[PATCH 4/4] Rationalize fasync return values

Jonathan Corbet
2009-02-02T18:21:42Z

Most fasync implementations do something like:

return fasync_helper(...);

But fasync_helper() will return a positive value at times - a feature used
in at least one place. Thus, a number of other drivers do:

err = fasync_helper(...);
if (err < 0)
return err;
return 0;

In the interests of consistency and more concise code, it makes sense to
map positive return values onto zero where ->fasync() is called.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
---
drivers/char/sonypi.c | 7 +------
drivers/gpu/drm/drm_fops.c | 6 +-----
drivers/hid/usbhid/hiddev.c | 5 +----
drivers/ieee1394/dv1394.c | 6 +-----
drivers/input/evdev.c | 5 +----
drivers/input/joydev.c | 5 +----
drivers/input/mousedev.c | 5 +----
drivers/input/serio/serio_raw.c | 4 +---
drivers/net/wan/cosa.c | 4 ++--
drivers/platform/x86/sony-laptop.c | 7 +------
drivers/scsi/sg.c | 4 +---
fs/fcntl.c | 2 ++
fs/ioctl.c | 2 +-
fs/pipe.c | 17 +++--------------
sound/core/control.c | 7 ++-----
sound/core/pcm_native.c | 4 +---
sound/core/timer.c | 6 +-----
17 files changed, 22 insertions(+), 74 deletions(-)

diff --git a/drivers/char/sonypi.c b/drivers/char/sonypi.c
index f437443..fd3dced 100644
--- a/drivers/char/sonypi.c
+++ b/drivers/char/sonypi.c
@@ -888,12 +888,7 @@ found:

static int sonypi_misc_fasync(int fd, struct file *filp, int on)
{
- int retval;
-
- retval = fasync_helper(fd, filp, on, &sonypi_device.fifo_async);
- if (retval < 0)
- return retval;
- return 0;
+ return fasync_helper(fd, filp, on, &sonypi_device.fifo_async);
}

static int sonypi_misc_release(struct inode *inode, struct file *file)
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index b06a537..9ec9d5d 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -337,14 +337,10 @@ int drm_fasync(int fd, struct file *filp, int on)
{
struct drm_file *priv = filp->private_data;
struct drm_device *dev = priv->minor->dev;
- int retcode;

DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
(long)old_encode_dev(priv->minor->device));
- retcode = fasync_helper(fd, filp, on, &dev->buf_async);
- if (retcode < 0)
- return retcode;
- return 0;
+ return fasync_helper(fd, filp, on, &dev->buf_async);
}
EXPORT_SYMBOL(drm_fasync);

diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index d73eea3..55828da 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -227,12 +227,9 @@ void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
*/
static int hiddev_fasync(int fd, struct file *file, int on)
{
- int retval;
struct hiddev_list *list = file->private_data;

- retval = fasync_helper(fd, file, on, &list->fasync);
-
- return retval < 0 ? retval : 0;
+ return fasync_helper(fd, file, on, &list->fasync);
}

diff --git a/drivers/ieee1394/dv1394.c b/drivers/ieee1394/dv1394.c
index a329e6b..22e5487 100644
--- a/drivers/ieee1394/dv1394.c
+++ b/drivers/ieee1394/dv1394.c
@@ -1325,11 +1325,7 @@ static int dv1394_fasync(int fd, struct file *file, int on)

struct video_card *video = file_to_video_card(file);

- int retval = fasync_helper(fd, file, on, &video->fasync);
-
- if (retval < 0)
- return retval;
- return 0;
+ return fasync_helper(fd, file, on, &video->fasync);
}

static ssize_t dv1394_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index ed8baa0..7a7a026 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -94,11 +94,8 @@ static void evdev_event(struct input_handle *handle,
static int evdev_fasync(int fd, struct file *file, int on)
{
struct evdev_client *client = file->private_data;
- int retval;
-
- retval = fasync_helper(fd, file, on, &client->fasync);

- return retval < 0 ? retval : 0;
+ return fasync_helper(fd, file, on, &client->fasync);
}

static int evdev_flush(struct file *file, fl_owner_t id)
diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c
index 6f23662..4224f01 100644
--- a/drivers/input/joydev.c
+++ b/drivers/input/joydev.c
@@ -159,12 +159,9 @@ static void joydev_event(struct input_handle *handle,

static int joydev_fasync(int fd, struct file *file, int on)
{
- int retval;
struct joydev_client *client = file->private_data;

- retval = fasync_helper(fd, file, on, &client->fasync);
-
- return retval < 0 ? retval : 0;
+ return fasync_helper(fd, file, on, &client->fasync);
}

static void joydev_free(struct device *dev)
diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c
index ef99a7e..17fd6d4 100644
--- a/drivers/input/mousedev.c
+++ b/drivers/input/mousedev.c
@@ -403,12 +403,9 @@ static void mousedev_event(struct input_handle *handle,

static int mousedev_fasync(int fd, struct file *file, int on)
{
- int retval;
struct mousedev_client *client = file->private_data;

- retval = fasync_helper(fd, file, on, &client->fasync);
-
- return retval < 0 ? retval : 0;
+ return fasync_helper(fd, file, on, &client->fasync);
}

static void mousedev_free(struct device *dev)
diff --git a/drivers/input/serio/serio_raw.c b/drivers/input/serio/serio_raw.c
index 06bbd0e..b03009b 100644
--- a/drivers/input/serio/serio_raw.c
+++ b/drivers/input/serio/serio_raw.c
@@ -58,10 +58,8 @@ static unsigned int serio_raw_no;
static int serio_raw_fasync(int fd, struct file *file, int on)
{
struct serio_raw_list *list = file->private_data;
- int retval;

- retval = fasync_helper(fd, file, on, &list->fasync);
- return retval < 0 ? retval : 0;
+ return fasync_helper(fd, file, on, &list->fasync);
}

static struct serio_raw *serio_raw_locate(int minor)
diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c
index d80b72e..ce753e9 100644
--- a/drivers/net/wan/cosa.c
+++ b/drivers/net/wan/cosa.c
@@ -993,8 +993,8 @@ static struct fasync_struct *fasync[256] = { NULL, };
static int cosa_fasync(struct inode *inode, struct file *file, int on)
{
int port = iminor(inode);
- int rv = fasync_helper(inode, file, on, &fasync[port]);
- return rv < 0 ? rv : 0;
+
+ return fasync_helper(inode, file, on, &fasync[port]);
}
#endif

diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index 537959d..bc8996c 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -1917,12 +1917,7 @@ static struct sonypi_compat_s sonypi_compat = {

static int sonypi_misc_fasync(int fd, struct file *filp, int on)
{
- int retval;
-
- retval = fasync_helper(fd, filp, on, &sonypi_compat.fifo_async);
- if (retval < 0)
- return retval;
- return 0;
+ return fasync_helper(fd, filp, on, &sonypi_compat.fifo_async);
}

static int sonypi_misc_release(struct inode *inode, struct file *file)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 8f0bd3f..b656cde 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1154,7 +1154,6 @@ sg_poll(struct file *filp, poll_table * wait)
static int
sg_fasync(int fd, struct file *filp, int mode)
{
- int retval;
Sg_device *sdp;
Sg_fd *sfp;

@@ -1163,8 +1162,7 @@ sg_fasync(int fd, struct file *filp, int mode)
SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
sdp->disk->disk_name, mode));

- retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
- return (retval < 0) ? retval : 0;
+ return fasync_helper(fd, filp, mode, &sfp->async_qp);
}

static int
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 7b641d9..7a74571 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -192,6 +192,8 @@ static int setfl(int fd, struct file * filp, unsigned long arg)
error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
if (error < 0)
goto out;
+ if (error > 0)
+ error = 0;
}
/*
* Now that we use bitops we have to tweak each bit individually.
diff --git a/fs/ioctl.c b/fs/ioctl.c
index bc32cb2..fcfd0e6 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -432,7 +432,7 @@ static int ioctl_fioasync(unsigned int fd, struct file *filp,
else
error = -ENOTTY;
}
- return error;
+ return error < 0 ? error : 0;
}

static int ioctl_fsfreeze(struct file *filp)
diff --git a/fs/pipe.c b/fs/pipe.c
index 3a48ba5..900de67 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -667,10 +667,7 @@ pipe_read_fasync(int fd, struct file *filp, int on)
retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_readers);
mutex_unlock(&inode->i_mutex);

- if (retval < 0)
- return retval;
-
- return 0;
+ return retval;
}

@@ -684,10 +681,7 @@ pipe_write_fasync(int fd, struct file *filp, int on)
retval = fasync_helper(fd, filp, on, &inode->i_pipe->fasync_writers);
mutex_unlock(&inode->i_mutex);

- if (retval < 0)
- return retval;
-
- return 0;
+ return retval;
}

@@ -701,16 +695,11 @@ pipe_rdwr_fasync(int fd, struct file *filp, int on)
mutex_lock(&inode->i_mutex);

retval = fasync_helper(fd, filp, on, &pipe->fasync_readers);
-
if (retval >= 0)
retval = fasync_helper(fd, filp, on, &pipe->fasync_writers);

mutex_unlock(&inode->i_mutex);
-
- if (retval < 0)
- return retval;
-
- return 0;
+ return retval;
}

diff --git a/sound/core/control.c b/sound/core/control.c
index 636b3b5..4b20fa2 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1373,12 +1373,9 @@ EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
static int snd_ctl_fasync(int fd, struct file * file, int on)
{
struct snd_ctl_file *ctl;
- int err;
+
ctl = file->private_data;
- err = fasync_helper(fd, file, on, &ctl->fasync);
- if (err < 0)
- return err;
- return 0;
+ return fasync_helper(fd, file, on, &ctl->fasync);
}

/*
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index a789efc..a75c194 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -3246,9 +3246,7 @@ static int snd_pcm_fasync(int fd, struct file * file, int on)
err = fasync_helper(fd, file, on, &runtime->fasync);
out:
unlock_kernel();
- if (err < 0)
- return err;
- return 0;
+ return err;
}

/*
diff --git a/sound/core/timer.c b/sound/core/timer.c
index 7965320..3f0050d 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1825,13 +1825,9 @@ static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
static int snd_timer_user_fasync(int fd, struct file * file, int on)
{
struct snd_timer_user *tu;
- int err;

tu = file->private_data;
- err = fasync_helper(fd, file, on, &tu->fasync);
- if (err < 0)
- return err;
- return 0;
+ return fasync_helper(fd, file, on, &tu->fasync);
}

static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
--
1.6.1.1