From c8b8e32d700fe943a935e435ae251364d016c497 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Thu, 7 Apr 2016 08:51:58 -0700
Subject: direct-io: eliminate the offset argument to ->direct_IO

Including blkdev_direct_IO and dax_do_io.  It has to be ki_pos to actually
work, so eliminate the superflous argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/nfs/direct.c | 17 +++++++----------
 fs/nfs/file.c   |  2 +-
 2 files changed, 8 insertions(+), 11 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index c93826e4a8c6..346b5d85ce92 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -250,7 +250,7 @@ static int nfs_direct_cmp_commit_data_verf(struct nfs_direct_req *dreq,
  * shunt off direct read and write requests before the VFS gets them,
  * so this method is only ever called for swap.
  */
-ssize_t nfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
+ssize_t nfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 {
 	struct inode *inode = iocb->ki_filp->f_mapping->host;
 
@@ -261,7 +261,7 @@ ssize_t nfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
 	VM_BUG_ON(iov_iter_count(iter) != PAGE_SIZE);
 
 	if (iov_iter_rw(iter) == READ)
-		return nfs_file_direct_read(iocb, iter, pos);
+		return nfs_file_direct_read(iocb, iter);
 	return nfs_file_direct_write(iocb, iter);
 }
 
@@ -545,7 +545,6 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
  * nfs_file_direct_read - file direct read operation for NFS files
  * @iocb: target I/O control block
  * @iter: vector of user buffers into which to read data
- * @pos: byte offset in file where reading starts
  *
  * We use this function for direct reads instead of calling
  * generic_file_aio_read() in order to avoid gfar's check to see if
@@ -561,8 +560,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
  * client must read the updated atime from the server back into its
  * cache.
  */
-ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
-				loff_t pos)
+ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter)
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
@@ -574,7 +572,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
 	nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count);
 
 	dfprintk(FILE, "NFS: direct read(%pD2, %zd@%Ld)\n",
-		file, count, (long long) pos);
+		file, count, (long long) iocb->ki_pos);
 
 	result = 0;
 	if (!count)
@@ -594,7 +592,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
 
 	dreq->inode = inode;
 	dreq->bytes_left = count;
-	dreq->io_start = pos;
+	dreq->io_start = iocb->ki_pos;
 	dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
 	l_ctx = nfs_get_lock_context(dreq->ctx);
 	if (IS_ERR(l_ctx)) {
@@ -606,14 +604,14 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
 		dreq->iocb = iocb;
 
 	NFS_I(inode)->read_io += count;
-	result = nfs_direct_read_schedule_iovec(dreq, iter, pos);
+	result = nfs_direct_read_schedule_iovec(dreq, iter, iocb->ki_pos);
 
 	inode_unlock(inode);
 
 	if (!result) {
 		result = nfs_direct_wait(dreq);
 		if (result > 0)
-			iocb->ki_pos = pos + result;
+			iocb->ki_pos += result;
 	}
 
 	nfs_direct_req_release(dreq);
@@ -969,7 +967,6 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
  * nfs_file_direct_write - file direct write operation for NFS files
  * @iocb: target I/O control block
  * @iter: vector of user buffers from which to write data
- * @pos: byte offset in file where writing starts
  *
  * We use this function for direct writes instead of calling
  * generic_file_aio_write() in order to avoid taking the inode
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index be01095b97ae..717a8d6af52d 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -164,7 +164,7 @@ nfs_file_read(struct kiocb *iocb, struct iov_iter *to)
 	ssize_t result;
 
 	if (iocb->ki_flags & IOCB_DIRECT)
-		return nfs_file_direct_read(iocb, to, iocb->ki_pos);
+		return nfs_file_direct_read(iocb, to);
 
 	dprintk("NFS: read(%pD2, %zu@%lu)\n",
 		iocb->ki_filp,
-- 
cgit v1.2.3


From dde0c2e79848298cc25621ad080d47f94dbd7cce Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Thu, 7 Apr 2016 08:52:00 -0700
Subject: fs: add IOCB_SYNC and IOCB_DSYNC

This will allow us to do per-I/O sync file writes, as required by a lot
of fileservers or storage targets.

XXX: Will need a few additional audits for O_DSYNC

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/block_dev.c     |  2 +-
 fs/btrfs/file.c    |  2 +-
 fs/cifs/file.c     |  2 +-
 fs/direct-io.c     |  2 +-
 fs/ext4/file.c     |  2 +-
 fs/f2fs/file.c     |  2 +-
 fs/gfs2/file.c     |  5 ++++-
 fs/nfs/direct.c    |  2 +-
 fs/ntfs/file.c     |  2 +-
 fs/udf/file.c      |  2 +-
 fs/xfs/xfs_file.c  |  2 +-
 include/linux/fs.h | 14 ++++++++++----
 mm/filemap.c       |  2 +-
 13 files changed, 25 insertions(+), 16 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 9e1f3fe25753..d8dc3512e927 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1662,7 +1662,7 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	ret = __generic_file_write_iter(iocb, from);
 	if (ret > 0) {
 		ssize_t err;
-		err = generic_write_sync(file, iocb->ki_pos - ret, ret);
+		err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
 		if (err < 0)
 			ret = err;
 	}
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 6c376311a9d7..35ce146cceec 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1852,7 +1852,7 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	BTRFS_I(inode)->last_sub_trans = root->log_transid;
 	spin_unlock(&BTRFS_I(inode)->lock);
 	if (num_written > 0) {
-		err = generic_write_sync(file, pos, num_written);
+		err = generic_write_sync(iocb, pos, num_written);
 		if (err < 0)
 			num_written = err;
 	}
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index cb070aa88e57..b22b68ccfbe5 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2688,7 +2688,7 @@ out:
 	inode_unlock(inode);
 
 	if (rc > 0) {
-		ssize_t err = generic_write_sync(file, iocb->ki_pos - rc, rc);
+		ssize_t err = generic_write_sync(iocb, iocb->ki_pos - rc, rc);
 		if (err < 0)
 			rc = err;
 	}
diff --git a/fs/direct-io.c b/fs/direct-io.c
index c61314b84b01..f7bcc0193dee 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -268,7 +268,7 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, bool is_async)
 		if (dio->rw & WRITE) {
 			int err;
 
-			err = generic_write_sync(dio->iocb->ki_filp, offset,
+			err = generic_write_sync(dio->iocb, offset,
 						 transferred);
 			if (err < 0 && ret > 0)
 				ret = err;
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index fa2208bae2e1..1417e129be51 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -172,7 +172,7 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (ret > 0) {
 		ssize_t err;
 
-		err = generic_write_sync(file, iocb->ki_pos - ret, ret);
+		err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
 		if (err < 0)
 			ret = err;
 	}
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 443e07705c2a..51ed8388e66c 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1885,7 +1885,7 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (ret > 0) {
 		ssize_t err;
 
-		err = generic_write_sync(file, iocb->ki_pos - ret, ret);
+		err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
 		if (err < 0)
 			ret = err;
 	}
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 208efc70ad49..5a7d69609309 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -895,7 +895,10 @@ static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t
 		mark_inode_dirty(inode);
 	}
 
-	return generic_write_sync(file, pos, count);
+	if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
+		return vfs_fsync_range(file, pos, pos + count - 1,
+			       (file->f_flags & __O_SYNC) ? 0 : 1);
+	return 0;
 
 out_trans_fail:
 	gfs2_inplace_release(ip);
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 346b5d85ce92..be86de9a77d7 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -1054,7 +1054,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
 			if (i_size_read(inode) < iocb->ki_pos)
 				i_size_write(inode, iocb->ki_pos);
 			spin_unlock(&inode->i_lock);
-			generic_write_sync(file, pos, result);
+			generic_write_sync(iocb, pos, result);
 		}
 	}
 	nfs_direct_req_release(dreq);
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index 91117ada8528..10dc38cc02bb 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -1953,7 +1953,7 @@ static ssize_t ntfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	current->backing_dev_info = NULL;
 	inode_unlock(vi);
 	if (likely(written > 0)) {
-		err = generic_write_sync(file, iocb->ki_pos, written);
+		err = generic_write_sync(iocb, iocb->ki_pos, written);
 		if (err < 0)
 			written = 0;
 	}
diff --git a/fs/udf/file.c b/fs/udf/file.c
index 7ab8d8196e90..8e3d1ae53b11 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -152,7 +152,7 @@ out:
 
 	if (retval > 0) {
 		mark_inode_dirty(inode);
-		err = generic_write_sync(file, iocb->ki_pos - retval, retval);
+		err = generic_write_sync(iocb, iocb->ki_pos - retval, retval);
 		if (err < 0)
 			retval = err;
 	}
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 5de047ab2411..b5d70e77195d 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -908,7 +908,7 @@ xfs_file_write_iter(
 		XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
 
 		/* Handle various SYNC-type writes */
-		err = generic_write_sync(file, iocb->ki_pos - ret, ret);
+		err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
 		if (err < 0)
 			ret = err;
 	}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e6b2de159736..310ca1ed9293 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -323,6 +323,8 @@ struct writeback_control;
 #define IOCB_APPEND		(1 << 1)
 #define IOCB_DIRECT		(1 << 2)
 #define IOCB_HIPRI		(1 << 3)
+#define IOCB_DSYNC		(1 << 4)
+#define IOCB_SYNC		(1 << 5)
 
 struct kiocb {
 	struct file		*ki_filp;
@@ -2485,12 +2487,12 @@ extern int filemap_fdatawrite_range(struct address_space *mapping,
 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
 			   int datasync);
 extern int vfs_fsync(struct file *file, int datasync);
-static inline int generic_write_sync(struct file *file, loff_t pos, loff_t count)
+static inline int generic_write_sync(struct kiocb *iocb, loff_t pos, loff_t count)
 {
-	if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
+	if (!(iocb->ki_flags & IOCB_DSYNC))
 		return 0;
-	return vfs_fsync_range(file, pos, pos + count - 1,
-			       (file->f_flags & __O_SYNC) ? 0 : 1);
+	return vfs_fsync_range(iocb->ki_filp, pos, pos + count - 1,
+			       (iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
 }
 extern void emergency_sync(void);
 extern void emergency_remount(void);
@@ -2942,6 +2944,10 @@ static inline int iocb_flags(struct file *file)
 		res |= IOCB_APPEND;
 	if (io_is_direct(file))
 		res |= IOCB_DIRECT;
+	if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
+		res |= IOCB_DSYNC;
+	if (file->f_flags & __O_SYNC)
+		res |= IOCB_SYNC;
 	return res;
 }
 
diff --git a/mm/filemap.c b/mm/filemap.c
index cb36db9f4107..8345d6d3436a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2794,7 +2794,7 @@ ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (ret > 0) {
 		ssize_t err;
 
-		err = generic_write_sync(file, iocb->ki_pos - ret, ret);
+		err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
 		if (err < 0)
 			ret = err;
 	}
-- 
cgit v1.2.3


From e259221763a40403d5bb232209998e8c45804ab8 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Thu, 7 Apr 2016 08:52:01 -0700
Subject: fs: simplify the generic_write_sync prototype

The kiocb already has the new position, so use that.  The only interesting
case is AIO, where we currently don't bother updating ki_pos.  We're about
to free the kiocb after we're done, so we might as well update it to make
everyone's life simpler.

While we're at it also return the bytes written argument passed in if
we were successful so that the boilerplate error switch code in the
callers can go away.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/block_dev.c     |  8 ++------
 fs/btrfs/file.c    |  7 ++-----
 fs/cifs/file.c     |  7 ++-----
 fs/direct-io.c     | 17 +++++++++--------
 fs/ext4/file.c     |  9 ++-------
 fs/f2fs/file.c     |  9 ++-------
 fs/nfs/direct.c    |  4 +++-
 fs/ntfs/file.c     |  7 ++-----
 fs/udf/file.c      |  4 +---
 fs/xfs/xfs_file.c  |  6 +-----
 include/linux/fs.h | 24 ++++++++++++++++++------
 mm/filemap.c       |  9 ++-------
 12 files changed, 46 insertions(+), 65 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/block_dev.c b/fs/block_dev.c
index d8dc3512e927..a063d4d8ac39 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1660,12 +1660,8 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 	blk_start_plug(&plug);
 	ret = __generic_file_write_iter(iocb, from);
-	if (ret > 0) {
-		ssize_t err;
-		err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
-		if (err < 0)
-			ret = err;
-	}
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
 	blk_finish_plug(&plug);
 	return ret;
 }
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 35ce146cceec..ea9f10bb089c 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1851,11 +1851,8 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	spin_lock(&BTRFS_I(inode)->lock);
 	BTRFS_I(inode)->last_sub_trans = root->log_transid;
 	spin_unlock(&BTRFS_I(inode)->lock);
-	if (num_written > 0) {
-		err = generic_write_sync(iocb, pos, num_written);
-		if (err < 0)
-			num_written = err;
-	}
+	if (num_written > 0)
+		num_written = generic_write_sync(iocb, num_written);
 
 	if (sync)
 		atomic_dec(&BTRFS_I(inode)->sync_writers);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index b22b68ccfbe5..9b51d4936a29 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2687,11 +2687,8 @@ cifs_writev(struct kiocb *iocb, struct iov_iter *from)
 out:
 	inode_unlock(inode);
 
-	if (rc > 0) {
-		ssize_t err = generic_write_sync(iocb, iocb->ki_pos - rc, rc);
-		if (err < 0)
-			rc = err;
-	}
+	if (rc > 0)
+		rc = generic_write_sync(iocb, rc);
 	up_read(&cinode->lock_sem);
 	return rc;
 }
diff --git a/fs/direct-io.c b/fs/direct-io.c
index f7bcc0193dee..3bf3f20f8ecc 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -256,6 +256,7 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, bool is_async)
 	if (dio->end_io) {
 		int err;
 
+		// XXX: ki_pos??
 		err = dio->end_io(dio->iocb, offset, ret, dio->private);
 		if (err)
 			ret = err;
@@ -265,15 +266,15 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, bool is_async)
 		inode_dio_end(dio->inode);
 
 	if (is_async) {
-		if (dio->rw & WRITE) {
-			int err;
-
-			err = generic_write_sync(dio->iocb, offset,
-						 transferred);
-			if (err < 0 && ret > 0)
-				ret = err;
-		}
+		/*
+		 * generic_write_sync expects ki_pos to have been updated
+		 * already, but the submission path only does this for
+		 * synchronous I/O.
+		 */
+		dio->iocb->ki_pos += transferred;
 
+		if (dio->rw & WRITE)
+			ret = generic_write_sync(dio->iocb,  transferred);
 		dio->iocb->ki_complete(dio->iocb, ret, 0);
 	}
 
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 1417e129be51..00ff6912adb3 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -169,13 +169,8 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	ret = __generic_file_write_iter(iocb, from);
 	inode_unlock(inode);
 
-	if (ret > 0) {
-		ssize_t err;
-
-		err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
-		if (err < 0)
-			ret = err;
-	}
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
 	if (o_direct)
 		blk_finish_plug(&plug);
 
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 51ed8388e66c..28f75a1fe4a7 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1882,13 +1882,8 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	}
 	inode_unlock(inode);
 
-	if (ret > 0) {
-		ssize_t err;
-
-		err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
-		if (err < 0)
-			ret = err;
-	}
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
 	return ret;
 }
 
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index be86de9a77d7..0b9fca040b0c 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -1054,7 +1054,9 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
 			if (i_size_read(inode) < iocb->ki_pos)
 				i_size_write(inode, iocb->ki_pos);
 			spin_unlock(&inode->i_lock);
-			generic_write_sync(iocb, pos, result);
+
+			/* XXX: should check the generic_write_sync retval */
+			generic_write_sync(iocb, result);
 		}
 	}
 	nfs_direct_req_release(dreq);
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index 10dc38cc02bb..5622ed5a201e 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -1952,12 +1952,9 @@ static ssize_t ntfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		written = ntfs_perform_write(file, from, iocb->ki_pos);
 	current->backing_dev_info = NULL;
 	inode_unlock(vi);
-	if (likely(written > 0)) {
-		err = generic_write_sync(iocb, iocb->ki_pos, written);
-		if (err < 0)
-			written = 0;
-	}
 	iocb->ki_pos += written;
+	if (likely(written > 0))
+		written = generic_write_sync(iocb, written);
 	return written ? written : err;
 }
 
diff --git a/fs/udf/file.c b/fs/udf/file.c
index 8e3d1ae53b11..632570617327 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -152,9 +152,7 @@ out:
 
 	if (retval > 0) {
 		mark_inode_dirty(inode);
-		err = generic_write_sync(iocb, iocb->ki_pos - retval, retval);
-		if (err < 0)
-			retval = err;
+		retval = generic_write_sync(iocb, retval);
 	}
 
 	return retval;
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index b5d70e77195d..cd3540997d65 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -903,14 +903,10 @@ xfs_file_write_iter(
 		ret = xfs_file_buffered_aio_write(iocb, from);
 
 	if (ret > 0) {
-		ssize_t err;
-
 		XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
 
 		/* Handle various SYNC-type writes */
-		err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
-		if (err < 0)
-			ret = err;
+		ret = generic_write_sync(iocb, ret);
 	}
 	return ret;
 }
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 310ca1ed9293..f6a8ed864651 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2487,13 +2487,25 @@ extern int filemap_fdatawrite_range(struct address_space *mapping,
 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
 			   int datasync);
 extern int vfs_fsync(struct file *file, int datasync);
-static inline int generic_write_sync(struct kiocb *iocb, loff_t pos, loff_t count)
-{
-	if (!(iocb->ki_flags & IOCB_DSYNC))
-		return 0;
-	return vfs_fsync_range(iocb->ki_filp, pos, pos + count - 1,
-			       (iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
+
+/*
+ * Sync the bytes written if this was a synchronous write.  Expect ki_pos
+ * to already be updated for the write, and will return either the amount
+ * of bytes passed in, or an error if syncing the file failed.
+ */
+static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
+{
+	if (iocb->ki_flags & IOCB_DSYNC) {
+		int ret = vfs_fsync_range(iocb->ki_filp,
+				iocb->ki_pos - count, iocb->ki_pos - 1,
+				(iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
+		if (ret)
+			return ret;
+	}
+
+	return count;
 }
+
 extern void emergency_sync(void);
 extern void emergency_remount(void);
 #ifdef CONFIG_BLOCK
diff --git a/mm/filemap.c b/mm/filemap.c
index 8345d6d3436a..182b21825255 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2791,13 +2791,8 @@ ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		ret = __generic_file_write_iter(iocb, from);
 	inode_unlock(inode);
 
-	if (ret > 0) {
-		ssize_t err;
-
-		err = generic_write_sync(iocb, iocb->ki_pos - ret, ret);
-		if (err < 0)
-			ret = err;
-	}
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
 	return ret;
 }
 EXPORT_SYMBOL(generic_file_write_iter);
-- 
cgit v1.2.3