ovl: verify index dir matches upper dir

[thirdparty/kernel/linux.git] / fs / overlayfs / overlayfs.h

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index caa36cb9c46de9838805dc40e21672217407d40e..58bbd135a7b3a64b3eb998f33973431da159a93a 100644 (file)
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -24,6 +24,11 @@ enum ovl_path_type {
 #define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
 #define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
 #define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
+#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
+
+enum ovl_flag {
+       OVL_IMPURE,
+};
 
 /*
  * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
@@ -37,6 +42,8 @@ enum ovl_path_type {
 /* CPU byte order required for fid decoding:  */
 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
+/* Is the real inode encoded in fid an upper inode? */
+#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
 
 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN)
 
@@ -55,12 +62,10 @@ struct ovl_fh {
        u8 len;         /* size of this header + size of fid */
        u8 flags;       /* OVL_FH_FLAG_* */
        u8 type;        /* fid_type of fid */
-       uuid_be uuid;   /* uuid of filesystem */
+       uuid_t uuid;    /* uuid of filesystem */
        u8 fid[0];      /* file identifier */
 } __packed;
 
-#define OVL_ISUPPER_MASK 1UL
-
 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
 {
        int err = vfs_rmdir(dir, dentry);
@@ -174,22 +179,14 @@ static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
        return ret;
 }
 
-static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper)
-{
-       unsigned long x = (unsigned long) READ_ONCE(inode->i_private);
-
-       if (is_upper)
-               *is_upper = x & OVL_ISUPPER_MASK;
-
-       return (struct inode *) (x & ~OVL_ISUPPER_MASK);
-}
-
 /* util.c */
 int ovl_want_write(struct dentry *dentry);
 void ovl_drop_write(struct dentry *dentry);
 struct dentry *ovl_workdir(struct dentry *dentry);
 const struct cred *ovl_override_creds(struct super_block *sb);
 struct super_block *ovl_same_sb(struct super_block *sb);
+bool ovl_can_decode_fh(struct super_block *sb);
+struct dentry *ovl_indexdir(struct super_block *sb);
 struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
 bool ovl_dentry_remote(struct dentry *dentry);
 bool ovl_dentry_weird(struct dentry *dentry);
@@ -200,27 +197,45 @@ enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
 struct dentry *ovl_dentry_upper(struct dentry *dentry);
 struct dentry *ovl_dentry_lower(struct dentry *dentry);
 struct dentry *ovl_dentry_real(struct dentry *dentry);
+struct inode *ovl_inode_upper(struct inode *inode);
+struct inode *ovl_inode_lower(struct inode *inode);
+struct inode *ovl_inode_real(struct inode *inode);
 struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
 bool ovl_dentry_is_opaque(struct dentry *dentry);
 bool ovl_dentry_is_whiteout(struct dentry *dentry);
 void ovl_dentry_set_opaque(struct dentry *dentry);
 bool ovl_redirect_dir(struct super_block *sb);
-void ovl_clear_redirect_dir(struct super_block *sb);
 const char *ovl_dentry_get_redirect(struct dentry *dentry);
 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
-void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
-void ovl_inode_init(struct inode *inode, struct inode *realinode,
-                   bool is_upper);
-void ovl_inode_update(struct inode *inode, struct inode *upperinode);
+void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
+                   struct dentry *lowerdentry);
+void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
 void ovl_dentry_version_inc(struct dentry *dentry);
 u64 ovl_dentry_version_get(struct dentry *dentry);
 bool ovl_is_whiteout(struct dentry *dentry);
 struct file *ovl_path_open(struct path *path, int flags);
 int ovl_copy_up_start(struct dentry *dentry);
 void ovl_copy_up_end(struct dentry *dentry);
+bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
+int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
+                      const char *name, const void *value, size_t size,
+                      int xerr);
+int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
+void ovl_set_flag(unsigned long flag, struct inode *inode);
+bool ovl_test_flag(unsigned long flag, struct inode *inode);
+bool ovl_inuse_trylock(struct dentry *dentry);
+void ovl_inuse_unlock(struct dentry *dentry);
+
+static inline bool ovl_is_impuredir(struct dentry *dentry)
+{
+       return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
+}
+
 
 /* namei.c */
+int ovl_verify_origin(struct dentry *dentry, struct vfsmount *mnt,
+                     struct dentry *origin, bool is_upper, bool set);
 int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags);
 bool ovl_lower_positive(struct dentry *dentry);
@@ -250,7 +265,7 @@ int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
 bool ovl_is_private_xattr(const char *name);
 
 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
-struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode);
+struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry);
 static inline void ovl_copyattr(struct inode *from, struct inode *to)
 {
        to->i_uid = from->i_uid;
@@ -263,7 +278,7 @@ static inline void ovl_copyattr(struct inode *from, struct inode *to)
 
 /* dir.c */
 extern const struct inode_operations ovl_dir_inode_operations;
-struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry);
+struct dentry *ovl_lookup_temp(struct dentry *workdir);
 struct cattr {
        dev_t rdev;
        umode_t mode;
@@ -279,3 +294,4 @@ int ovl_copy_up(struct dentry *dentry);
 int ovl_copy_up_flags(struct dentry *dentry, int flags);
 int ovl_copy_xattr(struct dentry *old, struct dentry *new);
 int ovl_set_attr(struct dentry *upper, struct kstat *stat);
+struct ovl_fh *ovl_encode_fh(struct dentry *lower, bool is_upper);