1/* -*- linux-c -*- --------------------------------------------------------- * 2 * 3 * linux/fs/autofs/inode.c 4 * 5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved 6 * 7 * This file is part of the Linux kernel and is made available under 8 * the terms of the GNU General Public License, version 2, or at your 9 * option, any later version, incorporated herein by reference. 10 * 11 * ------------------------------------------------------------------------- */ 12 13#include <linux/kernel.h> 14#include <linux/mm.h> 15#include <linux/slab.h> 16#include <linux/file.h> 17#include <linux/parser.h> 18#include <linux/bitops.h> 19#include <linux/magic.h> 20#include "autofs_i.h" 21#include <linux/module.h> 22 23void autofs_kill_sb(struct super_block *sb) 24{ 25 struct autofs_sb_info *sbi = autofs_sbi(sb); 26 unsigned int n; 27 28 /* 29 * In the event of a failure in get_sb_nodev the superblock 30 * info is not present so nothing else has been setup, so 31 * just call kill_anon_super when we are called from 32 * deactivate_super. 33 */ 34 if (!sbi) 35 goto out_kill_sb; 36 37 if (!sbi->catatonic) 38 autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */ 39 40 put_pid(sbi->oz_pgrp); 41 42 autofs_hash_nuke(sbi); 43 for (n = 0; n < AUTOFS_MAX_SYMLINKS; n++) { 44 if (test_bit(n, sbi->symlink_bitmap)) 45 kfree(sbi->symlink[n].data); 46 } 47 48 kfree(sb->s_fs_info); 49 50out_kill_sb: 51 DPRINTK(("autofs: shutting down\n")); 52 kill_anon_super(sb); 53} 54 55static void autofs_read_inode(struct inode *inode); 56 57static const struct super_operations autofs_sops = { 58 .read_inode = autofs_read_inode, 59 .statfs = simple_statfs, 60}; 61 62enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto}; 63 64static match_table_t autofs_tokens = { 65 {Opt_fd, "fd=%u"}, 66 {Opt_uid, "uid=%u"}, 67 {Opt_gid, "gid=%u"}, 68 {Opt_pgrp, "pgrp=%u"}, 69 {Opt_minproto, "minproto=%u"}, 70 {Opt_maxproto, "maxproto=%u"}, 71 {Opt_err, NULL} 72}; 73 74static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, 75 pid_t *pgrp, int *minproto, int *maxproto) 76{ 77 char *p; 78 substring_t args[MAX_OPT_ARGS]; 79 int option; 80 81 *uid = current->uid; 82 *gid = current->gid; 83 *pgrp = process_group(current); 84 85 *minproto = *maxproto = AUTOFS_PROTO_VERSION; 86 87 *pipefd = -1; 88 89 if (!options) 90 return 1; 91 92 while ((p = strsep(&options, ",")) != NULL) { 93 int token; 94 if (!*p) 95 continue; 96 97 token = match_token(p, autofs_tokens, args); 98 switch (token) { 99 case Opt_fd: 100 if (match_int(&args[0], &option)) 101 return 1; 102 *pipefd = option; 103 break; 104 case Opt_uid: 105 if (match_int(&args[0], &option)) 106 return 1; 107 *uid = option; 108 break; 109 case Opt_gid: 110 if (match_int(&args[0], &option)) 111 return 1; 112 *gid = option; 113 break; 114 case Opt_pgrp: 115 if (match_int(&args[0], &option)) 116 return 1; 117 *pgrp = option; 118 break; 119 case Opt_minproto: 120 if (match_int(&args[0], &option)) 121 return 1; 122 *minproto = option; 123 break; 124 case Opt_maxproto: 125 if (match_int(&args[0], &option)) 126 return 1; 127 *maxproto = option; 128 break; 129 default: 130 return 1; 131 } 132 } 133 return (*pipefd < 0); 134} 135 136int autofs_fill_super(struct super_block *s, void *data, int silent) 137{ 138 struct inode * root_inode; 139 struct dentry * root; 140 struct file * pipe; 141 int pipefd; 142 struct autofs_sb_info *sbi; 143 int minproto, maxproto; 144 pid_t pgid; 145 146 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); 147 if (!sbi) 148 goto fail_unlock; 149 DPRINTK(("autofs: starting up, sbi = %p\n",sbi)); 150 151 s->s_fs_info = sbi; 152 sbi->magic = AUTOFS_SBI_MAGIC; 153 sbi->pipe = NULL; 154 sbi->catatonic = 1; 155 sbi->exp_timeout = 0; 156 autofs_initialize_hash(&sbi->dirhash); 157 sbi->queues = NULL; 158 memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN); 159 sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO; 160 s->s_blocksize = 1024; 161 s->s_blocksize_bits = 10; 162 s->s_magic = AUTOFS_SUPER_MAGIC; 163 s->s_op = &autofs_sops; 164 s->s_time_gran = 1; 165 sbi->sb = s; 166 167 root_inode = iget(s, AUTOFS_ROOT_INO); 168 root = d_alloc_root(root_inode); 169 pipe = NULL; 170 171 if (!root) 172 goto fail_iput; 173 174 /* Can this call block? - WTF cares? s is locked. */ 175 if (parse_options(data, &pipefd, &root_inode->i_uid, 176 &root_inode->i_gid, &pgid, &minproto, 177 &maxproto)) { 178 printk("autofs: called with bogus options\n"); 179 goto fail_dput; 180 } 181 182 /* Couldn't this be tested earlier? */ 183 if (minproto > AUTOFS_PROTO_VERSION || 184 maxproto < AUTOFS_PROTO_VERSION) { 185 printk("autofs: kernel does not match daemon version\n"); 186 goto fail_dput; 187 } 188 189 DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, pgid)); 190 sbi->oz_pgrp = find_get_pid(pgid); 191 192 if (!sbi->oz_pgrp) { 193 printk("autofs: could not find process group %d\n", pgid); 194 goto fail_dput; 195 } 196 197 pipe = fget(pipefd); 198 199 if (!pipe) { 200 printk("autofs: could not open pipe file descriptor\n"); 201 goto fail_put_pid; 202 } 203 204 if (!pipe->f_op || !pipe->f_op->write) 205 goto fail_fput; 206 sbi->pipe = pipe; 207 sbi->catatonic = 0; 208 209 /* 210 * Success! Install the root dentry now to indicate completion. 211 */ 212 s->s_root = root; 213 return 0; 214 215fail_fput: 216 printk("autofs: pipe file descriptor does not contain proper ops\n"); 217 fput(pipe); 218fail_put_pid: 219 put_pid(sbi->oz_pgrp); 220fail_dput: 221 dput(root); 222 goto fail_free; 223fail_iput: 224 printk("autofs: get root dentry failed\n"); 225 iput(root_inode); 226fail_free: 227 kfree(sbi); 228 s->s_fs_info = NULL; 229fail_unlock: 230 return -EINVAL; 231} 232 233static void autofs_read_inode(struct inode *inode) 234{ 235 ino_t ino = inode->i_ino; 236 unsigned int n; 237 struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb); 238 239 /* Initialize to the default case (stub directory) */ 240 241 inode->i_op = &simple_dir_inode_operations; 242 inode->i_fop = &simple_dir_operations; 243 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO; 244 inode->i_nlink = 2; 245 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 246 inode->i_blocks = 0; 247 248 if (ino == AUTOFS_ROOT_INO) { 249 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR; 250 inode->i_op = &autofs_root_inode_operations; 251 inode->i_fop = &autofs_root_operations; 252 inode->i_uid = inode->i_gid = 0; /* Changed in read_super */ 253 return; 254 } 255 256 inode->i_uid = inode->i_sb->s_root->d_inode->i_uid; 257 inode->i_gid = inode->i_sb->s_root->d_inode->i_gid; 258 259 if (ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO) { 260 /* Symlink inode - should be in symlink list */ 261 struct autofs_symlink *sl; 262 263 n = ino - AUTOFS_FIRST_SYMLINK; 264 if (n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) { 265 printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino); 266 return; 267 } 268 269 inode->i_op = &autofs_symlink_inode_operations; 270 sl = &sbi->symlink[n]; 271 inode->i_private = sl; 272 inode->i_mode = S_IFLNK | S_IRWXUGO; 273 inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime; 274 inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 275 inode->i_size = sl->len; 276 inode->i_nlink = 1; 277 } 278} 279