xfs: define bug_on_assert debug mode sysfs tunable

In DEBUG mode, assert failures unconditionally trigger a kernel BUG.
This is useful in diagnostic situations to panic a system and
collect detailed state information at the time of a failure.

This can also cause problems in cases where DEBUG mode code is
desired but it is preferable not trigger kernel BUGs on assert
failure. For example, during development of new code or during
certain xfstests tests that intentionally cause corruption and test
the kernel for survival (but otherwise may expect to trigger assert
failures).

To provide additional flexibility, create the
<sysfs>/fs/xfs/debug/bug_on_assert tunable to configure assert
failure behavior at runtime. This tunable is only available in DEBUG
mode and is enabled by default to preserve existing default
behavior. When disabled, assert failures in DEBUG mode result in
kernel warnings.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/xfs/xfs_sysctl.h b/fs/xfs/xfs_sysctl.h
index 984a3499cfe3..82afee005140 100644
--- a/fs/xfs/xfs_sysctl.h
+++ b/fs/xfs/xfs_sysctl.h
@@ -95,6 +95,7 @@ extern xfs_param_t	xfs_params;
 
 struct xfs_globals {
 	int	log_recovery_delay;	/* log recovery delay (secs) */
+	bool	bug_on_assert;		/* BUG() the kernel on assert failure */
 };
 extern struct xfs_globals	xfs_globals;