[PATCH] shmem: let shared anonymous be nonlinear again

[PATCH] shmem: let shared anonymous be nonlinear again

[Hugh Dickins]

Up to 2.6.22, you could use remap_file_pages(2) on a tmpfs file or a
shared mapping of /dev/zero or a shared anonymous mapping.  In 2.6.23
we disabled it by default, but set VM_CAN_NONLINEAR to enable it on
safe mappings.  We made sure to set it in shmem_mmap() for tmpfs files,
but missed it in shmem_zero_setup() for the others.  Fix that at last.

Reported-by: Kenny Simpson <theonetruekenny@yahoo.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
---

 mm/shmem.c |    1 +
 1 file changed, 1 insertion(+)

--- 2.6.38/mm/shmem.c	2011-03-14 18:20:32.000000000 -0700
+++ linux/mm/shmem.c	2011-03-19 15:09:26.000000000 -0700
@@ -2791,5 +2791,6 @@ int shmem_zero_setup(struct vm_area_stru
 		fput(vma->vm_file);
 	vma->vm_file = file;
 	vma->vm_ops = &shmem_vm_ops;
+	vma->vm_flags |= VM_CAN_NONLINEAR;
 	return 0;
 }

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