On Sun, May 01, 2022 at 10:38:12AM -0700, Dai Ngo wrote:
> This patch moves create/destroy of laundry_wq from nfs4_state_start
> and nfs4_state_shutdown_net to init_nfsd and exit_nfsd to prevent
> the laundromat from being freed while a thread is processing a
> conflicting lock.
Reviewed-by: J. Bruce Fields <bfields@xxxxxxxxxxxx>
>
> Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4state.c | 28 ++++++++++++++++------------
> fs/nfsd/nfsctl.c | 4 ++++
> fs/nfsd/nfsd.h | 4 ++++
> 3 files changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 0e98e9c16e3e..f369142da79f 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -127,6 +127,21 @@ static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops;
>
> static struct workqueue_struct *laundry_wq;
>
> +int nfsd4_create_laundry_wq(void)
> +{
> + int rc = 0;
> +
> + laundry_wq = alloc_workqueue("%s", WQ_UNBOUND, 0, "nfsd4");
> + if (laundry_wq == NULL)
> + rc = -ENOMEM;
> + return rc;
> +}
> +
> +void nfsd4_destroy_laundry_wq(void)
> +{
> + destroy_workqueue(laundry_wq);
> +}
> +
> static bool is_session_dead(struct nfsd4_session *ses)
> {
> return ses->se_flags & NFS4_SESSION_DEAD;
> @@ -7748,22 +7763,12 @@ nfs4_state_start(void)
> {
> int ret;
>
> - laundry_wq = alloc_workqueue("%s", WQ_UNBOUND, 0, "nfsd4");
> - if (laundry_wq == NULL) {
> - ret = -ENOMEM;
> - goto out;
> - }
> ret = nfsd4_create_callback_queue();
> if (ret)
> - goto out_free_laundry;
> + return ret;
>
> set_max_delegations();
> return 0;
> -
> -out_free_laundry:
> - destroy_workqueue(laundry_wq);
> -out:
> - return ret;
> }
>
> void
> @@ -7800,7 +7805,6 @@ nfs4_state_shutdown_net(struct net *net)
> void
> nfs4_state_shutdown(void)
> {
> - destroy_workqueue(laundry_wq);
> nfsd4_destroy_callback_queue();
> }
>
> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> index 16920e4512bd..322a208878f2 100644
> --- a/fs/nfsd/nfsctl.c
> +++ b/fs/nfsd/nfsctl.c
> @@ -1544,6 +1544,9 @@ static int __init init_nfsd(void)
> retval = register_cld_notifier();
> if (retval)
> goto out_free_all;
> + retval = nfsd4_create_laundry_wq();
> + if (retval)
> + goto out_free_all;
> return 0;
> out_free_all:
> unregister_pernet_subsys(&nfsd_net_ops);
> @@ -1566,6 +1569,7 @@ static int __init init_nfsd(void)
>
> static void __exit exit_nfsd(void)
> {
> + nfsd4_destroy_laundry_wq();
> unregister_cld_notifier();
> unregister_pernet_subsys(&nfsd_net_ops);
> nfsd_drc_slab_free();
> diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
> index 23996c6ca75e..847b482155ae 100644
> --- a/fs/nfsd/nfsd.h
> +++ b/fs/nfsd/nfsd.h
> @@ -162,6 +162,8 @@ void nfs4_state_shutdown_net(struct net *net);
> int nfs4_reset_recoverydir(char *recdir);
> char * nfs4_recoverydir(void);
> bool nfsd4_spo_must_allow(struct svc_rqst *rqstp);
> +int nfsd4_create_laundry_wq(void);
> +void nfsd4_destroy_laundry_wq(void);
> #else
> static inline int nfsd4_init_slabs(void) { return 0; }
> static inline void nfsd4_free_slabs(void) { }
> @@ -175,6 +177,8 @@ static inline bool nfsd4_spo_must_allow(struct svc_rqst *rqstp)
> {
> return false;
> }
> +static inline int nfsd4_create_laundry_wq(void) { return 0; };
> +static inline void nfsd4_destroy_laundry_wq(void) {};
> #endif
>
> /*
> --
> 2.9.5
