lkml.org 
[lkml]   [2009]   [Aug]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] [11/19] HWPOISON: Refactor truncate to allow direct truncating of page v2
    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);


    \
     
     \ /
      Last update: 2009-08-05 14:41    [W:0.040 / U:59.304 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site