Commit 1ac3629b authored by NeilBrown's avatar NeilBrown Committed by Chuck Lever
Browse files

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: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 3f29cc82

fs/nfsd/nfs4state.c

+84 −1
Original line number Diff line number Diff line
@@ -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 @@ 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;

	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;

}

fs/nfsd/nfsctl.c

+1 −0
Original line number Diff line number Diff line
@@ -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;

fs/nfsd/nfsd.h

+1 −0
Original line number Diff line number Diff line
@@ -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)

fs/nfsd/state.h

+10 −0
Original line number Diff line number Diff line
@@ -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);

fs/nfsd/trace.h

+2 −1
Original line number Diff line number Diff line
@@ -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(