[3/7] iomap: use a function pointer for dio submits
diff mbox series

Message ID 20191115161700.12305-4-rgoldwyn@suse.de
State New
Headers show
Series
  • [1/7] fs: Export generic_file_buffered_read()
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Commit Message

Goldwyn Rodrigues Nov. 15, 2019, 4:16 p.m. UTC
From: Goldwyn Rodrigues <rgoldwyn@suse.com>

This helps filesystems to perform tasks on the bio while
submitting for I/O. This could be post-write operations
such as data CRC or data replication for fs-handled RAID.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
 fs/iomap/direct-io.c  | 14 +++++++++-----
 include/linux/iomap.h |  2 ++
 2 files changed, 11 insertions(+), 5 deletions(-)

Comments

Christoph Hellwig Nov. 15, 2019, 4:47 p.m. UTC | #1
The subject is a little odd, as we only optionally override submit_bio.
Maybe something like:

iomap: add a file system hook for direct I/O bio submission

On Fri, Nov 15, 2019 at 10:16:56AM -0600, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> This helps filesystems to perform tasks on the bio while
> submitting for I/O. This could be post-write operations
> such as data CRC or data replication for fs-handled RAID.

You can use up to 73 chars for the commit log.

> +	if (dio->dops && dio->dops->submit_io)
> +		dio->submit.cookie = dio->dops->submit_io(bio,
> +				file_inode(dio->iocb->ki_filp),	pos);

Any reason to not simply pass the file?
Goldwyn Rodrigues Nov. 15, 2019, 8:11 p.m. UTC | #2
On  8:47 15/11, Christoph Hellwig wrote:
> The subject is a little odd, as we only optionally override submit_bio.
> Maybe something like:
> 
> iomap: add a file system hook for direct I/O bio submission
> 
> On Fri, Nov 15, 2019 at 10:16:56AM -0600, Goldwyn Rodrigues wrote:
> > From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> > 
> > This helps filesystems to perform tasks on the bio while
> > submitting for I/O. This could be post-write operations
> > such as data CRC or data replication for fs-handled RAID.
> 
> You can use up to 73 chars for the commit log.
> 
> > +	if (dio->dops && dio->dops->submit_io)
> > +		dio->submit.cookie = dio->dops->submit_io(bio,
> > +				file_inode(dio->iocb->ki_filp),	pos);
> 
> Any reason to not simply pass the file?

No, I just didn't change the original btrfs_submit_direct(). Passing
filp will be much neater. I will incorporate this.

I agree with all of your comments, and will implement them in the next
patchset.

Patch
diff mbox series

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 2f88d64c2a4d..1e93a8d99439 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 +67,11 @@  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 (dio->dops && dio->dops->submit_io)
+		dio->submit.cookie = dio->dops->submit_io(bio,
+				file_inode(dio->iocb->ki_filp),	pos);
+	else
+		dio->submit.cookie = submit_bio(bio);
 }
 
 static ssize_t iomap_dio_complete(struct iomap_dio *dio)
@@ -191,7 +195,7 @@  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
@@ -297,11 +301,11 @@  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 8b09463dae0d..386ac8ff58d0 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -252,6 +252,8 @@  int iomap_writepages(struct address_space *mapping,
 struct iomap_dio_ops {
 	int (*end_io)(struct kiocb *iocb, ssize_t size, int error,
 		      unsigned flags);
+	blk_qc_t (*submit_io)(struct bio *bio, struct inode *inode,
+			  loff_t file_offset);
 };
 
 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,