nfsd: add nfsd/clients directory

I plan to expose some information about nfsv4 clients here.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

5 files changed, 133 insertions, 10 deletions

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index df4ba4b8b540..ad1d74383d67 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -45,6 +45,8 @@ struct nfsd_net {
         /* internal mount of the "nfsd" pseudofilesystem: */
         struct vfsmount *nfsd_mnt;
 
+        struct dentry *nfsd_client_dir;
+
         /*
          * reclaim_str_hashtbl[] holds known client info from previous reset/reboot
          * used in reboot/reset lease grace period processing
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index de68c3cbea2b..7d8d1fcc8831 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1881,20 +1881,19 @@ err_no_name:
 
 static void __free_client(struct kref *k)
 {
-        struct nfs4_client *clp = container_of(k, struct nfs4_client, cl_ref);
+        struct nfsdfs_client *c = container_of(k, struct nfsdfs_client, cl_ref);
+        struct nfs4_client *clp = container_of(c, struct nfs4_client, cl_nfsdfs);
 
         free_svc_cred(&clp->cl_cred);
         kfree(clp->cl_ownerstr_hashtbl);
         kfree(clp->cl_name.data);
         idr_destroy(&clp->cl_stateids);
-        if (clp->cl_nfsd_dentry)
-                nfsd_client_rmdir(clp->cl_nfsd_dentry);
         kmem_cache_free(client_slab, clp);
 }
 
 void drop_client(struct nfs4_client *clp)
 {
-        kref_put(&clp->cl_ref, __free_client);
+        kref_put(&clp->cl_nfsdfs.cl_ref, __free_client);
 }
 
 static void
@@ -1909,6 +1908,8 @@ free_client(struct nfs4_client *clp)
                 free_session(ses);
         }
         rpc_destroy_wait_queue(&clp->cl_cb_waitq);
+        if (clp->cl_nfsd_dentry)
+                nfsd_client_rmdir(clp->cl_nfsd_dentry);
         drop_client(clp);
 }
 
@@ -2220,6 +2221,7 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
         struct sockaddr *sa = svc_addr(rqstp);
         int ret;
         struct net *net = SVC_NET(rqstp);
+        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
         clp = alloc_client(name);
         if (clp == NULL)
@@ -2230,8 +2232,8 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
                 free_client(clp);
                 return NULL;
         }
-
-        kref_init(&clp->cl_ref);
+        gen_clid(clp, nn);
+        kref_init(&clp->cl_nfsdfs.cl_ref);
         nfsd4_init_cb(&clp->cl_cb_null, clp, NULL, NFSPROC4_CLNT_CB_NULL);
         clp->cl_time = get_seconds();
         clear_bit(0, &clp->cl_cb_slot_busy);
@@ -2239,6 +2241,12 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
         rpc_copy_addr((struct sockaddr *) &clp->cl_addr, sa);
         clp->cl_cb_session = NULL;
         clp->net = net;
+        clp->cl_nfsd_dentry = nfsd_client_mkdir(nn, &clp->cl_nfsdfs,
+                                                clp->cl_clientid.cl_id);
+        if (!clp->cl_nfsd_dentry) {
+                free_client(clp);
+                return NULL;
+        }
         return clp;
 }
 
@@ -2683,7 +2691,6 @@ out_new:
         new->cl_spo_must_allow.u.words[0] = exid->spo_must_allow[0];
         new->cl_spo_must_allow.u.words[1] = exid->spo_must_allow[1];
 
-        gen_clid(new, nn);
         add_to_unconfirmed(new);
         swap(new, conf);
 out_copy:
@@ -3427,7 +3434,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                 copy_clid(new, conf);
                 gen_confirm(new, nn);
         } else /* case 4 (new client) or cases 2, 3 (client reboot): */
-                gen_clid(new, nn);
+                ;
         new->cl_minorversion = 0;
         gen_callback(new, setclid, rqstp);
         add_to_unconfirmed(new);
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 25910a7d21cc..5a1920a2de27 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -16,6 +16,7 @@
 #include <linux/sunrpc/gss_krb5_enctypes.h>
 #include <linux/sunrpc/rpc_pipe_fs.h>
 #include <linux/module.h>
+#include <linux/fsnotify.h>
 
 #include "idmap.h"
 #include "nfsd.h"
@@ -53,6 +54,7 @@ enum {
         NFSD_RecoveryDir,
         NFSD_V4EndGrace,
 #endif
+        NFSD_MaxReserved
 };
 
 /*
@@ -1147,8 +1149,99 @@ static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
  *      populating the filesystem.
  */
 
+/* Basically copying rpc_get_inode. */
+static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode)
+{
+        struct inode *inode = new_inode(sb);
+        if (!inode)
+                return NULL;
+        /* Following advice from simple_fill_super documentation: */
+        inode->i_ino = iunique(sb, NFSD_MaxReserved);
+        inode->i_mode = mode;
+        inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+        switch (mode & S_IFMT) {
+        case S_IFDIR:
+                inode->i_fop = &simple_dir_operations;
+                inode->i_op = &simple_dir_inode_operations;
+                inc_nlink(inode);
+        default:
+                break;
+        }
+        return inode;
+}
+
+static int __nfsd_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+        struct inode *inode;
+
+        inode = nfsd_get_inode(dir->i_sb, mode);
+        if (!inode)
+                return -ENOMEM;
+        d_add(dentry, inode);
+        inc_nlink(dir);
+        fsnotify_mkdir(dir, dentry);
+        return 0;
+}
+
+static struct dentry *nfsd_mkdir(struct dentry *parent, struct nfsdfs_client *ncl, char *name)
+{
+        struct inode *dir = parent->d_inode;
+        struct dentry *dentry;
+        int ret = -ENOMEM;
+
+        inode_lock(dir);
+        dentry = d_alloc_name(parent, name);
+        if (!dentry)
+                goto out_err;
+        ret = __nfsd_mkdir(d_inode(parent), dentry, S_IFDIR | 0600);
+        if (ret)
+                goto out_err;
+        if (ncl) {
+                d_inode(dentry)->i_private = ncl;
+                kref_get(&ncl->cl_ref);
+        }
+out:
+        inode_unlock(dir);
+        return dentry;
+out_err:
+        dentry = ERR_PTR(ret);
+        goto out;
+}
+
+/* on success, returns positive number unique to that client. */
+struct dentry *nfsd_client_mkdir(struct nfsd_net *nn, struct nfsdfs_client *ncl, u32 id)
+{
+        char name[11];
+
+        sprintf(name, "%d", id++);
+
+        return nfsd_mkdir(nn->nfsd_client_dir, ncl, name);
+}
+
+/* Taken from __rpc_rmdir: */
+void nfsd_client_rmdir(struct dentry *dentry)
+{
+        struct inode *dir = d_inode(dentry->d_parent);
+        struct inode *inode = d_inode(dentry);
+        struct nfsdfs_client *ncl = inode->i_private;
+        int ret;
+
+        inode->i_private = NULL;
+        synchronize_rcu();
+        kref_put(&ncl->cl_ref, ncl->cl_release);
+        dget(dentry);
+        ret = simple_rmdir(dir, dentry);
+        WARN_ON_ONCE(ret);
+        d_delete(dentry);
+}
+
 static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
 {
+        struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
+                                                        nfsd_net_id);
+        struct dentry *dentry;
+        int ret;
+
         static const struct tree_descr nfsd_files[] = {
                 [NFSD_List] = {"exports", &exports_nfsd_operations, S_IRUGO},
                 [NFSD_Export_features] = {"export_features",
@@ -1178,7 +1271,15 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
                 /* last one */ {""}
         };
         get_net(sb->s_fs_info);
-        return simple_fill_super(sb, 0x6e667364, nfsd_files);
+        ret = simple_fill_super(sb, 0x6e667364, nfsd_files);
+        if (ret)
+                return ret;
+        dentry = nfsd_mkdir(sb->s_root, NULL, "clients");
+        if (IS_ERR(dentry))
+                return PTR_ERR(dentry);
+        nn->nfsd_client_dir = dentry;
+        return 0;
+
 }
 
 static struct dentry *nfsd_mount(struct file_system_type *fs_type,
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 24187b5dd638..85525dcbf77d 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -22,6 +22,7 @@
 
 #include <uapi/linux/nfsd/debug.h>
 
+#include "netns.h"
 #include "stats.h"
 #include "export.h"
 
@@ -86,6 +87,14 @@ int		nfsd_pool_stats_release(struct inode *, struct file *);
 
 void            nfsd_destroy(struct net *net);
 
+struct nfsdfs_client {
+        struct kref cl_ref;
+        void (*cl_release)(struct kref *kref);
+};
+
+struct dentry *nfsd_client_mkdir(struct nfsd_net *nn, struct nfsdfs_client *ncl, u32 id);
+void nfsd_client_rmdir(struct dentry *dentry);
+
 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
 #ifdef CONFIG_NFSD_V2_ACL
 extern const struct svc_version nfsd_acl_version2;
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 8eacdbc50cd7..81852cbf6b0a 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -39,6 +39,7 @@
 #include <linux/refcount.h>
 #include <linux/sunrpc/svc_xprt.h>
 #include "nfsfh.h"
+#include "nfsd.h"
 
 typedef struct {
         u32             cl_boot;
@@ -348,9 +349,12 @@ struct nfs4_client {
         u32                     cl_exchange_flags;
         /* number of rpc's in progress over an associated session: */
         atomic_t                cl_rpc_users;
-        struct kref             cl_ref;
+        struct nfsdfs_client    cl_nfsdfs;
         struct nfs4_op_map      cl_spo_must_allow;
 
+        /* debugging info directory under nfsd/clients/ : */
+        struct dentry           *cl_nfsd_dentry;
+
         /* for nfs41 callbacks */
         /* We currently support a single back channel with a single slot */
         unsigned long           cl_cb_slot_busy;