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Commit abbec2da authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Use raw_write_seqcount_begin/end int nfs4_reclaim_open_state 



The addition of lockdep code to write_seqcount_begin/end has lead to
a bunch of false positive claims of ABBA deadlocks with the so_lock
spinlock. Audits show that this simply cannot happen because the
read side code does not spin while holding so_lock.

Cc: <stable@vger.kernel.org> # 3.13.x
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent 7b160cfd

fs/nfs/nfs4state.c

+3 −3
Original line number Diff line number Diff line
@@ -1456,7 +1456,7 @@ static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs 
	 * server that doesn't support a grace period.

	 */

	spin_lock(&sp->so_lock);

	write_seqcount_begin(&sp->so_reclaim_seqcount);

	raw_write_seqcount_begin(&sp->so_reclaim_seqcount);

restart:

	list_for_each_entry(state, &sp->so_states, open_states) {

		if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
@@ -1519,13 +1519,13 @@ static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs 
		spin_lock(&sp->so_lock);

		goto restart;

	}

	write_seqcount_end(&sp->so_reclaim_seqcount);

	raw_write_seqcount_end(&sp->so_reclaim_seqcount);

	spin_unlock(&sp->so_lock);

	return 0;

out_err:

	nfs4_put_open_state(state);

	spin_lock(&sp->so_lock);

	write_seqcount_end(&sp->so_reclaim_seqcount);

	raw_write_seqcount_end(&sp->so_reclaim_seqcount);

	spin_unlock(&sp->so_lock);

	return status;

}