[mirror_ubuntu-artful-kernel.git] / fs / nilfs2 / dat.c

/*
 * dat.c - NILFS disk address translation.
 *
 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Written by Koji Sato <koji@osrg.net>.
 */

#include <linux/types.h>
#include <linux/buffer_head.h>
#include <linux/string.h>
#include <linux/errno.h>
#include "nilfs.h"
#include "mdt.h"
#include "alloc.h"
#include "dat.h"


#define NILFS_CNO_MIN	((__u64)1)
#define NILFS_CNO_MAX	(~(__u64)0)

static int nilfs_dat_prepare_entry(struct inode *dat,
				   struct nilfs_palloc_req *req, int create)
{
	return nilfs_palloc_get_entry_block(dat, req->pr_entry_nr,
					    create, &req->pr_entry_bh);
}

static void nilfs_dat_commit_entry(struct inode *dat,
				   struct nilfs_palloc_req *req)
{
	nilfs_mdt_mark_buffer_dirty(req->pr_entry_bh);
	nilfs_mdt_mark_dirty(dat);
	brelse(req->pr_entry_bh);
}

static void nilfs_dat_abort_entry(struct inode *dat,
				  struct nilfs_palloc_req *req)
{
	brelse(req->pr_entry_bh);
}

int nilfs_dat_prepare_alloc(struct inode *dat, struct nilfs_palloc_req *req)
{
	int ret;

	ret = nilfs_palloc_prepare_alloc_entry(dat, req);
	if (ret < 0)
		return ret;

	ret = nilfs_dat_prepare_entry(dat, req, 1);
	if (ret < 0)
		nilfs_palloc_abort_alloc_entry(dat, req);

	return ret;
}

void nilfs_dat_commit_alloc(struct inode *dat, struct nilfs_palloc_req *req)
{
	struct nilfs_dat_entry *entry;
	void *kaddr;

	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
					     req->pr_entry_bh, kaddr);
	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
	entry->de_end = cpu_to_le64(NILFS_CNO_MAX);
	entry->de_blocknr = cpu_to_le64(0);
	kunmap_atomic(kaddr, KM_USER0);

	nilfs_palloc_commit_alloc_entry(dat, req);
	nilfs_dat_commit_entry(dat, req);
}

void nilfs_dat_abort_alloc(struct inode *dat, struct nilfs_palloc_req *req)
{
	nilfs_dat_abort_entry(dat, req);
	nilfs_palloc_abort_alloc_entry(dat, req);
}

int nilfs_dat_prepare_free(struct inode *dat, struct nilfs_palloc_req *req)
{
	int ret;

	ret = nilfs_palloc_prepare_free_entry(dat, req);
	if (ret < 0)
		return ret;
	ret = nilfs_dat_prepare_entry(dat, req, 0);
	if (ret < 0) {
		nilfs_palloc_abort_free_entry(dat, req);
		return ret;
	}
	return 0;
}

void nilfs_dat_commit_free(struct inode *dat, struct nilfs_palloc_req *req)
{
	struct nilfs_dat_entry *entry;
	void *kaddr;

	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
					     req->pr_entry_bh, kaddr);
	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
	entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
	entry->de_blocknr = cpu_to_le64(0);
	kunmap_atomic(kaddr, KM_USER0);

	nilfs_dat_commit_entry(dat, req);
	nilfs_palloc_commit_free_entry(dat, req);
}

void nilfs_dat_abort_free(struct inode *dat, struct nilfs_palloc_req *req)
{
	nilfs_dat_abort_entry(dat, req);
	nilfs_palloc_abort_free_entry(dat, req);
}

int nilfs_dat_prepare_start(struct inode *dat, struct nilfs_palloc_req *req)
{
	int ret;

	ret = nilfs_dat_prepare_entry(dat, req, 0);
	BUG_ON(ret == -ENOENT);
	return ret;
}

void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req,
			    sector_t blocknr)
{
	struct nilfs_dat_entry *entry;
	void *kaddr;

	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
					     req->pr_entry_bh, kaddr);
	entry->de_start = cpu_to_le64(nilfs_mdt_cno(dat));
	if (entry->de_blocknr != cpu_to_le64(0) ||
	    entry->de_end != cpu_to_le64(NILFS_CNO_MAX)) {
		printk(KERN_CRIT
		       "%s: vbn = %llu, start = %llu, end = %llu, pbn = %llu\n",
		       __func__, (unsigned long long)req->pr_entry_nr,
		       (unsigned long long)le64_to_cpu(entry->de_start),
		       (unsigned long long)le64_to_cpu(entry->de_end),
		       (unsigned long long)le64_to_cpu(entry->de_blocknr));
		BUG();
	}
	entry->de_blocknr = cpu_to_le64(blocknr);
	kunmap_atomic(kaddr, KM_USER0);

	nilfs_dat_commit_entry(dat, req);
}

void nilfs_dat_abort_start(struct inode *dat, struct nilfs_palloc_req *req)
{
	nilfs_dat_abort_entry(dat, req);
}

int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req)
{
	struct nilfs_dat_entry *entry;
	__u64 start;
	sector_t blocknr;
	void *kaddr;
	int ret;

	ret = nilfs_dat_prepare_entry(dat, req, 0);
	if (ret < 0) {
		BUG_ON(ret == -ENOENT);
		return ret;
	}

	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
					     req->pr_entry_bh, kaddr);
	start = le64_to_cpu(entry->de_start);
	blocknr = le64_to_cpu(entry->de_blocknr);
	kunmap_atomic(kaddr, KM_USER0);

	if (blocknr == 0) {
		ret = nilfs_palloc_prepare_free_entry(dat, req);
		if (ret < 0) {
			nilfs_dat_abort_entry(dat, req);
			return ret;
		}
	}

	return 0;
}

void nilfs_dat_commit_end(struct inode *dat, struct nilfs_palloc_req *req,
			  int dead)
{
	struct nilfs_dat_entry *entry;
	__u64 start, end;
	sector_t blocknr;
	void *kaddr;

	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
					     req->pr_entry_bh, kaddr);
	end = start = le64_to_cpu(entry->de_start);
	if (!dead) {
		end = nilfs_mdt_cno(dat);
		BUG_ON(start > end);
	}
	entry->de_end = cpu_to_le64(end);
	blocknr = le64_to_cpu(entry->de_blocknr);
	kunmap_atomic(kaddr, KM_USER0);

	if (blocknr == 0)
		nilfs_dat_commit_free(dat, req);
	else
		nilfs_dat_commit_entry(dat, req);
}

void nilfs_dat_abort_end(struct inode *dat, struct nilfs_palloc_req *req)
{
	struct nilfs_dat_entry *entry;
	__u64 start;
	sector_t blocknr;
	void *kaddr;

	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
					     req->pr_entry_bh, kaddr);
	start = le64_to_cpu(entry->de_start);
	blocknr = le64_to_cpu(entry->de_blocknr);
	kunmap_atomic(kaddr, KM_USER0);

	if (start == nilfs_mdt_cno(dat) && blocknr == 0)
		nilfs_palloc_abort_free_entry(dat, req);
	nilfs_dat_abort_entry(dat, req);
}

/**
 * nilfs_dat_mark_dirty -
 * @dat: DAT file inode
 * @vblocknr: virtual block number
 *
 * Description:
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 */
int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
{
	struct nilfs_palloc_req req;
	int ret;

	req.pr_entry_nr = vblocknr;
	ret = nilfs_dat_prepare_entry(dat, &req, 0);
	if (ret == 0)
		nilfs_dat_commit_entry(dat, &req);
	return ret;
}

/**
 * nilfs_dat_freev - free virtual block numbers
 * @dat: DAT file inode
 * @vblocknrs: array of virtual block numbers
 * @nitems: number of virtual block numbers
 *
 * Description: nilfs_dat_freev() frees the virtual block numbers specified by
 * @vblocknrs and @nitems.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * nagative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 *
 * %-ENOENT - The virtual block number have not been allocated.
 */
int nilfs_dat_freev(struct inode *dat, __u64 *vblocknrs, size_t nitems)
{
	return nilfs_palloc_freev(dat, vblocknrs, nitems);
}

/**
 * nilfs_dat_move - change a block number
 * @dat: DAT file inode
 * @vblocknr: virtual block number
 * @blocknr: block number
 *
 * Description: nilfs_dat_move() changes the block number associated with
 * @vblocknr to @blocknr.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 */
int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
{
	struct buffer_head *entry_bh;
	struct nilfs_dat_entry *entry;
	void *kaddr;
	int ret;

	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
	if (ret < 0)
		return ret;
	kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
	if (entry->de_blocknr == cpu_to_le64(0)) {
		printk(KERN_CRIT "%s: vbn = %llu, [%llu, %llu)\n", __func__,
		       (unsigned long long)vblocknr,
		       (unsigned long long)le64_to_cpu(entry->de_start),
		       (unsigned long long)le64_to_cpu(entry->de_end));
		BUG();
	}
	BUG_ON(blocknr == 0);
	entry->de_blocknr = cpu_to_le64(blocknr);
	kunmap_atomic(kaddr, KM_USER0);

	nilfs_mdt_mark_buffer_dirty(entry_bh);
	nilfs_mdt_mark_dirty(dat);

	brelse(entry_bh);

	return 0;
}

/**
 * nilfs_dat_translate - translate a virtual block number to a block number
 * @dat: DAT file inode
 * @vblocknr: virtual block number
 * @blocknrp: pointer to a block number
 *
 * Description: nilfs_dat_translate() maps the virtual block number @vblocknr
 * to the corresponding block number.
 *
 * Return Value: On success, 0 is returned and the block number associated
 * with @vblocknr is stored in the place pointed by @blocknrp. On error, one
 * of the following negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 *
 * %-ENOENT - A block number associated with @vblocknr does not exist.
 */
int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp)
{
	struct buffer_head *entry_bh;
	struct nilfs_dat_entry *entry;
	sector_t blocknr;
	void *kaddr;
	int ret;

	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
	if (ret < 0)
		return ret;

	kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
	blocknr = le64_to_cpu(entry->de_blocknr);
	if (blocknr == 0) {
		ret = -ENOENT;
		goto out;
	}
	if (blocknrp != NULL)
		*blocknrp = blocknr;

 out:
	kunmap_atomic(kaddr, KM_USER0);
	brelse(entry_bh);
	return ret;
}

ssize_t nilfs_dat_get_vinfo(struct inode *dat, struct nilfs_vinfo *vinfo,
			    size_t nvi)
{
	struct buffer_head *entry_bh;
	struct nilfs_dat_entry *entry;
	__u64 first, last;
	void *kaddr;
	unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
	int i, j, n, ret;

	for (i = 0; i < nvi; i += n) {
		ret = nilfs_palloc_get_entry_block(dat, vinfo[i].vi_vblocknr,
						   0, &entry_bh);
		if (ret < 0)
			return ret;
		kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
		/* last virtual block number in this block */
		first = vinfo[i].vi_vblocknr;
		do_div(first, entries_per_block);
		first *= entries_per_block;
		last = first + entries_per_block - 1;
		for (j = i, n = 0;
		     j < nvi && vinfo[j].vi_vblocknr >= first &&
			     vinfo[j].vi_vblocknr <= last;
		     j++, n++) {
			entry = nilfs_palloc_block_get_entry(
				dat, vinfo[j].vi_vblocknr, entry_bh, kaddr);
			vinfo[j].vi_start = le64_to_cpu(entry->de_start);
			vinfo[j].vi_end = le64_to_cpu(entry->de_end);
			vinfo[j].vi_blocknr = le64_to_cpu(entry->de_blocknr);
		}
		kunmap_atomic(kaddr, KM_USER0);
		brelse(entry_bh);
	}

	return nvi;
}
Commit	Line	Data
a17564f5 KS	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	static int nilfs_dat_prepare_entry(struct inode *dat,
	37	struct nilfs_palloc_req *req, int create)
	38	{
	39	return nilfs_palloc_get_entry_block(dat, req->pr_entry_nr,
	40	create, &req->pr_entry_bh);
	41	}
	42
	43	static void nilfs_dat_commit_entry(struct inode *dat,
	44	struct nilfs_palloc_req *req)
	45	{
	46	nilfs_mdt_mark_buffer_dirty(req->pr_entry_bh);
	47	nilfs_mdt_mark_dirty(dat);
	48	brelse(req->pr_entry_bh);
	49	}
	50
	51	static void nilfs_dat_abort_entry(struct inode *dat,
	52	struct nilfs_palloc_req *req)
	53	{
	54	brelse(req->pr_entry_bh);
	55	}
	56
	57	int nilfs_dat_prepare_alloc(struct inode dat, struct nilfs_palloc_req req)
	58	{
	59	int ret;
	60
	61	ret = nilfs_palloc_prepare_alloc_entry(dat, req);
	62	if (ret < 0)
	63	return ret;
	64
65	ret = nilfs_dat_prepare_entry(dat, req, 1);
66	if (ret < 0)
67	nilfs_palloc_abort_alloc_entry(dat, req);
68
69	return ret;
70	}
71
72	void nilfs_dat_commit_alloc(struct inode dat, struct nilfs_palloc_req req)
73	{
74	struct nilfs_dat_entry *entry;
75	void *kaddr;
76
77	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
78	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
79	req->pr_entry_bh, kaddr);
80	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
81	entry->de_end = cpu_to_le64(NILFS_CNO_MAX);
82	entry->de_blocknr = cpu_to_le64(0);
83	kunmap_atomic(kaddr, KM_USER0);
84
85	nilfs_palloc_commit_alloc_entry(dat, req);
86	nilfs_dat_commit_entry(dat, req);
87	}
88
89	void nilfs_dat_abort_alloc(struct inode dat, struct nilfs_palloc_req req)
90	{
91	nilfs_dat_abort_entry(dat, req);
92	nilfs_palloc_abort_alloc_entry(dat, req);
93	}
94
95	int nilfs_dat_prepare_free(struct inode dat, struct nilfs_palloc_req req)
96	{
97	int ret;
98
99	ret = nilfs_palloc_prepare_free_entry(dat, req);
100	if (ret < 0)
101	return ret;
102	ret = nilfs_dat_prepare_entry(dat, req, 0);
103	if (ret < 0) {
104	nilfs_palloc_abort_free_entry(dat, req);
105	return ret;
106	}
107	return 0;
108	}
109
110	void nilfs_dat_commit_free(struct inode dat, struct nilfs_palloc_req req)
111	{
112	struct nilfs_dat_entry *entry;
113	void *kaddr;
114
115	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
116	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
117	req->pr_entry_bh, kaddr);
118	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
119	entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
120	entry->de_blocknr = cpu_to_le64(0);
121	kunmap_atomic(kaddr, KM_USER0);
122
123	nilfs_dat_commit_entry(dat, req);
124	nilfs_palloc_commit_free_entry(dat, req);
125	}
126
127	void nilfs_dat_abort_free(struct inode dat, struct nilfs_palloc_req req)
128	{
129	nilfs_dat_abort_entry(dat, req);
130	nilfs_palloc_abort_free_entry(dat, req);
131	}
132
133	int nilfs_dat_prepare_start(struct inode dat, struct nilfs_palloc_req req)
134	{
135	int ret;
136
137	ret = nilfs_dat_prepare_entry(dat, req, 0);
138	BUG_ON(ret == -ENOENT);
139	return ret;
140	}
141
142	void 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_atomic(req->pr_entry_bh->b_page, KM_USER0);
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	if (entry->de_blocknr != cpu_to_le64(0) \|\|
153	entry->de_end != cpu_to_le64(NILFS_CNO_MAX)) {
154	printk(KERN_CRIT
155	"%s: vbn = %llu, start = %llu, end = %llu, pbn = %llu\n",
156	__func__, (unsigned long long)req->pr_entry_nr,
157	(unsigned long long)le64_to_cpu(entry->de_start),
158	(unsigned long long)le64_to_cpu(entry->de_end),
159	(unsigned long long)le64_to_cpu(entry->de_blocknr));
160	BUG();
161	}
162	entry->de_blocknr = cpu_to_le64(blocknr);
163	kunmap_atomic(kaddr, KM_USER0);
164
165	nilfs_dat_commit_entry(dat, req);
166	}
167
168	void nilfs_dat_abort_start(struct inode dat, struct nilfs_palloc_req req)
169	{
170	nilfs_dat_abort_entry(dat, req);
171	}
172
173	int nilfs_dat_prepare_end(struct inode dat, struct nilfs_palloc_req req)
174	{
175	struct nilfs_dat_entry *entry;
176	__u64 start;
177	sector_t blocknr;
178	void *kaddr;
179	int ret;
180
181	ret = nilfs_dat_prepare_entry(dat, req, 0);
182	if (ret < 0) {
183	BUG_ON(ret == -ENOENT);
184	return ret;
185	}
186
187	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
188	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
189	req->pr_entry_bh, kaddr);
190	start = le64_to_cpu(entry->de_start);
191	blocknr = le64_to_cpu(entry->de_blocknr);
192	kunmap_atomic(kaddr, KM_USER0);
193
194	if (blocknr == 0) {
195	ret = nilfs_palloc_prepare_free_entry(dat, req);
196	if (ret < 0) {
197	nilfs_dat_abort_entry(dat, req);
198	return ret;
199	}
200	}
201
202	return 0;
203	}
204
205	void nilfs_dat_commit_end(struct inode dat, struct nilfs_palloc_req req,
206	int dead)
207	{
208	struct nilfs_dat_entry *entry;
209	__u64 start, end;
210	sector_t blocknr;
211	void *kaddr;
212
213	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
214	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
215	req->pr_entry_bh, kaddr);
216	end = start = le64_to_cpu(entry->de_start);
217	if (!dead) {
218	end = nilfs_mdt_cno(dat);
219	BUG_ON(start > end);
220	}
221	entry->de_end = cpu_to_le64(end);
222	blocknr = le64_to_cpu(entry->de_blocknr);
223	kunmap_atomic(kaddr, KM_USER0);
224
225	if (blocknr == 0)
226	nilfs_dat_commit_free(dat, req);
227	else
228	nilfs_dat_commit_entry(dat, req);
229	}
230
231	void nilfs_dat_abort_end(struct inode dat, struct nilfs_palloc_req req)
232	{
233	struct nilfs_dat_entry *entry;
234	__u64 start;
235	sector_t blocknr;
236	void *kaddr;
237
238	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
239	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
240	req->pr_entry_bh, kaddr);
241	start = le64_to_cpu(entry->de_start);
242	blocknr = le64_to_cpu(entry->de_blocknr);
243	kunmap_atomic(kaddr, KM_USER0);
244
245	if (start == nilfs_mdt_cno(dat) && blocknr == 0)
246	nilfs_palloc_abort_free_entry(dat, req);
247	nilfs_dat_abort_entry(dat, req);
248	}
249
250	/**
251	* nilfs_dat_mark_dirty -
252	* @dat: DAT file inode
253	* @vblocknr: virtual block number
254	*
255	* Description:
256	*
257	* Return Value: On success, 0 is returned. On error, one of the following
258	* negative error codes is returned.
259	*
260	* %-EIO - I/O error.
261	*
262	* %-ENOMEM - Insufficient amount of memory available.
263	*/
264	int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
265	{
266	struct nilfs_palloc_req req;
267	int ret;
268
269	req.pr_entry_nr = vblocknr;
270	ret = nilfs_dat_prepare_entry(dat, &req, 0);
271	if (ret == 0)
272	nilfs_dat_commit_entry(dat, &req);
273	return ret;
274	}
275
276	/**
277	* nilfs_dat_freev - free virtual block numbers
278	* @dat: DAT file inode
279	* @vblocknrs: array of virtual block numbers
280	* @nitems: number of virtual block numbers
281	*
282	* Description: nilfs_dat_freev() frees the virtual block numbers specified by
283	* @vblocknrs and @nitems.
284	*
285	* Return Value: On success, 0 is returned. On error, one of the following
286	* nagative error codes is returned.
287	*
288	* %-EIO - I/O error.
289	*
290	* %-ENOMEM - Insufficient amount of memory available.
291	*
292	* %-ENOENT - The virtual block number have not been allocated.
293	*/
294	int nilfs_dat_freev(struct inode dat, __u64 vblocknrs, size_t nitems)
295	{
296	return nilfs_palloc_freev(dat, vblocknrs, nitems);
297	}
298
299	/**
300	* nilfs_dat_move - change a block number
301	* @dat: DAT file inode
302	* @vblocknr: virtual block number
303	* @blocknr: block number
304	*
305	* Description: nilfs_dat_move() changes the block number associated with
306	* @vblocknr to @blocknr.
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	int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
316	{
317	struct buffer_head *entry_bh;
318	struct nilfs_dat_entry *entry;
319	void *kaddr;
320	int ret;
321
322	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
323	if (ret < 0)
324	return ret;
325	kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
326	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
327	if (entry->de_blocknr == cpu_to_le64(0)) {
328	printk(KERN_CRIT "%s: vbn = %llu, [%llu, %llu)\n", __func__,
329	(unsigned long long)vblocknr,
330	(unsigned long long)le64_to_cpu(entry->de_start),
331	(unsigned long long)le64_to_cpu(entry->de_end));
332	BUG();
333	}
334	BUG_ON(blocknr == 0);
335	entry->de_blocknr = cpu_to_le64(blocknr);
336	kunmap_atomic(kaddr, KM_USER0);
337
338	nilfs_mdt_mark_buffer_dirty(entry_bh);
339	nilfs_mdt_mark_dirty(dat);
340
341	brelse(entry_bh);
342
343	return 0;
344	}
345
346	/**
347	* nilfs_dat_translate - translate a virtual block number to a block number
348	* @dat: DAT file inode
349	* @vblocknr: virtual block number
350	* @blocknrp: pointer to a block number
351	*
352	* Description: nilfs_dat_translate() maps the virtual block number @vblocknr
353	* to the corresponding block number.
354	*
355	* Return Value: On success, 0 is returned and the block number associated
356	* with @vblocknr is stored in the place pointed by @blocknrp. On error, one
357	* of the following negative error codes is returned.
358	*
359	* %-EIO - I/O error.
360	*
361	* %-ENOMEM - Insufficient amount of memory available.
362	*
363	* %-ENOENT - A block number associated with @vblocknr does not exist.
364	*/
365	int nilfs_dat_translate(struct inode dat, __u64 vblocknr, sector_t blocknrp)
366	{
367	struct buffer_head *entry_bh;
368	struct nilfs_dat_entry *entry;
369	sector_t blocknr;
370	void *kaddr;
371	int ret;
372
373	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
374	if (ret < 0)
375	return ret;
376
377	kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
378	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
379	blocknr = le64_to_cpu(entry->de_blocknr);
380	if (blocknr == 0) {
381	ret = -ENOENT;
382	goto out;
383	}
384	if (blocknrp != NULL)
385	*blocknrp = blocknr;
386
387	out:
388	kunmap_atomic(kaddr, KM_USER0);
389	brelse(entry_bh);
390	return ret;
391	}
392
393	ssize_t nilfs_dat_get_vinfo(struct inode dat, struct nilfs_vinfo vinfo,
394	size_t nvi)
395	{
396	struct buffer_head *entry_bh;
397	struct nilfs_dat_entry *entry;
398	__u64 first, last;
399	void *kaddr;
400	unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
401	int i, j, n, ret;
402
403	for (i = 0; i < nvi; i += n) {
404	ret = nilfs_palloc_get_entry_block(dat, vinfo[i].vi_vblocknr,
405	0, &entry_bh);
406	if (ret < 0)
407	return ret;
408	kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
409	/* last virtual block number in this block */
410	first = vinfo[i].vi_vblocknr;
411	do_div(first, entries_per_block);
412	first *= entries_per_block;
413	last = first + entries_per_block - 1;
414	for (j = i, n = 0;
415	j < nvi && vinfo[j].vi_vblocknr >= first &&
416	vinfo[j].vi_vblocknr <= last;
417	j++, n++) {
418	entry = nilfs_palloc_block_get_entry(
419	dat, vinfo[j].vi_vblocknr, entry_bh, kaddr);
420	vinfo[j].vi_start = le64_to_cpu(entry->de_start);
421	vinfo[j].vi_end = le64_to_cpu(entry->de_end);
422	vinfo[j].vi_blocknr = le64_to_cpu(entry->de_blocknr);
423	}
424	kunmap_atomic(kaddr, KM_USER0);
425	brelse(entry_bh);
426	}
427
428	return nvi;
429	}