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 <[email protected]>
---
changes from v2: fix 0-day build issues.
---
fs/nfs/nfs4file.c | 40 +++++++++++--
fs/nfs/nfs4super.c | 6 ++
fs/nfs/super.c | 20 +++++++
fs/nfs_common/Makefile | 1 +
fs/nfs_common/nfs_ssc.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/nfsd/Kconfig | 2 +-
fs/nfsd/nfs4proc.c | 3 +-
include/linux/nfs_ssc.h | 77 +++++++++++++++++++++++++
8 files changed, 289 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 fdfc77486ace..7d242fcb134a 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 +398,42 @@ struct file *
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_owner = THIS_MODULE,
+ .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:
+ * On success, returns 0
+ * %-EINVAL if validation check fails
+ */
+int nfs42_ssc_register_ops(void)
+{
+ return 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 0c1ab846b83d..ed0c1f9fc890 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"
@@ -273,6 +274,10 @@ static int __init init_nfs_v4(void)
err = nfs4_xattr_cache_init();
if (err)
goto out2;
+
+ err = nfs42_ssc_register_ops();
+ if (err)
+ goto out2;
#endif
err = nfs4_register_sysctl();
@@ -297,6 +302,7 @@ 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 7a70287f21a2..65636fef6a00 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 +86,11 @@
};
EXPORT_SYMBOL_GPL(nfs_sops);
+static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
+ .sco_owner = THIS_MODULE,
+ .sco_sb_deactive = nfs_sb_deactive,
+};
+
#if IS_ENABLED(CONFIG_NFS_V4)
static int __init register_nfs4_fs(void)
{
@@ -106,6 +112,16 @@ static void unregister_nfs4_fs(void)
}
#endif
+static int nfs_ssc_register_ops(void)
+{
+ return 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 +149,9 @@ int __init register_nfs_fs(void)
ret = register_shrinker(&acl_shrinker);
if (ret < 0)
goto error_3;
+ ret = nfs_ssc_register_ops();
+ if (ret < 0)
+ goto error_3;
return 0;
error_3:
nfs_unregister_sysctl();
@@ -152,6 +171,7 @@ 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 4bebe834c009..fa82f5aaa6d9 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 000000000000..6d99a6d2d6b9
--- /dev/null
+++ b/fs/nfs_common/nfs_ssc.c
@@ -0,0 +1,148 @@
+// 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 <[email protected]>
+ *
+ * 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");
+
+/*
+ * NFS_FS
+ */
+static void nfs_sb_deactive_def(struct super_block *sb);
+
+static struct nfs_ssc_client_ops nfs_ssc_clnt_ops_def = {
+ .sco_owner = THIS_MODULE,
+ .sco_sb_deactive = nfs_sb_deactive_def,
+};
+
+/*
+ * NFS_V4
+ */
+static struct file *nfs42_ssc_open_def(struct vfsmount *ss_mnt,
+ struct nfs_fh *src_fh, nfs4_stateid *stateid);
+static void nfs42_ssc_close_def(struct file *filep);
+
+static struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_def = {
+ .sco_owner = THIS_MODULE,
+ .sco_open = nfs42_ssc_open_def,
+ .sco_close = nfs42_ssc_close_def,
+};
+
+
+struct nfs_ssc_client_ops_tbl nfs_ssc_client_tbl = {
+ .ssc_nfs4_ops = &nfs4_ssc_clnt_ops_def,
+ .ssc_nfs_ops = &nfs_ssc_clnt_ops_def
+};
+EXPORT_SYMBOL_GPL(nfs_ssc_client_tbl);
+
+
+static struct file *nfs42_ssc_open_def(struct vfsmount *ss_mnt,
+ struct nfs_fh *src_fh, nfs4_stateid *stateid)
+{
+ return ERR_PTR(-EIO);
+}
+
+static void nfs42_ssc_close_def(struct file *filep)
+{
+}
+
+#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:
+ * On success, return 0
+ * %-EINVAL if validation check fails
+ */
+int nfs42_ssc_register(const struct nfs4_ssc_client_ops *ops)
+{
+ if (ops == NULL || ops->sco_open == NULL || ops->sco_close == NULL)
+ return -EINVAL;
+ nfs_ssc_client_tbl.ssc_nfs4_ops = ops;
+ return 0;
+}
+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 = &nfs4_ssc_clnt_ops_def;
+}
+EXPORT_SYMBOL_GPL(nfs42_ssc_unregister);
+#endif /* CONFIG_NFS_V4_2 */
+
+/*
+ * NFS_FS
+ */
+static void nfs_sb_deactive_def(struct super_block *sb)
+{
+}
+
+#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:
+ * On success, return 0
+ * %-EINVAL if validation check fails
+ */
+int nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
+{
+ if (ops == NULL || ops->sco_sb_deactive == NULL)
+ return -EINVAL;
+ nfs_ssc_client_tbl.ssc_nfs_ops = ops;
+ return 0;
+}
+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 = &nfs_ssc_clnt_ops_def;
+}
+EXPORT_SYMBOL_GPL(nfs_ssc_unregister);
+
+#else
+int nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
+{
+ return 0;
+}
+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 99d2cae91bd6..f368f3215f88 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 eaf50eafa935..84e10aef1417 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 @@ extern struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
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 000000000000..45a763bd6b0b
--- /dev/null
+++ b/include/linux/nfs_ssc.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * include/linux/nfs_ssc.h
+ *
+ * Author: Dai Ngo <[email protected]>
+ *
+ * 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 module *sco_owner;
+ 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 {
+ struct module *sco_owner;
+ 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 int nfs42_ssc_register_ops(void);
+extern void nfs42_ssc_unregister_ops(void);
+
+extern int 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)
+{
+ struct file *file;
+
+ if (!try_module_get(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner))
+ return ERR_PTR(-EIO);
+ file = (*nfs_ssc_client_tbl.ssc_nfs4_ops->sco_open)(ss_mnt, src_fh, stateid);
+ module_put(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner);
+ return file;
+}
+
+static inline void nfs42_ssc_close(struct file *filep)
+{
+ if (!try_module_get(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner))
+ return;
+ (*nfs_ssc_client_tbl.ssc_nfs4_ops->sco_close)(filep);
+ module_put(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner);
+}
+#endif
+
+/*
+ * NFS_FS
+ */
+extern int 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 (!try_module_get(nfs_ssc_client_tbl.ssc_nfs_ops->sco_owner))
+ return;
+ (*nfs_ssc_client_tbl.ssc_nfs_ops->sco_sb_deactive)(sb);
+ module_put(nfs_ssc_client_tbl.ssc_nfs_ops->sco_owner);
+}
--
1.8.3.1
On Fri, Oct 09, 2020 at 02:28:19AM -0400, Dai Ngo wrote:
> 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.
This looks like a good start, but I think it could be a lot simpler:
>
> Fixes: 3ac3711adb88 ("NFSD: Fix NFS server build errors")
> Signed-off-by: Dai Ngo <[email protected]>
> ---
> changes from v2: fix 0-day build issues.
> ---
> fs/nfs/nfs4file.c | 40 +++++++++++--
> fs/nfs/nfs4super.c | 6 ++
> fs/nfs/super.c | 20 +++++++
> fs/nfs_common/Makefile | 1 +
> fs/nfs_common/nfs_ssc.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++
> fs/nfsd/Kconfig | 2 +-
> fs/nfsd/nfs4proc.c | 3 +-
> include/linux/nfs_ssc.h | 77 +++++++++++++++++++++++++
> 8 files changed, 289 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 fdfc77486ace..7d242fcb134a 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 +398,42 @@ struct file *
> 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_owner = THIS_MODULE,
> + .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:
> + * On success, returns 0
> + * %-EINVAL if validation check fails
> + */
> +int nfs42_ssc_register_ops(void)
> +{
> + return 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 0c1ab846b83d..ed0c1f9fc890 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"
> @@ -273,6 +274,10 @@ static int __init init_nfs_v4(void)
> err = nfs4_xattr_cache_init();
> if (err)
> goto out2;
> +
> + err = nfs42_ssc_register_ops();
> + if (err)
> + goto out2;
> #endif
>
> err = nfs4_register_sysctl();
> @@ -297,6 +302,7 @@ 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 7a70287f21a2..65636fef6a00 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 +86,11 @@
> };
> EXPORT_SYMBOL_GPL(nfs_sops);
>
> +static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
> + .sco_owner = THIS_MODULE,
> + .sco_sb_deactive = nfs_sb_deactive,
> +};
> +
> #if IS_ENABLED(CONFIG_NFS_V4)
> static int __init register_nfs4_fs(void)
> {
> @@ -106,6 +112,16 @@ static void unregister_nfs4_fs(void)
> }
> #endif
>
> +static int nfs_ssc_register_ops(void)
> +{
> + return 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 +149,9 @@ int __init register_nfs_fs(void)
> ret = register_shrinker(&acl_shrinker);
> if (ret < 0)
> goto error_3;
> + ret = nfs_ssc_register_ops();
> + if (ret < 0)
> + goto error_3;
> return 0;
> error_3:
> nfs_unregister_sysctl();
> @@ -152,6 +171,7 @@ 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 4bebe834c009..fa82f5aaa6d9 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 000000000000..6d99a6d2d6b9
> --- /dev/null
> +++ b/fs/nfs_common/nfs_ssc.c
> @@ -0,0 +1,148 @@
> +// 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 <[email protected]>
> + *
> + * 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");
> +
> +/*
> + * NFS_FS
> + */
> +static void nfs_sb_deactive_def(struct super_block *sb);
> +
> +static struct nfs_ssc_client_ops nfs_ssc_clnt_ops_def = {
> + .sco_owner = THIS_MODULE,
> + .sco_sb_deactive = nfs_sb_deactive_def,
> +};
> +
> +/*
> + * NFS_V4
> + */
> +static struct file *nfs42_ssc_open_def(struct vfsmount *ss_mnt,
> + struct nfs_fh *src_fh, nfs4_stateid *stateid);
> +static void nfs42_ssc_close_def(struct file *filep);
> +
> +static struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_def = {
> + .sco_owner = THIS_MODULE,
> + .sco_open = nfs42_ssc_open_def,
> + .sco_close = nfs42_ssc_close_def,
> +};
> +
> +
> +struct nfs_ssc_client_ops_tbl nfs_ssc_client_tbl = {
> + .ssc_nfs4_ops = &nfs4_ssc_clnt_ops_def,
> + .ssc_nfs_ops = &nfs_ssc_clnt_ops_def
> +};
> +EXPORT_SYMBOL_GPL(nfs_ssc_client_tbl);
> +
> +
> +static struct file *nfs42_ssc_open_def(struct vfsmount *ss_mnt,
> + struct nfs_fh *src_fh, nfs4_stateid *stateid)
> +{
> + return ERR_PTR(-EIO);
> +}
> +
> +static void nfs42_ssc_close_def(struct file *filep)
> +{
> +}
I don't think we need any of these "_def" ops. We just shouldn't be
calling any of these ops in the case the operations aren't loaded.
> +
> +#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:
> + * On success, return 0
> + * %-EINVAL if validation check fails
> + */
> +int nfs42_ssc_register(const struct nfs4_ssc_client_ops *ops)
> +{
> + if (ops == NULL || ops->sco_open == NULL || ops->sco_close == NULL)
> + return -EINVAL;
This function only has one caller, and we know it won't do these things.
It's not worth the check and the error handling in the caller for
something so unlikely.
> + nfs_ssc_client_tbl.ssc_nfs4_ops = ops;
> + return 0;
> +}
> +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 = &nfs4_ssc_clnt_ops_def;
> +}
> +EXPORT_SYMBOL_GPL(nfs42_ssc_unregister);
> +#endif /* CONFIG_NFS_V4_2 */
> +
> +/*
> + * NFS_FS
> + */
> +static void nfs_sb_deactive_def(struct super_block *sb)
> +{
> +}
> +
> +#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:
> + * On success, return 0
> + * %-EINVAL if validation check fails
> + */
> +int nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
> +{
> + if (ops == NULL || ops->sco_sb_deactive == NULL)
> + return -EINVAL;
Ditto, let's drop these checks.
> + nfs_ssc_client_tbl.ssc_nfs_ops = ops;
> + return 0;
> +}
> +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 = &nfs_ssc_clnt_ops_def;
> +}
> +EXPORT_SYMBOL_GPL(nfs_ssc_unregister);
> +
> +#else
> +int nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
> +{
> + return 0;
> +}
> +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 99d2cae91bd6..f368f3215f88 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 eaf50eafa935..84e10aef1417 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 @@ extern struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
> 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 000000000000..45a763bd6b0b
> --- /dev/null
> +++ b/include/linux/nfs_ssc.h
> @@ -0,0 +1,77 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * include/linux/nfs_ssc.h
> + *
> + * Author: Dai Ngo <[email protected]>
> + *
> + * 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 module *sco_owner;
> + 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 {
> + struct module *sco_owner;
> + 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 int nfs42_ssc_register_ops(void);
> +extern void nfs42_ssc_unregister_ops(void);
> +
> +extern int 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)
> +{
> + struct file *file;
> +
> + if (!try_module_get(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner))
> + return ERR_PTR(-EIO);
The module load already happened back when we did the get_fs_type in
nfsd4_interssc_connect(), and it's not going away at this point (or
there's something already terribly wrong with ss_mnt).
So I don't think we need any try_module_get()s or module_put()s.
--b.
> + file = (*nfs_ssc_client_tbl.ssc_nfs4_ops->sco_open)(ss_mnt, src_fh, stateid);
> + module_put(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner);
> + return file;
> +}
> +
> +static inline void nfs42_ssc_close(struct file *filep)
> +{
> + if (!try_module_get(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner))
> + return;
> + (*nfs_ssc_client_tbl.ssc_nfs4_ops->sco_close)(filep);
> + module_put(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner);
> +}
> +#endif
> +
> +/*
> + * NFS_FS
> + */
> +extern int 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 (!try_module_get(nfs_ssc_client_tbl.ssc_nfs_ops->sco_owner))
> + return;
> + (*nfs_ssc_client_tbl.ssc_nfs_ops->sco_sb_deactive)(sb);
> + module_put(nfs_ssc_client_tbl.ssc_nfs_ops->sco_owner);
> +}
> --
> 1.8.3.1
Thanks Bruce for reviewing the patch.
I'll update the patch in v3.
-Dai
On 10/16/20 10:59 AM, J. Bruce Fields wrote:
> On Fri, Oct 09, 2020 at 02:28:19AM -0400, Dai Ngo wrote:
>> 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.
> This looks like a good start, but I think it could be a lot simpler:
>
>> Fixes: 3ac3711adb88 ("NFSD: Fix NFS server build errors")
>> Signed-off-by: Dai Ngo <[email protected]>
>> ---
>> changes from v2: fix 0-day build issues.
>> ---
>> fs/nfs/nfs4file.c | 40 +++++++++++--
>> fs/nfs/nfs4super.c | 6 ++
>> fs/nfs/super.c | 20 +++++++
>> fs/nfs_common/Makefile | 1 +
>> fs/nfs_common/nfs_ssc.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++
>> fs/nfsd/Kconfig | 2 +-
>> fs/nfsd/nfs4proc.c | 3 +-
>> include/linux/nfs_ssc.h | 77 +++++++++++++++++++++++++
>> 8 files changed, 289 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 fdfc77486ace..7d242fcb134a 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 +398,42 @@ struct file *
>> 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_owner = THIS_MODULE,
>> + .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:
>> + * On success, returns 0
>> + * %-EINVAL if validation check fails
>> + */
>> +int nfs42_ssc_register_ops(void)
>> +{
>> + return 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 0c1ab846b83d..ed0c1f9fc890 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"
>> @@ -273,6 +274,10 @@ static int __init init_nfs_v4(void)
>> err = nfs4_xattr_cache_init();
>> if (err)
>> goto out2;
>> +
>> + err = nfs42_ssc_register_ops();
>> + if (err)
>> + goto out2;
>> #endif
>>
>> err = nfs4_register_sysctl();
>> @@ -297,6 +302,7 @@ 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 7a70287f21a2..65636fef6a00 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 +86,11 @@
>> };
>> EXPORT_SYMBOL_GPL(nfs_sops);
>>
>> +static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
>> + .sco_owner = THIS_MODULE,
>> + .sco_sb_deactive = nfs_sb_deactive,
>> +};
>> +
>> #if IS_ENABLED(CONFIG_NFS_V4)
>> static int __init register_nfs4_fs(void)
>> {
>> @@ -106,6 +112,16 @@ static void unregister_nfs4_fs(void)
>> }
>> #endif
>>
>> +static int nfs_ssc_register_ops(void)
>> +{
>> + return 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 +149,9 @@ int __init register_nfs_fs(void)
>> ret = register_shrinker(&acl_shrinker);
>> if (ret < 0)
>> goto error_3;
>> + ret = nfs_ssc_register_ops();
>> + if (ret < 0)
>> + goto error_3;
>> return 0;
>> error_3:
>> nfs_unregister_sysctl();
>> @@ -152,6 +171,7 @@ 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 4bebe834c009..fa82f5aaa6d9 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 000000000000..6d99a6d2d6b9
>> --- /dev/null
>> +++ b/fs/nfs_common/nfs_ssc.c
>> @@ -0,0 +1,148 @@
>> +// 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 <[email protected]>
>> + *
>> + * 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");
>> +
>> +/*
>> + * NFS_FS
>> + */
>> +static void nfs_sb_deactive_def(struct super_block *sb);
>> +
>> +static struct nfs_ssc_client_ops nfs_ssc_clnt_ops_def = {
>> + .sco_owner = THIS_MODULE,
>> + .sco_sb_deactive = nfs_sb_deactive_def,
>> +};
>> +
>> +/*
>> + * NFS_V4
>> + */
>> +static struct file *nfs42_ssc_open_def(struct vfsmount *ss_mnt,
>> + struct nfs_fh *src_fh, nfs4_stateid *stateid);
>> +static void nfs42_ssc_close_def(struct file *filep);
>> +
>> +static struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_def = {
>> + .sco_owner = THIS_MODULE,
>> + .sco_open = nfs42_ssc_open_def,
>> + .sco_close = nfs42_ssc_close_def,
>> +};
>> +
>> +
>> +struct nfs_ssc_client_ops_tbl nfs_ssc_client_tbl = {
>> + .ssc_nfs4_ops = &nfs4_ssc_clnt_ops_def,
>> + .ssc_nfs_ops = &nfs_ssc_clnt_ops_def
>> +};
>> +EXPORT_SYMBOL_GPL(nfs_ssc_client_tbl);
>> +
>> +
>> +static struct file *nfs42_ssc_open_def(struct vfsmount *ss_mnt,
>> + struct nfs_fh *src_fh, nfs4_stateid *stateid)
>> +{
>> + return ERR_PTR(-EIO);
>> +}
>> +
>> +static void nfs42_ssc_close_def(struct file *filep)
>> +{
>> +}
> I don't think we need any of these "_def" ops. We just shouldn't be
> calling any of these ops in the case the operations aren't loaded.
>
>> +
>> +#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:
>> + * On success, return 0
>> + * %-EINVAL if validation check fails
>> + */
>> +int nfs42_ssc_register(const struct nfs4_ssc_client_ops *ops)
>> +{
>> + if (ops == NULL || ops->sco_open == NULL || ops->sco_close == NULL)
>> + return -EINVAL;
> This function only has one caller, and we know it won't do these things.
>
> It's not worth the check and the error handling in the caller for
> something so unlikely.
>
>> + nfs_ssc_client_tbl.ssc_nfs4_ops = ops;
>> + return 0;
>> +}
>> +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 = &nfs4_ssc_clnt_ops_def;
>> +}
>> +EXPORT_SYMBOL_GPL(nfs42_ssc_unregister);
>> +#endif /* CONFIG_NFS_V4_2 */
>> +
>> +/*
>> + * NFS_FS
>> + */
>> +static void nfs_sb_deactive_def(struct super_block *sb)
>> +{
>> +}
>> +
>> +#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:
>> + * On success, return 0
>> + * %-EINVAL if validation check fails
>> + */
>> +int nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
>> +{
>> + if (ops == NULL || ops->sco_sb_deactive == NULL)
>> + return -EINVAL;
> Ditto, let's drop these checks.
>
>> + nfs_ssc_client_tbl.ssc_nfs_ops = ops;
>> + return 0;
>> +}
>> +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 = &nfs_ssc_clnt_ops_def;
>> +}
>> +EXPORT_SYMBOL_GPL(nfs_ssc_unregister);
>> +
>> +#else
>> +int nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
>> +{
>> + return 0;
>> +}
>> +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 99d2cae91bd6..f368f3215f88 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 eaf50eafa935..84e10aef1417 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 @@ extern struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
>> 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 000000000000..45a763bd6b0b
>> --- /dev/null
>> +++ b/include/linux/nfs_ssc.h
>> @@ -0,0 +1,77 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * include/linux/nfs_ssc.h
>> + *
>> + * Author: Dai Ngo <[email protected]>
>> + *
>> + * 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 module *sco_owner;
>> + 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 {
>> + struct module *sco_owner;
>> + 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 int nfs42_ssc_register_ops(void);
>> +extern void nfs42_ssc_unregister_ops(void);
>> +
>> +extern int 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)
>> +{
>> + struct file *file;
>> +
>> + if (!try_module_get(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner))
>> + return ERR_PTR(-EIO);
> The module load already happened back when we did the get_fs_type in
> nfsd4_interssc_connect(), and it's not going away at this point (or
> there's something already terribly wrong with ss_mnt).
>
> So I don't think we need any try_module_get()s or module_put()s.
>
> --b.
>
>> + file = (*nfs_ssc_client_tbl.ssc_nfs4_ops->sco_open)(ss_mnt, src_fh, stateid);
>> + module_put(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner);
>> + return file;
>> +}
>> +
>> +static inline void nfs42_ssc_close(struct file *filep)
>> +{
>> + if (!try_module_get(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner))
>> + return;
>> + (*nfs_ssc_client_tbl.ssc_nfs4_ops->sco_close)(filep);
>> + module_put(nfs_ssc_client_tbl.ssc_nfs4_ops->sco_owner);
>> +}
>> +#endif
>> +
>> +/*
>> + * NFS_FS
>> + */
>> +extern int 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 (!try_module_get(nfs_ssc_client_tbl.ssc_nfs_ops->sco_owner))
>> + return;
>> + (*nfs_ssc_client_tbl.ssc_nfs_ops->sco_sb_deactive)(sb);
>> + module_put(nfs_ssc_client_tbl.ssc_nfs_ops->sco_owner);
>> +}
>> --
>> 1.8.3.1