1 files changed, 430 insertions, 135 deletions

diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 35efb9a31dd7..839a22280606 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -17,8 +17,15 @@
 #include <linux/uaccess.h>
 #include "internal.h"
 
-static struct proc_dir_entry *proc_afs;
+static inline struct afs_net *afs_proc2net(struct file *f)
+{
+	return &__afs_net;
+}
 
+static inline struct afs_net *afs_seq2net(struct seq_file *m)
+{
+	return &__afs_net; // TODO: use seq_file_net(m)
+}
 
 static int afs_proc_cells_open(struct inode *inode, struct file *file);
 static void *afs_proc_cells_start(struct seq_file *p, loff_t *pos);
@@ -98,47 +105,78 @@ static const struct file_operations afs_proc_cell_vlservers_fops = {
 	.release	= seq_release,
 };
 
-static int afs_proc_cell_servers_open(struct inode *inode, struct file *file);
-static void *afs_proc_cell_servers_start(struct seq_file *p, loff_t *pos);
-static void *afs_proc_cell_servers_next(struct seq_file *p, void *v,
+static int afs_proc_servers_open(struct inode *inode, struct file *file);
+static void *afs_proc_servers_start(struct seq_file *p, loff_t *pos);
+static void *afs_proc_servers_next(struct seq_file *p, void *v,
 					loff_t *pos);
-static void afs_proc_cell_servers_stop(struct seq_file *p, void *v);
-static int afs_proc_cell_servers_show(struct seq_file *m, void *v);
-
-static const struct seq_operations afs_proc_cell_servers_ops = {
-	.start	= afs_proc_cell_servers_start,
-	.next	= afs_proc_cell_servers_next,
-	.stop	= afs_proc_cell_servers_stop,
-	.show	= afs_proc_cell_servers_show,
+static void afs_proc_servers_stop(struct seq_file *p, void *v);
+static int afs_proc_servers_show(struct seq_file *m, void *v);
+
+static const struct seq_operations afs_proc_servers_ops = {
+	.start	= afs_proc_servers_start,
+	.next	= afs_proc_servers_next,
+	.stop	= afs_proc_servers_stop,
+	.show	= afs_proc_servers_show,
 };
 
-static const struct file_operations afs_proc_cell_servers_fops = {
-	.open		= afs_proc_cell_servers_open,
+static const struct file_operations afs_proc_servers_fops = {
+	.open		= afs_proc_servers_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
 
+static int afs_proc_sysname_open(struct inode *inode, struct file *file);
+static int afs_proc_sysname_release(struct inode *inode, struct file *file);
+static void *afs_proc_sysname_start(struct seq_file *p, loff_t *pos);
+static void *afs_proc_sysname_next(struct seq_file *p, void *v,
+					loff_t *pos);
+static void afs_proc_sysname_stop(struct seq_file *p, void *v);
+static int afs_proc_sysname_show(struct seq_file *m, void *v);
+static ssize_t afs_proc_sysname_write(struct file *file,
+				      const char __user *buf,
+				      size_t size, loff_t *_pos);
+
+static const struct seq_operations afs_proc_sysname_ops = {
+	.start	= afs_proc_sysname_start,
+	.next	= afs_proc_sysname_next,
+	.stop	= afs_proc_sysname_stop,
+	.show	= afs_proc_sysname_show,
+};
+
+static const struct file_operations afs_proc_sysname_fops = {
+	.open		= afs_proc_sysname_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= afs_proc_sysname_release,
+	.write		= afs_proc_sysname_write,
+};
+
+static const struct file_operations afs_proc_stats_fops;
+
 /*
  * initialise the /proc/fs/afs/ directory
  */
-int afs_proc_init(void)
+int afs_proc_init(struct afs_net *net)
 {
 	_enter("");
 
-	proc_afs = proc_mkdir("fs/afs", NULL);
-	if (!proc_afs)
+	net->proc_afs = proc_mkdir("fs/afs", NULL);
+	if (!net->proc_afs)
 		goto error_dir;
 
-	if (!proc_create("cells", 0644, proc_afs, &afs_proc_cells_fops) ||
-	    !proc_create("rootcell", 0644, proc_afs, &afs_proc_rootcell_fops))
+	if (!proc_create("cells", 0644, net->proc_afs, &afs_proc_cells_fops) ||
+	    !proc_create("rootcell", 0644, net->proc_afs, &afs_proc_rootcell_fops) ||
+	    !proc_create("servers", 0644, net->proc_afs, &afs_proc_servers_fops) ||
+	    !proc_create("stats", 0644, net->proc_afs, &afs_proc_stats_fops) ||
+	    !proc_create("sysname", 0644, net->proc_afs, &afs_proc_sysname_fops))
 		goto error_tree;
 
 	_leave(" = 0");
 	return 0;
 
 error_tree:
-	remove_proc_subtree("fs/afs", NULL);
+	proc_remove(net->proc_afs);
 error_dir:
 	_leave(" = -ENOMEM");
 	return -ENOMEM;
@@ -147,9 +185,10 @@ error_dir:
 /*
  * clean up the /proc/fs/afs/ directory
  */
-void afs_proc_cleanup(void)
+void afs_proc_cleanup(struct afs_net *net)
 {
-	remove_proc_subtree("fs/afs", NULL);
+	proc_remove(net->proc_afs);
+	net->proc_afs = NULL;
 }
 
 /*
@@ -166,7 +205,6 @@ static int afs_proc_cells_open(struct inode *inode, struct file *file)
 
 	m = file->private_data;
 	m->private = PDE_DATA(inode);
-
 	return 0;
 }
 
@@ -175,26 +213,31 @@ static int afs_proc_cells_open(struct inode *inode, struct file *file)
  * first item
  */
 static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
+	__acquires(rcu)
 {
-	/* lock the list against modification */
-	down_read(&afs_proc_cells_sem);
-	return seq_list_start_head(&afs_proc_cells, *_pos);
+	struct afs_net *net = afs_seq2net(m);
+
+	rcu_read_lock();
+	return seq_list_start_head(&net->proc_cells, *_pos);
 }
 
 /*
  * move to next cell in cells list
  */
-static void *afs_proc_cells_next(struct seq_file *p, void *v, loff_t *pos)
+static void *afs_proc_cells_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	return seq_list_next(v, &afs_proc_cells, pos);
+	struct afs_net *net = afs_seq2net(m);
+
+	return seq_list_next(v, &net->proc_cells, pos);
 }
 
 /*
  * clean up after reading from the cells list
  */
-static void afs_proc_cells_stop(struct seq_file *p, void *v)
+static void afs_proc_cells_stop(struct seq_file *m, void *v)
+	__releases(rcu)
 {
-	up_read(&afs_proc_cells_sem);
+	rcu_read_unlock();
 }
 
 /*
@@ -203,16 +246,16 @@ static void afs_proc_cells_stop(struct seq_file *p, void *v)
 static int afs_proc_cells_show(struct seq_file *m, void *v)
 {
 	struct afs_cell *cell = list_entry(v, struct afs_cell, proc_link);
+	struct afs_net *net = afs_seq2net(m);
 
-	if (v == &afs_proc_cells) {
+	if (v == &net->proc_cells) {
 		/* display header on line 1 */
 		seq_puts(m, "USE NAME\n");
 		return 0;
 	}
 
 	/* display one cell per line on subsequent lines */
-	seq_printf(m, "%3d %s\n",
-		   atomic_read(&cell->usage), cell->name);
+	seq_printf(m, "%3u %s\n", atomic_read(&cell->usage), cell->name);
 	return 0;
 }
 
@@ -223,6 +266,7 @@ static int afs_proc_cells_show(struct seq_file *m, void *v)
 static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
 				    size_t size, loff_t *_pos)
 {
+	struct afs_net *net = afs_proc2net(file);
 	char *kbuf, *name, *args;
 	int ret;
 
@@ -264,13 +308,14 @@ static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
 	if (strcmp(kbuf, "add") == 0) {
 		struct afs_cell *cell;
 
-		cell = afs_cell_create(name, strlen(name), args, false);
+		cell = afs_lookup_cell(net, name, strlen(name), args, true);
 		if (IS_ERR(cell)) {
 			ret = PTR_ERR(cell);
 			goto done;
 		}
 
-		afs_put_cell(cell);
+		if (test_and_set_bit(AFS_CELL_FL_NO_GC, &cell->flags))
+			afs_put_cell(net, cell);
 		printk("kAFS: Added new cell '%s'\n", name);
 	} else {
 		goto inval;
@@ -292,7 +337,40 @@ inval:
 static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
 				      size_t size, loff_t *_pos)
 {
-	return 0;
+	struct afs_cell *cell;
+	struct afs_net *net = afs_proc2net(file);
+	unsigned int seq = 0;
+	char name[AFS_MAXCELLNAME + 1];
+	int len;
+
+	if (*_pos > 0)
+		return 0;
+	if (!net->ws_cell)
+		return 0;
+
+	rcu_read_lock();
+	do {
+		read_seqbegin_or_lock(&net->cells_lock, &seq);
+		len = 0;
+		cell = rcu_dereference_raw(net->ws_cell);
+		if (cell) {
+			len = cell->name_len;
+			memcpy(name, cell->name, len);
+		}
+	} while (need_seqretry(&net->cells_lock, seq));
+	done_seqretry(&net->cells_lock, seq);
+	rcu_read_unlock();
+
+	if (!len)
+		return 0;
+
+	name[len++] = '\n';
+	if (len > size)
+		len = size;
+	if (copy_to_user(buf, name, len) != 0)
+		return -EFAULT;
+	*_pos = 1;
+	return len;
 }
 
 /*
@@ -303,6 +381,7 @@ static ssize_t afs_proc_rootcell_write(struct file *file,
 				       const char __user *buf,
 				       size_t size, loff_t *_pos)
 {
+	struct afs_net *net = afs_proc2net(file);
 	char *kbuf, *s;
 	int ret;
 
@@ -314,6 +393,12 @@ static ssize_t afs_proc_rootcell_write(struct file *file,
 	if (IS_ERR(kbuf))
 		return PTR_ERR(kbuf);
 
+	ret = -EINVAL;
+	if (kbuf[0] == '.')
+		goto out;
+	if (memchr(kbuf, '/', size))
+		goto out;
+
 	/* trim to first NL */
 	s = memchr(kbuf, '\n', size);
 	if (s)
@@ -322,10 +407,11 @@ static ssize_t afs_proc_rootcell_write(struct file *file,
 	/* determine command to perform */
 	_debug("rootcell=%s", kbuf);
 
-	ret = afs_cell_init(kbuf);
+	ret = afs_cell_init(net, kbuf);
 	if (ret >= 0)
 		ret = size;	/* consume everything, always */
 
+out:
 	kfree(kbuf);
 	_leave(" = %d", ret);
 	return ret;
@@ -334,29 +420,27 @@ static ssize_t afs_proc_rootcell_write(struct file *file,
 /*
  * initialise /proc/fs/afs/<cell>/
  */
-int afs_proc_cell_setup(struct afs_cell *cell)
+int afs_proc_cell_setup(struct afs_net *net, struct afs_cell *cell)
 {
 	struct proc_dir_entry *dir;
 
-	_enter("%p{%s}", cell, cell->name);
+	_enter("%p{%s},%p", cell, cell->name, net->proc_afs);
 
-	dir = proc_mkdir(cell->name, proc_afs);
+	dir = proc_mkdir(cell->name, net->proc_afs);
 	if (!dir)
 		goto error_dir;
 
-	if (!proc_create_data("servers", 0, dir,
-			     &afs_proc_cell_servers_fops, cell) ||
-	    !proc_create_data("vlservers", 0, dir,
-			     &afs_proc_cell_vlservers_fops, cell) ||
+	if (!proc_create_data("vlservers", 0, dir,
+			      &afs_proc_cell_vlservers_fops, cell) ||
 	    !proc_create_data("volumes", 0, dir,
-			     &afs_proc_cell_volumes_fops, cell))
+			      &afs_proc_cell_volumes_fops, cell))
 		goto error_tree;
 
 	_leave(" = 0");
 	return 0;
 
 error_tree:
-	remove_proc_subtree(cell->name, proc_afs);
+	remove_proc_subtree(cell->name, net->proc_afs);
 error_dir:
 	_leave(" = -ENOMEM");
 	return -ENOMEM;
@@ -365,11 +449,11 @@ error_dir:
 /*
  * remove /proc/fs/afs/<cell>/
  */
-void afs_proc_cell_remove(struct afs_cell *cell)
+void afs_proc_cell_remove(struct afs_net *net, struct afs_cell *cell)
 {
 	_enter("");
 
-	remove_proc_subtree(cell->name, proc_afs);
+	remove_proc_subtree(cell->name, net->proc_afs);
 
 	_leave("");
 }
@@ -402,14 +486,14 @@ static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file)
  * first item
  */
 static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
+	__acquires(cell->proc_lock)
 {
 	struct afs_cell *cell = m->private;
 
 	_enter("cell=%p pos=%Ld", cell, *_pos);
 
-	/* lock the list against modification */
-	down_read(&cell->vl_sem);
-	return seq_list_start_head(&cell->vl_list, *_pos);
+	read_lock(&cell->proc_lock);
+	return seq_list_start_head(&cell->proc_volumes, *_pos);
 }
 
 /*
@@ -421,27 +505,24 @@ static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
 	struct afs_cell *cell = p->private;
 
 	_enter("cell=%p pos=%Ld", cell, *_pos);
-	return seq_list_next(v, &cell->vl_list, _pos);
+	return seq_list_next(v, &cell->proc_volumes, _pos);
 }
 
 /*
  * clean up after reading from the cells list
  */
 static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v)
+	__releases(cell->proc_lock)
 {
 	struct afs_cell *cell = p->private;
 
-	up_read(&cell->vl_sem);
+	read_unlock(&cell->proc_lock);
 }
 
-static const char afs_vlocation_states[][4] = {
-	[AFS_VL_NEW]			= "New",
-	[AFS_VL_CREATING]		= "Crt",
-	[AFS_VL_VALID]			= "Val",
-	[AFS_VL_NO_VOLUME]		= "NoV",
-	[AFS_VL_UPDATING]		= "Upd",
-	[AFS_VL_VOLUME_DELETED]		= "Del",
-	[AFS_VL_UNCERTAIN]		= "Unc",
+static const char afs_vol_types[3][3] = {
+	[AFSVL_RWVOL]	= "RW",
+	[AFSVL_ROVOL]	= "RO",
+	[AFSVL_BACKVOL]	= "BK",
 };
 
 /*
@@ -450,23 +531,17 @@ static const char afs_vlocation_states[][4] = {
 static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
 {
 	struct afs_cell *cell = m->private;
-	struct afs_vlocation *vlocation =
-		list_entry(v, struct afs_vlocation, link);
+	struct afs_volume *vol = list_entry(v, struct afs_volume, proc_link);
 
-	/* display header on line 1 */
-	if (v == &cell->vl_list) {
-		seq_puts(m, "USE STT VLID[0]  VLID[1]  VLID[2]  NAME\n");
+	/* Display header on line 1 */
+	if (v == &cell->proc_volumes) {
+		seq_puts(m, "USE VID      TY\n");
 		return 0;
 	}
 
-	/* display one cell per line on subsequent lines */
-	seq_printf(m, "%3d %s %08x %08x %08x %s\n",
-		   atomic_read(&vlocation->usage),
-		   afs_vlocation_states[vlocation->state],
-		   vlocation->vldb.vid[0],
-		   vlocation->vldb.vid[1],
-		   vlocation->vldb.vid[2],
-		   vlocation->vldb.name);
+	seq_printf(m, "%3d %08x %s\n",
+		   atomic_read(&vol->usage), vol->vid,
+		   afs_vol_types[vol->type]);
 
 	return 0;
 }
@@ -500,24 +575,25 @@ static int afs_proc_cell_vlservers_open(struct inode *inode, struct file *file)
  * first item
  */
 static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
+	__acquires(rcu)
 {
+	struct afs_addr_list *alist;
 	struct afs_cell *cell = m->private;
 	loff_t pos = *_pos;
 
-	_enter("cell=%p pos=%Ld", cell, *_pos);
+	rcu_read_lock();
 
-	/* lock the list against modification */
-	down_read(&cell->vl_sem);
+	alist = rcu_dereference(cell->vl_addrs);
 
 	/* allow for the header line */
 	if (!pos)
 		return (void *) 1;
 	pos--;
 
-	if (pos >= cell->vl_naddrs)
+	if (!alist || pos >= alist->nr_addrs)
 		return NULL;
 
-	return &cell->vl_addrs[pos];
+	return alist->addrs + pos;
 }
 
 /*
@@ -526,27 +602,27 @@ static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
 static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
 					  loff_t *_pos)
 {
+	struct afs_addr_list *alist;
 	struct afs_cell *cell = p->private;
 	loff_t pos;
 
-	_enter("cell=%p{nad=%u} pos=%Ld", cell, cell->vl_naddrs, *_pos);
+	alist = rcu_dereference(cell->vl_addrs);
 
 	pos = *_pos;
 	(*_pos)++;
-	if (pos >= cell->vl_naddrs)
+	if (!alist || pos >= alist->nr_addrs)
 		return NULL;
 
-	return &cell->vl_addrs[pos];
+	return alist->addrs + pos;
 }
 
 /*
  * clean up after reading from the cells list
  */
 static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v)
+	__releases(rcu)
 {
-	struct afs_cell *cell = p->private;
-
-	up_read(&cell->vl_sem);
+	rcu_read_unlock();
 }
 
 /*
@@ -554,100 +630,319 @@ static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v)
  */
 static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
 {
-	struct in_addr *addr = v;
+	struct sockaddr_rxrpc *addr = v;
 
 	/* display header on line 1 */
-	if (v == (struct in_addr *) 1) {
+	if (v == (void *)1) {
 		seq_puts(m, "ADDRESS\n");
 		return 0;
 	}
 
 	/* display one cell per line on subsequent lines */
-	seq_printf(m, "%pI4\n", &addr->s_addr);
+	seq_printf(m, "%pISp\n", &addr->transport);
 	return 0;
 }
 
 /*
- * open "/proc/fs/afs/<cell>/servers" which provides a summary of active
+ * open "/proc/fs/afs/servers" which provides a summary of active
  * servers
  */
-static int afs_proc_cell_servers_open(struct inode *inode, struct file *file)
+static int afs_proc_servers_open(struct inode *inode, struct file *file)
 {
-	struct afs_cell *cell;
-	struct seq_file *m;
-	int ret;
-
-	cell = PDE_DATA(inode);
-	if (!cell)
-		return -ENOENT;
+	return seq_open(file, &afs_proc_servers_ops);
+}
 
-	ret = seq_open(file, &afs_proc_cell_servers_ops);
-	if (ret < 0)
-		return ret;
+/*
+ * Set up the iterator to start reading from the server list and return the
+ * first item.
+ */
+static void *afs_proc_servers_start(struct seq_file *m, loff_t *_pos)
+	__acquires(rcu)
+{
+	struct afs_net *net = afs_seq2net(m);
 
-	m = file->private_data;
-	m->private = cell;
-	return 0;
+	rcu_read_lock();
+	return seq_hlist_start_head_rcu(&net->fs_proc, *_pos);
 }
 
 /*
- * set up the iterator to start reading from the cells list and return the
- * first item
+ * move to next cell in cells list
  */
-static void *afs_proc_cell_servers_start(struct seq_file *m, loff_t *_pos)
-	__acquires(m->private->servers_lock)
+static void *afs_proc_servers_next(struct seq_file *m, void *v, loff_t *_pos)
 {
-	struct afs_cell *cell = m->private;
+	struct afs_net *net = afs_seq2net(m);
 
-	_enter("cell=%p pos=%Ld", cell, *_pos);
+	return seq_hlist_next_rcu(v, &net->fs_proc, _pos);
+}
 
-	/* lock the list against modification */
-	read_lock(&cell->servers_lock);
-	return seq_list_start_head(&cell->servers, *_pos);
+/*
+ * clean up after reading from the cells list
+ */
+static void afs_proc_servers_stop(struct seq_file *p, void *v)
+	__releases(rcu)
+{
+	rcu_read_unlock();
 }
 
 /*
- * move to next cell in cells list
+ * display a header line followed by a load of volume lines
  */
-static void *afs_proc_cell_servers_next(struct seq_file *p, void *v,
-					loff_t *_pos)
+static int afs_proc_servers_show(struct seq_file *m, void *v)
 {
-	struct afs_cell *cell = p->private;
+	struct afs_server *server;
+	struct afs_addr_list *alist;
 
-	_enter("cell=%p pos=%Ld", cell, *_pos);
-	return seq_list_next(v, &cell->servers, _pos);
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(m, "UUID                                 USE ADDR\n");
+		return 0;
+	}
+
+	server = list_entry(v, struct afs_server, proc_link);
+	alist = rcu_dereference(server->addresses);
+	seq_printf(m, "%pU %3d %pISp\n",
+		   &server->uuid,
+		   atomic_read(&server->usage),
+		   &alist->addrs[alist->index].transport);
+	return 0;
+}
+
+void afs_put_sysnames(struct afs_sysnames *sysnames)
+{
+	int i;
+
+	if (sysnames && refcount_dec_and_test(&sysnames->usage)) {
+		for (i = 0; i < sysnames->nr; i++)
+			if (sysnames->subs[i] != afs_init_sysname &&
+			    sysnames->subs[i] != sysnames->blank)
+				kfree(sysnames->subs[i]);
+	}
 }
 
 /*
- * clean up after reading from the cells list
+ * Handle opening of /proc/fs/afs/sysname.  If it is opened for writing, we
+ * assume the caller wants to change the substitution list and we allocate a
+ * buffer to hold the list.
  */
-static void afs_proc_cell_servers_stop(struct seq_file *p, void *v)
-	__releases(p->private->servers_lock)
+static int afs_proc_sysname_open(struct inode *inode, struct file *file)
 {
-	struct afs_cell *cell = p->private;
+	struct afs_sysnames *sysnames;
+	struct seq_file *m;
+	int ret;
+
+	ret = seq_open(file, &afs_proc_sysname_ops);
+	if (ret < 0)
+		return ret;
+
+	if (file->f_mode & FMODE_WRITE) {
+		sysnames = kzalloc(sizeof(*sysnames), GFP_KERNEL);
+		if (!sysnames) {
+			seq_release(inode, file);
+			return -ENOMEM;
+		}
+
+		refcount_set(&sysnames->usage, 1);
+		m = file->private_data;
+		m->private = sysnames;
+	}
 
-	read_unlock(&cell->servers_lock);
+	return 0;
 }
 
 /*
- * display a header line followed by a load of volume lines
+ * Handle writes to /proc/fs/afs/sysname to set the @sys substitution.
  */
-static int afs_proc_cell_servers_show(struct seq_file *m, void *v)
+static ssize_t afs_proc_sysname_write(struct file *file,
+				      const char __user *buf,
+				      size_t size, loff_t *_pos)
 {
-	struct afs_cell *cell = m->private;
-	struct afs_server *server = list_entry(v, struct afs_server, link);
-	char ipaddr[20];
+	struct afs_sysnames *sysnames;
+	struct seq_file *m = file->private_data;
+	char *kbuf = NULL, *s, *p, *sub;
+	int ret, len;
 
-	/* display header on line 1 */
-	if (v == &cell->servers) {
-		seq_puts(m, "USE ADDR            STATE\n");
+	sysnames = m->private;
+	if (!sysnames)
+		return -EINVAL;
+	if (sysnames->error)
+		return sysnames->error;
+
+	if (size >= PAGE_SIZE - 1) {
+		sysnames->error = -EINVAL;
+		return -EINVAL;
+	}
+	if (size == 0)
 		return 0;
+
+	kbuf = memdup_user_nul(buf, size);
+	if (IS_ERR(kbuf))
+		return PTR_ERR(kbuf);
+
+	inode_lock(file_inode(file));
+
+	p = kbuf;
+	while ((s = strsep(&p, " \t\n"))) {
+		len = strlen(s);
+		if (len == 0)
+			continue;
+		ret = -ENAMETOOLONG;
+		if (len >= AFSNAMEMAX)
+			goto error;
+
+		if (len >= 4 &&
+		    s[len - 4] == '@' &&
+		    s[len - 3] == 's' &&
+		    s[len - 2] == 'y' &&
+		    s[len - 1] == 's')
+			/* Protect against recursion */
+			goto invalid;
+
+		if (s[0] == '.' &&
+		    (len < 2 || (len == 2 && s[1] == '.')))
+			goto invalid;
+
+		if (memchr(s, '/', len))
+			goto invalid;
+
+		ret = -EFBIG;
+		if (sysnames->nr >= AFS_NR_SYSNAME)
+			goto out;
+
+		if (strcmp(s, afs_init_sysname) == 0) {
+			sub = (char *)afs_init_sysname;
+		} else {
+			ret = -ENOMEM;
+			sub = kmemdup(s, len + 1, GFP_KERNEL);
+			if (!sub)
+				goto out;
+		}
+
+		sysnames->subs[sysnames->nr] = sub;
+		sysnames->nr++;
 	}
 
-	/* display one cell per line on subsequent lines */
-	sprintf(ipaddr, "%pI4", &server->addr);
-	seq_printf(m, "%3d %-15.15s %5d\n",
-		   atomic_read(&server->usage), ipaddr, server->fs_state);
+	ret = size;	/* consume everything, always */
+out:
+	inode_unlock(file_inode(file));
+	kfree(kbuf);
+	return ret;
+
+invalid:
+	ret = -EINVAL;
+error:
+	sysnames->error = ret;
+	goto out;
+}
+
+static int afs_proc_sysname_release(struct inode *inode, struct file *file)
+{
+	struct afs_sysnames *sysnames, *kill = NULL;
+	struct seq_file *m = file->private_data;
+	struct afs_net *net = afs_seq2net(m);
+
+	sysnames = m->private;
+	if (sysnames) {
+		if (!sysnames->error) {
+			kill = sysnames;
+			if (sysnames->nr == 0) {
+				sysnames->subs[0] = sysnames->blank;
+				sysnames->nr++;
+			}
+			write_lock(&net->sysnames_lock);
+			kill = net->sysnames;
+			net->sysnames = sysnames;
+			write_unlock(&net->sysnames_lock);
+		}
+		afs_put_sysnames(kill);
+	}
+
+	return seq_release(inode, file);
+}
 
+static void *afs_proc_sysname_start(struct seq_file *m, loff_t *pos)
+	__acquires(&net->sysnames_lock)
+{
+	struct afs_net *net = afs_seq2net(m);
+	struct afs_sysnames *names = net->sysnames;
+
+	read_lock(&net->sysnames_lock);
+
+	if (*pos >= names->nr)
+		return NULL;
+	return (void *)(unsigned long)(*pos + 1);
+}
+
+static void *afs_proc_sysname_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	struct afs_net *net = afs_seq2net(m);
+	struct afs_sysnames *names = net->sysnames;
+
+	*pos += 1;
+	if (*pos >= names->nr)
+		return NULL;
+	return (void *)(unsigned long)(*pos + 1);
+}
+
+static void afs_proc_sysname_stop(struct seq_file *m, void *v)
+	__releases(&net->sysnames_lock)
+{
+	struct afs_net *net = afs_seq2net(m);
+
+	read_unlock(&net->sysnames_lock);
+}
+
+static int afs_proc_sysname_show(struct seq_file *m, void *v)
+{
+	struct afs_net *net = afs_seq2net(m);
+	struct afs_sysnames *sysnames = net->sysnames;
+	unsigned int i = (unsigned long)v - 1;
+
+	if (i < sysnames->nr)
+		seq_printf(m, "%s\n", sysnames->subs[i]);
 	return 0;
 }
+
+/*
+ * Display general per-net namespace statistics
+ */
+static int afs_proc_stats_show(struct seq_file *m, void *v)
+{
+	struct afs_net *net = afs_seq2net(m);
+
+	seq_puts(m, "kAFS statistics\n");
+
+	seq_printf(m, "dir-mgmt: look=%u reval=%u inval=%u relpg=%u\n",
+		   atomic_read(&net->n_lookup),
+		   atomic_read(&net->n_reval),
+		   atomic_read(&net->n_inval),
+		   atomic_read(&net->n_relpg));
+
+	seq_printf(m, "dir-data: rdpg=%u\n",
+		   atomic_read(&net->n_read_dir));
+
+	seq_printf(m, "dir-edit: cr=%u rm=%u\n",
+		   atomic_read(&net->n_dir_cr),
+		   atomic_read(&net->n_dir_rm));
+
+	seq_printf(m, "file-rd : n=%u nb=%lu\n",
+		   atomic_read(&net->n_fetches),
+		   atomic_long_read(&net->n_fetch_bytes));
+	seq_printf(m, "file-wr : n=%u nb=%lu\n",
+		   atomic_read(&net->n_stores),
+		   atomic_long_read(&net->n_store_bytes));
+	return 0;
+}
+
+/*
+ * Open "/proc/fs/afs/stats" to allow reading of the stat counters.
+ */
+static int afs_proc_stats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, afs_proc_stats_show, NULL);
+}
+
+static const struct file_operations afs_proc_stats_fops = {
+	.open		= afs_proc_stats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release        = single_release,
+};