Re: [RFC PATCH 6/8] nfsd - use namespace if not executing in init namespace

From: J. Bruce Fields
Date: Wed Feb 18 2015 - 12:37:42 EST


On Thu, Feb 05, 2015 at 10:34:31AM +0800, Ian Kent wrote:
> If nfsd is running within a container the client tracking operations
> should run within the container also.
>
> Signed-off-by: Ian Kent <ikent@xxxxxxxxxx>
> Cc: Benjamin Coddington <bcodding@xxxxxxxxxx>
> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Cc: J. Bruce Fields <bfields@xxxxxxxxxxxx>
> Cc: David Howells <dhowells@xxxxxxxxxx>
> Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> Cc: Oleg Nesterov <onestero@xxxxxxxxxx>
> Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
> Cc: Jeff Layton <jeff.layton@xxxxxxxxxxxxxxx>
> ---
> fs/nfsd/netns.h | 2 ++
> fs/nfsd/nfs4recover.c | 48 ++++++++++++++++++++++++++++++++----------------
> 2 files changed, 34 insertions(+), 16 deletions(-)
>
> diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
> index ea6749a..c168196 100644
> --- a/fs/nfsd/netns.h
> +++ b/fs/nfsd/netns.h
> @@ -112,6 +112,8 @@ struct nfsd_net {
> u32 clientid_counter;
>
> struct svc_serv *nfsd_serv;
> +
> + int umh_flags;
> };
>
> /* Simple check to find out if a given net was properly initialized */
> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> index cc6a760..b962856 100644
> --- a/fs/nfsd/nfs4recover.c
> +++ b/fs/nfsd/nfs4recover.c
> @@ -1184,7 +1184,9 @@ nfsd4_cltrack_grace_start(time_t grace_start)
> }
>
> static int
> -nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
> +nfsd4_umh_cltrack_upcall(char *cmd,
> + char *arg, char *env0, char *env1,
> + int flags)
> {
> char *envp[3];
> char *argv[4];
> @@ -1209,7 +1211,7 @@ nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
> argv[2] = arg;
> argv[3] = NULL;
>
> - ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
> + ret = call_usermodehelper(argv[0], argv, envp, flags);
> /*
> * Disable the upcall mechanism if we're getting an ENOENT or EACCES
> * error. The admin can re-enable it on the fly by using sysfs
> @@ -1252,14 +1254,13 @@ nfsd4_umh_cltrack_init(struct net *net)
> struct nfsd_net *nn = net_generic(net, nfsd_net_id);
> char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
>
> - /* XXX: The usermode helper s not working in container yet. */
> - if (net != &init_net) {
> - WARN(1, KERN_ERR "NFSD: attempt to initialize umh client "
> - "tracking in a container!\n");
> - return -EINVAL;
> - }
> + nn->umh_flags = UMH_WAIT_PROC;
> + if (net != &init_net)
> + nn->umh_flags |= UMH_USE_NS;
>
> - ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
> + ret = nfsd4_umh_cltrack_upcall("init",
> + NULL, grace_start, NULL,
> + nn->umh_flags);

This code is always run from a kernel thread, so I assume this isn't
actually going to do anything different.

--b.

> kfree(grace_start);
> return ret;
> }
> @@ -1285,6 +1286,7 @@ nfsd4_umh_cltrack_create(struct nfs4_client *clp)
> {
> char *hexid, *has_session, *grace_start;
> struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
> + int ret;
>
> /*
> * With v4.0 clients, there's little difference in outcome between a
> @@ -1312,7 +1314,10 @@ nfsd4_umh_cltrack_create(struct nfs4_client *clp)
> grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
>
> nfsd4_cltrack_upcall_lock(clp);
> - if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
> + ret = nfsd4_umh_cltrack_upcall("create",
> + hexid, has_session, grace_start,
> + nn->umh_flags);
> + if (!ret)
> set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
> nfsd4_cltrack_upcall_unlock(clp);
>
> @@ -1324,7 +1329,9 @@ nfsd4_umh_cltrack_create(struct nfs4_client *clp)
> static void
> nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
> {
> + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
> char *hexid;
> + int ret;
>
> if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
> return;
> @@ -1336,9 +1343,13 @@ nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
> }
>
> nfsd4_cltrack_upcall_lock(clp);
> - if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
> - nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
> - clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
> + if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
> + ret = nfsd4_umh_cltrack_upcall("remove",
> + hexid, NULL, NULL,
> + nn->umh_flags);
> + if (ret == 0)
> + clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
> + }
> nfsd4_cltrack_upcall_unlock(clp);
>
> kfree(hexid);
> @@ -1347,8 +1358,9 @@ nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
> static int
> nfsd4_umh_cltrack_check(struct nfs4_client *clp)
> {
> - int ret;
> + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
> char *hexid, *has_session, *legacy;
> + int ret;
>
> if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
> return 0;
> @@ -1366,7 +1378,9 @@ nfsd4_umh_cltrack_check(struct nfs4_client *clp)
> if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
> ret = 0;
> } else {
> - ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
> + ret = nfsd4_umh_cltrack_upcall("check", hexid,
> + has_session, legacy,
> + mm->umh_flags);
> if (ret == 0)
> set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
> }
> @@ -1386,7 +1400,9 @@ nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
>
> sprintf(timestr, "%ld", nn->boot_time);
> legacy = nfsd4_cltrack_legacy_topdir();
> - nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
> + nfsd4_umh_cltrack_upcall("gracedone",
> + timestr, legacy, NULL,
> + nn->umh_flags);
> kfree(legacy);
> }
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/