[PATCH 1/2] mm: cleanup flags usage in faultin_page

[PATCH 1/2] mm: cleanup flags usage in faultin_page

[Josef Bacik]

We're passing a pointer to the foll_flags for faultin_page, however we
never modify the flags in this call.  Change this to just take the flags
value instead.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mm/gup.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index 54d0dc3831fb..985d5141592f 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1153,19 +1153,19 @@ static int get_gate_page(struct mm_struct *mm, unsigned long address,
  * to 0 and -EBUSY returned.
  */
 static int faultin_page(struct vm_area_struct *vma,
-		unsigned long address, unsigned int *flags, bool unshare,
+		unsigned long address, unsigned int flags, bool unshare,
 		int *locked)
 {
 	unsigned int fault_flags = 0;
 	vm_fault_t ret;
 
-	if (*flags & FOLL_NOFAULT)
+	if (flags & FOLL_NOFAULT)
 		return -EFAULT;
-	if (*flags & FOLL_WRITE)
+	if (flags & FOLL_WRITE)
 		fault_flags |= FAULT_FLAG_WRITE;
-	if (*flags & FOLL_REMOTE)
+	if (flags & FOLL_REMOTE)
 		fault_flags |= FAULT_FLAG_REMOTE;
-	if (*flags & FOLL_UNLOCKABLE) {
+	if (flags & FOLL_UNLOCKABLE) {
 		fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 		/*
 		 * FAULT_FLAG_INTERRUPTIBLE is opt-in. GUP callers must set
@@ -1173,12 +1173,12 @@ static int faultin_page(struct vm_area_struct *vma,
 		 * That's because some callers may not be prepared to
 		 * handle early exits caused by non-fatal signals.
 		 */
-		if (*flags & FOLL_INTERRUPTIBLE)
+		if (flags & FOLL_INTERRUPTIBLE)
 			fault_flags |= FAULT_FLAG_INTERRUPTIBLE;
 	}
-	if (*flags & FOLL_NOWAIT)
+	if (flags & FOLL_NOWAIT)
 		fault_flags |= FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_RETRY_NOWAIT;
-	if (*flags & FOLL_TRIED) {
+	if (flags & FOLL_TRIED) {
 		/*
 		 * Note: FAULT_FLAG_ALLOW_RETRY and FAULT_FLAG_TRIED
 		 * can co-exist
@@ -1212,7 +1212,7 @@ static int faultin_page(struct vm_area_struct *vma,
 	}
 
 	if (ret & VM_FAULT_ERROR) {
-		int err = vm_fault_to_errno(ret, *flags);
+		int err = vm_fault_to_errno(ret, flags);
 
 		if (err)
 			return err;
@@ -1490,7 +1490,7 @@ static long __get_user_pages(struct mm_struct *mm,
 
 		page = follow_page_mask(vma, start, foll_flags, &ctx);
 		if (!page || PTR_ERR(page) == -EMLINK) {
-			ret = faultin_page(vma, start, &foll_flags,
+			ret = faultin_page(vma, start, foll_flags,
 					   PTR_ERR(page) == -EMLINK, locked);
 			switch (ret) {
 			case 0:
-- 
2.43.0

[PATCH 2/2] mm: remove foll_flags in __get_user_pages

[Josef Bacik]

Now that we're not passing around a pointer to the flags, there's no
reason to have an extra variable for the gup_flags, simply pass the
gup_flags directly everywhere.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 mm/gup.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index 985d5141592f..120740cf5a34 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1437,7 +1437,6 @@ static long __get_user_pages(struct mm_struct *mm,
 
 	do {
 		struct page *page;
-		unsigned int foll_flags = gup_flags;
 		unsigned int page_increm;
 
 		/* first iteration or cross vma bound */
@@ -1488,9 +1487,9 @@ static long __get_user_pages(struct mm_struct *mm,
 		}
 		cond_resched();
 
-		page = follow_page_mask(vma, start, foll_flags, &ctx);
+		page = follow_page_mask(vma, start, gup_flags, &ctx);
 		if (!page || PTR_ERR(page) == -EMLINK) {
-			ret = faultin_page(vma, start, foll_flags,
+			ret = faultin_page(vma, start, gup_flags,
 					   PTR_ERR(page) == -EMLINK, locked);
 			switch (ret) {
 			case 0:
@@ -1547,13 +1546,12 @@ static long __get_user_pages(struct mm_struct *mm,
 				 * large folio, this should never fail.
 				 */
 				if (try_grab_folio(folio, page_increm - 1,
-						   foll_flags)) {
+						   gup_flags)) {
 					/*
 					 * Release the 1st page ref if the
 					 * folio is problematic, fail hard.
 					 */
-					gup_put_folio(folio, 1,
-						      foll_flags);
+					gup_put_folio(folio, 1, gup_flags);
 					ret = -EFAULT;
 					goto out;
 				}
-- 
2.43.0

Re: [PATCH 1/2] mm: cleanup flags usage in faultin_page

[David Hildenbrand]

On 18.07.24 23:26, Josef Bacik wrote:
> We're passing a pointer to the foll_flags for faultin_page, however we
> never modify the flags in this call.  Change this to just take the flags
> value instead.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---

Acked-by: David Hildenbrand <david@redhat.com>

-- 
Cheers,

David / dhildenb

Re: [PATCH 2/2] mm: remove foll_flags in __get_user_pages

[David Hildenbrand]

On 18.07.24 23:26, Josef Bacik wrote:
> Now that we're not passing around a pointer to the flags, there's no
> reason to have an extra variable for the gup_flags, simply pass the
> gup_flags directly everywhere.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---

Acked-by: David Hildenbrand <david@redhat.com>

-- 
Cheers,

David / dhildenb