[GitHub/mt8127/android_kernel_alcatel_ttab.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)

struct nilfs_dat_info {
	struct nilfs_mdt_info mi;
	struct nilfs_palloc_cache palloc_cache;
	struct nilfs_shadow_map shadow;
};

static inline struct nilfs_dat_info *NILFS_DAT_I(struct inode *dat)
{
	return (struct nilfs_dat_info *)NILFS_MDT(dat);
}

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);
}

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);
}

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

	ret = nilfs_dat_prepare_entry(dat, req, 0);
	WARN_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));
	entry->de_blocknr = cpu_to_le64(blocknr);
	kunmap_atomic(kaddr, KM_USER0);

	nilfs_dat_commit_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) {
		WARN_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);
		WARN_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);
}

int nilfs_dat_prepare_update(struct inode *dat,
			     struct nilfs_palloc_req *oldreq,
			     struct nilfs_palloc_req *newreq)
{
	int ret;

	ret = nilfs_dat_prepare_end(dat, oldreq);
	if (!ret) {
		ret = nilfs_dat_prepare_alloc(dat, newreq);
		if (ret < 0)
			nilfs_dat_abort_end(dat, oldreq);
	}
	return ret;
}

void nilfs_dat_commit_update(struct inode *dat,
			     struct nilfs_palloc_req *oldreq,
			     struct nilfs_palloc_req *newreq, int dead)
{
	nilfs_dat_commit_end(dat, oldreq, dead);
	nilfs_dat_commit_alloc(dat, newreq);
}

void nilfs_dat_abort_update(struct inode *dat,
			    struct nilfs_palloc_req *oldreq,
			    struct nilfs_palloc_req *newreq)
{
	nilfs_dat_abort_end(dat, oldreq);
	nilfs_dat_abort_alloc(dat, newreq);
}

/**
 * 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
 * negative 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;

	/*
	 * The given disk block number (blocknr) is not yet written to
	 * the device at this point.
	 *
	 * To prevent nilfs_dat_translate() from returning the
	 * uncommited block number, this makes a copy of the entry
	 * buffer and redirects nilfs_dat_translate() to the copy.
	 */
	if (!buffer_nilfs_redirected(entry_bh)) {
		ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
		if (ret) {
			brelse(entry_bh);
			return ret;
		}
	}

	kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
	if (unlikely(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));
		kunmap_atomic(kaddr, KM_USER0);
		brelse(entry_bh);
		return -EINVAL;
	}
	WARN_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, *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;

	if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
		bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
		if (bh) {
			WARN_ON(!buffer_uptodate(bh));
			brelse(entry_bh);
			entry_bh = bh;
		}
	}

	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;
	}
	*blocknrp = blocknr;

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

ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned visz,
			    size_t nvi)
{
	struct buffer_head *entry_bh;
	struct nilfs_dat_entry *entry;
	struct nilfs_vinfo *vinfo = buf;
	__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->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->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->vi_vblocknr >= first &&
			     vinfo->vi_vblocknr <= last;
		     j++, n++, vinfo = (void *)vinfo + visz) {
			entry = nilfs_palloc_block_get_entry(
				dat, vinfo->vi_vblocknr, entry_bh, kaddr);
			vinfo->vi_start = le64_to_cpu(entry->de_start);
			vinfo->vi_end = le64_to_cpu(entry->de_end);
			vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr);
		}
		kunmap_atomic(kaddr, KM_USER0);
		brelse(entry_bh);
	}

	return nvi;
}

/**
 * nilfs_dat_read - read dat inode
 * @dat: dat inode
 * @raw_inode: on-disk dat inode
 */
int nilfs_dat_read(struct inode *dat, struct nilfs_inode *raw_inode)
{
	return nilfs_read_inode_common(dat, raw_inode);
}

/**
 * nilfs_dat_new - create dat file
 * @nilfs: nilfs object
 * @entry_size: size of a dat entry
 */
struct inode *nilfs_dat_new(struct the_nilfs *nilfs, size_t entry_size)
{
	static struct lock_class_key dat_lock_key;
	struct inode *dat;
	struct nilfs_dat_info *di;
	int err;

	dat = nilfs_mdt_new(nilfs, NULL, NILFS_DAT_INO, sizeof(*di));
	if (dat) {
		err = nilfs_palloc_init_blockgroup(dat, entry_size);
		if (unlikely(err)) {
			nilfs_mdt_destroy(dat);
			return NULL;
		}

		di = NILFS_DAT_I(dat);
		lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
		nilfs_palloc_setup_cache(dat, &di->palloc_cache);
		nilfs_mdt_setup_shadow_map(dat, &di->shadow);
	}
	return dat;
}
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
8908b2f7 RK	36	struct nilfs_dat_info {
	37	struct nilfs_mdt_info mi;
	38	struct nilfs_palloc_cache palloc_cache;
c1c1d709	39	struct nilfs_shadow_map shadow;
8908b2f7 RK	40	};
	41
	42	static inline struct nilfs_dat_info NILFS_DAT_I(struct inode dat)
	43	{
	44	return (struct nilfs_dat_info *)NILFS_MDT(dat);
	45	}
	46
a17564f5 KS	47	static 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
	54	static void nilfs_dat_commit_entry(struct inode *dat,
	55	struct nilfs_palloc_req *req)
	56	{
	57	nilfs_mdt_mark_buffer_dirty(req->pr_entry_bh);
	58	nilfs_mdt_mark_dirty(dat);
	59	brelse(req->pr_entry_bh);
	60	}
	61
	62	static void nilfs_dat_abort_entry(struct inode *dat,
	63	struct nilfs_palloc_req *req)
	64	{
	65	brelse(req->pr_entry_bh);
	66	}
	67
	68	int 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
	83	void 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, KM_USER0);
	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, KM_USER0);
	95
	96	nilfs_palloc_commit_alloc_entry(dat, req);
	97	nilfs_dat_commit_entry(dat, req);
	98	}
	99
	100	void 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
a17564f5 KS	106	void nilfs_dat_commit_free(struct inode dat, struct nilfs_palloc_req req)
	107	{
	108	struct nilfs_dat_entry *entry;
	109	void *kaddr;
	110
	111	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
	112	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
	113	req->pr_entry_bh, kaddr);
	114	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
	115	entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
	116	entry->de_blocknr = cpu_to_le64(0);
	117	kunmap_atomic(kaddr, KM_USER0);
	118
	119	nilfs_dat_commit_entry(dat, req);
	120	nilfs_palloc_commit_free_entry(dat, req);
	121	}
	122
a17564f5 KS	123	int nilfs_dat_prepare_start(struct inode dat, struct nilfs_palloc_req req)
	124	{
	125	int ret;
	126
	127	ret = nilfs_dat_prepare_entry(dat, req, 0);
1f5abe7e	128	WARN_ON(ret == -ENOENT);
a17564f5 KS	129	return ret;
	130	}
	131
	132	void nilfs_dat_commit_start(struct inode dat, struct nilfs_palloc_req req,
	133	sector_t blocknr)
	134	{
	135	struct nilfs_dat_entry *entry;
	136	void *kaddr;
	137
	138	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
	139	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
	140	req->pr_entry_bh, kaddr);
	141	entry->de_start = cpu_to_le64(nilfs_mdt_cno(dat));
a17564f5 KS	142	entry->de_blocknr = cpu_to_le64(blocknr);
	143	kunmap_atomic(kaddr, KM_USER0);
	144
	145	nilfs_dat_commit_entry(dat, req);
	146	}
	147
a17564f5 KS	148	int nilfs_dat_prepare_end(struct inode dat, struct nilfs_palloc_req req)
	149	{
	150	struct nilfs_dat_entry *entry;
	151	__u64 start;
	152	sector_t blocknr;
	153	void *kaddr;
	154	int ret;
	155
	156	ret = nilfs_dat_prepare_entry(dat, req, 0);
	157	if (ret < 0) {
1f5abe7e	158	WARN_ON(ret == -ENOENT);
a17564f5 KS	159	return ret;
	160	}
	161
	162	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
	163	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
	164	req->pr_entry_bh, kaddr);
	165	start = le64_to_cpu(entry->de_start);
	166	blocknr = le64_to_cpu(entry->de_blocknr);
	167	kunmap_atomic(kaddr, KM_USER0);
	168
	169	if (blocknr == 0) {
	170	ret = nilfs_palloc_prepare_free_entry(dat, req);
	171	if (ret < 0) {
	172	nilfs_dat_abort_entry(dat, req);
	173	return ret;
	174	}
	175	}
	176
	177	return 0;
	178	}
	179
	180	void nilfs_dat_commit_end(struct inode dat, struct nilfs_palloc_req req,
	181	int dead)
	182	{
	183	struct nilfs_dat_entry *entry;
	184	__u64 start, end;
	185	sector_t blocknr;
	186	void *kaddr;
	187
	188	kaddr = kmap_atomic(req->pr_entry_bh->b_page, KM_USER0);
	189	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
	190	req->pr_entry_bh, kaddr);
	191	end = start = le64_to_cpu(entry->de_start);
	192	if (!dead) {
	193	end = nilfs_mdt_cno(dat);
1f5abe7e	194	WARN_ON(start > end);
a17564f5 KS	195	}
	196	entry->de_end = cpu_to_le64(end);
	197	blocknr = le64_to_cpu(entry->de_blocknr);
	198	kunmap_atomic(kaddr, KM_USER0);
	199
	200	if (blocknr == 0)
	201	nilfs_dat_commit_free(dat, req);
	202	else
	203	nilfs_dat_commit_entry(dat, req);
	204	}
	205
	206	void nilfs_dat_abort_end(struct inode dat, struct nilfs_palloc_req req)
	207	{
	208	struct nilfs_dat_entry *entry;
	209	__u64 start;
	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	start = le64_to_cpu(entry->de_start);
	217	blocknr = le64_to_cpu(entry->de_blocknr);
	218	kunmap_atomic(kaddr, KM_USER0);
	219
	220	if (start == nilfs_mdt_cno(dat) && blocknr == 0)
	221	nilfs_palloc_abort_free_entry(dat, req);
	222	nilfs_dat_abort_entry(dat, req);
	223	}
	224
bd8169ef RK	225	int nilfs_dat_prepare_update(struct inode *dat,
	226	struct nilfs_palloc_req *oldreq,
	227	struct nilfs_palloc_req *newreq)
	228	{
	229	int ret;
	230
	231	ret = nilfs_dat_prepare_end(dat, oldreq);
	232	if (!ret) {
	233	ret = nilfs_dat_prepare_alloc(dat, newreq);
	234	if (ret < 0)
	235	nilfs_dat_abort_end(dat, oldreq);
	236	}
	237	return ret;
	238	}
	239
	240	void nilfs_dat_commit_update(struct inode *dat,
	241	struct nilfs_palloc_req *oldreq,
	242	struct nilfs_palloc_req *newreq, int dead)
	243	{
	244	nilfs_dat_commit_end(dat, oldreq, dead);
	245	nilfs_dat_commit_alloc(dat, newreq);
	246	}
	247
	248	void nilfs_dat_abort_update(struct inode *dat,
	249	struct nilfs_palloc_req *oldreq,
	250	struct nilfs_palloc_req *newreq)
	251	{
	252	nilfs_dat_abort_end(dat, oldreq);
	253	nilfs_dat_abort_alloc(dat, newreq);
	254	}
	255
a17564f5 KS	256	/**
	257	* nilfs_dat_mark_dirty -
	258	* @dat: DAT file inode
	259	* @vblocknr: virtual block number
	260	*
	261	* Description:
	262	*
	263	* Return Value: On success, 0 is returned. On error, one of the following
	264	* negative error codes is returned.
	265	*
	266	* %-EIO - I/O error.
	267	*
	268	* %-ENOMEM - Insufficient amount of memory available.
	269	*/
	270	int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
	271	{
	272	struct nilfs_palloc_req req;
	273	int ret;
	274
	275	req.pr_entry_nr = vblocknr;
	276	ret = nilfs_dat_prepare_entry(dat, &req, 0);
	277	if (ret == 0)
	278	nilfs_dat_commit_entry(dat, &req);
	279	return ret;
	280	}
	281
	282	/**
	283	* nilfs_dat_freev - free virtual block numbers
	284	* @dat: DAT file inode
	285	* @vblocknrs: array of virtual block numbers
	286	* @nitems: number of virtual block numbers
	287	*
	288	* Description: nilfs_dat_freev() frees the virtual block numbers specified by
	289	* @vblocknrs and @nitems.
	290	*
	291	* Return Value: On success, 0 is returned. On error, one of the following
7a65004b	292	* negative error codes is returned.
a17564f5 KS	293	*
	294	* %-EIO - I/O error.
	295	*
	296	* %-ENOMEM - Insufficient amount of memory available.
	297	*
	298	* %-ENOENT - The virtual block number have not been allocated.
	299	*/
	300	int nilfs_dat_freev(struct inode dat, __u64 vblocknrs, size_t nitems)
	301	{
	302	return nilfs_palloc_freev(dat, vblocknrs, nitems);
	303	}
	304
	305	/**
	306	* nilfs_dat_move - change a block number
	307	* @dat: DAT file inode
	308	* @vblocknr: virtual block number
	309	* @blocknr: block number
	310	*
	311	* Description: nilfs_dat_move() changes the block number associated with
	312	* @vblocknr to @blocknr.
	313	*
	314	* Return Value: On success, 0 is returned. On error, one of the following
	315	* negative error codes is returned.
	316	*
	317	* %-EIO - I/O error.
	318	*
	319	* %-ENOMEM - Insufficient amount of memory available.
	320	*/
	321	int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
	322	{
	323	struct buffer_head *entry_bh;
	324	struct nilfs_dat_entry *entry;
	325	void *kaddr;
	326	int ret;
	327
	328	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
	329	if (ret < 0)
	330	return ret;
c1c1d709 RK	331
	332	/*
	333	* The given disk block number (blocknr) is not yet written to
	334	* the device at this point.
	335	*
	336	* To prevent nilfs_dat_translate() from returning the
	337	* uncommited block number, this makes a copy of the entry
	338	* buffer and redirects nilfs_dat_translate() to the copy.
	339	*/
	340	if (!buffer_nilfs_redirected(entry_bh)) {
	341	ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
	342	if (ret) {
	343	brelse(entry_bh);
	344	return ret;
	345	}
	346	}
	347
a17564f5 KS	348	kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
a17564f5 KS	349	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
1f5abe7e	350	if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
a17564f5 KS	351	printk(KERN_CRIT "%s: vbn = %llu, [%llu, %llu)\n", __func__,
	352	(unsigned long long)vblocknr,
	353	(unsigned long long)le64_to_cpu(entry->de_start),
	354	(unsigned long long)le64_to_cpu(entry->de_end));
1f5abe7e RK	355	kunmap_atomic(kaddr, KM_USER0);
	356	brelse(entry_bh);
	357	return -EINVAL;
a17564f5	358	}
1f5abe7e	359	WARN_ON(blocknr == 0);
a17564f5 KS	360	entry->de_blocknr = cpu_to_le64(blocknr);
	361	kunmap_atomic(kaddr, KM_USER0);
	362
	363	nilfs_mdt_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	*/
	390	int nilfs_dat_translate(struct inode dat, __u64 vblocknr, sector_t blocknrp)
	391	{
c1c1d709	392	struct buffer_head entry_bh, bh;
a17564f5 KS	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
c1c1d709 RK	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
a17564f5 KS	411	kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
	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	}
086d1764	418	*blocknrp = blocknr;
a17564f5 KS	419
	420	out:
	421	kunmap_atomic(kaddr, KM_USER0);
	422	brelse(entry_bh);
	423	return ret;
	424	}
	425
003ff182	426	ssize_t nilfs_dat_get_vinfo(struct inode dat, void buf, unsigned visz,
a17564f5 KS	427	size_t nvi)
	428	{
	429	struct buffer_head *entry_bh;
	430	struct nilfs_dat_entry *entry;
003ff182	431	struct nilfs_vinfo *vinfo = buf;
a17564f5 KS	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) {
003ff182	438	ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
a17564f5 KS	439	0, &entry_bh);
	440	if (ret < 0)
	441	return ret;
	442	kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
	443	/* last virtual block number in this block */
003ff182	444	first = vinfo->vi_vblocknr;
a17564f5 KS	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;
003ff182 RK	449	j < nvi && vinfo->vi_vblocknr >= first &&
	450	vinfo->vi_vblocknr <= last;
	451	j++, n++, vinfo = (void *)vinfo + visz) {
a17564f5	452	entry = nilfs_palloc_block_get_entry(
003ff182 RK	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);
a17564f5 KS	457	}
	458	kunmap_atomic(kaddr, KM_USER0);
	459	brelse(entry_bh);
	460	}
	461
	462	return nvi;
	463	}
79739565	464
8707df38 RK	465	/**
	466	* nilfs_dat_read - read dat inode
	467	* @dat: dat inode
	468	* @raw_inode: on-disk dat inode
	469	*/
	470	int nilfs_dat_read(struct inode dat, struct nilfs_inode raw_inode)
	471	{
	472	return nilfs_read_inode_common(dat, raw_inode);
	473	}
	474
79739565 RK	475	/**
	476	* nilfs_dat_new - create dat file
	477	* @nilfs: nilfs object
	478	* @entry_size: size of a dat entry
	479	*/
	480	struct inode nilfs_dat_new(struct the_nilfs nilfs, size_t entry_size)
	481	{
	482	static struct lock_class_key dat_lock_key;
	483	struct inode *dat;
8908b2f7	484	struct nilfs_dat_info *di;
79739565 RK	485	int err;
79739565 RK	486
8908b2f7	487	dat = nilfs_mdt_new(nilfs, NULL, NILFS_DAT_INO, sizeof(*di));
79739565 RK	488	if (dat) {
	489	err = nilfs_palloc_init_blockgroup(dat, entry_size);
	490	if (unlikely(err)) {
	491	nilfs_mdt_destroy(dat);
	492	return NULL;
	493	}
8908b2f7 RK	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);
c1c1d709	498	nilfs_mdt_setup_shadow_map(dat, &di->shadow);
79739565 RK	499	}
	500	return dat;
	501	}