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authorKonstantin Khlebnikov <khlebnikov@openvz.org>2012-10-08 16:28:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-09 16:22:17 +0900
commit4b6e1e37026ec7dae9b23d78ffcebdd5ddb1bfa1 (patch)
tree10200483a705005f41f543ed433581409cf2bf5f /mm/memory.c
parentcc2383ec06be093789469852e1fe96e1148e9a2c (diff)
downloadlinux-4b6e1e37026ec7dae9b23d78ffcebdd5ddb1bfa1.tar.gz
mm: kill vma flag VM_INSERTPAGE
Merge VM_INSERTPAGE into VM_MIXEDMAP. VM_MIXEDMAP VMA can mix pure-pfn ptes, special ptes and normal ptes. Now copy_page_range() always copies VM_MIXEDMAP VMA on fork like VM_PFNMAP. If driver populates whole VMA at mmap() it probably not expects page-faults. This patch removes special check from vma_wants_writenotify() which disables pages write tracking for VMA populated via vm_instert_page(). BDI below mapped file should not use dirty-accounting, moreover do_wp_page() can handle this. vm_insert_page() still marks vma after first usage. Usually it is called from f_op->mmap() handler under mm->mmap_sem write-lock, so it able to change vma->vm_flags. Caller must set VM_MIXEDMAP at mmap time if it wants to call this function from other places, for example from page-fault handler. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Eric Paris <eparis@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Venkatesh Pallipadi <venki@google.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
-rw-r--r--mm/memory.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 655e1429388..7b1e4feaec0 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1047,7 +1047,8 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
* readonly mappings. The tradeoff is that copy_page_range is more
* efficient than faulting.
*/
- if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_PFNMAP|VM_INSERTPAGE))) {
+ if (!(vma->vm_flags & (VM_HUGETLB | VM_NONLINEAR |
+ VM_PFNMAP | VM_MIXEDMAP))) {
if (!vma->anon_vma)
return 0;
}
@@ -2085,6 +2086,11 @@ out:
* ask for a shared writable mapping!
*
* The page does not need to be reserved.
+ *
+ * Usually this function is called from f_op->mmap() handler
+ * under mm->mmap_sem write-lock, so it can change vma->vm_flags.
+ * Caller must set VM_MIXEDMAP on vma if it wants to call this
+ * function from other places, for example from page-fault handler.
*/
int vm_insert_page(struct vm_area_struct *vma, unsigned long addr,
struct page *page)
@@ -2093,7 +2099,11 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr,
return -EFAULT;
if (!page_count(page))
return -EINVAL;
- vma->vm_flags |= VM_INSERTPAGE;
+ if (!(vma->vm_flags & VM_MIXEDMAP)) {
+ BUG_ON(down_read_trylock(&vma->vm_mm->mmap_sem));
+ BUG_ON(vma->vm_flags & VM_PFNMAP);
+ vma->vm_flags |= VM_MIXEDMAP;
+ }
return insert_page(vma, addr, page, vma->vm_page_prot);
}
EXPORT_SYMBOL(vm_insert_page);