From d75a6a0e3933acbba44e4ad8d8f3c4d4f76b6e03 Mon Sep 17 00:00:00 2001 From: Benjamin Coddington Date: Fri, 18 Nov 2016 21:11:39 -0500 Subject: [PATCH] NFSv4.1: Keep a reference on lock states while checking While walking the list of lock_states, keep a reference on each nfs4_lock_state to be checked, otherwise the lock state could be removed while the check performs TEST_STATEID and possible FREE_STATEID. Signed-off-by: Benjamin Coddington Signed-off-by: Anna Schumaker --- fs/nfs/nfs4proc.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 2d1481eb1929..e6dc95e0f97e 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2564,15 +2564,23 @@ static void nfs41_check_delegation_stateid(struct nfs4_state *state) static int nfs41_check_expired_locks(struct nfs4_state *state) { int status, ret = NFS_OK; - struct nfs4_lock_state *lsp; + struct nfs4_lock_state *lsp, *prev = NULL; struct nfs_server *server = NFS_SERVER(state->inode); if (!test_bit(LK_STATE_IN_USE, &state->flags)) goto out; + + spin_lock(&state->state_lock); list_for_each_entry(lsp, &state->lock_states, ls_locks) { if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) { struct rpc_cred *cred = lsp->ls_state->owner->so_cred; + atomic_inc(&lsp->ls_count); + spin_unlock(&state->state_lock); + + nfs4_put_lock_state(prev); + prev = lsp; + status = nfs41_test_and_free_expired_stateid(server, &lsp->ls_stateid, cred); @@ -2585,10 +2593,14 @@ static int nfs41_check_expired_locks(struct nfs4_state *state) set_bit(NFS_LOCK_LOST, &lsp->ls_flags); } else if (status != NFS_OK) { ret = status; - break; + nfs4_put_lock_state(prev); + goto out; } + spin_lock(&state->state_lock); } - }; + } + spin_unlock(&state->state_lock); + nfs4_put_lock_state(prev); out: return ret; }