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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2008-03-31 10:03:38 +0900
committerJames Bottomley <James.Bottomley@HansenPartnership.com>2008-04-18 11:47:19 -0500
commitd45ac4fa8f277e1ec5acfb67ce5d6406555760cf (patch)
treef620055da979b1af58bfdac16f35f90cd67e6f13 /block
parent0e4ff797d7f2f2bb860b8f31dc5d1f2273b2f05a (diff)
downloadlwn-d45ac4fa8f277e1ec5acfb67ce5d6406555760cf.tar.gz
lwn-d45ac4fa8f277e1ec5acfb67ce5d6406555760cf.zip
[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: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Diffstat (limited to 'block')
-rw-r--r--block/bsg.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/block/bsg.c b/block/bsg.c
index 8917c5174dc2..d8e0cb8dd6be 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -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);