From f9c72d10d6fbf949558cd088389a42213ed7b12d Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 31 Mar 2015 12:03:28 -0400 Subject: sunrpc: make debugfs file creation failure non-fatal We currently have a problem that SELinux policy is being enforced when creating debugfs files. If a debugfs file is created as a side effect of doing some syscall, then that creation can fail if the SELinux policy for that process prevents it. This seems wrong. We don't do that for files under /proc, for instance, so Bruce has proposed a patch to fix that. While discussing that patch however, Greg K.H. stated: "No kernel code should care / fail if a debugfs function fails, so please fix up the sunrpc code first." This patch converts all of the sunrpc debugfs setup code to be void return functins, and the callers to not look for errors from those functions. This should allow rpc_clnt and rpc_xprt creation to work, even if the kernel fails to create debugfs files for some reason. Symptoms were failing krb5 mounts on systems using gss-proxy and selinux. Fixes: 388f0c776781 "sunrpc: add a debugfs rpc_xprt directory..." Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton Acked-by: Greg Kroah-Hartman Signed-off-by: J. Bruce Fields --- net/sunrpc/debugfs.c | 52 +++++++++++++++++++++++++++++----------------------- 1 file changed, 29 insertions(+), 23 deletions(-) (limited to 'net/sunrpc/debugfs.c') diff --git a/net/sunrpc/debugfs.c b/net/sunrpc/debugfs.c index e811f390f9f6..82962f7e6e88 100644 --- a/net/sunrpc/debugfs.c +++ b/net/sunrpc/debugfs.c @@ -129,48 +129,52 @@ static const struct file_operations tasks_fops = { .release = tasks_release, }; -int +void rpc_clnt_debugfs_register(struct rpc_clnt *clnt) { - int len, err; + int len; char name[24]; /* enough for "../../rpc_xprt/ + 8 hex digits + NULL */ + struct rpc_xprt *xprt; /* Already registered? */ - if (clnt->cl_debugfs) - return 0; + if (clnt->cl_debugfs || !rpc_clnt_dir) + return; len = snprintf(name, sizeof(name), "%x", clnt->cl_clid); if (len >= sizeof(name)) - return -EINVAL; + return; /* make the per-client dir */ clnt->cl_debugfs = debugfs_create_dir(name, rpc_clnt_dir); if (!clnt->cl_debugfs) - return -ENOMEM; + return; /* make tasks file */ - err = -ENOMEM; if (!debugfs_create_file("tasks", S_IFREG | S_IRUSR, clnt->cl_debugfs, clnt, &tasks_fops)) goto out_err; - err = -EINVAL; rcu_read_lock(); + xprt = rcu_dereference(clnt->cl_xprt); + /* no "debugfs" dentry? Don't bother with the symlink. */ + if (!xprt->debugfs) { + rcu_read_unlock(); + return; + } len = snprintf(name, sizeof(name), "../../rpc_xprt/%s", - rcu_dereference(clnt->cl_xprt)->debugfs->d_name.name); + xprt->debugfs->d_name.name); rcu_read_unlock(); + if (len >= sizeof(name)) goto out_err; - err = -ENOMEM; if (!debugfs_create_symlink("xprt", clnt->cl_debugfs, name)) goto out_err; - return 0; + return; out_err: debugfs_remove_recursive(clnt->cl_debugfs); clnt->cl_debugfs = NULL; - return err; } void @@ -226,33 +230,33 @@ static const struct file_operations xprt_info_fops = { .release = xprt_info_release, }; -int +void rpc_xprt_debugfs_register(struct rpc_xprt *xprt) { int len, id; static atomic_t cur_id; char name[9]; /* 8 hex digits + NULL term */ + if (!rpc_xprt_dir) + return; + id = (unsigned int)atomic_inc_return(&cur_id); len = snprintf(name, sizeof(name), "%x", id); if (len >= sizeof(name)) - return -EINVAL; + return; /* make the per-client dir */ xprt->debugfs = debugfs_create_dir(name, rpc_xprt_dir); if (!xprt->debugfs) - return -ENOMEM; + return; /* make tasks file */ if (!debugfs_create_file("info", S_IFREG | S_IRUSR, xprt->debugfs, xprt, &xprt_info_fops)) { debugfs_remove_recursive(xprt->debugfs); xprt->debugfs = NULL; - return -ENOMEM; } - - return 0; } void @@ -266,14 +270,17 @@ void __exit sunrpc_debugfs_exit(void) { debugfs_remove_recursive(topdir); + topdir = NULL; + rpc_clnt_dir = NULL; + rpc_xprt_dir = NULL; } -int __init +void __init sunrpc_debugfs_init(void) { topdir = debugfs_create_dir("sunrpc", NULL); if (!topdir) - goto out; + return; rpc_clnt_dir = debugfs_create_dir("rpc_clnt", topdir); if (!rpc_clnt_dir) @@ -283,10 +290,9 @@ sunrpc_debugfs_init(void) if (!rpc_xprt_dir) goto out_remove; - return 0; + return; out_remove: debugfs_remove_recursive(topdir); topdir = NULL; -out: - return -ENOMEM; + rpc_clnt_dir = NULL; } -- cgit v1.2.3