Commit fdce895e authored by Li Hong's avatar Li Hong Committed by Ryusuke Konishi
Browse files

nilfs2: change sc_timer from a pointer to an embedded one in struct nilfs_sc_info 



In nilfs_segctor_thread(), timer is a local variable allocated on stack. Its
address can't be set to sci->sc_timer and passed in several procedures.

It works now by chance, just because other procedures are called by
nilfs_segctor_thread() directly or indirectly and the stack hasn't been
deallocated yet.

Signed-off-by: default avatarLi Hong <lihong.hi@gmail.com>
Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
parent 154ac5a8

fs/nilfs2/segment.c

+13 −18
Original line number Diff line number Diff line
@@ -2159,9 +2159,9 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode) 
static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)

{

	spin_lock(&sci->sc_state_lock);

	if (sci->sc_timer && !(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {

		sci->sc_timer->expires = jiffies + sci->sc_interval;

		add_timer(sci->sc_timer);

	if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {

		sci->sc_timer.expires = jiffies + sci->sc_interval;

		add_timer(&sci->sc_timer);

		sci->sc_state |= NILFS_SEGCTOR_COMMIT;

	}

	spin_unlock(&sci->sc_state_lock);
@@ -2366,9 +2366,7 @@ static void nilfs_segctor_accept(struct nilfs_sc_info *sci) 
	spin_lock(&sci->sc_state_lock);

	sci->sc_seq_accepted = sci->sc_seq_request;

	spin_unlock(&sci->sc_state_lock);



	if (sci->sc_timer)

		del_timer_sync(sci->sc_timer);

	del_timer_sync(&sci->sc_timer);

}



/**
@@ -2394,9 +2392,9 @@ static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err) 
			sci->sc_flush_request &= ~FLUSH_DAT_BIT;



		/* re-enable timer if checkpoint creation was not done */

		if (sci->sc_timer && (sci->sc_state & NILFS_SEGCTOR_COMMIT) &&

		    time_before(jiffies, sci->sc_timer->expires))

			add_timer(sci->sc_timer);

		if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&

		    time_before(jiffies, sci->sc_timer.expires))

			add_timer(&sci->sc_timer);

	}

	spin_unlock(&sci->sc_state_lock);

}
@@ -2575,13 +2573,10 @@ static int nilfs_segctor_thread(void *arg) 
{

	struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;

	struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;

	struct timer_list timer;

	int timeout = 0;



	init_timer(&timer);

	timer.data = (unsigned long)current;

	timer.function = nilfs_construction_timeout;

	sci->sc_timer = &timer;

	sci->sc_timer.data = (unsigned long)current;

	sci->sc_timer.function = nilfs_construction_timeout;



	/* start sync. */

	sci->sc_task = current;
@@ -2630,7 +2625,7 @@ static int nilfs_segctor_thread(void *arg) 
			should_sleep = 0;

		else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)

			should_sleep = time_before(jiffies,

						   sci->sc_timer->expires);

					sci->sc_timer.expires);



		if (should_sleep) {

			spin_unlock(&sci->sc_state_lock);
@@ -2639,7 +2634,7 @@ static int nilfs_segctor_thread(void *arg) 
		}

		finish_wait(&sci->sc_wait_daemon, &wait);

		timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&

			   time_after_eq(jiffies, sci->sc_timer->expires));

			   time_after_eq(jiffies, sci->sc_timer.expires));



		if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))

			set_nilfs_discontinued(nilfs);
@@ -2648,8 +2643,6 @@ static int nilfs_segctor_thread(void *arg) 


 end_thread:

	spin_unlock(&sci->sc_state_lock);

	del_timer_sync(sci->sc_timer);

	sci->sc_timer = NULL;



	/* end sync. */

	sci->sc_task = NULL;
@@ -2708,6 +2701,7 @@ static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi) 
	INIT_LIST_HEAD(&sci->sc_write_logs);

	INIT_LIST_HEAD(&sci->sc_gc_inodes);

	INIT_LIST_HEAD(&sci->sc_copied_buffers);

	init_timer(&sci->sc_timer);



	sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;

	sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
@@ -2774,6 +2768,7 @@ static void nilfs_segctor_destroy(struct nilfs_sc_info *sci) 


	down_write(&sbi->s_nilfs->ns_segctor_sem);



	del_timer_sync(&sci->sc_timer);

	kfree(sci);

}

fs/nilfs2/segment.h

+1 −1
Original line number Diff line number Diff line
@@ -177,7 +177,7 @@ struct nilfs_sc_info { 
	unsigned long		sc_lseg_stime;	/* in 1/HZ seconds */

	unsigned long		sc_watermark;



	struct timer_list      *sc_timer;

	struct timer_list	sc_timer;

	struct task_struct     *sc_task;

};

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