switch simple cases of fget_light to fdget

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 43 insertions, 54 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 2bd199b..bd9c5bc 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -467,14 +467,13 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
 {
 	struct perf_cgroup *cgrp;
 	struct cgroup_subsys_state *css;
-	struct file *file;
-	int ret = 0, fput_needed;
+	struct fd f = fdget(fd);
+	int ret = 0;
 
-	file = fget_light(fd, &fput_needed);
-	if (!file)
+	if (!f.file)
 		return -EBADF;
 
-	css = cgroup_css_from_dir(file, perf_subsys_id);
+	css = cgroup_css_from_dir(f.file, perf_subsys_id);
 	if (IS_ERR(css)) {
 		ret = PTR_ERR(css);
 		goto out;
@@ -500,7 +499,7 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
 		ret = -EINVAL;
 	}
 out:
-	fput_light(file, fput_needed);
+	fdput(f);
 	return ret;
 }
 
@@ -3233,21 +3232,18 @@ unlock:
 
 static const struct file_operations perf_fops;
 
-static struct file *perf_fget_light(int fd, int *fput_needed)
+static inline int perf_fget_light(int fd, struct fd *p)
 {
-	struct file *file;
-
-	file = fget_light(fd, fput_needed);
-	if (!file)
-		return ERR_PTR(-EBADF);
+	struct fd f = fdget(fd);
+	if (!f.file)
+		return -EBADF;
 
-	if (file->f_op != &perf_fops) {
-		fput_light(file, *fput_needed);
-		*fput_needed = 0;
-		return ERR_PTR(-EBADF);
+	if (f.file->f_op != &perf_fops) {
+		fdput(f);
+		return -EBADF;
 	}
-
-	return file;
+	*p = f;
+	return 0;
 }
 
 static int perf_event_set_output(struct perf_event *event,
@@ -3279,22 +3275,19 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 	case PERF_EVENT_IOC_SET_OUTPUT:
 	{
-		struct file *output_file = NULL;
-		struct perf_event *output_event = NULL;
-		int fput_needed = 0;
 		int ret;
-
 		if (arg != -1) {
-			output_file = perf_fget_light(arg, &fput_needed);
-			if (IS_ERR(output_file))
-				return PTR_ERR(output_file);
-			output_event = output_file->private_data;
+			struct perf_event *output_event;
+			struct fd output;
+			ret = perf_fget_light(arg, &output);
+			if (ret)
+				return ret;
+			output_event = output.file->private_data;
+			ret = perf_event_set_output(event, output_event);
+			fdput(output);
+		} else {
+			ret = perf_event_set_output(event, NULL);
 		}
-
-		ret = perf_event_set_output(event, output_event);
-		if (output_event)
-			fput_light(output_file, fput_needed);
-
 		return ret;
 	}
 
@@ -6229,12 +6222,11 @@ SYSCALL_DEFINE5(perf_event_open,
 	struct perf_event_attr attr;
 	struct perf_event_context *ctx;
 	struct file *event_file = NULL;
-	struct file *group_file = NULL;
+	struct fd group = {NULL, 0};
 	struct task_struct *task = NULL;
 	struct pmu *pmu;
 	int event_fd;
 	int move_group = 0;
-	int fput_needed = 0;
 	int err;
 
 	/* for future expandability... */
@@ -6269,12 +6261,10 @@ SYSCALL_DEFINE5(perf_event_open,
 		return event_fd;
 
 	if (group_fd != -1) {
-		group_file = perf_fget_light(group_fd, &fput_needed);
-		if (IS_ERR(group_file)) {
-			err = PTR_ERR(group_file);
+		err = perf_fget_light(group_fd, &group);
+		if (err)
 			goto err_fd;
-		}
-		group_leader = group_file->private_data;
+		group_leader = group.file->private_data;
 		if (flags & PERF_FLAG_FD_OUTPUT)
 			output_event = group_leader;
 		if (flags & PERF_FLAG_FD_NO_GROUP)
@@ -6450,7 +6440,7 @@ SYSCALL_DEFINE5(perf_event_open,
 	 * of the group leader will find the pointer to itself in
 	 * perf_group_detach().
 	 */
-	fput_light(group_file, fput_needed);
+	fdput(group);
 	fd_install(event_fd, event_file);
 	return event_fd;
 
@@ -6464,7 +6454,7 @@ err_task:
 	if (task)
 		put_task_struct(task);
 err_group_fd:
-	fput_light(group_file, fput_needed);
+	fdput(group);
 err_fd:
 	put_unused_fd(event_fd);
 	return err;
diff --git a/kernel/sys.c b/kernel/sys.c
index 0cb4283..f949228 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1788,15 +1788,15 @@ SYSCALL_DEFINE1(umask, int, mask)
 #ifdef CONFIG_CHECKPOINT_RESTORE
 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
 {
-	struct file *exe_file;
+	struct fd exe;
 	struct dentry *dentry;
-	int err, fput_needed;
+	int err;
 
-	exe_file = fget_light(fd, &fput_needed);
-	if (!exe_file)
+	exe = fdget(fd);
+	if (!exe.file)
 		return -EBADF;
 
-	dentry = exe_file->f_path.dentry;
+	dentry = exe.file->f_path.dentry;
 
 	/*
 	 * Because the original mm->exe_file points to executable file, make
@@ -1805,7 +1805,7 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
 	 */
 	err = -EACCES;
 	if (!S_ISREG(dentry->d_inode->i_mode)	||
-	    exe_file->f_path.mnt->mnt_flags & MNT_NOEXEC)
+	    exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC)
 		goto exit;
 
 	err = inode_permission(dentry->d_inode, MAY_EXEC);
@@ -1839,12 +1839,12 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
 		goto exit_unlock;
 
 	err = 0;
-	set_mm_exe_file(mm, exe_file);	/* this grabs a reference to exe_file */
+	set_mm_exe_file(mm, exe.file);	/* this grabs a reference to exe.file */
 exit_unlock:
 	up_write(&mm->mmap_sem);
 
 exit:
-	fput_light(exe_file, fput_needed);
+	fdput(exe);
 	return err;
 }
 
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index d0a3279..5116b7e 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -415,16 +415,15 @@ static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
 	struct nlattr *na;
 	size_t size;
 	u32 fd;
-	struct file *file;
-	int fput_needed;
+	struct fd f;
 
 	na = info->attrs[CGROUPSTATS_CMD_ATTR_FD];
 	if (!na)
 		return -EINVAL;
 
 	fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]);
-	file = fget_light(fd, &fput_needed);
-	if (!file)
+	f = fdget(fd);
+	if (!f.file)
 		return 0;
 
 	size = nla_total_size(sizeof(struct cgroupstats));
@@ -444,7 +443,7 @@ static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
 	stats = nla_data(na);
 	memset(stats, 0, sizeof(*stats));
 
-	rc = cgroupstats_build(stats, file->f_dentry);
+	rc = cgroupstats_build(stats, f.file->f_dentry);
 	if (rc < 0) {
 		nlmsg_free(rep_skb);
 		goto err;
@@ -453,7 +452,7 @@ static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
 	rc = send_reply(rep_skb, info);
 
 err:
-	fput_light(file, fput_needed);
+	fdput(f);
 	return rc;
 }