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 "autofs_i.h" 20 #include <linux/module.h> 21 22 static void autofs_put_super(struct super_block *sb) 23 { 24 struct autofs_sb_info *sbi = autofs_sbi(sb); 25 unsigned int n; 26 27 if ( !sbi->catatonic ) 28 autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */ 29 30 autofs_hash_nuke(&sbi->dirhash); 31 for ( n = 0 ; n < AUTOFS_MAX_SYMLINKS ; n++ ) { 32 if ( test_bit(n, sbi->symlink_bitmap) ) 33 kfree(sbi->symlink[n].data); 34 } 35 36 kfree(sb->s_fs_info); 37 38 DPRINTK(("autofs: shutting down\n")); 39 } 40 41 static void autofs_read_inode(struct inode *inode); 42 43 static struct super_operations autofs_sops = { 44 .read_inode = autofs_read_inode, 45 .put_super = autofs_put_super, 46 .statfs = simple_statfs, 47 }; 48 49 enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto}; 50 51 static match_table_t autofs_tokens = { 52 {Opt_fd, "fd=%u"}, 53 {Opt_uid, "uid=%u"}, 54 {Opt_gid, "gid=%u"}, 55 {Opt_pgrp, "pgrp=%u"}, 56 {Opt_minproto, "minproto=%u"}, 57 {Opt_maxproto, "maxproto=%u"}, 58 {Opt_err, NULL} 59 }; 60 61 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, pid_t *pgrp, int *minproto, int *maxproto) 62 { 63 char *p; 64 substring_t args[MAX_OPT_ARGS]; 65 int option; 66 67 *uid = current->uid; 68 *gid = current->gid; 69 *pgrp = process_group(current); 70 71 *minproto = *maxproto = AUTOFS_PROTO_VERSION; 72 73 *pipefd = -1; 74 75 if (!options) 76 return 1; 77 78 while ((p = strsep(&options, ",")) != NULL) { 79 int token; 80 if (!*p) 81 continue; 82 83 token = match_token(p, autofs_tokens, args); 84 switch (token) { 85 case Opt_fd: 86 if (match_int(&args[0], &option)) 87 return 1; 88 *pipefd = option; 89 break; 90 case Opt_uid: 91 if (match_int(&args[0], &option)) 92 return 1; 93 *uid = option; 94 break; 95 case Opt_gid: 96 if (match_int(&args[0], &option)) 97 return 1; 98 *gid = option; 99 break; 100 case Opt_pgrp: 101 if (match_int(&args[0], &option)) 102 return 1; 103 *pgrp = option; 104 break; 105 case Opt_minproto: 106 if (match_int(&args[0], &option)) 107 return 1; 108 *minproto = option; 109 break; 110 case Opt_maxproto: 111 if (match_int(&args[0], &option)) 112 return 1; 113 *maxproto = option; 114 break; 115 default: 116 return 1; 117 } 118 } 119 return (*pipefd < 0); 120 } 121 122 int autofs_fill_super(struct super_block *s, void *data, int silent) 123 { 124 struct inode * root_inode; 125 struct dentry * root; 126 struct file * pipe; 127 int pipefd; 128 struct autofs_sb_info *sbi; 129 int minproto, maxproto; 130 131 sbi = kmalloc(sizeof(*sbi), GFP_KERNEL); 132 if ( !sbi ) 133 goto fail_unlock; 134 memset(sbi, 0, sizeof(*sbi)); 135 DPRINTK(("autofs: starting up, sbi = %p\n",sbi)); 136 137 s->s_fs_info = sbi; 138 sbi->magic = AUTOFS_SBI_MAGIC; 139 sbi->catatonic = 0; 140 sbi->exp_timeout = 0; 141 sbi->oz_pgrp = process_group(current); 142 autofs_initialize_hash(&sbi->dirhash); 143 sbi->queues = NULL; 144 memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN); 145 sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO; 146 s->s_blocksize = 1024; 147 s->s_blocksize_bits = 10; 148 s->s_magic = AUTOFS_SUPER_MAGIC; 149 s->s_op = &autofs_sops; 150 s->s_time_gran = 1; 151 152 root_inode = iget(s, AUTOFS_ROOT_INO); 153 root = d_alloc_root(root_inode); 154 pipe = NULL; 155 156 if (!root) 157 goto fail_iput; 158 159 /* Can this call block? - WTF cares? s is locked. */ 160 if ( parse_options(data,&pipefd,&root_inode->i_uid,&root_inode->i_gid,&sbi->oz_pgrp,&minproto,&maxproto) ) { 161 printk("autofs: called with bogus options\n"); 162 goto fail_dput; 163 } 164 165 /* Couldn't this be tested earlier? */ 166 if ( minproto > AUTOFS_PROTO_VERSION || 167 maxproto < AUTOFS_PROTO_VERSION ) { 168 printk("autofs: kernel does not match daemon version\n"); 169 goto fail_dput; 170 } 171 172 DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp)); 173 pipe = fget(pipefd); 174 175 if ( !pipe ) { 176 printk("autofs: could not open pipe file descriptor\n"); 177 goto fail_dput; 178 } 179 if ( !pipe->f_op || !pipe->f_op->write ) 180 goto fail_fput; 181 sbi->pipe = pipe; 182 183 /* 184 * Success! Install the root dentry now to indicate completion. 185 */ 186 s->s_root = root; 187 return 0; 188 189 fail_fput: 190 printk("autofs: pipe file descriptor does not contain proper ops\n"); 191 fput(pipe); 192 fail_dput: 193 dput(root); 194 goto fail_free; 195 fail_iput: 196 printk("autofs: get root dentry failed\n"); 197 iput(root_inode); 198 fail_free: 199 kfree(sbi); 200 fail_unlock: 201 return -EINVAL; 202 } 203 204 static void autofs_read_inode(struct inode *inode) 205 { 206 ino_t ino = inode->i_ino; 207 unsigned int n; 208 struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb); 209 210 /* Initialize to the default case (stub directory) */ 211 212 inode->i_op = &simple_dir_inode_operations; 213 inode->i_fop = &simple_dir_operations; 214 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO; 215 inode->i_nlink = 2; 216 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 217 inode->i_blocks = 0; 218 inode->i_blksize = 1024; 219 220 if ( ino == AUTOFS_ROOT_INO ) { 221 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR; 222 inode->i_op = &autofs_root_inode_operations; 223 inode->i_fop = &autofs_root_operations; 224 inode->i_uid = inode->i_gid = 0; /* Changed in read_super */ 225 return; 226 } 227 228 inode->i_uid = inode->i_sb->s_root->d_inode->i_uid; 229 inode->i_gid = inode->i_sb->s_root->d_inode->i_gid; 230 231 if ( ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO ) { 232 /* Symlink inode - should be in symlink list */ 233 struct autofs_symlink *sl; 234 235 n = ino - AUTOFS_FIRST_SYMLINK; 236 if ( n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) { 237 printk("autofs: Looking for bad symlink inode %u\n", (unsigned int) ino); 238 return; 239 } 240 241 inode->i_op = &autofs_symlink_inode_operations; 242 sl = &sbi->symlink[n]; 243 inode->u.generic_ip = sl; 244 inode->i_mode = S_IFLNK | S_IRWXUGO; 245 inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime; 246 inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; 247 inode->i_size = sl->len; 248 inode->i_nlink = 1; 249 } 250 } 251