fdget(), trivial conversions

fdget() is the first thing done in scope, all matching fdput() are
immediately followed by leaving the scope.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

5 files changed, 16 insertions, 31 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 85b209626dd7..075ce7299973 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -966,22 +966,20 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
 {
 	struct perf_cgroup *cgrp;
 	struct cgroup_subsys_state *css;
-	struct fd f = fdget(fd);
+	CLASS(fd, f)(fd);
 	int ret = 0;
 
-	if (!fd_file(f))
+	if (fd_empty(f))
 		return -EBADF;
 
 	css = css_tryget_online_from_dir(fd_file(f)->f_path.dentry,
 					 &perf_event_cgrp_subsys);
-	if (IS_ERR(css)) {
-		ret = PTR_ERR(css);
-		goto out;
-	}
+	if (IS_ERR(css))
+		return PTR_ERR(css);
 
 	ret = perf_cgroup_ensure_storage(event, css);
 	if (ret)
-		goto out;
+		return ret;
 
 	cgrp = container_of(css, struct perf_cgroup, css);
 	event->cgrp = cgrp;
@@ -995,8 +993,6 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
 		perf_detach_cgroup(event);
 		ret = -EINVAL;
 	}
-out:
-	fdput(f);
 	return ret;
 }
 
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index dc952c3b05af..c9d97ed20122 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -545,12 +545,12 @@ static void commit_nsset(struct nsset *nsset)
 
 SYSCALL_DEFINE2(setns, int, fd, int, flags)
 {
-	struct fd f = fdget(fd);
+	CLASS(fd, f)(fd);
 	struct ns_common *ns = NULL;
 	struct nsset nsset = {};
 	int err = 0;
 
-	if (!fd_file(f))
+	if (fd_empty(f))
 		return -EBADF;
 
 	if (proc_ns_file(fd_file(f))) {
@@ -580,7 +580,6 @@ SYSCALL_DEFINE2(setns, int, fd, int, flags)
 	}
 	put_nsset(&nsset);
 out:
-	fdput(f);
 	return err;
 }
 
diff --git a/kernel/pid.c b/kernel/pid.c
index 2715afb77eab..b5bbc1a8a6e4 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -536,11 +536,10 @@ EXPORT_SYMBOL_GPL(find_ge_pid);
 
 struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags)
 {
-	struct fd f;
+	CLASS(fd, f)(fd);
 	struct pid *pid;
 
-	f = fdget(fd);
-	if (!fd_file(f))
+	if (fd_empty(f))
 		return ERR_PTR(-EBADF);
 
 	pid = pidfd_pid(fd_file(f));
@@ -548,8 +547,6 @@ struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags)
 		get_pid(pid);
 		*flags = fd_file(f)->f_flags;
 	}
-
-	fdput(f);
 	return pid;
 }
 
diff --git a/kernel/sys.c b/kernel/sys.c
index 4da31f28fda8..ebe10c27a9f4 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1911,12 +1911,11 @@ SYSCALL_DEFINE1(umask, int, mask)
 
 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
 {
-	struct fd exe;
+	CLASS(fd, exe)(fd);
 	struct inode *inode;
 	int err;
 
-	exe = fdget(fd);
-	if (!fd_file(exe))
+	if (fd_empty(exe))
 		return -EBADF;
 
 	inode = file_inode(fd_file(exe));
@@ -1926,18 +1925,14 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
 	 * sure that this one is executable as well, to avoid breaking an
 	 * overall picture.
 	 */
-	err = -EACCES;
 	if (!S_ISREG(inode->i_mode) || path_noexec(&fd_file(exe)->f_path))
-		goto exit;
+		return -EACCES;
 
 	err = file_permission(fd_file(exe), MAY_EXEC);
 	if (err)
-		goto exit;
+		return err;
 
-	err = replace_mm_exe_file(mm, fd_file(exe));
-exit:
-	fdput(exe);
-	return err;
+	return replace_mm_exe_file(mm, fd_file(exe));
 }
 
 /*
diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c
index d36242fd4936..1895fbc32bcb 100644
--- a/kernel/watch_queue.c
+++ b/kernel/watch_queue.c
@@ -663,16 +663,14 @@ struct watch_queue *get_watch_queue(int fd)
 {
 	struct pipe_inode_info *pipe;
 	struct watch_queue *wqueue = ERR_PTR(-EINVAL);
-	struct fd f;
+	CLASS(fd, f)(fd);
 
-	f = fdget(fd);
-	if (fd_file(f)) {
+	if (!fd_empty(f)) {
 		pipe = get_pipe_info(fd_file(f), false);
 		if (pipe && pipe->watch_queue) {
 			wqueue = pipe->watch_queue;
 			kref_get(&wqueue->usage);
 		}
-		fdput(f);
 	}
 
 	return wqueue;