[RFC PATCH 5 5/7] nfs - objlayout use service thread if not executing in init namespace

From: Ian Kent
Date: Mon Mar 30 2015 - 23:15:49 EST


From: Ian Kent <ikent@xxxxxxxxxx>

If the caller is running within a container then execute the usermode
helper callback 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/nfs/objlayout/objlayout.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/objlayout/objlayout.c b/fs/nfs/objlayout/objlayout.c
index 919efd4..1d4fd11 100644
--- a/fs/nfs/objlayout/objlayout.c
+++ b/fs/nfs/objlayout/objlayout.c
@@ -600,8 +600,14 @@ static int __objlayout_upcall(struct __auto_login *login)
NULL
};
char *argv[8];
+ int umh_token;
int ret;

+ /* If running within a container use the container namespace */
+ umh_token = 0;
+ if (current->nsproxy->net_ns != &init_net)
+ umh_token = umh_wq_get_token(0, "objlayout");
+
if (unlikely(!osd_login_prog[0])) {
dprintk("%s: osd_login_prog is disabled\n", __func__);
return -EACCES;
@@ -620,7 +626,13 @@ static int __objlayout_upcall(struct __auto_login *login)
argv[6] = login->systemid_hex;
argv[7] = NULL;

- ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+ if (!umh_token)
+ ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+ else {
+ ret = call_usermodehelper_service(argv[0], argv, envp,
+ umh_token, UMH_WAIT_PROC);
+ umh_wq_put_token(umh_token);
+ }
/*
* Disable the upcall mechanism if we're getting an ENOENT or
* EACCES error. The admin can re-enable it on the fly by using

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