asgardius/android_kernel_samsung_heroqlte
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
android_kernel_samsung_hero.../fs/autofs4/root.c

931 lines
24 KiB
C
Raw Normal View History

init: OSRC G9300ZCU2APF7
2016-08-17 10:41:52 +02:00
/* -*- c -*- --------------------------------------------------------------- *
*
* linux/fs/autofs/root.c
*
* 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 autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
static int autofs4_dir_unlink(struct inode *,struct dentry *);
static int autofs4_dir_rmdir(struct inode *,struct dentry *);
static int autofs4_dir_mkdir(struct inode *,struct dentry *,umode_t);
static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long);
#ifdef CONFIG_COMPAT
static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long);
#endif
static int autofs4_dir_open(struct inode *inode, struct file *file);
static struct dentry *autofs4_lookup(struct inode *,struct dentry *, unsigned int);
static struct vfsmount *autofs4_d_automount(struct path *);
static int autofs4_d_manage(struct dentry *, bool);
static void autofs4_dentry_release(struct dentry *);
const struct file_operations autofs4_root_operations = {
.open = dcache_dir_open,
.release = dcache_dir_close,
.read = generic_read_dir,
.iterate = dcache_readdir,
.llseek = dcache_dir_lseek,
.unlocked_ioctl = autofs4_root_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = autofs4_root_compat_ioctl,
#endif
};
const struct file_operations autofs4_dir_operations = {
.open = autofs4_dir_open,
.release = dcache_dir_close,
.read = generic_read_dir,
.iterate = dcache_readdir,
.llseek = dcache_dir_lseek,
};
const struct inode_operations autofs4_dir_inode_operations = {
.lookup = autofs4_lookup,
.unlink = autofs4_dir_unlink,
.symlink = autofs4_dir_symlink,
.mkdir = autofs4_dir_mkdir,
.rmdir = autofs4_dir_rmdir,
};
const struct dentry_operations autofs4_dentry_operations = {
.d_automount = autofs4_d_automount,
.d_manage = autofs4_d_manage,
.d_release = autofs4_dentry_release,
};
static void autofs4_add_active(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_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);
}
return;
}
static void autofs4_del_active(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_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);
}
return;
}
static int autofs4_dir_open(struct inode *inode, struct file *file)
{
struct dentry *dentry = file->f_path.dentry;
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
DPRINTK("file=%p dentry=%p %.*s",
file, dentry, dentry->d_name.len, dentry->d_name.name);
if (autofs4_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 (!d_mountpoint(dentry) && simple_empty(dentry)) {
spin_unlock(&sbi->lookup_lock);
return -ENOENT;
}
spin_unlock(&sbi->lookup_lock);
out:
return dcache_dir_open(inode, file);
}
static void autofs4_dentry_release(struct dentry *de)
{
struct autofs_info *ino = autofs4_dentry_ino(de);
struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
DPRINTK("releasing %p", 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);
}
autofs4_free_ino(ino);
}
static struct dentry *autofs4_lookup_active(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct dentry *parent = dentry->d_parent;
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;
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 *autofs4_lookup_expiring(struct dentry *dentry,
bool rcu_walk)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct dentry *parent = dentry->d_parent;
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;
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 (!expiring->d_inode)
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 autofs4_mount_wait(struct dentry *dentry, bool rcu_walk)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
int status = 0;
if (ino->flags & AUTOFS_INF_PENDING) {
if (rcu_walk)
return -ECHILD;
DPRINTK("waiting for mount name=%.*s",
dentry->d_name.len, dentry->d_name.name);
status = autofs4_wait(sbi, dentry, NFY_MOUNT);
DPRINTK("mount wait done status=%d", status);
}
ino->last_used = jiffies;
return status;
}
static int do_expire_wait(struct dentry *dentry, bool rcu_walk)
{
struct dentry *expiring;
expiring = autofs4_lookup_expiring(dentry, rcu_walk);
if (IS_ERR(expiring))
return PTR_ERR(expiring);
if (!expiring)
return autofs4_expire_wait(dentry, rcu_walk);
else {
/*
* 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.
*/
autofs4_expire_wait(expiring, 0);
autofs4_del_expiring(expiring);
dput(expiring);
}
return 0;
}
static struct dentry *autofs4_mountpoint_changed(struct path *path)
{
struct dentry *dentry = path->dentry;
struct autofs_sb_info *sbi = autofs4_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 = d_lookup(parent, &dentry->d_name);
if (!new)
return NULL;
ino = autofs4_dentry_ino(new);
ino->last_used = jiffies;
dput(path->dentry);
path->dentry = new;
}
return path->dentry;
}
static struct vfsmount *autofs4_d_automount(struct path *path)
{
struct dentry *dentry = path->dentry;
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
int status;
DPRINTK("dentry=%p %.*s",
dentry, dentry->d_name.len, dentry->d_name.name);
/* The daemon never triggers a mount. */
if (autofs4_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(dentry, 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 = autofs4_mount_wait(dentry, 0);
if (status)
return ERR_PTR(status);
goto done;
}
/*
* If the dentry is a symlink it's equivalent to a directory
* having d_mountpoint() true, so there's no need to call back
* to the daemon.
*/
if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) {
spin_unlock(&sbi->fs_lock);
goto done;
}
if (!d_mountpoint(dentry)) {
/*
* It's possible that user space hasn't removed directories
* after umounting a rootless multi-mount, although it
* should. For v5 have_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 (have_submounts(dentry)) {
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 = autofs4_mount_wait(dentry, 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 = autofs4_mountpoint_changed(path);
if (!dentry)
return ERR_PTR(-ENOENT);
return NULL;
}
static int autofs4_d_manage(struct dentry *dentry, bool rcu_walk)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
int status;
DPRINTK("dentry=%p %.*s",
dentry, dentry->d_name.len, dentry->d_name.name);
/* The daemon never waits. */
if (autofs4_oz_mode(sbi)) {
if (!d_mountpoint(dentry))
return -EISDIR;
return 0;
}
/* Wait for pending expires */
if (do_expire_wait(dentry, rcu_walk) == -ECHILD)
return -ECHILD;
/*
* This dentry may be under construction so wait on mount
* completion.
*/
status = autofs4_mount_wait(dentry, 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_EXPIRING | AUTOFS_INF_NO_RCU))
return 0;
if (d_mountpoint(dentry))
return 0;
inode = ACCESS_ONCE(dentry->d_inode);
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 ((!d_mountpoint(dentry) && !simple_empty(dentry)) ||
(dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)))
status = -EISDIR;
}
spin_unlock(&sbi->fs_lock);
return status;
}
/* Lookups in the root directory */
static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
struct autofs_sb_info *sbi;
struct autofs_info *ino;
struct dentry *active;
DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name);
/* File name too long to exist */
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
sbi = autofs4_sbi(dir->i_sb);
DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
current->pid, task_pgrp_nr(current), sbi->catatonic,
autofs4_oz_mode(sbi));
active = autofs4_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 (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent))
return ERR_PTR(-ENOENT);
/* Mark entries in the root as mount triggers */
if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent))
__managed_dentry_set_managed(dentry);
ino = autofs4_new_ino(sbi);
if (!ino)
return ERR_PTR(-ENOMEM);
dentry->d_fsdata = ino;
ino->dentry = dentry;
autofs4_add_active(dentry);
d_instantiate(dentry, NULL);
}
return NULL;
}
static int autofs4_dir_symlink(struct inode *dir,
struct dentry *dentry,
const char *symname)
{
struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
struct autofs_info *p_ino;
struct inode *inode;
size_t size = strlen(symname);
char *cp;
DPRINTK("%s <- %.*s", symname,
dentry->d_name.len, dentry->d_name.name);
if (!autofs4_oz_mode(sbi))
return -EACCES;
BUG_ON(!ino);
autofs4_clean_ino(ino);
autofs4_del_active(dentry);
cp = kmalloc(size + 1, GFP_KERNEL);
if (!cp)
return -ENOMEM;
strcpy(cp, symname);
inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555);
if (!inode) {
kfree(cp);
if (!dentry->d_fsdata)
kfree(ino);
return -ENOMEM;
}
inode->i_private = cp;
inode->i_size = size;
d_add(dentry, inode);
dget(dentry);
atomic_inc(&ino->count);
p_ino = autofs4_dentry_ino(dentry->d_parent);
if (p_ino && !IS_ROOT(dentry))
atomic_inc(&p_ino->count);
dir->i_mtime = CURRENT_TIME;
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 autofs4_dir_rmdir()..
*/
static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
struct autofs_info *p_ino;
/* This allows root to remove symlinks */
if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
return -EPERM;
if (atomic_dec_and_test(&ino->count)) {
p_ino = autofs4_dentry_ino(dentry->d_parent);
if (p_ino && !IS_ROOT(dentry))
atomic_dec(&p_ino->count);
}
dput(ino->dentry);
dentry->d_inode->i_size = 0;
clear_nlink(dentry->d_inode);
dir->i_mtime = CURRENT_TIME;
spin_lock(&sbi->lookup_lock);
__autofs4_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);
return;
}
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);
return;
}
static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
struct autofs_info *p_ino;
DPRINTK("dentry %p, removing %.*s",
dentry, dentry->d_name.len, dentry->d_name.name);
if (!autofs4_oz_mode(sbi))
return -EACCES;
spin_lock(&sbi->lookup_lock);
if (!simple_empty(dentry)) {
spin_unlock(&sbi->lookup_lock);
return -ENOTEMPTY;
}
__autofs4_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 = autofs4_dentry_ino(dentry->d_parent);
if (p_ino && dentry->d_parent != dentry)
atomic_dec(&p_ino->count);
}
dput(ino->dentry);
dentry->d_inode->i_size = 0;
clear_nlink(dentry->d_inode);
if (dir->i_nlink)
drop_nlink(dir);
return 0;
}
static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
struct autofs_info *p_ino;
struct inode *inode;
if (!autofs4_oz_mode(sbi))
return -EACCES;
DPRINTK("dentry %p, creating %.*s",
dentry, dentry->d_name.len, dentry->d_name.name);
BUG_ON(!ino);
autofs4_clean_ino(ino);
autofs4_del_active(dentry);
inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555);
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 = autofs4_dentry_ino(dentry->d_parent);
if (p_ino && !IS_ROOT(dentry))
atomic_inc(&p_ino->count);
inc_nlink(dir);
dir->i_mtime = CURRENT_TIME;
return 0;
}
/* Get/set timeout ioctl() operation */
#ifdef CONFIG_COMPAT
static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi,
compat_ulong_t __user *p)
{
int rv;
unsigned long ntimeout;
if ((rv = get_user(ntimeout, p)) ||
(rv = put_user(sbi->exp_timeout/HZ, p)))
return rv;
if (ntimeout > UINT_MAX/HZ)
sbi->exp_timeout = 0;
else
sbi->exp_timeout = ntimeout * HZ;
return 0;
}
#endif
static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi,
unsigned long __user *p)
{
int rv;
unsigned long ntimeout;
if ((rv = get_user(ntimeout, p)) ||
(rv = put_user(sbi->exp_timeout/HZ, p)))
return rv;
if (ntimeout > ULONG_MAX/HZ)
sbi->exp_timeout = 0;
else
sbi->exp_timeout = ntimeout * HZ;
return 0;
}
/* Return protocol version */
static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p)
{
return put_user(sbi->version, p);
}
/* Return protocol sub version */
static inline int autofs4_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 autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
{
int status = 0;
if (may_umount(mnt))
status = 1;
DPRINTK("returning %d", status);
status = put_user(status, p);
return status;
}
/* Identify autofs4_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_autofs4_dentry(struct dentry *dentry)
{
return dentry && dentry->d_inode &&
dentry->d_op == &autofs4_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 autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
void __user *p = (void __user *)arg;
DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
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 (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
return -EPERM;
switch(cmd) {
case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0);
case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
autofs4_catatonic_mode(sbi);
return 0;
case AUTOFS_IOC_PROTOVER: /* Get protocol version */
return autofs4_get_protover(sbi, p);
case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
return autofs4_get_protosubver(sbi, p);
case AUTOFS_IOC_SETTIMEOUT:
return autofs4_get_set_timeout(sbi, p);
#ifdef CONFIG_COMPAT
case AUTOFS_IOC_SETTIMEOUT32:
return autofs4_compat_get_set_timeout(sbi, p);
#endif
case AUTOFS_IOC_ASKUMOUNT:
return autofs4_ask_umount(filp->f_path.mnt, p);
/* return a single thing to expire */
case AUTOFS_IOC_EXPIRE:
return autofs4_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 autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p);
default:
return -ENOSYS;
}
}
static long autofs4_root_ioctl(struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
}
#ifdef CONFIG_COMPAT
static long autofs4_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 = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
else
ret = autofs4_root_ioctl_unlocked(inode, filp, cmd,
(unsigned long)compat_ptr(arg));
return ret;
}
#endif
Reference in a new issue Copy permalink