Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | } |