From: Tim Sell <timothy.s...@unisys.com>
Previously, if visorhba ever failed to create its thread, it would have
subsequently attempted to do a kthread_stop() on an invalid task_struct
pointer. This was fixed via the new visor_thread_stop() function, which
validates the task_struct pointer before doing the kthread_stop().
Also, the other thread-related fields in visor_thread_info (has_stopped
and id) were not being used, so visor_thead_info was just removed.
We also now spit out an error message if thread creation fails.
Signed-off-by: Tim Sell <timothy.s...@unisys.com>
Signed-off-by: David Kershner <david.kersh...@unisys.com>
---
drivers/staging/unisys/visorhba/visorhba_main.c | 54 +++++++++++++------------
1 file changed, 28 insertions(+), 26 deletions(-)
diff --git a/drivers/staging/unisys/visorhba/visorhba_main.c
b/drivers/staging/unisys/visorhba/visorhba_main.c
index 6f53f3d..176bcc3 100644
--- a/drivers/staging/unisys/visorhba/visorhba_main.c
+++ b/drivers/staging/unisys/visorhba/visorhba_main.c
@@ -85,12 +85,6 @@ static struct visor_driver visorhba_driver = {
MODULE_DEVICE_TABLE(visorbus, visorhba_channel_types);
MODULE_ALIAS("visorbus:" SPAR_VHBA_CHANNEL_PROTOCOL_UUID_STR);
-struct visor_thread_info {
- struct task_struct *task;
- struct completion has_stopped;
- int id;
-};
-
struct visordisk_info {
u32 valid;
u32 channel, id, lun; /* Disk Path */
@@ -137,7 +131,7 @@ struct visorhba_devdata {
struct visordisk_info head;
unsigned int max_buff_len;
int devnum;
- struct visor_thread_info threadinfo;
+ struct task_struct *thread;
int thread_wait_ms;
};
@@ -154,28 +148,36 @@ static struct visorhba_devices_open
visorhbas_open[VISORHBA_OPEN_MAX];
(iter->lun == match->lun))
/**
* visor_thread_start - starts a thread for the device
- * @thrinfo: The thread to start
* @threadfn: Function the thread starts
* @thrcontext: Context to pass to the thread, i.e. devdata
* @name: string describing name of thread
*
* Starts a thread for the device.
*
- * Return 0 on success;
+ * Return the task_struct * denoting the thread on success,
+ * or NULL on failure
*/
-static int visor_thread_start(struct visor_thread_info *thrinfo,
- int (*threadfn)(void *),
- void *thrcontext, char *name)
+static struct task_struct *visor_thread_start
+(int (*threadfn)(void *), void *thrcontext, char *name)
{
- /* used to stop the thread */
- init_completion(&thrinfo->has_stopped);
- thrinfo->task = kthread_run(threadfn, thrcontext, "%s", name);
- if (IS_ERR(thrinfo->task)) {
- thrinfo->id = 0;
- return PTR_ERR(thrinfo->task);
+ struct task_struct *task;
+
+ task = kthread_run(threadfn, thrcontext, "%s", name);
+ if (IS_ERR(task)) {
+ pr_err("visorbus failed to start thread\n");
+ return NULL;
}
- thrinfo->id = thrinfo->task->pid;
- return 0;
+ return task;
+}
+
+/**
+ * visor_thread_stop - stops the thread if it is running
+ */
+static void visor_thread_stop(struct task_struct *task)
+{
+ if (!task)
+ return; /* no thread running */
+ kthread_stop(task);
}
/**
@@ -683,7 +685,7 @@ static void visorhba_serverdown_complete(struct
visorhba_devdata *devdata)
/* Stop using the IOVM response queue (queue should be drained
* by the end)
*/
- kthread_stop(devdata->threadinfo.task);
+ visor_thread_stop(devdata->thread);
/* Fail commands that weren't completed */
spin_lock_irqsave(&devdata->privlock, flags);
@@ -1082,8 +1084,8 @@ static int visorhba_resume(struct visor_device *dev,
if (devdata->serverdown && !devdata->serverchangingstate)
devdata->serverchangingstate = true;
- visor_thread_start(&devdata->threadinfo, process_incoming_rsps,
- devdata, "vhba_incming");
+ devdata->thread = visor_thread_start(process_incoming_rsps, devdata,
+ "vhba_incming");
devdata->serverdown = false;
devdata->serverchangingstate = false;
@@ -1159,8 +1161,8 @@ static int visorhba_probe(struct visor_device *dev)
goto err_scsi_remove_host;
devdata->thread_wait_ms = 2;
- visor_thread_start(&devdata->threadinfo, process_incoming_rsps,
- devdata, "vhba_incoming");
+ devdata->thread = visor_thread_start(process_incoming_rsps, devdata,
+ "vhba_incoming");
scsi_scan_host(scsihost);
@@ -1190,7 +1192,7 @@ static void visorhba_remove(struct visor_device *dev)
return;
scsihost = devdata->scsihost;
- kthread_stop(devdata->threadinfo.task);
+ visor_thread_stop(devdata->thread);
scsi_remove_host(scsihost);
scsi_host_put(scsihost);
--
1.9.1
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