Reimplement fuse backend

The magic inode numbers we used before are problematic.

The inode nrs are tied to the file names, so inode changes on rename, which breaks posix expectations.

Also, it relied on 64bit inode space which is not true on i386.

So, this is a new implementation that uses a more traditional approach
of dynamically allocating inodes as needed.

document-portal/xdp-fuse.h

@@ -7,18 +7,16 @@
 G_BEGIN_DECLS
 
 char **        xdp_list_apps  (void);
-guint32 *      xdp_list_docs  (void);
-XdgAppDbEntry *xdp_lookup_doc (guint32 id);
+char **        xdp_list_docs  (void);
+XdgAppDbEntry *xdp_lookup_doc (const char *doc_id);
 
 gboolean    xdp_fuse_init               (GError     **error);
 void        xdp_fuse_exit               (void);
 const char *xdp_fuse_get_mountpoint     (void);
 void        xdp_fuse_invalidate_doc_app (const char  *doc_id,
-                                         const char  *app_id,
+                                         const char  *opt_app_id,
                                          XdgAppDbEntry *entry);
-void        xdp_fuse_invalidate_doc     (const char  *doc_id,
-                                         XdgAppDbEntry *entry);
-guint32     xdp_fuse_lookup_id_for_inode (ino_t inode);
+char      *xdp_fuse_lookup_id_for_inode (ino_t inode);
 
 
 G_END_DECLS

document-portal/xdp-main.c

@@ -51,37 +51,16 @@ xdp_list_apps (void)
   return xdg_app_db_list_apps (db);
 }
 
-guint32 *
+char **
 xdp_list_docs (void)
 {
-  GArray *res;
-  g_auto(GStrv) ids = NULL;
-  guint32 id;
-  int i;
-
   AUTOLOCK(db);
-
-  res = g_array_new (TRUE, FALSE, sizeof (guint32));
-
-  ids = xdg_app_db_list_ids (db);
-
-  for (i = 0; ids[i] != NULL; i++)
-    {
-      guint32 id = xdp_id_from_name (ids[i]);
-      g_array_append_val (res, id);
-    }
-
-  id = 0;
-  g_array_append_val (res, id);
-
-  return (guint32 *)g_array_free (res, FALSE);
+  return xdg_app_db_list_ids (db);
 }
 
 XdgAppDbEntry *
-xdp_lookup_doc (guint32 id)
+xdp_lookup_doc (const char *doc_id)
 {
-  g_autofree char *doc_id = xdp_name_from_id (id);
-
   AUTOLOCK(db);
   return xdg_app_db_lookup (db, doc_id);
 }
@@ -252,7 +231,7 @@ portal_delete (GDBusMethodInvocation *invocation,
   old_apps = xdg_app_db_entry_list_apps (entry);
   for (i = 0; old_apps[i] != NULL; i++)
     xdp_fuse_invalidate_doc_app (id, old_apps[i], entry);
-  xdp_fuse_invalidate_doc (id, entry);
+  xdp_fuse_invalidate_doc_app (id, NULL, entry);
 
   if (persist_entry (entry))
     xdg_app_permission_store_call_delete (permission_store, TABLE_NAME,
@@ -305,7 +284,7 @@ do_create_doc (struct stat *parent_st_buf, const char *path, gboolean reuse_exis
   entry = xdg_app_db_entry_new (data);
   xdg_app_db_set_entry (db, id, entry);
 
-  xdp_fuse_invalidate_doc (id, entry);
+  xdp_fuse_invalidate_doc_app (id, NULL, entry);
 
   if (persistent)
     xdg_app_permission_store_call_set (permission_store,
@@ -402,12 +381,11 @@ portal_add (GDBusMethodInvocation *invocation,
   if (st_buf.st_dev == fuse_dev)
     {
       /* The passed in fd is on the fuse filesystem itself */
-      guint32 old_id;
       g_autoptr(XdgAppDbEntry) old_entry = NULL;
 
-      old_id = xdp_fuse_lookup_id_for_inode (st_buf.st_ino);
-      g_debug ("path on fuse, id %x\n", old_id);
-      if (old_id == 0)
+      id = xdp_fuse_lookup_id_for_inode (st_buf.st_ino);
+      g_debug ("path on fuse, id %s\n", id);
+      if (id == NULL)
         {
           g_dbus_method_invocation_return_error (invocation,
                                                  XDG_APP_PORTAL_ERROR, XDG_APP_PORTAL_ERROR_INVALID_ARGUMENT,
@@ -415,8 +393,6 @@ portal_add (GDBusMethodInvocation *invocation,
           return;
         }
 
-      id = xdp_name_from_id (old_id);
-
       /* If the entry doesn't exist anymore, fail.  Also fail if not
          resuse_existing, because otherwise the user could use this to
          get a copy with permissions and thus escape later permission

document-portal/xdp-util.c

@@ -74,12 +74,6 @@ xdp_entry_has_permissions (XdgAppDbEntry *entry,
   return (current_perms & perms) == perms;
 }
 
-guint32
-xdp_id_from_name (const char *name)
-{
-  return g_ascii_strtoull (name, NULL, 16);
-}
-
 char *
 xdp_name_from_id (guint32 doc_id)
 {
@@ -133,50 +127,3 @@ xdp_entry_get_flags (XdgAppDbEntry *entry)
   g_autoptr(GVariant) c = g_variant_get_child_value (v, 3);
   return g_variant_get_uint32 (c);
 }
-
-int
-xdp_entry_open_dir (XdgAppDbEntry *entry)
-{
-  g_autofree char *dirname = xdp_entry_dup_dirname (entry);
-  struct stat st_buf;
-  int fd;
-
-  fd = open (dirname, O_CLOEXEC | O_PATH | O_DIRECTORY);
-  if (fd == -1)
-    return -1;
-
-  if (fstat (fd, &st_buf) < 0)
-    {
-      close (fd);
-      errno = ENOENT;
-      return -1;
-    }
-
-  if (st_buf.st_ino != xdp_entry_get_inode (entry) ||
-      st_buf.st_dev != xdp_entry_get_device (entry))
-    {
-      close (fd);
-      errno = ENOENT;
-      return -1;
-    }
-
-  return fd;
-}
-
-int
-xdp_entry_stat (XdgAppDbEntry *entry,
-                struct stat *buf,
-                int flags)
-{
-  glnx_fd_close int fd = -1;
-  g_autofree char *basename = xdp_entry_dup_basename (entry);
-
-  fd = xdp_entry_open_dir (entry);
-  if (fd < 0)
-    return -1;
-
-  if (fstatat (fd, basename, buf, flags) != 0)
-    return -1;
-
-  return 0;
-}

document-portal/xdp-util.h

@@ -24,12 +24,7 @@ char *             xdp_entry_dup_dirname     (XdgAppDbEntry      *entry);
 guint64            xdp_entry_get_device      (XdgAppDbEntry      *entry);
 guint64            xdp_entry_get_inode       (XdgAppDbEntry      *entry);
 guint32            xdp_entry_get_flags       (XdgAppDbEntry      *entry);
-int                xdp_entry_open_dir        (XdgAppDbEntry      *entry);
-int                xdp_entry_stat            (XdgAppDbEntry      *entry,
-                                              struct stat        *buf,
-                                              int                 flags);
 
-guint32 xdp_id_from_name (const char *name);
 char *  xdp_name_from_id (guint32     doc_id);