/* -*- 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->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; }