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  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * NILFS disk address translation.
  4 *
  5 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
  6 *
  7 * Written by Koji Sato.
  8 */
  9
 10#include <linux/types.h>
 11#include <linux/buffer_head.h>
 12#include <linux/string.h>
 13#include <linux/errno.h>
 14#include "nilfs.h"
 15#include "mdt.h"
 16#include "alloc.h"
 17#include "dat.h"
 18
 19
 20#define NILFS_CNO_MIN	((__u64)1)
 21#define NILFS_CNO_MAX	(~(__u64)0)
 22
 23/**
 24 * struct nilfs_dat_info - on-memory private data of DAT file
 25 * @mi: on-memory private data of metadata file
 26 * @palloc_cache: persistent object allocator cache of DAT file
 27 * @shadow: shadow map of DAT file
 28 */
 29struct nilfs_dat_info {
 30	struct nilfs_mdt_info mi;
 31	struct nilfs_palloc_cache palloc_cache;
 32	struct nilfs_shadow_map shadow;
 33};
 34
 35static inline struct nilfs_dat_info *NILFS_DAT_I(struct inode *dat)
 36{
 37	return (struct nilfs_dat_info *)NILFS_MDT(dat);
 38}
 39
 40static int nilfs_dat_prepare_entry(struct inode *dat,
 41				   struct nilfs_palloc_req *req, int create)
 42{
 43	int ret;
 44
 45	ret = nilfs_palloc_get_entry_block(dat, req->pr_entry_nr,
 46					   create, &req->pr_entry_bh);
 47	if (unlikely(ret == -ENOENT)) {
 48		nilfs_err(dat->i_sb,
 49			  "DAT doesn't have a block to manage vblocknr = %llu",
 50			  (unsigned long long)req->pr_entry_nr);
 51		/*
 52		 * Return internal code -EINVAL to notify bmap layer of
 53		 * metadata corruption.
 54		 */
 55		ret = -EINVAL;
 56	}
 57	return ret;
 58}
 59
 60static void nilfs_dat_commit_entry(struct inode *dat,
 61				   struct nilfs_palloc_req *req)
 62{
 63	mark_buffer_dirty(req->pr_entry_bh);
 64	nilfs_mdt_mark_dirty(dat);
 65	brelse(req->pr_entry_bh);
 66}
 67
 68static void nilfs_dat_abort_entry(struct inode *dat,
 69				  struct nilfs_palloc_req *req)
 70{
 71	brelse(req->pr_entry_bh);
 72}
 73
 74int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
 75{
 76	int ret;
 77
 78	ret = nilfs_palloc_prepare_alloc_entry(dat, req);
 79	if (ret < 0)
 80		return ret;
 81
 82	ret = nilfs_dat_prepare_entry(dat, req, 1);
 83	if (ret < 0)
 84		nilfs_palloc_abort_alloc_entry(dat, req);
 85
 86	return ret;
 87}
 88
 89void nilfs_dat_commit_alloc(struct inode *dat, struct nilfs_palloc_req *req)
 90{
 91	struct nilfs_dat_entry *entry;
 92	void *kaddr;
 93
 94	kaddr = kmap_local_page(req->pr_entry_bh->b_page);
 95	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
 96					     req->pr_entry_bh, kaddr);
 97	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
 98	entry->de_end = cpu_to_le64(NILFS_CNO_MAX);
 99	entry->de_blocknr = cpu_to_le64(0);
100	kunmap_local(kaddr);
101
102	nilfs_palloc_commit_alloc_entry(dat, req);
103	nilfs_dat_commit_entry(dat, req);
104}
105
106void nilfs_dat_abort_alloc(struct inode *dat, struct nilfs_palloc_req *req)
107{
108	nilfs_dat_abort_entry(dat, req);
109	nilfs_palloc_abort_alloc_entry(dat, req);
110}
111
112static void nilfs_dat_commit_free(struct inode *dat,
113				  struct nilfs_palloc_req *req)
114{
115	struct nilfs_dat_entry *entry;
116	void *kaddr;
117
118	kaddr = kmap_local_page(req->pr_entry_bh->b_page);
119	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
120					     req->pr_entry_bh, kaddr);
121	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
122	entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
123	entry->de_blocknr = cpu_to_le64(0);
124	kunmap_local(kaddr);
125
126	nilfs_dat_commit_entry(dat, req);
127
128	if (unlikely(req->pr_desc_bh == NULL || req->pr_bitmap_bh == NULL)) {
129		nilfs_error(dat->i_sb,
130			    "state inconsistency probably due to duplicate use of vblocknr = %llu",
131			    (unsigned long long)req->pr_entry_nr);
132		return;
133	}
134	nilfs_palloc_commit_free_entry(dat, req);
135}
136
137int nilfs_dat_prepare_start(struct inode *dat, struct nilfs_palloc_req *req)
138{
139	return nilfs_dat_prepare_entry(dat, req, 0);
140}
141
142void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req,
143			    sector_t blocknr)
144{
145	struct nilfs_dat_entry *entry;
146	void *kaddr;
147
148	kaddr = kmap_local_page(req->pr_entry_bh->b_page);
149	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
150					     req->pr_entry_bh, kaddr);
151	entry->de_start = cpu_to_le64(nilfs_mdt_cno(dat));
152	entry->de_blocknr = cpu_to_le64(blocknr);
153	kunmap_local(kaddr);
154
155	nilfs_dat_commit_entry(dat, req);
156}
157
158int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req)
159{
160	struct nilfs_dat_entry *entry;
161	__u64 start;
162	sector_t blocknr;
163	void *kaddr;
164	int ret;
165
166	ret = nilfs_dat_prepare_entry(dat, req, 0);
167	if (ret < 0)
168		return ret;
169
170	kaddr = kmap_local_page(req->pr_entry_bh->b_page);
171	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
172					     req->pr_entry_bh, kaddr);
173	start = le64_to_cpu(entry->de_start);
174	blocknr = le64_to_cpu(entry->de_blocknr);
175	kunmap_local(kaddr);
176
177	if (blocknr == 0) {
178		ret = nilfs_palloc_prepare_free_entry(dat, req);
179		if (ret < 0) {
180			nilfs_dat_abort_entry(dat, req);
181			return ret;
182		}
183	}
184	if (unlikely(start > nilfs_mdt_cno(dat))) {
185		nilfs_err(dat->i_sb,
186			  "vblocknr = %llu has abnormal lifetime: start cno (= %llu) > current cno (= %llu)",
187			  (unsigned long long)req->pr_entry_nr,
188			  (unsigned long long)start,
189			  (unsigned long long)nilfs_mdt_cno(dat));
190		nilfs_dat_abort_entry(dat, req);
191		return -EINVAL;
192	}
193
194	return 0;
195}
196
197void nilfs_dat_commit_end(struct inode *dat, struct nilfs_palloc_req *req,
198			  int dead)
199{
200	struct nilfs_dat_entry *entry;
201	__u64 start, end;
202	sector_t blocknr;
203	void *kaddr;
204
205	kaddr = kmap_local_page(req->pr_entry_bh->b_page);
206	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
207					     req->pr_entry_bh, kaddr);
208	end = start = le64_to_cpu(entry->de_start);
209	if (!dead) {
210		end = nilfs_mdt_cno(dat);
211		WARN_ON(start > end);
212	}
213	entry->de_end = cpu_to_le64(end);
214	blocknr = le64_to_cpu(entry->de_blocknr);
215	kunmap_local(kaddr);
216
217	if (blocknr == 0)
218		nilfs_dat_commit_free(dat, req);
219	else
220		nilfs_dat_commit_entry(dat, req);
221}
222
223void nilfs_dat_abort_end(struct inode *dat, struct nilfs_palloc_req *req)
224{
225	struct nilfs_dat_entry *entry;
226	__u64 start;
227	sector_t blocknr;
228	void *kaddr;
229
230	kaddr = kmap_local_page(req->pr_entry_bh->b_page);
231	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
232					     req->pr_entry_bh, kaddr);
233	start = le64_to_cpu(entry->de_start);
234	blocknr = le64_to_cpu(entry->de_blocknr);
235	kunmap_local(kaddr);
236
237	if (start == nilfs_mdt_cno(dat) && blocknr == 0)
238		nilfs_palloc_abort_free_entry(dat, req);
239	nilfs_dat_abort_entry(dat, req);
240}
241
242int nilfs_dat_prepare_update(struct inode *dat,
243			     struct nilfs_palloc_req *oldreq,
244			     struct nilfs_palloc_req *newreq)
245{
246	int ret;
247
248	ret = nilfs_dat_prepare_end(dat, oldreq);
249	if (!ret) {
250		ret = nilfs_dat_prepare_alloc(dat, newreq);
251		if (ret < 0)
252			nilfs_dat_abort_end(dat, oldreq);
253	}
254	return ret;
255}
256
257void nilfs_dat_commit_update(struct inode *dat,
258			     struct nilfs_palloc_req *oldreq,
259			     struct nilfs_palloc_req *newreq, int dead)
260{
261	nilfs_dat_commit_end(dat, oldreq, dead);
262	nilfs_dat_commit_alloc(dat, newreq);
263}
264
265void nilfs_dat_abort_update(struct inode *dat,
266			    struct nilfs_palloc_req *oldreq,
267			    struct nilfs_palloc_req *newreq)
268{
269	nilfs_dat_abort_end(dat, oldreq);
270	nilfs_dat_abort_alloc(dat, newreq);
271}
272
273/**
274 * nilfs_dat_mark_dirty -
275 * @dat: DAT file inode
276 * @vblocknr: virtual block number
277 *
278 * Description:
279 *
280 * Return Value: On success, 0 is returned. On error, one of the following
281 * negative error codes is returned.
282 *
283 * %-EIO - I/O error.
284 *
285 * %-ENOMEM - Insufficient amount of memory available.
286 */
287int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
288{
289	struct nilfs_palloc_req req;
290	int ret;
291
292	req.pr_entry_nr = vblocknr;
293	ret = nilfs_dat_prepare_entry(dat, &req, 0);
294	if (ret == 0)
295		nilfs_dat_commit_entry(dat, &req);
296	return ret;
297}
298
299/**
300 * nilfs_dat_freev - free virtual block numbers
301 * @dat: DAT file inode
302 * @vblocknrs: array of virtual block numbers
303 * @nitems: number of virtual block numbers
304 *
305 * Description: nilfs_dat_freev() frees the virtual block numbers specified by
306 * @vblocknrs and @nitems.
307 *
308 * Return Value: On success, 0 is returned. On error, one of the following
309 * negative error codes is returned.
310 *
311 * %-EIO - I/O error.
312 *
313 * %-ENOMEM - Insufficient amount of memory available.
314 *
315 * %-ENOENT - The virtual block number have not been allocated.
316 */
317int nilfs_dat_freev(struct inode *dat, __u64 *vblocknrs, size_t nitems)
318{
319	return nilfs_palloc_freev(dat, vblocknrs, nitems);
320}
321
322/**
323 * nilfs_dat_move - change a block number
324 * @dat: DAT file inode
325 * @vblocknr: virtual block number
326 * @blocknr: block number
327 *
328 * Description: nilfs_dat_move() changes the block number associated with
329 * @vblocknr to @blocknr.
330 *
331 * Return Value: On success, 0 is returned. On error, one of the following
332 * negative error codes is returned.
333 *
334 * %-EIO - I/O error.
335 *
336 * %-ENOMEM - Insufficient amount of memory available.
337 */
338int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
339{
340	struct buffer_head *entry_bh;
341	struct nilfs_dat_entry *entry;
342	void *kaddr;
343	int ret;
344
345	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
346	if (ret < 0)
347		return ret;
348
349	/*
350	 * The given disk block number (blocknr) is not yet written to
351	 * the device at this point.
352	 *
353	 * To prevent nilfs_dat_translate() from returning the
354	 * uncommitted block number, this makes a copy of the entry
355	 * buffer and redirects nilfs_dat_translate() to the copy.
356	 */
357	if (!buffer_nilfs_redirected(entry_bh)) {
358		ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
359		if (ret) {
360			brelse(entry_bh);
361			return ret;
362		}
363	}
364
365	kaddr = kmap_local_page(entry_bh->b_page);
366	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
367	if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
368		nilfs_crit(dat->i_sb,
369			   "%s: invalid vblocknr = %llu, [%llu, %llu)",
370			   __func__, (unsigned long long)vblocknr,
371			   (unsigned long long)le64_to_cpu(entry->de_start),
372			   (unsigned long long)le64_to_cpu(entry->de_end));
373		kunmap_local(kaddr);
374		brelse(entry_bh);
375		return -EINVAL;
376	}
377	WARN_ON(blocknr == 0);
378	entry->de_blocknr = cpu_to_le64(blocknr);
379	kunmap_local(kaddr);
380
381	mark_buffer_dirty(entry_bh);
382	nilfs_mdt_mark_dirty(dat);
383
384	brelse(entry_bh);
385
386	return 0;
387}
388
389/**
390 * nilfs_dat_translate - translate a virtual block number to a block number
391 * @dat: DAT file inode
392 * @vblocknr: virtual block number
393 * @blocknrp: pointer to a block number
394 *
395 * Description: nilfs_dat_translate() maps the virtual block number @vblocknr
396 * to the corresponding block number.
397 *
398 * Return Value: On success, 0 is returned and the block number associated
399 * with @vblocknr is stored in the place pointed by @blocknrp. On error, one
400 * of the following negative error codes is returned.
401 *
402 * %-EIO - I/O error.
403 *
404 * %-ENOMEM - Insufficient amount of memory available.
405 *
406 * %-ENOENT - A block number associated with @vblocknr does not exist.
407 */
408int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
409{
410	struct buffer_head *entry_bh, *bh;
411	struct nilfs_dat_entry *entry;
412	sector_t blocknr;
413	void *kaddr;
414	int ret;
415
416	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
417	if (ret < 0)
418		return ret;
419
420	if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
421		bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
422		if (bh) {
423			WARN_ON(!buffer_uptodate(bh));
424			brelse(entry_bh);
425			entry_bh = bh;
426		}
427	}
428
429	kaddr = kmap_local_page(entry_bh->b_page);
430	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
431	blocknr = le64_to_cpu(entry->de_blocknr);
432	if (blocknr == 0) {
433		ret = -ENOENT;
434		goto out;
435	}
436	*blocknrp = blocknr;
437
438 out:
439	kunmap_local(kaddr);
440	brelse(entry_bh);
441	return ret;
442}
443
444ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned int visz,
445			    size_t nvi)
446{
447	struct buffer_head *entry_bh;
448	struct nilfs_dat_entry *entry;
449	struct nilfs_vinfo *vinfo = buf;
450	__u64 first, last;
451	void *kaddr;
452	unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
453	int i, j, n, ret;
454
455	for (i = 0; i < nvi; i += n) {
456		ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
457						   0, &entry_bh);
458		if (ret < 0)
459			return ret;
460		kaddr = kmap_local_page(entry_bh->b_page);
461		/* last virtual block number in this block */
462		first = vinfo->vi_vblocknr;
463		first = div64_ul(first, entries_per_block);
464		first *= entries_per_block;
465		last = first + entries_per_block - 1;
466		for (j = i, n = 0;
467		     j < nvi && vinfo->vi_vblocknr >= first &&
468			     vinfo->vi_vblocknr <= last;
469		     j++, n++, vinfo = (void *)vinfo + visz) {
470			entry = nilfs_palloc_block_get_entry(
471				dat, vinfo->vi_vblocknr, entry_bh, kaddr);
472			vinfo->vi_start = le64_to_cpu(entry->de_start);
473			vinfo->vi_end = le64_to_cpu(entry->de_end);
474			vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr);
475		}
476		kunmap_local(kaddr);
477		brelse(entry_bh);
478	}
479
480	return nvi;
481}
482
483/**
484 * nilfs_dat_read - read or get dat inode
485 * @sb: super block instance
486 * @entry_size: size of a dat entry
487 * @raw_inode: on-disk dat inode
488 * @inodep: buffer to store the inode
489 */
490int nilfs_dat_read(struct super_block *sb, size_t entry_size,
491		   struct nilfs_inode *raw_inode, struct inode **inodep)
492{
493	static struct lock_class_key dat_lock_key;
494	struct inode *dat;
495	struct nilfs_dat_info *di;
496	int err;
497
498	if (entry_size > sb->s_blocksize) {
499		nilfs_err(sb, "too large DAT entry size: %zu bytes",
500			  entry_size);
501		return -EINVAL;
502	} else if (entry_size < NILFS_MIN_DAT_ENTRY_SIZE) {
503		nilfs_err(sb, "too small DAT entry size: %zu bytes",
504			  entry_size);
505		return -EINVAL;
506	}
507
508	dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
509	if (unlikely(!dat))
510		return -ENOMEM;
511	if (!(dat->i_state & I_NEW))
512		goto out;
513
514	err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
515	if (err)
516		goto failed;
517
518	err = nilfs_palloc_init_blockgroup(dat, entry_size);
519	if (err)
520		goto failed;
521
522	di = NILFS_DAT_I(dat);
523	lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
524	nilfs_palloc_setup_cache(dat, &di->palloc_cache);
525	err = nilfs_mdt_setup_shadow_map(dat, &di->shadow);
526	if (err)
527		goto failed;
528
529	err = nilfs_read_inode_common(dat, raw_inode);
530	if (err)
531		goto failed;
532
533	unlock_new_inode(dat);
534 out:
535	*inodep = dat;
536	return 0;
537 failed:
538	iget_failed(dat);
539	return err;
540}
  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 * You should have received a copy of the GNU General Public License
 17 * along with this program; if not, write to the Free Software
 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 19 *
 20 * Written by Koji Sato <koji@osrg.net>.
 21 */
 22
 23#include <linux/types.h>
 24#include <linux/buffer_head.h>
 25#include <linux/string.h>
 26#include <linux/errno.h>
 27#include "nilfs.h"
 28#include "mdt.h"
 29#include "alloc.h"
 30#include "dat.h"
 31
 32
 33#define NILFS_CNO_MIN	((__u64)1)
 34#define NILFS_CNO_MAX	(~(__u64)0)
 35
 36/**
 37 * struct nilfs_dat_info - on-memory private data of DAT file
 38 * @mi: on-memory private data of metadata file
 39 * @palloc_cache: persistent object allocator cache of DAT file
 40 * @shadow: shadow map of DAT file
 41 */
 42struct nilfs_dat_info {
 43	struct nilfs_mdt_info mi;
 44	struct nilfs_palloc_cache palloc_cache;
 45	struct nilfs_shadow_map shadow;
 46};
 47
 48static inline struct nilfs_dat_info *NILFS_DAT_I(struct inode *dat)
 49{
 50	return (struct nilfs_dat_info *)NILFS_MDT(dat);
 51}
 52
 53static int nilfs_dat_prepare_entry(struct inode *dat,
 54				   struct nilfs_palloc_req *req, int create)
 55{
 56	return nilfs_palloc_get_entry_block(dat, req->pr_entry_nr,
 57					    create, &req->pr_entry_bh);
 58}
 59
 60static void nilfs_dat_commit_entry(struct inode *dat,
 61				   struct nilfs_palloc_req *req)
 62{
 63	mark_buffer_dirty(req->pr_entry_bh);
 64	nilfs_mdt_mark_dirty(dat);
 65	brelse(req->pr_entry_bh);
 66}
 67
 68static void nilfs_dat_abort_entry(struct inode *dat,
 69				  struct nilfs_palloc_req *req)
 70{
 71	brelse(req->pr_entry_bh);
 72}
 73
 74int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
 75{
 76	int ret;
 77
 78	ret = nilfs_palloc_prepare_alloc_entry(dat, req);
 79	if (ret < 0)
 80		return ret;
 81
 82	ret = nilfs_dat_prepare_entry(dat, req, 1);
 83	if (ret < 0)
 84		nilfs_palloc_abort_alloc_entry(dat, req);
 85
 86	return ret;
 87}
 88
 89void nilfs_dat_commit_alloc(struct inode *dat, struct nilfs_palloc_req *req)
 90{
 91	struct nilfs_dat_entry *entry;
 92	void *kaddr;
 93
 94	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
 95	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
 96					     req->pr_entry_bh, kaddr);
 97	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
 98	entry->de_end = cpu_to_le64(NILFS_CNO_MAX);
 99	entry->de_blocknr = cpu_to_le64(0);
100	kunmap_atomic(kaddr);
101
102	nilfs_palloc_commit_alloc_entry(dat, req);
103	nilfs_dat_commit_entry(dat, req);
104}
105
106void nilfs_dat_abort_alloc(struct inode *dat, struct nilfs_palloc_req *req)
107{
108	nilfs_dat_abort_entry(dat, req);
109	nilfs_palloc_abort_alloc_entry(dat, req);
110}
111
112static void nilfs_dat_commit_free(struct inode *dat,
113				  struct nilfs_palloc_req *req)
114{
115	struct nilfs_dat_entry *entry;
116	void *kaddr;
117
118	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
119	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
120					     req->pr_entry_bh, kaddr);
121	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
122	entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
123	entry->de_blocknr = cpu_to_le64(0);
124	kunmap_atomic(kaddr);
125
126	nilfs_dat_commit_entry(dat, req);
127	nilfs_palloc_commit_free_entry(dat, req);
128}
129
130int nilfs_dat_prepare_start(struct inode *dat, struct nilfs_palloc_req *req)
131{
132	int ret;
133
134	ret = nilfs_dat_prepare_entry(dat, req, 0);
135	WARN_ON(ret == -ENOENT);
136	return ret;
137}
138
139void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req,
140			    sector_t blocknr)
141{
142	struct nilfs_dat_entry *entry;
143	void *kaddr;
144
145	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
146	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
147					     req->pr_entry_bh, kaddr);
148	entry->de_start = cpu_to_le64(nilfs_mdt_cno(dat));
149	entry->de_blocknr = cpu_to_le64(blocknr);
150	kunmap_atomic(kaddr);
151
152	nilfs_dat_commit_entry(dat, req);
153}
154
155int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req)
156{
157	struct nilfs_dat_entry *entry;
158	sector_t blocknr;
159	void *kaddr;
160	int ret;
161
162	ret = nilfs_dat_prepare_entry(dat, req, 0);
163	if (ret < 0) {
164		WARN_ON(ret == -ENOENT);
165		return ret;
166	}
167
168	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
169	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
170					     req->pr_entry_bh, kaddr);
171	blocknr = le64_to_cpu(entry->de_blocknr);
172	kunmap_atomic(kaddr);
173
174	if (blocknr == 0) {
175		ret = nilfs_palloc_prepare_free_entry(dat, req);
176		if (ret < 0) {
177			nilfs_dat_abort_entry(dat, req);
178			return ret;
179		}
180	}
181
182	return 0;
183}
184
185void nilfs_dat_commit_end(struct inode *dat, struct nilfs_palloc_req *req,
186			  int dead)
187{
188	struct nilfs_dat_entry *entry;
189	__u64 start, end;
190	sector_t blocknr;
191	void *kaddr;
192
193	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
194	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
195					     req->pr_entry_bh, kaddr);
196	end = start = le64_to_cpu(entry->de_start);
197	if (!dead) {
198		end = nilfs_mdt_cno(dat);
199		WARN_ON(start > end);
200	}
201	entry->de_end = cpu_to_le64(end);
202	blocknr = le64_to_cpu(entry->de_blocknr);
203	kunmap_atomic(kaddr);
204
205	if (blocknr == 0)
206		nilfs_dat_commit_free(dat, req);
207	else
208		nilfs_dat_commit_entry(dat, req);
209}
210
211void nilfs_dat_abort_end(struct inode *dat, struct nilfs_palloc_req *req)
212{
213	struct nilfs_dat_entry *entry;
214	__u64 start;
215	sector_t blocknr;
216	void *kaddr;
217
218	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
219	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
220					     req->pr_entry_bh, kaddr);
221	start = le64_to_cpu(entry->de_start);
222	blocknr = le64_to_cpu(entry->de_blocknr);
223	kunmap_atomic(kaddr);
224
225	if (start == nilfs_mdt_cno(dat) && blocknr == 0)
226		nilfs_palloc_abort_free_entry(dat, req);
227	nilfs_dat_abort_entry(dat, req);
228}
229
230int nilfs_dat_prepare_update(struct inode *dat,
231			     struct nilfs_palloc_req *oldreq,
232			     struct nilfs_palloc_req *newreq)
233{
234	int ret;
235
236	ret = nilfs_dat_prepare_end(dat, oldreq);
237	if (!ret) {
238		ret = nilfs_dat_prepare_alloc(dat, newreq);
239		if (ret < 0)
240			nilfs_dat_abort_end(dat, oldreq);
241	}
242	return ret;
243}
244
245void nilfs_dat_commit_update(struct inode *dat,
246			     struct nilfs_palloc_req *oldreq,
247			     struct nilfs_palloc_req *newreq, int dead)
248{
249	nilfs_dat_commit_end(dat, oldreq, dead);
250	nilfs_dat_commit_alloc(dat, newreq);
251}
252
253void nilfs_dat_abort_update(struct inode *dat,
254			    struct nilfs_palloc_req *oldreq,
255			    struct nilfs_palloc_req *newreq)
256{
257	nilfs_dat_abort_end(dat, oldreq);
258	nilfs_dat_abort_alloc(dat, newreq);
259}
260
261/**
262 * nilfs_dat_mark_dirty -
263 * @dat: DAT file inode
264 * @vblocknr: virtual block number
265 *
266 * Description:
267 *
268 * Return Value: On success, 0 is returned. On error, one of the following
269 * negative error codes is returned.
270 *
271 * %-EIO - I/O error.
272 *
273 * %-ENOMEM - Insufficient amount of memory available.
274 */
275int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
276{
277	struct nilfs_palloc_req req;
278	int ret;
279
280	req.pr_entry_nr = vblocknr;
281	ret = nilfs_dat_prepare_entry(dat, &req, 0);
282	if (ret == 0)
283		nilfs_dat_commit_entry(dat, &req);
284	return ret;
285}
286
287/**
288 * nilfs_dat_freev - free virtual block numbers
289 * @dat: DAT file inode
290 * @vblocknrs: array of virtual block numbers
291 * @nitems: number of virtual block numbers
292 *
293 * Description: nilfs_dat_freev() frees the virtual block numbers specified by
294 * @vblocknrs and @nitems.
295 *
296 * Return Value: On success, 0 is returned. On error, one of the following
297 * negative error codes is returned.
298 *
299 * %-EIO - I/O error.
300 *
301 * %-ENOMEM - Insufficient amount of memory available.
302 *
303 * %-ENOENT - The virtual block number have not been allocated.
304 */
305int nilfs_dat_freev(struct inode *dat, __u64 *vblocknrs, size_t nitems)
306{
307	return nilfs_palloc_freev(dat, vblocknrs, nitems);
308}
309
310/**
311 * nilfs_dat_move - change a block number
312 * @dat: DAT file inode
313 * @vblocknr: virtual block number
314 * @blocknr: block number
315 *
316 * Description: nilfs_dat_move() changes the block number associated with
317 * @vblocknr to @blocknr.
318 *
319 * Return Value: On success, 0 is returned. On error, one of the following
320 * negative error codes is returned.
321 *
322 * %-EIO - I/O error.
323 *
324 * %-ENOMEM - Insufficient amount of memory available.
325 */
326int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
327{
328	struct buffer_head *entry_bh;
329	struct nilfs_dat_entry *entry;
330	void *kaddr;
331	int ret;
332
333	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
334	if (ret < 0)
335		return ret;
336
337	/*
338	 * The given disk block number (blocknr) is not yet written to
339	 * the device at this point.
340	 *
341	 * To prevent nilfs_dat_translate() from returning the
342	 * uncommitted block number, this makes a copy of the entry
343	 * buffer and redirects nilfs_dat_translate() to the copy.
344	 */
345	if (!buffer_nilfs_redirected(entry_bh)) {
346		ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
347		if (ret) {
348			brelse(entry_bh);
349			return ret;
350		}
351	}
352
353	kaddr = kmap_atomic(entry_bh->b_page);
354	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
355	if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
356		printk(KERN_CRIT "%s: vbn = %llu, [%llu, %llu)\n", __func__,
357		       (unsigned long long)vblocknr,
358		       (unsigned long long)le64_to_cpu(entry->de_start),
359		       (unsigned long long)le64_to_cpu(entry->de_end));
360		kunmap_atomic(kaddr);
361		brelse(entry_bh);
362		return -EINVAL;
363	}
364	WARN_ON(blocknr == 0);
365	entry->de_blocknr = cpu_to_le64(blocknr);
366	kunmap_atomic(kaddr);
367
368	mark_buffer_dirty(entry_bh);
369	nilfs_mdt_mark_dirty(dat);
370
371	brelse(entry_bh);
372
373	return 0;
374}
375
376/**
377 * nilfs_dat_translate - translate a virtual block number to a block number
378 * @dat: DAT file inode
379 * @vblocknr: virtual block number
380 * @blocknrp: pointer to a block number
381 *
382 * Description: nilfs_dat_translate() maps the virtual block number @vblocknr
383 * to the corresponding block number.
384 *
385 * Return Value: On success, 0 is returned and the block number associated
386 * with @vblocknr is stored in the place pointed by @blocknrp. On error, one
387 * of the following negative error codes is returned.
388 *
389 * %-EIO - I/O error.
390 *
391 * %-ENOMEM - Insufficient amount of memory available.
392 *
393 * %-ENOENT - A block number associated with @vblocknr does not exist.
394 */
395int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
396{
397	struct buffer_head *entry_bh, *bh;
398	struct nilfs_dat_entry *entry;
399	sector_t blocknr;
400	void *kaddr;
401	int ret;
402
403	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
404	if (ret < 0)
405		return ret;
406
407	if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
408		bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
409		if (bh) {
410			WARN_ON(!buffer_uptodate(bh));
411			brelse(entry_bh);
412			entry_bh = bh;
413		}
414	}
415
416	kaddr = kmap_atomic(entry_bh->b_page);
417	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
418	blocknr = le64_to_cpu(entry->de_blocknr);
419	if (blocknr == 0) {
420		ret = -ENOENT;
421		goto out;
422	}
423	*blocknrp = blocknr;
424
425 out:
426	kunmap_atomic(kaddr);
427	brelse(entry_bh);
428	return ret;
429}
430
431ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned visz,
432			    size_t nvi)
433{
434	struct buffer_head *entry_bh;
435	struct nilfs_dat_entry *entry;
436	struct nilfs_vinfo *vinfo = buf;
437	__u64 first, last;
438	void *kaddr;
439	unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
440	int i, j, n, ret;
441
442	for (i = 0; i < nvi; i += n) {
443		ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
444						   0, &entry_bh);
445		if (ret < 0)
446			return ret;
447		kaddr = kmap_atomic(entry_bh->b_page);
448		/* last virtual block number in this block */
449		first = vinfo->vi_vblocknr;
450		do_div(first, entries_per_block);
451		first *= entries_per_block;
452		last = first + entries_per_block - 1;
453		for (j = i, n = 0;
454		     j < nvi && vinfo->vi_vblocknr >= first &&
455			     vinfo->vi_vblocknr <= last;
456		     j++, n++, vinfo = (void *)vinfo + visz) {
457			entry = nilfs_palloc_block_get_entry(
458				dat, vinfo->vi_vblocknr, entry_bh, kaddr);
459			vinfo->vi_start = le64_to_cpu(entry->de_start);
460			vinfo->vi_end = le64_to_cpu(entry->de_end);
461			vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr);
462		}
463		kunmap_atomic(kaddr);
464		brelse(entry_bh);
465	}
466
467	return nvi;
468}
469
470/**
471 * nilfs_dat_read - read or get dat inode
472 * @sb: super block instance
473 * @entry_size: size of a dat entry
474 * @raw_inode: on-disk dat inode
475 * @inodep: buffer to store the inode
476 */
477int nilfs_dat_read(struct super_block *sb, size_t entry_size,
478		   struct nilfs_inode *raw_inode, struct inode **inodep)
479{
480	static struct lock_class_key dat_lock_key;
481	struct inode *dat;
482	struct nilfs_dat_info *di;
483	int err;
484
485	if (entry_size > sb->s_blocksize) {
486		printk(KERN_ERR
487		       "NILFS: too large DAT entry size: %zu bytes.\n",
488		       entry_size);
489		return -EINVAL;
490	} else if (entry_size < NILFS_MIN_DAT_ENTRY_SIZE) {
491		printk(KERN_ERR
492		       "NILFS: too small DAT entry size: %zu bytes.\n",
493		       entry_size);
494		return -EINVAL;
495	}
496
497	dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
498	if (unlikely(!dat))
499		return -ENOMEM;
500	if (!(dat->i_state & I_NEW))
501		goto out;
502
503	err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
504	if (err)
505		goto failed;
506
507	err = nilfs_palloc_init_blockgroup(dat, entry_size);
508	if (err)
509		goto failed;
510
511	di = NILFS_DAT_I(dat);
512	lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
513	nilfs_palloc_setup_cache(dat, &di->palloc_cache);
514	nilfs_mdt_setup_shadow_map(dat, &di->shadow);
515
516	err = nilfs_read_inode_common(dat, raw_inode);
517	if (err)
518		goto failed;
519
520	unlock_new_inode(dat);
521 out:
522	*inodep = dat;
523	return 0;
524 failed:
525	iget_failed(dat);
526	return err;
527}