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Diffstat (limited to 'mm/fremap.c')
-rw-r--r--mm/fremap.c51
1 files changed, 27 insertions, 24 deletions
diff --git a/mm/fremap.c b/mm/fremap.c
index a0aaf0e..0cd4c11 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;
@@ -160,15 +161,11 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
/*
* Make sure the vma is shared, that it supports prefaulting,
* and that the remapped range is valid and fully within
- * the single existing vma. vm_private_data is used as a
- * swapout cursor in a VM_NONLINEAR vma.
+ * the single existing vma.
*/
if (!vma || !(vma->vm_flags & VM_SHARED))
goto out;
- if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR))
- goto out;
-
if (!vma->vm_ops || !vma->vm_ops->remap_pages)
goto out;
@@ -177,6 +174,13 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
/* Must set VM_NONLINEAR before any pages are populated. */
if (!(vma->vm_flags & VM_NONLINEAR)) {
+ /*
+ * vm_private_data is used as a swapout cursor
+ * in a VM_NONLINEAR vma.
+ */
+ if (vma->vm_private_data)
+ goto out;
+
/* Don't need a nonlinear mapping, exit success */
if (pgoff == linear_page_index(vma, start)) {
err = 0;
@@ -184,6 +188,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
}
if (!has_write_lock) {
+get_write_lock:
up_read(&mm->mmap_sem);
down_write(&mm->mmap_sem);
has_write_lock = 1;
@@ -199,9 +204,10 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
unsigned long addr;
struct file *file = get_file(vma->vm_file);
- flags &= MAP_NONBLOCK;
- addr = mmap_region(file, start, size,
- flags, vma->vm_flags, pgoff);
+ vm_flags = vma->vm_flags;
+ if (!(flags & MAP_NONBLOCK))
+ vm_flags |= VM_POPULATE;
+ addr = mmap_region(file, start, size, vm_flags, pgoff);
fput(file);
if (IS_ERR_VALUE(addr)) {
err = addr;
@@ -220,32 +226,26 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
mutex_unlock(&mapping->i_mmap_mutex);
}
+ if (!(flags & MAP_NONBLOCK) && !(vma->vm_flags & VM_POPULATE)) {
+ if (!has_write_lock)
+ goto get_write_lock;
+ vma->vm_flags |= VM_POPULATE;
+ }
+
if (vma->vm_flags & VM_LOCKED) {
/*
* 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 && !(flags & MAP_NONBLOCK)) {
- if (vma->vm_flags & VM_LOCKED) {
- /*
- * might be mapping previously unmapped range of file
- */
- mlock_vma_pages_range(vma, start, start + size);
- } else {
- 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
@@ -254,10 +254,13 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
*/
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;
}