[PATCH 0/4][Diskdump]Update patches

Takao Indoh
2004-06-22T13:46:52Z

Hi!

I update the Diskdump patches!

- fix timer problem
- support kernel 2.6.7

Source code of tool(diskdumptuils) can be downloaded from
http://sourceforge.net/projects/lkdump

TODO:
- Replace proc interface with sysfs.
- Merge scsi_dump with scsi_mod.

I solved the timer problem by the method which Ingo Molnar proposed.

On Thu, 17 Jun 2004 14:13:56 +0200, Ingo Molnar wrote:

>but there's another possible method (suggested by Alan Cox) that
>requires no changes to the timer API hotpaths: 'clear' all timer lists
>upon a crash [once all CPUs have stopped and irqs are disabled] and just
>let the drivers use the normal timer APIs. Drive timer execution via a
>polling method.
>
>this basically approximates your polling based implementation but uses
>the existing kernel timer data structures and timer mechanism so should
>be robust and compatible. It doesnt rely on any previous state (because
>all currently pending timers are discarded) so it's as crash-safe as
>possible.

The following is core part of patches related to timer problem.
The complete patch is posted later.

diff -Nur linux-2.6.7.org/include/linux/interrupt.h linux-2.6.7/include/linux/interrupt.h
--- linux-2.6.7.org/include/linux/interrupt.h 2004-06-22 10:27:34.000000000 +0900
+++ linux-2.6.7/include/linux/interrupt.h 2004-06-22 22:26:39.000000000 +0900
@@ -246,4 +246,8 @@
extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */
extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */

+
+extern void dump_clear_tasklet(void);
+extern void dump_run_tasklet(void);
+
#endif
diff -Nur linux-2.6.7.org/include/linux/timer.h linux-2.6.7/include/linux/timer.h
--- linux-2.6.7.org/include/linux/timer.h 2004-06-22 10:27:31.000000000 +0900
+++ linux-2.6.7/include/linux/timer.h 2004-06-22 22:26:39.000000000 +0900
@@ -99,4 +99,7 @@
extern void run_local_timers(void);
extern void it_real_fn(unsigned long);

+extern void dump_clear_timers(void);
+extern void dump_run_timers(void);
+
#endif
diff -Nur linux-2.6.7.org/include/linux/workqueue.h linux-2.6.7/include/linux/workqueue.h
--- linux-2.6.7.org/include/linux/workqueue.h 2004-06-22 10:27:35.000000000 +0900
+++ linux-2.6.7/include/linux/workqueue.h 2004-06-22 22:26:39.000000000 +0900
@@ -84,4 +84,7 @@
return ret;
}

+extern void dump_clear_workqueue(void);
+extern void dump_run_workqueue(void);
+
#endif
diff -Nur linux-2.6.7.org/kernel/softirq.c linux-2.6.7/kernel/softirq.c
--- linux-2.6.7.org/kernel/softirq.c 2004-06-22 10:27:25.000000000 +0900
+++ linux-2.6.7/kernel/softirq.c 2004-06-22 22:26:39.000000000 +0900
@@ -314,6 +314,38 @@

EXPORT_SYMBOL(tasklet_kill);

+struct tasklet_head saved_tasklet;
+
+void dump_clear_tasklet(void)
+{
+ saved_tasklet.list = __get_cpu_var(tasklet_vec).list;
+ __get_cpu_var(tasklet_vec).list = NULL;
+}
+
+EXPORT_SYMBOL(dump_clear_tasklet);
+
+void dump_run_tasklet(void)
+{
+ struct tasklet_struct *list;
+
+ list = __get_cpu_var(tasklet_vec).list;
+ __get_cpu_var(tasklet_vec).list = NULL;
+
+ while (list) {
+ struct tasklet_struct *t = list;
+ list = list->next;
+
+ if (!atomic_read(&t->count) &&
+ (test_and_clear_bit(TASKLET_STATE_SCHED, &t->state)))
+ t->func(t->data);
+
+ t->next = __get_cpu_var(tasklet_vec).list;
+ __get_cpu_var(tasklet_vec).list = t;
+ }
+}
+
+EXPORT_SYMBOL(dump_run_tasklet);
+
void __init softirq_init(void)
{
open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL);
diff -Nur linux-2.6.7.org/kernel/timer.c linux-2.6.7/kernel/timer.c
--- linux-2.6.7.org/kernel/timer.c 2004-06-22 10:27:25.000000000 +0900
+++ linux-2.6.7/kernel/timer.c 2004-06-22 22:26:39.000000000 +0900
@@ -31,6 +31,7 @@
#include <linux/time.h>
#include <linux/jiffies.h>
#include <linux/cpu.h>
+#include <linux/delay.h>

#include <asm/uaccess.h>
#include <asm/unistd.h>
@@ -424,7 +425,6 @@
{
struct timer_list *timer;

- spin_lock_irq(&base->lock);
while (time_after_eq(jiffies, base->timer_jiffies)) {
struct list_head work_list = LIST_HEAD_INIT(work_list);
struct list_head *head = &work_list;
@@ -460,6 +460,12 @@
}
}
set_running_timer(base, NULL);
+}
+
+static inline void _run_timers(tvec_base_t *base)
+{
+ spin_lock_irq(&base->lock);
+ __run_timers(base);
spin_unlock_irq(&base->lock);
}

@@ -909,7 +915,7 @@
tvec_base_t *base = &__get_cpu_var(tvec_bases);

if (time_after_eq(jiffies, base->timer_jiffies))
- __run_timers(base);
+ _run_timers(base);
}

/*
@@ -1105,6 +1111,12 @@
struct timer_list timer;
unsigned long expire;

+ if (unlikely(crashdump_mode())) {
+ mdelay(timeout);
+ set_current_state(TASK_RUNNING);
+ return timeout;
+ }
+
switch (timeout)
{
case MAX_SCHEDULE_TIMEOUT:
@@ -1308,7 +1320,7 @@
return 0;
}

-static void __devinit init_timers_cpu(int cpu)
+static void /* __devinit */ init_timers_cpu(int cpu)
{
int j;
tvec_base_t *base;
@@ -1327,6 +1339,27 @@
base->timer_jiffies = jiffies;
}

+static tvec_base_t saved_tvec_base;
+
+void dump_clear_timers(void)
+{
+ tvec_base_t *base = &per_cpu(tvec_bases, smp_processor_id());
+
+ memcpy(&saved_tvec_base, base, sizeof(saved_tvec_base));
+ init_timers_cpu(smp_processor_id());
+}
+
+EXPORT_SYMBOL(dump_clear_timers);
+
+void dump_run_timers(void)
+{
+ tvec_base_t *base = &__get_cpu_var(tvec_bases);
+
+ __run_timers(base);
+}
+
+EXPORT_SYMBOL(dump_run_timers);
+
#ifdef CONFIG_HOTPLUG_CPU
static int migrate_timer_list(tvec_base_t *new_base, struct list_head *head)
{
diff -Nur linux-2.6.7.org/kernel/workqueue.c linux-2.6.7/kernel/workqueue.c
--- linux-2.6.7.org/kernel/workqueue.c 2004-06-22 10:27:25.000000000 +0900
+++ linux-2.6.7/kernel/workqueue.c 2004-06-22 22:26:39.000000000 +0900
@@ -424,6 +424,37 @@

}

+struct cpu_workqueue_struct saved_cwq;
+
+void dump_clear_workqueue(void)
+{
+ int cpu = smp_processor_id();
+ struct cpu_workqueue_struct *cwq = keventd_wq->cpu_wq + cpu;
+
+ memcpy(&saved_cwq, cwq, sizeof(saved_cwq));
+ spin_lock_init(&cwq->lock);
+ INIT_LIST_HEAD(&cwq->worklist);
+ init_waitqueue_head(&cwq->more_work);
+ init_waitqueue_head(&cwq->work_done);
+}
+
+void dump_run_workqueue(void)
+{
+ struct cpu_workqueue_struct *cwq;
+
+ cwq = keventd_wq->cpu_wq + smp_processor_id();
+ while (!list_empty(&cwq->worklist)) {
+ struct work_struct *work = list_entry(cwq->worklist.next,
+ struct work_struct, entry);
+ void (*f) (void *) = work->func;
+ void *data = work->data;
+
+ list_del_init(cwq->worklist.next);
+ clear_bit(0, &work->pending);
+ f(data);
+ }
+}
+
#ifdef CONFIG_HOTPLUG_CPU
/* Take the work from this (downed) CPU. */
static void take_over_work(struct workqueue_struct *wq, unsigned int cpu)
@@ -507,3 +538,6 @@
EXPORT_SYMBOL(schedule_delayed_work);
EXPORT_SYMBOL(flush_scheduled_work);

+EXPORT_SYMBOL(dump_clear_workqueue);
+EXPORT_SYMBOL(dump_run_workqueue);
+