feat: add support for dfs remount functionality

2025-01-06T11:34:16Z

This patch introduces a remount feature for the DFS, allowing for the modification of mount parameters without unmounting the filesystem, the remount functionality helps modify certain mount flags (like `MS_RDONLY`) without requiring an unmount, providing more control over mounted filesystems in the system. The updates is essential for user space init proc to cleanup the runtime resource, ensuring clean handling of cached data and enhancing system robustness during power down processing. Changes: - Defined new constants for remount flags in `dfs_fs.h`. - Added the `dfs_remount()` function in `dfs_fs.c` to handle remount operations. - Introduced a check for unsupported flags and handle error conditions such as invalid paths or non-directory targets. - Updated the `dfs_mnt` structure in `dfs_mnt.h` to include a read-only flag (`MNT_RDONLY`). - The `dfs_remount()` function allows changing the read-only status of a mounted filesystem. - Added `MNT_LAZY_UMNT` and `MNT_RDONLY` flags to `dfs_mnt` structure. - Introduced `dfs_mnt_setflags` function for dynamic flag management. - Updated `dfs_remount` to utilize `dfs_mnt_setflags` for flag setting. - Enhanced unmount operations with `dfs_mnt_umount_iter` and lazy unmounting. - Added `dfs_pcache_clean` to handle cache cleanup for read-only mounts. - Improved error reporting in `dfs_umount` for better user feedback. - Refactored `sys_mount` to streamline parameter handling and support remounts. - Introduced `_cp_from_usr_string` helper for user-space string operations. - Updated internal APIs to ensure consistency in reference count management. Signed-off-by: Shell

sync smart & dfs (#8672)

2024-03-28T15:42:56Z

Signed-off-by: xqyjlj Signed-off-by: Shell Co-authored-by: xqyjlj

add sys_utimensat (#8124)

2023-10-13T11:21:49Z

update dfs (#7887)

2023-08-02T05:59:43Z

[dfs] Add DFS v2.0 (#7606)

2023-06-10T13:35:25Z

[DFS] prepare for dfs_v2.0 (#7200)

2023-04-08T14:25:51Z

* [DFS] prepare for dfs_v2. dfs_fd -> dfs_file; dfs_fnode -> dfs_vnode. * [BSP] fix code analysis warning * [smart] fix the pointer overflow. * code format * [smart] fix the lwp->lwp_obj checking.

[DFS] add Kconfig for dfs-v2.0 (#7156)

2023-04-04T07:02:56Z

* [DFS] add Kconfig for dfs-v2.0 * [DFS] Optimize the SConscript. * [dfs] move old dfs to dfs/dfs_v1