From 1ac3629bf012592cb0320e52a1cceb319a05ad17 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 30 Jan 2024 12:08:26 +1100 Subject: nfsd: prepare for supporting admin-revocation of state The NFSv4 protocol allows state to be revoked by the admin and has error codes which allow this to be communicated to the client. This patch - introduces a new state-id status SC_STATUS_ADMIN_REVOKED which can be set on open, lock, or delegation state. - reports NFS4ERR_ADMIN_REVOKED when these are accessed - introduces a per-client counter of these states and returns SEQ4_STATUS_ADMIN_STATE_REVOKED when the counter is not zero. Decrements this when freeing any admin-revoked state. - introduces stub code to find all interesting states for a given superblock so they can be revoked via the 'unlock_filesystem' file in /proc/fs/nfsd/ No actual states are handled yet. Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Signed-off-by: Chuck Lever --- fs/nfsd/nfs4state.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++- fs/nfsd/nfsctl.c | 1 + fs/nfsd/nfsd.h | 1 + fs/nfsd/state.h | 10 +++++++ fs/nfsd/trace.h | 3 +- 5 files changed, 98 insertions(+), 2 deletions(-) (limited to 'fs/nfsd') diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 86b28dbf1bf2..80b02b528f61 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1210,6 +1210,8 @@ nfs4_put_stid(struct nfs4_stid *s) return; } idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id); + if (s->sc_status & SC_STATUS_ADMIN_REVOKED) + atomic_dec(&s->sc_client->cl_admin_revoked); nfs4_free_cpntf_statelist(clp->net, s); spin_unlock(&clp->cl_lock); s->sc_free(s); @@ -1529,6 +1531,8 @@ static void put_ol_stateid_locked(struct nfs4_ol_stateid *stp, } idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id); + if (s->sc_status & SC_STATUS_ADMIN_REVOKED) + atomic_dec(&s->sc_client->cl_admin_revoked); list_add(&stp->st_locks, reaplist); } @@ -1674,6 +1678,68 @@ static void release_openowner(struct nfs4_openowner *oo) nfs4_put_stateowner(&oo->oo_owner); } +static struct nfs4_stid *find_one_sb_stid(struct nfs4_client *clp, + struct super_block *sb, + unsigned int sc_types) +{ + unsigned long id, tmp; + struct nfs4_stid *stid; + + spin_lock(&clp->cl_lock); + idr_for_each_entry_ul(&clp->cl_stateids, stid, tmp, id) + if ((stid->sc_type & sc_types) && + stid->sc_status == 0 && + stid->sc_file->fi_inode->i_sb == sb) { + refcount_inc(&stid->sc_count); + break; + } + spin_unlock(&clp->cl_lock); + return stid; +} + +/** + * nfsd4_revoke_states - revoke all nfsv4 states associated with given filesystem + * @net: used to identify instance of nfsd (there is one per net namespace) + * @sb: super_block used to identify target filesystem + * + * All nfs4 states (open, lock, delegation, layout) held by the server instance + * and associated with a file on the given filesystem will be revoked resulting + * in any files being closed and so all references from nfsd to the filesystem + * being released. Thus nfsd will no longer prevent the filesystem from being + * unmounted. + * + * The clients which own the states will subsequently being notified that the + * states have been "admin-revoked". + */ +void nfsd4_revoke_states(struct net *net, struct super_block *sb) +{ + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + unsigned int idhashval; + unsigned int sc_types; + + sc_types = 0; + + spin_lock(&nn->client_lock); + for (idhashval = 0; idhashval < CLIENT_HASH_MASK; idhashval++) { + struct list_head *head = &nn->conf_id_hashtbl[idhashval]; + struct nfs4_client *clp; + retry: + list_for_each_entry(clp, head, cl_idhash) { + struct nfs4_stid *stid = find_one_sb_stid(clp, sb, + sc_types); + if (stid) { + spin_unlock(&nn->client_lock); + switch (stid->sc_type) { + } + nfs4_put_stid(stid); + spin_lock(&nn->client_lock); + goto retry; + } + } + } + spin_unlock(&nn->client_lock); +} + static inline int hash_sessionid(struct nfs4_sessionid *sessionid) { @@ -2545,6 +2611,8 @@ static int client_info_show(struct seq_file *m, void *v) } seq_printf(m, "callback state: %s\n", cb_state2str(clp->cl_cb_state)); seq_printf(m, "callback address: %pISpc\n", &clp->cl_cb_conn.cb_addr); + seq_printf(m, "admin-revoked states: %d\n", + atomic_read(&clp->cl_admin_revoked)); drop_client(clp); return 0; @@ -4058,6 +4126,8 @@ out: } if (!list_empty(&clp->cl_revoked)) seq->status_flags |= SEQ4_STATUS_RECALLABLE_STATE_REVOKED; + if (atomic_read(&clp->cl_admin_revoked)) + seq->status_flags |= SEQ4_STATUS_ADMIN_STATE_REVOKED; trace_nfsd_seq4_status(rqstp, seq); out_no_session: if (conn) @@ -4547,7 +4617,9 @@ nfsd4_verify_open_stid(struct nfs4_stid *s) { __be32 ret = nfs_ok; - if (s->sc_status & SC_STATUS_REVOKED) + if (s->sc_status & SC_STATUS_ADMIN_REVOKED) + ret = nfserr_admin_revoked; + else if (s->sc_status & SC_STATUS_REVOKED) ret = nfserr_deleg_revoked; else if (s->sc_status & SC_STATUS_CLOSED) ret = nfserr_bad_stateid; @@ -5136,6 +5208,11 @@ nfs4_check_deleg(struct nfs4_client *cl, struct nfsd4_open *open, deleg = find_deleg_stateid(cl, &open->op_delegate_stateid); if (deleg == NULL) goto out; + if (deleg->dl_stid.sc_status & SC_STATUS_ADMIN_REVOKED) { + nfs4_put_stid(&deleg->dl_stid); + status = nfserr_admin_revoked; + goto out; + } if (deleg->dl_stid.sc_status & SC_STATUS_REVOKED) { nfs4_put_stid(&deleg->dl_stid); status = nfserr_deleg_revoked; @@ -6443,6 +6520,8 @@ nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate, */ statusmask |= SC_STATUS_REVOKED; + statusmask |= SC_STATUS_ADMIN_REVOKED; + if (ZERO_STATEID(stateid) || ONE_STATEID(stateid) || CLOSE_STATEID(stateid)) return nfserr_bad_stateid; @@ -6461,6 +6540,10 @@ nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate, nfs4_put_stid(stid); return nfserr_deleg_revoked; } + if (stid->sc_status & SC_STATUS_ADMIN_REVOKED) { + nfs4_put_stid(stid); + return nfserr_admin_revoked; + } *s = stid; return nfs_ok; } diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 5a5547bd6ecf..ecd18bffeebc 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -281,6 +281,7 @@ static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size) * 3. Is that directory the root of an exported file system? */ error = nlmsvc_unlock_all_by_sb(path.dentry->d_sb); + nfsd4_revoke_states(netns(file), path.dentry->d_sb); path_put(&path); return error; diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index be2ea3d6d2a2..8daf22d766c6 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -275,6 +275,7 @@ void nfsd_lockd_shutdown(void); #define nfserr_no_grace cpu_to_be32(NFSERR_NO_GRACE) #define nfserr_reclaim_bad cpu_to_be32(NFSERR_RECLAIM_BAD) #define nfserr_badname cpu_to_be32(NFSERR_BADNAME) +#define nfserr_admin_revoked cpu_to_be32(NFS4ERR_ADMIN_REVOKED) #define nfserr_cb_path_down cpu_to_be32(NFSERR_CB_PATH_DOWN) #define nfserr_locked cpu_to_be32(NFSERR_LOCKED) #define nfserr_wrongsec cpu_to_be32(NFSERR_WRONGSEC) diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 1d4bf1a7d229..be02bf1a16bd 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -112,6 +112,7 @@ struct nfs4_stid { #define SC_STATUS_CLOSED BIT(0) /* For a deleg stateid kept around only to process free_stateid's: */ #define SC_STATUS_REVOKED BIT(1) +#define SC_STATUS_ADMIN_REVOKED BIT(2) unsigned short sc_status; struct list_head sc_cp_list; @@ -367,6 +368,7 @@ struct nfs4_client { clientid_t cl_clientid; /* generated by server */ nfs4_verifier cl_confirm; /* generated by server */ u32 cl_minorversion; + atomic_t cl_admin_revoked; /* count of admin-revoked states */ /* NFSv4.1 client implementation id: */ struct xdr_netobj cl_nii_domain; struct xdr_netobj cl_nii_name; @@ -730,6 +732,14 @@ static inline void get_nfs4_file(struct nfs4_file *fi) } struct nfsd_file *find_any_file(struct nfs4_file *f); +#ifdef CONFIG_NFSD_V4 +void nfsd4_revoke_states(struct net *net, struct super_block *sb); +#else +static inline void nfsd4_revoke_states(struct net *net, struct super_block *sb) +{ +} +#endif + /* grace period management */ void nfsd4_end_grace(struct nfsd_net *nn); diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h index f87dad1fa1d6..d8e56268a250 100644 --- a/fs/nfsd/trace.h +++ b/fs/nfsd/trace.h @@ -653,7 +653,8 @@ DEFINE_STATESEQID_EVENT(open_confirm); #define show_stid_status(x) \ __print_flags(x, "|", \ { SC_STATUS_CLOSED, "CLOSED" }, \ - { SC_STATUS_REVOKED, "REVOKED" }) \ + { SC_STATUS_REVOKED, "REVOKED" }, \ + { SC_STATUS_ADMIN_REVOKED, "ADMIN_REVOKED" }) DECLARE_EVENT_CLASS(nfsd_stid_class, TP_PROTO( -- cgit v1.2.3