Messages in this thread Patch in this message | | | Subject | Re: [PATCH] video4linux: Push down the BKL | From | Andy Walls <> | Date | Thu, 22 May 2008 22:08:04 -0400 |
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On Thu, 2008-05-22 at 22:37 +0100, Alan Cox wrote: > For most drivers the generic ioctl handler does the work and we update it > and it becomes the unlocked_ioctl method. Older drivers use the usercopy > method so we make it do the work. Finally there are a few special cases. > > Signed-off-by: Alan Cox <alan@redhat.com>
I'd like to start planning out the changes to eliminate the BKL from cx18.
Could someone give me a brief education as to what elements of cx18/ivtv_v4l2_do_ioctl() would be forcing the use of the BKL for these drivers' ioctls? I'm assuming it's not the mutex_un/lock(&....->serialize_lock) and that the answer's not in the diff.
Thanks. Andy
> diff --git a/drivers/media/video/cx18/cx18-ioctl.c b/drivers/media/video/cx18/cx18-ioctl.c > index dbdcb86..faf3a31 100644 > --- a/drivers/media/video/cx18/cx18-ioctl.c > +++ b/drivers/media/video/cx18/cx18-ioctl.c > @@ -837,15 +837,16 @@ static int cx18_v4l2_do_ioctl(struct inode *inode, struct file *filp, > return 0; > } > > -int cx18_v4l2_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, > - unsigned long arg) > +long cx18_v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > { > struct cx18_open_id *id = (struct cx18_open_id *)filp->private_data; > struct cx18 *cx = id->cx; > int res; > > + lock_kernel(); > mutex_lock(&cx->serialize_lock); > - res = video_usercopy(inode, filp, cmd, arg, cx18_v4l2_do_ioctl); > + res = video_usercopy(filp, cmd, arg, cx18_v4l2_do_ioctl); > mutex_unlock(&cx->serialize_lock); > + unlock_kernel(); > return res; > } > diff --git a/drivers/media/video/cx18/cx18-ioctl.h b/drivers/media/video/cx18/cx18-ioctl.h > index 9f4c7eb..32bede3 100644 > --- a/drivers/media/video/cx18/cx18-ioctl.h > +++ b/drivers/media/video/cx18/cx18-ioctl.h > @@ -1,4 +1,4 @@ > -/* > + /* > * cx18 ioctl system call > * > * Derived from ivtv-ioctl.h > @@ -24,7 +24,6 @@ > u16 cx18_service2vbi(int type); > void cx18_expand_service_set(struct v4l2_sliced_vbi_format *fmt, int is_pal); > u16 cx18_get_service_set(struct v4l2_sliced_vbi_format *fmt); > -int cx18_v4l2_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, > - unsigned long arg); > +long cx18_v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg); > int cx18_v4l2_ioctls(struct cx18 *cx, struct file *filp, unsigned cmd, > void *arg); > diff --git a/drivers/media/video/cx18/cx18-streams.c b/drivers/media/video/cx18/cx18-streams.c > index afb141b..7348b82 100644 > --- a/drivers/media/video/cx18/cx18-streams.c > +++ b/drivers/media/video/cx18/cx18-streams.c > @@ -39,7 +39,7 @@ static struct file_operations cx18_v4l2_enc_fops = { > .owner = THIS_MODULE, > .read = cx18_v4l2_read, > .open = cx18_v4l2_open, > - .ioctl = cx18_v4l2_ioctl, > + .unlocked_ioctl = cx18_v4l2_ioctl, > .release = cx18_v4l2_close, > .poll = cx18_v4l2_enc_poll, > };
> diff --git a/drivers/media/video/ivtv/ivtv-ioctl.c b/drivers/media/video/ivtv/ivtv-ioctl.c > index d508b5d..a481b2d 100644 > --- a/drivers/media/video/ivtv/ivtv-ioctl.c > +++ b/drivers/media/video/ivtv/ivtv-ioctl.c > @@ -1726,7 +1726,7 @@ static int ivtv_v4l2_do_ioctl(struct inode *inode, struct file *filp, > return 0; > } > > -static int ivtv_serialized_ioctl(struct ivtv *itv, struct inode *inode, struct file *filp, > +static int ivtv_serialized_ioctl(struct ivtv *itv, struct file *filp, > unsigned int cmd, unsigned long arg) > { > /* Filter dvb ioctls that cannot be handled by video_usercopy */ > @@ -1761,18 +1761,19 @@ static int ivtv_serialized_ioctl(struct ivtv *itv, struct inode *inode, struct f > default: > break; > } > - return video_usercopy(inode, filp, cmd, arg, ivtv_v4l2_do_ioctl); > + return video_usercopy(filp, cmd, arg, ivtv_v4l2_do_ioctl); > } > > -int ivtv_v4l2_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, > - unsigned long arg) > +long ivtv_v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > { > struct ivtv_open_id *id = (struct ivtv_open_id *)filp->private_data; > struct ivtv *itv = id->itv; > int res; > > + lock_kernel(); > mutex_lock(&itv->serialize_lock); > - res = ivtv_serialized_ioctl(itv, inode, filp, cmd, arg); > + res = ivtv_serialized_ioctl(itv, filp, cmd, arg); > mutex_unlock(&itv->serialize_lock); > + unlock_kernel(); > return res; > } > diff --git a/drivers/media/video/ivtv/ivtv-ioctl.h b/drivers/media/video/ivtv/ivtv-ioctl.h > index a03351b..6708ea0 100644 > --- a/drivers/media/video/ivtv/ivtv-ioctl.h > +++ b/drivers/media/video/ivtv/ivtv-ioctl.h > @@ -24,8 +24,7 @@ > u16 service2vbi(int type); > void expand_service_set(struct v4l2_sliced_vbi_format *fmt, int is_pal); > u16 get_service_set(struct v4l2_sliced_vbi_format *fmt); > -int ivtv_v4l2_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, > - unsigned long arg); > +long ivtv_v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg); > int ivtv_v4l2_ioctls(struct ivtv *itv, struct file *filp, unsigned int cmd, void *arg); > void ivtv_set_osd_alpha(struct ivtv *itv); > int ivtv_set_speed(struct ivtv *itv, int speed); > diff --git a/drivers/media/video/ivtv/ivtv-streams.c b/drivers/media/video/ivtv/ivtv-streams.c > index 4ab8d36..3131f68 100644 > --- a/drivers/media/video/ivtv/ivtv-streams.c > +++ b/drivers/media/video/ivtv/ivtv-streams.c > @@ -48,7 +48,7 @@ static const struct file_operations ivtv_v4l2_enc_fops = { > .read = ivtv_v4l2_read, > .write = ivtv_v4l2_write, > .open = ivtv_v4l2_open, > - .ioctl = ivtv_v4l2_ioctl, > + .unlocked_ioctl = ivtv_v4l2_ioctl, > .release = ivtv_v4l2_close, > .poll = ivtv_v4l2_enc_poll, > }; > @@ -58,7 +58,7 @@ static const struct file_operations ivtv_v4l2_dec_fops = { > .read = ivtv_v4l2_read, > .write = ivtv_v4l2_write, > .open = ivtv_v4l2_open, > - .ioctl = ivtv_v4l2_ioctl, > + .unlocked_ioctl = ivtv_v4l2_ioctl, > .release = ivtv_v4l2_close, > .poll = ivtv_v4l2_dec_poll, > };
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