Merge branch 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull AFS updates from Al Viro:
 "Assorted AFS stuff - ended up in vfs.git since most of that consists
  of David's AFS-related followups to Christoph's procfs series"

* 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  afs: Optimise callback breaking by not repeating volume lookup
  afs: Display manually added cells in dynamic root mount
  afs: Enable IPv6 DNS lookups
  afs: Show all of a server's addresses in /proc/fs/afs/servers
  afs: Handle CONFIG_PROC_FS=n
  proc: Make inline name size calculation automatic
  afs: Implement network namespacing
  afs: Mark afs_net::ws_cell as __rcu and set using rcu functions
  afs: Fix a Sparse warning in xdr_decode_AFSFetchStatus()
  proc: Add a way to make network proc files writable
  afs: Rearrange fs/afs/proc.c to remove remaining predeclarations.
  afs: Rearrange fs/afs/proc.c to move the show routines up
  afs: Rearrange fs/afs/proc.c by moving fops and open functions down
  afs: Move /proc management functions to the end of the file

Author: torvalds

fs/afs/Makefile

@@ -5,7 +5,7 @@
 
 afs-cache-$(CONFIG_AFS_FSCACHE) := cache.o
 
-kafs-objs := \
+kafs-y := \
 	$(afs-cache-y) \
 	addr_list.o \
 	callback.o \
@@ -21,7 +21,6 @@ kafs-objs := \
 	main.o \
 	misc.o \
 	mntpt.o \
-	proc.o \
 	rotate.o \
 	rxrpc.o \
 	security.o \
@@ -34,4 +33,5 @@ kafs-objs := \
 	write.o \
 	xattr.o
 
+kafs-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_AFS_FS)  := kafs.o

fs/afs/addr_list.c

@@ -215,7 +215,7 @@ struct afs_addr_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry)
 	_enter("%s", cell->name);
 
 	ret = dns_query("afsdb", cell->name, cell->name_len,
-			"ipv4", &vllist, _expiry);
+			"", &vllist, _expiry);
 	if (ret < 0)
 		return ERR_PTR(ret);
 

fs/afs/callback.c

@@ -20,6 +20,66 @@
 #include <linux/sched.h>
 #include "internal.h"
 
+/*
+ * Create volume and callback interests on a server.
+ */
+static struct afs_cb_interest *afs_create_interest(struct afs_server *server,
+						   struct afs_vnode *vnode)
+{
+	struct afs_vol_interest *new_vi, *vi;
+	struct afs_cb_interest *new;
+	struct hlist_node **pp;
+
+	new_vi = kzalloc(sizeof(struct afs_vol_interest), GFP_KERNEL);
+	if (!new_vi)
+		return NULL;
+
+	new = kzalloc(sizeof(struct afs_cb_interest), GFP_KERNEL);
+	if (!new) {
+		kfree(new_vi);
+		return NULL;
+	}
+
+	new_vi->usage = 1;
+	new_vi->vid = vnode->volume->vid;
+	INIT_HLIST_NODE(&new_vi->srv_link);
+	INIT_HLIST_HEAD(&new_vi->cb_interests);
+
+	refcount_set(&new->usage, 1);
+	new->sb = vnode->vfs_inode.i_sb;
+	new->vid = vnode->volume->vid;
+	new->server = afs_get_server(server);
+	INIT_HLIST_NODE(&new->cb_vlink);
+
+	write_lock(&server->cb_break_lock);
+
+	for (pp = &server->cb_volumes.first; *pp; pp = &(*pp)->next) {
+		vi = hlist_entry(*pp, struct afs_vol_interest, srv_link);
+		if (vi->vid < new_vi->vid)
+			continue;
+		if (vi->vid > new_vi->vid)
+			break;
+		vi->usage++;
+		goto found_vi;
+	}
+
+	new_vi->srv_link.pprev = pp;
+	new_vi->srv_link.next = *pp;
+	if (*pp)
+		(*pp)->pprev = &new_vi->srv_link.next;
+	*pp = &new_vi->srv_link;
+	vi = new_vi;
+	new_vi = NULL;
+found_vi:
+
+	new->vol_interest = vi;
+	hlist_add_head(&new->cb_vlink, &vi->cb_interests);
+
+	write_unlock(&server->cb_break_lock);
+	kfree(new_vi);
+	return new;
+}
+
 /*
  * Set up an interest-in-callbacks record for a volume on a server and
  * register it with the server.
@@ -77,20 +137,10 @@ int afs_register_server_cb_interest(struct afs_vnode *vnode,
 	}
 
 	if (!cbi) {
-		new = kzalloc(sizeof(struct afs_cb_interest), GFP_KERNEL);
+		new = afs_create_interest(server, vnode);
 		if (!new)
 			return -ENOMEM;
 
-		refcount_set(&new->usage, 1);
-		new->sb = vnode->vfs_inode.i_sb;
-		new->vid = vnode->volume->vid;
-		new->server = afs_get_server(server);
-		INIT_LIST_HEAD(&new->cb_link);
-
-		write_lock(&server->cb_break_lock);
-		list_add_tail(&new->cb_link, &server->cb_interests);
-		write_unlock(&server->cb_break_lock);
-
 		write_lock(&slist->lock);
 		if (!entry->cb_interest) {
 			entry->cb_interest = afs_get_cb_interest(new);
@@ -126,11 +176,22 @@ int afs_register_server_cb_interest(struct afs_vnode *vnode,
  */
 void afs_put_cb_interest(struct afs_net *net, struct afs_cb_interest *cbi)
 {
+	struct afs_vol_interest *vi;
+
 	if (cbi && refcount_dec_and_test(&cbi->usage)) {
-		if (!list_empty(&cbi->cb_link)) {
+		if (!hlist_unhashed(&cbi->cb_vlink)) {
 			write_lock(&cbi->server->cb_break_lock);
-			list_del_init(&cbi->cb_link);
+
+			hlist_del_init(&cbi->cb_vlink);
+			vi = cbi->vol_interest;
+			cbi->vol_interest = NULL;
+			if (--vi->usage == 0)
+				hlist_del(&vi->srv_link);
+			else
+				vi = NULL;
+
 			write_unlock(&cbi->server->cb_break_lock);
+			kfree(vi);
 			afs_put_server(net, cbi->server);
 		}
 		kfree(cbi);
@@ -182,20 +243,34 @@ void afs_break_callback(struct afs_vnode *vnode)
 static void afs_break_one_callback(struct afs_server *server,
 				   struct afs_fid *fid)
 {
+	struct afs_vol_interest *vi;
 	struct afs_cb_interest *cbi;
 	struct afs_iget_data data;
 	struct afs_vnode *vnode;
 	struct inode *inode;
 
 	read_lock(&server->cb_break_lock);
+	hlist_for_each_entry(vi, &server->cb_volumes, srv_link) {
+		if (vi->vid < fid->vid)
+			continue;
+		if (vi->vid > fid->vid) {
+			vi = NULL;
+			break;
+		}
+		//atomic_inc(&vi->usage);
+		break;
+	}
+
+	/* TODO: Find all matching volumes if we couldn't match the server and
+	 * break them anyway.
+	 */
+	if (!vi)
+		goto out;
 
 	/* Step through all interested superblocks.  There may be more than one
 	 * because of cell aliasing.
 	 */
-	list_for_each_entry(cbi, &server->cb_interests, cb_link) {
-		if (cbi->vid != fid->vid)
-			continue;
-
+	hlist_for_each_entry(cbi, &vi->cb_interests, cb_vlink) {
 		if (fid->vnode == 0 && fid->unique == 0) {
 			/* The callback break applies to an entire volume. */
 			struct afs_super_info *as = AFS_FS_S(cbi->sb);
@@ -217,6 +292,7 @@ static void afs_break_one_callback(struct afs_server *server,
 		}
 	}
 
+out:
 	read_unlock(&server->cb_break_lock);
 }
 

fs/afs/cell.c

@@ -15,6 +15,7 @@
 #include <linux/dns_resolver.h>
 #include <linux/sched.h>
 #include <linux/inet.h>
+#include <linux/namei.h>
 #include <keys/rxrpc-type.h>
 #include "internal.h"
 
@@ -341,8 +342,8 @@ 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);
@@ -528,12 +529,14 @@ 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);
+
+	mutex_lock(&net->proc_cells_lock);
 	list_add_tail(&cell->proc_link, &net->proc_cells);
-	spin_unlock(&net->proc_cells_lock);
+	afs_dynroot_mkdir(net, cell);
+	mutex_unlock(&net->proc_cells_lock);
 	return 0;
 }
 
@@ -544,11 +547,12 @@ 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);
+	mutex_lock(&net->proc_cells_lock);
 	list_del_init(&cell->proc_link);
-	spin_unlock(&net->proc_cells_lock);
+	afs_dynroot_rmdir(net, cell);
+	mutex_unlock(&net->proc_cells_lock);
 
 #ifdef CONFIG_AFS_FSCACHE
 	fscache_relinquish_cookie(cell->cache, NULL, false);
@@ -755,8 +759,8 @@ 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);
 

fs/afs/cmservice.c

@@ -526,7 +526,7 @@ 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;