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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; | |
bba0b5c2 | 141 | #ifdef CONFIG_BLOCK |
b8639077 JE |
142 | if (sb->s_bdev) |
143 | sb->s_bdi = &bdev_get_queue(sb->s_bdev)->backing_dev_info; | |
bba0b5c2 JE |
144 | #endif |
145 | #ifdef CONFIG_MTD | |
b8639077 JE |
146 | if (sb->s_mtd) |
147 | sb->s_bdi = sb->s_mtd->backing_dev_info; | |
bba0b5c2 | 148 | #endif |
5db53f3e JE |
149 | return 0; |
150 | } | |
151 | ||
152 | static int logfs_sb_test(struct super_block *sb, void *_super) | |
153 | { | |
154 | struct logfs_super *super = _super; | |
155 | struct mtd_info *mtd = super->s_mtd; | |
156 | ||
157 | if (mtd && sb->s_mtd == mtd) | |
158 | return 1; | |
159 | if (super->s_bdev && sb->s_bdev == super->s_bdev) | |
160 | return 1; | |
161 | return 0; | |
162 | } | |
163 | ||
164 | static void set_segment_header(struct logfs_segment_header *sh, u8 type, | |
165 | u8 level, u32 segno, u32 ec) | |
166 | { | |
167 | sh->pad = 0; | |
168 | sh->type = type; | |
169 | sh->level = level; | |
170 | sh->segno = cpu_to_be32(segno); | |
171 | sh->ec = cpu_to_be32(ec); | |
172 | sh->gec = cpu_to_be64(segno); | |
173 | sh->crc = logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4); | |
174 | } | |
175 | ||
176 | static void logfs_write_ds(struct super_block *sb, struct logfs_disk_super *ds, | |
177 | u32 segno, u32 ec) | |
178 | { | |
179 | struct logfs_super *super = logfs_super(sb); | |
180 | struct logfs_segment_header *sh = &ds->ds_sh; | |
181 | int i; | |
182 | ||
183 | memset(ds, 0, sizeof(*ds)); | |
184 | set_segment_header(sh, SEG_SUPER, 0, segno, ec); | |
185 | ||
186 | ds->ds_ifile_levels = super->s_ifile_levels; | |
187 | ds->ds_iblock_levels = super->s_iblock_levels; | |
188 | ds->ds_data_levels = super->s_data_levels; /* XXX: Remove */ | |
189 | ds->ds_segment_shift = super->s_segshift; | |
190 | ds->ds_block_shift = sb->s_blocksize_bits; | |
191 | ds->ds_write_shift = super->s_writeshift; | |
192 | ds->ds_filesystem_size = cpu_to_be64(super->s_size); | |
193 | ds->ds_segment_size = cpu_to_be32(super->s_segsize); | |
194 | ds->ds_bad_seg_reserve = cpu_to_be32(super->s_bad_seg_reserve); | |
195 | ds->ds_feature_incompat = cpu_to_be64(super->s_feature_incompat); | |
196 | ds->ds_feature_ro_compat= cpu_to_be64(super->s_feature_ro_compat); | |
197 | ds->ds_feature_compat = cpu_to_be64(super->s_feature_compat); | |
198 | ds->ds_feature_flags = cpu_to_be64(super->s_feature_flags); | |
199 | ds->ds_root_reserve = cpu_to_be64(super->s_root_reserve); | |
200 | ds->ds_speed_reserve = cpu_to_be64(super->s_speed_reserve); | |
201 | journal_for_each(i) | |
202 | ds->ds_journal_seg[i] = cpu_to_be32(super->s_journal_seg[i]); | |
203 | ds->ds_magic = cpu_to_be64(LOGFS_MAGIC); | |
204 | ds->ds_crc = logfs_crc32(ds, sizeof(*ds), | |
205 | LOGFS_SEGMENT_HEADERSIZE + 12); | |
206 | } | |
207 | ||
208 | static int write_one_sb(struct super_block *sb, | |
209 | struct page *(*find_sb)(struct super_block *sb, u64 *ofs)) | |
210 | { | |
211 | struct logfs_super *super = logfs_super(sb); | |
212 | struct logfs_disk_super *ds; | |
213 | struct logfs_segment_entry se; | |
214 | struct page *page; | |
215 | u64 ofs; | |
216 | u32 ec, segno; | |
217 | int err; | |
218 | ||
219 | page = find_sb(sb, &ofs); | |
220 | if (!page) | |
221 | return -EIO; | |
222 | ds = page_address(page); | |
223 | segno = seg_no(sb, ofs); | |
224 | logfs_get_segment_entry(sb, segno, &se); | |
225 | ec = be32_to_cpu(se.ec_level) >> 4; | |
226 | ec++; | |
227 | logfs_set_segment_erased(sb, segno, ec, 0); | |
228 | logfs_write_ds(sb, ds, segno, ec); | |
229 | err = super->s_devops->write_sb(sb, page); | |
230 | page_cache_release(page); | |
231 | return err; | |
232 | } | |
233 | ||
234 | int logfs_write_sb(struct super_block *sb) | |
235 | { | |
236 | struct logfs_super *super = logfs_super(sb); | |
237 | int err; | |
238 | ||
239 | /* First superblock */ | |
240 | err = write_one_sb(sb, super->s_devops->find_first_sb); | |
241 | if (err) | |
242 | return err; | |
243 | ||
244 | /* Last superblock */ | |
245 | err = write_one_sb(sb, super->s_devops->find_last_sb); | |
246 | if (err) | |
247 | return err; | |
248 | return 0; | |
249 | } | |
250 | ||
251 | static int ds_cmp(const void *ds0, const void *ds1) | |
252 | { | |
253 | size_t len = sizeof(struct logfs_disk_super); | |
254 | ||
255 | /* We know the segment headers differ, so ignore them */ | |
256 | len -= LOGFS_SEGMENT_HEADERSIZE; | |
257 | ds0 += LOGFS_SEGMENT_HEADERSIZE; | |
258 | ds1 += LOGFS_SEGMENT_HEADERSIZE; | |
259 | return memcmp(ds0, ds1, len); | |
260 | } | |
261 | ||
262 | static int logfs_recover_sb(struct super_block *sb) | |
263 | { | |
264 | struct logfs_super *super = logfs_super(sb); | |
265 | struct logfs_disk_super _ds0, *ds0 = &_ds0; | |
266 | struct logfs_disk_super _ds1, *ds1 = &_ds1; | |
267 | int err, valid0, valid1; | |
268 | ||
269 | /* read first superblock */ | |
270 | err = wbuf_read(sb, super->s_sb_ofs[0], sizeof(*ds0), ds0); | |
271 | if (err) | |
272 | return err; | |
273 | /* read last superblock */ | |
274 | err = wbuf_read(sb, super->s_sb_ofs[1], sizeof(*ds1), ds1); | |
275 | if (err) | |
276 | return err; | |
277 | valid0 = logfs_check_ds(ds0) == 0; | |
278 | valid1 = logfs_check_ds(ds1) == 0; | |
279 | ||
280 | if (!valid0 && valid1) { | |
281 | printk(KERN_INFO"First superblock is invalid - fixing.\n"); | |
282 | return write_one_sb(sb, super->s_devops->find_first_sb); | |
283 | } | |
284 | if (valid0 && !valid1) { | |
285 | printk(KERN_INFO"Last superblock is invalid - fixing.\n"); | |
286 | return write_one_sb(sb, super->s_devops->find_last_sb); | |
287 | } | |
288 | if (valid0 && valid1 && ds_cmp(ds0, ds1)) { | |
289 | printk(KERN_INFO"Superblocks don't match - fixing.\n"); | |
faaa27ab | 290 | return logfs_write_sb(sb); |
5db53f3e JE |
291 | } |
292 | /* If neither is valid now, something's wrong. Didn't we properly | |
293 | * check them before?!? */ | |
294 | BUG_ON(!valid0 && !valid1); | |
295 | return 0; | |
296 | } | |
297 | ||
298 | static int logfs_make_writeable(struct super_block *sb) | |
299 | { | |
300 | int err; | |
301 | ||
49137f2e JE |
302 | err = logfs_open_segfile(sb); |
303 | if (err) | |
304 | return err; | |
305 | ||
5db53f3e JE |
306 | /* Repair any broken superblock copies */ |
307 | err = logfs_recover_sb(sb); | |
308 | if (err) | |
309 | return err; | |
310 | ||
311 | /* Check areas for trailing unaccounted data */ | |
312 | err = logfs_check_areas(sb); | |
313 | if (err) | |
314 | return err; | |
315 | ||
5db53f3e JE |
316 | /* Do one GC pass before any data gets dirtied */ |
317 | logfs_gc_pass(sb); | |
318 | ||
319 | /* after all initializations are done, replay the journal | |
320 | * for rw-mounts, if necessary */ | |
321 | err = logfs_replay_journal(sb); | |
322 | if (err) | |
323 | return err; | |
324 | ||
325 | return 0; | |
326 | } | |
327 | ||
328 | static int logfs_get_sb_final(struct super_block *sb, struct vfsmount *mnt) | |
329 | { | |
9421502b | 330 | struct logfs_super *super = logfs_super(sb); |
5db53f3e JE |
331 | struct inode *rootdir; |
332 | int err; | |
333 | ||
334 | /* root dir */ | |
335 | rootdir = logfs_iget(sb, LOGFS_INO_ROOT); | |
336 | if (IS_ERR(rootdir)) | |
337 | goto fail; | |
338 | ||
339 | sb->s_root = d_alloc_root(rootdir); | |
26562449 AV |
340 | if (!sb->s_root) { |
341 | iput(rootdir); | |
342 | goto fail; | |
343 | } | |
5db53f3e | 344 | |
8e22c1a4 | 345 | /* at that point we know that ->put_super() will be called */ |
9421502b JE |
346 | super->s_erase_page = alloc_pages(GFP_KERNEL, 0); |
347 | if (!super->s_erase_page) | |
8e22c1a4 | 348 | return -ENOMEM; |
9421502b JE |
349 | memset(page_address(super->s_erase_page), 0xFF, PAGE_SIZE); |
350 | ||
5db53f3e JE |
351 | /* FIXME: check for read-only mounts */ |
352 | err = logfs_make_writeable(sb); | |
8e22c1a4 AV |
353 | if (err) { |
354 | __free_page(super->s_erase_page); | |
355 | return err; | |
356 | } | |
5db53f3e JE |
357 | |
358 | log_super("LogFS: Finished mounting\n"); | |
359 | simple_set_mnt(mnt, sb); | |
360 | return 0; | |
361 | ||
5db53f3e | 362 | fail: |
8e22c1a4 AV |
363 | iput(super->s_master_inode); |
364 | iput(super->s_segfile_inode); | |
365 | iput(super->s_mapping_inode); | |
5db53f3e JE |
366 | return -EIO; |
367 | } | |
368 | ||
369 | int logfs_check_ds(struct logfs_disk_super *ds) | |
370 | { | |
371 | struct logfs_segment_header *sh = &ds->ds_sh; | |
372 | ||
373 | if (ds->ds_magic != cpu_to_be64(LOGFS_MAGIC)) | |
374 | return -EINVAL; | |
375 | if (sh->crc != logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4)) | |
376 | return -EINVAL; | |
377 | if (ds->ds_crc != logfs_crc32(ds, sizeof(*ds), | |
378 | LOGFS_SEGMENT_HEADERSIZE + 12)) | |
379 | return -EINVAL; | |
380 | return 0; | |
381 | } | |
382 | ||
383 | static struct page *find_super_block(struct super_block *sb) | |
384 | { | |
385 | struct logfs_super *super = logfs_super(sb); | |
386 | struct page *first, *last; | |
387 | ||
388 | first = super->s_devops->find_first_sb(sb, &super->s_sb_ofs[0]); | |
389 | if (!first || IS_ERR(first)) | |
390 | return NULL; | |
391 | last = super->s_devops->find_last_sb(sb, &super->s_sb_ofs[1]); | |
3272c8a5 | 392 | if (!last || IS_ERR(last)) { |
5db53f3e JE |
393 | page_cache_release(first); |
394 | return NULL; | |
395 | } | |
396 | ||
397 | if (!logfs_check_ds(page_address(first))) { | |
398 | page_cache_release(last); | |
399 | return first; | |
400 | } | |
401 | ||
402 | /* First one didn't work, try the second superblock */ | |
403 | if (!logfs_check_ds(page_address(last))) { | |
404 | page_cache_release(first); | |
405 | return last; | |
406 | } | |
407 | ||
408 | /* Neither worked, sorry folks */ | |
409 | page_cache_release(first); | |
410 | page_cache_release(last); | |
411 | return NULL; | |
412 | } | |
413 | ||
414 | static int __logfs_read_sb(struct super_block *sb) | |
415 | { | |
416 | struct logfs_super *super = logfs_super(sb); | |
417 | struct page *page; | |
418 | struct logfs_disk_super *ds; | |
419 | int i; | |
420 | ||
421 | page = find_super_block(sb); | |
422 | if (!page) | |
ad342631 | 423 | return -EINVAL; |
5db53f3e JE |
424 | |
425 | ds = page_address(page); | |
426 | super->s_size = be64_to_cpu(ds->ds_filesystem_size); | |
427 | super->s_root_reserve = be64_to_cpu(ds->ds_root_reserve); | |
428 | super->s_speed_reserve = be64_to_cpu(ds->ds_speed_reserve); | |
429 | super->s_bad_seg_reserve = be32_to_cpu(ds->ds_bad_seg_reserve); | |
430 | super->s_segsize = 1 << ds->ds_segment_shift; | |
431 | super->s_segmask = (1 << ds->ds_segment_shift) - 1; | |
432 | super->s_segshift = ds->ds_segment_shift; | |
433 | sb->s_blocksize = 1 << ds->ds_block_shift; | |
434 | sb->s_blocksize_bits = ds->ds_block_shift; | |
435 | super->s_writesize = 1 << ds->ds_write_shift; | |
436 | super->s_writeshift = ds->ds_write_shift; | |
437 | super->s_no_segs = super->s_size >> super->s_segshift; | |
438 | super->s_no_blocks = super->s_segsize >> sb->s_blocksize_bits; | |
439 | super->s_feature_incompat = be64_to_cpu(ds->ds_feature_incompat); | |
440 | super->s_feature_ro_compat = be64_to_cpu(ds->ds_feature_ro_compat); | |
441 | super->s_feature_compat = be64_to_cpu(ds->ds_feature_compat); | |
442 | super->s_feature_flags = be64_to_cpu(ds->ds_feature_flags); | |
443 | ||
444 | journal_for_each(i) | |
445 | super->s_journal_seg[i] = be32_to_cpu(ds->ds_journal_seg[i]); | |
446 | ||
447 | super->s_ifile_levels = ds->ds_ifile_levels; | |
448 | super->s_iblock_levels = ds->ds_iblock_levels; | |
449 | super->s_data_levels = ds->ds_data_levels; | |
450 | super->s_total_levels = super->s_ifile_levels + super->s_iblock_levels | |
451 | + super->s_data_levels; | |
452 | page_cache_release(page); | |
453 | return 0; | |
454 | } | |
455 | ||
6a08ab84 | 456 | static int logfs_read_sb(struct super_block *sb, int read_only) |
5db53f3e JE |
457 | { |
458 | struct logfs_super *super = logfs_super(sb); | |
459 | int ret; | |
460 | ||
461 | super->s_btree_pool = mempool_create(32, btree_alloc, btree_free, NULL); | |
462 | if (!super->s_btree_pool) | |
463 | return -ENOMEM; | |
464 | ||
465 | btree_init_mempool64(&super->s_shadow_tree.new, super->s_btree_pool); | |
466 | btree_init_mempool64(&super->s_shadow_tree.old, super->s_btree_pool); | |
032d8f72 JE |
467 | btree_init_mempool32(&super->s_shadow_tree.segment_map, |
468 | super->s_btree_pool); | |
5db53f3e JE |
469 | |
470 | ret = logfs_init_mapping(sb); | |
471 | if (ret) | |
472 | return ret; | |
473 | ||
474 | ret = __logfs_read_sb(sb); | |
475 | if (ret) | |
476 | return ret; | |
477 | ||
6a08ab84 JE |
478 | if (super->s_feature_incompat & ~LOGFS_FEATURES_INCOMPAT) |
479 | return -EIO; | |
480 | if ((super->s_feature_ro_compat & ~LOGFS_FEATURES_RO_COMPAT) && | |
481 | !read_only) | |
482 | return -EIO; | |
483 | ||
5db53f3e JE |
484 | mutex_init(&super->s_dirop_mutex); |
485 | mutex_init(&super->s_object_alias_mutex); | |
486 | INIT_LIST_HEAD(&super->s_freeing_list); | |
487 | ||
488 | ret = logfs_init_rw(sb); | |
489 | if (ret) | |
490 | return ret; | |
491 | ||
492 | ret = logfs_init_areas(sb); | |
493 | if (ret) | |
494 | return ret; | |
495 | ||
496 | ret = logfs_init_gc(sb); | |
497 | if (ret) | |
498 | return ret; | |
499 | ||
500 | ret = logfs_init_journal(sb); | |
501 | if (ret) | |
502 | return ret; | |
503 | ||
504 | return 0; | |
505 | } | |
506 | ||
507 | static void logfs_kill_sb(struct super_block *sb) | |
508 | { | |
509 | struct logfs_super *super = logfs_super(sb); | |
510 | ||
511 | log_super("LogFS: Start unmounting\n"); | |
512 | /* Alias entries slow down mount, so evict as many as possible */ | |
513 | sync_filesystem(sb); | |
c6d38301 | 514 | logfs_write_anchor(sb); |
5db53f3e JE |
515 | |
516 | /* | |
517 | * From this point on alias entries are simply dropped - and any | |
518 | * writes to the object store are considered bugs. | |
519 | */ | |
520 | super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN; | |
521 | log_super("LogFS: Now in shutdown\n"); | |
522 | generic_shutdown_super(sb); | |
523 | ||
524 | BUG_ON(super->s_dirty_used_bytes || super->s_dirty_free_bytes); | |
525 | ||
526 | logfs_cleanup_gc(sb); | |
527 | logfs_cleanup_journal(sb); | |
528 | logfs_cleanup_areas(sb); | |
529 | logfs_cleanup_rw(sb); | |
9421502b JE |
530 | if (super->s_erase_page) |
531 | __free_page(super->s_erase_page); | |
5db53f3e | 532 | super->s_devops->put_device(sb); |
1f1b0008 JE |
533 | logfs_mempool_destroy(super->s_btree_pool); |
534 | logfs_mempool_destroy(super->s_alias_pool); | |
5db53f3e JE |
535 | kfree(super); |
536 | log_super("LogFS: Finished unmounting\n"); | |
537 | } | |
538 | ||
539 | int logfs_get_sb_device(struct file_system_type *type, int flags, | |
540 | struct mtd_info *mtd, struct block_device *bdev, | |
541 | const struct logfs_device_ops *devops, struct vfsmount *mnt) | |
542 | { | |
543 | struct logfs_super *super; | |
544 | struct super_block *sb; | |
545 | int err = -ENOMEM; | |
546 | static int mount_count; | |
547 | ||
548 | log_super("LogFS: Start mount %x\n", mount_count++); | |
549 | super = kzalloc(sizeof(*super), GFP_KERNEL); | |
550 | if (!super) | |
551 | goto err0; | |
552 | ||
553 | super->s_mtd = mtd; | |
554 | super->s_bdev = bdev; | |
555 | err = -EINVAL; | |
556 | sb = sget(type, logfs_sb_test, logfs_sb_set, super); | |
557 | if (IS_ERR(sb)) | |
558 | goto err0; | |
559 | ||
560 | if (sb->s_root) { | |
561 | /* Device is already in use */ | |
562 | err = 0; | |
563 | simple_set_mnt(mnt, sb); | |
564 | goto err0; | |
565 | } | |
566 | ||
567 | super->s_devops = devops; | |
568 | ||
569 | /* | |
570 | * sb->s_maxbytes is limited to 8TB. On 32bit systems, the page cache | |
571 | * only covers 16TB and the upper 8TB are used for indirect blocks. | |
572 | * On 64bit system we could bump up the limit, but that would make | |
573 | * the filesystem incompatible with 32bit systems. | |
574 | */ | |
575 | sb->s_maxbytes = (1ull << 43) - 1; | |
576 | sb->s_op = &logfs_super_operations; | |
577 | sb->s_flags = flags | MS_NOATIME; | |
578 | ||
6a08ab84 | 579 | err = logfs_read_sb(sb, sb->s_flags & MS_RDONLY); |
5db53f3e JE |
580 | if (err) |
581 | goto err1; | |
582 | ||
583 | sb->s_flags |= MS_ACTIVE; | |
584 | err = logfs_get_sb_final(sb, mnt); | |
585 | if (err) | |
8e22c1a4 AV |
586 | deactivate_locked_super(sb); |
587 | return err; | |
5db53f3e JE |
588 | |
589 | err1: | |
8e22c1a4 AV |
590 | /* no ->s_root, no ->put_super() */ |
591 | iput(super->s_master_inode); | |
592 | iput(super->s_segfile_inode); | |
593 | iput(super->s_mapping_inode); | |
6f2e9e6a | 594 | deactivate_locked_super(sb); |
5db53f3e JE |
595 | return err; |
596 | err0: | |
597 | kfree(super); | |
598 | //devops->put_device(sb); | |
599 | return err; | |
600 | } | |
601 | ||
602 | static int logfs_get_sb(struct file_system_type *type, int flags, | |
603 | const char *devname, void *data, struct vfsmount *mnt) | |
604 | { | |
605 | ulong mtdnr; | |
606 | ||
607 | if (!devname) | |
608 | return logfs_get_sb_bdev(type, flags, devname, mnt); | |
609 | if (strncmp(devname, "mtd", 3)) | |
610 | return logfs_get_sb_bdev(type, flags, devname, mnt); | |
611 | ||
612 | { | |
613 | char *garbage; | |
614 | mtdnr = simple_strtoul(devname+3, &garbage, 0); | |
615 | if (*garbage) | |
616 | return -EINVAL; | |
617 | } | |
618 | ||
619 | return logfs_get_sb_mtd(type, flags, mtdnr, mnt); | |
620 | } | |
621 | ||
622 | static struct file_system_type logfs_fs_type = { | |
623 | .owner = THIS_MODULE, | |
624 | .name = "logfs", | |
625 | .get_sb = logfs_get_sb, | |
626 | .kill_sb = logfs_kill_sb, | |
627 | .fs_flags = FS_REQUIRES_DEV, | |
628 | ||
629 | }; | |
630 | ||
631 | static int __init logfs_init(void) | |
632 | { | |
633 | int ret; | |
634 | ||
635 | emergency_page = alloc_pages(GFP_KERNEL, 0); | |
636 | if (!emergency_page) | |
637 | return -ENOMEM; | |
638 | ||
639 | ret = logfs_compr_init(); | |
640 | if (ret) | |
641 | goto out1; | |
642 | ||
643 | ret = logfs_init_inode_cache(); | |
644 | if (ret) | |
645 | goto out2; | |
646 | ||
647 | return register_filesystem(&logfs_fs_type); | |
648 | out2: | |
649 | logfs_compr_exit(); | |
650 | out1: | |
651 | __free_pages(emergency_page, 0); | |
652 | return ret; | |
653 | } | |
654 | ||
655 | static void __exit logfs_exit(void) | |
656 | { | |
657 | unregister_filesystem(&logfs_fs_type); | |
658 | logfs_destroy_inode_cache(); | |
659 | logfs_compr_exit(); | |
660 | __free_pages(emergency_page, 0); | |
661 | } | |
662 | ||
663 | module_init(logfs_init); | |
664 | module_exit(logfs_exit); | |
665 | ||
666 | MODULE_LICENSE("GPL v2"); | |
667 | MODULE_AUTHOR("Joern Engel <joern@logfs.org>"); | |
668 | MODULE_DESCRIPTION("scalable flash filesystem"); |