pNFS: Remove unwanted optimisation of layoutget

trondmy · amschuma-ntap · commit 0af4c8be97a1 · 2018-08-21T13:39:08.000-04:00
If we knew that the file was empty, we wouldn't be asking for a layout.
Any optimisation here is already done before calling pnfs_update_layout().
As it stands, we sometimes end up doing an unnecessary inband read to
the MDS even when holding a layout.

Signed-off-by: Trond Myklebust &lt;trond.myklebust@hammerspace.com&gt;
Signed-off-by: Anna Schumaker &lt;Anna.Schumaker@Netapp.com&gt;
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
@@ -1823,12 +1823,6 @@ pnfs_update_layout(struct inode *ino,
 		goto out;
 	}
 
-	if (iomode == IOMODE_READ && i_size_read(ino) == 0) {
-		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
-				 PNFS_UPDATE_LAYOUT_RD_ZEROLEN);
-		goto out;
-	}
-
 	if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
 		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
 				 PNFS_UPDATE_LAYOUT_MDSTHRESH);
