linux-kernel - [PATCH 20/64] mm/madvise: use mm locking wrappers

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Date:   Mon,  5 Feb 2018 02:27:10 +0100
From:   Davidlohr Bueso <dbueso@...e.de>
To:     akpm@...ux-foundation.org, mingo@...nel.org
Cc:     peterz@...radead.org, ldufour@...ux.vnet.ibm.com, jack@...e.cz,
        mhocko@...nel.org, kirill.shutemov@...ux.intel.com,
        mawilcox@...rosoft.com, mgorman@...hsingularity.net,
        dave@...olabs.net, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, Davidlohr Bueso <dbueso@...e.de>
Subject: [PATCH 20/64] mm/madvise: use mm locking wrappers

From: Davidlohr Bueso <dave@...olabs.net>

mmap_sem users are already aware of mmrange, thus a
straightforward conversion. No changes in semantics.

Signed-off-by: Davidlohr Bueso <dbueso@...e.de>
---
 mm/madvise.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index eaec6bfc2b08..de8fb035955c 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -532,7 +532,7 @@ static long madvise_dontneed_free(struct vm_area_struct *vma,
 	if (!userfaultfd_remove(vma, start, end)) {
 		*prev = NULL; /* mmap_sem has been dropped, prev is stale */
 
-		down_read(&current->mm->mmap_sem);
+		mm_read_lock(current->mm, mmrange);
 		vma = find_vma(current->mm, start);
 		if (!vma)
 			return -ENOMEM;
@@ -582,7 +582,8 @@ static long madvise_dontneed_free(struct vm_area_struct *vma,
  */
 static long madvise_remove(struct vm_area_struct *vma,
 				struct vm_area_struct **prev,
-				unsigned long start, unsigned long end)
+				unsigned long start, unsigned long end,
+				struct range_lock *mmrange)
 {
 	loff_t offset;
 	int error;
@@ -614,13 +615,13 @@ static long madvise_remove(struct vm_area_struct *vma,
 	get_file(f);
 	if (userfaultfd_remove(vma, start, end)) {
 		/* mmap_sem was not released by userfaultfd_remove() */
-		up_read(&current->mm->mmap_sem);
+		mm_read_unlock(current->mm, mmrange);
 	}
 	error = vfs_fallocate(f,
 				FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
 				offset, end - start);
 	fput(f);
-	down_read(&current->mm->mmap_sem);
+	mm_read_lock(current->mm, mmrange);
 	return error;
 }
 
@@ -690,7 +691,7 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
 {
 	switch (behavior) {
 	case MADV_REMOVE:
-		return madvise_remove(vma, prev, start, end);
+		return madvise_remove(vma, prev, start, end, mmrange);
 	case MADV_WILLNEED:
 		return madvise_willneed(vma, prev, start, end, mmrange);
 	case MADV_FREE:
@@ -809,6 +810,7 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
 	int write;
 	size_t len;
 	struct blk_plug plug;
+
 	DEFINE_RANGE_LOCK_FULL(mmrange);
 	if (!madvise_behavior_valid(behavior))
 		return error;
@@ -836,10 +838,10 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
 
 	write = madvise_need_mmap_write(behavior);
 	if (write) {
-		if (down_write_killable(&current->mm->mmap_sem))
+		if (mm_write_lock_killable(current->mm, &mmrange))
 			return -EINTR;
 	} else {
-		down_read(&current->mm->mmap_sem);
+		mm_read_lock(current->mm, &mmrange);
 	}
 
 	/*
@@ -889,9 +891,9 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
 out:
 	blk_finish_plug(&plug);
 	if (write)
-		up_write(&current->mm->mmap_sem);
+		mm_write_unlock(current->mm, &mmrange);
 	else
-		up_read(&current->mm->mmap_sem);
+		mm_read_unlock(current->mm, &mmrange);
 
 	return error;
 }
-- 
2.13.6