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From: Michel Lespinasse <walken@google.com>
To: Andy Lutomirski <luto@amacapital.net>,
	Ingo Molnar <mingo@kernel.org>, Al Viro <viro@zeniv.linux.org.uk>,
	Hugh Dickins <hughd@google.com>, Jorn_Engel <joern@logfs.org>,
	Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH 4/9] mm: use mm_populate() for blocking remap_file_pages()
Date: Thu, 20 Dec 2012 16:49:52 -0800	[thread overview]
Message-ID: <1356050997-2688-5-git-send-email-walken@google.com> (raw)
In-Reply-To: <1356050997-2688-1-git-send-email-walken@google.com>

Signed-off-by: Michel Lespinasse <walken@google.com>

---
 mm/fremap.c |   22 ++++++----------------
 1 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/mm/fremap.c b/mm/fremap.c
index 2db886e31044..b42e32171530 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -129,6 +129,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 	struct vm_area_struct *vma;
 	int err = -EINVAL;
 	int has_write_lock = 0;
+	vm_flags_t vm_flags;
 
 	if (prot)
 		return err;
@@ -228,30 +229,16 @@ get_write_lock:
 		/*
 		 * drop PG_Mlocked flag for over-mapped range
 		 */
-		vm_flags_t saved_flags = vma->vm_flags;
 		if (!has_write_lock)
 			goto get_write_lock;
+		vm_flags = vma->vm_flags;
 		munlock_vma_pages_range(vma, start, start + size);
-		vma->vm_flags = saved_flags;
+		vma->vm_flags = vm_flags;
 	}
 
 	mmu_notifier_invalidate_range_start(mm, start, start + size);
 	err = vma->vm_ops->remap_pages(vma, start, size, pgoff);
 	mmu_notifier_invalidate_range_end(mm, start, start + size);
-	if (!err) {
-		if (vma->vm_flags & VM_LOCKED) {
-			/*
-			 * might be mapping previously unmapped range of file
-			 */
-			mlock_vma_pages_range(vma, start, start + size);
-		} else if (!(flags & MAP_NONBLOCK)) {
-			if (unlikely(has_write_lock)) {
-				downgrade_write(&mm->mmap_sem);
-				has_write_lock = 0;
-			}
-			make_pages_present(start, start+size);
-		}
-	}
 
 	/*
 	 * We can't clear VM_NONLINEAR because we'd have to do
@@ -260,10 +247,13 @@ get_write_lock:
 	 */
 
 out:
+	vm_flags = vma->vm_flags;
 	if (likely(!has_write_lock))
 		up_read(&mm->mmap_sem);
 	else
 		up_write(&mm->mmap_sem);
+	if (!err && ((vm_flags & VM_LOCKED) || !(flags & MAP_NONBLOCK)))
+		mm_populate(start, size);
 
 	return err;
 }
-- 
1.7.7.3

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  parent reply	other threads:[~2012-12-21  0:50 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-21  0:49 [PATCH 0/9] Avoid populating unbounded num of ptes with mmap_sem held Michel Lespinasse
2012-12-21  0:49 ` [PATCH 1/9] mm: make mlockall preserve flags other than VM_LOCKED in def_flags Michel Lespinasse
2012-12-22  4:25   ` Rik van Riel
2012-12-21  0:49 ` [PATCH 2/9] mm: remap_file_pages() fixes Michel Lespinasse
2013-01-03  0:31   ` Rik van Riel
2012-12-21  0:49 ` [PATCH 3/9] mm: introduce mm_populate() for populating new vmas Michel Lespinasse
2013-01-03  2:14   ` Rik van Riel
2012-12-21  0:49 ` Michel Lespinasse [this message]
2013-01-03  2:25   ` [PATCH 4/9] mm: use mm_populate() for blocking remap_file_pages() Rik van Riel
2013-03-10 18:55   ` Tommi Rantala
2013-03-11 23:03     ` Andrew Morton
2013-03-12  0:24       ` Michel Lespinasse
2013-03-12  4:23         ` Hillf Danton
2013-03-12  5:01           ` Michel Lespinasse
2013-03-12 20:47         ` Andrew Morton
2012-12-21  0:49 ` [PATCH 5/9] mm: use mm_populate() when adjusting brk with MCL_FUTURE in effect Michel Lespinasse
2013-01-03  2:56   ` Rik van Riel
2012-12-21  0:49 ` [PATCH 6/9] mm: use mm_populate() for mremap() of VM_LOCKED vmas Michel Lespinasse
2013-01-03  5:47   ` Rik van Riel
2012-12-21  0:49 ` [PATCH 7/9] mm: remove flags argument to mmap_region Michel Lespinasse
2013-01-03  5:49   ` Rik van Riel
2012-12-21  0:49 ` [PATCH 8/9] mm: directly use __mlock_vma_pages_range() in find_extend_vma() Michel Lespinasse
2013-01-03  5:50   ` Rik van Riel
2012-12-21  0:49 ` [PATCH 9/9] mm: introduce VM_POPULATE flag to better deal with racy userspace programs Michel Lespinasse
2013-01-03  6:20   ` Rik van Riel
2012-12-21 10:46 ` [PATCH 0/9] Avoid populating unbounded num of ptes with mmap_sem held Michel Lespinasse
2012-12-22 15:02   ` Greg Ungerer
2013-01-23 13:37   ` Greg Ungerer
2012-12-22  0:36 ` Andy Lutomirski
2012-12-22  0:59   ` Michel Lespinasse
2012-12-22  1:09     ` Andy Lutomirski
2012-12-22  1:59       ` Michel Lespinasse
2012-12-22  2:16         ` Andy Lutomirski
2012-12-22  9:37           ` Michel Lespinasse
2012-12-22  9:45             ` [PATCH 10/9] mm: make do_mmap_pgoff return populate as a size in bytes, not as a bool Michel Lespinasse
2013-01-03  6:21               ` Rik van Riel
2013-01-03 18:54               ` Andy Lutomirski
2013-01-03 18:56             ` [PATCH 0/9] Avoid populating unbounded num of ptes with mmap_sem held Andy Lutomirski
2013-01-04 18:16 ` Andy Lutomirski
2013-01-04 22:58   ` Michel Lespinasse

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