Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3f13e66e authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
Browse files

[PATCH] PATCH: usb-storage: use kthread API 



This patch is originally from Alan Stern (as569).  It has been rediffed
against a current tree.

This patch converts usb-storage to use the kthread API for creating its
control and scanning threads.  The new code doesn't use kthread_stop
because the threads need (or will need in the future) to exit
asynchronously.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarMatthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent ce2596df

drivers/usb/storage/usb.c

+21 −42
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ 
#include <linux/module.h>

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/kthread.h>



#include <scsi/scsi.h>

#include <scsi/scsi_cmnd.h>
@@ -310,22 +311,7 @@ static int usb_stor_control_thread(void * __us) 
	struct us_data *us = (struct us_data *)__us;

	struct Scsi_Host *host = us_to_host(us);



	lock_kernel();



	/*

	 * This thread doesn't need any user-level access,

	 * so get rid of all our resources.

	 */

	daemonize("usb-storage");

	current->flags |= PF_NOFREEZE;

	unlock_kernel();



	/* acquire a reference to the host, so it won't be deallocated

	 * until we're ready to exit */

	scsi_host_get(host);



	/* signal that we've started the thread */

	complete(&(us->notify));



	for(;;) {

		US_DEBUGP("*** thread sleeping.\n");
@@ -768,6 +754,7 @@ static int get_pipes(struct us_data *us) 
static int usb_stor_acquire_resources(struct us_data *us)

{

	int p;

	struct task_struct *th;



	us->current_urb = usb_alloc_urb(0, GFP_KERNEL);

	if (!us->current_urb) {
@@ -784,17 +771,19 @@ static int usb_stor_acquire_resources(struct us_data *us) 
	}



	/* Start up our control thread */

	p = kernel_thread(usb_stor_control_thread, us, CLONE_VM);

	if (p < 0) {

	th = kthread_create(usb_stor_control_thread, us, "usb-storage");

	if (IS_ERR(th)) {

		printk(KERN_WARNING USB_STORAGE 

		       "Unable to start control thread\n");

		return p;

		return PTR_ERR(th);

	}

	us->pid = p;

	atomic_inc(&total_threads);



	/* Wait for the thread to start */

	wait_for_completion(&(us->notify));

	/* Take a reference to the host for the control thread and

	 * count it among all the threads we have launched.  Then

	 * start it up. */

	scsi_host_get(us_to_host(us));

	atomic_inc(&total_threads);

	wake_up_process(th);



	return 0;

}
@@ -890,21 +879,6 @@ static int usb_stor_scan_thread(void * __us) 
{

	struct us_data *us = (struct us_data *)__us;



	/*

	 * This thread doesn't need any user-level access,

	 * so get rid of all our resources.

	 */

	lock_kernel();

	daemonize("usb-stor-scan");

	unlock_kernel();



	/* Acquire a reference to the host, so it won't be deallocated

	 * until we're ready to exit */

	scsi_host_get(us_to_host(us));



	/* Signal that we've started the thread */

	complete(&(us->notify));



	printk(KERN_DEBUG

		"usb-storage: device found at %d\n", us->pusb_dev->devnum);
@@ -949,6 +923,7 @@ static int storage_probe(struct usb_interface *intf, 
	struct us_data *us;

	const int id_index = id - storage_usb_ids; 

	int result;

	struct task_struct *th;



	US_DEBUGP("USB Mass Storage device detected\n");
@@ -1029,17 +1004,21 @@ static int storage_probe(struct usb_interface *intf, 
	}



	/* Start up the thread for delayed SCSI-device scanning */

	result = kernel_thread(usb_stor_scan_thread, us, CLONE_VM);

	if (result < 0) {

	th = kthread_create(usb_stor_scan_thread, us, "usb-stor-scan");

	if (IS_ERR(th)) {

		printk(KERN_WARNING USB_STORAGE 

		       "Unable to start the device-scanning thread\n");

		quiesce_and_remove_host(us);

		result = PTR_ERR(th);

		goto BadDevice;

	}

	atomic_inc(&total_threads);



	/* Wait for the thread to start */

	wait_for_completion(&(us->notify));

	/* Take a reference to the host for the scanning thread and

	 * count it among all the threads we have launched.  Then

	 * start it up. */

	scsi_host_get(us_to_host(us));

	atomic_inc(&total_threads);

	wake_up_process(th);



	return 0;

drivers/usb/storage/usb.h

+0 −3
Original line number Diff line number Diff line
@@ -161,9 +161,6 @@ struct us_data { 
	struct scsi_cmnd	*srb;		 /* current srb		*/

	unsigned int		tag;		 /* current dCBWTag	*/



	/* thread information */

	int			pid;		 /* control thread	 */



	/* control and bulk communications data */

	struct urb		*current_urb;	 /* USB requests	 */

	struct usb_ctrlrequest	*cr;		 /* control requests	 */