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Diffstat (limited to 'mm')
-rw-r--r--mm/filemap.c22
-rw-r--r--mm/hugetlb.c13
-rw-r--r--mm/mempolicy.c7
3 files changed, 26 insertions, 16 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index ab98557e228..df343d1e634 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1742,21 +1742,27 @@ size_t iov_iter_copy_from_user(struct page *page,
}
EXPORT_SYMBOL(iov_iter_copy_from_user);
-static void __iov_iter_advance_iov(struct iov_iter *i, size_t bytes)
+void iov_iter_advance(struct iov_iter *i, size_t bytes)
{
+ BUG_ON(i->count < bytes);
+
if (likely(i->nr_segs == 1)) {
i->iov_offset += bytes;
+ i->count -= bytes;
} else {
const struct iovec *iov = i->iov;
size_t base = i->iov_offset;
/*
* The !iov->iov_len check ensures we skip over unlikely
- * zero-length segments.
+ * zero-length segments (without overruning the iovec).
*/
- while (bytes || !iov->iov_len) {
- int copy = min(bytes, iov->iov_len - base);
+ while (bytes || unlikely(!iov->iov_len && i->count)) {
+ int copy;
+ copy = min(bytes, iov->iov_len - base);
+ BUG_ON(!i->count || i->count < copy);
+ i->count -= copy;
bytes -= copy;
base += copy;
if (iov->iov_len == base) {
@@ -1768,14 +1774,6 @@ static void __iov_iter_advance_iov(struct iov_iter *i, size_t bytes)
i->iov_offset = base;
}
}
-
-void iov_iter_advance(struct iov_iter *i, size_t bytes)
-{
- BUG_ON(i->count < bytes);
-
- __iov_iter_advance_iov(i, bytes);
- i->count -= bytes;
-}
EXPORT_SYMBOL(iov_iter_advance);
/*
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index dcacc811e70..74c1b6b0b37 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -286,6 +286,12 @@ static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma,
spin_lock(&hugetlb_lock);
if (page) {
+ /*
+ * This page is now managed by the hugetlb allocator and has
+ * no users -- drop the buddy allocator's reference.
+ */
+ put_page_testzero(page);
+ VM_BUG_ON(page_count(page));
nid = page_to_nid(page);
set_compound_page_dtor(page, free_huge_page);
/*
@@ -369,13 +375,14 @@ free:
enqueue_huge_page(page);
else {
/*
- * Decrement the refcount and free the page using its
- * destructor. This must be done with hugetlb_lock
+ * The page has a reference count of zero already, so
+ * call free_huge_page directly instead of using
+ * put_page. This must be done with hugetlb_lock
* unlocked which is safe because free_huge_page takes
* hugetlb_lock before deciding how to free the page.
*/
spin_unlock(&hugetlb_lock);
- put_page(page);
+ free_huge_page(page);
spin_lock(&hugetlb_lock);
}
}
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 6c7ba1a63d2..3c360112150 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1296,7 +1296,9 @@ struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
unsigned nid;
nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT);
- __mpol_free(pol); /* finished with pol */
+ if (unlikely(pol != &default_policy &&
+ pol != current->mempolicy))
+ __mpol_free(pol); /* finished with pol */
return NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_flags);
}
@@ -1360,6 +1362,9 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
unsigned nid;
nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
+ if (unlikely(pol != &default_policy &&
+ pol != current->mempolicy))
+ __mpol_free(pol); /* finished with pol */
return alloc_page_interleave(gfp, 0, nid);
}
zl = zonelist_policy(gfp, pol);