[PATCH 5/7]: Do not unregister from callout

From: Chandra Seetharaman
Date: Wed Nov 23 2005 - 18:40:23 EST


There were two places where notifier_chain_unregister was called from
within a callout routine, which is not the correct usage of this
interface. This patch fixes the problem by using a new flag.

Signed-off-by: Chandra Seetharaman <sekharan@xxxxxxxxxx>
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
-----
drivers/parisc/led.c | 14 ++++++++++++--
drivers/scsi/gdth.c | 17 ++++++++---------
2 files changed, 20 insertions(+), 11 deletions(-)

Index: l2615-rc1-notifiers/drivers/parisc/led.c
===================================================================
--- l2615-rc1-notifiers.orig/drivers/parisc/led.c
+++ l2615-rc1-notifiers/drivers/parisc/led.c
@@ -498,11 +498,16 @@ static int led_halt(struct notifier_bloc
static struct notifier_block led_notifier = {
.notifier_call = led_halt,
};
+static int notifier_disabled = 0;

static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
{
char *txt;
-
+
+ if (notifier_disabled)
+ return NOTIFY_OK;
+
+ notifier_disabled = 1;
switch (event) {
case SYS_RESTART: txt = "SYSTEM RESTART";
break;
@@ -526,7 +531,6 @@ static int led_halt(struct notifier_bloc
if (led_func_ptr)
led_func_ptr(0xff); /* turn all LEDs ON */

- unregister_reboot_notifier(&led_notifier);
return NOTIFY_OK;
}

@@ -757,6 +761,12 @@ not_found:
return 1;
}

+static void __exit led_exit(void)
+{
+ unregister_reboot_notifier(&led_notifier);
+ return;
+}
+
#ifdef CONFIG_PROC_FS
module_init(led_create_procfs)
#endif
Index: l2615-rc1-notifiers/drivers/scsi/gdth.c
===================================================================
--- l2615-rc1-notifiers.orig/drivers/scsi/gdth.c
+++ l2615-rc1-notifiers/drivers/scsi/gdth.c
@@ -671,7 +671,7 @@ static struct file_operations gdth_fops
static struct notifier_block gdth_notifier = {
gdth_halt, NULL, 0
};
-
+static int notifier_disabled = 0;

static void gdth_delay(int milliseconds)
{
@@ -4595,13 +4595,13 @@ static int __init gdth_detect(struct scs
add_timer(&gdth_timer);
#endif
major = register_chrdev(0,"gdth",&gdth_fops);
+ notifier_disabled = 0;
register_reboot_notifier(&gdth_notifier);
}
gdth_polling = FALSE;
return gdth_ctr_vcount;
}

-
static int gdth_release(struct Scsi_Host *shp)
{
int hanum;
@@ -5632,10 +5632,14 @@ static int gdth_halt(struct notifier_blo
char cmnd[MAX_COMMAND_SIZE];
#endif

+ if (notifier_disabled)
+ return NOTIFY_OK;
+
TRACE2(("gdth_halt() event %d\n",(int)event));
if (event != SYS_RESTART && event != SYS_HALT && event != SYS_POWER_OFF)
return NOTIFY_DONE;

+ notifier_disabled = 1;
printk("GDT-HA: Flushing all host drives .. ");
for (hanum = 0; hanum < gdth_ctr_count; ++hanum) {
gdth_flush(hanum);
@@ -5650,10 +5654,8 @@ static int gdth_halt(struct notifier_blo
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
sdev = scsi_get_host_dev(gdth_ctr_tab[hanum]);
srp = scsi_allocate_request(sdev, GFP_KERNEL);
- if (!srp) {
- unregister_reboot_notifier(&gdth_notifier);
+ if (!srp)
return NOTIFY_OK;
- }
srp->sr_cmd_len = 12;
srp->sr_use_sg = 0;
gdth_do_req(srp, &gdtcmd, cmnd, 10);
@@ -5662,10 +5664,8 @@ static int gdth_halt(struct notifier_blo
#else
sdev = scsi_get_host_dev(gdth_ctr_tab[hanum]);
scp = scsi_allocate_device(sdev, 1, FALSE);
- if (!scp) {
- unregister_reboot_notifier(&gdth_notifier);
+ if (!scp)
return NOTIFY_OK;
- }
scp->cmd_len = 12;
scp->use_sg = 0;
gdth_do_cmd(scp, &gdtcmd, cmnd, 10);
@@ -5679,7 +5679,6 @@ static int gdth_halt(struct notifier_blo
#ifdef GDTH_STATISTICS
del_timer(&gdth_timer);
#endif
- unregister_reboot_notifier(&gdth_notifier);
return NOTIFY_OK;
}


--

----------------------------------------------------------------------
Chandra Seetharaman | Be careful what you choose....
- sekharan@xxxxxxxxxx | .......you may get it.
----------------------------------------------------------------------


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