fs/autofs4/inode.c

   1 /* -*- 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/slab.h>
  15 #include <linux/file.h>
  16 #include <linux/locks.h>
  17 #include <asm/bitops.h>
  18 #include "autofs_i.h"
  19 #define __NO_VERSION__
  20 #include <linux/module.h>
  21
  22 static void ino_lnkfree(struct autofs_info *ino)
  23 {
  24         if (ino->u.symlink) {
  25                 kfree(ino->u.symlink);
  26                 ino->u.symlink = NULL;
  27         }
  28 }
  29
  30 struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
  31                                      struct autofs_sb_info *sbi, mode_t mode)
  32 {
  33         int reinit = 1;
  34
  35         if (ino == NULL) {
  36                 reinit = 0;
  37                 ino = kmalloc(sizeof(*ino), GFP_KERNEL);
  38         }
  39
  40         if (ino == NULL)
  41                 return NULL;
  42
  43         ino->flags = 0;
  44         ino->mode = mode;
  45         ino->inode = NULL;
  46         ino->dentry = NULL;
  47         ino->size = 0;
  48
  49         ino->last_used = jiffies;
  50
  51         ino->sbi = sbi;
  52
  53         if (reinit && ino->free)
  54                 (ino->free)(ino);
  55
  56         memset(&ino->u, 0, sizeof(ino->u));
  57
  58         ino->free = NULL;
  59
  60         if (S_ISLNK(mode))
  61                 ino->free = ino_lnkfree;
  62
  63         return ino;
  64 }
  65
  66 void autofs4_free_ino(struct autofs_info *ino)
  67 {
  68         if (ino->dentry) {
  69                 ino->dentry->d_fsdata = NULL;
  70                 if (ino->dentry->d_inode)
  71                         dput(ino->dentry);
  72                 ino->dentry = NULL;
  73         }
  74         if (ino->free)
  75                 (ino->free)(ino);
  76         kfree(ino);
  77 }
  78
  79 static void autofs4_put_super(struct super_block *sb)
  80 {
  81         struct autofs_sb_info *sbi = autofs4_sbi(sb);
  82
  83         sb->u.generic_sbp = NULL;
  84
  85         if ( !sbi->catatonic )
  86                 autofs4_catatonic_mode(sbi); /* Free wait queues, close pipe */
  87
  88         kfree(sbi);
  89
  90         DPRINTK(("autofs: shutting down\n"));
  91 }
  92
  93 static int autofs4_statfs(struct super_block *sb, struct statfs *buf);
  94
  95 static struct super_operations autofs4_sops = {
  96         put_super:      autofs4_put_super,
  97         statfs:         autofs4_statfs,
  98 };
  99
 100 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
 101                          pid_t *pgrp, int *minproto, int *maxproto)
 102 {
 103         char *this_char, *value;
 104
 105         *uid = current->uid;
 106         *gid = current->gid;
 107         *pgrp = current->pgrp;
 108
 109         *minproto = AUTOFS_MIN_PROTO_VERSION;
 110         *maxproto = AUTOFS_MAX_PROTO_VERSION;
 111
 112         *pipefd = -1;
 113
 114         if ( !options ) return 1;
 115         for (this_char = strtok(options,","); this_char; this_char = strtok(NULL,",")) {
 116                 if ((value = strchr(this_char,'=')) != NULL)
 117                         *value++ = 0;
 118                 if (!strcmp(this_char,"fd")) {
 119                         if (!value || !*value)
 120                                 return 1;
 121                         *pipefd = simple_strtoul(value,&value,0);
 122                         if (*value)
 123                                 return 1;
 124                 }
 125                 else if (!strcmp(this_char,"uid")) {
 126                         if (!value || !*value)
 127                                 return 1;
 128                         *uid = simple_strtoul(value,&value,0);
 129                         if (*value)
 130                                 return 1;
 131                 }
 132                 else if (!strcmp(this_char,"gid")) {
 133                         if (!value || !*value)
 134                                 return 1;
 135                         *gid = simple_strtoul(value,&value,0);
 136                         if (*value)
 137                                 return 1;
 138                 }
 139                 else if (!strcmp(this_char,"pgrp")) {
 140                         if (!value || !*value)
 141                                 return 1;
 142                         *pgrp = simple_strtoul(value,&value,0);
 143                         if (*value)
 144                                 return 1;
 145                 }
 146                 else if (!strcmp(this_char,"minproto")) {
 147                         if (!value || !*value)
 148                                 return 1;
 149                         *minproto = simple_strtoul(value,&value,0);
 150                         if (*value)
 151                                 return 1;
 152                 }
 153                 else if (!strcmp(this_char,"maxproto")) {
 154                         if (!value || !*value)
 155                                 return 1;
 156                         *maxproto = simple_strtoul(value,&value,0);
 157                         if (*value)
 158                                 return 1;
 159                 }
 160                 else break;
 161         }
 162         return (*pipefd < 0);
 163 }
 164
 165 static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi)
 166 {
 167         struct autofs_info *ino;
 168
 169         ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755);
 170         if (!ino)
 171                 return NULL;
 172
 173         return ino;
 174 }
 175
 176 struct super_block *autofs4_read_super(struct super_block *s, void *data,
 177                                       int silent)
 178 {
 179         struct inode * root_inode;
 180         struct dentry * root;
 181         struct file * pipe;
 182         int pipefd;
 183         struct autofs_sb_info *sbi;
 184         int minproto, maxproto;
 185
 186         sbi = (struct autofs_sb_info *) kmalloc(sizeof(*sbi), GFP_KERNEL);
 187         if ( !sbi )
 188                 goto fail_unlock;
 189         DPRINTK(("autofs: starting up, sbi = %p\n",sbi));
 190
 191         memset(sbi, 0, sizeof(*sbi));
 192
 193         s->u.generic_sbp = sbi;
 194         sbi->magic = AUTOFS_SBI_MAGIC;
 195         sbi->catatonic = 0;
 196         sbi->exp_timeout = 0;
 197         sbi->oz_pgrp = current->pgrp;
 198         sbi->sb = s;
 199         sbi->version = 0;
 200         sbi->queues = NULL;
 201         s->s_blocksize = 1024;
 202         s->s_blocksize_bits = 10;
 203         s->s_magic = AUTOFS_SUPER_MAGIC;
 204         s->s_op = &autofs4_sops;
 205
 206         /*
 207          * Get the root inode and dentry, but defer checking for errors.
 208          */
 209         root_inode = autofs4_get_inode(s, autofs4_mkroot(sbi));
 210         root_inode->i_op = &autofs4_root_inode_operations;
 211         root_inode->i_fop = &autofs4_root_operations;
 212         root = d_alloc_root(root_inode);
 213         pipe = NULL;
 214
 215         if (!root)
 216                 goto fail_iput;
 217
 218         /* Can this call block? */
 219         if (parse_options(data, &pipefd,
 220                           &root_inode->i_uid, &root_inode->i_gid,
 221                           &sbi->oz_pgrp,
 222                           &minproto, &maxproto)) {
 223                 printk("autofs: called with bogus options\n");
 224                 goto fail_dput;
 225         }
 226
 227         /* Couldn't this be tested earlier? */
 228         if (maxproto < AUTOFS_MIN_PROTO_VERSION ||
 229             minproto > AUTOFS_MAX_PROTO_VERSION) {
 230                 printk("autofs: kernel does not match daemon version "
 231                        "daemon (%d, %d) kernel (%d, %d)\n",
 232                         minproto, maxproto,
 233                         AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
 234                 goto fail_dput;
 235         }
 236
 237         sbi->version = maxproto > AUTOFS_MAX_PROTO_VERSION ? AUTOFS_MAX_PROTO_VERSION : maxproto;
 238
 239         DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp));
 240         pipe = fget(pipefd);
 241
 242         if ( !pipe ) {
 243                 printk("autofs: could not open pipe file descriptor\n");
 244                 goto fail_dput;
 245         }
 246         if ( !pipe->f_op || !pipe->f_op->write )
 247                 goto fail_fput;
 248         sbi->pipe = pipe;
 249
 250         /*
 251          * Success! Install the root dentry now to indicate completion.
 252          */
 253         s->s_root = root;
 254         return s;
 255
 256         /*
 257          * Failure ... clean up.
 258          */
 259 fail_fput:
 260         printk("autofs: pipe file descriptor does not contain proper ops\n");
 261         /*
 262          * fput() can block, so we clear the super block first.
 263          */
 264         fput(pipe);
 265         /* fall through */
 266 fail_dput:
 267         /*
 268          * dput() can block, so we clear the super block first.
 269          */
 270         dput(root);
 271         goto fail_free;
 272 fail_iput:
 273         printk("autofs: get root dentry failed\n");
 274         /*
 275          * iput() can block, so we clear the super block first.
 276          */
 277         iput(root_inode);
 278 fail_free:
 279         kfree(sbi);
 280 fail_unlock:
 281         return NULL;
 282 }
 283
 284 static int autofs4_statfs(struct super_block *sb, struct statfs *buf)
 285 {
 286         buf->f_type = AUTOFS_SUPER_MAGIC;
 287         buf->f_bsize = 1024;
 288         buf->f_namelen = NAME_MAX;
 289         return 0;
 290 }
 291
 292 struct inode *autofs4_get_inode(struct super_block *sb,
 293                                 struct autofs_info *inf)
 294 {
 295         struct inode *inode = new_inode(sb);
 296
 297         if (inode == NULL)
 298                 return NULL;
 299
 300         inf->inode = inode;
 301         inode->i_mode = inf->mode;
 302         if (sb->s_root) {
 303                 inode->i_uid = sb->s_root->d_inode->i_uid;
 304                 inode->i_gid = sb->s_root->d_inode->i_gid;
 305         } else {
 306                 inode->i_uid = 0;
 307                 inode->i_gid = 0;
 308         }
 309         inode->i_blksize = PAGE_CACHE_SIZE;
 310         inode->i_blocks = 0;
 311         inode->i_rdev = 0;
 312         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 313
 314         if (S_ISDIR(inf->mode)) {
 315                 inode->i_nlink = 2;
 316                 inode->i_op = &autofs4_dir_inode_operations;
 317                 inode->i_fop = &dcache_dir_ops;
 318         } else if (S_ISLNK(inf->mode)) {
 319                 inode->i_size = inf->size;
 320                 inode->i_op = &autofs4_symlink_inode_operations;
 321         }
 322
 323         return inode;
 324 }