[RFC PATCH 03/10] mm/gup: Pass flags down to __gup_device_huge* calls

From: ira . weiny
Date: Mon Apr 29 2019 - 00:54:28 EST


From: Ira Weiny <ira.weiny@xxxxxxxxx>

In order to support taking and/or checking for a LONGTERM lease on a FS
DAX inode these calls need to know if FOLL_LONGTERM was specified.

This patch passes the flags down but does not use them. It does this in
prep for 2 future patches.
---
mm/gup.c | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index 42680823fbbe..a8ac75bc1452 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1853,7 +1853,8 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,

#if defined(__HAVE_ARCH_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
static int __gup_device_huge(unsigned long pfn, unsigned long addr,
- unsigned long end, struct page **pages, int *nr)
+ unsigned long end, struct page **pages, int *nr,
+ unsigned int flags)
{
int nr_start = *nr;
struct dev_pagemap *pgmap = NULL;
@@ -1886,30 +1887,33 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr,
}

static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
- unsigned long end, struct page **pages, int *nr)
+ unsigned long end, struct page **pages, int *nr,
+ unsigned int flags)
{
unsigned long fault_pfn;
int nr_start = *nr;

fault_pfn = pmd_pfn(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
- if (!__gup_device_huge(fault_pfn, addr, end, pages, nr))
+ if (!__gup_device_huge(fault_pfn, addr, end, pages, nr, flags))
return 0;

if (unlikely(pmd_val(orig) != pmd_val(*pmdp))) {
undo_dev_pagemap(nr, nr_start, pages);
return 0;
}
+
return 1;
}

static int __gup_device_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
- unsigned long end, struct page **pages, int *nr)
+ unsigned long end, struct page **pages, int *nr,
+ unsigned int flags)
{
unsigned long fault_pfn;
int nr_start = *nr;

fault_pfn = pud_pfn(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
- if (!__gup_device_huge(fault_pfn, addr, end, pages, nr))
+ if (!__gup_device_huge(fault_pfn, addr, end, pages, nr, flags))
return 0;

if (unlikely(pud_val(orig) != pud_val(*pudp))) {
@@ -1920,14 +1924,16 @@ static int __gup_device_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
}
#else
static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
- unsigned long end, struct page **pages, int *nr)
+ unsigned long end, struct page **pages, int *nr,
+ unsigned int flags)
{
BUILD_BUG();
return 0;
}

static int __gup_device_huge_pud(pud_t pud, pud_t *pudp, unsigned long addr,
- unsigned long end, struct page **pages, int *nr)
+ unsigned long end, struct page **pages, int *nr,
+ unsigned int flags)
{
BUILD_BUG();
return 0;
@@ -1946,7 +1952,8 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
if (pmd_devmap(orig)) {
if (unlikely(flags & FOLL_LONGTERM))
return 0;
- return __gup_device_huge_pmd(orig, pmdp, addr, end, pages, nr);
+ return __gup_device_huge_pmd(orig, pmdp, addr, end, pages, nr,
+ flags);
}

refs = 0;
@@ -1988,7 +1995,8 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
if (pud_devmap(orig)) {
if (unlikely(flags & FOLL_LONGTERM))
return 0;
- return __gup_device_huge_pud(orig, pudp, addr, end, pages, nr);
+ return __gup_device_huge_pud(orig, pudp, addr, end, pages, nr,
+ flags);
}

refs = 0;
--
2.20.1