linux/fs/autofs/inode.c
Eric Sandeen 748cddf13d
autofs: Convert to new uid/gid option parsing helpers
Convert to new uid/gid option parsing helpers

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Link: https://lore.kernel.org/r/faccdd51-07d6-413f-aa55-41bb0e7660df@redhat.com
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-07-02 06:21:17 +02:00

454 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
* Copyright 2005-2006 Ian Kent <raven@themaw.net>
*/
#include <linux/seq_file.h>
#include <linux/pagemap.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;
ino->count = 1;
}
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_rcu(ino, rcu);
}
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_puts(m, ",offset");
else if (autofs_type_direct(sbi->type))
seq_puts(m, ",direct");
else
seq_puts(m, ",indirect");
if (sbi->flags & AUTOFS_SBI_STRICTEXPIRE)
seq_puts(m, ",strictexpire");
if (sbi->flags & AUTOFS_SBI_IGNORE)
seq_puts(m, ",ignore");
#ifdef CONFIG_CHECKPOINT_RESTORE
if (sbi->pipe)
seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino);
else
seq_puts(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_direct,
Opt_fd,
Opt_gid,
Opt_ignore,
Opt_indirect,
Opt_maxproto,
Opt_minproto,
Opt_offset,
Opt_pgrp,
Opt_strictexpire,
Opt_uid,
};
const struct fs_parameter_spec autofs_param_specs[] = {
fsparam_flag ("direct", Opt_direct),
fsparam_fd ("fd", Opt_fd),
fsparam_gid ("gid", Opt_gid),
fsparam_flag ("ignore", Opt_ignore),
fsparam_flag ("indirect", Opt_indirect),
fsparam_u32 ("maxproto", Opt_maxproto),
fsparam_u32 ("minproto", Opt_minproto),
fsparam_flag ("offset", Opt_offset),
fsparam_u32 ("pgrp", Opt_pgrp),
fsparam_flag ("strictexpire", Opt_strictexpire),
fsparam_uid ("uid", Opt_uid),
{}
};
struct autofs_fs_context {
kuid_t uid;
kgid_t gid;
int pgrp;
bool pgrp_set;
};
/*
* Open the fd. We do it here rather than in get_tree so that it's done in the
* context of the system call that passed the data and not the one that
* triggered the superblock creation, lest the fd gets reassigned.
*/
static int autofs_parse_fd(struct fs_context *fc, struct autofs_sb_info *sbi,
struct fs_parameter *param,
struct fs_parse_result *result)
{
struct file *pipe;
int ret;
if (param->type == fs_value_is_file) {
/* came through the new api */
pipe = param->file;
param->file = NULL;
} else {
pipe = fget(result->uint_32);
}
if (!pipe) {
errorf(fc, "could not open pipe file descriptor");
return -EBADF;
}
ret = autofs_check_pipe(pipe);
if (ret < 0) {
errorf(fc, "Invalid/unusable pipe");
if (param->type != fs_value_is_file)
fput(pipe);
return -EBADF;
}
autofs_set_packet_pipe_flags(pipe);
if (sbi->pipe)
fput(sbi->pipe);
sbi->pipefd = result->uint_32;
sbi->pipe = pipe;
return 0;
}
static int autofs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
struct autofs_fs_context *ctx = fc->fs_private;
struct autofs_sb_info *sbi = fc->s_fs_info;
struct fs_parse_result result;
int opt;
opt = fs_parse(fc, autofs_param_specs, param, &result);
if (opt < 0)
return opt;
switch (opt) {
case Opt_fd:
return autofs_parse_fd(fc, sbi, param, &result);
case Opt_uid:
ctx->uid = result.uid;
break;
case Opt_gid:
ctx->gid = result.gid;
break;
case Opt_pgrp:
ctx->pgrp = result.uint_32;
ctx->pgrp_set = true;
break;
case Opt_minproto:
sbi->min_proto = result.uint_32;
break;
case Opt_maxproto:
sbi->max_proto = result.uint_32;
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;
case Opt_strictexpire:
sbi->flags |= AUTOFS_SBI_STRICTEXPIRE;
break;
case Opt_ignore:
sbi->flags |= AUTOFS_SBI_IGNORE;
}
return 0;
}
static struct autofs_sb_info *autofs_alloc_sbi(void)
{
struct autofs_sb_info *sbi;
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
return NULL;
sbi->magic = AUTOFS_SBI_MAGIC;
sbi->flags = AUTOFS_SBI_CATATONIC;
sbi->min_proto = AUTOFS_MIN_PROTO_VERSION;
sbi->max_proto = AUTOFS_MAX_PROTO_VERSION;
sbi->pipefd = -1;
set_autofs_type_indirect(&sbi->type);
mutex_init(&sbi->wq_mutex);
mutex_init(&sbi->pipe_mutex);
spin_lock_init(&sbi->fs_lock);
spin_lock_init(&sbi->lookup_lock);
INIT_LIST_HEAD(&sbi->active_list);
INIT_LIST_HEAD(&sbi->expiring_list);
return sbi;
}
static int autofs_validate_protocol(struct fs_context *fc)
{
struct autofs_sb_info *sbi = fc->s_fs_info;
/* Test versions first */
if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
errorf(fc, "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);
return -EINVAL;
}
/* 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;
switch (sbi->version) {
case 4:
sbi->sub_version = 7;
break;
case 5:
sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
break;
default:
sbi->sub_version = 0;
}
return 0;
}
static int autofs_fill_super(struct super_block *s, struct fs_context *fc)
{
struct autofs_fs_context *ctx = fc->fs_private;
struct autofs_sb_info *sbi = s->s_fs_info;
struct inode *root_inode;
struct autofs_info *ino;
pr_debug("starting up, sbi = %p\n", sbi);
sbi->sb = s;
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)
return -ENOMEM;
root_inode = autofs_get_inode(s, S_IFDIR | 0755);
if (!root_inode)
return -ENOMEM;
root_inode->i_uid = ctx->uid;
root_inode->i_gid = ctx->gid;
root_inode->i_fop = &autofs_root_operations;
root_inode->i_op = &autofs_dir_inode_operations;
s->s_root = d_make_root(root_inode);
if (unlikely(!s->s_root)) {
autofs_free_ino(ino);
return -ENOMEM;
}
s->s_root->d_fsdata = ino;
if (ctx->pgrp_set) {
sbi->oz_pgrp = find_get_pid(ctx->pgrp);
if (!sbi->oz_pgrp)
return invalf(fc, "Could not find process group %d",
ctx->pgrp);
} else
sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
if (autofs_type_trigger(sbi->type))
/* s->s_root won't be contended so there's little to
* be gained by not taking the d_lock when setting
* d_flags, even when a lot mounts are being done.
*/
managed_dentry_set_managed(s->s_root);
pr_debug("pipe fd = %d, pgrp = %u\n",
sbi->pipefd, pid_nr(sbi->oz_pgrp));
sbi->flags &= ~AUTOFS_SBI_CATATONIC;
return 0;
}
/*
* Validate the parameters and then request a superblock.
*/
static int autofs_get_tree(struct fs_context *fc)
{
struct autofs_sb_info *sbi = fc->s_fs_info;
int ret;
ret = autofs_validate_protocol(fc);
if (ret)
return ret;
if (sbi->pipefd < 0)
return invalf(fc, "No control pipe specified");
return get_tree_nodev(fc, autofs_fill_super);
}
static void autofs_free_fc(struct fs_context *fc)
{
struct autofs_fs_context *ctx = fc->fs_private;
struct autofs_sb_info *sbi = fc->s_fs_info;
if (sbi) {
if (sbi->pipe)
fput(sbi->pipe);
kfree(sbi);
}
kfree(ctx);
}
static const struct fs_context_operations autofs_context_ops = {
.free = autofs_free_fc,
.parse_param = autofs_parse_param,
.get_tree = autofs_get_tree,
};
/*
* Set up the filesystem mount context.
*/
int autofs_init_fs_context(struct fs_context *fc)
{
struct autofs_fs_context *ctx;
struct autofs_sb_info *sbi;
ctx = kzalloc(sizeof(struct autofs_fs_context), GFP_KERNEL);
if (!ctx)
goto nomem;
ctx->uid = current_uid();
ctx->gid = current_gid();
sbi = autofs_alloc_sbi();
if (!sbi)
goto nomem_ctx;
fc->fs_private = ctx;
fc->s_fs_info = sbi;
fc->ops = &autofs_context_ops;
return 0;
nomem_ctx:
kfree(ctx);
nomem:
return -ENOMEM;
}
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;
}
simple_inode_init_ts(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;
}