Messages in this thread | | | 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 |
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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 <npiggin@suse.de> > > > > 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 <ak@linux.intel.com> > > > > --- > > 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_SHIFT, > > - 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_SHIFT, > > - 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);
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