diff mbox series

[v9,8/8] xfs: Add dax dedupe support

Message ID 20210915104501.4146910-9-ruansy.fnst@fujitsu.com (mailing list archive)
State Superseded
Headers show
Series fsdax,xfs: Add reflink&dedupe support for fsdax | expand

Commit Message

Shiyang Ruan Sept. 15, 2021, 10:45 a.m. UTC
Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files
who are going to be deduped.  After that, call compare range function
only when files are both DAX or not.

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_file.c    |  2 +-
 fs/xfs/xfs_inode.c   | 80 +++++++++++++++++++++++++++++++++++++++++---
 fs/xfs/xfs_inode.h   |  1 +
 fs/xfs/xfs_reflink.c |  4 +--
 4 files changed, 80 insertions(+), 7 deletions(-)

Comments

Darrick J. Wong Sept. 16, 2021, 12:30 a.m. UTC | #1
On Wed, Sep 15, 2021 at 06:45:01PM +0800, Shiyang Ruan wrote:
> Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files
> who are going to be deduped.  After that, call compare range function
> only when files are both DAX or not.
> 
> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_file.c    |  2 +-
>  fs/xfs/xfs_inode.c   | 80 +++++++++++++++++++++++++++++++++++++++++---
>  fs/xfs/xfs_inode.h   |  1 +
>  fs/xfs/xfs_reflink.c |  4 +--
>  4 files changed, 80 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 2ef1930374d2..c3061723613c 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -846,7 +846,7 @@ xfs_wait_dax_page(
>  	xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
>  }
>  
> -static int
> +int
>  xfs_break_dax_layouts(
>  	struct inode		*inode,
>  	bool			*retry)
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index a4f6f034fb81..bdc084cdbf46 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -3790,6 +3790,61 @@ xfs_iolock_two_inodes_and_break_layout(
>  	return 0;
>  }
>  
> +static int
> +xfs_mmaplock_two_inodes_and_break_dax_layout(
> +	struct xfs_inode	*ip1,
> +	struct xfs_inode	*ip2)
> +{
> +	int			error, attempts = 0;
> +	bool			retry;
> +	struct page		*page;
> +	struct xfs_log_item	*lp;
> +
> +	if (ip1->i_ino > ip2->i_ino)
> +		swap(ip1, ip2);
> +
> +again:
> +	retry = false;
> +	/* Lock the first inode */
> +	xfs_ilock(ip1, XFS_MMAPLOCK_EXCL);
> +	error = xfs_break_dax_layouts(VFS_I(ip1), &retry);
> +	if (error || retry) {
> +		xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
> +		if (error == 0 && retry)
> +			goto again;
> +		return error;
> +	}
> +
> +	if (ip1 == ip2)
> +		return 0;
> +
> +	/* Nested lock the second inode */
> +	lp = &ip1->i_itemp->ili_item;
> +	if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) {
> +		if (!xfs_ilock_nowait(ip2,
> +		    xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1))) {
> +			xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
> +			if ((++attempts % 5) == 0)
> +				delay(1); /* Don't just spin the CPU */
> +			goto again;
> +		}

I suspect we don't need this part for grabbing the MMAPLOCK^W pagecache
invalidatelock.  The AIL only grabs the ILOCK, never the IOLOCK or the
MMAPLOCK.

> +	} else
> +		xfs_ilock(ip2, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1));
> +	/*
> +	 * We cannot use xfs_break_dax_layouts() directly here because it may
> +	 * need to unlock & lock the XFS_MMAPLOCK_EXCL which is not suitable
> +	 * for this nested lock case.
> +	 */
> +	page = dax_layout_busy_page(VFS_I(ip2)->i_mapping);
> +	if (page && page_ref_count(page) != 1) {

Do you think the patch "ext4/xfs: add page refcount helper" would be a
good cleanup to head this series?

https://lore.kernel.org/linux-xfs/20210913161604.31981-1-alex.sierra@amd.com/T/#m59cf7cd5c0d521ad487fa3a15d31c3865db88bdf

The rest of the logic looks ok.

--D

> +		xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
> +		xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
> +		goto again;
> +	}
> +
> +	return 0;
> +}
> +
>  /*
>   * Lock two inodes so that userspace cannot initiate I/O via file syscalls or
>   * mmap activity.
> @@ -3804,8 +3859,19 @@ xfs_ilock2_io_mmap(
>  	ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
>  	if (ret)
>  		return ret;
> -	filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
> -				    VFS_I(ip2)->i_mapping);
> +
> +	if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
> +		ret = xfs_mmaplock_two_inodes_and_break_dax_layout(ip1, ip2);
> +		if (ret) {
> +			inode_unlock(VFS_I(ip2));
> +			if (ip1 != ip2)
> +				inode_unlock(VFS_I(ip1));
> +			return ret;
> +		}
> +	} else
> +		filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
> +					    VFS_I(ip2)->i_mapping);
> +
>  	return 0;
>  }
>  
> @@ -3815,8 +3881,14 @@ xfs_iunlock2_io_mmap(
>  	struct xfs_inode	*ip1,
>  	struct xfs_inode	*ip2)
>  {
> -	filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
> -				      VFS_I(ip2)->i_mapping);
> +	if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
> +		xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
> +		if (ip1 != ip2)
> +			xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
> +	} else
> +		filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
> +					      VFS_I(ip2)->i_mapping);
> +
>  	inode_unlock(VFS_I(ip2));
>  	if (ip1 != ip2)
>  		inode_unlock(VFS_I(ip1));
> diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> index b21b177832d1..f7e26fe31a26 100644
> --- a/fs/xfs/xfs_inode.h
> +++ b/fs/xfs/xfs_inode.h
> @@ -472,6 +472,7 @@ enum xfs_prealloc_flags {
>  
>  int	xfs_update_prealloc_flags(struct xfs_inode *ip,
>  				  enum xfs_prealloc_flags flags);
> +int	xfs_break_dax_layouts(struct inode *inode, bool *retry);
>  int	xfs_break_layouts(struct inode *inode, uint *iolock,
>  		enum layout_break_reason reason);
>  
> diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> index 9d876e268734..3b99c9dfcf0d 100644
> --- a/fs/xfs/xfs_reflink.c
> +++ b/fs/xfs/xfs_reflink.c
> @@ -1327,8 +1327,8 @@ xfs_reflink_remap_prep(
>  	if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
>  		goto out_unlock;
>  
> -	/* Don't share DAX file data for now. */
> -	if (IS_DAX(inode_in) || IS_DAX(inode_out))
> +	/* Don't share DAX file data with non-DAX file. */
> +	if (IS_DAX(inode_in) != IS_DAX(inode_out))
>  		goto out_unlock;
>  
>  	if (!IS_DAX(inode_in))
> -- 
> 2.33.0
> 
> 
>
Shiyang Ruan Sept. 16, 2021, 4:01 a.m. UTC | #2
On 2021/9/16 8:30, Darrick J. Wong wrote:
> On Wed, Sep 15, 2021 at 06:45:01PM +0800, Shiyang Ruan wrote:
>> Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files
>> who are going to be deduped.  After that, call compare range function
>> only when files are both DAX or not.
>>
>> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
>> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>> ---
>>   fs/xfs/xfs_file.c    |  2 +-
>>   fs/xfs/xfs_inode.c   | 80 +++++++++++++++++++++++++++++++++++++++++---
>>   fs/xfs/xfs_inode.h   |  1 +
>>   fs/xfs/xfs_reflink.c |  4 +--
>>   4 files changed, 80 insertions(+), 7 deletions(-)
>>
>> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
>> index 2ef1930374d2..c3061723613c 100644
>> --- a/fs/xfs/xfs_file.c
>> +++ b/fs/xfs/xfs_file.c
>> @@ -846,7 +846,7 @@ xfs_wait_dax_page(
>>   	xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
>>   }
>>   
>> -static int
>> +int
>>   xfs_break_dax_layouts(
>>   	struct inode		*inode,
>>   	bool			*retry)
>> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
>> index a4f6f034fb81..bdc084cdbf46 100644
>> --- a/fs/xfs/xfs_inode.c
>> +++ b/fs/xfs/xfs_inode.c
>> @@ -3790,6 +3790,61 @@ xfs_iolock_two_inodes_and_break_layout(
>>   	return 0;
>>   }
>>   
>> +static int
>> +xfs_mmaplock_two_inodes_and_break_dax_layout(
>> +	struct xfs_inode	*ip1,
>> +	struct xfs_inode	*ip2)
>> +{
>> +	int			error, attempts = 0;
>> +	bool			retry;
>> +	struct page		*page;
>> +	struct xfs_log_item	*lp;
>> +
>> +	if (ip1->i_ino > ip2->i_ino)
>> +		swap(ip1, ip2);
>> +
>> +again:
>> +	retry = false;
>> +	/* Lock the first inode */
>> +	xfs_ilock(ip1, XFS_MMAPLOCK_EXCL);
>> +	error = xfs_break_dax_layouts(VFS_I(ip1), &retry);
>> +	if (error || retry) {
>> +		xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
>> +		if (error == 0 && retry)
>> +			goto again;
>> +		return error;
>> +	}
>> +
>> +	if (ip1 == ip2)
>> +		return 0;
>> +
>> +	/* Nested lock the second inode */
>> +	lp = &ip1->i_itemp->ili_item;
>> +	if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) {
>> +		if (!xfs_ilock_nowait(ip2,
>> +		    xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1))) {
>> +			xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
>> +			if ((++attempts % 5) == 0)
>> +				delay(1); /* Don't just spin the CPU */
>> +			goto again;
>> +		}
> 
> I suspect we don't need this part for grabbing the MMAPLOCK^W pagecache
> invalidatelock.  The AIL only grabs the ILOCK, never the IOLOCK or the
> MMAPLOCK.

Maybe I have misunderstood this part.

What I want is to lock the two inode nestedly.  This code is copied from 
xfs_lock_two_inodes(), which checks this AIL during locking two inode 
with each of the three kinds of locks.

But I also found the recent merged function: 
filemap_invalidate_lock_two() just locks two inode directly without 
checking AIL.  So, I am not if the AIL check is needed in this case.

> 
>> +	} else
>> +		xfs_ilock(ip2, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1));
>> +	/*
>> +	 * We cannot use xfs_break_dax_layouts() directly here because it may
>> +	 * need to unlock & lock the XFS_MMAPLOCK_EXCL which is not suitable
>> +	 * for this nested lock case.
>> +	 */
>> +	page = dax_layout_busy_page(VFS_I(ip2)->i_mapping);
>> +	if (page && page_ref_count(page) != 1) {
> 
> Do you think the patch "ext4/xfs: add page refcount helper" would be a
> good cleanup to head this series?
> 
> https://lore.kernel.org/linux-xfs/20210913161604.31981-1-alex.sierra@amd.com/T/#m59cf7cd5c0d521ad487fa3a15d31c3865db88bdf

Got it.


--
Thanks,
Ruan

> 
> The rest of the logic looks ok.
> 
> --D
> 
>> +		xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
>> +		xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
>> +		goto again;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>   /*
>>    * Lock two inodes so that userspace cannot initiate I/O via file syscalls or
>>    * mmap activity.
>> @@ -3804,8 +3859,19 @@ xfs_ilock2_io_mmap(
>>   	ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
>>   	if (ret)
>>   		return ret;
>> -	filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
>> -				    VFS_I(ip2)->i_mapping);
>> +
>> +	if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
>> +		ret = xfs_mmaplock_two_inodes_and_break_dax_layout(ip1, ip2);
>> +		if (ret) {
>> +			inode_unlock(VFS_I(ip2));
>> +			if (ip1 != ip2)
>> +				inode_unlock(VFS_I(ip1));
>> +			return ret;
>> +		}
>> +	} else
>> +		filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
>> +					    VFS_I(ip2)->i_mapping);
>> +
>>   	return 0;
>>   }
>>   
>> @@ -3815,8 +3881,14 @@ xfs_iunlock2_io_mmap(
>>   	struct xfs_inode	*ip1,
>>   	struct xfs_inode	*ip2)
>>   {
>> -	filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
>> -				      VFS_I(ip2)->i_mapping);
>> +	if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
>> +		xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
>> +		if (ip1 != ip2)
>> +			xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
>> +	} else
>> +		filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
>> +					      VFS_I(ip2)->i_mapping);
>> +
>>   	inode_unlock(VFS_I(ip2));
>>   	if (ip1 != ip2)
>>   		inode_unlock(VFS_I(ip1));
>> diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
>> index b21b177832d1..f7e26fe31a26 100644
>> --- a/fs/xfs/xfs_inode.h
>> +++ b/fs/xfs/xfs_inode.h
>> @@ -472,6 +472,7 @@ enum xfs_prealloc_flags {
>>   
>>   int	xfs_update_prealloc_flags(struct xfs_inode *ip,
>>   				  enum xfs_prealloc_flags flags);
>> +int	xfs_break_dax_layouts(struct inode *inode, bool *retry);
>>   int	xfs_break_layouts(struct inode *inode, uint *iolock,
>>   		enum layout_break_reason reason);
>>   
>> diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
>> index 9d876e268734..3b99c9dfcf0d 100644
>> --- a/fs/xfs/xfs_reflink.c
>> +++ b/fs/xfs/xfs_reflink.c
>> @@ -1327,8 +1327,8 @@ xfs_reflink_remap_prep(
>>   	if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
>>   		goto out_unlock;
>>   
>> -	/* Don't share DAX file data for now. */
>> -	if (IS_DAX(inode_in) || IS_DAX(inode_out))
>> +	/* Don't share DAX file data with non-DAX file. */
>> +	if (IS_DAX(inode_in) != IS_DAX(inode_out))
>>   		goto out_unlock;
>>   
>>   	if (!IS_DAX(inode_in))
>> -- 
>> 2.33.0
>>
>>
>>
Darrick J. Wong Sept. 16, 2021, 4:18 a.m. UTC | #3
On Thu, Sep 16, 2021 at 12:01:18PM +0800, Shiyang Ruan wrote:
> 
> 
> On 2021/9/16 8:30, Darrick J. Wong wrote:
> > On Wed, Sep 15, 2021 at 06:45:01PM +0800, Shiyang Ruan wrote:
> > > Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files
> > > who are going to be deduped.  After that, call compare range function
> > > only when files are both DAX or not.
> > > 
> > > Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> > > Reviewed-by: Darrick J. Wong <djwong@kernel.org>
> > > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > > ---
> > >   fs/xfs/xfs_file.c    |  2 +-
> > >   fs/xfs/xfs_inode.c   | 80 +++++++++++++++++++++++++++++++++++++++++---
> > >   fs/xfs/xfs_inode.h   |  1 +
> > >   fs/xfs/xfs_reflink.c |  4 +--
> > >   4 files changed, 80 insertions(+), 7 deletions(-)
> > > 
> > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> > > index 2ef1930374d2..c3061723613c 100644
> > > --- a/fs/xfs/xfs_file.c
> > > +++ b/fs/xfs/xfs_file.c
> > > @@ -846,7 +846,7 @@ xfs_wait_dax_page(
> > >   	xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
> > >   }
> > > -static int
> > > +int
> > >   xfs_break_dax_layouts(
> > >   	struct inode		*inode,
> > >   	bool			*retry)
> > > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> > > index a4f6f034fb81..bdc084cdbf46 100644
> > > --- a/fs/xfs/xfs_inode.c
> > > +++ b/fs/xfs/xfs_inode.c
> > > @@ -3790,6 +3790,61 @@ xfs_iolock_two_inodes_and_break_layout(
> > >   	return 0;
> > >   }
> > > +static int
> > > +xfs_mmaplock_two_inodes_and_break_dax_layout(
> > > +	struct xfs_inode	*ip1,
> > > +	struct xfs_inode	*ip2)
> > > +{
> > > +	int			error, attempts = 0;
> > > +	bool			retry;
> > > +	struct page		*page;
> > > +	struct xfs_log_item	*lp;
> > > +
> > > +	if (ip1->i_ino > ip2->i_ino)
> > > +		swap(ip1, ip2);
> > > +
> > > +again:
> > > +	retry = false;
> > > +	/* Lock the first inode */
> > > +	xfs_ilock(ip1, XFS_MMAPLOCK_EXCL);
> > > +	error = xfs_break_dax_layouts(VFS_I(ip1), &retry);
> > > +	if (error || retry) {
> > > +		xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
> > > +		if (error == 0 && retry)
> > > +			goto again;
> > > +		return error;
> > > +	}
> > > +
> > > +	if (ip1 == ip2)
> > > +		return 0;
> > > +
> > > +	/* Nested lock the second inode */
> > > +	lp = &ip1->i_itemp->ili_item;
> > > +	if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) {
> > > +		if (!xfs_ilock_nowait(ip2,
> > > +		    xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1))) {
> > > +			xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
> > > +			if ((++attempts % 5) == 0)
> > > +				delay(1); /* Don't just spin the CPU */
> > > +			goto again;
> > > +		}
> > 
> > I suspect we don't need this part for grabbing the MMAPLOCK^W pagecache
> > invalidatelock.  The AIL only grabs the ILOCK, never the IOLOCK or the
> > MMAPLOCK.
> 
> Maybe I have misunderstood this part.
> 
> What I want is to lock the two inode nestedly.  This code is copied from
> xfs_lock_two_inodes(), which checks this AIL during locking two inode with
> each of the three kinds of locks.

<nod> It's totally reasonable to copy-paste the function you want and
change it as needed...

> But I also found the recent merged function: filemap_invalidate_lock_two()
> just locks two inode directly without checking AIL.  So, I am not if the AIL
> check is needed in this case.

...especially when even the maintainer is only 99% sure that the AIL
checking chunk here can be removed.  Anyone else have an opinion?

--D

> > 
> > > +	} else
> > > +		xfs_ilock(ip2, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1));
> > > +	/*
> > > +	 * We cannot use xfs_break_dax_layouts() directly here because it may
> > > +	 * need to unlock & lock the XFS_MMAPLOCK_EXCL which is not suitable
> > > +	 * for this nested lock case.
> > > +	 */
> > > +	page = dax_layout_busy_page(VFS_I(ip2)->i_mapping);
> > > +	if (page && page_ref_count(page) != 1) {
> > 
> > Do you think the patch "ext4/xfs: add page refcount helper" would be a
> > good cleanup to head this series?
> > 
> > https://lore.kernel.org/linux-xfs/20210913161604.31981-1-alex.sierra@amd.com/T/#m59cf7cd5c0d521ad487fa3a15d31c3865db88bdf
> 
> Got it.
> 
> 
> --
> Thanks,
> Ruan
> 
> > 
> > The rest of the logic looks ok.
> > 
> > --D
> > 
> > > +		xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
> > > +		xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
> > > +		goto again;
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > >   /*
> > >    * Lock two inodes so that userspace cannot initiate I/O via file syscalls or
> > >    * mmap activity.
> > > @@ -3804,8 +3859,19 @@ xfs_ilock2_io_mmap(
> > >   	ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
> > >   	if (ret)
> > >   		return ret;
> > > -	filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
> > > -				    VFS_I(ip2)->i_mapping);
> > > +
> > > +	if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
> > > +		ret = xfs_mmaplock_two_inodes_and_break_dax_layout(ip1, ip2);
> > > +		if (ret) {
> > > +			inode_unlock(VFS_I(ip2));
> > > +			if (ip1 != ip2)
> > > +				inode_unlock(VFS_I(ip1));
> > > +			return ret;
> > > +		}
> > > +	} else
> > > +		filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
> > > +					    VFS_I(ip2)->i_mapping);
> > > +
> > >   	return 0;
> > >   }
> > > @@ -3815,8 +3881,14 @@ xfs_iunlock2_io_mmap(
> > >   	struct xfs_inode	*ip1,
> > >   	struct xfs_inode	*ip2)
> > >   {
> > > -	filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
> > > -				      VFS_I(ip2)->i_mapping);
> > > +	if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
> > > +		xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
> > > +		if (ip1 != ip2)
> > > +			xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
> > > +	} else
> > > +		filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
> > > +					      VFS_I(ip2)->i_mapping);
> > > +
> > >   	inode_unlock(VFS_I(ip2));
> > >   	if (ip1 != ip2)
> > >   		inode_unlock(VFS_I(ip1));
> > > diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> > > index b21b177832d1..f7e26fe31a26 100644
> > > --- a/fs/xfs/xfs_inode.h
> > > +++ b/fs/xfs/xfs_inode.h
> > > @@ -472,6 +472,7 @@ enum xfs_prealloc_flags {
> > >   int	xfs_update_prealloc_flags(struct xfs_inode *ip,
> > >   				  enum xfs_prealloc_flags flags);
> > > +int	xfs_break_dax_layouts(struct inode *inode, bool *retry);
> > >   int	xfs_break_layouts(struct inode *inode, uint *iolock,
> > >   		enum layout_break_reason reason);
> > > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> > > index 9d876e268734..3b99c9dfcf0d 100644
> > > --- a/fs/xfs/xfs_reflink.c
> > > +++ b/fs/xfs/xfs_reflink.c
> > > @@ -1327,8 +1327,8 @@ xfs_reflink_remap_prep(
> > >   	if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
> > >   		goto out_unlock;
> > > -	/* Don't share DAX file data for now. */
> > > -	if (IS_DAX(inode_in) || IS_DAX(inode_out))
> > > +	/* Don't share DAX file data with non-DAX file. */
> > > +	if (IS_DAX(inode_in) != IS_DAX(inode_out))
> > >   		goto out_unlock;
> > >   	if (!IS_DAX(inode_in))
> > > -- 
> > > 2.33.0
> > > 
> > > 
> > > 
> 
>
diff mbox series

Patch

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 2ef1930374d2..c3061723613c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -846,7 +846,7 @@  xfs_wait_dax_page(
 	xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
 }
 
-static int
+int
 xfs_break_dax_layouts(
 	struct inode		*inode,
 	bool			*retry)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index a4f6f034fb81..bdc084cdbf46 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3790,6 +3790,61 @@  xfs_iolock_two_inodes_and_break_layout(
 	return 0;
 }
 
+static int
+xfs_mmaplock_two_inodes_and_break_dax_layout(
+	struct xfs_inode	*ip1,
+	struct xfs_inode	*ip2)
+{
+	int			error, attempts = 0;
+	bool			retry;
+	struct page		*page;
+	struct xfs_log_item	*lp;
+
+	if (ip1->i_ino > ip2->i_ino)
+		swap(ip1, ip2);
+
+again:
+	retry = false;
+	/* Lock the first inode */
+	xfs_ilock(ip1, XFS_MMAPLOCK_EXCL);
+	error = xfs_break_dax_layouts(VFS_I(ip1), &retry);
+	if (error || retry) {
+		xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+		if (error == 0 && retry)
+			goto again;
+		return error;
+	}
+
+	if (ip1 == ip2)
+		return 0;
+
+	/* Nested lock the second inode */
+	lp = &ip1->i_itemp->ili_item;
+	if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) {
+		if (!xfs_ilock_nowait(ip2,
+		    xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1))) {
+			xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+			if ((++attempts % 5) == 0)
+				delay(1); /* Don't just spin the CPU */
+			goto again;
+		}
+	} else
+		xfs_ilock(ip2, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1));
+	/*
+	 * We cannot use xfs_break_dax_layouts() directly here because it may
+	 * need to unlock & lock the XFS_MMAPLOCK_EXCL which is not suitable
+	 * for this nested lock case.
+	 */
+	page = dax_layout_busy_page(VFS_I(ip2)->i_mapping);
+	if (page && page_ref_count(page) != 1) {
+		xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
+		xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+		goto again;
+	}
+
+	return 0;
+}
+
 /*
  * Lock two inodes so that userspace cannot initiate I/O via file syscalls or
  * mmap activity.
@@ -3804,8 +3859,19 @@  xfs_ilock2_io_mmap(
 	ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
 	if (ret)
 		return ret;
-	filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
-				    VFS_I(ip2)->i_mapping);
+
+	if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
+		ret = xfs_mmaplock_two_inodes_and_break_dax_layout(ip1, ip2);
+		if (ret) {
+			inode_unlock(VFS_I(ip2));
+			if (ip1 != ip2)
+				inode_unlock(VFS_I(ip1));
+			return ret;
+		}
+	} else
+		filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
+					    VFS_I(ip2)->i_mapping);
+
 	return 0;
 }
 
@@ -3815,8 +3881,14 @@  xfs_iunlock2_io_mmap(
 	struct xfs_inode	*ip1,
 	struct xfs_inode	*ip2)
 {
-	filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
-				      VFS_I(ip2)->i_mapping);
+	if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) {
+		xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
+		if (ip1 != ip2)
+			xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+	} else
+		filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
+					      VFS_I(ip2)->i_mapping);
+
 	inode_unlock(VFS_I(ip2));
 	if (ip1 != ip2)
 		inode_unlock(VFS_I(ip1));
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index b21b177832d1..f7e26fe31a26 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -472,6 +472,7 @@  enum xfs_prealloc_flags {
 
 int	xfs_update_prealloc_flags(struct xfs_inode *ip,
 				  enum xfs_prealloc_flags flags);
+int	xfs_break_dax_layouts(struct inode *inode, bool *retry);
 int	xfs_break_layouts(struct inode *inode, uint *iolock,
 		enum layout_break_reason reason);
 
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 9d876e268734..3b99c9dfcf0d 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1327,8 +1327,8 @@  xfs_reflink_remap_prep(
 	if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
 		goto out_unlock;
 
-	/* Don't share DAX file data for now. */
-	if (IS_DAX(inode_in) || IS_DAX(inode_out))
+	/* Don't share DAX file data with non-DAX file. */
+	if (IS_DAX(inode_in) != IS_DAX(inode_out))
 		goto out_unlock;
 
 	if (!IS_DAX(inode_in))