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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}
v3.15
 
  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	__u64 start;
159	sector_t blocknr;
160	void *kaddr;
161	int ret;
162
163	ret = nilfs_dat_prepare_entry(dat, req, 0);
164	if (ret < 0) {
165		WARN_ON(ret == -ENOENT);
166		return ret;
167	}
168
169	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
170	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
171					     req->pr_entry_bh, kaddr);
172	start = le64_to_cpu(entry->de_start);
173	blocknr = le64_to_cpu(entry->de_blocknr);
174	kunmap_atomic(kaddr);
175
176	if (blocknr == 0) {
177		ret = nilfs_palloc_prepare_free_entry(dat, req);
178		if (ret < 0) {
179			nilfs_dat_abort_entry(dat, req);
180			return ret;
181		}
182	}
183
184	return 0;
185}
186
187void nilfs_dat_commit_end(struct inode *dat, struct nilfs_palloc_req *req,
188			  int dead)
189{
190	struct nilfs_dat_entry *entry;
191	__u64 start, end;
192	sector_t blocknr;
193	void *kaddr;
194
195	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
196	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
197					     req->pr_entry_bh, kaddr);
198	end = start = le64_to_cpu(entry->de_start);
199	if (!dead) {
200		end = nilfs_mdt_cno(dat);
201		WARN_ON(start > end);
202	}
203	entry->de_end = cpu_to_le64(end);
204	blocknr = le64_to_cpu(entry->de_blocknr);
205	kunmap_atomic(kaddr);
206
207	if (blocknr == 0)
208		nilfs_dat_commit_free(dat, req);
209	else
210		nilfs_dat_commit_entry(dat, req);
211}
212
213void nilfs_dat_abort_end(struct inode *dat, struct nilfs_palloc_req *req)
214{
215	struct nilfs_dat_entry *entry;
216	__u64 start;
217	sector_t blocknr;
218	void *kaddr;
219
220	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
221	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
222					     req->pr_entry_bh, kaddr);
223	start = le64_to_cpu(entry->de_start);
224	blocknr = le64_to_cpu(entry->de_blocknr);
225	kunmap_atomic(kaddr);
226
227	if (start == nilfs_mdt_cno(dat) && blocknr == 0)
228		nilfs_palloc_abort_free_entry(dat, req);
229	nilfs_dat_abort_entry(dat, req);
230}
231
232int nilfs_dat_prepare_update(struct inode *dat,
233			     struct nilfs_palloc_req *oldreq,
234			     struct nilfs_palloc_req *newreq)
235{
236	int ret;
237
238	ret = nilfs_dat_prepare_end(dat, oldreq);
239	if (!ret) {
240		ret = nilfs_dat_prepare_alloc(dat, newreq);
241		if (ret < 0)
242			nilfs_dat_abort_end(dat, oldreq);
243	}
244	return ret;
245}
246
247void nilfs_dat_commit_update(struct inode *dat,
248			     struct nilfs_palloc_req *oldreq,
249			     struct nilfs_palloc_req *newreq, int dead)
250{
251	nilfs_dat_commit_end(dat, oldreq, dead);
252	nilfs_dat_commit_alloc(dat, newreq);
253}
254
255void nilfs_dat_abort_update(struct inode *dat,
256			    struct nilfs_palloc_req *oldreq,
257			    struct nilfs_palloc_req *newreq)
258{
259	nilfs_dat_abort_end(dat, oldreq);
260	nilfs_dat_abort_alloc(dat, newreq);
261}
262
263/**
264 * nilfs_dat_mark_dirty -
265 * @dat: DAT file inode
266 * @vblocknr: virtual block number
267 *
268 * Description:
269 *
270 * Return Value: On success, 0 is returned. On error, one of the following
271 * negative error codes is returned.
272 *
273 * %-EIO - I/O error.
274 *
275 * %-ENOMEM - Insufficient amount of memory available.
276 */
277int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
278{
279	struct nilfs_palloc_req req;
280	int ret;
281
282	req.pr_entry_nr = vblocknr;
283	ret = nilfs_dat_prepare_entry(dat, &req, 0);
284	if (ret == 0)
285		nilfs_dat_commit_entry(dat, &req);
286	return ret;
287}
288
289/**
290 * nilfs_dat_freev - free virtual block numbers
291 * @dat: DAT file inode
292 * @vblocknrs: array of virtual block numbers
293 * @nitems: number of virtual block numbers
294 *
295 * Description: nilfs_dat_freev() frees the virtual block numbers specified by
296 * @vblocknrs and @nitems.
297 *
298 * Return Value: On success, 0 is returned. On error, one of the following
299 * negative error codes is returned.
300 *
301 * %-EIO - I/O error.
302 *
303 * %-ENOMEM - Insufficient amount of memory available.
304 *
305 * %-ENOENT - The virtual block number have not been allocated.
306 */
307int nilfs_dat_freev(struct inode *dat, __u64 *vblocknrs, size_t nitems)
308{
309	return nilfs_palloc_freev(dat, vblocknrs, nitems);
310}
311
312/**
313 * nilfs_dat_move - change a block number
314 * @dat: DAT file inode
315 * @vblocknr: virtual block number
316 * @blocknr: block number
317 *
318 * Description: nilfs_dat_move() changes the block number associated with
319 * @vblocknr to @blocknr.
320 *
321 * Return Value: On success, 0 is returned. On error, one of the following
322 * negative error codes is returned.
323 *
324 * %-EIO - I/O error.
325 *
326 * %-ENOMEM - Insufficient amount of memory available.
327 */
328int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
329{
330	struct buffer_head *entry_bh;
331	struct nilfs_dat_entry *entry;
332	void *kaddr;
333	int ret;
334
335	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
336	if (ret < 0)
337		return ret;
338
339	/*
340	 * The given disk block number (blocknr) is not yet written to
341	 * the device at this point.
342	 *
343	 * To prevent nilfs_dat_translate() from returning the
344	 * uncommitted block number, this makes a copy of the entry
345	 * buffer and redirects nilfs_dat_translate() to the copy.
346	 */
347	if (!buffer_nilfs_redirected(entry_bh)) {
348		ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
349		if (ret) {
350			brelse(entry_bh);
351			return ret;
352		}
353	}
354
355	kaddr = kmap_atomic(entry_bh->b_page);
356	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
357	if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
358		printk(KERN_CRIT "%s: vbn = %llu, [%llu, %llu)\n", __func__,
359		       (unsigned long long)vblocknr,
360		       (unsigned long long)le64_to_cpu(entry->de_start),
361		       (unsigned long long)le64_to_cpu(entry->de_end));
 
362		kunmap_atomic(kaddr);
363		brelse(entry_bh);
364		return -EINVAL;
365	}
366	WARN_ON(blocknr == 0);
367	entry->de_blocknr = cpu_to_le64(blocknr);
368	kunmap_atomic(kaddr);
369
370	mark_buffer_dirty(entry_bh);
371	nilfs_mdt_mark_dirty(dat);
372
373	brelse(entry_bh);
374
375	return 0;
376}
377
378/**
379 * nilfs_dat_translate - translate a virtual block number to a block number
380 * @dat: DAT file inode
381 * @vblocknr: virtual block number
382 * @blocknrp: pointer to a block number
383 *
384 * Description: nilfs_dat_translate() maps the virtual block number @vblocknr
385 * to the corresponding block number.
386 *
387 * Return Value: On success, 0 is returned and the block number associated
388 * with @vblocknr is stored in the place pointed by @blocknrp. On error, one
389 * of the following negative error codes is returned.
390 *
391 * %-EIO - I/O error.
392 *
393 * %-ENOMEM - Insufficient amount of memory available.
394 *
395 * %-ENOENT - A block number associated with @vblocknr does not exist.
396 */
397int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
398{
399	struct buffer_head *entry_bh, *bh;
400	struct nilfs_dat_entry *entry;
401	sector_t blocknr;
402	void *kaddr;
403	int ret;
404
405	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
406	if (ret < 0)
407		return ret;
408
409	if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
410		bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
411		if (bh) {
412			WARN_ON(!buffer_uptodate(bh));
413			brelse(entry_bh);
414			entry_bh = bh;
415		}
416	}
417
418	kaddr = kmap_atomic(entry_bh->b_page);
419	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
420	blocknr = le64_to_cpu(entry->de_blocknr);
421	if (blocknr == 0) {
422		ret = -ENOENT;
423		goto out;
424	}
425	*blocknrp = blocknr;
426
427 out:
428	kunmap_atomic(kaddr);
429	brelse(entry_bh);
430	return ret;
431}
432
433ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned visz,
434			    size_t nvi)
435{
436	struct buffer_head *entry_bh;
437	struct nilfs_dat_entry *entry;
438	struct nilfs_vinfo *vinfo = buf;
439	__u64 first, last;
440	void *kaddr;
441	unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
442	int i, j, n, ret;
443
444	for (i = 0; i < nvi; i += n) {
445		ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
446						   0, &entry_bh);
447		if (ret < 0)
448			return ret;
449		kaddr = kmap_atomic(entry_bh->b_page);
450		/* last virtual block number in this block */
451		first = vinfo->vi_vblocknr;
452		do_div(first, entries_per_block);
453		first *= entries_per_block;
454		last = first + entries_per_block - 1;
455		for (j = i, n = 0;
456		     j < nvi && vinfo->vi_vblocknr >= first &&
457			     vinfo->vi_vblocknr <= last;
458		     j++, n++, vinfo = (void *)vinfo + visz) {
459			entry = nilfs_palloc_block_get_entry(
460				dat, vinfo->vi_vblocknr, entry_bh, kaddr);
461			vinfo->vi_start = le64_to_cpu(entry->de_start);
462			vinfo->vi_end = le64_to_cpu(entry->de_end);
463			vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr);
464		}
465		kunmap_atomic(kaddr);
466		brelse(entry_bh);
467	}
468
469	return nvi;
470}
471
472/**
473 * nilfs_dat_read - read or get dat inode
474 * @sb: super block instance
475 * @entry_size: size of a dat entry
476 * @raw_inode: on-disk dat inode
477 * @inodep: buffer to store the inode
478 */
479int nilfs_dat_read(struct super_block *sb, size_t entry_size,
480		   struct nilfs_inode *raw_inode, struct inode **inodep)
481{
482	static struct lock_class_key dat_lock_key;
483	struct inode *dat;
484	struct nilfs_dat_info *di;
485	int err;
486
487	if (entry_size > sb->s_blocksize) {
488		printk(KERN_ERR
489		       "NILFS: too large DAT entry size: %zu bytes.\n",
490		       entry_size);
491		return -EINVAL;
492	} else if (entry_size < NILFS_MIN_DAT_ENTRY_SIZE) {
493		printk(KERN_ERR
494		       "NILFS: too small DAT entry size: %zu bytes.\n",
495		       entry_size);
496		return -EINVAL;
497	}
498
499	dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
500	if (unlikely(!dat))
501		return -ENOMEM;
502	if (!(dat->i_state & I_NEW))
503		goto out;
504
505	err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
506	if (err)
507		goto failed;
508
509	err = nilfs_palloc_init_blockgroup(dat, entry_size);
510	if (err)
511		goto failed;
512
513	di = NILFS_DAT_I(dat);
514	lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
515	nilfs_palloc_setup_cache(dat, &di->palloc_cache);
516	nilfs_mdt_setup_shadow_map(dat, &di->shadow);
 
 
517
518	err = nilfs_read_inode_common(dat, raw_inode);
519	if (err)
520		goto failed;
521
522	unlock_new_inode(dat);
523 out:
524	*inodep = dat;
525	return 0;
526 failed:
527	iget_failed(dat);
528	return err;
529}