static const char *autofs4_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 = autofs4_sbi(dentry->d_sb);
ino = autofs4_dentry_ino(dentry);
if (ino && !autofs4_oz_mode(sbi))
ino->last_used = jiffies;
return d_inode(dentry)->i_private;
}
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 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);
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);
/* This allows root to remove symlinks */
if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
return -EACCES;
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;
}
/*
* 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);
DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",
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, (int *)arg);
case AUTOFS_IOC_SETTIMEOUT:
return autofs4_get_set_timeout(sbi,(unsigned long *)arg);
/* return a single thing to expire */
case AUTOFS_IOC_EXPIRE:
return autofs4_expire_run(inode->i_sb,filp->f_vfsmnt,sbi,
(struct autofs_packet_expire *)arg);
/* 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,
(int *)arg);
default:
return -ENOSYS;
}
}
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 autofs4_dcache_readdir(file, dirent, filldir);
}
/*
* 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 = 1;
/* Pending dentry */
if (autofs4_ispending(dentry)) {
if (!oz_mode)
status = try_to_fill_dentry(dentry, dir->i_sb, sbi, flags);
return status;
}
/* Negative dentry.. invalidate if "old" */
if (dentry->d_inode == NULL)
return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
/* Check for a non-mountpoint directory with no contents */
spin_lock(&dcache_lock);
if (S_ISDIR(dentry->d_inode->i_mode) &&
!d_mountpoint(dentry) &&
list_empty(&dentry->d_subdirs)) {
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, dir->i_sb, sbi, flags);
return status;
}
spin_unlock(&dcache_lock);
/* Update the usage list */
if (!oz_mode)
autofs4_update_usage(dentry);
return 1;
}
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 inode *inode;
lock_kernel();
if ( !autofs4_oz_mode(sbi) ) {
unlock_kernel();
return -EACCES;
}
DPRINTK(("autofs_dir_mkdir: dentry %p, creating %.*s\n",
dentry, dentry->d_name.len, dentry->d_name.name));
ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
if (ino == NULL) {
unlock_kernel();
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);
ino->inode = inode;
dir->i_nlink++;
dir->i_mtime = CURRENT_TIME;
unlock_kernel();
return 0;
}
/* 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;
/* only root can play with this */
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
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;
}
/* 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;
/* The validate routine above always sets the version */
if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD)
goto done;
fn = lookup_dev_ioctl(cmd);
if (!fn) {
AUTOFS_WARN("unknown command 0x%08x", command);
return -ENOTTY;
}
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.
*/
if (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;
}
if (!fp->f_op) {
err = -ENOTTY;
fput(fp);
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 (!autofs4_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);
done:
if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
err = -EFAULT;
out:
free_dev_ioctl(param);
return err;
}
static int try_to_fill_dentry(struct dentry *dentry,
struct super_block *sb,
struct autofs_sb_info *sbi)
{
struct autofs_info *de_info = 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 (de_info && (de_info->flags & AUTOFS_INF_EXPIRING)) {
DPRINTK(("try_to_fill_entry: waiting for expire %p name=%.*s, flags&PENDING=%s de_info=%p de_info->flags=%x\n",
dentry, dentry->d_name.len, dentry->d_name.name,
dentry->d_flags & DCACHE_AUTOFS_PENDING?"t":"f",
de_info, de_info?de_info->flags:0));
status = autofs4_wait(sbi, &dentry->d_name, NFY_NONE);
DPRINTK(("try_to_fill_entry: expire done status=%d\n", status));
return 0;
}
DPRINTK(("try_to_fill_entry: dentry=%p %.*s ino=%p\n",
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 */
while(dentry->d_inode == NULL) {
DPRINTK(("try_to_fill_entry: waiting for mount name=%.*s, de_info=%p de_info->flags=%x\n",
dentry->d_name.len, dentry->d_name.name,
de_info, de_info?de_info->flags:0));
status = autofs4_wait(sbi, &dentry->d_name, NFY_MOUNT);
DPRINTK(("try_to_fill_entry: mount done status=%d\n", status));
if (status && dentry->d_inode)
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;
}
}
/* If this is an unused directory that isn't a mount point,
bitch at the daemon and fix it in user space */
spin_lock(&dcache_lock);
if (S_ISDIR(dentry->d_inode->i_mode) &&
!d_mountpoint(dentry) &&
list_empty(&dentry->d_subdirs)) {
DPRINTK(("try_to_fill_entry: mounting existing dir\n"));
spin_unlock(&dcache_lock);
return autofs4_wait(sbi, &dentry->d_name, NFY_MOUNT) == 0;
}
spin_unlock(&dcache_lock);
/* We don't update the usages for the autofs daemon itself, this
is necessary for recursive autofs mounts */
if (!autofs4_oz_mode(sbi))
autofs4_update_usage(dentry);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
return 1;
}
/* Lookups in the root directory */
static struct dentry *autofs4_root_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
struct autofs_sb_info *sbi;
int oz_mode;
DPRINTK(("autofs_root_lookup: name = %.*s\n",
dentry->d_name.len, dentry->d_name.name));
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
sbi = autofs4_sbi(dir->i_sb);
lock_kernel();
oz_mode = autofs4_oz_mode(sbi);
DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
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)
dentry->d_flags |= DCACHE_AUTOFS_PENDING;
dentry->d_fsdata = NULL;
d_add(dentry, NULL);
if (dentry->d_op && dentry->d_op->d_revalidate) {
up(&dir->i_sem);
(dentry->d_op->d_revalidate)(dentry, nd);
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)) {
unlock_kernel();
return ERR_PTR(-ERESTARTNOINTR);
}
}
unlock_kernel();
/*
* 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 try_to_fill_dentry(struct dentry *dentry,
struct super_block *sb,
struct autofs_sb_info *sbi, int flags)
{
struct autofs_info *de_info = 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 (de_info && (de_info->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);
return 0;
}
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 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;
spin_lock(&dentry->d_lock);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
return 1;
} else if (status) {
/* Return a negative dentry, but leave it "pending" */
return 1;
}
/* 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 0;
}
}
/* We don't update the usages for the autofs daemon itself, this
is necessary for recursive autofs mounts */
if (!autofs4_oz_mode(sbi))
autofs4_update_usage(dentry);
spin_lock(&dentry->d_lock);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
return 1;
}
