iomap: update ki_pos in iomap_file_buffered_write

All callers of iomap_file_buffered_write need to updated ki_pos, move it
into common code.

Link: https://lkml.kernel.org/r/20230601145904.1385409-8-hch@lst.deSigned-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Damien Le Moal <dlemoal@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/gfs2/file.c

@@ -1044,10 +1044,8 @@ static ssize_t gfs2_file_buffered_write(struct kiocb *iocb,
 	pagefault_disable();
 	ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
 	pagefault_enable();
-	if (ret > 0) {
-		iocb->ki_pos += ret;
+	if (ret > 0)
 		written += ret;
-	}
 
 	if (inode == sdp->sd_rindex)
 		gfs2_glock_dq_uninit(statfs_gh);

fs/iomap/buffered-io.c

@@ -864,16 +864,19 @@ iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *i,
 		.len		= iov_iter_count(i),
 		.flags		= IOMAP_WRITE,
 	};
-	int ret;
+	ssize_t ret;
 
 	if (iocb->ki_flags & IOCB_NOWAIT)
 		iter.flags |= IOMAP_NOWAIT;
 
 	while ((ret = iomap_iter(&iter, ops)) > 0)
 		iter.processed = iomap_write_iter(&iter, i);
-	if (iter.pos == iocb->ki_pos)
+
+	if (unlikely(ret < 0))
 		return ret;
-	return iter.pos - iocb->ki_pos;
+	ret = iter.pos - iocb->ki_pos;
+	iocb->ki_pos += ret;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(iomap_file_buffered_write);
 

fs/xfs/xfs_file.c

@@ -720,8 +720,6 @@ xfs_file_buffered_write(
 	trace_xfs_file_buffered_write(iocb, from);
 	ret = iomap_file_buffered_write(iocb, from,
 			&xfs_buffered_write_iomap_ops);
-	if (likely(ret >= 0))
-		iocb->ki_pos += ret;
 
 	/*
 	 * If we hit a space limit, try to free up some lingering preallocated

fs/zonefs/file.c

@@ -643,9 +643,7 @@ static ssize_t zonefs_file_buffered_write(struct kiocb *iocb,
 		goto inode_unlock;
 
 	ret = iomap_file_buffered_write(iocb, from, &zonefs_write_iomap_ops);
-	if (ret > 0)
-		iocb->ki_pos += ret;
-	else if (ret == -EIO)
+	if (ret == -EIO)
 		zonefs_io_error(inode, true);
 
 inode_unlock: