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

[Marco Elver]

On Tue, 11 Aug 2026 at 18:04, Timothy Day
<timday@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> 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.

Acked-by: Marco Elver <elver@xxxxxxxxxx>

But ultimately up to maintainers. Also, thanks for helping improve the
Clang side (FWIW, Clang 23 will release August 23)!

> 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
>