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| author | Alan Stern <stern@rowland.harvard.edu> | 2007-06-07 17:12:25 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-07-12 16:34:31 -0700 |
| commit | ed76cacbea08ebfdb678c8687f98237cb7c67bb6 (patch) | |
| tree | bb3c3f759e36d1ae3c6c5b422ec74304e4ce2502 | |
| parent | 3fc154b6b8134b98bb94d60cad9a46ec1ffbe372 (diff) | |
| download | linux-ed76cacbea08ebfdb678c8687f98237cb7c67bb6.tar.gz linux-ed76cacbea08ebfdb678c8687f98237cb7c67bb6.tar.bz2 linux-ed76cacbea08ebfdb678c8687f98237cb7c67bb6.zip | |
USB: usb-storage: use kthread_stop() for the control thread
This patch (as923) makes usb-storage's control thread use
kthread_should_stop()/kthread_stop(). The scanning thread can't be
similarly converted until the core kthread implementation allows
threads to call do_exit().
The advantage of this change is that we can now be certain the control
thread has terminated before storage_disconnect() returns. This will
simplify the locking requirements when autosuspend support is added.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/usb/storage/usb.c | 38 | ||||
| -rw-r--r-- | drivers/usb/storage/usb.h | 1 |
2 files changed, 14 insertions, 25 deletions
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index 00521f1d6a6b..cf3fc91234e7 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -425,23 +425,15 @@ SkipForAbort: mutex_unlock(&us->dev_mutex); } /* for (;;) */ - scsi_host_put(host); - - /* notify the exit routine that we're actually exiting now - * - * complete()/wait_for_completion() is similar to up()/down(), - * except that complete() is safe in the case where the structure - * is getting deleted in a parallel mode of execution (i.e. just - * after the down() -- that's necessary for the thread-shutdown - * case. - * - * complete_and_exit() goes even further than this -- it is safe in - * the case that the thread of the caller is going away (not just - * the structure) -- this is necessary for the module-remove case. - * This is important in preemption kernels, which transfer the flow - * of execution immediately upon a complete(). - */ - complete_and_exit(&threads_gone, 0); + /* Wait until we are told to stop */ + for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + if (kthread_should_stop()) + break; + schedule(); + } + __set_current_state(TASK_RUNNING); + return 0; } /*********************************************************************** @@ -809,19 +801,13 @@ static int usb_stor_acquire_resources(struct us_data *us) } /* Start up our control thread */ - th = kthread_create(usb_stor_control_thread, us, "usb-storage"); + th = kthread_run(usb_stor_control_thread, us, "usb-storage"); if (IS_ERR(th)) { printk(KERN_WARNING USB_STORAGE "Unable to start control thread\n"); return PTR_ERR(th); } - - /* 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); + us->ctl_thread = th; return 0; } @@ -838,6 +824,8 @@ static void usb_stor_release_resources(struct us_data *us) US_DEBUGP("-- sending exit command to thread\n"); set_bit(US_FLIDX_DISCONNECTING, &us->flags); up(&us->sema); + if (us->ctl_thread) + kthread_stop(us->ctl_thread); /* Call the destructor routine, if it exists */ if (us->extra_destructor) { diff --git a/drivers/usb/storage/usb.h b/drivers/usb/storage/usb.h index 6dac1ffdde86..6445665b1577 100644 --- a/drivers/usb/storage/usb.h +++ b/drivers/usb/storage/usb.h @@ -144,6 +144,7 @@ struct us_data { unsigned char *sensebuf; /* sense data buffer */ dma_addr_t cr_dma; /* buffer DMA addresses */ dma_addr_t iobuf_dma; + struct task_struct *ctl_thread; /* the control thread */ /* mutual exclusion and synchronization structures */ struct semaphore sema; /* to sleep thread on */ |