[for-6.13 PATCH 10/19] nfs_common: move localio_lock to new lock member of nfs_uuid_t

Mike Snitzer
2024-11-08T23:40:17Z

Remove cl_localio_lock from 'struct nfs_client' in favor of adding a
lock to the nfs_uuid_t struct (which is embedded in each nfs_client).

Push nfs_local_{enable,disable} implementation down to nfs_common.
Those methods now call nfs_localio_{enable,disable}_client.

This allows implementing nfs_localio_invalidate_clients in terms of
nfs_localio_disable_client.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
---
fs/nfs/client.c | 1 -
fs/nfs/localio.c | 18 ++++++------
fs/nfs_common/nfslocalio.c | 57 ++++++++++++++++++++++++++------------
include/linux/nfs_fs_sb.h | 1 -
include/linux/nfslocalio.h | 8 +++++-
5 files changed, 55 insertions(+), 30 deletions(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 03ecc7765615..124232054807 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -182,7 +182,6 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
seqlock_init(&clp->cl_boot_lock);
ktime_get_real_ts64(&clp->cl_nfssvc_boot);
nfs_uuid_init(&clp->cl_uuid);
- spin_lock_init(&clp->cl_localio_lock);
#endif /* CONFIG_NFS_LOCALIO */

clp->cl_principal = "*";
diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index cab2a8819259..4c75ffc5efa2 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -125,10 +125,8 @@ const struct rpc_program nfslocalio_program = {
*/
static void nfs_local_enable(struct nfs_client *clp)
{
- spin_lock(&clp->cl_localio_lock);
- set_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
trace_nfs_local_enable(clp);
- spin_unlock(&clp->cl_localio_lock);
+ nfs_localio_enable_client(clp);
}

/*
@@ -136,12 +134,8 @@ static void nfs_local_enable(struct nfs_client *clp)
*/
void nfs_local_disable(struct nfs_client *clp)
{
- spin_lock(&clp->cl_localio_lock);
- if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
- trace_nfs_local_disable(clp);
- nfs_localio_disable_client(&clp->cl_uuid);
- }
- spin_unlock(&clp->cl_localio_lock);
+ trace_nfs_local_disable(clp);
+ nfs_localio_disable_client(clp);
}

/*
@@ -183,8 +177,12 @@ static bool nfs_server_uuid_is_local(struct nfs_client *clp)
rpc_shutdown_client(rpcclient_localio);

/* Server is only local if it initialized required struct members */
- if (status || !clp->cl_uuid.net || !clp->cl_uuid.dom)
+ rcu_read_lock();
+ if (status || !rcu_access_pointer(clp->cl_uuid.net) || !clp->cl_uuid.dom) {
+ rcu_read_unlock();
return false;
+ }
+ rcu_read_unlock();

return true;
}
diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index 904439e4bb85..cf2f47ea4f8d 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -7,6 +7,9 @@
#include <linux/module.h>
#include <linux/list.h>
#include <linux/nfslocalio.h>
+#include <linux/nfs3.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs_sb.h>
#include <net/netns/generic.h>

MODULE_LICENSE("GPL");
@@ -25,6 +28,7 @@ void nfs_uuid_init(nfs_uuid_t *nfs_uuid)
nfs_uuid->net = NULL;
nfs_uuid->dom = NULL;
INIT_LIST_HEAD(&nfs_uuid->list);
+ spin_lock_init(&nfs_uuid->lock);
}
EXPORT_SYMBOL_GPL(nfs_uuid_init);

@@ -94,12 +98,23 @@ void nfs_uuid_is_local(const uuid_t *uuid, struct list_head *list,
}
EXPORT_SYMBOL_GPL(nfs_uuid_is_local);

+void nfs_localio_enable_client(struct nfs_client *clp)
+{
+ nfs_uuid_t *nfs_uuid = &clp->cl_uuid;
+
+ spin_lock(&nfs_uuid->lock);
+ set_bit(NFS_CS_LOCAL_IO, &clp->cl_flags);
+ spin_unlock(&nfs_uuid->lock);
+}
+EXPORT_SYMBOL_GPL(nfs_localio_enable_client);
+
static void nfs_uuid_put_locked(nfs_uuid_t *nfs_uuid)
{
- if (nfs_uuid->net) {
- module_put(nfsd_mod);
- nfs_uuid->net = NULL;
- }
+ if (!nfs_uuid->net)
+ return;
+ module_put(nfsd_mod);
+ rcu_assign_pointer(nfs_uuid->net, NULL);
+
if (nfs_uuid->dom) {
auth_domain_put(nfs_uuid->dom);
nfs_uuid->dom = NULL;
@@ -107,27 +122,35 @@ static void nfs_uuid_put_locked(nfs_uuid_t *nfs_uuid)
list_del_init(&nfs_uuid->list);
}

-void nfs_localio_invalidate_clients(struct list_head *list)
+void nfs_localio_disable_client(struct nfs_client *clp)
+{
+ nfs_uuid_t *nfs_uuid = &clp->cl_uuid;
+
+ spin_lock(&nfs_uuid->lock);
+ if (test_and_clear_bit(NFS_CS_LOCAL_IO, &clp->cl_flags)) {
+ spin_lock(&nfs_uuid_lock);
+ nfs_uuid_put_locked(nfs_uuid);
+ spin_unlock(&nfs_uuid_lock);
+ }
+ spin_unlock(&nfs_uuid->lock);
+}
+EXPORT_SYMBOL_GPL(nfs_localio_disable_client);
+
+void nfs_localio_invalidate_clients(struct list_head *cl_uuid_list)
{
nfs_uuid_t *nfs_uuid, *tmp;

spin_lock(&nfs_uuid_lock);
- list_for_each_entry_safe(nfs_uuid, tmp, list, list)
- nfs_uuid_put_locked(nfs_uuid);
+ list_for_each_entry_safe(nfs_uuid, tmp, cl_uuid_list, list) {
+ struct nfs_client *clp =
+ container_of(nfs_uuid, struct nfs_client, cl_uuid);
+
+ nfs_localio_disable_client(clp);
+ }
spin_unlock(&nfs_uuid_lock);
}
EXPORT_SYMBOL_GPL(nfs_localio_invalidate_clients);

-void nfs_localio_disable_client(nfs_uuid_t *nfs_uuid)
-{
- if (nfs_uuid->net) {
- spin_lock(&nfs_uuid_lock);
- nfs_uuid_put_locked(nfs_uuid);
- spin_unlock(&nfs_uuid_lock);
- }
-}
-EXPORT_SYMBOL_GPL(nfs_localio_disable_client);
-
struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *uuid,
struct rpc_clnt *rpc_clnt, const struct cred *cred,
const struct nfs_fh *nfs_fh, const fmode_t fmode)
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index b804346a9741..239d86ef166c 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -132,7 +132,6 @@ struct nfs_client {
struct timespec64 cl_nfssvc_boot;
seqlock_t cl_boot_lock;
nfs_uuid_t cl_uuid;
- spinlock_t cl_localio_lock;
#endif /* CONFIG_NFS_LOCALIO */
};

diff --git a/include/linux/nfslocalio.h b/include/linux/nfslocalio.h
index a05d1043f2b0..4d5583873f41 100644
--- a/include/linux/nfslocalio.h
+++ b/include/linux/nfslocalio.h
@@ -6,6 +6,7 @@
#ifndef __LINUX_NFSLOCALIO_H
#define __LINUX_NFSLOCALIO_H

+
/* nfsd_file structure is purposely kept opaque to NFS client */
struct nfsd_file;

@@ -19,6 +20,8 @@ struct nfsd_file;
#include <linux/nfs.h>
#include <net/net_namespace.h>

+struct nfs_client;
+
/*
* Useful to allow a client to negotiate if localio
* possible with its server.
@@ -27,6 +30,8 @@ struct nfsd_file;
*/
typedef struct {
uuid_t uuid;
+ /* sadly this struct is just over a cacheline, avoid bouncing */
+ spinlock_t ____cacheline_aligned lock;
struct list_head list;
struct net __rcu *net; /* nfsd's network namespace */
struct auth_domain *dom; /* auth_domain for localio */
@@ -38,7 +43,8 @@ void nfs_uuid_end(nfs_uuid_t *);
void nfs_uuid_is_local(const uuid_t *, struct list_head *,
struct net *, struct auth_domain *, struct module *);

-void nfs_localio_disable_client(nfs_uuid_t *nfs_uuid);
+void nfs_localio_enable_client(struct nfs_client *clp);
+void nfs_localio_disable_client(struct nfs_client *clp);
void nfs_localio_invalidate_clients(struct list_head *list);

/* localio needs to map filehandle -> struct nfsd_file */
--
2.44.0