[1/6] iomap: Convert wait_for_completion to flags
diff mbox series

Message ID 20200622152457.7118-2-rgoldwyn@suse.de
State New
Headers show
Series
  • btrfs direct-io using iomap
Related show

Commit Message

Goldwyn Rodrigues June 22, 2020, 3:24 p.m. UTC
From: Goldwyn Rodrigues <rgoldwyn@suse.com>

Convert wait_for_completion boolean to flags so we can pass more flags
to iomap_dio_rw()

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
 fs/ext4/file.c        | 11 +++++++++--
 fs/gfs2/file.c        |  7 ++++---
 fs/iomap/direct-io.c  |  3 ++-
 fs/xfs/xfs_file.c     | 10 ++++++----
 fs/zonefs/super.c     |  8 ++++++--
 include/linux/iomap.h |  9 ++++++++-
 6 files changed, 35 insertions(+), 13 deletions(-)

Comments

Johannes Thumshirn June 22, 2020, 3:49 p.m. UTC | #1
On 22/06/2020 17:25, Goldwyn Rodrigues wrote:
> diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
> index 07bc42d62673..88dc5aa70d1b 100644
> --- a/fs/zonefs/super.c
> +++ b/fs/zonefs/super.c
> @@ -715,7 +715,8 @@ static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
>  		ret = zonefs_file_dio_append(iocb, from);
>  	else
>  		ret = iomap_dio_rw(iocb, from, &zonefs_iomap_ops,
> -				   &zonefs_write_dio_ops, sync);
> +				   &zonefs_write_dio_ops,
> +				   sync ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0);

Not a huge fan of that construct above but for zonefs:
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Darrick J. Wong June 22, 2020, 5:34 p.m. UTC | #2
On Mon, Jun 22, 2020 at 10:24:52AM -0500, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> Convert wait_for_completion boolean to flags so we can pass more flags
> to iomap_dio_rw()
> 
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
> ---
>  fs/ext4/file.c        | 11 +++++++++--
>  fs/gfs2/file.c        |  7 ++++---
>  fs/iomap/direct-io.c  |  3 ++-
>  fs/xfs/xfs_file.c     | 10 ++++++----
>  fs/zonefs/super.c     |  8 ++++++--
>  include/linux/iomap.h |  9 ++++++++-
>  6 files changed, 35 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index 2a01e31a032c..d20120c4d833 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -53,6 +53,7 @@ static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
>  {
>  	ssize_t ret;
>  	struct inode *inode = file_inode(iocb->ki_filp);
> +	int flags = 0;
>  
>  	if (iocb->ki_flags & IOCB_NOWAIT) {
>  		if (!inode_trylock_shared(inode))
> @@ -74,8 +75,11 @@ static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
>  		return generic_file_read_iter(iocb, to);
>  	}
>  
> +	if (is_sync_kiocb(iocb))
> +		flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;
> +
>  	ret = iomap_dio_rw(iocb, to, &ext4_iomap_ops, NULL,
> -			   is_sync_kiocb(iocb));
> +			   flags);
>  	inode_unlock_shared(inode);
>  
>  	file_accessed(iocb->ki_filp);
> @@ -457,6 +461,7 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
>  	const struct iomap_ops *iomap_ops = &ext4_iomap_ops;
>  	bool extend = false, unaligned_io = false;
>  	bool ilock_shared = true;
> +	int flags = 0;
>  
>  	/*
>  	 * We initially start with shared inode lock unless it is
> @@ -540,10 +545,12 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
>  		ext4_journal_stop(handle);
>  	}
>  
> +	if (is_sync_kiocb(iocb) || unaligned_io || extend)
> +		flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;
>  	if (ilock_shared)
>  		iomap_ops = &ext4_iomap_overwrite_ops;
>  	ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops,
> -			   is_sync_kiocb(iocb) || unaligned_io || extend);
> +			   flags);
>  
>  	if (extend)
>  		ret = ext4_handle_inode_extension(inode, offset, ret, count);
> diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
> index fe305e4bfd37..232f06338e0a 100644
> --- a/fs/gfs2/file.c
> +++ b/fs/gfs2/file.c
> @@ -767,6 +767,7 @@ static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
>  	size_t count = iov_iter_count(to);
>  	struct gfs2_holder gh;
>  	ssize_t ret;
> +	int flags = is_sync_kiocb(iocb) ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0;
>  
>  	if (!count)
>  		return 0; /* skip atime */
> @@ -777,7 +778,7 @@ static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
>  		goto out_uninit;
>  
>  	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL,
> -			   is_sync_kiocb(iocb));
> +			   flags);
>  
>  	gfs2_glock_dq(&gh);
>  out_uninit:
> @@ -794,6 +795,7 @@ static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
>  	loff_t offset = iocb->ki_pos;
>  	struct gfs2_holder gh;
>  	ssize_t ret;
> +	int flags = is_sync_kiocb(iocb) ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0;
>  
>  	/*
>  	 * Deferred lock, even if its a write, since we do no allocation on
> @@ -812,8 +814,7 @@ static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
>  	if (offset + len > i_size_read(&ip->i_inode))
>  		goto out;
>  
> -	ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
> -			   is_sync_kiocb(iocb));
> +	ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL, flags);
>  
>  out:
>  	gfs2_glock_dq(&gh);
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index ec7b78e6feca..7ed857196a39 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -405,7 +405,7 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
>  ssize_t
>  iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
>  		const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
> -		bool wait_for_completion)
> +		int dio_flags)
>  {
>  	struct address_space *mapping = iocb->ki_filp->f_mapping;
>  	struct inode *inode = file_inode(iocb->ki_filp);
> @@ -415,6 +415,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
>  	unsigned int flags = IOMAP_DIRECT;
>  	struct blk_plug plug;
>  	struct iomap_dio *dio;
> +	bool wait_for_completion = !!(dio_flags & IOMAP_DIOF_WAIT_FOR_COMPLETION);
>  
>  	if (!count)
>  		return 0;
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 00db81eac80d..38683b7c6013 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -169,6 +169,7 @@ xfs_file_dio_aio_read(
>  	struct xfs_inode	*ip = XFS_I(file_inode(iocb->ki_filp));
>  	size_t			count = iov_iter_count(to);
>  	ssize_t			ret;
> +	int flags = is_sync_kiocb(iocb) ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0;
>  
>  	trace_xfs_file_direct_read(ip, count, iocb->ki_pos);
>  
> @@ -183,8 +184,7 @@ xfs_file_dio_aio_read(
>  	} else {
>  		xfs_ilock(ip, XFS_IOLOCK_SHARED);
>  	}
> -	ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL,
> -			is_sync_kiocb(iocb));
> +	ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL,	flags);
>  	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
>  
>  	return ret;
> @@ -483,6 +483,7 @@ xfs_file_dio_aio_write(
>  	int			iolock;
>  	size_t			count = iov_iter_count(from);
>  	struct xfs_buftarg      *target = xfs_inode_buftarg(ip);
> +	int flags = 0;

The variable names ought to be lined up.

>  	/* DIO must be aligned to device logical sector size */
>  	if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
> @@ -546,9 +547,10 @@ xfs_file_dio_aio_write(
>  	 * If unaligned, this is the only IO in-flight. Wait on it before we
>  	 * release the iolock to prevent subsequent overlapping IO.
>  	 */
> +	if (is_sync_kiocb(iocb) || unaligned_io)
> +		flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;
>  	ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
> -			   &xfs_dio_write_ops,
> -			   is_sync_kiocb(iocb) || unaligned_io);
> +			   &xfs_dio_write_ops, flags);
>  out:
>  	xfs_iunlock(ip, iolock);
>  
> diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
> index 07bc42d62673..88dc5aa70d1b 100644
> --- a/fs/zonefs/super.c
> +++ b/fs/zonefs/super.c
> @@ -715,7 +715,8 @@ static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
>  		ret = zonefs_file_dio_append(iocb, from);
>  	else
>  		ret = iomap_dio_rw(iocb, from, &zonefs_iomap_ops,
> -				   &zonefs_write_dio_ops, sync);
> +				   &zonefs_write_dio_ops,
> +				   sync ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0);
>  	if (zi->i_ztype == ZONEFS_ZTYPE_SEQ &&
>  	    (ret > 0 || ret == -EIOCBQUEUED)) {
>  		if (ret > 0)
> @@ -814,6 +815,7 @@ static ssize_t zonefs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
>  	struct super_block *sb = inode->i_sb;
>  	loff_t isize;
>  	ssize_t ret;
> +	int flags = 0;
>  
>  	/* Offline zones cannot be read */
>  	if (unlikely(IS_IMMUTABLE(inode) && !(inode->i_mode & 0777)))
> @@ -848,8 +850,10 @@ static ssize_t zonefs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
>  			goto inode_unlock;
>  		}
>  		file_accessed(iocb->ki_filp);
> +		if (is_sync_kiocb(iocb))
> +			flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;
>  		ret = iomap_dio_rw(iocb, to, &zonefs_iomap_ops,
> -				   &zonefs_read_dio_ops, is_sync_kiocb(iocb));
> +				   &zonefs_read_dio_ops, flags);
>  	} else {
>  		ret = generic_file_read_iter(iocb, to);
>  		if (ret == -EIO)
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 4d1d3c3469e9..f6230446b08d 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -255,9 +255,16 @@ struct iomap_dio_ops {
>  			struct bio *bio, loff_t file_offset);
>  };
>  
> +/*
> + * Flags to pass iomap_dio_rw()
> + */
> +
> +/* Wait for completion of DIO */
> +#define IOMAP_DIOF_WAIT_FOR_COMPLETION 		0x1

There's a space after "COMPLETION" but before the tabs.

--D

> +
>  ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
>  		const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
> -		bool wait_for_completion);
> +		int flags);
>  int iomap_dio_iopoll(struct kiocb *kiocb, bool spin);
>  
>  #ifdef CONFIG_SWAP
> -- 
> 2.25.0
>
Dave Chinner June 23, 2020, 5:57 a.m. UTC | #3
On Mon, Jun 22, 2020 at 10:24:52AM -0500, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> Convert wait_for_completion boolean to flags so we can pass more flags
> to iomap_dio_rw()
> 
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
> ---
>  fs/ext4/file.c        | 11 +++++++++--
>  fs/gfs2/file.c        |  7 ++++---
>  fs/iomap/direct-io.c  |  3 ++-
>  fs/xfs/xfs_file.c     | 10 ++++++----
>  fs/zonefs/super.c     |  8 ++++++--
>  include/linux/iomap.h |  9 ++++++++-
>  6 files changed, 35 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index 2a01e31a032c..d20120c4d833 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -53,6 +53,7 @@ static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
>  {
>  	ssize_t ret;
>  	struct inode *inode = file_inode(iocb->ki_filp);
> +	int flags = 0;
>  
>  	if (iocb->ki_flags & IOCB_NOWAIT) {
>  		if (!inode_trylock_shared(inode))
> @@ -74,8 +75,11 @@ static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
>  		return generic_file_read_iter(iocb, to);
>  	}
>  
> +	if (is_sync_kiocb(iocb))
> +		flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;

The name of the flag conflates implementation with intent. "wait for
completion" is the implementation, "synchronous IO" is the intent.

Can you name this <namespace>_SYNCIO, please? Read further below for
comments on the flag namespace issues...

>  		ext4_journal_stop(handle);
>  	}
>  
> +	if (is_sync_kiocb(iocb) || unaligned_io || extend)
> +		flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;

Then stuff like this is self documenting:

	if (any of this is true)
		IO needs to be issued synchronously

> @@ -767,6 +767,7 @@ static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
>  	size_t count = iov_iter_count(to);
>  	struct gfs2_holder gh;
>  	ssize_t ret;
> +	int flags = is_sync_kiocb(iocb) ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0;
>  
>  	if (!count)
>  		return 0; /* skip atime */
> @@ -777,7 +778,7 @@ static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
>  		goto out_uninit;
>  
>  	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL,
> -			   is_sync_kiocb(iocb));
> +			   flags);

Why do we need a new flags variable here, but not for other
conversions that are identical? 

Hmmm - you use 3 different methods of calculating flags to pass
to iomap_dio_rw() in this patchset. Can you pick one method and use
it for all the code? e.g. make all the code look like this:

	int	flags = 0;


	....
	if (is_sync_kiocb(iocb)
		flags |= IOMAP_DIOF_SYNCIO;
	ret = iomap_dio_rw(....., flags);
	....

So the setting of the flags is right next to the iomap_dio_rw()
call and we don't have to go searching for them?


> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index ec7b78e6feca..7ed857196a39 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -405,7 +405,7 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
>  ssize_t
>  iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
>  		const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
> -		bool wait_for_completion)
> +		int dio_flags)
>  {
>  	struct address_space *mapping = iocb->ki_filp->f_mapping;
>  	struct inode *inode = file_inode(iocb->ki_filp);
> @@ -415,6 +415,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
>  	unsigned int flags = IOMAP_DIRECT;
>  	struct blk_plug plug;
>  	struct iomap_dio *dio;
> +	bool wait_for_completion = !!(dio_flags & IOMAP_DIOF_WAIT_FOR_COMPLETION);

1. the compiler will squash (x & y) down to a boolean state
correctly without needing to add double negatives.

2. I don't like variable names shadowing core kernel API functions
(i.e. wait_for_completion()). Especially as this has nothign to do
with the completion API...

> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 4d1d3c3469e9..f6230446b08d 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -255,9 +255,16 @@ struct iomap_dio_ops {
>  			struct bio *bio, loff_t file_offset);
>  };
>  
> +/*
> + * Flags to pass iomap_dio_rw()
> + */
> +
> +/* Wait for completion of DIO */
> +#define IOMAP_DIOF_WAIT_FOR_COMPLETION 		0x1

Hmmm. Namespace issues. We already have a IOMAP_DIO_* flags defined
for passing to ->end_io. It's going to be confusing having a set of
flags with almost exactly the namespace but with an "F" for flags
and no indication which iomap operation the flags actually belong to.

This is simples, though:

#define IOMAP_DIO_RWF_SYNCIO		(1 << 0)

And it might also be worthwhile renaming the ->endio flags to:

#define IOMAP_DIO_ENDIO_UNWRITTEN	(1 << 0)
#define IOMAP_DIO_ENDIO_COW		(1 << 1)

So there's no confusion there either.

Cheers,

Dave.
Goldwyn Rodrigues June 25, 2020, 5:42 p.m. UTC | #4
On 15:57 23/06, Dave Chinner wrote:
> On Mon, Jun 22, 2020 at 10:24:52AM -0500, Goldwyn Rodrigues wrote:
> > From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> > 
> > Convert wait_for_completion boolean to flags so we can pass more flags
> > to iomap_dio_rw()
> > 
> > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
> > ---
> >  fs/ext4/file.c        | 11 +++++++++--
> >  fs/gfs2/file.c        |  7 ++++---
> >  fs/iomap/direct-io.c  |  3 ++-
> >  fs/xfs/xfs_file.c     | 10 ++++++----
> >  fs/zonefs/super.c     |  8 ++++++--
> >  include/linux/iomap.h |  9 ++++++++-
> >  6 files changed, 35 insertions(+), 13 deletions(-)
> > 
> > diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> > index 2a01e31a032c..d20120c4d833 100644
> > --- a/fs/ext4/file.c
> > +++ b/fs/ext4/file.c
> > @@ -53,6 +53,7 @@ static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
> >  {
> >  	ssize_t ret;
> >  	struct inode *inode = file_inode(iocb->ki_filp);
> > +	int flags = 0;
> >  
> >  	if (iocb->ki_flags & IOCB_NOWAIT) {
> >  		if (!inode_trylock_shared(inode))
> > @@ -74,8 +75,11 @@ static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
> >  		return generic_file_read_iter(iocb, to);
> >  	}
> >  
> > +	if (is_sync_kiocb(iocb))
> > +		flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;
> 
> The name of the flag conflates implementation with intent. "wait for
> completion" is the implementation, "synchronous IO" is the intent.
> 
> Can you name this <namespace>_SYNCIO, please? Read further below for
> comments on the flag namespace issues...

Yes, sure. I just hope it is not confused with RWF_SYNC.

> 
> >  		ext4_journal_stop(handle);
> >  	}
> >  
> > +	if (is_sync_kiocb(iocb) || unaligned_io || extend)
> > +		flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;
> 
> Then stuff like this is self documenting:
> 
> 	if (any of this is true)
> 		IO needs to be issued synchronously
> 
> > @@ -767,6 +767,7 @@ static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
> >  	size_t count = iov_iter_count(to);
> >  	struct gfs2_holder gh;
> >  	ssize_t ret;
> > +	int flags = is_sync_kiocb(iocb) ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0;
> >  
> >  	if (!count)
> >  		return 0; /* skip atime */
> > @@ -777,7 +778,7 @@ static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
> >  		goto out_uninit;
> >  
> >  	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL,
> > -			   is_sync_kiocb(iocb));
> > +			   flags);
> 
> Why do we need a new flags variable here, but not for other
> conversions that are identical? 
> 
> Hmmm - you use 3 different methods of calculating flags to pass
> to iomap_dio_rw() in this patchset. Can you pick one method and use
> it for all the code? e.g. make all the code look like this:
> 
> 	int	flags = 0;
> 
> 
> 	....
> 	if (is_sync_kiocb(iocb)
> 		flags |= IOMAP_DIOF_SYNCIO;
> 	ret = iomap_dio_rw(....., flags);
> 	....
> 
> So the setting of the flags is right next to the iomap_dio_rw()
> call and we don't have to go searching for them?
> 

I agree. Will change this.

> 
> > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> > index ec7b78e6feca..7ed857196a39 100644
> > --- a/fs/iomap/direct-io.c
> > +++ b/fs/iomap/direct-io.c
> > @@ -405,7 +405,7 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
> >  ssize_t
> >  iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> >  		const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
> > -		bool wait_for_completion)
> > +		int dio_flags)
> >  {
> >  	struct address_space *mapping = iocb->ki_filp->f_mapping;
> >  	struct inode *inode = file_inode(iocb->ki_filp);
> > @@ -415,6 +415,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> >  	unsigned int flags = IOMAP_DIRECT;
> >  	struct blk_plug plug;
> >  	struct iomap_dio *dio;
> > +	bool wait_for_completion = !!(dio_flags & IOMAP_DIOF_WAIT_FOR_COMPLETION);
> 
> 1. the compiler will squash (x & y) down to a boolean state
> correctly without needing to add double negatives.
> 

okay, will change this.

> 2. I don't like variable names shadowing core kernel API functions
> (i.e. wait_for_completion()). Especially as this has nothign to do
> with the completion API...

hmm, the change moves the wait_for_completion from function prototype to
a derived variable in the function. This should be a separate patch and
not combined with this change, if really required. wait_for_completion
is also a variable in struct iomap_dio as well.

> 
> > diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> > index 4d1d3c3469e9..f6230446b08d 100644
> > --- a/include/linux/iomap.h
> > +++ b/include/linux/iomap.h
> > @@ -255,9 +255,16 @@ struct iomap_dio_ops {
> >  			struct bio *bio, loff_t file_offset);
> >  };
> >  
> > +/*
> > + * Flags to pass iomap_dio_rw()
> > + */
> > +
> > +/* Wait for completion of DIO */
> > +#define IOMAP_DIOF_WAIT_FOR_COMPLETION 		0x1
> 
> Hmmm. Namespace issues. We already have a IOMAP_DIO_* flags defined
> for passing to ->end_io. It's going to be confusing having a set of
> flags with almost exactly the namespace but with an "F" for flags
> and no indication which iomap operation the flags actually belong to.
> 
> This is simples, though:
> 
> #define IOMAP_DIO_RWF_SYNCIO		(1 << 0)

Agree with this one.

> 
> And it might also be worthwhile renaming the ->endio flags to:
> 
> #define IOMAP_DIO_ENDIO_UNWRITTEN	(1 << 0)
> #define IOMAP_DIO_ENDIO_COW		(1 << 1)
> 
> So there's no confusion there either.
> 

This again should be a separate patch.
I will incorporate the changes relevant to this series.

Patch
diff mbox series

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 2a01e31a032c..d20120c4d833 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -53,6 +53,7 @@  static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	ssize_t ret;
 	struct inode *inode = file_inode(iocb->ki_filp);
+	int flags = 0;
 
 	if (iocb->ki_flags & IOCB_NOWAIT) {
 		if (!inode_trylock_shared(inode))
@@ -74,8 +75,11 @@  static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
 		return generic_file_read_iter(iocb, to);
 	}
 
+	if (is_sync_kiocb(iocb))
+		flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;
+
 	ret = iomap_dio_rw(iocb, to, &ext4_iomap_ops, NULL,
-			   is_sync_kiocb(iocb));
+			   flags);
 	inode_unlock_shared(inode);
 
 	file_accessed(iocb->ki_filp);
@@ -457,6 +461,7 @@  static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	const struct iomap_ops *iomap_ops = &ext4_iomap_ops;
 	bool extend = false, unaligned_io = false;
 	bool ilock_shared = true;
+	int flags = 0;
 
 	/*
 	 * We initially start with shared inode lock unless it is
@@ -540,10 +545,12 @@  static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		ext4_journal_stop(handle);
 	}
 
+	if (is_sync_kiocb(iocb) || unaligned_io || extend)
+		flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;
 	if (ilock_shared)
 		iomap_ops = &ext4_iomap_overwrite_ops;
 	ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops,
-			   is_sync_kiocb(iocb) || unaligned_io || extend);
+			   flags);
 
 	if (extend)
 		ret = ext4_handle_inode_extension(inode, offset, ret, count);
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index fe305e4bfd37..232f06338e0a 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -767,6 +767,7 @@  static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
 	size_t count = iov_iter_count(to);
 	struct gfs2_holder gh;
 	ssize_t ret;
+	int flags = is_sync_kiocb(iocb) ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0;
 
 	if (!count)
 		return 0; /* skip atime */
@@ -777,7 +778,7 @@  static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
 		goto out_uninit;
 
 	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL,
-			   is_sync_kiocb(iocb));
+			   flags);
 
 	gfs2_glock_dq(&gh);
 out_uninit:
@@ -794,6 +795,7 @@  static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
 	loff_t offset = iocb->ki_pos;
 	struct gfs2_holder gh;
 	ssize_t ret;
+	int flags = is_sync_kiocb(iocb) ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0;
 
 	/*
 	 * Deferred lock, even if its a write, since we do no allocation on
@@ -812,8 +814,7 @@  static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
 	if (offset + len > i_size_read(&ip->i_inode))
 		goto out;
 
-	ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
-			   is_sync_kiocb(iocb));
+	ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL, flags);
 
 out:
 	gfs2_glock_dq(&gh);
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index ec7b78e6feca..7ed857196a39 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -405,7 +405,7 @@  iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
 ssize_t
 iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 		const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
-		bool wait_for_completion)
+		int dio_flags)
 {
 	struct address_space *mapping = iocb->ki_filp->f_mapping;
 	struct inode *inode = file_inode(iocb->ki_filp);
@@ -415,6 +415,7 @@  iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 	unsigned int flags = IOMAP_DIRECT;
 	struct blk_plug plug;
 	struct iomap_dio *dio;
+	bool wait_for_completion = !!(dio_flags & IOMAP_DIOF_WAIT_FOR_COMPLETION);
 
 	if (!count)
 		return 0;
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 00db81eac80d..38683b7c6013 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -169,6 +169,7 @@  xfs_file_dio_aio_read(
 	struct xfs_inode	*ip = XFS_I(file_inode(iocb->ki_filp));
 	size_t			count = iov_iter_count(to);
 	ssize_t			ret;
+	int flags = is_sync_kiocb(iocb) ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0;
 
 	trace_xfs_file_direct_read(ip, count, iocb->ki_pos);
 
@@ -183,8 +184,7 @@  xfs_file_dio_aio_read(
 	} else {
 		xfs_ilock(ip, XFS_IOLOCK_SHARED);
 	}
-	ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL,
-			is_sync_kiocb(iocb));
+	ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL,	flags);
 	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
 
 	return ret;
@@ -483,6 +483,7 @@  xfs_file_dio_aio_write(
 	int			iolock;
 	size_t			count = iov_iter_count(from);
 	struct xfs_buftarg      *target = xfs_inode_buftarg(ip);
+	int flags = 0;
 
 	/* DIO must be aligned to device logical sector size */
 	if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
@@ -546,9 +547,10 @@  xfs_file_dio_aio_write(
 	 * If unaligned, this is the only IO in-flight. Wait on it before we
 	 * release the iolock to prevent subsequent overlapping IO.
 	 */
+	if (is_sync_kiocb(iocb) || unaligned_io)
+		flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;
 	ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
-			   &xfs_dio_write_ops,
-			   is_sync_kiocb(iocb) || unaligned_io);
+			   &xfs_dio_write_ops, flags);
 out:
 	xfs_iunlock(ip, iolock);
 
diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index 07bc42d62673..88dc5aa70d1b 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -715,7 +715,8 @@  static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
 		ret = zonefs_file_dio_append(iocb, from);
 	else
 		ret = iomap_dio_rw(iocb, from, &zonefs_iomap_ops,
-				   &zonefs_write_dio_ops, sync);
+				   &zonefs_write_dio_ops,
+				   sync ? IOMAP_DIOF_WAIT_FOR_COMPLETION : 0);
 	if (zi->i_ztype == ZONEFS_ZTYPE_SEQ &&
 	    (ret > 0 || ret == -EIOCBQUEUED)) {
 		if (ret > 0)
@@ -814,6 +815,7 @@  static ssize_t zonefs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 	struct super_block *sb = inode->i_sb;
 	loff_t isize;
 	ssize_t ret;
+	int flags = 0;
 
 	/* Offline zones cannot be read */
 	if (unlikely(IS_IMMUTABLE(inode) && !(inode->i_mode & 0777)))
@@ -848,8 +850,10 @@  static ssize_t zonefs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 			goto inode_unlock;
 		}
 		file_accessed(iocb->ki_filp);
+		if (is_sync_kiocb(iocb))
+			flags |= IOMAP_DIOF_WAIT_FOR_COMPLETION;
 		ret = iomap_dio_rw(iocb, to, &zonefs_iomap_ops,
-				   &zonefs_read_dio_ops, is_sync_kiocb(iocb));
+				   &zonefs_read_dio_ops, flags);
 	} else {
 		ret = generic_file_read_iter(iocb, to);
 		if (ret == -EIO)
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 4d1d3c3469e9..f6230446b08d 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -255,9 +255,16 @@  struct iomap_dio_ops {
 			struct bio *bio, loff_t file_offset);
 };
 
+/*
+ * Flags to pass iomap_dio_rw()
+ */
+
+/* Wait for completion of DIO */
+#define IOMAP_DIOF_WAIT_FOR_COMPLETION 		0x1
+
 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 		const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
-		bool wait_for_completion);
+		int flags);
 int iomap_dio_iopoll(struct kiocb *kiocb, bool spin);
 
 #ifdef CONFIG_SWAP