[PATCH] block/aoe: discover_timer: Convert timers to use timer_setup()

From: Kees Cook
Date: Thu Nov 02 2017 - 19:32:07 EST


In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

This refactors the discover_timer to remove the needless locking and
state machine used for synchronizing timer death. Using del_timer_sync()
will already do the right thing.

Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: "Ed L. Cashin" <ed.cashin@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
drivers/block/aoe/aoemain.c | 44 ++++++++------------------------------------
1 file changed, 8 insertions(+), 36 deletions(-)

diff --git a/drivers/block/aoe/aoemain.c b/drivers/block/aoe/aoemain.c
index 4b987c2fefbe..251482066977 100644
--- a/drivers/block/aoe/aoemain.c
+++ b/drivers/block/aoe/aoemain.c
@@ -15,49 +15,19 @@ MODULE_AUTHOR("Sam Hopkins <sah@xxxxxxxxxx>");
MODULE_DESCRIPTION("AoE block/char driver for 2.6.2 and newer 2.6 kernels");
MODULE_VERSION(VERSION);

-enum { TINIT, TRUN, TKILL };
+static struct timer_list timer;

-static void
-discover_timer(ulong vp)
+static void discover_timer(struct timer_list *t)
{
- static struct timer_list t;
- static volatile ulong die;
- static spinlock_t lock;
- ulong flags;
- enum { DTIMERTICK = HZ * 60 }; /* one minute */
-
- switch (vp) {
- case TINIT:
- init_timer(&t);
- spin_lock_init(&lock);
- t.data = TRUN;
- t.function = discover_timer;
- die = 0;
- case TRUN:
- spin_lock_irqsave(&lock, flags);
- if (!die) {
- t.expires = jiffies + DTIMERTICK;
- add_timer(&t);
- }
- spin_unlock_irqrestore(&lock, flags);
-
- aoecmd_cfg(0xffff, 0xff);
- return;
- case TKILL:
- spin_lock_irqsave(&lock, flags);
- die = 1;
- spin_unlock_irqrestore(&lock, flags);
+ mod_timer(t, jiffies + HZ * 60); /* one minute */

- del_timer_sync(&t);
- default:
- return;
- }
+ aoecmd_cfg(0xffff, 0xff);
}

static void
aoe_exit(void)
{
- discover_timer(TKILL);
+ del_timer_sync(&timer);

aoenet_exit();
unregister_blkdev(AOE_MAJOR, DEVICE_NAME);
@@ -93,7 +63,9 @@ aoe_init(void)
goto blkreg_fail;
}
printk(KERN_INFO "aoe: AoE v%s initialised.\n", VERSION);
- discover_timer(TINIT);
+
+ timer_setup(&timer, discover_timer, 0);
+ discover_timer(&timer);
return 0;
blkreg_fail:
aoecmd_exit();
--
2.7.4


--
Kees Cook
Pixel Security