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linux/fs/autofs4/root.c
Ian Kent a537055395 [PATCH] autofs4: NFY_NONE wait race fix 
This patch fixes two problems.

First, the comparison of entries in the waitq.c was incorrect.

Second, the NFY_NONE check was incorrect. The test of whether the dentry
is mounted if ineffective, for example, if an expire fails then we could
wait forever on a non existant expire. The bug was identified by Jeff
Moyer.

The patch changes autofs4 to wait on expires only as this is all that's
needed.  If there is no existing wait when autofs4_wait is call with a type
of NFY_NONE it delays until either a wait appears or the the expire flag is
cleared.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-15 11:20:54 -07:00

851 lines
22 KiB
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/* -*- 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/param.h>
#include <linux/time.h>
#include <linux/smp_lock.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 *,int);
static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
static int autofs4_dir_open(struct inode *inode, struct file *file);
static int autofs4_dir_close(struct inode *inode, struct file *file);
static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir);
static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir);
static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
static void *autofs4_follow_link(struct dentry *, struct nameidata *);
const struct file_operations autofs4_root_operations = {
.open = dcache_dir_open,
.release = dcache_dir_close,
.read = generic_read_dir,
.readdir = autofs4_root_readdir,
.ioctl = autofs4_root_ioctl,
};
const struct file_operations autofs4_dir_operations = {
.open = autofs4_dir_open,
.release = autofs4_dir_close,
.read = generic_read_dir,
.readdir = autofs4_dir_readdir,
};
struct inode_operations autofs4_indirect_root_inode_operations = {
.lookup = autofs4_lookup,
.unlink = autofs4_dir_unlink,
.symlink = autofs4_dir_symlink,
.mkdir = autofs4_dir_mkdir,
.rmdir = autofs4_dir_rmdir,
};
struct inode_operations autofs4_direct_root_inode_operations = {
.lookup = autofs4_lookup,
.unlink = autofs4_dir_unlink,
.mkdir = autofs4_dir_mkdir,
.rmdir = autofs4_dir_rmdir,
.follow_link = autofs4_follow_link,
};
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,
};
static int autofs4_root_readdir(struct file *file, void *dirent,
filldir_t filldir)
{
struct autofs_sb_info *sbi = autofs4_sbi(file->f_dentry->d_sb);
int oz_mode = autofs4_oz_mode(sbi);
DPRINTK("called, filp->f_pos = %lld", file->f_pos);
/*
* Don't set reghost flag if:
* 1) f_pos is larger than zero -- we've already been here.
* 2) we haven't even enabled reghosting in the 1st place.
* 3) this is the daemon doing a readdir
*/
if (oz_mode && file->f_pos == 0 && sbi->reghost_enabled)
sbi->needs_reghost = 1;
DPRINTK("needs_reghost = %d", sbi->needs_reghost);
return dcache_readdir(file, dirent, filldir);
}
static int autofs4_dir_open(struct inode *inode, struct file *file)
{
struct dentry *dentry = file->f_dentry;
struct vfsmount *mnt = file->f_vfsmnt;
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct dentry *cursor;
int status;
status = dcache_dir_open(inode, file);
if (status)
goto out;
cursor = file->private_data;
cursor->d_fsdata = NULL;
DPRINTK("file=%p dentry=%p %.*s",
file, dentry, dentry->d_name.len, dentry->d_name.name);
if (autofs4_oz_mode(sbi))
goto out;
if (autofs4_ispending(dentry)) {
DPRINTK("dentry busy");
dcache_dir_close(inode, file);
status = -EBUSY;
goto out;
}
status = -ENOENT;
if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) {
struct nameidata nd;
int empty, ret;
/* In case there are stale directory dentrys from a failed mount */
spin_lock(&dcache_lock);
empty = list_empty(&dentry->d_subdirs);
spin_unlock(&dcache_lock);
if (!empty)
d_invalidate(dentry);
nd.flags = LOOKUP_DIRECTORY;
ret = (dentry->d_op->d_revalidate)(dentry, &nd);
if (!ret) {
dcache_dir_close(inode, file);
goto out;
}
}
if (d_mountpoint(dentry)) {
struct file *fp = NULL;
struct vfsmount *fp_mnt = mntget(mnt);
struct dentry *fp_dentry = dget(dentry);
if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) {
dput(fp_dentry);
mntput(fp_mnt);
dcache_dir_close(inode, file);
goto out;
}
fp = dentry_open(fp_dentry, fp_mnt, file->f_flags);
status = PTR_ERR(fp);
if (IS_ERR(fp)) {
dcache_dir_close(inode, file);
goto out;
}
cursor->d_fsdata = fp;
}
return 0;
out:
return status;
}
static int autofs4_dir_close(struct inode *inode, struct file *file)
{
struct dentry *dentry = file->f_dentry;
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct dentry *cursor = file->private_data;
int status = 0;
DPRINTK("file=%p dentry=%p %.*s",
file, dentry, dentry->d_name.len, dentry->d_name.name);
if (autofs4_oz_mode(sbi))
goto out;
if (autofs4_ispending(dentry)) {
DPRINTK("dentry busy");
status = -EBUSY;
goto out;
}
if (d_mountpoint(dentry)) {
struct file *fp = cursor->d_fsdata;
if (!fp) {
status = -ENOENT;
goto out;
}
filp_close(fp, current->files);
}
out:
dcache_dir_close(inode, file);
return status;
}
static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir)
{
struct dentry *dentry = file->f_dentry;
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct dentry *cursor = file->private_data;
int status;
DPRINTK("file=%p dentry=%p %.*s",
file, dentry, dentry->d_name.len, dentry->d_name.name);
if (autofs4_oz_mode(sbi))
goto out;
if (autofs4_ispending(dentry)) {
DPRINTK("dentry busy");
return -EBUSY;
}
if (d_mountpoint(dentry)) {
struct file *fp = cursor->d_fsdata;
if (!fp)
return -ENOENT;
if (!fp->f_op || !fp->f_op->readdir)
goto out;
status = vfs_readdir(fp, filldir, dirent);
file->f_pos = fp->f_pos;
if (status)
autofs4_copy_atime(file, fp);
return status;
}
out:
return dcache_readdir(file, dirent, filldir);
}
static int try_to_fill_dentry(struct dentry *dentry, int flags)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
int status = 0;
/* Block on any pending expiry here; invalidate the dentry
when expiration is done to trigger mount request with a new
dentry */
if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
DPRINTK("waiting for expire %p name=%.*s",
dentry, dentry->d_name.len, dentry->d_name.name);
status = autofs4_wait(sbi, dentry, NFY_NONE);
DPRINTK("expire done status=%d", status);
/*
* If the directory still exists the mount request must
* continue otherwise it can't be followed at the right
* time during the walk.
*/
status = d_invalidate(dentry);
if (status != -EBUSY)
return -ENOENT;
}
DPRINTK("dentry=%p %.*s ino=%p",
dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
/*
* Wait for a pending mount, triggering one if there
* isn't one already
*/
if (dentry->d_inode == NULL) {
DPRINTK("waiting for mount name=%.*s",
dentry->d_name.len, dentry->d_name.name);
status = autofs4_wait(sbi, dentry, NFY_MOUNT);
DPRINTK("mount done status=%d", status);
if (status && dentry->d_inode)
return status; /* Try to get the kernel to invalidate this dentry */
/* Turn this into a real negative dentry? */
if (status == -ENOENT) {
spin_lock(&dentry->d_lock);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
return status;
} else if (status) {
/* Return a negative dentry, but leave it "pending" */
return status;
}
/* Trigger mount for path component or follow link */
} else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) ||
current->link_count) {
DPRINTK("waiting for mount name=%.*s",
dentry->d_name.len, dentry->d_name.name);
spin_lock(&dentry->d_lock);
dentry->d_flags |= DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
status = autofs4_wait(sbi, dentry, NFY_MOUNT);
DPRINTK("mount done status=%d", status);
if (status) {
spin_lock(&dentry->d_lock);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
return status;
}
}
/* Initialize expiry counter after successful mount */
if (ino)
ino->last_used = jiffies;
spin_lock(&dentry->d_lock);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
return status;
}
/* For autofs direct mounts the follow link triggers the mount */
static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
int oz_mode = autofs4_oz_mode(sbi);
unsigned int lookup_type;
int status;
DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,
nd->flags);
/* If it's our master or we shouldn't trigger a mount we're done */
lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY);
if (oz_mode || !lookup_type)
goto done;
/* If an expire request is pending wait for it. */
if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
DPRINTK("waiting for active request %p name=%.*s",
dentry, dentry->d_name.len, dentry->d_name.name);
status = autofs4_wait(sbi, dentry, NFY_NONE);
DPRINTK("request done status=%d", status);
}
/*
* If the dentry contains directories then it is an
* autofs multi-mount with no root mount offset. So
* don't try to mount it again.
*/
spin_lock(&dcache_lock);
if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
spin_unlock(&dcache_lock);
status = try_to_fill_dentry(dentry, 0);
if (status)
goto out_error;
/*
* The mount succeeded but if there is no root mount
* it must be an autofs multi-mount with no root offset
* so we don't need to follow the mount.
*/
if (d_mountpoint(dentry)) {
if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) {
status = -ENOENT;
goto out_error;
}
}
goto done;
}
spin_unlock(&dcache_lock);
done:
return NULL;
out_error:
path_release(nd);
return ERR_PTR(status);
}
/*
* Revalidate is called on every cache lookup. Some of those
* cache lookups may actually happen while the dentry is not
* yet completely filled in, and revalidate has to delay such
* lookups..
*/
static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode *dir = dentry->d_parent->d_inode;
struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
int oz_mode = autofs4_oz_mode(sbi);
int flags = nd ? nd->flags : 0;
int status = 0;
/* Pending dentry */
if (autofs4_ispending(dentry)) {
if (!oz_mode)
status = try_to_fill_dentry(dentry, flags);
return !status;
}
/* Negative dentry.. invalidate if "old" */
if (dentry->d_inode == NULL)
return 0;
/* Check for a non-mountpoint directory with no contents */
spin_lock(&dcache_lock);
if (S_ISDIR(dentry->d_inode->i_mode) &&
!d_mountpoint(dentry) &&
__simple_empty(dentry)) {
DPRINTK("dentry=%p %.*s, emptydir",
dentry, dentry->d_name.len, dentry->d_name.name);
spin_unlock(&dcache_lock);
if (!oz_mode)
status = try_to_fill_dentry(dentry, flags);
return !status;
}
spin_unlock(&dcache_lock);
return 1;
}
void autofs4_dentry_release(struct dentry *de)
{
struct autofs_info *inf;
DPRINTK("releasing %p", de);
inf = autofs4_dentry_ino(de);
de->d_fsdata = NULL;
if (inf) {
inf->dentry = NULL;
inf->inode = NULL;
autofs4_free_ino(inf);
}
}
/* For dentries of directories in the root dir */
static struct dentry_operations autofs4_root_dentry_operations = {
.d_revalidate = autofs4_revalidate,
.d_release = autofs4_dentry_release,
};
/* For other dentries */
static struct dentry_operations autofs4_dentry_operations = {
.d_revalidate = autofs4_revalidate,
.d_release = autofs4_dentry_release,
};
/* Lookups in the root directory */
static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
struct autofs_sb_info *sbi;
int oz_mode;
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);
oz_mode = autofs4_oz_mode(sbi);
DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
current->pid, process_group(current), sbi->catatonic, oz_mode);
/*
* Mark the dentry incomplete, but add it. This is needed so
* that the VFS layer knows about the dentry, and we can count
* on catching any lookups through the revalidate.
*
* Let all the hard work be done by the revalidate function that
* needs to be able to do this anyway..
*
* We need to do this before we release the directory semaphore.
*/
dentry->d_op = &autofs4_root_dentry_operations;
if (!oz_mode) {
spin_lock(&dentry->d_lock);
dentry->d_flags |= DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
}
dentry->d_fsdata = NULL;
d_add(dentry, NULL);
if (dentry->d_op && dentry->d_op->d_revalidate) {
mutex_unlock(&dir->i_mutex);
(dentry->d_op->d_revalidate)(dentry, nd);
mutex_lock(&dir->i_mutex);
}
/*
* If we are still pending, check if we had to handle
* a signal. If so we can force a restart..
*/
if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
/* See if we were interrupted */
if (signal_pending(current)) {
sigset_t *sigset = &current->pending.signal;
if (sigismember (sigset, SIGKILL) ||
sigismember (sigset, SIGQUIT) ||
sigismember (sigset, SIGINT)) {
return ERR_PTR(-ERESTARTNOINTR);
}
}
}
/*
* If this dentry is unhashed, then we shouldn't honour this
* lookup even if the dentry is positive. Returning ENOENT here
* doesn't do the right thing for all system calls, but it should
* be OK for the operations we permit from an autofs.
*/
if (dentry->d_inode && d_unhashed(dentry))
return ERR_PTR(-ENOENT);
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;
char *cp;
DPRINTK("%s <- %.*s", symname,
dentry->d_name.len, dentry->d_name.name);
if (!autofs4_oz_mode(sbi))
return -EACCES;
ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
if (ino == NULL)
return -ENOSPC;
ino->size = strlen(symname);
ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL);
if (cp == NULL) {
kfree(ino);
return -ENOSPC;
}
strcpy(cp, symname);
inode = autofs4_get_inode(dir->i_sb, ino);
d_instantiate(dentry, inode);
if (dir == dir->i_sb->s_root->d_inode)
dentry->d_op = &autofs4_root_dentry_operations;
else
dentry->d_op = &autofs4_dentry_operations;
dentry->d_fsdata = ino;
ino->dentry = dget(dentry);
atomic_inc(&ino->count);
p_ino = autofs4_dentry_ino(dentry->d_parent);
if (p_ino && dentry->d_parent != dentry)
atomic_inc(&p_ino->count);
ino->inode = inode;
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 since the unlink is probably the result of an expire.
* We simply d_drop it, which allows the dentry lookup to remount it
* if necessary.
*
* 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 -EACCES;
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;
dentry->d_inode->i_nlink = 0;
dir->i_mtime = CURRENT_TIME;
d_drop(dentry);
return 0;
}
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;
if (!autofs4_oz_mode(sbi))
return -EACCES;
spin_lock(&dcache_lock);
if (!list_empty(&dentry->d_subdirs)) {
spin_unlock(&dcache_lock);
return -ENOTEMPTY;
}
spin_lock(&dentry->d_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
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;
dentry->d_inode->i_nlink = 0;
if (dir->i_nlink)
dir->i_nlink--;
return 0;
}
static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int 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);
ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
if (ino == NULL)
return -ENOSPC;
inode = autofs4_get_inode(dir->i_sb, ino);
d_instantiate(dentry, inode);
if (dir == dir->i_sb->s_root->d_inode)
dentry->d_op = &autofs4_root_dentry_operations;
else
dentry->d_op = &autofs4_dentry_operations;
dentry->d_fsdata = ino;
ino->dentry = dget(dentry);
atomic_inc(&ino->count);
p_ino = autofs4_dentry_ino(dentry->d_parent);
if (p_ino && dentry->d_parent != dentry)
atomic_inc(&p_ino->count);
ino->inode = inode;
dir->i_nlink++;
dir->i_mtime = CURRENT_TIME;
return 0;
}
/* Get/set timeout ioctl() operation */
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 we need to reghost or not. Also, clears
* the reghost_needed flag.
*/
static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p)
{
int status;
DPRINTK("returning %d", sbi->needs_reghost);
status = put_user(sbi->needs_reghost, p);
if ( status )
return status;
sbi->needs_reghost = 0;
return 0;
}
/*
* Enable / Disable reghosting ioctl() operation
*/
static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p)
{
int status;
int val;
status = get_user(val, p);
DPRINTK("reghost = %d", val);
if (status)
return status;
/* turn on/off reghosting, with the val */
sbi->reghost_enabled = val;
return 0;
}
/*
* 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_root_dentry_operations ||
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(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,process_group(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);
case AUTOFS_IOC_TOGGLEREGHOST:
return autofs4_toggle_reghost(sbi, p);
case AUTOFS_IOC_ASKREGHOST:
return autofs4_ask_reghost(sbi, p);
case AUTOFS_IOC_ASKUMOUNT:
return autofs4_ask_umount(filp->f_vfsmnt, p);
/* return a single thing to expire */
case AUTOFS_IOC_EXPIRE:
return autofs4_expire_run(inode->i_sb,filp->f_vfsmnt,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_vfsmnt,sbi, p);
default:
return -ENOSYS;
}
}
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