[PATCH v2 0/8] Support Clang context analysis for ext2

[Timothy Day]

This description is mostly copied from v1:

This series adds annotations for Clang's context analysis to ext2.
Clang context analysis was recently added in a series by Marco
Elver [1]. This allows the compiler to validate different
locking patterns at compile time.

This series enables context analysis, fixes pre-existing warnings,
and adds new annotations. It is inspired by similar series in the
block layer (NVMe host driver, for example [2]).

I'm starting with ext2 since it's smaller and simpler compared to
ext4/btrfs/etc. After ext2, I'd be interested in converting the
other filesystems and infrastructure code in fs/. I think the ultimate
goal would be to enable this by default across all of fs/.

The series was built and tested with Clang 23 with
CONFIG_WARN_CONTEXT_ANALYSIS enabled. I based on 7.2-rc7.

Thanks!

Changes from v1:

* A false positive has been fixed in Clang [3] and ported to Clang 23.
  Hence, the first patch (silencing that false positive) has been dropped.
* Use guard() and scoped_guard() instead of context_unsafe(), when
  possible, to express that certain fields are being protected by a newly
  initialized lock during init.

Link to v1: https://lore.kernel.org/linux-fsdevel/20260712165610.366474-1-timday@xxxxxxxxxxxxxxxxxxxxxxx/

[1] https://lore.kernel.org/lkml/20251219154418.3592607-1-elver@xxxxxxxxxx/
[2] https://lore.kernel.org/all/20260706141452.3008233-1-nilay@xxxxxxxxxxxxx/
[3] https://github.com/llvm/llvm-project/pull/209796

Timothy Day (8):
  ext2: mark s_next_generation as guarded by s_next_gen_lock
  ext2: annotate ext2_update_dynamic_rev() as requiring s_lock
  ext2: mark statfs overhead cache as guarded by s_lock
  ext2: mark s_mount_state as guarded by s_lock
  ext2: annotate ext2_init_block_alloc_info() as requiring
    truncate_mutex
  ext2: annotate block-mapping helpers as requiring truncate_mutex
  ext2: annotate s_rsv_window_root as requiring s_rsv_window_lock
  ext2: enable context analysis support for ext2 filesystem

 fs/ext2/Makefile |  2 ++
 fs/ext2/balloc.c |  4 ++++
 fs/ext2/ext2.h   | 19 +++++++++++--------
 fs/ext2/inode.c  |  7 +++++++
 fs/ext2/super.c  | 35 +++++++++++++++++++----------------
 5 files changed, 43 insertions(+), 24 deletions(-)

-- 
2.43.0