On 3/17/22 8:03 AM, Chuck Lever III wrote:
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?
The CLIENT_EXPIRED can be set when either the client is reconnecting or when a thread tries to resolve the conflict with the courtesy client. The reconnecting client and the laundromat are synced by nn->client_lock. For thread that tries to resolve conflict and set CLIENT_EXPIRED, if the laundromat misses detecting CLIENT_EXPIRED then it will get it the next time it runs. The CLIENT_COURTESY state is only set by the laundromat so there is no need for any lock when checking it here. -Dai
+ 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
