[PATCH 7/8] soundcore_open: Reduce the area BKL coverage

Arnd Bergmann
2010-07-03T22:03:05Z

From: John Kacur <jkacur@redhat.com>

Most of this function is protected by the sound_loader_lock.
We can push down the BKL to this call out err = file->f_op->open(inode,file);

In order to build the sound core without the BKL, we
will need to push the lock_kernel() call into the ~20
device drivers that register their file operations.

Signed-off-by: John Kacur <jkacur@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
---
sound/sound_core.c | 13 ++++++++-----
1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/sound/sound_core.c b/sound/sound_core.c
index 7c2d677..c8627fc 100644
--- a/sound/sound_core.c
+++ b/sound/sound_core.c
@@ -576,8 +576,6 @@ static int soundcore_open(struct inode *inode, struct file *file)
struct sound_unit *s;
const struct file_operations *new_fops = NULL;

- lock_kernel ();
-
chain=unit&0x0F;
if(chain==4 || chain==5) /* dsp/audio/dsp16 */
{
@@ -630,18 +628,23 @@ static int soundcore_open(struct inode *inode, struct file *file)
const struct file_operations *old_fops = file->f_op;
file->f_op = new_fops;
spin_unlock(&sound_loader_lock);
- if(file->f_op->open)
+
+ if (file->f_op->open) {
+ /* TODO: push down BKL into indivial open functions */
+ lock_kernel();
err = file->f_op->open(inode,file);
+ unlock_kernel();
+ }
+
if (err) {
fops_put(file->f_op);
file->f_op = fops_get(old_fops);
}
+
fops_put(old_fops);
- unlock_kernel();
return err;
}
spin_unlock(&sound_loader_lock);
- unlock_kernel();
return -ENODEV;
}

--
1.7.1