[PATCH v6 11/18] nfs: implement v3 and v4 client support for NFS_LOCALIO_PROGRAM

Mike Snitzer
2024-06-19T20:40:49Z

LOCALIOPROC_GETUUID allows client to discover server's uuid.

nfs_local_probe() will retrieve server's uuid via LOCALIO protocol and
verify the server with that uuid it is known to be local. This ensures
client and server 1: support localio 2: are local to each other.

While doing so, factor out nfs_init_localioclient() so it is used by
both nfs3client.c and nfs4client.c

Get nfsd_open_local_fh and store it in rpc_client during client
creation, put the symbol during nfs_local_disable -- which is also
called during client destruction.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
fs/nfs/client.c | 6 ++-
fs/nfs/internal.h | 27 ++++++++++++
fs/nfs/localio.c | 90 ++++++++++++++++++++++++++++++++++++----
fs/nfs/nfs3_fs.h | 1 +
fs/nfs/nfs3client.c | 25 +++++++++++
fs/nfs/nfs3proc.c | 3 ++
fs/nfs/nfs3xdr.c | 67 ++++++++++++++++++++++++++++++
fs/nfs/nfs4_fs.h | 2 +
fs/nfs/nfs4client.c | 23 ++++++++++
fs/nfs/nfs4proc.c | 3 ++
fs/nfs/nfs4xdr.c | 52 +++++++++++++++++++++++
include/linux/nfs_xdr.h | 10 +++++
include/uapi/linux/nfs.h | 4 ++
13 files changed, 302 insertions(+), 11 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 1300c388f971..6faa9fdc444d 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -434,8 +434,10 @@ struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
list_add_tail(&new->cl_share_link,
&nn->nfs_client_list);
spin_unlock(&nn->nfs_client_lock);
- nfs_local_probe(new);
- return rpc_ops->init_client(new, cl_init);
+ new = rpc_ops->init_client(new, cl_init);
+ if (!IS_ERR(new))
+ nfs_local_probe(new);
+ return new;
}

spin_unlock(&nn->nfs_client_lock);
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 9251a357d097..404524cd4d4a 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -453,6 +453,33 @@ extern bool nfs_check_cache_invalid(struct inode *, unsigned long);
extern int nfs_wait_bit_killable(struct wait_bit_key *key, int mode);

#if IS_ENABLED(CONFIG_NFS_LOCALIO)
+/*
+ * Initialise an NFS localio client connection.
+ * Inlined here to allow nfs[34]client.c to share this code.
+ */
+static __always_inline void
+nfs_init_localioclient(struct nfs_client *clp,
+ const struct rpc_program *program, u32 vers)
+{
+ if (unlikely(!IS_ERR(clp->cl_rpcclient_localio)))
+ goto out;
+ clp->cl_rpcclient_localio = rpc_bind_new_program(clp->cl_rpcclient,
+ program, vers);
+ if (IS_ERR(clp->cl_rpcclient_localio))
+ goto out;
+ /* No errors! Assume that localio is supported */
+ clp->nfsd_open_local_fh = get_nfsd_open_local_fh();
+ if (!clp->nfsd_open_local_fh) {
+ rpc_shutdown_client(clp->cl_rpcclient_localio);
+ clp->cl_rpcclient_localio = ERR_PTR(-EINVAL);
+ }
+out:
+ dfprintk_rcu(CLIENT, "%s: server (%s) %s NFSv%u LOCALIO, nfsd_open_local_fh is %s.\n",
+ __func__, rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR),
+ (IS_ERR(clp->cl_rpcclient_localio) ? "does not support" : "supports"), vers,
+ (clp->nfsd_open_local_fh ? "set" : "not set"));
+}
+
/* localio.c */
extern void nfs_local_disable(struct nfs_client *);
extern void nfs_local_probe(struct nfs_client *);
diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index a0577bbd71ad..27fc941d9dfa 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -15,6 +15,7 @@
#include <linux/sunrpc/addr.h>
#include <linux/inetdevice.h>
#include <net/addrconf.h>
+#include <linux/nfslocalio.h>
#include <linux/module.h>
#include <linux/bvec.h>

@@ -123,10 +124,14 @@ nfs4errno(int errno)
static bool localio_enabled __read_mostly = true;
module_param(localio_enabled, bool, 0644);

+static inline bool nfs_client_is_local(const struct nfs_client *clp)
+{
+ return !!test_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
+}
+
bool nfs_server_is_local(const struct nfs_client *clp)
{
- return test_bit(NFS_CS_LOCAL_IO, &clp->cl_flags) != 0 &&
- localio_enabled;
+ return nfs_client_is_local(clp) && localio_enabled;
}
EXPORT_SYMBOL_GPL(nfs_server_is_local);

@@ -149,20 +154,86 @@ void nfs_local_disable(struct nfs_client *clp)
{
if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
trace_nfs_local_disable(clp);
+ put_nfsd_open_local_fh();
+ clp->nfsd_open_local_fh = NULL;
+ if (!IS_ERR(clp->cl_rpcclient_localio)) {
+ rpc_shutdown_client(clp->cl_rpcclient_localio);
+ clp->cl_rpcclient_localio = ERR_PTR(-EINVAL);
+ }
clp->cl_nfssvc_net = NULL;
}
}

+static bool nfs_local_server_getuuid(struct nfs_client *clp, uuid_t *nfsd_uuid)
+{
+ u8 uuid[UUID_SIZE];
+ struct nfs_getuuidres res = {
+ uuid,
+ };
+ struct rpc_message msg = {
+ .rpc_resp = &res,
+ };
+ int status;
+
+ clp->rpc_ops->init_localioclient(clp);
+ if (IS_ERR(clp->cl_rpcclient_localio))
+ return false;
+
+ dprintk("%s: NFS issuing getuuid\n", __func__);
+ msg.rpc_proc = &clp->cl_rpcclient_localio->cl_procinfo[LOCALIOPROC_GETUUID];
+ status = rpc_call_sync(clp->cl_rpcclient_localio, &msg, 0);
+ dprintk("%s: NFS reply getuuid: status=%d uuid=%pU\n",
+ __func__, status, res.uuid);
+ if (status)
+ return false;
+
+ import_uuid(nfsd_uuid, res.uuid);
+
+ return true;
+}
+
/*
- * nfs_local_probe - probe local i/o support for an nfs_client
+ * nfs_local_probe - probe local i/o support for an nfs_server and nfs_client
+ * - called after alloc_client and init_client (so cl_rpcclient exists)
+ * - this function is idempotent, it can be called for old or new clients
*/
-void
-nfs_local_probe(struct nfs_client *clp)
+void nfs_local_probe(struct nfs_client *clp)
{
- bool enable = false;
+ uuid_t uuid;
+ struct net *net = NULL;

- if (enable)
- nfs_local_enable(clp);
+ if (!localio_enabled)
+ goto unsupported;
+
+ if (nfs_client_is_local(clp)) {
+ /* If already enabled, disable and re-enable */
+ nfs_local_disable(clp);
+ }
+
+ switch (clp->cl_rpcclient->cl_vers) {
+ case 3:
+ case 4:
+ /*
+ * Retrieve server's uuid via LOCALIO protocol and verify the
+ * server with that uuid it is known to be local. This ensures
+ * client and server 1: support localio 2: are local to each other
+ * by verifying client's nfsd, with specified uuid, is local.
+ */
+ if (!nfs_local_server_getuuid(clp, &uuid) ||
+ !nfsd_uuid_is_local(&uuid, &net))
+ goto unsupported;
+ break;
+ default:
+ goto unsupported;
+ }
+
+ dprintk("%s: detected local server.\n", __func__);
+ nfs_local_enable(clp, net);
+ return;
+
+unsupported:
+ /* localio not supported */
+ nfs_local_disable(clp);
}
EXPORT_SYMBOL_GPL(nfs_local_probe);

@@ -189,7 +260,8 @@ nfs_local_open_fh(struct nfs_client *clp, const struct cred *cred,
trace_nfs_local_open_fh(fh, mode, status);
switch (status) {
case -ENXIO:
- nfs_local_disable(clp);
+ /* Revalidate localio, will disable if unsupported */
+ nfs_local_probe(clp);
fallthrough;
case -ETIMEDOUT:
status = -EAGAIN;
diff --git a/fs/nfs/nfs3_fs.h b/fs/nfs/nfs3_fs.h
index b333ea119ef5..efdf2b6519e9 100644
--- a/fs/nfs/nfs3_fs.h
+++ b/fs/nfs/nfs3_fs.h
@@ -30,6 +30,7 @@ static inline int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
struct nfs_server *nfs3_create_server(struct fs_context *);
struct nfs_server *nfs3_clone_server(struct nfs_server *, struct nfs_fh *,
struct nfs_fattr *, rpc_authflavor_t);
+void nfs3_init_localioclient(struct nfs_client *);

/* nfs3super.c */
extern struct nfs_subversion nfs_v3;
diff --git a/fs/nfs/nfs3client.c b/fs/nfs/nfs3client.c
index b0c8a39c2bbd..123e7c1fd339 100644
--- a/fs/nfs/nfs3client.c
+++ b/fs/nfs/nfs3client.c
@@ -7,6 +7,8 @@
#include "netns.h"
#include "sysfs.h"

+#define NFSDBG_FACILITY NFSDBG_CLIENT
+
#ifdef CONFIG_NFS_V3_ACL
static struct rpc_stat nfsacl_rpcstat = { &nfsacl_program };
static const struct rpc_version *nfsacl_version[] = {
@@ -130,3 +132,26 @@ struct nfs_client *nfs3_set_ds_client(struct nfs_server *mds_srv,
return clp;
}
EXPORT_SYMBOL_GPL(nfs3_set_ds_client);
+
+#if defined(CONFIG_NFS_V3_LOCALIO)
+static struct rpc_stat nfslocalio_rpcstat = { &nfslocalio_program3 };
+static const struct rpc_version *nfslocalio_version[] = {
+ [3] = &nfslocalio_version3,
+};
+
+const struct rpc_program nfslocalio_program3 = {
+ .name = "nfslocalio",
+ .number = NFS_LOCALIO_PROGRAM,
+ .nrvers = ARRAY_SIZE(nfslocalio_version),
+ .version = nfslocalio_version,
+ .stats = &nfslocalio_rpcstat,
+};
+
+/*
+ * Initialise an NFSv3 localio client connection
+ */
+void nfs3_init_localioclient(struct nfs_client *clp)
+{
+ nfs_init_localioclient(clp, &nfslocalio_program3, 3);
+}
+#endif /* CONFIG_NFS_V3_LOCALIO */
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 74bda639a7cf..40b6e4d1e7be 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -1067,4 +1067,7 @@ const struct nfs_rpc_ops nfs_v3_clientops = {
.free_client = nfs_free_client,
.create_server = nfs3_create_server,
.clone_server = nfs3_clone_server,
+#if defined(CONFIG_NFS_V3_LOCALIO)
+ .init_localioclient = nfs3_init_localioclient,
+#endif
};
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index 60f032be805a..d2a17ecd12b8 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -2579,3 +2579,70 @@ const struct rpc_version nfsacl_version3 = {
.counts = nfs3_acl_counts,
};
#endif /* CONFIG_NFS_V3_ACL */
+
+#if defined(CONFIG_NFS_V3_LOCALIO)
+
+#define LOCALIO3_getuuidres_sz (1+XDR_QUADLEN(UUID_SIZE))
+
+static void nfs3_xdr_enc_getuuidargs(struct rpc_rqst *req,
+ struct xdr_stream *xdr,
+ const void *data)
+{
+ /* void function */
+}
+
+// FIXME: factor out from fs/nfs/nfs4xdr.c
+static int decode_opaque_fixed(struct xdr_stream *xdr, void *buf, size_t len)
+{
+ ssize_t ret = xdr_stream_decode_opaque_fixed(xdr, buf, len);
+ if (unlikely(ret < 0))
+ return -EIO;
+ return 0;
+}
+
+static inline int nfs3_decode_getuuidresok(struct xdr_stream *xdr,
+ struct nfs_getuuidres *result)
+{
+ return decode_opaque_fixed(xdr, result->uuid, UUID_SIZE);
+}
+
+static int nfs3_xdr_dec_getuuidres(struct rpc_rqst *req,
+ struct xdr_stream *xdr,
+ void *result)
+{
+ enum nfs_stat status;
+ int error;
+
+ error = decode_nfsstat3(xdr, &status);
+ if (unlikely(error))
+ goto out;
+ if (status != NFS3_OK)
+ goto out_default;
+ error = nfs3_decode_getuuidresok(xdr, result);
+out:
+ return error;
+out_default:
+ return nfs3_stat_to_errno(status);
+}
+
+static const struct rpc_procinfo nfs3_localio_procedures[] = {
+ [LOCALIOPROC_GETUUID] = {
+ .p_proc = LOCALIOPROC_GETUUID,
+ .p_encode = nfs3_xdr_enc_getuuidargs,
+ .p_decode = nfs3_xdr_dec_getuuidres,
+ .p_arglen = 1,
+ .p_replen = LOCALIO3_getuuidres_sz,
+ .p_timer = 0,
+ .p_name = "GETUUID",
+ },
+};
+
+static unsigned int nfs3_localio_counts[ARRAY_SIZE(nfs3_localio_procedures)];
+const struct rpc_version nfslocalio_version3 = {
+ .number = 3,
+ .nrprocs = ARRAY_SIZE(nfs3_localio_procedures),
+ .procs = nfs3_localio_procedures,
+ .counts = nfs3_localio_counts,
+};
+
+#endif /* CONFIG_NFS_V3_LOCALIO */
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 7024230f0d1d..a0a41917dec2 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -538,6 +538,8 @@ extern int nfs4_proc_commit(struct file *dst, __u64 offset, __u32 count, struct
extern const nfs4_stateid zero_stateid;
extern const nfs4_stateid invalid_stateid;

+extern void nfs4_init_localioclient(struct nfs_client *);
+
/* nfs4super.c */
struct nfs_mount_info;
extern struct nfs_subversion nfs_v4;
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 84573df5cf5a..d2f634aa1e1b 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -1384,3 +1384,26 @@ int nfs4_update_server(struct nfs_server *server, const char *hostname,

return nfs_probe_server(server, NFS_FH(d_inode(server->super->s_root)));
}
+
+#if defined(CONFIG_NFS_V4_LOCALIO)
+static struct rpc_stat nfslocalio_rpcstat = { &nfslocalio_program4 };
+static const struct rpc_version *nfslocalio_version[] = {
+ [4] = &nfslocalio_version4,
+};
+
+const struct rpc_program nfslocalio_program4 = {
+ .name = "nfslocalio",
+ .number = NFS_LOCALIO_PROGRAM,
+ .nrvers = ARRAY_SIZE(nfslocalio_version),
+ .version = nfslocalio_version,
+ .stats = &nfslocalio_rpcstat,
+};
+
+/*
+ * Initialise an NFSv4 localio client connection
+ */
+void nfs4_init_localioclient(struct nfs_client *clp)
+{
+ nfs_init_localioclient(clp, &nfslocalio_program4, 4);
+}
+#endif /* CONFIG_NFS_V4_LOCALIO */
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index c93c12063b3a..060bc8dbee61 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -10745,6 +10745,9 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
.discover_trunking = nfs4_discover_trunking,
.enable_swap = nfs4_enable_swap,
.disable_swap = nfs4_disable_swap,
+#if defined(CONFIG_NFS_V4_LOCALIO)
+ .init_localioclient = nfs4_init_localioclient,
+#endif
};

static const struct xattr_handler nfs4_xattr_nfs4_acl_handler = {
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 1416099dfcd1..d3b4fa3245f0 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -7728,3 +7728,55 @@ const struct rpc_version nfs_version4 = {
.procs = nfs4_procedures,
.counts = nfs_version4_counts,
};
+
+#if defined(CONFIG_NFS_V4_LOCALIO)
+
+#define LOCALIO4_getuuidres_sz (op_decode_hdr_maxsz+XDR_QUADLEN(UUID_SIZE))
+
+static void nfs4_xdr_enc_getuuidargs(struct rpc_rqst *req,
+ struct xdr_stream *xdr,
+ const void *data)
+{
+ /* void function */
+}
+
+static inline int nfs4_decode_getuuidresok(struct xdr_stream *xdr,
+ struct nfs_getuuidres *result)
+{
+ return decode_opaque_fixed(xdr, result->uuid, UUID_SIZE);
+}
+
+static int nfs4_xdr_dec_getuuidres(struct rpc_rqst *req,
+ struct xdr_stream *xdr,
+ void *result)
+{
+ // FIXME: need proper handling that isn't abusing nfs_opnum4
+ int error = decode_op_hdr(xdr, LOCALIOPROC_GETUUID);
+ if (unlikely(error))
+ goto out;
+ error = nfs4_decode_getuuidresok(xdr, result);
+out:
+ return error;
+}
+
+static const struct rpc_procinfo nfs4_localio_procedures[] = {
+ [LOCALIOPROC_GETUUID] = {
+ .p_proc = LOCALIOPROC_GETUUID,
+ .p_encode = nfs4_xdr_enc_getuuidargs,
+ .p_decode = nfs4_xdr_dec_getuuidres,
+ .p_arglen = 1,
+ .p_replen = LOCALIO4_getuuidres_sz,
+ .p_statidx = LOCALIOPROC_GETUUID,
+ .p_name = "GETUUID",
+ },
+};
+
+static unsigned int nfs4_localio_counts[ARRAY_SIZE(nfs4_localio_procedures)];
+const struct rpc_version nfslocalio_version4 = {
+ .number = 4,
+ .nrprocs = ARRAY_SIZE(nfs4_localio_procedures),
+ .procs = nfs4_localio_procedures,
+ .counts = nfs4_localio_counts,
+};
+
+#endif /* CONFIG_NFS_V4_LOCALIO */
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 764513a61601..2a438f4c2d6d 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1002,6 +1002,10 @@ struct nfs3_getaclres {
struct posix_acl * acl_default;
};

+struct nfs_getuuidres {
+ __u8 * uuid;
+};
+
#if IS_ENABLED(CONFIG_NFS_V4)

typedef u64 clientid4;
@@ -1819,6 +1823,7 @@ struct nfs_rpc_ops {
int (*discover_trunking)(struct nfs_server *, struct nfs_fh *);
void (*enable_swap)(struct inode *inode);
void (*disable_swap)(struct inode *inode);
+ void (*init_localioclient)(struct nfs_client *);
};

/*
@@ -1834,4 +1839,9 @@ extern const struct rpc_version nfs_version4;
extern const struct rpc_version nfsacl_version3;
extern const struct rpc_program nfsacl_program;

+extern const struct rpc_version nfslocalio_version3;
+extern const struct rpc_program nfslocalio_program3;
+extern const struct rpc_version nfslocalio_version4;
+extern const struct rpc_program nfslocalio_program4;
+
#endif
diff --git a/include/uapi/linux/nfs.h b/include/uapi/linux/nfs.h
index f356f2ba3814..81eb865d99ef 100644
--- a/include/uapi/linux/nfs.h
+++ b/include/uapi/linux/nfs.h
@@ -33,6 +33,10 @@
#define NFS_MNT_VERSION 1
#define NFS_MNT3_VERSION 3

+#define NFS_LOCALIO_PROGRAM 0x20000002
+#define LOCALIOPROC_NULL 0
+#define LOCALIOPROC_GETUUID 1
+
#define NFS_PIPE_DIRNAME "nfs"

/*
--
2.44.0