hmm, at this point, the page must have been removed from pagecache, > so I don't know if you need to pass an error back? Me think so too. When called from hwpoison, the page count and lock have both be taken, so at least _in this case_, (page->mapping != mapping) can be equally written as (page->mapping == NULL) But anyway, the return value is now ignored in upper layer :) Thanks, Fengguang > > > if (page_has_private(page)) > > do_invalidatepage(page, 0); > > @@ -108,6 +108,7 @@ truncate_complete_page(struct address_sp > > remove_from_page_cache(page); > > ClearPageMappedToDisk(page); > > page_cache_release(page); /* pagecache ref */ > > + return 0; > > } > > > > /* > > @@ -135,6 +136,16 @@ invalidate_complete_page(struct address_ > > return ret; > > } > > > > +int 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); > > + } > > + return truncate_complete_page(mapping, page); > > +} > > + > > /** > > * truncate_inode_pages - truncate range of pages specified by start & end byte offsets > > * @mapping: mapping to truncate > > @@ -196,12 +207,7 @@ void truncate_inode_pages_range(struct a > > unlock_page(page); > > continue; > > } > > - if (page_mapped(page)) { > > - unmap_mapping_range(mapping, > > - (loff_t)page_index< > - PAGE_CACHE_SIZE, 0); > > - } > > - truncate_complete_page(mapping, page); > > + truncate_inode_page(mapping, page); > > unlock_page(page); > > } > > pagevec_release(&pvec); > > @@ -238,15 +244,10 @@ void truncate_inode_pages_range(struct a > > break; > > lock_page(page); > > wait_on_page_writeback(page); > > - if (page_mapped(page)) { > > - unmap_mapping_range(mapping, > > - (loff_t)page->index< > - PAGE_CACHE_SIZE, 0); > > - } > > + truncate_inode_page(mapping, page); > > if (page->index > next) > > next = page->index; > > next++; > > - truncate_complete_page(mapping, page); > > unlock_page(page); > > } > > pagevec_release(&pvec); > > Index: linux/include/linux/mm.h > > =================================================================== > > --- linux.orig/include/linux/mm.h > > +++ linux/include/linux/mm.h > > @@ -809,6 +809,8 @@ 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); > > > > +int 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, unsigned int flags); -- 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