mbox series

[Concept,v2,00/30] ext4l: Add write support (part L)

Message ID 20260102005112.552256-1-sjg@u-boot.org
Headers
Series ext4l: Add write support (part L) |

Message

Simon Glass Jan. 2, 2026, 12:50 a.m. UTC 
  From: Simon Glass <simon.glass@canonical.com>

This series adds write support to the new ext4l filesystem driver,
supporting file creation, modification, and deletion.

The main additions are:
- File write with journalling support
- File deletion (unlink)
- Directory creation (mkdir)
- Symbolic link creation (ln)
- File and directory rename

Infrastructure improvements include proper cleanup of journal references
when unmounting, safeguards to handle probe without explicit close, and
prevention of use-after-free issues with buffer_heads that have active
journal_heads.

Unlike Linux, which does not need to meticulously free every resource on
unmount (since it can do so later as needed), U-Boot must fully clean up.
The bootloader may mount and unmount filesystems multiple times during a
session, such as loading a kernel from one partition and a device tree
from another, or when running tests. Memory leaks accumulate and cause
failures, so ext4l includes extra cleanup code that the Linux ext4 driver
does not require.

The series also enables ext4l for sandbox testing and allows the use of
metadata_csum checksums which the existing ext4 driver does not support.

Some other tweaks are included:
- a fix for mcheck to avoid filling up pre-relocation malloc()
- use the correct logo for readthedocs
- add a flag to avoid using the video console in tests
- a fallback option for finding persistent data-dir

At this point ext4l is useable, but there is more work needed,
including:

- Add MAINTAINERS entry
- Add more Kconfig options for various features (to reduce code size)
- Enable for ARM and x86 targets
- Documentation
- Tests for failure cases (to check that the journal is doing its job)

(no changes since v1)

Simon Glass (30):
  Update claude file to use uman instead of crosfw
  sandbox: os: Check executable directory for persistent files
  sandbox: Add --quiet_vidconsole option to speed up output
  video: Avoid uclass allocation in video_idle() cyclic
  video: Unregister cyclic on the last video-device removal
  video: Correct the U-Boot logo
  blkmap: Handle read-only slices in write path
  mcheck: Add Kconfig option for caller string length
  mcheck: Skip mcheck overhead for pre-relocation allocations
  Revert "lib: Add CONFIG_LIB_KMEM_CACHE for full kmem_cache support"
  ext4l: doc: Document ext4l_msgs environment variable
  ext4l: Move message buffer functions to support.c
  ext4l: Add inode-tracking lists
  ext4l: Fix a few problems with handling bh_cache
  ext4l: Clean up fully when unmounting
  ext4l: Remove duplicate atomic_add declarations
  ext4l: Use the real crc16 implementation
  ext4l: Add a few Kconfig dependencies
  ext4l: Add bh_cache_release_jbd() to clean up journal references
  ext4l: Add safeguard to close previous mount in probe
  ext4l: Prevent freeing buffer_heads with active journal_heads
  ext4l: Add support for read-only devices
  ext4l: Add write support
  ext4l: Add unlink support for file deletion
  ext4l: Add mkdir support for directory creation
  ext4l: Add symlink support
  ext4l: Update symlink to replace existing files
  ext4l: Add rename support
  test: fs_helper: Keep metadata_csum enabled for ext4l
  sandbox: Enable CONFIG_FS_EXT4L

 CLAUDE.md                           |  14 +-
 Kconfig                             |  11 +
 arch/sandbox/cpu/os.c               |  27 +-
 arch/sandbox/cpu/start.c            |  10 +
 arch/sandbox/include/asm/state.h    |   1 +
 board/sandbox/sandbox.c             |  16 +
 common/dlmalloc.c                   |  33 +-
 common/mcheck_core.inc.h            |   5 +-
 configs/sandbox_defconfig           |   2 +
 doc/arch/sandbox/sandbox.rst        |   7 +
 doc/conf.py                         |   2 +-
 doc/usage/environment.rst           |   6 +
 drivers/block/blkmap.c              |   3 +
 drivers/video/video-uclass.c        |  40 +-
 fs/ext4l/Kconfig                    |   3 +
 fs/ext4l/ext4.h                     |   6 +
 fs/ext4l/ext4_uboot.h               |  48 +-
 fs/ext4l/interface.c                | 679 ++++++++++++++++++++++++++--
 fs/ext4l/mballoc.c                  |   4 +
 fs/ext4l/stub.c                     |   8 +-
 fs/ext4l/super.c                    |  25 +-
 fs/ext4l/support.c                  | 156 ++++++-
 fs/fs_legacy.c                      |  10 +-
 include/ext4l.h                     |  67 +++
 include/linux/fs.h                  |   1 +
 include/linux/slab.h                |  27 +-
 lib/Kconfig                         |   8 -
 lib/Makefile                        |   1 -
 lib/kmem_cache.c                    |  20 -
 test/fs/ext4l.c                     | 251 ++++++++++
 test/py/tests/fs_helper.py          |  13 +-
 test/py/tests/test_event_dump.py    |   1 +
 test/py/tests/test_fs/test_ext4l.py |  25 +
 tools/logos/u-boot-logo-text.svg    | Bin 0 -> 8552 bytes
 34 files changed, 1376 insertions(+), 154 deletions(-)
 delete mode 100644 lib/kmem_cache.c
 create mode 100644 tools/logos/u-boot-logo-text.svg