From: Trond Myklebust <trondmy@gmail.com>
Date: Tue, 21 Aug 2018 14:25:34 +0000 (-0400)
Subject: pNFS: Remove unwanted optimisation of layoutget
X-Git-Tag: v4.19~180^2~5
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0af4c8be97a14d1df8a78b4993a09e8dff545a18;p=platform%2Fkernel%2Flinux-rpi3.git

pNFS: Remove unwanted optimisation of layoutget

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 <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
---

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index e11e666..e8f232d 100644
--- 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);