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Commit ddd3e077 authored by Cyrill Gorcunov's avatar Cyrill Gorcunov Committed by Al Viro
Browse files

procfs: Convert /proc/pid/fdinfo/ handling routines to seq-file v2 



This patch converts /proc/pid/fdinfo/ handling routines to seq-file which
is needed to extend seq operations and plug in auxiliary fdinfo provides
from subsystems like eventfd/eventpoll/fsnotify.

Note the proc_fd_link no longer call for proc_fd_info, simply because
the guts of proc_fd_info() got merged into ->show() of that seq_file

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent faf60af1

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 @@ static int proc_readfd_common(struct file * filp, void * dirent, 
	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);