From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 6 Mar 2025 17:30:42 +0000 (-1000)
Subject: fs/pipe: express 'pipe_empty()' in terms of 'pipe_occupancy()'
X-Git-Tag: v6.14-rc6~32
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=74d42bdb3a4673b1c10d1f457184e4d3c9cb0196;p=thirdparty%2Fkernel%2Fstable.git

fs/pipe: express 'pipe_empty()' in terms of 'pipe_occupancy()'

That's what 'pipe_full()' does, so it's more consistent. But more
importantly it gets the type limits right when the pipe head and tail
are no longer necessarily 'unsigned int'.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index e572e6fc4f81f..4d0a2267e6efc 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -177,23 +177,23 @@ static inline bool pipe_has_watch_queue(const struct pipe_inode_info *pipe)
 }
 
 /**
- * pipe_empty - Return true if the pipe is empty
+ * pipe_occupancy - Return number of slots used in the pipe
  * @head: The pipe ring head pointer
  * @tail: The pipe ring tail pointer
  */
-static inline bool pipe_empty(unsigned int head, unsigned int tail)
+static inline unsigned int pipe_occupancy(unsigned int head, unsigned int tail)
 {
-	return head == tail;
+	return (pipe_index_t)(head - tail);
 }
 
 /**
- * pipe_occupancy - Return number of slots used in the pipe
+ * pipe_empty - Return true if the pipe is empty
  * @head: The pipe ring head pointer
  * @tail: The pipe ring tail pointer
  */
-static inline unsigned int pipe_occupancy(unsigned int head, unsigned int tail)
+static inline bool pipe_empty(unsigned int head, unsigned int tail)
 {
-	return (pipe_index_t)(head - tail);
+	return !pipe_occupancy(head, tail);
 }
 
 /**