linux/fs/autofs/inode.c
Ian Kent 9bf964c9ce autofs: simplify parse_options() function call
The parse_options() function uses a long list of parameters, most of
which are present in the super block info structure already.

The mount parameters set in parse_options() options don't require
cleanup so using the super block info struct directly is simpler.

Link: http://lkml.kernel.org/r/154296972423.9889.9368859245676473329.stgit@pluto-themaw-net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:46 -08:00

374 lines
8.4 KiB
C

/*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
* Copyright 2005-2006 Ian Kent <raven@themaw.net>
*
* This file is part of the Linux kernel and is made available under
* the terms of the GNU General Public License, version 2, or at your
* option, any later version, incorporated herein by reference.
*/
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/parser.h>
#include "autofs_i.h"
struct autofs_info *autofs_new_ino(struct autofs_sb_info *sbi)
{
struct autofs_info *ino;
ino = kzalloc(sizeof(*ino), GFP_KERNEL);
if (ino) {
INIT_LIST_HEAD(&ino->active);
INIT_LIST_HEAD(&ino->expiring);
ino->last_used = jiffies;
ino->sbi = sbi;
}
return ino;
}
void autofs_clean_ino(struct autofs_info *ino)
{
ino->uid = GLOBAL_ROOT_UID;
ino->gid = GLOBAL_ROOT_GID;
ino->last_used = jiffies;
}
void autofs_free_ino(struct autofs_info *ino)
{
kfree(ino);
}
void autofs_kill_sb(struct super_block *sb)
{
struct autofs_sb_info *sbi = autofs_sbi(sb);
/*
* In the event of a failure in get_sb_nodev the superblock
* info is not present so nothing else has been setup, so
* just call kill_anon_super when we are called from
* deactivate_super.
*/
if (sbi) {
/* Free wait queues, close pipe */
autofs_catatonic_mode(sbi);
put_pid(sbi->oz_pgrp);
}
pr_debug("shutting down\n");
kill_litter_super(sb);
if (sbi)
kfree_rcu(sbi, rcu);
}
static int autofs_show_options(struct seq_file *m, struct dentry *root)
{
struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
struct inode *root_inode = d_inode(root->d_sb->s_root);
if (!sbi)
return 0;
seq_printf(m, ",fd=%d", sbi->pipefd);
if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID))
seq_printf(m, ",uid=%u",
from_kuid_munged(&init_user_ns, root_inode->i_uid));
if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID))
seq_printf(m, ",gid=%u",
from_kgid_munged(&init_user_ns, root_inode->i_gid));
seq_printf(m, ",pgrp=%d", pid_vnr(sbi->oz_pgrp));
seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
seq_printf(m, ",minproto=%d", sbi->min_proto);
seq_printf(m, ",maxproto=%d", sbi->max_proto);
if (autofs_type_offset(sbi->type))
seq_printf(m, ",offset");
else if (autofs_type_direct(sbi->type))
seq_printf(m, ",direct");
else
seq_printf(m, ",indirect");
#ifdef CONFIG_CHECKPOINT_RESTORE
if (sbi->pipe)
seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino);
else
seq_printf(m, ",pipe_ino=-1");
#endif
return 0;
}
static void autofs_evict_inode(struct inode *inode)
{
clear_inode(inode);
kfree(inode->i_private);
}
static const struct super_operations autofs_sops = {
.statfs = simple_statfs,
.show_options = autofs_show_options,
.evict_inode = autofs_evict_inode,
};
enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
Opt_indirect, Opt_direct, Opt_offset};
static const match_table_t tokens = {
{Opt_fd, "fd=%u"},
{Opt_uid, "uid=%u"},
{Opt_gid, "gid=%u"},
{Opt_pgrp, "pgrp=%u"},
{Opt_minproto, "minproto=%u"},
{Opt_maxproto, "maxproto=%u"},
{Opt_indirect, "indirect"},
{Opt_direct, "direct"},
{Opt_offset, "offset"},
{Opt_err, NULL}
};
static int parse_options(char *options,
struct inode *root, int *pgrp, bool *pgrp_set,
struct autofs_sb_info *sbi)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
int pipefd = -1;
kuid_t uid;
kgid_t gid;
root->i_uid = current_uid();
root->i_gid = current_gid();
sbi->min_proto = AUTOFS_MIN_PROTO_VERSION;
sbi->max_proto = AUTOFS_MAX_PROTO_VERSION;
sbi->pipefd = -1;
if (!options)
return 1;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_fd:
if (match_int(args, &pipefd))
return 1;
sbi->pipefd = pipefd;
break;
case Opt_uid:
if (match_int(args, &option))
return 1;
uid = make_kuid(current_user_ns(), option);
if (!uid_valid(uid))
return 1;
root->i_uid = uid;
break;
case Opt_gid:
if (match_int(args, &option))
return 1;
gid = make_kgid(current_user_ns(), option);
if (!gid_valid(gid))
return 1;
root->i_gid = gid;
break;
case Opt_pgrp:
if (match_int(args, &option))
return 1;
*pgrp = option;
*pgrp_set = true;
break;
case Opt_minproto:
if (match_int(args, &option))
return 1;
sbi->min_proto = option;
break;
case Opt_maxproto:
if (match_int(args, &option))
return 1;
sbi->max_proto = option;
break;
case Opt_indirect:
set_autofs_type_indirect(&sbi->type);
break;
case Opt_direct:
set_autofs_type_direct(&sbi->type);
break;
case Opt_offset:
set_autofs_type_offset(&sbi->type);
break;
default:
return 1;
}
}
return (sbi->pipefd < 0);
}
int autofs_fill_super(struct super_block *s, void *data, int silent)
{
struct inode *root_inode;
struct dentry *root;
struct file *pipe;
struct autofs_sb_info *sbi;
struct autofs_info *ino;
int pgrp = 0;
bool pgrp_set = false;
int ret = -EINVAL;
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
pr_debug("starting up, sbi = %p\n", sbi);
s->s_fs_info = sbi;
sbi->magic = AUTOFS_SBI_MAGIC;
sbi->pipefd = -1;
sbi->pipe = NULL;
sbi->catatonic = 1;
sbi->exp_timeout = 0;
sbi->oz_pgrp = NULL;
sbi->sb = s;
sbi->version = 0;
sbi->sub_version = 0;
set_autofs_type_indirect(&sbi->type);
sbi->min_proto = 0;
sbi->max_proto = 0;
mutex_init(&sbi->wq_mutex);
mutex_init(&sbi->pipe_mutex);
spin_lock_init(&sbi->fs_lock);
sbi->queues = NULL;
spin_lock_init(&sbi->lookup_lock);
INIT_LIST_HEAD(&sbi->active_list);
INIT_LIST_HEAD(&sbi->expiring_list);
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
s->s_magic = AUTOFS_SUPER_MAGIC;
s->s_op = &autofs_sops;
s->s_d_op = &autofs_dentry_operations;
s->s_time_gran = 1;
/*
* Get the root inode and dentry, but defer checking for errors.
*/
ino = autofs_new_ino(sbi);
if (!ino) {
ret = -ENOMEM;
goto fail_free;
}
root_inode = autofs_get_inode(s, S_IFDIR | 0755);
root = d_make_root(root_inode);
if (!root)
goto fail_ino;
pipe = NULL;
root->d_fsdata = ino;
/* Can this call block? */
if (parse_options(data, root_inode, &pgrp, &pgrp_set, sbi)) {
pr_err("called with bogus options\n");
goto fail_dput;
}
/* Test versions first */
if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
pr_err("kernel does not match daemon version "
"daemon (%d, %d) kernel (%d, %d)\n",
sbi->min_proto, sbi->max_proto,
AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
goto fail_dput;
}
/* Establish highest kernel protocol version */
if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
sbi->version = AUTOFS_MAX_PROTO_VERSION;
else
sbi->version = sbi->max_proto;
sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
if (pgrp_set) {
sbi->oz_pgrp = find_get_pid(pgrp);
if (!sbi->oz_pgrp) {
pr_err("could not find process group %d\n",
pgrp);
goto fail_dput;
}
} else {
sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
}
if (autofs_type_trigger(sbi->type))
__managed_dentry_set_managed(root);
root_inode->i_fop = &autofs_root_operations;
root_inode->i_op = &autofs_dir_inode_operations;
pr_debug("pipe fd = %d, pgrp = %u\n",
sbi->pipefd, pid_nr(sbi->oz_pgrp));
pipe = fget(sbi->pipefd);
if (!pipe) {
pr_err("could not open pipe file descriptor\n");
goto fail_put_pid;
}
ret = autofs_prepare_pipe(pipe);
if (ret < 0)
goto fail_fput;
sbi->pipe = pipe;
sbi->catatonic = 0;
/*
* Success! Install the root dentry now to indicate completion.
*/
s->s_root = root;
return 0;
/*
* Failure ... clean up.
*/
fail_fput:
pr_err("pipe file descriptor does not contain proper ops\n");
fput(pipe);
fail_put_pid:
put_pid(sbi->oz_pgrp);
fail_dput:
dput(root);
goto fail_free;
fail_ino:
autofs_free_ino(ino);
fail_free:
kfree(sbi);
s->s_fs_info = NULL;
return ret;
}
struct inode *autofs_get_inode(struct super_block *sb, umode_t mode)
{
struct inode *inode = new_inode(sb);
if (inode == NULL)
return NULL;
inode->i_mode = mode;
if (sb->s_root) {
inode->i_uid = d_inode(sb->s_root)->i_uid;
inode->i_gid = d_inode(sb->s_root)->i_gid;
}
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
inode->i_ino = get_next_ino();
if (S_ISDIR(mode)) {
set_nlink(inode, 2);
inode->i_op = &autofs_dir_inode_operations;
inode->i_fop = &autofs_dir_operations;
} else if (S_ISLNK(mode)) {
inode->i_op = &autofs_symlink_inode_operations;
} else
WARN_ON(1);
return inode;
}