X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=mm%2Fmadvise.c;h=4e196155a0c3635801bd0f8dcff0b18ce1bbcf37;hb=4a61f17378c2cdd9bd8f34ef8bd7422861d0c1f1;hp=c8c01a12fea43719b034e6f394d8d72faa1aea16;hpb=a2e30e529a48ef4e106e405f91cf4ae525bb01c4;p=powerpc.git

diff --git a/mm/madvise.c b/mm/madvise.c
index c8c01a12fe..4e196155a0 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -22,22 +22,29 @@ static long madvise_behavior(struct vm_area_struct * vma,
 	struct mm_struct * mm = vma->vm_mm;
 	int error = 0;
 	pgoff_t pgoff;
-	int new_flags = vma->vm_flags & ~VM_READHINTMASK;
+	int new_flags = vma->vm_flags;
 
 	switch (behavior) {
+	case MADV_NORMAL:
+		new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ;
+		break;
 	case MADV_SEQUENTIAL:
-		new_flags |= VM_SEQ_READ;
+		new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ;
 		break;
 	case MADV_RANDOM:
-		new_flags |= VM_RAND_READ;
+		new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ;
 		break;
-	default:
+	case MADV_DONTFORK:
+		new_flags |= VM_DONTCOPY;
+		break;
+	case MADV_DOFORK:
+		new_flags &= ~VM_DONTCOPY;
 		break;
 	}
 
 	if (new_flags == vma->vm_flags) {
 		*prev = vma;
-		goto success;
+		goto out;
 	}
 
 	pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
@@ -62,6 +69,7 @@ static long madvise_behavior(struct vm_area_struct * vma,
 			goto out;
 	}
 
+success:
 	/*
 	 * vm_flags is protected by the mmap_sem held in write mode.
 	 */
@@ -70,7 +78,6 @@ static long madvise_behavior(struct vm_area_struct * vma,
 out:
 	if (error == -ENOMEM)
 		error = -EAGAIN;
-success:
 	return error;
 }
 
@@ -83,6 +90,9 @@ static long madvise_willneed(struct vm_area_struct * vma,
 {
 	struct file *file = vma->vm_file;
 
+	if (!file)
+		return -EBADF;
+
 	if (file->f_mapping->a_ops->get_xip_page) {
 		/* no bad return value, but ignore advice */
 		return 0;
@@ -123,7 +133,7 @@ static long madvise_dontneed(struct vm_area_struct * vma,
 			     unsigned long start, unsigned long end)
 {
 	*prev = vma;
-	if ((vma->vm_flags & VM_LOCKED) || is_vm_hugetlb_page(vma))
+	if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP))
 		return -EINVAL;
 
 	if (unlikely(vma->vm_flags & VM_NONLINEAR)) {
@@ -137,22 +147,60 @@ static long madvise_dontneed(struct vm_area_struct * vma,
 	return 0;
 }
 
+/*
+ * Application wants to free up the pages and associated backing store.
+ * This is effectively punching a hole into the middle of a file.
+ *
+ * NOTE: Currently, only shmfs/tmpfs is supported for this operation.
+ * Other filesystems return -ENOSYS.
+ */
+static long madvise_remove(struct vm_area_struct *vma,
+				unsigned long start, unsigned long end)
+{
+	struct address_space *mapping;
+        loff_t offset, endoff;
+
+	if (vma->vm_flags & (VM_LOCKED|VM_NONLINEAR|VM_HUGETLB))
+		return -EINVAL;
+
+	if (!vma->vm_file || !vma->vm_file->f_mapping
+		|| !vma->vm_file->f_mapping->host) {
+			return -EINVAL;
+	}
+
+	if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE))
+		return -EACCES;
+
+	mapping = vma->vm_file->f_mapping;
+
+	offset = (loff_t)(start - vma->vm_start)
+			+ ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
+	endoff = (loff_t)(end - vma->vm_start - 1)
+			+ ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
+	return  vmtruncate_range(mapping->host, offset, endoff);
+}
+
 static long
 madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
 		unsigned long start, unsigned long end, int behavior)
 {
-	struct file *filp = vma->vm_file;
-	long error = -EBADF;
-
-	if (!filp)
-		goto  out;
+	long error;
 
 	switch (behavior) {
+	case MADV_DOFORK:
+		if (vma->vm_flags & VM_IO) {
+			error = -EINVAL;
+			break;
+		}
+	case MADV_DONTFORK:
 	case MADV_NORMAL:
 	case MADV_SEQUENTIAL:
 	case MADV_RANDOM:
 		error = madvise_behavior(vma, prev, start, end, behavior);
 		break;
+	case MADV_REMOVE:
+		error = madvise_remove(vma, start, end);
+		break;
 
 	case MADV_WILLNEED:
 		error = madvise_willneed(vma, prev, start, end);
@@ -166,8 +214,6 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
 		error = -EINVAL;
 		break;
 	}
-		
-out:
 	return error;
 }
 
@@ -193,6 +239,8 @@ out:
  *		some pages ahead.
  *  MADV_DONTNEED - the application is finished with the given range,
  *		so the kernel can free resources associated with it.
+ *  MADV_REMOVE - the application wants to free up the given range of
+ *		pages and associated backing store.
  *
  * return values:
  *  zero    - success
@@ -237,8 +285,9 @@ asmlinkage long sys_madvise(unsigned long start, size_t len_in, int behavior)
 	 * - different from the way of handling in mlock etc.
 	 */
 	vma = find_vma_prev(current->mm, start, &prev);
-	if (!vma && prev)
-		vma = prev->vm_next;
+	if (vma && start > vma->vm_start)
+		prev = vma;
+
 	for (;;) {
 		/* Still start < end. */
 		error = -ENOMEM;