[PATCH v2 2/6] fs: add rename infrastructure

[Ilias Apalodimas]

Hi Gabriel,

On Mon, 17 Feb 2025 at 20:31, Gabriel Dalimonte
<gabriel.dalimonte at gmail.com> wrote:
>
> The selection for *rename as the name for the rename/move operation
> derives from the POSIX specification where they name the function
> rename/renameat. [1] This aligns with Linux where the syscalls for
> renaming/moving also use the rename/renameat naming.
>
> [1] https://pubs.opengroup.org/onlinepubs/9799919799/functions/rename.html
>
> Signed-off-by: Gabriel Dalimonte <gabriel.dalimonte at gmail.com>
>
> ---
>
> Changes in v2:
>  - cleanup log message and verbosity in fs_rename()
>  - update fs_close() docstring with reference to fs_rename()
>  - clarify fs_rename() behaviour in docstring
>
>
> ---
>  fs/fs.c      | 32 ++++++++++++++++++++++++++++++++
>  include/fs.h | 14 +++++++++++++-
>  2 files changed, 45 insertions(+), 1 deletion(-)
>
> diff --git a/fs/fs.c b/fs/fs.c
> index 99ddcc5e37b..fdff83719b1 100644
> --- a/fs/fs.c
> +++ b/fs/fs.c
> @@ -143,6 +143,12 @@ static inline int fs_mkdir_unsupported(const char *dirname)
>         return -1;
>  }
>
> +static inline int fs_rename_unsupported(const char *old_path,
> +                                       const char *new_path)
> +{
> +       return -1;
> +}
> +
>  struct fstype_info {
>         int fstype;
>         char *name;
> @@ -183,6 +189,7 @@ struct fstype_info {
>         int (*unlink)(const char *filename);
>         int (*mkdir)(const char *dirname);
>         int (*ln)(const char *filename, const char *target);
> +       int (*rename)(const char *old_path, const char *new_path);
>  };
>
>  static struct fstype_info fstypes[] = {
> @@ -206,6 +213,7 @@ static struct fstype_info fstypes[] = {
>                 .unlink = fs_unlink_unsupported,
>                 .mkdir = fs_mkdir_unsupported,
>  #endif
> +               .rename = fs_rename_unsupported,
>                 .uuid = fat_uuid,
>                 .opendir = fat_opendir,
>                 .readdir = fat_readdir,
> @@ -238,6 +246,7 @@ static struct fstype_info fstypes[] = {
>                 .closedir = ext4fs_closedir,
>                 .unlink = fs_unlink_unsupported,
>                 .mkdir = fs_mkdir_unsupported,
> +               .rename = fs_rename_unsupported,
>         },
>  #endif
>  #if IS_ENABLED(CONFIG_SANDBOX) && !IS_ENABLED(CONFIG_XPL_BUILD)
> @@ -257,6 +266,7 @@ static struct fstype_info fstypes[] = {
>                 .unlink = fs_unlink_unsupported,
>                 .mkdir = fs_mkdir_unsupported,
>                 .ln = fs_ln_unsupported,
> +               .rename = fs_rename_unsupported,
>         },
>  #endif
>  #if CONFIG_IS_ENABLED(SEMIHOSTING)
> @@ -276,6 +286,7 @@ static struct fstype_info fstypes[] = {
>                 .unlink = fs_unlink_unsupported,
>                 .mkdir = fs_mkdir_unsupported,
>                 .ln = fs_ln_unsupported,
> +               .rename = fs_rename_unsupported,
>         },
>  #endif
>  #ifndef CONFIG_XPL_BUILD
> @@ -296,6 +307,7 @@ static struct fstype_info fstypes[] = {
>                 .unlink = fs_unlink_unsupported,
>                 .mkdir = fs_mkdir_unsupported,
>                 .ln = fs_ln_unsupported,
> +               .rename = fs_rename_unsupported,
>         },
>  #endif
>  #endif
> @@ -317,6 +329,7 @@ static struct fstype_info fstypes[] = {
>                 .unlink = fs_unlink_unsupported,
>                 .mkdir = fs_mkdir_unsupported,
>                 .ln = fs_ln_unsupported,
> +               .rename = fs_rename_unsupported,
>         },
>  #endif
>  #endif
> @@ -339,6 +352,7 @@ static struct fstype_info fstypes[] = {
>                 .ln = fs_ln_unsupported,
>                 .unlink = fs_unlink_unsupported,
>                 .mkdir = fs_mkdir_unsupported,
> +               .rename = fs_rename_unsupported,
>         },
>  #endif
>  #if IS_ENABLED(CONFIG_FS_EROFS)
> @@ -360,6 +374,7 @@ static struct fstype_info fstypes[] = {
>                 .ln = fs_ln_unsupported,
>                 .unlink = fs_unlink_unsupported,
>                 .mkdir = fs_mkdir_unsupported,
> +               .rename = fs_rename_unsupported,
>         },
>  #endif
>         {
> @@ -378,6 +393,7 @@ static struct fstype_info fstypes[] = {
>                 .unlink = fs_unlink_unsupported,
>                 .mkdir = fs_mkdir_unsupported,
>                 .ln = fs_ln_unsupported,
> +               .rename = fs_rename_unsupported,
>         },
>  };
>
> @@ -713,6 +729,22 @@ int fs_ln(const char *fname, const char *target)
>         return ret;
>  }
>
> +int fs_rename(const char *old_path, const char *new_path)
> +{
> +       struct fstype_info *info = fs_get_info(fs_type);
> +       int ret;
> +
> +       ret = info->rename(old_path, new_path);
> +
> +       if (ret < 0) {
> +               log_debug("Unable to rename %s -> %s\n", old_path, new_path);
> +               ret = -1;
> +       }
> +       fs_close();
> +
> +       return ret;
> +}
> +
>  int do_size(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[],
>             int fstype)
>  {
> diff --git a/include/fs.h b/include/fs.h
> index 2474880385d..5b272eb9f5e 100644
> --- a/include/fs.h
> +++ b/include/fs.h
> @@ -86,7 +86,7 @@ int fs_set_blk_dev_with_part(struct blk_desc *desc, int part);
>   *
>   * Many file functions implicitly call fs_close(), e.g. fs_closedir(),
>   * fs_exist(), fs_ln(), fs_ls(), fs_mkdir(), fs_read(), fs_size(), fs_write(),
> - * fs_unlink().
> + * fs_unlink(), fs_rename().
>   */
>  void fs_close(void);
>
> @@ -270,6 +270,18 @@ int fs_unlink(const char *filename);
>   */
>  int fs_mkdir(const char *filename);
>
> +/**
> + * fs_rename - rename/move a file or directory
> + *
> + * @old_path: existing path of the file/directory to rename
> + * @new_path: new path of the file/directory. If this points to an existing
> + * file or empty directory, the existing file/directory will be unlinked.
> + * If this points to a non-empty directory, the rename will fail.
> + *
> + * Return: 0 on success, -1 on error conditions
> + */
> +int fs_rename(const char *old_path, const char *new_path);
> +
>  /*
>   * Common implementation for various filesystem commands, optionally limited
>   * to a specific filesystem type via the fstype parameter.
> --
> 2.34.1
>

I am by no means an expert on our FS support but this looks reasonable
Acked-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>