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authorAnton Altaparmakov <aia21@cantab.net>2005-06-23 11:26:22 +0100
committerAnton Altaparmakov <aia21@cantab.net>2005-06-23 11:26:22 +0100
commit3357d4c75f1fb67e7304998c4ad4e9a9fed66fa4 (patch)
treeceba46966a5a1112a05d257d8ecb25ae5eee95e0 /mm/rmap.c
parent364f6c717deef4a3ac4982e670fa9846b43cd060 (diff)
parentee98689be1b054897ff17655008c3048fe88be94 (diff)
downloadlinux-3357d4c75f1fb67e7304998c4ad4e9a9fed66fa4.tar.gz
linux-3357d4c75f1fb67e7304998c4ad4e9a9fed66fa4.tar.xz
Automatic merge with /usr/src/ntfs-2.6.git.
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c21
1 files changed, 0 insertions, 21 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 9827409eb7c7..89770bd25f31 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -539,27 +539,6 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma)
goto out_unmap;
}
- /*
- * Don't pull an anonymous page out from under get_user_pages.
- * GUP carefully breaks COW and raises page count (while holding
- * page_table_lock, as we have here) to make sure that the page
- * cannot be freed. If we unmap that page here, a user write
- * access to the virtual address will bring back the page, but
- * its raised count will (ironically) be taken to mean it's not
- * an exclusive swap page, do_wp_page will replace it by a copy
- * page, and the user never get to see the data GUP was holding
- * the original page for.
- *
- * This test is also useful for when swapoff (unuse_process) has
- * to drop page lock: its reference to the page stops existing
- * ptes from being unmapped, so swapoff can make progress.
- */
- if (PageSwapCache(page) &&
- page_count(page) != page_mapcount(page) + 2) {
- ret = SWAP_FAIL;
- goto out_unmap;
- }
-
/* Nuke the page table entry. */
flush_cache_page(vma, address, page_to_pfn(page));
pteval = ptep_clear_flush(vma, address, pte);