vfs: Add helper to check for missing VFS functions

Some VFS modules want to ensure that they implement all VFS functions.
This helper can be used to detect missing functions in the developer
build.

Signed-off-by: Christof Schmitt <cs@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/source3/include/vfs.h b/source3/include/vfs.h
index 6ab9a7e36b2bb39b9c14be4a4ffca47352f054c9..9360802a535cd221615b2eb2b3a4f9c2cd8f3a6e 100644 (file)
--- a/source3/include/vfs.h
+++ b/source3/include/vfs.h
@@ -1381,4 +1381,7 @@ void vfs_remove_all_fsp_extensions(struct files_struct *fsp);
 void *vfs_memctx_fsp_extension(vfs_handle_struct *handle, files_struct *fsp);
 void *vfs_fetch_fsp_extension(vfs_handle_struct *handle, files_struct *fsp);
 
+void smb_vfs_assert_all_fns(const struct vfs_fn_pointers* fns,
+                           const char *module);
+
 #endif /* _VFS_H */

diff --git a/source3/smbd/vfs.c b/source3/smbd/vfs.c
index efed2683a6ab992e01212017a0361cc91a2809af..605f9ade70381f248c93e4a6eafe6f46728710f0 100644 (file)
--- a/source3/smbd/vfs.c
+++ b/source3/smbd/vfs.c
@@ -316,6 +316,36 @@ void *vfs_fetch_fsp_extension(vfs_handle_struct *handle, files_struct *fsp)
 
 #undef EXT_DATA_AREA
 
+/*
+ * Ensure this module catches all VFS functions.
+ */
+#ifdef DEVELOPER
+void smb_vfs_assert_all_fns(const struct vfs_fn_pointers* fns,
+                           const char *module)
+{
+       bool missing_fn = false;
+       unsigned int idx;
+       const uintptr_t *end = (const uintptr_t *)(fns + 1);
+
+       for (idx = 0; ((const uintptr_t *)fns + idx) < end; idx++) {
+               if (*((const uintptr_t *)fns + idx) == 0) {
+                       DBG_ERR("VFS function at index %d not implemented "
+                               "in module %s\n", idx, module);
+                       missing_fn = true;
+               }
+       }
+
+       if (missing_fn) {
+               smb_panic("Required VFS function not implemented in module.\n");
+       }
+}
+#else
+void smb_vfs_assert_all_fns(const struct vfs_fn_pointers* fns,
+                           const char *module)
+{
+}
+#endif
+
 /*****************************************************************
  Generic VFS init.
 ******************************************************************/