fdget(), more trivial conversions

all failure exits prior to fdget() leave the scope, all matching fdput()
are immediately followed by leaving the scope.

[xfs_ioc_commit_range() chunk moved here as well]

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

4 files changed, 23 insertions, 48 deletions

diff --git a/kernel/module/main.c b/kernel/module/main.c
index d785973d8a51..4490924fe24e 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -3219,10 +3219,7 @@ static int idempotent_init_module(struct file *f, const char __user * uargs, int
 
 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
 {
-	int err;
-	struct fd f;
-
-	err = may_init_module();
+	int err = may_init_module();
 	if (err)
 		return err;
 
@@ -3233,12 +3230,10 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
 		      |MODULE_INIT_COMPRESSED_FILE))
 		return -EINVAL;
 
-	f = fdget(fd);
+	CLASS(fd, f)(fd);
 	if (fd_empty(f))
 		return -EBADF;
-	err = idempotent_init_module(fd_file(f), uargs, flags);
-	fdput(f);
-	return err;
+	return idempotent_init_module(fd_file(f), uargs, flags);
 }
 
 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
diff --git a/kernel/pid.c b/kernel/pid.c
index b5bbc1a8a6e4..115448e89c3e 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -744,23 +744,18 @@ SYSCALL_DEFINE3(pidfd_getfd, int, pidfd, int, fd,
 		unsigned int, flags)
 {
 	struct pid *pid;
-	struct fd f;
-	int ret;
 
 	/* flags is currently unused - make sure it's unset */
 	if (flags)
 		return -EINVAL;
 
-	f = fdget(pidfd);
-	if (!fd_file(f))
+	CLASS(fd, f)(pidfd);
+	if (fd_empty(f))
 		return -EBADF;
 
 	pid = pidfd_pid(fd_file(f));
 	if (IS_ERR(pid))
-		ret = PTR_ERR(pid);
-	else
-		ret = pidfd_getfd(pid, fd);
+		return PTR_ERR(pid);
 
-	fdput(f);
-	return ret;
+	return pidfd_getfd(pid, fd);
 }
diff --git a/kernel/signal.c b/kernel/signal.c
index 4344860ffcac..6be807ecb94c 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3908,7 +3908,6 @@ SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig,
 		siginfo_t __user *, info, unsigned int, flags)
 {
 	int ret;
-	struct fd f;
 	struct pid *pid;
 	kernel_siginfo_t kinfo;
 	enum pid_type type;
@@ -3921,20 +3920,17 @@ SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig,
 	if (hweight32(flags & PIDFD_SEND_SIGNAL_FLAGS) > 1)
 		return -EINVAL;
 
-	f = fdget(pidfd);
-	if (!fd_file(f))
+	CLASS(fd, f)(pidfd);
+	if (fd_empty(f))
 		return -EBADF;
 
 	/* Is this a pidfd? */
 	pid = pidfd_to_pid(fd_file(f));
-	if (IS_ERR(pid)) {
-		ret = PTR_ERR(pid);
-		goto err;
-	}
+	if (IS_ERR(pid))
+		return PTR_ERR(pid);
 
-	ret = -EINVAL;
 	if (!access_pidfd_pidns(pid))
-		goto err;
+		return -EINVAL;
 
 	switch (flags) {
 	case 0:
@@ -3958,28 +3954,23 @@ SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig,
 	if (info) {
 		ret = copy_siginfo_from_user_any(&kinfo, info);
 		if (unlikely(ret))
-			goto err;
+			return ret;
 
-		ret = -EINVAL;
 		if (unlikely(sig != kinfo.si_signo))
-			goto err;
+			return -EINVAL;
 
 		/* Only allow sending arbitrary signals to yourself. */
-		ret = -EPERM;
 		if ((task_pid(current) != pid || type > PIDTYPE_TGID) &&
 		    (kinfo.si_code >= 0 || kinfo.si_code == SI_TKILL))
-			goto err;
+			return -EPERM;
 	} else {
 		prepare_kill_siginfo(sig, &kinfo, type);
 	}
 
 	if (type == PIDTYPE_PGID)
-		ret = kill_pgrp_info(sig, &kinfo, pid);
+		return kill_pgrp_info(sig, &kinfo, pid);
 	else
-		ret = kill_pid_info_type(sig, &kinfo, pid, type);
-err:
-	fdput(f);
-	return ret;
+		return kill_pid_info_type(sig, &kinfo, pid, type);
 }
 
 static int
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 0700f40c53ac..0cd680ccc7e5 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -411,15 +411,14 @@ static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
 	struct nlattr *na;
 	size_t size;
 	u32 fd;
-	struct fd f;
 
 	na = info->attrs[CGROUPSTATS_CMD_ATTR_FD];
 	if (!na)
 		return -EINVAL;
 
 	fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]);
-	f = fdget(fd);
-	if (!fd_file(f))
+	CLASS(fd, f)(fd);
+	if (fd_empty(f))
 		return 0;
 
 	size = nla_total_size(sizeof(struct cgroupstats));
@@ -427,14 +426,13 @@ static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
 	rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb,
 				size);
 	if (rc < 0)
-		goto err;
+		return rc;
 
 	na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS,
 				sizeof(struct cgroupstats));
 	if (na == NULL) {
 		nlmsg_free(rep_skb);
-		rc = -EMSGSIZE;
-		goto err;
+		return -EMSGSIZE;
 	}
 
 	stats = nla_data(na);
@@ -443,14 +441,10 @@ static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
 	rc = cgroupstats_build(stats, fd_file(f)->f_path.dentry);
 	if (rc < 0) {
 		nlmsg_free(rep_skb);
-		goto err;
+		return rc;
 	}
 
-	rc = send_reply(rep_skb, info);
-
-err:
-	fdput(f);
-	return rc;
+	return send_reply(rep_skb, info);
 }
 
 static int cmd_attr_register_cpumask(struct genl_info *info)