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> |
143cb494 | 16 | #include <linux/module.h> |
5db53f3e JE |
17 | #include <linux/mtd/mtd.h> |
18 | #include <linux/statfs.h> | |
19 | #include <linux/buffer_head.h> | |
20 | ||
21 | static DEFINE_MUTEX(emergency_mutex); | |
22 | static struct page *emergency_page; | |
23 | ||
24 | struct page *emergency_read_begin(struct address_space *mapping, pgoff_t index) | |
25 | { | |
26 | filler_t *filler = (filler_t *)mapping->a_ops->readpage; | |
27 | struct page *page; | |
28 | int err; | |
29 | ||
30 | page = read_cache_page(mapping, index, filler, NULL); | |
31 | if (page) | |
32 | return page; | |
33 | ||
34 | /* No more pages available, switch to emergency page */ | |
35 | printk(KERN_INFO"Logfs: Using emergency page\n"); | |
36 | mutex_lock(&emergency_mutex); | |
37 | err = filler(NULL, emergency_page); | |
38 | if (err) { | |
39 | mutex_unlock(&emergency_mutex); | |
40 | printk(KERN_EMERG"Logfs: Error reading emergency page\n"); | |
41 | return ERR_PTR(err); | |
42 | } | |
43 | return emergency_page; | |
44 | } | |
45 | ||
46 | void emergency_read_end(struct page *page) | |
47 | { | |
48 | if (page == emergency_page) | |
49 | mutex_unlock(&emergency_mutex); | |
50 | else | |
51 | page_cache_release(page); | |
52 | } | |
53 | ||
54 | static void dump_segfile(struct super_block *sb) | |
55 | { | |
56 | struct logfs_super *super = logfs_super(sb); | |
57 | struct logfs_segment_entry se; | |
58 | u32 segno; | |
59 | ||
60 | for (segno = 0; segno < super->s_no_segs; segno++) { | |
61 | logfs_get_segment_entry(sb, segno, &se); | |
62 | printk("%3x: %6x %8x", segno, be32_to_cpu(se.ec_level), | |
63 | be32_to_cpu(se.valid)); | |
64 | if (++segno < super->s_no_segs) { | |
65 | logfs_get_segment_entry(sb, segno, &se); | |
66 | printk(" %6x %8x", be32_to_cpu(se.ec_level), | |
67 | be32_to_cpu(se.valid)); | |
68 | } | |
69 | if (++segno < super->s_no_segs) { | |
70 | logfs_get_segment_entry(sb, segno, &se); | |
71 | printk(" %6x %8x", be32_to_cpu(se.ec_level), | |
72 | be32_to_cpu(se.valid)); | |
73 | } | |
74 | if (++segno < super->s_no_segs) { | |
75 | logfs_get_segment_entry(sb, segno, &se); | |
76 | printk(" %6x %8x", be32_to_cpu(se.ec_level), | |
77 | be32_to_cpu(se.valid)); | |
78 | } | |
79 | printk("\n"); | |
80 | } | |
81 | } | |
82 | ||
83 | /* | |
84 | * logfs_crash_dump - dump debug information to device | |
85 | * | |
86 | * The LogFS superblock only occupies part of a segment. This function will | |
87 | * write as much debug information as it can gather into the spare space. | |
88 | */ | |
89 | void logfs_crash_dump(struct super_block *sb) | |
90 | { | |
91 | dump_segfile(sb); | |
92 | } | |
93 | ||
5db53f3e JE |
94 | /* |
95 | * FIXME: There should be a reserve for root, similar to ext2. | |
96 | */ | |
97 | int logfs_statfs(struct dentry *dentry, struct kstatfs *stats) | |
98 | { | |
99 | struct super_block *sb = dentry->d_sb; | |
100 | struct logfs_super *super = logfs_super(sb); | |
101 | ||
102 | stats->f_type = LOGFS_MAGIC_U32; | |
103 | stats->f_bsize = sb->s_blocksize; | |
104 | stats->f_blocks = super->s_size >> LOGFS_BLOCK_BITS >> 3; | |
105 | stats->f_bfree = super->s_free_bytes >> sb->s_blocksize_bits; | |
106 | stats->f_bavail = super->s_free_bytes >> sb->s_blocksize_bits; | |
107 | stats->f_files = 0; | |
108 | stats->f_ffree = 0; | |
109 | stats->f_namelen = LOGFS_MAX_NAMELEN; | |
110 | return 0; | |
111 | } | |
112 | ||
113 | static int logfs_sb_set(struct super_block *sb, void *_super) | |
114 | { | |
115 | struct logfs_super *super = _super; | |
116 | ||
117 | sb->s_fs_info = super; | |
118 | sb->s_mtd = super->s_mtd; | |
119 | sb->s_bdev = super->s_bdev; | |
bba0b5c2 | 120 | #ifdef CONFIG_BLOCK |
b8639077 JE |
121 | if (sb->s_bdev) |
122 | sb->s_bdi = &bdev_get_queue(sb->s_bdev)->backing_dev_info; | |
bba0b5c2 JE |
123 | #endif |
124 | #ifdef CONFIG_MTD | |
b8639077 JE |
125 | if (sb->s_mtd) |
126 | sb->s_bdi = sb->s_mtd->backing_dev_info; | |
bba0b5c2 | 127 | #endif |
5db53f3e JE |
128 | return 0; |
129 | } | |
130 | ||
131 | static int logfs_sb_test(struct super_block *sb, void *_super) | |
132 | { | |
133 | struct logfs_super *super = _super; | |
134 | struct mtd_info *mtd = super->s_mtd; | |
135 | ||
136 | if (mtd && sb->s_mtd == mtd) | |
137 | return 1; | |
138 | if (super->s_bdev && sb->s_bdev == super->s_bdev) | |
139 | return 1; | |
140 | return 0; | |
141 | } | |
142 | ||
143 | static void set_segment_header(struct logfs_segment_header *sh, u8 type, | |
144 | u8 level, u32 segno, u32 ec) | |
145 | { | |
146 | sh->pad = 0; | |
147 | sh->type = type; | |
148 | sh->level = level; | |
149 | sh->segno = cpu_to_be32(segno); | |
150 | sh->ec = cpu_to_be32(ec); | |
151 | sh->gec = cpu_to_be64(segno); | |
152 | sh->crc = logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4); | |
153 | } | |
154 | ||
155 | static void logfs_write_ds(struct super_block *sb, struct logfs_disk_super *ds, | |
156 | u32 segno, u32 ec) | |
157 | { | |
158 | struct logfs_super *super = logfs_super(sb); | |
159 | struct logfs_segment_header *sh = &ds->ds_sh; | |
160 | int i; | |
161 | ||
162 | memset(ds, 0, sizeof(*ds)); | |
163 | set_segment_header(sh, SEG_SUPER, 0, segno, ec); | |
164 | ||
165 | ds->ds_ifile_levels = super->s_ifile_levels; | |
166 | ds->ds_iblock_levels = super->s_iblock_levels; | |
167 | ds->ds_data_levels = super->s_data_levels; /* XXX: Remove */ | |
168 | ds->ds_segment_shift = super->s_segshift; | |
169 | ds->ds_block_shift = sb->s_blocksize_bits; | |
170 | ds->ds_write_shift = super->s_writeshift; | |
171 | ds->ds_filesystem_size = cpu_to_be64(super->s_size); | |
172 | ds->ds_segment_size = cpu_to_be32(super->s_segsize); | |
173 | ds->ds_bad_seg_reserve = cpu_to_be32(super->s_bad_seg_reserve); | |
174 | ds->ds_feature_incompat = cpu_to_be64(super->s_feature_incompat); | |
175 | ds->ds_feature_ro_compat= cpu_to_be64(super->s_feature_ro_compat); | |
176 | ds->ds_feature_compat = cpu_to_be64(super->s_feature_compat); | |
177 | ds->ds_feature_flags = cpu_to_be64(super->s_feature_flags); | |
178 | ds->ds_root_reserve = cpu_to_be64(super->s_root_reserve); | |
179 | ds->ds_speed_reserve = cpu_to_be64(super->s_speed_reserve); | |
180 | journal_for_each(i) | |
181 | ds->ds_journal_seg[i] = cpu_to_be32(super->s_journal_seg[i]); | |
182 | ds->ds_magic = cpu_to_be64(LOGFS_MAGIC); | |
183 | ds->ds_crc = logfs_crc32(ds, sizeof(*ds), | |
184 | LOGFS_SEGMENT_HEADERSIZE + 12); | |
185 | } | |
186 | ||
187 | static int write_one_sb(struct super_block *sb, | |
188 | struct page *(*find_sb)(struct super_block *sb, u64 *ofs)) | |
189 | { | |
190 | struct logfs_super *super = logfs_super(sb); | |
191 | struct logfs_disk_super *ds; | |
192 | struct logfs_segment_entry se; | |
193 | struct page *page; | |
194 | u64 ofs; | |
195 | u32 ec, segno; | |
196 | int err; | |
197 | ||
198 | page = find_sb(sb, &ofs); | |
199 | if (!page) | |
200 | return -EIO; | |
201 | ds = page_address(page); | |
202 | segno = seg_no(sb, ofs); | |
203 | logfs_get_segment_entry(sb, segno, &se); | |
204 | ec = be32_to_cpu(se.ec_level) >> 4; | |
205 | ec++; | |
206 | logfs_set_segment_erased(sb, segno, ec, 0); | |
207 | logfs_write_ds(sb, ds, segno, ec); | |
208 | err = super->s_devops->write_sb(sb, page); | |
209 | page_cache_release(page); | |
210 | return err; | |
211 | } | |
212 | ||
213 | int logfs_write_sb(struct super_block *sb) | |
214 | { | |
215 | struct logfs_super *super = logfs_super(sb); | |
216 | int err; | |
217 | ||
218 | /* First superblock */ | |
219 | err = write_one_sb(sb, super->s_devops->find_first_sb); | |
220 | if (err) | |
221 | return err; | |
222 | ||
223 | /* Last superblock */ | |
224 | err = write_one_sb(sb, super->s_devops->find_last_sb); | |
225 | if (err) | |
226 | return err; | |
227 | return 0; | |
228 | } | |
229 | ||
230 | static int ds_cmp(const void *ds0, const void *ds1) | |
231 | { | |
232 | size_t len = sizeof(struct logfs_disk_super); | |
233 | ||
234 | /* We know the segment headers differ, so ignore them */ | |
235 | len -= LOGFS_SEGMENT_HEADERSIZE; | |
236 | ds0 += LOGFS_SEGMENT_HEADERSIZE; | |
237 | ds1 += LOGFS_SEGMENT_HEADERSIZE; | |
238 | return memcmp(ds0, ds1, len); | |
239 | } | |
240 | ||
241 | static int logfs_recover_sb(struct super_block *sb) | |
242 | { | |
243 | struct logfs_super *super = logfs_super(sb); | |
244 | struct logfs_disk_super _ds0, *ds0 = &_ds0; | |
245 | struct logfs_disk_super _ds1, *ds1 = &_ds1; | |
246 | int err, valid0, valid1; | |
247 | ||
248 | /* read first superblock */ | |
249 | err = wbuf_read(sb, super->s_sb_ofs[0], sizeof(*ds0), ds0); | |
250 | if (err) | |
251 | return err; | |
252 | /* read last superblock */ | |
253 | err = wbuf_read(sb, super->s_sb_ofs[1], sizeof(*ds1), ds1); | |
254 | if (err) | |
255 | return err; | |
256 | valid0 = logfs_check_ds(ds0) == 0; | |
257 | valid1 = logfs_check_ds(ds1) == 0; | |
258 | ||
259 | if (!valid0 && valid1) { | |
260 | printk(KERN_INFO"First superblock is invalid - fixing.\n"); | |
261 | return write_one_sb(sb, super->s_devops->find_first_sb); | |
262 | } | |
263 | if (valid0 && !valid1) { | |
264 | printk(KERN_INFO"Last superblock is invalid - fixing.\n"); | |
265 | return write_one_sb(sb, super->s_devops->find_last_sb); | |
266 | } | |
267 | if (valid0 && valid1 && ds_cmp(ds0, ds1)) { | |
268 | printk(KERN_INFO"Superblocks don't match - fixing.\n"); | |
faaa27ab | 269 | return logfs_write_sb(sb); |
5db53f3e JE |
270 | } |
271 | /* If neither is valid now, something's wrong. Didn't we properly | |
272 | * check them before?!? */ | |
273 | BUG_ON(!valid0 && !valid1); | |
274 | return 0; | |
275 | } | |
276 | ||
277 | static int logfs_make_writeable(struct super_block *sb) | |
278 | { | |
279 | int err; | |
280 | ||
49137f2e JE |
281 | err = logfs_open_segfile(sb); |
282 | if (err) | |
283 | return err; | |
284 | ||
5db53f3e JE |
285 | /* Repair any broken superblock copies */ |
286 | err = logfs_recover_sb(sb); | |
287 | if (err) | |
288 | return err; | |
289 | ||
290 | /* Check areas for trailing unaccounted data */ | |
291 | err = logfs_check_areas(sb); | |
292 | if (err) | |
293 | return err; | |
294 | ||
5db53f3e JE |
295 | /* Do one GC pass before any data gets dirtied */ |
296 | logfs_gc_pass(sb); | |
297 | ||
298 | /* after all initializations are done, replay the journal | |
299 | * for rw-mounts, if necessary */ | |
300 | err = logfs_replay_journal(sb); | |
301 | if (err) | |
302 | return err; | |
303 | ||
304 | return 0; | |
305 | } | |
306 | ||
a1da9e8a | 307 | static int logfs_get_sb_final(struct super_block *sb) |
5db53f3e | 308 | { |
9421502b | 309 | struct logfs_super *super = logfs_super(sb); |
5db53f3e JE |
310 | struct inode *rootdir; |
311 | int err; | |
312 | ||
313 | /* root dir */ | |
314 | rootdir = logfs_iget(sb, LOGFS_INO_ROOT); | |
315 | if (IS_ERR(rootdir)) | |
316 | goto fail; | |
317 | ||
318 | sb->s_root = d_alloc_root(rootdir); | |
26562449 AV |
319 | if (!sb->s_root) { |
320 | iput(rootdir); | |
321 | goto fail; | |
322 | } | |
5db53f3e | 323 | |
8e22c1a4 | 324 | /* at that point we know that ->put_super() will be called */ |
9421502b JE |
325 | super->s_erase_page = alloc_pages(GFP_KERNEL, 0); |
326 | if (!super->s_erase_page) | |
8e22c1a4 | 327 | return -ENOMEM; |
9421502b JE |
328 | memset(page_address(super->s_erase_page), 0xFF, PAGE_SIZE); |
329 | ||
5db53f3e JE |
330 | /* FIXME: check for read-only mounts */ |
331 | err = logfs_make_writeable(sb); | |
8e22c1a4 AV |
332 | if (err) { |
333 | __free_page(super->s_erase_page); | |
334 | return err; | |
335 | } | |
5db53f3e JE |
336 | |
337 | log_super("LogFS: Finished mounting\n"); | |
5db53f3e JE |
338 | return 0; |
339 | ||
5db53f3e | 340 | fail: |
8e22c1a4 AV |
341 | iput(super->s_master_inode); |
342 | iput(super->s_segfile_inode); | |
343 | iput(super->s_mapping_inode); | |
5db53f3e JE |
344 | return -EIO; |
345 | } | |
346 | ||
347 | int logfs_check_ds(struct logfs_disk_super *ds) | |
348 | { | |
349 | struct logfs_segment_header *sh = &ds->ds_sh; | |
350 | ||
351 | if (ds->ds_magic != cpu_to_be64(LOGFS_MAGIC)) | |
352 | return -EINVAL; | |
353 | if (sh->crc != logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4)) | |
354 | return -EINVAL; | |
355 | if (ds->ds_crc != logfs_crc32(ds, sizeof(*ds), | |
356 | LOGFS_SEGMENT_HEADERSIZE + 12)) | |
357 | return -EINVAL; | |
358 | return 0; | |
359 | } | |
360 | ||
361 | static struct page *find_super_block(struct super_block *sb) | |
362 | { | |
363 | struct logfs_super *super = logfs_super(sb); | |
364 | struct page *first, *last; | |
365 | ||
366 | first = super->s_devops->find_first_sb(sb, &super->s_sb_ofs[0]); | |
367 | if (!first || IS_ERR(first)) | |
368 | return NULL; | |
369 | last = super->s_devops->find_last_sb(sb, &super->s_sb_ofs[1]); | |
3272c8a5 | 370 | if (!last || IS_ERR(last)) { |
5db53f3e JE |
371 | page_cache_release(first); |
372 | return NULL; | |
373 | } | |
374 | ||
375 | if (!logfs_check_ds(page_address(first))) { | |
376 | page_cache_release(last); | |
377 | return first; | |
378 | } | |
379 | ||
380 | /* First one didn't work, try the second superblock */ | |
381 | if (!logfs_check_ds(page_address(last))) { | |
382 | page_cache_release(first); | |
383 | return last; | |
384 | } | |
385 | ||
386 | /* Neither worked, sorry folks */ | |
387 | page_cache_release(first); | |
388 | page_cache_release(last); | |
389 | return NULL; | |
390 | } | |
391 | ||
392 | static int __logfs_read_sb(struct super_block *sb) | |
393 | { | |
394 | struct logfs_super *super = logfs_super(sb); | |
395 | struct page *page; | |
396 | struct logfs_disk_super *ds; | |
397 | int i; | |
398 | ||
399 | page = find_super_block(sb); | |
400 | if (!page) | |
ad342631 | 401 | return -EINVAL; |
5db53f3e JE |
402 | |
403 | ds = page_address(page); | |
404 | super->s_size = be64_to_cpu(ds->ds_filesystem_size); | |
405 | super->s_root_reserve = be64_to_cpu(ds->ds_root_reserve); | |
406 | super->s_speed_reserve = be64_to_cpu(ds->ds_speed_reserve); | |
407 | super->s_bad_seg_reserve = be32_to_cpu(ds->ds_bad_seg_reserve); | |
408 | super->s_segsize = 1 << ds->ds_segment_shift; | |
409 | super->s_segmask = (1 << ds->ds_segment_shift) - 1; | |
410 | super->s_segshift = ds->ds_segment_shift; | |
411 | sb->s_blocksize = 1 << ds->ds_block_shift; | |
412 | sb->s_blocksize_bits = ds->ds_block_shift; | |
413 | super->s_writesize = 1 << ds->ds_write_shift; | |
414 | super->s_writeshift = ds->ds_write_shift; | |
415 | super->s_no_segs = super->s_size >> super->s_segshift; | |
416 | super->s_no_blocks = super->s_segsize >> sb->s_blocksize_bits; | |
417 | super->s_feature_incompat = be64_to_cpu(ds->ds_feature_incompat); | |
418 | super->s_feature_ro_compat = be64_to_cpu(ds->ds_feature_ro_compat); | |
419 | super->s_feature_compat = be64_to_cpu(ds->ds_feature_compat); | |
420 | super->s_feature_flags = be64_to_cpu(ds->ds_feature_flags); | |
421 | ||
422 | journal_for_each(i) | |
423 | super->s_journal_seg[i] = be32_to_cpu(ds->ds_journal_seg[i]); | |
424 | ||
425 | super->s_ifile_levels = ds->ds_ifile_levels; | |
426 | super->s_iblock_levels = ds->ds_iblock_levels; | |
427 | super->s_data_levels = ds->ds_data_levels; | |
428 | super->s_total_levels = super->s_ifile_levels + super->s_iblock_levels | |
429 | + super->s_data_levels; | |
430 | page_cache_release(page); | |
431 | return 0; | |
432 | } | |
433 | ||
6a08ab84 | 434 | static int logfs_read_sb(struct super_block *sb, int read_only) |
5db53f3e JE |
435 | { |
436 | struct logfs_super *super = logfs_super(sb); | |
437 | int ret; | |
438 | ||
439 | super->s_btree_pool = mempool_create(32, btree_alloc, btree_free, NULL); | |
440 | if (!super->s_btree_pool) | |
441 | return -ENOMEM; | |
442 | ||
443 | btree_init_mempool64(&super->s_shadow_tree.new, super->s_btree_pool); | |
444 | btree_init_mempool64(&super->s_shadow_tree.old, super->s_btree_pool); | |
032d8f72 JE |
445 | btree_init_mempool32(&super->s_shadow_tree.segment_map, |
446 | super->s_btree_pool); | |
5db53f3e JE |
447 | |
448 | ret = logfs_init_mapping(sb); | |
449 | if (ret) | |
450 | return ret; | |
451 | ||
452 | ret = __logfs_read_sb(sb); | |
453 | if (ret) | |
454 | return ret; | |
455 | ||
6a08ab84 JE |
456 | if (super->s_feature_incompat & ~LOGFS_FEATURES_INCOMPAT) |
457 | return -EIO; | |
458 | if ((super->s_feature_ro_compat & ~LOGFS_FEATURES_RO_COMPAT) && | |
459 | !read_only) | |
460 | return -EIO; | |
461 | ||
5db53f3e JE |
462 | ret = logfs_init_rw(sb); |
463 | if (ret) | |
464 | return ret; | |
465 | ||
466 | ret = logfs_init_areas(sb); | |
467 | if (ret) | |
468 | return ret; | |
469 | ||
470 | ret = logfs_init_gc(sb); | |
471 | if (ret) | |
472 | return ret; | |
473 | ||
474 | ret = logfs_init_journal(sb); | |
475 | if (ret) | |
476 | return ret; | |
477 | ||
478 | return 0; | |
479 | } | |
480 | ||
481 | static void logfs_kill_sb(struct super_block *sb) | |
482 | { | |
483 | struct logfs_super *super = logfs_super(sb); | |
484 | ||
485 | log_super("LogFS: Start unmounting\n"); | |
486 | /* Alias entries slow down mount, so evict as many as possible */ | |
487 | sync_filesystem(sb); | |
c6d38301 | 488 | logfs_write_anchor(sb); |
1bcceaff | 489 | free_areas(sb); |
5db53f3e JE |
490 | |
491 | /* | |
492 | * From this point on alias entries are simply dropped - and any | |
493 | * writes to the object store are considered bugs. | |
494 | */ | |
5db53f3e JE |
495 | log_super("LogFS: Now in shutdown\n"); |
496 | generic_shutdown_super(sb); | |
ecfd8909 | 497 | super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN; |
5db53f3e JE |
498 | |
499 | BUG_ON(super->s_dirty_used_bytes || super->s_dirty_free_bytes); | |
500 | ||
501 | logfs_cleanup_gc(sb); | |
502 | logfs_cleanup_journal(sb); | |
503 | logfs_cleanup_areas(sb); | |
504 | logfs_cleanup_rw(sb); | |
9421502b JE |
505 | if (super->s_erase_page) |
506 | __free_page(super->s_erase_page); | |
e5a0726a | 507 | super->s_devops->put_device(super); |
1f1b0008 JE |
508 | logfs_mempool_destroy(super->s_btree_pool); |
509 | logfs_mempool_destroy(super->s_alias_pool); | |
5db53f3e JE |
510 | kfree(super); |
511 | log_super("LogFS: Finished unmounting\n"); | |
512 | } | |
513 | ||
a1da9e8a AV |
514 | static struct dentry *logfs_get_sb_device(struct logfs_super *super, |
515 | struct file_system_type *type, int flags) | |
5db53f3e | 516 | { |
5db53f3e JE |
517 | struct super_block *sb; |
518 | int err = -ENOMEM; | |
519 | static int mount_count; | |
520 | ||
521 | log_super("LogFS: Start mount %x\n", mount_count++); | |
5db53f3e | 522 | |
5db53f3e JE |
523 | err = -EINVAL; |
524 | sb = sget(type, logfs_sb_test, logfs_sb_set, super); | |
a1da9e8a AV |
525 | if (IS_ERR(sb)) { |
526 | super->s_devops->put_device(super); | |
527 | kfree(super); | |
528 | return ERR_CAST(sb); | |
529 | } | |
5db53f3e JE |
530 | |
531 | if (sb->s_root) { | |
532 | /* Device is already in use */ | |
a1da9e8a AV |
533 | super->s_devops->put_device(super); |
534 | kfree(super); | |
535 | return dget(sb->s_root); | |
5db53f3e JE |
536 | } |
537 | ||
5db53f3e JE |
538 | /* |
539 | * sb->s_maxbytes is limited to 8TB. On 32bit systems, the page cache | |
540 | * only covers 16TB and the upper 8TB are used for indirect blocks. | |
541 | * On 64bit system we could bump up the limit, but that would make | |
542 | * the filesystem incompatible with 32bit systems. | |
543 | */ | |
544 | sb->s_maxbytes = (1ull << 43) - 1; | |
8de52778 | 545 | sb->s_max_links = LOGFS_LINK_MAX; |
5db53f3e JE |
546 | sb->s_op = &logfs_super_operations; |
547 | sb->s_flags = flags | MS_NOATIME; | |
548 | ||
6a08ab84 | 549 | err = logfs_read_sb(sb, sb->s_flags & MS_RDONLY); |
5db53f3e JE |
550 | if (err) |
551 | goto err1; | |
552 | ||
553 | sb->s_flags |= MS_ACTIVE; | |
a1da9e8a AV |
554 | err = logfs_get_sb_final(sb); |
555 | if (err) { | |
8e22c1a4 | 556 | deactivate_locked_super(sb); |
a1da9e8a AV |
557 | return ERR_PTR(err); |
558 | } | |
559 | return dget(sb->s_root); | |
5db53f3e JE |
560 | |
561 | err1: | |
8e22c1a4 AV |
562 | /* no ->s_root, no ->put_super() */ |
563 | iput(super->s_master_inode); | |
564 | iput(super->s_segfile_inode); | |
565 | iput(super->s_mapping_inode); | |
6f2e9e6a | 566 | deactivate_locked_super(sb); |
a1da9e8a | 567 | return ERR_PTR(err); |
5db53f3e JE |
568 | } |
569 | ||
a1da9e8a AV |
570 | static struct dentry *logfs_mount(struct file_system_type *type, int flags, |
571 | const char *devname, void *data) | |
5db53f3e JE |
572 | { |
573 | ulong mtdnr; | |
71a1c012 | 574 | struct logfs_super *super; |
7d945a3a | 575 | int err; |
71a1c012 AV |
576 | |
577 | super = kzalloc(sizeof(*super), GFP_KERNEL); | |
578 | if (!super) | |
a1da9e8a | 579 | return ERR_PTR(-ENOMEM); |
5db53f3e | 580 | |
cce2c56e LT |
581 | mutex_init(&super->s_dirop_mutex); |
582 | mutex_init(&super->s_object_alias_mutex); | |
583 | INIT_LIST_HEAD(&super->s_freeing_list); | |
584 | ||
5db53f3e | 585 | if (!devname) |
7d945a3a AV |
586 | err = logfs_get_sb_bdev(super, type, devname); |
587 | else if (strncmp(devname, "mtd", 3)) | |
588 | err = logfs_get_sb_bdev(super, type, devname); | |
589 | else { | |
5db53f3e JE |
590 | char *garbage; |
591 | mtdnr = simple_strtoul(devname+3, &garbage, 0); | |
7d945a3a AV |
592 | if (*garbage) |
593 | err = -EINVAL; | |
594 | else | |
595 | err = logfs_get_sb_mtd(super, mtdnr); | |
596 | } | |
597 | ||
598 | if (err) { | |
599 | kfree(super); | |
a1da9e8a | 600 | return ERR_PTR(err); |
5db53f3e JE |
601 | } |
602 | ||
a1da9e8a | 603 | return logfs_get_sb_device(super, type, flags); |
5db53f3e JE |
604 | } |
605 | ||
606 | static struct file_system_type logfs_fs_type = { | |
607 | .owner = THIS_MODULE, | |
608 | .name = "logfs", | |
a1da9e8a | 609 | .mount = logfs_mount, |
5db53f3e JE |
610 | .kill_sb = logfs_kill_sb, |
611 | .fs_flags = FS_REQUIRES_DEV, | |
612 | ||
613 | }; | |
614 | ||
615 | static int __init logfs_init(void) | |
616 | { | |
617 | int ret; | |
618 | ||
619 | emergency_page = alloc_pages(GFP_KERNEL, 0); | |
620 | if (!emergency_page) | |
621 | return -ENOMEM; | |
622 | ||
623 | ret = logfs_compr_init(); | |
624 | if (ret) | |
625 | goto out1; | |
626 | ||
627 | ret = logfs_init_inode_cache(); | |
628 | if (ret) | |
629 | goto out2; | |
630 | ||
631 | return register_filesystem(&logfs_fs_type); | |
632 | out2: | |
633 | logfs_compr_exit(); | |
634 | out1: | |
635 | __free_pages(emergency_page, 0); | |
636 | return ret; | |
637 | } | |
638 | ||
639 | static void __exit logfs_exit(void) | |
640 | { | |
641 | unregister_filesystem(&logfs_fs_type); | |
642 | logfs_destroy_inode_cache(); | |
643 | logfs_compr_exit(); | |
644 | __free_pages(emergency_page, 0); | |
645 | } | |
646 | ||
647 | module_init(logfs_init); | |
648 | module_exit(logfs_exit); | |
649 | ||
650 | MODULE_LICENSE("GPL v2"); | |
651 | MODULE_AUTHOR("Joern Engel <joern@logfs.org>"); | |
652 | MODULE_DESCRIPTION("scalable flash filesystem"); |