diff options
Diffstat (limited to 'drivers/staging/comedi/comedi_fops.c')
-rw-r--r-- | drivers/staging/comedi/comedi_fops.c | 44 |
1 files changed, 31 insertions, 13 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index aced00e5cd10..aeb2c00875cd 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -83,7 +83,7 @@ static int do_subdinfo_ioctl(struct comedi_device *dev, static int do_chaninfo_ioctl(struct comedi_device *dev, struct comedi_chaninfo __user *arg); static int do_bufinfo_ioctl(struct comedi_device *dev, - struct comedi_bufinfo __user *arg); + struct comedi_bufinfo __user *arg, void *file); static int do_cmd_ioctl(struct comedi_device *dev, struct comedi_cmd __user *arg, void *file); static int do_lock_ioctl(struct comedi_device *dev, unsigned int arg, @@ -169,7 +169,8 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, break; case COMEDI_BUFINFO: rc = do_bufinfo_ioctl(dev, - (struct comedi_bufinfo __user *)arg); + (struct comedi_bufinfo __user *)arg, + file); break; case COMEDI_LOCK: rc = do_lock_ioctl(dev, arg, file); @@ -563,7 +564,7 @@ static int do_chaninfo_ioctl(struct comedi_device *dev, */ static int do_bufinfo_ioctl(struct comedi_device *dev, - struct comedi_bufinfo __user *arg) + struct comedi_bufinfo __user *arg, void *file) { struct comedi_bufinfo bi; struct comedi_subdevice *s; @@ -576,6 +577,10 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, return -EINVAL; s = dev->subdevices + bi.subdevice; + + if (s->lock && s->lock != file) + return -EACCES; + async = s->async; if (!async) { @@ -584,8 +589,17 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, bi.buf_read_ptr = 0; bi.buf_write_count = 0; bi.buf_read_count = 0; + bi.bytes_read = 0; + bi.bytes_written = 0; goto copyback; } + if (!s->busy) { + bi.bytes_read = 0; + bi.bytes_written = 0; + goto copyback_position; + } + if (s->busy != file) + return -EACCES; if (bi.bytes_read && (s->subdev_flags & SDF_CMD_READ)) { bi.bytes_read = comedi_buf_read_alloc(async, bi.bytes_read); @@ -604,6 +618,7 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, comedi_buf_write_free(async, bi.bytes_written); } +copyback_position: bi.buf_write_count = async->buf_write_count; bi.buf_write_ptr = async->buf_write_ptr; bi.buf_read_count = async->buf_read_count; @@ -1576,6 +1591,19 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, while (nbytes > 0 && !retval) { set_current_state(TASK_INTERRUPTIBLE); + if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) { + if (count == 0) { + if (comedi_get_subdevice_runflags(s) & + SRF_ERROR) { + retval = -EPIPE; + } else { + retval = 0; + } + do_become_nonbusy(dev, s); + } + break; + } + n = nbytes; m = n; @@ -1588,16 +1616,6 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, n = m; if (n == 0) { - if (!(comedi_get_subdevice_runflags(s) & SRF_RUNNING)) { - if (comedi_get_subdevice_runflags(s) & - SRF_ERROR) { - retval = -EPIPE; - } else { - retval = 0; - } - do_become_nonbusy(dev, s); - break; - } if (file->f_flags & O_NONBLOCK) { retval = -EAGAIN; break; |