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autofs: copy autofs4 to autofs

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Copy source files from the autofs4 directory to the autofs directory.

Link: http://lkml.kernel.org/r/152626705013.28589.931913083997578251.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>
This commit is contained in:
Ian Kent 2018-06-07 17:11:13 -07:00 committed by Linus Torvalds
parent 47206e012a
commit ebc921ca9b
8 changed files with 3618 additions and 0 deletions
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273
fs/autofs/autofs_i.h Normal file
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/*
* 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.
*/
/* Internal header file for autofs */
#include <linux/auto_fs.h>
#include <linux/auto_dev-ioctl.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/string.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/uaccess.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/completion.h>
#include <asm/current.h>
/* This is the range of ioctl() numbers we claim as ours */
#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
#define AUTOFS_IOC_COUNT 32
#define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
#define AUTOFS_DEV_IOCTL_IOC_COUNT \
(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
#ifdef pr_fmt
#undef pr_fmt
#endif
#define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__
/*
* Unified info structure. This is pointed to by both the dentry and
* inode structures. Each file in the filesystem has an instance of this
* structure. It holds a reference to the dentry, so dentries are never
* flushed while the file exists. All name lookups are dealt with at the
* dentry level, although the filesystem can interfere in the validation
* process. Readdir is implemented by traversing the dentry lists.
*/
struct autofs_info {
struct dentry *dentry;
struct inode *inode;
int flags;
struct completion expire_complete;
struct list_head active;
int active_count;
struct list_head expiring;
struct autofs_sb_info *sbi;
unsigned long last_used;
atomic_t count;
kuid_t uid;
kgid_t gid;
};
#define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */
#define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered
* for expiry, so RCU_walk is
* not permitted. If it progresses to
* actual expiry attempt, the flag is
* not cleared when EXPIRING is set -
* in that case it gets cleared only
* when it comes to clearing EXPIRING.
*/
#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
struct autofs_wait_queue {
wait_queue_head_t queue;
struct autofs_wait_queue *next;
autofs_wqt_t wait_queue_token;
/* We use the following to see what we are waiting for */
struct qstr name;
u32 dev;
u64 ino;
kuid_t uid;
kgid_t gid;
pid_t pid;
pid_t tgid;
/* This is for status reporting upon return */
int status;
unsigned int wait_ctr;
};
#define AUTOFS_SBI_MAGIC 0x6d4a556d
struct autofs_sb_info {
u32 magic;
int pipefd;
struct file *pipe;
struct pid *oz_pgrp;
int catatonic;
int version;
int sub_version;
int min_proto;
int max_proto;
unsigned long exp_timeout;
unsigned int type;
struct super_block *sb;
struct mutex wq_mutex;
struct mutex pipe_mutex;
spinlock_t fs_lock;
struct autofs_wait_queue *queues; /* Wait queue pointer */
spinlock_t lookup_lock;
struct list_head active_list;
struct list_head expiring_list;
struct rcu_head rcu;
};
static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
{
return (struct autofs_sb_info *)(sb->s_fs_info);
}
static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry)
{
return (struct autofs_info *)(dentry->d_fsdata);
}
/* autofs_oz_mode(): do we see the man behind the curtain? (The
* processes which do manipulations for us in user space sees the raw
* filesystem without "magic".)
*/
static inline int autofs_oz_mode(struct autofs_sb_info *sbi)
{
return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
}
struct inode *autofs_get_inode(struct super_block *, umode_t);
void autofs_free_ino(struct autofs_info *);
/* Expiration */
int is_autofs_dentry(struct dentry *);
int autofs_expire_wait(const struct path *path, int rcu_walk);
int autofs_expire_run(struct super_block *, struct vfsmount *,
struct autofs_sb_info *,
struct autofs_packet_expire __user *);
int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
struct autofs_sb_info *sbi, int when);
int autofs_expire_multi(struct super_block *, struct vfsmount *,
struct autofs_sb_info *, int __user *);
struct dentry *autofs_expire_direct(struct super_block *sb,
struct vfsmount *mnt,
struct autofs_sb_info *sbi, int how);
struct dentry *autofs_expire_indirect(struct super_block *sb,
struct vfsmount *mnt,
struct autofs_sb_info *sbi, int how);
/* Device node initialization */
int autofs_dev_ioctl_init(void);
void autofs_dev_ioctl_exit(void);
/* Operations structures */
extern const struct inode_operations autofs_symlink_inode_operations;
extern const struct inode_operations autofs_dir_inode_operations;
extern const struct file_operations autofs_dir_operations;
extern const struct file_operations autofs_root_operations;
extern const struct dentry_operations autofs_dentry_operations;
/* VFS automount flags management functions */
static inline void __managed_dentry_set_managed(struct dentry *dentry)
{
dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
}
static inline void managed_dentry_set_managed(struct dentry *dentry)
{
spin_lock(&dentry->d_lock);
__managed_dentry_set_managed(dentry);
spin_unlock(&dentry->d_lock);
}
static inline void __managed_dentry_clear_managed(struct dentry *dentry)
{
dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
}
static inline void managed_dentry_clear_managed(struct dentry *dentry)
{
spin_lock(&dentry->d_lock);
__managed_dentry_clear_managed(dentry);
spin_unlock(&dentry->d_lock);
}
/* Initializing function */
int autofs_fill_super(struct super_block *, void *, int);
struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
void autofs_clean_ino(struct autofs_info *);
static inline int autofs_prepare_pipe(struct file *pipe)
{
if (!(pipe->f_mode & FMODE_CAN_WRITE))
return -EINVAL;
if (!S_ISFIFO(file_inode(pipe)->i_mode))
return -EINVAL;
/* We want a packet pipe */
pipe->f_flags |= O_DIRECT;
return 0;
}
/* Queue management functions */
int autofs_wait(struct autofs_sb_info *,
const struct path *, enum autofs_notify);
int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
void autofs_catatonic_mode(struct autofs_sb_info *);
static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
{
return new_encode_dev(sbi->sb->s_dev);
}
static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
{
return d_inode(sbi->sb->s_root)->i_ino;
}
static inline void __autofs_add_expiring(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
if (ino) {
if (list_empty(&ino->expiring))
list_add(&ino->expiring, &sbi->expiring_list);
}
}
static inline void autofs_add_expiring(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
if (ino) {
spin_lock(&sbi->lookup_lock);
if (list_empty(&ino->expiring))
list_add(&ino->expiring, &sbi->expiring_list);
spin_unlock(&sbi->lookup_lock);
}
}
static inline void autofs_del_expiring(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
if (ino) {
spin_lock(&sbi->lookup_lock);
if (!list_empty(&ino->expiring))
list_del_init(&ino->expiring);
spin_unlock(&sbi->lookup_lock);
}
}
void autofs_kill_sb(struct super_block *);

761
fs/autofs/dev-ioctl.c Normal file
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/*
* Copyright 2008 Red Hat, Inc. All rights reserved.
* Copyright 2008 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/module.h>
#include <linux/vmalloc.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/namei.h>
#include <linux/fcntl.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/sched.h>
#include <linux/cred.h>
#include <linux/compat.h>
#include <linux/syscalls.h>
#include <linux/magic.h>
#include <linux/dcache.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include "autofs_i.h"
/*
* This module implements an interface for routing autofs ioctl control
* commands via a miscellaneous device file.
*
* The alternate interface is needed because we need to be able open
* an ioctl file descriptor on an autofs mount that may be covered by
* another mount. This situation arises when starting automount(8)
* or other user space daemon which uses direct mounts or offset
* mounts (used for autofs lazy mount/umount of nested mount trees),
* which have been left busy at at service shutdown.
*/
typedef int (*ioctl_fn)(struct file *, struct autofs_sb_info *,
struct autofs_dev_ioctl *);
static int check_name(const char *name)
{
if (!strchr(name, '/'))
return -EINVAL;
return 0;
}
/*
* Check a string doesn't overrun the chunk of
* memory we copied from user land.
*/
static int invalid_str(char *str, size_t size)
{
if (memchr(str, 0, size))
return 0;
return -EINVAL;
}
/*
* Check that the user compiled against correct version of autofs
* misc device code.
*
* As well as checking the version compatibility this always copies
* the kernel interface version out.
*/
static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param)
{
int err = 0;
if ((param->ver_major != AUTOFS_DEV_IOCTL_VERSION_MAJOR) ||
(param->ver_minor > AUTOFS_DEV_IOCTL_VERSION_MINOR)) {
pr_warn("ioctl control interface version mismatch: "
"kernel(%u.%u), user(%u.%u), cmd(0x%08x)\n",
AUTOFS_DEV_IOCTL_VERSION_MAJOR,
AUTOFS_DEV_IOCTL_VERSION_MINOR,
param->ver_major, param->ver_minor, cmd);
err = -EINVAL;
}
/* Fill in the kernel version. */
param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
return err;
}
/*
* Copy parameter control struct, including a possible path allocated
* at the end of the struct.
*/
static struct autofs_dev_ioctl *
copy_dev_ioctl(struct autofs_dev_ioctl __user *in)
{
struct autofs_dev_ioctl tmp, *res;
if (copy_from_user(&tmp, in, AUTOFS_DEV_IOCTL_SIZE))
return ERR_PTR(-EFAULT);
if (tmp.size < AUTOFS_DEV_IOCTL_SIZE)
return ERR_PTR(-EINVAL);
if (tmp.size > AUTOFS_DEV_IOCTL_SIZE + PATH_MAX)
return ERR_PTR(-ENAMETOOLONG);
res = memdup_user(in, tmp.size);
if (!IS_ERR(res))
res->size = tmp.size;
return res;
}
static inline void free_dev_ioctl(struct autofs_dev_ioctl *param)
{
kfree(param);
}
/*
* Check sanity of parameter control fields and if a path is present
* check that it is terminated and contains at least one "/".
*/
static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param)
{
int err;
err = check_dev_ioctl_version(cmd, param);
if (err) {
pr_warn("invalid device control module version "
"supplied for cmd(0x%08x)\n", cmd);
goto out;
}
if (param->size > AUTOFS_DEV_IOCTL_SIZE) {
err = invalid_str(param->path, param->size - AUTOFS_DEV_IOCTL_SIZE);
if (err) {
pr_warn(
"path string terminator missing for cmd(0x%08x)\n",
cmd);
goto out;
}
err = check_name(param->path);
if (err) {
pr_warn("invalid path supplied for cmd(0x%08x)\n",
cmd);
goto out;
}
}
err = 0;
out:
return err;
}
/*
* Get the autofs super block info struct from the file opened on
* the autofs mount point.
*/
static struct autofs_sb_info *autofs_dev_ioctl_sbi(struct file *f)
{
struct autofs_sb_info *sbi = NULL;
struct inode *inode;
if (f) {
inode = file_inode(f);
sbi = autofs_sbi(inode->i_sb);
}
return sbi;
}
/* Return autofs dev ioctl version */
static int autofs_dev_ioctl_version(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
/* This should have already been set. */
param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
return 0;
}
/* Return autofs module protocol version */
static int autofs_dev_ioctl_protover(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
param->protover.version = sbi->version;
return 0;
}
/* Return autofs module protocol sub version */
static int autofs_dev_ioctl_protosubver(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
param->protosubver.sub_version = sbi->sub_version;
return 0;
}
/* Find the topmost mount satisfying test() */
static int find_autofs_mount(const char *pathname,
struct path *res,
int test(const struct path *path, void *data),
void *data)
{
struct path path;
int err;
err = kern_path_mountpoint(AT_FDCWD, pathname, &path, 0);
if (err)
return err;
err = -ENOENT;
while (path.dentry == path.mnt->mnt_root) {
if (path.dentry->d_sb->s_magic == AUTOFS_SUPER_MAGIC) {
if (test(&path, data)) {
path_get(&path);
*res = path;
err = 0;
break;
}
}
if (!follow_up(&path))
break;
}
path_put(&path);
return err;
}
static int test_by_dev(const struct path *path, void *p)
{
return path->dentry->d_sb->s_dev == *(dev_t *)p;
}
static int test_by_type(const struct path *path, void *p)
{
struct autofs_info *ino = autofs_dentry_ino(path->dentry);
return ino && ino->sbi->type & *(unsigned *)p;
}
/*
* Open a file descriptor on the autofs mount point corresponding
* to the given path and device number (aka. new_encode_dev(sb->s_dev)).
*/
static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid)
{
int err, fd;
fd = get_unused_fd_flags(O_CLOEXEC);
if (likely(fd >= 0)) {
struct file *filp;
struct path path;
err = find_autofs_mount(name, &path, test_by_dev, &devid);
if (err)
goto out;
filp = dentry_open(&path, O_RDONLY, current_cred());
path_put(&path);
if (IS_ERR(filp)) {
err = PTR_ERR(filp);
goto out;
}
fd_install(fd, filp);
}
return fd;
out:
put_unused_fd(fd);
return err;
}
/* Open a file descriptor on an autofs mount point */
static int autofs_dev_ioctl_openmount(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
const char *path;
dev_t devid;
int err, fd;
/* param->path has already been checked */
if (!param->openmount.devid)
return -EINVAL;
param->ioctlfd = -1;
path = param->path;
devid = new_decode_dev(param->openmount.devid);
err = 0;
fd = autofs_dev_ioctl_open_mountpoint(path, devid);
if (unlikely(fd < 0)) {
err = fd;
goto out;
}
param->ioctlfd = fd;
out:
return err;
}
/* Close file descriptor allocated above (user can also use close(2)). */
static int autofs_dev_ioctl_closemount(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
return ksys_close(param->ioctlfd);
}
/*
* Send "ready" status for an existing wait (either a mount or an expire
* request).
*/
static int autofs_dev_ioctl_ready(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
autofs_wqt_t token;
token = (autofs_wqt_t) param->ready.token;
return autofs_wait_release(sbi, token, 0);
}
/*
* Send "fail" status for an existing wait (either a mount or an expire
* request).
*/
static int autofs_dev_ioctl_fail(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
autofs_wqt_t token;
int status;
token = (autofs_wqt_t) param->fail.token;
status = param->fail.status < 0 ? param->fail.status : -ENOENT;
return autofs_wait_release(sbi, token, status);
}
/*
* Set the pipe fd for kernel communication to the daemon.
*
* Normally this is set at mount using an option but if we
* are reconnecting to a busy mount then we need to use this
* to tell the autofs mount about the new kernel pipe fd. In
* order to protect mounts against incorrectly setting the
* pipefd we also require that the autofs mount be catatonic.
*
* This also sets the process group id used to identify the
* controlling process (eg. the owning automount(8) daemon).
*/
static int autofs_dev_ioctl_setpipefd(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
int pipefd;
int err = 0;
struct pid *new_pid = NULL;
if (param->setpipefd.pipefd == -1)
return -EINVAL;
pipefd = param->setpipefd.pipefd;
mutex_lock(&sbi->wq_mutex);
if (!sbi->catatonic) {
mutex_unlock(&sbi->wq_mutex);
return -EBUSY;
} else {
struct file *pipe;
new_pid = get_task_pid(current, PIDTYPE_PGID);
if (ns_of_pid(new_pid) != ns_of_pid(sbi->oz_pgrp)) {
pr_warn("not allowed to change PID namespace\n");
err = -EINVAL;
goto out;
}
pipe = fget(pipefd);
if (!pipe) {
err = -EBADF;
goto out;
}
if (autofs_prepare_pipe(pipe) < 0) {
err = -EPIPE;
fput(pipe);
goto out;
}
swap(sbi->oz_pgrp, new_pid);
sbi->pipefd = pipefd;
sbi->pipe = pipe;
sbi->catatonic = 0;
}
out:
put_pid(new_pid);
mutex_unlock(&sbi->wq_mutex);
return err;
}
/*
* Make the autofs mount point catatonic, no longer responsive to
* mount requests. Also closes the kernel pipe file descriptor.
*/
static int autofs_dev_ioctl_catatonic(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
autofs_catatonic_mode(sbi);
return 0;
}
/* Set the autofs mount timeout */
static int autofs_dev_ioctl_timeout(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
unsigned long timeout;
timeout = param->timeout.timeout;
param->timeout.timeout = sbi->exp_timeout / HZ;
sbi->exp_timeout = timeout * HZ;
return 0;
}
/*
* Return the uid and gid of the last request for the mount
*
* When reconstructing an autofs mount tree with active mounts
* we need to re-connect to mounts that may have used the original
* process uid and gid (or string variations of them) for mount
* lookups within the map entry.
*/
static int autofs_dev_ioctl_requester(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
struct autofs_info *ino;
struct path path;
dev_t devid;
int err = -ENOENT;
if (param->size <= AUTOFS_DEV_IOCTL_SIZE) {
err = -EINVAL;
goto out;
}
devid = sbi->sb->s_dev;
param->requester.uid = param->requester.gid = -1;
err = find_autofs_mount(param->path, &path, test_by_dev, &devid);
if (err)
goto out;
ino = autofs_dentry_ino(path.dentry);
if (ino) {
err = 0;
autofs_expire_wait(&path, 0);
spin_lock(&sbi->fs_lock);
param->requester.uid =
from_kuid_munged(current_user_ns(), ino->uid);
param->requester.gid =
from_kgid_munged(current_user_ns(), ino->gid);
spin_unlock(&sbi->fs_lock);
}
path_put(&path);
out:
return err;
}
/*
* Call repeatedly until it returns -EAGAIN, meaning there's nothing
* more that can be done.
*/
static int autofs_dev_ioctl_expire(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
struct vfsmount *mnt;
int how;
how = param->expire.how;
mnt = fp->f_path.mnt;
return autofs_do_expire_multi(sbi->sb, mnt, sbi, how);
}
/* Check if autofs mount point is in use */
static int autofs_dev_ioctl_askumount(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
param->askumount.may_umount = 0;
if (may_umount(fp->f_path.mnt))
param->askumount.may_umount = 1;
return 0;
}
/*
* Check if the given path is a mountpoint.
*
* If we are supplied with the file descriptor of an autofs
* mount we're looking for a specific mount. In this case
* the path is considered a mountpoint if it is itself a
* mountpoint or contains a mount, such as a multi-mount
* without a root mount. In this case we return 1 if the
* path is a mount point and the super magic of the covering
* mount if there is one or 0 if it isn't a mountpoint.
*
* If we aren't supplied with a file descriptor then we
* lookup the path and check if it is the root of a mount.
* If a type is given we are looking for a particular autofs
* mount and if we don't find a match we return fail. If the
* located path is the root of a mount we return 1 along with
* the super magic of the mount or 0 otherwise.
*
* In both cases the the device number (as returned by
* new_encode_dev()) is also returned.
*/
static int autofs_dev_ioctl_ismountpoint(struct file *fp,
struct autofs_sb_info *sbi,
struct autofs_dev_ioctl *param)
{
struct path path;
const char *name;
unsigned int type;
unsigned int devid, magic;
int err = -ENOENT;
if (param->size <= AUTOFS_DEV_IOCTL_SIZE) {
err = -EINVAL;
goto out;
}
name = param->path;
type = param->ismountpoint.in.type;
param->ismountpoint.out.devid = devid = 0;
param->ismountpoint.out.magic = magic = 0;
if (!fp || param->ioctlfd == -1) {
if (autofs_type_any(type))
err = kern_path_mountpoint(AT_FDCWD,
name, &path, LOOKUP_FOLLOW);
else
err = find_autofs_mount(name, &path,
test_by_type, &type);
if (err)
goto out;
devid = new_encode_dev(path.dentry->d_sb->s_dev);
err = 0;
if (path.mnt->mnt_root == path.dentry) {
err = 1;
magic = path.dentry->d_sb->s_magic;
}
} else {
dev_t dev = sbi->sb->s_dev;
err = find_autofs_mount(name, &path, test_by_dev, &dev);
if (err)
goto out;
devid = new_encode_dev(dev);
err = path_has_submounts(&path);
if (follow_down_one(&path))
magic = path.dentry->d_sb->s_magic;
}
param->ismountpoint.out.devid = devid;
param->ismountpoint.out.magic = magic;
path_put(&path);
out:
return err;
}
/*
* Our range of ioctl numbers isn't 0 based so we need to shift
* the array index by _IOC_NR(AUTOFS_CTL_IOC_FIRST) for the table
* lookup.
*/
#define cmd_idx(cmd) (cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST))
static ioctl_fn lookup_dev_ioctl(unsigned int cmd)
{
static ioctl_fn _ioctls[] = {
autofs_dev_ioctl_version,
autofs_dev_ioctl_protover,
autofs_dev_ioctl_protosubver,
autofs_dev_ioctl_openmount,
autofs_dev_ioctl_closemount,
autofs_dev_ioctl_ready,
autofs_dev_ioctl_fail,
autofs_dev_ioctl_setpipefd,
autofs_dev_ioctl_catatonic,
autofs_dev_ioctl_timeout,
autofs_dev_ioctl_requester,
autofs_dev_ioctl_expire,
autofs_dev_ioctl_askumount,
autofs_dev_ioctl_ismountpoint,
};
unsigned int idx = cmd_idx(cmd);
return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx];
}
/* ioctl dispatcher */
static int _autofs_dev_ioctl(unsigned int command,
struct autofs_dev_ioctl __user *user)
{
struct autofs_dev_ioctl *param;
struct file *fp;
struct autofs_sb_info *sbi;
unsigned int cmd_first, cmd;
ioctl_fn fn = NULL;
int err = 0;
cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST);
cmd = _IOC_NR(command);
if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) ||
cmd - cmd_first > AUTOFS_DEV_IOCTL_IOC_COUNT) {
return -ENOTTY;
}
/* Only root can use ioctls other than AUTOFS_DEV_IOCTL_VERSION_CMD
* and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD
*/
if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
cmd != AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD &&
!capable(CAP_SYS_ADMIN))
return -EPERM;
/* Copy the parameters into kernel space. */
param = copy_dev_ioctl(user);
if (IS_ERR(param))
return PTR_ERR(param);
err = validate_dev_ioctl(command, param);
if (err)
goto out;
fn = lookup_dev_ioctl(cmd);
if (!fn) {
pr_warn("unknown command 0x%08x\n", command);
err = -ENOTTY;
goto out;
}
fp = NULL;
sbi = NULL;
/*
* For obvious reasons the openmount can't have a file
* descriptor yet. We don't take a reference to the
* file during close to allow for immediate release,
* and the same for retrieving ioctl version.
*/
if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) {
fp = fget(param->ioctlfd);
if (!fp) {
if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
goto cont;
err = -EBADF;
goto out;
}
sbi = autofs_dev_ioctl_sbi(fp);
if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) {
err = -EINVAL;
fput(fp);
goto out;
}
/*
* Admin needs to be able to set the mount catatonic in
* order to be able to perform the re-open.
*/
if (!autofs_oz_mode(sbi) &&
cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) {
err = -EACCES;
fput(fp);
goto out;
}
}
cont:
err = fn(fp, sbi, param);
if (fp)
fput(fp);
if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
err = -EFAULT;
out:
free_dev_ioctl(param);
return err;
}
static long autofs_dev_ioctl(struct file *file, unsigned int command,
unsigned long u)
{
int err;
err = _autofs_dev_ioctl(command, (struct autofs_dev_ioctl __user *) u);
return (long) err;
}
#ifdef CONFIG_COMPAT
static long autofs_dev_ioctl_compat(struct file *file, unsigned int command,
unsigned long u)
{
return autofs_dev_ioctl(file, command, (unsigned long) compat_ptr(u));
}
#else
#define autofs_dev_ioctl_compat NULL
#endif
static const struct file_operations _dev_ioctl_fops = {
.unlocked_ioctl = autofs_dev_ioctl,
.compat_ioctl = autofs_dev_ioctl_compat,
.owner = THIS_MODULE,
.llseek = noop_llseek,
};
static struct miscdevice _autofs_dev_ioctl_misc = {
.minor = AUTOFS_MINOR,
.name = AUTOFS_DEVICE_NAME,
.fops = &_dev_ioctl_fops,
.mode = 0644,
};
MODULE_ALIAS_MISCDEV(AUTOFS_MINOR);
MODULE_ALIAS("devname:autofs");
/* Register/deregister misc character device */
int __init autofs_dev_ioctl_init(void)
{
int r;
r = misc_register(&_autofs_dev_ioctl_misc);
if (r) {
pr_err("misc_register failed for control device\n");
return r;
}
return 0;
}
void autofs_dev_ioctl_exit(void)
{
misc_deregister(&_autofs_dev_ioctl_misc);
}

631
fs/autofs/expire.c Normal file
View file

@ -0,0 +1,631 @@
/*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
* Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
* Copyright 2001-2006 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 "autofs_i.h"
static unsigned long now;
/* Check if a dentry can be expired */
static inline int autofs_can_expire(struct dentry *dentry,
unsigned long timeout, int do_now)
{
struct autofs_info *ino = autofs_dentry_ino(dentry);
/* dentry in the process of being deleted */
if (ino == NULL)
return 0;
if (!do_now) {
/* Too young to die */
if (!timeout || time_after(ino->last_used + timeout, now))
return 0;
}
return 1;
}
/* Check a mount point for busyness */
static int autofs_mount_busy(struct vfsmount *mnt, struct dentry *dentry)
{
struct dentry *top = dentry;
struct path path = {.mnt = mnt, .dentry = dentry};
int status = 1;
pr_debug("dentry %p %pd\n", dentry, dentry);
path_get(&path);
if (!follow_down_one(&path))
goto done;
if (is_autofs_dentry(path.dentry)) {
struct autofs_sb_info *sbi = autofs_sbi(path.dentry->d_sb);
/* This is an autofs submount, we can't expire it */
if (autofs_type_indirect(sbi->type))
goto done;
}
/* Update the expiry counter if fs is busy */
if (!may_umount_tree(path.mnt)) {
struct autofs_info *ino;
ino = autofs_dentry_ino(top);
ino->last_used = jiffies;
goto done;
}
status = 0;
done:
pr_debug("returning = %d\n", status);
path_put(&path);
return status;
}
/*
* Calculate and dget next entry in the subdirs list under root.
*/
static struct dentry *get_next_positive_subdir(struct dentry *prev,
struct dentry *root)
{
struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
struct list_head *next;
struct dentry *q;
spin_lock(&sbi->lookup_lock);
spin_lock(&root->d_lock);
if (prev)
next = prev->d_child.next;
else {
prev = dget_dlock(root);
next = prev->d_subdirs.next;
}
cont:
if (next == &root->d_subdirs) {
spin_unlock(&root->d_lock);
spin_unlock(&sbi->lookup_lock);
dput(prev);
return NULL;
}
q = list_entry(next, struct dentry, d_child);
spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED);
/* Already gone or negative dentry (under construction) - try next */
if (!d_count(q) || !simple_positive(q)) {
spin_unlock(&q->d_lock);
next = q->d_child.next;
goto cont;
}
dget_dlock(q);
spin_unlock(&q->d_lock);
spin_unlock(&root->d_lock);
spin_unlock(&sbi->lookup_lock);
dput(prev);
return q;
}
/*
* Calculate and dget next entry in top down tree traversal.
*/
static struct dentry *get_next_positive_dentry(struct dentry *prev,
struct dentry *root)
{
struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
struct list_head *next;
struct dentry *p, *ret;
if (prev == NULL)
return dget(root);
spin_lock(&sbi->lookup_lock);
relock:
p = prev;
spin_lock(&p->d_lock);
again:
next = p->d_subdirs.next;
if (next == &p->d_subdirs) {
while (1) {
struct dentry *parent;
if (p == root) {
spin_unlock(&p->d_lock);
spin_unlock(&sbi->lookup_lock);
dput(prev);
return NULL;
}
parent = p->d_parent;
if (!spin_trylock(&parent->d_lock)) {
spin_unlock(&p->d_lock);
cpu_relax();
goto relock;
}
spin_unlock(&p->d_lock);
next = p->d_child.next;
p = parent;
if (next != &parent->d_subdirs)
break;
}
}
ret = list_entry(next, struct dentry, d_child);
spin_lock_nested(&ret->d_lock, DENTRY_D_LOCK_NESTED);
/* Negative dentry - try next */
if (!simple_positive(ret)) {
spin_unlock(&p->d_lock);
lock_set_subclass(&ret->d_lock.dep_map, 0, _RET_IP_);
p = ret;
goto again;
}
dget_dlock(ret);
spin_unlock(&ret->d_lock);
spin_unlock(&p->d_lock);
spin_unlock(&sbi->lookup_lock);
dput(prev);
return ret;
}
/*
* Check a direct mount point for busyness.
* Direct mounts have similar expiry semantics to tree mounts.
* The tree is not busy iff no mountpoints are busy and there are no
* autofs submounts.
*/
static int autofs_direct_busy(struct vfsmount *mnt,
struct dentry *top,
unsigned long timeout,
int do_now)
{
pr_debug("top %p %pd\n", top, top);
/* If it's busy update the expiry counters */
if (!may_umount_tree(mnt)) {
struct autofs_info *ino;
ino = autofs_dentry_ino(top);
if (ino)
ino->last_used = jiffies;
return 1;
}
/* Timeout of a direct mount is determined by its top dentry */
if (!autofs_can_expire(top, timeout, do_now))
return 1;
return 0;
}
/*
* Check a directory tree of mount points for busyness
* The tree is not busy iff no mountpoints are busy
*/
static int autofs_tree_busy(struct vfsmount *mnt,
struct dentry *top,
unsigned long timeout,
int do_now)
{
struct autofs_info *top_ino = autofs_dentry_ino(top);
struct dentry *p;
pr_debug("top %p %pd\n", top, top);
/* Negative dentry - give up */
if (!simple_positive(top))
return 1;
p = NULL;
while ((p = get_next_positive_dentry(p, top))) {
pr_debug("dentry %p %pd\n", p, p);
/*
* Is someone visiting anywhere in the subtree ?
* If there's no mount we need to check the usage
* count for the autofs dentry.
* If the fs is busy update the expiry counter.
*/
if (d_mountpoint(p)) {
if (autofs_mount_busy(mnt, p)) {
top_ino->last_used = jiffies;
dput(p);
return 1;
}
} else {
struct autofs_info *ino = autofs_dentry_ino(p);
unsigned int ino_count = atomic_read(&ino->count);
/* allow for dget above and top is already dgot */
if (p == top)
ino_count += 2;
else
ino_count++;
if (d_count(p) > ino_count) {
top_ino->last_used = jiffies;
dput(p);
return 1;
}
}
}
/* Timeout of a tree mount is ultimately determined by its top dentry */
if (!autofs_can_expire(top, timeout, do_now))
return 1;
return 0;
}
static struct dentry *autofs_check_leaves(struct vfsmount *mnt,
struct dentry *parent,
unsigned long timeout,
int do_now)
{
struct dentry *p;
pr_debug("parent %p %pd\n", parent, parent);
p = NULL;
while ((p = get_next_positive_dentry(p, parent))) {
pr_debug("dentry %p %pd\n", p, p);
if (d_mountpoint(p)) {
/* Can we umount this guy */
if (autofs_mount_busy(mnt, p))
continue;
/* Can we expire this guy */
if (autofs_can_expire(p, timeout, do_now))
return p;
}
}
return NULL;
}
/* Check if we can expire a direct mount (possibly a tree) */
struct dentry *autofs_expire_direct(struct super_block *sb,
struct vfsmount *mnt,
struct autofs_sb_info *sbi,
int how)
{
unsigned long timeout;
struct dentry *root = dget(sb->s_root);
int do_now = how & AUTOFS_EXP_IMMEDIATE;
struct autofs_info *ino;
if (!root)
return NULL;
now = jiffies;
timeout = sbi->exp_timeout;
if (!autofs_direct_busy(mnt, root, timeout, do_now)) {
spin_lock(&sbi->fs_lock);
ino = autofs_dentry_ino(root);
/* No point expiring a pending mount */
if (ino->flags & AUTOFS_INF_PENDING) {
spin_unlock(&sbi->fs_lock);
goto out;
}
ino->flags |= AUTOFS_INF_WANT_EXPIRE;
spin_unlock(&sbi->fs_lock);
synchronize_rcu();
if (!autofs_direct_busy(mnt, root, timeout, do_now)) {
spin_lock(&sbi->fs_lock);
ino->flags |= AUTOFS_INF_EXPIRING;
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
return root;
}
spin_lock(&sbi->fs_lock);
ino->flags &= ~AUTOFS_INF_WANT_EXPIRE;
spin_unlock(&sbi->fs_lock);
}
out:
dput(root);
return NULL;
}
/* Check if 'dentry' should expire, or return a nearby
* dentry that is suitable.
* If returned dentry is different from arg dentry,
* then a dget() reference was taken, else not.
*/
static struct dentry *should_expire(struct dentry *dentry,
struct vfsmount *mnt,
unsigned long timeout,
int how)
{
int do_now = how & AUTOFS_EXP_IMMEDIATE;
int exp_leaves = how & AUTOFS_EXP_LEAVES;
struct autofs_info *ino = autofs_dentry_ino(dentry);
unsigned int ino_count;
/* No point expiring a pending mount */
if (ino->flags & AUTOFS_INF_PENDING)
return NULL;
/*
* Case 1: (i) indirect mount or top level pseudo direct mount
* (autofs-4.1).
* (ii) indirect mount with offset mount, check the "/"
* offset (autofs-5.0+).
*/
if (d_mountpoint(dentry)) {
pr_debug("checking mountpoint %p %pd\n", dentry, dentry);
/* Can we umount this guy */
if (autofs_mount_busy(mnt, dentry))
return NULL;
/* Can we expire this guy */
if (autofs_can_expire(dentry, timeout, do_now))
return dentry;
return NULL;
}
if (d_really_is_positive(dentry) && d_is_symlink(dentry)) {
pr_debug("checking symlink %p %pd\n", dentry, dentry);
/*
* A symlink can't be "busy" in the usual sense so
* just check last used for expire timeout.
*/
if (autofs_can_expire(dentry, timeout, do_now))
return dentry;
return NULL;
}
if (simple_empty(dentry))
return NULL;
/* Case 2: tree mount, expire iff entire tree is not busy */
if (!exp_leaves) {
/* Path walk currently on this dentry? */
ino_count = atomic_read(&ino->count) + 1;
if (d_count(dentry) > ino_count)
return NULL;
if (!autofs_tree_busy(mnt, dentry, timeout, do_now))
return dentry;
/*
* Case 3: pseudo direct mount, expire individual leaves
* (autofs-4.1).
*/
} else {
/* Path walk currently on this dentry? */
struct dentry *expired;
ino_count = atomic_read(&ino->count) + 1;
if (d_count(dentry) > ino_count)
return NULL;
expired = autofs_check_leaves(mnt, dentry, timeout, do_now);
if (expired) {
if (expired == dentry)
dput(dentry);
return expired;
}
}
return NULL;
}
/*
* Find an eligible tree to time-out
* A tree is eligible if :-
* - it is unused by any user process
* - it has been unused for exp_timeout time
*/
struct dentry *autofs_expire_indirect(struct super_block *sb,
struct vfsmount *mnt,
struct autofs_sb_info *sbi,
int how)
{
unsigned long timeout;
struct dentry *root = sb->s_root;
struct dentry *dentry;
struct dentry *expired;
struct dentry *found;
struct autofs_info *ino;
if (!root)
return NULL;
now = jiffies;
timeout = sbi->exp_timeout;
dentry = NULL;
while ((dentry = get_next_positive_subdir(dentry, root))) {
int flags = how;
spin_lock(&sbi->fs_lock);
ino = autofs_dentry_ino(dentry);
if (ino->flags & AUTOFS_INF_WANT_EXPIRE) {
spin_unlock(&sbi->fs_lock);
continue;
}
spin_unlock(&sbi->fs_lock);
expired = should_expire(dentry, mnt, timeout, flags);
if (!expired)
continue;
spin_lock(&sbi->fs_lock);
ino = autofs_dentry_ino(expired);
ino->flags |= AUTOFS_INF_WANT_EXPIRE;
spin_unlock(&sbi->fs_lock);
synchronize_rcu();
/* Make sure a reference is not taken on found if
* things have changed.
*/
flags &= ~AUTOFS_EXP_LEAVES;
found = should_expire(expired, mnt, timeout, how);
if (!found || found != expired)
/* Something has changed, continue */
goto next;
if (expired != dentry)
dput(dentry);
spin_lock(&sbi->fs_lock);
goto found;
next:
spin_lock(&sbi->fs_lock);
ino->flags &= ~AUTOFS_INF_WANT_EXPIRE;
spin_unlock(&sbi->fs_lock);
if (expired != dentry)
dput(expired);
}
return NULL;
found:
pr_debug("returning %p %pd\n", expired, expired);
ino->flags |= AUTOFS_INF_EXPIRING;
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
return expired;
}
int autofs_expire_wait(const struct path *path, int rcu_walk)
{
struct dentry *dentry = path->dentry;
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
int status;
int state;
/* Block on any pending expire */
if (!(ino->flags & AUTOFS_INF_WANT_EXPIRE))
return 0;
if (rcu_walk)
return -ECHILD;
retry:
spin_lock(&sbi->fs_lock);
state = ino->flags & (AUTOFS_INF_WANT_EXPIRE | AUTOFS_INF_EXPIRING);
if (state == AUTOFS_INF_WANT_EXPIRE) {
spin_unlock(&sbi->fs_lock);
/*
* Possibly being selected for expire, wait until
* it's selected or not.
*/
schedule_timeout_uninterruptible(HZ/10);
goto retry;
}
if (state & AUTOFS_INF_EXPIRING) {
spin_unlock(&sbi->fs_lock);
pr_debug("waiting for expire %p name=%pd\n", dentry, dentry);
status = autofs_wait(sbi, path, NFY_NONE);
wait_for_completion(&ino->expire_complete);
pr_debug("expire done status=%d\n", status);
if (d_unhashed(dentry))
return -EAGAIN;
return status;
}
spin_unlock(&sbi->fs_lock);
return 0;
}
/* Perform an expiry operation */
int autofs_expire_run(struct super_block *sb,
struct vfsmount *mnt,
struct autofs_sb_info *sbi,
struct autofs_packet_expire __user *pkt_p)
{
struct autofs_packet_expire pkt;
struct autofs_info *ino;
struct dentry *dentry;
int ret = 0;
memset(&pkt, 0, sizeof(pkt));
pkt.hdr.proto_version = sbi->version;
pkt.hdr.type = autofs_ptype_expire;
dentry = autofs_expire_indirect(sb, mnt, sbi, 0);
if (!dentry)
return -EAGAIN;
pkt.len = dentry->d_name.len;
memcpy(pkt.name, dentry->d_name.name, pkt.len);
pkt.name[pkt.len] = '\0';
dput(dentry);
if (copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)))
ret = -EFAULT;
spin_lock(&sbi->fs_lock);
ino = autofs_dentry_ino(dentry);
/* avoid rapid-fire expire attempts if expiry fails */
ino->last_used = now;
ino->flags &= ~(AUTOFS_INF_EXPIRING|AUTOFS_INF_WANT_EXPIRE);
complete_all(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
return ret;
}
int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
struct autofs_sb_info *sbi, int when)
{
struct dentry *dentry;
int ret = -EAGAIN;
if (autofs_type_trigger(sbi->type))
dentry = autofs_expire_direct(sb, mnt, sbi, when);
else
dentry = autofs_expire_indirect(sb, mnt, sbi, when);
if (dentry) {
struct autofs_info *ino = autofs_dentry_ino(dentry);
const struct path path = { .mnt = mnt, .dentry = dentry };
/* This is synchronous because it makes the daemon a
* little easier
*/
ret = autofs_wait(sbi, &path, NFY_EXPIRE);
spin_lock(&sbi->fs_lock);
/* avoid rapid-fire expire attempts if expiry fails */
ino->last_used = now;
ino->flags &= ~(AUTOFS_INF_EXPIRING|AUTOFS_INF_WANT_EXPIRE);
complete_all(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
dput(dentry);
}
return ret;
}
/*
* Call repeatedly until it returns -EAGAIN, meaning there's nothing
* more to be done.
*/
int autofs_expire_multi(struct super_block *sb, struct vfsmount *mnt,
struct autofs_sb_info *sbi, int __user *arg)
{
int do_now = 0;
if (arg && get_user(do_now, arg))
return -EFAULT;
return autofs_do_expire_multi(sb, mnt, sbi, do_now);
}

48
fs/autofs/init.c Normal file
View file

@ -0,0 +1,48 @@
/*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
*
* 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/module.h>
#include <linux/init.h>
#include "autofs_i.h"
static struct dentry *autofs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_nodev(fs_type, flags, data, autofs_fill_super);
}
static struct file_system_type autofs_fs_type = {
.owner = THIS_MODULE,
.name = "autofs",
.mount = autofs_mount,
.kill_sb = autofs_kill_sb,
};
MODULE_ALIAS_FS("autofs");
static int __init init_autofs_fs(void)
{
int err;
autofs_dev_ioctl_init();
err = register_filesystem(&autofs_fs_type);
if (err)
autofs_dev_ioctl_exit();
return err;
}
static void __exit exit_autofs_fs(void)
{
autofs_dev_ioctl_exit();
unregister_filesystem(&autofs_fs_type);
}
module_init(init_autofs_fs)
module_exit(exit_autofs_fs)
MODULE_LICENSE("GPL");

375
fs/autofs/inode.c Normal file
View file

@ -0,0 +1,375 @@
/*
* 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/kernel.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/parser.h>
#include <linux/bitops.h>
#include <linux/magic.h>
#include "autofs_i.h"
#include <linux/module.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, int *pipefd, kuid_t *uid, kgid_t *gid,
int *pgrp, bool *pgrp_set, unsigned int *type,
int *minproto, int *maxproto)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
*uid = current_uid();
*gid = current_gid();
*minproto = AUTOFS_MIN_PROTO_VERSION;
*maxproto = AUTOFS_MAX_PROTO_VERSION;
*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;
break;
case Opt_uid:
if (match_int(args, &option))
return 1;
*uid = make_kuid(current_user_ns(), option);
if (!uid_valid(*uid))
return 1;
break;
case Opt_gid:
if (match_int(args, &option))
return 1;
*gid = make_kgid(current_user_ns(), option);
if (!gid_valid(*gid))
return 1;
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;
*minproto = option;
break;
case Opt_maxproto:
if (match_int(args, &option))
return 1;
*maxproto = option;
break;
case Opt_indirect:
set_autofs_type_indirect(type);
break;
case Opt_direct:
set_autofs_type_direct(type);
break;
case Opt_offset:
set_autofs_type_offset(type);
break;
default:
return 1;
}
}
return (*pipefd < 0);
}
int autofs_fill_super(struct super_block *s, void *data, int silent)
{
struct inode *root_inode;
struct dentry *root;
struct file *pipe;
int pipefd;
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, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
&pgrp, &pgrp_set, &sbi->type, &sbi->min_proto,
&sbi->max_proto)) {
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", pipefd, pid_nr(sbi->oz_pgrp));
pipe = fget(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->pipefd = pipefd;
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;
}

942
fs/autofs/root.c Normal file
View file

@ -0,0 +1,942 @@
/*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
* Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
* Copyright 2001-2006 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/capability.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/param.h>
#include <linux/time.h>
#include <linux/compat.h>
#include <linux/mutex.h>
#include "autofs_i.h"
static int autofs_dir_symlink(struct inode *, struct dentry *, const char *);
static int autofs_dir_unlink(struct inode *, struct dentry *);
static int autofs_dir_rmdir(struct inode *, struct dentry *);
static int autofs_dir_mkdir(struct inode *, struct dentry *, umode_t);
static long autofs_root_ioctl(struct file *, unsigned int, unsigned long);
#ifdef CONFIG_COMPAT
static long autofs_root_compat_ioctl(struct file *,
unsigned int, unsigned long);
#endif
static int autofs_dir_open(struct inode *inode, struct file *file);
static struct dentry *autofs_lookup(struct inode *,
struct dentry *, unsigned int);
static struct vfsmount *autofs_d_automount(struct path *);
static int autofs_d_manage(const struct path *, bool);
static void autofs_dentry_release(struct dentry *);
const struct file_operations autofs_root_operations = {
.open = dcache_dir_open,
.release = dcache_dir_close,
.read = generic_read_dir,
.iterate_shared = dcache_readdir,
.llseek = dcache_dir_lseek,
.unlocked_ioctl = autofs_root_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = autofs_root_compat_ioctl,
#endif
};
const struct file_operations autofs_dir_operations = {
.open = autofs_dir_open,
.release = dcache_dir_close,
.read = generic_read_dir,
.iterate_shared = dcache_readdir,
.llseek = dcache_dir_lseek,
};
const struct inode_operations autofs_dir_inode_operations = {
.lookup = autofs_lookup,
.unlink = autofs_dir_unlink,
.symlink = autofs_dir_symlink,
.mkdir = autofs_dir_mkdir,
.rmdir = autofs_dir_rmdir,
};
const struct dentry_operations autofs_dentry_operations = {
.d_automount = autofs_d_automount,
.d_manage = autofs_d_manage,
.d_release = autofs_dentry_release,
};
static void autofs_add_active(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino;
ino = autofs_dentry_ino(dentry);
if (ino) {
spin_lock(&sbi->lookup_lock);
if (!ino->active_count) {
if (list_empty(&ino->active))
list_add(&ino->active, &sbi->active_list);
}
ino->active_count++;
spin_unlock(&sbi->lookup_lock);
}
}
static void autofs_del_active(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino;
ino = autofs_dentry_ino(dentry);
if (ino) {
spin_lock(&sbi->lookup_lock);
ino->active_count--;
if (!ino->active_count) {
if (!list_empty(&ino->active))
list_del_init(&ino->active);
}
spin_unlock(&sbi->lookup_lock);
}
}
static int autofs_dir_open(struct inode *inode, struct file *file)
{
struct dentry *dentry = file->f_path.dentry;
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
pr_debug("file=%p dentry=%p %pd\n", file, dentry, dentry);
if (autofs_oz_mode(sbi))
goto out;
/*
* An empty directory in an autofs file system is always a
* mount point. The daemon must have failed to mount this
* during lookup so it doesn't exist. This can happen, for
* example, if user space returns an incorrect status for a
* mount request. Otherwise we're doing a readdir on the
* autofs file system so just let the libfs routines handle
* it.
*/
spin_lock(&sbi->lookup_lock);
if (!path_is_mountpoint(&file->f_path) && simple_empty(dentry)) {
spin_unlock(&sbi->lookup_lock);
return -ENOENT;
}
spin_unlock(&sbi->lookup_lock);
out:
return dcache_dir_open(inode, file);
}
static void autofs_dentry_release(struct dentry *de)
{
struct autofs_info *ino = autofs_dentry_ino(de);
struct autofs_sb_info *sbi = autofs_sbi(de->d_sb);
pr_debug("releasing %p\n", de);
if (!ino)
return;
if (sbi) {
spin_lock(&sbi->lookup_lock);
if (!list_empty(&ino->active))
list_del(&ino->active);
if (!list_empty(&ino->expiring))
list_del(&ino->expiring);
spin_unlock(&sbi->lookup_lock);
}
autofs_free_ino(ino);
}
static struct dentry *autofs_lookup_active(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct dentry *parent = dentry->d_parent;
const struct qstr *name = &dentry->d_name;
unsigned int len = name->len;
unsigned int hash = name->hash;
const unsigned char *str = name->name;
struct list_head *p, *head;
head = &sbi->active_list;
if (list_empty(head))
return NULL;
spin_lock(&sbi->lookup_lock);
list_for_each(p, head) {
struct autofs_info *ino;
struct dentry *active;
const struct qstr *qstr;
ino = list_entry(p, struct autofs_info, active);
active = ino->dentry;
spin_lock(&active->d_lock);
/* Already gone? */
if ((int) d_count(active) <= 0)
goto next;
qstr = &active->d_name;
if (active->d_name.hash != hash)
goto next;
if (active->d_parent != parent)
goto next;
if (qstr->len != len)
goto next;
if (memcmp(qstr->name, str, len))
goto next;
if (d_unhashed(active)) {
dget_dlock(active);
spin_unlock(&active->d_lock);
spin_unlock(&sbi->lookup_lock);
return active;
}
next:
spin_unlock(&active->d_lock);
}
spin_unlock(&sbi->lookup_lock);
return NULL;
}
static struct dentry *autofs_lookup_expiring(struct dentry *dentry,
bool rcu_walk)
{
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct dentry *parent = dentry->d_parent;
const struct qstr *name = &dentry->d_name;
unsigned int len = name->len;
unsigned int hash = name->hash;
const unsigned char *str = name->name;
struct list_head *p, *head;
head = &sbi->expiring_list;
if (list_empty(head))
return NULL;
spin_lock(&sbi->lookup_lock);
list_for_each(p, head) {
struct autofs_info *ino;
struct dentry *expiring;
const struct qstr *qstr;
if (rcu_walk) {
spin_unlock(&sbi->lookup_lock);
return ERR_PTR(-ECHILD);
}
ino = list_entry(p, struct autofs_info, expiring);
expiring = ino->dentry;
spin_lock(&expiring->d_lock);
/* We've already been dentry_iput or unlinked */
if (d_really_is_negative(expiring))
goto next;
qstr = &expiring->d_name;
if (expiring->d_name.hash != hash)
goto next;
if (expiring->d_parent != parent)
goto next;
if (qstr->len != len)
goto next;
if (memcmp(qstr->name, str, len))
goto next;
if (d_unhashed(expiring)) {
dget_dlock(expiring);
spin_unlock(&expiring->d_lock);
spin_unlock(&sbi->lookup_lock);
return expiring;
}
next:
spin_unlock(&expiring->d_lock);
}
spin_unlock(&sbi->lookup_lock);
return NULL;
}
static int autofs_mount_wait(const struct path *path, bool rcu_walk)
{
struct autofs_sb_info *sbi = autofs_sbi(path->dentry->d_sb);
struct autofs_info *ino = autofs_dentry_ino(path->dentry);
int status = 0;
if (ino->flags & AUTOFS_INF_PENDING) {
if (rcu_walk)
return -ECHILD;
pr_debug("waiting for mount name=%pd\n", path->dentry);
status = autofs_wait(sbi, path, NFY_MOUNT);
pr_debug("mount wait done status=%d\n", status);
}
ino->last_used = jiffies;
return status;
}
static int do_expire_wait(const struct path *path, bool rcu_walk)
{
struct dentry *dentry = path->dentry;
struct dentry *expiring;
expiring = autofs_lookup_expiring(dentry, rcu_walk);
if (IS_ERR(expiring))
return PTR_ERR(expiring);
if (!expiring)
return autofs_expire_wait(path, rcu_walk);
else {
const struct path this = { .mnt = path->mnt, .dentry = expiring };
/*
* If we are racing with expire the request might not
* be quite complete, but the directory has been removed
* so it must have been successful, just wait for it.
*/
autofs_expire_wait(&this, 0);
autofs_del_expiring(expiring);
dput(expiring);
}
return 0;
}
static struct dentry *autofs_mountpoint_changed(struct path *path)
{
struct dentry *dentry = path->dentry;
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
/*
* If this is an indirect mount the dentry could have gone away
* as a result of an expire and a new one created.
*/
if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) {
struct dentry *parent = dentry->d_parent;
struct autofs_info *ino;
struct dentry *new;
new = d_lookup(parent, &dentry->d_name);
if (!new)
return NULL;
ino = autofs_dentry_ino(new);
ino->last_used = jiffies;
dput(path->dentry);
path->dentry = new;
}
return path->dentry;
}
static struct vfsmount *autofs_d_automount(struct path *path)
{
struct dentry *dentry = path->dentry;
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
int status;
pr_debug("dentry=%p %pd\n", dentry, dentry);
/* The daemon never triggers a mount. */
if (autofs_oz_mode(sbi))
return NULL;
/*
* If an expire request is pending everyone must wait.
* If the expire fails we're still mounted so continue
* the follow and return. A return of -EAGAIN (which only
* happens with indirect mounts) means the expire completed
* and the directory was removed, so just go ahead and try
* the mount.
*/
status = do_expire_wait(path, 0);
if (status && status != -EAGAIN)
return NULL;
/* Callback to the daemon to perform the mount or wait */
spin_lock(&sbi->fs_lock);
if (ino->flags & AUTOFS_INF_PENDING) {
spin_unlock(&sbi->fs_lock);
status = autofs_mount_wait(path, 0);
if (status)
return ERR_PTR(status);
goto done;
}
/*
* If the dentry is a symlink it's equivalent to a directory
* having path_is_mountpoint() true, so there's no need to call
* back to the daemon.
*/
if (d_really_is_positive(dentry) && d_is_symlink(dentry)) {
spin_unlock(&sbi->fs_lock);
goto done;
}
if (!path_is_mountpoint(path)) {
/*
* It's possible that user space hasn't removed directories
* after umounting a rootless multi-mount, although it
* should. For v5 path_has_submounts() is sufficient to
* handle this because the leaves of the directory tree under
* the mount never trigger mounts themselves (they have an
* autofs trigger mount mounted on them). But v4 pseudo direct
* mounts do need the leaves to trigger mounts. In this case
* we have no choice but to use the list_empty() check and
* require user space behave.
*/
if (sbi->version > 4) {
if (path_has_submounts(path)) {
spin_unlock(&sbi->fs_lock);
goto done;
}
} else {
if (!simple_empty(dentry)) {
spin_unlock(&sbi->fs_lock);
goto done;
}
}
ino->flags |= AUTOFS_INF_PENDING;
spin_unlock(&sbi->fs_lock);
status = autofs_mount_wait(path, 0);
spin_lock(&sbi->fs_lock);
ino->flags &= ~AUTOFS_INF_PENDING;
if (status) {
spin_unlock(&sbi->fs_lock);
return ERR_PTR(status);
}
}
spin_unlock(&sbi->fs_lock);
done:
/* Mount succeeded, check if we ended up with a new dentry */
dentry = autofs_mountpoint_changed(path);
if (!dentry)
return ERR_PTR(-ENOENT);
return NULL;
}
static int autofs_d_manage(const struct path *path, bool rcu_walk)
{
struct dentry *dentry = path->dentry;
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
int status;
pr_debug("dentry=%p %pd\n", dentry, dentry);
/* The daemon never waits. */
if (autofs_oz_mode(sbi)) {
if (!path_is_mountpoint(path))
return -EISDIR;
return 0;
}
/* Wait for pending expires */
if (do_expire_wait(path, rcu_walk) == -ECHILD)
return -ECHILD;
/*
* This dentry may be under construction so wait on mount
* completion.
*/
status = autofs_mount_wait(path, rcu_walk);
if (status)
return status;
if (rcu_walk) {
/* We don't need fs_lock in rcu_walk mode,
* just testing 'AUTOFS_INFO_NO_RCU' is enough.
* simple_empty() takes a spinlock, so leave it
* to last.
* We only return -EISDIR when certain this isn't
* a mount-trap.
*/
struct inode *inode;
if (ino->flags & AUTOFS_INF_WANT_EXPIRE)
return 0;
if (path_is_mountpoint(path))
return 0;
inode = d_inode_rcu(dentry);
if (inode && S_ISLNK(inode->i_mode))
return -EISDIR;
if (list_empty(&dentry->d_subdirs))
return 0;
if (!simple_empty(dentry))
return -EISDIR;
return 0;
}
spin_lock(&sbi->fs_lock);
/*
* If the dentry has been selected for expire while we slept
* on the lock then it might go away. We'll deal with that in
* ->d_automount() and wait on a new mount if the expire
* succeeds or return here if it doesn't (since there's no
* mount to follow with a rootless multi-mount).
*/
if (!(ino->flags & AUTOFS_INF_EXPIRING)) {
/*
* Any needed mounting has been completed and the path
* updated so check if this is a rootless multi-mount so
* we can avoid needless calls ->d_automount() and avoid
* an incorrect ELOOP error return.
*/
if ((!path_is_mountpoint(path) && !simple_empty(dentry)) ||
(d_really_is_positive(dentry) && d_is_symlink(dentry)))
status = -EISDIR;
}
spin_unlock(&sbi->fs_lock);
return status;
}
/* Lookups in the root directory */
static struct dentry *autofs_lookup(struct inode *dir,
struct dentry *dentry, unsigned int flags)
{
struct autofs_sb_info *sbi;
struct autofs_info *ino;
struct dentry *active;
pr_debug("name = %pd\n", dentry);
/* File name too long to exist */
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
sbi = autofs_sbi(dir->i_sb);
pr_debug("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
current->pid, task_pgrp_nr(current), sbi->catatonic,
autofs_oz_mode(sbi));
active = autofs_lookup_active(dentry);
if (active)
return active;
else {
/*
* A dentry that is not within the root can never trigger a
* mount operation, unless the directory already exists, so we
* can return fail immediately. The daemon however does need
* to create directories within the file system.
*/
if (!autofs_oz_mode(sbi) && !IS_ROOT(dentry->d_parent))
return ERR_PTR(-ENOENT);
/* Mark entries in the root as mount triggers */
if (IS_ROOT(dentry->d_parent) &&
autofs_type_indirect(sbi->type))
__managed_dentry_set_managed(dentry);
ino = autofs_new_ino(sbi);
if (!ino)
return ERR_PTR(-ENOMEM);
dentry->d_fsdata = ino;
ino->dentry = dentry;
autofs_add_active(dentry);
}
return NULL;
}
static int autofs_dir_symlink(struct inode *dir,
struct dentry *dentry,
const char *symname)
{
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
struct autofs_info *p_ino;
struct inode *inode;
size_t size = strlen(symname);
char *cp;
pr_debug("%s <- %pd\n", symname, dentry);
if (!autofs_oz_mode(sbi))
return -EACCES;
BUG_ON(!ino);
autofs_clean_ino(ino);
autofs_del_active(dentry);
cp = kmalloc(size + 1, GFP_KERNEL);
if (!cp)
return -ENOMEM;
strcpy(cp, symname);
inode = autofs_get_inode(dir->i_sb, S_IFLNK | 0555);
if (!inode) {
kfree(cp);
return -ENOMEM;
}
inode->i_private = cp;
inode->i_size = size;
d_add(dentry, inode);
dget(dentry);
atomic_inc(&ino->count);
p_ino = autofs_dentry_ino(dentry->d_parent);
if (p_ino && !IS_ROOT(dentry))
atomic_inc(&p_ino->count);
dir->i_mtime = current_time(dir);
return 0;
}
/*
* NOTE!
*
* Normal filesystems would do a "d_delete()" to tell the VFS dcache
* that the file no longer exists. However, doing that means that the
* VFS layer can turn the dentry into a negative dentry. We don't want
* this, because the unlink is probably the result of an expire.
* We simply d_drop it and add it to a expiring list in the super block,
* which allows the dentry lookup to check for an incomplete expire.
*
* If a process is blocked on the dentry waiting for the expire to finish,
* it will invalidate the dentry and try to mount with a new one.
*
* Also see autofs_dir_rmdir()..
*/
static int autofs_dir_unlink(struct inode *dir, struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
struct autofs_info *p_ino;
/* This allows root to remove symlinks */
if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
return -EPERM;
if (atomic_dec_and_test(&ino->count)) {
p_ino = autofs_dentry_ino(dentry->d_parent);
if (p_ino && !IS_ROOT(dentry))
atomic_dec(&p_ino->count);
}
dput(ino->dentry);
d_inode(dentry)->i_size = 0;
clear_nlink(d_inode(dentry));
dir->i_mtime = current_time(dir);
spin_lock(&sbi->lookup_lock);
__autofs_add_expiring(dentry);
d_drop(dentry);
spin_unlock(&sbi->lookup_lock);
return 0;
}
/*
* Version 4 of autofs provides a pseudo direct mount implementation
* that relies on directories at the leaves of a directory tree under
* an indirect mount to trigger mounts. To allow for this we need to
* set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves
* of the directory tree. There is no need to clear the automount flag
* following a mount or restore it after an expire because these mounts
* are always covered. However, it is necessary to ensure that these
* flags are clear on non-empty directories to avoid unnecessary calls
* during path walks.
*/
static void autofs_set_leaf_automount_flags(struct dentry *dentry)
{
struct dentry *parent;
/* root and dentrys in the root are already handled */
if (IS_ROOT(dentry->d_parent))
return;
managed_dentry_set_managed(dentry);
parent = dentry->d_parent;
/* only consider parents below dentrys in the root */
if (IS_ROOT(parent->d_parent))
return;
managed_dentry_clear_managed(parent);
}
static void autofs_clear_leaf_automount_flags(struct dentry *dentry)
{
struct list_head *d_child;
struct dentry *parent;
/* flags for dentrys in the root are handled elsewhere */
if (IS_ROOT(dentry->d_parent))
return;
managed_dentry_clear_managed(dentry);
parent = dentry->d_parent;
/* only consider parents below dentrys in the root */
if (IS_ROOT(parent->d_parent))
return;
d_child = &dentry->d_child;
/* Set parent managed if it's becoming empty */
if (d_child->next == &parent->d_subdirs &&
d_child->prev == &parent->d_subdirs)
managed_dentry_set_managed(parent);
}
static int autofs_dir_rmdir(struct inode *dir, struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
struct autofs_info *p_ino;
pr_debug("dentry %p, removing %pd\n", dentry, dentry);
if (!autofs_oz_mode(sbi))
return -EACCES;
spin_lock(&sbi->lookup_lock);
if (!simple_empty(dentry)) {
spin_unlock(&sbi->lookup_lock);
return -ENOTEMPTY;
}
__autofs_add_expiring(dentry);
d_drop(dentry);
spin_unlock(&sbi->lookup_lock);
if (sbi->version < 5)
autofs_clear_leaf_automount_flags(dentry);
if (atomic_dec_and_test(&ino->count)) {
p_ino = autofs_dentry_ino(dentry->d_parent);
if (p_ino && dentry->d_parent != dentry)
atomic_dec(&p_ino->count);
}
dput(ino->dentry);
d_inode(dentry)->i_size = 0;
clear_nlink(d_inode(dentry));
if (dir->i_nlink)
drop_nlink(dir);
return 0;
}
static int autofs_dir_mkdir(struct inode *dir,
struct dentry *dentry, umode_t mode)
{
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
struct autofs_info *p_ino;
struct inode *inode;
if (!autofs_oz_mode(sbi))
return -EACCES;
pr_debug("dentry %p, creating %pd\n", dentry, dentry);
BUG_ON(!ino);
autofs_clean_ino(ino);
autofs_del_active(dentry);
inode = autofs_get_inode(dir->i_sb, S_IFDIR | mode);
if (!inode)
return -ENOMEM;
d_add(dentry, inode);
if (sbi->version < 5)
autofs_set_leaf_automount_flags(dentry);
dget(dentry);
atomic_inc(&ino->count);
p_ino = autofs_dentry_ino(dentry->d_parent);
if (p_ino && !IS_ROOT(dentry))
atomic_inc(&p_ino->count);
inc_nlink(dir);
dir->i_mtime = current_time(dir);
return 0;
}
/* Get/set timeout ioctl() operation */
#ifdef CONFIG_COMPAT
static inline int autofs_compat_get_set_timeout(struct autofs_sb_info *sbi,
compat_ulong_t __user *p)
{
unsigned long ntimeout;
int rv;
rv = get_user(ntimeout, p);
if (rv)
goto error;
rv = put_user(sbi->exp_timeout/HZ, p);
if (rv)
goto error;
if (ntimeout > UINT_MAX/HZ)
sbi->exp_timeout = 0;
else
sbi->exp_timeout = ntimeout * HZ;
return 0;
error:
return rv;
}
#endif
static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
unsigned long __user *p)
{
unsigned long ntimeout;
int rv;
rv = get_user(ntimeout, p);
if (rv)
goto error;
rv = put_user(sbi->exp_timeout/HZ, p);
if (rv)
goto error;
if (ntimeout > ULONG_MAX/HZ)
sbi->exp_timeout = 0;
else
sbi->exp_timeout = ntimeout * HZ;
return 0;
error:
return rv;
}
/* Return protocol version */
static inline int autofs_get_protover(struct autofs_sb_info *sbi,
int __user *p)
{
return put_user(sbi->version, p);
}
/* Return protocol sub version */
static inline int autofs_get_protosubver(struct autofs_sb_info *sbi,
int __user *p)
{
return put_user(sbi->sub_version, p);
}
/*
* Tells the daemon whether it can umount the autofs mount.
*/
static inline int autofs_ask_umount(struct vfsmount *mnt, int __user *p)
{
int status = 0;
if (may_umount(mnt))
status = 1;
pr_debug("may umount %d\n", status);
status = put_user(status, p);
return status;
}
/* Identify autofs_dentries - this is so we can tell if there's
* an extra dentry refcount or not. We only hold a refcount on the
* dentry if its non-negative (ie, d_inode != NULL)
*/
int is_autofs_dentry(struct dentry *dentry)
{
return dentry && d_really_is_positive(dentry) &&
dentry->d_op == &autofs_dentry_operations &&
dentry->d_fsdata != NULL;
}
/*
* ioctl()'s on the root directory is the chief method for the daemon to
* generate kernel reactions
*/
static int autofs_root_ioctl_unlocked(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
void __user *p = (void __user *)arg;
pr_debug("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",
cmd, arg, sbi, task_pgrp_nr(current));
if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
_IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
return -ENOTTY;
if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
return -EPERM;
switch (cmd) {
case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
return autofs_wait_release(sbi, (autofs_wqt_t) arg, 0);
case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
return autofs_wait_release(sbi, (autofs_wqt_t) arg, -ENOENT);
case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
autofs_catatonic_mode(sbi);
return 0;
case AUTOFS_IOC_PROTOVER: /* Get protocol version */
return autofs_get_protover(sbi, p);
case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
return autofs_get_protosubver(sbi, p);
case AUTOFS_IOC_SETTIMEOUT:
return autofs_get_set_timeout(sbi, p);
#ifdef CONFIG_COMPAT
case AUTOFS_IOC_SETTIMEOUT32:
return autofs_compat_get_set_timeout(sbi, p);
#endif
case AUTOFS_IOC_ASKUMOUNT:
return autofs_ask_umount(filp->f_path.mnt, p);
/* return a single thing to expire */
case AUTOFS_IOC_EXPIRE:
return autofs_expire_run(inode->i_sb, filp->f_path.mnt, sbi, p);
/* same as above, but can send multiple expires through pipe */
case AUTOFS_IOC_EXPIRE_MULTI:
return autofs_expire_multi(inode->i_sb,
filp->f_path.mnt, sbi, p);
default:
return -EINVAL;
}
}
static long autofs_root_ioctl(struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
return autofs_root_ioctl_unlocked(inode, filp, cmd, arg);
}
#ifdef CONFIG_COMPAT
static long autofs_root_compat_ioctl(struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
int ret;
if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL)
ret = autofs_root_ioctl_unlocked(inode, filp, cmd, arg);
else
ret = autofs_root_ioctl_unlocked(inode, filp, cmd,
(unsigned long) compat_ptr(arg));
return ret;
}
#endif

29
fs/autofs/symlink.c Normal file
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@ -0,0 +1,29 @@
/*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
*
* 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 "autofs_i.h"
static const char *autofs_get_link(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
struct autofs_sb_info *sbi;
struct autofs_info *ino;
if (!dentry)
return ERR_PTR(-ECHILD);
sbi = autofs_sbi(dentry->d_sb);
ino = autofs_dentry_ino(dentry);
if (ino && !autofs_oz_mode(sbi))
ino->last_used = jiffies;
return d_inode(dentry)->i_private;
}
const struct inode_operations autofs_symlink_inode_operations = {
.get_link = autofs_get_link
};

559
fs/autofs/waitq.c Normal file
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@ -0,0 +1,559 @@
/*
* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
* Copyright 2001-2006 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/slab.h>
#include <linux/time.h>
#include <linux/signal.h>
#include <linux/sched/signal.h>
#include <linux/file.h>
#include "autofs_i.h"
/* We make this a static variable rather than a part of the superblock; it
* is better if we don't reassign numbers easily even across filesystems
*/
static autofs_wqt_t autofs_next_wait_queue = 1;
void autofs_catatonic_mode(struct autofs_sb_info *sbi)
{
struct autofs_wait_queue *wq, *nwq;
mutex_lock(&sbi->wq_mutex);
if (sbi->catatonic) {
mutex_unlock(&sbi->wq_mutex);
return;
}
pr_debug("entering catatonic mode\n");
sbi->catatonic = 1;
wq = sbi->queues;
sbi->queues = NULL; /* Erase all wait queues */
while (wq) {
nwq = wq->next;
wq->status = -ENOENT; /* Magic is gone - report failure */
kfree(wq->name.name);
wq->name.name = NULL;
wq->wait_ctr--;
wake_up_interruptible(&wq->queue);
wq = nwq;
}
fput(sbi->pipe); /* Close the pipe */
sbi->pipe = NULL;
sbi->pipefd = -1;
mutex_unlock(&sbi->wq_mutex);
}
static int autofs_write(struct autofs_sb_info *sbi,
struct file *file, const void *addr, int bytes)
{
unsigned long sigpipe, flags;
const char *data = (const char *)addr;
ssize_t wr = 0;
sigpipe = sigismember(&current->pending.signal, SIGPIPE);
mutex_lock(&sbi->pipe_mutex);
while (bytes) {
wr = __kernel_write(file, data, bytes, &file->f_pos);
if (wr <= 0)
break;
data += wr;
bytes -= wr;
}
mutex_unlock(&sbi->pipe_mutex);
/* Keep the currently executing process from receiving a
* SIGPIPE unless it was already supposed to get one
*/
if (wr == -EPIPE && !sigpipe) {
spin_lock_irqsave(&current->sighand->siglock, flags);
sigdelset(&current->pending.signal, SIGPIPE);
recalc_sigpending();
spin_unlock_irqrestore(&current->sighand->siglock, flags);
}
/* if 'wr' returned 0 (impossible) we assume -EIO (safe) */
return bytes == 0 ? 0 : wr < 0 ? wr : -EIO;
}
static void autofs_notify_daemon(struct autofs_sb_info *sbi,
struct autofs_wait_queue *wq,
int type)
{
union {
struct autofs_packet_hdr hdr;
union autofs_packet_union v4_pkt;
union autofs_v5_packet_union v5_pkt;
} pkt;
struct file *pipe = NULL;
size_t pktsz;
int ret;
pr_debug("wait id = 0x%08lx, name = %.*s, type=%d\n",
(unsigned long) wq->wait_queue_token,
wq->name.len, wq->name.name, type);
memset(&pkt, 0, sizeof(pkt)); /* For security reasons */
pkt.hdr.proto_version = sbi->version;
pkt.hdr.type = type;
switch (type) {
/* Kernel protocol v4 missing and expire packets */
case autofs_ptype_missing:
{
struct autofs_packet_missing *mp = &pkt.v4_pkt.missing;
pktsz = sizeof(*mp);
mp->wait_queue_token = wq->wait_queue_token;
mp->len = wq->name.len;
memcpy(mp->name, wq->name.name, wq->name.len);
mp->name[wq->name.len] = '\0';
break;
}
case autofs_ptype_expire_multi:
{
struct autofs_packet_expire_multi *ep =
&pkt.v4_pkt.expire_multi;
pktsz = sizeof(*ep);
ep->wait_queue_token = wq->wait_queue_token;
ep->len = wq->name.len;
memcpy(ep->name, wq->name.name, wq->name.len);
ep->name[wq->name.len] = '\0';
break;
}
/*
* Kernel protocol v5 packet for handling indirect and direct
* mount missing and expire requests
*/
case autofs_ptype_missing_indirect:
case autofs_ptype_expire_indirect:
case autofs_ptype_missing_direct:
case autofs_ptype_expire_direct:
{
struct autofs_v5_packet *packet = &pkt.v5_pkt.v5_packet;
struct user_namespace *user_ns = sbi->pipe->f_cred->user_ns;
pktsz = sizeof(*packet);
packet->wait_queue_token = wq->wait_queue_token;
packet->len = wq->name.len;
memcpy(packet->name, wq->name.name, wq->name.len);
packet->name[wq->name.len] = '\0';
packet->dev = wq->dev;
packet->ino = wq->ino;
packet->uid = from_kuid_munged(user_ns, wq->uid);
packet->gid = from_kgid_munged(user_ns, wq->gid);
packet->pid = wq->pid;
packet->tgid = wq->tgid;
break;
}
default:
pr_warn("bad type %d!\n", type);
mutex_unlock(&sbi->wq_mutex);
return;
}
pipe = get_file(sbi->pipe);
mutex_unlock(&sbi->wq_mutex);
switch (ret = autofs_write(sbi, pipe, &pkt, pktsz)) {
case 0:
break;
case -ENOMEM:
case -ERESTARTSYS:
/* Just fail this one */
autofs_wait_release(sbi, wq->wait_queue_token, ret);
break;
default:
autofs_catatonic_mode(sbi);
break;
}
fput(pipe);
}
static int autofs_getpath(struct autofs_sb_info *sbi,
struct dentry *dentry, char **name)
{
struct dentry *root = sbi->sb->s_root;
struct dentry *tmp;
char *buf;
char *p;
int len;
unsigned seq;
rename_retry:
buf = *name;
len = 0;
seq = read_seqbegin(&rename_lock);
rcu_read_lock();
spin_lock(&sbi->fs_lock);
for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
len += tmp->d_name.len + 1;
if (!len || --len > NAME_MAX) {
spin_unlock(&sbi->fs_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
return 0;
}
*(buf + len) = '\0';
p = buf + len - dentry->d_name.len;
strncpy(p, dentry->d_name.name, dentry->d_name.len);
for (tmp = dentry->d_parent; tmp != root ; tmp = tmp->d_parent) {
*(--p) = '/';
p -= tmp->d_name.len;
strncpy(p, tmp->d_name.name, tmp->d_name.len);
}
spin_unlock(&sbi->fs_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
return len;
}
static struct autofs_wait_queue *
autofs_find_wait(struct autofs_sb_info *sbi, const struct qstr *qstr)
{
struct autofs_wait_queue *wq;
for (wq = sbi->queues; wq; wq = wq->next) {
if (wq->name.hash == qstr->hash &&
wq->name.len == qstr->len &&
wq->name.name &&
!memcmp(wq->name.name, qstr->name, qstr->len))
break;
}
return wq;
}
/*
* Check if we have a valid request.
* Returns
* 1 if the request should continue.
* In this case we can return an autofs_wait_queue entry if one is
* found or NULL to idicate a new wait needs to be created.
* 0 or a negative errno if the request shouldn't continue.
*/
static int validate_request(struct autofs_wait_queue **wait,
struct autofs_sb_info *sbi,
const struct qstr *qstr,
const struct path *path, enum autofs_notify notify)
{
struct dentry *dentry = path->dentry;
struct autofs_wait_queue *wq;
struct autofs_info *ino;
if (sbi->catatonic)
return -ENOENT;
/* Wait in progress, continue; */
wq = autofs_find_wait(sbi, qstr);
if (wq) {
*wait = wq;
return 1;
}
*wait = NULL;
/* If we don't yet have any info this is a new request */
ino = autofs_dentry_ino(dentry);
if (!ino)
return 1;
/*
* If we've been asked to wait on an existing expire (NFY_NONE)
* but there is no wait in the queue ...
*/
if (notify == NFY_NONE) {
/*
* Either we've betean the pending expire to post it's
* wait or it finished while we waited on the mutex.
* So we need to wait till either, the wait appears
* or the expire finishes.
*/
while (ino->flags & AUTOFS_INF_EXPIRING) {
mutex_unlock(&sbi->wq_mutex);
schedule_timeout_interruptible(HZ/10);
if (mutex_lock_interruptible(&sbi->wq_mutex))
return -EINTR;
if (sbi->catatonic)
return -ENOENT;
wq = autofs_find_wait(sbi, qstr);
if (wq) {
*wait = wq;
return 1;
}
}
/*
* Not ideal but the status has already gone. Of the two
* cases where we wait on NFY_NONE neither depend on the
* return status of the wait.
*/
return 0;
}
/*
* If we've been asked to trigger a mount and the request
* completed while we waited on the mutex ...
*/
if (notify == NFY_MOUNT) {
struct dentry *new = NULL;
struct path this;
int valid = 1;
/*
* If the dentry was successfully mounted while we slept
* on the wait queue mutex we can return success. If it
* isn't mounted (doesn't have submounts for the case of
* a multi-mount with no mount at it's base) we can
* continue on and create a new request.
*/
if (!IS_ROOT(dentry)) {
if (d_unhashed(dentry) &&
d_really_is_positive(dentry)) {
struct dentry *parent = dentry->d_parent;
new = d_lookup(parent, &dentry->d_name);
if (new)
dentry = new;
}
}
this.mnt = path->mnt;
this.dentry = dentry;
if (path_has_submounts(&this))
valid = 0;
if (new)
dput(new);
return valid;
}
return 1;
}
int autofs_wait(struct autofs_sb_info *sbi,
const struct path *path, enum autofs_notify notify)
{
struct dentry *dentry = path->dentry;
struct autofs_wait_queue *wq;
struct qstr qstr;
char *name;
int status, ret, type;
pid_t pid;
pid_t tgid;
/* In catatonic mode, we don't wait for nobody */
if (sbi->catatonic)
return -ENOENT;
/*
* Try translating pids to the namespace of the daemon.
*
* Zero means failure: we are in an unrelated pid namespace.
*/
pid = task_pid_nr_ns(current, ns_of_pid(sbi->oz_pgrp));
tgid = task_tgid_nr_ns(current, ns_of_pid(sbi->oz_pgrp));
if (pid == 0 || tgid == 0)
return -ENOENT;
if (d_really_is_negative(dentry)) {
/*
* A wait for a negative dentry is invalid for certain
* cases. A direct or offset mount "always" has its mount
* point directory created and so the request dentry must
* be positive or the map key doesn't exist. The situation
* is very similar for indirect mounts except only dentrys
* in the root of the autofs file system may be negative.
*/
if (autofs_type_trigger(sbi->type))
return -ENOENT;
else if (!IS_ROOT(dentry->d_parent))
return -ENOENT;
}
name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
if (!name)
return -ENOMEM;
/* If this is a direct mount request create a dummy name */
if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type))
qstr.len = sprintf(name, "%p", dentry);
else {
qstr.len = autofs_getpath(sbi, dentry, &name);
if (!qstr.len) {
kfree(name);
return -ENOENT;
}
}
qstr.name = name;
qstr.hash = full_name_hash(dentry, name, qstr.len);
if (mutex_lock_interruptible(&sbi->wq_mutex)) {
kfree(qstr.name);
return -EINTR;
}
ret = validate_request(&wq, sbi, &qstr, path, notify);
if (ret <= 0) {
if (ret != -EINTR)
mutex_unlock(&sbi->wq_mutex);
kfree(qstr.name);
return ret;
}
if (!wq) {
/* Create a new wait queue */
wq = kmalloc(sizeof(struct autofs_wait_queue), GFP_KERNEL);
if (!wq) {
kfree(qstr.name);
mutex_unlock(&sbi->wq_mutex);
return -ENOMEM;
}
wq->wait_queue_token = autofs_next_wait_queue;
if (++autofs_next_wait_queue == 0)
autofs_next_wait_queue = 1;
wq->next = sbi->queues;
sbi->queues = wq;
init_waitqueue_head(&wq->queue);
memcpy(&wq->name, &qstr, sizeof(struct qstr));
wq->dev = autofs_get_dev(sbi);
wq->ino = autofs_get_ino(sbi);
wq->uid = current_uid();
wq->gid = current_gid();
wq->pid = pid;
wq->tgid = tgid;
wq->status = -EINTR; /* Status return if interrupted */
wq->wait_ctr = 2;
if (sbi->version < 5) {
if (notify == NFY_MOUNT)
type = autofs_ptype_missing;
else
type = autofs_ptype_expire_multi;
} else {
if (notify == NFY_MOUNT)
type = autofs_type_trigger(sbi->type) ?
autofs_ptype_missing_direct :
autofs_ptype_missing_indirect;
else
type = autofs_type_trigger(sbi->type) ?
autofs_ptype_expire_direct :
autofs_ptype_expire_indirect;
}
pr_debug("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
(unsigned long) wq->wait_queue_token, wq->name.len,
wq->name.name, notify);
/*
* autofs_notify_daemon() may block; it will unlock ->wq_mutex
*/
autofs_notify_daemon(sbi, wq, type);
} else {
wq->wait_ctr++;
pr_debug("existing wait id = 0x%08lx, name = %.*s, nfy=%d\n",
(unsigned long) wq->wait_queue_token, wq->name.len,
wq->name.name, notify);
mutex_unlock(&sbi->wq_mutex);
kfree(qstr.name);
}
/*
* wq->name.name is NULL iff the lock is already released
* or the mount has been made catatonic.
*/
wait_event_killable(wq->queue, wq->name.name == NULL);
status = wq->status;
/*
* For direct and offset mounts we need to track the requester's
* uid and gid in the dentry info struct. This is so it can be
* supplied, on request, by the misc device ioctl interface.
* This is needed during daemon resatart when reconnecting
* to existing, active, autofs mounts. The uid and gid (and
* related string values) may be used for macro substitution
* in autofs mount maps.
*/
if (!status) {
struct autofs_info *ino;
struct dentry *de = NULL;
/* direct mount or browsable map */
ino = autofs_dentry_ino(dentry);
if (!ino) {
/* If not lookup actual dentry used */
de = d_lookup(dentry->d_parent, &dentry->d_name);
if (de)
ino = autofs_dentry_ino(de);
}
/* Set mount requester */
if (ino) {
spin_lock(&sbi->fs_lock);
ino->uid = wq->uid;
ino->gid = wq->gid;
spin_unlock(&sbi->fs_lock);
}
if (de)
dput(de);
}
/* Are we the last process to need status? */
mutex_lock(&sbi->wq_mutex);
if (!--wq->wait_ctr)
kfree(wq);
mutex_unlock(&sbi->wq_mutex);
return status;
}
int autofs_wait_release(struct autofs_sb_info *sbi,
autofs_wqt_t wait_queue_token, int status)
{
struct autofs_wait_queue *wq, **wql;
mutex_lock(&sbi->wq_mutex);
for (wql = &sbi->queues; (wq = *wql) != NULL; wql = &wq->next) {
if (wq->wait_queue_token == wait_queue_token)
break;
}
if (!wq) {
mutex_unlock(&sbi->wq_mutex);
return -EINVAL;
}
*wql = wq->next; /* Unlink from chain */
kfree(wq->name.name);
wq->name.name = NULL; /* Do not wait on this queue */
wq->status = status;
wake_up(&wq->queue);
if (!--wq->wait_ctr)
kfree(wq);
mutex_unlock(&sbi->wq_mutex);
return 0;
}