diff options
Diffstat (limited to 'fs/autofs4')
| -rw-r--r-- | fs/autofs4/Kconfig | 20 | ||||
| -rw-r--r-- | fs/autofs4/Makefile | 7 | ||||
| -rw-r--r-- | fs/autofs4/autofs_i.h | 297 | ||||
| -rw-r--r-- | fs/autofs4/dev-ioctl.c | 757 | ||||
| -rw-r--r-- | fs/autofs4/expire.c | 526 | ||||
| -rw-r--r-- | fs/autofs4/init.c | 51 | ||||
| -rw-r--r-- | fs/autofs4/inode.c | 412 | ||||
| -rw-r--r-- | fs/autofs4/root.c | 1011 | ||||
| -rw-r--r-- | fs/autofs4/symlink.c | 25 | ||||
| -rw-r--r-- | fs/autofs4/waitq.c | 524 |
10 files changed, 3630 insertions, 0 deletions
diff --git a/fs/autofs4/Kconfig b/fs/autofs4/Kconfig new file mode 100644 index 00000000..1204d638 --- /dev/null +++ b/fs/autofs4/Kconfig @@ -0,0 +1,20 @@ +config AUTOFS4_FS + tristate "Kernel automounter version 4 support (also supports v3)" + help + The automounter is a tool to automatically mount remote file systems + on demand. This implementation is partially kernel-based to reduce + overhead in the already-mounted case; this is unlike the BSD + automounter (amd), which is a pure user space daemon. + + To use the automounter you need the user-space tools from + <ftp://ftp.kernel.org/pub/linux/daemons/autofs/v4/>; you also + want to answer Y to "NFS file system support", below. + + To compile this support as a module, choose M here: the module will be + called autofs4. You will need to add "alias autofs autofs4" to your + modules configuration file. + + If you are not a part of a fairly large, distributed network or + don't have a laptop which needs to dynamically reconfigure to the + local network, you probably do not need an automounter, and can say + N here. diff --git a/fs/autofs4/Makefile b/fs/autofs4/Makefile new file mode 100644 index 00000000..a811c1f7 --- /dev/null +++ b/fs/autofs4/Makefile @@ -0,0 +1,7 @@ +# +# Makefile for the linux autofs-filesystem routines. +# + +obj-$(CONFIG_AUTOFS4_FS) += autofs4.o + +autofs4-objs := init.o inode.o root.o symlink.o waitq.o expire.o dev-ioctl.o diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h new file mode 100644 index 00000000..3d283abf --- /dev/null +++ b/fs/autofs4/autofs_i.h @@ -0,0 +1,297 @@ +/* -*- c -*- ------------------------------------------------------------- * + * + * linux/fs/autofs/autofs_i.h + * + * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved + * Copyright 2005-2006 Ian Kent <raven@themaw.net> + * + * This file is part of the Linux kernel and is made available under + * the terms of the GNU General Public License, version 2, or at your + * option, any later version, incorporated herein by reference. + * + * ----------------------------------------------------------------------- */ + +/* Internal header file for autofs */ + +#include <linux/auto_fs4.h> +#include <linux/auto_dev-ioctl.h> +#include <linux/mutex.h> +#include <linux/list.h> + +/* This is the range of ioctl() numbers we claim as ours */ +#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY +#define AUTOFS_IOC_COUNT 32 + +#define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION) +#define AUTOFS_DEV_IOCTL_IOC_COUNT (AUTOFS_IOC_COUNT - 11) + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/time.h> +#include <linux/string.h> +#include <linux/wait.h> +#include <linux/sched.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <asm/current.h> +#include <asm/uaccess.h> + +/* #define DEBUG */ + +#ifdef DEBUG +#define DPRINTK(fmt, args...) \ +do { \ + printk(KERN_DEBUG "pid %d: %s: " fmt "\n", \ + current->pid, __func__, ##args); \ +} while (0) +#else +#define DPRINTK(fmt, args...) do {} while (0) +#endif + +#define AUTOFS_WARN(fmt, args...) \ +do { \ + printk(KERN_WARNING "pid %d: %s: " fmt "\n", \ + current->pid, __func__, ##args); \ +} while (0) + +#define AUTOFS_ERROR(fmt, args...) \ +do { \ + printk(KERN_ERR "pid %d: %s: " fmt "\n", \ + current->pid, __func__, ##args); \ +} while (0) + +/* 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 + flushed while the file exists. All name lookups are dealt with at the + dentry level, although the filesystem can interfere in the validation + process. Readdir is implemented by traversing the dentry lists. */ +struct autofs_info { + struct dentry *dentry; + struct inode *inode; + + int flags; + + struct completion expire_complete; + + struct list_head active; + int active_count; + + struct list_head expiring; + + struct autofs_sb_info *sbi; + unsigned long last_used; + atomic_t count; + + uid_t uid; + gid_t gid; + + mode_t mode; + size_t size; + + void (*free)(struct autofs_info *); + union { + const char *symlink; + } u; +}; + +#define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */ +#define AUTOFS_INF_MOUNTPOINT (1<<1) /* mountpoint status for direct expire */ +#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */ + +struct autofs_wait_queue { + wait_queue_head_t queue; + struct autofs_wait_queue *next; + autofs_wqt_t wait_queue_token; + /* We use the following to see what we are waiting for */ + struct qstr name; + u32 dev; + u64 ino; + uid_t uid; + gid_t gid; + pid_t pid; + pid_t tgid; + /* This is for status reporting upon return */ + int status; + unsigned int wait_ctr; +}; + +#define AUTOFS_SBI_MAGIC 0x6d4a556d + +struct autofs_sb_info { + u32 magic; + int pipefd; + struct file *pipe; + pid_t oz_pgrp; + int catatonic; + int version; + int sub_version; + int min_proto; + int max_proto; + unsigned long exp_timeout; + unsigned int type; + int reghost_enabled; + int needs_reghost; + struct super_block *sb; + struct mutex wq_mutex; + spinlock_t fs_lock; + struct autofs_wait_queue *queues; /* Wait queue pointer */ + spinlock_t lookup_lock; + struct list_head active_list; + struct list_head expiring_list; +}; + +static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb) +{ + return (struct autofs_sb_info *)(sb->s_fs_info); +} + +static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry) +{ + return (struct autofs_info *)(dentry->d_fsdata); +} + +/* autofs4_oz_mode(): do we see the man behind the curtain? (The + processes which do manipulations for us in user space sees the raw + filesystem without "magic".) */ + +static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) { + return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp; +} + +/* Does a dentry have some pending activity? */ +static inline int autofs4_ispending(struct dentry *dentry) +{ + struct autofs_info *inf = autofs4_dentry_ino(dentry); + + if (inf->flags & AUTOFS_INF_PENDING) + return 1; + + if (inf->flags & AUTOFS_INF_EXPIRING) + return 1; + + return 0; +} + +static inline void autofs4_copy_atime(struct file *src, struct file *dst) +{ + dst->f_path.dentry->d_inode->i_atime = + src->f_path.dentry->d_inode->i_atime; + return; +} + +struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *); +void autofs4_free_ino(struct autofs_info *); + +/* Expiration */ +int is_autofs4_dentry(struct dentry *); +int autofs4_expire_wait(struct dentry *dentry); +int autofs4_expire_run(struct super_block *, struct vfsmount *, + struct autofs_sb_info *, + struct autofs_packet_expire __user *); +int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt, + struct autofs_sb_info *sbi, int when); +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); + +/* Operations structures */ + +extern const struct inode_operations autofs4_symlink_inode_operations; +extern const struct inode_operations autofs4_dir_inode_operations; +extern const struct inode_operations autofs4_root_inode_operations; +extern const struct inode_operations autofs4_indirect_root_inode_operations; +extern const struct inode_operations autofs4_direct_root_inode_operations; +extern const struct file_operations autofs4_dir_operations; +extern const struct file_operations autofs4_root_operations; + +/* Initializing function */ + +int autofs4_fill_super(struct super_block *, void *, int); +struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode); + +/* Queue management functions */ + +int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify); +int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int); +void autofs4_catatonic_mode(struct autofs_sb_info *); + +static inline int autofs4_follow_mount(struct path *path) +{ + int res = 0; + + while (d_mountpoint(path->dentry)) { + int followed = follow_down(path); + if (!followed) + break; + res = 1; + } + return res; +} + +static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi) +{ + return new_encode_dev(sbi->sb->s_dev); +} + +static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi) +{ + return sbi->sb->s_root->d_inode->i_ino; +} + +static inline int simple_positive(struct dentry *dentry) +{ + return dentry->d_inode && !d_unhashed(dentry); +} + +static inline int __simple_empty(struct dentry *dentry) +{ + struct dentry *child; + int ret = 0; + + list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) + if (simple_positive(child)) + goto out; + ret = 1; +out: + return ret; +} + +static inline void autofs4_add_expiring(struct dentry *dentry) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + if (ino) { + spin_lock(&sbi->lookup_lock); + if (list_empty(&ino->expiring)) + list_add(&ino->expiring, &sbi->expiring_list); + spin_unlock(&sbi->lookup_lock); + } + return; +} + +static inline void autofs4_del_expiring(struct dentry *dentry) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + if (ino) { + spin_lock(&sbi->lookup_lock); + if (!list_empty(&ino->expiring)) + list_del_init(&ino->expiring); + spin_unlock(&sbi->lookup_lock); + } + return; +} + +void autofs4_dentry_release(struct dentry *); +extern void autofs4_kill_sb(struct super_block *); diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c new file mode 100644 index 00000000..ba4a38b9 --- /dev/null +++ b/fs/autofs4/dev-ioctl.c @@ -0,0 +1,757 @@ +/* + * Copyright 2008 Red Hat, Inc. All rights reserved. + * Copyright 2008 Ian Kent <raven@themaw.net> + * + * This file is part of the Linux kernel and is made available under + * the terms of the GNU General Public License, version 2, or at your + * option, any later version, incorporated herein by reference. + */ + +#include <linux/module.h> +#include <linux/vmalloc.h> +#include <linux/miscdevice.h> +#include <linux/init.h> +#include <linux/wait.h> +#include <linux/namei.h> +#include <linux/fcntl.h> +#include <linux/file.h> +#include <linux/fdtable.h> +#include <linux/sched.h> +#include <linux/compat.h> +#include <linux/syscalls.h> +#include <linux/magic.h> +#include <linux/dcache.h> +#include <linux/uaccess.h> +#include <linux/slab.h> + +#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_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, size_t size) +{ + if (memchr(str, 0, size)) + return 0; + return -EINVAL; +} + +/* + * Check that the user compiled against correct version of autofs + * misc device code. + * + * As well as checking the version compatibility this always copies + * the kernel interface version out. + */ +static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param) +{ + int err = 0; + + if ((AUTOFS_DEV_IOCTL_VERSION_MAJOR != param->ver_major) || + (AUTOFS_DEV_IOCTL_VERSION_MINOR < param->ver_minor)) { + AUTOFS_WARN("ioctl control interface version mismatch: " + "kernel(%u.%u), user(%u.%u), cmd(%d)", + AUTOFS_DEV_IOCTL_VERSION_MAJOR, + AUTOFS_DEV_IOCTL_VERSION_MINOR, + param->ver_major, param->ver_minor, cmd); + err = -EINVAL; + } + + /* Fill in the kernel version. */ + param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR; + param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR; + + return err; +} + +/* + * Copy parameter control struct, including a possible path allocated + * at the end of the struct. + */ +static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *in) +{ + struct autofs_dev_ioctl tmp; + + if (copy_from_user(&tmp, in, sizeof(tmp))) + return ERR_PTR(-EFAULT); + + if (tmp.size < sizeof(tmp)) + return ERR_PTR(-EINVAL); + + return memdup_user(in, tmp.size); +} + +static inline void free_dev_ioctl(struct autofs_dev_ioctl *param) +{ + kfree(param); + return; +} + +/* + * Check sanity of parameter control fields and if a path is present + * check that it is terminated and contains at least one "/". + */ +static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param) +{ + int err; + + err = check_dev_ioctl_version(cmd, param); + if (err) { + AUTOFS_WARN("invalid device control module version " + "supplied for cmd(0x%08x)", cmd); + goto out; + } + + if (param->size > sizeof(*param)) { + err = invalid_str(param->path, param->size - sizeof(*param)); + if (err) { + AUTOFS_WARN( + "path string terminator missing for cmd(0x%08x)", + cmd); + goto out; + } + + err = check_name(param->path); + if (err) { + AUTOFS_WARN("invalid path supplied for cmd(0x%08x)", + cmd); + goto out; + } + } + + err = 0; +out: + return err; +} + +/* + * 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) { + inode = f->f_path.dentry->d_inode; + sbi = autofs4_sbi(inode->i_sb); + } + return sbi; +} + +/* Return autofs module protocol version */ +static int autofs_dev_ioctl_protover(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + param->protover.version = sbi->version; + return 0; +} + +/* Return autofs module protocol sub version */ +static int autofs_dev_ioctl_protosubver(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + param->protosubver.sub_version = sbi->sub_version; + return 0; +} + +static int find_autofs_mount(const char *pathname, + struct path *res, + int test(struct path *path, void *data), + void *data) +{ + struct path path; + int err = kern_path(pathname, 0, &path); + if (err) + return err; + err = -ENOENT; + while (path.dentry == path.mnt->mnt_root) { + if (path.mnt->mnt_sb->s_magic == AUTOFS_SUPER_MAGIC) { + if (test(&path, data)) { + path_get(&path); + if (!err) /* already found some */ + path_put(res); + *res = path; + err = 0; + } + } + if (!follow_up(&path)) + break; + } + path_put(&path); + return err; +} + +static int test_by_dev(struct path *path, void *p) +{ + return path->mnt->mnt_sb->s_dev == *(dev_t *)p; +} + +static int test_by_type(struct path *path, void *p) +{ + struct autofs_info *ino = autofs4_dentry_ino(path->dentry); + return ino && ino->sbi->type & *(unsigned *)p; +} + +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); +} + + +/* + * Open a file descriptor on the autofs mount point corresponding + * to the given path and device number (aka. new_encode_dev(sb->s_dev)). + */ +static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid) +{ + int err, fd; + + fd = get_unused_fd(); + if (likely(fd >= 0)) { + struct file *filp; + struct path path; + + err = find_autofs_mount(name, &path, test_by_dev, &devid); + if (err) + goto out; + + /* + * Find autofs super block that has the device number + * corresponding to the autofs fs we want to open. + */ + + filp = dentry_open(path.dentry, path.mnt, O_RDONLY, + current_cred()); + if (IS_ERR(filp)) { + err = PTR_ERR(filp); + goto out; + } + + autofs_dev_ioctl_fd_install(fd, filp); + } + + return fd; + +out: + put_unused_fd(fd); + return err; +} + +/* Open a file descriptor on an autofs mount point */ +static int autofs_dev_ioctl_openmount(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + const char *path; + dev_t devid; + int err, fd; + + /* param->path has already been checked */ + if (!param->openmount.devid) + return -EINVAL; + + param->ioctlfd = -1; + + path = param->path; + devid = new_decode_dev(param->openmount.devid); + + err = 0; + fd = autofs_dev_ioctl_open_mountpoint(path, devid); + if (unlikely(fd < 0)) { + err = fd; + goto out; + } + + param->ioctlfd = fd; +out: + return err; +} + +/* Close file descriptor allocated above (user can also use close(2)). */ +static int autofs_dev_ioctl_closemount(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + return sys_close(param->ioctlfd); +} + +/* + * Send "ready" status for an existing wait (either a mount or an expire + * request). + */ +static int autofs_dev_ioctl_ready(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + autofs_wqt_t token; + + token = (autofs_wqt_t) param->ready.token; + return autofs4_wait_release(sbi, token, 0); +} + +/* + * Send "fail" status for an existing wait (either a mount or an expire + * request). + */ +static int autofs_dev_ioctl_fail(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + autofs_wqt_t token; + int status; + + token = (autofs_wqt_t) param->fail.token; + status = param->fail.status ? param->fail.status : -ENOENT; + return autofs4_wait_release(sbi, token, status); +} + +/* + * 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->setpipefd.pipefd == -1) + return -EINVAL; + + pipefd = param->setpipefd.pipefd; + + mutex_lock(&sbi->wq_mutex); + if (!sbi->catatonic) { + mutex_unlock(&sbi->wq_mutex); + 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: + mutex_unlock(&sbi->wq_mutex); + return err; +} + +/* + * Make the autofs mount point catatonic, no longer responsive to + * mount requests. Also closes the kernel pipe file descriptor. + */ +static int autofs_dev_ioctl_catatonic(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + autofs4_catatonic_mode(sbi); + return 0; +} + +/* Set the autofs mount timeout */ +static int autofs_dev_ioctl_timeout(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + unsigned long timeout; + + timeout = param->timeout.timeout; + param->timeout.timeout = sbi->exp_timeout / HZ; + sbi->exp_timeout = timeout * HZ; + return 0; +} + +/* + * 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 int autofs_dev_ioctl_requester(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + struct autofs_info *ino; + struct path path; + dev_t devid; + int err = -ENOENT; + + if (param->size <= sizeof(*param)) { + err = -EINVAL; + goto out; + } + + devid = sbi->sb->s_dev; + + param->requester.uid = param->requester.gid = -1; + + err = find_autofs_mount(param->path, &path, test_by_dev, &devid); + if (err) + goto out; + + ino = autofs4_dentry_ino(path.dentry); + if (ino) { + err = 0; + autofs4_expire_wait(path.dentry); + spin_lock(&sbi->fs_lock); + param->requester.uid = ino->uid; + param->requester.gid = ino->gid; + spin_unlock(&sbi->fs_lock); + } + path_put(&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 vfsmount *mnt; + int how; + + how = param->expire.how; + mnt = fp->f_path.mnt; + + return autofs4_do_expire_multi(sbi->sb, mnt, sbi, how); +} + +/* Check if autofs mount point is in use */ +static int autofs_dev_ioctl_askumount(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + param->askumount.may_umount = 0; + if (may_umount(fp->f_path.mnt)) + param->askumount.may_umount = 1; + return 0; +} + +/* + * Check if the given path is a mountpoint. + * + * If we are supplied with the file descriptor of an 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. In this case we return 1 if the + * path is a mount point and the super magic of the covering + * mount if there is one or 0 if it isn't a mountpoint. + * + * If we aren't supplied with a file descriptor then we + * lookup the nameidata of the path and check if it is the + * root of a mount. If a type is given we are looking for + * a particular autofs mount and if we don't find a match + * we return fail. If the located nameidata path is the + * root of a mount we return 1 along with the super magic + * of the mount or 0 otherwise. + * + * In both cases the the device number (as returned by + * new_encode_dev()) is also returned. + */ +static int autofs_dev_ioctl_ismountpoint(struct file *fp, + struct autofs_sb_info *sbi, + struct autofs_dev_ioctl *param) +{ + struct path path; + const char *name; + unsigned int type; + unsigned int devid, magic; + int err = -ENOENT; + + if (param->size <= sizeof(*param)) { + err = -EINVAL; + goto out; + } + + name = param->path; + type = param->ismountpoint.in.type; + + param->ismountpoint.out.devid = devid = 0; + param->ismountpoint.out.magic = magic = 0; + + if (!fp || param->ioctlfd == -1) { + if (autofs_type_any(type)) + err = kern_path(name, LOOKUP_FOLLOW, &path); + else + err = find_autofs_mount(name, &path, test_by_type, &type); + if (err) + goto out; + devid = new_encode_dev(path.mnt->mnt_sb->s_dev); + err = 0; + if (path.mnt->mnt_root == path.dentry) { + err = 1; + magic = path.mnt->mnt_sb->s_magic; + } + } else { + dev_t dev = sbi->sb->s_dev; + + err = find_autofs_mount(name, &path, test_by_dev, &dev); + if (err) + goto out; + + devid = new_encode_dev(dev); + + err = have_submounts(path.dentry); + + if (follow_down(&path)) + magic = path.mnt->mnt_sb->s_magic; + } + + param->ismountpoint.out.devid = devid; + param->ismountpoint.out.magic = magic; + path_put(&path); +out: + return err; +} + +/* + * 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_REQUESTER_CMD), + autofs_dev_ioctl_requester}, + {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} + }; + unsigned int idx = cmd_idx(cmd); + + 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_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 long autofs_dev_ioctl(struct file *file, uint command, ulong u) +{ + int err; + err = _autofs_dev_ioctl(command, (struct autofs_dev_ioctl __user *) u); + return (long) err; +} + +#ifdef CONFIG_COMPAT +static long autofs_dev_ioctl_compat(struct file *file, uint command, ulong u) +{ + return (long) autofs_dev_ioctl(file, command, (ulong) compat_ptr(u)); +} +#else +#define autofs_dev_ioctl_compat NULL +#endif + +static const struct file_operations _dev_ioctl_fops = { + .unlocked_ioctl = autofs_dev_ioctl, + .compat_ioctl = autofs_dev_ioctl_compat, + .owner = THIS_MODULE, +}; + +static struct miscdevice _autofs_dev_ioctl_misc = { + .minor = AUTOFS_MINOR, + .name = AUTOFS_DEVICE_NAME, + .fops = &_dev_ioctl_fops +}; + +MODULE_ALIAS_MISCDEV(AUTOFS_MINOR); +MODULE_ALIAS("devname:autofs"); + +/* Register/deregister misc character device */ +int autofs_dev_ioctl_init(void) +{ + int r; + + r = misc_register(&_autofs_dev_ioctl_misc); + if (r) { + AUTOFS_ERROR("misc_register failed for control device"); + return r; + } + + return 0; +} + +void autofs_dev_ioctl_exit(void) +{ + misc_deregister(&_autofs_dev_ioctl_misc); + return; +} + diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c new file mode 100644 index 00000000..a796c941 --- /dev/null +++ b/fs/autofs4/expire.c @@ -0,0 +1,526 @@ +/* -*- c -*- --------------------------------------------------------------- * + * + * linux/fs/autofs/expire.c + * + * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved + * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> + * Copyright 2001-2006 Ian Kent <raven@themaw.net> + * + * This file is part of the Linux kernel and is made available under + * the terms of the GNU General Public License, version 2, or at your + * option, any later version, incorporated herein by reference. + * + * ------------------------------------------------------------------------- */ + +#include "autofs_i.h" + +static unsigned long now; + +/* Check if a dentry can be expired */ +static inline int autofs4_can_expire(struct dentry *dentry, + unsigned long timeout, int do_now) +{ + struct autofs_info *ino = autofs4_dentry_ino(dentry); + + /* dentry in the process of being deleted */ + if (ino == NULL) + return 0; + + /* No point expiring a pending mount */ + if (ino->flags & AUTOFS_INF_PENDING) + return 0; + + if (!do_now) { + /* Too young to die */ + if (!timeout || time_after(ino->last_used + timeout, now)) + return 0; + + /* update last_used here :- + - obviously makes sense if it is in use now + - less obviously, prevents rapid-fire expire + attempts if expire fails the first time */ + ino->last_used = now; + } + return 1; +} + +/* Check a mount point for busyness */ +static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry) +{ + struct dentry *top = dentry; + struct path path = {.mnt = mnt, .dentry = dentry}; + int status = 1; + + DPRINTK("dentry %p %.*s", + dentry, (int)dentry->d_name.len, dentry->d_name.name); + + path_get(&path); + + if (!follow_down(&path)) + goto done; + + if (is_autofs4_dentry(path.dentry)) { + struct autofs_sb_info *sbi = autofs4_sbi(path.dentry->d_sb); + + /* This is an autofs submount, we can't expire it */ + if (autofs_type_indirect(sbi->type)) + goto done; + + /* + * Otherwise it's an offset mount and we need to check + * if we can umount its mount, if there is one. + */ + if (!d_mountpoint(path.dentry)) { + status = 0; + goto done; + } + } + + /* Update the expiry counter if fs is busy */ + if (!may_umount_tree(path.mnt)) { + struct autofs_info *ino = autofs4_dentry_ino(top); + ino->last_used = jiffies; + goto done; + } + + status = 0; +done: + DPRINTK("returning = %d", status); + path_put(&path); + return status; +} + +/* + * Calculate next entry in top down tree traversal. + * From next_mnt in namespace.c - elegant. + */ +static struct dentry *next_dentry(struct dentry *p, struct dentry *root) +{ + struct list_head *next = p->d_subdirs.next; + + if (next == &p->d_subdirs) { + while (1) { + if (p == root) + return NULL; + next = p->d_u.d_child.next; + if (next != &p->d_parent->d_subdirs) + break; + p = p->d_parent; + } + } + return list_entry(next, struct dentry, d_u.d_child); +} + +/* + * Check a direct mount point for busyness. + * Direct mounts have similar expiry semantics to tree mounts. + * The tree is not busy iff no mountpoints are busy and there are no + * autofs submounts. + */ +static int autofs4_direct_busy(struct vfsmount *mnt, + struct dentry *top, + unsigned long timeout, + int do_now) +{ + DPRINTK("top %p %.*s", + top, (int) top->d_name.len, top->d_name.name); + + /* If it's busy update the expiry counters */ + if (!may_umount_tree(mnt)) { + struct autofs_info *ino = autofs4_dentry_ino(top); + if (ino) + ino->last_used = jiffies; + return 1; + } + + /* Timeout of a direct mount is determined by its top dentry */ + if (!autofs4_can_expire(top, timeout, do_now)) + return 1; + + return 0; +} + +/* Check a directory tree of mount points for busyness + * The tree is not busy iff no mountpoints are busy + */ +static int autofs4_tree_busy(struct vfsmount *mnt, + struct dentry *top, + unsigned long timeout, + int do_now) +{ + struct autofs_info *top_ino = autofs4_dentry_ino(top); + struct dentry *p; + + DPRINTK("top %p %.*s", + top, (int)top->d_name.len, top->d_name.name); + + /* Negative dentry - give up */ + if (!simple_positive(top)) + return 1; + + spin_lock(&dcache_lock); + for (p = top; p; p = next_dentry(p, top)) { + /* Negative dentry - give up */ + if (!simple_positive(p)) + continue; + + DPRINTK("dentry %p %.*s", + p, (int) p->d_name.len, p->d_name.name); + + p = dget(p); + spin_unlock(&dcache_lock); + + /* + * Is someone visiting anywhere in the subtree ? + * If there's no mount we need to check the usage + * count for the autofs dentry. + * If the fs is busy update the expiry counter. + */ + if (d_mountpoint(p)) { + if (autofs4_mount_busy(mnt, p)) { + top_ino->last_used = jiffies; + dput(p); + return 1; + } + } else { + struct autofs_info *ino = autofs4_dentry_ino(p); + unsigned int ino_count = atomic_read(&ino->count); + + /* + * Clean stale dentries below that have not been + * invalidated after a mount fail during lookup + */ + d_invalidate(p); + + /* allow for dget above and top is already dgot */ + if (p == top) + ino_count += 2; + else + ino_count++; + + if (atomic_read(&p->d_count) > ino_count) { + top_ino->last_used = jiffies; + dput(p); + return 1; + } + } + dput(p); + spin_lock(&dcache_lock); + } + spin_unlock(&dcache_lock); + + /* Timeout of a tree mount is ultimately determined by its top dentry */ + if (!autofs4_can_expire(top, timeout, do_now)) + return 1; + + return 0; +} + +static struct dentry *autofs4_check_leaves(struct vfsmount *mnt, + struct dentry *parent, + unsigned long timeout, + int do_now) +{ + struct dentry *p; + + DPRINTK("parent %p %.*s", + parent, (int)parent->d_name.len, parent->d_name.name); + + spin_lock(&dcache_lock); + for (p = parent; p; p = next_dentry(p, parent)) { + /* Negative dentry - give up */ + if (!simple_positive(p)) + continue; + + DPRINTK("dentry %p %.*s", + p, (int) p->d_name.len, p->d_name.name); + + p = dget(p); + spin_unlock(&dcache_lock); + + if (d_mountpoint(p)) { + /* Can we umount this guy */ + if (autofs4_mount_busy(mnt, p)) + goto cont; + + /* Can we expire this guy */ + if (autofs4_can_expire(p, timeout, do_now)) + return p; + } +cont: + dput(p); + spin_lock(&dcache_lock); + } + spin_unlock(&dcache_lock); + return NULL; +} + +/* Check if we can expire a direct mount (possibly a tree) */ +struct dentry *autofs4_expire_direct(struct super_block *sb, + struct vfsmount *mnt, + struct autofs_sb_info *sbi, + int how) +{ + unsigned long timeout; + struct dentry *root = dget(sb->s_root); + int do_now = how & AUTOFS_EXP_IMMEDIATE; + + if (!root) + return NULL; + + now = jiffies; + timeout = sbi->exp_timeout; + + spin_lock(&sbi->fs_lock); + if (!autofs4_direct_busy(mnt, root, timeout, do_now)) { + struct autofs_info *ino = autofs4_dentry_ino(root); + if (d_mountpoint(root)) { + ino->flags |= AUTOFS_INF_MOUNTPOINT; + root->d_mounted--; + } + ino->flags |= AUTOFS_INF_EXPIRING; + init_completion(&ino->expire_complete); + spin_unlock(&sbi->fs_lock); + return root; + } + spin_unlock(&sbi->fs_lock); + dput(root); + + return NULL; +} + +/* + * Find an eligible tree to time-out + * A tree is eligible if :- + * - it is unused by any user process + * - it has been unused for exp_timeout time + */ +struct dentry *autofs4_expire_indirect(struct super_block *sb, + struct vfsmount *mnt, + struct autofs_sb_info *sbi, + int how) +{ + unsigned long timeout; + struct dentry *root = sb->s_root; + struct dentry *expired = NULL; + struct list_head *next; + int do_now = how & AUTOFS_EXP_IMMEDIATE; + int exp_leaves = how & AUTOFS_EXP_LEAVES; + struct autofs_info *ino; + unsigned int ino_count; + + if (!root) + return NULL; + + now = jiffies; + timeout = sbi->exp_timeout; + + spin_lock(&dcache_lock); + next = root->d_subdirs.next; + + /* On exit from the loop expire is set to a dgot dentry + * to expire or it's NULL */ + while ( next != &root->d_subdirs ) { + struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child); + + /* Negative dentry - give up */ + if (!simple_positive(dentry)) { + next = next->next; + continue; + } + + dentry = dget(dentry); + spin_unlock(&dcache_lock); + + spin_lock(&sbi->fs_lock); + ino = autofs4_dentry_ino(dentry); + + /* + * Case 1: (i) indirect mount or top level pseudo direct mount + * (autofs-4.1). + * (ii) indirect mount with offset mount, check the "/" + * offset (autofs-5.0+). + */ + if (d_mountpoint(dentry)) { + DPRINTK("checking mountpoint %p %.*s", + dentry, (int)dentry->d_name.len, dentry->d_name.name); + + /* Path walk currently on this dentry? */ + ino_count = atomic_read(&ino->count) + 2; + if (atomic_read(&dentry->d_count) > ino_count) + goto next; + + /* Can we umount this guy */ + if (autofs4_mount_busy(mnt, dentry)) + goto next; + + /* Can we expire this guy */ + if (autofs4_can_expire(dentry, timeout, do_now)) { + expired = dentry; + goto found; + } + goto next; + } + + if (simple_empty(dentry)) + goto next; + + /* Case 2: tree mount, expire iff entire tree is not busy */ + if (!exp_leaves) { + /* Path walk currently on this dentry? */ + ino_count = atomic_read(&ino->count) + 1; + if (atomic_read(&dentry->d_count) > ino_count) + goto next; + + if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) { + expired = dentry; + goto found; + } + /* + * Case 3: pseudo direct mount, expire individual leaves + * (autofs-4.1). + */ + } else { + /* Path walk currently on this dentry? */ + ino_count = atomic_read(&ino->count) + 1; + if (atomic_read(&dentry->d_count) > ino_count) + goto next; + + expired = autofs4_check_leaves(mnt, dentry, timeout, do_now); + if (expired) { + dput(dentry); + goto found; + } + } +next: + spin_unlock(&sbi->fs_lock); + dput(dentry); + spin_lock(&dcache_lock); + next = next->next; + } + spin_unlock(&dcache_lock); + return NULL; + +found: + DPRINTK("returning %p %.*s", + expired, (int)expired->d_name.len, expired->d_name.name); + ino = autofs4_dentry_ino(expired); + ino->flags |= AUTOFS_INF_EXPIRING; + init_completion(&ino->expire_complete); + spin_unlock(&sbi->fs_lock); + spin_lock(&dcache_lock); + list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child); + spin_unlock(&dcache_lock); + return expired; +} + +int autofs4_expire_wait(struct dentry *dentry) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + int status; + + /* Block on any pending expire */ + spin_lock(&sbi->fs_lock); + if (ino->flags & AUTOFS_INF_EXPIRING) { + spin_unlock(&sbi->fs_lock); + + DPRINTK("waiting for expire %p name=%.*s", + dentry, dentry->d_name.len, dentry->d_name.name); + + status = autofs4_wait(sbi, dentry, NFY_NONE); + wait_for_completion(&ino->expire_complete); + + DPRINTK("expire done status=%d", status); + + if (d_unhashed(dentry)) + return -EAGAIN; + + return status; + } + spin_unlock(&sbi->fs_lock); + + return 0; +} + +/* Perform an expiry operation */ +int autofs4_expire_run(struct super_block *sb, + struct vfsmount *mnt, + struct autofs_sb_info *sbi, + struct autofs_packet_expire __user *pkt_p) +{ + struct autofs_packet_expire pkt; + struct autofs_info *ino; + struct dentry *dentry; + int ret = 0; + + memset(&pkt,0,sizeof pkt); + + pkt.hdr.proto_version = sbi->version; + pkt.hdr.type = autofs_ptype_expire; + + if ((dentry = autofs4_expire_indirect(sb, mnt, sbi, 0)) == NULL) + return -EAGAIN; + + pkt.len = dentry->d_name.len; + memcpy(pkt.name, dentry->d_name.name, pkt.len); + pkt.name[pkt.len] = '\0'; + dput(dentry); + + if ( copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)) ) + ret = -EFAULT; + + spin_lock(&sbi->fs_lock); + ino = autofs4_dentry_ino(dentry); + ino->flags &= ~AUTOFS_INF_EXPIRING; + complete_all(&ino->expire_complete); + spin_unlock(&sbi->fs_lock); + + return ret; +} + +int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt, + struct autofs_sb_info *sbi, int when) +{ + struct dentry *dentry; + int ret = -EAGAIN; + + if (autofs_type_trigger(sbi->type)) + dentry = autofs4_expire_direct(sb, mnt, sbi, when); + else + dentry = autofs4_expire_indirect(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 */ + ret = autofs4_wait(sbi, dentry, NFY_EXPIRE); + + spin_lock(&sbi->fs_lock); + if (ino->flags & AUTOFS_INF_MOUNTPOINT) { + sb->s_root->d_mounted++; + ino->flags &= ~AUTOFS_INF_MOUNTPOINT; + } + ino->flags &= ~AUTOFS_INF_EXPIRING; + complete_all(&ino->expire_complete); + spin_unlock(&sbi->fs_lock); + dput(dentry); + } + + return ret; +} + +/* Call repeatedly until it returns -EAGAIN, meaning there's nothing + more to be done */ +int autofs4_expire_multi(struct super_block *sb, struct vfsmount *mnt, + struct autofs_sb_info *sbi, int __user *arg) +{ + int do_now = 0; + + if (arg && get_user(do_now, arg)) + return -EFAULT; + + return autofs4_do_expire_multi(sb, mnt, sbi, do_now); +} + diff --git a/fs/autofs4/init.c b/fs/autofs4/init.c new file mode 100644 index 00000000..9722e4bd --- /dev/null +++ b/fs/autofs4/init.c @@ -0,0 +1,51 @@ +/* -*- c -*- --------------------------------------------------------------- * + * + * linux/fs/autofs/init.c + * + * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved + * + * This file is part of the Linux kernel and is made available under + * the terms of the GNU General Public License, version 2, or at your + * option, any later version, incorporated herein by reference. + * + * ------------------------------------------------------------------------- */ + +#include <linux/module.h> +#include <linux/init.h> +#include "autofs_i.h" + +static int autofs_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data, struct vfsmount *mnt) +{ + return get_sb_nodev(fs_type, flags, data, autofs4_fill_super, mnt); +} + +static struct file_system_type autofs_fs_type = { + .owner = THIS_MODULE, + .name = "autofs", + .get_sb = autofs_get_sb, + .kill_sb = autofs4_kill_sb, +}; + +static int __init init_autofs4_fs(void) +{ + int err; + + err = register_filesystem(&autofs_fs_type); + if (err) + return err; + + autofs_dev_ioctl_init(); + + return err; +} + +static void __exit exit_autofs4_fs(void) +{ + autofs_dev_ioctl_exit(); + unregister_filesystem(&autofs_fs_type); +} + +module_init(init_autofs4_fs) +module_exit(exit_autofs4_fs) +MODULE_LICENSE("GPL"); diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c new file mode 100644 index 00000000..821b2b95 --- /dev/null +++ b/fs/autofs4/inode.c @@ -0,0 +1,412 @@ +/* -*- c -*- --------------------------------------------------------------- * + * + * linux/fs/autofs/inode.c + * + * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved + * Copyright 2005-2006 Ian Kent <raven@themaw.net> + * + * This file is part of the Linux kernel and is made available under + * the terms of the GNU General Public License, version 2, or at your + * option, any later version, incorporated herein by reference. + * + * ------------------------------------------------------------------------- */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/file.h> +#include <linux/seq_file.h> +#include <linux/pagemap.h> +#include <linux/parser.h> +#include <linux/bitops.h> +#include <linux/magic.h> +#include "autofs_i.h" +#include <linux/module.h> + +static void ino_lnkfree(struct autofs_info *ino) +{ + if (ino->u.symlink) { + kfree(ino->u.symlink); + ino->u.symlink = NULL; + } +} + +struct autofs_info *autofs4_init_ino(struct autofs_info *ino, + struct autofs_sb_info *sbi, mode_t mode) +{ + int reinit = 1; + + if (ino == NULL) { + reinit = 0; + ino = kmalloc(sizeof(*ino), GFP_KERNEL); + } + + if (ino == NULL) + return NULL; + + if (!reinit) { + ino->flags = 0; + ino->inode = NULL; + ino->dentry = NULL; + ino->size = 0; + INIT_LIST_HEAD(&ino->active); + ino->active_count = 0; + INIT_LIST_HEAD(&ino->expiring); + atomic_set(&ino->count, 0); + } + + ino->uid = 0; + ino->gid = 0; + ino->mode = mode; + ino->last_used = jiffies; + + ino->sbi = sbi; + + if (reinit && ino->free) + (ino->free)(ino); + + memset(&ino->u, 0, sizeof(ino->u)); + + ino->free = NULL; + + if (S_ISLNK(mode)) + ino->free = ino_lnkfree; + + return ino; +} + +void autofs4_free_ino(struct autofs_info *ino) +{ + struct autofs_info *p_ino; + + if (ino->dentry) { + ino->dentry->d_fsdata = NULL; + if (ino->dentry->d_inode) { + struct dentry *parent = ino->dentry->d_parent; + if (atomic_dec_and_test(&ino->count)) { + p_ino = autofs4_dentry_ino(parent); + if (p_ino && parent != ino->dentry) + atomic_dec(&p_ino->count); + } + dput(ino->dentry); + } + ino->dentry = NULL; + } + if (ino->free) + (ino->free)(ino); + kfree(ino); +} + +void autofs4_kill_sb(struct super_block *sb) +{ + struct autofs_sb_info *sbi = autofs4_sbi(sb); + + /* + * In the event of a failure in get_sb_nodev the superblock + * info is not present so nothing else has been setup, so + * just call kill_anon_super when we are called from + * deactivate_super. + */ + if (!sbi) + goto out_kill_sb; + + /* Free wait queues, close pipe */ + autofs4_catatonic_mode(sbi); + + sb->s_fs_info = NULL; + kfree(sbi); + +out_kill_sb: + DPRINTK("shutting down"); + kill_litter_super(sb); +} + +static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt) +{ + struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb); + struct inode *root_inode = mnt->mnt_sb->s_root->d_inode; + + if (!sbi) + return 0; + + seq_printf(m, ",fd=%d", sbi->pipefd); + if (root_inode->i_uid != 0) + seq_printf(m, ",uid=%u", root_inode->i_uid); + if (root_inode->i_gid != 0) + seq_printf(m, ",gid=%u", root_inode->i_gid); + seq_printf(m, ",pgrp=%d", sbi->oz_pgrp); + seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ); + seq_printf(m, ",minproto=%d", sbi->min_proto); + seq_printf(m, ",maxproto=%d", sbi->max_proto); + + if (autofs_type_offset(sbi->type)) + seq_printf(m, ",offset"); + else if (autofs_type_direct(sbi->type)) + seq_printf(m, ",direct"); + else + seq_printf(m, ",indirect"); + + return 0; +} + +static const struct super_operations autofs4_sops = { + .statfs = simple_statfs, + .show_options = autofs4_show_options, +}; + +enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto, + Opt_indirect, Opt_direct, Opt_offset}; + +static const match_table_t tokens = { + {Opt_fd, "fd=%u"}, + {Opt_uid, "uid=%u"}, + {Opt_gid, "gid=%u"}, + {Opt_pgrp, "pgrp=%u"}, + {Opt_minproto, "minproto=%u"}, + {Opt_maxproto, "maxproto=%u"}, + {Opt_indirect, "indirect"}, + {Opt_direct, "direct"}, + {Opt_offset, "offset"}, + {Opt_err, NULL} +}; + +static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, + pid_t *pgrp, unsigned int *type, int *minproto, int *maxproto) +{ + char *p; + substring_t args[MAX_OPT_ARGS]; + int option; + + *uid = current_uid(); + *gid = current_gid(); + *pgrp = task_pgrp_nr(current); + + *minproto = AUTOFS_MIN_PROTO_VERSION; + *maxproto = AUTOFS_MAX_PROTO_VERSION; + + *pipefd = -1; + + if (!options) + return 1; + + while ((p = strsep(&options, ",")) != NULL) { + int token; + if (!*p) + continue; + + token = match_token(p, tokens, args); + switch (token) { + case Opt_fd: + if (match_int(args, pipefd)) + return 1; + break; + case Opt_uid: + if (match_int(args, &option)) + return 1; + *uid = option; + break; + case Opt_gid: + if (match_int(args, &option)) + return 1; + *gid = option; + break; + case Opt_pgrp: + if (match_int(args, &option)) + return 1; + *pgrp = option; + break; + case Opt_minproto: + if (match_int(args, &option)) + return 1; + *minproto = option; + break; + case Opt_maxproto: + if (match_int(args, &option)) + return 1; + *maxproto = option; + break; + case Opt_indirect: + set_autofs_type_indirect(type); + break; + case Opt_direct: + set_autofs_type_direct(type); + break; + case Opt_offset: + set_autofs_type_offset(type); + break; + default: + return 1; + } + } + return (*pipefd < 0); +} + +static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi) +{ + struct autofs_info *ino; + + ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755); + if (!ino) + return NULL; + + return ino; +} + +static const struct dentry_operations autofs4_sb_dentry_operations = { + .d_release = autofs4_dentry_release, +}; + +int autofs4_fill_super(struct super_block *s, void *data, int silent) +{ + struct inode * root_inode; + struct dentry * root; + struct file * pipe; + int pipefd; + struct autofs_sb_info *sbi; + struct autofs_info *ino; + + sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); + if (!sbi) + goto fail_unlock; + DPRINTK("starting up, sbi = %p",sbi); + + s->s_fs_info = sbi; + sbi->magic = AUTOFS_SBI_MAGIC; + sbi->pipefd = -1; + sbi->pipe = NULL; + sbi->catatonic = 1; + sbi->exp_timeout = 0; + sbi->oz_pgrp = task_pgrp_nr(current); + sbi->sb = s; + sbi->version = 0; + sbi->sub_version = 0; + set_autofs_type_indirect(&sbi->type); + sbi->min_proto = 0; + sbi->max_proto = 0; + mutex_init(&sbi->wq_mutex); + spin_lock_init(&sbi->fs_lock); + sbi->queues = NULL; + spin_lock_init(&sbi->lookup_lock); + INIT_LIST_HEAD(&sbi->active_list); + INIT_LIST_HEAD(&sbi->expiring_list); + s->s_blocksize = 1024; + s->s_blocksize_bits = 10; + s->s_magic = AUTOFS_SUPER_MAGIC; + s->s_op = &autofs4_sops; + s->s_time_gran = 1; + + /* + * Get the root inode and dentry, but defer checking for errors. + */ + ino = autofs4_mkroot(sbi); + if (!ino) + goto fail_free; + root_inode = autofs4_get_inode(s, ino); + if (!root_inode) + goto fail_ino; + + root = d_alloc_root(root_inode); + if (!root) + goto fail_iput; + pipe = NULL; + + root->d_op = &autofs4_sb_dentry_operations; + root->d_fsdata = ino; + + /* Can this call block? */ + if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid, + &sbi->oz_pgrp, &sbi->type, &sbi->min_proto, + &sbi->max_proto)) { + printk("autofs: called with bogus options\n"); + goto fail_dput; + } + + root_inode->i_fop = &autofs4_root_operations; + root_inode->i_op = autofs_type_trigger(sbi->type) ? + &autofs4_direct_root_inode_operations : + &autofs4_indirect_root_inode_operations; + + /* Couldn't this be tested earlier? */ + if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION || + sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) { + printk("autofs: kernel does not match daemon version " + "daemon (%d, %d) kernel (%d, %d)\n", + sbi->min_proto, sbi->max_proto, + AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION); + goto fail_dput; + } + + /* Establish highest kernel protocol version */ + if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION) + sbi->version = AUTOFS_MAX_PROTO_VERSION; + else + sbi->version = sbi->max_proto; + sbi->sub_version = AUTOFS_PROTO_SUBVERSION; + + DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp); + pipe = fget(pipefd); + + if (!pipe) { + printk("autofs: could not open pipe file descriptor\n"); + goto fail_dput; + } + if (!pipe->f_op || !pipe->f_op->write) + goto fail_fput; + sbi->pipe = pipe; + sbi->pipefd = pipefd; + sbi->catatonic = 0; + + /* + * Success! Install the root dentry now to indicate completion. + */ + s->s_root = root; + return 0; + + /* + * Failure ... clean up. + */ +fail_fput: + printk("autofs: pipe file descriptor does not contain proper ops\n"); + fput(pipe); + /* fall through */ +fail_dput: + dput(root); + goto fail_free; +fail_iput: + printk("autofs: get root dentry failed\n"); + iput(root_inode); +fail_ino: + kfree(ino); +fail_free: + kfree(sbi); + s->s_fs_info = NULL; +fail_unlock: + return -EINVAL; +} + +struct inode *autofs4_get_inode(struct super_block *sb, + struct autofs_info *inf) +{ + struct inode *inode = new_inode(sb); + + if (inode == NULL) + return NULL; + + inf->inode = inode; + inode->i_mode = inf->mode; + if (sb->s_root) { + inode->i_uid = sb->s_root->d_inode->i_uid; + inode->i_gid = sb->s_root->d_inode->i_gid; + } + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + + if (S_ISDIR(inf->mode)) { + inode->i_nlink = 2; + inode->i_op = &autofs4_dir_inode_operations; + inode->i_fop = &autofs4_dir_operations; + } else if (S_ISLNK(inf->mode)) { + inode->i_size = inf->size; + inode->i_op = &autofs4_symlink_inode_operations; + } + + return inode; +} diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c new file mode 100644 index 00000000..cb1bd38d --- /dev/null +++ b/fs/autofs4/root.c @@ -0,0 +1,1011 @@ +/* -*- c -*- --------------------------------------------------------------- * + * + * linux/fs/autofs/root.c + * + * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved + * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> + * Copyright 2001-2006 Ian Kent <raven@themaw.net> + * + * This file is part of the Linux kernel and is made available under + * the terms of the GNU General Public License, version 2, or at your + * option, any later version, incorporated herein by reference. + * + * ------------------------------------------------------------------------- */ + +#include <linux/capability.h> +#include <linux/errno.h> +#include <linux/stat.h> +#include <linux/slab.h> +#include <linux/param.h> +#include <linux/time.h> +#include <linux/compat.h> +#include <linux/smp_lock.h> + +#include "autofs_i.h" + +static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); +static int autofs4_dir_unlink(struct inode *,struct dentry *); +static int autofs4_dir_rmdir(struct inode *,struct dentry *); +static int autofs4_dir_mkdir(struct inode *,struct dentry *,int); +static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long); +static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long); +static int autofs4_dir_open(struct inode *inode, struct file *file); +static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *); +static void *autofs4_follow_link(struct dentry *, struct nameidata *); + +#define TRIGGER_FLAGS (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) +#define TRIGGER_INTENTS (LOOKUP_OPEN | LOOKUP_CREATE) + +const struct file_operations autofs4_root_operations = { + .open = dcache_dir_open, + .release = dcache_dir_close, + .read = generic_read_dir, + .readdir = dcache_readdir, + .llseek = dcache_dir_lseek, + .unlocked_ioctl = autofs4_root_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = autofs4_root_compat_ioctl, +#endif +}; + +const struct file_operations autofs4_dir_operations = { + .open = autofs4_dir_open, + .release = dcache_dir_close, + .read = generic_read_dir, + .readdir = dcache_readdir, + .llseek = dcache_dir_lseek, +}; + +const struct inode_operations autofs4_indirect_root_inode_operations = { + .lookup = autofs4_lookup, + .unlink = autofs4_dir_unlink, + .symlink = autofs4_dir_symlink, + .mkdir = autofs4_dir_mkdir, + .rmdir = autofs4_dir_rmdir, +}; + +const struct inode_operations autofs4_direct_root_inode_operations = { + .lookup = autofs4_lookup, + .unlink = autofs4_dir_unlink, + .mkdir = autofs4_dir_mkdir, + .rmdir = autofs4_dir_rmdir, + .follow_link = autofs4_follow_link, +}; + +const struct inode_operations autofs4_dir_inode_operations = { + .lookup = autofs4_lookup, + .unlink = autofs4_dir_unlink, + .symlink = autofs4_dir_symlink, + .mkdir = autofs4_dir_mkdir, + .rmdir = autofs4_dir_rmdir, +}; + +static void autofs4_add_active(struct dentry *dentry) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + if (ino) { + spin_lock(&sbi->lookup_lock); + if (!ino->active_count) { + if (list_empty(&ino->active)) + list_add(&ino->active, &sbi->active_list); + } + ino->active_count++; + spin_unlock(&sbi->lookup_lock); + } + return; +} + +static void autofs4_del_active(struct dentry *dentry) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + if (ino) { + spin_lock(&sbi->lookup_lock); + ino->active_count--; + if (!ino->active_count) { + if (!list_empty(&ino->active)) + list_del_init(&ino->active); + } + spin_unlock(&sbi->lookup_lock); + } + return; +} + +static unsigned int autofs4_need_mount(unsigned int flags) +{ + unsigned int res = 0; + if (flags & (TRIGGER_FLAGS | TRIGGER_INTENTS)) + res = 1; + return res; +} + +static int autofs4_dir_open(struct inode *inode, struct file *file) +{ + struct dentry *dentry = file->f_path.dentry; + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + + DPRINTK("file=%p dentry=%p %.*s", + file, dentry, dentry->d_name.len, dentry->d_name.name); + + if (autofs4_oz_mode(sbi)) + goto out; + + /* + * An empty directory in an autofs file system is always a + * mount point. The daemon must have failed to mount this + * during lookup so it doesn't exist. This can happen, for + * example, if user space returns an incorrect status for a + * mount request. Otherwise we're doing a readdir on the + * autofs file system so just let the libfs routines handle + * it. + */ + spin_lock(&dcache_lock); + if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { + spin_unlock(&dcache_lock); + return -ENOENT; + } + spin_unlock(&dcache_lock); + +out: + return dcache_dir_open(inode, file); +} + +static int try_to_fill_dentry(struct dentry *dentry, int flags) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + int status; + + 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); + + /* Turn this into a real negative dentry? */ + if (status == -ENOENT) { + spin_lock(&sbi->fs_lock); + ino->flags &= ~AUTOFS_INF_PENDING; + spin_unlock(&sbi->fs_lock); + return status; + } else if (status) { + /* Return a negative dentry, but leave it "pending" */ + return status; + } + /* Trigger mount for path component or follow link */ + } else if (ino->flags & AUTOFS_INF_PENDING || + autofs4_need_mount(flags)) { + DPRINTK("waiting for mount name=%.*s", + dentry->d_name.len, dentry->d_name.name); + + spin_lock(&sbi->fs_lock); + ino->flags |= AUTOFS_INF_PENDING; + spin_unlock(&sbi->fs_lock); + status = autofs4_wait(sbi, dentry, NFY_MOUNT); + + DPRINTK("mount done status=%d", status); + + if (status) { + spin_lock(&sbi->fs_lock); + ino->flags &= ~AUTOFS_INF_PENDING; + spin_unlock(&sbi->fs_lock); + return status; + } + } + + /* Initialize expiry counter after successful mount */ + ino->last_used = jiffies; + + spin_lock(&sbi->fs_lock); + ino->flags &= ~AUTOFS_INF_PENDING; + spin_unlock(&sbi->fs_lock); + + return 0; +} + +/* For autofs direct mounts the follow link triggers the mount */ +static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + int oz_mode = autofs4_oz_mode(sbi); + unsigned int lookup_type; + int status; + + DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d", + dentry, dentry->d_name.len, dentry->d_name.name, oz_mode, + nd->flags); + /* + * For an expire of a covered direct or offset mount we need + * to break out of follow_down() at the autofs mount trigger + * (d_mounted--), so we can see the expiring flag, and manage + * the blocking and following here until the expire is completed. + */ + if (oz_mode) { + spin_lock(&sbi->fs_lock); + if (ino->flags & AUTOFS_INF_EXPIRING) { + spin_unlock(&sbi->fs_lock); + /* Follow down to our covering mount. */ + if (!follow_down(&nd->path)) + goto done; + goto follow; + } + spin_unlock(&sbi->fs_lock); + goto done; + } + + /* If an expire request is pending everyone must wait. */ + autofs4_expire_wait(dentry); + + /* We trigger a mount for almost all flags */ + lookup_type = autofs4_need_mount(nd->flags); + spin_lock(&sbi->fs_lock); + spin_lock(&dcache_lock); + if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) { + spin_unlock(&dcache_lock); + spin_unlock(&sbi->fs_lock); + goto follow; + } + + /* + * If the dentry contains directories then it is an autofs + * multi-mount with no root mount offset. So don't try to + * mount it again. + */ + if (ino->flags & AUTOFS_INF_PENDING || + (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) { + spin_unlock(&dcache_lock); + spin_unlock(&sbi->fs_lock); + + status = try_to_fill_dentry(dentry, nd->flags); + if (status) + goto out_error; + + goto follow; + } + spin_unlock(&dcache_lock); + spin_unlock(&sbi->fs_lock); +follow: + /* + * If there is no root mount it must be an autofs + * multi-mount with no root offset so we don't need + * to follow it. + */ + if (d_mountpoint(dentry)) { + if (!autofs4_follow_mount(&nd->path)) { + status = -ENOENT; + goto out_error; + } + } + +done: + return NULL; + +out_error: + path_put(&nd->path); + return ERR_PTR(status); +} + +/* + * 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 */ + spin_lock(&sbi->fs_lock); + if (autofs4_ispending(dentry)) { + /* The daemon never causes a mount to trigger */ + spin_unlock(&sbi->fs_lock); + + if (oz_mode) + return 1; + + /* + * If the directory has gone away due to an expire + * we have been called as ->d_revalidate() and so + * we need to return false and proceed to ->lookup(). + */ + if (autofs4_expire_wait(dentry) == -EAGAIN) + return 0; + + /* + * A zero status is success otherwise we have a + * negative error code. + */ + status = try_to_fill_dentry(dentry, flags); + if (status == 0) + return 1; + + return status; + } + spin_unlock(&sbi->fs_lock); + + /* Negative dentry.. invalidate if "old" */ + if (dentry->d_inode == NULL) + return 0; + + /* 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); + + /* The daemon never causes a mount to trigger */ + if (oz_mode) + return 1; + + /* + * A zero status is success otherwise we have a + * negative error code. + */ + status = try_to_fill_dentry(dentry, flags); + if (status == 0) + return 1; + + return status; + } + spin_unlock(&dcache_lock); + + return 1; +} + +void autofs4_dentry_release(struct dentry *de) +{ + struct autofs_info *inf; + + DPRINTK("releasing %p", de); + + inf = autofs4_dentry_ino(de); + de->d_fsdata = NULL; + + if (inf) { + struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); + + if (sbi) { + spin_lock(&sbi->lookup_lock); + if (!list_empty(&inf->active)) + list_del(&inf->active); + if (!list_empty(&inf->expiring)) + list_del(&inf->expiring); + spin_unlock(&sbi->lookup_lock); + } + + inf->dentry = NULL; + inf->inode = NULL; + + autofs4_free_ino(inf); + } +} + +/* For dentries of directories in the root dir */ +static const struct dentry_operations autofs4_root_dentry_operations = { + .d_revalidate = autofs4_revalidate, + .d_release = autofs4_dentry_release, +}; + +/* For other dentries */ +static const struct dentry_operations autofs4_dentry_operations = { + .d_revalidate = autofs4_revalidate, + .d_release = autofs4_dentry_release, +}; + +static struct dentry *autofs4_lookup_active(struct dentry *dentry) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct dentry *parent = dentry->d_parent; + struct qstr *name = &dentry->d_name; + unsigned int len = name->len; + unsigned int hash = name->hash; + const unsigned char *str = name->name; + struct list_head *p, *head; + + spin_lock(&dcache_lock); + spin_lock(&sbi->lookup_lock); + head = &sbi->active_list; + list_for_each(p, head) { + struct autofs_info *ino; + struct dentry *active; + struct qstr *qstr; + + ino = list_entry(p, struct autofs_info, active); + active = ino->dentry; + + spin_lock(&active->d_lock); + + /* Already gone? */ + if (atomic_read(&active->d_count) == 0) + goto next; + + qstr = &active->d_name; + + if (active->d_name.hash != hash) + goto next; + if (active->d_parent != parent) + goto next; + + if (qstr->len != len) + goto next; + if (memcmp(qstr->name, str, len)) + goto next; + + if (d_unhashed(active)) { + dget(active); + spin_unlock(&active->d_lock); + spin_unlock(&sbi->lookup_lock); + spin_unlock(&dcache_lock); + return active; + } +next: + spin_unlock(&active->d_lock); + } + spin_unlock(&sbi->lookup_lock); + spin_unlock(&dcache_lock); + + return NULL; +} + +static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct dentry *parent = dentry->d_parent; + struct qstr *name = &dentry->d_name; + unsigned int len = name->len; + unsigned int hash = name->hash; + const unsigned char *str = name->name; + struct list_head *p, *head; + + spin_lock(&dcache_lock); + spin_lock(&sbi->lookup_lock); + head = &sbi->expiring_list; + list_for_each(p, head) { + struct autofs_info *ino; + struct dentry *expiring; + struct qstr *qstr; + + ino = list_entry(p, struct autofs_info, expiring); + expiring = ino->dentry; + + spin_lock(&expiring->d_lock); + + /* Bad luck, we've already been dentry_iput */ + if (!expiring->d_inode) + goto next; + + qstr = &expiring->d_name; + + if (expiring->d_name.hash != hash) + goto next; + if (expiring->d_parent != parent) + goto next; + + if (qstr->len != len) + goto next; + if (memcmp(qstr->name, str, len)) + goto next; + + if (d_unhashed(expiring)) { + dget(expiring); + spin_unlock(&expiring->d_lock); + spin_unlock(&sbi->lookup_lock); + spin_unlock(&dcache_lock); + return expiring; + } +next: + spin_unlock(&expiring->d_lock); + } + spin_unlock(&sbi->lookup_lock); + spin_unlock(&dcache_lock); + + return NULL; +} + +/* Lookups in the root directory */ +static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) +{ + struct autofs_sb_info *sbi; + struct autofs_info *ino; + struct dentry *expiring, *active; + int oz_mode; + + DPRINTK("name = %.*s", + dentry->d_name.len, dentry->d_name.name); + + /* File name too long to exist */ + if (dentry->d_name.len > NAME_MAX) + return ERR_PTR(-ENAMETOOLONG); + + sbi = autofs4_sbi(dir->i_sb); + oz_mode = autofs4_oz_mode(sbi); + + DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", + current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); + + active = autofs4_lookup_active(dentry); + if (active) { + dentry = active; + ino = autofs4_dentry_ino(dentry); + } 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; + + autofs4_add_active(dentry); + + d_instantiate(dentry, NULL); + } + + if (!oz_mode) { + mutex_unlock(&dir->i_mutex); + expiring = autofs4_lookup_expiring(dentry); + if (expiring) { + /* + * If we are racing with expire the request might not + * be quite complete but the directory has been removed + * so it must have been successful, so just wait for it. + */ + autofs4_expire_wait(expiring); + autofs4_del_expiring(expiring); + dput(expiring); + } + + spin_lock(&sbi->fs_lock); + ino->flags |= AUTOFS_INF_PENDING; + spin_unlock(&sbi->fs_lock); + if (dentry->d_op && dentry->d_op->d_revalidate) + (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 (ino->flags & AUTOFS_INF_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 (active) + dput(active); + return ERR_PTR(-ERESTARTNOINTR); + } + } + if (!oz_mode) { + spin_lock(&sbi->fs_lock); + ino->flags &= ~AUTOFS_INF_PENDING; + spin_unlock(&sbi->fs_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 (active) + dput(active); + + return dentry; + } + + if (active) + return active; + + 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; + + autofs4_del_active(dentry); + + 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); + autofs4_add_expiring(dentry); + 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; + } + autofs4_add_expiring(dentry); + 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; + + autofs4_del_active(dentry); + + 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 */ +#ifdef CONFIG_COMPAT +static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, + compat_ulong_t __user *p) +{ + int rv; + unsigned long ntimeout; + + if ((rv = get_user(ntimeout, p)) || + (rv = put_user(sbi->exp_timeout/HZ, p))) + return rv; + + if (ntimeout > UINT_MAX/HZ) + sbi->exp_timeout = 0; + else + sbi->exp_timeout = ntimeout * HZ; + + return 0; +} +#endif + +static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, + unsigned long __user *p) +{ + int rv; + unsigned long ntimeout; + + if ((rv = get_user(ntimeout, p)) || + (rv = put_user(sbi->exp_timeout/HZ, p))) + return rv; + + if (ntimeout > ULONG_MAX/HZ) + sbi->exp_timeout = 0; + else + sbi->exp_timeout = ntimeout * HZ; + + return 0; +} + +/* Return protocol version */ +static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) +{ + return put_user(sbi->version, p); +} + +/* Return protocol sub version */ +static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) +{ + return put_user(sbi->sub_version, p); +} + +/* +* Tells the daemon whether it can umount the autofs mount. +*/ +static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) +{ + int status = 0; + + if (may_umount(mnt)) + status = 1; + + DPRINTK("returning %d", status); + + status = put_user(status, p); + + return status; +} + +/* Identify autofs4_dentries - this is so we can tell if there's + an extra dentry refcount or not. We only hold a refcount on the + dentry if its non-negative (ie, d_inode != NULL) +*/ +int is_autofs4_dentry(struct dentry *dentry) +{ + return dentry && dentry->d_inode && + (dentry->d_op == &autofs4_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_unlocked(struct inode *inode, struct file *filp, + unsigned int cmd, unsigned long arg) +{ + struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); + void __user *p = (void __user *)arg; + + DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", + cmd,arg,sbi,task_pgrp_nr(current)); + + if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || + _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) + return -ENOTTY; + + if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + switch(cmd) { + case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ + return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); + case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ + return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); + case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ + autofs4_catatonic_mode(sbi); + return 0; + case AUTOFS_IOC_PROTOVER: /* Get protocol version */ + return autofs4_get_protover(sbi, p); + case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ + return autofs4_get_protosubver(sbi, p); + case AUTOFS_IOC_SETTIMEOUT: + return autofs4_get_set_timeout(sbi, p); +#ifdef CONFIG_COMPAT + case AUTOFS_IOC_SETTIMEOUT32: + return autofs4_compat_get_set_timeout(sbi, p); +#endif + + case AUTOFS_IOC_ASKUMOUNT: + return autofs4_ask_umount(filp->f_path.mnt, p); + + /* return a single thing to expire */ + case AUTOFS_IOC_EXPIRE: + return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); + /* same as above, but can send multiple expires through pipe */ + case AUTOFS_IOC_EXPIRE_MULTI: + return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); + + default: + return -ENOSYS; + } +} + +static long autofs4_root_ioctl(struct file *filp, + unsigned int cmd, unsigned long arg) +{ + long ret; + struct inode *inode = filp->f_dentry->d_inode; + + lock_kernel(); + ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); + unlock_kernel(); + + return ret; +} + +#ifdef CONFIG_COMPAT +static long autofs4_root_compat_ioctl(struct file *filp, + unsigned int cmd, unsigned long arg) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + int ret; + + lock_kernel(); + if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) + ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); + else + ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, + (unsigned long)compat_ptr(arg)); + unlock_kernel(); + + return ret; +} +#endif diff --git a/fs/autofs4/symlink.c b/fs/autofs4/symlink.c new file mode 100644 index 00000000..b4ea8293 --- /dev/null +++ b/fs/autofs4/symlink.c @@ -0,0 +1,25 @@ +/* -*- c -*- --------------------------------------------------------------- * + * + * linux/fs/autofs/symlink.c + * + * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved + * + * 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 "autofs_i.h" + +static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + struct autofs_info *ino = autofs4_dentry_ino(dentry); + nd_set_link(nd, (char *)ino->u.symlink); + return NULL; +} + +const struct inode_operations autofs4_symlink_inode_operations = { + .readlink = generic_readlink, + .follow_link = autofs4_follow_link +}; diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c new file mode 100644 index 00000000..23413753 --- /dev/null +++ b/fs/autofs4/waitq.c @@ -0,0 +1,524 @@ +/* -*- c -*- --------------------------------------------------------------- * + * + * linux/fs/autofs/waitq.c + * + * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved + * Copyright 2001-2006 Ian Kent <raven@themaw.net> + * + * This file is part of the Linux kernel and is made available under + * the terms of the GNU General Public License, version 2, or at your + * option, any later version, incorporated herein by reference. + * + * ------------------------------------------------------------------------- */ + +#include <linux/slab.h> +#include <linux/time.h> +#include <linux/signal.h> +#include <linux/file.h> +#include "autofs_i.h" + +/* We make this a static variable rather than a part of the superblock; it + is better if we don't reassign numbers easily even across filesystems */ +static autofs_wqt_t autofs4_next_wait_queue = 1; + +/* These are the signals we allow interrupting a pending mount */ +#define SHUTDOWN_SIGS (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGQUIT)) + +void autofs4_catatonic_mode(struct autofs_sb_info *sbi) +{ + struct autofs_wait_queue *wq, *nwq; + + mutex_lock(&sbi->wq_mutex); + if (sbi->catatonic) { + mutex_unlock(&sbi->wq_mutex); + return; + } + + DPRINTK("entering catatonic mode"); + + sbi->catatonic = 1; + wq = sbi->queues; + sbi->queues = NULL; /* Erase all wait queues */ + while (wq) { + nwq = wq->next; + wq->status = -ENOENT; /* Magic is gone - report failure */ + if (wq->name.name) { + kfree(wq->name.name); + wq->name.name = NULL; + } + wq->wait_ctr--; + wake_up_interruptible(&wq->queue); + wq = nwq; + } + fput(sbi->pipe); /* Close the pipe */ + sbi->pipe = NULL; + sbi->pipefd = -1; + mutex_unlock(&sbi->wq_mutex); +} + +static int autofs4_write(struct file *file, const void *addr, int bytes) +{ + unsigned long sigpipe, flags; + mm_segment_t fs; + const char *data = (const char *)addr; + ssize_t wr = 0; + + /** WARNING: this is not safe for writing more than PIPE_BUF bytes! **/ + + sigpipe = sigismember(¤t->pending.signal, SIGPIPE); + + /* Save pointer to user space and point back to kernel space */ + fs = get_fs(); + set_fs(KERNEL_DS); + + while (bytes && + (wr = file->f_op->write(file,data,bytes,&file->f_pos)) > 0) { + data += wr; + bytes -= wr; + } + + set_fs(fs); + + /* Keep the currently executing process from receiving a + SIGPIPE unless it was already supposed to get one */ + if (wr == -EPIPE && !sigpipe) { + spin_lock_irqsave(¤t->sighand->siglock, flags); + sigdelset(¤t->pending.signal, SIGPIPE); + recalc_sigpending(); + spin_unlock_irqrestore(¤t->sighand->siglock, flags); + } + + return (bytes > 0); +} + +static void autofs4_notify_daemon(struct autofs_sb_info *sbi, + struct autofs_wait_queue *wq, + int type) +{ + union { + struct autofs_packet_hdr hdr; + union autofs_packet_union v4_pkt; + union autofs_v5_packet_union v5_pkt; + } pkt; + struct file *pipe = NULL; + size_t pktsz; + + DPRINTK("wait id = 0x%08lx, name = %.*s, type=%d", + wq->wait_queue_token, wq->name.len, wq->name.name, type); + + memset(&pkt,0,sizeof pkt); /* For security reasons */ + + pkt.hdr.proto_version = sbi->version; + pkt.hdr.type = type; + switch (type) { + /* Kernel protocol v4 missing and expire packets */ + case autofs_ptype_missing: + { + struct autofs_packet_missing *mp = &pkt.v4_pkt.missing; + + pktsz = sizeof(*mp); + + mp->wait_queue_token = wq->wait_queue_token; + mp->len = wq->name.len; + memcpy(mp->name, wq->name.name, wq->name.len); + mp->name[wq->name.len] = '\0'; + break; + } + case autofs_ptype_expire_multi: + { + struct autofs_packet_expire_multi *ep = &pkt.v4_pkt.expire_multi; + + pktsz = sizeof(*ep); + + ep->wait_queue_token = wq->wait_queue_token; + ep->len = wq->name.len; + memcpy(ep->name, wq->name.name, wq->name.len); + ep->name[wq->name.len] = '\0'; + break; + } + /* + * Kernel protocol v5 packet for handling indirect and direct + * mount missing and expire requests + */ + case autofs_ptype_missing_indirect: + case autofs_ptype_expire_indirect: + case autofs_ptype_missing_direct: + case autofs_ptype_expire_direct: + { + struct autofs_v5_packet *packet = &pkt.v5_pkt.v5_packet; + + pktsz = sizeof(*packet); + + packet->wait_queue_token = wq->wait_queue_token; + packet->len = wq->name.len; + memcpy(packet->name, wq->name.name, wq->name.len); + packet->name[wq->name.len] = '\0'; + packet->dev = wq->dev; + packet->ino = wq->ino; + packet->uid = wq->uid; + packet->gid = wq->gid; + packet->pid = wq->pid; + packet->tgid = wq->tgid; + break; + } + default: + printk("autofs4_notify_daemon: bad type %d!\n", type); + return; + } + + /* Check if we have become catatonic */ + mutex_lock(&sbi->wq_mutex); + if (!sbi->catatonic) { + pipe = sbi->pipe; + get_file(pipe); + } + mutex_unlock(&sbi->wq_mutex); + + if (pipe) { + if (autofs4_write(pipe, &pkt, pktsz)) + autofs4_catatonic_mode(sbi); + fput(pipe); + } +} + +static int autofs4_getpath(struct autofs_sb_info *sbi, + struct dentry *dentry, char **name) +{ + struct dentry *root = sbi->sb->s_root; + struct dentry *tmp; + char *buf = *name; + char *p; + int len = 0; + + spin_lock(&dcache_lock); + for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent) + len += tmp->d_name.len + 1; + + if (!len || --len > NAME_MAX) { + spin_unlock(&dcache_lock); + return 0; + } + + *(buf + len) = '\0'; + p = buf + len - dentry->d_name.len; + strncpy(p, dentry->d_name.name, dentry->d_name.len); + + for (tmp = dentry->d_parent; tmp != root ; tmp = tmp->d_parent) { + *(--p) = '/'; + p -= tmp->d_name.len; + strncpy(p, tmp->d_name.name, tmp->d_name.len); + } + spin_unlock(&dcache_lock); + + return len; +} + +static struct autofs_wait_queue * +autofs4_find_wait(struct autofs_sb_info *sbi, struct qstr *qstr) +{ + struct autofs_wait_queue *wq; + + for (wq = sbi->queues; wq; wq = wq->next) { + if (wq->name.hash == qstr->hash && + wq->name.len == qstr->len && + wq->name.name && + !memcmp(wq->name.name, qstr->name, qstr->len)) + break; + } + return wq; +} + +/* + * Check if we have a valid request. + * Returns + * 1 if the request should continue. + * In this case we can return an autofs_wait_queue entry if one is + * found or NULL to idicate a new wait needs to be created. + * 0 or a negative errno if the request shouldn't continue. + */ +static int validate_request(struct autofs_wait_queue **wait, + struct autofs_sb_info *sbi, + struct qstr *qstr, + struct dentry*dentry, enum autofs_notify notify) +{ + struct autofs_wait_queue *wq; + struct autofs_info *ino; + + /* Wait in progress, continue; */ + wq = autofs4_find_wait(sbi, qstr); + if (wq) { + *wait = wq; + return 1; + } + + *wait = NULL; + + /* If we don't yet have any info this is a new request */ + ino = autofs4_dentry_ino(dentry); + if (!ino) + return 1; + + /* + * If we've been asked to wait on an existing expire (NFY_NONE) + * but there is no wait in the queue ... + */ + if (notify == NFY_NONE) { + /* + * Either we've betean the pending expire to post it's + * wait or it finished while we waited on the mutex. + * So we need to wait till either, the wait appears + * or the expire finishes. + */ + + while (ino->flags & AUTOFS_INF_EXPIRING) { + mutex_unlock(&sbi->wq_mutex); + schedule_timeout_interruptible(HZ/10); + if (mutex_lock_interruptible(&sbi->wq_mutex)) + return -EINTR; + + wq = autofs4_find_wait(sbi, qstr); + if (wq) { + *wait = wq; + return 1; + } + } + + /* + * Not ideal but the status has already gone. Of the two + * cases where we wait on NFY_NONE neither depend on the + * return status of the wait. + */ + return 0; + } + + /* + * If we've been asked to trigger a mount and the request + * completed while we waited on the mutex ... + */ + if (notify == NFY_MOUNT) { + /* + * If the dentry was successfully mounted while we slept + * on the wait queue mutex we can return success. If it + * isn't mounted (doesn't have submounts for the case of + * a multi-mount with no mount at it's base) we can + * continue on and create a new request. + */ + if (have_submounts(dentry)) + return 0; + } + + return 1; +} + +int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry, + enum autofs_notify notify) +{ + struct autofs_wait_queue *wq; + struct qstr qstr; + char *name; + int status, ret, type; + + /* In catatonic mode, we don't wait for nobody */ + if (sbi->catatonic) + return -ENOENT; + + if (!dentry->d_inode) { + /* + * A wait for a negative dentry is invalid for certain + * cases. A direct or offset mount "always" has its mount + * point directory created and so the request dentry must + * be positive or the map key doesn't exist. The situation + * is very similar for indirect mounts except only dentrys + * in the root of the autofs file system may be negative. + */ + if (autofs_type_trigger(sbi->type)) + return -ENOENT; + else if (!IS_ROOT(dentry->d_parent)) + return -ENOENT; + } + + name = kmalloc(NAME_MAX + 1, GFP_KERNEL); + if (!name) + return -ENOMEM; + + /* If this is a direct mount request create a dummy name */ + if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type)) + qstr.len = sprintf(name, "%p", dentry); + else { + qstr.len = autofs4_getpath(sbi, dentry, &name); + if (!qstr.len) { + kfree(name); + return -ENOENT; + } + } + qstr.name = name; + qstr.hash = full_name_hash(name, qstr.len); + + if (mutex_lock_interruptible(&sbi->wq_mutex)) { + kfree(qstr.name); + return -EINTR; + } + + ret = validate_request(&wq, sbi, &qstr, dentry, notify); + if (ret <= 0) { + if (ret == 0) + mutex_unlock(&sbi->wq_mutex); + kfree(qstr.name); + return ret; + } + + if (!wq) { + /* Create a new wait queue */ + wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL); + if (!wq) { + kfree(qstr.name); + mutex_unlock(&sbi->wq_mutex); + return -ENOMEM; + } + + wq->wait_queue_token = autofs4_next_wait_queue; + if (++autofs4_next_wait_queue == 0) + autofs4_next_wait_queue = 1; + wq->next = sbi->queues; + sbi->queues = wq; + init_waitqueue_head(&wq->queue); + memcpy(&wq->name, &qstr, sizeof(struct qstr)); + wq->dev = autofs4_get_dev(sbi); + wq->ino = autofs4_get_ino(sbi); + wq->uid = current_uid(); + wq->gid = current_gid(); + wq->pid = current->pid; + wq->tgid = current->tgid; + wq->status = -EINTR; /* Status return if interrupted */ + wq->wait_ctr = 2; + mutex_unlock(&sbi->wq_mutex); + + if (sbi->version < 5) { + if (notify == NFY_MOUNT) + type = autofs_ptype_missing; + else + type = autofs_ptype_expire_multi; + } else { + if (notify == NFY_MOUNT) + type = autofs_type_trigger(sbi->type) ? + autofs_ptype_missing_direct : + autofs_ptype_missing_indirect; + else + type = autofs_type_trigger(sbi->type) ? + autofs_ptype_expire_direct : + autofs_ptype_expire_indirect; + } + + DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d\n", + (unsigned long) wq->wait_queue_token, wq->name.len, + wq->name.name, notify); + + /* autofs4_notify_daemon() may block */ + autofs4_notify_daemon(sbi, wq, type); + } else { + wq->wait_ctr++; + mutex_unlock(&sbi->wq_mutex); + kfree(qstr.name); + DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d", + (unsigned long) wq->wait_queue_token, wq->name.len, + wq->name.name, notify); + } + + /* + * wq->name.name is NULL iff the lock is already released + * or the mount has been made catatonic. + */ + if (wq->name.name) { + /* Block all but "shutdown" signals while waiting */ + sigset_t oldset; + unsigned long irqflags; + + spin_lock_irqsave(¤t->sighand->siglock, irqflags); + oldset = current->blocked; + siginitsetinv(¤t->blocked, SHUTDOWN_SIGS & ~oldset.sig[0]); + recalc_sigpending(); + spin_unlock_irqrestore(¤t->sighand->siglock, irqflags); + + wait_event_interruptible(wq->queue, wq->name.name == NULL); + + spin_lock_irqsave(¤t->sighand->siglock, irqflags); + current->blocked = oldset; + recalc_sigpending(); + spin_unlock_irqrestore(¤t->sighand->siglock, irqflags); + } else { + DPRINTK("skipped sleeping"); + } + + status = wq->status; + + /* + * For direct and offset mounts we need to track the requester's + * uid and gid in the dentry info struct. This is so it can be + * supplied, on request, by the misc device ioctl interface. + * This is needed during daemon resatart when reconnecting + * to existing, active, autofs mounts. The uid and gid (and + * related string values) may be used for macro substitution + * in autofs mount maps. + */ + if (!status) { + struct autofs_info *ino; + struct dentry *de = NULL; + + /* direct mount or browsable map */ + ino = autofs4_dentry_ino(dentry); + if (!ino) { + /* If not lookup actual dentry used */ + de = d_lookup(dentry->d_parent, &dentry->d_name); + if (de) + ino = autofs4_dentry_ino(de); + } + + /* Set mount requester */ + if (ino) { + spin_lock(&sbi->fs_lock); + ino->uid = wq->uid; + ino->gid = wq->gid; + spin_unlock(&sbi->fs_lock); + } + + if (de) + dput(de); + } + + /* Are we the last process to need status? */ + mutex_lock(&sbi->wq_mutex); + if (!--wq->wait_ctr) + kfree(wq); + mutex_unlock(&sbi->wq_mutex); + + return status; +} + + +int autofs4_wait_release(struct autofs_sb_info *sbi, autofs_wqt_t wait_queue_token, int status) +{ + struct autofs_wait_queue *wq, **wql; + + mutex_lock(&sbi->wq_mutex); + for (wql = &sbi->queues; (wq = *wql) != NULL; wql = &wq->next) { + if (wq->wait_queue_token == wait_queue_token) + break; + } + + if (!wq) { + mutex_unlock(&sbi->wq_mutex); + return -EINVAL; + } + + *wql = wq->next; /* Unlink from chain */ + kfree(wq->name.name); + wq->name.name = NULL; /* Do not wait on this queue */ + wq->status = status; + wake_up_interruptible(&wq->queue); + if (!--wq->wait_ctr) + kfree(wq); + mutex_unlock(&sbi->wq_mutex); + + return 0; +} + |