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, 1 insertions, 18 deletions

diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index b875bedf7c9a..3b8e028b9601 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -1321,13 +1321,11 @@ static ssize_t binary_sysctl(const int *name, int nlen,
         void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
         const struct bin_table *table = NULL;
-        struct nameidata nd;
         struct vfsmount *mnt;
         struct file *file;
         ssize_t result;
         char *pathname;
         int flags;
-        int acc_mode;
 
         pathname = sysctl_getname(name, nlen, &table);
         result = PTR_ERR(pathname);
@@ -1337,28 +1335,17 @@ static ssize_t binary_sysctl(const int *name, int nlen,
         /* How should the sysctl be accessed? */
         if (oldval && oldlen && newval && newlen) {
                 flags = O_RDWR;
-                acc_mode = MAY_READ | MAY_WRITE;
         } else if (newval && newlen) {
                 flags = O_WRONLY;
-                acc_mode = MAY_WRITE;
         } else if (oldval && oldlen) {
                 flags = O_RDONLY;
-                acc_mode = MAY_READ;
         } else {
                 result = 0;
                 goto out_putname;
         }
 
         mnt = current->nsproxy->pid_ns->proc_mnt;
-        result = vfs_path_lookup(mnt->mnt_root, mnt, pathname, 0, &nd);
-        if (result)
-                goto out_putname;
-
-        result = may_open(&nd.path, acc_mode, flags);
-        if (result)
-                goto out_putpath;
-
-        file = dentry_open(nd.path.dentry, nd.path.mnt, flags, current_cred());
+        file = file_open_root(mnt->mnt_root, mnt, pathname, flags);
         result = PTR_ERR(file);
         if (IS_ERR(file))
                 goto out_putname;
@@ -1370,10 +1357,6 @@ out_putname:
         putname(pathname);
 out:
         return result;
-
-out_putpath:
-        path_put(&nd.path);
-        goto out_putname;
 }