Merge commit '0072a0c14d5b7cb72c611d396f143f5dcd73ebe2' into patchwork

Merge from Upstream after the latest media fixes branch, because we
need one patch that it is there.

* commit '0072a0c14d5b7cb72c611d396f143f5dcd73ebe2': (1108 commits)
  ide: Change to use DEFINE_SHOW_ATTRIBUTE macro
  ide: pmac: add of_node_put()
  drivers/tty: add missing of_node_put()
  drivers/sbus/char: add of_node_put()
  sbus: char: add of_node_put()
  Linux 4.20-rc5
  PCI: Fix incorrect value returned from pcie_get_speed_cap()
  MAINTAINERS: Update linux-mips mailing list address
  ocfs2: fix potential use after free
  mm/khugepaged: fix the xas_create_range() error path
  mm/khugepaged: collapse_shmem() do not crash on Compound
  mm/khugepaged: collapse_shmem() without freezing new_page
  mm/khugepaged: minor reorderings in collapse_shmem()
  mm/khugepaged: collapse_shmem() remember to clear holes
  mm/khugepaged: fix crashes due to misaccounted holes
  mm/khugepaged: collapse_shmem() stop if punched or truncated
  mm/huge_memory: fix lockdep complaint on 32-bit i_size_read()
  mm/huge_memory: splitting set mapping+index before unfreeze
  mm/huge_memory: rename freeze_page() to unmap_page()
  initramfs: clean old path before creating a hardlink
  ...

1 files changed, 9 insertions, 4 deletions

diff --git a/mm/gup.c b/mm/gup.c
index f76e77a2d34b..8cb68a50dbdf 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -385,11 +385,17 @@ static struct page *follow_p4d_mask(struct vm_area_struct *vma,
  * @vma: vm_area_struct mapping @address
  * @address: virtual address to look up
  * @flags: flags modifying lookup behaviour
- * @page_mask: on output, *page_mask is set according to the size of the page
+ * @ctx: contains dev_pagemap for %ZONE_DEVICE memory pinning and a
+ *       pointer to output page_mask
  *
  * @flags can have FOLL_ flags set, defined in <linux/mm.h>
  *
- * Returns the mapped (struct page *), %NULL if no mapping exists, or
+ * When getting pages from ZONE_DEVICE memory, the @ctx->pgmap caches
+ * the device's dev_pagemap metadata to avoid repeating expensive lookups.
+ *
+ * On output, the @ctx->page_mask is set according to the size of the page.
+ *
+ * Return: the mapped (struct page *), %NULL if no mapping exists, or
  * an error pointer if there is a mapping to something not represented
  * by a page descriptor (see also vm_normal_page()).
  */
@@ -696,12 +702,11 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 		if (!vma || start >= vma->vm_end) {
 			vma = find_extend_vma(mm, start);
 			if (!vma && in_gate_area(mm, start)) {
-				int ret;
 				ret = get_gate_page(mm, start & PAGE_MASK,
 						gup_flags, &vma,
 						pages ? &pages[i] : NULL);
 				if (ret)
-					return i ? : ret;
+					goto out;
 				ctx.page_mask = 0;
 				goto next_page;
 			}