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author | 2009-12-07 12:52:03 +0100 | |
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committer | 2009-12-07 12:51:36 +0100 | |
commit | 8fd138c366a8a302d9da8a428c6e927c8bff7d35 (patch) | |
tree | 23b406a120390a6631fab5ca2f35d91395971c3c /drivers/s390/char/tape_core.c | |
parent | [S390] tape: fix tape remove function (diff) | |
download | linux-8fd138c366a8a302d9da8a428c6e927c8bff7d35.tar.gz linux-8fd138c366a8a302d9da8a428c6e927c8bff7d35.tar.bz2 linux-8fd138c366a8a302d9da8a428c6e927c8bff7d35.zip |
[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 <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/char/tape_core.c')
-rw-r--r-- | drivers/s390/char/tape_core.c | 61 |
1 files changed, 29 insertions, 32 deletions
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); |