mm: kill vma flag VM_RESERVED and mm->reserved_vm counter

A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA,
currently it lost original meaning but still has some effects:

 | effect                 | alternative flags
-+------------------------+---------------------------------------------
1| account as reserved_vm | VM_IO
2| skip in core dump      | VM_IO, VM_DONTDUMP
3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP
4| do not mlock           | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP

This patch removes reserved_vm counter from mm_struct.  Seems like nobody
cares about it, it does not exported into userspace directly, it only
reduces total_vm showed in proc.

Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP.

remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP.
remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP.

[[email protected]: drivers/vfio/pci/vfio_pci.c fixup]
Signed-off-by: Konstantin Khlebnikov <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Carsten Otte <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Cyrill Gorcunov <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Morris <[email protected]>
Cc: Jason Baron <[email protected]>
Cc: Kentaro Takeda <[email protected]>
Cc: Matt Helsley <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Robert Richter <[email protected]>
Cc: Suresh Siddha <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Venkatesh Pallipadi <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

drivers/media/pci/meye/meye.c

@@ -1647,7 +1647,7 @@ static int meye_mmap(struct file *file, struct vm_area_struct *vma)
 
 	vma->vm_ops = &meye_vm_ops;
 	vma->vm_flags &= ~VM_IO;	/* not I/O memory */
-	vma->vm_flags |= VM_RESERVED;	/* avoid to swap out this VMA */
+	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 	vma->vm_private_data = (void *) (offset / gbufsize);
 	meye_vm_open(vma);
 

drivers/media/platform/omap/omap_vout.c

@@ -911,7 +911,7 @@ static int omap_vout_mmap(struct file *file, struct vm_area_struct *vma)
 
 	q->bufs[i]->baddr = vma->vm_start;
 
-	vma->vm_flags |= VM_RESERVED;
+	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 	vma->vm_ops = &omap_vout_vm_ops;
 	vma->vm_private_data = (void *) vout;

drivers/media/platform/vino.c

@@ -3950,7 +3950,7 @@ found:
 
 	fb->map_count = 1;
 
-	vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
+	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 	vma->vm_flags &= ~VM_IO;
 	vma->vm_private_data = fb;
 	vma->vm_file = file;

drivers/media/usb/sn9c102/sn9c102_core.c

@@ -2126,8 +2126,7 @@ static int sn9c102_mmap(struct file* filp, struct vm_area_struct *vma)
 		return -EINVAL;
 	}
 
-	vma->vm_flags |= VM_IO;
-	vma->vm_flags |= VM_RESERVED;
+	vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
 
 	pos = cam->frame[i].bufmem;
 	while (size > 0) { /* size is page-aligned */

drivers/media/usb/usbvision/usbvision-video.c

@@ -1108,8 +1108,7 @@ static int usbvision_mmap(struct file *file, struct vm_area_struct *vma)
 	}
 
 	/* VM_IO is eventually going to replace PageReserved altogether */
-	vma->vm_flags |= VM_IO;
-	vma->vm_flags |= VM_RESERVED;	/* avoid to swap out this VMA */
+	vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
 
 	pos = usbvision->frame[i].data;
 	while (size > 0) {

drivers/media/v4l2-core/videobuf-dma-sg.c

@@ -582,7 +582,7 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
 	map->count    = 1;
 	map->q        = q;
 	vma->vm_ops   = &videobuf_vm_ops;
-	vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
+	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 	vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */
 	vma->vm_private_data = map;
 	dprintk(1, "mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n",

drivers/media/v4l2-core/videobuf-vmalloc.c

@@ -270,7 +270,7 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
 	}
 
 	vma->vm_ops          = &videobuf_vm_ops;
-	vma->vm_flags       |= VM_DONTEXPAND | VM_RESERVED;
+	vma->vm_flags       |= VM_DONTEXPAND | VM_DONTDUMP;
 	vma->vm_private_data = map;
 
 	dprintk(1, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",

drivers/media/v4l2-core/videobuf2-memops.c

@@ -163,7 +163,7 @@ int vb2_mmap_pfn_range(struct vm_area_struct *vma, unsigned long paddr,
 		return ret;
 	}
 
-	vma->vm_flags		|= VM_DONTEXPAND | VM_RESERVED;
+	vma->vm_flags		|= VM_DONTEXPAND | VM_DONTDUMP;
 	vma->vm_private_data	= priv;
 	vma->vm_ops		= vm_ops;