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v4.10.11
  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}
v3.5.6
  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
 
 
 
 
 
 
 36struct nilfs_dat_info {
 37	struct nilfs_mdt_info mi;
 38	struct nilfs_palloc_cache palloc_cache;
 39	struct nilfs_shadow_map shadow;
 40};
 41
 42static inline struct nilfs_dat_info *NILFS_DAT_I(struct inode *dat)
 43{
 44	return (struct nilfs_dat_info *)NILFS_MDT(dat);
 45}
 46
 47static int nilfs_dat_prepare_entry(struct inode *dat,
 48				   struct nilfs_palloc_req *req, int create)
 49{
 50	return nilfs_palloc_get_entry_block(dat, req->pr_entry_nr,
 51					    create, &req->pr_entry_bh);
 52}
 53
 54static void nilfs_dat_commit_entry(struct inode *dat,
 55				   struct nilfs_palloc_req *req)
 56{
 57	mark_buffer_dirty(req->pr_entry_bh);
 58	nilfs_mdt_mark_dirty(dat);
 59	brelse(req->pr_entry_bh);
 60}
 61
 62static void nilfs_dat_abort_entry(struct inode *dat,
 63				  struct nilfs_palloc_req *req)
 64{
 65	brelse(req->pr_entry_bh);
 66}
 67
 68int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
 69{
 70	int ret;
 71
 72	ret = nilfs_palloc_prepare_alloc_entry(dat, req);
 73	if (ret < 0)
 74		return ret;
 75
 76	ret = nilfs_dat_prepare_entry(dat, req, 1);
 77	if (ret < 0)
 78		nilfs_palloc_abort_alloc_entry(dat, req);
 79
 80	return ret;
 81}
 82
 83void nilfs_dat_commit_alloc(struct inode *dat, struct nilfs_palloc_req *req)
 84{
 85	struct nilfs_dat_entry *entry;
 86	void *kaddr;
 87
 88	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
 89	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
 90					     req->pr_entry_bh, kaddr);
 91	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
 92	entry->de_end = cpu_to_le64(NILFS_CNO_MAX);
 93	entry->de_blocknr = cpu_to_le64(0);
 94	kunmap_atomic(kaddr);
 95
 96	nilfs_palloc_commit_alloc_entry(dat, req);
 97	nilfs_dat_commit_entry(dat, req);
 98}
 99
100void nilfs_dat_abort_alloc(struct inode *dat, struct nilfs_palloc_req *req)
101{
102	nilfs_dat_abort_entry(dat, req);
103	nilfs_palloc_abort_alloc_entry(dat, req);
104}
105
106static void nilfs_dat_commit_free(struct inode *dat,
107				  struct nilfs_palloc_req *req)
108{
109	struct nilfs_dat_entry *entry;
110	void *kaddr;
111
112	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
113	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
114					     req->pr_entry_bh, kaddr);
115	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
116	entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
117	entry->de_blocknr = cpu_to_le64(0);
118	kunmap_atomic(kaddr);
119
120	nilfs_dat_commit_entry(dat, req);
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	__u64 start;
153	sector_t blocknr;
154	void *kaddr;
155	int ret;
156
157	ret = nilfs_dat_prepare_entry(dat, req, 0);
158	if (ret < 0) {
159		WARN_ON(ret == -ENOENT);
160		return ret;
161	}
162
163	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
164	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
165					     req->pr_entry_bh, kaddr);
166	start = le64_to_cpu(entry->de_start);
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		printk(KERN_CRIT "%s: vbn = %llu, [%llu, %llu)\n", __func__,
353		       (unsigned long long)vblocknr,
354		       (unsigned long long)le64_to_cpu(entry->de_start),
355		       (unsigned long long)le64_to_cpu(entry->de_end));
 
356		kunmap_atomic(kaddr);
357		brelse(entry_bh);
358		return -EINVAL;
359	}
360	WARN_ON(blocknr == 0);
361	entry->de_blocknr = cpu_to_le64(blocknr);
362	kunmap_atomic(kaddr);
363
364	mark_buffer_dirty(entry_bh);
365	nilfs_mdt_mark_dirty(dat);
366
367	brelse(entry_bh);
368
369	return 0;
370}
371
372/**
373 * nilfs_dat_translate - translate a virtual block number to a block number
374 * @dat: DAT file inode
375 * @vblocknr: virtual block number
376 * @blocknrp: pointer to a block number
377 *
378 * Description: nilfs_dat_translate() maps the virtual block number @vblocknr
379 * to the corresponding block number.
380 *
381 * Return Value: On success, 0 is returned and the block number associated
382 * with @vblocknr is stored in the place pointed by @blocknrp. On error, one
383 * of the following negative error codes is returned.
384 *
385 * %-EIO - I/O error.
386 *
387 * %-ENOMEM - Insufficient amount of memory available.
388 *
389 * %-ENOENT - A block number associated with @vblocknr does not exist.
390 */
391int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
392{
393	struct buffer_head *entry_bh, *bh;
394	struct nilfs_dat_entry *entry;
395	sector_t blocknr;
396	void *kaddr;
397	int ret;
398
399	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
400	if (ret < 0)
401		return ret;
402
403	if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
404		bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
405		if (bh) {
406			WARN_ON(!buffer_uptodate(bh));
407			brelse(entry_bh);
408			entry_bh = bh;
409		}
410	}
411
412	kaddr = kmap_atomic(entry_bh->b_page);
413	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
414	blocknr = le64_to_cpu(entry->de_blocknr);
415	if (blocknr == 0) {
416		ret = -ENOENT;
417		goto out;
418	}
419	*blocknrp = blocknr;
420
421 out:
422	kunmap_atomic(kaddr);
423	brelse(entry_bh);
424	return ret;
425}
426
427ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned visz,
428			    size_t nvi)
429{
430	struct buffer_head *entry_bh;
431	struct nilfs_dat_entry *entry;
432	struct nilfs_vinfo *vinfo = buf;
433	__u64 first, last;
434	void *kaddr;
435	unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
436	int i, j, n, ret;
437
438	for (i = 0; i < nvi; i += n) {
439		ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
440						   0, &entry_bh);
441		if (ret < 0)
442			return ret;
443		kaddr = kmap_atomic(entry_bh->b_page);
444		/* last virtual block number in this block */
445		first = vinfo->vi_vblocknr;
446		do_div(first, entries_per_block);
447		first *= entries_per_block;
448		last = first + entries_per_block - 1;
449		for (j = i, n = 0;
450		     j < nvi && vinfo->vi_vblocknr >= first &&
451			     vinfo->vi_vblocknr <= last;
452		     j++, n++, vinfo = (void *)vinfo + visz) {
453			entry = nilfs_palloc_block_get_entry(
454				dat, vinfo->vi_vblocknr, entry_bh, kaddr);
455			vinfo->vi_start = le64_to_cpu(entry->de_start);
456			vinfo->vi_end = le64_to_cpu(entry->de_end);
457			vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr);
458		}
459		kunmap_atomic(kaddr);
460		brelse(entry_bh);
461	}
462
463	return nvi;
464}
465
466/**
467 * nilfs_dat_read - read or get dat inode
468 * @sb: super block instance
469 * @entry_size: size of a dat entry
470 * @raw_inode: on-disk dat inode
471 * @inodep: buffer to store the inode
472 */
473int nilfs_dat_read(struct super_block *sb, size_t entry_size,
474		   struct nilfs_inode *raw_inode, struct inode **inodep)
475{
476	static struct lock_class_key dat_lock_key;
477	struct inode *dat;
478	struct nilfs_dat_info *di;
479	int err;
 
 
 
 
 
 
 
 
 
 
480
481	dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
482	if (unlikely(!dat))
483		return -ENOMEM;
484	if (!(dat->i_state & I_NEW))
485		goto out;
486
487	err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
488	if (err)
489		goto failed;
490
491	err = nilfs_palloc_init_blockgroup(dat, entry_size);
492	if (err)
493		goto failed;
494
495	di = NILFS_DAT_I(dat);
496	lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
497	nilfs_palloc_setup_cache(dat, &di->palloc_cache);
498	nilfs_mdt_setup_shadow_map(dat, &di->shadow);
499
500	err = nilfs_read_inode_common(dat, raw_inode);
501	if (err)
502		goto failed;
503
504	unlock_new_inode(dat);
505 out:
506	*inodep = dat;
507	return 0;
508 failed:
509	iget_failed(dat);
510	return err;
511}