linux-next: manual merge of the kvm tree with the vfs-brauner tree

linux-next: manual merge of the kvm tree with the vfs-brauner tree

[Stephen Rothwell]

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Hi all,

Today's linux-next merge of the kvm tree got a conflict in:

  include/linux/pagemap.h

between commit:

  762321dab9a7 ("filemap: add a per-mapping stable writes flag")

from the vfs-brauner tree and commit:

  0003e2a41468 ("mm: Add AS_UNMOVABLE to mark mapping as completely unmovable")

from the kvm tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc include/linux/pagemap.h
index 06142ff7f9ce,bf2965b01b35..000000000000
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@@ -203,9 -203,8 +203,10 @@@ enum mapping_flags 
  	/* writeback related tags are not used */
  	AS_NO_WRITEBACK_TAGS = 5,
  	AS_LARGE_FOLIO_SUPPORT = 6,
- 	AS_RELEASE_ALWAYS,	/* Call ->release_folio(), even if no private data */
+ 	AS_RELEASE_ALWAYS = 7,	/* Call ->release_folio(), even if no private data */
+ 	AS_UNMOVABLE	= 8,	/* The mapping cannot be moved, ever */
 +	AS_STABLE_WRITES,	/* must wait for writeback before modifying
 +				   folio contents */
  };
  
  /**
@@@ -291,21 -290,22 +292,37 @@@ static inline void mapping_clear_releas
  	clear_bit(AS_RELEASE_ALWAYS, &mapping->flags);
  }
  
+ static inline void mapping_set_unmovable(struct address_space *mapping)
+ {
+ 	/*
+ 	 * It's expected unmovable mappings are also unevictable. Compaction
+ 	 * migrate scanner (isolate_migratepages_block()) relies on this to
+ 	 * reduce page locking.
+ 	 */
+ 	set_bit(AS_UNEVICTABLE, &mapping->flags);
+ 	set_bit(AS_UNMOVABLE, &mapping->flags);
+ }
+ 
+ static inline bool mapping_unmovable(struct address_space *mapping)
+ {
+ 	return test_bit(AS_UNMOVABLE, &mapping->flags);
+ }
+ 
 +static inline bool mapping_stable_writes(const struct address_space *mapping)
 +{
 +	return test_bit(AS_STABLE_WRITES, &mapping->flags);
 +}
 +
 +static inline void mapping_set_stable_writes(struct address_space *mapping)
 +{
 +	set_bit(AS_STABLE_WRITES, &mapping->flags);
 +}
 +
 +static inline void mapping_clear_stable_writes(struct address_space *mapping)
 +{
 +	clear_bit(AS_STABLE_WRITES, &mapping->flags);
 +}
 +
  static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
  {
  	return mapping->gfp_mask;

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Re: linux-next: manual merge of the kvm tree with the vfs-brauner tree

[Christoph Hellwig]

On Wed, Nov 22, 2023 at 12:55:39PM +1100, Stephen Rothwell wrote:
> index 06142ff7f9ce,bf2965b01b35..000000000000
> --- a/include/linux/pagemap.h
> +++ b/include/linux/pagemap.h
> @@@ -203,9 -203,8 +203,10 @@@ enum mapping_flags 
>   	/* writeback related tags are not used */
>   	AS_NO_WRITEBACK_TAGS = 5,
>   	AS_LARGE_FOLIO_SUPPORT = 6,
> - 	AS_RELEASE_ALWAYS,	/* Call ->release_folio(), even if no private data */
> + 	AS_RELEASE_ALWAYS = 7,	/* Call ->release_folio(), even if no private data */
> + 	AS_UNMOVABLE	= 8,	/* The mapping cannot be moved, ever */
>  +	AS_STABLE_WRITES,	/* must wait for writeback before modifying
>  +				   folio contents */
>   };

Note that AS_STABLE_WRITES, is a fix for 6.7, so this will probably
end up getting reordered.  It might also be worth to remove all the
explicit number assignments here to make the merge conflict resolution
a bit easier in the future.

Re: linux-next: manual merge of the kvm tree with the vfs-brauner tree

[Christian Brauner]

On Wed, Nov 22, 2023 at 08:10:40AM +0100, Christoph Hellwig wrote:
> On Wed, Nov 22, 2023 at 12:55:39PM +1100, Stephen Rothwell wrote:
> > index 06142ff7f9ce,bf2965b01b35..000000000000
> > --- a/include/linux/pagemap.h
> > +++ b/include/linux/pagemap.h
> > @@@ -203,9 -203,8 +203,10 @@@ enum mapping_flags 
> >   	/* writeback related tags are not used */
> >   	AS_NO_WRITEBACK_TAGS = 5,
> >   	AS_LARGE_FOLIO_SUPPORT = 6,
> > - 	AS_RELEASE_ALWAYS,	/* Call ->release_folio(), even if no private data */
> > + 	AS_RELEASE_ALWAYS = 7,	/* Call ->release_folio(), even if no private data */
> > + 	AS_UNMOVABLE	= 8,	/* The mapping cannot be moved, ever */
> >  +	AS_STABLE_WRITES,	/* must wait for writeback before modifying
> >  +				   folio contents */
> >   };
> 
> Note that AS_STABLE_WRITES, is a fix for 6.7, so this will probably

Yes, I plan on sending a fixes pr on Friday. I've wanted this in -next
for a few days.

Re: linux-next: manual merge of the kvm tree with the vfs-brauner tree

[Stephen Rothwell]

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Hi Christoph,

On Wed, 22 Nov 2023 08:10:40 +0100 Christoph Hellwig <hch@lst.de> wrote:
>
> On Wed, Nov 22, 2023 at 12:55:39PM +1100, Stephen Rothwell wrote:
> > index 06142ff7f9ce,bf2965b01b35..000000000000
> > --- a/include/linux/pagemap.h
> > +++ b/include/linux/pagemap.h
> > @@@ -203,9 -203,8 +203,10 @@@ enum mapping_flags 
> >   	/* writeback related tags are not used */
> >   	AS_NO_WRITEBACK_TAGS = 5,
> >   	AS_LARGE_FOLIO_SUPPORT = 6,
> > - 	AS_RELEASE_ALWAYS,	/* Call ->release_folio(), even if no private data */
> > + 	AS_RELEASE_ALWAYS = 7,	/* Call ->release_folio(), even if no private data */
> > + 	AS_UNMOVABLE	= 8,	/* The mapping cannot be moved, ever */
> >  +	AS_STABLE_WRITES,	/* must wait for writeback before modifying
> >  +				   folio contents */
> >   };  
> 
> Note that AS_STABLE_WRITES, is a fix for 6.7, so this will probably
> end up getting reordered.  It might also be worth to remove all the
> explicit number assignments here to make the merge conflict resolution
> a bit easier in the future.

Thanks, I will reorder them from today (and drop the numbering on the
added ones).

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: manual merge of the kvm tree with the vfs-brauner tree

[Stephen Rothwell]

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Hi all,

On Wed, 22 Nov 2023 12:55:39 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Today's linux-next merge of the kvm tree got a conflict in:
> 
>   include/linux/pagemap.h
> 
> between commit:
> 
>   762321dab9a7 ("filemap: add a per-mapping stable writes flag")

This is now in Linus' tree.

> from the vfs-brauner tree and commit:
> 
>   0003e2a41468 ("mm: Add AS_UNMOVABLE to mark mapping as completely unmovable")
> 
> from the kvm tree.
> 
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging.  You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.

The current resolution is below.

-- 
Cheers,
Stephen Rothwell

diff --cc include/linux/pagemap.h
index 06142ff7f9ce,bf2965b01b35..c2d90588c0bf
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@@ -203,9 -203,8 +203,10 @@@ enum mapping_flags 
  	/* writeback related tags are not used */
  	AS_NO_WRITEBACK_TAGS = 5,
  	AS_LARGE_FOLIO_SUPPORT = 6,
 -	AS_RELEASE_ALWAYS = 7,	/* Call ->release_folio(), even if no private data */
 -	AS_UNMOVABLE	= 8,	/* The mapping cannot be moved, ever */
 +	AS_RELEASE_ALWAYS,	/* Call ->release_folio(), even if no private data */
 +	AS_STABLE_WRITES,	/* must wait for writeback before modifying
 +				   folio contents */
++	AS_UNMOVABLE,		/* The mapping cannot be moved, ever */
  };
  
  /**
@@@ -291,21 -290,22 +292,37 @@@ static inline void mapping_clear_releas
  	clear_bit(AS_RELEASE_ALWAYS, &mapping->flags);
  }
  
+ static inline void mapping_set_unmovable(struct address_space *mapping)
+ {
+ 	/*
+ 	 * It's expected unmovable mappings are also unevictable. Compaction
+ 	 * migrate scanner (isolate_migratepages_block()) relies on this to
+ 	 * reduce page locking.
+ 	 */
+ 	set_bit(AS_UNEVICTABLE, &mapping->flags);
+ 	set_bit(AS_UNMOVABLE, &mapping->flags);
+ }
+ 
+ static inline bool mapping_unmovable(struct address_space *mapping)
+ {
+ 	return test_bit(AS_UNMOVABLE, &mapping->flags);
+ }
+ 
 +static inline bool mapping_stable_writes(const struct address_space *mapping)
 +{
 +	return test_bit(AS_STABLE_WRITES, &mapping->flags);
 +}
 +
 +static inline void mapping_set_stable_writes(struct address_space *mapping)
 +{
 +	set_bit(AS_STABLE_WRITES, &mapping->flags);
 +}
 +
 +static inline void mapping_clear_stable_writes(struct address_space *mapping)
 +{
 +	clear_bit(AS_STABLE_WRITES, &mapping->flags);
 +}
 +
  static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
  {
  	return mapping->gfp_mask;

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