diff options
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 83b4682ec85c..d0dfc85b209b 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -131,6 +131,47 @@ void unlink_file_vma(struct vm_area_struct *vma) } } +void unlink_file_vma_batch_init(struct unlink_vma_file_batch *vb) +{ + vb->count = 0; +} + +static void unlink_file_vma_batch_process(struct unlink_vma_file_batch *vb) +{ + struct address_space *mapping; + int i; + + mapping = vb->vmas[0]->vm_file->f_mapping; + i_mmap_lock_write(mapping); + for (i = 0; i < vb->count; i++) { + VM_WARN_ON_ONCE(vb->vmas[i]->vm_file->f_mapping != mapping); + __remove_shared_vm_struct(vb->vmas[i], mapping); + } + i_mmap_unlock_write(mapping); + + unlink_file_vma_batch_init(vb); +} + +void unlink_file_vma_batch_add(struct unlink_vma_file_batch *vb, + struct vm_area_struct *vma) +{ + if (vma->vm_file == NULL) + return; + + if ((vb->count > 0 && vb->vmas[0]->vm_file != vma->vm_file) || + vb->count == ARRAY_SIZE(vb->vmas)) + unlink_file_vma_batch_process(vb); + + vb->vmas[vb->count] = vma; + vb->count++; +} + +void unlink_file_vma_batch_final(struct unlink_vma_file_batch *vb) +{ + if (vb->count > 0) + unlink_file_vma_batch_process(vb); +} + /* * Close a vm structure and free it. */ @@ -1369,6 +1410,36 @@ unsigned long do_mmap(struct file *file, unsigned long addr, pgoff = 0; vm_flags |= VM_SHARED | VM_MAYSHARE; break; + case MAP_DROPPABLE: + if (VM_DROPPABLE == VM_NONE) + return -ENOTSUPP; + /* + * A locked or stack area makes no sense to be droppable. + * + * Also, since droppable pages can just go away at any time + * it makes no sense to copy them on fork or dump them. + * + * And don't attempt to combine with hugetlb for now. + */ + if (flags & (MAP_LOCKED | MAP_HUGETLB)) + return -EINVAL; + if (vm_flags & (VM_GROWSDOWN | VM_GROWSUP)) + return -EINVAL; + + vm_flags |= VM_DROPPABLE; + + /* + * If the pages can be dropped, then it doesn't make + * sense to reserve them. + */ + vm_flags |= VM_NORESERVE; + + /* + * Likewise, they're volatile enough that they + * shouldn't survive forks or coredumps. + */ + vm_flags |= VM_WIPEONFORK | VM_DONTDUMP; + fallthrough; case MAP_PRIVATE: /* * Set pgoff according to addr for anon_vma. |