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-rw-r--r--mm/rmap.c41
1 files changed, 32 insertions, 9 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 02f0bfc3c80a..30b739ce0ffa 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1715,14 +1715,21 @@ static struct anon_vma *rmap_walk_anon_lock(struct page *page,
* vm_flags for that VMA. That should be OK, because that vma shouldn't be
* LOCKED.
*/
-static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
+static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
+ bool locked)
{
struct anon_vma *anon_vma;
pgoff_t pgoff;
struct anon_vma_chain *avc;
int ret = SWAP_AGAIN;
- anon_vma = rmap_walk_anon_lock(page, rwc);
+ if (locked) {
+ anon_vma = page_anon_vma(page);
+ /* anon_vma disappear under us? */
+ VM_BUG_ON_PAGE(!anon_vma, page);
+ } else {
+ anon_vma = rmap_walk_anon_lock(page, rwc);
+ }
if (!anon_vma)
return ret;
@@ -1742,7 +1749,9 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
if (rwc->done && rwc->done(page))
break;
}
- anon_vma_unlock_read(anon_vma);
+
+ if (!locked)
+ anon_vma_unlock_read(anon_vma);
return ret;
}
@@ -1759,9 +1768,10 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
* vm_flags for that VMA. That should be OK, because that vma shouldn't be
* LOCKED.
*/
-static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
+static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
+ bool locked)
{
- struct address_space *mapping = page->mapping;
+ struct address_space *mapping = page_mapping(page);
pgoff_t pgoff;
struct vm_area_struct *vma;
int ret = SWAP_AGAIN;
@@ -1778,7 +1788,8 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
return ret;
pgoff = page_to_pgoff(page);
- i_mmap_lock_read(mapping);
+ if (!locked)
+ i_mmap_lock_read(mapping);
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
unsigned long address = vma_address(page, vma);
@@ -1795,7 +1806,8 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
}
done:
- i_mmap_unlock_read(mapping);
+ if (!locked)
+ i_mmap_unlock_read(mapping);
return ret;
}
@@ -1804,9 +1816,20 @@ int rmap_walk(struct page *page, struct rmap_walk_control *rwc)
if (unlikely(PageKsm(page)))
return rmap_walk_ksm(page, rwc);
else if (PageAnon(page))
- return rmap_walk_anon(page, rwc);
+ return rmap_walk_anon(page, rwc, false);
+ else
+ return rmap_walk_file(page, rwc, false);
+}
+
+/* Like rmap_walk, but caller holds relevant rmap lock */
+int rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc)
+{
+ /* no ksm support for now */
+ VM_BUG_ON_PAGE(PageKsm(page), page);
+ if (PageAnon(page))
+ return rmap_walk_anon(page, rwc, true);
else
- return rmap_walk_file(page, rwc);
+ return rmap_walk_file(page, rwc, true);
}
#ifdef CONFIG_HUGETLB_PAGE