Patch "NFSv4.1: work around -Wmaybe-uninitialized warning" has been added to the 4.8-stable tree

Patch "NFSv4.1: work around -Wmaybe-uninitialized warning" has been added to the 4.8-stable tree

[gregkh]

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

    NFSv4.1: work around -Wmaybe-uninitialized warning

to the 4.8-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:
     nfsv4.1-work-around-wmaybe-uninitialized-warning.patch
and it can be found in the queue-4.8 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 68a564006a21ae59c7c51b4359e2e8efa42ae4af Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 18 Oct 2016 00:05:35 +0200
Subject: NFSv4.1: work around -Wmaybe-uninitialized warning

From: Arnd Bergmann <arnd@arndb.de>

commit 68a564006a21ae59c7c51b4359e2e8efa42ae4af upstream.

A bugfix introduced a harmless gcc warning in nfs4_slot_seqid_in_use
if we enable -Wmaybe-uninitialized again:

fs/nfs/nfs4session.c:203:54: error: 'cur_seq' may be used uninitialized in this function [-Werror=maybe-uninitialized]

gcc is not smart enough to conclude that the IS_ERR/PTR_ERR pair
results in a nonzero return value here. Using PTR_ERR_OR_ZERO()
instead makes this clear to the compiler.

The warning originally did not appear in v4.8 as it was globally
disabled, but the bugfix that introduced the warning got backported
to stable kernels which again enable it, and this is now the only
warning in the v4.7 builds.

Fixes: e09c978aae5b ("NFSv4.1: Fix Oopsable condition in server callback races")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfs/nfs4session.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--- a/fs/nfs/nfs4session.c
+++ b/fs/nfs/nfs4session.c
@@ -178,12 +178,14 @@ static int nfs4_slot_get_seqid(struct nf
 	__must_hold(&tbl->slot_tbl_lock)
 {
 	struct nfs4_slot *slot;
+	int ret;
 
 	slot = nfs4_lookup_slot(tbl, slotid);
-	if (IS_ERR(slot))
-		return PTR_ERR(slot);
-	*seq_nr = slot->seq_nr;
-	return 0;
+	ret = PTR_ERR_OR_ZERO(slot);
+	if (!ret)
+		*seq_nr = slot->seq_nr;
+
+	return ret;
 }
 
 /*


Patches currently in stable-queue which might be from arnd@arndb.de are

queue-4.8/nfsv4.1-work-around-wmaybe-uninitialized-warning.patch
queue-4.8/staging-iio-ad5933-avoid-uninitialized-variable-in-error-case.patch
queue-4.8/dib0700-fix-nec-repeat-handling.patch