![Ian Kent](/assets/img/avatar_default.png)
The ioctls AUTOFS_IOC_TOGGLEREGHOST and AUTOFS_IOC_ASKREGHOST were added several years ago but what they were intended for has never been implemented (as far as I'm aware noone uses them) so remove them. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
916 lines
24 KiB
C
916 lines
24 KiB
C
/* -*- c -*- --------------------------------------------------------------- *
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*
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* linux/fs/autofs/root.c
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*
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* Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
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* Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
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* Copyright 2001-2006 Ian Kent <raven@themaw.net>
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*
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* This file is part of the Linux kernel and is made available under
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* the terms of the GNU General Public License, version 2, or at your
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* option, any later version, incorporated herein by reference.
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*
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* ------------------------------------------------------------------------- */
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#include <linux/capability.h>
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#include <linux/errno.h>
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#include <linux/stat.h>
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#include <linux/param.h>
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#include <linux/time.h>
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#include "autofs_i.h"
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static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
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static int autofs4_dir_unlink(struct inode *,struct dentry *);
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static int autofs4_dir_rmdir(struct inode *,struct dentry *);
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static int autofs4_dir_mkdir(struct inode *,struct dentry *,int);
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static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
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static int autofs4_dir_open(struct inode *inode, struct file *file);
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static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
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static void *autofs4_follow_link(struct dentry *, struct nameidata *);
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#define TRIGGER_FLAGS (LOOKUP_CONTINUE | LOOKUP_DIRECTORY)
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#define TRIGGER_INTENTS (LOOKUP_OPEN | LOOKUP_CREATE)
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const struct file_operations autofs4_root_operations = {
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.open = dcache_dir_open,
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.release = dcache_dir_close,
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.read = generic_read_dir,
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.readdir = dcache_readdir,
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.ioctl = autofs4_root_ioctl,
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};
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const struct file_operations autofs4_dir_operations = {
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.open = autofs4_dir_open,
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.release = dcache_dir_close,
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.read = generic_read_dir,
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.readdir = dcache_readdir,
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};
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const struct inode_operations autofs4_indirect_root_inode_operations = {
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.lookup = autofs4_lookup,
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.unlink = autofs4_dir_unlink,
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.symlink = autofs4_dir_symlink,
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.mkdir = autofs4_dir_mkdir,
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.rmdir = autofs4_dir_rmdir,
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};
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const struct inode_operations autofs4_direct_root_inode_operations = {
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.lookup = autofs4_lookup,
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.unlink = autofs4_dir_unlink,
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.mkdir = autofs4_dir_mkdir,
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.rmdir = autofs4_dir_rmdir,
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.follow_link = autofs4_follow_link,
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};
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const struct inode_operations autofs4_dir_inode_operations = {
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.lookup = autofs4_lookup,
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.unlink = autofs4_dir_unlink,
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.symlink = autofs4_dir_symlink,
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.mkdir = autofs4_dir_mkdir,
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.rmdir = autofs4_dir_rmdir,
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};
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static int autofs4_dir_open(struct inode *inode, struct file *file)
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{
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struct dentry *dentry = file->f_path.dentry;
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struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
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DPRINTK("file=%p dentry=%p %.*s",
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file, dentry, dentry->d_name.len, dentry->d_name.name);
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if (autofs4_oz_mode(sbi))
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goto out;
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/*
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* An empty directory in an autofs file system is always a
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* mount point. The daemon must have failed to mount this
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* during lookup so it doesn't exist. This can happen, for
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* example, if user space returns an incorrect status for a
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* mount request. Otherwise we're doing a readdir on the
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* autofs file system so just let the libfs routines handle
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* it.
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*/
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spin_lock(&dcache_lock);
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if (!d_mountpoint(dentry) && __simple_empty(dentry)) {
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spin_unlock(&dcache_lock);
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return -ENOENT;
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}
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spin_unlock(&dcache_lock);
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out:
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return dcache_dir_open(inode, file);
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}
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static int try_to_fill_dentry(struct dentry *dentry, int flags)
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{
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struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
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struct autofs_info *ino = autofs4_dentry_ino(dentry);
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int status;
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DPRINTK("dentry=%p %.*s ino=%p",
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dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
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/*
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* Wait for a pending mount, triggering one if there
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* isn't one already
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*/
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if (dentry->d_inode == NULL) {
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DPRINTK("waiting for mount name=%.*s",
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dentry->d_name.len, dentry->d_name.name);
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status = autofs4_wait(sbi, dentry, NFY_MOUNT);
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DPRINTK("mount done status=%d", status);
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/* Turn this into a real negative dentry? */
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if (status == -ENOENT) {
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spin_lock(&dentry->d_lock);
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dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
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spin_unlock(&dentry->d_lock);
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return status;
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} else if (status) {
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/* Return a negative dentry, but leave it "pending" */
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return status;
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}
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/* Trigger mount for path component or follow link */
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} else if (dentry->d_flags & DCACHE_AUTOFS_PENDING ||
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flags & (TRIGGER_FLAGS | TRIGGER_INTENTS) ||
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current->link_count) {
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DPRINTK("waiting for mount name=%.*s",
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dentry->d_name.len, dentry->d_name.name);
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spin_lock(&dentry->d_lock);
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dentry->d_flags |= DCACHE_AUTOFS_PENDING;
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spin_unlock(&dentry->d_lock);
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status = autofs4_wait(sbi, dentry, NFY_MOUNT);
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DPRINTK("mount done status=%d", status);
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if (status) {
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spin_lock(&dentry->d_lock);
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dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
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spin_unlock(&dentry->d_lock);
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return status;
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}
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}
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/* Initialize expiry counter after successful mount */
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if (ino)
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ino->last_used = jiffies;
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spin_lock(&dentry->d_lock);
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dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
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spin_unlock(&dentry->d_lock);
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return 0;
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}
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/* For autofs direct mounts the follow link triggers the mount */
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static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
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{
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struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
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struct autofs_info *ino = autofs4_dentry_ino(dentry);
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int oz_mode = autofs4_oz_mode(sbi);
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unsigned int lookup_type;
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int status;
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DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
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dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,
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nd->flags);
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/*
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* For an expire of a covered direct or offset mount we need
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* to beeak out of follow_down() at the autofs mount trigger
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* (d_mounted--), so we can see the expiring flag, and manage
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* the blocking and following here until the expire is completed.
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*/
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if (oz_mode) {
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spin_lock(&sbi->fs_lock);
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if (ino->flags & AUTOFS_INF_EXPIRING) {
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spin_unlock(&sbi->fs_lock);
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/* Follow down to our covering mount. */
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if (!follow_down(&nd->path.mnt, &nd->path.dentry))
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goto done;
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goto follow;
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}
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spin_unlock(&sbi->fs_lock);
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goto done;
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}
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/* If an expire request is pending everyone must wait. */
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autofs4_expire_wait(dentry);
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/* We trigger a mount for almost all flags */
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lookup_type = nd->flags & (TRIGGER_FLAGS | TRIGGER_INTENTS);
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if (!(lookup_type || dentry->d_flags & DCACHE_AUTOFS_PENDING))
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goto follow;
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/*
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* If the dentry contains directories then it is an autofs
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* multi-mount with no root mount offset. So don't try to
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* mount it again.
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*/
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spin_lock(&dcache_lock);
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if (dentry->d_flags & DCACHE_AUTOFS_PENDING ||
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(!d_mountpoint(dentry) && __simple_empty(dentry))) {
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spin_unlock(&dcache_lock);
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status = try_to_fill_dentry(dentry, 0);
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if (status)
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goto out_error;
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goto follow;
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}
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spin_unlock(&dcache_lock);
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follow:
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/*
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* If there is no root mount it must be an autofs
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* multi-mount with no root offset so we don't need
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* to follow it.
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*/
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if (d_mountpoint(dentry)) {
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if (!autofs4_follow_mount(&nd->path.mnt,
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&nd->path.dentry)) {
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status = -ENOENT;
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goto out_error;
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}
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}
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done:
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return NULL;
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out_error:
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path_put(&nd->path);
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return ERR_PTR(status);
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}
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/*
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* Revalidate is called on every cache lookup. Some of those
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* cache lookups may actually happen while the dentry is not
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* yet completely filled in, and revalidate has to delay such
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* lookups..
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*/
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static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
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{
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struct inode *dir = dentry->d_parent->d_inode;
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struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
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int oz_mode = autofs4_oz_mode(sbi);
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int flags = nd ? nd->flags : 0;
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int status = 1;
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/* Pending dentry */
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spin_lock(&sbi->fs_lock);
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if (autofs4_ispending(dentry)) {
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/* The daemon never causes a mount to trigger */
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spin_unlock(&sbi->fs_lock);
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if (oz_mode)
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return 1;
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/*
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* If the directory has gone away due to an expire
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* we have been called as ->d_revalidate() and so
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* we need to return false and proceed to ->lookup().
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*/
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if (autofs4_expire_wait(dentry) == -EAGAIN)
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return 0;
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/*
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* A zero status is success otherwise we have a
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* negative error code.
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*/
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status = try_to_fill_dentry(dentry, flags);
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if (status == 0)
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return 1;
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return status;
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}
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spin_unlock(&sbi->fs_lock);
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/* Negative dentry.. invalidate if "old" */
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if (dentry->d_inode == NULL)
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return 0;
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/* Check for a non-mountpoint directory with no contents */
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spin_lock(&dcache_lock);
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if (S_ISDIR(dentry->d_inode->i_mode) &&
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!d_mountpoint(dentry) &&
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__simple_empty(dentry)) {
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DPRINTK("dentry=%p %.*s, emptydir",
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dentry, dentry->d_name.len, dentry->d_name.name);
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spin_unlock(&dcache_lock);
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/* The daemon never causes a mount to trigger */
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if (oz_mode)
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return 1;
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/*
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* A zero status is success otherwise we have a
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* negative error code.
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*/
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status = try_to_fill_dentry(dentry, flags);
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if (status == 0)
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return 1;
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return status;
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}
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spin_unlock(&dcache_lock);
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return 1;
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}
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void autofs4_dentry_release(struct dentry *de)
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{
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struct autofs_info *inf;
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DPRINTK("releasing %p", de);
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inf = autofs4_dentry_ino(de);
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de->d_fsdata = NULL;
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if (inf) {
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struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
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if (sbi) {
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spin_lock(&sbi->lookup_lock);
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if (!list_empty(&inf->active))
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list_del(&inf->active);
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if (!list_empty(&inf->expiring))
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list_del(&inf->expiring);
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spin_unlock(&sbi->lookup_lock);
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}
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inf->dentry = NULL;
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inf->inode = NULL;
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autofs4_free_ino(inf);
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}
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}
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/* For dentries of directories in the root dir */
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static struct dentry_operations autofs4_root_dentry_operations = {
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.d_revalidate = autofs4_revalidate,
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.d_release = autofs4_dentry_release,
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};
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/* For other dentries */
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static struct dentry_operations autofs4_dentry_operations = {
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.d_revalidate = autofs4_revalidate,
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.d_release = autofs4_dentry_release,
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};
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static struct dentry *autofs4_lookup_active(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
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{
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unsigned int len = name->len;
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unsigned int hash = name->hash;
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const unsigned char *str = name->name;
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struct list_head *p, *head;
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spin_lock(&dcache_lock);
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spin_lock(&sbi->lookup_lock);
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head = &sbi->active_list;
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list_for_each(p, head) {
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struct autofs_info *ino;
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struct dentry *dentry;
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struct qstr *qstr;
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ino = list_entry(p, struct autofs_info, active);
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dentry = ino->dentry;
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spin_lock(&dentry->d_lock);
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/* Already gone? */
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if (atomic_read(&dentry->d_count) == 0)
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goto next;
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qstr = &dentry->d_name;
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if (dentry->d_name.hash != hash)
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goto next;
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if (dentry->d_parent != parent)
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goto next;
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if (qstr->len != len)
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goto next;
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if (memcmp(qstr->name, str, len))
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goto next;
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if (d_unhashed(dentry)) {
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dget(dentry);
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spin_unlock(&dentry->d_lock);
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spin_unlock(&sbi->lookup_lock);
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spin_unlock(&dcache_lock);
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return dentry;
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}
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next:
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spin_unlock(&dentry->d_lock);
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}
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spin_unlock(&sbi->lookup_lock);
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spin_unlock(&dcache_lock);
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return NULL;
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}
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static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
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{
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unsigned int len = name->len;
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unsigned int hash = name->hash;
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const unsigned char *str = name->name;
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struct list_head *p, *head;
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spin_lock(&dcache_lock);
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spin_lock(&sbi->lookup_lock);
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head = &sbi->expiring_list;
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list_for_each(p, head) {
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struct autofs_info *ino;
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struct dentry *dentry;
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struct qstr *qstr;
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ino = list_entry(p, struct autofs_info, expiring);
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dentry = ino->dentry;
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spin_lock(&dentry->d_lock);
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/* Bad luck, we've already been dentry_iput */
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if (!dentry->d_inode)
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goto next;
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qstr = &dentry->d_name;
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if (dentry->d_name.hash != hash)
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goto next;
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if (dentry->d_parent != parent)
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goto next;
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if (qstr->len != len)
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goto next;
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if (memcmp(qstr->name, str, len))
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goto next;
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|
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if (d_unhashed(dentry)) {
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dget(dentry);
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spin_unlock(&dentry->d_lock);
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spin_unlock(&sbi->lookup_lock);
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spin_unlock(&dcache_lock);
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return dentry;
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}
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next:
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spin_unlock(&dentry->d_lock);
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}
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spin_unlock(&sbi->lookup_lock);
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spin_unlock(&dcache_lock);
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return NULL;
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}
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|
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/* Lookups in the root directory */
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static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
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{
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struct autofs_sb_info *sbi;
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struct autofs_info *ino;
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struct dentry *expiring, *unhashed;
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int oz_mode;
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DPRINTK("name = %.*s",
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dentry->d_name.len, dentry->d_name.name);
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/* File name too long to exist */
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if (dentry->d_name.len > NAME_MAX)
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return ERR_PTR(-ENAMETOOLONG);
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sbi = autofs4_sbi(dir->i_sb);
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oz_mode = autofs4_oz_mode(sbi);
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DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
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current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode);
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expiring = autofs4_lookup_expiring(sbi, dentry->d_parent, &dentry->d_name);
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if (expiring) {
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/*
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* If we are racing with expire the request might not
|
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* be quite complete but the directory has been removed
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* so it must have been successful, so just wait for it.
|
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*/
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ino = autofs4_dentry_ino(expiring);
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autofs4_expire_wait(expiring);
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spin_lock(&sbi->lookup_lock);
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if (!list_empty(&ino->expiring))
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list_del_init(&ino->expiring);
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spin_unlock(&sbi->lookup_lock);
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dput(expiring);
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}
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|
|
unhashed = autofs4_lookup_active(sbi, dentry->d_parent, &dentry->d_name);
|
|
if (unhashed)
|
|
dentry = unhashed;
|
|
else {
|
|
/*
|
|
* Mark the dentry incomplete but don't hash it. We do this
|
|
* to serialize our inode creation operations (symlink and
|
|
* mkdir) which prevents deadlock during the callback to
|
|
* the daemon. Subsequent user space lookups for the same
|
|
* dentry are placed on the wait queue while the daemon
|
|
* itself is allowed passage unresticted so the create
|
|
* operation itself can then hash the dentry. Finally,
|
|
* we check for the hashed dentry and return the newly
|
|
* hashed dentry.
|
|
*/
|
|
dentry->d_op = &autofs4_root_dentry_operations;
|
|
|
|
/*
|
|
* And we need to ensure that the same dentry is used for
|
|
* all following lookup calls until it is hashed so that
|
|
* the dentry flags are persistent throughout the request.
|
|
*/
|
|
ino = autofs4_init_ino(NULL, sbi, 0555);
|
|
if (!ino)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
dentry->d_fsdata = ino;
|
|
ino->dentry = dentry;
|
|
|
|
spin_lock(&sbi->lookup_lock);
|
|
list_add(&ino->active, &sbi->active_list);
|
|
spin_unlock(&sbi->lookup_lock);
|
|
|
|
d_instantiate(dentry, NULL);
|
|
}
|
|
|
|
if (!oz_mode) {
|
|
spin_lock(&dentry->d_lock);
|
|
dentry->d_flags |= DCACHE_AUTOFS_PENDING;
|
|
spin_unlock(&dentry->d_lock);
|
|
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 = ¤t->pending.signal;
|
|
if (sigismember (sigset, SIGKILL) ||
|
|
sigismember (sigset, SIGQUIT) ||
|
|
sigismember (sigset, SIGINT)) {
|
|
if (unhashed)
|
|
dput(unhashed);
|
|
return ERR_PTR(-ERESTARTNOINTR);
|
|
}
|
|
}
|
|
if (!oz_mode) {
|
|
spin_lock(&dentry->d_lock);
|
|
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
|
|
spin_unlock(&dentry->d_lock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If this dentry is unhashed, then we shouldn't honour this
|
|
* lookup. 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 (!oz_mode && d_unhashed(dentry)) {
|
|
/*
|
|
* A user space application can (and has done in the past)
|
|
* remove and re-create this directory during the callback.
|
|
* This can leave us with an unhashed dentry, but a
|
|
* successful mount! So we need to perform another
|
|
* cached lookup in case the dentry now exists.
|
|
*/
|
|
struct dentry *parent = dentry->d_parent;
|
|
struct dentry *new = d_lookup(parent, &dentry->d_name);
|
|
if (new != NULL)
|
|
dentry = new;
|
|
else
|
|
dentry = ERR_PTR(-ENOENT);
|
|
|
|
if (unhashed)
|
|
dput(unhashed);
|
|
|
|
return dentry;
|
|
}
|
|
|
|
if (unhashed)
|
|
return unhashed;
|
|
|
|
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)
|
|
return -ENOMEM;
|
|
|
|
spin_lock(&sbi->lookup_lock);
|
|
if (!list_empty(&ino->active))
|
|
list_del_init(&ino->active);
|
|
spin_unlock(&sbi->lookup_lock);
|
|
|
|
ino->size = strlen(symname);
|
|
cp = kmalloc(ino->size + 1, GFP_KERNEL);
|
|
if (!cp) {
|
|
if (!dentry->d_fsdata)
|
|
kfree(ino);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
strcpy(cp, symname);
|
|
|
|
inode = autofs4_get_inode(dir->i_sb, ino);
|
|
if (!inode) {
|
|
kfree(cp);
|
|
if (!dentry->d_fsdata)
|
|
kfree(ino);
|
|
return -ENOMEM;
|
|
}
|
|
d_add(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;
|
|
|
|
ino->u.symlink = cp;
|
|
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(&dcache_lock);
|
|
spin_lock(&sbi->lookup_lock);
|
|
if (list_empty(&ino->expiring))
|
|
list_add(&ino->expiring, &sbi->expiring_list);
|
|
spin_unlock(&sbi->lookup_lock);
|
|
spin_lock(&dentry->d_lock);
|
|
__d_drop(dentry);
|
|
spin_unlock(&dentry->d_lock);
|
|
spin_unlock(&dcache_lock);
|
|
|
|
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;
|
|
|
|
DPRINTK("dentry %p, removing %.*s",
|
|
dentry, dentry->d_name.len, dentry->d_name.name);
|
|
|
|
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(&sbi->lookup_lock);
|
|
if (list_empty(&ino->expiring))
|
|
list_add(&ino->expiring, &sbi->expiring_list);
|
|
spin_unlock(&sbi->lookup_lock);
|
|
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;
|
|
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);
|
|
|
|
ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
|
|
if (!ino)
|
|
return -ENOMEM;
|
|
|
|
spin_lock(&sbi->lookup_lock);
|
|
if (!list_empty(&ino->active))
|
|
list_del_init(&ino->active);
|
|
spin_unlock(&sbi->lookup_lock);
|
|
|
|
inode = autofs4_get_inode(dir->i_sb, ino);
|
|
if (!inode) {
|
|
if (!dentry->d_fsdata)
|
|
kfree(ino);
|
|
return -ENOMEM;
|
|
}
|
|
d_add(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;
|
|
inc_nlink(dir);
|
|
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 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,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);
|
|
|
|
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;
|
|
}
|
|
}
|