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1da177e4 LT |
1 | /* |
2 | * Copyright (c) 2002 Red Hat, Inc. All rights reserved. | |
3 | * | |
4 | * This software may be freely redistributed under the terms of the | |
5 | * GNU General Public License. | |
6 | * | |
7 | * You should have received a copy of the GNU General Public License | |
8 | * along with this program; if not, write to the Free Software | |
9 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
10 | * | |
11 | * Authors: David Howells <dhowells@redhat.com> | |
12 | * David Woodhouse <dwmw2@cambridge.redhat.com> | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/kernel.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/fs.h> | |
21 | #include <linux/pagemap.h> | |
22 | #include "vnode.h" | |
23 | #include "volume.h" | |
24 | #include "cell.h" | |
25 | #include "cmservice.h" | |
26 | #include "fsclient.h" | |
27 | #include "super.h" | |
28 | #include "internal.h" | |
29 | ||
30 | #define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */ | |
31 | ||
32 | struct afs_mount_params { | |
33 | int rwpath; | |
34 | struct afs_cell *default_cell; | |
35 | struct afs_volume *volume; | |
36 | }; | |
37 | ||
38 | static void afs_i_init_once(void *foo, kmem_cache_t *cachep, | |
39 | unsigned long flags); | |
40 | ||
41 | static struct super_block *afs_get_sb(struct file_system_type *fs_type, | |
42 | int flags, const char *dev_name, | |
43 | void *data); | |
44 | ||
45 | static struct inode *afs_alloc_inode(struct super_block *sb); | |
46 | ||
47 | static void afs_put_super(struct super_block *sb); | |
48 | ||
49 | static void afs_destroy_inode(struct inode *inode); | |
50 | ||
51 | static struct file_system_type afs_fs_type = { | |
52 | .owner = THIS_MODULE, | |
53 | .name = "afs", | |
54 | .get_sb = afs_get_sb, | |
55 | .kill_sb = kill_anon_super, | |
56 | .fs_flags = FS_BINARY_MOUNTDATA, | |
57 | }; | |
58 | ||
59 | static struct super_operations afs_super_ops = { | |
60 | .statfs = simple_statfs, | |
61 | .alloc_inode = afs_alloc_inode, | |
62 | .drop_inode = generic_delete_inode, | |
63 | .destroy_inode = afs_destroy_inode, | |
64 | .clear_inode = afs_clear_inode, | |
65 | .put_super = afs_put_super, | |
66 | }; | |
67 | ||
68 | static kmem_cache_t *afs_inode_cachep; | |
69 | static atomic_t afs_count_active_inodes; | |
70 | ||
71 | /*****************************************************************************/ | |
72 | /* | |
73 | * initialise the filesystem | |
74 | */ | |
75 | int __init afs_fs_init(void) | |
76 | { | |
77 | int ret; | |
78 | ||
79 | _enter(""); | |
80 | ||
81 | afs_timer_init(&afs_mntpt_expiry_timer, &afs_mntpt_expiry_timer_ops); | |
82 | ||
83 | /* create ourselves an inode cache */ | |
84 | atomic_set(&afs_count_active_inodes, 0); | |
85 | ||
86 | ret = -ENOMEM; | |
87 | afs_inode_cachep = kmem_cache_create("afs_inode_cache", | |
88 | sizeof(struct afs_vnode), | |
89 | 0, | |
90 | SLAB_HWCACHE_ALIGN, | |
91 | afs_i_init_once, | |
92 | NULL); | |
93 | if (!afs_inode_cachep) { | |
94 | printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n"); | |
95 | return ret; | |
96 | } | |
97 | ||
98 | /* now export our filesystem to lesser mortals */ | |
99 | ret = register_filesystem(&afs_fs_type); | |
100 | if (ret < 0) { | |
101 | kmem_cache_destroy(afs_inode_cachep); | |
102 | kleave(" = %d", ret); | |
103 | return ret; | |
104 | } | |
105 | ||
106 | kleave(" = 0"); | |
107 | return 0; | |
108 | } /* end afs_fs_init() */ | |
109 | ||
110 | /*****************************************************************************/ | |
111 | /* | |
112 | * clean up the filesystem | |
113 | */ | |
114 | void __exit afs_fs_exit(void) | |
115 | { | |
116 | unregister_filesystem(&afs_fs_type); | |
117 | ||
118 | if (atomic_read(&afs_count_active_inodes) != 0) { | |
119 | printk("kAFS: %d active inode objects still present\n", | |
120 | atomic_read(&afs_count_active_inodes)); | |
121 | BUG(); | |
122 | } | |
123 | ||
124 | kmem_cache_destroy(afs_inode_cachep); | |
125 | ||
126 | } /* end afs_fs_exit() */ | |
127 | ||
128 | /*****************************************************************************/ | |
129 | /* | |
130 | * check that an argument has a value | |
131 | */ | |
132 | static int want_arg(char **_value, const char *option) | |
133 | { | |
134 | if (!_value || !*_value || !**_value) { | |
135 | printk(KERN_NOTICE "kAFS: %s: argument missing\n", option); | |
136 | return 0; | |
137 | } | |
138 | return 1; | |
139 | } /* end want_arg() */ | |
140 | ||
141 | /*****************************************************************************/ | |
142 | /* | |
143 | * check that there's no subsequent value | |
144 | */ | |
145 | static int want_no_value(char *const *_value, const char *option) | |
146 | { | |
147 | if (*_value && **_value) { | |
148 | printk(KERN_NOTICE "kAFS: %s: Invalid argument: %s\n", | |
149 | option, *_value); | |
150 | return 0; | |
151 | } | |
152 | return 1; | |
153 | } /* end want_no_value() */ | |
154 | ||
155 | /*****************************************************************************/ | |
156 | /* | |
157 | * parse the mount options | |
158 | * - this function has been shamelessly adapted from the ext3 fs which | |
159 | * shamelessly adapted it from the msdos fs | |
160 | */ | |
161 | static int afs_super_parse_options(struct afs_mount_params *params, | |
162 | char *options, | |
163 | const char **devname) | |
164 | { | |
165 | char *key, *value; | |
166 | int ret; | |
167 | ||
168 | _enter("%s", options); | |
169 | ||
170 | options[PAGE_SIZE - 1] = 0; | |
171 | ||
172 | ret = 0; | |
173 | while ((key = strsep(&options, ",")) != 0) | |
174 | { | |
175 | value = strchr(key, '='); | |
176 | if (value) | |
177 | *value++ = 0; | |
178 | ||
179 | printk("kAFS: KEY: %s, VAL:%s\n", key, value ?: "-"); | |
180 | ||
181 | if (strcmp(key, "rwpath") == 0) { | |
182 | if (!want_no_value(&value, "rwpath")) | |
183 | return -EINVAL; | |
184 | params->rwpath = 1; | |
185 | continue; | |
186 | } | |
187 | else if (strcmp(key, "vol") == 0) { | |
188 | if (!want_arg(&value, "vol")) | |
189 | return -EINVAL; | |
190 | *devname = value; | |
191 | continue; | |
192 | } | |
193 | else if (strcmp(key, "cell") == 0) { | |
194 | if (!want_arg(&value, "cell")) | |
195 | return -EINVAL; | |
196 | afs_put_cell(params->default_cell); | |
197 | ret = afs_cell_lookup(value, | |
198 | strlen(value), | |
199 | ¶ms->default_cell); | |
200 | if (ret < 0) | |
201 | return -EINVAL; | |
202 | continue; | |
203 | } | |
204 | ||
205 | printk("kAFS: Unknown mount option: '%s'\n", key); | |
206 | ret = -EINVAL; | |
207 | goto error; | |
208 | } | |
209 | ||
210 | ret = 0; | |
211 | ||
212 | error: | |
213 | _leave(" = %d", ret); | |
214 | return ret; | |
215 | } /* end afs_super_parse_options() */ | |
216 | ||
217 | /*****************************************************************************/ | |
218 | /* | |
219 | * check a superblock to see if it's the one we're looking for | |
220 | */ | |
221 | static int afs_test_super(struct super_block *sb, void *data) | |
222 | { | |
223 | struct afs_mount_params *params = data; | |
224 | struct afs_super_info *as = sb->s_fs_info; | |
225 | ||
226 | return as->volume == params->volume; | |
227 | } /* end afs_test_super() */ | |
228 | ||
229 | /*****************************************************************************/ | |
230 | /* | |
231 | * fill in the superblock | |
232 | */ | |
233 | static int afs_fill_super(struct super_block *sb, void *data, int silent) | |
234 | { | |
235 | struct afs_mount_params *params = data; | |
236 | struct afs_super_info *as = NULL; | |
237 | struct afs_fid fid; | |
238 | struct dentry *root = NULL; | |
239 | struct inode *inode = NULL; | |
240 | int ret; | |
241 | ||
242 | kenter(""); | |
243 | ||
244 | /* allocate a superblock info record */ | |
245 | as = kmalloc(sizeof(struct afs_super_info), GFP_KERNEL); | |
246 | if (!as) { | |
247 | _leave(" = -ENOMEM"); | |
248 | return -ENOMEM; | |
249 | } | |
250 | ||
251 | memset(as, 0, sizeof(struct afs_super_info)); | |
252 | ||
253 | afs_get_volume(params->volume); | |
254 | as->volume = params->volume; | |
255 | ||
256 | /* fill in the superblock */ | |
257 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
258 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
259 | sb->s_magic = AFS_FS_MAGIC; | |
260 | sb->s_op = &afs_super_ops; | |
261 | sb->s_fs_info = as; | |
262 | ||
263 | /* allocate the root inode and dentry */ | |
264 | fid.vid = as->volume->vid; | |
265 | fid.vnode = 1; | |
266 | fid.unique = 1; | |
267 | ret = afs_iget(sb, &fid, &inode); | |
268 | if (ret < 0) | |
269 | goto error; | |
270 | ||
271 | ret = -ENOMEM; | |
272 | root = d_alloc_root(inode); | |
273 | if (!root) | |
274 | goto error; | |
275 | ||
276 | sb->s_root = root; | |
277 | ||
278 | kleave(" = 0"); | |
279 | return 0; | |
280 | ||
281 | error: | |
282 | iput(inode); | |
283 | afs_put_volume(as->volume); | |
284 | kfree(as); | |
285 | ||
286 | sb->s_fs_info = NULL; | |
287 | ||
288 | kleave(" = %d", ret); | |
289 | return ret; | |
290 | } /* end afs_fill_super() */ | |
291 | ||
292 | /*****************************************************************************/ | |
293 | /* | |
294 | * get an AFS superblock | |
295 | * - TODO: don't use get_sb_nodev(), but rather call sget() directly | |
296 | */ | |
297 | static struct super_block *afs_get_sb(struct file_system_type *fs_type, | |
298 | int flags, | |
299 | const char *dev_name, | |
300 | void *options) | |
301 | { | |
302 | struct afs_mount_params params; | |
303 | struct super_block *sb; | |
304 | int ret; | |
305 | ||
306 | _enter(",,%s,%p", dev_name, options); | |
307 | ||
308 | memset(¶ms, 0, sizeof(params)); | |
309 | ||
310 | /* start the cache manager */ | |
311 | ret = afscm_start(); | |
312 | if (ret < 0) { | |
313 | _leave(" = %d", ret); | |
314 | return ERR_PTR(ret); | |
315 | } | |
316 | ||
317 | /* parse the options */ | |
318 | if (options) { | |
319 | ret = afs_super_parse_options(¶ms, options, &dev_name); | |
320 | if (ret < 0) | |
321 | goto error; | |
322 | if (!dev_name) { | |
323 | printk("kAFS: no volume name specified\n"); | |
324 | ret = -EINVAL; | |
325 | goto error; | |
326 | } | |
327 | } | |
328 | ||
329 | /* parse the device name */ | |
330 | ret = afs_volume_lookup(dev_name, | |
331 | params.default_cell, | |
332 | params.rwpath, | |
333 | ¶ms.volume); | |
334 | if (ret < 0) | |
335 | goto error; | |
336 | ||
337 | /* allocate a deviceless superblock */ | |
338 | sb = sget(fs_type, afs_test_super, set_anon_super, ¶ms); | |
339 | if (IS_ERR(sb)) | |
340 | goto error; | |
341 | ||
342 | sb->s_flags = flags; | |
343 | ||
344 | ret = afs_fill_super(sb, ¶ms, flags & MS_VERBOSE ? 1 : 0); | |
345 | if (ret < 0) { | |
346 | up_write(&sb->s_umount); | |
347 | deactivate_super(sb); | |
348 | goto error; | |
349 | } | |
350 | sb->s_flags |= MS_ACTIVE; | |
351 | ||
352 | afs_put_volume(params.volume); | |
353 | afs_put_cell(params.default_cell); | |
354 | _leave(" = %p", sb); | |
355 | return sb; | |
356 | ||
357 | error: | |
358 | afs_put_volume(params.volume); | |
359 | afs_put_cell(params.default_cell); | |
360 | afscm_stop(); | |
361 | _leave(" = %d", ret); | |
362 | return ERR_PTR(ret); | |
363 | } /* end afs_get_sb() */ | |
364 | ||
365 | /*****************************************************************************/ | |
366 | /* | |
367 | * finish the unmounting process on the superblock | |
368 | */ | |
369 | static void afs_put_super(struct super_block *sb) | |
370 | { | |
371 | struct afs_super_info *as = sb->s_fs_info; | |
372 | ||
373 | _enter(""); | |
374 | ||
375 | afs_put_volume(as->volume); | |
376 | afscm_stop(); | |
377 | ||
378 | _leave(""); | |
379 | } /* end afs_put_super() */ | |
380 | ||
381 | /*****************************************************************************/ | |
382 | /* | |
383 | * initialise an inode cache slab element prior to any use | |
384 | */ | |
385 | static void afs_i_init_once(void *_vnode, kmem_cache_t *cachep, | |
386 | unsigned long flags) | |
387 | { | |
388 | struct afs_vnode *vnode = (struct afs_vnode *) _vnode; | |
389 | ||
390 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
391 | SLAB_CTOR_CONSTRUCTOR) { | |
392 | memset(vnode, 0, sizeof(*vnode)); | |
393 | inode_init_once(&vnode->vfs_inode); | |
394 | init_waitqueue_head(&vnode->update_waitq); | |
395 | spin_lock_init(&vnode->lock); | |
396 | INIT_LIST_HEAD(&vnode->cb_link); | |
397 | INIT_LIST_HEAD(&vnode->cb_hash_link); | |
398 | afs_timer_init(&vnode->cb_timeout, | |
399 | &afs_vnode_cb_timed_out_ops); | |
400 | } | |
401 | ||
402 | } /* end afs_i_init_once() */ | |
403 | ||
404 | /*****************************************************************************/ | |
405 | /* | |
406 | * allocate an AFS inode struct from our slab cache | |
407 | */ | |
408 | static struct inode *afs_alloc_inode(struct super_block *sb) | |
409 | { | |
410 | struct afs_vnode *vnode; | |
411 | ||
412 | vnode = (struct afs_vnode *) | |
413 | kmem_cache_alloc(afs_inode_cachep, SLAB_KERNEL); | |
414 | if (!vnode) | |
415 | return NULL; | |
416 | ||
417 | atomic_inc(&afs_count_active_inodes); | |
418 | ||
419 | memset(&vnode->fid, 0, sizeof(vnode->fid)); | |
420 | memset(&vnode->status, 0, sizeof(vnode->status)); | |
421 | ||
422 | vnode->volume = NULL; | |
423 | vnode->update_cnt = 0; | |
424 | vnode->flags = 0; | |
425 | ||
426 | return &vnode->vfs_inode; | |
427 | } /* end afs_alloc_inode() */ | |
428 | ||
429 | /*****************************************************************************/ | |
430 | /* | |
431 | * destroy an AFS inode struct | |
432 | */ | |
433 | static void afs_destroy_inode(struct inode *inode) | |
434 | { | |
435 | _enter("{%lu}", inode->i_ino); | |
436 | ||
437 | kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode)); | |
438 | ||
439 | atomic_dec(&afs_count_active_inodes); | |
440 | ||
441 | } /* end afs_destroy_inode() */ |