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Message-ID: <152626705013.28589.931913083997578251.stgit@pluto.themaw.net>
Date: Mon, 14 May 2018 11:04:10 +0800
From: Ian Kent <raven@...maw.net>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-fsdevel <linux-fsdevel@...r.kernel.org>,
autofs mailing list <autofs@...r.kernel.org>,
Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: [PATCH 03/10] autofs - copy autofs4 to autofs
Copy source files from the autofs4 directory to the autofs directory.
Signed-off-by: Ian Kent <raven@...maw.net>
---
fs/autofs/autofs_i.h | 273 ++++++++++++++
fs/autofs/dev-ioctl.c | 761 ++++++++++++++++++++++++++++++++++++++++
fs/autofs/expire.c | 632 +++++++++++++++++++++++++++++++++
fs/autofs/init.c | 48 ++
fs/autofs/inode.c | 375 ++++++++++++++++++++
fs/autofs/root.c | 942 +++++++++++++++++++++++++++++++++++++++++++++++++
fs/autofs/symlink.c | 29 ++
fs/autofs/waitq.c | 559 +++++++++++++++++++++++++++++
8 files changed, 3619 insertions(+)
create mode 100644 fs/autofs/autofs_i.h
create mode 100644 fs/autofs/dev-ioctl.c
create mode 100644 fs/autofs/expire.c
create mode 100644 fs/autofs/init.c
create mode 100644 fs/autofs/inode.c
create mode 100644 fs/autofs/root.c
create mode 100644 fs/autofs/symlink.c
create mode 100644 fs/autofs/waitq.c
diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h
new file mode 100644
index 000000000000..9110b66c7ef1
--- /dev/null
+++ b/fs/autofs/autofs_i.h
@@ -0,0 +1,273 @@
+/*
+ * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
+ * Copyright 2005-2006 Ian Kent <raven@...maw.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_fs.h>
+#include <linux/auto_dev-ioctl.h>
+
+#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 <linux/uaccess.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/completion.h>
+#include <asm/current.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_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
+
+#ifdef pr_fmt
+#undef pr_fmt
+#endif
+#define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__
+
+/*
+ * 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;
+
+ kuid_t uid;
+ kgid_t gid;
+};
+
+#define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */
+#define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered
+ * for expiry, so RCU_walk is
+ * not permitted. If it progresses to
+ * actual expiry attempt, the flag is
+ * not cleared when EXPIRING is set -
+ * in that case it gets cleared only
+ * when it comes to clearing EXPIRING.
+ */
+#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;
+ kuid_t uid;
+ kgid_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;
+ struct pid *oz_pgrp;
+ int catatonic;
+ int version;
+ int sub_version;
+ int min_proto;
+ int max_proto;
+ unsigned long exp_timeout;
+ unsigned int type;
+ struct super_block *sb;
+ struct mutex wq_mutex;
+ struct mutex pipe_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;
+ struct rcu_head rcu;
+};
+
+static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
+{
+ return (struct autofs_sb_info *)(sb->s_fs_info);
+}
+
+static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry)
+{
+ return (struct autofs_info *)(dentry->d_fsdata);
+}
+
+/* autofs_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 autofs_oz_mode(struct autofs_sb_info *sbi)
+{
+ return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
+}
+
+struct inode *autofs_get_inode(struct super_block *, umode_t);
+void autofs_free_ino(struct autofs_info *);
+
+/* Expiration */
+int is_autofs_dentry(struct dentry *);
+int autofs_expire_wait(const struct path *path, int rcu_walk);
+int autofs_expire_run(struct super_block *, struct vfsmount *,
+ struct autofs_sb_info *,
+ struct autofs_packet_expire __user *);
+int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
+ struct autofs_sb_info *sbi, int when);
+int autofs_expire_multi(struct super_block *, struct vfsmount *,
+ struct autofs_sb_info *, int __user *);
+struct dentry *autofs_expire_direct(struct super_block *sb,
+ struct vfsmount *mnt,
+ struct autofs_sb_info *sbi, int how);
+struct dentry *autofs_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 autofs_symlink_inode_operations;
+extern const struct inode_operations autofs_dir_inode_operations;
+extern const struct file_operations autofs_dir_operations;
+extern const struct file_operations autofs_root_operations;
+extern const struct dentry_operations autofs_dentry_operations;
+
+/* VFS automount flags management functions */
+static inline void __managed_dentry_set_managed(struct dentry *dentry)
+{
+ dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
+}
+
+static inline void managed_dentry_set_managed(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ __managed_dentry_set_managed(dentry);
+ spin_unlock(&dentry->d_lock);
+}
+
+static inline void __managed_dentry_clear_managed(struct dentry *dentry)
+{
+ dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
+}
+
+static inline void managed_dentry_clear_managed(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ __managed_dentry_clear_managed(dentry);
+ spin_unlock(&dentry->d_lock);
+}
+
+/* Initializing function */
+
+int autofs_fill_super(struct super_block *, void *, int);
+struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
+void autofs_clean_ino(struct autofs_info *);
+
+static inline int autofs_prepare_pipe(struct file *pipe)
+{
+ if (!(pipe->f_mode & FMODE_CAN_WRITE))
+ return -EINVAL;
+ if (!S_ISFIFO(file_inode(pipe)->i_mode))
+ return -EINVAL;
+ /* We want a packet pipe */
+ pipe->f_flags |= O_DIRECT;
+ return 0;
+}
+
+/* Queue management functions */
+
+int autofs_wait(struct autofs_sb_info *,
+ const struct path *, enum autofs_notify);
+int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
+void autofs_catatonic_mode(struct autofs_sb_info *);
+
+static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
+{
+ return new_encode_dev(sbi->sb->s_dev);
+}
+
+static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
+{
+ return d_inode(sbi->sb->s_root)->i_ino;
+}
+
+static inline void __autofs_add_expiring(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+
+ if (ino) {
+ if (list_empty(&ino->expiring))
+ list_add(&ino->expiring, &sbi->expiring_list);
+ }
+}
+
+static inline void autofs_add_expiring(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs_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);
+ }
+}
+
+static inline void autofs_del_expiring(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs_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);
+ }
+}
+
+void autofs_kill_sb(struct super_block *);
diff --git a/fs/autofs/dev-ioctl.c b/fs/autofs/dev-ioctl.c
new file mode 100644
index 000000000000..a2281ab2b957
--- /dev/null
+++ b/fs/autofs/dev-ioctl.c
@@ -0,0 +1,761 @@
+/*
+ * Copyright 2008 Red Hat, Inc. All rights reserved.
+ * Copyright 2008 Ian Kent <raven@...maw.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/cred.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.
+ */
+
+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 ((param->ver_major != AUTOFS_DEV_IOCTL_VERSION_MAJOR) ||
+ (param->ver_minor > AUTOFS_DEV_IOCTL_VERSION_MINOR)) {
+ pr_warn("ioctl control interface version mismatch: "
+ "kernel(%u.%u), user(%u.%u), cmd(0x%08x)\n",
+ 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, *res;
+
+ if (copy_from_user(&tmp, in, AUTOFS_DEV_IOCTL_SIZE))
+ return ERR_PTR(-EFAULT);
+
+ if (tmp.size < AUTOFS_DEV_IOCTL_SIZE)
+ return ERR_PTR(-EINVAL);
+
+ if (tmp.size > AUTOFS_DEV_IOCTL_SIZE + PATH_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ res = memdup_user(in, tmp.size);
+ if (!IS_ERR(res))
+ res->size = tmp.size;
+
+ return res;
+}
+
+static inline void free_dev_ioctl(struct autofs_dev_ioctl *param)
+{
+ kfree(param);
+}
+
+/*
+ * 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) {
+ pr_warn("invalid device control module version "
+ "supplied for cmd(0x%08x)\n", cmd);
+ goto out;
+ }
+
+ if (param->size > AUTOFS_DEV_IOCTL_SIZE) {
+ err = invalid_str(param->path, param->size - AUTOFS_DEV_IOCTL_SIZE);
+ if (err) {
+ pr_warn(
+ "path string terminator missing for cmd(0x%08x)\n",
+ cmd);
+ goto out;
+ }
+
+ err = check_name(param->path);
+ if (err) {
+ pr_warn("invalid path supplied for cmd(0x%08x)\n",
+ 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 = file_inode(f);
+ sbi = autofs_sbi(inode->i_sb);
+ }
+ return sbi;
+}
+
+/* Return autofs dev ioctl version */
+static int autofs_dev_ioctl_version(struct file *fp,
+ struct autofs_sb_info *sbi,
+ struct autofs_dev_ioctl *param)
+{
+ /* This should have already been set. */
+ param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
+ param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
+ return 0;
+}
+
+/* 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;
+}
+
+/* Find the topmost mount satisfying test() */
+static int find_autofs_mount(const char *pathname,
+ struct path *res,
+ int test(const struct path *path, void *data),
+ void *data)
+{
+ struct path path;
+ int err;
+
+ err = kern_path_mountpoint(AT_FDCWD, pathname, &path, 0);
+ if (err)
+ return err;
+ err = -ENOENT;
+ while (path.dentry == path.mnt->mnt_root) {
+ if (path.dentry->d_sb->s_magic == AUTOFS_SUPER_MAGIC) {
+ if (test(&path, data)) {
+ path_get(&path);
+ *res = path;
+ err = 0;
+ break;
+ }
+ }
+ if (!follow_up(&path))
+ break;
+ }
+ path_put(&path);
+ return err;
+}
+
+static int test_by_dev(const struct path *path, void *p)
+{
+ return path->dentry->d_sb->s_dev == *(dev_t *)p;
+}
+
+static int test_by_type(const struct path *path, void *p)
+{
+ struct autofs_info *ino = autofs_dentry_ino(path->dentry);
+
+ return ino && ino->sbi->type & *(unsigned *)p;
+}
+
+/*
+ * 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_flags(O_CLOEXEC);
+ if (likely(fd >= 0)) {
+ struct file *filp;
+ struct path path;
+
+ err = find_autofs_mount(name, &path, test_by_dev, &devid);
+ if (err)
+ goto out;
+
+ filp = dentry_open(&path, O_RDONLY, current_cred());
+ path_put(&path);
+ if (IS_ERR(filp)) {
+ err = PTR_ERR(filp);
+ goto out;
+ }
+
+ 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 ksys_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 autofs_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 < 0 ? param->fail.status : -ENOENT;
+ return autofs_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;
+ struct pid *new_pid = NULL;
+
+ 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;
+
+ new_pid = get_task_pid(current, PIDTYPE_PGID);
+
+ if (ns_of_pid(new_pid) != ns_of_pid(sbi->oz_pgrp)) {
+ pr_warn("not allowed to change PID namespace\n");
+ err = -EINVAL;
+ goto out;
+ }
+
+ pipe = fget(pipefd);
+ if (!pipe) {
+ err = -EBADF;
+ goto out;
+ }
+ if (autofs_prepare_pipe(pipe) < 0) {
+ err = -EPIPE;
+ fput(pipe);
+ goto out;
+ }
+ swap(sbi->oz_pgrp, new_pid);
+ sbi->pipefd = pipefd;
+ sbi->pipe = pipe;
+ sbi->catatonic = 0;
+ }
+out:
+ put_pid(new_pid);
+ 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)
+{
+ autofs_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 <= AUTOFS_DEV_IOCTL_SIZE) {
+ 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 = autofs_dentry_ino(path.dentry);
+ if (ino) {
+ err = 0;
+ autofs_expire_wait(&path, 0);
+ spin_lock(&sbi->fs_lock);
+ param->requester.uid =
+ from_kuid_munged(current_user_ns(), ino->uid);
+ param->requester.gid =
+ from_kgid_munged(current_user_ns(), 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 autofs_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 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 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 <= AUTOFS_DEV_IOCTL_SIZE) {
+ 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_mountpoint(AT_FDCWD,
+ name, &path, LOOKUP_FOLLOW);
+ else
+ err = find_autofs_mount(name, &path,
+ test_by_type, &type);
+ if (err)
+ goto out;
+ devid = new_encode_dev(path.dentry->d_sb->s_dev);
+ err = 0;
+ if (path.mnt->mnt_root == path.dentry) {
+ err = 1;
+ magic = path.dentry->d_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 = path_has_submounts(&path);
+
+ if (follow_down_one(&path))
+ magic = path.dentry->d_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 ioctl_fn _ioctls[] = {
+ autofs_dev_ioctl_version,
+ autofs_dev_ioctl_protover,
+ autofs_dev_ioctl_protosubver,
+ autofs_dev_ioctl_openmount,
+ autofs_dev_ioctl_closemount,
+ autofs_dev_ioctl_ready,
+ autofs_dev_ioctl_fail,
+ autofs_dev_ioctl_setpipefd,
+ autofs_dev_ioctl_catatonic,
+ autofs_dev_ioctl_timeout,
+ autofs_dev_ioctl_requester,
+ autofs_dev_ioctl_expire,
+ autofs_dev_ioctl_askumount,
+ autofs_dev_ioctl_ismountpoint,
+ };
+ unsigned int idx = cmd_idx(cmd);
+
+ return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx];
+}
+
+/* ioctl dispatcher */
+static int _autofs_dev_ioctl(unsigned int command,
+ struct autofs_dev_ioctl __user *user)
+{
+ struct autofs_dev_ioctl *param;
+ struct file *fp;
+ struct autofs_sb_info *sbi;
+ unsigned int cmd_first, cmd;
+ ioctl_fn fn = NULL;
+ int err = 0;
+
+ cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST);
+ cmd = _IOC_NR(command);
+
+ if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) ||
+ cmd - cmd_first > AUTOFS_DEV_IOCTL_IOC_COUNT) {
+ return -ENOTTY;
+ }
+
+ /* Only root can use ioctls other than AUTOFS_DEV_IOCTL_VERSION_CMD
+ * and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD
+ */
+ if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
+ cmd != AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD &&
+ !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ /* Copy the parameters into kernel space. */
+ param = copy_dev_ioctl(user);
+ if (IS_ERR(param))
+ return PTR_ERR(param);
+
+ err = validate_dev_ioctl(command, param);
+ if (err)
+ goto out;
+
+ fn = lookup_dev_ioctl(cmd);
+ if (!fn) {
+ pr_warn("unknown command 0x%08x\n", command);
+ err = -ENOTTY;
+ goto out;
+ }
+
+ fp = NULL;
+ sbi = NULL;
+
+ /*
+ * For obvious reasons the openmount can't have a file
+ * descriptor yet. We don't take a reference to the
+ * file during close to allow for immediate release,
+ * and the same for retrieving ioctl version.
+ */
+ if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
+ cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
+ cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) {
+ fp = fget(param->ioctlfd);
+ if (!fp) {
+ if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
+ goto cont;
+ err = -EBADF;
+ 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 (!autofs_oz_mode(sbi) &&
+ cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) {
+ err = -EACCES;
+ fput(fp);
+ goto out;
+ }
+ }
+cont:
+ err = fn(fp, sbi, param);
+
+ if (fp)
+ fput(fp);
+ if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
+ err = -EFAULT;
+out:
+ free_dev_ioctl(param);
+ return err;
+}
+
+static long autofs_dev_ioctl(struct file *file, unsigned int command,
+ unsigned long 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, unsigned int command,
+ unsigned long u)
+{
+ return autofs_dev_ioctl(file, command, (unsigned long) 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,
+ .llseek = noop_llseek,
+};
+
+static struct miscdevice _autofs_dev_ioctl_misc = {
+ .minor = AUTOFS_MINOR,
+ .name = AUTOFS_DEVICE_NAME,
+ .fops = &_dev_ioctl_fops,
+ .mode = 0644,
+};
+
+MODULE_ALIAS_MISCDEV(AUTOFS_MINOR);
+MODULE_ALIAS("devname:autofs");
+
+/* Register/deregister misc character device */
+int __init autofs_dev_ioctl_init(void)
+{
+ int r;
+
+ r = misc_register(&_autofs_dev_ioctl_misc);
+ if (r) {
+ pr_err("misc_register failed for control device\n");
+ return r;
+ }
+
+ return 0;
+}
+
+void autofs_dev_ioctl_exit(void)
+{
+ misc_deregister(&_autofs_dev_ioctl_misc);
+}
diff --git a/fs/autofs/expire.c b/fs/autofs/expire.c
new file mode 100644
index 000000000000..36f16b67a3bf
--- /dev/null
+++ b/fs/autofs/expire.c
@@ -0,0 +1,632 @@
+/*
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@...p.org>
+ * Copyright 2001-2006 Ian Kent <raven@...maw.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 autofs_can_expire(struct dentry *dentry,
+ unsigned long timeout, int do_now)
+{
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+
+ /* dentry in the process of being deleted */
+ if (ino == NULL)
+ return 0;
+
+ if (!do_now) {
+ /* Too young to die */
+ if (!timeout || time_after(ino->last_used + timeout, now))
+ return 0;
+ }
+ return 1;
+}
+
+/* Check a mount point for busyness */
+static int autofs_mount_busy(struct vfsmount *mnt, struct dentry *dentry)
+{
+ struct dentry *top = dentry;
+ struct path path = {.mnt = mnt, .dentry = dentry};
+ int status = 1;
+
+ pr_debug("dentry %p %pd\n", dentry, dentry);
+
+ path_get(&path);
+
+ if (!follow_down_one(&path))
+ goto done;
+
+ if (is_autofs_dentry(path.dentry)) {
+ struct autofs_sb_info *sbi = autofs_sbi(path.dentry->d_sb);
+
+ /* This is an autofs submount, we can't expire it */
+ if (autofs_type_indirect(sbi->type))
+ goto done;
+ }
+
+ /* Update the expiry counter if fs is busy */
+ if (!may_umount_tree(path.mnt)) {
+ struct autofs_info *ino;
+
+ ino = autofs_dentry_ino(top);
+ ino->last_used = jiffies;
+ goto done;
+ }
+
+ status = 0;
+done:
+ pr_debug("returning = %d\n", status);
+ path_put(&path);
+ return status;
+}
+
+/*
+ * Calculate and dget next entry in the subdirs list under root.
+ */
+static struct dentry *get_next_positive_subdir(struct dentry *prev,
+ struct dentry *root)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
+ struct list_head *next;
+ struct dentry *q;
+
+ spin_lock(&sbi->lookup_lock);
+ spin_lock(&root->d_lock);
+
+ if (prev)
+ next = prev->d_child.next;
+ else {
+ prev = dget_dlock(root);
+ next = prev->d_subdirs.next;
+ }
+
+cont:
+ if (next == &root->d_subdirs) {
+ spin_unlock(&root->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ dput(prev);
+ return NULL;
+ }
+
+ q = list_entry(next, struct dentry, d_child);
+
+ spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED);
+ /* Already gone or negative dentry (under construction) - try next */
+ if (!d_count(q) || !simple_positive(q)) {
+ spin_unlock(&q->d_lock);
+ next = q->d_child.next;
+ goto cont;
+ }
+ dget_dlock(q);
+ spin_unlock(&q->d_lock);
+ spin_unlock(&root->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+
+ dput(prev);
+
+ return q;
+}
+
+/*
+ * Calculate and dget next entry in top down tree traversal.
+ */
+static struct dentry *get_next_positive_dentry(struct dentry *prev,
+ struct dentry *root)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
+ struct list_head *next;
+ struct dentry *p, *ret;
+
+ if (prev == NULL)
+ return dget(root);
+
+ spin_lock(&sbi->lookup_lock);
+relock:
+ p = prev;
+ spin_lock(&p->d_lock);
+again:
+ next = p->d_subdirs.next;
+ if (next == &p->d_subdirs) {
+ while (1) {
+ struct dentry *parent;
+
+ if (p == root) {
+ spin_unlock(&p->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ dput(prev);
+ return NULL;
+ }
+
+ parent = p->d_parent;
+ if (!spin_trylock(&parent->d_lock)) {
+ spin_unlock(&p->d_lock);
+ cpu_relax();
+ goto relock;
+ }
+ spin_unlock(&p->d_lock);
+ next = p->d_child.next;
+ p = parent;
+ if (next != &parent->d_subdirs)
+ break;
+ }
+ }
+ ret = list_entry(next, struct dentry, d_child);
+
+ spin_lock_nested(&ret->d_lock, DENTRY_D_LOCK_NESTED);
+ /* Negative dentry - try next */
+ if (!simple_positive(ret)) {
+ spin_unlock(&p->d_lock);
+ lock_set_subclass(&ret->d_lock.dep_map, 0, _RET_IP_);
+ p = ret;
+ goto again;
+ }
+ dget_dlock(ret);
+ spin_unlock(&ret->d_lock);
+ spin_unlock(&p->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+
+ dput(prev);
+
+ return ret;
+}
+
+/*
+ * 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 autofs_direct_busy(struct vfsmount *mnt,
+ struct dentry *top,
+ unsigned long timeout,
+ int do_now)
+{
+ pr_debug("top %p %pd\n", top, top);
+
+ /* If it's busy update the expiry counters */
+ if (!may_umount_tree(mnt)) {
+ struct autofs_info *ino;
+
+ ino = autofs_dentry_ino(top);
+ if (ino)
+ ino->last_used = jiffies;
+ return 1;
+ }
+
+ /* Timeout of a direct mount is determined by its top dentry */
+ if (!autofs_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 autofs_tree_busy(struct vfsmount *mnt,
+ struct dentry *top,
+ unsigned long timeout,
+ int do_now)
+{
+ struct autofs_info *top_ino = autofs_dentry_ino(top);
+ struct dentry *p;
+
+ pr_debug("top %p %pd\n", top, top);
+
+ /* Negative dentry - give up */
+ if (!simple_positive(top))
+ return 1;
+
+ p = NULL;
+ while ((p = get_next_positive_dentry(p, top))) {
+ pr_debug("dentry %p %pd\n", p, p);
+
+ /*
+ * 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 (autofs_mount_busy(mnt, p)) {
+ top_ino->last_used = jiffies;
+ dput(p);
+ return 1;
+ }
+ } else {
+ struct autofs_info *ino = autofs_dentry_ino(p);
+ unsigned int ino_count = atomic_read(&ino->count);
+
+ /* allow for dget above and top is already dgot */
+ if (p == top)
+ ino_count += 2;
+ else
+ ino_count++;
+
+ if (d_count(p) > ino_count) {
+ top_ino->last_used = jiffies;
+ dput(p);
+ return 1;
+ }
+ }
+ }
+
+ /* Timeout of a tree mount is ultimately determined by its top dentry */
+ if (!autofs_can_expire(top, timeout, do_now))
+ return 1;
+
+ return 0;
+}
+
+static struct dentry *autofs_check_leaves(struct vfsmount *mnt,
+ struct dentry *parent,
+ unsigned long timeout,
+ int do_now)
+{
+ struct dentry *p;
+
+ pr_debug("parent %p %pd\n", parent, parent);
+
+ p = NULL;
+ while ((p = get_next_positive_dentry(p, parent))) {
+ pr_debug("dentry %p %pd\n", p, p);
+
+ if (d_mountpoint(p)) {
+ /* Can we umount this guy */
+ if (autofs_mount_busy(mnt, p))
+ continue;
+
+ /* Can we expire this guy */
+ if (autofs_can_expire(p, timeout, do_now))
+ return p;
+ }
+ }
+ return NULL;
+}
+
+/* Check if we can expire a direct mount (possibly a tree) */
+struct dentry *autofs_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;
+ struct autofs_info *ino;
+
+ if (!root)
+ return NULL;
+
+ now = jiffies;
+ timeout = sbi->exp_timeout;
+
+ if (!autofs_direct_busy(mnt, root, timeout, do_now)) {
+ spin_lock(&sbi->fs_lock);
+ ino = autofs_dentry_ino(root);
+ /* No point expiring a pending mount */
+ if (ino->flags & AUTOFS_INF_PENDING) {
+ spin_unlock(&sbi->fs_lock);
+ goto out;
+ }
+ ino->flags |= AUTOFS_INF_WANT_EXPIRE;
+ spin_unlock(&sbi->fs_lock);
+ synchronize_rcu();
+ if (!autofs_direct_busy(mnt, root, timeout, do_now)) {
+ spin_lock(&sbi->fs_lock);
+ ino->flags |= AUTOFS_INF_EXPIRING;
+ init_completion(&ino->expire_complete);
+ spin_unlock(&sbi->fs_lock);
+ return root;
+ }
+ spin_lock(&sbi->fs_lock);
+ ino->flags &= ~AUTOFS_INF_WANT_EXPIRE;
+ spin_unlock(&sbi->fs_lock);
+ }
+out:
+ dput(root);
+
+ return NULL;
+}
+
+/* Check if 'dentry' should expire, or return a nearby
+ * dentry that is suitable.
+ * If returned dentry is different from arg dentry,
+ * then a dget() reference was taken, else not.
+ */
+static struct dentry *should_expire(struct dentry *dentry,
+ struct vfsmount *mnt,
+ unsigned long timeout,
+ int how)
+{
+ int do_now = how & AUTOFS_EXP_IMMEDIATE;
+ int exp_leaves = how & AUTOFS_EXP_LEAVES;
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+ unsigned int ino_count;
+
+ /* No point expiring a pending mount */
+ if (ino->flags & AUTOFS_INF_PENDING)
+ return NULL;
+
+ /*
+ * 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)) {
+ pr_debug("checking mountpoint %p %pd\n", dentry, dentry);
+
+ /* Can we umount this guy */
+ if (autofs_mount_busy(mnt, dentry))
+ return NULL;
+
+ /* Can we expire this guy */
+ if (autofs_can_expire(dentry, timeout, do_now))
+ return dentry;
+ return NULL;
+ }
+
+ if (d_really_is_positive(dentry) && d_is_symlink(dentry)) {
+ pr_debug("checking symlink %p %pd\n", dentry, dentry);
+ /*
+ * A symlink can't be "busy" in the usual sense so
+ * just check last used for expire timeout.
+ */
+ if (autofs_can_expire(dentry, timeout, do_now))
+ return dentry;
+ return NULL;
+ }
+
+ if (simple_empty(dentry))
+ return NULL;
+
+ /* 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 (d_count(dentry) > ino_count)
+ return NULL;
+
+ if (!autofs_tree_busy(mnt, dentry, timeout, do_now))
+ return dentry;
+ /*
+ * Case 3: pseudo direct mount, expire individual leaves
+ * (autofs-4.1).
+ */
+ } else {
+ /* Path walk currently on this dentry? */
+ struct dentry *expired;
+
+ ino_count = atomic_read(&ino->count) + 1;
+ if (d_count(dentry) > ino_count)
+ return NULL;
+
+ expired = autofs_check_leaves(mnt, dentry, timeout, do_now);
+ if (expired) {
+ if (expired == dentry)
+ dput(dentry);
+ return expired;
+ }
+ }
+ 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 *autofs_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 *dentry;
+ struct dentry *expired;
+ struct dentry *found;
+ struct autofs_info *ino;
+
+ if (!root)
+ return NULL;
+
+ now = jiffies;
+ timeout = sbi->exp_timeout;
+
+ dentry = NULL;
+ while ((dentry = get_next_positive_subdir(dentry, root))) {
+ int flags = how;
+
+ spin_lock(&sbi->fs_lock);
+ ino = autofs_dentry_ino(dentry);
+ if (ino->flags & AUTOFS_INF_WANT_EXPIRE) {
+ spin_unlock(&sbi->fs_lock);
+ continue;
+ }
+ spin_unlock(&sbi->fs_lock);
+
+ expired = should_expire(dentry, mnt, timeout, flags);
+ if (!expired)
+ continue;
+
+ spin_lock(&sbi->fs_lock);
+ ino = autofs_dentry_ino(expired);
+ ino->flags |= AUTOFS_INF_WANT_EXPIRE;
+ spin_unlock(&sbi->fs_lock);
+ synchronize_rcu();
+
+ /* Make sure a reference is not taken on found if
+ * things have changed.
+ */
+ flags &= ~AUTOFS_EXP_LEAVES;
+ found = should_expire(expired, mnt, timeout, how);
+ if (!found || found != expired)
+ /* Something has changed, continue */
+ goto next;
+
+ if (expired != dentry)
+ dput(dentry);
+
+ spin_lock(&sbi->fs_lock);
+ goto found;
+next:
+ spin_lock(&sbi->fs_lock);
+ ino->flags &= ~AUTOFS_INF_WANT_EXPIRE;
+ spin_unlock(&sbi->fs_lock);
+ if (expired != dentry)
+ dput(expired);
+ }
+ return NULL;
+
+found:
+ pr_debug("returning %p %pd\n", expired, expired);
+ ino->flags |= AUTOFS_INF_EXPIRING;
+ init_completion(&ino->expire_complete);
+ spin_unlock(&sbi->fs_lock);
+ return expired;
+}
+
+int autofs_expire_wait(const struct path *path, int rcu_walk)
+{
+ struct dentry *dentry = path->dentry;
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+ int status;
+ int state;
+
+ /* Block on any pending expire */
+ if (!(ino->flags & AUTOFS_INF_WANT_EXPIRE))
+ return 0;
+ if (rcu_walk)
+ return -ECHILD;
+
+retry:
+ spin_lock(&sbi->fs_lock);
+ state = ino->flags & (AUTOFS_INF_WANT_EXPIRE | AUTOFS_INF_EXPIRING);
+ if (state == AUTOFS_INF_WANT_EXPIRE) {
+ spin_unlock(&sbi->fs_lock);
+ /*
+ * Possibly being selected for expire, wait until
+ * it's selected or not.
+ */
+ schedule_timeout_uninterruptible(HZ/10);
+ goto retry;
+ }
+ if (state & AUTOFS_INF_EXPIRING) {
+ spin_unlock(&sbi->fs_lock);
+
+ pr_debug("waiting for expire %p name=%pd\n", dentry, dentry);
+
+ status = autofs_wait(sbi, path, NFY_NONE);
+ wait_for_completion(&ino->expire_complete);
+
+ pr_debug("expire done status=%d\n", status);
+
+ if (d_unhashed(dentry))
+ return -EAGAIN;
+
+ return status;
+ }
+ spin_unlock(&sbi->fs_lock);
+
+ return 0;
+}
+
+/* Perform an expiry operation */
+int autofs_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;
+
+ dentry = autofs_expire_indirect(sb, mnt, sbi, 0);
+ if (!dentry)
+ 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 = autofs_dentry_ino(dentry);
+ /* avoid rapid-fire expire attempts if expiry fails */
+ ino->last_used = now;
+ ino->flags &= ~(AUTOFS_INF_EXPIRING|AUTOFS_INF_WANT_EXPIRE);
+ complete_all(&ino->expire_complete);
+ spin_unlock(&sbi->fs_lock);
+
+ return ret;
+}
+
+int autofs_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 = autofs_expire_direct(sb, mnt, sbi, when);
+ else
+ dentry = autofs_expire_indirect(sb, mnt, sbi, when);
+
+ if (dentry) {
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+ const struct path path = { .mnt = mnt, .dentry = dentry };
+
+ /* This is synchronous because it makes the daemon a
+ * little easier
+ */
+ ret = autofs_wait(sbi, &path, NFY_EXPIRE);
+
+ spin_lock(&sbi->fs_lock);
+ /* avoid rapid-fire expire attempts if expiry fails */
+ ino->last_used = now;
+ ino->flags &= ~(AUTOFS_INF_EXPIRING|AUTOFS_INF_WANT_EXPIRE);
+ 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 autofs_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 autofs_do_expire_multi(sb, mnt, sbi, do_now);
+}
+
diff --git a/fs/autofs/init.c b/fs/autofs/init.c
new file mode 100644
index 000000000000..16fb61315843
--- /dev/null
+++ b/fs/autofs/init.c
@@ -0,0 +1,48 @@
+/*
+ * 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 struct dentry *autofs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_nodev(fs_type, flags, data, autofs_fill_super);
+}
+
+static struct file_system_type autofs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "autofs",
+ .mount = autofs_mount,
+ .kill_sb = autofs_kill_sb,
+};
+MODULE_ALIAS_FS("autofs");
+
+static int __init init_autofs_fs(void)
+{
+ int err;
+
+ autofs_dev_ioctl_init();
+
+ err = register_filesystem(&autofs_fs_type);
+ if (err)
+ autofs_dev_ioctl_exit();
+
+ return err;
+}
+
+static void __exit exit_autofs_fs(void)
+{
+ autofs_dev_ioctl_exit();
+ unregister_filesystem(&autofs_fs_type);
+}
+
+module_init(init_autofs_fs)
+module_exit(exit_autofs_fs)
+MODULE_LICENSE("GPL");
diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c
new file mode 100644
index 000000000000..6262819ede45
--- /dev/null
+++ b/fs/autofs/inode.c
@@ -0,0 +1,375 @@
+/*
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ * Copyright 2005-2006 Ian Kent <raven@...maw.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>
+
+struct autofs_info *autofs_new_ino(struct autofs_sb_info *sbi)
+{
+ struct autofs_info *ino;
+
+ ino = kzalloc(sizeof(*ino), GFP_KERNEL);
+ if (ino) {
+ INIT_LIST_HEAD(&ino->active);
+ INIT_LIST_HEAD(&ino->expiring);
+ ino->last_used = jiffies;
+ ino->sbi = sbi;
+ }
+ return ino;
+}
+
+void autofs_clean_ino(struct autofs_info *ino)
+{
+ ino->uid = GLOBAL_ROOT_UID;
+ ino->gid = GLOBAL_ROOT_GID;
+ ino->last_used = jiffies;
+}
+
+void autofs_free_ino(struct autofs_info *ino)
+{
+ kfree(ino);
+}
+
+void autofs_kill_sb(struct super_block *sb)
+{
+ struct autofs_sb_info *sbi = autofs_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) {
+ /* Free wait queues, close pipe */
+ autofs_catatonic_mode(sbi);
+ put_pid(sbi->oz_pgrp);
+ }
+
+ pr_debug("shutting down\n");
+ kill_litter_super(sb);
+ if (sbi)
+ kfree_rcu(sbi, rcu);
+}
+
+static int autofs_show_options(struct seq_file *m, struct dentry *root)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
+ struct inode *root_inode = d_inode(root->d_sb->s_root);
+
+ if (!sbi)
+ return 0;
+
+ seq_printf(m, ",fd=%d", sbi->pipefd);
+ if (!uid_eq(root_inode->i_uid, GLOBAL_ROOT_UID))
+ seq_printf(m, ",uid=%u",
+ from_kuid_munged(&init_user_ns, root_inode->i_uid));
+ if (!gid_eq(root_inode->i_gid, GLOBAL_ROOT_GID))
+ seq_printf(m, ",gid=%u",
+ from_kgid_munged(&init_user_ns, root_inode->i_gid));
+ seq_printf(m, ",pgrp=%d", pid_vnr(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");
+#ifdef CONFIG_CHECKPOINT_RESTORE
+ if (sbi->pipe)
+ seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino);
+ else
+ seq_printf(m, ",pipe_ino=-1");
+#endif
+ return 0;
+}
+
+static void autofs_evict_inode(struct inode *inode)
+{
+ clear_inode(inode);
+ kfree(inode->i_private);
+}
+
+static const struct super_operations autofs_sops = {
+ .statfs = simple_statfs,
+ .show_options = autofs_show_options,
+ .evict_inode = autofs_evict_inode,
+};
+
+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, kuid_t *uid, kgid_t *gid,
+ int *pgrp, bool *pgrp_set, unsigned int *type,
+ int *minproto, int *maxproto)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+
+ *uid = current_uid();
+ *gid = current_gid();
+
+ *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 = make_kuid(current_user_ns(), option);
+ if (!uid_valid(*uid))
+ return 1;
+ break;
+ case Opt_gid:
+ if (match_int(args, &option))
+ return 1;
+ *gid = make_kgid(current_user_ns(), option);
+ if (!gid_valid(*gid))
+ return 1;
+ break;
+ case Opt_pgrp:
+ if (match_int(args, &option))
+ return 1;
+ *pgrp = option;
+ *pgrp_set = true;
+ 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);
+}
+
+int autofs_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;
+ int pgrp = 0;
+ bool pgrp_set = false;
+ int ret = -EINVAL;
+
+ sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+ if (!sbi)
+ return -ENOMEM;
+ pr_debug("starting up, sbi = %p\n", 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 = NULL;
+ 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);
+ mutex_init(&sbi->pipe_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 = &autofs_sops;
+ s->s_d_op = &autofs_dentry_operations;
+ s->s_time_gran = 1;
+
+ /*
+ * Get the root inode and dentry, but defer checking for errors.
+ */
+ ino = autofs_new_ino(sbi);
+ if (!ino) {
+ ret = -ENOMEM;
+ goto fail_free;
+ }
+ root_inode = autofs_get_inode(s, S_IFDIR | 0755);
+ root = d_make_root(root_inode);
+ if (!root)
+ goto fail_ino;
+ pipe = NULL;
+
+ root->d_fsdata = ino;
+
+ /* Can this call block? */
+ if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
+ &pgrp, &pgrp_set, &sbi->type, &sbi->min_proto,
+ &sbi->max_proto)) {
+ pr_err("called with bogus options\n");
+ goto fail_dput;
+ }
+
+ /* Test versions first */
+ if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
+ sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
+ pr_err("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;
+
+ if (pgrp_set) {
+ sbi->oz_pgrp = find_get_pid(pgrp);
+ if (!sbi->oz_pgrp) {
+ pr_err("could not find process group %d\n",
+ pgrp);
+ goto fail_dput;
+ }
+ } else {
+ sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID);
+ }
+
+ if (autofs_type_trigger(sbi->type))
+ __managed_dentry_set_managed(root);
+
+ root_inode->i_fop = &autofs_root_operations;
+ root_inode->i_op = &autofs_dir_inode_operations;
+
+ pr_debug("pipe fd = %d, pgrp = %u\n", pipefd, pid_nr(sbi->oz_pgrp));
+ pipe = fget(pipefd);
+
+ if (!pipe) {
+ pr_err("could not open pipe file descriptor\n");
+ goto fail_put_pid;
+ }
+ ret = autofs_prepare_pipe(pipe);
+ if (ret < 0)
+ 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:
+ pr_err("pipe file descriptor does not contain proper ops\n");
+ fput(pipe);
+fail_put_pid:
+ put_pid(sbi->oz_pgrp);
+fail_dput:
+ dput(root);
+ goto fail_free;
+fail_ino:
+ autofs_free_ino(ino);
+fail_free:
+ kfree(sbi);
+ s->s_fs_info = NULL;
+ return ret;
+}
+
+struct inode *autofs_get_inode(struct super_block *sb, umode_t mode)
+{
+ struct inode *inode = new_inode(sb);
+
+ if (inode == NULL)
+ return NULL;
+
+ inode->i_mode = mode;
+ if (sb->s_root) {
+ inode->i_uid = d_inode(sb->s_root)->i_uid;
+ inode->i_gid = d_inode(sb->s_root)->i_gid;
+ }
+ inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+ inode->i_ino = get_next_ino();
+
+ if (S_ISDIR(mode)) {
+ set_nlink(inode, 2);
+ inode->i_op = &autofs_dir_inode_operations;
+ inode->i_fop = &autofs_dir_operations;
+ } else if (S_ISLNK(mode)) {
+ inode->i_op = &autofs_symlink_inode_operations;
+ } else
+ WARN_ON(1);
+
+ return inode;
+}
diff --git a/fs/autofs/root.c b/fs/autofs/root.c
new file mode 100644
index 000000000000..a4b36e44f73c
--- /dev/null
+++ b/fs/autofs/root.c
@@ -0,0 +1,942 @@
+/*
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@...p.org>
+ * Copyright 2001-2006 Ian Kent <raven@...maw.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/mutex.h>
+
+#include "autofs_i.h"
+
+static int autofs_dir_symlink(struct inode *, struct dentry *, const char *);
+static int autofs_dir_unlink(struct inode *, struct dentry *);
+static int autofs_dir_rmdir(struct inode *, struct dentry *);
+static int autofs_dir_mkdir(struct inode *, struct dentry *, umode_t);
+static long autofs_root_ioctl(struct file *, unsigned int, unsigned long);
+#ifdef CONFIG_COMPAT
+static long autofs_root_compat_ioctl(struct file *,
+ unsigned int, unsigned long);
+#endif
+static int autofs_dir_open(struct inode *inode, struct file *file);
+static struct dentry *autofs_lookup(struct inode *,
+ struct dentry *, unsigned int);
+static struct vfsmount *autofs_d_automount(struct path *);
+static int autofs_d_manage(const struct path *, bool);
+static void autofs_dentry_release(struct dentry *);
+
+const struct file_operations autofs_root_operations = {
+ .open = dcache_dir_open,
+ .release = dcache_dir_close,
+ .read = generic_read_dir,
+ .iterate_shared = dcache_readdir,
+ .llseek = dcache_dir_lseek,
+ .unlocked_ioctl = autofs_root_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = autofs_root_compat_ioctl,
+#endif
+};
+
+const struct file_operations autofs_dir_operations = {
+ .open = autofs_dir_open,
+ .release = dcache_dir_close,
+ .read = generic_read_dir,
+ .iterate_shared = dcache_readdir,
+ .llseek = dcache_dir_lseek,
+};
+
+const struct inode_operations autofs_dir_inode_operations = {
+ .lookup = autofs_lookup,
+ .unlink = autofs_dir_unlink,
+ .symlink = autofs_dir_symlink,
+ .mkdir = autofs_dir_mkdir,
+ .rmdir = autofs_dir_rmdir,
+};
+
+const struct dentry_operations autofs_dentry_operations = {
+ .d_automount = autofs_d_automount,
+ .d_manage = autofs_d_manage,
+ .d_release = autofs_dentry_release,
+};
+
+static void autofs_add_active(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+ struct autofs_info *ino;
+
+ ino = autofs_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);
+ }
+}
+
+static void autofs_del_active(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+ struct autofs_info *ino;
+
+ ino = autofs_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);
+ }
+}
+
+static int autofs_dir_open(struct inode *inode, struct file *file)
+{
+ struct dentry *dentry = file->f_path.dentry;
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+
+ pr_debug("file=%p dentry=%p %pd\n", file, dentry, dentry);
+
+ if (autofs_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(&sbi->lookup_lock);
+ if (!path_is_mountpoint(&file->f_path) && simple_empty(dentry)) {
+ spin_unlock(&sbi->lookup_lock);
+ return -ENOENT;
+ }
+ spin_unlock(&sbi->lookup_lock);
+
+out:
+ return dcache_dir_open(inode, file);
+}
+
+static void autofs_dentry_release(struct dentry *de)
+{
+ struct autofs_info *ino = autofs_dentry_ino(de);
+ struct autofs_sb_info *sbi = autofs_sbi(de->d_sb);
+
+ pr_debug("releasing %p\n", de);
+
+ if (!ino)
+ return;
+
+ if (sbi) {
+ spin_lock(&sbi->lookup_lock);
+ if (!list_empty(&ino->active))
+ list_del(&ino->active);
+ if (!list_empty(&ino->expiring))
+ list_del(&ino->expiring);
+ spin_unlock(&sbi->lookup_lock);
+ }
+
+ autofs_free_ino(ino);
+}
+
+static struct dentry *autofs_lookup_active(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+ struct dentry *parent = dentry->d_parent;
+ const 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;
+
+ head = &sbi->active_list;
+ if (list_empty(head))
+ return NULL;
+ spin_lock(&sbi->lookup_lock);
+ list_for_each(p, head) {
+ struct autofs_info *ino;
+ struct dentry *active;
+ const struct qstr *qstr;
+
+ ino = list_entry(p, struct autofs_info, active);
+ active = ino->dentry;
+
+ spin_lock(&active->d_lock);
+
+ /* Already gone? */
+ if ((int) d_count(active) <= 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_dlock(active);
+ spin_unlock(&active->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ return active;
+ }
+next:
+ spin_unlock(&active->d_lock);
+ }
+ spin_unlock(&sbi->lookup_lock);
+
+ return NULL;
+}
+
+static struct dentry *autofs_lookup_expiring(struct dentry *dentry,
+ bool rcu_walk)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+ struct dentry *parent = dentry->d_parent;
+ const 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;
+
+ head = &sbi->expiring_list;
+ if (list_empty(head))
+ return NULL;
+ spin_lock(&sbi->lookup_lock);
+ list_for_each(p, head) {
+ struct autofs_info *ino;
+ struct dentry *expiring;
+ const struct qstr *qstr;
+
+ if (rcu_walk) {
+ spin_unlock(&sbi->lookup_lock);
+ return ERR_PTR(-ECHILD);
+ }
+
+ ino = list_entry(p, struct autofs_info, expiring);
+ expiring = ino->dentry;
+
+ spin_lock(&expiring->d_lock);
+
+ /* We've already been dentry_iput or unlinked */
+ if (d_really_is_negative(expiring))
+ 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_dlock(expiring);
+ spin_unlock(&expiring->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ return expiring;
+ }
+next:
+ spin_unlock(&expiring->d_lock);
+ }
+ spin_unlock(&sbi->lookup_lock);
+
+ return NULL;
+}
+
+static int autofs_mount_wait(const struct path *path, bool rcu_walk)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(path->dentry->d_sb);
+ struct autofs_info *ino = autofs_dentry_ino(path->dentry);
+ int status = 0;
+
+ if (ino->flags & AUTOFS_INF_PENDING) {
+ if (rcu_walk)
+ return -ECHILD;
+ pr_debug("waiting for mount name=%pd\n", path->dentry);
+ status = autofs_wait(sbi, path, NFY_MOUNT);
+ pr_debug("mount wait done status=%d\n", status);
+ }
+ ino->last_used = jiffies;
+ return status;
+}
+
+static int do_expire_wait(const struct path *path, bool rcu_walk)
+{
+ struct dentry *dentry = path->dentry;
+ struct dentry *expiring;
+
+ expiring = autofs_lookup_expiring(dentry, rcu_walk);
+ if (IS_ERR(expiring))
+ return PTR_ERR(expiring);
+ if (!expiring)
+ return autofs_expire_wait(path, rcu_walk);
+ else {
+ const struct path this = { .mnt = path->mnt, .dentry = 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, just wait for it.
+ */
+ autofs_expire_wait(&this, 0);
+ autofs_del_expiring(expiring);
+ dput(expiring);
+ }
+ return 0;
+}
+
+static struct dentry *autofs_mountpoint_changed(struct path *path)
+{
+ struct dentry *dentry = path->dentry;
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+
+ /*
+ * If this is an indirect mount the dentry could have gone away
+ * as a result of an expire and a new one created.
+ */
+ if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) {
+ struct dentry *parent = dentry->d_parent;
+ struct autofs_info *ino;
+ struct dentry *new;
+
+ new = d_lookup(parent, &dentry->d_name);
+ if (!new)
+ return NULL;
+ ino = autofs_dentry_ino(new);
+ ino->last_used = jiffies;
+ dput(path->dentry);
+ path->dentry = new;
+ }
+ return path->dentry;
+}
+
+static struct vfsmount *autofs_d_automount(struct path *path)
+{
+ struct dentry *dentry = path->dentry;
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+ int status;
+
+ pr_debug("dentry=%p %pd\n", dentry, dentry);
+
+ /* The daemon never triggers a mount. */
+ if (autofs_oz_mode(sbi))
+ return NULL;
+
+ /*
+ * If an expire request is pending everyone must wait.
+ * If the expire fails we're still mounted so continue
+ * the follow and return. A return of -EAGAIN (which only
+ * happens with indirect mounts) means the expire completed
+ * and the directory was removed, so just go ahead and try
+ * the mount.
+ */
+ status = do_expire_wait(path, 0);
+ if (status && status != -EAGAIN)
+ return NULL;
+
+ /* Callback to the daemon to perform the mount or wait */
+ spin_lock(&sbi->fs_lock);
+ if (ino->flags & AUTOFS_INF_PENDING) {
+ spin_unlock(&sbi->fs_lock);
+ status = autofs_mount_wait(path, 0);
+ if (status)
+ return ERR_PTR(status);
+ goto done;
+ }
+
+ /*
+ * If the dentry is a symlink it's equivalent to a directory
+ * having path_is_mountpoint() true, so there's no need to call
+ * back to the daemon.
+ */
+ if (d_really_is_positive(dentry) && d_is_symlink(dentry)) {
+ spin_unlock(&sbi->fs_lock);
+ goto done;
+ }
+
+ if (!path_is_mountpoint(path)) {
+ /*
+ * It's possible that user space hasn't removed directories
+ * after umounting a rootless multi-mount, although it
+ * should. For v5 path_has_submounts() is sufficient to
+ * handle this because the leaves of the directory tree under
+ * the mount never trigger mounts themselves (they have an
+ * autofs trigger mount mounted on them). But v4 pseudo direct
+ * mounts do need the leaves to trigger mounts. In this case
+ * we have no choice but to use the list_empty() check and
+ * require user space behave.
+ */
+ if (sbi->version > 4) {
+ if (path_has_submounts(path)) {
+ spin_unlock(&sbi->fs_lock);
+ goto done;
+ }
+ } else {
+ if (!simple_empty(dentry)) {
+ spin_unlock(&sbi->fs_lock);
+ goto done;
+ }
+ }
+ ino->flags |= AUTOFS_INF_PENDING;
+ spin_unlock(&sbi->fs_lock);
+ status = autofs_mount_wait(path, 0);
+ spin_lock(&sbi->fs_lock);
+ ino->flags &= ~AUTOFS_INF_PENDING;
+ if (status) {
+ spin_unlock(&sbi->fs_lock);
+ return ERR_PTR(status);
+ }
+ }
+ spin_unlock(&sbi->fs_lock);
+done:
+ /* Mount succeeded, check if we ended up with a new dentry */
+ dentry = autofs_mountpoint_changed(path);
+ if (!dentry)
+ return ERR_PTR(-ENOENT);
+
+ return NULL;
+}
+
+static int autofs_d_manage(const struct path *path, bool rcu_walk)
+{
+ struct dentry *dentry = path->dentry;
+ struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+ int status;
+
+ pr_debug("dentry=%p %pd\n", dentry, dentry);
+
+ /* The daemon never waits. */
+ if (autofs_oz_mode(sbi)) {
+ if (!path_is_mountpoint(path))
+ return -EISDIR;
+ return 0;
+ }
+
+ /* Wait for pending expires */
+ if (do_expire_wait(path, rcu_walk) == -ECHILD)
+ return -ECHILD;
+
+ /*
+ * This dentry may be under construction so wait on mount
+ * completion.
+ */
+ status = autofs_mount_wait(path, rcu_walk);
+ if (status)
+ return status;
+
+ if (rcu_walk) {
+ /* We don't need fs_lock in rcu_walk mode,
+ * just testing 'AUTOFS_INFO_NO_RCU' is enough.
+ * simple_empty() takes a spinlock, so leave it
+ * to last.
+ * We only return -EISDIR when certain this isn't
+ * a mount-trap.
+ */
+ struct inode *inode;
+
+ if (ino->flags & AUTOFS_INF_WANT_EXPIRE)
+ return 0;
+ if (path_is_mountpoint(path))
+ return 0;
+ inode = d_inode_rcu(dentry);
+ if (inode && S_ISLNK(inode->i_mode))
+ return -EISDIR;
+ if (list_empty(&dentry->d_subdirs))
+ return 0;
+ if (!simple_empty(dentry))
+ return -EISDIR;
+ return 0;
+ }
+
+ spin_lock(&sbi->fs_lock);
+ /*
+ * If the dentry has been selected for expire while we slept
+ * on the lock then it might go away. We'll deal with that in
+ * ->d_automount() and wait on a new mount if the expire
+ * succeeds or return here if it doesn't (since there's no
+ * mount to follow with a rootless multi-mount).
+ */
+ if (!(ino->flags & AUTOFS_INF_EXPIRING)) {
+ /*
+ * Any needed mounting has been completed and the path
+ * updated so check if this is a rootless multi-mount so
+ * we can avoid needless calls ->d_automount() and avoid
+ * an incorrect ELOOP error return.
+ */
+ if ((!path_is_mountpoint(path) && !simple_empty(dentry)) ||
+ (d_really_is_positive(dentry) && d_is_symlink(dentry)))
+ status = -EISDIR;
+ }
+ spin_unlock(&sbi->fs_lock);
+
+ return status;
+}
+
+/* Lookups in the root directory */
+static struct dentry *autofs_lookup(struct inode *dir,
+ struct dentry *dentry, unsigned int flags)
+{
+ struct autofs_sb_info *sbi;
+ struct autofs_info *ino;
+ struct dentry *active;
+
+ pr_debug("name = %pd\n", dentry);
+
+ /* File name too long to exist */
+ if (dentry->d_name.len > NAME_MAX)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ sbi = autofs_sbi(dir->i_sb);
+
+ pr_debug("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
+ current->pid, task_pgrp_nr(current), sbi->catatonic,
+ autofs_oz_mode(sbi));
+
+ active = autofs_lookup_active(dentry);
+ if (active)
+ return active;
+ else {
+ /*
+ * A dentry that is not within the root can never trigger a
+ * mount operation, unless the directory already exists, so we
+ * can return fail immediately. The daemon however does need
+ * to create directories within the file system.
+ */
+ if (!autofs_oz_mode(sbi) && !IS_ROOT(dentry->d_parent))
+ return ERR_PTR(-ENOENT);
+
+ /* Mark entries in the root as mount triggers */
+ if (IS_ROOT(dentry->d_parent) &&
+ autofs_type_indirect(sbi->type))
+ __managed_dentry_set_managed(dentry);
+
+ ino = autofs_new_ino(sbi);
+ if (!ino)
+ return ERR_PTR(-ENOMEM);
+
+ dentry->d_fsdata = ino;
+ ino->dentry = dentry;
+
+ autofs_add_active(dentry);
+ }
+ return NULL;
+}
+
+static int autofs_dir_symlink(struct inode *dir,
+ struct dentry *dentry,
+ const char *symname)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+ struct autofs_info *p_ino;
+ struct inode *inode;
+ size_t size = strlen(symname);
+ char *cp;
+
+ pr_debug("%s <- %pd\n", symname, dentry);
+
+ if (!autofs_oz_mode(sbi))
+ return -EACCES;
+
+ BUG_ON(!ino);
+
+ autofs_clean_ino(ino);
+
+ autofs_del_active(dentry);
+
+ cp = kmalloc(size + 1, GFP_KERNEL);
+ if (!cp)
+ return -ENOMEM;
+
+ strcpy(cp, symname);
+
+ inode = autofs_get_inode(dir->i_sb, S_IFLNK | 0555);
+ if (!inode) {
+ kfree(cp);
+ return -ENOMEM;
+ }
+ inode->i_private = cp;
+ inode->i_size = size;
+ d_add(dentry, inode);
+
+ dget(dentry);
+ atomic_inc(&ino->count);
+ p_ino = autofs_dentry_ino(dentry->d_parent);
+ if (p_ino && !IS_ROOT(dentry))
+ atomic_inc(&p_ino->count);
+
+ dir->i_mtime = current_time(dir);
+
+ 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 autofs_dir_rmdir()..
+ */
+static int autofs_dir_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+ struct autofs_info *p_ino;
+
+ /* This allows root to remove symlinks */
+ if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (atomic_dec_and_test(&ino->count)) {
+ p_ino = autofs_dentry_ino(dentry->d_parent);
+ if (p_ino && !IS_ROOT(dentry))
+ atomic_dec(&p_ino->count);
+ }
+ dput(ino->dentry);
+
+ d_inode(dentry)->i_size = 0;
+ clear_nlink(d_inode(dentry));
+
+ dir->i_mtime = current_time(dir);
+
+ spin_lock(&sbi->lookup_lock);
+ __autofs_add_expiring(dentry);
+ d_drop(dentry);
+ spin_unlock(&sbi->lookup_lock);
+
+ return 0;
+}
+
+/*
+ * Version 4 of autofs provides a pseudo direct mount implementation
+ * that relies on directories at the leaves of a directory tree under
+ * an indirect mount to trigger mounts. To allow for this we need to
+ * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves
+ * of the directory tree. There is no need to clear the automount flag
+ * following a mount or restore it after an expire because these mounts
+ * are always covered. However, it is necessary to ensure that these
+ * flags are clear on non-empty directories to avoid unnecessary calls
+ * during path walks.
+ */
+static void autofs_set_leaf_automount_flags(struct dentry *dentry)
+{
+ struct dentry *parent;
+
+ /* root and dentrys in the root are already handled */
+ if (IS_ROOT(dentry->d_parent))
+ return;
+
+ managed_dentry_set_managed(dentry);
+
+ parent = dentry->d_parent;
+ /* only consider parents below dentrys in the root */
+ if (IS_ROOT(parent->d_parent))
+ return;
+ managed_dentry_clear_managed(parent);
+}
+
+static void autofs_clear_leaf_automount_flags(struct dentry *dentry)
+{
+ struct list_head *d_child;
+ struct dentry *parent;
+
+ /* flags for dentrys in the root are handled elsewhere */
+ if (IS_ROOT(dentry->d_parent))
+ return;
+
+ managed_dentry_clear_managed(dentry);
+
+ parent = dentry->d_parent;
+ /* only consider parents below dentrys in the root */
+ if (IS_ROOT(parent->d_parent))
+ return;
+ d_child = &dentry->d_child;
+ /* Set parent managed if it's becoming empty */
+ if (d_child->next == &parent->d_subdirs &&
+ d_child->prev == &parent->d_subdirs)
+ managed_dentry_set_managed(parent);
+}
+
+static int autofs_dir_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+ struct autofs_info *p_ino;
+
+ pr_debug("dentry %p, removing %pd\n", dentry, dentry);
+
+ if (!autofs_oz_mode(sbi))
+ return -EACCES;
+
+ spin_lock(&sbi->lookup_lock);
+ if (!simple_empty(dentry)) {
+ spin_unlock(&sbi->lookup_lock);
+ return -ENOTEMPTY;
+ }
+ __autofs_add_expiring(dentry);
+ d_drop(dentry);
+ spin_unlock(&sbi->lookup_lock);
+
+ if (sbi->version < 5)
+ autofs_clear_leaf_automount_flags(dentry);
+
+ if (atomic_dec_and_test(&ino->count)) {
+ p_ino = autofs_dentry_ino(dentry->d_parent);
+ if (p_ino && dentry->d_parent != dentry)
+ atomic_dec(&p_ino->count);
+ }
+ dput(ino->dentry);
+ d_inode(dentry)->i_size = 0;
+ clear_nlink(d_inode(dentry));
+
+ if (dir->i_nlink)
+ drop_nlink(dir);
+
+ return 0;
+}
+
+static int autofs_dir_mkdir(struct inode *dir,
+ struct dentry *dentry, umode_t mode)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
+ struct autofs_info *ino = autofs_dentry_ino(dentry);
+ struct autofs_info *p_ino;
+ struct inode *inode;
+
+ if (!autofs_oz_mode(sbi))
+ return -EACCES;
+
+ pr_debug("dentry %p, creating %pd\n", dentry, dentry);
+
+ BUG_ON(!ino);
+
+ autofs_clean_ino(ino);
+
+ autofs_del_active(dentry);
+
+ inode = autofs_get_inode(dir->i_sb, S_IFDIR | mode);
+ if (!inode)
+ return -ENOMEM;
+ d_add(dentry, inode);
+
+ if (sbi->version < 5)
+ autofs_set_leaf_automount_flags(dentry);
+
+ dget(dentry);
+ atomic_inc(&ino->count);
+ p_ino = autofs_dentry_ino(dentry->d_parent);
+ if (p_ino && !IS_ROOT(dentry))
+ atomic_inc(&p_ino->count);
+ inc_nlink(dir);
+ dir->i_mtime = current_time(dir);
+
+ return 0;
+}
+
+/* Get/set timeout ioctl() operation */
+#ifdef CONFIG_COMPAT
+static inline int autofs_compat_get_set_timeout(struct autofs_sb_info *sbi,
+ compat_ulong_t __user *p)
+{
+ unsigned long ntimeout;
+ int rv;
+
+ rv = get_user(ntimeout, p);
+ if (rv)
+ goto error;
+
+ rv = put_user(sbi->exp_timeout/HZ, p);
+ if (rv)
+ goto error;
+
+ if (ntimeout > UINT_MAX/HZ)
+ sbi->exp_timeout = 0;
+ else
+ sbi->exp_timeout = ntimeout * HZ;
+
+ return 0;
+error:
+ return rv;
+}
+#endif
+
+static inline int autofs_get_set_timeout(struct autofs_sb_info *sbi,
+ unsigned long __user *p)
+{
+ unsigned long ntimeout;
+ int rv;
+
+ rv = get_user(ntimeout, p);
+ if (rv)
+ goto error;
+
+ rv = put_user(sbi->exp_timeout/HZ, p);
+ if (rv)
+ goto error;
+
+ if (ntimeout > ULONG_MAX/HZ)
+ sbi->exp_timeout = 0;
+ else
+ sbi->exp_timeout = ntimeout * HZ;
+
+ return 0;
+error:
+ return rv;
+}
+
+/* Return protocol version */
+static inline int autofs_get_protover(struct autofs_sb_info *sbi,
+ int __user *p)
+{
+ return put_user(sbi->version, p);
+}
+
+/* Return protocol sub version */
+static inline int autofs_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 autofs_ask_umount(struct vfsmount *mnt, int __user *p)
+{
+ int status = 0;
+
+ if (may_umount(mnt))
+ status = 1;
+
+ pr_debug("may umount %d\n", status);
+
+ status = put_user(status, p);
+
+ return status;
+}
+
+/* Identify autofs_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_autofs_dentry(struct dentry *dentry)
+{
+ return dentry && d_really_is_positive(dentry) &&
+ dentry->d_op == &autofs_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 autofs_root_ioctl_unlocked(struct inode *inode, struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
+ void __user *p = (void __user *)arg;
+
+ pr_debug("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",
+ cmd, arg, sbi, task_pgrp_nr(current));
+
+ if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
+ _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
+ return -ENOTTY;
+
+ if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ switch (cmd) {
+ case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
+ return autofs_wait_release(sbi, (autofs_wqt_t) arg, 0);
+ case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
+ return autofs_wait_release(sbi, (autofs_wqt_t) arg, -ENOENT);
+ case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
+ autofs_catatonic_mode(sbi);
+ return 0;
+ case AUTOFS_IOC_PROTOVER: /* Get protocol version */
+ return autofs_get_protover(sbi, p);
+ case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
+ return autofs_get_protosubver(sbi, p);
+ case AUTOFS_IOC_SETTIMEOUT:
+ return autofs_get_set_timeout(sbi, p);
+#ifdef CONFIG_COMPAT
+ case AUTOFS_IOC_SETTIMEOUT32:
+ return autofs_compat_get_set_timeout(sbi, p);
+#endif
+
+ case AUTOFS_IOC_ASKUMOUNT:
+ return autofs_ask_umount(filp->f_path.mnt, p);
+
+ /* return a single thing to expire */
+ case AUTOFS_IOC_EXPIRE:
+ return autofs_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 autofs_expire_multi(inode->i_sb,
+ filp->f_path.mnt, sbi, p);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static long autofs_root_ioctl(struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+
+ return autofs_root_ioctl_unlocked(inode, filp, cmd, arg);
+}
+
+#ifdef CONFIG_COMPAT
+static long autofs_root_compat_ioctl(struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ int ret;
+
+ if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL)
+ ret = autofs_root_ioctl_unlocked(inode, filp, cmd, arg);
+ else
+ ret = autofs_root_ioctl_unlocked(inode, filp, cmd,
+ (unsigned long) compat_ptr(arg));
+
+ return ret;
+}
+#endif
diff --git a/fs/autofs/symlink.c b/fs/autofs/symlink.c
new file mode 100644
index 000000000000..aad3902c0cc1
--- /dev/null
+++ b/fs/autofs/symlink.c
@@ -0,0 +1,29 @@
+/*
+ * 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 const char *autofs_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
+{
+ struct autofs_sb_info *sbi;
+ struct autofs_info *ino;
+
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+ sbi = autofs_sbi(dentry->d_sb);
+ ino = autofs_dentry_ino(dentry);
+ if (ino && !autofs_oz_mode(sbi))
+ ino->last_used = jiffies;
+ return d_inode(dentry)->i_private;
+}
+
+const struct inode_operations autofs_symlink_inode_operations = {
+ .get_link = autofs_get_link
+};
diff --git a/fs/autofs/waitq.c b/fs/autofs/waitq.c
new file mode 100644
index 000000000000..8a566fa66afe
--- /dev/null
+++ b/fs/autofs/waitq.c
@@ -0,0 +1,559 @@
+/*
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ * Copyright 2001-2006 Ian Kent <raven@...maw.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/sched/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 autofs_next_wait_queue = 1;
+
+void autofs_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;
+ }
+
+ pr_debug("entering catatonic mode\n");
+
+ 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 */
+ 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 autofs_write(struct autofs_sb_info *sbi,
+ struct file *file, const void *addr, int bytes)
+{
+ unsigned long sigpipe, flags;
+ const char *data = (const char *)addr;
+ ssize_t wr = 0;
+
+ sigpipe = sigismember(¤t->pending.signal, SIGPIPE);
+
+ mutex_lock(&sbi->pipe_mutex);
+ while (bytes) {
+ wr = __kernel_write(file, data, bytes, &file->f_pos);
+ if (wr <= 0)
+ break;
+ data += wr;
+ bytes -= wr;
+ }
+ mutex_unlock(&sbi->pipe_mutex);
+
+ /* 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);
+ }
+
+ /* if 'wr' returned 0 (impossible) we assume -EIO (safe) */
+ return bytes == 0 ? 0 : wr < 0 ? wr : -EIO;
+}
+
+static void autofs_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;
+ int ret;
+
+ pr_debug("wait id = 0x%08lx, name = %.*s, type=%d\n",
+ (unsigned long) 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;
+ struct user_namespace *user_ns = sbi->pipe->f_cred->user_ns;
+
+ 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 = from_kuid_munged(user_ns, wq->uid);
+ packet->gid = from_kgid_munged(user_ns, wq->gid);
+ packet->pid = wq->pid;
+ packet->tgid = wq->tgid;
+ break;
+ }
+ default:
+ pr_warn("bad type %d!\n", type);
+ mutex_unlock(&sbi->wq_mutex);
+ return;
+ }
+
+ pipe = get_file(sbi->pipe);
+
+ mutex_unlock(&sbi->wq_mutex);
+
+ switch (ret = autofs_write(sbi, pipe, &pkt, pktsz)) {
+ case 0:
+ break;
+ case -ENOMEM:
+ case -ERESTARTSYS:
+ /* Just fail this one */
+ autofs_wait_release(sbi, wq->wait_queue_token, ret);
+ break;
+ default:
+ autofs_catatonic_mode(sbi);
+ break;
+ }
+ fput(pipe);
+}
+
+static int autofs_getpath(struct autofs_sb_info *sbi,
+ struct dentry *dentry, char **name)
+{
+ struct dentry *root = sbi->sb->s_root;
+ struct dentry *tmp;
+ char *buf;
+ char *p;
+ int len;
+ unsigned seq;
+
+rename_retry:
+ buf = *name;
+ len = 0;
+
+ seq = read_seqbegin(&rename_lock);
+ rcu_read_lock();
+ spin_lock(&sbi->fs_lock);
+ for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
+ len += tmp->d_name.len + 1;
+
+ if (!len || --len > NAME_MAX) {
+ spin_unlock(&sbi->fs_lock);
+ rcu_read_unlock();
+ if (read_seqretry(&rename_lock, seq))
+ goto rename_retry;
+ 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(&sbi->fs_lock);
+ rcu_read_unlock();
+ if (read_seqretry(&rename_lock, seq))
+ goto rename_retry;
+
+ return len;
+}
+
+static struct autofs_wait_queue *
+autofs_find_wait(struct autofs_sb_info *sbi, const 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,
+ const struct qstr *qstr,
+ const struct path *path, enum autofs_notify notify)
+{
+ struct dentry *dentry = path->dentry;
+ struct autofs_wait_queue *wq;
+ struct autofs_info *ino;
+
+ if (sbi->catatonic)
+ return -ENOENT;
+
+ /* Wait in progress, continue; */
+ wq = autofs_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 = autofs_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;
+
+ if (sbi->catatonic)
+ return -ENOENT;
+
+ wq = autofs_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) {
+ struct dentry *new = NULL;
+ struct path this;
+ int valid = 1;
+
+ /*
+ * 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 (!IS_ROOT(dentry)) {
+ if (d_unhashed(dentry) &&
+ d_really_is_positive(dentry)) {
+ struct dentry *parent = dentry->d_parent;
+
+ new = d_lookup(parent, &dentry->d_name);
+ if (new)
+ dentry = new;
+ }
+ }
+ this.mnt = path->mnt;
+ this.dentry = dentry;
+ if (path_has_submounts(&this))
+ valid = 0;
+
+ if (new)
+ dput(new);
+ return valid;
+ }
+
+ return 1;
+}
+
+int autofs_wait(struct autofs_sb_info *sbi,
+ const struct path *path, enum autofs_notify notify)
+{
+ struct dentry *dentry = path->dentry;
+ struct autofs_wait_queue *wq;
+ struct qstr qstr;
+ char *name;
+ int status, ret, type;
+ pid_t pid;
+ pid_t tgid;
+
+ /* In catatonic mode, we don't wait for nobody */
+ if (sbi->catatonic)
+ return -ENOENT;
+
+ /*
+ * Try translating pids to the namespace of the daemon.
+ *
+ * Zero means failure: we are in an unrelated pid namespace.
+ */
+ pid = task_pid_nr_ns(current, ns_of_pid(sbi->oz_pgrp));
+ tgid = task_tgid_nr_ns(current, ns_of_pid(sbi->oz_pgrp));
+ if (pid == 0 || tgid == 0)
+ return -ENOENT;
+
+ if (d_really_is_negative(dentry)) {
+ /*
+ * 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 = autofs_getpath(sbi, dentry, &name);
+ if (!qstr.len) {
+ kfree(name);
+ return -ENOENT;
+ }
+ }
+ qstr.name = name;
+ qstr.hash = full_name_hash(dentry, name, qstr.len);
+
+ if (mutex_lock_interruptible(&sbi->wq_mutex)) {
+ kfree(qstr.name);
+ return -EINTR;
+ }
+
+ ret = validate_request(&wq, sbi, &qstr, path, notify);
+ if (ret <= 0) {
+ if (ret != -EINTR)
+ 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 = autofs_next_wait_queue;
+ if (++autofs_next_wait_queue == 0)
+ autofs_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 = autofs_get_dev(sbi);
+ wq->ino = autofs_get_ino(sbi);
+ wq->uid = current_uid();
+ wq->gid = current_gid();
+ wq->pid = pid;
+ wq->tgid = tgid;
+ wq->status = -EINTR; /* Status return if interrupted */
+ wq->wait_ctr = 2;
+
+ 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;
+ }
+
+ pr_debug("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
+ (unsigned long) wq->wait_queue_token, wq->name.len,
+ wq->name.name, notify);
+
+ /*
+ * autofs_notify_daemon() may block; it will unlock ->wq_mutex
+ */
+ autofs_notify_daemon(sbi, wq, type);
+ } else {
+ wq->wait_ctr++;
+ pr_debug("existing wait id = 0x%08lx, name = %.*s, nfy=%d\n",
+ (unsigned long) wq->wait_queue_token, wq->name.len,
+ wq->name.name, notify);
+ mutex_unlock(&sbi->wq_mutex);
+ kfree(qstr.name);
+ }
+
+ /*
+ * wq->name.name is NULL iff the lock is already released
+ * or the mount has been made catatonic.
+ */
+ wait_event_killable(wq->queue, wq->name.name == NULL);
+ 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 = autofs_dentry_ino(dentry);
+ if (!ino) {
+ /* If not lookup actual dentry used */
+ de = d_lookup(dentry->d_parent, &dentry->d_name);
+ if (de)
+ ino = autofs_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 autofs_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(&wq->queue);
+ if (!--wq->wait_ctr)
+ kfree(wq);
+ mutex_unlock(&sbi->wq_mutex);
+
+ return 0;
+}
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