summaryrefslogtreecommitdiffstats
path: root/fs/nfs
diff options
context:
space:
mode:
authorTrond Myklebust <trond.myklebust@hammerspace.com>2019-01-29 21:40:10 -0500
committerTrond Myklebust <trond.myklebust@hammerspace.com>2019-07-06 14:54:49 -0400
commitbf11fbdb20b385157b046ea7781f04d0c62554a3 (patch)
treefc24ca63f5e1529f713cc9243716dfc45075bd36 /fs/nfs
parent10b7a70cbb81a62353f763c3343ac0c48410696f (diff)
downloadlinux-bf11fbdb20b385157b046ea7781f04d0c62554a3.tar.bz2
NFS: Add sysfs support for per-container identifier
In order to identify containers to the NFS client, we add a per-net sysfs attribute that udev can fill with the appropriate identifier. The identifier could be a unique hostname, but in most cases it will probably be a persisted uuid. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/client.c4
-rw-r--r--fs/nfs/netns.h3
-rw-r--r--fs/nfs/sysfs.c118
-rw-r--r--fs/nfs/sysfs.h10
4 files changed, 135 insertions, 0 deletions
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 0acb104f7b00..6e7aeb543f6a 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -49,6 +49,7 @@
#include "pnfs.h"
#include "nfs.h"
#include "netns.h"
+#include "sysfs.h"
#define NFSDBG_FACILITY NFSDBG_CLIENT
@@ -1072,12 +1073,15 @@ void nfs_clients_init(struct net *net)
#endif
spin_lock_init(&nn->nfs_client_lock);
nn->boot_time = ktime_get_real();
+
+ nfs_netns_sysfs_setup(nn, net);
}
void nfs_clients_exit(struct net *net)
{
struct nfs_net *nn = net_generic(net, nfs_net_id);
+ nfs_netns_sysfs_destroy(nn);
nfs_cleanup_cb_ident_idr(net);
WARN_ON_ONCE(!list_empty(&nn->nfs_client_list));
WARN_ON_ONCE(!list_empty(&nn->nfs_volume_list));
diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index fc9978c58265..c8374f74dce1 100644
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -15,6 +15,8 @@ struct bl_dev_msg {
uint32_t major, minor;
};
+struct nfs_netns_client;
+
struct nfs_net {
struct cache_detail *nfs_dns_resolve;
struct rpc_pipe *bl_device_pipe;
@@ -29,6 +31,7 @@ struct nfs_net {
unsigned short nfs_callback_tcpport6;
int cb_users[NFS4_MAX_MINOR_VERSION + 1];
#endif
+ struct nfs_netns_client *nfs_client;
spinlock_t nfs_client_lock;
ktime_t boot_time;
#ifdef CONFIG_PROC_FS
diff --git a/fs/nfs/sysfs.c b/fs/nfs/sysfs.c
index 7070711ff6c5..4f3390b20239 100644
--- a/fs/nfs/sysfs.c
+++ b/fs/nfs/sysfs.c
@@ -9,7 +9,12 @@
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
+#include <linux/string.h>
+#include <linux/nfs_fs.h>
+#include <linux/rcupdate.h>
+#include "nfs4_fs.h"
+#include "netns.h"
#include "sysfs.h"
struct kobject *nfs_client_kobj;
@@ -67,3 +72,116 @@ void nfs_sysfs_exit(void)
kobject_put(nfs_client_kobj);
kset_unregister(nfs_client_kset);
}
+
+static ssize_t nfs_netns_identifier_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct nfs_netns_client *c = container_of(kobj,
+ struct nfs_netns_client,
+ kobject);
+ return scnprintf(buf, PAGE_SIZE, "%s\n", c->identifier);
+}
+
+/* Strip trailing '\n' */
+static size_t nfs_string_strip(const char *c, size_t len)
+{
+ while (len > 0 && c[len-1] == '\n')
+ --len;
+ return len;
+}
+
+static ssize_t nfs_netns_identifier_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct nfs_netns_client *c = container_of(kobj,
+ struct nfs_netns_client,
+ kobject);
+ const char *old;
+ char *p;
+ size_t len;
+
+ len = nfs_string_strip(buf, min_t(size_t, count, CONTAINER_ID_MAXLEN));
+ if (!len)
+ return 0;
+ p = kmemdup_nul(buf, len, GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ old = xchg(&c->identifier, p);
+ if (old) {
+ synchronize_rcu();
+ kfree(old);
+ }
+ return count;
+}
+
+static void nfs_netns_client_release(struct kobject *kobj)
+{
+ struct nfs_netns_client *c = container_of(kobj,
+ struct nfs_netns_client,
+ kobject);
+
+ if (c->identifier)
+ kfree(c->identifier);
+ kfree(c);
+}
+
+static const void *nfs_netns_client_namespace(struct kobject *kobj)
+{
+ return container_of(kobj, struct nfs_netns_client, kobject)->net;
+}
+
+static struct kobj_attribute nfs_netns_client_id = __ATTR(identifier,
+ 0644, nfs_netns_identifier_show, nfs_netns_identifier_store);
+
+static struct attribute *nfs_netns_client_attrs[] = {
+ &nfs_netns_client_id.attr,
+ NULL,
+};
+
+static struct kobj_type nfs_netns_client_type = {
+ .release = nfs_netns_client_release,
+ .default_attrs = nfs_netns_client_attrs,
+ .sysfs_ops = &kobj_sysfs_ops,
+ .namespace = nfs_netns_client_namespace,
+};
+
+static struct nfs_netns_client *nfs_netns_client_alloc(struct kobject *parent,
+ struct net *net)
+{
+ struct nfs_netns_client *p;
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (p) {
+ p->net = net;
+ p->kobject.kset = nfs_client_kset;
+ if (kobject_init_and_add(&p->kobject, &nfs_netns_client_type,
+ parent, "nfs_client") == 0)
+ return p;
+ kobject_put(&p->kobject);
+ }
+ return NULL;
+}
+
+void nfs_netns_sysfs_setup(struct nfs_net *netns, struct net *net)
+{
+ struct nfs_netns_client *clp;
+
+ clp = nfs_netns_client_alloc(nfs_client_kobj, net);
+ if (clp) {
+ netns->nfs_client = clp;
+ kobject_uevent(&clp->kobject, KOBJ_ADD);
+ }
+}
+
+void nfs_netns_sysfs_destroy(struct nfs_net *netns)
+{
+ struct nfs_netns_client *clp = netns->nfs_client;
+
+ if (clp) {
+ kobject_uevent(&clp->kobject, KOBJ_REMOVE);
+ kobject_del(&clp->kobject);
+ kobject_put(&clp->kobject);
+ netns->nfs_client = NULL;
+ }
+}
diff --git a/fs/nfs/sysfs.h b/fs/nfs/sysfs.h
index 666f8db2ba92..f1b27411dcc0 100644
--- a/fs/nfs/sysfs.h
+++ b/fs/nfs/sysfs.h
@@ -6,10 +6,20 @@
#ifndef __NFS_SYSFS_H
#define __NFS_SYSFS_H
+#define CONTAINER_ID_MAXLEN (64)
+
+struct nfs_netns_client {
+ struct kobject kobject;
+ struct net *net;
+ const char *identifier;
+};
extern struct kobject *nfs_client_kobj;
extern int nfs_sysfs_init(void);
extern void nfs_sysfs_exit(void);
+void nfs_netns_sysfs_setup(struct nfs_net *netns, struct net *net);
+void nfs_netns_sysfs_destroy(struct nfs_net *netns);
+
#endif