[PATCH 5.9 559/757] NFSv4.2: Fix NFS4ERR_STALE error when doing inter server copy

From: Greg Kroah-Hartman
Date: Tue Oct 27 2020 - 12:40:02 EST


From: Dai Ngo <dai.ngo@xxxxxxxxxx>

[ Upstream commit 0cfcd405e758ba1d277e58436fb32f06888c3e41 ]

NFS_FS=y as dependency of CONFIG_NFSD_V4_2_INTER_SSC still have
build errors and some configs with NFSD=m to get NFS4ERR_STALE
error when doing inter server copy.

Added ops table in nfs_common for knfsd to access NFS client modules.

Fixes: 3ac3711adb88 ("NFSD: Fix NFS server build errors")
Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/nfs/nfs4file.c | 38 ++++++++++++++---
fs/nfs/nfs4super.c | 5 +++
fs/nfs/super.c | 17 ++++++++
fs/nfs_common/Makefile | 1 +
fs/nfs_common/nfs_ssc.c | 94 +++++++++++++++++++++++++++++++++++++++++
fs/nfsd/Kconfig | 2 +-
fs/nfsd/nfs4proc.c | 3 +-
include/linux/nfs_ssc.h | 67 +++++++++++++++++++++++++++++
8 files changed, 219 insertions(+), 8 deletions(-)
create mode 100644 fs/nfs_common/nfs_ssc.c
create mode 100644 include/linux/nfs_ssc.h

diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index fdfc77486acee..984938024011b 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -9,6 +9,7 @@
#include <linux/falloc.h>
#include <linux/mount.h>
#include <linux/nfs_fs.h>
+#include <linux/nfs_ssc.h>
#include "delegation.h"
#include "internal.h"
#include "iostat.h"
@@ -314,9 +315,8 @@ static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
static int read_name_gen = 1;
#define SSC_READ_NAME_BODY "ssc_read_%d"

-struct file *
-nfs42_ssc_open(struct vfsmount *ss_mnt, struct nfs_fh *src_fh,
- nfs4_stateid *stateid)
+static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
+ struct nfs_fh *src_fh, nfs4_stateid *stateid)
{
struct nfs_fattr fattr;
struct file *filep, *res;
@@ -398,14 +398,40 @@ nfs42_ssc_open(struct vfsmount *ss_mnt, struct nfs_fh *src_fh,
fput(filep);
goto out_free_name;
}
-EXPORT_SYMBOL_GPL(nfs42_ssc_open);
-void nfs42_ssc_close(struct file *filep)
+
+static void __nfs42_ssc_close(struct file *filep)
{
struct nfs_open_context *ctx = nfs_file_open_context(filep);

ctx->state->flags = 0;
}
-EXPORT_SYMBOL_GPL(nfs42_ssc_close);
+
+static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
+ .sco_open = __nfs42_ssc_open,
+ .sco_close = __nfs42_ssc_close,
+};
+
+/**
+ * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
+ *
+ * Return values:
+ * None
+ */
+void nfs42_ssc_register_ops(void)
+{
+ nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
+}
+
+/**
+ * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
+ *
+ * Return values:
+ * None.
+ */
+void nfs42_ssc_unregister_ops(void)
+{
+ nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
+}
#endif /* CONFIG_NFS_V4_2 */

const struct file_operations nfs4_file_operations = {
diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
index 0c1ab846b83dd..93f5c1678ec29 100644
--- a/fs/nfs/nfs4super.c
+++ b/fs/nfs/nfs4super.c
@@ -7,6 +7,7 @@
#include <linux/mount.h>
#include <linux/nfs4_mount.h>
#include <linux/nfs_fs.h>
+#include <linux/nfs_ssc.h>
#include "delegation.h"
#include "internal.h"
#include "nfs4_fs.h"
@@ -279,6 +280,9 @@ static int __init init_nfs_v4(void)
if (err)
goto out2;

+#ifdef CONFIG_NFS_V4_2
+ nfs42_ssc_register_ops();
+#endif
register_nfs_version(&nfs_v4);
return 0;
out2:
@@ -297,6 +301,7 @@ static void __exit exit_nfs_v4(void)
unregister_nfs_version(&nfs_v4);
#ifdef CONFIG_NFS_V4_2
nfs4_xattr_cache_exit();
+ nfs42_ssc_unregister_ops();
#endif
nfs4_unregister_sysctl();
nfs_idmap_quit();
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 7a70287f21a2c..f7dad8227a5f4 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -57,6 +57,7 @@
#include <linux/rcupdate.h>

#include <linux/uaccess.h>
+#include <linux/nfs_ssc.h>

#include "nfs4_fs.h"
#include "callback.h"
@@ -85,6 +86,10 @@ const struct super_operations nfs_sops = {
};
EXPORT_SYMBOL_GPL(nfs_sops);

+static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
+ .sco_sb_deactive = nfs_sb_deactive,
+};
+
#if IS_ENABLED(CONFIG_NFS_V4)
static int __init register_nfs4_fs(void)
{
@@ -106,6 +111,16 @@ static void unregister_nfs4_fs(void)
}
#endif

+static void nfs_ssc_register_ops(void)
+{
+ nfs_ssc_register(&nfs_ssc_clnt_ops_tbl);
+}
+
+static void nfs_ssc_unregister_ops(void)
+{
+ nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl);
+}
+
static struct shrinker acl_shrinker = {
.count_objects = nfs_access_cache_count,
.scan_objects = nfs_access_cache_scan,
@@ -133,6 +148,7 @@ int __init register_nfs_fs(void)
ret = register_shrinker(&acl_shrinker);
if (ret < 0)
goto error_3;
+ nfs_ssc_register_ops();
return 0;
error_3:
nfs_unregister_sysctl();
@@ -152,6 +168,7 @@ void __exit unregister_nfs_fs(void)
unregister_shrinker(&acl_shrinker);
nfs_unregister_sysctl();
unregister_nfs4_fs();
+ nfs_ssc_unregister_ops();
unregister_filesystem(&nfs_fs_type);
}

diff --git a/fs/nfs_common/Makefile b/fs/nfs_common/Makefile
index 4bebe834c0091..fa82f5aaa6d95 100644
--- a/fs/nfs_common/Makefile
+++ b/fs/nfs_common/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_NFS_ACL_SUPPORT) += nfs_acl.o
nfs_acl-objs := nfsacl.o

obj-$(CONFIG_GRACE_PERIOD) += grace.o
+obj-$(CONFIG_GRACE_PERIOD) += nfs_ssc.o
diff --git a/fs/nfs_common/nfs_ssc.c b/fs/nfs_common/nfs_ssc.c
new file mode 100644
index 0000000000000..f43bbb3739134
--- /dev/null
+++ b/fs/nfs_common/nfs_ssc.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * fs/nfs_common/nfs_ssc_comm.c
+ *
+ * Helper for knfsd's SSC to access ops in NFS client modules
+ *
+ * Author: Dai Ngo <dai.ngo@xxxxxxxxxx>
+ *
+ * Copyright (c) 2020, Oracle and/or its affiliates.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/nfs_ssc.h>
+#include "../nfs/nfs4_fs.h"
+
+MODULE_LICENSE("GPL");
+
+struct nfs_ssc_client_ops_tbl nfs_ssc_client_tbl;
+EXPORT_SYMBOL_GPL(nfs_ssc_client_tbl);
+
+#ifdef CONFIG_NFS_V4_2
+/**
+ * nfs42_ssc_register - install the NFS_V4 client ops in the nfs_ssc_client_tbl
+ * @ops: NFS_V4 ops to be installed
+ *
+ * Return values:
+ * None
+ */
+void nfs42_ssc_register(const struct nfs4_ssc_client_ops *ops)
+{
+ nfs_ssc_client_tbl.ssc_nfs4_ops = ops;
+}
+EXPORT_SYMBOL_GPL(nfs42_ssc_register);
+
+/**
+ * nfs42_ssc_unregister - uninstall the NFS_V4 client ops from
+ * the nfs_ssc_client_tbl
+ * @ops: ops to be uninstalled
+ *
+ * Return values:
+ * None
+ */
+void nfs42_ssc_unregister(const struct nfs4_ssc_client_ops *ops)
+{
+ if (nfs_ssc_client_tbl.ssc_nfs4_ops != ops)
+ return;
+
+ nfs_ssc_client_tbl.ssc_nfs4_ops = NULL;
+}
+EXPORT_SYMBOL_GPL(nfs42_ssc_unregister);
+#endif /* CONFIG_NFS_V4_2 */
+
+#ifdef CONFIG_NFS_V4_2
+/**
+ * nfs_ssc_register - install the NFS_FS client ops in the nfs_ssc_client_tbl
+ * @ops: NFS_FS ops to be installed
+ *
+ * Return values:
+ * None
+ */
+void nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
+{
+ nfs_ssc_client_tbl.ssc_nfs_ops = ops;
+}
+EXPORT_SYMBOL_GPL(nfs_ssc_register);
+
+/**
+ * nfs_ssc_unregister - uninstall the NFS_FS client ops from
+ * the nfs_ssc_client_tbl
+ * @ops: ops to be uninstalled
+ *
+ * Return values:
+ * None
+ */
+void nfs_ssc_unregister(const struct nfs_ssc_client_ops *ops)
+{
+ if (nfs_ssc_client_tbl.ssc_nfs_ops != ops)
+ return;
+ nfs_ssc_client_tbl.ssc_nfs_ops = NULL;
+}
+EXPORT_SYMBOL_GPL(nfs_ssc_unregister);
+
+#else
+void nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
+{
+}
+EXPORT_SYMBOL_GPL(nfs_ssc_register);
+
+void nfs_ssc_unregister(const struct nfs_ssc_client_ops *ops)
+{
+}
+EXPORT_SYMBOL_GPL(nfs_ssc_unregister);
+#endif /* CONFIG_NFS_V4_2 */
diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
index 99d2cae91bd68..f368f3215f88f 100644
--- a/fs/nfsd/Kconfig
+++ b/fs/nfsd/Kconfig
@@ -136,7 +136,7 @@ config NFSD_FLEXFILELAYOUT

config NFSD_V4_2_INTER_SSC
bool "NFSv4.2 inter server to server COPY"
- depends on NFSD_V4 && NFS_V4_1 && NFS_V4_2 && NFS_FS=y
+ depends on NFSD_V4 && NFS_V4_1 && NFS_V4_2
help
This option enables support for NFSv4.2 inter server to
server copy where the destination server calls the NFSv4.2
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index eaf50eafa9359..84e10aef14175 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -38,6 +38,7 @@
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/sunrpc/addr.h>
+#include <linux/nfs_ssc.h>

#include "idmap.h"
#include "cache.h"
@@ -1247,7 +1248,7 @@ nfsd4_interssc_connect(struct nl4_server *nss, struct svc_rqst *rqstp,
static void
nfsd4_interssc_disconnect(struct vfsmount *ss_mnt)
{
- nfs_sb_deactive(ss_mnt->mnt_sb);
+ nfs_do_sb_deactive(ss_mnt->mnt_sb);
mntput(ss_mnt);
}

diff --git a/include/linux/nfs_ssc.h b/include/linux/nfs_ssc.h
new file mode 100644
index 0000000000000..f5ba0fbff72fe
--- /dev/null
+++ b/include/linux/nfs_ssc.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * include/linux/nfs_ssc.h
+ *
+ * Author: Dai Ngo <dai.ngo@xxxxxxxxxx>
+ *
+ * Copyright (c) 2020, Oracle and/or its affiliates.
+ */
+
+#include <linux/nfs_fs.h>
+
+extern struct nfs_ssc_client_ops_tbl nfs_ssc_client_tbl;
+
+/*
+ * NFS_V4
+ */
+struct nfs4_ssc_client_ops {
+ struct file *(*sco_open)(struct vfsmount *ss_mnt,
+ struct nfs_fh *src_fh, nfs4_stateid *stateid);
+ void (*sco_close)(struct file *filep);
+};
+
+/*
+ * NFS_FS
+ */
+struct nfs_ssc_client_ops {
+ void (*sco_sb_deactive)(struct super_block *sb);
+};
+
+struct nfs_ssc_client_ops_tbl {
+ const struct nfs4_ssc_client_ops *ssc_nfs4_ops;
+ const struct nfs_ssc_client_ops *ssc_nfs_ops;
+};
+
+extern void nfs42_ssc_register_ops(void);
+extern void nfs42_ssc_unregister_ops(void);
+
+extern void nfs42_ssc_register(const struct nfs4_ssc_client_ops *ops);
+extern void nfs42_ssc_unregister(const struct nfs4_ssc_client_ops *ops);
+
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+static inline struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
+ struct nfs_fh *src_fh, nfs4_stateid *stateid)
+{
+ if (nfs_ssc_client_tbl.ssc_nfs4_ops)
+ return (*nfs_ssc_client_tbl.ssc_nfs4_ops->sco_open)(ss_mnt, src_fh, stateid);
+ return ERR_PTR(-EIO);
+}
+
+static inline void nfs42_ssc_close(struct file *filep)
+{
+ if (nfs_ssc_client_tbl.ssc_nfs4_ops)
+ (*nfs_ssc_client_tbl.ssc_nfs4_ops->sco_close)(filep);
+}
+#endif
+
+/*
+ * NFS_FS
+ */
+extern void nfs_ssc_register(const struct nfs_ssc_client_ops *ops);
+extern void nfs_ssc_unregister(const struct nfs_ssc_client_ops *ops);
+
+static inline void nfs_do_sb_deactive(struct super_block *sb)
+{
+ if (nfs_ssc_client_tbl.ssc_nfs_ops)
+ (*nfs_ssc_client_tbl.ssc_nfs_ops->sco_sb_deactive)(sb);
+}
--
2.25.1