[PATCH 3.13 036/187] sunrpc: replace sunrpc_net->gssd_running flag with a more reliable check

Kamal Mostafa
2014-09-15T22:20:48Z

From: Jeff Layton <jlayton@redhat.com>

commit 89f842435c630f8426f414e6030bc2ffea0d6f81 upstream.

Now that we have a more reliable method to tell if gssd is running, we
can replace the sn->gssd_running flag with a function that will query to
see if it's up and running.

There's also no need to attempt an upcall that we know will fail, so
just return -EACCES if gssd isn't running. Finally, fix the warn_gss()
message not to claim that that the upcall timed out since we don't
necesarily perform one now when gssd isn't running, and remove the
extraneous newline from the message.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[ kamal: 3.13-stable prereq for 6aa23d76 "nfs: check if gssd is running
before attempting to use krb5i auth in SETCLIENTID call" ]
Cc: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
include/linux/sunrpc/rpc_pipe_fs.h | 2 ++
net/sunrpc/auth_gss/auth_gss.c | 17 +++++++----------
net/sunrpc/netns.h | 2 --
net/sunrpc/rpc_pipe.c | 14 ++++++++++----
4 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/include/linux/sunrpc/rpc_pipe_fs.h b/include/linux/sunrpc/rpc_pipe_fs.h
index 85f1342..7f490be 100644
--- a/include/linux/sunrpc/rpc_pipe_fs.h
+++ b/include/linux/sunrpc/rpc_pipe_fs.h
@@ -131,5 +131,7 @@ extern int rpc_unlink(struct dentry *);
extern int register_rpc_pipefs(void);
extern void unregister_rpc_pipefs(void);

+extern bool gssd_running(struct net *net);
+
#endif
#endif
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 1eebf22..154c504 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -541,8 +541,7 @@ static void warn_gssd(void)
unsigned long now = jiffies;

if (time_after(now, ratelimit)) {
- printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
- "Please check user daemon is running.\n");
+ pr_warn("RPC: AUTH_GSS upcall failed. Please check user daemon is running.\n");
ratelimit = now + 15*HZ;
}
}
@@ -605,7 +604,6 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
struct rpc_pipe *pipe;
struct rpc_cred *cred = &gss_cred->gc_base;
struct gss_upcall_msg *gss_msg;
- unsigned long timeout;
DEFINE_WAIT(wait);
int err;

@@ -613,17 +611,16 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
__func__, from_kuid(&init_user_ns, cred->cr_uid));
retry:
err = 0;
- /* Default timeout is 15s unless we know that gssd is not running */
- timeout = 15 * HZ;
- if (!sn->gssd_running)
- timeout = HZ >> 2;
+ /* if gssd is down, just skip upcalling altogether */
+ if (!gssd_running(net)) {
+ warn_gssd();
+ return -EACCES;
+ }
gss_msg = gss_setup_upcall(gss_auth, cred);
if (PTR_ERR(gss_msg) == -EAGAIN) {
err = wait_event_interruptible_timeout(pipe_version_waitqueue,
- sn->pipe_version >= 0, timeout);
+ sn->pipe_version >= 0, 15 * HZ);
if (sn->pipe_version < 0) {
- if (err == 0)
- sn->gssd_running = 0;
warn_gssd();
err = -EACCES;
}
diff --git a/net/sunrpc/netns.h b/net/sunrpc/netns.h
index c804ed4..df58268 100644
--- a/net/sunrpc/netns.h
+++ b/net/sunrpc/netns.h
@@ -32,8 +32,6 @@ struct sunrpc_net {
int pipe_version;
atomic_t pipe_users;
struct proc_dir_entry *use_gssp_proc;
-
- unsigned int gssd_running;
};

extern int sunrpc_net_id;
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index c23458b..5cd7ad1 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -216,14 +216,11 @@ rpc_destroy_inode(struct inode *inode)
static int
rpc_pipe_open(struct inode *inode, struct file *filp)
{
- struct net *net = inode->i_sb->s_fs_info;
- struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
struct rpc_pipe *pipe;
int first_open;
int res = -ENXIO;

mutex_lock(&inode->i_mutex);
- sn->gssd_running = 1;
pipe = RPC_I(inode)->pipe;
if (pipe == NULL)
goto out;
@@ -1222,7 +1219,6 @@ int rpc_pipefs_init_net(struct net *net)
return PTR_ERR(sn->gssd_dummy);

mutex_init(&sn->pipefs_sb_lock);
- sn->gssd_running = 1;
sn->pipe_version = -1;
return 0;
}
@@ -1376,6 +1372,16 @@ err_depopulate:
return err;
}

+bool
+gssd_running(struct net *net)
+{
+ struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+ struct rpc_pipe *pipe = sn->gssd_dummy;
+
+ return pipe->nreaders || pipe->nwriters;
+}
+EXPORT_SYMBOL_GPL(gssd_running);
+
static struct dentry *
rpc_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
--
1.9.1