Supporting ERR/NULL names in putname() makes callers code cleaner, and
is what some other path walking functions already support for the same
reason.

This also removes a few existing IS_ERR checks before putname().

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/io-uring/CAHk-=wgCac9hBsYzKMpHk0EbLgQaXR=OUAjHaBtaY+G8A9KhFg@mail.gmail.com/ (local)
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <redacted>
Signed-off-by: Dmitry Kadashev <redacted>
---
 fs/namei.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 79b0ff9b151e..70caf4ef1134 100644
--- a/fs/namei.c
+++ b/fs/namei.c

@@ -247,6 +247,9 @@ getname_kernel(const char * filename)
 
 void putname(struct filename *name)
 {
+	if (IS_ERR_OR_NULL(name))
+		return;
+
 	BUG_ON(name->refcnt <= 0);
 
 	if (--name->refcnt > 0)

@@ -4718,11 +4721,9 @@ int do_renameat2(int olddfd, struct filename *from, int newdfd,
 		goto retry;
 	}
 put_both:
-	if (!IS_ERR(from))
-		putname(from);
+	putname(from);
 put_new:
-	if (!IS_ERR(to))
-		putname(to);
+	putname(to);
 	return error;
 }
 

-- 
2.30.2