nfsd: report client confirmation status in "info" file

mountd can now monitor clients appearing and disappearing in
/proc/fs/nfsd/clients, and will log these events, in liu of the logging
of mount/unmount events for NFSv3.

Currently it cannot distinguish between unconfirmed clients (which might
be transient and totally uninteresting) and confirmed clients.

So add a "status: " line which reports either "confirmed" or
"unconfirmed", and use fsnotify to report that the info file
has been modified.

This requires a bit of infrastructure to keep the dentry for the "info"
file.  There is no need to take a counted reference as the dentry must
remain around until the client is removed.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e011b40..7698172 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -43,6 +43,7 @@
 #include <linux/sunrpc/addr.h>
 #include <linux/jhash.h>
 #include <linux/string_helpers.h>
+#include <linux/fsnotify.h>
 #include "xdr4.h"
 #include "xdr4cb.h"
 #include "vfs.h"
@@ -2352,6 +2353,10 @@ static int client_info_show(struct seq_file *m, void *v)
        memcpy(&clid, &clp->cl_clientid, sizeof(clid));
        seq_printf(m, "clientid: 0x%llx\n", clid);
        seq_printf(m, "address: \"%pISpc\"\n", (struct sockaddr *)&clp->cl_addr);
+       if (test_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags))
+               seq_puts(m, "status: confirmed\n");
+       else
+               seq_puts(m, "status: unconfirmed\n");
        seq_printf(m, "name: ");
        seq_quote_mem(m, clp->cl_name.data, clp->cl_name.len);
        seq_printf(m, "\nminor version: %d\n", clp->cl_minorversion);
@@ -2702,6 +2707,7 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
        int ret;
        struct net *net = SVC_NET(rqstp);
        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+       struct dentry *dentries[ARRAY_SIZE(client_files)];
 
        clp = alloc_client(name);
        if (clp == NULL)
@@ -2721,9 +2727,11 @@ static struct nfs4_client *create_client(struct xdr_netobj name,
        memcpy(&clp->cl_addr, sa, sizeof(struct sockaddr_storage));
        clp->cl_cb_session = NULL;
        clp->net = net;
-       clp->cl_nfsd_dentry = nfsd_client_mkdir(nn, &clp->cl_nfsdfs,
-                       clp->cl_clientid.cl_id - nn->clientid_base,
-                       client_files);
+       clp->cl_nfsd_dentry = nfsd_client_mkdir(
+               nn, &clp->cl_nfsdfs,
+               clp->cl_clientid.cl_id - nn->clientid_base,
+               client_files, dentries);
+       clp->cl_nfsd_info_dentry = dentries[0];
        if (!clp->cl_nfsd_dentry) {
                free_client(clp);
                return NULL;
@@ -2798,7 +2806,10 @@ move_to_confirmed(struct nfs4_client *clp)
        list_move(&clp->cl_idhash, &nn->conf_id_hashtbl[idhashval]);
        rb_erase(&clp->cl_namenode, &nn->unconf_name_tree);
        add_clp_to_name_tree(clp, &nn->conf_name_tree);
-       set_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags);
+       if (!test_and_set_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags) &&
+           clp->cl_nfsd_dentry &&
+           clp->cl_nfsd_info_dentry)
+               fsnotify_dentry(clp->cl_nfsd_info_dentry, FS_MODIFY);
        renew_client_locked(clp);
 }
 

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 02ff7f7..853bf50 100644 (file)
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1266,7 +1266,8 @@ static void nfsdfs_remove_files(struct dentry *root)
 /* XXX: cut'n'paste from simple_fill_super; figure out if we could share
  * code instead. */
 static  int nfsdfs_create_files(struct dentry *root,
-                                       const struct tree_descr *files)
+                               const struct tree_descr *files,
+                               struct dentry **fdentries)
 {
        struct inode *dir = d_inode(root);
        struct inode *inode;
@@ -1275,8 +1276,6 @@ static  int nfsdfs_create_files(struct dentry *root,
 
        inode_lock(dir);
        for (i = 0; files->name && files->name[0]; i++, files++) {
-               if (!files->name)
-                       continue;
                dentry = d_alloc_name(root, files->name);
                if (!dentry)
                        goto out;
@@ -1290,6 +1289,8 @@ static  int nfsdfs_create_files(struct dentry *root,
                inode->i_private = __get_nfsdfs_client(dir);
                d_add(dentry, inode);
                fsnotify_create(dir, dentry);
+               if (fdentries)
+                       fdentries[i] = dentry;
        }
        inode_unlock(dir);
        return 0;
@@ -1301,8 +1302,9 @@ 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,
-               const struct tree_descr *files)
+                                struct nfsdfs_client *ncl, u32 id,
+                                const struct tree_descr *files,
+                                struct dentry **fdentries)
 {
        struct dentry *dentry;
        char name[11];
@@ -1313,7 +1315,7 @@ struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
        dentry = nfsd_mkdir(nn->nfsd_client_dir, ncl, name);
        if (IS_ERR(dentry)) /* XXX: tossing errors? */
                return NULL;
-       ret = nfsdfs_create_files(dentry, files);
+       ret = nfsdfs_create_files(dentry, files, fdentries);
        if (ret) {
                nfsd_client_rmdir(dentry);
                return NULL;

diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 27c1308..14dbfa7 100644 (file)
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -106,7 +106,9 @@ struct nfsdfs_client {
 
 struct nfsdfs_client *get_nfsdfs_client(struct inode *);
 struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
-               struct nfsdfs_client *ncl, u32 id, const struct tree_descr *);
+                                struct nfsdfs_client *ncl, u32 id,
+                                const struct tree_descr *,
+                                struct dentry **fdentries);
 void nfsd_client_rmdir(struct dentry *dentry);
 
 

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 73deea3..54cab65 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -371,6 +371,10 @@ struct nfs4_client {
 
        /* debugging info directory under nfsd/clients/ : */
        struct dentry           *cl_nfsd_dentry;
+       /* 'info' file within that directory. Ref is not counted,
+        * but will remain valid iff cl_nfsd_dentry != NULL
+        */
+       struct dentry           *cl_nfsd_info_dentry;
 
        /* for nfs41 callbacks */
        /* We currently support a single back channel with a single slot */