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Date: Sat, 13 Jun 2009 00:45:00 +0300
From: Izik Eidus <ieidus@...hat.com>
To: hugh.dickins@...cali.co.uk
Cc: linux-kernel@...r.kernel.org, Izik Eidus <ieidus@...hat.com>
Subject: [PATCH 3/3] withdraw ksm-add-page_wrprotect-write-protecting-page.patch
Now that ksm have its private write_protect_page(), we dont need this helper
function to do the write-protecting work for us.
Signed-off-by: Izik Eidus <ieidus@...hat.com>
---
include/linux/rmap.h | 12 ----
mm/rmap.c | 139 --------------------------------------------------
2 files changed, 0 insertions(+), 151 deletions(-)
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 8b98536..350e76d 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -118,10 +118,6 @@ static inline int try_to_munlock(struct page *page)
}
#endif
-#ifdef CONFIG_KSM
-int page_wrprotect(struct page *page, int *odirect_sync, int count_offset);
-#endif
-
#else /* !CONFIG_MMU */
#define anon_vma_init() do {} while (0)
@@ -136,14 +132,6 @@ static inline int page_mkclean(struct page *page)
return 0;
}
-#ifdef CONFIG_KSM
-static inline int page_wrprotect(struct page *page, int *odirect_sync,
- int count_offset)
-{
- return 0;
-}
-#endif
-
#endif /* CONFIG_MMU */
/*
diff --git a/mm/rmap.c b/mm/rmap.c
index 34a2029..c3ba0b9 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -585,145 +585,6 @@ int page_mkclean(struct page *page)
}
EXPORT_SYMBOL_GPL(page_mkclean);
-#ifdef CONFIG_KSM
-
-static int page_wrprotect_one(struct page *page, struct vm_area_struct *vma,
- int *odirect_sync, int count_offset)
-{
- struct mm_struct *mm = vma->vm_mm;
- unsigned long address;
- pte_t *pte;
- spinlock_t *ptl;
- int ret = 0;
-
- address = vma_address(page, vma);
- if (address == -EFAULT)
- goto out;
-
- pte = page_check_address(page, mm, address, &ptl, 0);
- if (!pte)
- goto out;
-
- if (pte_write(*pte)) {
- pte_t entry;
-
- flush_cache_page(vma, address, pte_pfn(*pte));
- /*
- * Ok this is tricky, when get_user_pages_fast() run it doesnt
- * take any lock, therefore the check that we are going to make
- * with the pagecount against the mapcount is racey and
- * O_DIRECT can happen right after the check.
- * So we clear the pte and flush the tlb before the check
- * this assure us that no O_DIRECT can happen after the check
- * or in the middle of the check.
- */
- entry = ptep_clear_flush(vma, address, pte);
- /*
- * Check that no O_DIRECT or similar I/O is in progress on the
- * page
- */
- if ((page_mapcount(page) + count_offset) != page_count(page)) {
- *odirect_sync = 0;
- set_pte_at_notify(mm, address, pte, entry);
- goto out_unlock;
- }
- entry = pte_wrprotect(entry);
- set_pte_at_notify(mm, address, pte, entry);
- }
- ret = 1;
-
-out_unlock:
- pte_unmap_unlock(pte, ptl);
-out:
- return ret;
-}
-
-static int page_wrprotect_file(struct page *page, int *odirect_sync,
- int count_offset)
-{
- struct address_space *mapping;
- struct prio_tree_iter iter;
- struct vm_area_struct *vma;
- pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
- int ret = 0;
-
- mapping = page_mapping(page);
- if (!mapping)
- return ret;
-
- spin_lock(&mapping->i_mmap_lock);
-
- vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff)
- ret += page_wrprotect_one(page, vma, odirect_sync,
- count_offset);
-
- spin_unlock(&mapping->i_mmap_lock);
-
- return ret;
-}
-
-static int page_wrprotect_anon(struct page *page, int *odirect_sync,
- int count_offset)
-{
- struct vm_area_struct *vma;
- struct anon_vma *anon_vma;
- int ret = 0;
-
- anon_vma = page_lock_anon_vma(page);
- if (!anon_vma)
- return ret;
-
- /*
- * If the page is inside the swap cache, its _count number was
- * increased by one, therefore we have to increase count_offset by one.
- */
- if (PageSwapCache(page))
- count_offset++;
-
- list_for_each_entry(vma, &anon_vma->head, anon_vma_node)
- ret += page_wrprotect_one(page, vma, odirect_sync,
- count_offset);
-
- page_unlock_anon_vma(anon_vma);
-
- return ret;
-}
-
-/**
- * page_wrprotect - set all ptes pointing to a page as readonly
- * @page: the page to set as readonly
- * @odirect_sync: boolean value that is set to 0 when some of the ptes were not
- * marked as readonly beacuse page_wrprotect_one() was not able
- * to mark this ptes as readonly without opening window to a race
- * with odirect
- * @count_offset: number of times page_wrprotect() caller had called get_page()
- * on the page
- *
- * returns the number of ptes which were marked as readonly.
- * (ptes that were readonly before this function was called are counted as well)
- */
-int page_wrprotect(struct page *page, int *odirect_sync, int count_offset)
-{
- int ret = 0;
-
- /*
- * Page lock is needed for anon pages for the PageSwapCache check,
- * and for page_mapping for filebacked pages
- */
- BUG_ON(!PageLocked(page));
-
- *odirect_sync = 1;
- if (PageAnon(page))
- ret = page_wrprotect_anon(page, odirect_sync, count_offset);
- else
- ret = page_wrprotect_file(page, odirect_sync, count_offset);
-
- return ret;
-}
-EXPORT_SYMBOL(page_wrprotect);
-
-#endif
-
/**
* __page_set_anon_rmap - setup new anonymous rmap
* @page: the page to add the mapping to
--
1.5.6.5
--
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