[v6,0/2] fix follow_page related issues

Message

Wang, Haiyue Aug. 16, 2022, 2:20 a.m. UTC

v6: Simplify the multiple layers of conditionals for if {}

-               if (page) {
-                       err = !is_zone_device_page(page) ? page_to_nid(page)
-                                                        : -ENOENT;
-                       if (foll_flags & FOLL_GET)
-                               put_page(page);
-               } else {
-                       err = -ENOENT;
-               }
+               err = -ENOENT;
+               if (!page)
+                       goto set_status;
+
+               if (!is_zone_device_page(page))
+                       err = page_to_nid(page);
+
+               if (foll_flags & FOLL_GET)
+                       put_page(page);

v5: reword the commit message for FOLL_GET with more information.

v4: add '()' for the function for readability.
    add more words about the Non-LRU pages fix in commit message.

v3: Merge the fix for handling Non-LRU pages into one patch.
    Drop the break_ksm zone device page check.

v2: Add the Non-LRU pages fix with two patches, so that
    'mm: migration: fix the FOLL_GET' can be applied directly
    on linux-5.19 stable branch.

Haiyue Wang (2):
  mm: migration: fix the FOLL_GET failure on following huge page
  mm: fix the handling Non-LRU pages returned by follow_page

 mm/huge_memory.c |  4 ++--
 mm/ksm.c         | 12 +++++++++---
 mm/migrate.c     | 23 +++++++++++++++++------
 3 files changed, 28 insertions(+), 11 deletions(-)