/* * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved * Copyright 2005-2006 Ian Kent <raven@themaw.net> * * This file is part of the Linux kernel and is made available under * the terms of the GNU General Public License, version 2, or at your * option, any later version, incorporated herein by reference. */ /* Internal header file for autofs */ #include <linux/auto_fs4.h> #include <linux/auto_dev-ioctl.h> #include <linux/mutex.h> #include <linux/spinlock.h> #include <linux/list.h> /* This is the range of ioctl() numbers we claim as ours */ #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY #define AUTOFS_IOC_COUNT 32 #define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION) #define AUTOFS_DEV_IOCTL_IOC_COUNT (AUTOFS_IOC_COUNT - 11) #include <linux/kernel.h> #include <linux/slab.h> #include <linux/time.h> #include <linux/string.h> #include <linux/wait.h> #include <linux/sched.h> #include <linux/mount.h> #include <linux/namei.h> #include <asm/current.h> #include <linux/uaccess.h> /* #define DEBUG */ #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; int reghost_enabled; int needs_reghost; 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 *autofs4_sbi(struct super_block *sb) { return (struct autofs_sb_info *)(sb->s_fs_info); } static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry) { return (struct autofs_info *)(dentry->d_fsdata); } /* autofs4_oz_mode(): do we see the man behind the curtain? (The * processes which do manipulations for us in user space sees the raw * filesystem without "magic".) */ static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) { return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp; } struct inode *autofs4_get_inode(struct super_block *, umode_t); void autofs4_free_ino(struct autofs_info *); /* Expiration */ int is_autofs4_dentry(struct dentry *); int autofs4_expire_wait(struct dentry *dentry, int rcu_walk); int autofs4_expire_run(struct super_block *, struct vfsmount *, struct autofs_sb_info *, struct autofs_packet_expire __user *); int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt, struct autofs_sb_info *sbi, int when); int autofs4_expire_multi(struct super_block *, struct vfsmount *, struct autofs_sb_info *, int __user *); struct dentry *autofs4_expire_direct(struct super_block *sb, struct vfsmount *mnt, struct autofs_sb_info *sbi, int how); struct dentry *autofs4_expire_indirect(struct super_block *sb, struct vfsmount *mnt, struct autofs_sb_info *sbi, int how); /* Device node initialization */ int autofs_dev_ioctl_init(void); void autofs_dev_ioctl_exit(void); /* Operations structures */ extern const struct inode_operations autofs4_symlink_inode_operations; extern const struct inode_operations autofs4_dir_inode_operations; extern const struct file_operations autofs4_dir_operations; extern const struct file_operations autofs4_root_operations; extern const struct dentry_operations autofs4_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 autofs4_fill_super(struct super_block *, void *, int); struct autofs_info *autofs4_new_ino(struct autofs_sb_info *); void autofs4_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 autofs4_wait(struct autofs_sb_info *, struct dentry *, enum autofs_notify); int autofs4_wait_release(struct autofs_sb_info *, autofs_wqt_t, int); void autofs4_catatonic_mode(struct autofs_sb_info *); static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi) { return new_encode_dev(sbi->sb->s_dev); } static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi) { return d_inode(sbi->sb->s_root)->i_ino; } static inline void __autofs4_add_expiring(struct dentry *dentry) { struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); if (ino) { if (list_empty(&ino->expiring)) list_add(&ino->expiring, &sbi->expiring_list); } } static inline void autofs4_add_expiring(struct dentry *dentry) { struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); if (ino) { spin_lock(&sbi->lookup_lock); if (list_empty(&ino->expiring)) list_add(&ino->expiring, &sbi->expiring_list); spin_unlock(&sbi->lookup_lock); } } static inline void autofs4_del_expiring(struct dentry *dentry) { struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); if (ino) { spin_lock(&sbi->lookup_lock); if (!list_empty(&ino->expiring)) list_del_init(&ino->expiring); spin_unlock(&sbi->lookup_lock); } } extern void autofs4_kill_sb(struct super_block *);