don't bother with path_get()/path_put() in unix_open_file()

Once unix_sock ->path is set, we are guaranteed that its ->path will remain
unchanged (and pinned) until the socket is closed.  OTOH, dentry_open()
does not modify the path passed to it.

IOW, there's no need to copy unix_sk(sk)->path in unix_open_file() - we
can just pass it to dentry_open() and be done with that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/20250712054157.GZ1880847@ZenIV
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index d52811321fceafb4498eb2928284c4b7b7700678..c247fb9ac761d22c8d51f588458483913a783851 100644 (file)
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -3201,7 +3201,6 @@ EXPORT_SYMBOL_GPL(unix_outq_len);
 
 static int unix_open_file(struct sock *sk)
 {
-       struct path path;
        struct file *f;
        int fd;
 
@@ -3211,27 +3210,20 @@ static int unix_open_file(struct sock *sk)
        if (!smp_load_acquire(&unix_sk(sk)->addr))
                return -ENOENT;
 
-       path = unix_sk(sk)->path;
-       if (!path.dentry)
+       if (!unix_sk(sk)->path.dentry)
                return -ENOENT;
 
-       path_get(&path);
-
        fd = get_unused_fd_flags(O_CLOEXEC);
        if (fd < 0)
-               goto out;
+               return fd;
 
-       f = dentry_open(&path, O_PATH, current_cred());
+       f = dentry_open(&unix_sk(sk)->path, O_PATH, current_cred());
        if (IS_ERR(f)) {
                put_unused_fd(fd);
-               fd = PTR_ERR(f);
-               goto out;
+               return PTR_ERR(f);
        }
 
        fd_install(fd, f);
-out:
-       path_put(&path);
-
        return fd;
 }