Commit 68a56400 authored Oct 18, 2016 by Arnd Bergmann Committed by Anna Schumaker Oct 24, 2016

NFSv4.1: work around -Wmaybe-uninitialized warning



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: e09c978a ("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>

parent 86a6c211

fs/nfs/nfs4session.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -178,12 +178,14 @@ static int nfs4_slot_get_seqid(struct nfs4_slot_table *tbl, u32 slotid,
		__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);
		ret = PTR_ERR_OR_ZERO(slot);
		if (!ret)
		*seq_nr = slot->seq_nr;
		return 0;

		return ret;
		}

		/*

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