[PATCH v3 6/9] pstore: do not run timer while pstore is not mounted

From: dragos . tatulea
Date: Thu Oct 18 2012 - 07:04:29 EST


From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

A timer is used to periodically check for new dumps.
The timer is not needed unless pstore is mounted,
so disable it otherwise.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
fs/pstore/inode.c | 3 +++
fs/pstore/internal.h | 2 ++
fs/pstore/platform.c | 36 +++++++++++++++++++++++++++++-------
3 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 4800c09..5e20a8d 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -397,6 +397,8 @@ static int pstore_fill_super(struct super_block *sb, void *data, int silent)

pstore_get_records(0);

+ pstore_add_timer();
+
return 0;
}

@@ -408,6 +410,7 @@ static struct dentry *pstore_mount(struct file_system_type *fs_type,

static void pstore_kill_sb(struct super_block *sb)
{
+ pstore_del_timer();
kill_litter_super(sb);
pstore_sb = NULL;
}
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index 4847f58..c7b8197 100644
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -54,4 +54,6 @@ extern int pstore_mkfile(enum pstore_type_id, char *psname, u64 id,
struct timespec time, struct pstore_info *psi);
extern int pstore_is_mounted(void);

+extern void pstore_add_timer(void);
+extern void pstore_del_timer(void);
#endif
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 63ff377..3a4c38f 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -54,6 +54,8 @@ static int pstore_new_entry;

static void pstore_timefunc(unsigned long);
static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0);
+static DEFINE_SPINLOCK(pstore_timer_lock);
+static int pstore_timer_on;

static void pstore_dowork(struct work_struct *);
static DECLARE_WORK(pstore_work, pstore_dowork);
@@ -351,12 +353,6 @@ int pstore_register(struct pstore_info *psi)
pstore_register_console();
pstore_register_ftrace();

- if (pstore_update_ms >= 0) {
- pstore_timer.expires = jiffies +
- msecs_to_jiffies(pstore_update_ms);
- add_timer(&pstore_timer);
- }
-
pstore_debugfs_init();

return 0;
@@ -411,12 +407,38 @@ static void pstore_dowork(struct work_struct *work)

static void pstore_timefunc(unsigned long dummy)
{
+ unsigned long flags;
+
if (pstore_new_entry) {
pstore_new_entry = 0;
schedule_work(&pstore_work);
}

- mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));
+ spin_lock_irqsave(&pstore_timer_lock, flags);
+ if (pstore_timer_on)
+ mod_timer(&pstore_timer,
+ jiffies + msecs_to_jiffies(pstore_update_ms));
+ spin_unlock_irqrestore(&pstore_timer_lock, flags);
+}
+
+void pstore_add_timer(void)
+{
+ pstore_timer_on = 1;
+ if (pstore_update_ms >= 0) {
+ pstore_timer.expires = jiffies +
+ msecs_to_jiffies(pstore_update_ms);
+ add_timer(&pstore_timer);
+ }
+}
+
+void pstore_del_timer(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&pstore_timer_lock, flags);
+ pstore_timer_on = 0;
+ spin_unlock_irqrestore(&pstore_timer_lock, flags);
+ del_timer_sync(&pstore_timer);
}

/* pstore_write must only be called from PSTORE_DUMP notifier callbacks */
--
1.7.9.5

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