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1da177e4 LT |
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/pagemap.h> | |
17 | #include <linux/parser.h> | |
18 | #include <linux/bitops.h> | |
104e49fc | 19 | #include <linux/smp_lock.h> |
1da177e4 LT |
20 | #include "autofs_i.h" |
21 | #include <linux/module.h> | |
22 | ||
23 | static void ino_lnkfree(struct autofs_info *ino) | |
24 | { | |
f99d49ad JJ |
25 | kfree(ino->u.symlink); |
26 | ino->u.symlink = NULL; | |
1da177e4 LT |
27 | } |
28 | ||
29 | struct autofs_info *autofs4_init_ino(struct autofs_info *ino, | |
30 | struct autofs_sb_info *sbi, mode_t mode) | |
31 | { | |
32 | int reinit = 1; | |
33 | ||
34 | if (ino == NULL) { | |
35 | reinit = 0; | |
36 | ino = kmalloc(sizeof(*ino), GFP_KERNEL); | |
37 | } | |
38 | ||
39 | if (ino == NULL) | |
40 | return NULL; | |
41 | ||
42 | ino->flags = 0; | |
43 | ino->mode = mode; | |
44 | ino->inode = NULL; | |
45 | ino->dentry = NULL; | |
46 | ino->size = 0; | |
47 | ||
48 | ino->last_used = jiffies; | |
49 | ||
50 | ino->sbi = sbi; | |
51 | ||
52 | if (reinit && ino->free) | |
53 | (ino->free)(ino); | |
54 | ||
55 | memset(&ino->u, 0, sizeof(ino->u)); | |
56 | ||
57 | ino->free = NULL; | |
58 | ||
59 | if (S_ISLNK(mode)) | |
60 | ino->free = ino_lnkfree; | |
61 | ||
62 | return ino; | |
63 | } | |
64 | ||
65 | void autofs4_free_ino(struct autofs_info *ino) | |
66 | { | |
67 | if (ino->dentry) { | |
68 | ino->dentry->d_fsdata = NULL; | |
69 | if (ino->dentry->d_inode) | |
70 | dput(ino->dentry); | |
71 | ino->dentry = NULL; | |
72 | } | |
73 | if (ino->free) | |
74 | (ino->free)(ino); | |
75 | kfree(ino); | |
76 | } | |
77 | ||
104e49fc IK |
78 | /* |
79 | * Deal with the infamous "Busy inodes after umount ..." message. | |
80 | * | |
81 | * Clean up the dentry tree. This happens with autofs if the user | |
82 | * space program goes away due to a SIGKILL, SIGSEGV etc. | |
83 | */ | |
84 | static void autofs4_force_release(struct autofs_sb_info *sbi) | |
85 | { | |
86 | struct dentry *this_parent = sbi->root; | |
87 | struct list_head *next; | |
88 | ||
89 | spin_lock(&dcache_lock); | |
90 | repeat: | |
91 | next = this_parent->d_subdirs.next; | |
92 | resume: | |
93 | while (next != &this_parent->d_subdirs) { | |
5160ee6f | 94 | struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child); |
104e49fc IK |
95 | |
96 | /* Negative dentry - don`t care */ | |
97 | if (!simple_positive(dentry)) { | |
98 | next = next->next; | |
99 | continue; | |
100 | } | |
101 | ||
102 | if (!list_empty(&dentry->d_subdirs)) { | |
103 | this_parent = dentry; | |
104 | goto repeat; | |
105 | } | |
106 | ||
107 | next = next->next; | |
108 | spin_unlock(&dcache_lock); | |
109 | ||
110 | DPRINTK("dentry %p %.*s", | |
111 | dentry, (int)dentry->d_name.len, dentry->d_name.name); | |
112 | ||
113 | dput(dentry); | |
114 | spin_lock(&dcache_lock); | |
115 | } | |
116 | ||
117 | if (this_parent != sbi->root) { | |
118 | struct dentry *dentry = this_parent; | |
119 | ||
5160ee6f | 120 | next = this_parent->d_u.d_child.next; |
104e49fc IK |
121 | this_parent = this_parent->d_parent; |
122 | spin_unlock(&dcache_lock); | |
123 | DPRINTK("parent dentry %p %.*s", | |
124 | dentry, (int)dentry->d_name.len, dentry->d_name.name); | |
125 | dput(dentry); | |
126 | spin_lock(&dcache_lock); | |
127 | goto resume; | |
128 | } | |
129 | spin_unlock(&dcache_lock); | |
130 | ||
131 | dput(sbi->root); | |
132 | sbi->root = NULL; | |
133 | shrink_dcache_sb(sbi->sb); | |
134 | ||
135 | return; | |
136 | } | |
137 | ||
1da177e4 LT |
138 | static void autofs4_put_super(struct super_block *sb) |
139 | { | |
140 | struct autofs_sb_info *sbi = autofs4_sbi(sb); | |
141 | ||
142 | sb->s_fs_info = NULL; | |
143 | ||
144 | if ( !sbi->catatonic ) | |
145 | autofs4_catatonic_mode(sbi); /* Free wait queues, close pipe */ | |
146 | ||
104e49fc IK |
147 | /* Clean up and release dangling references */ |
148 | if (sbi) | |
149 | autofs4_force_release(sbi); | |
150 | ||
1da177e4 LT |
151 | kfree(sbi); |
152 | ||
153 | DPRINTK("shutting down"); | |
154 | } | |
155 | ||
156 | static struct super_operations autofs4_sops = { | |
157 | .put_super = autofs4_put_super, | |
158 | .statfs = simple_statfs, | |
159 | }; | |
160 | ||
161 | enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto}; | |
162 | ||
163 | static match_table_t tokens = { | |
164 | {Opt_fd, "fd=%u"}, | |
165 | {Opt_uid, "uid=%u"}, | |
166 | {Opt_gid, "gid=%u"}, | |
167 | {Opt_pgrp, "pgrp=%u"}, | |
168 | {Opt_minproto, "minproto=%u"}, | |
169 | {Opt_maxproto, "maxproto=%u"}, | |
170 | {Opt_err, NULL} | |
171 | }; | |
172 | ||
173 | static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, | |
174 | pid_t *pgrp, int *minproto, int *maxproto) | |
175 | { | |
176 | char *p; | |
177 | substring_t args[MAX_OPT_ARGS]; | |
178 | int option; | |
179 | ||
180 | *uid = current->uid; | |
181 | *gid = current->gid; | |
182 | *pgrp = process_group(current); | |
183 | ||
184 | *minproto = AUTOFS_MIN_PROTO_VERSION; | |
185 | *maxproto = AUTOFS_MAX_PROTO_VERSION; | |
186 | ||
187 | *pipefd = -1; | |
188 | ||
189 | if (!options) | |
190 | return 1; | |
191 | ||
192 | while ((p = strsep(&options, ",")) != NULL) { | |
193 | int token; | |
194 | if (!*p) | |
195 | continue; | |
196 | ||
197 | token = match_token(p, tokens, args); | |
198 | switch (token) { | |
199 | case Opt_fd: | |
200 | if (match_int(args, pipefd)) | |
201 | return 1; | |
202 | break; | |
203 | case Opt_uid: | |
204 | if (match_int(args, &option)) | |
205 | return 1; | |
206 | *uid = option; | |
207 | break; | |
208 | case Opt_gid: | |
209 | if (match_int(args, &option)) | |
210 | return 1; | |
211 | *gid = option; | |
212 | break; | |
213 | case Opt_pgrp: | |
214 | if (match_int(args, &option)) | |
215 | return 1; | |
216 | *pgrp = option; | |
217 | break; | |
218 | case Opt_minproto: | |
219 | if (match_int(args, &option)) | |
220 | return 1; | |
221 | *minproto = option; | |
222 | break; | |
223 | case Opt_maxproto: | |
224 | if (match_int(args, &option)) | |
225 | return 1; | |
226 | *maxproto = option; | |
227 | break; | |
228 | default: | |
229 | return 1; | |
230 | } | |
231 | } | |
232 | return (*pipefd < 0); | |
233 | } | |
234 | ||
235 | static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi) | |
236 | { | |
237 | struct autofs_info *ino; | |
238 | ||
239 | ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755); | |
240 | if (!ino) | |
241 | return NULL; | |
242 | ||
243 | return ino; | |
244 | } | |
245 | ||
246 | int autofs4_fill_super(struct super_block *s, void *data, int silent) | |
247 | { | |
248 | struct inode * root_inode; | |
249 | struct dentry * root; | |
250 | struct file * pipe; | |
251 | int pipefd; | |
252 | struct autofs_sb_info *sbi; | |
253 | struct autofs_info *ino; | |
254 | int minproto, maxproto; | |
255 | ||
256 | sbi = (struct autofs_sb_info *) kmalloc(sizeof(*sbi), GFP_KERNEL); | |
257 | if ( !sbi ) | |
258 | goto fail_unlock; | |
259 | DPRINTK("starting up, sbi = %p",sbi); | |
260 | ||
261 | memset(sbi, 0, sizeof(*sbi)); | |
262 | ||
263 | s->s_fs_info = sbi; | |
264 | sbi->magic = AUTOFS_SBI_MAGIC; | |
104e49fc | 265 | sbi->root = NULL; |
1da177e4 LT |
266 | sbi->catatonic = 0; |
267 | sbi->exp_timeout = 0; | |
268 | sbi->oz_pgrp = process_group(current); | |
269 | sbi->sb = s; | |
270 | sbi->version = 0; | |
271 | sbi->sub_version = 0; | |
272 | init_MUTEX(&sbi->wq_sem); | |
3a9720ce | 273 | spin_lock_init(&sbi->fs_lock); |
1da177e4 LT |
274 | sbi->queues = NULL; |
275 | s->s_blocksize = 1024; | |
276 | s->s_blocksize_bits = 10; | |
277 | s->s_magic = AUTOFS_SUPER_MAGIC; | |
278 | s->s_op = &autofs4_sops; | |
279 | s->s_time_gran = 1; | |
280 | ||
281 | /* | |
282 | * Get the root inode and dentry, but defer checking for errors. | |
283 | */ | |
284 | ino = autofs4_mkroot(sbi); | |
285 | if (!ino) | |
286 | goto fail_free; | |
287 | root_inode = autofs4_get_inode(s, ino); | |
288 | kfree(ino); | |
289 | if (!root_inode) | |
290 | goto fail_free; | |
291 | ||
292 | root_inode->i_op = &autofs4_root_inode_operations; | |
293 | root_inode->i_fop = &autofs4_root_operations; | |
294 | root = d_alloc_root(root_inode); | |
295 | pipe = NULL; | |
296 | ||
297 | if (!root) | |
298 | goto fail_iput; | |
299 | ||
300 | /* Can this call block? */ | |
301 | if (parse_options(data, &pipefd, | |
302 | &root_inode->i_uid, &root_inode->i_gid, | |
303 | &sbi->oz_pgrp, | |
304 | &minproto, &maxproto)) { | |
305 | printk("autofs: called with bogus options\n"); | |
306 | goto fail_dput; | |
307 | } | |
308 | ||
309 | /* Couldn't this be tested earlier? */ | |
310 | if (maxproto < AUTOFS_MIN_PROTO_VERSION || | |
311 | minproto > AUTOFS_MAX_PROTO_VERSION) { | |
312 | printk("autofs: kernel does not match daemon version " | |
313 | "daemon (%d, %d) kernel (%d, %d)\n", | |
314 | minproto, maxproto, | |
315 | AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION); | |
316 | goto fail_dput; | |
317 | } | |
318 | ||
319 | sbi->version = maxproto > AUTOFS_MAX_PROTO_VERSION ? AUTOFS_MAX_PROTO_VERSION : maxproto; | |
320 | sbi->sub_version = AUTOFS_PROTO_SUBVERSION; | |
321 | ||
322 | DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp); | |
323 | pipe = fget(pipefd); | |
324 | ||
325 | if ( !pipe ) { | |
326 | printk("autofs: could not open pipe file descriptor\n"); | |
327 | goto fail_dput; | |
328 | } | |
329 | if ( !pipe->f_op || !pipe->f_op->write ) | |
330 | goto fail_fput; | |
331 | sbi->pipe = pipe; | |
332 | ||
104e49fc IK |
333 | /* |
334 | * Take a reference to the root dentry so we get a chance to | |
335 | * clean up the dentry tree on umount. | |
336 | * See autofs4_force_release. | |
337 | */ | |
338 | sbi->root = dget(root); | |
339 | ||
1da177e4 LT |
340 | /* |
341 | * Success! Install the root dentry now to indicate completion. | |
342 | */ | |
343 | s->s_root = root; | |
344 | return 0; | |
345 | ||
346 | /* | |
347 | * Failure ... clean up. | |
348 | */ | |
349 | fail_fput: | |
350 | printk("autofs: pipe file descriptor does not contain proper ops\n"); | |
351 | fput(pipe); | |
352 | /* fall through */ | |
353 | fail_dput: | |
354 | dput(root); | |
355 | goto fail_free; | |
356 | fail_iput: | |
357 | printk("autofs: get root dentry failed\n"); | |
358 | iput(root_inode); | |
359 | fail_free: | |
360 | kfree(sbi); | |
361 | fail_unlock: | |
362 | return -EINVAL; | |
363 | } | |
364 | ||
365 | struct inode *autofs4_get_inode(struct super_block *sb, | |
366 | struct autofs_info *inf) | |
367 | { | |
368 | struct inode *inode = new_inode(sb); | |
369 | ||
370 | if (inode == NULL) | |
371 | return NULL; | |
372 | ||
373 | inf->inode = inode; | |
374 | inode->i_mode = inf->mode; | |
375 | if (sb->s_root) { | |
376 | inode->i_uid = sb->s_root->d_inode->i_uid; | |
377 | inode->i_gid = sb->s_root->d_inode->i_gid; | |
378 | } else { | |
379 | inode->i_uid = 0; | |
380 | inode->i_gid = 0; | |
381 | } | |
382 | inode->i_blksize = PAGE_CACHE_SIZE; | |
383 | inode->i_blocks = 0; | |
384 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
385 | ||
386 | if (S_ISDIR(inf->mode)) { | |
387 | inode->i_nlink = 2; | |
388 | inode->i_op = &autofs4_dir_inode_operations; | |
389 | inode->i_fop = &autofs4_dir_operations; | |
390 | } else if (S_ISLNK(inf->mode)) { | |
391 | inode->i_size = inf->size; | |
392 | inode->i_op = &autofs4_symlink_inode_operations; | |
393 | } | |
394 | ||
395 | return inode; | |
396 | } |