Commit d45ac4fa authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by James Bottomley

[SCSI] bsg: takes a ref to struct device in fops->open

bsg_register_queue() takes a ref to struct device that a caller
passes. For example, bsg takes a ref to the sdev_gendev for scsi
devices. However, bsg doesn't inrease the refcount in fops->open. So
while an application opens a bsg device, the scsi device that the bsg
device holds can go away (bsg also takes a ref to a queue, but it
doesn't prevent the device from going away).

With this patch, bsg increases the refcount of struct device in
fops->open and decreases it in fops->release.
Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 0e4ff797
......@@ -705,6 +705,7 @@ static struct bsg_device *bsg_alloc_device(void)
static int bsg_put_device(struct bsg_device *bd)
{
int ret = 0;
struct device *dev = bd->queue->bsg_dev.dev;
mutex_lock(&bsg_mutex);
......@@ -730,6 +731,7 @@ static int bsg_put_device(struct bsg_device *bd)
kfree(bd);
out:
mutex_unlock(&bsg_mutex);
put_device(dev);
return ret;
}
......@@ -789,21 +791,27 @@ static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
struct bsg_device *bd;
struct bsg_class_device *bcd;
bd = __bsg_get_device(iminor(inode));
if (bd)
return bd;
/*
* find the class device
*/
mutex_lock(&bsg_mutex);
bcd = idr_find(&bsg_minor_idr, iminor(inode));
if (bcd)
get_device(bcd->dev);
mutex_unlock(&bsg_mutex);
if (!bcd)
return ERR_PTR(-ENODEV);
return bsg_add_device(inode, bcd->queue, file);
bd = __bsg_get_device(iminor(inode));
if (bd)
return bd;
bd = bsg_add_device(inode, bcd->queue, file);
if (IS_ERR(bd))
put_device(bcd->dev);
return bd;
}
static int bsg_open(struct inode *inode, struct file *file)
......@@ -942,7 +950,6 @@ void bsg_unregister_queue(struct request_queue *q)
class_device_unregister(bcd->class_dev);
put_device(bcd->dev);
bcd->class_dev = NULL;
bcd->dev = NULL;
mutex_unlock(&bsg_mutex);
}
EXPORT_SYMBOL_GPL(bsg_unregister_queue);
......
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