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>
This commit is contained in:
NeilBrown 2021-03-20 09:38:04 +11:00 committed by Chuck Lever
parent e7a833e9cc
commit 472d155a06
4 changed files with 30 additions and 11 deletions

View File

@ -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);
}

View File

@ -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;

View File

@ -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);

View File

@ -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 */