diff options
| -rw-r--r-- | mm/fremap.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/mm/fremap.c b/mm/fremap.c index a0aaf0e56800..2db886e31044 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -160,15 +160,11 @@ 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 +173,13 @@ 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 +187,7 @@ 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; @@ -199,7 +203,7 @@ 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; + flags = (flags & MAP_NONBLOCK) | MAP_POPULATE; addr = mmap_region(file, start, size, flags, vma->vm_flags, pgoff); fput(file); @@ -225,6 +229,8 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, * drop PG_Mlocked flag for over-mapped range */ vm_flags_t saved_flags = vma->vm_flags; + if (!has_write_lock) + goto get_write_lock; munlock_vma_pages_range(vma, start, start + size); vma->vm_flags = saved_flags; } @@ -232,13 +238,13 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, 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 (!err) { if (vma->vm_flags & VM_LOCKED) { /* * might be mapping previously unmapped range of file */ mlock_vma_pages_range(vma, start, start + size); - } else { + } else if (!(flags & MAP_NONBLOCK)) { if (unlikely(has_write_lock)) { downgrade_write(&mm->mmap_sem); has_write_lock = 0; |