@@ -377,6 +377,9 @@ config NFS_ACL_SUPPORT
tristate
select FS_POSIX_ACL
+config NFS_COMMON_LOCALIO_SUPPORT
+ bool
+
config NFS_COMMON
bool
depends on NFSD || NFS_FS || LOCKD
@@ -90,6 +90,20 @@ config NFSD_V4
If unsure, say N.
+config NFSD_LOCALIO
+ bool "NFS server support for the LOCALIO auxiliary protocol"
+ depends on NFSD
+ select NFS_COMMON_LOCALIO_SUPPORT
+ help
+ Some NFS servers support an auxiliary NFS LOCALIO protocol
+ that is not an official part of the NFS protocol.
+
+ This option enables support for the LOCALIO protocol in the
+ kernel's NFS server. Enable this to bypass using the NFS
+ protocol when issuing reads, writes and commits to the server.
+
+ If unsure, say N.
+
config NFSD_PNFS
bool
@@ -23,3 +23,4 @@ nfsd-$(CONFIG_NFSD_PNFS) += nfs4layouts.o
nfsd-$(CONFIG_NFSD_BLOCKLAYOUT) += blocklayout.o blocklayoutxdr.o
nfsd-$(CONFIG_NFSD_SCSILAYOUT) += blocklayout.o blocklayoutxdr.o
nfsd-$(CONFIG_NFSD_FLEXFILELAYOUT) += flexfilelayout.o flexfilelayoutxdr.o
+nfsd-$(CONFIG_NFSD_LOCALIO) += localio.o
@@ -52,7 +52,7 @@
#define NFSD_FILE_CACHE_UP (0)
/* We only care about NFSD_MAY_READ/WRITE for this cache */
-#define NFSD_FILE_MAY_MASK (NFSD_MAY_READ|NFSD_MAY_WRITE)
+#define NFSD_FILE_MAY_MASK (NFSD_MAY_READ|NFSD_MAY_WRITE|NFSD_MAY_LOCALIO)
static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits);
static DEFINE_PER_CPU(unsigned long, nfsd_file_acquisitions);
new file mode 100644
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * NFS server support for local clients to bypass network stack
+ *
+ * Copyright (C) 2014 Weston Andros Adamson <dros@primarydata.com>
+ * Copyright (C) 2019 Trond Myklebust <trond.myklebust@hammerspace.com>
+ * Copyright (C) 2024 Mike Snitzer <snitzer@hammerspace.com>
+ */
+
+#include <linux/exportfs.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs.h>
+#include <linux/nfs_common.h>
+#include <linux/nfslocalio.h>
+#include <linux/string.h>
+
+#include "nfsd.h"
+#include "vfs.h"
+#include "netns.h"
+#include "filecache.h"
+
+/**
+ * nfsd_open_local_fh - lookup a local filehandle @nfs_fh and map to @file
+ *
+ * @cl_nfssvc_net: the 'struct net' to use to get the proper nfsd_net
+ * @cl_nfssvc_dom: the 'struct auth_domain' required for localio access
+ * @rpc_clnt: rpc_clnt that the client established, used for sockaddr and cred
+ * @cred: cred that the client established
+ * @nfs_fh: filehandle to lookup
+ * @fmode: fmode_t to use for open
+ * @pfilp: returned file pointer that maps to @nfs_fh
+ *
+ * This function maps a local fh to a path on a local filesystem.
+ * This is useful when the nfs client has the local server mounted - it can
+ * avoid all the NFS overhead with reads, writes and commits.
+ *
+ * On successful return, caller is responsible for calling path_put. Also
+ * note that this is called from nfs.ko via find_symbol() to avoid an explicit
+ * dependency on knfsd. So, there is no forward declaration in a header file
+ * for it that is shared with the client.
+ */
+int nfsd_open_local_fh(struct net *cl_nfssvc_net,
+ struct auth_domain *cl_nfssvc_dom,
+ struct rpc_clnt *rpc_clnt,
+ const struct cred *cred,
+ const struct nfs_fh *nfs_fh,
+ const fmode_t fmode,
+ struct file **pfilp)
+{
+ int mayflags = NFSD_MAY_LOCALIO;
+ int status = 0;
+ struct nfsd_net *nn;
+ const struct cred *save_cred;
+ struct svc_cred rq_cred;
+ struct svc_fh fh;
+ struct nfsd_file *nf;
+ __be32 beres;
+
+ if (nfs_fh->size > NFS4_FHSIZE)
+ return -EINVAL;
+
+ /* Not running in nfsd context, must safely get reference on nfsd_serv */
+ cl_nfssvc_net = maybe_get_net(cl_nfssvc_net);
+ if (!cl_nfssvc_net)
+ return -ENXIO;
+ nn = net_generic(cl_nfssvc_net, nfsd_net_id);
+
+ /* The server may already be shutting down, disallow new localio */
+ if (unlikely(!nfsd_serv_try_get(nn))) {
+ status = -ENXIO;
+ goto out_net;
+ }
+
+ /* Save client creds before calling nfsd_file_acquire_local which calls nfsd_setuser */
+ save_cred = get_current_cred();
+
+ /* nfs_fh -> svc_fh */
+ fh_init(&fh, NFS4_FHSIZE);
+ fh.fh_handle.fh_size = nfs_fh->size;
+ memcpy(fh.fh_handle.fh_raw, nfs_fh->data, nfs_fh->size);
+
+ if (fmode & FMODE_READ)
+ mayflags |= NFSD_MAY_READ;
+ if (fmode & FMODE_WRITE)
+ mayflags |= NFSD_MAY_WRITE;
+
+ rpcauth_map_clnt_to_svc_cred_local(rpc_clnt, cred, &rq_cred);
+
+ beres = nfsd_file_acquire_local(cl_nfssvc_net, &rq_cred, rpc_clnt->cl_vers,
+ cl_nfssvc_dom, &fh, mayflags, &nf);
+ if (beres) {
+ status = nfs_stat_to_errno(be32_to_cpu(beres));
+ goto out_fh_put;
+ }
+ *pfilp = get_file(nf->nf_file);
+ nfsd_file_put(nf);
+out_fh_put:
+ fh_put(&fh);
+ if (rq_cred.cr_group_info)
+ put_group_info(rq_cred.cr_group_info);
+ revert_creds(save_cred);
+ nfsd_serv_put(nn);
+out_net:
+ put_net(cl_nfssvc_net);
+ return status;
+}
+EXPORT_SYMBOL_GPL(nfsd_open_local_fh);
+
+/* Compile time type checking, not used by anything */
+static nfs_to_nfsd_open_t __maybe_unused nfsd_open_local_fh_typecheck = nfsd_open_local_fh;
@@ -13,6 +13,7 @@
#include <linux/filelock.h>
#include <linux/nfs4.h>
#include <linux/percpu_counter.h>
+#include <linux/percpu-refcount.h>
#include <linux/siphash.h>
#include <linux/sunrpc/stats.h>
@@ -139,7 +140,9 @@ struct nfsd_net {
struct svc_info nfsd_info;
#define nfsd_serv nfsd_info.serv
-
+ struct percpu_ref nfsd_serv_ref;
+ struct completion nfsd_serv_confirm_done;
+ struct completion nfsd_serv_free_done;
/*
* clientid and stateid data for construction of net unique COPY
@@ -221,6 +224,9 @@ struct nfsd_net {
extern bool nfsd_support_version(int vers);
extern unsigned int nfsd_net_id;
+bool nfsd_serv_try_get(struct nfsd_net *nn);
+void nfsd_serv_put(struct nfsd_net *nn);
+
void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn);
void nfsd_reset_write_verifier(struct nfsd_net *nn);
#endif /* __NFSD_NETNS_H__ */
@@ -193,6 +193,30 @@ int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change
return 0;
}
+bool nfsd_serv_try_get(struct nfsd_net *nn)
+{
+ return percpu_ref_tryget_live(&nn->nfsd_serv_ref);
+}
+
+void nfsd_serv_put(struct nfsd_net *nn)
+{
+ percpu_ref_put(&nn->nfsd_serv_ref);
+}
+
+static void nfsd_serv_done(struct percpu_ref *ref)
+{
+ struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_serv_ref);
+
+ complete(&nn->nfsd_serv_confirm_done);
+}
+
+static void nfsd_serv_free(struct percpu_ref *ref)
+{
+ struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_serv_ref);
+
+ complete(&nn->nfsd_serv_free_done);
+}
+
/*
* Maximum number of nfsd processes
*/
@@ -392,6 +416,7 @@ static void nfsd_shutdown_net(struct net *net)
lockd_down(net);
nn->lockd_up = false;
}
+ percpu_ref_exit(&nn->nfsd_serv_ref);
nn->nfsd_net_up = false;
nfsd_shutdown_generic();
}
@@ -471,6 +496,13 @@ void nfsd_destroy_serv(struct net *net)
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct svc_serv *serv = nn->nfsd_serv;
+ lockdep_assert_held(&nfsd_mutex);
+
+ percpu_ref_kill_and_confirm(&nn->nfsd_serv_ref, nfsd_serv_done);
+ wait_for_completion(&nn->nfsd_serv_confirm_done);
+ wait_for_completion(&nn->nfsd_serv_free_done);
+ /* percpu_ref_exit is called in nfsd_shutdown_net */
+
spin_lock(&nfsd_notifier_lock);
nn->nfsd_serv = NULL;
spin_unlock(&nfsd_notifier_lock);
@@ -595,6 +627,13 @@ int nfsd_create_serv(struct net *net)
if (nn->nfsd_serv)
return 0;
+ error = percpu_ref_init(&nn->nfsd_serv_ref, nfsd_serv_free,
+ 0, GFP_KERNEL);
+ if (error)
+ return error;
+ init_completion(&nn->nfsd_serv_free_done);
+ init_completion(&nn->nfsd_serv_confirm_done);
+
if (nfsd_max_blksize == 0)
nfsd_max_blksize = nfsd_get_default_max_blksize();
nfsd_reset_versions(nn);
@@ -86,7 +86,8 @@ DEFINE_NFSD_XDR_ERR_EVENT(cant_encode);
{ NFSD_MAY_NOT_BREAK_LEASE, "NOT_BREAK_LEASE" }, \
{ NFSD_MAY_BYPASS_GSS, "BYPASS_GSS" }, \
{ NFSD_MAY_READ_IF_EXEC, "READ_IF_EXEC" }, \
- { NFSD_MAY_64BIT_COOKIE, "64BIT_COOKIE" })
+ { NFSD_MAY_64BIT_COOKIE, "64BIT_COOKIE" }, \
+ { NFSD_MAY_LOCALIO, "LOCALIO" })
TRACE_EVENT(nfsd_compound,
TP_PROTO(
@@ -33,6 +33,8 @@
#define NFSD_MAY_64BIT_COOKIE 0x1000 /* 64 bit readdir cookies for >= NFSv3 */
+#define NFSD_MAY_LOCALIO 0x2000 /* for tracing, reflects when localio used */
+
#define NFSD_MAY_CREATE (NFSD_MAY_EXEC|NFSD_MAY_WRITE)
#define NFSD_MAY_REMOVE (NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC)
@@ -158,6 +160,14 @@ __be32 nfsd_permission(struct svc_cred *cred, struct svc_export *exp,
void nfsd_filp_close(struct file *fp);
+int nfsd_open_local_fh(struct net *net,
+ struct auth_domain *dom,
+ struct rpc_clnt *rpc_clnt,
+ const struct cred *cred,
+ const struct nfs_fh *nfs_fh,
+ const fmode_t fmode,
+ struct file **pfilp);
+
static inline int fh_want_write(struct svc_fh *fh)
{
int ret;