[PATCH 05/11] nfsd: prepare for supporting admin-revocation of state
From: NeilBrown <hidden>
Date: 2023-11-24 04:20:34
Subsystem:
filesystems (vfs and infrastructure), kernel nfsd, sunrpc, and lockd servers, the rest · Maintainers:
Alexander Viro, Christian Brauner, Chuck Lever, Jeff Layton, Linus Torvalds
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 NFS4_STID_ADMIN_REVOKE 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. Signed-off-by: NeilBrown <redacted> --- fs/nfsd/nfs4state.c | 71 ++++++++++++++++++++++++++++++++++++++++++++- fs/nfsd/nfsctl.c | 1 + fs/nfsd/nfsd.h | 1 + fs/nfsd/state.h | 10 +++++++ fs/nfsd/trace.h | 3 +- 5 files changed, 84 insertions(+), 2 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index b9239f2ebc79..477a9e9aebbd 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c@@ -1215,6 +1215,8 @@ nfs4_put_stid(struct nfs4_stid *s) return; } idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id); + if (s->sc_status & NFS4_STID_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);
@@ -1534,6 +1536,8 @@ 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 & NFS4_STID_ADMIN_REVOKED) + atomic_dec(&s->sc_client->cl_admin_revoked); list_add(&stp->st_locks, reaplist); }
@@ -1679,6 +1683,54 @@ 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; +} + +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) {
@@ -2550,6 +2602,8 @@ 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;
@@ -4109,6 +4163,8 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, } 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; out_no_session: if (conn) free_conn(conn);
@@ -4597,7 +4653,9 @@ nfsd4_verify_open_stid(struct nfs4_stid *s) { __be32 ret = nfs_ok; - if (s->sc_status & NFS4_STID_REVOKED) + if (s->sc_status & NFS4_STID_ADMIN_REVOKED) + ret = nfserr_admin_revoked; + else if (s->sc_status & NFS4_STID_REVOKED) ret = nfserr_deleg_revoked; else if (s->sc_status & NFS4_STID_CLOSED) ret = nfserr_bad_stateid;
@@ -5188,6 +5246,11 @@ 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 & NFS4_STID_ADMIN_REVOKED) { + nfs4_put_stid(&deleg->dl_stid); + status = nfserr_admin_revoked; + goto out; + } if (deleg->dl_stid.sc_status & NFS4_STID_REVOKED) { nfs4_put_stid(&deleg->dl_stid); status = nfserr_deleg_revoked;
@@ -6508,6 +6571,8 @@ nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate, */ statusmask |= NFS4_STID_REVOKED; + statusmask |= NFS4_STID_ADMIN_REVOKED; + if (ZERO_STATEID(stateid) || ONE_STATEID(stateid) || CLOSE_STATEID(stateid)) return nfserr_bad_stateid;
@@ -6526,6 +6591,10 @@ nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate, nfs4_put_stid(stid); return nfserr_deleg_revoked; } + if (stid->sc_type & NFS4_STID_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 d6eeee149370..a622d773f428 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c@@ -285,6 +285,7 @@ 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 f5ff42f41ee7..d46203eac3c8 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h@@ -280,6 +280,7 @@ 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 bb00dcd4c1ba..584378c43e0a 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h@@ -112,6 +112,7 @@ struct nfs4_stid { #define NFS4_STID_CLOSED BIT(0) /* For a deleg stateid kept around only to process free_stateid's: */ #define NFS4_STID_REVOKED BIT(1) +#define NFS4_STID_ADMIN_REVOKED BIT(2) unsigned short sc_status; struct list_head sc_cp_list;
@@ -388,6 +389,7 @@ 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;
@@ -752,6 +754,14 @@ 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 568b4ec9a2af..281aeb42c9eb 100644
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h@@ -651,7 +651,8 @@ DEFINE_STATESEQID_EVENT(open_confirm); #define show_stid_status(x) \ __print_flags(x, "|", \ { NFS4_STID_CLOSED, "CLOSED" }, \ - { NFS4_STID_REVOKED, "REVOKED" }) \ + { NFS4_STID_REVOKED, "REVOKED" }, \ + { NFS4_STID_ADMIN_REVOKED, "ADMIN_REVOKED" }) DECLARE_EVENT_CLASS(nfsd_stid_class, TP_PROTO(
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2.42.1