From: Peng Tao <tao.peng@primarydata.com>
Date: Fri, 11 Sep 2015 03:14:06 +0000 (+0800)
Subject: nfs: fix pg_test page count calculation
X-Git-Tag: v4.1.11~106
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=0fe83960ecd61b82fb436728712330b61b47d53a;p=users%2Fjedix%2Flinux-maple.git

nfs: fix pg_test page count calculation

commit 048883e0b934d9a5103d40e209cb14b7f33d2933 upstream.

We really want sizeof(struct page *) instead. Otherwise we limit
maximum IO size to 64 pages rather than 512 pages on a 64bit system.

Fixes 2e11f829(nfs: cap request size to fit a kmalloced page array).

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Fixes: 2e11f8296d22 ("nfs: cap request size to fit a kmalloced page array")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 069914ce7641..93d355c8b467 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -508,7 +508,7 @@ size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
 	 * for it without upsetting the slab allocator.
 	 */
 	if (((mirror->pg_count + req->wb_bytes) >> PAGE_SHIFT) *
-			sizeof(struct page) > PAGE_SIZE)
+			sizeof(struct page *) > PAGE_SIZE)
 		return 0;
 
 	return min(mirror->pg_bsize - mirror->pg_count, (size_t)req->wb_bytes);