NFS: drop unused nfs_direct_req bytes_left

Now that we're calculating how large a remaining IO should be based
on the current request's offset, we no longer need to track bytes_left on
each struct nfs_direct_req.  Drop the field, and clean up the direct
request tracepoints.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/direct.c

@@ -369,7 +369,6 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
 			bytes -= req_len;
 			requested_bytes += req_len;
 			pos += req_len;
-			dreq->bytes_left -= req_len;
 		}
 		nfs_direct_release_pages(pagevec, npages);
 		kvfree(pagevec);
@@ -441,7 +440,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
 		goto out;
 
 	dreq->inode = inode;
-	dreq->bytes_left = dreq->max_count = count;
+	dreq->max_count = count;
 	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);
@@ -874,7 +873,6 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 			bytes -= req_len;
 			requested_bytes += req_len;
 			pos += req_len;
-			dreq->bytes_left -= req_len;
 
 			if (defer) {
 				nfs_mark_request_commit(req, NULL, &cinfo, 0);
@@ -981,7 +979,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
 		goto out;
 
 	dreq->inode = inode;
-	dreq->bytes_left = dreq->max_count = count;
+	dreq->max_count = count;
 	dreq->io_start = pos;
 	dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
 	l_ctx = nfs_get_lock_context(dreq->ctx);

fs/nfs/internal.h

@@ -936,7 +936,6 @@ struct nfs_direct_req {
 	loff_t			io_start;	/* Start offset for I/O */
 	ssize_t			count,		/* bytes actually processed */
 				max_count,	/* max expected count */
-				bytes_left,	/* bytes left to be sent */
 				error;		/* any reported error */
 	struct completion	completion;	/* wait for i/o completion */
 

fs/nfs/nfstrace.h

@@ -1545,7 +1545,6 @@ DECLARE_EVENT_CLASS(nfs_direct_req_class,
 			__field(u32, fhandle)
 			__field(loff_t, offset)
 			__field(ssize_t, count)
-			__field(ssize_t, bytes_left)
 			__field(ssize_t, error)
 			__field(int, flags)
 		),
@@ -1560,19 +1559,18 @@ DECLARE_EVENT_CLASS(nfs_direct_req_class,
 			__entry->fhandle = nfs_fhandle_hash(fh);
 			__entry->offset = dreq->io_start;
 			__entry->count = dreq->count;
-			__entry->bytes_left = dreq->bytes_left;
 			__entry->error = dreq->error;
 			__entry->flags = dreq->flags;
 		),
 
 		TP_printk(
 			"error=%zd fileid=%02x:%02x:%llu fhandle=0x%08x "
-			"offset=%lld count=%zd bytes_left=%zd flags=%s",
+			"offset=%lld count=%zd flags=%s",
 			__entry->error, MAJOR(__entry->dev),
 			MINOR(__entry->dev),
 			(unsigned long long)__entry->fileid,
 			__entry->fhandle, __entry->offset,
-			__entry->count, __entry->bytes_left,
+			__entry->count,
 			nfs_show_direct_req_flags(__entry->flags)
 		)
 );