From: Trond Myklebust Date: Wed, 30 Jul 2014 01:34:06 +0000 (-0400) Subject: nfsd: Add reference counting to the lock and open stateids X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6011695da2d7c588f2dfe57c318758f0bf1154dd;p=linux-beck.git nfsd: Add reference counting to the lock and open stateids When we remove the client_mutex, we'll need to be able to ensure that these objects aren't destroyed while we're not holding locks. Add a ->free() callback to the struct nfs4_stid, so that we can release a reference to the stid without caring about the contents. Signed-off-by: Trond Myklebust Reviewed-by: Christoph Hellwig Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index e9813389687b..8574c708cf8c 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -905,7 +905,7 @@ static void nfsd4_cb_recall_release(void *calldata) spin_lock(&clp->cl_lock); list_del(&cb->cb_per_client); spin_unlock(&clp->cl_lock); - nfs4_put_delegation(dp); + nfs4_put_stid(&dp->dl_stid); } } diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index b0f83beeca75..60ab22b6e099 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -71,6 +71,7 @@ static u64 current_sessionid = 1; /* forward declarations */ static bool check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner); +static void nfs4_free_ol_stateid(struct nfs4_stid *stid); /* Locking: */ @@ -463,8 +464,8 @@ static void nfs4_file_put_access(struct nfs4_file *fp, u32 access) __nfs4_file_put_access(fp, O_RDONLY); } -static struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct -kmem_cache *slab) +static struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, + struct kmem_cache *slab) { struct idr *stateids = &cl->cl_stateids; struct nfs4_stid *stid; @@ -500,7 +501,26 @@ out_free: static struct nfs4_ol_stateid * nfs4_alloc_stateid(struct nfs4_client *clp) { - return openlockstateid(nfs4_alloc_stid(clp, stateid_slab)); + struct nfs4_stid *stid; + struct nfs4_ol_stateid *stp; + + stid = nfs4_alloc_stid(clp, stateid_slab); + if (!stid) + return NULL; + + stp = openlockstateid(stid); + stp->st_stid.sc_free = nfs4_free_ol_stateid; + return stp; +} + +static void nfs4_free_deleg(struct nfs4_stid *stid) +{ + struct nfs4_delegation *dp = delegstateid(stid); + + if (dp->dl_file) + put_nfs4_file(dp->dl_file); + kmem_cache_free(deleg_slab, stid); + atomic_long_dec(&num_delegations); } /* @@ -594,6 +614,8 @@ alloc_init_deleg(struct nfs4_client *clp, struct svc_fh *current_fh) dp = delegstateid(nfs4_alloc_stid(clp, deleg_slab)); if (dp == NULL) goto out_dec; + + dp->dl_stid.sc_free = nfs4_free_deleg; /* * delegation seqid's are never incremented. The 4.1 special * meaning of seqid 0 isn't meaningful, really, but let's avoid @@ -611,28 +633,15 @@ out_dec: return NULL; } -static void remove_stid(struct nfs4_stid *s) -{ - struct idr *stateids = &s->sc_client->cl_stateids; - - idr_remove(stateids, s->sc_stateid.si_opaque.so_id); -} - -static void nfs4_free_stid(struct kmem_cache *slab, struct nfs4_stid *s) -{ - kmem_cache_free(slab, s); -} - void -nfs4_put_delegation(struct nfs4_delegation *dp) +nfs4_put_stid(struct nfs4_stid *s) { - if (atomic_dec_and_test(&dp->dl_stid.sc_count)) { - if (dp->dl_file) - put_nfs4_file(dp->dl_file); - remove_stid(&dp->dl_stid); - nfs4_free_stid(deleg_slab, &dp->dl_stid); - atomic_long_dec(&num_delegations); - } + struct nfs4_client *clp = s->sc_client; + + if (!atomic_dec_and_test(&s->sc_count)) + return; + idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id); + s->sc_free(s); } static void nfs4_put_deleg_lease(struct nfs4_file *fp) @@ -689,7 +698,7 @@ static void destroy_delegation(struct nfs4_delegation *dp) spin_lock(&state_lock); unhash_delegation_locked(dp); spin_unlock(&state_lock); - nfs4_put_delegation(dp); + nfs4_put_stid(&dp->dl_stid); } static void revoke_delegation(struct nfs4_delegation *dp) @@ -699,7 +708,7 @@ static void revoke_delegation(struct nfs4_delegation *dp) WARN_ON(!list_empty(&dp->dl_recall_lru)); if (clp->cl_minorversion == 0) - nfs4_put_delegation(dp); + nfs4_put_stid(&dp->dl_stid); else { dp->dl_stid.sc_type = NFS4_REVOKED_DELEG_STID; spin_lock(&clp->cl_lock); @@ -885,17 +894,14 @@ static void unhash_generic_stateid(struct nfs4_ol_stateid *stp) list_del(&stp->st_perstateowner); } -static void close_generic_stateid(struct nfs4_ol_stateid *stp) +static void nfs4_free_ol_stateid(struct nfs4_stid *stid) { - release_all_access(stp); -} + struct nfs4_ol_stateid *stp = openlockstateid(stid); -static void free_generic_stateid(struct nfs4_ol_stateid *stp) -{ + release_all_access(stp); if (stp->st_file) put_nfs4_file(stp->st_file); - remove_stid(&stp->st_stid); - nfs4_free_stid(stateid_slab, &stp->st_stid); + kmem_cache_free(stateid_slab, stid); } static void __release_lock_stateid(struct nfs4_ol_stateid *stp) @@ -908,8 +914,7 @@ static void __release_lock_stateid(struct nfs4_ol_stateid *stp) file = find_any_file(stp->st_file); if (file) filp_close(file, (fl_owner_t)lockowner(stp->st_stateowner)); - close_generic_stateid(stp); - free_generic_stateid(stp); + nfs4_put_stid(&stp->st_stid); } static void unhash_lockowner(struct nfs4_lockowner *lo) @@ -966,13 +971,12 @@ static void unhash_open_stateid(struct nfs4_ol_stateid *stp) { unhash_generic_stateid(stp); release_open_stateid_locks(stp); - close_generic_stateid(stp); } static void release_open_stateid(struct nfs4_ol_stateid *stp) { unhash_open_stateid(stp); - free_generic_stateid(stp); + nfs4_put_stid(&stp->st_stid); } static void unhash_openowner(struct nfs4_openowner *oo) @@ -993,7 +997,7 @@ static void release_last_closed_stateid(struct nfs4_openowner *oo) struct nfs4_ol_stateid *s = oo->oo_last_closed_stid; if (s) { - free_generic_stateid(s); + nfs4_put_stid(&s->st_stid); oo->oo_last_closed_stid = NULL; } } @@ -1467,12 +1471,12 @@ destroy_client(struct nfs4_client *clp) while (!list_empty(&reaplist)) { dp = list_entry(reaplist.next, struct nfs4_delegation, dl_recall_lru); list_del_init(&dp->dl_recall_lru); - nfs4_put_delegation(dp); + nfs4_put_stid(&dp->dl_stid); } while (!list_empty(&clp->cl_revoked)) { dp = list_entry(reaplist.next, struct nfs4_delegation, dl_recall_lru); list_del_init(&dp->dl_recall_lru); - nfs4_put_delegation(dp); + nfs4_put_stid(&dp->dl_stid); } while (!list_empty(&clp->cl_openowners)) { oo = list_entry(clp->cl_openowners.next, struct nfs4_openowner, oo_perclient); @@ -3588,7 +3592,7 @@ out_unlock: spin_unlock(&state_lock); out: if (status) { - nfs4_put_delegation(dp); + nfs4_put_stid(&dp->dl_stid); return ERR_PTR(status); } return dp; @@ -3818,7 +3822,7 @@ void nfsd4_cleanup_open_state(struct nfsd4_open *open, __be32 status) if (open->op_file) nfsd4_free_file(open->op_file); if (open->op_stp) - free_generic_stateid(open->op_stp); + nfs4_put_stid(&open->op_stp->st_stid); } __be32 @@ -4266,7 +4270,7 @@ nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, spin_lock(&cl->cl_lock); list_del_init(&dp->dl_recall_lru); spin_unlock(&cl->cl_lock); - nfs4_put_delegation(dp); + nfs4_put_stid(s); ret = nfs_ok; break; default: @@ -4477,19 +4481,22 @@ static void nfsd4_close_open_stateid(struct nfs4_ol_stateid *s) unhash_open_stateid(s); if (clp->cl_minorversion) { - free_generic_stateid(s); if (list_empty(&oo->oo_owner.so_stateids)) release_openowner(oo); + nfs4_put_stid(&s->st_stid); } else { + /* + * In the 4.0 case we need to keep the owners around a + * little while to handle CLOSE replay. We still do need + * to release any file access that is held by them + * before returning however. + */ + release_all_access(s); if (s->st_file) { put_nfs4_file(s->st_file); s->st_file = NULL; } oo->oo_last_closed_stid = s; - /* - * In the 4.0 case we need to keep the owners around a - * little while to handle CLOSE replay. - */ if (list_empty(&oo->oo_owner.so_stateids)) move_to_close_lru(oo, clp->net); } @@ -5665,7 +5672,7 @@ nfs4_state_shutdown_net(struct net *net) list_for_each_safe(pos, next, &reaplist) { dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); list_del_init(&dp->dl_recall_lru); - nfs4_put_delegation(dp); + nfs4_put_stid(&dp->dl_stid); } nfsd4_client_tracking_exit(net); diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 39747736e83b..32c466265ac1 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -85,6 +85,7 @@ struct nfs4_stid { unsigned char sc_type; stateid_t sc_stateid; struct nfs4_client *sc_client; + void (*sc_free)(struct nfs4_stid *); }; struct nfs4_delegation { @@ -429,6 +430,7 @@ extern __be32 nfs4_preprocess_stateid_op(struct net *net, stateid_t *stateid, int flags, struct file **filp); extern void nfs4_lock_state(void); extern void nfs4_unlock_state(void); +void nfs4_put_stid(struct nfs4_stid *s); void nfs4_remove_reclaim_record(struct nfs4_client_reclaim *, struct nfsd_net *); extern void nfs4_release_reclaim(struct nfsd_net *); extern struct nfs4_client_reclaim *nfsd4_find_reclaim_client(const char *recdir, @@ -446,7 +448,6 @@ extern int nfsd4_create_callback_queue(void); extern void nfsd4_destroy_callback_queue(void); extern void nfsd4_shutdown_callback(struct nfs4_client *); extern void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp); -extern void nfs4_put_delegation(struct nfs4_delegation *dp); extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(const char *name, struct nfsd_net *nn); extern bool nfs4_has_reclaimed_state(const char *name, struct nfsd_net *nn);