[PATCH 0/1] mm: move ->mremap() from file_operations to vm_operations_struct

[PATCH 0/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Oleg Nesterov]

On 06/22, Andy Lutomirski wrote:
>
> On Mon, Jun 22, 2015 at 5:47 PM, Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > I never understood why ->mremap() lives in file_operations, not in
> > vm_operations_struct. To me vma->vm_file->f_op in move_vma() just
> > looks strange, vma->vm_ops->mremap(new_vma) looks "obviously better".
> >
> > And afaics more useful. CRIU remaps vdso, but this does not update
> > mm->context.vdso. OK, probably this does not matter currently, CRIU
> > can't c/r the compat tasks, and 64-bit apps do not use context.vdso.
> > Afaics. Still, I think we might want to have special_mapping_remap()
> > and we can't do this because ->vm_file == NULL.
>
> I would like this.  Then I could clean up and resubmit my patch to
> keep context.vdso up to date.

Cough... where can I find this patch ? ;)

> Oleg, can you let me know what patch, if any, I should be reviewing?

This one, it looks really trivial. And of course I will appreciate it
if you can review the special_mapping_fault() fixes.

The change in move_vma() textually depends on another patch I sent,

	[PATCH 1/4] mremap: don't leak new_vma if f_op->mremap() fails
	http://marc.info/?l=linux-kernel&m=143475603713622

Oleg.

[PATCH 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Oleg Nesterov]

vma->vm_ops->mremap() looks more natural and clean in move_vma(),
and this way ->mremap() can have more users. Say, vdso.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 fs/aio.c           |   25 ++++++++++++++++---------
 include/linux/fs.h |    1 -
 include/linux/mm.h |    1 +
 mm/mremap.c        |    4 ++--
 4 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 9bc1335..6fe662a 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -308,15 +308,9 @@ static void aio_free_ring(struct kioctx *ctx)
 	}
 }
 
-static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
-{
-	vma->vm_flags |= VM_DONTEXPAND;
-	vma->vm_ops = &generic_file_vm_ops;
-	return 0;
-}
-
-static int aio_ring_remap(struct file *file, struct vm_area_struct *vma)
+static int aio_ring_remap(struct vm_area_struct *vma)
 {
+	struct file *file = vma->vm_file;
 	struct mm_struct *mm = vma->vm_mm;
 	struct kioctx_table *table;
 	int i, res = -EINVAL;
@@ -339,9 +333,22 @@ static int aio_ring_remap(struct file *file, struct vm_area_struct *vma)
 	return res;
 }
 
+static const struct vm_operations_struct aio_ring_vm_ops = {
+	.mremap		= aio_ring_remap,
+	.fault		= filemap_fault,
+	.map_pages	= filemap_map_pages,
+	.page_mkwrite	= filemap_page_mkwrite,
+};
+
+static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	vma->vm_flags |= VM_DONTEXPAND;
+	vma->vm_ops = &aio_ring_vm_ops;
+	return 0;
+}
+
 static const struct file_operations aio_ring_fops = {
 	.mmap = aio_ring_mmap,
-	.mremap = aio_ring_remap,
 };
 
 #if IS_ENABLED(CONFIG_MIGRATION)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 35ec87e..42aac09 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1582,7 +1582,6 @@ struct file_operations {
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
 	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
 	int (*mmap) (struct file *, struct vm_area_struct *);
-	int (*mremap)(struct file *, struct vm_area_struct *);
 	int (*open) (struct inode *, struct file *);
 	int (*flush) (struct file *, fl_owner_t id);
 	int (*release) (struct inode *, struct file *);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a0fe3d3..0295b4a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -244,6 +244,7 @@ struct vm_fault {
 struct vm_operations_struct {
 	void (*open)(struct vm_area_struct * area);
 	void (*close)(struct vm_area_struct * area);
+	int (*mremap)(struct vm_area_struct * area);
 	int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
 	void (*map_pages)(struct vm_area_struct *vma, struct vm_fault *vmf);
 
diff --git a/mm/mremap.c b/mm/mremap.c
index ed1b13a..aeba807 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -276,8 +276,8 @@ static unsigned long move_vma(struct vm_area_struct *vma,
 				     need_rmap_locks);
 	if (moved_len < old_len) {
 		err = -ENOMEM;
-	} else if (vma->vm_file && vma->vm_file->f_op->mremap) {
-		err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
+	} else if (vma->vm_ops && vma->vm_ops->mremap) {
+		err = vma->vm_ops->mremap(new_vma);
 	}
 
 	if (unlikely(err)) {
-- 
1.5.5.1

Re: [PATCH 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Kirill A. Shutemov]

On Tue, Jun 23, 2015 at 08:02:51PM +0200, Oleg Nesterov wrote:
> vma->vm_ops->mremap() looks more natural and clean in move_vma(),
> and this way ->mremap() can have more users. Say, vdso.
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> ---
>  fs/aio.c           |   25 ++++++++++++++++---------
>  include/linux/fs.h |    1 -
>  include/linux/mm.h |    1 +
>  mm/mremap.c        |    4 ++--

Please, update Documentation/filesystems/Locking.

>  4 files changed, 19 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/aio.c b/fs/aio.c
> index 9bc1335..6fe662a 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -308,15 +308,9 @@ static void aio_free_ring(struct kioctx *ctx)
>  	}
>  }
>  
> -static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
> -{
> -	vma->vm_flags |= VM_DONTEXPAND;
> -	vma->vm_ops = &generic_file_vm_ops;
> -	return 0;
> -}
> -
> -static int aio_ring_remap(struct file *file, struct vm_area_struct *vma)
> +static int aio_ring_remap(struct vm_area_struct *vma)

I guess aio_ring_mremap() would be a better name.

>  {
> +	struct file *file = vma->vm_file;
>  	struct mm_struct *mm = vma->vm_mm;
>  	struct kioctx_table *table;
>  	int i, res = -EINVAL;
-- 
 Kirill A. Shutemov

Re: [PATCH 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Oleg Nesterov]

On 06/23, Kirill A. Shutemov wrote:
>
> On Tue, Jun 23, 2015 at 08:02:51PM +0200, Oleg Nesterov wrote:
> > vma->vm_ops->mremap() looks more natural and clean in move_vma(),
> > and this way ->mremap() can have more users. Say, vdso.
> >
> > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> > ---
> >  fs/aio.c           |   25 ++++++++++++++++---------
> >  include/linux/fs.h |    1 -
> >  include/linux/mm.h |    1 +
> >  mm/mremap.c        |    4 ++--
>
> Please, update Documentation/filesystems/Locking.

OK, thanks, will do.

> > -static int aio_ring_remap(struct file *file, struct vm_area_struct *vma)
> > +static int aio_ring_remap(struct vm_area_struct *vma)
>
> I guess aio_ring_mremap() would be a better name.

Yes, agreed.

OK, I'll wait for other comments then send v2 with these changes.

Oleg.

Re: [PATCH 0/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Andy Lutomirski]

On Tue, Jun 23, 2015 at 11:02 AM, Oleg Nesterov <oleg@redhat.com> wrote:
> On 06/22, Andy Lutomirski wrote:
>>
>> On Mon, Jun 22, 2015 at 5:47 PM, Oleg Nesterov <oleg@redhat.com> wrote:
>> >
>> > I never understood why ->mremap() lives in file_operations, not in
>> > vm_operations_struct. To me vma->vm_file->f_op in move_vma() just
>> > looks strange, vma->vm_ops->mremap(new_vma) looks "obviously better".
>> >
>> > And afaics more useful. CRIU remaps vdso, but this does not update
>> > mm->context.vdso. OK, probably this does not matter currently, CRIU
>> > can't c/r the compat tasks, and 64-bit apps do not use context.vdso.
>> > Afaics. Still, I think we might want to have special_mapping_remap()
>> > and we can't do this because ->vm_file == NULL.
>>
>> I would like this.  Then I could clean up and resubmit my patch to
>> keep context.vdso up to date.
>
> Cough... where can I find this patch ? ;)
>

https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/log/?h=vdso/vma_tracking

--Andy

Re: [PATCH 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Andy Lutomirski]

On Tue, Jun 23, 2015 at 11:02 AM, Oleg Nesterov <oleg@redhat.com> wrote:
> vma->vm_ops->mremap() looks more natural and clean in move_vma(),
> and this way ->mremap() can have more users. Say, vdso.
>

Looks generally reasonable.

--Andy

Re: [PATCH 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Pavel Emelyanov]

On 06/23/2015 09:02 PM, Oleg Nesterov wrote:
> vma->vm_ops->mremap() looks more natural and clean in move_vma(),
> and this way ->mremap() can have more users. Say, vdso.
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Looks-good-to: /me :) Thanks!

Re: [PATCH 0/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Oleg Nesterov]

On 06/23, Andy Lutomirski wrote:
>
> On Tue, Jun 23, 2015 at 11:02 AM, Oleg Nesterov <oleg@redhat.com> wrote:
> > On 06/22, Andy Lutomirski wrote:
> >>
> >> On Mon, Jun 22, 2015 at 5:47 PM, Oleg Nesterov <oleg@redhat.com> wrote:
> >> >
> >> > I never understood why ->mremap() lives in file_operations, not in
> >> > vm_operations_struct. To me vma->vm_file->f_op in move_vma() just
> >> > looks strange, vma->vm_ops->mremap(new_vma) looks "obviously better".
> >> >
> >> > And afaics more useful. CRIU remaps vdso, but this does not update
> >> > mm->context.vdso. OK, probably this does not matter currently, CRIU
> >> > can't c/r the compat tasks, and 64-bit apps do not use context.vdso.
> >> > Afaics. Still, I think we might want to have special_mapping_remap()
> >> > and we can't do this because ->vm_file == NULL.
> >>
> >> I would like this.  Then I could clean up and resubmit my patch to
> >> keep context.vdso up to date.
> >
> > Cough... where can I find this patch ? ;)
> >
>
> https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/log/?h=vdso/vma_tracking

Aha, thanks. So yes, looks like your "Add a mechanism to track the current
address of a special mapping" can rely on vm_ops->mremap().

Oleg.

Re: [PATCH 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Oleg Nesterov]

On 06/23, Oleg Nesterov wrote:
>
> On 06/23, Kirill A. Shutemov wrote:
> >
> > On Tue, Jun 23, 2015 at 08:02:51PM +0200, Oleg Nesterov wrote:
> > > vma->vm_ops->mremap() looks more natural and clean in move_vma(),
> > > and this way ->mremap() can have more users. Say, vdso.
> > >
> > > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> > > ---
> > >  fs/aio.c           |   25 ++++++++++++++++---------
> > >  include/linux/fs.h |    1 -
> > >  include/linux/mm.h |    1 +
> > >  mm/mremap.c        |    4 ++--
> >
> > Please, update Documentation/filesystems/Locking.
>
> OK, thanks, will do.

Wait... Documentation/filesystems/Locking doesn't mention
->mremap() at all.

So you actually ask me to add the new documentation? ;)

Oh well... OK, I'll try if you think this is necessary.

I tried to make the minimal change before ->mremap() finds another
user in file_operations. I thinks it needs more arguments, at least
new_addr and new_len, otherwise it is not easy to document it. The
same for f_op->mremap() of course.

Currently this does not matter, the only user is aio.c and
VM_DONTEXPAND means that it is not mergeable, so mremap() always
creates the new vma.

Hmm. Can't we do this change and add the documentation later?

Oleg.

Re: [PATCH 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Kirill A. Shutemov]

On Wed, Jun 24, 2015 at 05:49:14PM +0200, Oleg Nesterov wrote:
> On 06/23, Oleg Nesterov wrote:
> >
> > On 06/23, Kirill A. Shutemov wrote:
> > >
> > > On Tue, Jun 23, 2015 at 08:02:51PM +0200, Oleg Nesterov wrote:
> > > > vma->vm_ops->mremap() looks more natural and clean in move_vma(),
> > > > and this way ->mremap() can have more users. Say, vdso.
> > > >
> > > > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> > > > ---
> > > >  fs/aio.c           |   25 ++++++++++++++++---------
> > > >  include/linux/fs.h |    1 -
> > > >  include/linux/mm.h |    1 +
> > > >  mm/mremap.c        |    4 ++--
> > >
> > > Please, update Documentation/filesystems/Locking.
> >
> > OK, thanks, will do.
> 
> Wait... Documentation/filesystems/Locking doesn't mention
> ->mremap() at all.
> 
> So you actually ask me to add the new documentation? ;)

I tried ;)

> Oh well... OK, I'll try if you think this is necessary.
> 
> I tried to make the minimal change before ->mremap() finds another
> user in file_operations. I thinks it needs more arguments, at least
> new_addr and new_len, otherwise it is not easy to document it. The
> same for f_op->mremap() of course.
> 
> Currently this does not matter, the only user is aio.c and
> VM_DONTEXPAND means that it is not mergeable, so mremap() always
> creates the new vma.
> 
> Hmm. Can't we do this change and add the documentation later?

I'm fine with that.

-- 
 Kirill A. Shutemov

Re: [PATCH 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Oleg Nesterov]

On 06/24, Kirill A. Shutemov wrote:
>
> On Wed, Jun 24, 2015 at 05:49:14PM +0200, Oleg Nesterov wrote:
> >
> > Wait... Documentation/filesystems/Locking doesn't mention
> > ->mremap() at all.
> >
> > So you actually ask me to add the new documentation? ;)
>
> I tried ;)

Understand ;) but I failed to do this. Serisouly, I simply don't
know what can I add into this (outadted anyway) section except
"called when move_page_tables() targets this vma".

> > I tried to make the minimal change before ->mremap() finds another
> > user in file_operations. I thinks it needs more arguments, at least
> > new_addr and new_len, otherwise it is not easy to document it. The
> > same for f_op->mremap() of course.
> >
> > Currently this does not matter, the only user is aio.c and
> > VM_DONTEXPAND means that it is not mergeable, so mremap() always
> > creates the new vma.
> >
> > Hmm. Can't we do this change and add the documentation later?
>
> I'm fine with that.

OK, so I am sending v2 with the only change: rename aio_ring_remap
to aio_ring_mremap as you suggested.

Oleg.

[PATCH v2 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Oleg Nesterov]

vma->vm_ops->mremap() looks more natural and clean in move_vma(),
and this way ->mremap() can have more users. Say, vdso.

While at it, s/aio_ring_remap/aio_ring_mremap/.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 fs/aio.c           |   25 ++++++++++++++++---------
 include/linux/fs.h |    1 -
 include/linux/mm.h |    1 +
 mm/mremap.c        |    4 ++--
 4 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 9bc1335..a632f14 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -308,15 +308,9 @@ static void aio_free_ring(struct kioctx *ctx)
 	}
 }
 
-static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
-{
-	vma->vm_flags |= VM_DONTEXPAND;
-	vma->vm_ops = &generic_file_vm_ops;
-	return 0;
-}
-
-static int aio_ring_remap(struct file *file, struct vm_area_struct *vma)
+static int aio_ring_mremap(struct vm_area_struct *vma)
 {
+	struct file *file = vma->vm_file;
 	struct mm_struct *mm = vma->vm_mm;
 	struct kioctx_table *table;
 	int i, res = -EINVAL;
@@ -339,9 +333,22 @@ static int aio_ring_remap(struct file *file, struct vm_area_struct *vma)
 	return res;
 }
 
+static const struct vm_operations_struct aio_ring_vm_ops = {
+	.mremap		= aio_ring_mremap,
+	.fault		= filemap_fault,
+	.map_pages	= filemap_map_pages,
+	.page_mkwrite	= filemap_page_mkwrite,
+};
+
+static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	vma->vm_flags |= VM_DONTEXPAND;
+	vma->vm_ops = &aio_ring_vm_ops;
+	return 0;
+}
+
 static const struct file_operations aio_ring_fops = {
 	.mmap = aio_ring_mmap,
-	.mremap = aio_ring_remap,
 };
 
 #if IS_ENABLED(CONFIG_MIGRATION)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 35ec87e..42aac09 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1582,7 +1582,6 @@ struct file_operations {
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
 	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
 	int (*mmap) (struct file *, struct vm_area_struct *);
-	int (*mremap)(struct file *, struct vm_area_struct *);
 	int (*open) (struct inode *, struct file *);
 	int (*flush) (struct file *, fl_owner_t id);
 	int (*release) (struct inode *, struct file *);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a0fe3d3..0295b4a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -244,6 +244,7 @@ struct vm_fault {
 struct vm_operations_struct {
 	void (*open)(struct vm_area_struct * area);
 	void (*close)(struct vm_area_struct * area);
+	int (*mremap)(struct vm_area_struct * area);
 	int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
 	void (*map_pages)(struct vm_area_struct *vma, struct vm_fault *vmf);
 
diff --git a/mm/mremap.c b/mm/mremap.c
index ed1b13a..aeba807 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -276,8 +276,8 @@ static unsigned long move_vma(struct vm_area_struct *vma,
 				     need_rmap_locks);
 	if (moved_len < old_len) {
 		err = -ENOMEM;
-	} else if (vma->vm_file && vma->vm_file->f_op->mremap) {
-		err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
+	} else if (vma->vm_ops && vma->vm_ops->mremap) {
+		err = vma->vm_ops->mremap(new_vma);
 	}
 
 	if (unlikely(err)) {
-- 
1.5.5.1

Re: [PATCH v2 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Kirill A. Shutemov]

On Thu, Jun 25, 2015 at 10:45:04PM +0200, Oleg Nesterov wrote:
> vma->vm_ops->mremap() looks more natural and clean in move_vma(),
> and this way ->mremap() can have more users. Say, vdso.
> 
> While at it, s/aio_ring_remap/aio_ring_mremap/.
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> ---
>  fs/aio.c           |   25 ++++++++++++++++---------
>  include/linux/fs.h |    1 -
>  include/linux/mm.h |    1 +
>  mm/mremap.c        |    4 ++--
>  4 files changed, 19 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/aio.c b/fs/aio.c
> index 9bc1335..a632f14 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -308,15 +308,9 @@ static void aio_free_ring(struct kioctx *ctx)
>  	}
>  }
>  
> -static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
> -{
> -	vma->vm_flags |= VM_DONTEXPAND;
> -	vma->vm_ops = &generic_file_vm_ops;
> -	return 0;
> -}
> -
> -static int aio_ring_remap(struct file *file, struct vm_area_struct *vma)
> +static int aio_ring_mremap(struct vm_area_struct *vma)
>  {
> +	struct file *file = vma->vm_file;
>  	struct mm_struct *mm = vma->vm_mm;
>  	struct kioctx_table *table;
>  	int i, res = -EINVAL;
> @@ -339,9 +333,22 @@ static int aio_ring_remap(struct file *file, struct vm_area_struct *vma)
>  	return res;
>  }
>  
> +static const struct vm_operations_struct aio_ring_vm_ops = {
> +	.mremap		= aio_ring_mremap,
> +	.fault		= filemap_fault,
> +	.map_pages	= filemap_map_pages,
> +	.page_mkwrite	= filemap_page_mkwrite,
> +};
> +
> +static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
> +{
> +	vma->vm_flags |= VM_DONTEXPAND;
> +	vma->vm_ops = &aio_ring_vm_ops;
> +	return 0;
> +}
> +
>  static const struct file_operations aio_ring_fops = {
>  	.mmap = aio_ring_mmap,
> -	.mremap = aio_ring_remap,
>  };
>  
>  #if IS_ENABLED(CONFIG_MIGRATION)
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 35ec87e..42aac09 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1582,7 +1582,6 @@ struct file_operations {
>  	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
>  	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
>  	int (*mmap) (struct file *, struct vm_area_struct *);
> -	int (*mremap)(struct file *, struct vm_area_struct *);
>  	int (*open) (struct inode *, struct file *);
>  	int (*flush) (struct file *, fl_owner_t id);
>  	int (*release) (struct inode *, struct file *);
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index a0fe3d3..0295b4a 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -244,6 +244,7 @@ struct vm_fault {
>  struct vm_operations_struct {
>  	void (*open)(struct vm_area_struct * area);
>  	void (*close)(struct vm_area_struct * area);
> +	int (*mremap)(struct vm_area_struct * area);
>  	int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
>  	void (*map_pages)(struct vm_area_struct *vma, struct vm_fault *vmf);
>  
> diff --git a/mm/mremap.c b/mm/mremap.c
> index ed1b13a..aeba807 100644
> --- a/mm/mremap.c
> +++ b/mm/mremap.c
> @@ -276,8 +276,8 @@ static unsigned long move_vma(struct vm_area_struct *vma,
>  				     need_rmap_locks);
>  	if (moved_len < old_len) {
>  		err = -ENOMEM;
> -	} else if (vma->vm_file && vma->vm_file->f_op->mremap) {
> -		err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
> +	} else if (vma->vm_ops && vma->vm_ops->mremap) {
> +		err = vma->vm_ops->mremap(new_vma);
>  	}
>  
>  	if (unlikely(err)) {

I'm not sure what is target tree for the patch. Last hunk is not going to
apply on Linus' tree or -next. Hm?

Otherwise, looks good.

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

-- 
 Kirill A. Shutemov

Re: [PATCH v2 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Oleg Nesterov]

On 06/26, Kirill A. Shutemov wrote:
>
> > --- a/mm/mremap.c
> > +++ b/mm/mremap.c
> > @@ -276,8 +276,8 @@ static unsigned long move_vma(struct vm_area_struct *vma,
> >  				     need_rmap_locks);
> >  	if (moved_len < old_len) {
> >  		err = -ENOMEM;
> > -	} else if (vma->vm_file && vma->vm_file->f_op->mremap) {
> > -		err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
> > +	} else if (vma->vm_ops && vma->vm_ops->mremap) {
> > +		err = vma->vm_ops->mremap(new_vma);
> >  	}
> >
> >  	if (unlikely(err)) {
>
> I'm not sure what is target tree for the patch.

I hope akpm can take this patch into -mm,

> Last hunk is not going to
> apply on Linus' tree or -next. Hm?

Yes, this depends on another fix I sent to Andrew (and you ;), as 0/1
explains the change in move_vma() textually depends on another patch I sent,

	[PATCH 1/4] mremap: don't leak new_vma if f_op->mremap() fails
	http://marc.info/?l=linux-kernel&m=143475603713622

> Otherwise, looks good.
>
> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Thanks!

Oleg.

Re: [PATCH v2 1/1] mm: move ->mremap() from file_operations to vm_operations_struct

[Pavel Emelyanov]

On 06/25/2015 11:45 PM, Oleg Nesterov wrote:
> vma->vm_ops->mremap() looks more natural and clean in move_vma(),
> and this way ->mremap() can have more users. Say, vdso.
> 
> While at it, s/aio_ring_remap/aio_ring_mremap/.
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Acked-by: Pavel Emelyanov <xemul@parallels.com>