[linux.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 <[email protected]>.
 */

#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)
{
	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);
	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);

	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);
}

static 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);
	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);

	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);
	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);

	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);
	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);

	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);
	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);

	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);
	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);

	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
	 * uncommitted 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);
	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);
		brelse(entry_bh);
		return -EINVAL;
	}
	WARN_ON(blocknr == 0);
	entry->de_blocknr = cpu_to_le64(blocknr);
	kunmap_atomic(kaddr);

	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);
	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);
	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);
		/* 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);
		brelse(entry_bh);
	}

	return nvi;
}

/**
 * nilfs_dat_read - read or get dat inode
 * @sb: super block instance
 * @entry_size: size of a dat entry
 * @raw_inode: on-disk dat inode
 * @inodep: buffer to store the inode
 */
int nilfs_dat_read(struct super_block *sb, size_t entry_size,
		   struct nilfs_inode *raw_inode, struct inode **inodep)
{
	static struct lock_class_key dat_lock_key;
	struct inode *dat;
	struct nilfs_dat_info *di;
	int err;

	dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
	if (unlikely(!dat))
		return -ENOMEM;
	if (!(dat->i_state & I_NEW))
		goto out;

	err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
	if (err)
		goto failed;

	err = nilfs_palloc_init_blockgroup(dat, entry_size);
	if (err)
		goto failed;

	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);

	err = nilfs_read_inode_common(dat, raw_inode);
	if (err)
		goto failed;

	unlock_new_inode(dat);
 out:
	*inodep = dat;
	return 0;
 failed:
	iget_failed(dat);
	return err;
}
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 <[email protected]>.
	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	{
5fc7b141	57	mark_buffer_dirty(req->pr_entry_bh);
a17564f5 KS	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
7b9c0976	88	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	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);
7b9c0976	94	kunmap_atomic(kaddr);
a17564f5 KS	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
abc0b50b JS	106	static void nilfs_dat_commit_free(struct inode *dat,
abc0b50b JS	107	struct nilfs_palloc_req *req)
a17564f5 KS	108	{
	109	struct nilfs_dat_entry *entry;
	110	void *kaddr;
	111
7b9c0976	112	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	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);
7b9c0976	118	kunmap_atomic(kaddr);
a17564f5 KS	119
	120	nilfs_dat_commit_entry(dat, req);
	121	nilfs_palloc_commit_free_entry(dat, req);
	122	}
	123
a17564f5 KS	124	int 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);
1f5abe7e	129	WARN_ON(ret == -ENOENT);
a17564f5 KS	130	return ret;
	131	}
	132
	133	void 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
7b9c0976	139	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	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));
a17564f5	143	entry->de_blocknr = cpu_to_le64(blocknr);
7b9c0976	144	kunmap_atomic(kaddr);
a17564f5 KS	145
	146	nilfs_dat_commit_entry(dat, req);
	147	}
	148
a17564f5 KS	149	int 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) {
1f5abe7e	159	WARN_ON(ret == -ENOENT);
a17564f5 KS	160	return ret;
	161	}
	162
7b9c0976	163	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	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);
7b9c0976	168	kunmap_atomic(kaddr);
a17564f5 KS	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
	181	void 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
7b9c0976	189	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	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);
1f5abe7e	195	WARN_ON(start > end);
a17564f5 KS	196	}
	197	entry->de_end = cpu_to_le64(end);
	198	blocknr = le64_to_cpu(entry->de_blocknr);
7b9c0976	199	kunmap_atomic(kaddr);
a17564f5 KS	200
	201	if (blocknr == 0)
	202	nilfs_dat_commit_free(dat, req);
	203	else
	204	nilfs_dat_commit_entry(dat, req);
	205	}
	206
	207	void 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
7b9c0976	214	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	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);
7b9c0976	219	kunmap_atomic(kaddr);
a17564f5 KS	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
bd8169ef RK	226	int 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
	241	void 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
	249	void 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
a17564f5 KS	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	*/
	271	int 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
7a65004b	293	* negative error codes is returned.
a17564f5 KS	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	*/
	301	int 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	*/
	322	int 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;
c1c1d709 RK	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
f6c26ec5	338	* uncommitted block number, this makes a copy of the entry
c1c1d709 RK	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
7b9c0976	349	kaddr = kmap_atomic(entry_bh->b_page);
a17564f5	350	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
1f5abe7e	351	if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
a17564f5 KS	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));
7b9c0976	356	kunmap_atomic(kaddr);
1f5abe7e RK	357	brelse(entry_bh);
1f5abe7e RK	358	return -EINVAL;
a17564f5	359	}
1f5abe7e	360	WARN_ON(blocknr == 0);
a17564f5	361	entry->de_blocknr = cpu_to_le64(blocknr);
7b9c0976	362	kunmap_atomic(kaddr);
a17564f5	363
5fc7b141	364	mark_buffer_dirty(entry_bh);
a17564f5 KS	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	*/
	391	int nilfs_dat_translate(struct inode dat, __u64 vblocknr, sector_t blocknrp)
	392	{
c1c1d709	393	struct buffer_head entry_bh, bh;
a17564f5 KS	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
c1c1d709 RK	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
7b9c0976	412	kaddr = kmap_atomic(entry_bh->b_page);
a17564f5 KS	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	}
086d1764	419	*blocknrp = blocknr;
a17564f5 KS	420
a17564f5 KS	421	out:
7b9c0976	422	kunmap_atomic(kaddr);
a17564f5 KS	423	brelse(entry_bh);
	424	return ret;
	425	}
	426
003ff182	427	ssize_t nilfs_dat_get_vinfo(struct inode dat, void buf, unsigned visz,
a17564f5 KS	428	size_t nvi)
	429	{
	430	struct buffer_head *entry_bh;
	431	struct nilfs_dat_entry *entry;
003ff182	432	struct nilfs_vinfo *vinfo = buf;
a17564f5 KS	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) {
003ff182	439	ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
a17564f5 KS	440	0, &entry_bh);
	441	if (ret < 0)
	442	return ret;
7b9c0976	443	kaddr = kmap_atomic(entry_bh->b_page);
a17564f5	444	/* last virtual block number in this block */
003ff182	445	first = vinfo->vi_vblocknr;
a17564f5 KS	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;
003ff182 RK	450	j < nvi && vinfo->vi_vblocknr >= first &&
	451	vinfo->vi_vblocknr <= last;
	452	j++, n++, vinfo = (void *)vinfo + visz) {
a17564f5	453	entry = nilfs_palloc_block_get_entry(
003ff182 RK	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);
a17564f5	458	}
7b9c0976	459	kunmap_atomic(kaddr);
a17564f5 KS	460	brelse(entry_bh);
	461	}
	462
	463	return nvi;
	464	}
79739565	465
8707df38	466	/**
f1e89c86 RK	467	* nilfs_dat_read - read or get dat inode
f1e89c86 RK	468	* @sb: super block instance
79739565	469	* @entry_size: size of a dat entry
f1e89c86 RK	470	* @raw_inode: on-disk dat inode
f1e89c86 RK	471	* @inodep: buffer to store the inode
79739565	472	*/
f1e89c86 RK	473	int nilfs_dat_read(struct super_block *sb, size_t entry_size,
f1e89c86 RK	474	struct nilfs_inode raw_inode, struct inode *inodep)
79739565 RK	475	{
	476	static struct lock_class_key dat_lock_key;
	477	struct inode *dat;
8908b2f7	478	struct nilfs_dat_info *di;
79739565 RK	479	int err;
79739565 RK	480
f1e89c86 RK	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;
8908b2f7	486
f1e89c86 RK	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;
79739565	511	}