Commit 97412950 authored by Vasiliy Kulikov's avatar Vasiliy Kulikov Committed by Linus Torvalds

procfs: parse mount options

Add support for procfs mount options.  Actual mount options are coming in
the next patches.
Signed-off-by: default avatarVasiliy Kulikov <segoon@openwall.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Theodore Tso <tytso@MIT.EDU>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: James Morris <jmorris@namei.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 640708a2
......@@ -7,6 +7,7 @@
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/kernel.h>
#include <linux/pid_namespace.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
......@@ -17,7 +18,9 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/sysctl.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/mount.h>
#include <asm/system.h>
#include <asm/uaccess.h>
......@@ -101,12 +104,19 @@ void __init proc_init_inodecache(void)
init_once);
}
static int proc_show_options(struct seq_file *seq, struct dentry *root)
{
return 0;
}
static const struct super_operations proc_sops = {
.alloc_inode = proc_alloc_inode,
.destroy_inode = proc_destroy_inode,
.drop_inode = generic_delete_inode,
.evict_inode = proc_evict_inode,
.statfs = simple_statfs,
.remount_fs = proc_remount,
.show_options = proc_show_options,
};
static void __pde_users_dec(struct proc_dir_entry *pde)
......
......@@ -117,6 +117,7 @@ void pde_put(struct proc_dir_entry *pde);
int proc_fill_super(struct super_block *);
struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
int proc_remount(struct super_block *sb, int *flags, char *data);
/*
* These are generic /proc routines that use the internal
......
......@@ -18,6 +18,7 @@
#include <linux/bitops.h>
#include <linux/mount.h>
#include <linux/pid_namespace.h>
#include <linux/parser.h>
#include "internal.h"
......@@ -36,6 +37,48 @@ static int proc_set_super(struct super_block *sb, void *data)
return err;
}
enum {
Opt_err,
};
static const match_table_t tokens = {
{Opt_err, NULL},
};
static int proc_parse_options(char *options, struct pid_namespace *pid)
{
char *p;
substring_t args[MAX_OPT_ARGS];
pr_debug("proc: options = %s\n", options);
if (!options)
return 1;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
args[0].to = args[0].from = 0;
token = match_token(p, tokens, args);
switch (token) {
default:
pr_err("proc: unrecognized mount option \"%s\" "
"or missing value\n", p);
return 0;
}
}
return 1;
}
int proc_remount(struct super_block *sb, int *flags, char *data)
{
struct pid_namespace *pid = sb->s_fs_info;
return !proc_parse_options(data, pid);
}
static struct dentry *proc_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
......@@ -43,11 +86,15 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
struct super_block *sb;
struct pid_namespace *ns;
struct proc_inode *ei;
char *options;
if (flags & MS_KERNMOUNT)
if (flags & MS_KERNMOUNT) {
ns = (struct pid_namespace *)data;
else
options = NULL;
} else {
ns = current->nsproxy->pid_ns;
options = data;
}
sb = sget(fs_type, proc_test_super, proc_set_super, ns);
if (IS_ERR(sb))
......@@ -55,6 +102,10 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
if (!sb->s_root) {
sb->s_flags = flags;
if (!proc_parse_options(options, ns)) {
deactivate_locked_super(sb);
return ERR_PTR(-EINVAL);
}
err = proc_fill_super(sb);
if (err) {
deactivate_locked_super(sb);
......
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