eventfd: convert do_eventfd() to FD_PREPARE()

Link: https://patch.msgid.link/20251123-work-fd-prepare-v4-3-b6efa1706cfd@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/eventfd.c b/fs/eventfd.c
index af42b2c7d2358c42841b6ea83a8e04866ab5750b..3219e0d596fe8a3986f96aa0333e68b1b7e90b8b 100644 (file)
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -378,9 +378,7 @@ EXPORT_SYMBOL_GPL(eventfd_ctx_fileget);
 
 static int do_eventfd(unsigned int count, int flags)
 {
-       struct eventfd_ctx *ctx;
-       struct file *file;
-       int fd;
+       struct eventfd_ctx *ctx __free(kfree) = NULL;
 
        /* Check the EFD_* constants for consistency.  */
        BUILD_BUG_ON(EFD_CLOEXEC != O_CLOEXEC);
@@ -398,26 +396,19 @@ static int do_eventfd(unsigned int count, int flags)
        init_waitqueue_head(&ctx->wqh);
        ctx->count = count;
        ctx->flags = flags;
-       ctx->id = ida_alloc(&eventfd_ida, GFP_KERNEL);
 
        flags &= EFD_SHARED_FCNTL_FLAGS;
        flags |= O_RDWR;
-       fd = get_unused_fd_flags(flags);
-       if (fd < 0)
-               goto err;
-
-       file = anon_inode_getfile_fmode("[eventfd]", &eventfd_fops,
-                                       ctx, flags, FMODE_NOWAIT);
-       if (IS_ERR(file)) {
-               put_unused_fd(fd);
-               fd = PTR_ERR(file);
-               goto err;
-       }
-       fd_install(fd, file);
-       return fd;
-err:
-       eventfd_free_ctx(ctx);
-       return fd;
+
+       FD_PREPARE(fdf, flags,
+                  anon_inode_getfile_fmode("[eventfd]", &eventfd_fops, ctx,
+                                           flags, FMODE_NOWAIT));
+       if (fdf.err)
+               return fdf.err;
+
+       ctx->id = ida_alloc(&eventfd_ida, GFP_KERNEL);
+       retain_and_null_ptr(ctx);
+       return fd_publish(fdf);
 }
 
 SYSCALL_DEFINE2(eventfd2, unsigned int, count, int, flags)