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v6.2
  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	return nilfs_palloc_get_entry_block(dat, req->pr_entry_nr,
 44					    create, &req->pr_entry_bh);
 45}
 46
 47static void nilfs_dat_commit_entry(struct inode *dat,
 48				   struct nilfs_palloc_req *req)
 49{
 50	mark_buffer_dirty(req->pr_entry_bh);
 51	nilfs_mdt_mark_dirty(dat);
 52	brelse(req->pr_entry_bh);
 53}
 54
 55static void nilfs_dat_abort_entry(struct inode *dat,
 56				  struct nilfs_palloc_req *req)
 57{
 58	brelse(req->pr_entry_bh);
 59}
 60
 61int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
 62{
 63	int ret;
 64
 65	ret = nilfs_palloc_prepare_alloc_entry(dat, req);
 66	if (ret < 0)
 67		return ret;
 68
 69	ret = nilfs_dat_prepare_entry(dat, req, 1);
 70	if (ret < 0)
 71		nilfs_palloc_abort_alloc_entry(dat, req);
 72
 73	return ret;
 74}
 75
 76void nilfs_dat_commit_alloc(struct inode *dat, struct nilfs_palloc_req *req)
 77{
 78	struct nilfs_dat_entry *entry;
 79	void *kaddr;
 80
 81	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
 82	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
 83					     req->pr_entry_bh, kaddr);
 84	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
 85	entry->de_end = cpu_to_le64(NILFS_CNO_MAX);
 86	entry->de_blocknr = cpu_to_le64(0);
 87	kunmap_atomic(kaddr);
 88
 89	nilfs_palloc_commit_alloc_entry(dat, req);
 90	nilfs_dat_commit_entry(dat, req);
 91}
 92
 93void nilfs_dat_abort_alloc(struct inode *dat, struct nilfs_palloc_req *req)
 94{
 95	nilfs_dat_abort_entry(dat, req);
 96	nilfs_palloc_abort_alloc_entry(dat, req);
 97}
 98
 99static void nilfs_dat_commit_free(struct inode *dat,
100				  struct nilfs_palloc_req *req)
101{
102	struct nilfs_dat_entry *entry;
103	void *kaddr;
104
105	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
106	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
107					     req->pr_entry_bh, kaddr);
108	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
109	entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
110	entry->de_blocknr = cpu_to_le64(0);
111	kunmap_atomic(kaddr);
112
113	nilfs_dat_commit_entry(dat, req);
114
115	if (unlikely(req->pr_desc_bh == NULL || req->pr_bitmap_bh == NULL)) {
116		nilfs_error(dat->i_sb,
117			    "state inconsistency probably due to duplicate use of vblocknr = %llu",
118			    (unsigned long long)req->pr_entry_nr);
119		return;
120	}
121	nilfs_palloc_commit_free_entry(dat, req);
122}
123
124int nilfs_dat_prepare_start(struct inode *dat, struct nilfs_palloc_req *req)
125{
126	int ret;
127
128	ret = nilfs_dat_prepare_entry(dat, req, 0);
129	WARN_ON(ret == -ENOENT);
130	return ret;
131}
132
133void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req,
134			    sector_t blocknr)
135{
136	struct nilfs_dat_entry *entry;
137	void *kaddr;
138
139	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
140	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
141					     req->pr_entry_bh, kaddr);
142	entry->de_start = cpu_to_le64(nilfs_mdt_cno(dat));
143	entry->de_blocknr = cpu_to_le64(blocknr);
144	kunmap_atomic(kaddr);
145
146	nilfs_dat_commit_entry(dat, req);
147}
148
149int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req)
150{
151	struct nilfs_dat_entry *entry;
152	sector_t blocknr;
153	void *kaddr;
154	int ret;
155
156	ret = nilfs_dat_prepare_entry(dat, req, 0);
157	if (ret < 0) {
158		WARN_ON(ret == -ENOENT);
159		return ret;
160	}
161
162	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
163	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
164					     req->pr_entry_bh, kaddr);
165	blocknr = le64_to_cpu(entry->de_blocknr);
166	kunmap_atomic(kaddr);
167
168	if (blocknr == 0) {
169		ret = nilfs_palloc_prepare_free_entry(dat, req);
170		if (ret < 0) {
171			nilfs_dat_abort_entry(dat, req);
172			return ret;
173		}
174	}
175
176	return 0;
177}
178
179void nilfs_dat_commit_end(struct inode *dat, struct nilfs_palloc_req *req,
180			  int dead)
181{
182	struct nilfs_dat_entry *entry;
183	__u64 start, end;
184	sector_t blocknr;
185	void *kaddr;
186
187	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
188	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
189					     req->pr_entry_bh, kaddr);
190	end = start = le64_to_cpu(entry->de_start);
191	if (!dead) {
192		end = nilfs_mdt_cno(dat);
193		WARN_ON(start > end);
194	}
195	entry->de_end = cpu_to_le64(end);
196	blocknr = le64_to_cpu(entry->de_blocknr);
197	kunmap_atomic(kaddr);
198
199	if (blocknr == 0)
200		nilfs_dat_commit_free(dat, req);
201	else
202		nilfs_dat_commit_entry(dat, req);
203}
204
205void nilfs_dat_abort_end(struct inode *dat, struct nilfs_palloc_req *req)
206{
207	struct nilfs_dat_entry *entry;
208	__u64 start;
209	sector_t blocknr;
210	void *kaddr;
211
212	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
213	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
214					     req->pr_entry_bh, kaddr);
215	start = le64_to_cpu(entry->de_start);
216	blocknr = le64_to_cpu(entry->de_blocknr);
217	kunmap_atomic(kaddr);
218
219	if (start == nilfs_mdt_cno(dat) && blocknr == 0)
220		nilfs_palloc_abort_free_entry(dat, req);
221	nilfs_dat_abort_entry(dat, req);
222}
223
224int nilfs_dat_prepare_update(struct inode *dat,
225			     struct nilfs_palloc_req *oldreq,
226			     struct nilfs_palloc_req *newreq)
227{
228	int ret;
229
230	ret = nilfs_dat_prepare_end(dat, oldreq);
231	if (!ret) {
232		ret = nilfs_dat_prepare_alloc(dat, newreq);
233		if (ret < 0)
234			nilfs_dat_abort_end(dat, oldreq);
235	}
236	return ret;
237}
238
239void nilfs_dat_commit_update(struct inode *dat,
240			     struct nilfs_palloc_req *oldreq,
241			     struct nilfs_palloc_req *newreq, int dead)
242{
243	nilfs_dat_commit_end(dat, oldreq, dead);
244	nilfs_dat_commit_alloc(dat, newreq);
245}
246
247void nilfs_dat_abort_update(struct inode *dat,
248			    struct nilfs_palloc_req *oldreq,
249			    struct nilfs_palloc_req *newreq)
250{
251	nilfs_dat_abort_end(dat, oldreq);
252	nilfs_dat_abort_alloc(dat, newreq);
253}
254
255/**
256 * nilfs_dat_mark_dirty -
257 * @dat: DAT file inode
258 * @vblocknr: virtual block number
259 *
260 * Description:
261 *
262 * Return Value: On success, 0 is returned. On error, one of the following
263 * negative error codes is returned.
264 *
265 * %-EIO - I/O error.
266 *
267 * %-ENOMEM - Insufficient amount of memory available.
268 */
269int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
270{
271	struct nilfs_palloc_req req;
272	int ret;
273
274	req.pr_entry_nr = vblocknr;
275	ret = nilfs_dat_prepare_entry(dat, &req, 0);
276	if (ret == 0)
277		nilfs_dat_commit_entry(dat, &req);
278	return ret;
279}
280
281/**
282 * nilfs_dat_freev - free virtual block numbers
283 * @dat: DAT file inode
284 * @vblocknrs: array of virtual block numbers
285 * @nitems: number of virtual block numbers
286 *
287 * Description: nilfs_dat_freev() frees the virtual block numbers specified by
288 * @vblocknrs and @nitems.
289 *
290 * Return Value: On success, 0 is returned. On error, one of the following
291 * negative error codes is returned.
292 *
293 * %-EIO - I/O error.
294 *
295 * %-ENOMEM - Insufficient amount of memory available.
296 *
297 * %-ENOENT - The virtual block number have not been allocated.
298 */
299int nilfs_dat_freev(struct inode *dat, __u64 *vblocknrs, size_t nitems)
300{
301	return nilfs_palloc_freev(dat, vblocknrs, nitems);
302}
303
304/**
305 * nilfs_dat_move - change a block number
306 * @dat: DAT file inode
307 * @vblocknr: virtual block number
308 * @blocknr: block number
309 *
310 * Description: nilfs_dat_move() changes the block number associated with
311 * @vblocknr to @blocknr.
312 *
313 * Return Value: On success, 0 is returned. On error, one of the following
314 * negative error codes is returned.
315 *
316 * %-EIO - I/O error.
317 *
318 * %-ENOMEM - Insufficient amount of memory available.
319 */
320int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
321{
322	struct buffer_head *entry_bh;
323	struct nilfs_dat_entry *entry;
324	void *kaddr;
325	int ret;
326
327	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
328	if (ret < 0)
329		return ret;
330
331	/*
332	 * The given disk block number (blocknr) is not yet written to
333	 * the device at this point.
334	 *
335	 * To prevent nilfs_dat_translate() from returning the
336	 * uncommitted block number, this makes a copy of the entry
337	 * buffer and redirects nilfs_dat_translate() to the copy.
338	 */
339	if (!buffer_nilfs_redirected(entry_bh)) {
340		ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
341		if (ret) {
342			brelse(entry_bh);
343			return ret;
344		}
345	}
346
347	kaddr = kmap_atomic(entry_bh->b_page);
348	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
349	if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
350		nilfs_crit(dat->i_sb,
351			   "%s: invalid vblocknr = %llu, [%llu, %llu)",
352			   __func__, (unsigned long long)vblocknr,
353			   (unsigned long long)le64_to_cpu(entry->de_start),
354			   (unsigned long long)le64_to_cpu(entry->de_end));
355		kunmap_atomic(kaddr);
356		brelse(entry_bh);
357		return -EINVAL;
358	}
359	WARN_ON(blocknr == 0);
360	entry->de_blocknr = cpu_to_le64(blocknr);
361	kunmap_atomic(kaddr);
362
363	mark_buffer_dirty(entry_bh);
364	nilfs_mdt_mark_dirty(dat);
365
366	brelse(entry_bh);
367
368	return 0;
369}
370
371/**
372 * nilfs_dat_translate - translate a virtual block number to a block number
373 * @dat: DAT file inode
374 * @vblocknr: virtual block number
375 * @blocknrp: pointer to a block number
376 *
377 * Description: nilfs_dat_translate() maps the virtual block number @vblocknr
378 * to the corresponding block number.
379 *
380 * Return Value: On success, 0 is returned and the block number associated
381 * with @vblocknr is stored in the place pointed by @blocknrp. On error, one
382 * of the following negative error codes is returned.
383 *
384 * %-EIO - I/O error.
385 *
386 * %-ENOMEM - Insufficient amount of memory available.
387 *
388 * %-ENOENT - A block number associated with @vblocknr does not exist.
389 */
390int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
391{
392	struct buffer_head *entry_bh, *bh;
393	struct nilfs_dat_entry *entry;
394	sector_t blocknr;
395	void *kaddr;
396	int ret;
397
398	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
399	if (ret < 0)
400		return ret;
401
402	if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
403		bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
404		if (bh) {
405			WARN_ON(!buffer_uptodate(bh));
406			brelse(entry_bh);
407			entry_bh = bh;
408		}
409	}
410
411	kaddr = kmap_atomic(entry_bh->b_page);
412	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
413	blocknr = le64_to_cpu(entry->de_blocknr);
414	if (blocknr == 0) {
415		ret = -ENOENT;
416		goto out;
417	}
418	*blocknrp = blocknr;
419
420 out:
421	kunmap_atomic(kaddr);
422	brelse(entry_bh);
423	return ret;
424}
425
426ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned int visz,
427			    size_t nvi)
428{
429	struct buffer_head *entry_bh;
430	struct nilfs_dat_entry *entry;
431	struct nilfs_vinfo *vinfo = buf;
432	__u64 first, last;
433	void *kaddr;
434	unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
435	int i, j, n, ret;
436
437	for (i = 0; i < nvi; i += n) {
438		ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
439						   0, &entry_bh);
440		if (ret < 0)
441			return ret;
442		kaddr = kmap_atomic(entry_bh->b_page);
443		/* last virtual block number in this block */
444		first = vinfo->vi_vblocknr;
445		do_div(first, entries_per_block);
446		first *= entries_per_block;
447		last = first + entries_per_block - 1;
448		for (j = i, n = 0;
449		     j < nvi && vinfo->vi_vblocknr >= first &&
450			     vinfo->vi_vblocknr <= last;
451		     j++, n++, vinfo = (void *)vinfo + visz) {
452			entry = nilfs_palloc_block_get_entry(
453				dat, vinfo->vi_vblocknr, entry_bh, kaddr);
454			vinfo->vi_start = le64_to_cpu(entry->de_start);
455			vinfo->vi_end = le64_to_cpu(entry->de_end);
456			vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr);
457		}
458		kunmap_atomic(kaddr);
459		brelse(entry_bh);
460	}
461
462	return nvi;
463}
464
465/**
466 * nilfs_dat_read - read or get dat inode
467 * @sb: super block instance
468 * @entry_size: size of a dat entry
469 * @raw_inode: on-disk dat inode
470 * @inodep: buffer to store the inode
471 */
472int nilfs_dat_read(struct super_block *sb, size_t entry_size,
473		   struct nilfs_inode *raw_inode, struct inode **inodep)
474{
475	static struct lock_class_key dat_lock_key;
476	struct inode *dat;
477	struct nilfs_dat_info *di;
478	int err;
479
480	if (entry_size > sb->s_blocksize) {
481		nilfs_err(sb, "too large DAT entry size: %zu bytes",
482			  entry_size);
483		return -EINVAL;
484	} else if (entry_size < NILFS_MIN_DAT_ENTRY_SIZE) {
485		nilfs_err(sb, "too small DAT entry size: %zu bytes",
486			  entry_size);
487		return -EINVAL;
488	}
489
490	dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
491	if (unlikely(!dat))
492		return -ENOMEM;
493	if (!(dat->i_state & I_NEW))
494		goto out;
495
496	err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
497	if (err)
498		goto failed;
499
500	err = nilfs_palloc_init_blockgroup(dat, entry_size);
501	if (err)
502		goto failed;
503
504	di = NILFS_DAT_I(dat);
505	lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
506	nilfs_palloc_setup_cache(dat, &di->palloc_cache);
507	err = nilfs_mdt_setup_shadow_map(dat, &di->shadow);
508	if (err)
509		goto failed;
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}
v4.17
 
  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 */
 38struct nilfs_dat_info {
 39	struct nilfs_mdt_info mi;
 40	struct nilfs_palloc_cache palloc_cache;
 41	struct nilfs_shadow_map shadow;
 42};
 43
 44static inline struct nilfs_dat_info *NILFS_DAT_I(struct inode *dat)
 45{
 46	return (struct nilfs_dat_info *)NILFS_MDT(dat);
 47}
 48
 49static 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
 56static 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
 64static void nilfs_dat_abort_entry(struct inode *dat,
 65				  struct nilfs_palloc_req *req)
 66{
 67	brelse(req->pr_entry_bh);
 68}
 69
 70int 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
 85void 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
102void 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
108static 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
126int 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
135void 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
151int 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
181void 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
207void 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
226int 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
241void 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
249void 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 */
271int 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 */
301int 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 */
322int 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 */
392int 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
428ssize_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 */
474int 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}