X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=mm%2Fgup.c;h=60c3915c8ee6c67e81fd2e675bd4cf9d2e895632;hb=bfe7b00de6d1e25fee08484c4fbf1c1ed175be78;hp=012060efddf18f8f75b8b56ad0447df9ce55d0c7;hpb=fb4fb04ff4dd377b3132e9b31259263ec37b830a;p=linux-block.git

diff --git a/mm/gup.c b/mm/gup.c
index 012060efddf1..60c3915c8ee6 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -384,7 +384,7 @@ retry_locked:
 		spin_unlock(ptl);
 		return follow_page_pte(vma, address, pmd, flags, &ctx->pgmap);
 	}
-	if (flags & FOLL_SPLIT) {
+	if (flags & (FOLL_SPLIT | FOLL_SPLIT_PMD)) {
 		int ret;
 		page = pmd_page(*pmd);
 		if (is_huge_zero_page(page)) {
@@ -393,7 +393,7 @@ retry_locked:
 			split_huge_pmd(vma, pmd, address);
 			if (pmd_trans_unstable(pmd))
 				ret = -EBUSY;
-		} else {
+		} else if (flags & FOLL_SPLIT) {
 			if (unlikely(!try_get_page(page))) {
 				spin_unlock(ptl);
 				return ERR_PTR(-ENOMEM);
@@ -405,6 +405,10 @@ retry_locked:
 			put_page(page);
 			if (pmd_none(*pmd))
 				return no_page_table(vma, flags);
+		} else {  /* flags & FOLL_SPLIT_PMD */
+			spin_unlock(ptl);
+			split_huge_pmd(vma, pmd, address);
+			ret = pte_alloc(mm, pmd) ? -ENOMEM : 0;
 		}
 
 		return ret ? ERR_PTR(ret) :