[U-Boot] [PATCH v3 0/6] Add support for symlink creation in EXT4

[Jean-Jacques Hiblot]

This series adds support for the creation of symbolic links on ext4
file-systems.
The motivation behind this work is to have the ability to "do" the job
of update-alternatives in u-boot.
Firmware on TI's platform are usually managed with update-alternatives and
are thus targeted by a symbolic link. In some situations we need the
ability to select an alternate firmware before the linux kernel is started
so that when a early driver needing the firmware comes up, it can be fed
the firmware of our choice.

Tested on a am57xx_evm, using a EXT4 partition on external SDcard.
The filesystem can be checked later with: fsck.ext4 -f <dev>

usage example:
=> ln mmc 0:2 zImage /boot/the_linux_kernel

Changes in v3:
- reworded commit log
- removed FS integrity test (fsck) in python tests

Changes in v2:
- Prevent write access if metadata checksum is enabled
- Fix issue in ext4fs_delete_file() when target in not stored in an
  allocated block
- Added python tests for symlinks under sandbox

Jean-Jacques Hiblot (6):
  fs: ext4: do not allow writes if metadata checksum is active
  test: fs: disable the metadata checksums on ext4 filesystems
  fs: ext4: constify the buffer passed to write functions
  fs: ext4: Add support for the creation of symbolic links
  fs: Add a new command to create symbolic links
  test: fs: Added tests for symlinks

 cmd/fs.c                              |  14 +++
 fs/ext4/ext4_common.c                 |   4 +-
 fs/ext4/ext4_common.h                 |   2 +-
 fs/ext4/ext4_write.c                  |  76 ++++++++++++----
 fs/fs.c                               |  44 +++++++++
 include/ext4fs.h                      |   6 +-
 include/fs.h                          |   2 +
 test/py/tests/test_fs/conftest.py     |  77 ++++++++++++++++
 test/py/tests/test_fs/fstest_defs.py  |   3 +
 test/py/tests/test_fs/test_symlink.py | 125 ++++++++++++++++++++++++++
 10 files changed, 331 insertions(+), 22 deletions(-)
 create mode 100644 test/py/tests/test_fs/test_symlink.py

-- 
2.17.1