Commit | Line | Data |
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5db53f3e JE |
1 | /* |
2 | * fs/logfs/super.c | |
3 | * | |
4 | * As should be obvious for Linux kernel code, license is GPLv2 | |
5 | * | |
6 | * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> | |
7 | * | |
8 | * Generally contains mount/umount code and also serves as a dump area for | |
9 | * any functions that don't fit elsewhere and neither justify a file of their | |
10 | * own. | |
11 | */ | |
12 | #include "logfs.h" | |
13 | #include <linux/bio.h> | |
5a0e3ad6 | 14 | #include <linux/slab.h> |
5db53f3e JE |
15 | #include <linux/mtd/mtd.h> |
16 | #include <linux/statfs.h> | |
17 | #include <linux/buffer_head.h> | |
18 | ||
19 | static DEFINE_MUTEX(emergency_mutex); | |
20 | static struct page *emergency_page; | |
21 | ||
22 | struct page *emergency_read_begin(struct address_space *mapping, pgoff_t index) | |
23 | { | |
24 | filler_t *filler = (filler_t *)mapping->a_ops->readpage; | |
25 | struct page *page; | |
26 | int err; | |
27 | ||
28 | page = read_cache_page(mapping, index, filler, NULL); | |
29 | if (page) | |
30 | return page; | |
31 | ||
32 | /* No more pages available, switch to emergency page */ | |
33 | printk(KERN_INFO"Logfs: Using emergency page\n"); | |
34 | mutex_lock(&emergency_mutex); | |
35 | err = filler(NULL, emergency_page); | |
36 | if (err) { | |
37 | mutex_unlock(&emergency_mutex); | |
38 | printk(KERN_EMERG"Logfs: Error reading emergency page\n"); | |
39 | return ERR_PTR(err); | |
40 | } | |
41 | return emergency_page; | |
42 | } | |
43 | ||
44 | void emergency_read_end(struct page *page) | |
45 | { | |
46 | if (page == emergency_page) | |
47 | mutex_unlock(&emergency_mutex); | |
48 | else | |
49 | page_cache_release(page); | |
50 | } | |
51 | ||
52 | static void dump_segfile(struct super_block *sb) | |
53 | { | |
54 | struct logfs_super *super = logfs_super(sb); | |
55 | struct logfs_segment_entry se; | |
56 | u32 segno; | |
57 | ||
58 | for (segno = 0; segno < super->s_no_segs; segno++) { | |
59 | logfs_get_segment_entry(sb, segno, &se); | |
60 | printk("%3x: %6x %8x", segno, be32_to_cpu(se.ec_level), | |
61 | be32_to_cpu(se.valid)); | |
62 | if (++segno < super->s_no_segs) { | |
63 | logfs_get_segment_entry(sb, segno, &se); | |
64 | printk(" %6x %8x", be32_to_cpu(se.ec_level), | |
65 | be32_to_cpu(se.valid)); | |
66 | } | |
67 | if (++segno < super->s_no_segs) { | |
68 | logfs_get_segment_entry(sb, segno, &se); | |
69 | printk(" %6x %8x", be32_to_cpu(se.ec_level), | |
70 | be32_to_cpu(se.valid)); | |
71 | } | |
72 | if (++segno < super->s_no_segs) { | |
73 | logfs_get_segment_entry(sb, segno, &se); | |
74 | printk(" %6x %8x", be32_to_cpu(se.ec_level), | |
75 | be32_to_cpu(se.valid)); | |
76 | } | |
77 | printk("\n"); | |
78 | } | |
79 | } | |
80 | ||
81 | /* | |
82 | * logfs_crash_dump - dump debug information to device | |
83 | * | |
84 | * The LogFS superblock only occupies part of a segment. This function will | |
85 | * write as much debug information as it can gather into the spare space. | |
86 | */ | |
87 | void logfs_crash_dump(struct super_block *sb) | |
88 | { | |
89 | dump_segfile(sb); | |
90 | } | |
91 | ||
92 | /* | |
93 | * TODO: move to lib/string.c | |
94 | */ | |
95 | /** | |
96 | * memchr_inv - Find a character in an area of memory. | |
97 | * @s: The memory area | |
98 | * @c: The byte to search for | |
99 | * @n: The size of the area. | |
100 | * | |
101 | * returns the address of the first character other than @c, or %NULL | |
102 | * if the whole buffer contains just @c. | |
103 | */ | |
104 | void *memchr_inv(const void *s, int c, size_t n) | |
105 | { | |
106 | const unsigned char *p = s; | |
107 | while (n-- != 0) | |
108 | if ((unsigned char)c != *p++) | |
109 | return (void *)(p - 1); | |
110 | ||
111 | return NULL; | |
112 | } | |
113 | ||
114 | /* | |
115 | * FIXME: There should be a reserve for root, similar to ext2. | |
116 | */ | |
117 | int logfs_statfs(struct dentry *dentry, struct kstatfs *stats) | |
118 | { | |
119 | struct super_block *sb = dentry->d_sb; | |
120 | struct logfs_super *super = logfs_super(sb); | |
121 | ||
122 | stats->f_type = LOGFS_MAGIC_U32; | |
123 | stats->f_bsize = sb->s_blocksize; | |
124 | stats->f_blocks = super->s_size >> LOGFS_BLOCK_BITS >> 3; | |
125 | stats->f_bfree = super->s_free_bytes >> sb->s_blocksize_bits; | |
126 | stats->f_bavail = super->s_free_bytes >> sb->s_blocksize_bits; | |
127 | stats->f_files = 0; | |
128 | stats->f_ffree = 0; | |
129 | stats->f_namelen = LOGFS_MAX_NAMELEN; | |
130 | return 0; | |
131 | } | |
132 | ||
133 | static int logfs_sb_set(struct super_block *sb, void *_super) | |
134 | { | |
135 | struct logfs_super *super = _super; | |
136 | ||
137 | sb->s_fs_info = super; | |
138 | sb->s_mtd = super->s_mtd; | |
139 | sb->s_bdev = super->s_bdev; | |
140 | return 0; | |
141 | } | |
142 | ||
143 | static int logfs_sb_test(struct super_block *sb, void *_super) | |
144 | { | |
145 | struct logfs_super *super = _super; | |
146 | struct mtd_info *mtd = super->s_mtd; | |
147 | ||
148 | if (mtd && sb->s_mtd == mtd) | |
149 | return 1; | |
150 | if (super->s_bdev && sb->s_bdev == super->s_bdev) | |
151 | return 1; | |
152 | return 0; | |
153 | } | |
154 | ||
155 | static void set_segment_header(struct logfs_segment_header *sh, u8 type, | |
156 | u8 level, u32 segno, u32 ec) | |
157 | { | |
158 | sh->pad = 0; | |
159 | sh->type = type; | |
160 | sh->level = level; | |
161 | sh->segno = cpu_to_be32(segno); | |
162 | sh->ec = cpu_to_be32(ec); | |
163 | sh->gec = cpu_to_be64(segno); | |
164 | sh->crc = logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4); | |
165 | } | |
166 | ||
167 | static void logfs_write_ds(struct super_block *sb, struct logfs_disk_super *ds, | |
168 | u32 segno, u32 ec) | |
169 | { | |
170 | struct logfs_super *super = logfs_super(sb); | |
171 | struct logfs_segment_header *sh = &ds->ds_sh; | |
172 | int i; | |
173 | ||
174 | memset(ds, 0, sizeof(*ds)); | |
175 | set_segment_header(sh, SEG_SUPER, 0, segno, ec); | |
176 | ||
177 | ds->ds_ifile_levels = super->s_ifile_levels; | |
178 | ds->ds_iblock_levels = super->s_iblock_levels; | |
179 | ds->ds_data_levels = super->s_data_levels; /* XXX: Remove */ | |
180 | ds->ds_segment_shift = super->s_segshift; | |
181 | ds->ds_block_shift = sb->s_blocksize_bits; | |
182 | ds->ds_write_shift = super->s_writeshift; | |
183 | ds->ds_filesystem_size = cpu_to_be64(super->s_size); | |
184 | ds->ds_segment_size = cpu_to_be32(super->s_segsize); | |
185 | ds->ds_bad_seg_reserve = cpu_to_be32(super->s_bad_seg_reserve); | |
186 | ds->ds_feature_incompat = cpu_to_be64(super->s_feature_incompat); | |
187 | ds->ds_feature_ro_compat= cpu_to_be64(super->s_feature_ro_compat); | |
188 | ds->ds_feature_compat = cpu_to_be64(super->s_feature_compat); | |
189 | ds->ds_feature_flags = cpu_to_be64(super->s_feature_flags); | |
190 | ds->ds_root_reserve = cpu_to_be64(super->s_root_reserve); | |
191 | ds->ds_speed_reserve = cpu_to_be64(super->s_speed_reserve); | |
192 | journal_for_each(i) | |
193 | ds->ds_journal_seg[i] = cpu_to_be32(super->s_journal_seg[i]); | |
194 | ds->ds_magic = cpu_to_be64(LOGFS_MAGIC); | |
195 | ds->ds_crc = logfs_crc32(ds, sizeof(*ds), | |
196 | LOGFS_SEGMENT_HEADERSIZE + 12); | |
197 | } | |
198 | ||
199 | static int write_one_sb(struct super_block *sb, | |
200 | struct page *(*find_sb)(struct super_block *sb, u64 *ofs)) | |
201 | { | |
202 | struct logfs_super *super = logfs_super(sb); | |
203 | struct logfs_disk_super *ds; | |
204 | struct logfs_segment_entry se; | |
205 | struct page *page; | |
206 | u64 ofs; | |
207 | u32 ec, segno; | |
208 | int err; | |
209 | ||
210 | page = find_sb(sb, &ofs); | |
211 | if (!page) | |
212 | return -EIO; | |
213 | ds = page_address(page); | |
214 | segno = seg_no(sb, ofs); | |
215 | logfs_get_segment_entry(sb, segno, &se); | |
216 | ec = be32_to_cpu(se.ec_level) >> 4; | |
217 | ec++; | |
218 | logfs_set_segment_erased(sb, segno, ec, 0); | |
219 | logfs_write_ds(sb, ds, segno, ec); | |
220 | err = super->s_devops->write_sb(sb, page); | |
221 | page_cache_release(page); | |
222 | return err; | |
223 | } | |
224 | ||
225 | int logfs_write_sb(struct super_block *sb) | |
226 | { | |
227 | struct logfs_super *super = logfs_super(sb); | |
228 | int err; | |
229 | ||
230 | /* First superblock */ | |
231 | err = write_one_sb(sb, super->s_devops->find_first_sb); | |
232 | if (err) | |
233 | return err; | |
234 | ||
235 | /* Last superblock */ | |
236 | err = write_one_sb(sb, super->s_devops->find_last_sb); | |
237 | if (err) | |
238 | return err; | |
239 | return 0; | |
240 | } | |
241 | ||
242 | static int ds_cmp(const void *ds0, const void *ds1) | |
243 | { | |
244 | size_t len = sizeof(struct logfs_disk_super); | |
245 | ||
246 | /* We know the segment headers differ, so ignore them */ | |
247 | len -= LOGFS_SEGMENT_HEADERSIZE; | |
248 | ds0 += LOGFS_SEGMENT_HEADERSIZE; | |
249 | ds1 += LOGFS_SEGMENT_HEADERSIZE; | |
250 | return memcmp(ds0, ds1, len); | |
251 | } | |
252 | ||
253 | static int logfs_recover_sb(struct super_block *sb) | |
254 | { | |
255 | struct logfs_super *super = logfs_super(sb); | |
256 | struct logfs_disk_super _ds0, *ds0 = &_ds0; | |
257 | struct logfs_disk_super _ds1, *ds1 = &_ds1; | |
258 | int err, valid0, valid1; | |
259 | ||
260 | /* read first superblock */ | |
261 | err = wbuf_read(sb, super->s_sb_ofs[0], sizeof(*ds0), ds0); | |
262 | if (err) | |
263 | return err; | |
264 | /* read last superblock */ | |
265 | err = wbuf_read(sb, super->s_sb_ofs[1], sizeof(*ds1), ds1); | |
266 | if (err) | |
267 | return err; | |
268 | valid0 = logfs_check_ds(ds0) == 0; | |
269 | valid1 = logfs_check_ds(ds1) == 0; | |
270 | ||
271 | if (!valid0 && valid1) { | |
272 | printk(KERN_INFO"First superblock is invalid - fixing.\n"); | |
273 | return write_one_sb(sb, super->s_devops->find_first_sb); | |
274 | } | |
275 | if (valid0 && !valid1) { | |
276 | printk(KERN_INFO"Last superblock is invalid - fixing.\n"); | |
277 | return write_one_sb(sb, super->s_devops->find_last_sb); | |
278 | } | |
279 | if (valid0 && valid1 && ds_cmp(ds0, ds1)) { | |
280 | printk(KERN_INFO"Superblocks don't match - fixing.\n"); | |
faaa27ab | 281 | return logfs_write_sb(sb); |
5db53f3e JE |
282 | } |
283 | /* If neither is valid now, something's wrong. Didn't we properly | |
284 | * check them before?!? */ | |
285 | BUG_ON(!valid0 && !valid1); | |
286 | return 0; | |
287 | } | |
288 | ||
289 | static int logfs_make_writeable(struct super_block *sb) | |
290 | { | |
291 | int err; | |
292 | ||
49137f2e JE |
293 | err = logfs_open_segfile(sb); |
294 | if (err) | |
295 | return err; | |
296 | ||
5db53f3e JE |
297 | /* Repair any broken superblock copies */ |
298 | err = logfs_recover_sb(sb); | |
299 | if (err) | |
300 | return err; | |
301 | ||
302 | /* Check areas for trailing unaccounted data */ | |
303 | err = logfs_check_areas(sb); | |
304 | if (err) | |
305 | return err; | |
306 | ||
5db53f3e JE |
307 | /* Do one GC pass before any data gets dirtied */ |
308 | logfs_gc_pass(sb); | |
309 | ||
310 | /* after all initializations are done, replay the journal | |
311 | * for rw-mounts, if necessary */ | |
312 | err = logfs_replay_journal(sb); | |
313 | if (err) | |
314 | return err; | |
315 | ||
316 | return 0; | |
317 | } | |
318 | ||
319 | static int logfs_get_sb_final(struct super_block *sb, struct vfsmount *mnt) | |
320 | { | |
9421502b | 321 | struct logfs_super *super = logfs_super(sb); |
5db53f3e JE |
322 | struct inode *rootdir; |
323 | int err; | |
324 | ||
325 | /* root dir */ | |
326 | rootdir = logfs_iget(sb, LOGFS_INO_ROOT); | |
327 | if (IS_ERR(rootdir)) | |
328 | goto fail; | |
329 | ||
330 | sb->s_root = d_alloc_root(rootdir); | |
331 | if (!sb->s_root) | |
7db8064c | 332 | goto fail2; |
5db53f3e | 333 | |
9421502b JE |
334 | super->s_erase_page = alloc_pages(GFP_KERNEL, 0); |
335 | if (!super->s_erase_page) | |
336 | goto fail2; | |
337 | memset(page_address(super->s_erase_page), 0xFF, PAGE_SIZE); | |
338 | ||
5db53f3e JE |
339 | /* FIXME: check for read-only mounts */ |
340 | err = logfs_make_writeable(sb); | |
341 | if (err) | |
9421502b | 342 | goto fail3; |
5db53f3e JE |
343 | |
344 | log_super("LogFS: Finished mounting\n"); | |
345 | simple_set_mnt(mnt, sb); | |
346 | return 0; | |
347 | ||
9421502b JE |
348 | fail3: |
349 | __free_page(super->s_erase_page); | |
5db53f3e JE |
350 | fail2: |
351 | iput(rootdir); | |
352 | fail: | |
353 | iput(logfs_super(sb)->s_master_inode); | |
354 | return -EIO; | |
355 | } | |
356 | ||
357 | int logfs_check_ds(struct logfs_disk_super *ds) | |
358 | { | |
359 | struct logfs_segment_header *sh = &ds->ds_sh; | |
360 | ||
361 | if (ds->ds_magic != cpu_to_be64(LOGFS_MAGIC)) | |
362 | return -EINVAL; | |
363 | if (sh->crc != logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4)) | |
364 | return -EINVAL; | |
365 | if (ds->ds_crc != logfs_crc32(ds, sizeof(*ds), | |
366 | LOGFS_SEGMENT_HEADERSIZE + 12)) | |
367 | return -EINVAL; | |
368 | return 0; | |
369 | } | |
370 | ||
371 | static struct page *find_super_block(struct super_block *sb) | |
372 | { | |
373 | struct logfs_super *super = logfs_super(sb); | |
374 | struct page *first, *last; | |
375 | ||
376 | first = super->s_devops->find_first_sb(sb, &super->s_sb_ofs[0]); | |
377 | if (!first || IS_ERR(first)) | |
378 | return NULL; | |
379 | last = super->s_devops->find_last_sb(sb, &super->s_sb_ofs[1]); | |
380 | if (!last || IS_ERR(first)) { | |
381 | page_cache_release(first); | |
382 | return NULL; | |
383 | } | |
384 | ||
385 | if (!logfs_check_ds(page_address(first))) { | |
386 | page_cache_release(last); | |
387 | return first; | |
388 | } | |
389 | ||
390 | /* First one didn't work, try the second superblock */ | |
391 | if (!logfs_check_ds(page_address(last))) { | |
392 | page_cache_release(first); | |
393 | return last; | |
394 | } | |
395 | ||
396 | /* Neither worked, sorry folks */ | |
397 | page_cache_release(first); | |
398 | page_cache_release(last); | |
399 | return NULL; | |
400 | } | |
401 | ||
402 | static int __logfs_read_sb(struct super_block *sb) | |
403 | { | |
404 | struct logfs_super *super = logfs_super(sb); | |
405 | struct page *page; | |
406 | struct logfs_disk_super *ds; | |
407 | int i; | |
408 | ||
409 | page = find_super_block(sb); | |
410 | if (!page) | |
411 | return -EIO; | |
412 | ||
413 | ds = page_address(page); | |
414 | super->s_size = be64_to_cpu(ds->ds_filesystem_size); | |
415 | super->s_root_reserve = be64_to_cpu(ds->ds_root_reserve); | |
416 | super->s_speed_reserve = be64_to_cpu(ds->ds_speed_reserve); | |
417 | super->s_bad_seg_reserve = be32_to_cpu(ds->ds_bad_seg_reserve); | |
418 | super->s_segsize = 1 << ds->ds_segment_shift; | |
419 | super->s_segmask = (1 << ds->ds_segment_shift) - 1; | |
420 | super->s_segshift = ds->ds_segment_shift; | |
421 | sb->s_blocksize = 1 << ds->ds_block_shift; | |
422 | sb->s_blocksize_bits = ds->ds_block_shift; | |
423 | super->s_writesize = 1 << ds->ds_write_shift; | |
424 | super->s_writeshift = ds->ds_write_shift; | |
425 | super->s_no_segs = super->s_size >> super->s_segshift; | |
426 | super->s_no_blocks = super->s_segsize >> sb->s_blocksize_bits; | |
427 | super->s_feature_incompat = be64_to_cpu(ds->ds_feature_incompat); | |
428 | super->s_feature_ro_compat = be64_to_cpu(ds->ds_feature_ro_compat); | |
429 | super->s_feature_compat = be64_to_cpu(ds->ds_feature_compat); | |
430 | super->s_feature_flags = be64_to_cpu(ds->ds_feature_flags); | |
431 | ||
432 | journal_for_each(i) | |
433 | super->s_journal_seg[i] = be32_to_cpu(ds->ds_journal_seg[i]); | |
434 | ||
435 | super->s_ifile_levels = ds->ds_ifile_levels; | |
436 | super->s_iblock_levels = ds->ds_iblock_levels; | |
437 | super->s_data_levels = ds->ds_data_levels; | |
438 | super->s_total_levels = super->s_ifile_levels + super->s_iblock_levels | |
439 | + super->s_data_levels; | |
440 | page_cache_release(page); | |
441 | return 0; | |
442 | } | |
443 | ||
6a08ab84 | 444 | static int logfs_read_sb(struct super_block *sb, int read_only) |
5db53f3e JE |
445 | { |
446 | struct logfs_super *super = logfs_super(sb); | |
447 | int ret; | |
448 | ||
449 | super->s_btree_pool = mempool_create(32, btree_alloc, btree_free, NULL); | |
450 | if (!super->s_btree_pool) | |
451 | return -ENOMEM; | |
452 | ||
453 | btree_init_mempool64(&super->s_shadow_tree.new, super->s_btree_pool); | |
454 | btree_init_mempool64(&super->s_shadow_tree.old, super->s_btree_pool); | |
455 | ||
456 | ret = logfs_init_mapping(sb); | |
457 | if (ret) | |
458 | return ret; | |
459 | ||
460 | ret = __logfs_read_sb(sb); | |
461 | if (ret) | |
462 | return ret; | |
463 | ||
6a08ab84 JE |
464 | if (super->s_feature_incompat & ~LOGFS_FEATURES_INCOMPAT) |
465 | return -EIO; | |
466 | if ((super->s_feature_ro_compat & ~LOGFS_FEATURES_RO_COMPAT) && | |
467 | !read_only) | |
468 | return -EIO; | |
469 | ||
5db53f3e JE |
470 | mutex_init(&super->s_dirop_mutex); |
471 | mutex_init(&super->s_object_alias_mutex); | |
472 | INIT_LIST_HEAD(&super->s_freeing_list); | |
473 | ||
474 | ret = logfs_init_rw(sb); | |
475 | if (ret) | |
476 | return ret; | |
477 | ||
478 | ret = logfs_init_areas(sb); | |
479 | if (ret) | |
480 | return ret; | |
481 | ||
482 | ret = logfs_init_gc(sb); | |
483 | if (ret) | |
484 | return ret; | |
485 | ||
486 | ret = logfs_init_journal(sb); | |
487 | if (ret) | |
488 | return ret; | |
489 | ||
490 | return 0; | |
491 | } | |
492 | ||
493 | static void logfs_kill_sb(struct super_block *sb) | |
494 | { | |
495 | struct logfs_super *super = logfs_super(sb); | |
496 | ||
497 | log_super("LogFS: Start unmounting\n"); | |
498 | /* Alias entries slow down mount, so evict as many as possible */ | |
499 | sync_filesystem(sb); | |
c6d38301 | 500 | logfs_write_anchor(sb); |
5db53f3e JE |
501 | |
502 | /* | |
503 | * From this point on alias entries are simply dropped - and any | |
504 | * writes to the object store are considered bugs. | |
505 | */ | |
506 | super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN; | |
507 | log_super("LogFS: Now in shutdown\n"); | |
508 | generic_shutdown_super(sb); | |
509 | ||
510 | BUG_ON(super->s_dirty_used_bytes || super->s_dirty_free_bytes); | |
511 | ||
512 | logfs_cleanup_gc(sb); | |
513 | logfs_cleanup_journal(sb); | |
514 | logfs_cleanup_areas(sb); | |
515 | logfs_cleanup_rw(sb); | |
9421502b JE |
516 | if (super->s_erase_page) |
517 | __free_page(super->s_erase_page); | |
5db53f3e JE |
518 | super->s_devops->put_device(sb); |
519 | mempool_destroy(super->s_btree_pool); | |
520 | mempool_destroy(super->s_alias_pool); | |
521 | kfree(super); | |
522 | log_super("LogFS: Finished unmounting\n"); | |
523 | } | |
524 | ||
525 | int logfs_get_sb_device(struct file_system_type *type, int flags, | |
526 | struct mtd_info *mtd, struct block_device *bdev, | |
527 | const struct logfs_device_ops *devops, struct vfsmount *mnt) | |
528 | { | |
529 | struct logfs_super *super; | |
530 | struct super_block *sb; | |
531 | int err = -ENOMEM; | |
532 | static int mount_count; | |
533 | ||
534 | log_super("LogFS: Start mount %x\n", mount_count++); | |
535 | super = kzalloc(sizeof(*super), GFP_KERNEL); | |
536 | if (!super) | |
537 | goto err0; | |
538 | ||
539 | super->s_mtd = mtd; | |
540 | super->s_bdev = bdev; | |
541 | err = -EINVAL; | |
542 | sb = sget(type, logfs_sb_test, logfs_sb_set, super); | |
543 | if (IS_ERR(sb)) | |
544 | goto err0; | |
545 | ||
546 | if (sb->s_root) { | |
547 | /* Device is already in use */ | |
548 | err = 0; | |
549 | simple_set_mnt(mnt, sb); | |
550 | goto err0; | |
551 | } | |
552 | ||
553 | super->s_devops = devops; | |
554 | ||
555 | /* | |
556 | * sb->s_maxbytes is limited to 8TB. On 32bit systems, the page cache | |
557 | * only covers 16TB and the upper 8TB are used for indirect blocks. | |
558 | * On 64bit system we could bump up the limit, but that would make | |
559 | * the filesystem incompatible with 32bit systems. | |
560 | */ | |
561 | sb->s_maxbytes = (1ull << 43) - 1; | |
562 | sb->s_op = &logfs_super_operations; | |
563 | sb->s_flags = flags | MS_NOATIME; | |
564 | ||
6a08ab84 | 565 | err = logfs_read_sb(sb, sb->s_flags & MS_RDONLY); |
5db53f3e JE |
566 | if (err) |
567 | goto err1; | |
568 | ||
569 | sb->s_flags |= MS_ACTIVE; | |
570 | err = logfs_get_sb_final(sb, mnt); | |
571 | if (err) | |
572 | goto err1; | |
573 | return 0; | |
574 | ||
575 | err1: | |
6f2e9e6a | 576 | deactivate_locked_super(sb); |
5db53f3e JE |
577 | return err; |
578 | err0: | |
579 | kfree(super); | |
580 | //devops->put_device(sb); | |
581 | return err; | |
582 | } | |
583 | ||
584 | static int logfs_get_sb(struct file_system_type *type, int flags, | |
585 | const char *devname, void *data, struct vfsmount *mnt) | |
586 | { | |
587 | ulong mtdnr; | |
588 | ||
589 | if (!devname) | |
590 | return logfs_get_sb_bdev(type, flags, devname, mnt); | |
591 | if (strncmp(devname, "mtd", 3)) | |
592 | return logfs_get_sb_bdev(type, flags, devname, mnt); | |
593 | ||
594 | { | |
595 | char *garbage; | |
596 | mtdnr = simple_strtoul(devname+3, &garbage, 0); | |
597 | if (*garbage) | |
598 | return -EINVAL; | |
599 | } | |
600 | ||
601 | return logfs_get_sb_mtd(type, flags, mtdnr, mnt); | |
602 | } | |
603 | ||
604 | static struct file_system_type logfs_fs_type = { | |
605 | .owner = THIS_MODULE, | |
606 | .name = "logfs", | |
607 | .get_sb = logfs_get_sb, | |
608 | .kill_sb = logfs_kill_sb, | |
609 | .fs_flags = FS_REQUIRES_DEV, | |
610 | ||
611 | }; | |
612 | ||
613 | static int __init logfs_init(void) | |
614 | { | |
615 | int ret; | |
616 | ||
617 | emergency_page = alloc_pages(GFP_KERNEL, 0); | |
618 | if (!emergency_page) | |
619 | return -ENOMEM; | |
620 | ||
621 | ret = logfs_compr_init(); | |
622 | if (ret) | |
623 | goto out1; | |
624 | ||
625 | ret = logfs_init_inode_cache(); | |
626 | if (ret) | |
627 | goto out2; | |
628 | ||
629 | return register_filesystem(&logfs_fs_type); | |
630 | out2: | |
631 | logfs_compr_exit(); | |
632 | out1: | |
633 | __free_pages(emergency_page, 0); | |
634 | return ret; | |
635 | } | |
636 | ||
637 | static void __exit logfs_exit(void) | |
638 | { | |
639 | unregister_filesystem(&logfs_fs_type); | |
640 | logfs_destroy_inode_cache(); | |
641 | logfs_compr_exit(); | |
642 | __free_pages(emergency_page, 0); | |
643 | } | |
644 | ||
645 | module_init(logfs_init); | |
646 | module_exit(logfs_exit); | |
647 | ||
648 | MODULE_LICENSE("GPL v2"); | |
649 | MODULE_AUTHOR("Joern Engel <joern@logfs.org>"); | |
650 | MODULE_DESCRIPTION("scalable flash filesystem"); |