| Message ID | 1406288067-20663-3-git-send-email-jlayton@primarydata.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jul 25, 2014 at 07:34:20AM -0400, Jeff Layton wrote: > @@ -698,11 +699,10 @@ static void revoke_delegation(struct nfs4_delegation *dp) > struct nfs4_client *clp = dp->dl_stid.sc_client; > > if (clp->cl_minorversion == 0) > - destroy_delegation(dp); > + destroy_revoked_delegation(dp); I don't understand this one--in the NFSv4.0 case, when is the delegation unhashed? (And, apologies if that's a repeat question. I remember wondering about this before but can't find mail in the archives....) --b. > else { > - unhash_delegation(dp); > dp->dl_stid.sc_type = NFS4_REVOKED_DELEG_STID; > - list_add(&dp->dl_recall_lru, &clp->cl_revoked); > + list_move(&dp->dl_recall_lru, &clp->cl_revoked); > } > } > > @@ -1458,15 +1458,14 @@ destroy_client(struct nfs4_client *clp) > spin_lock(&state_lock); > while (!list_empty(&clp->cl_delegations)) { > dp = list_entry(clp->cl_delegations.next, struct nfs4_delegation, dl_perclnt); > - list_del_init(&dp->dl_perclnt); > - /* Ensure that deleg break won't try to requeue it */ > - ++dp->dl_time; > - list_move(&dp->dl_recall_lru, &reaplist); > + unhash_delegation_locked(dp); > + list_add(&dp->dl_recall_lru, &reaplist); > } > spin_unlock(&state_lock); > while (!list_empty(&reaplist)) { > dp = list_entry(reaplist.next, struct nfs4_delegation, dl_recall_lru); > - destroy_delegation(dp); > + list_del_init(&dp->dl_recall_lru); > + nfs4_put_delegation(dp); > } > list_splice_init(&clp->cl_revoked, &reaplist); > while (!list_empty(&reaplist)) { > @@ -3662,7 +3661,7 @@ nfs4_open_delegation(struct net *net, struct svc_fh *fh, > open->op_delegate_type = NFS4_OPEN_DELEGATE_READ; > return; > out_free: > - destroy_delegation(dp); > + nfs4_put_delegation(dp); > out_no_deleg: > open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE; > if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS && > @@ -3900,7 +3899,8 @@ nfs4_laundromat(struct nfsd_net *nn) > new_timeo = min(new_timeo, t); > break; > } > - list_move(&dp->dl_recall_lru, &reaplist); > + unhash_delegation_locked(dp); > + list_add(&dp->dl_recall_lru, &reaplist); > } > spin_unlock(&state_lock); > list_for_each_safe(pos, next, &reaplist) { > @@ -5382,12 +5382,8 @@ static u64 nfsd_find_all_delegations(struct nfs4_client *clp, u64 max, > if (dp->dl_time != 0) > continue; > > - /* > - * Increment dl_time to ensure that delegation breaks > - * don't monkey with it now that we are. > - */ > - ++dp->dl_time; > - list_move(&dp->dl_recall_lru, victims); > + unhash_delegation_locked(dp); > + list_add(&dp->dl_recall_lru, victims); > } > if (++count == max) > break; > @@ -5642,12 +5638,14 @@ nfs4_state_shutdown_net(struct net *net) > spin_lock(&state_lock); > list_for_each_safe(pos, next, &nn->del_recall_lru) { > dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); > - list_move(&dp->dl_recall_lru, &reaplist); > + unhash_delegation_locked(dp); > + list_add(&dp->dl_recall_lru, &reaplist); > } > spin_unlock(&state_lock); > list_for_each_safe(pos, next, &reaplist) { > dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); > - destroy_delegation(dp); > + list_del_init(&dp->dl_recall_lru); > + nfs4_put_delegation(dp); > } > > nfsd4_client_tracking_exit(net); > -- > 1.9.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 29 Jul 2014 10:53:31 -0400 "J. Bruce Fields" <bfields@fieldses.org> wrote: > On Fri, Jul 25, 2014 at 07:34:20AM -0400, Jeff Layton wrote: > > @@ -698,11 +699,10 @@ static void revoke_delegation(struct nfs4_delegation *dp) > > struct nfs4_client *clp = dp->dl_stid.sc_client; > > > > if (clp->cl_minorversion == 0) > > - destroy_delegation(dp); > > + destroy_revoked_delegation(dp); > > I don't understand this one--in the NFSv4.0 case, when is the delegation > unhashed? > > (And, apologies if that's a repeat question. I remember wondering about > this before but can't find mail in the archives....) > > --b. > It's unhashed by the laundromat (or the fault injection code). The deltas that change that are later in this patch, but it doesn't have much context so it's a little tricky to spot. Here's the relevant code chunk from nfs4_laundromat: ---------------[snip]----------------- spin_lock(&state_lock); list_for_each_safe(pos, next, &nn->del_recall_lru) { dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); if (net_generic(dp->dl_stid.sc_client->net, nfsd_net_id) != nn) continue; if (time_after((unsigned long)dp->dl_time, (unsigned long)cutoff)) { t = dp->dl_time - cutoff; new_timeo = min(new_timeo, t); break; } unhash_delegation_locked(dp); list_add(&dp->dl_recall_lru, &reaplist); } spin_unlock(&state_lock); list_for_each_safe(pos, next, &reaplist) { dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); revoke_delegation(dp); } ---------------[snip]----------------- ...so the laundromat walks the nn->del_recall_lru list, unhashes any delegation that has expired and gathers them up onto the list. Then, it calls revoke_delegation on each outside of the lock. As a side note, that net_generic comparison there looks bogus to me. How could you ever end up with an entry from a different namespace on this list? I left it in for now since it didn't seem relevant (or terribly expensive), but I suspect that it can be removed (or turned into a WARN or something). > > else { > > - unhash_delegation(dp); > > dp->dl_stid.sc_type = NFS4_REVOKED_DELEG_STID; > > - list_add(&dp->dl_recall_lru, &clp->cl_revoked); > > + list_move(&dp->dl_recall_lru, &clp->cl_revoked); > > } > > } > > > > @@ -1458,15 +1458,14 @@ destroy_client(struct nfs4_client *clp) > > spin_lock(&state_lock); > > while (!list_empty(&clp->cl_delegations)) { > > dp = list_entry(clp->cl_delegations.next, struct > > nfs4_delegation, dl_perclnt); > > - list_del_init(&dp->dl_perclnt); > > - /* Ensure that deleg break won't try to requeue it > > */ > > - ++dp->dl_time; > > - list_move(&dp->dl_recall_lru, &reaplist); > > + unhash_delegation_locked(dp); > > + list_add(&dp->dl_recall_lru, &reaplist); > > } > > spin_unlock(&state_lock); > > while (!list_empty(&reaplist)) { > > dp = list_entry(reaplist.next, struct > > nfs4_delegation, dl_recall_lru); > > - destroy_delegation(dp); > > + list_del_init(&dp->dl_recall_lru); > > + nfs4_put_delegation(dp); > > } > > list_splice_init(&clp->cl_revoked, &reaplist); > > while (!list_empty(&reaplist)) { > > @@ -3662,7 +3661,7 @@ nfs4_open_delegation(struct net *net, struct > > svc_fh *fh, open->op_delegate_type = NFS4_OPEN_DELEGATE_READ; > > return; > > out_free: > > - destroy_delegation(dp); > > + nfs4_put_delegation(dp); > > out_no_deleg: > > open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE; > > if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS && > > @@ -3900,7 +3899,8 @@ nfs4_laundromat(struct nfsd_net *nn) > > new_timeo = min(new_timeo, t); > > break; > > } > > - list_move(&dp->dl_recall_lru, &reaplist); > > + unhash_delegation_locked(dp); > > + list_add(&dp->dl_recall_lru, &reaplist); > > } > > spin_unlock(&state_lock); > > list_for_each_safe(pos, next, &reaplist) { > > @@ -5382,12 +5382,8 @@ static u64 nfsd_find_all_delegations(struct > > nfs4_client *clp, u64 max, if (dp->dl_time != 0) > > continue; > > > > - /* > > - * Increment dl_time to ensure that > > delegation breaks > > - * don't monkey with it now that we are. > > - */ > > - ++dp->dl_time; > > - list_move(&dp->dl_recall_lru, victims); > > + unhash_delegation_locked(dp); > > + list_add(&dp->dl_recall_lru, victims); > > } > > if (++count == max) > > break; > > @@ -5642,12 +5638,14 @@ nfs4_state_shutdown_net(struct net *net) > > spin_lock(&state_lock); > > list_for_each_safe(pos, next, &nn->del_recall_lru) { > > dp = list_entry (pos, struct nfs4_delegation, > > dl_recall_lru); > > - list_move(&dp->dl_recall_lru, &reaplist); > > + unhash_delegation_locked(dp); > > + list_add(&dp->dl_recall_lru, &reaplist); > > } > > spin_unlock(&state_lock); > > list_for_each_safe(pos, next, &reaplist) { > > dp = list_entry (pos, struct nfs4_delegation, > > dl_recall_lru); > > - destroy_delegation(dp); > > + list_del_init(&dp->dl_recall_lru); > > + nfs4_put_delegation(dp); > > } > > > > nfsd4_client_tracking_exit(net); > > -- > > 1.9.3 > >
On Tue, Jul 29, 2014 at 12:41:43PM -0400, Jeff Layton wrote: > On Tue, 29 Jul 2014 10:53:31 -0400 > "J. Bruce Fields" <bfields@fieldses.org> wrote: > > > On Fri, Jul 25, 2014 at 07:34:20AM -0400, Jeff Layton wrote: > > > @@ -698,11 +699,10 @@ static void revoke_delegation(struct nfs4_delegation *dp) > > > struct nfs4_client *clp = dp->dl_stid.sc_client; > > > > > > if (clp->cl_minorversion == 0) > > > - destroy_delegation(dp); > > > + destroy_revoked_delegation(dp); > > > > I don't understand this one--in the NFSv4.0 case, when is the delegation > > unhashed? > > > > (And, apologies if that's a repeat question. I remember wondering about > > this before but can't find mail in the archives....) > > > > --b. > > > > It's unhashed by the laundromat (or the fault injection code). The > deltas that change that are later in this patch, but it doesn't have > much context so it's a little tricky to spot. Here's the relevant code > chunk from nfs4_laundromat: > > ---------------[snip]----------------- > spin_lock(&state_lock); > list_for_each_safe(pos, next, &nn->del_recall_lru) { > dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); > if (net_generic(dp->dl_stid.sc_client->net, nfsd_net_id) != nn) > continue; > if (time_after((unsigned long)dp->dl_time, (unsigned long)cutoff)) { > t = dp->dl_time - cutoff; > new_timeo = min(new_timeo, t); > break; > } > unhash_delegation_locked(dp); > list_add(&dp->dl_recall_lru, &reaplist); > } > spin_unlock(&state_lock); > list_for_each_safe(pos, next, &reaplist) { > dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); > revoke_delegation(dp); > } > ---------------[snip]----------------- > > ...so the laundromat walks the nn->del_recall_lru list, unhashes any > delegation that has expired and gathers them up onto the list. Then, it > calls revoke_delegation on each outside of the lock. Got it, thanks. > As a side note, that net_generic comparison there looks bogus to me. > How could you ever end up with an entry from a different namespace on > this list? I left it in for now since it didn't seem relevant (or > terribly expensive), but I suspect that it can be removed (or turned > into a WARN or something). Looks like this was an oversight from e8c69d17d1ef. I'd be fine with just removing it. --b. > > > > else { > > > - unhash_delegation(dp); > > > dp->dl_stid.sc_type = NFS4_REVOKED_DELEG_STID; > > > - list_add(&dp->dl_recall_lru, &clp->cl_revoked); > > > + list_move(&dp->dl_recall_lru, &clp->cl_revoked); > > > } > > > } > > > > > > @@ -1458,15 +1458,14 @@ destroy_client(struct nfs4_client *clp) > > > spin_lock(&state_lock); > > > while (!list_empty(&clp->cl_delegations)) { > > > dp = list_entry(clp->cl_delegations.next, struct > > > nfs4_delegation, dl_perclnt); > > > - list_del_init(&dp->dl_perclnt); > > > - /* Ensure that deleg break won't try to requeue it > > > */ > > > - ++dp->dl_time; > > > - list_move(&dp->dl_recall_lru, &reaplist); > > > + unhash_delegation_locked(dp); > > > + list_add(&dp->dl_recall_lru, &reaplist); > > > } > > > spin_unlock(&state_lock); > > > while (!list_empty(&reaplist)) { > > > dp = list_entry(reaplist.next, struct > > > nfs4_delegation, dl_recall_lru); > > > - destroy_delegation(dp); > > > + list_del_init(&dp->dl_recall_lru); > > > + nfs4_put_delegation(dp); > > > } > > > list_splice_init(&clp->cl_revoked, &reaplist); > > > while (!list_empty(&reaplist)) { > > > @@ -3662,7 +3661,7 @@ nfs4_open_delegation(struct net *net, struct > > > svc_fh *fh, open->op_delegate_type = NFS4_OPEN_DELEGATE_READ; > > > return; > > > out_free: > > > - destroy_delegation(dp); > > > + nfs4_put_delegation(dp); > > > out_no_deleg: > > > open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE; > > > if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS && > > > @@ -3900,7 +3899,8 @@ nfs4_laundromat(struct nfsd_net *nn) > > > new_timeo = min(new_timeo, t); > > > break; > > > } > > > - list_move(&dp->dl_recall_lru, &reaplist); > > > + unhash_delegation_locked(dp); > > > + list_add(&dp->dl_recall_lru, &reaplist); > > > } > > > spin_unlock(&state_lock); > > > list_for_each_safe(pos, next, &reaplist) { > > > @@ -5382,12 +5382,8 @@ static u64 nfsd_find_all_delegations(struct > > > nfs4_client *clp, u64 max, if (dp->dl_time != 0) > > > continue; > > > > > > - /* > > > - * Increment dl_time to ensure that > > > delegation breaks > > > - * don't monkey with it now that we are. > > > - */ > > > - ++dp->dl_time; > > > - list_move(&dp->dl_recall_lru, victims); > > > + unhash_delegation_locked(dp); > > > + list_add(&dp->dl_recall_lru, victims); > > > } > > > if (++count == max) > > > break; > > > @@ -5642,12 +5638,14 @@ nfs4_state_shutdown_net(struct net *net) > > > spin_lock(&state_lock); > > > list_for_each_safe(pos, next, &nn->del_recall_lru) { > > > dp = list_entry (pos, struct nfs4_delegation, > > > dl_recall_lru); > > > - list_move(&dp->dl_recall_lru, &reaplist); > > > + unhash_delegation_locked(dp); > > > + list_add(&dp->dl_recall_lru, &reaplist); > > > } > > > spin_unlock(&state_lock); > > > list_for_each_safe(pos, next, &reaplist) { > > > dp = list_entry (pos, struct nfs4_delegation, > > > dl_recall_lru); > > > - destroy_delegation(dp); > > > + list_del_init(&dp->dl_recall_lru); > > > + nfs4_put_delegation(dp); > > > } > > > > > > nfsd4_client_tracking_exit(net); > > > -- > > > 1.9.3 > > > > > > -- > Jeff Layton <jlayton@primarydata.com> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index fdbfbcb70914..618daa0d4109 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -661,13 +661,13 @@ hash_delegation_locked(struct nfs4_delegation *dp, struct nfs4_file *fp) list_add(&dp->dl_perclnt, &dp->dl_stid.sc_client->cl_delegations); } -/* Called under the state lock. */ static void -unhash_delegation(struct nfs4_delegation *dp) +unhash_delegation_locked(struct nfs4_delegation *dp) { struct nfs4_file *fp = dp->dl_file; - spin_lock(&state_lock); + lockdep_assert_held(&state_lock); + dp->dl_stid.sc_type = NFS4_CLOSED_DELEG_STID; /* Ensure that deleg break won't try to requeue it */ ++dp->dl_time; @@ -678,7 +678,6 @@ unhash_delegation(struct nfs4_delegation *dp) spin_unlock(&fp->fi_lock); if (fp) nfs4_put_deleg_lease(fp); - spin_unlock(&state_lock); } static void destroy_revoked_delegation(struct nfs4_delegation *dp) @@ -689,7 +688,9 @@ static void destroy_revoked_delegation(struct nfs4_delegation *dp) static void destroy_delegation(struct nfs4_delegation *dp) { - unhash_delegation(dp); + spin_lock(&state_lock); + unhash_delegation_locked(dp); + spin_unlock(&state_lock); nfs4_put_delegation(dp); } @@ -698,11 +699,10 @@ static void revoke_delegation(struct nfs4_delegation *dp) struct nfs4_client *clp = dp->dl_stid.sc_client; if (clp->cl_minorversion == 0) - destroy_delegation(dp); + destroy_revoked_delegation(dp); else { - unhash_delegation(dp); dp->dl_stid.sc_type = NFS4_REVOKED_DELEG_STID; - list_add(&dp->dl_recall_lru, &clp->cl_revoked); + list_move(&dp->dl_recall_lru, &clp->cl_revoked); } } @@ -1458,15 +1458,14 @@ destroy_client(struct nfs4_client *clp) spin_lock(&state_lock); while (!list_empty(&clp->cl_delegations)) { dp = list_entry(clp->cl_delegations.next, struct nfs4_delegation, dl_perclnt); - list_del_init(&dp->dl_perclnt); - /* Ensure that deleg break won't try to requeue it */ - ++dp->dl_time; - list_move(&dp->dl_recall_lru, &reaplist); + unhash_delegation_locked(dp); + list_add(&dp->dl_recall_lru, &reaplist); } spin_unlock(&state_lock); while (!list_empty(&reaplist)) { dp = list_entry(reaplist.next, struct nfs4_delegation, dl_recall_lru); - destroy_delegation(dp); + list_del_init(&dp->dl_recall_lru); + nfs4_put_delegation(dp); } list_splice_init(&clp->cl_revoked, &reaplist); while (!list_empty(&reaplist)) { @@ -3662,7 +3661,7 @@ nfs4_open_delegation(struct net *net, struct svc_fh *fh, open->op_delegate_type = NFS4_OPEN_DELEGATE_READ; return; out_free: - destroy_delegation(dp); + nfs4_put_delegation(dp); out_no_deleg: open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE; if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS && @@ -3900,7 +3899,8 @@ nfs4_laundromat(struct nfsd_net *nn) new_timeo = min(new_timeo, t); break; } - list_move(&dp->dl_recall_lru, &reaplist); + unhash_delegation_locked(dp); + list_add(&dp->dl_recall_lru, &reaplist); } spin_unlock(&state_lock); list_for_each_safe(pos, next, &reaplist) { @@ -5382,12 +5382,8 @@ static u64 nfsd_find_all_delegations(struct nfs4_client *clp, u64 max, if (dp->dl_time != 0) continue; - /* - * Increment dl_time to ensure that delegation breaks - * don't monkey with it now that we are. - */ - ++dp->dl_time; - list_move(&dp->dl_recall_lru, victims); + unhash_delegation_locked(dp); + list_add(&dp->dl_recall_lru, victims); } if (++count == max) break; @@ -5642,12 +5638,14 @@ nfs4_state_shutdown_net(struct net *net) spin_lock(&state_lock); list_for_each_safe(pos, next, &nn->del_recall_lru) { dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); - list_move(&dp->dl_recall_lru, &reaplist); + unhash_delegation_locked(dp); + list_add(&dp->dl_recall_lru, &reaplist); } spin_unlock(&state_lock); list_for_each_safe(pos, next, &reaplist) { dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); - destroy_delegation(dp); + list_del_init(&dp->dl_recall_lru); + nfs4_put_delegation(dp); } nfsd4_client_tracking_exit(net);