staging:rts_pstor: fix thread synchronization flow
Using different completion variables to synchronize different kernel threads This patch fix a bug that may cause memory leak when driver disconnected. This is not a very urgent bug. Because with the default setting, driver disconnectting routine won't be called except when Linux is shut down. But if the option auto_delink_en is set, a small number of memory would leak out after memory card unplugged. Signed-off-by: wwang <wei_wang@realsil.com.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
wwang
Greg Kroah-Hartman
Родитель
f8d73aa362
Коммит
f704648281
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@ -66,12 +66,6 @@ static int msi_en;
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module_param(msi_en, int, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(msi_en, "enable msi");
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/* These are used to make sure the module doesn't unload before all the
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* threads have exited.
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*/
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static atomic_t total_threads = ATOMIC_INIT(0);
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static DECLARE_COMPLETION(threads_gone);
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static irqreturn_t rtsx_interrupt(int irq, void *dev_id);
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/***********************************************************************
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@ -192,7 +186,7 @@ static int queuecommand_lck(struct scsi_cmnd *srb,
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/* enqueue the command and wake up the control thread */
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srb->scsi_done = done;
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chip->srb = srb;
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up(&(dev->sema));
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complete(&dev->cmnd_ready);
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return 0;
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}
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@ -475,7 +469,7 @@ static int rtsx_control_thread(void *__dev)
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current->flags |= PF_NOFREEZE;
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for (;;) {
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if (down_interruptible(&dev->sema))
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if (wait_for_completion_interruptible(&dev->cmnd_ready))
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break;
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/* lock the device pointers */
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@ -557,8 +551,6 @@ SkipForAbort:
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mutex_unlock(&dev->dev_mutex);
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} /* for (;;) */
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scsi_host_put(host);
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/* notify the exit routine that we're actually exiting now
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*
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* complete()/wait_for_completion() is similar to up()/down(),
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@ -573,7 +565,7 @@ SkipForAbort:
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* This is important in preemption kernels, which transfer the flow
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* of execution immediately upon a complete().
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*/
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complete_and_exit(&threads_gone, 0);
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complete_and_exit(&dev->control_exit, 0);
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}
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@ -581,7 +573,6 @@ static int rtsx_polling_thread(void *__dev)
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{
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struct rtsx_dev *dev = (struct rtsx_dev *)__dev;
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struct rtsx_chip *chip = dev->chip;
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struct Scsi_Host *host = rtsx_to_host(dev);
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struct sd_info *sd_card = &(chip->sd_card);
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struct xd_info *xd_card = &(chip->xd_card);
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struct ms_info *ms_card = &(chip->ms_card);
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@ -621,8 +612,7 @@ static int rtsx_polling_thread(void *__dev)
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mutex_unlock(&dev->dev_mutex);
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}
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scsi_host_put(host);
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complete_and_exit(&threads_gone, 0);
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complete_and_exit(&dev->polling_exit, 0);
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}
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/*
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@ -699,29 +689,38 @@ static void rtsx_release_resources(struct rtsx_dev *dev)
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{
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printk(KERN_INFO "-- %s\n", __func__);
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if (dev->rtsx_resv_buf) {
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dma_free_coherent(&(dev->pci->dev), HOST_CMDS_BUF_LEN,
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dev->rtsx_resv_buf, dev->rtsx_resv_buf_addr);
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dev->chip->host_cmds_ptr = NULL;
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dev->chip->host_sg_tbl_ptr = NULL;
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}
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pci_disable_device(dev->pci);
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pci_release_regions(dev->pci);
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if (dev->irq > 0) {
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free_irq(dev->irq, (void *)dev);
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}
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if (dev->chip->msi_en) {
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pci_disable_msi(dev->pci);
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}
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/* Tell the control thread to exit. The SCSI host must
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* already have been removed so it won't try to queue
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* any more commands.
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*/
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printk(KERN_INFO "-- sending exit command to thread\n");
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up(&dev->sema);
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complete(&dev->cmnd_ready);
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if (dev->ctl_thread)
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wait_for_completion(&dev->control_exit);
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if (dev->polling_thread)
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wait_for_completion(&dev->polling_exit);
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wait_timeout(200);
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if (dev->rtsx_resv_buf) {
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dma_free_coherent(&(dev->pci->dev), RTSX_RESV_BUF_LEN,
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dev->rtsx_resv_buf, dev->rtsx_resv_buf_addr);
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dev->chip->host_cmds_ptr = NULL;
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dev->chip->host_sg_tbl_ptr = NULL;
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}
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if (dev->irq > 0)
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free_irq(dev->irq, (void *)dev);
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if (dev->chip->msi_en)
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pci_disable_msi(dev->pci);
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if (dev->remap_addr)
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iounmap(dev->remap_addr);
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pci_disable_device(dev->pci);
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pci_release_regions(dev->pci);
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rtsx_release_chip(dev->chip);
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kfree(dev->chip);
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}
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/* First stage of disconnect processing: stop all commands and remove
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@ -739,6 +738,7 @@ static void quiesce_and_remove_host(struct rtsx_dev *dev)
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scsi_unlock(host);
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mutex_unlock(&dev->dev_mutex);
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wake_up(&dev->delay_wait);
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wait_for_completion(&dev->scanning_done);
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/* Wait some time to let other threads exist */
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wait_timeout(100);
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@ -793,8 +793,7 @@ static int rtsx_scan_thread(void *__dev)
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/* Should we unbind if no devices were detected? */
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}
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scsi_host_put(rtsx_to_host(dev));
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complete_and_exit(&threads_gone, 0);
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complete_and_exit(&dev->scanning_done, 0);
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}
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static void rtsx_init_options(struct rtsx_chip *chip)
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@ -941,8 +940,11 @@ static int __devinit rtsx_probe(struct pci_dev *pci, const struct pci_device_id
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spin_lock_init(&dev->reg_lock);
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mutex_init(&(dev->dev_mutex));
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sema_init(&(dev->sema), 0);
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init_completion(&dev->cmnd_ready);
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init_completion(&dev->control_exit);
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init_completion(&dev->polling_exit);
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init_completion(&(dev->notify));
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init_completion(&dev->scanning_done);
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init_waitqueue_head(&dev->delay_wait);
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dev->pci = pci;
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@ -992,28 +994,22 @@ static int __devinit rtsx_probe(struct pci_dev *pci, const struct pci_device_id
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pci_set_master(pci);
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synchronize_irq(dev->irq);
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err = scsi_add_host(host, &pci->dev);
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if (err) {
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printk(KERN_ERR "Unable to add the scsi host\n");
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goto errout;
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}
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rtsx_init_chip(dev->chip);
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/* Start up our control thread */
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th = kthread_create(rtsx_control_thread, dev, CR_DRIVER_NAME);
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th = kthread_run(rtsx_control_thread, dev, CR_DRIVER_NAME);
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if (IS_ERR(th)) {
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printk(KERN_ERR "Unable to start control thread\n");
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err = PTR_ERR(th);
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goto errout;
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}
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dev->ctl_thread = th;
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/* Take a reference to the host for the control thread and
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* count it among all the threads we have launched. Then
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* start it up. */
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scsi_host_get(rtsx_to_host(dev));
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atomic_inc(&total_threads);
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wake_up_process(th);
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err = scsi_add_host(host, &pci->dev);
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if (err) {
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printk(KERN_ERR "Unable to add the scsi host\n");
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goto errout;
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}
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/* Start up the thread for delayed SCSI-device scanning */
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th = kthread_create(rtsx_scan_thread, dev, "rtsx-scan");
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@ -1024,28 +1020,17 @@ static int __devinit rtsx_probe(struct pci_dev *pci, const struct pci_device_id
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goto errout;
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}
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/* Take a reference to the host for the scanning thread and
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* count it among all the threads we have launched. Then
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* start it up. */
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scsi_host_get(rtsx_to_host(dev));
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atomic_inc(&total_threads);
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wake_up_process(th);
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/* Start up the thread for polling thread */
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th = kthread_create(rtsx_polling_thread, dev, "rtsx-polling");
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th = kthread_run(rtsx_polling_thread, dev, "rtsx-polling");
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if (IS_ERR(th)) {
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printk(KERN_ERR "Unable to start the device-polling thread\n");
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quiesce_and_remove_host(dev);
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err = PTR_ERR(th);
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goto errout;
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}
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/* Take a reference to the host for the polling thread and
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* count it among all the threads we have launched. Then
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* start it up. */
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scsi_host_get(rtsx_to_host(dev));
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atomic_inc(&total_threads);
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wake_up_process(th);
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dev->polling_thread = th;
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pci_set_drvdata(pci, dev);
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@ -1108,16 +1093,6 @@ static void __exit rtsx_exit(void)
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pci_unregister_driver(&driver);
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/* Don't return until all of our control and scanning threads
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* have exited. Since each thread signals threads_gone as its
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* last act, we have to call wait_for_completion the right number
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* of times.
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*/
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while (atomic_read(&total_threads) > 0) {
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wait_for_completion(&threads_gone);
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atomic_dec(&total_threads);
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}
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printk(KERN_INFO "%s module exit\n", CR_DRIVER_NAME);
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}
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@ -112,9 +112,16 @@ struct rtsx_dev {
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/* locks */
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spinlock_t reg_lock;
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struct task_struct *ctl_thread; /* the control thread */
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struct task_struct *polling_thread; /* the polling thread */
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/* mutual exclusion and synchronization structures */
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struct semaphore sema; /* to sleep thread on */
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struct completion cmnd_ready; /* to sleep thread on */
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struct completion control_exit; /* control thread exit */
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struct completion polling_exit; /* polling thread exit */
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struct completion notify; /* thread begin/end */
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struct completion scanning_done; /* wait for scan thread */
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wait_queue_head_t delay_wait; /* wait during scan, reset */
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struct mutex dev_mutex;
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