open-style analog of vfs_path_lookup()

new function: file_open_root(dentry, mnt, name, flags) opens the file
vfs_path_lookup would arrive to.

Note that name can be empty; in that case the usual requirement that
dentry should be a directory is lifted.

open-coded equivalents switched to it, may_open() got down exactly
one caller and became static.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 19 deletions

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 975613b23dcf..c70e047eed72 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -124,35 +124,18 @@ void mconsole_log(struct mc_request *req)
 #if 0
 void mconsole_proc(struct mc_request *req)
 {
-        struct nameidata nd;
         struct vfsmount *mnt = current->nsproxy->pid_ns->proc_mnt;
         struct file *file;
-        int n, err;
+        int n;
         char *ptr = req->request.data, *buf;
         mm_segment_t old_fs = get_fs();
 
         ptr += strlen("proc");
         ptr = skip_spaces(ptr);
 
-        err = vfs_path_lookup(mnt->mnt_root, mnt, ptr, LOOKUP_FOLLOW, &nd);
-        if (err) {
-                mconsole_reply(req, "Failed to look up file", 1, 0);
-                goto out;
-        }
-
-        err = may_open(&nd.path, MAY_READ, O_RDONLY);
-        if (result) {
-                mconsole_reply(req, "Failed to open file", 1, 0);
-                path_put(&nd.path);
-                goto out;
-        }
-
-        file = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY,
-                           current_cred());
-        err = PTR_ERR(file);
+        file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY);
         if (IS_ERR(file)) {
                 mconsole_reply(req, "Failed to open file", 1, 0);
-                path_put(&nd.path);
                 goto out;
         }