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Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c43
1 files changed, 37 insertions, 6 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 32351c045bae..d049d3972695 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2598,8 +2598,9 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
}
EXPORT_SYMBOL(vfs_path_lookup);
-static int lookup_one_len_common(const char *name, struct dentry *base,
- int len, struct qstr *this)
+static int lookup_one_common(struct user_namespace *mnt_userns,
+ const char *name, struct dentry *base, int len,
+ struct qstr *this)
{
this->name = name;
this->len = len;
@@ -2627,7 +2628,7 @@ static int lookup_one_len_common(const char *name, struct dentry *base,
return err;
}
- return inode_permission(&init_user_ns, base->d_inode, MAY_EXEC);
+ return inode_permission(mnt_userns, base->d_inode, MAY_EXEC);
}
/**
@@ -2651,7 +2652,7 @@ struct dentry *try_lookup_one_len(const char *name, struct dentry *base, int len
WARN_ON_ONCE(!inode_is_locked(base->d_inode));
- err = lookup_one_len_common(name, base, len, &this);
+ err = lookup_one_common(&init_user_ns, name, base, len, &this);
if (err)
return ERR_PTR(err);
@@ -2678,7 +2679,7 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
WARN_ON_ONCE(!inode_is_locked(base->d_inode));
- err = lookup_one_len_common(name, base, len, &this);
+ err = lookup_one_common(&init_user_ns, name, base, len, &this);
if (err)
return ERR_PTR(err);
@@ -2688,6 +2689,36 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
EXPORT_SYMBOL(lookup_one_len);
/**
+ * lookup_one - filesystem helper to lookup single pathname component
+ * @mnt_userns: user namespace of the mount the lookup is performed from
+ * @name: pathname component to lookup
+ * @base: base directory to lookup from
+ * @len: maximum length @len should be interpreted to
+ *
+ * Note that this routine is purely a helper for filesystem usage and should
+ * not be called by generic code.
+ *
+ * The caller must hold base->i_mutex.
+ */
+struct dentry *lookup_one(struct user_namespace *mnt_userns, const char *name,
+ struct dentry *base, int len)
+{
+ struct dentry *dentry;
+ struct qstr this;
+ int err;
+
+ WARN_ON_ONCE(!inode_is_locked(base->d_inode));
+
+ err = lookup_one_common(mnt_userns, name, base, len, &this);
+ if (err)
+ return ERR_PTR(err);
+
+ dentry = lookup_dcache(&this, base, 0);
+ return dentry ? dentry : __lookup_slow(&this, base, 0);
+}
+EXPORT_SYMBOL(lookup_one);
+
+/**
* lookup_one_len_unlocked - filesystem helper to lookup single pathname component
* @name: pathname component to lookup
* @base: base directory to lookup from
@@ -2706,7 +2737,7 @@ struct dentry *lookup_one_len_unlocked(const char *name,
int err;
struct dentry *ret;
- err = lookup_one_len_common(name, base, len, &this);
+ err = lookup_one_common(&init_user_ns, name, base, len, &this);
if (err)
return ERR_PTR(err);