5a37db302e
... so ->d_fsdata will have been set up before we get there Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
914 lines
24 KiB
C
914 lines
24 KiB
C
/* -*- 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"
|
|
|
|
DEFINE_SPINLOCK(autofs4_lock);
|
|
|
|
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 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 *, struct nameidata *);
|
|
static struct vfsmount *autofs4_d_automount(struct path *);
|
|
static int autofs4_d_manage(struct dentry *, bool, bool);
|
|
|
|
const struct file_operations autofs4_root_operations = {
|
|
.open = dcache_dir_open,
|
|
.release = dcache_dir_close,
|
|
.read = generic_read_dir,
|
|
.readdir = 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,
|
|
.readdir = 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(&autofs4_lock);
|
|
spin_lock(&dentry->d_lock);
|
|
if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
|
|
spin_unlock(&dentry->d_lock);
|
|
spin_unlock(&autofs4_lock);
|
|
return -ENOENT;
|
|
}
|
|
spin_unlock(&dentry->d_lock);
|
|
spin_unlock(&autofs4_lock);
|
|
|
|
out:
|
|
return dcache_dir_open(inode, file);
|
|
}
|
|
|
|
void autofs4_dentry_release(struct dentry *de)
|
|
{
|
|
struct autofs_info *inf;
|
|
|
|
DPRINTK("releasing %p", de);
|
|
|
|
inf = autofs4_dentry_ino(de);
|
|
if (inf) {
|
|
struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
|
|
if (sbi) {
|
|
spin_lock(&sbi->lookup_lock);
|
|
if (!list_empty(&inf->active))
|
|
list_del(&inf->active);
|
|
if (!list_empty(&inf->expiring))
|
|
list_del(&inf->expiring);
|
|
spin_unlock(&sbi->lookup_lock);
|
|
}
|
|
autofs4_free_ino(inf);
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
spin_lock(&autofs4_lock);
|
|
spin_lock(&sbi->lookup_lock);
|
|
head = &sbi->active_list;
|
|
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 (active->d_count == 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);
|
|
spin_unlock(&autofs4_lock);
|
|
return active;
|
|
}
|
|
next:
|
|
spin_unlock(&active->d_lock);
|
|
}
|
|
spin_unlock(&sbi->lookup_lock);
|
|
spin_unlock(&autofs4_lock);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct dentry *autofs4_lookup_expiring(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;
|
|
|
|
spin_lock(&autofs4_lock);
|
|
spin_lock(&sbi->lookup_lock);
|
|
head = &sbi->expiring_list;
|
|
list_for_each(p, head) {
|
|
struct autofs_info *ino;
|
|
struct dentry *expiring;
|
|
struct qstr *qstr;
|
|
|
|
ino = list_entry(p, struct autofs_info, expiring);
|
|
expiring = ino->dentry;
|
|
|
|
spin_lock(&expiring->d_lock);
|
|
|
|
/* Bad luck, we've already been dentry_iput */
|
|
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);
|
|
spin_unlock(&autofs4_lock);
|
|
return expiring;
|
|
}
|
|
next:
|
|
spin_unlock(&expiring->d_lock);
|
|
}
|
|
spin_unlock(&sbi->lookup_lock);
|
|
spin_unlock(&autofs4_lock);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static int autofs4_mount_wait(struct dentry *dentry)
|
|
{
|
|
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
|
|
struct autofs_info *ino = autofs4_dentry_ino(dentry);
|
|
int status;
|
|
|
|
if (ino->flags & AUTOFS_INF_PENDING) {
|
|
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;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int do_expire_wait(struct dentry *dentry)
|
|
{
|
|
struct dentry *expiring;
|
|
|
|
expiring = autofs4_lookup_expiring(dentry);
|
|
if (!expiring)
|
|
return autofs4_expire_wait(dentry);
|
|
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);
|
|
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 dentry *new = d_lookup(parent, &dentry->d_name);
|
|
if (!new)
|
|
return NULL;
|
|
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);
|
|
|
|
/*
|
|
* Someone may have manually umounted this or it was a submount
|
|
* that has gone away.
|
|
*/
|
|
spin_lock(&dentry->d_lock);
|
|
if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
|
|
if (!(dentry->d_flags & DCACHE_MANAGE_TRANSIT) &&
|
|
(dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
|
|
__managed_dentry_set_transit(path->dentry);
|
|
}
|
|
spin_unlock(&dentry->d_lock);
|
|
|
|
/* 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);
|
|
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);
|
|
if (status)
|
|
return ERR_PTR(status);
|
|
spin_lock(&sbi->fs_lock);
|
|
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))
|
|
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 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))
|
|
goto done;
|
|
} else {
|
|
spin_lock(&dentry->d_lock);
|
|
if (!list_empty(&dentry->d_subdirs)) {
|
|
spin_unlock(&dentry->d_lock);
|
|
goto done;
|
|
}
|
|
spin_unlock(&dentry->d_lock);
|
|
}
|
|
ino->flags |= AUTOFS_INF_PENDING;
|
|
spin_unlock(&sbi->fs_lock);
|
|
status = autofs4_mount_wait(dentry);
|
|
if (status)
|
|
return ERR_PTR(status);
|
|
spin_lock(&sbi->fs_lock);
|
|
ino->flags &= ~AUTOFS_INF_PENDING;
|
|
}
|
|
done:
|
|
if (!(ino->flags & AUTOFS_INF_EXPIRING)) {
|
|
/*
|
|
* Any needed mounting has been completed and the path updated
|
|
* so turn this into a normal dentry so we don't continually
|
|
* call ->d_automount() and ->d_manage().
|
|
*/
|
|
spin_lock(&dentry->d_lock);
|
|
__managed_dentry_clear_transit(dentry);
|
|
/*
|
|
* Only clear DMANAGED_AUTOMOUNT for rootless multi-mounts and
|
|
* symlinks as in all other cases the dentry will be covered by
|
|
* an actual mount so ->d_automount() won't be called during
|
|
* the follow.
|
|
*/
|
|
if ((!d_mountpoint(dentry) &&
|
|
!list_empty(&dentry->d_subdirs)) ||
|
|
(dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)))
|
|
__managed_dentry_clear_automount(dentry);
|
|
spin_unlock(&dentry->d_lock);
|
|
}
|
|
spin_unlock(&sbi->fs_lock);
|
|
|
|
/* Mount succeeded, check if we ended up with a new dentry */
|
|
dentry = autofs4_mountpoint_changed(path);
|
|
if (!dentry)
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int autofs4_d_manage(struct dentry *dentry, bool mounting_here, bool rcu_walk)
|
|
{
|
|
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
|
|
|
|
DPRINTK("dentry=%p %.*s",
|
|
dentry, dentry->d_name.len, dentry->d_name.name);
|
|
|
|
/* The daemon never waits. */
|
|
if (autofs4_oz_mode(sbi) || mounting_here) {
|
|
if (!d_mountpoint(dentry))
|
|
return -EISDIR;
|
|
return 0;
|
|
}
|
|
|
|
/* We need to sleep, so we need pathwalk to be in ref-mode */
|
|
if (rcu_walk)
|
|
return -ECHILD;
|
|
|
|
/* Wait for pending expires */
|
|
do_expire_wait(dentry);
|
|
|
|
/*
|
|
* This dentry may be under construction so wait on mount
|
|
* completion.
|
|
*/
|
|
return autofs4_mount_wait(dentry);
|
|
}
|
|
|
|
/* Lookups in the root directory */
|
|
static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
|
|
{
|
|
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_init_ino(NULL, 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_init_ino(ino, sbi);
|
|
|
|
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 && dentry->d_parent != 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 -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;
|
|
clear_nlink(dentry->d_inode);
|
|
|
|
dir->i_mtime = CURRENT_TIME;
|
|
|
|
spin_lock(&autofs4_lock);
|
|
autofs4_add_expiring(dentry);
|
|
spin_lock(&dentry->d_lock);
|
|
__d_drop(dentry);
|
|
spin_unlock(&dentry->d_lock);
|
|
spin_unlock(&autofs4_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 neccessary 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_u.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(&autofs4_lock);
|
|
spin_lock(&sbi->lookup_lock);
|
|
spin_lock(&dentry->d_lock);
|
|
if (!list_empty(&dentry->d_subdirs)) {
|
|
spin_unlock(&dentry->d_lock);
|
|
spin_unlock(&sbi->lookup_lock);
|
|
spin_unlock(&autofs4_lock);
|
|
return -ENOTEMPTY;
|
|
}
|
|
__autofs4_add_expiring(dentry);
|
|
spin_unlock(&sbi->lookup_lock);
|
|
__d_drop(dentry);
|
|
spin_unlock(&dentry->d_lock);
|
|
spin_unlock(&autofs4_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, 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);
|
|
|
|
BUG_ON(!ino);
|
|
|
|
autofs4_init_ino(ino, sbi);
|
|
|
|
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 && dentry->d_parent != 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 = filp->f_dentry->d_inode;
|
|
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 = filp->f_path.dentry->d_inode;
|
|
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
|