From 8fd138c366a8a302d9da8a428c6e927c8bff7d35 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 7 Dec 2009 12:52:03 +0100 Subject: [PATCH] [S390] tape: cleanup reference counting Rename tape_get_device to tape_find_device and tape_get_device_reference to tape_get_device. The old names didn't make too much sense. Follow the get_device()/put_device() semantic and convert tape_put_device to a void function. Signed-off-by: Martin Schwidefsky --- drivers/s390/char/tape.h | 6 ++-- drivers/s390/char/tape_34xx.c | 8 ++--- drivers/s390/char/tape_3590.c | 2 +- drivers/s390/char/tape_block.c | 15 +++++---- drivers/s390/char/tape_char.c | 7 ++-- drivers/s390/char/tape_core.c | 61 ++++++++++++++++------------------ drivers/s390/char/tape_proc.c | 2 +- 7 files changed, 50 insertions(+), 51 deletions(-) diff --git a/drivers/s390/char/tape.h b/drivers/s390/char/tape.h index a26333774701..fbe41e0377b8 100644 --- a/drivers/s390/char/tape.h +++ b/drivers/s390/char/tape.h @@ -292,9 +292,9 @@ extern int tape_generic_pm_suspend(struct ccw_device *); extern int tape_generic_probe(struct ccw_device *); extern void tape_generic_remove(struct ccw_device *); -extern struct tape_device *tape_get_device(int devindex); -extern struct tape_device *tape_get_device_reference(struct tape_device *); -extern struct tape_device *tape_put_device(struct tape_device *); +extern struct tape_device *tape_find_device(int devindex); +extern struct tape_device *tape_get_device(struct tape_device *); +extern void tape_put_device(struct tape_device *); /* Externals from tape_char.c */ extern int tapechar_init(void); diff --git a/drivers/s390/char/tape_34xx.c b/drivers/s390/char/tape_34xx.c index 2fe45ff77b75..3657fe103c27 100644 --- a/drivers/s390/char/tape_34xx.c +++ b/drivers/s390/char/tape_34xx.c @@ -113,16 +113,16 @@ tape_34xx_work_handler(struct work_struct *work) { struct tape_34xx_work *p = container_of(work, struct tape_34xx_work, work); + struct tape_device *device = p->device; switch(p->op) { case TO_MSEN: - tape_34xx_medium_sense(p->device); + tape_34xx_medium_sense(device); break; default: DBF_EVENT(3, "T34XX: internal error: unknown work\n"); } - - p->device = tape_put_device(p->device); + tape_put_device(device); kfree(p); } @@ -136,7 +136,7 @@ tape_34xx_schedule_work(struct tape_device *device, enum tape_op op) INIT_WORK(&p->work, tape_34xx_work_handler); - p->device = tape_get_device_reference(device); + p->device = tape_get_device(device); p->op = op; schedule_work(&p->work); diff --git a/drivers/s390/char/tape_3590.c b/drivers/s390/char/tape_3590.c index e4cc3aae9162..0c72aadb8391 100644 --- a/drivers/s390/char/tape_3590.c +++ b/drivers/s390/char/tape_3590.c @@ -608,7 +608,7 @@ tape_3590_schedule_work(struct tape_device *device, enum tape_op op) INIT_WORK(&p->work, tape_3590_work_handler); - p->device = tape_get_device_reference(device); + p->device = tape_get_device(device); p->op = op; schedule_work(&p->work); diff --git a/drivers/s390/char/tape_block.c b/drivers/s390/char/tape_block.c index 0c0705b91c28..c97c6aac8ed5 100644 --- a/drivers/s390/char/tape_block.c +++ b/drivers/s390/char/tape_block.c @@ -239,7 +239,7 @@ tapeblock_setup_device(struct tape_device * device) disk->major = tapeblock_major; disk->first_minor = device->first_minor; disk->fops = &tapeblock_fops; - disk->private_data = tape_get_device_reference(device); + disk->private_data = tape_get_device(device); disk->queue = blkdat->request_queue; set_capacity(disk, 0); sprintf(disk->disk_name, "btibm%d", @@ -247,11 +247,11 @@ tapeblock_setup_device(struct tape_device * device) blkdat->disk = disk; blkdat->medium_changed = 1; - blkdat->request_queue->queuedata = tape_get_device_reference(device); + blkdat->request_queue->queuedata = tape_get_device(device); add_disk(disk); - tape_get_device_reference(device); + tape_get_device(device); INIT_WORK(&blkdat->requeue_task, tapeblock_requeue); return 0; @@ -274,13 +274,14 @@ tapeblock_cleanup_device(struct tape_device *device) } del_gendisk(device->blk_data.disk); - device->blk_data.disk->private_data = - tape_put_device(device->blk_data.disk->private_data); + device->blk_data.disk->private_data = NULL; + tape_put_device(device); put_disk(device->blk_data.disk); device->blk_data.disk = NULL; cleanup_queue: - device->blk_data.request_queue->queuedata = tape_put_device(device); + device->blk_data.request_queue->queuedata = NULL; + tape_put_device(device); blk_cleanup_queue(device->blk_data.request_queue); device->blk_data.request_queue = NULL; @@ -363,7 +364,7 @@ tapeblock_open(struct block_device *bdev, fmode_t mode) struct tape_device * device; int rc; - device = tape_get_device_reference(disk->private_data); + device = tape_get_device(disk->private_data); if (device->required_tapemarks) { DBF_EVENT(2, "TBLOCK: missing tapemarks\n"); diff --git a/drivers/s390/char/tape_char.c b/drivers/s390/char/tape_char.c index b47e20d3d1da..d44e6981eeac 100644 --- a/drivers/s390/char/tape_char.c +++ b/drivers/s390/char/tape_char.c @@ -286,9 +286,9 @@ tapechar_open (struct inode *inode, struct file *filp) lock_kernel(); minor = iminor(filp->f_path.dentry->d_inode); - device = tape_get_device(minor / TAPE_MINORS_PER_DEV); + device = tape_find_device(minor / TAPE_MINORS_PER_DEV); if (IS_ERR(device)) { - DBF_EVENT(3, "TCHAR:open: tape_get_device() failed\n"); + DBF_EVENT(3, "TCHAR:open: tape_find_device() failed\n"); rc = PTR_ERR(device); goto out; } @@ -340,7 +340,8 @@ tapechar_release(struct inode *inode, struct file *filp) device->char_data.idal_buf = NULL; } tape_release(device); - filp->private_data = tape_put_device(device); + filp->private_data = NULL; + tape_put_device(device); return 0; } diff --git a/drivers/s390/char/tape_core.c b/drivers/s390/char/tape_core.c index 6311018e6543..a7b7e72c691b 100644 --- a/drivers/s390/char/tape_core.c +++ b/drivers/s390/char/tape_core.c @@ -511,11 +511,12 @@ tape_alloc_device(void) * increment the reference count. */ struct tape_device * -tape_get_device_reference(struct tape_device *device) +tape_get_device(struct tape_device *device) { - DBF_EVENT(4, "tape_get_device_reference(%p) = %i\n", device, - atomic_inc_return(&device->ref_count)); + int count; + count = atomic_inc_return(&device->ref_count); + DBF_EVENT(4, "tape_get_device(%p) = %i\n", device, count); return device; } @@ -525,32 +526,25 @@ tape_get_device_reference(struct tape_device *device) * The function returns a NULL pointer to be used by the caller * for clearing reference pointers. */ -struct tape_device * +void tape_put_device(struct tape_device *device) { - int remain; + int count; - remain = atomic_dec_return(&device->ref_count); - if (remain > 0) { - DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, remain); - } else { - if (remain < 0) { - DBF_EVENT(4, "put device without reference\n"); - } else { - DBF_EVENT(4, "tape_free_device(%p)\n", device); - kfree(device->modeset_byte); - kfree(device); - } + count = atomic_dec_return(&device->ref_count); + DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, count); + BUG_ON(count < 0); + if (count == 0) { + kfree(device->modeset_byte); + kfree(device); } - - return NULL; } /* * Find tape device by a device index. */ struct tape_device * -tape_get_device(int devindex) +tape_find_device(int devindex) { struct tape_device *device, *tmp; @@ -558,7 +552,7 @@ tape_get_device(int devindex) read_lock(&tape_device_lock); list_for_each_entry(tmp, &tape_device_list, node) { if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) { - device = tape_get_device_reference(tmp); + device = tape_get_device(tmp); break; } } @@ -607,7 +601,8 @@ __tape_discard_requests(struct tape_device *device) list_del(&request->list); /* Decrease ref_count for removed request. */ - request->device = tape_put_device(device); + request->device = NULL; + tape_put_device(device); request->rc = -EIO; if (request->callback != NULL) request->callback(request, request->callback_data); @@ -665,9 +660,11 @@ tape_generic_remove(struct ccw_device *cdev) tape_cleanup_device(device); } - if (dev_get_drvdata(&cdev->dev)) { + device = dev_get_drvdata(&cdev->dev); + if (device) { sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group); - dev_set_drvdata(&cdev->dev, tape_put_device(dev_get_drvdata(&cdev->dev))); + dev_set_drvdata(&cdev->dev, NULL); + tape_put_device(device); } } @@ -722,9 +719,8 @@ tape_free_request (struct tape_request * request) { DBF_LH(6, "Free request %p\n", request); - if (request->device != NULL) { - request->device = tape_put_device(request->device); - } + if (request->device) + tape_put_device(request->device); kfree(request->cpdata); kfree(request->cpaddr); kfree(request); @@ -839,7 +835,8 @@ static void tape_long_busy_timeout(unsigned long data) BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY); DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id); __tape_start_next_request(device); - device->lb_timeout.data = (unsigned long) tape_put_device(device); + device->lb_timeout.data = 0UL; + tape_put_device(device); spin_unlock_irq(get_ccwdev_lock(device->cdev)); } @@ -919,7 +916,7 @@ __tape_start_request(struct tape_device *device, struct tape_request *request) } /* Increase use count of device for the added request. */ - request->device = tape_get_device_reference(device); + request->device = tape_get_device(device); if (list_empty(&device->req_queue)) { /* No other requests are on the queue. Start this one. */ @@ -1118,8 +1115,8 @@ __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb) if (req->status == TAPE_REQUEST_LONG_BUSY) { DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id); if (del_timer(&device->lb_timeout)) { - device->lb_timeout.data = (unsigned long) - tape_put_device(device); + device->lb_timeout.data = 0UL; + tape_put_device(device); __tape_start_next_request(device); } return; @@ -1174,7 +1171,7 @@ __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb) break; case TAPE_IO_LONG_BUSY: device->lb_timeout.data = - (unsigned long)tape_get_device_reference(device); + (unsigned long) tape_get_device(device); device->lb_timeout.expires = jiffies + LONG_BUSY_TIMEOUT * HZ; DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id); @@ -1327,7 +1324,7 @@ EXPORT_SYMBOL(tape_generic_online); EXPORT_SYMBOL(tape_generic_offline); EXPORT_SYMBOL(tape_generic_pm_suspend); EXPORT_SYMBOL(tape_put_device); -EXPORT_SYMBOL(tape_get_device_reference); +EXPORT_SYMBOL(tape_get_device); EXPORT_SYMBOL(tape_state_verbose); EXPORT_SYMBOL(tape_op_verbose); EXPORT_SYMBOL(tape_state_set); diff --git a/drivers/s390/char/tape_proc.c b/drivers/s390/char/tape_proc.c index 202f42132939..ebd820ccfb24 100644 --- a/drivers/s390/char/tape_proc.c +++ b/drivers/s390/char/tape_proc.c @@ -45,7 +45,7 @@ static int tape_proc_show(struct seq_file *m, void *v) seq_printf(m, "TapeNo\tBusID CuType/Model\t" "DevType/Model\tBlkSize\tState\tOp\tMedState\n"); } - device = tape_get_device(n); + device = tape_find_device(n); if (IS_ERR(device)) return 0; spin_lock_irq(get_ccwdev_lock(device->cdev)); -- 2.20.1