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> |
b8639077 | 15 | #include <linux/blkdev.h> |
5db53f3e JE |
16 | #include <linux/mtd/mtd.h> |
17 | #include <linux/statfs.h> | |
18 | #include <linux/buffer_head.h> | |
19 | ||
20 | static DEFINE_MUTEX(emergency_mutex); | |
21 | static struct page *emergency_page; | |
22 | ||
23 | struct page *emergency_read_begin(struct address_space *mapping, pgoff_t index) | |
24 | { | |
25 | filler_t *filler = (filler_t *)mapping->a_ops->readpage; | |
26 | struct page *page; | |
27 | int err; | |
28 | ||
29 | page = read_cache_page(mapping, index, filler, NULL); | |
30 | if (page) | |
31 | return page; | |
32 | ||
33 | /* No more pages available, switch to emergency page */ | |
34 | printk(KERN_INFO"Logfs: Using emergency page\n"); | |
35 | mutex_lock(&emergency_mutex); | |
36 | err = filler(NULL, emergency_page); | |
37 | if (err) { | |
38 | mutex_unlock(&emergency_mutex); | |
39 | printk(KERN_EMERG"Logfs: Error reading emergency page\n"); | |
40 | return ERR_PTR(err); | |
41 | } | |
42 | return emergency_page; | |
43 | } | |
44 | ||
45 | void emergency_read_end(struct page *page) | |
46 | { | |
47 | if (page == emergency_page) | |
48 | mutex_unlock(&emergency_mutex); | |
49 | else | |
50 | page_cache_release(page); | |
51 | } | |
52 | ||
53 | static void dump_segfile(struct super_block *sb) | |
54 | { | |
55 | struct logfs_super *super = logfs_super(sb); | |
56 | struct logfs_segment_entry se; | |
57 | u32 segno; | |
58 | ||
59 | for (segno = 0; segno < super->s_no_segs; segno++) { | |
60 | logfs_get_segment_entry(sb, segno, &se); | |
61 | printk("%3x: %6x %8x", segno, be32_to_cpu(se.ec_level), | |
62 | be32_to_cpu(se.valid)); | |
63 | if (++segno < super->s_no_segs) { | |
64 | logfs_get_segment_entry(sb, segno, &se); | |
65 | printk(" %6x %8x", be32_to_cpu(se.ec_level), | |
66 | be32_to_cpu(se.valid)); | |
67 | } | |
68 | if (++segno < super->s_no_segs) { | |
69 | logfs_get_segment_entry(sb, segno, &se); | |
70 | printk(" %6x %8x", be32_to_cpu(se.ec_level), | |
71 | be32_to_cpu(se.valid)); | |
72 | } | |
73 | if (++segno < super->s_no_segs) { | |
74 | logfs_get_segment_entry(sb, segno, &se); | |
75 | printk(" %6x %8x", be32_to_cpu(se.ec_level), | |
76 | be32_to_cpu(se.valid)); | |
77 | } | |
78 | printk("\n"); | |
79 | } | |
80 | } | |
81 | ||
82 | /* | |
83 | * logfs_crash_dump - dump debug information to device | |
84 | * | |
85 | * The LogFS superblock only occupies part of a segment. This function will | |
86 | * write as much debug information as it can gather into the spare space. | |
87 | */ | |
88 | void logfs_crash_dump(struct super_block *sb) | |
89 | { | |
90 | dump_segfile(sb); | |
91 | } | |
92 | ||
93 | /* | |
94 | * TODO: move to lib/string.c | |
95 | */ | |
96 | /** | |
97 | * memchr_inv - Find a character in an area of memory. | |
98 | * @s: The memory area | |
99 | * @c: The byte to search for | |
100 | * @n: The size of the area. | |
101 | * | |
102 | * returns the address of the first character other than @c, or %NULL | |
103 | * if the whole buffer contains just @c. | |
104 | */ | |
105 | void *memchr_inv(const void *s, int c, size_t n) | |
106 | { | |
107 | const unsigned char *p = s; | |
108 | while (n-- != 0) | |
109 | if ((unsigned char)c != *p++) | |
110 | return (void *)(p - 1); | |
111 | ||
112 | return NULL; | |
113 | } | |
114 | ||
115 | /* | |
116 | * FIXME: There should be a reserve for root, similar to ext2. | |
117 | */ | |
118 | int logfs_statfs(struct dentry *dentry, struct kstatfs *stats) | |
119 | { | |
120 | struct super_block *sb = dentry->d_sb; | |
121 | struct logfs_super *super = logfs_super(sb); | |
122 | ||
123 | stats->f_type = LOGFS_MAGIC_U32; | |
124 | stats->f_bsize = sb->s_blocksize; | |
125 | stats->f_blocks = super->s_size >> LOGFS_BLOCK_BITS >> 3; | |
126 | stats->f_bfree = super->s_free_bytes >> sb->s_blocksize_bits; | |
127 | stats->f_bavail = super->s_free_bytes >> sb->s_blocksize_bits; | |
128 | stats->f_files = 0; | |
129 | stats->f_ffree = 0; | |
130 | stats->f_namelen = LOGFS_MAX_NAMELEN; | |
131 | return 0; | |
132 | } | |
133 | ||
134 | static int logfs_sb_set(struct super_block *sb, void *_super) | |
135 | { | |
136 | struct logfs_super *super = _super; | |
137 | ||
138 | sb->s_fs_info = super; | |
139 | sb->s_mtd = super->s_mtd; | |
140 | sb->s_bdev = super->s_bdev; | |
b8639077 JE |
141 | if (sb->s_bdev) |
142 | sb->s_bdi = &bdev_get_queue(sb->s_bdev)->backing_dev_info; | |
143 | if (sb->s_mtd) | |
144 | sb->s_bdi = sb->s_mtd->backing_dev_info; | |
5db53f3e JE |
145 | return 0; |
146 | } | |
147 | ||
148 | static int logfs_sb_test(struct super_block *sb, void *_super) | |
149 | { | |
150 | struct logfs_super *super = _super; | |
151 | struct mtd_info *mtd = super->s_mtd; | |
152 | ||
153 | if (mtd && sb->s_mtd == mtd) | |
154 | return 1; | |
155 | if (super->s_bdev && sb->s_bdev == super->s_bdev) | |
156 | return 1; | |
157 | return 0; | |
158 | } | |
159 | ||
160 | static void set_segment_header(struct logfs_segment_header *sh, u8 type, | |
161 | u8 level, u32 segno, u32 ec) | |
162 | { | |
163 | sh->pad = 0; | |
164 | sh->type = type; | |
165 | sh->level = level; | |
166 | sh->segno = cpu_to_be32(segno); | |
167 | sh->ec = cpu_to_be32(ec); | |
168 | sh->gec = cpu_to_be64(segno); | |
169 | sh->crc = logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4); | |
170 | } | |
171 | ||
172 | static void logfs_write_ds(struct super_block *sb, struct logfs_disk_super *ds, | |
173 | u32 segno, u32 ec) | |
174 | { | |
175 | struct logfs_super *super = logfs_super(sb); | |
176 | struct logfs_segment_header *sh = &ds->ds_sh; | |
177 | int i; | |
178 | ||
179 | memset(ds, 0, sizeof(*ds)); | |
180 | set_segment_header(sh, SEG_SUPER, 0, segno, ec); | |
181 | ||
182 | ds->ds_ifile_levels = super->s_ifile_levels; | |
183 | ds->ds_iblock_levels = super->s_iblock_levels; | |
184 | ds->ds_data_levels = super->s_data_levels; /* XXX: Remove */ | |
185 | ds->ds_segment_shift = super->s_segshift; | |
186 | ds->ds_block_shift = sb->s_blocksize_bits; | |
187 | ds->ds_write_shift = super->s_writeshift; | |
188 | ds->ds_filesystem_size = cpu_to_be64(super->s_size); | |
189 | ds->ds_segment_size = cpu_to_be32(super->s_segsize); | |
190 | ds->ds_bad_seg_reserve = cpu_to_be32(super->s_bad_seg_reserve); | |
191 | ds->ds_feature_incompat = cpu_to_be64(super->s_feature_incompat); | |
192 | ds->ds_feature_ro_compat= cpu_to_be64(super->s_feature_ro_compat); | |
193 | ds->ds_feature_compat = cpu_to_be64(super->s_feature_compat); | |
194 | ds->ds_feature_flags = cpu_to_be64(super->s_feature_flags); | |
195 | ds->ds_root_reserve = cpu_to_be64(super->s_root_reserve); | |
196 | ds->ds_speed_reserve = cpu_to_be64(super->s_speed_reserve); | |
197 | journal_for_each(i) | |
198 | ds->ds_journal_seg[i] = cpu_to_be32(super->s_journal_seg[i]); | |
199 | ds->ds_magic = cpu_to_be64(LOGFS_MAGIC); | |
200 | ds->ds_crc = logfs_crc32(ds, sizeof(*ds), | |
201 | LOGFS_SEGMENT_HEADERSIZE + 12); | |
202 | } | |
203 | ||
204 | static int write_one_sb(struct super_block *sb, | |
205 | struct page *(*find_sb)(struct super_block *sb, u64 *ofs)) | |
206 | { | |
207 | struct logfs_super *super = logfs_super(sb); | |
208 | struct logfs_disk_super *ds; | |
209 | struct logfs_segment_entry se; | |
210 | struct page *page; | |
211 | u64 ofs; | |
212 | u32 ec, segno; | |
213 | int err; | |
214 | ||
215 | page = find_sb(sb, &ofs); | |
216 | if (!page) | |
217 | return -EIO; | |
218 | ds = page_address(page); | |
219 | segno = seg_no(sb, ofs); | |
220 | logfs_get_segment_entry(sb, segno, &se); | |
221 | ec = be32_to_cpu(se.ec_level) >> 4; | |
222 | ec++; | |
223 | logfs_set_segment_erased(sb, segno, ec, 0); | |
224 | logfs_write_ds(sb, ds, segno, ec); | |
225 | err = super->s_devops->write_sb(sb, page); | |
226 | page_cache_release(page); | |
227 | return err; | |
228 | } | |
229 | ||
230 | int logfs_write_sb(struct super_block *sb) | |
231 | { | |
232 | struct logfs_super *super = logfs_super(sb); | |
233 | int err; | |
234 | ||
235 | /* First superblock */ | |
236 | err = write_one_sb(sb, super->s_devops->find_first_sb); | |
237 | if (err) | |
238 | return err; | |
239 | ||
240 | /* Last superblock */ | |
241 | err = write_one_sb(sb, super->s_devops->find_last_sb); | |
242 | if (err) | |
243 | return err; | |
244 | return 0; | |
245 | } | |
246 | ||
247 | static int ds_cmp(const void *ds0, const void *ds1) | |
248 | { | |
249 | size_t len = sizeof(struct logfs_disk_super); | |
250 | ||
251 | /* We know the segment headers differ, so ignore them */ | |
252 | len -= LOGFS_SEGMENT_HEADERSIZE; | |
253 | ds0 += LOGFS_SEGMENT_HEADERSIZE; | |
254 | ds1 += LOGFS_SEGMENT_HEADERSIZE; | |
255 | return memcmp(ds0, ds1, len); | |
256 | } | |
257 | ||
258 | static int logfs_recover_sb(struct super_block *sb) | |
259 | { | |
260 | struct logfs_super *super = logfs_super(sb); | |
261 | struct logfs_disk_super _ds0, *ds0 = &_ds0; | |
262 | struct logfs_disk_super _ds1, *ds1 = &_ds1; | |
263 | int err, valid0, valid1; | |
264 | ||
265 | /* read first superblock */ | |
266 | err = wbuf_read(sb, super->s_sb_ofs[0], sizeof(*ds0), ds0); | |
267 | if (err) | |
268 | return err; | |
269 | /* read last superblock */ | |
270 | err = wbuf_read(sb, super->s_sb_ofs[1], sizeof(*ds1), ds1); | |
271 | if (err) | |
272 | return err; | |
273 | valid0 = logfs_check_ds(ds0) == 0; | |
274 | valid1 = logfs_check_ds(ds1) == 0; | |
275 | ||
276 | if (!valid0 && valid1) { | |
277 | printk(KERN_INFO"First superblock is invalid - fixing.\n"); | |
278 | return write_one_sb(sb, super->s_devops->find_first_sb); | |
279 | } | |
280 | if (valid0 && !valid1) { | |
281 | printk(KERN_INFO"Last superblock is invalid - fixing.\n"); | |
282 | return write_one_sb(sb, super->s_devops->find_last_sb); | |
283 | } | |
284 | if (valid0 && valid1 && ds_cmp(ds0, ds1)) { | |
285 | printk(KERN_INFO"Superblocks don't match - fixing.\n"); | |
faaa27ab | 286 | return logfs_write_sb(sb); |
5db53f3e JE |
287 | } |
288 | /* If neither is valid now, something's wrong. Didn't we properly | |
289 | * check them before?!? */ | |
290 | BUG_ON(!valid0 && !valid1); | |
291 | return 0; | |
292 | } | |
293 | ||
294 | static int logfs_make_writeable(struct super_block *sb) | |
295 | { | |
296 | int err; | |
297 | ||
49137f2e JE |
298 | err = logfs_open_segfile(sb); |
299 | if (err) | |
300 | return err; | |
301 | ||
5db53f3e JE |
302 | /* Repair any broken superblock copies */ |
303 | err = logfs_recover_sb(sb); | |
304 | if (err) | |
305 | return err; | |
306 | ||
307 | /* Check areas for trailing unaccounted data */ | |
308 | err = logfs_check_areas(sb); | |
309 | if (err) | |
310 | return err; | |
311 | ||
5db53f3e JE |
312 | /* Do one GC pass before any data gets dirtied */ |
313 | logfs_gc_pass(sb); | |
314 | ||
315 | /* after all initializations are done, replay the journal | |
316 | * for rw-mounts, if necessary */ | |
317 | err = logfs_replay_journal(sb); | |
318 | if (err) | |
319 | return err; | |
320 | ||
321 | return 0; | |
322 | } | |
323 | ||
324 | static int logfs_get_sb_final(struct super_block *sb, struct vfsmount *mnt) | |
325 | { | |
9421502b | 326 | struct logfs_super *super = logfs_super(sb); |
5db53f3e JE |
327 | struct inode *rootdir; |
328 | int err; | |
329 | ||
330 | /* root dir */ | |
331 | rootdir = logfs_iget(sb, LOGFS_INO_ROOT); | |
332 | if (IS_ERR(rootdir)) | |
333 | goto fail; | |
334 | ||
335 | sb->s_root = d_alloc_root(rootdir); | |
336 | if (!sb->s_root) | |
7db8064c | 337 | goto fail2; |
5db53f3e | 338 | |
9421502b JE |
339 | super->s_erase_page = alloc_pages(GFP_KERNEL, 0); |
340 | if (!super->s_erase_page) | |
341 | goto fail2; | |
342 | memset(page_address(super->s_erase_page), 0xFF, PAGE_SIZE); | |
343 | ||
5db53f3e JE |
344 | /* FIXME: check for read-only mounts */ |
345 | err = logfs_make_writeable(sb); | |
346 | if (err) | |
9421502b | 347 | goto fail3; |
5db53f3e JE |
348 | |
349 | log_super("LogFS: Finished mounting\n"); | |
350 | simple_set_mnt(mnt, sb); | |
351 | return 0; | |
352 | ||
9421502b JE |
353 | fail3: |
354 | __free_page(super->s_erase_page); | |
5db53f3e JE |
355 | fail2: |
356 | iput(rootdir); | |
357 | fail: | |
358 | iput(logfs_super(sb)->s_master_inode); | |
359 | return -EIO; | |
360 | } | |
361 | ||
362 | int logfs_check_ds(struct logfs_disk_super *ds) | |
363 | { | |
364 | struct logfs_segment_header *sh = &ds->ds_sh; | |
365 | ||
366 | if (ds->ds_magic != cpu_to_be64(LOGFS_MAGIC)) | |
367 | return -EINVAL; | |
368 | if (sh->crc != logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4)) | |
369 | return -EINVAL; | |
370 | if (ds->ds_crc != logfs_crc32(ds, sizeof(*ds), | |
371 | LOGFS_SEGMENT_HEADERSIZE + 12)) | |
372 | return -EINVAL; | |
373 | return 0; | |
374 | } | |
375 | ||
376 | static struct page *find_super_block(struct super_block *sb) | |
377 | { | |
378 | struct logfs_super *super = logfs_super(sb); | |
379 | struct page *first, *last; | |
380 | ||
381 | first = super->s_devops->find_first_sb(sb, &super->s_sb_ofs[0]); | |
382 | if (!first || IS_ERR(first)) | |
383 | return NULL; | |
384 | last = super->s_devops->find_last_sb(sb, &super->s_sb_ofs[1]); | |
385 | if (!last || IS_ERR(first)) { | |
386 | page_cache_release(first); | |
387 | return NULL; | |
388 | } | |
389 | ||
390 | if (!logfs_check_ds(page_address(first))) { | |
391 | page_cache_release(last); | |
392 | return first; | |
393 | } | |
394 | ||
395 | /* First one didn't work, try the second superblock */ | |
396 | if (!logfs_check_ds(page_address(last))) { | |
397 | page_cache_release(first); | |
398 | return last; | |
399 | } | |
400 | ||
401 | /* Neither worked, sorry folks */ | |
402 | page_cache_release(first); | |
403 | page_cache_release(last); | |
404 | return NULL; | |
405 | } | |
406 | ||
407 | static int __logfs_read_sb(struct super_block *sb) | |
408 | { | |
409 | struct logfs_super *super = logfs_super(sb); | |
410 | struct page *page; | |
411 | struct logfs_disk_super *ds; | |
412 | int i; | |
413 | ||
414 | page = find_super_block(sb); | |
415 | if (!page) | |
416 | return -EIO; | |
417 | ||
418 | ds = page_address(page); | |
419 | super->s_size = be64_to_cpu(ds->ds_filesystem_size); | |
420 | super->s_root_reserve = be64_to_cpu(ds->ds_root_reserve); | |
421 | super->s_speed_reserve = be64_to_cpu(ds->ds_speed_reserve); | |
422 | super->s_bad_seg_reserve = be32_to_cpu(ds->ds_bad_seg_reserve); | |
423 | super->s_segsize = 1 << ds->ds_segment_shift; | |
424 | super->s_segmask = (1 << ds->ds_segment_shift) - 1; | |
425 | super->s_segshift = ds->ds_segment_shift; | |
426 | sb->s_blocksize = 1 << ds->ds_block_shift; | |
427 | sb->s_blocksize_bits = ds->ds_block_shift; | |
428 | super->s_writesize = 1 << ds->ds_write_shift; | |
429 | super->s_writeshift = ds->ds_write_shift; | |
430 | super->s_no_segs = super->s_size >> super->s_segshift; | |
431 | super->s_no_blocks = super->s_segsize >> sb->s_blocksize_bits; | |
432 | super->s_feature_incompat = be64_to_cpu(ds->ds_feature_incompat); | |
433 | super->s_feature_ro_compat = be64_to_cpu(ds->ds_feature_ro_compat); | |
434 | super->s_feature_compat = be64_to_cpu(ds->ds_feature_compat); | |
435 | super->s_feature_flags = be64_to_cpu(ds->ds_feature_flags); | |
436 | ||
437 | journal_for_each(i) | |
438 | super->s_journal_seg[i] = be32_to_cpu(ds->ds_journal_seg[i]); | |
439 | ||
440 | super->s_ifile_levels = ds->ds_ifile_levels; | |
441 | super->s_iblock_levels = ds->ds_iblock_levels; | |
442 | super->s_data_levels = ds->ds_data_levels; | |
443 | super->s_total_levels = super->s_ifile_levels + super->s_iblock_levels | |
444 | + super->s_data_levels; | |
445 | page_cache_release(page); | |
446 | return 0; | |
447 | } | |
448 | ||
6a08ab84 | 449 | static int logfs_read_sb(struct super_block *sb, int read_only) |
5db53f3e JE |
450 | { |
451 | struct logfs_super *super = logfs_super(sb); | |
452 | int ret; | |
453 | ||
454 | super->s_btree_pool = mempool_create(32, btree_alloc, btree_free, NULL); | |
455 | if (!super->s_btree_pool) | |
456 | return -ENOMEM; | |
457 | ||
458 | btree_init_mempool64(&super->s_shadow_tree.new, super->s_btree_pool); | |
459 | btree_init_mempool64(&super->s_shadow_tree.old, super->s_btree_pool); | |
032d8f72 JE |
460 | btree_init_mempool32(&super->s_shadow_tree.segment_map, |
461 | super->s_btree_pool); | |
5db53f3e JE |
462 | |
463 | ret = logfs_init_mapping(sb); | |
464 | if (ret) | |
465 | return ret; | |
466 | ||
467 | ret = __logfs_read_sb(sb); | |
468 | if (ret) | |
469 | return ret; | |
470 | ||
6a08ab84 JE |
471 | if (super->s_feature_incompat & ~LOGFS_FEATURES_INCOMPAT) |
472 | return -EIO; | |
473 | if ((super->s_feature_ro_compat & ~LOGFS_FEATURES_RO_COMPAT) && | |
474 | !read_only) | |
475 | return -EIO; | |
476 | ||
5db53f3e JE |
477 | mutex_init(&super->s_dirop_mutex); |
478 | mutex_init(&super->s_object_alias_mutex); | |
479 | INIT_LIST_HEAD(&super->s_freeing_list); | |
480 | ||
481 | ret = logfs_init_rw(sb); | |
482 | if (ret) | |
483 | return ret; | |
484 | ||
485 | ret = logfs_init_areas(sb); | |
486 | if (ret) | |
487 | return ret; | |
488 | ||
489 | ret = logfs_init_gc(sb); | |
490 | if (ret) | |
491 | return ret; | |
492 | ||
493 | ret = logfs_init_journal(sb); | |
494 | if (ret) | |
495 | return ret; | |
496 | ||
497 | return 0; | |
498 | } | |
499 | ||
500 | static void logfs_kill_sb(struct super_block *sb) | |
501 | { | |
502 | struct logfs_super *super = logfs_super(sb); | |
503 | ||
504 | log_super("LogFS: Start unmounting\n"); | |
505 | /* Alias entries slow down mount, so evict as many as possible */ | |
506 | sync_filesystem(sb); | |
c6d38301 | 507 | logfs_write_anchor(sb); |
5db53f3e JE |
508 | |
509 | /* | |
510 | * From this point on alias entries are simply dropped - and any | |
511 | * writes to the object store are considered bugs. | |
512 | */ | |
513 | super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN; | |
514 | log_super("LogFS: Now in shutdown\n"); | |
515 | generic_shutdown_super(sb); | |
516 | ||
517 | BUG_ON(super->s_dirty_used_bytes || super->s_dirty_free_bytes); | |
518 | ||
519 | logfs_cleanup_gc(sb); | |
520 | logfs_cleanup_journal(sb); | |
521 | logfs_cleanup_areas(sb); | |
522 | logfs_cleanup_rw(sb); | |
9421502b JE |
523 | if (super->s_erase_page) |
524 | __free_page(super->s_erase_page); | |
5db53f3e | 525 | super->s_devops->put_device(sb); |
1f1b0008 JE |
526 | logfs_mempool_destroy(super->s_btree_pool); |
527 | logfs_mempool_destroy(super->s_alias_pool); | |
5db53f3e JE |
528 | kfree(super); |
529 | log_super("LogFS: Finished unmounting\n"); | |
530 | } | |
531 | ||
532 | int logfs_get_sb_device(struct file_system_type *type, int flags, | |
533 | struct mtd_info *mtd, struct block_device *bdev, | |
534 | const struct logfs_device_ops *devops, struct vfsmount *mnt) | |
535 | { | |
536 | struct logfs_super *super; | |
537 | struct super_block *sb; | |
538 | int err = -ENOMEM; | |
539 | static int mount_count; | |
540 | ||
541 | log_super("LogFS: Start mount %x\n", mount_count++); | |
542 | super = kzalloc(sizeof(*super), GFP_KERNEL); | |
543 | if (!super) | |
544 | goto err0; | |
545 | ||
546 | super->s_mtd = mtd; | |
547 | super->s_bdev = bdev; | |
548 | err = -EINVAL; | |
549 | sb = sget(type, logfs_sb_test, logfs_sb_set, super); | |
550 | if (IS_ERR(sb)) | |
551 | goto err0; | |
552 | ||
553 | if (sb->s_root) { | |
554 | /* Device is already in use */ | |
555 | err = 0; | |
556 | simple_set_mnt(mnt, sb); | |
557 | goto err0; | |
558 | } | |
559 | ||
560 | super->s_devops = devops; | |
561 | ||
562 | /* | |
563 | * sb->s_maxbytes is limited to 8TB. On 32bit systems, the page cache | |
564 | * only covers 16TB and the upper 8TB are used for indirect blocks. | |
565 | * On 64bit system we could bump up the limit, but that would make | |
566 | * the filesystem incompatible with 32bit systems. | |
567 | */ | |
568 | sb->s_maxbytes = (1ull << 43) - 1; | |
569 | sb->s_op = &logfs_super_operations; | |
570 | sb->s_flags = flags | MS_NOATIME; | |
571 | ||
6a08ab84 | 572 | err = logfs_read_sb(sb, sb->s_flags & MS_RDONLY); |
5db53f3e JE |
573 | if (err) |
574 | goto err1; | |
575 | ||
576 | sb->s_flags |= MS_ACTIVE; | |
577 | err = logfs_get_sb_final(sb, mnt); | |
578 | if (err) | |
579 | goto err1; | |
580 | return 0; | |
581 | ||
582 | err1: | |
6f2e9e6a | 583 | deactivate_locked_super(sb); |
5db53f3e JE |
584 | return err; |
585 | err0: | |
586 | kfree(super); | |
587 | //devops->put_device(sb); | |
588 | return err; | |
589 | } | |
590 | ||
591 | static int logfs_get_sb(struct file_system_type *type, int flags, | |
592 | const char *devname, void *data, struct vfsmount *mnt) | |
593 | { | |
594 | ulong mtdnr; | |
595 | ||
596 | if (!devname) | |
597 | return logfs_get_sb_bdev(type, flags, devname, mnt); | |
598 | if (strncmp(devname, "mtd", 3)) | |
599 | return logfs_get_sb_bdev(type, flags, devname, mnt); | |
600 | ||
601 | { | |
602 | char *garbage; | |
603 | mtdnr = simple_strtoul(devname+3, &garbage, 0); | |
604 | if (*garbage) | |
605 | return -EINVAL; | |
606 | } | |
607 | ||
608 | return logfs_get_sb_mtd(type, flags, mtdnr, mnt); | |
609 | } | |
610 | ||
611 | static struct file_system_type logfs_fs_type = { | |
612 | .owner = THIS_MODULE, | |
613 | .name = "logfs", | |
614 | .get_sb = logfs_get_sb, | |
615 | .kill_sb = logfs_kill_sb, | |
616 | .fs_flags = FS_REQUIRES_DEV, | |
617 | ||
618 | }; | |
619 | ||
620 | static int __init logfs_init(void) | |
621 | { | |
622 | int ret; | |
623 | ||
624 | emergency_page = alloc_pages(GFP_KERNEL, 0); | |
625 | if (!emergency_page) | |
626 | return -ENOMEM; | |
627 | ||
628 | ret = logfs_compr_init(); | |
629 | if (ret) | |
630 | goto out1; | |
631 | ||
632 | ret = logfs_init_inode_cache(); | |
633 | if (ret) | |
634 | goto out2; | |
635 | ||
636 | return register_filesystem(&logfs_fs_type); | |
637 | out2: | |
638 | logfs_compr_exit(); | |
639 | out1: | |
640 | __free_pages(emergency_page, 0); | |
641 | return ret; | |
642 | } | |
643 | ||
644 | static void __exit logfs_exit(void) | |
645 | { | |
646 | unregister_filesystem(&logfs_fs_type); | |
647 | logfs_destroy_inode_cache(); | |
648 | logfs_compr_exit(); | |
649 | __free_pages(emergency_page, 0); | |
650 | } | |
651 | ||
652 | module_init(logfs_init); | |
653 | module_exit(logfs_exit); | |
654 | ||
655 | MODULE_LICENSE("GPL v2"); | |
656 | MODULE_AUTHOR("Joern Engel <joern@logfs.org>"); | |
657 | MODULE_DESCRIPTION("scalable flash filesystem"); |