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authorFrank Zago <frank@zago.net>2008-09-28 08:12:22 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2008-10-12 09:37:12 -0200
commit6b060ffea0722cfe4f5156a73a6424130d3d804a (patch)
treefa3351600d2fe6dd3ac955e2954c42d6675e78bf /drivers/media
parent6c49da7f169c25eb39b80ff168f5bdbacf8457e1 (diff)
V4L/DVB (9086): gspca: Use a kref to avoid potentialy blocking forever in disconnect.
Signed-off-by: Frank Zago <frank@zago.net> Signed-off-by: Jean-Francois Moine <moinejf@free.fr> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/video/gspca/gspca.c39
-rw-r--r--drivers/media/video/gspca/gspca.h1
2 files changed, 28 insertions, 12 deletions
diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index 3f0fd44f19a..342a0f39e5d 100644
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -29,6 +29,7 @@
#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/io.h>
+#include <linux/kref.h>
#include <asm/page.h>
#include <linux/uaccess.h>
#include <linux/jiffies.h>
@@ -834,6 +835,16 @@ out:
return ret;
}
+static void gspca_delete(struct kref *kref)
+{
+ struct gspca_dev *gspca_dev = container_of(kref, struct gspca_dev, kref);
+
+ PDEBUG(D_STREAM, "device deleted");
+
+ kfree(gspca_dev->usb_buf);
+ kfree(gspca_dev);
+}
+
static int dev_open(struct inode *inode, struct file *file)
{
struct gspca_dev *gspca_dev;
@@ -853,6 +864,10 @@ static int dev_open(struct inode *inode, struct file *file)
goto out;
}
gspca_dev->users++;
+
+ /* one more user */
+ kref_get(&gspca_dev->kref);
+
file->private_data = gspca_dev;
#ifdef GSPCA_DEBUG
/* activate the v4l2 debug */
@@ -895,7 +910,11 @@ static int dev_close(struct inode *inode, struct file *file)
}
file->private_data = NULL;
mutex_unlock(&gspca_dev->queue_lock);
+
PDEBUG(D_STREAM, "close done");
+
+ kref_put(&gspca_dev->kref, gspca_delete);
+
return 0;
}
@@ -1809,6 +1828,7 @@ int gspca_dev_probe(struct usb_interface *intf,
err("couldn't kzalloc gspca struct");
return -EIO;
}
+ kref_init(&gspca_dev->kref);
gspca_dev->usb_buf = kmalloc(USB_BUF_SZ, GFP_KERNEL);
if (!gspca_dev->usb_buf) {
err("out of memory");
@@ -1858,8 +1878,7 @@ int gspca_dev_probe(struct usb_interface *intf,
PDEBUG(D_PROBE, "probe ok");
return 0;
out:
- kfree(gspca_dev->usb_buf);
- kfree(gspca_dev);
+ kref_put(&gspca_dev->kref, gspca_delete);
return ret;
}
EXPORT_SYMBOL(gspca_dev_probe);
@@ -1874,8 +1893,8 @@ void gspca_disconnect(struct usb_interface *intf)
{
struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
- if (!gspca_dev)
- return;
+ usb_set_intfdata(intf, NULL);
+
gspca_dev->present = 0;
mutex_lock(&gspca_dev->queue_lock);
mutex_lock(&gspca_dev->usb_lock);
@@ -1883,16 +1902,12 @@ void gspca_disconnect(struct usb_interface *intf)
destroy_urbs(gspca_dev);
mutex_unlock(&gspca_dev->usb_lock);
mutex_unlock(&gspca_dev->queue_lock);
- while (gspca_dev->users != 0) { /* wait until fully closed */
- atomic_inc(&gspca_dev->nevent);
- wake_up_interruptible(&gspca_dev->wq); /* wake processes */
- schedule();
- }
+
/* We don't want people trying to open up the device */
video_unregister_device(&gspca_dev->vdev);
-/* Free the memory */
- kfree(gspca_dev->usb_buf);
- kfree(gspca_dev);
+
+ kref_put(&gspca_dev->kref, gspca_delete);
+
PDEBUG(D_PROBE, "disconnect complete");
}
EXPORT_SYMBOL(gspca_disconnect);
diff --git a/drivers/media/video/gspca/gspca.h b/drivers/media/video/gspca/gspca.h
index b0bdae194bb..192dffdcd9c 100644
--- a/drivers/media/video/gspca/gspca.h
+++ b/drivers/media/video/gspca/gspca.h
@@ -121,6 +121,7 @@ struct gspca_dev {
struct video_device vdev; /* !! must be the first item */
struct file_operations fops;
struct usb_device *dev;
+ struct kref kref;
struct file *capt_file; /* file doing video capture */
struct cam cam; /* device information */