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authorBrian Foster <bfoster@redhat.com>2017-06-15 07:29:12 +0300
committerDarrick J. Wong <darrick.wong@oracle.com>2017-06-19 18:59:10 +0300
commitccdab3d6e881649f05110d9098fd248d2753aaf3 (patch)
treed684f89dab1b5a2c9579e307e841cd0629b24399
parente1a4e37cc7b665b6804fba812aca2f4d7402c249 (diff)
downloadlinux-ccdab3d6e881649f05110d9098fd248d2753aaf3.tar.xz
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>
-rw-r--r--fs/xfs/xfs_globals.c2
-rw-r--r--fs/xfs/xfs_message.c5
-rw-r--r--fs/xfs/xfs_sysctl.h1
-rw-r--r--fs/xfs/xfs_sysfs.c33
4 files changed, 40 insertions, 1 deletions
diff --git a/fs/xfs/xfs_globals.c b/fs/xfs/xfs_globals.c
index 687a4b01fc53..673adf0a40cc 100644
--- a/fs/xfs/xfs_globals.c
+++ b/fs/xfs/xfs_globals.c
@@ -47,4 +47,6 @@ 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 */
};
diff --git a/fs/xfs/xfs_message.c b/fs/xfs/xfs_message.c
index 11792d888e4e..e68bd1050eab 100644
--- a/fs/xfs/xfs_message.c
+++ b/fs/xfs/xfs_message.c
@@ -110,7 +110,10 @@ assfail(char *expr, char *file, int line)
{
xfs_emerg(NULL, "Assertion failed: %s, file: %s, line: %d",
expr, file, line);
- BUG();
+ if (xfs_globals.bug_on_assert)
+ BUG();
+ else
+ WARN_ON(1);
}
void
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;
diff --git a/fs/xfs/xfs_sysfs.c b/fs/xfs/xfs_sysfs.c
index 80ac15fb9638..ec6e0e2f95d6 100644
--- a/fs/xfs/xfs_sysfs.c
+++ b/fs/xfs/xfs_sysfs.c
@@ -146,6 +146,38 @@ struct kobj_type xfs_mp_ktype = {
/* debug */
STATIC ssize_t
+bug_on_assert_store(
+ struct kobject *kobject,
+ const char *buf,
+ size_t count)
+{
+ int ret;
+ int val;
+
+ ret = kstrtoint(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ if (val == 1)
+ xfs_globals.bug_on_assert = true;
+ else if (val == 0)
+ xfs_globals.bug_on_assert = false;
+ else
+ return -EINVAL;
+
+ return count;
+}
+
+STATIC ssize_t
+bug_on_assert_show(
+ struct kobject *kobject,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%d\n", xfs_globals.bug_on_assert ? 1 : 0);
+}
+XFS_SYSFS_ATTR_RW(bug_on_assert);
+
+STATIC ssize_t
log_recovery_delay_store(
struct kobject *kobject,
const char *buf,
@@ -176,6 +208,7 @@ log_recovery_delay_show(
XFS_SYSFS_ATTR_RW(log_recovery_delay);
static struct attribute *xfs_dbg_attrs[] = {
+ ATTR_LIST(bug_on_assert),
ATTR_LIST(log_recovery_delay),
NULL,
};