[PATCH 0/8] afs: Network-namespacing

[PATCH 0/8] afs: Network-namespacing

[David Howells]

Hi Al,

Can you pull these patches on top of Christoph's procfs changes?  The patches
do:

 (*) Rearrange fs/afs/proc.c to get rid of the forward declarations and
     simplify the commenting.

 (*) Supply functions that allow writable net proc files to be created
     (this could be extended to provide writing on non-net proc files).

 (*) Implement network namespacing in AFS and simplify the proc usage,
     using the new convenience functions provided.

I've included another couple of small patches also:

 (*) afs_net::ws_cell should be annotated and accessed for RCU.  This patch
     would conflict with the other patches if separate.

 (*) Fix a sparse warning where sparse can't manage to follow the locking
     in a function.

Note that these patches don't quite complete network namespacing; the last
bit requires the mount API patches to allow propagation of the network
namespace across automounts.

The patches are tagged here:

	git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git
	afs-namespace-20180523

The patches can be found here also:

	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=afs-namespace

David
---
David Howells (8):
      afs: Move /proc management functions to the end of the file
      afs: Rearrange fs/afs/proc.c by moving fops and open functions down
      afs: Rearrange fs/afs/proc.c to move the show routines up
      afs: Rearrange fs/afs/proc.c to remove remaining predeclarations.
      proc: Add a way to make network proc files writable
      afs: Fix a Sparse warning in xdr_decode_AFSFetchStatus()
      afs: Mark afs_net::ws_cell as __rcu and set using rcu functions
      afs: Implement network namespacing


 fs/afs/cell.c           |   12 -
 fs/afs/cmservice.c      |    2 
 fs/afs/fsclient.c       |   97 +++---
 fs/afs/internal.h       |   45 +--
 fs/afs/main.c           |   33 ++
 fs/afs/netdevices.c     |    6 
 fs/afs/proc.c           |  787 +++++++++++++++++------------------------------
 fs/afs/rxrpc.c          |    2 
 fs/afs/super.c          |   20 +
 fs/proc/generic.c       |   24 +
 fs/proc/internal.h      |    2 
 fs/proc/proc_net.c      |   92 +++++
 include/linux/proc_fs.h |   12 +
 13 files changed, 552 insertions(+), 582 deletions(-)

[PATCH 1/8] afs: Move /proc management functions to the end of the file

[David Howells]

In fs/afs/proc.c, move functions that create and remove /proc files to the
end of the source file as a first stage in getting rid of all the forward
declarations.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/proc.c |  160 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 79 insertions(+), 81 deletions(-)

diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 3aad32762989..4bb612b04f3c 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -127,45 +127,6 @@ static const struct file_operations afs_proc_sysname_fops = {
 	.write		= afs_proc_sysname_write,
 };
 
-static int afs_proc_stats_show(struct seq_file *m, void *v);
-
-/*
- * initialise the /proc/fs/afs/ directory
- */
-int afs_proc_init(struct afs_net *net)
-{
-	_enter("");
-
-	net->proc_afs = proc_mkdir("fs/afs", NULL);
-	if (!net->proc_afs)
-		goto error_dir;
-
-	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_seq("servers", 0644, net->proc_afs, &afs_proc_servers_ops) ||
-	    !proc_create_single("stats", 0644, net->proc_afs, afs_proc_stats_show) ||
-	    !proc_create("sysname", 0644, net->proc_afs, &afs_proc_sysname_fops))
-		goto error_tree;
-
-	_leave(" = 0");
-	return 0;
-
-error_tree:
-	proc_remove(net->proc_afs);
-error_dir:
-	_leave(" = -ENOMEM");
-	return -ENOMEM;
-}
-
-/*
- * clean up the /proc/fs/afs/ directory
- */
-void afs_proc_cleanup(struct afs_net *net)
-{
-	proc_remove(net->proc_afs);
-	net->proc_afs = NULL;
-}
-
 /*
  * open "/proc/fs/afs/cells" which provides a summary of extant cells
  */
@@ -383,48 +344,6 @@ static ssize_t afs_proc_rootcell_write(struct file *file,
 	return ret;
 }
 
-/*
- * initialise /proc/fs/afs/<cell>/
- */
-int afs_proc_cell_setup(struct afs_net *net, struct afs_cell *cell)
-{
-	struct proc_dir_entry *dir;
-
-	_enter("%p{%s},%p", cell, cell->name, net->proc_afs);
-
-	dir = proc_mkdir(cell->name, net->proc_afs);
-	if (!dir)
-		goto error_dir;
-
-	if (!proc_create_seq_data("vlservers", 0, dir,
-			&afs_proc_cell_vlservers_ops, cell))
-		goto error_tree;
-	if (!proc_create_seq_data("volumes", 0, dir, &afs_proc_cell_volumes_ops,
-			cell))
-		goto error_tree;
-
-	_leave(" = 0");
-	return 0;
-
-error_tree:
-	remove_proc_subtree(cell->name, net->proc_afs);
-error_dir:
-	_leave(" = -ENOMEM");
-	return -ENOMEM;
-}
-
-/*
- * remove /proc/fs/afs/<cell>/
- */
-void afs_proc_cell_remove(struct afs_net *net, struct afs_cell *cell)
-{
-	_enter("");
-
-	remove_proc_subtree(cell->name, net->proc_afs);
-
-	_leave("");
-}
-
 /*
  * set up the iterator to start reading from the cells list and return the
  * first item
@@ -842,3 +761,82 @@ static int afs_proc_stats_show(struct seq_file *m, void *v)
 		   atomic_long_read(&net->n_store_bytes));
 	return 0;
 }
+
+/*
+ * initialise /proc/fs/afs/<cell>/
+ */
+int afs_proc_cell_setup(struct afs_net *net, struct afs_cell *cell)
+{
+	struct proc_dir_entry *dir;
+
+	_enter("%p{%s},%p", cell, cell->name, net->proc_afs);
+
+	dir = proc_mkdir(cell->name, net->proc_afs);
+	if (!dir)
+		goto error_dir;
+
+	if (!proc_create_seq_data("vlservers", 0, dir,
+				  &afs_proc_cell_vlservers_ops, cell))
+		goto error_tree;
+	if (!proc_create_seq_data("volumes", 0, dir,
+				  &afs_proc_cell_volumes_ops, cell))
+		goto error_tree;
+
+	_leave(" = 0");
+	return 0;
+
+error_tree:
+	remove_proc_subtree(cell->name, net->proc_afs);
+error_dir:
+	_leave(" = -ENOMEM");
+	return -ENOMEM;
+}
+
+/*
+ * remove /proc/fs/afs/<cell>/
+ */
+void afs_proc_cell_remove(struct afs_net *net, struct afs_cell *cell)
+{
+	_enter("");
+
+	remove_proc_subtree(cell->name, net->proc_afs);
+
+	_leave("");
+}
+
+/*
+ * initialise the /proc/fs/afs/ directory
+ */
+int afs_proc_init(struct afs_net *net)
+{
+	_enter("");
+
+	net->proc_afs = proc_mkdir("fs/afs", NULL);
+	if (!net->proc_afs)
+		goto error_dir;
+
+	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_seq("servers", 0644, net->proc_afs, &afs_proc_servers_ops) ||
+	    !proc_create_single("stats", 0644, net->proc_afs, afs_proc_stats_show) ||
+	    !proc_create("sysname", 0644, net->proc_afs, &afs_proc_sysname_fops))
+		goto error_tree;
+
+	_leave(" = 0");
+	return 0;
+
+error_tree:
+	proc_remove(net->proc_afs);
+error_dir:
+	_leave(" = -ENOMEM");
+	return -ENOMEM;
+}
+
+/*
+ * clean up the /proc/fs/afs/ directory
+ */
+void afs_proc_cleanup(struct afs_net *net)
+{
+	proc_remove(net->proc_afs);
+	net->proc_afs = NULL;
+}

[PATCH 2/8] afs: Rearrange fs/afs/proc.c by moving fops and open functions down

[David Howells]

Rearrange fs/afs/proc.c by moving fops and open functions down so as to
remove predeclarations.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/proc.c |   71 ++++++++++++++++++++++-----------------------------------
 1 file changed, 27 insertions(+), 44 deletions(-)

diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 4bb612b04f3c..22ce99df3208 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -27,13 +27,10 @@ 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);
 static void *afs_proc_cells_next(struct seq_file *p, void *v, loff_t *pos);
 static void afs_proc_cells_stop(struct seq_file *p, void *v);
 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);
 
 static const struct seq_operations afs_proc_cells_ops = {
 	.start	= afs_proc_cells_start,
@@ -42,26 +39,6 @@ static const struct seq_operations afs_proc_cells_ops = {
 	.show	= afs_proc_cells_show,
 };
 
-static const struct file_operations afs_proc_cells_fops = {
-	.open		= afs_proc_cells_open,
-	.read		= seq_read,
-	.write		= afs_proc_cells_write,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
-
-static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
-				      size_t size, loff_t *_pos);
-static ssize_t afs_proc_rootcell_write(struct file *file,
-				       const char __user *buf,
-				       size_t size, loff_t *_pos);
-
-static const struct file_operations afs_proc_rootcell_fops = {
-	.read		= afs_proc_rootcell_read,
-	.write		= afs_proc_rootcell_write,
-	.llseek		= no_llseek,
-};
-
 static void *afs_proc_cell_volumes_start(struct seq_file *p, loff_t *pos);
 static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
 					loff_t *pos);
@@ -101,16 +78,11 @@ static const struct seq_operations afs_proc_servers_ops = {
 	.show	= afs_proc_servers_show,
 };
 
-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,
@@ -119,22 +91,6 @@ static const struct seq_operations afs_proc_sysname_ops = {
 	.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,
-};
-
-/*
- * open "/proc/fs/afs/cells" which provides a summary of extant cells
- */
-static int afs_proc_cells_open(struct inode *inode, struct file *file)
-{
-	return seq_open(file, &afs_proc_cells_ops);
-}
-
 /*
  * set up the iterator to start reading from the cells list and return the
  * first item
@@ -261,6 +217,19 @@ static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
 	goto done;
 }
 
+static int afs_proc_cells_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &afs_proc_cells_ops);
+}
+
+static const struct file_operations afs_proc_cells_fops = {
+	.open		= afs_proc_cells_open,
+	.read		= seq_read,
+	.write		= afs_proc_cells_write,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
 static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
 				      size_t size, loff_t *_pos)
 {
@@ -344,6 +313,12 @@ static ssize_t afs_proc_rootcell_write(struct file *file,
 	return ret;
 }
 
+static const struct file_operations afs_proc_rootcell_fops = {
+	.read		= afs_proc_rootcell_read,
+	.write		= afs_proc_rootcell_write,
+	.llseek		= no_llseek,
+};
+
 /*
  * set up the iterator to start reading from the cells list and return the
  * first item
@@ -731,6 +706,14 @@ static int afs_proc_sysname_show(struct seq_file *m, void *v)
 	return 0;
 }
 
+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,
+};
+
 /*
  * Display general per-net namespace statistics
  */

[PATCH 3/8] afs: Rearrange fs/afs/proc.c to move the show routines up

[David Howells]

Rearrange fs/afs/proc.c to move the show routines up to the top of each
block so the order is show, iteration, ops, file ops, fops.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/proc.c |  150 +++++++++++++++++++++++++++++----------------------------
 1 file changed, 75 insertions(+), 75 deletions(-)

diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 22ce99df3208..b20098b7b7ee 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -91,6 +91,25 @@ static const struct seq_operations afs_proc_sysname_ops = {
 	.show	= afs_proc_sysname_show,
 };
 
+/*
+ * display a header line followed by a load of cell lines
+ */
+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 == &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, "%3u %s\n", atomic_read(&cell->usage), cell->name);
+	return 0;
+}
+
 /*
  * set up the iterator to start reading from the cells list and return the
  * first item
@@ -123,25 +142,6 @@ static void afs_proc_cells_stop(struct seq_file *m, void *v)
 	rcu_read_unlock();
 }
 
-/*
- * display a header line followed by a load of cell lines
- */
-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 == &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, "%3u %s\n", atomic_read(&cell->usage), cell->name);
-	return 0;
-}
-
 /*
  * handle writes to /proc/fs/afs/cells
  * - to add cells: echo "add <cellname> <IP>[:<IP>][:<IP>]"
@@ -319,6 +319,33 @@ static const struct file_operations afs_proc_rootcell_fops = {
 	.llseek		= no_llseek,
 };
 
+static const char afs_vol_types[3][3] = {
+	[AFSVL_RWVOL]	= "RW",
+	[AFSVL_ROVOL]	= "RO",
+	[AFSVL_BACKVOL]	= "BK",
+};
+
+/*
+ * display a header line followed by a load of volume lines
+ */
+static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
+{
+	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
+	struct afs_volume *vol = list_entry(v, struct afs_volume, proc_link);
+
+	/* Display header on line 1 */
+	if (v == &cell->proc_volumes) {
+		seq_puts(m, "USE VID      TY\n");
+		return 0;
+	}
+
+	seq_printf(m, "%3d %08x %s\n",
+		   atomic_read(&vol->usage), vol->vid,
+		   afs_vol_types[vol->type]);
+
+	return 0;
+}
+
 /*
  * set up the iterator to start reading from the cells list and return the
  * first item
@@ -357,30 +384,21 @@ static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v)
 	read_unlock(&cell->proc_lock);
 }
 
-static const char afs_vol_types[3][3] = {
-	[AFSVL_RWVOL]	= "RW",
-	[AFSVL_ROVOL]	= "RO",
-	[AFSVL_BACKVOL]	= "BK",
-};
-
 /*
  * display a header line followed by a load of volume lines
  */
-static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
+static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
 {
-	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
-	struct afs_volume *vol = list_entry(v, struct afs_volume, proc_link);
+	struct sockaddr_rxrpc *addr = v;
 
-	/* Display header on line 1 */
-	if (v == &cell->proc_volumes) {
-		seq_puts(m, "USE VID      TY\n");
+	/* display header on line 1 */
+	if (v == (void *)1) {
+		seq_puts(m, "ADDRESS\n");
 		return 0;
 	}
 
-	seq_printf(m, "%3d %08x %s\n",
-		   atomic_read(&vol->usage), vol->vid,
-		   afs_vol_types[vol->type]);
-
+	/* display one cell per line on subsequent lines */
+	seq_printf(m, "%pISp\n", &addr->transport);
 	return 0;
 }
 
@@ -442,18 +460,22 @@ static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v)
 /*
  * display a header line followed by a load of volume lines
  */
-static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
+static int afs_proc_servers_show(struct seq_file *m, void *v)
 {
-	struct sockaddr_rxrpc *addr = v;
+	struct afs_server *server;
+	struct afs_addr_list *alist;
 
-	/* display header on line 1 */
-	if (v == (void *)1) {
-		seq_puts(m, "ADDRESS\n");
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(m, "UUID                                 USE ADDR\n");
 		return 0;
 	}
 
-	/* display one cell per line on subsequent lines */
-	seq_printf(m, "%pISp\n", &addr->transport);
+	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;
 }
 
@@ -489,28 +511,6 @@ static void afs_proc_servers_stop(struct seq_file *p, void *v)
 	rcu_read_unlock();
 }
 
-/*
- * display a header line followed by a load of volume lines
- */
-static int afs_proc_servers_show(struct seq_file *m, void *v)
-{
-	struct afs_server *server;
-	struct afs_addr_list *alist;
-
-	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;
@@ -663,6 +663,17 @@ static int afs_proc_sysname_release(struct inode *inode, struct file *file)
 	return seq_release(inode, file);
 }
 
+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;
+}
+
 static void *afs_proc_sysname_start(struct seq_file *m, loff_t *pos)
 	__acquires(&net->sysnames_lock)
 {
@@ -695,17 +706,6 @@ static void afs_proc_sysname_stop(struct seq_file *m, void *v)
 	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;
-}
-
 static const struct file_operations afs_proc_sysname_fops = {
 	.open		= afs_proc_sysname_open,
 	.read		= seq_read,

[PATCH 4/8] afs: Rearrange fs/afs/proc.c to remove remaining predeclarations.

[David Howells]

Rearrange fs/afs/proc.c to get rid of all the remaining predeclarations.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/proc.c |  352 ++++++++++++++++++++++++++-------------------------------
 1 file changed, 160 insertions(+), 192 deletions(-)

diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index b20098b7b7ee..b45ee7576aa8 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -27,72 +27,8 @@ static inline struct afs_net *afs_seq2net(struct seq_file *m)
 	return &__afs_net; // TODO: use seq_file_net(m)
 }
 
-static void *afs_proc_cells_start(struct seq_file *p, loff_t *pos);
-static void *afs_proc_cells_next(struct seq_file *p, void *v, loff_t *pos);
-static void afs_proc_cells_stop(struct seq_file *p, void *v);
-static int afs_proc_cells_show(struct seq_file *m, void *v);
-
-static const struct seq_operations afs_proc_cells_ops = {
-	.start	= afs_proc_cells_start,
-	.next	= afs_proc_cells_next,
-	.stop	= afs_proc_cells_stop,
-	.show	= afs_proc_cells_show,
-};
-
-static void *afs_proc_cell_volumes_start(struct seq_file *p, loff_t *pos);
-static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
-					loff_t *pos);
-static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v);
-static int afs_proc_cell_volumes_show(struct seq_file *m, void *v);
-
-static const struct seq_operations afs_proc_cell_volumes_ops = {
-	.start	= afs_proc_cell_volumes_start,
-	.next	= afs_proc_cell_volumes_next,
-	.stop	= afs_proc_cell_volumes_stop,
-	.show	= afs_proc_cell_volumes_show,
-};
-
-static void *afs_proc_cell_vlservers_start(struct seq_file *p, loff_t *pos);
-static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
-					  loff_t *pos);
-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);
-
-static const struct seq_operations afs_proc_cell_vlservers_ops = {
-	.start	= afs_proc_cell_vlservers_start,
-	.next	= afs_proc_cell_vlservers_next,
-	.stop	= afs_proc_cell_vlservers_stop,
-	.show	= afs_proc_cell_vlservers_show,
-};
-
-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_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 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 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,
-};
-
 /*
- * display a header line followed by a load of cell lines
+ * Display the list of cells known to the namespace.
  */
 static int afs_proc_cells_show(struct seq_file *m, void *v)
 {
@@ -110,38 +46,31 @@ static int afs_proc_cells_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-/*
- * set up the iterator to start reading from the cells list and return the
- * first item
- */
 static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
 	__acquires(rcu)
 {
-	struct afs_net *net = afs_seq2net(m);
-
 	rcu_read_lock();
-	return seq_list_start_head(&net->proc_cells, *_pos);
+	return seq_list_start_head(&afs_seq2net(m)->proc_cells, *_pos);
 }
 
-/*
- * move to next cell in cells list
- */
 static void *afs_proc_cells_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	struct afs_net *net = afs_seq2net(m);
-
-	return seq_list_next(v, &net->proc_cells, pos);
+	return seq_list_next(v, &afs_seq2net(m)->proc_cells, pos);
 }
 
-/*
- * clean up after reading from the cells list
- */
 static void afs_proc_cells_stop(struct seq_file *m, void *v)
 	__releases(rcu)
 {
 	rcu_read_unlock();
 }
 
+static const struct seq_operations afs_proc_cells_ops = {
+	.start	= afs_proc_cells_start,
+	.next	= afs_proc_cells_next,
+	.stop	= afs_proc_cells_stop,
+	.show	= afs_proc_cells_show,
+};
+
 /*
  * handle writes to /proc/fs/afs/cells
  * - to add cells: echo "add <cellname> <IP>[:<IP>][:<IP>]"
@@ -230,6 +159,9 @@ static const struct file_operations afs_proc_cells_fops = {
 	.release	= seq_release,
 };
 
+/*
+ * Read the name of the current workstation cell.
+ */
 static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
 				      size_t size, loff_t *_pos)
 {
@@ -270,8 +202,10 @@ static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
 }
 
 /*
- * handle writes to /proc/fs/afs/rootcell
- * - to initialize rootcell: echo "cell.name:192.168.231.14"
+ * Set the current workstation cell and optionally supply its list of volume
+ * location servers.
+ *
+ *	echo "cell.name:192.168.231.14" >/proc/fs/afs/rootcell
  */
 static ssize_t afs_proc_rootcell_write(struct file *file,
 				       const char __user *buf,
@@ -326,7 +260,7 @@ static const char afs_vol_types[3][3] = {
 };
 
 /*
- * display a header line followed by a load of volume lines
+ * Display the list of volumes known to a cell.
  */
 static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
 {
@@ -346,36 +280,23 @@ static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-/*
- * set up the iterator to start reading from the cells list and return the
- * first item
- */
 static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
 	__acquires(cell->proc_lock)
 {
 	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
 
-	_enter("cell=%p pos=%Ld", cell, *_pos);
-
 	read_lock(&cell->proc_lock);
 	return seq_list_start_head(&cell->proc_volumes, *_pos);
 }
 
-/*
- * move to next cell in cells list
- */
 static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
 					loff_t *_pos)
 {
 	struct afs_cell *cell = PDE_DATA(file_inode(p->file));
 
-	_enter("cell=%p pos=%Ld", cell, *_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)
 {
@@ -384,8 +305,15 @@ static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v)
 	read_unlock(&cell->proc_lock);
 }
 
+static const struct seq_operations afs_proc_cell_volumes_ops = {
+	.start	= afs_proc_cell_volumes_start,
+	.next	= afs_proc_cell_volumes_next,
+	.stop	= afs_proc_cell_volumes_stop,
+	.show	= afs_proc_cell_volumes_show,
+};
+
 /*
- * display a header line followed by a load of volume lines
+ * Display the list of Volume Location servers we're using for a cell.
  */
 static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
 {
@@ -402,10 +330,6 @@ static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-/*
- * set up the iterator to start reading from the cells list and return the
- * first item
- */
 static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
 	__acquires(rcu)
 {
@@ -428,9 +352,6 @@ static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
 	return alist->addrs + pos;
 }
 
-/*
- * move to next cell in cells list
- */
 static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
 					  loff_t *_pos)
 {
@@ -448,17 +369,48 @@ static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
 	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)
 {
 	rcu_read_unlock();
 }
 
+static const struct seq_operations afs_proc_cell_vlservers_ops = {
+	.start	= afs_proc_cell_vlservers_start,
+	.next	= afs_proc_cell_vlservers_next,
+	.stop	= afs_proc_cell_vlservers_stop,
+	.show	= afs_proc_cell_vlservers_show,
+};
+
+static int afs_proc_cell_vlservers_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;
+
+	ret = seq_open(file, &afs_proc_cell_vlservers_ops);
+	if (ret<0)
+		return ret;
+
+	m = file->private_data;
+	m->private = cell;
+
+	return 0;
+}
+
+static const struct file_operations afs_proc_cell_vlservers_fops = {
+	.open		= afs_proc_cell_vlservers_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
 /*
- * display a header line followed by a load of volume lines
+ * Display the list of fileservers we're using within a namespace.
  */
 static int afs_proc_servers_show(struct seq_file *m, void *v)
 {
@@ -479,82 +431,99 @@ static int afs_proc_servers_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-/*
- * 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);
-
 	rcu_read_lock();
-	return seq_hlist_start_head_rcu(&net->fs_proc, *_pos);
+	return seq_hlist_start_head_rcu(&afs_seq2net(m)->fs_proc, *_pos);
 }
 
-/*
- * move to next cell in cells list
- */
 static void *afs_proc_servers_next(struct seq_file *m, void *v, loff_t *_pos)
 {
-	struct afs_net *net = afs_seq2net(m);
-
-	return seq_hlist_next_rcu(v, &net->fs_proc, _pos);
+	return seq_hlist_next_rcu(v, &afs_seq2net(m)->fs_proc, _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();
 }
 
-void afs_put_sysnames(struct afs_sysnames *sysnames)
-{
-	int i;
+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,
+};
 
-	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]);
-	}
+static int afs_proc_servers_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &afs_proc_servers_ops);
 }
 
+static const struct file_operations afs_proc_servers_fops = {
+	.open		= afs_proc_servers_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
 /*
- * 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.
+ * Display the list of strings that may be substituted for the @sys pathname
+ * macro.
  */
-static int afs_proc_sysname_open(struct inode *inode, struct file *file)
+static int afs_proc_sysname_show(struct seq_file *m, void *v)
 {
-	struct afs_sysnames *sysnames;
-	struct seq_file *m;
-	int ret;
+	struct afs_net *net = afs_seq2net(m);
+	struct afs_sysnames *sysnames = net->sysnames;
+	unsigned int i = (unsigned long)v - 1;
 
-	ret = seq_open(file, &afs_proc_sysname_ops);
-	if (ret < 0)
-		return ret;
+	if (i < sysnames->nr)
+		seq_printf(m, "%s\n", sysnames->subs[i]);
+	return 0;
+}
 
-	if (file->f_mode & FMODE_WRITE) {
-		sysnames = kzalloc(sizeof(*sysnames), GFP_KERNEL);
-		if (!sysnames) {
-			seq_release(inode, file);
-			return -ENOMEM;
-		}
+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;
 
-		refcount_set(&sysnames->usage, 1);
-		m = file->private_data;
-		m->private = sysnames;
-	}
+	read_lock(&net->sysnames_lock);
 
-	return 0;
+	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 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,
+};
+
 /*
- * Handle writes to /proc/fs/afs/sysname to set the @sys substitution.
+ * Allow the @sys substitution to be configured.
  */
 static ssize_t afs_proc_sysname_write(struct file *file,
 				      const char __user *buf,
@@ -638,6 +607,18 @@ static ssize_t afs_proc_sysname_write(struct file *file,
 	goto out;
 }
 
+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]);
+	}
+}
+
 static int afs_proc_sysname_release(struct inode *inode, struct file *file)
 {
 	struct afs_sysnames *sysnames, *kill = NULL;
@@ -663,47 +644,34 @@ static int afs_proc_sysname_release(struct inode *inode, struct file *file)
 	return seq_release(inode, file);
 }
 
-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;
-}
-
-static void *afs_proc_sysname_start(struct seq_file *m, loff_t *pos)
-	__acquires(&net->sysnames_lock)
+/*
+ * 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 int afs_proc_sysname_open(struct inode *inode, struct file *file)
 {
-	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);
-}
+	struct afs_sysnames *sysnames;
+	struct seq_file *m;
+	int ret;
 
-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;
+	ret = seq_open(file, &afs_proc_sysname_ops);
+	if (ret < 0)
+		return ret;
 
-	*pos += 1;
-	if (*pos >= names->nr)
-		return NULL;
-	return (void *)(unsigned long)(*pos + 1);
-}
+	if (file->f_mode & FMODE_WRITE) {
+		sysnames = kzalloc(sizeof(*sysnames), GFP_KERNEL);
+		if (!sysnames) {
+			seq_release(inode, file);
+			return -ENOMEM;
+		}
 
-static void afs_proc_sysname_stop(struct seq_file *m, void *v)
-	__releases(&net->sysnames_lock)
-{
-	struct afs_net *net = afs_seq2net(m);
+		refcount_set(&sysnames->usage, 1);
+		m = file->private_data;
+		m->private = sysnames;
+	}
 
-	read_unlock(&net->sysnames_lock);
+	return 0;
 }
 
 static const struct file_operations afs_proc_sysname_fops = {

[PATCH 5/8] proc: Add a way to make network proc files writable

[David Howells]

Provide two extra functions, proc_create_net_data_write() and
proc_create_net_single_write() that act like their non-write versions but
also set a write method in the proc_dir_entry struct.

An internal simple write function is provided that will copy its buffer and
hand it to the pde->write() method if available (or give an error if not).
The buffer may be modified by the write method.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/proc/generic.c       |   24 ++++++++++++
 fs/proc/internal.h      |    2 +
 fs/proc/proc_net.c      |   92 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/proc_fs.h |   12 ++++++
 4 files changed, 130 insertions(+)

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 02bb1914f5f7..d0e5a68ae14a 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -741,3 +741,27 @@ void *PDE_DATA(const struct inode *inode)
 	return __PDE_DATA(inode);
 }
 EXPORT_SYMBOL(PDE_DATA);
+
+/*
+ * Pull a user buffer into memory and pass it to the file's write handler if
+ * one is supplied.  The ->write() method is permitted to modify the
+ * kernel-side buffer.
+ */
+ssize_t proc_simple_write(struct file *f, const char __user *ubuf, size_t size,
+			  loff_t *_pos)
+{
+	struct proc_dir_entry *pde = PDE(file_inode(f));
+	char *buf;
+	int ret;
+
+	if (!pde->write)
+		return -EACCES;
+	if (size == 0 || size > PAGE_SIZE - 1)
+		return -EINVAL;
+	buf = memdup_user_nul(ubuf, size);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+	ret = pde->write(f, buf, size);
+	kfree(buf);
+	return ret == 0 ? size : ret;
+}
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index a318ae5b36b4..916ccc39073d 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -48,6 +48,7 @@ struct proc_dir_entry {
 		const struct seq_operations *seq_ops;
 		int (*single_show)(struct seq_file *, void *);
 	};
+	proc_write_t write;
 	void *data;
 	unsigned int state_size;
 	unsigned int low_ino;
@@ -187,6 +188,7 @@ static inline bool is_empty_pde(const struct proc_dir_entry *pde)
 {
 	return S_ISDIR(pde->mode) && !pde->proc_iops;
 }
+extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *);
 
 /*
  * inode.c
diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
index 7d94fa005b0d..d5e0fcb3439e 100644
--- a/fs/proc/proc_net.c
+++ b/fs/proc/proc_net.c
@@ -46,6 +46,9 @@ static int seq_open_net(struct inode *inode, struct file *file)
 
 	WARN_ON_ONCE(state_size < sizeof(*p));
 
+	if (file->f_mode & FMODE_WRITE && !PDE(inode)->write)
+		return -EACCES;
+
 	net = get_proc_net(inode);
 	if (!net)
 		return -ENXIO;
@@ -73,6 +76,7 @@ static int seq_release_net(struct inode *ino, struct file *f)
 static const struct file_operations proc_net_seq_fops = {
 	.open		= seq_open_net,
 	.read		= seq_read,
+	.write		= proc_simple_write,
 	.llseek		= seq_lseek,
 	.release	= seq_release_net,
 };
@@ -93,6 +97,50 @@ struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
 }
 EXPORT_SYMBOL_GPL(proc_create_net_data);
 
+/**
+ * proc_create_net_data_write - Create a writable net_ns-specific proc file
+ * @name: The name of the file.
+ * @mode: The file's access mode.
+ * @parent: The parent directory in which to create.
+ * @ops: The seq_file ops with which to read the file.
+ * @write: The write method which which to 'modify' the file.
+ * @data: Data for retrieval by PDE_DATA().
+ *
+ * Create a network namespaced proc file in the @parent directory with the
+ * specified @name and @mode that allows reading of a file that displays a
+ * series of elements and also provides for the file accepting writes that have
+ * some arbitrary effect.
+ *
+ * The functions in the @ops table are used to iterate over items to be
+ * presented and extract the readable content using the seq_file interface.
+ *
+ * The @write function is called with the data copied into a kernel space
+ * scratch buffer and has a NUL appended for convenience.  The buffer may be
+ * modified by the @write function.  @write should return 0 on success.
+ *
+ * The @data value is accessible from the @show and @write functions by calling
+ * PDE_DATA() on the file inode.  The network namespace must be accessed by
+ * calling seq_file_net() on the seq_file struct.
+ */
+struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode,
+						  struct proc_dir_entry *parent,
+						  const struct seq_operations *ops,
+						  proc_write_t write,
+						  unsigned int state_size, void *data)
+{
+	struct proc_dir_entry *p;
+
+	p = proc_create_reg(name, mode, &parent, data);
+	if (!p)
+		return NULL;
+	p->proc_fops = &proc_net_seq_fops;
+	p->seq_ops = ops;
+	p->state_size = state_size;
+	p->write = write;
+	return proc_register(parent, p);
+}
+EXPORT_SYMBOL_GPL(proc_create_net_data_write);
+
 static int single_open_net(struct inode *inode, struct file *file)
 {
 	struct proc_dir_entry *de = PDE(inode);
@@ -119,6 +167,7 @@ static int single_release_net(struct inode *ino, struct file *f)
 static const struct file_operations proc_net_single_fops = {
 	.open		= single_open_net,
 	.read		= seq_read,
+	.write		= proc_simple_write,
 	.llseek		= seq_lseek,
 	.release	= single_release_net,
 };
@@ -138,6 +187,49 @@ struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
 }
 EXPORT_SYMBOL_GPL(proc_create_net_single);
 
+/**
+ * proc_create_net_single_write - Create a writable net_ns-specific proc file
+ * @name: The name of the file.
+ * @mode: The file's access mode.
+ * @parent: The parent directory in which to create.
+ * @show: The seqfile show method with which to read the file.
+ * @write: The write method which which to 'modify' the file.
+ * @data: Data for retrieval by PDE_DATA().
+ *
+ * Create a network-namespaced proc file in the @parent directory with the
+ * specified @name and @mode that allows reading of a file that displays a
+ * single element rather than a series and also provides for the file accepting
+ * writes that have some arbitrary effect.
+ *
+ * The @show function is called to extract the readable content via the
+ * seq_file interface.
+ *
+ * The @write function is called with the data copied into a kernel space
+ * scratch buffer and has a NUL appended for convenience.  The buffer may be
+ * modified by the @write function.  @write should return 0 on success.
+ *
+ * The @data value is accessible from the @show and @write functions by calling
+ * PDE_DATA() on the file inode.  The network namespace must be accessed by
+ * calling seq_file_single_net() on the seq_file struct.
+ */
+struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mode,
+						    struct proc_dir_entry *parent,
+						    int (*show)(struct seq_file *, void *),
+						    proc_write_t write,
+						    void *data)
+{
+	struct proc_dir_entry *p;
+
+	p = proc_create_reg(name, mode, &parent, data);
+	if (!p)
+		return NULL;
+	p->proc_fops = &proc_net_single_fops;
+	p->single_show = show;
+	p->write = write;
+	return proc_register(parent, p);
+}
+EXPORT_SYMBOL_GPL(proc_create_net_single_write);
+
 static struct net *get_proc_task_net(struct inode *dir)
 {
 	struct task_struct *task;
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index e518352137e7..626fc65c4336 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -14,6 +14,8 @@ struct seq_operations;
 
 #ifdef CONFIG_PROC_FS
 
+typedef int (*proc_write_t)(struct file *, char *, size_t);
+
 extern void proc_root_init(void);
 extern void proc_flush_task(struct task_struct *);
 
@@ -61,6 +63,16 @@ struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
 struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
 		struct proc_dir_entry *parent,
 		int (*show)(struct seq_file *, void *), void *data);
+struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode,
+						  struct proc_dir_entry *parent,
+						  const struct seq_operations *ops,
+						  proc_write_t write,
+						  unsigned int state_size, void *data);
+struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mode,
+						    struct proc_dir_entry *parent,
+						    int (*show)(struct seq_file *, void *),
+						    proc_write_t write,
+						    void *data);
 
 #else /* CONFIG_PROC_FS */
 

[PATCH 6/8] afs: Fix a Sparse warning in xdr_decode_AFSFetchStatus()

[David Howells]

Sparse doesn't appear able to handle the conditionally-taken locks in
xdr_decode_AFSFetchStatus(), even though the lock and unlock are both
contingent on the same unvarying function argument.

Deal with this by interpolating a wrapper function that takes the lock if
needed and calls xdr_decode_AFSFetchStatus() on two separate branches, one
with the lock held and one without.

This allows Sparse to work out the locking.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/fsclient.c |   97 ++++++++++++++++++++++++++++++-----------------------
 1 file changed, 55 insertions(+), 42 deletions(-)

diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index efacdb7c1dee..b695d9e16c65 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -137,10 +137,6 @@ static int xdr_decode_AFSFetchStatus(struct afs_call *call,
 	u64 data_version, size;
 	u32 type, abort_code;
 	u8 flags = 0;
-	int ret;
-
-	if (vnode)
-		write_seqlock(&vnode->cb_lock);
 
 	if (xdr->if_version != htonl(AFS_FSTATUS_VERSION)) {
 		pr_warn("Unknown AFSFetchStatus version %u\n", ntohl(xdr->if_version));
@@ -168,8 +164,7 @@ static int xdr_decode_AFSFetchStatus(struct afs_call *call,
 	case AFS_FTYPE_INVALID:
 		if (abort_code != 0) {
 			status->abort_code = abort_code;
-			ret = 0;
-			goto out;
+			return 0;
 		}
 		/* Fall through */
 	default:
@@ -222,17 +217,35 @@ static int xdr_decode_AFSFetchStatus(struct afs_call *call,
 					     flags);
 	}
 
-	ret = 0;
-
-out:
-	if (vnode)
-		write_sequnlock(&vnode->cb_lock);
-	return ret;
+	return 0;
 
 bad:
 	xdr_dump_bad(*_bp);
-	ret = afs_protocol_error(call, -EBADMSG);
-	goto out;
+	return afs_protocol_error(call, -EBADMSG);
+}
+
+/*
+ * Decode the file status.  We need to lock the target vnode if we're going to
+ * update its status so that stat() sees the attributes update atomically.
+ */
+static int afs_decode_status(struct afs_call *call,
+			     const __be32 **_bp,
+			     struct afs_file_status *status,
+			     struct afs_vnode *vnode,
+			     const afs_dataversion_t *expected_version,
+			     struct afs_read *read_req)
+{
+	int ret;
+
+	if (!vnode)
+		return xdr_decode_AFSFetchStatus(call, _bp, status, vnode,
+						 expected_version, read_req);
+
+	write_seqlock(&vnode->cb_lock);
+	ret = xdr_decode_AFSFetchStatus(call, _bp, status, vnode,
+					expected_version, read_req);
+	write_sequnlock(&vnode->cb_lock);
+	return ret;
 }
 
 /*
@@ -374,8 +387,8 @@ static int afs_deliver_fs_fetch_status_vnode(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (xdr_decode_AFSFetchStatus(call, &bp, &vnode->status, vnode,
-				      &call->expected_version, NULL) < 0)
+	if (afs_decode_status(call, &bp, &vnode->status, vnode,
+			      &call->expected_version, NULL) < 0)
 		return afs_protocol_error(call, -EBADMSG);
 	xdr_decode_AFSCallBack(call, vnode, &bp);
 	if (call->reply[1])
@@ -555,8 +568,8 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 			return ret;
 
 		bp = call->buffer;
-		if (xdr_decode_AFSFetchStatus(call, &bp, &vnode->status, vnode,
-					      &vnode->status.data_version, req) < 0)
+		if (afs_decode_status(call, &bp, &vnode->status, vnode,
+				      &vnode->status.data_version, req) < 0)
 			return afs_protocol_error(call, -EBADMSG);
 		xdr_decode_AFSCallBack(call, vnode, &bp);
 		if (call->reply[1])
@@ -708,9 +721,9 @@ static int afs_deliver_fs_create_vnode(struct afs_call *call)
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
 	xdr_decode_AFSFid(&bp, call->reply[1]);
-	if (xdr_decode_AFSFetchStatus(call, &bp, call->reply[2], NULL, NULL, NULL) < 0 ||
-	    xdr_decode_AFSFetchStatus(call, &bp, &vnode->status, vnode,
-				      &call->expected_version, NULL) < 0)
+	if (afs_decode_status(call, &bp, call->reply[2], NULL, NULL, NULL) < 0 ||
+	    afs_decode_status(call, &bp, &vnode->status, vnode,
+			      &call->expected_version, NULL) < 0)
 		return afs_protocol_error(call, -EBADMSG);
 	xdr_decode_AFSCallBack_raw(&bp, call->reply[3]);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
@@ -814,8 +827,8 @@ static int afs_deliver_fs_remove(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (xdr_decode_AFSFetchStatus(call, &bp, &vnode->status, vnode,
-				      &call->expected_version, NULL) < 0)
+	if (afs_decode_status(call, &bp, &vnode->status, vnode,
+			      &call->expected_version, NULL) < 0)
 		return afs_protocol_error(call, -EBADMSG);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
@@ -904,9 +917,9 @@ static int afs_deliver_fs_link(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (xdr_decode_AFSFetchStatus(call, &bp, &vnode->status, vnode, NULL, NULL) < 0 ||
-	    xdr_decode_AFSFetchStatus(call, &bp, &dvnode->status, dvnode,
-				      &call->expected_version, NULL) < 0)
+	if (afs_decode_status(call, &bp, &vnode->status, vnode, NULL, NULL) < 0 ||
+	    afs_decode_status(call, &bp, &dvnode->status, dvnode,
+			      &call->expected_version, NULL) < 0)
 		return afs_protocol_error(call, -EBADMSG);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
@@ -991,9 +1004,9 @@ static int afs_deliver_fs_symlink(struct afs_call *call)
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
 	xdr_decode_AFSFid(&bp, call->reply[1]);
-	if (xdr_decode_AFSFetchStatus(call, &bp, call->reply[2], NULL, NULL, NULL) ||
-	    xdr_decode_AFSFetchStatus(call, &bp, &vnode->status, vnode,
-				      &call->expected_version, NULL) < 0)
+	if (afs_decode_status(call, &bp, call->reply[2], NULL, NULL, NULL) ||
+	    afs_decode_status(call, &bp, &vnode->status, vnode,
+			      &call->expected_version, NULL) < 0)
 		return afs_protocol_error(call, -EBADMSG);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
@@ -1097,12 +1110,12 @@ static int afs_deliver_fs_rename(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (xdr_decode_AFSFetchStatus(call, &bp, &orig_dvnode->status, orig_dvnode,
-				      &call->expected_version, NULL) < 0)
+	if (afs_decode_status(call, &bp, &orig_dvnode->status, orig_dvnode,
+			      &call->expected_version, NULL) < 0)
 		return afs_protocol_error(call, -EBADMSG);
 	if (new_dvnode != orig_dvnode &&
-	    xdr_decode_AFSFetchStatus(call, &bp, &new_dvnode->status, new_dvnode,
-				      &call->expected_version_2, NULL) < 0)
+	    afs_decode_status(call, &bp, &new_dvnode->status, new_dvnode,
+			      &call->expected_version_2, NULL) < 0)
 		return afs_protocol_error(call, -EBADMSG);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
@@ -1206,8 +1219,8 @@ static int afs_deliver_fs_store_data(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (xdr_decode_AFSFetchStatus(call, &bp, &vnode->status, vnode,
-				      &call->expected_version, NULL) < 0)
+	if (afs_decode_status(call, &bp, &vnode->status, vnode,
+			      &call->expected_version, NULL) < 0)
 		return afs_protocol_error(call, -EBADMSG);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
@@ -1382,8 +1395,8 @@ static int afs_deliver_fs_store_status(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (xdr_decode_AFSFetchStatus(call, &bp, &vnode->status, vnode,
-				      &call->expected_version, NULL) < 0)
+	if (afs_decode_status(call, &bp, &vnode->status, vnode,
+			      &call->expected_version, NULL) < 0)
 		return afs_protocol_error(call, -EBADMSG);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
@@ -2084,8 +2097,8 @@ static int afs_deliver_fs_fetch_status(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	xdr_decode_AFSFetchStatus(call, &bp, status, vnode,
-				  &call->expected_version, NULL);
+	afs_decode_status(call, &bp, status, vnode,
+			  &call->expected_version, NULL);
 	callback[call->count].version	= ntohl(bp[0]);
 	callback[call->count].expiry	= ntohl(bp[1]);
 	callback[call->count].type	= ntohl(bp[2]);
@@ -2196,9 +2209,9 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 
 		bp = call->buffer;
 		statuses = call->reply[1];
-		if (xdr_decode_AFSFetchStatus(call, &bp, &statuses[call->count],
-					      call->count == 0 ? vnode : NULL,
-					      NULL, NULL) < 0)
+		if (afs_decode_status(call, &bp, &statuses[call->count],
+				      call->count == 0 ? vnode : NULL,
+				      NULL, NULL) < 0)
 			return afs_protocol_error(call, -EBADMSG);
 
 		call->count++;

[PATCH 7/8] afs: Mark afs_net::ws_cell as __rcu and set using rcu functions

[David Howells]

The afs_net::ws_cell member is sometimes used under RCU conditions from
within an seq-readlock.  It isn't, however, marked __rcu and it isn't set
using the proper RCU barrier-imposing functions.

Fix this by annotating it with __rcu and using appropriate barriers to
make sure accesses are correctly ordered.

Without this, the code can produce the following warning:

>> fs/afs/proc.c:151:24: sparse: incompatible types in comparison expression (different address spaces)

Fixes: f044c8847bb6 ("afs: Lay the groundwork for supporting network namespaces")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/cell.c     |    8 ++++----
 fs/afs/internal.h |    2 +-
 fs/afs/proc.c     |    2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index fdf4c36cff79..80fd127239ce 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -341,8 +341,8 @@ int afs_cell_init(struct afs_net *net, const char *rootcell)
 
 	/* install the new cell */
 	write_seqlock(&net->cells_lock);
-	old_root = net->ws_cell;
-	net->ws_cell = new_root;
+	old_root = rcu_access_pointer(net->ws_cell);
+	rcu_assign_pointer(net->ws_cell, new_root);
 	write_sequnlock(&net->cells_lock);
 
 	afs_put_cell(net, old_root);
@@ -755,8 +755,8 @@ void afs_cell_purge(struct afs_net *net)
 	_enter("");
 
 	write_seqlock(&net->cells_lock);
-	ws = net->ws_cell;
-	net->ws_cell = NULL;
+	ws = rcu_access_pointer(net->ws_cell);
+	RCU_INIT_POINTER(net->ws_cell, NULL);
 	write_sequnlock(&net->cells_lock);
 	afs_put_cell(net, ws);
 
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index f8086ec95e24..5d922ad148a8 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -231,7 +231,7 @@ struct afs_net {
 
 	/* Cell database */
 	struct rb_root		cells;
-	struct afs_cell		*ws_cell;
+	struct afs_cell __rcu	*ws_cell;
 	struct work_struct	cells_manager;
 	struct timer_list	cells_timer;
 	atomic_t		cells_outstanding;
diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index b45ee7576aa8..362f281b1b16 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -173,7 +173,7 @@ static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
 
 	if (*_pos > 0)
 		return 0;
-	if (!net->ws_cell)
+	if (!rcu_access_pointer(net->ws_cell))
 		return 0;
 
 	rcu_read_lock();

[PATCH 8/8] afs: Implement network namespacing

[David Howells]

Implement network namespacing within AFS, but don't yet let mounts occur
outside the init namespace.  An additional patch will be required propagate
the network namespace across automounts.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/cell.c       |    4 -
 fs/afs/cmservice.c  |    2 
 fs/afs/internal.h   |   43 +++---
 fs/afs/main.c       |   33 ++++-
 fs/afs/netdevices.c |    6 -
 fs/afs/proc.c       |  358 +++++++++++++++------------------------------------
 fs/afs/rxrpc.c      |    2 
 fs/afs/super.c      |   20 ++-
 8 files changed, 173 insertions(+), 295 deletions(-)

diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index 80fd127239ce..bb92b54d2a4a 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -528,7 +528,7 @@ static int afs_activate_cell(struct afs_net *net, struct afs_cell *cell)
 					     NULL, 0,
 					     cell, 0, true);
 #endif
-	ret = afs_proc_cell_setup(net, cell);
+	ret = afs_proc_cell_setup(cell);
 	if (ret < 0)
 		return ret;
 	spin_lock(&net->proc_cells_lock);
@@ -544,7 +544,7 @@ static void afs_deactivate_cell(struct afs_net *net, struct afs_cell *cell)
 {
 	_enter("%s", cell->name);
 
-	afs_proc_cell_remove(net, cell);
+	afs_proc_cell_remove(cell);
 
 	spin_lock(&net->proc_cells_lock);
 	list_del_init(&cell->proc_link);
diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 357de908df3a..4c89b1f4c02b 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -550,7 +550,7 @@ static void SRXAFSCB_TellMeAboutYourself(struct work_struct *work)
 	nifs = 0;
 	ifs = kcalloc(32, sizeof(*ifs), GFP_KERNEL);
 	if (ifs) {
-		nifs = afs_get_ipv4_interfaces(ifs, 32, false);
+		nifs = afs_get_ipv4_interfaces(call->net, ifs, 32, false);
 		if (nifs < 0) {
 			kfree(ifs);
 			ifs = NULL;
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 5d922ad148a8..e6cef5702ae2 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -22,6 +22,8 @@
 #include <linux/backing-dev.h>
 #include <linux/uuid.h>
 #include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/sock.h>
 #include <net/af_rxrpc.h>
 
 #include "afs.h"
@@ -40,7 +42,8 @@ struct afs_mount_params {
 	afs_voltype_t		type;		/* type of volume requested */
 	int			volnamesz;	/* size of volume name */
 	const char		*volname;	/* name of volume to mount */
-	struct afs_net		*net;		/* Network namespace in effect */
+	struct net		*net_ns;	/* Network namespace in effect */
+	struct afs_net		*net;		/* the AFS net namespace stuff */
 	struct afs_cell		*cell;		/* cell in which to find volume */
 	struct afs_volume	*volume;	/* volume record */
 	struct key		*key;		/* key to use for secure mounting */
@@ -189,7 +192,7 @@ struct afs_read {
  * - there's one superblock per volume
  */
 struct afs_super_info {
-	struct afs_net		*net;		/* Network namespace */
+	struct net		*net_ns;	/* Network namespace */
 	struct afs_cell		*cell;		/* The cell in which the volume resides */
 	struct afs_volume	*volume;	/* volume record */
 	bool			dyn_root;	/* True if dynamic root */
@@ -210,7 +213,6 @@ struct afs_sysnames {
 	char			*subs[AFS_NR_SYSNAME];
 	refcount_t		usage;
 	unsigned short		nr;
-	short			error;
 	char			blank[1];
 };
 
@@ -218,6 +220,7 @@ struct afs_sysnames {
  * AFS network namespace record.
  */
 struct afs_net {
+	struct net		*net;		/* Backpointer to the owning net namespace */
 	struct afs_uuid		uuid;
 	bool			live;		/* F if this namespace is being removed */
 
@@ -280,7 +283,6 @@ struct afs_net {
 };
 
 extern const char afs_init_sysname[];
-extern struct afs_net __afs_net;// Dummy AFS network namespace; TODO: replace with real netns
 
 enum afs_cell_state {
 	AFS_CELL_UNSET,
@@ -787,34 +789,36 @@ extern int afs_drop_inode(struct inode *);
  * main.c
  */
 extern struct workqueue_struct *afs_wq;
+extern int afs_net_id;
 
-static inline struct afs_net *afs_d2net(struct dentry *dentry)
+static inline struct afs_net *afs_net(struct net *net)
 {
-	return &__afs_net;
+	return net_generic(net, afs_net_id);
 }
 
-static inline struct afs_net *afs_i2net(struct inode *inode)
+static inline struct afs_net *afs_sb2net(struct super_block *sb)
 {
-	return &__afs_net;
+	return afs_net(AFS_FS_S(sb)->net_ns);
 }
 
-static inline struct afs_net *afs_v2net(struct afs_vnode *vnode)
+static inline struct afs_net *afs_d2net(struct dentry *dentry)
 {
-	return &__afs_net;
+	return afs_sb2net(dentry->d_sb);
 }
 
-static inline struct afs_net *afs_sock2net(struct sock *sk)
+static inline struct afs_net *afs_i2net(struct inode *inode)
 {
-	return &__afs_net;
+	return afs_sb2net(inode->i_sb);
 }
 
-static inline struct afs_net *afs_get_net(struct afs_net *net)
+static inline struct afs_net *afs_v2net(struct afs_vnode *vnode)
 {
-	return net;
+	return afs_i2net(&vnode->vfs_inode);
 }
 
-static inline void afs_put_net(struct afs_net *net)
+static inline struct afs_net *afs_sock2net(struct sock *sk)
 {
+	return net_generic(sock_net(sk), afs_net_id);
 }
 
 static inline void __afs_stat(atomic_t *s)
@@ -842,15 +846,16 @@ extern void afs_mntpt_kill_timer(void);
 /*
  * netdevices.c
  */
-extern int afs_get_ipv4_interfaces(struct afs_interface *, size_t, bool);
+extern int afs_get_ipv4_interfaces(struct afs_net *, struct afs_interface *,
+				   size_t, bool);
 
 /*
  * proc.c
  */
 extern int __net_init afs_proc_init(struct afs_net *);
 extern void __net_exit afs_proc_cleanup(struct afs_net *);
-extern int afs_proc_cell_setup(struct afs_net *, struct afs_cell *);
-extern void afs_proc_cell_remove(struct afs_net *, struct afs_cell *);
+extern int afs_proc_cell_setup(struct afs_cell *);
+extern void afs_proc_cell_remove(struct afs_cell *);
 extern void afs_put_sysnames(struct afs_sysnames *);
 
 /*
@@ -983,7 +988,7 @@ extern bool afs_annotate_server_list(struct afs_server_list *, struct afs_server
  * super.c
  */
 extern int __init afs_fs_init(void);
-extern void __exit afs_fs_exit(void);
+extern void afs_fs_exit(void);
 
 /*
  * vlclient.c
diff --git a/fs/afs/main.c b/fs/afs/main.c
index d7560168b3bf..7d2c1354e2ca 100644
--- a/fs/afs/main.c
+++ b/fs/afs/main.c
@@ -15,6 +15,7 @@
 #include <linux/completion.h>
 #include <linux/sched.h>
 #include <linux/random.h>
+#include <linux/proc_fs.h>
 #define CREATE_TRACE_POINTS
 #include "internal.h"
 
@@ -32,7 +33,7 @@ module_param(rootcell, charp, 0);
 MODULE_PARM_DESC(rootcell, "root AFS cell name and VL server IP addr list");
 
 struct workqueue_struct *afs_wq;
-struct afs_net __afs_net;
+static struct proc_dir_entry *afs_proc_symlink;
 
 #if defined(CONFIG_ALPHA)
 const char afs_init_sysname[] = "alpha_linux26";
@@ -67,11 +68,13 @@ const char afs_init_sysname[] = "unknown_linux26";
 /*
  * Initialise an AFS network namespace record.
  */
-static int __net_init afs_net_init(struct afs_net *net)
+static int __net_init afs_net_init(struct net *net_ns)
 {
 	struct afs_sysnames *sysnames;
+	struct afs_net *net = afs_net(net_ns);
 	int ret;
 
+	net->net = net_ns;
 	net->live = true;
 	generate_random_uuid((unsigned char *)&net->uuid);
 
@@ -142,8 +145,10 @@ static int __net_init afs_net_init(struct afs_net *net)
 /*
  * Clean up and destroy an AFS network namespace record.
  */
-static void __net_exit afs_net_exit(struct afs_net *net)
+static void __net_exit afs_net_exit(struct net *net_ns)
 {
+	struct afs_net *net = afs_net(net_ns);
+
 	net->live = false;
 	afs_cell_purge(net);
 	afs_purge_servers(net);
@@ -152,6 +157,13 @@ static void __net_exit afs_net_exit(struct afs_net *net)
 	afs_put_sysnames(net->sysnames);
 }
 
+static struct pernet_operations afs_net_ops = {
+	.init	= afs_net_init,
+	.exit	= afs_net_exit,
+	.id	= &afs_net_id,
+	.size	= sizeof(struct afs_net),
+};
+
 /*
  * initialise the AFS client FS module
  */
@@ -178,7 +190,7 @@ static int __init afs_init(void)
 		goto error_cache;
 #endif
 
-	ret = afs_net_init(&__afs_net);
+	ret = register_pernet_subsys(&afs_net_ops);
 	if (ret < 0)
 		goto error_net;
 
@@ -187,10 +199,18 @@ static int __init afs_init(void)
 	if (ret < 0)
 		goto error_fs;
 
+	afs_proc_symlink = proc_symlink("fs/afs", NULL, "../self/net/afs");
+	if (IS_ERR(afs_proc_symlink)) {
+		ret = PTR_ERR(afs_proc_symlink);
+		goto error_proc;
+	}
+
 	return ret;
 
+error_proc:
+	afs_fs_exit();
 error_fs:
-	afs_net_exit(&__afs_net);
+	unregister_pernet_subsys(&afs_net_ops);
 error_net:
 #ifdef CONFIG_AFS_FSCACHE
 	fscache_unregister_netfs(&afs_cache_netfs);
@@ -219,8 +239,9 @@ static void __exit afs_exit(void)
 {
 	printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 unregistering.\n");
 
+	proc_remove(afs_proc_symlink);
 	afs_fs_exit();
-	afs_net_exit(&__afs_net);
+	unregister_pernet_subsys(&afs_net_ops);
 #ifdef CONFIG_AFS_FSCACHE
 	fscache_unregister_netfs(&afs_cache_netfs);
 #endif
diff --git a/fs/afs/netdevices.c b/fs/afs/netdevices.c
index 50bd5bb1c4fb..2a009d1939d7 100644
--- a/fs/afs/netdevices.c
+++ b/fs/afs/netdevices.c
@@ -17,8 +17,8 @@
  * - maxbufs must be at least 1
  * - returns the number of interface records in the buffer
  */
-int afs_get_ipv4_interfaces(struct afs_interface *bufs, size_t maxbufs,
-			    bool wantloopback)
+int afs_get_ipv4_interfaces(struct afs_net *net, struct afs_interface *bufs,
+			    size_t maxbufs, bool wantloopback)
 {
 	struct net_device *dev;
 	struct in_device *idev;
@@ -27,7 +27,7 @@ int afs_get_ipv4_interfaces(struct afs_interface *bufs, size_t maxbufs,
 	ASSERT(maxbufs > 0);
 
 	rtnl_lock();
-	for_each_netdev(&init_net, dev) {
+	for_each_netdev(net->net, dev) {
 		if (dev->type == ARPHRD_LOOPBACK && !wantloopback)
 			continue;
 		idev = __in_dev_get_rtnl(dev);
diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 362f281b1b16..3512b9b66caf 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -17,14 +17,14 @@
 #include <linux/uaccess.h>
 #include "internal.h"
 
-static inline struct afs_net *afs_proc2net(struct file *f)
+static inline struct afs_net *afs_seq2net(struct seq_file *m)
 {
-	return &__afs_net;
+	return afs_net(seq_file_net(m));
 }
 
-static inline struct afs_net *afs_seq2net(struct seq_file *m)
+static inline struct afs_net *afs_seq2net_single(struct seq_file *m)
 {
-	return &__afs_net; // TODO: use seq_file_net(m)
+	return afs_net(seq_file_single_net(m));
 }
 
 /*
@@ -75,28 +75,20 @@ static const struct seq_operations afs_proc_cells_ops = {
  * handle writes to /proc/fs/afs/cells
  * - to add cells: echo "add <cellname> <IP>[:<IP>][:<IP>]"
  */
-static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
-				    size_t size, loff_t *_pos)
+static int afs_proc_cells_write(struct file *file, char *buf, size_t size)
 {
-	struct afs_net *net = afs_proc2net(file);
-	char *kbuf, *name, *args;
+	struct seq_file *m = file->private_data;
+	struct afs_net *net = afs_seq2net(m);
+	char *name, *args;
 	int ret;
 
-	/* start by dragging the command into memory */
-	if (size <= 1 || size >= PAGE_SIZE)
-		return -EINVAL;
-
-	kbuf = memdup_user_nul(buf, size);
-	if (IS_ERR(kbuf))
-		return PTR_ERR(kbuf);
-
 	/* trim to first NL */
-	name = memchr(kbuf, '\n', size);
+	name = memchr(buf, '\n', size);
 	if (name)
 		*name = 0;
 
 	/* split into command, name and argslist */
-	name = strchr(kbuf, ' ');
+	name = strchr(buf, ' ');
 	if (!name)
 		goto inval;
 	do {
@@ -115,9 +107,9 @@ static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
 		goto inval;
 
 	/* determine command to perform */
-	_debug("cmd=%s name=%s args=%s", kbuf, name, args);
+	_debug("cmd=%s name=%s args=%s", buf, name, args);
 
-	if (strcmp(kbuf, "add") == 0) {
+	if (strcmp(buf, "add") == 0) {
 		struct afs_cell *cell;
 
 		cell = afs_lookup_cell(net, name, strlen(name), args, true);
@@ -133,10 +125,9 @@ static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
 		goto inval;
 	}
 
-	ret = size;
+	ret = 0;
 
 done:
-	kfree(kbuf);
 	_leave(" = %d", ret);
 	return ret;
 
@@ -146,59 +137,23 @@ static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
 	goto done;
 }
 
-static int afs_proc_cells_open(struct inode *inode, struct file *file)
-{
-	return seq_open(file, &afs_proc_cells_ops);
-}
-
-static const struct file_operations afs_proc_cells_fops = {
-	.open		= afs_proc_cells_open,
-	.read		= seq_read,
-	.write		= afs_proc_cells_write,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
-
 /*
- * Read the name of the current workstation cell.
+ * Display the name of the current workstation cell.
  */
-static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
-				      size_t size, loff_t *_pos)
+static int afs_proc_rootcell_show(struct seq_file *m, void *v)
 {
 	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 (!rcu_access_pointer(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;
+	struct afs_net *net;
+
+	net = afs_seq2net_single(m);
+	if (rcu_access_pointer(net->ws_cell)) {
+		rcu_read_lock();
+		cell = rcu_dereference(net->ws_cell);
+		if (cell)
+			seq_printf(m, "%s\n", cell->name);
+		rcu_read_unlock();
+	}
+	return 0;
 }
 
 /*
@@ -207,52 +162,34 @@ static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
  *
  *	echo "cell.name:192.168.231.14" >/proc/fs/afs/rootcell
  */
-static ssize_t afs_proc_rootcell_write(struct file *file,
-				       const char __user *buf,
-				       size_t size, loff_t *_pos)
+static int afs_proc_rootcell_write(struct file *file, char *buf, size_t size)
 {
-	struct afs_net *net = afs_proc2net(file);
-	char *kbuf, *s;
+	struct seq_file *m = file->private_data;
+	struct afs_net *net = afs_seq2net_single(m);
+	char *s;
 	int ret;
 
-	/* start by dragging the command into memory */
-	if (size <= 1 || size >= PAGE_SIZE)
-		return -EINVAL;
-
-	kbuf = memdup_user_nul(buf, size);
-	if (IS_ERR(kbuf))
-		return PTR_ERR(kbuf);
-
 	ret = -EINVAL;
-	if (kbuf[0] == '.')
+	if (buf[0] == '.')
 		goto out;
-	if (memchr(kbuf, '/', size))
+	if (memchr(buf, '/', size))
 		goto out;
 
 	/* trim to first NL */
-	s = memchr(kbuf, '\n', size);
+	s = memchr(buf, '\n', size);
 	if (s)
 		*s = 0;
 
 	/* determine command to perform */
-	_debug("rootcell=%s", kbuf);
+	_debug("rootcell=%s", buf);
 
-	ret = afs_cell_init(net, kbuf);
-	if (ret >= 0)
-		ret = size;	/* consume everything, always */
+	ret = afs_cell_init(net, buf);
 
 out:
-	kfree(kbuf);
 	_leave(" = %d", ret);
 	return ret;
 }
 
-static const struct file_operations afs_proc_rootcell_fops = {
-	.read		= afs_proc_rootcell_read,
-	.write		= afs_proc_rootcell_write,
-	.llseek		= no_llseek,
-};
-
 static const char afs_vol_types[3][3] = {
 	[AFSVL_RWVOL]	= "RW",
 	[AFSVL_ROVOL]	= "RO",
@@ -289,18 +226,18 @@ static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
 	return seq_list_start_head(&cell->proc_volumes, *_pos);
 }
 
-static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
+static void *afs_proc_cell_volumes_next(struct seq_file *m, void *v,
 					loff_t *_pos)
 {
-	struct afs_cell *cell = PDE_DATA(file_inode(p->file));
+	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
 
 	return seq_list_next(v, &cell->proc_volumes, _pos);
 }
 
-static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v)
+static void afs_proc_cell_volumes_stop(struct seq_file *m, void *v)
 	__releases(cell->proc_lock)
 {
-	struct afs_cell *cell = PDE_DATA(file_inode(p->file));
+	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
 
 	read_unlock(&cell->proc_lock);
 }
@@ -352,11 +289,11 @@ static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
 	return alist->addrs + pos;
 }
 
-static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
+static void *afs_proc_cell_vlservers_next(struct seq_file *m, void *v,
 					  loff_t *_pos)
 {
 	struct afs_addr_list *alist;
-	struct afs_cell *cell = PDE_DATA(file_inode(p->file));
+	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
 	loff_t pos;
 
 	alist = rcu_dereference(cell->vl_addrs);
@@ -369,7 +306,7 @@ static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
 	return alist->addrs + pos;
 }
 
-static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v)
+static void afs_proc_cell_vlservers_stop(struct seq_file *m, void *v)
 	__releases(rcu)
 {
 	rcu_read_unlock();
@@ -382,33 +319,6 @@ static const struct seq_operations afs_proc_cell_vlservers_ops = {
 	.show	= afs_proc_cell_vlservers_show,
 };
 
-static int afs_proc_cell_vlservers_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;
-
-	ret = seq_open(file, &afs_proc_cell_vlservers_ops);
-	if (ret<0)
-		return ret;
-
-	m = file->private_data;
-	m->private = cell;
-
-	return 0;
-}
-
-static const struct file_operations afs_proc_cell_vlservers_fops = {
-	.open		= afs_proc_cell_vlservers_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
-
 /*
  * Display the list of fileservers we're using within a namespace.
  */
@@ -443,7 +353,7 @@ static void *afs_proc_servers_next(struct seq_file *m, void *v, loff_t *_pos)
 	return seq_hlist_next_rcu(v, &afs_seq2net(m)->fs_proc, _pos);
 }
 
-static void afs_proc_servers_stop(struct seq_file *p, void *v)
+static void afs_proc_servers_stop(struct seq_file *m, void *v)
 	__releases(rcu)
 {
 	rcu_read_unlock();
@@ -456,18 +366,6 @@ static const struct seq_operations afs_proc_servers_ops = {
 	.show	= afs_proc_servers_show,
 };
 
-static int afs_proc_servers_open(struct inode *inode, struct file *file)
-{
-	return seq_open(file, &afs_proc_servers_ops);
-}
-
-static const struct file_operations afs_proc_servers_fops = {
-	.open		= afs_proc_servers_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
-
 /*
  * Display the list of strings that may be substituted for the @sys pathname
  * macro.
@@ -487,10 +385,11 @@ 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;
+	struct afs_sysnames *names;
 
 	read_lock(&net->sysnames_lock);
 
+	names = net->sysnames;
 	if (*pos >= names->nr)
 		return NULL;
 	return (void *)(unsigned long)(*pos + 1);
@@ -525,35 +424,21 @@ static const struct seq_operations afs_proc_sysname_ops = {
 /*
  * Allow the @sys substitution to be configured.
  */
-static ssize_t afs_proc_sysname_write(struct file *file,
-				      const char __user *buf,
-				      size_t size, loff_t *_pos)
+static int afs_proc_sysname_write(struct file *file, char *buf, size_t size)
 {
-	struct afs_sysnames *sysnames;
+	struct afs_sysnames *sysnames, *kill;
 	struct seq_file *m = file->private_data;
-	char *kbuf = NULL, *s, *p, *sub;
+	struct afs_net *net = afs_seq2net(m);
+	char *s, *p, *sub;
 	int ret, len;
 
-	sysnames = m->private;
+	sysnames = kzalloc(sizeof(*sysnames), GFP_KERNEL);
 	if (!sysnames)
-		return -EINVAL;
-	if (sysnames->error)
-		return sysnames->error;
+		return -ENOMEM;
+	refcount_set(&sysnames->usage, 1);
+	kill = sysnames;
 
-	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;
+	p = buf;
 	while ((s = strsep(&p, " \t\n"))) {
 		len = strlen(s);
 		if (len == 0)
@@ -594,16 +479,23 @@ static ssize_t afs_proc_sysname_write(struct file *file,
 		sysnames->nr++;
 	}
 
-	ret = size;	/* consume everything, always */
+	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);
+	ret = 0;
 out:
-	inode_unlock(file_inode(file));
-	kfree(kbuf);
+	afs_put_sysnames(kill);
 	return ret;
 
 invalid:
 	ret = -EINVAL;
 error:
-	sysnames->error = ret;
 	goto out;
 }
 
@@ -619,75 +511,12 @@ void afs_put_sysnames(struct afs_sysnames *sysnames)
 	}
 }
 
-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);
-}
-
-/*
- * 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 int afs_proc_sysname_open(struct inode *inode, struct file *file)
-{
-	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;
-	}
-
-	return 0;
-}
-
-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,
-};
-
 /*
  * 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);
+	struct afs_net *net = afs_seq2net_single(m);
 
 	seq_puts(m, "kAFS statistics\n");
 
@@ -716,21 +545,25 @@ static int afs_proc_stats_show(struct seq_file *m, void *v)
 /*
  * initialise /proc/fs/afs/<cell>/
  */
-int afs_proc_cell_setup(struct afs_net *net, struct afs_cell *cell)
+int afs_proc_cell_setup(struct afs_cell *cell)
 {
 	struct proc_dir_entry *dir;
+	struct afs_net *net = cell->net;
 
 	_enter("%p{%s},%p", cell, cell->name, net->proc_afs);
 
-	dir = proc_mkdir(cell->name, net->proc_afs);
+	dir = proc_net_mkdir(net->net, cell->name, net->proc_afs);
 	if (!dir)
 		goto error_dir;
 
-	if (!proc_create_seq_data("vlservers", 0, dir,
-				  &afs_proc_cell_vlservers_ops, cell))
-		goto error_tree;
-	if (!proc_create_seq_data("volumes", 0, dir,
-				  &afs_proc_cell_volumes_ops, cell))
+	if (!proc_create_net_data("vlservers", 0444, dir,
+				  &afs_proc_cell_vlservers_ops,
+				  sizeof(struct seq_net_private),
+				  cell) ||
+	    !proc_create_net_data("volumes", 0444, dir,
+				  &afs_proc_cell_volumes_ops,
+				  sizeof(struct seq_net_private),
+				  cell))
 		goto error_tree;
 
 	_leave(" = 0");
@@ -746,12 +579,12 @@ int afs_proc_cell_setup(struct afs_net *net, struct afs_cell *cell)
 /*
  * remove /proc/fs/afs/<cell>/
  */
-void afs_proc_cell_remove(struct afs_net *net, struct afs_cell *cell)
+void afs_proc_cell_remove(struct afs_cell *cell)
 {
-	_enter("");
+	struct afs_net *net = cell->net;
 
+	_enter("");
 	remove_proc_subtree(cell->name, net->proc_afs);
-
 	_leave("");
 }
 
@@ -760,24 +593,39 @@ void afs_proc_cell_remove(struct afs_net *net, struct afs_cell *cell)
  */
 int afs_proc_init(struct afs_net *net)
 {
+	struct proc_dir_entry *p;
+
 	_enter("");
 
-	net->proc_afs = proc_mkdir("fs/afs", NULL);
-	if (!net->proc_afs)
+	p = proc_net_mkdir(net->net, "afs", net->net->proc_net);
+	if (!p)
 		goto error_dir;
 
-	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_seq("servers", 0644, net->proc_afs, &afs_proc_servers_ops) ||
-	    !proc_create_single("stats", 0644, net->proc_afs, afs_proc_stats_show) ||
-	    !proc_create("sysname", 0644, net->proc_afs, &afs_proc_sysname_fops))
+	if (!proc_create_net_data_write("cells", 0644, p,
+					&afs_proc_cells_ops,
+					afs_proc_cells_write,
+					sizeof(struct seq_net_private),
+					NULL) ||
+	    !proc_create_net_single_write("rootcell", 0644, p,
+					  afs_proc_rootcell_show,
+					  afs_proc_rootcell_write,
+					  NULL) ||
+	    !proc_create_net("servers", 0444, p, &afs_proc_servers_ops,
+			     sizeof(struct seq_net_private)) ||
+	    !proc_create_net_single("stats", 0444, p, afs_proc_stats_show, NULL) ||
+	    !proc_create_net_data_write("sysname", 0644, p,
+					&afs_proc_sysname_ops,
+					afs_proc_sysname_write,
+					sizeof(struct seq_net_private),
+					NULL))
 		goto error_tree;
 
+	net->proc_afs = p;
 	_leave(" = 0");
 	return 0;
 
 error_tree:
-	proc_remove(net->proc_afs);
+	proc_remove(p);
 error_dir:
 	_leave(" = -ENOMEM");
 	return -ENOMEM;
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 5c6263972ec9..e58fa0e15798 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -45,7 +45,7 @@ int afs_open_socket(struct afs_net *net)
 
 	_enter("");
 
-	ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
+	ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
 	if (ret < 0)
 		goto error_1;
 
diff --git a/fs/afs/super.c b/fs/afs/super.c
index 65081ec3c36e..593820372848 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -48,6 +48,8 @@ struct file_system_type afs_fs_type = {
 };
 MODULE_ALIAS_FS("afs");
 
+int afs_net_id;
+
 static const struct super_operations afs_super_ops = {
 	.statfs		= afs_statfs,
 	.alloc_inode	= afs_alloc_inode,
@@ -117,7 +119,7 @@ int __init afs_fs_init(void)
 /*
  * clean up the filesystem
  */
-void __exit afs_fs_exit(void)
+void afs_fs_exit(void)
 {
 	_enter("");
 
@@ -351,7 +353,7 @@ static int afs_test_super(struct super_block *sb, void *data)
 	struct afs_super_info *as1 = data;
 	struct afs_super_info *as = AFS_FS_S(sb);
 
-	return (as->net == as1->net &&
+	return (as->net_ns == as1->net_ns &&
 		as->volume &&
 		as->volume->vid == as1->volume->vid);
 }
@@ -437,7 +439,7 @@ static struct afs_super_info *afs_alloc_sbi(struct afs_mount_params *params)
 
 	as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
 	if (as) {
-		as->net = afs_get_net(params->net);
+		as->net_ns = get_net(params->net_ns);
 		if (params->dyn_root)
 			as->dyn_root = true;
 		else
@@ -450,8 +452,8 @@ static void afs_destroy_sbi(struct afs_super_info *as)
 {
 	if (as) {
 		afs_put_volume(as->cell, as->volume);
-		afs_put_cell(as->net, as->cell);
-		afs_put_net(as->net);
+		afs_put_cell(afs_net(as->net_ns), as->cell);
+		put_net(as->net_ns);
 		kfree(as);
 	}
 }
@@ -472,12 +474,13 @@ static struct dentry *afs_mount(struct file_system_type *fs_type,
 	_enter(",,%s,%p", dev_name, options);
 
 	memset(&params, 0, sizeof(params));
-	params.net = &__afs_net;
 
 	ret = -EINVAL;
 	if (current->nsproxy->net_ns != &init_net)
 		goto error;
-
+	params.net_ns = current->nsproxy->net_ns;
+	params.net = afs_net(params.net_ns);
+	
 	/* parse the options and device name */
 	if (options) {
 		ret = afs_parse_options(&params, options, &dev_name);
@@ -571,7 +574,8 @@ static void afs_kill_super(struct super_block *sb)
 	 * deactivating the superblock.
 	 */
 	if (as->volume)
-		afs_clear_callback_interests(as->net, as->volume->servers);
+		afs_clear_callback_interests(afs_net(as->net_ns),
+					     as->volume->servers);
 	kill_anon_super(sb);
 	if (as->volume)
 		afs_deactivate_volume(as->volume);