After sleep it is not certain that the scsi netlink state is no longer busy.
The uncertainty is fixed as possible as 20 ticks permit.
And the state word of scsi netlink is redefined to be the native word
of most hardwares.
Signed-off-by: Hillf Danton <dhillf@xxxxxxxxx>
---
--- a/drivers/scsi/scsi_netlink.c 2010-09-13 07:07:38.000000000 +0800
+++ b/drivers/scsi/scsi_netlink.c 2010-11-02 20:48:02.000000000 +0800
@@ -35,7 +35,8 @@ EXPORT_SYMBOL_GPL(scsi_nl_sock);
static DEFINE_SPINLOCK(scsi_nl_lock);
static struct list_head scsi_nl_drivers;
-static u32 scsi_nl_state;
+static unsigned long scsi_nl_state;
+
#define STATE_EHANDLER_BSY 0x00000001
struct scsi_nl_transport {
@@ -315,16 +316,21 @@ scsi_nl_add_transport(u8 tport,
{
unsigned long flags;
int err = 0;
+ unsigned int msecs = jiffies_to_msecs(20);
if (tport >= SCSI_NL_MAX_TRANSPORTS)
return -EINVAL;
+check_busy:
spin_lock_irqsave(&scsi_nl_lock, flags);
if (scsi_nl_state & STATE_EHANDLER_BSY) {
spin_unlock_irqrestore(&scsi_nl_lock, flags);
- msleep(1);
- spin_lock_irqsave(&scsi_nl_lock, flags);
+ if (msecs--) {
+ msleep(1);
+ goto check_busy;
+ }
+ return -EBUSY;
}
if (transports[tport].msg_handler || transports[tport].event_handler) {
@@ -407,6 +413,7 @@ scsi_nl_add_driver(u64 vendor_id, struct
{
struct scsi_nl_drvr *driver;
unsigned long flags;
+ unsigned int msecs = jiffies_to_msecs(20);
driver = kzalloc(sizeof(*driver), GFP_KERNEL);
if (unlikely(!driver)) {
@@ -419,11 +426,16 @@ scsi_nl_add_driver(u64 vendor_id, struct
driver->hostt = hostt;
driver->vendor_id = vendor_id;
+check_busy:
spin_lock_irqsave(&scsi_nl_lock, flags);
if (scsi_nl_state & STATE_EHANDLER_BSY) {
spin_unlock_irqrestore(&scsi_nl_lock, flags);
- msleep(1);
- spin_lock_irqsave(&scsi_nl_lock, flags);
+ if (msecs--) {
+ msleep(1);
+ goto check_busy;
+ }
+ kfree(driver);
+ return -EBUSY;
}
list_add_tail(&driver->next, &scsi_nl_drivers);
spin_unlock_irqrestore(&scsi_nl_lock, flags);
--
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