>From 031b50dd4bc3c94687c8e587672aff2ffeefee9b Mon Sep 17 00:00:00 2001
From: Li Hong <lihong.hi@xxxxxxxxx>
Date: Sat, 10 Apr 2010 23:25:39 +0800
Subject: [PATCH] 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: Li Hong <lihong.hi@xxxxxxxxx>
---
fs/nilfs2/segment.c | 31 +++++++++++++------------------
fs/nilfs2/segment.h | 2 +-
2 files changed, 14 insertions(+), 19 deletions(-)
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 514620d..b523112 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2158,9 +2158,9 @@ 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);
@@ -2365,9 +2365,7 @@ 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);
}
/**
@@ -2393,9 +2391,9 @@ 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);
}
@@ -2574,13 +2572,10 @@ 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;
@@ -2629,7 +2624,7 @@ 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);
@@ -2638,7 +2633,7 @@ 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);
@@ -2647,8 +2642,6 @@ 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;
@@ -2707,6 +2700,7 @@ 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;
@@ -2773,6 +2767,7 @@ 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);
}
diff --git a/fs/nilfs2/segment.h b/fs/nilfs2/segment.h
index 7aca765..dca1423 100644
--- a/fs/nilfs2/segment.h
+++ b/fs/nilfs2/segment.h
@@ -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;
};
--
1.6.3.3
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