X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;ds=sidebyside;f=mm%2Fmadvise.c;h=603c5257ed6efecaadde1e4047ec60ff1f22dfaa;hb=refs%2Fheads%2Fvserver;hp=4e196155a0c3635801bd0f8dcff0b18ce1bbcf37;hpb=43bc926fffd92024b46cafaf7350d669ba9ca884;p=linux-2.6.git

diff --git a/mm/madvise.c b/mm/madvise.c
index 4e196155a..603c5257e 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -155,10 +155,14 @@ static long madvise_dontneed(struct vm_area_struct * vma,
  * Other filesystems return -ENOSYS.
  */
 static long madvise_remove(struct vm_area_struct *vma,
+				struct vm_area_struct **prev,
 				unsigned long start, unsigned long end)
 {
 	struct address_space *mapping;
-        loff_t offset, endoff;
+	loff_t offset, endoff;
+	int error;
+
+	*prev = NULL;	/* tell sys_madvise we drop mmap_sem */
 
 	if (vma->vm_flags & (VM_LOCKED|VM_NONLINEAR|VM_HUGETLB))
 		return -EINVAL;
@@ -177,7 +181,12 @@ static long madvise_remove(struct vm_area_struct *vma,
 			+ ((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);
+
+	/* vmtruncate_range needs to take i_mutex and i_alloc_sem */
+	up_write(&current->mm->mmap_sem);
+	error = vmtruncate_range(mapping->host, offset, endoff);
+	down_write(&current->mm->mmap_sem);
+	return error;
 }
 
 static long
@@ -199,7 +208,7 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
 		error = madvise_behavior(vma, prev, start, end, behavior);
 		break;
 	case MADV_REMOVE:
-		error = madvise_remove(vma, start, end);
+		error = madvise_remove(vma, prev, start, end);
 		break;
 
 	case MADV_WILLNEED:
@@ -312,12 +321,15 @@ asmlinkage long sys_madvise(unsigned long start, size_t len_in, int behavior)
 		if (error)
 			goto out;
 		start = tmp;
-		if (start < prev->vm_end)
+		if (prev && start < prev->vm_end)
 			start = prev->vm_end;
 		error = unmapped_error;
 		if (start >= end)
 			goto out;
-		vma = prev->vm_next;
+		if (prev)
+			vma = prev->vm_next;
+		else	/* madvise_remove dropped mmap_sem */
+			vma = find_vma(current->mm, start);
 	}
 out:
 	up_write(&current->mm->mmap_sem);