|  | /* -*- c -*- --------------------------------------------------------------- * | 
|  | * | 
|  | * linux/fs/autofs/inode.c | 
|  | * | 
|  | *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved | 
|  | *  Copyright 2005-2006 Ian Kent <raven@themaw.net> | 
|  | * | 
|  | * This file is part of the Linux kernel and is made available under | 
|  | * the terms of the GNU General Public License, version 2, or at your | 
|  | * option, any later version, incorporated herein by reference. | 
|  | * | 
|  | * ------------------------------------------------------------------------- */ | 
|  |  | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/file.h> | 
|  | #include <linux/seq_file.h> | 
|  | #include <linux/pagemap.h> | 
|  | #include <linux/parser.h> | 
|  | #include <linux/bitops.h> | 
|  | #include <linux/magic.h> | 
|  | #include "autofs_i.h" | 
|  | #include <linux/module.h> | 
|  |  | 
|  | static void ino_lnkfree(struct autofs_info *ino) | 
|  | { | 
|  | if (ino->u.symlink) { | 
|  | kfree(ino->u.symlink); | 
|  | ino->u.symlink = NULL; | 
|  | } | 
|  | } | 
|  |  | 
|  | struct autofs_info *autofs4_init_ino(struct autofs_info *ino, | 
|  | struct autofs_sb_info *sbi, mode_t mode) | 
|  | { | 
|  | int reinit = 1; | 
|  |  | 
|  | if (ino == NULL) { | 
|  | reinit = 0; | 
|  | ino = kmalloc(sizeof(*ino), GFP_KERNEL); | 
|  | } | 
|  |  | 
|  | if (ino == NULL) | 
|  | return NULL; | 
|  |  | 
|  | if (!reinit) { | 
|  | ino->flags = 0; | 
|  | ino->inode = NULL; | 
|  | ino->dentry = NULL; | 
|  | ino->size = 0; | 
|  | INIT_LIST_HEAD(&ino->active); | 
|  | INIT_LIST_HEAD(&ino->expiring); | 
|  | atomic_set(&ino->count, 0); | 
|  | } | 
|  |  | 
|  | ino->uid = 0; | 
|  | ino->gid = 0; | 
|  | ino->mode = mode; | 
|  | ino->last_used = jiffies; | 
|  |  | 
|  | ino->sbi = sbi; | 
|  |  | 
|  | if (reinit && ino->free) | 
|  | (ino->free)(ino); | 
|  |  | 
|  | memset(&ino->u, 0, sizeof(ino->u)); | 
|  |  | 
|  | ino->free = NULL; | 
|  |  | 
|  | if (S_ISLNK(mode)) | 
|  | ino->free = ino_lnkfree; | 
|  |  | 
|  | return ino; | 
|  | } | 
|  |  | 
|  | void autofs4_free_ino(struct autofs_info *ino) | 
|  | { | 
|  | struct autofs_info *p_ino; | 
|  |  | 
|  | if (ino->dentry) { | 
|  | ino->dentry->d_fsdata = NULL; | 
|  | if (ino->dentry->d_inode) { | 
|  | struct dentry *parent = ino->dentry->d_parent; | 
|  | if (atomic_dec_and_test(&ino->count)) { | 
|  | p_ino = autofs4_dentry_ino(parent); | 
|  | if (p_ino && parent != ino->dentry) | 
|  | atomic_dec(&p_ino->count); | 
|  | } | 
|  | dput(ino->dentry); | 
|  | } | 
|  | ino->dentry = NULL; | 
|  | } | 
|  | if (ino->free) | 
|  | (ino->free)(ino); | 
|  | kfree(ino); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Deal with the infamous "Busy inodes after umount ..." message. | 
|  | * | 
|  | * Clean up the dentry tree. This happens with autofs if the user | 
|  | * space program goes away due to a SIGKILL, SIGSEGV etc. | 
|  | */ | 
|  | static void autofs4_force_release(struct autofs_sb_info *sbi) | 
|  | { | 
|  | struct dentry *this_parent = sbi->sb->s_root; | 
|  | struct list_head *next; | 
|  |  | 
|  | if (!sbi->sb->s_root) | 
|  | return; | 
|  |  | 
|  | spin_lock(&dcache_lock); | 
|  | repeat: | 
|  | next = this_parent->d_subdirs.next; | 
|  | resume: | 
|  | while (next != &this_parent->d_subdirs) { | 
|  | struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child); | 
|  |  | 
|  | /* Negative dentry - don`t care */ | 
|  | if (!simple_positive(dentry)) { | 
|  | next = next->next; | 
|  | continue; | 
|  | } | 
|  |  | 
|  | if (!list_empty(&dentry->d_subdirs)) { | 
|  | this_parent = dentry; | 
|  | goto repeat; | 
|  | } | 
|  |  | 
|  | next = next->next; | 
|  | spin_unlock(&dcache_lock); | 
|  |  | 
|  | DPRINTK("dentry %p %.*s", | 
|  | dentry, (int)dentry->d_name.len, dentry->d_name.name); | 
|  |  | 
|  | dput(dentry); | 
|  | spin_lock(&dcache_lock); | 
|  | } | 
|  |  | 
|  | if (this_parent != sbi->sb->s_root) { | 
|  | struct dentry *dentry = this_parent; | 
|  |  | 
|  | next = this_parent->d_u.d_child.next; | 
|  | this_parent = this_parent->d_parent; | 
|  | spin_unlock(&dcache_lock); | 
|  | DPRINTK("parent dentry %p %.*s", | 
|  | dentry, (int)dentry->d_name.len, dentry->d_name.name); | 
|  | dput(dentry); | 
|  | spin_lock(&dcache_lock); | 
|  | goto resume; | 
|  | } | 
|  | spin_unlock(&dcache_lock); | 
|  | } | 
|  |  | 
|  | void autofs4_kill_sb(struct super_block *sb) | 
|  | { | 
|  | struct autofs_sb_info *sbi = autofs4_sbi(sb); | 
|  |  | 
|  | /* | 
|  | * In the event of a failure in get_sb_nodev the superblock | 
|  | * info is not present so nothing else has been setup, so | 
|  | * just call kill_anon_super when we are called from | 
|  | * deactivate_super. | 
|  | */ | 
|  | if (!sbi) | 
|  | goto out_kill_sb; | 
|  |  | 
|  | /* Free wait queues, close pipe */ | 
|  | autofs4_catatonic_mode(sbi); | 
|  |  | 
|  | /* Clean up and release dangling references */ | 
|  | autofs4_force_release(sbi); | 
|  |  | 
|  | sb->s_fs_info = NULL; | 
|  | kfree(sbi); | 
|  |  | 
|  | out_kill_sb: | 
|  | DPRINTK("shutting down"); | 
|  | kill_anon_super(sb); | 
|  | } | 
|  |  | 
|  | static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt) | 
|  | { | 
|  | struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb); | 
|  | struct inode *root_inode = mnt->mnt_sb->s_root->d_inode; | 
|  |  | 
|  | if (!sbi) | 
|  | return 0; | 
|  |  | 
|  | seq_printf(m, ",fd=%d", sbi->pipefd); | 
|  | if (root_inode->i_uid != 0) | 
|  | seq_printf(m, ",uid=%u", root_inode->i_uid); | 
|  | if (root_inode->i_gid != 0) | 
|  | seq_printf(m, ",gid=%u", root_inode->i_gid); | 
|  | seq_printf(m, ",pgrp=%d", sbi->oz_pgrp); | 
|  | seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ); | 
|  | seq_printf(m, ",minproto=%d", sbi->min_proto); | 
|  | seq_printf(m, ",maxproto=%d", sbi->max_proto); | 
|  |  | 
|  | if (sbi->type & AUTOFS_TYPE_OFFSET) | 
|  | seq_printf(m, ",offset"); | 
|  | else if (sbi->type & AUTOFS_TYPE_DIRECT) | 
|  | seq_printf(m, ",direct"); | 
|  | else | 
|  | seq_printf(m, ",indirect"); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct super_operations autofs4_sops = { | 
|  | .statfs		= simple_statfs, | 
|  | .show_options	= autofs4_show_options, | 
|  | }; | 
|  |  | 
|  | enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto, | 
|  | Opt_indirect, Opt_direct, Opt_offset}; | 
|  |  | 
|  | static const match_table_t tokens = { | 
|  | {Opt_fd, "fd=%u"}, | 
|  | {Opt_uid, "uid=%u"}, | 
|  | {Opt_gid, "gid=%u"}, | 
|  | {Opt_pgrp, "pgrp=%u"}, | 
|  | {Opt_minproto, "minproto=%u"}, | 
|  | {Opt_maxproto, "maxproto=%u"}, | 
|  | {Opt_indirect, "indirect"}, | 
|  | {Opt_direct, "direct"}, | 
|  | {Opt_offset, "offset"}, | 
|  | {Opt_err, NULL} | 
|  | }; | 
|  |  | 
|  | static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, | 
|  | pid_t *pgrp, unsigned int *type, int *minproto, int *maxproto) | 
|  | { | 
|  | char *p; | 
|  | substring_t args[MAX_OPT_ARGS]; | 
|  | int option; | 
|  |  | 
|  | *uid = current->uid; | 
|  | *gid = current->gid; | 
|  | *pgrp = task_pgrp_nr(current); | 
|  |  | 
|  | *minproto = AUTOFS_MIN_PROTO_VERSION; | 
|  | *maxproto = AUTOFS_MAX_PROTO_VERSION; | 
|  |  | 
|  | *pipefd = -1; | 
|  |  | 
|  | if (!options) | 
|  | return 1; | 
|  |  | 
|  | while ((p = strsep(&options, ",")) != NULL) { | 
|  | int token; | 
|  | if (!*p) | 
|  | continue; | 
|  |  | 
|  | token = match_token(p, tokens, args); | 
|  | switch (token) { | 
|  | case Opt_fd: | 
|  | if (match_int(args, pipefd)) | 
|  | return 1; | 
|  | break; | 
|  | case Opt_uid: | 
|  | if (match_int(args, &option)) | 
|  | return 1; | 
|  | *uid = option; | 
|  | break; | 
|  | case Opt_gid: | 
|  | if (match_int(args, &option)) | 
|  | return 1; | 
|  | *gid = option; | 
|  | break; | 
|  | case Opt_pgrp: | 
|  | if (match_int(args, &option)) | 
|  | return 1; | 
|  | *pgrp = option; | 
|  | break; | 
|  | case Opt_minproto: | 
|  | if (match_int(args, &option)) | 
|  | return 1; | 
|  | *minproto = option; | 
|  | break; | 
|  | case Opt_maxproto: | 
|  | if (match_int(args, &option)) | 
|  | return 1; | 
|  | *maxproto = option; | 
|  | break; | 
|  | case Opt_indirect: | 
|  | *type = AUTOFS_TYPE_INDIRECT; | 
|  | break; | 
|  | case Opt_direct: | 
|  | *type = AUTOFS_TYPE_DIRECT; | 
|  | break; | 
|  | case Opt_offset: | 
|  | *type = AUTOFS_TYPE_OFFSET; | 
|  | break; | 
|  | default: | 
|  | return 1; | 
|  | } | 
|  | } | 
|  | return (*pipefd < 0); | 
|  | } | 
|  |  | 
|  | static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi) | 
|  | { | 
|  | struct autofs_info *ino; | 
|  |  | 
|  | ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755); | 
|  | if (!ino) | 
|  | return NULL; | 
|  |  | 
|  | return ino; | 
|  | } | 
|  |  | 
|  | static struct dentry_operations autofs4_sb_dentry_operations = { | 
|  | .d_release      = autofs4_dentry_release, | 
|  | }; | 
|  |  | 
|  | int autofs4_fill_super(struct super_block *s, void *data, int silent) | 
|  | { | 
|  | struct inode * root_inode; | 
|  | struct dentry * root; | 
|  | struct file * pipe; | 
|  | int pipefd; | 
|  | struct autofs_sb_info *sbi; | 
|  | struct autofs_info *ino; | 
|  |  | 
|  | sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); | 
|  | if (!sbi) | 
|  | goto fail_unlock; | 
|  | DPRINTK("starting up, sbi = %p",sbi); | 
|  |  | 
|  | s->s_fs_info = sbi; | 
|  | sbi->magic = AUTOFS_SBI_MAGIC; | 
|  | sbi->pipefd = -1; | 
|  | sbi->pipe = NULL; | 
|  | sbi->catatonic = 1; | 
|  | sbi->exp_timeout = 0; | 
|  | sbi->oz_pgrp = task_pgrp_nr(current); | 
|  | sbi->sb = s; | 
|  | sbi->version = 0; | 
|  | sbi->sub_version = 0; | 
|  | sbi->type = AUTOFS_TYPE_INDIRECT; | 
|  | sbi->min_proto = 0; | 
|  | sbi->max_proto = 0; | 
|  | mutex_init(&sbi->wq_mutex); | 
|  | spin_lock_init(&sbi->fs_lock); | 
|  | sbi->queues = NULL; | 
|  | spin_lock_init(&sbi->lookup_lock); | 
|  | INIT_LIST_HEAD(&sbi->active_list); | 
|  | INIT_LIST_HEAD(&sbi->expiring_list); | 
|  | s->s_blocksize = 1024; | 
|  | s->s_blocksize_bits = 10; | 
|  | s->s_magic = AUTOFS_SUPER_MAGIC; | 
|  | s->s_op = &autofs4_sops; | 
|  | s->s_time_gran = 1; | 
|  |  | 
|  | /* | 
|  | * Get the root inode and dentry, but defer checking for errors. | 
|  | */ | 
|  | ino = autofs4_mkroot(sbi); | 
|  | if (!ino) | 
|  | goto fail_free; | 
|  | root_inode = autofs4_get_inode(s, ino); | 
|  | if (!root_inode) | 
|  | goto fail_ino; | 
|  |  | 
|  | root = d_alloc_root(root_inode); | 
|  | if (!root) | 
|  | goto fail_iput; | 
|  | pipe = NULL; | 
|  |  | 
|  | root->d_op = &autofs4_sb_dentry_operations; | 
|  | root->d_fsdata = ino; | 
|  |  | 
|  | /* Can this call block? */ | 
|  | if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid, | 
|  | &sbi->oz_pgrp, &sbi->type, &sbi->min_proto, | 
|  | &sbi->max_proto)) { | 
|  | printk("autofs: called with bogus options\n"); | 
|  | goto fail_dput; | 
|  | } | 
|  |  | 
|  | root_inode->i_fop = &autofs4_root_operations; | 
|  | root_inode->i_op = sbi->type & AUTOFS_TYPE_TRIGGER ? | 
|  | &autofs4_direct_root_inode_operations : | 
|  | &autofs4_indirect_root_inode_operations; | 
|  |  | 
|  | /* Couldn't this be tested earlier? */ | 
|  | if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION || | 
|  | sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) { | 
|  | printk("autofs: kernel does not match daemon version " | 
|  | "daemon (%d, %d) kernel (%d, %d)\n", | 
|  | sbi->min_proto, sbi->max_proto, | 
|  | AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION); | 
|  | goto fail_dput; | 
|  | } | 
|  |  | 
|  | /* Establish highest kernel protocol version */ | 
|  | if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION) | 
|  | sbi->version = AUTOFS_MAX_PROTO_VERSION; | 
|  | else | 
|  | sbi->version = sbi->max_proto; | 
|  | sbi->sub_version = AUTOFS_PROTO_SUBVERSION; | 
|  |  | 
|  | DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp); | 
|  | pipe = fget(pipefd); | 
|  |  | 
|  | if (!pipe) { | 
|  | printk("autofs: could not open pipe file descriptor\n"); | 
|  | goto fail_dput; | 
|  | } | 
|  | if (!pipe->f_op || !pipe->f_op->write) | 
|  | goto fail_fput; | 
|  | sbi->pipe = pipe; | 
|  | sbi->pipefd = pipefd; | 
|  | sbi->catatonic = 0; | 
|  |  | 
|  | /* | 
|  | * Success! Install the root dentry now to indicate completion. | 
|  | */ | 
|  | s->s_root = root; | 
|  | return 0; | 
|  |  | 
|  | /* | 
|  | * Failure ... clean up. | 
|  | */ | 
|  | fail_fput: | 
|  | printk("autofs: pipe file descriptor does not contain proper ops\n"); | 
|  | fput(pipe); | 
|  | /* fall through */ | 
|  | fail_dput: | 
|  | dput(root); | 
|  | goto fail_free; | 
|  | fail_iput: | 
|  | printk("autofs: get root dentry failed\n"); | 
|  | iput(root_inode); | 
|  | fail_ino: | 
|  | kfree(ino); | 
|  | fail_free: | 
|  | kfree(sbi); | 
|  | s->s_fs_info = NULL; | 
|  | fail_unlock: | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | struct inode *autofs4_get_inode(struct super_block *sb, | 
|  | struct autofs_info *inf) | 
|  | { | 
|  | struct inode *inode = new_inode(sb); | 
|  |  | 
|  | if (inode == NULL) | 
|  | return NULL; | 
|  |  | 
|  | inf->inode = inode; | 
|  | inode->i_mode = inf->mode; | 
|  | if (sb->s_root) { | 
|  | inode->i_uid = sb->s_root->d_inode->i_uid; | 
|  | inode->i_gid = sb->s_root->d_inode->i_gid; | 
|  | } else { | 
|  | inode->i_uid = 0; | 
|  | inode->i_gid = 0; | 
|  | } | 
|  | inode->i_blocks = 0; | 
|  | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | 
|  |  | 
|  | if (S_ISDIR(inf->mode)) { | 
|  | inode->i_nlink = 2; | 
|  | inode->i_op = &autofs4_dir_inode_operations; | 
|  | inode->i_fop = &autofs4_dir_operations; | 
|  | } else if (S_ISLNK(inf->mode)) { | 
|  | inode->i_size = inf->size; | 
|  | inode->i_op = &autofs4_symlink_inode_operations; | 
|  | } | 
|  |  | 
|  | return inode; | 
|  | } |