From: Ian Abbott Date: Wed, 2 Jul 2014 11:02:16 +0000 (+0100) Subject: staging: comedi: allow COMEDI_BUFINFO, COMEDI_CANCEL and COMEDI_POLL on locked subdevice X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=0e02dcae1ce238a2afda25da8cfd829c540088bb;p=deliverable%2Flinux.git staging: comedi: allow COMEDI_BUFINFO, COMEDI_CANCEL and COMEDI_POLL on locked subdevice Comedi subdevices can be locked for mostly exclusive access by a particular file object by means of the COMEDI_LOCK ioctl. Some operations disregard the lock. For example, the read() and write() file operations are allowed for the file object that set up an asynchronous command on the subdevice (making it "busy") regardless of whether it is locked. The COMEDI_BUFINFO, COMEDI_CANCEL and COMEDI_POLL ioctls are also associated with the file object that made the subdevice "busy" with a command. They currently obey the exclusive access lock on the subdevice as well, but it makes more sense for them to ignore it like the read() and write() file operations. Remove the exclusive subdevice access checks for these ioctls. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index d4904cc50f77..e8e38098dcf8 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -968,9 +968,6 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, s = &dev->subdevices[bi.subdevice]; - if (s->lock && s->lock != file) - return -EACCES; - async = s->async; if (!async) { @@ -1744,9 +1741,6 @@ static int do_cancel_ioctl(struct comedi_device *dev, unsigned int arg, if (s->async == NULL) return -EINVAL; - if (s->lock && s->lock != file) - return -EACCES; - if (!s->busy) return 0; @@ -1781,9 +1775,6 @@ static int do_poll_ioctl(struct comedi_device *dev, unsigned int arg, return -EINVAL; s = &dev->subdevices[arg]; - if (s->lock && s->lock != file) - return -EACCES; - if (!s->busy) return 0;