diff mbox series

[v5,05/12] iomap: Allow forcing of waiting for running DIO in iomap_dio_rw()

Message ID 5dc3085af89a3e7c20db22e9e7012b4676b440a9.1571647179.git.mbobrowski@mbobrowski.org
State Superseded
Headers show
Series ext4: port direct I/O to iomap infrastructure | expand

Commit Message

Matthew Bobrowski Oct. 21, 2019, 9:18 a.m. UTC 
Filesystems do not support doing IO as asynchronous in some cases. For
example in case of unaligned writes or in case file size needs to be
extended (e.g. for ext4). Instead of forcing filesystem to wait for AIO
in such cases, add argument to iomap_dio_rw() which makes the function
wait for IO completion. This also results in executing
iomap_dio_complete() inline in iomap_dio_rw() providing its return value
to the caller as for ordinary sync IO.

Signed-off-by: Jan Kara <jack@suse.cz>
---

This patch has already been posted through by Jan, but I've just
included it within this patch series to mark that it's a clear
dependency.

 fs/gfs2/file.c        | 6 ++++--
 fs/iomap/direct-io.c  | 7 +++++--
 fs/xfs/xfs_file.c     | 5 +++--
 include/linux/iomap.h | 3 ++-
 4 files changed, 14 insertions(+), 7 deletions(-)

Comments

Christoph Hellwig Oct. 24, 2019, 1:41 a.m. UTC | #1 
On Mon, Oct 21, 2019 at 08:18:18PM +1100, mbobrowski@mbobrowski.org wrote:
> This patch has already been posted through by Jan, but I've just
> included it within this patch series to mark that it's a clear
> dependency.

You probably want to resend the next iteration against the
iomap-for-next branch, which includes this plus an iomap_begin
API change.  Darrick plans to have it as a stable branch, so that it can
also be pulled into the ext4 tree.
Matthew Bobrowski Oct. 24, 2019, 11:17 a.m. UTC | #2 
On Wed, Oct 23, 2019 at 06:41:53PM -0700, Christoph Hellwig wrote:
> On Mon, Oct 21, 2019 at 08:18:18PM +1100, mbobrowski@mbobrowski.org wrote:
> > This patch has already been posted through by Jan, but I've just
> > included it within this patch series to mark that it's a clear
> > dependency.
> 
> You probably want to resend the next iteration against the
> iomap-for-next branch, which includes this plus an iomap_begin
> API change.  Darrick plans to have it as a stable branch, so that it can
> also be pulled into the ext4 tree.

OK, noted! Checking out and rebasing. :)

--<M>--
diff mbox series

Patch

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 997b326247e2..f0caee2b7c00 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -732,7 +732,8 @@  static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
 	if (ret)
 		goto out_uninit;
 
-	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL);
+	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL,
+			   is_sync_kiocb(iocb));
 
 	gfs2_glock_dq(&gh);
 out_uninit:
@@ -767,7 +768,8 @@  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);
+	ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
+			   is_sync_kiocb(iocb));
 
 out:
 	gfs2_glock_dq(&gh);
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 1fc28c2da279..da124cee1783 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -392,7 +392,8 @@  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)
+		const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
+		bool wait_for_completion)
 {
 	struct address_space *mapping = iocb->ki_filp->f_mapping;
 	struct inode *inode = file_inode(iocb->ki_filp);
@@ -400,7 +401,6 @@  iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 	loff_t pos = iocb->ki_pos, start = pos;
 	loff_t end = iocb->ki_pos + count - 1, ret = 0;
 	unsigned int flags = IOMAP_DIRECT;
-	bool wait_for_completion = is_sync_kiocb(iocb);
 	struct blk_plug plug;
 	struct iomap_dio *dio;
 
@@ -409,6 +409,9 @@  iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 	if (!count)
 		return 0;
 
+	if (WARN_ON(is_sync_kiocb(iocb) && !wait_for_completion))
+		return -EIO;
+
 	dio = kmalloc(sizeof(*dio), GFP_KERNEL);
 	if (!dio)
 		return -ENOMEM;
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 1ffb179f35d2..0739ba72a82e 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -188,7 +188,7 @@  xfs_file_dio_aio_read(
 	file_accessed(iocb->ki_filp);
 
 	xfs_ilock(ip, XFS_IOLOCK_SHARED);
-	ret = iomap_dio_rw(iocb, to, &xfs_iomap_ops, NULL);
+	ret = iomap_dio_rw(iocb, to, &xfs_iomap_ops, NULL, is_sync_kiocb(iocb));
 	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
 
 	return ret;
@@ -547,7 +547,8 @@  xfs_file_dio_aio_write(
 	}
 
 	trace_xfs_file_direct_write(ip, count, iocb->ki_pos);
-	ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, &xfs_dio_write_ops);
+	ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, &xfs_dio_write_ops,
+			   is_sync_kiocb(iocb));
 
 	/*
 	 * If unaligned, this is the only IO in-flight. If it has not yet
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 7aa5d6117936..76b14cb729dc 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -195,7 +195,8 @@  struct iomap_dio_ops {
 };
 
 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
-		const struct iomap_ops *ops, const struct iomap_dio_ops *dops);
+		const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
+		bool wait_for_completion);
 int iomap_dio_iopoll(struct kiocb *kiocb, bool spin);
 
 #ifdef CONFIG_SWAP