UIO: BKL removal
Fill in needed locking around idr accesses, then remove the big kernel lock
from the UIO driver. Since there are no in-tree UIO drivers with open()
methods, no further BKL pushdown is required.
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 3a6934b..4f28f4b 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -47,6 +47,9 @@
struct class *class;
} *uio_class;
+/* Protect idr accesses */
+static DEFINE_MUTEX(minor_lock);
+
/*
* attributes
*/
@@ -231,7 +234,6 @@
static int uio_get_minor(struct uio_device *idev)
{
- static DEFINE_MUTEX(minor_lock);
int retval = -ENOMEM;
int id;
@@ -253,7 +255,9 @@
static void uio_free_minor(struct uio_device *idev)
{
+ mutex_lock(&minor_lock);
idr_remove(&uio_idr, idev->minor);
+ mutex_unlock(&minor_lock);
}
/**
@@ -297,8 +301,9 @@
struct uio_listener *listener;
int ret = 0;
- lock_kernel();
+ mutex_lock(&minor_lock);
idev = idr_find(&uio_idr, iminor(inode));
+ mutex_unlock(&minor_lock);
if (!idev) {
ret = -ENODEV;
goto out;
@@ -324,18 +329,15 @@
if (ret)
goto err_infoopen;
}
- unlock_kernel();
return 0;
err_infoopen:
-
kfree(listener);
-err_alloc_listener:
+err_alloc_listener:
module_put(idev->owner);
out:
- unlock_kernel();
return ret;
}