The remaining uses for nfsd_mutex are all to protect per-netns
resources.
This patch replaces the global mutex with one per netns. The "svc_info"
struct now contains that mutex rather than a pointer to the mutex.
Macros are provided to make it easy to take the mutex given a file or net.
Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
---
.../admin-guide/nfs/nfsd-admin-interfaces.rst | 2 +-
fs/nfsd/nfsctl.c | 113 +++++++++---------
fs/nfsd/nfsd.h | 1 -
fs/nfsd/nfssvc.c | 33 ++---
include/linux/sunrpc/svc.h | 2 +-
net/sunrpc/svc_xprt.c | 4 +-
6 files changed, 72 insertions(+), 83 deletions(-)
diff --git a/Documentation/admin-guide/nfs/nfsd-admin-interfaces.rst b/Documentation/admin-guide/nfs/nfsd-admin-interfaces.rst
index c05926f79054..9548e4ab35b6 100644
--- a/Documentation/admin-guide/nfs/nfsd-admin-interfaces.rst
+++ b/Documentation/admin-guide/nfs/nfsd-admin-interfaces.rst
@@ -37,4 +37,4 @@ Implementation notes
Note that the rpc server requires the caller to serialize addition and
removal of listening sockets, and startup and shutdown of the server.
-For nfsd this is done using nfsd_mutex.
+For nfsd this is done using nfsd_info.mutex in struct nfsd_net.
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 3710a1992d17..70eddf2640f0 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -95,6 +95,13 @@ static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
#endif
};
+#define with_nfsd_net_locked(__net) \
+ for (struct nfsd_net *__nn = net_generic(__net, nfsd_net_id); \
+ __nn ? ({mutex_lock(&__nn->nfsd_info.mutex); 1; }) : 0; \
+ ({mutex_unlock(&__nn->nfsd_info.mutex); __nn = NULL;}))
+#define with_nfsd_file_locked(__file) \
+ with_nfsd_net_locked(netns(__file))
+
static ssize_t nfsctl_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
{
ino_t ino = file_inode(file)->i_ino;
@@ -249,9 +256,8 @@ static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size)
{
ssize_t rv;
- mutex_lock(&nfsd_mutex);
- rv = __write_unlock_ip(file, buf, size);
- mutex_unlock(&nfsd_mutex);
+ with_nfsd_file_locked(file)
+ rv = __write_unlock_ip(file, buf, size);
return rv;
}
@@ -315,9 +321,8 @@ static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size)
{
ssize_t rv;
- mutex_lock(&nfsd_mutex);
- rv = __write_unlock_fs(file, buf, size);
- mutex_unlock(&nfsd_mutex);
+ with_nfsd_file_locked(file)
+ rv = __write_unlock_fs(file, buf, size);
return rv;
}
@@ -440,9 +445,8 @@ static ssize_t write_threads(struct file *file, char *buf, size_t size)
if (newthreads < 0)
return -EINVAL;
trace_nfsd_ctl_threads(net, newthreads);
- mutex_lock(&nfsd_mutex);
- rv = nfsd_svc(1, &newthreads, net, file->f_cred, NULL);
- mutex_unlock(&nfsd_mutex);
+ with_nfsd_net_locked(net)
+ rv = nfsd_svc(1, &newthreads, net, file->f_cred, NULL);
if (rv < 0)
return rv;
} else
@@ -473,7 +477,7 @@ static ssize_t write_threads(struct file *file, char *buf, size_t size)
* return code is the size in bytes of the string
* On error: return code is zero or a negative errno value
*/
-static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
+static ssize_t __write_pool_threads(struct file *file, char *buf, size_t size)
{
/* if size > 0, look for an array of number of threads per node
* and apply them then write out number of threads per node as reply
@@ -486,7 +490,6 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
int *nthreads;
struct net *net = netns(file);
- mutex_lock(&nfsd_mutex);
npools = nfsd_nrpools(net);
if (npools == 0) {
/*
@@ -494,7 +497,6 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
* writing to the threads file but NOT the pool_threads
* file, sorry. Report zero threads.
*/
- mutex_unlock(&nfsd_mutex);
strcpy(buf, "0\n");
return strlen(buf);
}
@@ -544,10 +546,18 @@ static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
rv = mesg - buf;
out_free:
kfree(nthreads);
- mutex_unlock(&nfsd_mutex);
return rv;
}
+static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
+{
+ ssize_t ret;
+
+ with_nfsd_file_locked(file)
+ ret = __write_pool_threads(file, buf, size);
+ return ret;
+}
+
static ssize_t
nfsd_print_version_support(struct nfsd_net *nn, char *buf, int remaining,
const char *sep, unsigned vers, int minor)
@@ -709,9 +719,9 @@ static ssize_t write_versions(struct file *file, char *buf, size_t size)
{
ssize_t rv;
- mutex_lock(&nfsd_mutex);
- rv = __write_versions(file, buf, size);
- mutex_unlock(&nfsd_mutex);
+ with_nfsd_file_locked(file)
+ rv = __write_versions(file, buf, size);
+
return rv;
}
@@ -868,9 +878,8 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size)
{
ssize_t rv;
- mutex_lock(&nfsd_mutex);
- rv = __write_ports(file, buf, size, netns(file));
- mutex_unlock(&nfsd_mutex);
+ with_nfsd_file_locked(file)
+ rv = __write_ports(file, buf, size, netns(file));
return rv;
}
@@ -916,13 +925,13 @@ static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
bsize = max_t(int, bsize, 1024);
bsize = min_t(int, bsize, NFSSVC_MAXBLKSIZE);
bsize &= ~(1024-1);
- mutex_lock(&nfsd_mutex);
+ mutex_lock(&nn->nfsd_info.mutex);
if (nn->nfsd_serv) {
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
return -EBUSY;
}
nfsd_max_blksize = bsize;
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
}
return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n",
@@ -971,9 +980,8 @@ static ssize_t nfsd4_write_time(struct file *file, char *buf, size_t size,
{
ssize_t rv;
- mutex_lock(&nfsd_mutex);
- rv = __nfsd4_write_time(file, buf, size, time, nn);
- mutex_unlock(&nfsd_mutex);
+ with_nfsd_file_locked(file)
+ rv = __nfsd4_write_time(file, buf, size, time, nn);
return rv;
}
@@ -1076,9 +1084,8 @@ static ssize_t write_recoverydir(struct file *file, char *buf, size_t size)
ssize_t rv;
struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
- mutex_lock(&nfsd_mutex);
- rv = __write_recoverydir(file, buf, size, nn);
- mutex_unlock(&nfsd_mutex);
+ with_nfsd_file_locked(file)
+ rv = __write_recoverydir(file, buf, size, nn);
return rv;
}
#endif
@@ -1130,9 +1137,8 @@ static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
{
ssize_t rv;
- mutex_lock(&nfsd_mutex);
- rv = __write_v4_end_grace(file, buf, size);
- mutex_unlock(&nfsd_mutex);
+ with_nfsd_file_locked(file)
+ rv = __write_v4_end_grace(file, buf, size);
return rv;
}
#endif
@@ -1552,9 +1558,8 @@ int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
int i, ret, rqstp_index = 0;
struct nfsd_net *nn;
- mutex_lock(&nfsd_mutex);
-
nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+ mutex_lock(&nn->nfsd_info.mutex);
if (!nn->nfsd_serv) {
ret = -ENODEV;
goto out_unlock;
@@ -1636,7 +1641,7 @@ int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
out:
rcu_read_unlock();
out_unlock:
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
return ret;
}
@@ -1665,7 +1670,7 @@ int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *info)
count++;
}
- mutex_lock(&nfsd_mutex);
+ mutex_lock(&nn->nfsd_info.mutex);
nrpools = max(count, nfsd_nrpools(net));
nthreads = kcalloc(nrpools, sizeof(int), GFP_KERNEL);
@@ -1720,7 +1725,7 @@ int nfsd_nl_threads_set_doit(struct sk_buff *skb, struct genl_info *info)
if (ret > 0)
ret = 0;
out_unlock:
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
kfree(nthreads);
return ret;
}
@@ -1749,7 +1754,7 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info)
goto err_free_msg;
}
- mutex_lock(&nfsd_mutex);
+ mutex_lock(&nn->nfsd_info.mutex);
err = nla_put_u32(skb, NFSD_A_SERVER_GRACETIME,
nn->nfsd4_grace) ||
@@ -1777,14 +1782,14 @@ int nfsd_nl_threads_get_doit(struct sk_buff *skb, struct genl_info *info)
goto err_unlock;
}
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
genlmsg_end(skb, hdr);
return genlmsg_reply(skb, info);
err_unlock:
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
err_free_msg:
nlmsg_free(skb);
@@ -1807,11 +1812,10 @@ int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info)
if (GENL_REQ_ATTR_CHECK(info, NFSD_A_SERVER_PROTO_VERSION))
return -EINVAL;
- mutex_lock(&nfsd_mutex);
-
nn = net_generic(genl_info_net(info), nfsd_net_id);
+ mutex_lock(&nn->nfsd_info.mutex);
if (nn->nfsd_serv) {
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
return -EBUSY;
}
@@ -1856,7 +1860,7 @@ int nfsd_nl_version_set_doit(struct sk_buff *skb, struct genl_info *info)
}
}
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
return 0;
}
@@ -1884,7 +1888,7 @@ int nfsd_nl_version_get_doit(struct sk_buff *skb, struct genl_info *info)
goto err_free_msg;
}
- mutex_lock(&nfsd_mutex);
+ mutex_lock(&nn->nfsd_info.mutex);
nn = net_generic(genl_info_net(info), nfsd_net_id);
for (i = 2; i <= 4; i++) {
@@ -1928,13 +1932,13 @@ int nfsd_nl_version_get_doit(struct sk_buff *skb, struct genl_info *info)
}
}
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
genlmsg_end(skb, hdr);
return genlmsg_reply(skb, info);
err_nfsd_unlock:
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
err_free_msg:
nlmsg_free(skb);
@@ -1959,15 +1963,16 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info)
bool delete = false;
int err, rem;
- mutex_lock(&nfsd_mutex);
+ nn = net_generic(net, nfsd_net_id);
+
+ mutex_lock(&nn->nfsd_info.mutex);
err = nfsd_create_serv(net);
if (err) {
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
return err;
}
- nn = net_generic(net, nfsd_net_id);
serv = nn->nfsd_serv;
spin_lock_bh(&serv->sv_lock);
@@ -2083,7 +2088,7 @@ int nfsd_nl_listener_set_doit(struct sk_buff *skb, struct genl_info *info)
nfsd_destroy_serv(net);
out_unlock_mtx:
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
return err;
}
@@ -2113,8 +2118,8 @@ int nfsd_nl_listener_get_doit(struct sk_buff *skb, struct genl_info *info)
goto err_free_msg;
}
- mutex_lock(&nfsd_mutex);
nn = net_generic(genl_info_net(info), nfsd_net_id);
+ mutex_lock(&nn->nfsd_info.mutex);
/* no nfs server? Just send empty socket list */
if (!nn->nfsd_serv)
@@ -2144,14 +2149,14 @@ int nfsd_nl_listener_get_doit(struct sk_buff *skb, struct genl_info *info)
}
spin_unlock_bh(&serv->sv_lock);
out_unlock_mtx:
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
genlmsg_end(skb, hdr);
return genlmsg_reply(skb, info);
err_serv_unlock:
spin_unlock_bh(&serv->sv_lock);
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
err_free_msg:
nlmsg_free(skb);
@@ -2253,7 +2258,7 @@ static __net_init int nfsd_net_init(struct net *net)
nn->nfsd_versions[i] = nfsd_support_version(i);
for (i = 0; i < sizeof(nn->nfsd4_minorversions); i++)
nn->nfsd4_minorversions[i] = nfsd_support_version(4);
- nn->nfsd_info.mutex = &nfsd_mutex;
+ mutex_init(&nn->nfsd_info.mutex);
nn->nfsd_serv = NULL;
nfsd4_init_leases_net(nn);
get_random_bytes(&nn->siphash_key, sizeof(nn->siphash_key));
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 8ad9fcc23789..3cbca4d34f48 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -77,7 +77,6 @@ struct nfsd_genl_rqstp {
extern struct svc_program nfsd_programs[];
extern const struct svc_version nfsd_version2, nfsd_version3, nfsd_version4;
-extern struct mutex nfsd_mutex;
extern atomic_t nfsd_th_cnt; /* number of available threads */
bool nfsd_startup_get(void);
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index b2080e5a71e6..9f70b1fbc55e 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -56,20 +56,6 @@ static __be32 nfsd_init_request(struct svc_rqst *,
const struct svc_program *,
struct svc_process_info *);
-/*
- * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and some members
- * of the svc_serv struct such as ->sv_temp_socks and ->sv_permsocks.
- *
- * Finally, the nfsd_mutex also protects some of the global variables that are
- * accessed when nfsd starts and that are settable via the write_* routines in
- * nfsctl.c. In particular:
- *
- * user_recovery_dirname
- * user_lease_time
- * nfsd_versions
- */
-DEFINE_MUTEX(nfsd_mutex);
-
#if IS_ENABLED(CONFIG_NFS_LOCALIO)
static const struct svc_version *localio_versions[] = {
[1] = &localio_version1,
@@ -242,10 +228,10 @@ int nfsd_nrthreads(struct net *net)
int rv = 0;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
- mutex_lock(&nfsd_mutex);
+ mutex_lock(&nn->nfsd_info.mutex);
if (nn->nfsd_serv)
rv = nn->nfsd_serv->sv_nrthreads;
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
return rv;
}
@@ -522,7 +508,6 @@ static struct notifier_block nfsd_inet6addr_notifier = {
};
#endif
-/* Only used under nfsd_mutex, so this atomic may be overkill: */
static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
/**
@@ -534,7 +519,7 @@ 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);
+ lockdep_assert_held(&nn->nfsd_info.mutex);
spin_lock(&nfsd_notifier_lock);
nn->nfsd_serv = NULL;
@@ -606,17 +591,17 @@ void nfsd_shutdown_threads(struct net *net)
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct svc_serv *serv;
- mutex_lock(&nfsd_mutex);
+ mutex_lock(&nn->nfsd_info.mutex);
serv = nn->nfsd_serv;
if (serv == NULL) {
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
return;
}
/* Kill outstanding nfsd threads */
svc_set_num_threads(serv, NULL, 0);
nfsd_destroy_serv(net);
- mutex_unlock(&nfsd_mutex);
+ mutex_unlock(&nn->nfsd_info.mutex);
}
struct svc_rqst *nfsd_current_rqst(void)
@@ -632,7 +617,7 @@ int nfsd_create_serv(struct net *net)
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct svc_serv *serv;
- WARN_ON(!mutex_is_locked(&nfsd_mutex));
+ WARN_ON(!mutex_is_locked(&nn->nfsd_info.mutex));
if (nn->nfsd_serv)
return 0;
@@ -714,7 +699,7 @@ int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
int err = 0;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
- lockdep_assert_held(&nfsd_mutex);
+ lockdep_assert_held(&nn->nfsd_info.mutex);
if (nn->nfsd_serv == NULL || n <= 0)
return 0;
@@ -787,7 +772,7 @@ nfsd_svc(int n, int *nthreads, struct net *net, const struct cred *cred, const c
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct svc_serv *serv;
- lockdep_assert_held(&nfsd_mutex);
+ lockdep_assert_held(&nn->nfsd_info.mutex);
dprintk("nfsd: creating service\n");
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 48666b83fe68..a12fe99156ec 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -98,7 +98,7 @@ struct svc_serv {
/* This is used by pool_stats to find and lock an svc */
struct svc_info {
struct svc_serv *serv;
- struct mutex *mutex;
+ struct mutex mutex;
};
void svc_destroy(struct svc_serv **svcp);
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 8b1837228799..b8352b7d6860 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -1399,7 +1399,7 @@ static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)
dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);
- mutex_lock(si->mutex);
+ mutex_lock(&si->mutex);
if (!pidx)
return SEQ_START_TOKEN;
@@ -1436,7 +1436,7 @@ static void svc_pool_stats_stop(struct seq_file *m, void *p)
{
struct svc_info *si = m->private;
- mutex_unlock(si->mutex);
+ mutex_unlock(&si->mutex);
}
static int svc_pool_stats_show(struct seq_file *m, void *p)
--
2.49.0
