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From: Ian Kent <raven@themaw.net>
To: Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: David Howells <dhowells@redhat.com>,
	Oleg Nesterov <onestero@redhat.com>,
	Trond Myklebust <trond.myklebust@primarydata.com>,
	"J. Bruce Fields" <bfields@fieldses.org>,
	Benjamin Coddington <bcodding@redhat.com>,
	Al Viro <viro@ZenIV.linux.org.uk>,
	Jeff Layton <jeff.layton@primarydata.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>
Subject: [RFC PATCH 5 4/7] nfs - cache_lib use service thread if not executing in init namespace
Date: Tue, 31 Mar 2015 11:15:06 +0800	[thread overview]
Message-ID: <20150331031505.10464.24498.stgit@pluto.fritz.box> (raw)
In-Reply-To: <20150331030340.10464.30272.stgit@pluto.fritz.box>

From: Ian Kent <ikent@redhat.com>

If pipefs is registered within a container pipefs requests should be run
within their originating container also. To do that get a token to a
service thread created within the container environment for usermode
helper calls.

Signed-off-by: Ian Kent <ikent@redhat.com>
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jeff Layton <jeff.layton@primarydata.com>
---
 fs/nfs/cache_lib.c           |    7 ++++++-
 include/linux/sunrpc/cache.h |    2 ++
 net/sunrpc/cache.c           |    5 +++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/cache_lib.c b/fs/nfs/cache_lib.c
index 5f7b053..78f9b6e 100644
--- a/fs/nfs/cache_lib.c
+++ b/fs/nfs/cache_lib.c
@@ -48,7 +48,12 @@ int nfs_cache_upcall(struct cache_detail *cd, char *entry_name)
 
 	if (nfs_cache_getent_prog[0] == '\0')
 		goto out;
-	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
+	if (cd->u.pipefs.umh_token) {
+		int token = cd->u.pipefs.umh_token;
+		ret = call_usermodehelper_service(argv[0], argv, envp,
+						  token, UMH_WAIT_EXEC);
+	} else
+		ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
 	/*
 	 * Disable the upcall mechanism if we're getting an ENOENT or
 	 * EACCES error. The admin can re-enable it on the fly by using
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index 437ddb6..bb57c7e 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -68,6 +68,8 @@ struct cache_detail_procfs {
 
 struct cache_detail_pipefs {
 	struct dentry *dir;
+	/* Namespace token */
+	int umh_token;
 };
 
 struct cache_detail {
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 5199bb1..eabc0d0 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -1811,6 +1811,9 @@ int sunrpc_cache_register_pipefs(struct dentry *parent,
 	if (IS_ERR(dir))
 		return PTR_ERR(dir);
 	cd->u.pipefs.dir = dir;
+	if (cd->net != &init_net)
+		cd->u.pipefs.umh_token =
+			 umh_wq_get_token(cd->u.pipefs.umh_token, "pipefs");
 	return 0;
 }
 EXPORT_SYMBOL_GPL(sunrpc_cache_register_pipefs);
@@ -1819,6 +1822,8 @@ void sunrpc_cache_unregister_pipefs(struct cache_detail *cd)
 {
 	rpc_remove_cache_dir(cd->u.pipefs.dir);
 	cd->u.pipefs.dir = NULL;
+	umh_wq_put_token(cd->u.pipefs.umh_token);
+	cd->u.pipefs.umh_token = 0;
 }
 EXPORT_SYMBOL_GPL(sunrpc_cache_unregister_pipefs);
 


  parent reply	other threads:[~2015-03-31  3:15 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-31  3:14 [RFC PATCH v5 0/7] Another attempt at contained helper execution Ian Kent
2015-03-31  3:14 ` [RFC PATCH 5 1/7] kmod - add workqueue service thread store Ian Kent
2015-03-31 11:21   ` Jeff Layton
2015-03-31 12:59     ` Ian Kent
2015-03-31  3:14 ` [RFC PATCH 5 2/7] kmod - teach usermodehelper to use service workqueues Ian Kent
2015-03-31  3:14 ` [RFC PATCH 5 3/7] nfsd - use service thread if not executing in init namespace Ian Kent
2015-03-31 13:14   ` J. Bruce Fields
2015-04-01  0:22     ` Ian Kent
2015-04-02 15:59       ` J. Bruce Fields
2015-03-31  3:15 ` Ian Kent [this message]
2015-03-31  3:15 ` [RFC PATCH 5 5/7] nfs - objlayout " Ian Kent
2015-03-31  3:15 ` [RFC PATCH 5 6/7] KEYS - use correct memory allocation flag in call_usermodehelper_keys() Ian Kent
2015-03-31  3:15 ` [RFC PATCH 5 7/7] KEYS: exec request key within service thread of key creator Ian Kent
2015-04-02 12:43 ` [RFC PATCH 5 1/7] kmod - add workqueue service thread store David Howells
2015-04-07  0:42   ` Ian Kent
2015-04-02 12:58 ` [RFC PATCH 5 7/7] KEYS: exec request key within service thread of key creator David Howells
2015-04-07  0:54   ` Ian Kent
2015-04-02 13:00 ` [RFC PATCH 5 6/7] KEYS - use correct memory allocation flag in call_usermodehelper_keys() David Howells

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