From: Trond Myklebust <trond.myklebust@primarydata.com>
Date: Mon, 31 Aug 2015 09:05:47 +0000 (-0700)
Subject: NFSv4.1/pNFS: Don't request a minimal read layout beyond the end of file
X-Git-Tag: v4.9.8~3612^2~12
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2d89a1d3c9ff8ceb115f001e66cff9788338ca47;p=platform%2Fkernel%2Flinux-rpi3.git

NFSv4.1/pNFS: Don't request a minimal read layout beyond the end of file

If we have a read layout, then sanity check the minimal layout length
so that it does not extend beyond the end of file.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index c4f918e..ba12464 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -868,6 +868,7 @@ send_layoutget(struct pnfs_layout_hdr *lo,
 	struct nfs_server *server = NFS_SERVER(ino);
 	struct nfs4_layoutget *lgp;
 	struct pnfs_layout_segment *lseg;
+	loff_t i_size;
 
 	dprintk("--> %s\n", __func__);
 
@@ -875,9 +876,17 @@ send_layoutget(struct pnfs_layout_hdr *lo,
 	if (lgp == NULL)
 		return NULL;
 
+	i_size = i_size_read(ino);
+
 	lgp->args.minlength = PAGE_CACHE_SIZE;
 	if (lgp->args.minlength > range->length)
 		lgp->args.minlength = range->length;
+	if (range->iomode == IOMODE_READ) {
+		if (range->offset >= i_size)
+			lgp->args.minlength = 0;
+		else if (i_size - range->offset < lgp->args.minlength)
+			lgp->args.minlength = i_size - range->offset;
+	}
 	lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
 	lgp->args.range = *range;
 	lgp->args.type = server->pnfs_curr_ld->id;