168 lines
4.1 KiB
Diff
168 lines
4.1 KiB
Diff
From: Vasiliy Kulikov <segooon@gmail.com>
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Date: Tue, 10 Jan 2012 15:11:27 -0800
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Subject: procfs: parse mount options
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commit 97412950b10e64f347aec4a9b759395c2465adf6 upstream.
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Add support for procfs mount options. Actual mount options are coming in
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the next patches.
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Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
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Cc: Alexey Dobriyan <adobriyan@gmail.com>
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Cc: Al Viro <viro@zeniv.linux.org.uk>
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Cc: Randy Dunlap <rdunlap@xenotime.net>
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Cc: "H. Peter Anvin" <hpa@zytor.com>
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Cc: Greg KH <greg@kroah.com>
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Cc: Theodore Tso <tytso@MIT.EDU>
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Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
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Cc: James Morris <jmorris@namei.org>
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Cc: Oleg Nesterov <oleg@redhat.com>
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Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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[bwh: Backported to 3.2: super_operations::show_options takes a
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struct vfsmount *, not struct dentry *]
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---
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fs/proc/inode.c | 10 ++++++++++
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fs/proc/internal.h | 1 +
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fs/proc/root.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++--
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3 files changed, 64 insertions(+), 2 deletions(-)
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--- a/fs/proc/inode.c
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+++ b/fs/proc/inode.c
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@@ -7,6 +7,7 @@
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#include <linux/time.h>
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#include <linux/proc_fs.h>
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#include <linux/kernel.h>
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+#include <linux/pid_namespace.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/stat.h>
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@@ -17,7 +18,9 @@
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/sysctl.h>
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+#include <linux/seq_file.h>
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#include <linux/slab.h>
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+#include <linux/mount.h>
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#include <asm/system.h>
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#include <asm/uaccess.h>
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@@ -102,12 +105,19 @@
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init_once);
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}
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+static int proc_show_options(struct seq_file *seq, struct vfsmount *vfs)
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+{
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+ return 0;
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+}
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+
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static const struct super_operations proc_sops = {
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.alloc_inode = proc_alloc_inode,
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.destroy_inode = proc_destroy_inode,
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.drop_inode = generic_delete_inode,
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.evict_inode = proc_evict_inode,
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.statfs = simple_statfs,
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+ .remount_fs = proc_remount,
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+ .show_options = proc_show_options,
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};
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static void __pde_users_dec(struct proc_dir_entry *pde)
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--- a/fs/proc/internal.h
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+++ b/fs/proc/internal.h
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@@ -117,6 +117,7 @@
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int proc_fill_super(struct super_block *);
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struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
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+int proc_remount(struct super_block *sb, int *flags, char *data);
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/*
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* These are generic /proc routines that use the internal
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--- a/fs/proc/root.c
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+++ b/fs/proc/root.c
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@@ -18,6 +18,7 @@
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#include <linux/bitops.h>
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#include <linux/mount.h>
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#include <linux/pid_namespace.h>
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+#include <linux/parser.h>
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#include "internal.h"
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@@ -36,6 +37,48 @@
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return err;
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}
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+enum {
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+ Opt_err,
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+};
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+
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+static const match_table_t tokens = {
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+ {Opt_err, NULL},
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+};
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+
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+static int proc_parse_options(char *options, struct pid_namespace *pid)
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+{
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+ char *p;
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+ substring_t args[MAX_OPT_ARGS];
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+
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+ pr_debug("proc: options = %s\n", options);
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+
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+ if (!options)
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+ return 1;
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+
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+ while ((p = strsep(&options, ",")) != NULL) {
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+ int token;
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+ if (!*p)
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+ continue;
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+
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+ args[0].to = args[0].from = 0;
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+ token = match_token(p, tokens, args);
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+ switch (token) {
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+ default:
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+ pr_err("proc: unrecognized mount option \"%s\" "
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+ "or missing value\n", p);
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+ return 0;
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+ }
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+ }
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+
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+ return 1;
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+}
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+
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+int proc_remount(struct super_block *sb, int *flags, char *data)
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+{
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+ struct pid_namespace *pid = sb->s_fs_info;
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+ return !proc_parse_options(data, pid);
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+}
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+
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static struct dentry *proc_mount(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data)
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{
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@@ -43,11 +86,15 @@
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struct super_block *sb;
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struct pid_namespace *ns;
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struct proc_inode *ei;
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+ char *options;
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- if (flags & MS_KERNMOUNT)
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+ if (flags & MS_KERNMOUNT) {
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ns = (struct pid_namespace *)data;
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- else
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+ options = NULL;
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+ } else {
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ns = current->nsproxy->pid_ns;
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+ options = data;
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+ }
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sb = sget(fs_type, proc_test_super, proc_set_super, ns);
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if (IS_ERR(sb))
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@@ -55,6 +102,10 @@
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if (!sb->s_root) {
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sb->s_flags = flags;
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+ if (!proc_parse_options(options, ns)) {
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+ deactivate_locked_super(sb);
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+ return ERR_PTR(-EINVAL);
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+ }
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err = proc_fill_super(sb);
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if (err) {
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deactivate_locked_super(sb);
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