Patch "nfs: fix pg_test page count calculation" has been added to the 4.2-stable tree

Patch "nfs: fix pg_test page count calculation" has been added to the 4.2-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    nfs: fix pg_test page count calculation

to the 4.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfs-fix-pg_test-page-count-calculation.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 048883e0b934d9a5103d40e209cb14b7f33d2933 Mon Sep 17 00:00:00 2001
From: Peng Tao <tao.peng@primarydata.com>
Date: Fri, 11 Sep 2015 11:14:06 +0800
Subject: nfs: fix pg_test page count calculation

From: Peng Tao <tao.peng@primarydata.com>

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>

---
 fs/nfs/pagelist.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -508,7 +508,7 @@ size_t nfs_generic_pg_test(struct nfs_pa
 	 * 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);


Patches currently in stable-queue which might be from tao.peng@primarydata.com are

queue-4.2/nfs-fix-pg_test-page-count-calculation.patch