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>

1 files changed, 3 insertions, 13 deletions

diff --git a/fs/pipe.c b/fs/pipe.c
index 14f502b89cf5..94ad15967cf9 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;
 }
 
 
@@ -706,11 +700,7 @@ pipe_rdwr_fasync(int fd, struct file *filp, int on)
                         fasync_helper(-1, filp, 0, &pipe->fasync_readers);
         }
         mutex_unlock(&inode->i_mutex);
-
-        if (retval < 0)
-                return retval;
-
-        return 0;
+        return retval;
 }