procfs: Convert /proc/pid/fdinfo/ handling routines to seq-file v2 (ddd3e077) · Commits · 戴 / test

fs/proc/fd.c

+64 −48

Original line number	Diff line number	Diff line
		@@ -6,61 +6,68 @@
		#include <linux/namei.h>
		#include <linux/pid.h>
		#include <linux/security.h>
		#include <linux/file.h>
		#include <linux/seq_file.h>

		#include <linux/proc_fs.h>

		#include "internal.h"
		#include "fd.h"

		#define PROC_FDINFO_MAX 64

		static int proc_fd_info(struct inode inode, struct path path, char *info)
		static int seq_show(struct seq_file m, void v)
		{
		struct task_struct *task = get_proc_task(inode);
		struct files_struct *files = NULL;
		int fd = proc_fd(inode);
		struct file *file;
		int f_flags = 0, ret = -ENOENT;
		struct file *file = NULL;
		struct task_struct *task;

		task = get_proc_task(m->private);
		if (!task)
		return -ENOENT;

		if (task) {
		files = get_files_struct(task);
		put_task_struct(task);
		}

		if (files) {
		/*
		* We are not taking a ref to the file structure, so we must
		* hold ->file_lock.
		*/
		int fd = proc_fd(m->private);

		spin_lock(&files->file_lock);
		file = fcheck_files(files, fd);
		if (file) {
		unsigned int f_flags;
		struct fdtable *fdt;
		struct fdtable *fdt = files_fdtable(files);

		fdt = files_fdtable(files);
		f_flags = file->f_flags & ~O_CLOEXEC;
		if (close_on_exec(fd, fdt))
		f_flags \|= O_CLOEXEC;

		if (path) {
		*path = file->f_path;
		path_get(&file->f_path);
		get_file(file);
		ret = 0;
		}
		if (info)
		snprintf(info, PROC_FDINFO_MAX,
		"pos:\t%lli\n"
		"flags:\t0%o\n",
		(long long) file->f_pos,
		f_flags);
		spin_unlock(&files->file_lock);
		put_files_struct(files);
		return 0;
		}
		spin_unlock(&files->file_lock);
		put_files_struct(files);

		if (!ret) {
		seq_printf(m, "pos:\t%lli\nflags:\t0%o\n",
		(long long)file->f_pos, f_flags);
		fput(file);
		}
		return -ENOENT;

		return ret;
		}

		static int seq_fdinfo_open(struct inode inode, struct file file)
		{
		return single_open(file, seq_show, inode);
		}

		static const struct file_operations proc_fdinfo_file_operations = {
		.open = seq_fdinfo_open,
		.read = seq_read,
		.llseek = seq_lseek,
		.release = single_release,
		};

		static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
		{
		struct files_struct *files;
		@@ -130,7 +137,32 @@ static const struct dentry_operations tid_fd_dentry_operations = {

		static int proc_fd_link(struct dentry dentry, struct path path)
		{
		return proc_fd_info(dentry->d_inode, path, NULL);
		struct files_struct *files = NULL;
		struct task_struct *task;
		int ret = -ENOENT;

		task = get_proc_task(dentry->d_inode);
		if (task) {
		files = get_files_struct(task);
		put_task_struct(task);
		}

		if (files) {
		int fd = proc_fd(dentry->d_inode);
		struct file *fd_file;

		spin_lock(&files->file_lock);
		fd_file = fcheck_files(files, fd);
		if (fd_file) {
		*path = fd_file->f_path;
		path_get(&fd_file->f_path);
		ret = 0;
		}
		spin_unlock(&files->file_lock);
		put_files_struct(files);
		}

		return ret;
		}

		static struct dentry *
		@@ -245,22 +277,6 @@ out_no_task:
		return retval;
		}

		static ssize_t proc_fdinfo_read(struct file file, char __user buf,
		size_t len, loff_t *ppos)
		{
		char tmp[PROC_FDINFO_MAX];
		int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
		if (!err)
		err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
		return err;
		}

		static const struct file_operations proc_fdinfo_file_operations = {
		.open = nonseekable_open,
		.read = proc_fdinfo_read,
		.llseek = no_llseek,
		};

		static int proc_readfd(struct file filp, void dirent, filldir_t filldir)
		{
		return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);

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