/*
* 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, which we
* obviously do not want (we're dropping the entry not because it
* doesn't exist, but because it has timed out).
*
* Also see autofs_root_rmdir()..
*/
static int autofs_root_unlink(struct inode *dir, struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
struct autofs_dirhash *dh = &sbi->dirhash;
struct autofs_dir_ent *ent;
unsigned int n;
/* This allows root to remove symlinks */
if ( !autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
return -EACCES;
ent = autofs_hash_lookup(dh, &dentry->d_name);
if ( !ent )
return -ENOENT;
n = ent->ino - AUTOFS_FIRST_SYMLINK;
if ( n >= AUTOFS_MAX_SYMLINKS )
return -EISDIR; /* It's a directory, dummy */
if ( !test_bit(n,sbi->symlink_bitmap) )
return -EINVAL; /* Nonexistent symlink? Shouldn't happen */
dentry->d_time = (unsigned long)(struct autofs_dirhash *)NULL;
autofs_hash_delete(ent);
clear_bit(n,sbi->symlink_bitmap);
kfree(sbi->symlink[n].data);
d_drop(dentry);
return 0;
}
static int autofs_root_ioctl(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
void __user *argp = (void __user *)arg;
DPRINTK(("autofs_ioctl: 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(argp);
case AUTOFS_IOC_SETTIMEOUT:
return autofs_get_set_timeout(sbi, argp);
case AUTOFS_IOC_EXPIRE:
return autofs_expire_run(inode->i_sb, sbi, filp->f_path.mnt,
argp);
default:
return -ENOSYS;
}
}
static int autofs_root_rmdir(struct inode *dir, struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
struct autofs_dirhash *dh = &sbi->dirhash;
struct autofs_dir_ent *ent;
lock_kernel();
if (!autofs_oz_mode(sbi)) {
unlock_kernel();
return -EACCES;
}
ent = autofs_hash_lookup(dh, &dentry->d_name);
if (!ent) {
unlock_kernel();
return -ENOENT;
}
if ((unsigned int)ent->ino < AUTOFS_FIRST_DIR_INO) {
unlock_kernel();
return -ENOTDIR; /* Not a directory */
}
if (ent->dentry != dentry) {
printk("autofs_rmdir: odentry != dentry for entry %s\n", dentry->d_name.name);
}
dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL;
autofs_hash_delete(ent);
drop_nlink(dir);
d_drop(dentry);
unlock_kernel();
return 0;
}
static int autofs_root_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
struct autofs_dirhash *dh = &sbi->dirhash;
struct autofs_dir_ent *ent;
struct inode *inode;
ino_t ino;
lock_kernel();
if (!autofs_oz_mode(sbi)) {
unlock_kernel();
return -EACCES;
}
ent = autofs_hash_lookup(dh, &dentry->d_name);
if (ent) {
unlock_kernel();
return -EEXIST;
}
if (sbi->next_dir_ino < AUTOFS_FIRST_DIR_INO) {
printk("autofs: Out of inode numbers -- what the heck did you do??\n");
unlock_kernel();
return -ENOSPC;
}
ino = sbi->next_dir_ino++;
ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
if (!ent) {
unlock_kernel();
return -ENOSPC;
}
ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
if (!ent->name) {
kfree(ent);
unlock_kernel();
return -ENOSPC;
}
ent->hash = dentry->d_name.hash;
memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
ent->ino = ino;
ent->dentry = dentry;
autofs_hash_insert(dh,ent);
inc_nlink(dir);
inode = autofs_iget(dir->i_sb, ino);
if (IS_ERR(inode)) {
drop_nlink(dir);
return PTR_ERR(inode);
}
d_instantiate(dentry, inode);
unlock_kernel();
return 0;
}
static int autofs_root_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
struct autofs_dirhash *dh = &sbi->dirhash;
struct autofs_dir_ent *ent;
unsigned int n;
int slsize;
struct autofs_symlink *sl;
DPRINTK(("autofs_root_symlink: %s <- ", symname));
autofs_say(dentry->d_name.name,dentry->d_name.len);
if ( !autofs_oz_mode(sbi) )
return -EACCES;
if ( autofs_hash_lookup(dh, &dentry->d_name) )
return -EEXIST;
n = find_first_zero_bit(sbi->symlink_bitmap,AUTOFS_MAX_SYMLINKS);
if ( n >= AUTOFS_MAX_SYMLINKS )
return -ENOSPC;
set_bit(n,sbi->symlink_bitmap);
sl = &sbi->symlink[n];
sl->len = strlen(symname);
sl->data = kmalloc(slsize = sl->len+1, GFP_KERNEL);
if ( !sl->data ) {
clear_bit(n,sbi->symlink_bitmap);
return -ENOSPC;
}
ent = kmalloc(sizeof(struct autofs_dir_ent), GFP_KERNEL);
if ( !ent ) {
kfree(sl->data);
clear_bit(n,sbi->symlink_bitmap);
return -ENOSPC;
}
ent->name = kmalloc(dentry->d_name.len+1, GFP_KERNEL);
if ( !ent->name ) {
kfree(sl->data);
kfree(ent);
clear_bit(n,sbi->symlink_bitmap);
return -ENOSPC;
}
memcpy(sl->data,symname,slsize);
sl->mtime = CURRENT_TIME;
ent->ino = AUTOFS_FIRST_SYMLINK + n;
ent->hash = dentry->d_name.hash;
memcpy(ent->name, dentry->d_name.name, 1+(ent->len = dentry->d_name.len));
ent->dentry = NULL; /* We don't keep the dentry for symlinks */
autofs_hash_insert(dh,ent);
d_instantiate(dentry, iget(dir->i_sb,ent->ino));
return 0;
}
static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
{
struct inode * dir;
struct autofs_sb_info *sbi;
struct autofs_dir_ent *ent;
int res;
lock_kernel();
dir = dentry->d_parent->d_inode;
sbi = autofs_sbi(dir->i_sb);
/* Pending dentry */
if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
if (autofs_oz_mode(sbi))
res = 1;
else
res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
unlock_kernel();
return res;
}
/* Negative dentry.. invalidate if "old" */
if (!dentry->d_inode) {
unlock_kernel();
return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
}
/* Check for a non-mountpoint directory */
if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
if (autofs_oz_mode(sbi))
res = 1;
else
res = try_to_fill_dentry(dentry, dir->i_sb, sbi);
unlock_kernel();
return res;
}
/* Update the usage list */
if (!autofs_oz_mode(sbi)) {
ent = (struct autofs_dir_ent *) dentry->d_time;
if (ent)
autofs_update_usage(&sbi->dirhash,ent);
}
unlock_kernel();
return 1;
}
static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, struct autofs_sb_info *sbi)
{
struct inode * inode;
struct autofs_dir_ent *ent;
int status = 0;
if (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name))) {
do {
if (status && dentry->d_inode) {
if (status != -ENOENT)
printk("autofs warning: lookup failure on positive dentry, status = %d, name = %s\n", status, dentry->d_name.name);
return 0; /* Try to get the kernel to invalidate this dentry */
}
/* Turn this into a real negative dentry? */
if (status == -ENOENT) {
dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
return 1;
} else if (status) {
/* Return a negative dentry, but leave it "pending" */
return 1;
}
status = autofs_wait(sbi, &dentry->d_name);
} while (!(ent = autofs_hash_lookup(&sbi->dirhash, &dentry->d_name)));
}
/* Abuse this field as a pointer to the directory entry, used to
find the expire list pointers */
dentry->d_time = (unsigned long) ent;
if (!dentry->d_inode) {
inode = autofs_iget(sb, ent->ino);
if (IS_ERR(inode)) {
/* Failed, but leave pending for next time */
return 1;
}
dentry->d_inode = inode;
}
/* If this is a directory that isn't a mount point, bitch at the
daemon and fix it in user space */
if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry)) {
return !autofs_wait(sbi, &dentry->d_name);
}
/* We don't update the usages for the autofs daemon itself, this
is necessary for recursive autofs mounts */
if (!autofs_oz_mode(sbi)) {
autofs_update_usage(&sbi->dirhash,ent);
}
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
return 1;
}
static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentry)
{
struct autofs_sb_info *sbi;
int oz_mode;
DPRINTK(("autofs_root_lookup: name = "));
autofs_say(dentry->d_name.name,dentry->d_name.len);
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
sbi = autofs_sbi(dir->i_sb);
oz_mode = autofs_oz_mode(sbi);
DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
current->pid, current->pgrp, 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 = &autofs_dentry_operations;
dentry->d_flags |= DCACHE_AUTOFS_PENDING;
d_add(dentry, NULL);
up(&dir->i_sem);
autofs_revalidate(dentry, 0);
down(&dir->i_sem);
/*
* 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) {
if (signal_pending(current))
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 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;
}
/* 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) {
struct super_block *sb;
fp = fget(param->ioctlfd);
if (!fp) {
if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
goto cont;
err = -EBADF;
goto out;
}
sb = file_inode(fp)->i_sb;
if (sb->s_type != &autofs_fs_type) {
err = -EINVAL;
fput(fp);
goto out;
}
sbi = autofs_sbi(sb);
/*
* 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;
}
