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| author |   Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2015-09-04 15:47:53 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-04 16:54:41 -0700 |
| commit | d899844e9c98c9c74b4d9926fd3bd66a225f6978 (patch) | |
| tree | f20414a3a4217e6befb38b5adeefdc2e6a4e8c00 | |
| parent | mm: memcontrol: bring back the VM_BUG_ON() in mem_cgroup_swapout() (diff) | |
| download | linux-dev-d899844e9c98c9c74b4d9926fd3bd66a225f6978.tar.xz linux-dev-d899844e9c98c9c74b4d9926fd3bd66a225f6978.zip | |
mm: fix status code which move_pages() returns for zero page
The manpage for move_pages(2) specifies that status code for zero page is
supposed to be -EFAULT. Currently kernel return -ENOENT in this case.
follow_page() can do it for us, if we would ask for FOLL_DUMP. The use of
FOLL_DUMP also means that the upper layer page tables pages are no longer
allocated.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/migrate.c | 18 |
1 files changed, 6 insertions, 12 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index eb4267107d1f..5c08cab5419e 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1226,7 +1226,9 @@ static int do_move_page_to_node_array(struct mm_struct *mm, if (!vma || pp->addr < vma->vm_start || !vma_migratable(vma)) goto set_status; - page = follow_page(vma, pp->addr, FOLL_GET|FOLL_SPLIT); + /* FOLL_DUMP to ignore special (like zero) pages */ + page = follow_page(vma, pp->addr, + FOLL_GET | FOLL_SPLIT | FOLL_DUMP); err = PTR_ERR(page); if (IS_ERR(page)) @@ -1236,10 +1238,6 @@ static int do_move_page_to_node_array(struct mm_struct *mm, if (!page) goto set_status; - /* Use PageReserved to check for zero page */ - if (PageReserved(page)) - goto put_and_set; - pp->page = page; err = page_to_nid(page); @@ -1396,18 +1394,14 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages, if (!vma || addr < vma->vm_start) goto set_status; - page = follow_page(vma, addr, 0); + /* FOLL_DUMP to ignore special (like zero) pages */ + page = follow_page(vma, addr, FOLL_DUMP); err = PTR_ERR(page); if (IS_ERR(page)) goto set_status; - err = -ENOENT; - /* Use PageReserved to check for zero page */ - if (!page || PageReserved(page)) - goto set_status; - - err = page_to_nid(page); + err = page ? page_to_nid(page) : -ENOENT; set_status: *status = err; |