Rationalize fasync return values

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.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

11 files changed, 12 insertions, 46 deletions

diff --git a/drivers/char/sonypi.c b/drivers/char/sonypi.c
index f4374437a033..fd3dced97776 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 f52663ebe016..e13cb62bbaee 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 4940e4d70c2d..3a7b4fe192a3 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 3838bc4acaba..cb15bfa38d70 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 ed8baa0aec3c..7a7a026ba712 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 6f2366220a50..4224f0112849 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 ef99a7e6d40c..17fd6d46d082 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 06bbd0e74c6f..b03009bb7468 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 d80b72e22dea..ce753e9c576b 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 537959d07148..bc8996c849ac 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 516925d8b570..b4ef2f84ea32 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