get rid of ->mnt_parent in tomoyo/realpath

[safe/jmp/linux-2.6] / security / tomoyo / realpath.c

diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 0b55faa..455bc39 100644 (file)
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -13,6 +13,8 @@
 #include <linux/mount.h>
 #include <linux/mnt_namespace.h>
 #include <linux/fs_struct.h>
+#include <linux/hash.h>
+
 #include "common.h"
 #include "realpath.h"
 
@@ -87,29 +89,14 @@ int tomoyo_realpath_from_path2(struct path *path, char *newname,
                sp = dentry->d_op->d_dname(dentry, newname + offset,
                                           newname_len - offset);
        } else {
-               /* Taken from d_namespace_path(). */
-               struct path root;
-               struct path ns_root = { };
-               struct path tmp;
-
-               read_lock(&current->fs->lock);
-               root = current->fs->root;
-               path_get(&root);
-               read_unlock(&current->fs->lock);
-               spin_lock(&vfsmount_lock);
-               if (root.mnt && root.mnt->mnt_ns)
-                       ns_root.mnt = mntget(root.mnt->mnt_ns->root);
-               if (ns_root.mnt)
-                       ns_root.dentry = dget(ns_root.mnt->mnt_root);
-               spin_unlock(&vfsmount_lock);
+               struct path ns_root = {.mnt = NULL, .dentry = NULL};
+
                spin_lock(&dcache_lock);
-               tmp = ns_root;
-               sp = __d_path(path, &tmp, newname, newname_len);
+               /* go to whatever namespace root we are under */
+               sp = __d_path(path, &ns_root, newname, newname_len);
                spin_unlock(&dcache_lock);
-               path_put(&root);
-               path_put(&ns_root);
                /* Prepend "/proc" prefix if using internal proc vfs mount. */
-               if (!IS_ERR(sp) && (path->mnt->mnt_parent == path->mnt) &&
+               if (!IS_ERR(sp) && (path->mnt->mnt_flags & MNT_INTERNAL) &&
                    (strcmp(path->mnt->mnt_sb->s_type->name, "proc") == 0)) {
                        sp -= 5;
                        if (sp >= newname)
@@ -272,7 +259,8 @@ static unsigned int tomoyo_quota_for_savename;
  * table. Frequency of appending strings is very low. So we don't need
  * large (e.g. 64k) hash size. 256 will be sufficient.
  */
-#define TOMOYO_MAX_HASH 256
+#define TOMOYO_HASH_BITS  8
+#define TOMOYO_MAX_HASH (1u<<TOMOYO_HASH_BITS)
 
 /*
  * tomoyo_name_entry is a structure which is used for linking
@@ -324,6 +312,7 @@ const struct tomoyo_path_info *tomoyo_save_name(const char *name)
        struct tomoyo_free_memory_block_list *fmb;
        int len;
        char *cp;
+       struct list_head *head;
 
        if (!name)
                return NULL;
@@ -334,9 +323,10 @@ const struct tomoyo_path_info *tomoyo_save_name(const char *name)
                return NULL;
        }
        hash = full_name_hash((const unsigned char *) name, len - 1);
+       head = &tomoyo_name_list[hash_long(hash, TOMOYO_HASH_BITS)];
+
        mutex_lock(&lock);
-       list_for_each_entry(ptr, &tomoyo_name_list[hash % TOMOYO_MAX_HASH],
-                            list) {
+       list_for_each_entry(ptr, head, list) {
                if (hash == ptr->entry.hash && !strcmp(name, ptr->entry.name))
                        goto out;
        }
@@ -374,7 +364,7 @@ const struct tomoyo_path_info *tomoyo_save_name(const char *name)
        tomoyo_fill_path_info(&ptr->entry);
        fmb->ptr += len;
        fmb->len -= len;
-       list_add_tail(&ptr->list, &tomoyo_name_list[hash % TOMOYO_MAX_HASH]);
+       list_add_tail(&ptr->list, head);
        if (fmb->len == 0) {
                list_del(&fmb->list);
                kfree(fmb);