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[mirror_ubuntu-zesty-kernel.git] / fs / nilfs2 / dat.c
1 /*
2 * dat.c - NILFS disk address translation.
3 *
4 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * Written by Koji Sato.
17 */
18
19 #include <linux/types.h>
20 #include <linux/buffer_head.h>
21 #include <linux/string.h>
22 #include <linux/errno.h>
23 #include "nilfs.h"
24 #include "mdt.h"
25 #include "alloc.h"
26 #include "dat.h"
27
28
29 #define NILFS_CNO_MIN ((__u64)1)
30 #define NILFS_CNO_MAX (~(__u64)0)
31
32 /**
33 * struct nilfs_dat_info - on-memory private data of DAT file
34 * @mi: on-memory private data of metadata file
35 * @palloc_cache: persistent object allocator cache of DAT file
36 * @shadow: shadow map of DAT file
37 */
38 struct nilfs_dat_info {
39 struct nilfs_mdt_info mi;
40 struct nilfs_palloc_cache palloc_cache;
41 struct nilfs_shadow_map shadow;
42 };
43
44 static inline struct nilfs_dat_info *NILFS_DAT_I(struct inode *dat)
45 {
46 return (struct nilfs_dat_info *)NILFS_MDT(dat);
47 }
48
49 static int nilfs_dat_prepare_entry(struct inode *dat,
50 struct nilfs_palloc_req *req, int create)
51 {
52 return nilfs_palloc_get_entry_block(dat, req->pr_entry_nr,
53 create, &req->pr_entry_bh);
54 }
55
56 static void nilfs_dat_commit_entry(struct inode *dat,
57 struct nilfs_palloc_req *req)
58 {
59 mark_buffer_dirty(req->pr_entry_bh);
60 nilfs_mdt_mark_dirty(dat);
61 brelse(req->pr_entry_bh);
62 }
63
64 static void nilfs_dat_abort_entry(struct inode *dat,
65 struct nilfs_palloc_req *req)
66 {
67 brelse(req->pr_entry_bh);
68 }
69
70 int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
71 {
72 int ret;
73
74 ret = nilfs_palloc_prepare_alloc_entry(dat, req);
75 if (ret < 0)
76 return ret;
77
78 ret = nilfs_dat_prepare_entry(dat, req, 1);
79 if (ret < 0)
80 nilfs_palloc_abort_alloc_entry(dat, req);
81
82 return ret;
83 }
84
85 void nilfs_dat_commit_alloc(struct inode *dat, struct nilfs_palloc_req *req)
86 {
87 struct nilfs_dat_entry *entry;
88 void *kaddr;
89
90 kaddr = kmap_atomic(req->pr_entry_bh->b_page);
91 entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
92 req->pr_entry_bh, kaddr);
93 entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
94 entry->de_end = cpu_to_le64(NILFS_CNO_MAX);
95 entry->de_blocknr = cpu_to_le64(0);
96 kunmap_atomic(kaddr);
97
98 nilfs_palloc_commit_alloc_entry(dat, req);
99 nilfs_dat_commit_entry(dat, req);
100 }
101
102 void nilfs_dat_abort_alloc(struct inode *dat, struct nilfs_palloc_req *req)
103 {
104 nilfs_dat_abort_entry(dat, req);
105 nilfs_palloc_abort_alloc_entry(dat, req);
106 }
107
108 static void nilfs_dat_commit_free(struct inode *dat,
109 struct nilfs_palloc_req *req)
110 {
111 struct nilfs_dat_entry *entry;
112 void *kaddr;
113
114 kaddr = kmap_atomic(req->pr_entry_bh->b_page);
115 entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
116 req->pr_entry_bh, kaddr);
117 entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
118 entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
119 entry->de_blocknr = cpu_to_le64(0);
120 kunmap_atomic(kaddr);
121
122 nilfs_dat_commit_entry(dat, req);
123 nilfs_palloc_commit_free_entry(dat, req);
124 }
125
126 int nilfs_dat_prepare_start(struct inode *dat, struct nilfs_palloc_req *req)
127 {
128 int ret;
129
130 ret = nilfs_dat_prepare_entry(dat, req, 0);
131 WARN_ON(ret == -ENOENT);
132 return ret;
133 }
134
135 void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req,
136 sector_t blocknr)
137 {
138 struct nilfs_dat_entry *entry;
139 void *kaddr;
140
141 kaddr = kmap_atomic(req->pr_entry_bh->b_page);
142 entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
143 req->pr_entry_bh, kaddr);
144 entry->de_start = cpu_to_le64(nilfs_mdt_cno(dat));
145 entry->de_blocknr = cpu_to_le64(blocknr);
146 kunmap_atomic(kaddr);
147
148 nilfs_dat_commit_entry(dat, req);
149 }
150
151 int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req)
152 {
153 struct nilfs_dat_entry *entry;
154 sector_t blocknr;
155 void *kaddr;
156 int ret;
157
158 ret = nilfs_dat_prepare_entry(dat, req, 0);
159 if (ret < 0) {
160 WARN_ON(ret == -ENOENT);
161 return ret;
162 }
163
164 kaddr = kmap_atomic(req->pr_entry_bh->b_page);
165 entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
166 req->pr_entry_bh, kaddr);
167 blocknr = le64_to_cpu(entry->de_blocknr);
168 kunmap_atomic(kaddr);
169
170 if (blocknr == 0) {
171 ret = nilfs_palloc_prepare_free_entry(dat, req);
172 if (ret < 0) {
173 nilfs_dat_abort_entry(dat, req);
174 return ret;
175 }
176 }
177
178 return 0;
179 }
180
181 void nilfs_dat_commit_end(struct inode *dat, struct nilfs_palloc_req *req,
182 int dead)
183 {
184 struct nilfs_dat_entry *entry;
185 __u64 start, end;
186 sector_t blocknr;
187 void *kaddr;
188
189 kaddr = kmap_atomic(req->pr_entry_bh->b_page);
190 entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
191 req->pr_entry_bh, kaddr);
192 end = start = le64_to_cpu(entry->de_start);
193 if (!dead) {
194 end = nilfs_mdt_cno(dat);
195 WARN_ON(start > end);
196 }
197 entry->de_end = cpu_to_le64(end);
198 blocknr = le64_to_cpu(entry->de_blocknr);
199 kunmap_atomic(kaddr);
200
201 if (blocknr == 0)
202 nilfs_dat_commit_free(dat, req);
203 else
204 nilfs_dat_commit_entry(dat, req);
205 }
206
207 void nilfs_dat_abort_end(struct inode *dat, struct nilfs_palloc_req *req)
208 {
209 struct nilfs_dat_entry *entry;
210 __u64 start;
211 sector_t blocknr;
212 void *kaddr;
213
214 kaddr = kmap_atomic(req->pr_entry_bh->b_page);
215 entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
216 req->pr_entry_bh, kaddr);
217 start = le64_to_cpu(entry->de_start);
218 blocknr = le64_to_cpu(entry->de_blocknr);
219 kunmap_atomic(kaddr);
220
221 if (start == nilfs_mdt_cno(dat) && blocknr == 0)
222 nilfs_palloc_abort_free_entry(dat, req);
223 nilfs_dat_abort_entry(dat, req);
224 }
225
226 int nilfs_dat_prepare_update(struct inode *dat,
227 struct nilfs_palloc_req *oldreq,
228 struct nilfs_palloc_req *newreq)
229 {
230 int ret;
231
232 ret = nilfs_dat_prepare_end(dat, oldreq);
233 if (!ret) {
234 ret = nilfs_dat_prepare_alloc(dat, newreq);
235 if (ret < 0)
236 nilfs_dat_abort_end(dat, oldreq);
237 }
238 return ret;
239 }
240
241 void nilfs_dat_commit_update(struct inode *dat,
242 struct nilfs_palloc_req *oldreq,
243 struct nilfs_palloc_req *newreq, int dead)
244 {
245 nilfs_dat_commit_end(dat, oldreq, dead);
246 nilfs_dat_commit_alloc(dat, newreq);
247 }
248
249 void nilfs_dat_abort_update(struct inode *dat,
250 struct nilfs_palloc_req *oldreq,
251 struct nilfs_palloc_req *newreq)
252 {
253 nilfs_dat_abort_end(dat, oldreq);
254 nilfs_dat_abort_alloc(dat, newreq);
255 }
256
257 /**
258 * nilfs_dat_mark_dirty -
259 * @dat: DAT file inode
260 * @vblocknr: virtual block number
261 *
262 * Description:
263 *
264 * Return Value: On success, 0 is returned. On error, one of the following
265 * negative error codes is returned.
266 *
267 * %-EIO - I/O error.
268 *
269 * %-ENOMEM - Insufficient amount of memory available.
270 */
271 int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
272 {
273 struct nilfs_palloc_req req;
274 int ret;
275
276 req.pr_entry_nr = vblocknr;
277 ret = nilfs_dat_prepare_entry(dat, &req, 0);
278 if (ret == 0)
279 nilfs_dat_commit_entry(dat, &req);
280 return ret;
281 }
282
283 /**
284 * nilfs_dat_freev - free virtual block numbers
285 * @dat: DAT file inode
286 * @vblocknrs: array of virtual block numbers
287 * @nitems: number of virtual block numbers
288 *
289 * Description: nilfs_dat_freev() frees the virtual block numbers specified by
290 * @vblocknrs and @nitems.
291 *
292 * Return Value: On success, 0 is returned. On error, one of the following
293 * negative error codes is returned.
294 *
295 * %-EIO - I/O error.
296 *
297 * %-ENOMEM - Insufficient amount of memory available.
298 *
299 * %-ENOENT - The virtual block number have not been allocated.
300 */
301 int nilfs_dat_freev(struct inode *dat, __u64 *vblocknrs, size_t nitems)
302 {
303 return nilfs_palloc_freev(dat, vblocknrs, nitems);
304 }
305
306 /**
307 * nilfs_dat_move - change a block number
308 * @dat: DAT file inode
309 * @vblocknr: virtual block number
310 * @blocknr: block number
311 *
312 * Description: nilfs_dat_move() changes the block number associated with
313 * @vblocknr to @blocknr.
314 *
315 * Return Value: On success, 0 is returned. On error, one of the following
316 * negative error codes is returned.
317 *
318 * %-EIO - I/O error.
319 *
320 * %-ENOMEM - Insufficient amount of memory available.
321 */
322 int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
323 {
324 struct buffer_head *entry_bh;
325 struct nilfs_dat_entry *entry;
326 void *kaddr;
327 int ret;
328
329 ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
330 if (ret < 0)
331 return ret;
332
333 /*
334 * The given disk block number (blocknr) is not yet written to
335 * the device at this point.
336 *
337 * To prevent nilfs_dat_translate() from returning the
338 * uncommitted block number, this makes a copy of the entry
339 * buffer and redirects nilfs_dat_translate() to the copy.
340 */
341 if (!buffer_nilfs_redirected(entry_bh)) {
342 ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
343 if (ret) {
344 brelse(entry_bh);
345 return ret;
346 }
347 }
348
349 kaddr = kmap_atomic(entry_bh->b_page);
350 entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
351 if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
352 nilfs_msg(dat->i_sb, KERN_CRIT,
353 "%s: invalid vblocknr = %llu, [%llu, %llu)",
354 __func__, (unsigned long long)vblocknr,
355 (unsigned long long)le64_to_cpu(entry->de_start),
356 (unsigned long long)le64_to_cpu(entry->de_end));
357 kunmap_atomic(kaddr);
358 brelse(entry_bh);
359 return -EINVAL;
360 }
361 WARN_ON(blocknr == 0);
362 entry->de_blocknr = cpu_to_le64(blocknr);
363 kunmap_atomic(kaddr);
364
365 mark_buffer_dirty(entry_bh);
366 nilfs_mdt_mark_dirty(dat);
367
368 brelse(entry_bh);
369
370 return 0;
371 }
372
373 /**
374 * nilfs_dat_translate - translate a virtual block number to a block number
375 * @dat: DAT file inode
376 * @vblocknr: virtual block number
377 * @blocknrp: pointer to a block number
378 *
379 * Description: nilfs_dat_translate() maps the virtual block number @vblocknr
380 * to the corresponding block number.
381 *
382 * Return Value: On success, 0 is returned and the block number associated
383 * with @vblocknr is stored in the place pointed by @blocknrp. On error, one
384 * of the following negative error codes is returned.
385 *
386 * %-EIO - I/O error.
387 *
388 * %-ENOMEM - Insufficient amount of memory available.
389 *
390 * %-ENOENT - A block number associated with @vblocknr does not exist.
391 */
392 int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
393 {
394 struct buffer_head *entry_bh, *bh;
395 struct nilfs_dat_entry *entry;
396 sector_t blocknr;
397 void *kaddr;
398 int ret;
399
400 ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
401 if (ret < 0)
402 return ret;
403
404 if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
405 bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
406 if (bh) {
407 WARN_ON(!buffer_uptodate(bh));
408 brelse(entry_bh);
409 entry_bh = bh;
410 }
411 }
412
413 kaddr = kmap_atomic(entry_bh->b_page);
414 entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
415 blocknr = le64_to_cpu(entry->de_blocknr);
416 if (blocknr == 0) {
417 ret = -ENOENT;
418 goto out;
419 }
420 *blocknrp = blocknr;
421
422 out:
423 kunmap_atomic(kaddr);
424 brelse(entry_bh);
425 return ret;
426 }
427
428 ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned int visz,
429 size_t nvi)
430 {
431 struct buffer_head *entry_bh;
432 struct nilfs_dat_entry *entry;
433 struct nilfs_vinfo *vinfo = buf;
434 __u64 first, last;
435 void *kaddr;
436 unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
437 int i, j, n, ret;
438
439 for (i = 0; i < nvi; i += n) {
440 ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
441 0, &entry_bh);
442 if (ret < 0)
443 return ret;
444 kaddr = kmap_atomic(entry_bh->b_page);
445 /* last virtual block number in this block */
446 first = vinfo->vi_vblocknr;
447 do_div(first, entries_per_block);
448 first *= entries_per_block;
449 last = first + entries_per_block - 1;
450 for (j = i, n = 0;
451 j < nvi && vinfo->vi_vblocknr >= first &&
452 vinfo->vi_vblocknr <= last;
453 j++, n++, vinfo = (void *)vinfo + visz) {
454 entry = nilfs_palloc_block_get_entry(
455 dat, vinfo->vi_vblocknr, entry_bh, kaddr);
456 vinfo->vi_start = le64_to_cpu(entry->de_start);
457 vinfo->vi_end = le64_to_cpu(entry->de_end);
458 vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr);
459 }
460 kunmap_atomic(kaddr);
461 brelse(entry_bh);
462 }
463
464 return nvi;
465 }
466
467 /**
468 * nilfs_dat_read - read or get dat inode
469 * @sb: super block instance
470 * @entry_size: size of a dat entry
471 * @raw_inode: on-disk dat inode
472 * @inodep: buffer to store the inode
473 */
474 int nilfs_dat_read(struct super_block *sb, size_t entry_size,
475 struct nilfs_inode *raw_inode, struct inode **inodep)
476 {
477 static struct lock_class_key dat_lock_key;
478 struct inode *dat;
479 struct nilfs_dat_info *di;
480 int err;
481
482 if (entry_size > sb->s_blocksize) {
483 nilfs_msg(sb, KERN_ERR, "too large DAT entry size: %zu bytes",
484 entry_size);
485 return -EINVAL;
486 } else if (entry_size < NILFS_MIN_DAT_ENTRY_SIZE) {
487 nilfs_msg(sb, KERN_ERR, "too small DAT entry size: %zu bytes",
488 entry_size);
489 return -EINVAL;
490 }
491
492 dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
493 if (unlikely(!dat))
494 return -ENOMEM;
495 if (!(dat->i_state & I_NEW))
496 goto out;
497
498 err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
499 if (err)
500 goto failed;
501
502 err = nilfs_palloc_init_blockgroup(dat, entry_size);
503 if (err)
504 goto failed;
505
506 di = NILFS_DAT_I(dat);
507 lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
508 nilfs_palloc_setup_cache(dat, &di->palloc_cache);
509 nilfs_mdt_setup_shadow_map(dat, &di->shadow);
510
511 err = nilfs_read_inode_common(dat, raw_inode);
512 if (err)
513 goto failed;
514
515 unlock_new_inode(dat);
516 out:
517 *inodep = dat;
518 return 0;
519 failed:
520 iget_failed(dat);
521 return err;
522 }