Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753293AbYB1GWZ (ORCPT ); Thu, 28 Feb 2008 01:22:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751101AbYB1GWO (ORCPT ); Thu, 28 Feb 2008 01:22:14 -0500 Received: from out3.smtp.messagingengine.com ([66.111.4.27]:58971 "EHLO out3.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751040AbYB1GWM (ORCPT ); Thu, 28 Feb 2008 01:22:12 -0500 X-Sasl-enc: uZbabjGoXBKCQUZhzIOJ8bmlRyvoeKe75YAVx1wEsL8E 1204179728 Subject: Re: [PATCH 4/4] autofs4 - add miscelaneous device for ioctls From: Ian Kent To: Andrew Morton Cc: Kernel Mailing List , autofs mailing list , linux-fsdevel , Christoph Hellwig , Al Viro In-Reply-To: <20080227211723.d5d27c09.akpm@linux-foundation.org> References: <20080227211723.d5d27c09.akpm@linux-foundation.org> Content-Type: text/plain Date: Thu, 28 Feb 2008 15:18:59 +0900 Message-Id: <1204179539.3501.17.camel@raven.themaw.net> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 (2.12.3-1.fc8) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 24811 Lines: 829 On Wed, 2008-02-27 at 21:17 -0800, Andrew Morton wrote: > On Tue, 26 Feb 2008 12:23:55 +0900 (WST) Ian Kent wrote: > > > Hi Andrew, > > > > Patch to add miscellaneous device to autofs4 module for > > ioctls. > > Could you please document the new kernel interface which you're proposing? > In Docmentation/ or in the changelog? Also a good suggestion. I'll include that too. > > We seem to be passing some string into a miscdevice ioctl and getting some > results back. Be aware that this won't be a terribly popular proposal, so > I'd suggest that you fully describe the problem which it's trying to solve, > and how it solves it, and why the various alternatives (sysfs, netlink, > mount options, etc) were judged unsuitable. Yes, as I said above. I don't expect that people that aren't close to the development of autofs will "get" the problem description in the leading post but I will try and expand on it as best I can. As for the possible alternatives, it sounds like I have some more work to do on that. Mount options can't be used as I described in the lead in post and, as far as my understanding of sysfs goes, I don't think it's appropriate. But, I'm not aware of what the netlink interface may be able to do for me so I will need to check on that. > > > > ... > > > > --- linux-2.6.25-rc2-mm1/fs/autofs4/init.c.device-node-ioctl 2008-01-25 07:58:37.000000000 +0900 > > +++ linux-2.6.25-rc2-mm1/fs/autofs4/init.c 2008-02-22 11:51:41.000000000 +0900 > > @@ -29,11 +29,20 @@ static struct file_system_type autofs_fs > > > > static int __init init_autofs4_fs(void) > > { > > - return register_filesystem(&autofs_fs_type); > > + int err; > > + > > + err = register_filesystem(&autofs_fs_type); > > + if (err) > > + return err; > > + > > + err = autofs_dev_ioctl_init(); > > + > > + return err; > > } > > We should run unregister_filesystem() if autofs_dev_ioctl_init() fails. > > > static void __exit exit_autofs4_fs(void) > > { > > + autofs_dev_ioctl_exit(); > > unregister_filesystem(&autofs_fs_type); > > } > > > > diff -up linux-2.6.25-rc2-mm1/fs/autofs4/autofs_i.h.device-node-ioctl linux-2.6.25-rc2-mm1/fs/autofs4/autofs_i.h > > --- linux-2.6.25-rc2-mm1/fs/autofs4/autofs_i.h.device-node-ioctl 2008-02-22 11:51:41.000000000 +0900 > > +++ linux-2.6.25-rc2-mm1/fs/autofs4/autofs_i.h 2008-02-22 11:51:41.000000000 +0900 > > @@ -14,6 +14,7 @@ > > /* Internal header file for autofs */ > > > > #include > > +#include > > #include > > #include > > > > @@ -40,6 +41,16 @@ > > #define DPRINTK(fmt,args...) do {} while(0) > > #endif > > > > +#define WARN(fmt,args...) \ > > +do { \ > > + printk("KERN_WARNING pid %d: %s: " fmt "\n" , current->pid , __FUNCTION__ , ##args); \ > > +} while(0) > > + > > +#define ERROR(fmt,args...) \ > > +do { \ > > + printk("KERN_ERR pid %d: %s: " fmt "\n" , current->pid , __FUNCTION__ , ##args); \ > > +} while(0) > > Please always pass all diffs through scripts/checkpatch.pl. > > > /* Unified info structure. This is pointed to by both the dentry and > > inode structures. Each file in the filesystem has an instance of this > > structure. It holds a reference to the dentry, so dentries are never > > @@ -172,6 +183,17 @@ int autofs4_expire_run(struct super_bloc > > struct autofs_packet_expire __user *); > > int autofs4_expire_multi(struct super_block *, struct vfsmount *, > > struct autofs_sb_info *, int __user *); > > +struct dentry *autofs4_expire_direct(struct super_block *sb, > > + struct vfsmount *mnt, > > + struct autofs_sb_info *sbi, int how); > > +struct dentry *autofs4_expire_indirect(struct super_block *sb, > > + struct vfsmount *mnt, > > + struct autofs_sb_info *sbi, int how); > > + > > +/* Device node initialization */ > > + > > +int autofs_dev_ioctl_init(void); > > +void autofs_dev_ioctl_exit(void); > > > > ... > > > > @@ -0,0 +1,788 @@ > > +/* > > + * linux/fs/autofs4/dev-ioctl.c > > We prefer not to bother with the filename-in-the-file thing. You know what > file you're reading, and these things tend to not get updated across > renames. > > > + * Copyright 2008 Red Hat, Inc. All rights reserved. > > + * Copyright 2008 Ian Kent > > + * > > + * 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 > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > Please include rather than if the former exists. > > > +#include "autofs_i.h" > > + > > +/* > > + * This module implements an interface for routing autofs ioctl control > > + * commands via a miscellaneous device file. > > + * > > + * The alternate interface is needed because we need to be able open > > + * an ioctl file descriptor on an autofs mount that may be covered by > > + * another mount. This situation arises when starting automount(8) > > + * or other user space daemon which uses direct mounts or offset > > + * mounts (used for autofs lazy mount/umount of nested mount trees), > > + * which have been left busy at at service shutdown. > > + */ > > + > > +#define AUTOFS_DEVICE_NAME "autofs" > > + > > +#define AUTOFS_DEV_IOCTL_IOC_FIRST AUTOFS_DEV_IOCTL_VERSION > > +#define AUTOFS_DEV_IOCTL_IOC_COUNT AUTOFS_IOC_COUNT - 11 > > This needs parentheses. > > Shouldn't these be in a header file, exported to userspace builds? > > > +#define AUTOFS_DEV_IOCTL_SIZE sizeof(struct autofs_dev_ioctl) > > + > > +typedef int (*ioctl_fn)(struct file *, struct autofs_sb_info *, struct autofs_dev_ioctl *); > > + > > +static int check_name(const char *name) > > +{ > > + if (!strchr(name, '/')) > > + return -EINVAL; > > + return 0; > > +} > > + > > +/* > > + * Check a string doesn't overrun the chunk of > > + * memory we copied from user land. > > + */ > > +static int invalid_str(char *str, void *end) > > +{ > > + while ((void *) str <= end) > > + if (!*str++) > > + return 0; > > + return -EINVAL; > > +} > > > > ... > > > > +/* > > + * Get the autofs super block info struct from the file opened on > > + * the autofs mount point. > > + */ > > +static struct autofs_sb_info *autofs_dev_ioctl_sbi(struct file *f) > > +{ > > + struct autofs_sb_info *sbi = NULL; > > + struct inode *inode; > > + > > + if (f) { > > `f' cannot be NULL here. > > > + inode = f->f_path.dentry->d_inode; > > + sbi = autofs4_sbi(inode->i_sb); > > + } > > + > > + return sbi; > > +} > > + > > +/* Return autofs module protocol version */ > > +static inline int autofs_dev_ioctl_protover(struct file *fp, > > + struct autofs_sb_info *sbi, > > + struct autofs_dev_ioctl *param) > > +{ > > + param->arg1 = sbi->version; > > + return 0; > > +} > > + > > +/* Return autofs module protocol sub version */ > > +static inline int autofs_dev_ioctl_protosubver(struct file *fp, > > + struct autofs_sb_info *sbi, > > + struct autofs_dev_ioctl *param) > > +{ > > + param->arg1 = sbi->sub_version; > > + return 0; > > +} > > Don't bother inlining things - the compiler will do it. > > > +/* > > + * Walk down the mount stack looking for an autofs mount that > > + * has the requested device number (aka. new_encode_dev(sb->s_dev). > > + */ > > +static int autofs_dev_ioctl_find_super(struct nameidata *nd, dev_t devno) > > +{ > > + struct dentry *dentry; > > + struct inode *inode; > > + struct super_block *sb; > > + dev_t s_dev; > > + unsigned int err; > > + > > + err = -ENOENT; > > + > > + /* Lookup the dentry name at the base of our mount point */ > > + dentry = d_lookup(nd->path.dentry, &nd->last); > > + if (!dentry) > > + goto out; > > + > > + dput(nd->path.dentry); > > + nd->path.dentry = dentry; > > + > > + /* And follow the mount stack looking for our autofs mount */ > > + while (1) { > > + inode = nd->path.dentry->d_inode; > > + if (!inode) > > + continue; > > + > > + sb = inode->i_sb; > > + s_dev = new_encode_dev(sb->s_dev); > > + if (devno == s_dev) { > > + if (sb->s_magic == AUTOFS_SUPER_MAGIC) { > > + err = 0; > > + break; > > + } > > + } > > + > > + if (!follow_down(&nd->path.mnt, &nd->path.dentry)) > > + goto out; > > + } > > + > > +out: > > + return err; > > +} > > hm. possibly-interested parties cc'ed. > > > +/* > > + * Install the file opened for autofs mount point control functions > > + * and set close on exec. > > + */ > > +static void autofs_dev_ioctl_fd_install(unsigned int fd, struct file *file) > > +{ > > + struct files_struct *files = current->files; > > + struct fdtable *fdt; > > + > > + spin_lock(&files->file_lock); > > + fdt = files_fdtable(files); > > + BUG_ON(fdt->fd[fd] != NULL); > > + rcu_assign_pointer(fdt->fd[fd], file); > > + FD_SET(fd, fdt->close_on_exec); > > + spin_unlock(&files->file_lock); > > +} > > That's fd_install() plus an add-on. It's not autofs-specific. Should be > in fs/open.c, methinks? > > > > > ... > > > > +/* Close file descriptor allocated above (user can also use close(2)). */ > > +static inline int autofs_dev_ioctl_closemount(struct file *fp, > > + struct autofs_sb_info *sbi, > > + struct autofs_dev_ioctl *param) > > +{ > > + return sys_close(param->ioctlfd); > > +} > > hm. > > > > > ... > > > > +/* > > + * Set the pipe fd for kernel communication to the daemon. > > + * > > + * Normally this is set at mount using an option but if we > > + * are reconnecting to a busy mount then we need to use this > > + * to tell the autofs mount about the new kernel pipe fd. In > > + * order to protect mounts against incorrectly setting the > > + * pipefd we also require that the autofs mount be catatonic. > > + * > > + * This also sets the process group id used to identify the > > + * controlling process (eg. the owning automount(8) daemon). > > + */ > > +static int autofs_dev_ioctl_setpipefd(struct file *fp, > > + struct autofs_sb_info *sbi, > > + struct autofs_dev_ioctl *param) > > +{ > > + int pipefd; > > + int err = 0; > > + > > + if (param->arg1 == -1) > > + return -EINVAL; > > + > > + pipefd = param->arg1; > > + > > + if (!sbi->catatonic) > > + return -EBUSY; > > + else { > > + struct file *pipe = fget(pipefd); > > + if (!pipe->f_op || !pipe->f_op->write) { > > + err = -EPIPE; > > + fput(pipe); > > + goto out; > > + } > > + sbi->oz_pgrp = task_pgrp_nr(current); > > + sbi->pipefd = pipefd; > > + sbi->pipe = pipe; > > + sbi->catatonic = 0; > > + } > > +out: > > + return err; > > +} > > We have a new filesystem type, a misc device with a mysterious ioctl, > hand-rolled mountpoint chasing, hand-rolled fd installation and now pipes > too. > > This is a complex interface. We really need to see the overall problem > statement, design and interface description, please. > > > +/* > > + * Make the autofs mount point catatonic, no longer responsive to > > + * mount requests. Also closes the kernel pipe file descriptor. > > + */ > > +static inline int autofs_dev_ioctl_catatonic(struct file *fp, > > + struct autofs_sb_info *sbi, > > + struct autofs_dev_ioctl *param) > > +{ > > + if (!sbi->catatonic) > > + autofs4_catatonic_mode(sbi); > > + return 0; > > +} > > + > > +/* Set the autofs mount timeout */ > > +static inline int autofs_dev_ioctl_timeout(struct file *fp, > > + struct autofs_sb_info *sbi, > > + struct autofs_dev_ioctl *param) > > +{ > > + unsigned long timeout; > > + > > + timeout = param->arg1; > > + param->arg1 = sbi->exp_timeout / HZ; > > + sbi->exp_timeout = timeout * HZ; > > + return 0; > > +} > > uninline everything... > > > +/* > > + * Return the uid and gid of the last request for the mount > > + * > > + * When reconstructing an autofs mount tree with active mounts > > + * we need to re-connect to mounts that may have used the original > > + * process uid and gid (or string variations of them) for mount > > + * lookups within the map entry. > > + */ > > +static inline int autofs_dev_ioctl_requestor(struct file *fp, > > + struct autofs_sb_info *sbi, > > + struct autofs_dev_ioctl *param) > > especially that - it's only ever called indirectly anwyay! > > > + struct autofs_info *ino; > > + struct nameidata nd; > > + const char *path; > > + dev_t devid; > > + int err = -ENOENT; > > + > > + if (param->size <= sizeof(*param)) { > > + err = -EINVAL; > > + goto out; > > + } > > + > > + path = param->path; > > + devid = sbi->sb->s_dev; > > + > > + param->arg1 = param->arg2 = -1; > > + > > + /* Get nameidata of the parent directory */ > > + err = path_lookup(path, LOOKUP_PARENT, &nd); > > + if (err) > > + goto out; > > + > > + err = autofs_dev_ioctl_find_super(&nd, devid); > > + if (err) > > + goto out_release; > > + > > + ino = autofs4_dentry_ino(nd.path.dentry); > > + if (ino) { > > + err = 0; > > + param->arg1 = ino->uid; > > + param->arg2 = ino->gid; > > + } > > + > > +out_release: > > + path_put(&nd.path); > > +out: > > + return err; > > +} > > + > > +/* > > + * Call repeatedly until it returns -EAGAIN, meaning there's nothing > > + * more that can be done. > > + */ > > +static int autofs_dev_ioctl_expire(struct file *fp, > > + struct autofs_sb_info *sbi, > > + struct autofs_dev_ioctl *param) > > +{ > > + struct dentry *dentry; > > + struct vfsmount *mnt; > > + int err = -EAGAIN; > > + int when; > > + > > + when = param->arg1; > > + mnt = fp->f_path.mnt; > > + > > + if (sbi->type & AUTOFS_TYPE_DIRECT) > > + dentry = autofs4_expire_direct(sbi->sb, mnt, sbi, when); > > + else > > + dentry = autofs4_expire_indirect(sbi->sb, mnt, sbi, when); > > + > > + if (dentry) { > > + struct autofs_info *ino = autofs4_dentry_ino(dentry); > > + > > + /* > > + * This is synchronous because it makes the daemon a > > + * little easier > > + */ > > + ino->flags |= AUTOFS_INF_EXPIRING; > > + err = autofs4_wait(sbi, dentry, NFY_EXPIRE); > > + ino->flags &= ~AUTOFS_INF_EXPIRING; > > Are there races around the modification of ino->flags here? > > > + dput(dentry); > > + } > > + > > + return err; > > +} > > + > > +/* Check if autofs mount point is in use */ > > +static inline int autofs_dev_ioctl_askumount(struct file *fp, > > + struct autofs_sb_info *sbi, > > + struct autofs_dev_ioctl *param) > > +{ > > + param->arg1 = 0; > > + if (may_umount(fp->f_path.mnt)) > > + param->arg1 = 1; > > + return 0; > > +} > > + > > +/* > > + * Check if the given path is a mountpoint. > > + * > > + * If we are supplied with the file descriptor of the autofs > > + * mount we're looking for a specific mount. In this case > > + * the path is considered a mountpoint if it is itself a > > + * mountpoint or contains a mount, such as a multi-mount > > + * without a root mount. > > + * > > + * If we aren't supplied with a file descriptor then we lookup > > + * the nameidata of the path and check if is a mounted autofs > > + * filesystem or a filesystem mounted within an autofs filesystem. > > + * > > + * In both cases we return an indication of whether the path > > + * is a mount point and the super magic of the covering mount. > > + */ > > +static inline int autofs_dev_ioctl_ismountpoint(struct file *fp, > > + struct autofs_sb_info *sbi, > > + struct autofs_dev_ioctl *param) > > uninline.. > > > + struct nameidata nd; > > + const char *path; > > + int err = -ENOENT; > > + > > + if (param->size <= sizeof(*param)) { > > + err = -EINVAL; > > + goto out; > > + } > > + > > + path = param->path; > > + > > + param->arg1 = param->arg2 = 0; > > + > > + if (param->ioctlfd == -1) { > > + unsigned long magic; > > + > > + err = path_lookup(path, LOOKUP_FOLLOW, &nd); > > + if (err) > > + goto out; > > + > > + magic = nd.path.dentry->d_inode->i_sb->s_magic; > > + > > + if (follow_up(&nd.path.mnt, &nd.path.dentry)) { > > + struct inode *inode = nd.path.dentry->d_inode; > > + if (magic == AUTOFS_SUPER_MAGIC || > > + inode->i_sb->s_magic == AUTOFS_SUPER_MAGIC) { > > + param->arg1 = 1; > > + param->arg2 = magic; > > + } > > + } > > + } else { > > + dev_t devid = sbi->sb->s_dev; > > + > > + err = path_lookup(path, LOOKUP_PARENT, &nd); > > + if (err) > > + goto out; > > + > > + err = autofs_dev_ioctl_find_super(&nd, devid); > > + if (err) > > + goto out_release; > > + > > + param->arg1 = have_submounts(nd.path.dentry); > > + > > + if (d_mountpoint(nd.path.dentry)) { > > + if (follow_down(&nd.path.mnt, &nd.path.dentry)) { > > + struct inode *inode = nd.path.dentry->d_inode; > > + param->arg2 = inode->i_sb->s_magic; > > + } > > + } > > + } > > + > > +out_release: > > + path_put(&nd.path); > > +out: > > + return err; > > +} > > Have you really carefully reviewed and tested what happens when non-autofs > fds are fed into all the ioctl modes? > > I hope all these ioctl entrypoints are root-only. What determines that? > The miscdevice permissions? > > > +/* > > + * Our range of ioctl numbers isn't 0 based so we need to shift > > + * the array index by _IOC_NR(AUTOFS_CTL_IOC_FIRST) for the table > > + * lookup. > > + */ > > +#define cmd_idx(cmd) (cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST)) > > + > > +static ioctl_fn lookup_dev_ioctl(unsigned int cmd) > > +{ > > + static struct { > > + int cmd; > > + ioctl_fn fn; > > + } _ioctls[] = { > > + {cmd_idx(AUTOFS_DEV_IOCTL_VERSION_CMD), NULL}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_PROTOVER_CMD), autofs_dev_ioctl_protover}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD), autofs_dev_ioctl_protosubver}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_OPENMOUNT_CMD), autofs_dev_ioctl_openmount}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD), autofs_dev_ioctl_closemount}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_READY_CMD), autofs_dev_ioctl_ready}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_FAIL_CMD), autofs_dev_ioctl_fail}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_SETPIPEFD_CMD), autofs_dev_ioctl_setpipefd}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_CATATONIC_CMD), autofs_dev_ioctl_catatonic}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_TIMEOUT_CMD), autofs_dev_ioctl_timeout}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_REQUESTOR_CMD), autofs_dev_ioctl_requestor}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_EXPIRE_CMD), autofs_dev_ioctl_expire}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD), autofs_dev_ioctl_askumount}, > > + {cmd_idx(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD), autofs_dev_ioctl_ismountpoint} > > + }; > > + int idx = cmd_idx(cmd); > > `idx' should have unsigned type. > > > + return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx].fn; > > +} > > + > > +/* 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; > > + ioctl_fn fn = NULL; > > + int err = 0; > > + > > + /* only root can play with this */ > > + if (!capable(CAP_SYS_ADMIN)) > > + return -EPERM; > > OK, I guess that answers my above question. > > > + cmd = _IOC_NR(command); > > + > > + if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) || > > + cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST) >= AUTOFS_DEV_IOCTL_IOC_COUNT) { > > + return -ENOTTY; > > + } > > + > > + fn = lookup_dev_ioctl(cmd); > > + if (!fn) { > > + WARN("unknown command 0x%08x", command); > > + return -ENOTTY; > > + } > > + > > + /* > > + * Trying to avoid low memory issues when a device is > > + * suspended. > > + */ > > + current->flags |= PF_MEMALLOC; > > whoa, what's this doing here? > > > + /* Copy the parameters into kernel space. */ > > + param = copy_dev_ioctl(user); > > + > > + current->flags &= ~PF_MEMALLOC; > > + > > + 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; > > + > > + 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) { > > + err = -EINVAL; > > + fput(fp); > > + goto out; > > + } > > + } > > +cont: > > + err = fn(fp, sbi, param); > > + > > + if (fp) > > + fput(fp); > > +done: > > + if (!err && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE)) > > + err = -EFAULT; > > +out: > > + free_dev_ioctl(param); > > + return err; > > +} > > + > > > > ... > > > > diff -up /dev/null linux-2.6.25-rc2-mm1/include/linux/auto_dev-ioctl.h > > --- /dev/null 2008-02-22 18:55:57.149000956 +0900 > > +++ linux-2.6.25-rc2-mm1/include/linux/auto_dev-ioctl.h 2008-02-22 11:51:41.000000000 +0900 > > @@ -0,0 +1,114 @@ > > +/* > > + * linux/include/linux/auto_dev-ioctl.h > > + * > > + * Copyright 2008 Red Hat, Inc. All rights reserved. > > + * Copyright 2008 Ian Kent > > + * > > + * 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. > > + */ > > + > > +#ifndef _LINUX_AUTO_DEV_IOCTL_H > > +#define _LINUX_AUTO_DEV_IOCTL_H > > + > > +#include > > + > > +#define AUTOFS_DEV_IOCTL_VERSION_MAJOR 1 > > +#define AUTOFS_DEV_IOCTL_VERSION_MINOR 0 > > + > > +#define AUTOFS_DEVID_LEN 16 > > + > > +/* > > + * An ioctl interface for autofs mount point control. > > + */ > > + > > +/* > > + * All the ioctls use this structure. > > + * When sending a path size must account for the total length > > + * of the chunk of memory otherwise is is the size of the > > + * structure. > > + */ > > + > > +struct autofs_dev_ioctl { > > + __u32 ver_major; > > + __u32 ver_minor; > > + __u32 size; /* total size of data passed in > > + * including this struct */ > > + __s32 ioctlfd; /* automount command fd */ > > + > > + __u32 arg1; /* Command parameters */ > > + __u32 arg2; > > + > > + char path[0]; > > +}; > > + > > +static inline void init_autofs_dev_ioctl(struct autofs_dev_ioctl *in) > > +{ > > + in->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR; > > + in->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR; > > + in->size = sizeof(struct autofs_dev_ioctl); > > + in->ioctlfd = -1; > > + in->arg1 = 0; > > + in->arg2 = 0; > > + return; > > +} > > uninline.. > > > +/* > > + * If you change this make sure you make the corresponding change > > + * to autofs-dev-ioctl.c:lookup_ioctl() > > Can we do this automatically via preprocessor tricks, or whatever? > > > + */ > > +enum { > > + /* Get various version info */ > > + AUTOFS_DEV_IOCTL_VERSION_CMD = 0x71, > > + AUTOFS_DEV_IOCTL_PROTOVER_CMD, > > + AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD, > > + > > + /* Open mount ioctl fd */ > > + AUTOFS_DEV_IOCTL_OPENMOUNT_CMD, > > + > > + /* Close mount ioctl fd */ > > + AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD, > > + > > + /* Mount/expire status returns */ > > + AUTOFS_DEV_IOCTL_READY_CMD, > > + AUTOFS_DEV_IOCTL_FAIL_CMD, > > + > > + /* Activate/deactivate autofs mount */ > > + AUTOFS_DEV_IOCTL_SETPIPEFD_CMD, > > + AUTOFS_DEV_IOCTL_CATATONIC_CMD, > > + > > + /* Expiry timeout */ > > + AUTOFS_DEV_IOCTL_TIMEOUT_CMD, > > + > > + /* Get mount last requesting uid and gid */ > > + AUTOFS_DEV_IOCTL_REQUESTOR_CMD, > > + > > + /* Check for eligible expire candidates */ > > + AUTOFS_DEV_IOCTL_EXPIRE_CMD, > > + > > + /* Request busy status */ > > + AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD, > > + > > + /* Check if path is a mountpoint */ > > + AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD, > > +}; > > + > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/