(nuttx) branch master updated: fs/vfs: add CONFIG_DISABLE_DIRECTORY_OPERATIONS

[ac...@apache.org]

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acassis pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 31ab2d6eeb3 fs/vfs: add CONFIG_DISABLE_DIRECTORY_OPERATIONS
31ab2d6eeb3 is described below

commit 31ab2d6eeb3673095eeeacaf4e5bda7824d5bdbc
Author: jingfei <ji...@xiaomi.com>
AuthorDate: Wed Oct 21 15:05:20 2026 +0800

    fs/vfs: add CONFIG_DISABLE_DIRECTORY_OPERATIONS
    
    Many small systems never list a directory, yet every image carries the
    directory file layer in fs/vfs/fs_dir.c: the pseudo and mountpoint
    readdir and seek paths, the stand-in inode and its file operations.
    
    Add DISABLE_DIRECTORY_OPERATIONS, default DEFAULT_SMALL. When set,
    fs_dir.c is not built and dir_allocate() returns -ENOSYS, so opendir()
    and open() with O_DIRECTORY fail with ENOSYS. dir_fstat() returns
    -ENOTTY, so fstat() keeps using the normal inode path.
    
    stm32f103-minimum:nsh: flash -996 bytes.
    Signed-off-by: jingfei <ji...@xiaomi.com>
---
 fs/Kconfig            |  9 +++++++++
 fs/inode/inode.h      | 16 ++++++++++++++++
 fs/vfs/CMakeLists.txt |  5 ++++-
 fs/vfs/Make.defs      |  6 +++++-
 4 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/fs/Kconfig b/fs/Kconfig
index 2ad6dbf4259..bcc9c29556b 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -86,6 +86,15 @@ config DISABLE_PSEUDOFS_OPERATIONS
 		However, in practical embedded system, they are seldom needed and
 		you can save a little FLASH space by disabling the capability.
 
+config DISABLE_DIRECTORY_OPERATIONS
+	bool "Disable directory operations"
+	default DEFAULT_SMALL
+	---help---
+		Disable opening directories: opendir() and open() with O_DIRECTORY
+		fail with ENOSYS, so readdir(), seekdir() and friends are not
+		available either.  Useful for small systems that never list a
+		directory; the directory file layer is not built at all.
+
 config PSEUDOFS_ATTRIBUTES
 	bool "Pseudo-filesystem attributes"
 	default n
diff --git a/fs/inode/inode.h b/fs/inode/inode.h
index beb3438e830..acc59284f26 100644
--- a/fs/inode/inode.h
+++ b/fs/inode/inode.h
@@ -33,6 +33,7 @@
 #include <sys/types.h>
 #include <stdint.h>
 #include <stdbool.h>
+#include <errno.h>
 #include <dirent.h>
 #include <sched.h>
 
@@ -522,7 +523,15 @@ int foreach_inode(foreach_inode_t handler, FAR void *arg);
  *
  ****************************************************************************/
 
+#ifdef CONFIG_DISABLE_DIRECTORY_OPERATIONS
+static inline int dir_allocate(FAR struct file *filep,
+                               FAR const char *relpath)
+{
+  return -ENOSYS;
+}
+#else
 int dir_allocate(FAR struct file *filep, FAR const char *relpath);
+#endif
 
 /****************************************************************************
  * Name: dir_fstat
@@ -533,7 +542,14 @@ int dir_allocate(FAR struct file *filep, FAR const char *relpath);
  *
  ****************************************************************************/
 
+#ifdef CONFIG_DISABLE_DIRECTORY_OPERATIONS
+static inline int dir_fstat(FAR struct file *filep, FAR struct stat *buf)
+{
+  return -ENOTTY;
+}
+#else
 int dir_fstat(FAR struct file *filep, FAR struct stat *buf);
+#endif
 
 /****************************************************************************
  * Name: pseudofile_create
diff --git a/fs/vfs/CMakeLists.txt b/fs/vfs/CMakeLists.txt
index 85a99add6ba..9d1d2127c2a 100644
--- a/fs/vfs/CMakeLists.txt
+++ b/fs/vfs/CMakeLists.txt
@@ -48,12 +48,15 @@ set(SRCS
     fs_uio.c
     fs_unlink.c
     fs_write.c
-    fs_dir.c
     fs_fsync.c
     fs_syncfs.c
     fs_truncate.c
     fs_link.c)
 
+if(NOT CONFIG_DISABLE_DIRECTORY_OPERATIONS)
+  list(APPEND SRCS fs_dir.c)
+endif()
+
 if(CONFIG_FS_CHROOT)
   list(APPEND SRCS fs_chroot.c)
 endif()
diff --git a/fs/vfs/Make.defs b/fs/vfs/Make.defs
index 172d779fc95..0b2b02bfcf5 100644
--- a/fs/vfs/Make.defs
+++ b/fs/vfs/Make.defs
@@ -26,9 +26,13 @@ CSRCS += fs_chstat.c fs_close.c fs_dup.c fs_dup2.c fs_dup3.c fs_fcntl.c
 CSRCS += fs_epoll.c fs_fchstat.c fs_fstat.c fs_fstatfs.c fs_ioctl.c fs_lseek.c
 CSRCS += fs_mkdir.c fs_open.c fs_poll.c fs_pread.c fs_pwrite.c fs_read.c
 CSRCS += fs_rename.c fs_rmdir.c fs_select.c fs_sendfile.c fs_stat.c
-CSRCS += fs_statfs.c fs_uio.c fs_unlink.c fs_write.c fs_dir.c fs_fsync.c
+CSRCS += fs_statfs.c fs_uio.c fs_unlink.c fs_write.c fs_fsync.c
 CSRCS += fs_syncfs.c fs_truncate.c fs_link.c
 
+ifneq ($(CONFIG_DISABLE_DIRECTORY_OPERATIONS),y)
+CSRCS += fs_dir.c
+endif
+
 ifeq ($(CONFIG_FS_CHROOT),y)
 CSRCS += fs_chroot.c
 endif