On Fri, 2019-08-02 at 17:21 -0700, Darrick J. Wong wrote:
> On Fri, Aug 02, 2019 at 05:00:45PM -0500, Goldwyn Rodrigues wrote:
> > From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
> >
> > This helps filesystems to perform tasks on the bio while
> > submitting for I/O. Since btrfs requires the position
> > we are working on, pass pos to iomap_dio_submit_bio()
>
> What /does/ btrfs_submit_direct do, anyway? Looks like it's a custom
> submission function that ... does something related to setting
> checksums? And, uh, RAID?
Yes and yes.
>
> > The correct place for submit_io() is not page_ops. Would it
> > better to rename the structure to something like iomap_io_ops
> > or put it directly under struct iomap?
>
> Seeing as the ->iomap_begin handler knows if the requested op is a
> buffered write or a direct write, what if we just declare a union of
> ops?
>
> e.g.
>
> struct iomap_page_ops;
> struct iomap_directio_ops;
>
> struct iomap {
> <usual stuff>
> union {
> const struct iomap_page_ops *page_ops;
> const struct iomap_directio_ops *directio_ops;
> };
> };
Yes, that looks good. Thanks. I will incorporate it.
>
> --D
>
> > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
> > ---
> > fs/iomap/direct-io.c | 16 +++++++++++-----
> > include/linux/iomap.h | 1 +
> > 2 files changed, 12 insertions(+), 5 deletions(-)
> >
> > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> > index 5279029c7a3c..a802e66bf11f 100644
> > --- a/fs/iomap/direct-io.c
> > +++ b/fs/iomap/direct-io.c
> > @@ -59,7 +59,7 @@ int iomap_dio_iopoll(struct kiocb *kiocb, bool
> > spin)
> > EXPORT_SYMBOL_GPL(iomap_dio_iopoll);
> >
> > static void iomap_dio_submit_bio(struct iomap_dio *dio, struct
> > iomap *iomap,
> > - struct bio *bio)
> > + struct bio *bio, loff_t pos)
> > {
> > atomic_inc(&dio->ref);
> >
> > @@ -67,7 +67,13 @@ static void iomap_dio_submit_bio(struct
> > iomap_dio *dio, struct iomap *iomap,
> > bio_set_polled(bio, dio->iocb);
> >
> > dio->submit.last_queue = bdev_get_queue(iomap->bdev);
> > - dio->submit.cookie = submit_bio(bio);
> > + if (iomap->page_ops && iomap->page_ops->submit_io) {
> > + iomap->page_ops->submit_io(bio, file_inode(dio-
> > >iocb->ki_filp),
> > + pos);
> > + dio->submit.cookie = BLK_QC_T_NONE;
> > + } else {
> > + dio->submit.cookie = submit_bio(bio);
> > + }
> > }
> >
> > static ssize_t iomap_dio_complete(struct iomap_dio *dio)
> > @@ -195,7 +201,7 @@ iomap_dio_zero(struct iomap_dio *dio, struct
> > iomap *iomap, loff_t pos,
> > get_page(page);
> > __bio_add_page(bio, page, len, 0);
> > bio_set_op_attrs(bio, REQ_OP_WRITE, flags);
> > - iomap_dio_submit_bio(dio, iomap, bio);
> > + iomap_dio_submit_bio(dio, iomap, bio, pos);
> > }
> >
> > static loff_t
> > @@ -301,11 +307,11 @@ iomap_dio_bio_actor(struct inode *inode,
> > loff_t pos, loff_t length,
> > iov_iter_advance(dio->submit.iter, n);
> >
> > dio->size += n;
> > - pos += n;
> > copied += n;
> >
> > nr_pages = iov_iter_npages(&iter, BIO_MAX_PAGES);
> > - iomap_dio_submit_bio(dio, iomap, bio);
> > + iomap_dio_submit_bio(dio, iomap, bio, pos);
> > + pos += n;
> > } while (nr_pages);
> >
> > /*
> > diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> > index 5b2055e8ca8a..6617e4b6fb6d 100644
> > --- a/include/linux/iomap.h
> > +++ b/include/linux/iomap.h
> > @@ -92,6 +92,7 @@ struct iomap_page_ops {
> > struct iomap *iomap);
> > void (*page_done)(struct inode *inode, loff_t pos,
> > unsigned copied,
> > struct page *page, struct iomap *iomap);
> > + dio_submit_t *submit_io;
> > };
> >
> > /*
> > --
> > 2.16.4
> >
>
>
