blob: 69c8142da8386577cba280ba13d229db16067580 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* -*- c -*- --------------------------------------------------------------- *
2 *
3 * linux/fs/autofs/inode.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
Ian Kent34ca9592006-03-27 01:14:54 -08006 * Copyright 2005-2006 Ian Kent <raven@themaw.net>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 *
8 * This file is part of the Linux kernel and is made available under
9 * the terms of the GNU General Public License, version 2, or at your
10 * option, any later version, incorporated herein by reference.
11 *
12 * ------------------------------------------------------------------------- */
13
14#include <linux/kernel.h>
15#include <linux/slab.h>
16#include <linux/file.h>
Ian Kentd7c4a5f2006-03-27 01:14:49 -080017#include <linux/seq_file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/pagemap.h>
19#include <linux/parser.h>
20#include <linux/bitops.h>
Jeff Garzike18fa702006-09-24 11:13:19 -040021#include <linux/magic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include "autofs_i.h"
23#include <linux/module.h>
24
25static void ino_lnkfree(struct autofs_info *ino)
26{
Ian Kent25767372008-07-23 21:30:12 -070027 if (ino->u.symlink) {
28 kfree(ino->u.symlink);
29 ino->u.symlink = NULL;
30 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070031}
32
33struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
34 struct autofs_sb_info *sbi, mode_t mode)
35{
36 int reinit = 1;
37
38 if (ino == NULL) {
39 reinit = 0;
40 ino = kmalloc(sizeof(*ino), GFP_KERNEL);
41 }
42
43 if (ino == NULL)
44 return NULL;
45
Ian Kent25767372008-07-23 21:30:12 -070046 if (!reinit) {
47 ino->flags = 0;
48 ino->inode = NULL;
49 ino->dentry = NULL;
50 ino->size = 0;
51 INIT_LIST_HEAD(&ino->active);
52 INIT_LIST_HEAD(&ino->expiring);
53 atomic_set(&ino->count, 0);
54 }
55
Ian Kentc0f54d32008-10-15 22:02:52 -070056 ino->uid = 0;
57 ino->gid = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 ino->mode = mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 ino->last_used = jiffies;
60
61 ino->sbi = sbi;
62
63 if (reinit && ino->free)
64 (ino->free)(ino);
65
66 memset(&ino->u, 0, sizeof(ino->u));
67
68 ino->free = NULL;
69
70 if (S_ISLNK(mode))
71 ino->free = ino_lnkfree;
72
73 return ino;
74}
75
76void autofs4_free_ino(struct autofs_info *ino)
77{
Ian Kent1aff3c82006-03-27 01:14:46 -080078 struct autofs_info *p_ino;
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 if (ino->dentry) {
81 ino->dentry->d_fsdata = NULL;
Ian Kent1aff3c82006-03-27 01:14:46 -080082 if (ino->dentry->d_inode) {
83 struct dentry *parent = ino->dentry->d_parent;
84 if (atomic_dec_and_test(&ino->count)) {
85 p_ino = autofs4_dentry_ino(parent);
86 if (p_ino && parent != ino->dentry)
87 atomic_dec(&p_ino->count);
88 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 dput(ino->dentry);
Ian Kent1aff3c82006-03-27 01:14:46 -080090 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 ino->dentry = NULL;
92 }
93 if (ino->free)
94 (ino->free)(ino);
95 kfree(ino);
96}
97
Ian Kent104e49f2005-07-27 11:43:45 -070098/*
99 * Deal with the infamous "Busy inodes after umount ..." message.
100 *
101 * Clean up the dentry tree. This happens with autofs if the user
102 * space program goes away due to a SIGKILL, SIGSEGV etc.
103 */
104static void autofs4_force_release(struct autofs_sb_info *sbi)
105{
David Howells6ce31522006-10-11 01:22:15 -0700106 struct dentry *this_parent = sbi->sb->s_root;
Ian Kent104e49f2005-07-27 11:43:45 -0700107 struct list_head *next;
108
Ian Kentba8df432006-11-14 02:03:29 -0800109 if (!sbi->sb->s_root)
110 return;
111
Ian Kent104e49f2005-07-27 11:43:45 -0700112 spin_lock(&dcache_lock);
113repeat:
114 next = this_parent->d_subdirs.next;
115resume:
116 while (next != &this_parent->d_subdirs) {
Eric Dumazet5160ee62006-01-08 01:03:32 -0800117 struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
Ian Kent104e49f2005-07-27 11:43:45 -0700118
119 /* Negative dentry - don`t care */
120 if (!simple_positive(dentry)) {
121 next = next->next;
122 continue;
123 }
124
125 if (!list_empty(&dentry->d_subdirs)) {
126 this_parent = dentry;
127 goto repeat;
128 }
129
130 next = next->next;
131 spin_unlock(&dcache_lock);
132
133 DPRINTK("dentry %p %.*s",
134 dentry, (int)dentry->d_name.len, dentry->d_name.name);
135
136 dput(dentry);
137 spin_lock(&dcache_lock);
138 }
139
David Howells6ce31522006-10-11 01:22:15 -0700140 if (this_parent != sbi->sb->s_root) {
Ian Kent104e49f2005-07-27 11:43:45 -0700141 struct dentry *dentry = this_parent;
142
Eric Dumazet5160ee62006-01-08 01:03:32 -0800143 next = this_parent->d_u.d_child.next;
Ian Kent104e49f2005-07-27 11:43:45 -0700144 this_parent = this_parent->d_parent;
145 spin_unlock(&dcache_lock);
146 DPRINTK("parent dentry %p %.*s",
147 dentry, (int)dentry->d_name.len, dentry->d_name.name);
148 dput(dentry);
149 spin_lock(&dcache_lock);
150 goto resume;
151 }
152 spin_unlock(&dcache_lock);
Ian Kent104e49f2005-07-27 11:43:45 -0700153}
154
David Howells6ce31522006-10-11 01:22:15 -0700155void autofs4_kill_sb(struct super_block *sb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156{
157 struct autofs_sb_info *sbi = autofs4_sbi(sb);
158
Ian Kentba8df432006-11-14 02:03:29 -0800159 /*
160 * In the event of a failure in get_sb_nodev the superblock
161 * info is not present so nothing else has been setup, so
Jiri Kosinac949d4e2006-12-06 20:39:38 -0800162 * just call kill_anon_super when we are called from
163 * deactivate_super.
Ian Kentba8df432006-11-14 02:03:29 -0800164 */
165 if (!sbi)
Jiri Kosinac949d4e2006-12-06 20:39:38 -0800166 goto out_kill_sb;
Ian Kentba8df432006-11-14 02:03:29 -0800167
Ian Kent5a11d4d2008-07-23 21:30:17 -0700168 /* Free wait queues, close pipe */
169 autofs4_catatonic_mode(sbi);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Ian Kent104e49f2005-07-27 11:43:45 -0700171 /* Clean up and release dangling references */
Dave Jones3370c742006-03-27 01:14:57 -0800172 autofs4_force_release(sbi);
Ian Kent104e49f2005-07-27 11:43:45 -0700173
Ian Kentf50b6f82007-02-20 13:58:10 -0800174 sb->s_fs_info = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 kfree(sbi);
176
Jiri Kosinac949d4e2006-12-06 20:39:38 -0800177out_kill_sb:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 DPRINTK("shutting down");
David Howells6ce31522006-10-11 01:22:15 -0700179 kill_anon_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180}
181
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800182static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
183{
184 struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb);
Miklos Szerediaef97cb2008-02-08 04:21:37 -0800185 struct inode *root_inode = mnt->mnt_sb->s_root->d_inode;
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800186
187 if (!sbi)
188 return 0;
189
190 seq_printf(m, ",fd=%d", sbi->pipefd);
Miklos Szerediaef97cb2008-02-08 04:21:37 -0800191 if (root_inode->i_uid != 0)
192 seq_printf(m, ",uid=%u", root_inode->i_uid);
193 if (root_inode->i_gid != 0)
194 seq_printf(m, ",gid=%u", root_inode->i_gid);
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800195 seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
196 seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
197 seq_printf(m, ",minproto=%d", sbi->min_proto);
198 seq_printf(m, ",maxproto=%d", sbi->max_proto);
199
Ian Kenta92daf62009-01-06 14:42:08 -0800200 if (autofs_type_offset(sbi->type))
Ian Kent34ca9592006-03-27 01:14:54 -0800201 seq_printf(m, ",offset");
Ian Kenta92daf62009-01-06 14:42:08 -0800202 else if (autofs_type_direct(sbi->type))
Ian Kent34ca9592006-03-27 01:14:54 -0800203 seq_printf(m, ",direct");
204 else
205 seq_printf(m, ",indirect");
206
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800207 return 0;
208}
209
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800210static const struct super_operations autofs4_sops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 .statfs = simple_statfs,
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800212 .show_options = autofs4_show_options,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213};
214
Ian Kent34ca9592006-03-27 01:14:54 -0800215enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
216 Opt_indirect, Opt_direct, Opt_offset};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217
Steven Whitehousea447c092008-10-13 10:46:57 +0100218static const match_table_t tokens = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 {Opt_fd, "fd=%u"},
220 {Opt_uid, "uid=%u"},
221 {Opt_gid, "gid=%u"},
222 {Opt_pgrp, "pgrp=%u"},
223 {Opt_minproto, "minproto=%u"},
224 {Opt_maxproto, "maxproto=%u"},
Ian Kent34ca9592006-03-27 01:14:54 -0800225 {Opt_indirect, "indirect"},
226 {Opt_direct, "direct"},
227 {Opt_offset, "offset"},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 {Opt_err, NULL}
229};
230
231static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700232 pid_t *pgrp, unsigned int *type, int *minproto, int *maxproto)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233{
234 char *p;
235 substring_t args[MAX_OPT_ARGS];
236 int option;
237
David Howells0eb790e2008-11-14 10:38:46 +1100238 *uid = current_uid();
239 *gid = current_gid();
Pavel Emelianova47afb02007-10-18 23:39:46 -0700240 *pgrp = task_pgrp_nr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
242 *minproto = AUTOFS_MIN_PROTO_VERSION;
243 *maxproto = AUTOFS_MAX_PROTO_VERSION;
244
245 *pipefd = -1;
246
247 if (!options)
248 return 1;
249
250 while ((p = strsep(&options, ",")) != NULL) {
251 int token;
252 if (!*p)
253 continue;
254
255 token = match_token(p, tokens, args);
256 switch (token) {
257 case Opt_fd:
258 if (match_int(args, pipefd))
259 return 1;
260 break;
261 case Opt_uid:
262 if (match_int(args, &option))
263 return 1;
264 *uid = option;
265 break;
266 case Opt_gid:
267 if (match_int(args, &option))
268 return 1;
269 *gid = option;
270 break;
271 case Opt_pgrp:
272 if (match_int(args, &option))
273 return 1;
274 *pgrp = option;
275 break;
276 case Opt_minproto:
277 if (match_int(args, &option))
278 return 1;
279 *minproto = option;
280 break;
281 case Opt_maxproto:
282 if (match_int(args, &option))
283 return 1;
284 *maxproto = option;
285 break;
Ian Kent34ca9592006-03-27 01:14:54 -0800286 case Opt_indirect:
Ian Kenta92daf62009-01-06 14:42:08 -0800287 set_autofs_type_indirect(type);
Ian Kent34ca9592006-03-27 01:14:54 -0800288 break;
289 case Opt_direct:
Ian Kenta92daf62009-01-06 14:42:08 -0800290 set_autofs_type_direct(type);
Ian Kent34ca9592006-03-27 01:14:54 -0800291 break;
292 case Opt_offset:
Ian Kenta92daf62009-01-06 14:42:08 -0800293 set_autofs_type_offset(type);
Ian Kent34ca9592006-03-27 01:14:54 -0800294 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 default:
296 return 1;
297 }
298 }
299 return (*pipefd < 0);
300}
301
302static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi)
303{
304 struct autofs_info *ino;
305
306 ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755);
307 if (!ino)
308 return NULL;
309
310 return ino;
311}
312
Al Viro08f11512009-02-20 05:56:19 +0000313static const struct dentry_operations autofs4_sb_dentry_operations = {
Ian Kent34ca9592006-03-27 01:14:54 -0800314 .d_release = autofs4_dentry_release,
315};
316
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317int autofs4_fill_super(struct super_block *s, void *data, int silent)
318{
319 struct inode * root_inode;
320 struct dentry * root;
321 struct file * pipe;
322 int pipefd;
323 struct autofs_sb_info *sbi;
324 struct autofs_info *ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325
Mariusz Kozlowskib63d50c2007-10-16 23:26:44 -0700326 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700327 if (!sbi)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 goto fail_unlock;
329 DPRINTK("starting up, sbi = %p",sbi);
330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 s->s_fs_info = sbi;
332 sbi->magic = AUTOFS_SBI_MAGIC;
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800333 sbi->pipefd = -1;
Ian Kentba8df432006-11-14 02:03:29 -0800334 sbi->pipe = NULL;
335 sbi->catatonic = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 sbi->exp_timeout = 0;
Pavel Emelianova47afb02007-10-18 23:39:46 -0700337 sbi->oz_pgrp = task_pgrp_nr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 sbi->sb = s;
339 sbi->version = 0;
340 sbi->sub_version = 0;
Ian Kenta92daf62009-01-06 14:42:08 -0800341 set_autofs_type_indirect(&sbi->type);
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800342 sbi->min_proto = 0;
343 sbi->max_proto = 0;
Ingo Molnar1d5599e2006-03-23 03:00:41 -0800344 mutex_init(&sbi->wq_mutex);
Ian Kent3a9720c2005-05-01 08:59:17 -0700345 spin_lock_init(&sbi->fs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 sbi->queues = NULL;
Ian Kent5f6f4f22008-07-23 21:30:09 -0700347 spin_lock_init(&sbi->lookup_lock);
Ian Kent25767372008-07-23 21:30:12 -0700348 INIT_LIST_HEAD(&sbi->active_list);
Ian Kent5f6f4f22008-07-23 21:30:09 -0700349 INIT_LIST_HEAD(&sbi->expiring_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 s->s_blocksize = 1024;
351 s->s_blocksize_bits = 10;
352 s->s_magic = AUTOFS_SUPER_MAGIC;
353 s->s_op = &autofs4_sops;
354 s->s_time_gran = 1;
355
356 /*
357 * Get the root inode and dentry, but defer checking for errors.
358 */
359 ino = autofs4_mkroot(sbi);
360 if (!ino)
361 goto fail_free;
362 root_inode = autofs4_get_inode(s, ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 if (!root_inode)
Ian Kent34ca9592006-03-27 01:14:54 -0800364 goto fail_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 root = d_alloc_root(root_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 if (!root)
368 goto fail_iput;
Ian Kent34ca9592006-03-27 01:14:54 -0800369 pipe = NULL;
370
371 root->d_op = &autofs4_sb_dentry_operations;
372 root->d_fsdata = ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373
374 /* Can this call block? */
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700375 if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
376 &sbi->oz_pgrp, &sbi->type, &sbi->min_proto,
377 &sbi->max_proto)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 printk("autofs: called with bogus options\n");
379 goto fail_dput;
380 }
381
Ian Kent34ca9592006-03-27 01:14:54 -0800382 root_inode->i_fop = &autofs4_root_operations;
Ian Kenta92daf62009-01-06 14:42:08 -0800383 root_inode->i_op = autofs_type_trigger(sbi->type) ?
Ian Kent34ca9592006-03-27 01:14:54 -0800384 &autofs4_direct_root_inode_operations :
385 &autofs4_indirect_root_inode_operations;
386
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 /* Couldn't this be tested earlier? */
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800388 if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
389 sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 printk("autofs: kernel does not match daemon version "
391 "daemon (%d, %d) kernel (%d, %d)\n",
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800392 sbi->min_proto, sbi->max_proto,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
394 goto fail_dput;
395 }
396
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800397 /* Establish highest kernel protocol version */
398 if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
399 sbi->version = AUTOFS_MAX_PROTO_VERSION;
400 else
401 sbi->version = sbi->max_proto;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
403
404 DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
405 pipe = fget(pipefd);
406
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700407 if (!pipe) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 printk("autofs: could not open pipe file descriptor\n");
409 goto fail_dput;
410 }
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700411 if (!pipe->f_op || !pipe->f_op->write)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 goto fail_fput;
413 sbi->pipe = pipe;
Ian Kentd7c4a5f2006-03-27 01:14:49 -0800414 sbi->pipefd = pipefd;
Ian Kentba8df432006-11-14 02:03:29 -0800415 sbi->catatonic = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
417 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 * Success! Install the root dentry now to indicate completion.
419 */
420 s->s_root = root;
421 return 0;
422
423 /*
424 * Failure ... clean up.
425 */
426fail_fput:
427 printk("autofs: pipe file descriptor does not contain proper ops\n");
428 fput(pipe);
429 /* fall through */
430fail_dput:
431 dput(root);
432 goto fail_free;
433fail_iput:
434 printk("autofs: get root dentry failed\n");
435 iput(root_inode);
Ian Kent34ca9592006-03-27 01:14:54 -0800436fail_ino:
437 kfree(ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438fail_free:
439 kfree(sbi);
Ian Kentba8df432006-11-14 02:03:29 -0800440 s->s_fs_info = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441fail_unlock:
442 return -EINVAL;
443}
444
445struct inode *autofs4_get_inode(struct super_block *sb,
446 struct autofs_info *inf)
447{
448 struct inode *inode = new_inode(sb);
449
450 if (inode == NULL)
451 return NULL;
452
453 inf->inode = inode;
454 inode->i_mode = inf->mode;
455 if (sb->s_root) {
456 inode->i_uid = sb->s_root->d_inode->i_uid;
457 inode->i_gid = sb->s_root->d_inode->i_gid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
460
461 if (S_ISDIR(inf->mode)) {
462 inode->i_nlink = 2;
463 inode->i_op = &autofs4_dir_inode_operations;
464 inode->i_fop = &autofs4_dir_operations;
465 } else if (S_ISLNK(inf->mode)) {
466 inode->i_size = inf->size;
467 inode->i_op = &autofs4_symlink_inode_operations;
468 }
469
470 return inode;
471}