On Wed, May 10, 2017 at 10:31:51AM -0400, Brian Foster wrote:
> While configurable at runtime, the DEBUG mode assert failure
> behavior is usually either desired or not for a particular
> situation. For example, developers using kernel modules may prefer
> for fatal asserts to remain disabled across module reloads while QE
> engineers doing broad regression testing may prefer to have fatal
> asserts enabled on boot to facilitate data collection for bug
> reports.
>
> To provide a compromise/convenience for developers, create a Kconfig
> option that sets the default value of the DEBUG mode 'bug_on_assert'
> sysfs tunable. The default behavior remains to trigger kernel BUGs
> on assert failures to preserve existing behavior across kernel
> configuration updates with DEBUG mode enabled.
>
> Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
> ---
> fs/xfs/Kconfig | 13 +++++++++++++
> fs/xfs/xfs.h | 4 ++++
> fs/xfs/xfs_globals.c | 7 +++++--
> 3 files changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/fs/xfs/Kconfig b/fs/xfs/Kconfig
> index 35faf12..1b98cfa 100644
> --- a/fs/xfs/Kconfig
> +++ b/fs/xfs/Kconfig
> @@ -96,3 +96,16 @@ config XFS_DEBUG
> not useful unless you are debugging a particular problem.
>
> Say N unless you are an XFS developer, or you play one on TV.
> +
> +config XFS_ASSERT_FATAL
> + bool "XFS fatal asserts"
> + default y
> + depends on XFS_FS && XFS_DEBUG
> + help
> + Set the default DEBUG mode ASSERT failure behavior.
> +
> + Say Y here to cause DEBUG mode ASSERT failures to result in fatal
> + errors that BUG() the kernel by default. If you say N, ASSERT failures
> + result in warnings.
> +
> + This behavior can be modified at runtime via sysfs.
> diff --git a/fs/xfs/xfs.h b/fs/xfs/xfs.h
> index a742c47..80cd0fd 100644
> --- a/fs/xfs/xfs.h
> +++ b/fs/xfs/xfs.h
> @@ -24,6 +24,10 @@
> #define XFS_BUF_LOCK_TRACKING 1
> #endif
>
> +#ifdef CONFIG_XFS_ASSERT_FATAL
> +#define XFS_ASSERT_FATAL 1
> +#endif
> +
> #ifdef CONFIG_XFS_WARN
> #define XFS_WARN 1
> #endif
> diff --git a/fs/xfs/xfs_globals.c b/fs/xfs/xfs_globals.c
> index 673adf0..3e1cc30 100644
> --- a/fs/xfs/xfs_globals.c
> +++ b/fs/xfs/xfs_globals.c
> @@ -47,6 +47,9 @@ xfs_param_t xfs_params = {
>
> struct xfs_globals xfs_globals = {
> .log_recovery_delay = 0, /* no delay by default */
> - .bug_on_assert = true, /* historical default in DEBUG
> - * mode */
> +#ifdef XFS_ASSERT_FATAL
Minor nit to pick, but if you're only testing that XFS_ASSERT_FATAL is
defined, you could just '#define XFS_ASSERT_FATAL' without providing a
value.... or '#if XFS_ASSERT_FATAL' here.
OTOH XFS_WARN also does that, and we reach the same ends regardless of
which way we do it. I'm willing to pull this in for 4.13 as-is, if
nobody objects.
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> + .bug_on_assert = true, /* assert failures BUG() */
> +#else
> + .bug_on_assert = false, /* assert failures WARN() */
> +#endif
> };
> --
> 2.7.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
