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

22 files changed, 892 insertions, 645 deletions

diff --git a/fs/afs/Makefile b/fs/afs/Makefile
index 532acae25453..546874057bd3 100644
--- a/fs/afs/Makefile
+++ b/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
diff --git a/fs/afs/addr_list.c b/fs/afs/addr_list.c
index 2c46c46f3a6d..025a9a5e1c32 100644
--- a/fs/afs/addr_list.c
+++ b/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);
 
diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index 571437dcb252..5f261fbf2182 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -21,6 +21,66 @@
 #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.
  * - Called with vnode->io_lock held.
@@ -77,20 +137,10 @@ again:
         }
 
         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 @@ again:
  */
 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;