ieee1394: mark char device files as not seekable
The
- raw1394 (/dev/raw1394),
- video1394 (/dev/video1394/*),
- dv1394 (/dev/dv1394/*)
character device file ABIs do not make any use of lseek(), pread(), or
pwrite(). Therefore use nonseekable_open() and, redundantly, set
file_operations.llseek to no_llseek to remove any doubt whether the BKL-
grabbing default_llseek handler is used.
Although all this is legacy code which should be left in peace until it
is eventually removed (as it is superseded by firewire-core's
<linux/firewire-cdev.h> ABI), this change seems still worth doing to
further minimize the presence of BKL usage in the kernel.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/ieee1394/dv1394.c b/drivers/ieee1394/dv1394.c
index 9fd4a0d..adaefab 100644
--- a/drivers/ieee1394/dv1394.c
+++ b/drivers/ieee1394/dv1394.c
@@ -1824,7 +1824,7 @@
"and will not be available in the new firewire driver stack. "
"Try libraw1394 based programs instead.\n", current->comm);
- return 0;
+ return nonseekable_open(inode, file);
}
@@ -2153,17 +2153,18 @@
static const struct file_operations dv1394_fops=
{
.owner = THIS_MODULE,
- .poll = dv1394_poll,
+ .poll = dv1394_poll,
.unlocked_ioctl = dv1394_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = dv1394_compat_ioctl,
#endif
.mmap = dv1394_mmap,
.open = dv1394_open,
- .write = dv1394_write,
- .read = dv1394_read,
+ .write = dv1394_write,
+ .read = dv1394_read,
.release = dv1394_release,
- .fasync = dv1394_fasync,
+ .fasync = dv1394_fasync,
+ .llseek = no_llseek,
};