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.

Fixes: e09c978aae5b ("NFSv4.1: Fix Oopsable condition in server callback races")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/nfs/nfs4session.c b/fs/nfs/nfs4session.c
index b62973045a3e048016f1af48f761fdb152f3908d..150c5a1879bff92e7c0658f8cb920e94ba457e09 100644 (file)
--- a/fs/nfs/nfs4session.c
+++ b/fs/nfs/nfs4session.c
@@ -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);
-       *seq_nr = slot->seq_nr;
-       return 0;
+       ret = PTR_ERR_OR_ZERO(slot);
+       if (!ret)
+               *seq_nr = slot->seq_nr;
+
+       return ret;
 }
 
 /*