[PATCH] pipe: remove redundant fifo_poll abstraction

Remove a redundant fifo_poll() abstraction from fs/pipe.c and adds a big
fat comment stating we set POLLERR for FIFOs too on Linux unlike most
Unices.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fs/pipe.c

@@ -415,6 +415,10 @@ pipe_poll(struct file *filp, poll_table *wait)
 
 	if (filp->f_mode & FMODE_WRITE) {
 		mask |= (nrbufs < PIPE_BUFFERS) ? POLLOUT | POLLWRNORM : 0;
+		/*
+		 * Most Unices do not set POLLERR for FIFOs but on Linux they
+		 * behave exactly like pipes for poll().
+		 */
 		if (!PIPE_READERS(*inode))
 			mask |= POLLERR;
 	}
@@ -422,9 +426,6 @@ pipe_poll(struct file *filp, poll_table *wait)
 	return mask;
 }
 
-/* FIXME: most Unices do not set POLLERR for fifos */
-#define fifo_poll pipe_poll
-
 static int
 pipe_release(struct inode *inode, int decr, int decw)
 {
@@ -568,7 +569,7 @@ struct file_operations read_fifo_fops = {
 	.read		= pipe_read,
 	.readv		= pipe_readv,
 	.write		= bad_pipe_w,
-	.poll		= fifo_poll,
+	.poll		= pipe_poll,
 	.ioctl		= pipe_ioctl,
 	.open		= pipe_read_open,
 	.release	= pipe_read_release,
@@ -580,7 +581,7 @@ struct file_operations write_fifo_fops = {
 	.read		= bad_pipe_r,
 	.write		= pipe_write,
 	.writev		= pipe_writev,
-	.poll		= fifo_poll,
+	.poll		= pipe_poll,
 	.ioctl		= pipe_ioctl,
 	.open		= pipe_write_open,
 	.release	= pipe_write_release,
@@ -593,7 +594,7 @@ struct file_operations rdwr_fifo_fops = {
 	.readv		= pipe_readv,
 	.write		= pipe_write,
 	.writev		= pipe_writev,
-	.poll		= fifo_poll,
+	.poll		= pipe_poll,
 	.ioctl		= pipe_ioctl,
 	.open		= pipe_rdwr_open,
 	.release	= pipe_rdwr_release,