> On Mar 17, 2022, at 3:43 AM, Dai Ngo <dai.ngo@xxxxxxxxxx> wrote:
>
> Add nfs4_anylock_blocker and nfs4_lockowner_has_blockers to check
> if an expired client has any lock blockers
>
> Update nfs4_get_client_reaplist to:
> . add courtesy client in CLIENT_EXPIRED state to reaplist.
> . detect if expired client still has state and no blockers then
> transit it to courtesy client by setting CLIENT_COURTESY state
> and removing the client record.
>
> Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4state.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 91 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index b4b976e00ce6..d5758c7101dc 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -5755,24 +5755,106 @@ static void nfsd4_ssc_expire_umount(struct nfsd_net *nn)
> }
> #endif
>
> +/* Check if any lock belonging to this lockowner has any blockers */
> +static bool
> +nfs4_lockowner_has_blockers(struct nfs4_lockowner *lo)
> +{
> + struct file_lock_context *ctx;
> + struct nfs4_ol_stateid *stp;
> + struct nfs4_file *nf;
> +
> + list_for_each_entry(stp, &lo->lo_owner.so_stateids, st_perstateowner) {
> + nf = stp->st_stid.sc_file;
> + ctx = nf->fi_inode->i_flctx;
> + if (!ctx)
> + continue;
> + if (locks_owner_has_blockers(ctx, lo))
> + return true;
> + }
> + return false;
> +}
> +
> +static bool
> +nfs4_anylock_blockers(struct nfs4_client *clp)
> +{
> + int i;
> + struct nfs4_stateowner *so;
> + struct nfs4_lockowner *lo;
> +
> + spin_lock(&clp->cl_lock);
> + for (i = 0; i < OWNER_HASH_SIZE; i++) {
> + list_for_each_entry(so, &clp->cl_ownerstr_hashtbl[i],
> + so_strhash) {
> + if (so->so_is_open_owner)
> + continue;
> + lo = lockowner(so);
> + if (nfs4_lockowner_has_blockers(lo)) {
> + spin_unlock(&clp->cl_lock);
> + return true;
> + }
> + }
> + }
> + spin_unlock(&clp->cl_lock);
> + return false;
> +}
> +
> static void
> nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist,
> struct laundry_time *lt)
> {
> struct list_head *pos, *next;
> struct nfs4_client *clp;
> + bool cour;
> + struct list_head cslist;
>
> INIT_LIST_HEAD(reaplist);
> + INIT_LIST_HEAD(&cslist);
> spin_lock(&nn->client_lock);
> list_for_each_safe(pos, next, &nn->client_lru) {
> clp = list_entry(pos, struct nfs4_client, cl_lru);
> if (!state_expired(lt, clp->cl_time))
> break;
> - if (mark_client_expired_locked(clp))
> +
> + if (!client_has_state(clp))
> + goto exp_client;
> +
> + if (clp->cl_cs_client_state == NFSD4_CLIENT_EXPIRED)
> + goto exp_client;
> + cour = (clp->cl_cs_client_state == NFSD4_CLIENT_COURTESY);
I've forgotten: why don't you need to hold clp->cl_cs_lock while
checking cs_client_state here?
> + if (cour && ktime_get_boottime_seconds() >=
> + (clp->cl_time + NFSD_COURTESY_CLIENT_TIMEOUT))
> + goto exp_client;
> + if (nfs4_anylock_blockers(clp)) {
> +exp_client:
> + if (mark_client_expired_locked(clp))
> + continue;
> + list_add(&clp->cl_lru, reaplist);
> continue;
> - list_add(&clp->cl_lru, reaplist);
> + }
> + if (!cour) {
> + spin_lock(&clp->cl_cs_lock);
> + clp->cl_cs_client_state = NFSD4_CLIENT_COURTESY;
> + spin_unlock(&clp->cl_cs_lock);
> + list_add(&clp->cl_cs_list, &cslist);
> + }
> }
> spin_unlock(&nn->client_lock);
> +
> + while (!list_empty(&cslist)) {
> + clp = list_first_entry(&cslist, struct nfs4_client, cl_cs_list);
> + list_del_init(&clp->cl_cs_list);
> + spin_lock(&clp->cl_cs_lock);
> + /*
> + * Client might have re-connected. Make sure it's
> + * still in courtesy state before removing its record.
> + */
> + if (clp->cl_cs_client_state != NFSD4_CLIENT_COURTESY) {
> + spin_unlock(&clp->cl_cs_lock);
> + continue;
> + }
> + spin_unlock(&clp->cl_cs_lock);
> + nfsd4_client_record_remove(clp);
> + }
> }
>
> static time64_t
> @@ -5818,6 +5900,13 @@ nfs4_laundromat(struct nfsd_net *nn)
> dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
> if (!state_expired(<, dp->dl_time))
> break;
> + spin_lock(&clp->cl_cs_lock);
> + if (clp->cl_cs_client_state == NFSD4_CLIENT_COURTESY) {
> + clp->cl_cs_client_state = NFSD4_CLIENT_EXPIRED;
> + spin_unlock(&clp->cl_cs_lock);
> + continue;
> + }
> + spin_unlock(&clp->cl_cs_lock);
> WARN_ON(!unhash_delegation_locked(dp));
> list_add(&dp->dl_recall_lru, &reaplist);
> }
> --
> 2.9.5
>
--
Chuck Lever
