[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 - on-memory private data of DAT file
 * @mi: on-memory private data of metadata file
 * @palloc_cache: persistent object allocator cache of DAT file
 * @shadow: shadow map of DAT file
 */
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
f5974c8f VD	36	/**
	37	* struct nilfs_dat_info - on-memory private data of DAT file
	38	* @mi: on-memory private data of metadata file
	39	* @palloc_cache: persistent object allocator cache of DAT file
	40	* @shadow: shadow map of DAT file
	41	*/
8908b2f7 RK	42	struct nilfs_dat_info {
	43	struct nilfs_mdt_info mi;
	44	struct nilfs_palloc_cache palloc_cache;
c1c1d709	45	struct nilfs_shadow_map shadow;
8908b2f7 RK	46	};
	47
	48	static inline struct nilfs_dat_info NILFS_DAT_I(struct inode dat)
	49	{
	50	return (struct nilfs_dat_info *)NILFS_MDT(dat);
	51	}
	52
a17564f5 KS	53	static int nilfs_dat_prepare_entry(struct inode *dat,
	54	struct nilfs_palloc_req *req, int create)
	55	{
	56	return nilfs_palloc_get_entry_block(dat, req->pr_entry_nr,
	57	create, &req->pr_entry_bh);
	58	}
	59
	60	static void nilfs_dat_commit_entry(struct inode *dat,
	61	struct nilfs_palloc_req *req)
	62	{
5fc7b141	63	mark_buffer_dirty(req->pr_entry_bh);
a17564f5 KS	64	nilfs_mdt_mark_dirty(dat);
	65	brelse(req->pr_entry_bh);
	66	}
	67
	68	static void nilfs_dat_abort_entry(struct inode *dat,
	69	struct nilfs_palloc_req *req)
	70	{
	71	brelse(req->pr_entry_bh);
	72	}
	73
	74	int nilfs_dat_prepare_alloc(struct inode dat, struct nilfs_palloc_req req)
	75	{
	76	int ret;
	77
	78	ret = nilfs_palloc_prepare_alloc_entry(dat, req);
	79	if (ret < 0)
	80	return ret;
	81
	82	ret = nilfs_dat_prepare_entry(dat, req, 1);
	83	if (ret < 0)
	84	nilfs_palloc_abort_alloc_entry(dat, req);
	85
	86	return ret;
	87	}
	88
	89	void nilfs_dat_commit_alloc(struct inode dat, struct nilfs_palloc_req req)
	90	{
	91	struct nilfs_dat_entry *entry;
	92	void *kaddr;
	93
7b9c0976	94	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	95	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
	96	req->pr_entry_bh, kaddr);
	97	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
	98	entry->de_end = cpu_to_le64(NILFS_CNO_MAX);
	99	entry->de_blocknr = cpu_to_le64(0);
7b9c0976	100	kunmap_atomic(kaddr);
a17564f5 KS	101
	102	nilfs_palloc_commit_alloc_entry(dat, req);
	103	nilfs_dat_commit_entry(dat, req);
	104	}
	105
	106	void nilfs_dat_abort_alloc(struct inode dat, struct nilfs_palloc_req req)
	107	{
	108	nilfs_dat_abort_entry(dat, req);
	109	nilfs_palloc_abort_alloc_entry(dat, req);
	110	}
	111
abc0b50b JS	112	static void nilfs_dat_commit_free(struct inode *dat,
abc0b50b JS	113	struct nilfs_palloc_req *req)
a17564f5 KS	114	{
	115	struct nilfs_dat_entry *entry;
	116	void *kaddr;
	117
7b9c0976	118	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	119	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
	120	req->pr_entry_bh, kaddr);
	121	entry->de_start = cpu_to_le64(NILFS_CNO_MIN);
	122	entry->de_end = cpu_to_le64(NILFS_CNO_MIN);
	123	entry->de_blocknr = cpu_to_le64(0);
7b9c0976	124	kunmap_atomic(kaddr);
a17564f5 KS	125
	126	nilfs_dat_commit_entry(dat, req);
	127	nilfs_palloc_commit_free_entry(dat, req);
	128	}
	129
a17564f5 KS	130	int nilfs_dat_prepare_start(struct inode dat, struct nilfs_palloc_req req)
	131	{
	132	int ret;
	133
	134	ret = nilfs_dat_prepare_entry(dat, req, 0);
1f5abe7e	135	WARN_ON(ret == -ENOENT);
a17564f5 KS	136	return ret;
	137	}
	138
	139	void nilfs_dat_commit_start(struct inode dat, struct nilfs_palloc_req req,
	140	sector_t blocknr)
	141	{
	142	struct nilfs_dat_entry *entry;
	143	void *kaddr;
	144
7b9c0976	145	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	146	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
	147	req->pr_entry_bh, kaddr);
	148	entry->de_start = cpu_to_le64(nilfs_mdt_cno(dat));
a17564f5	149	entry->de_blocknr = cpu_to_le64(blocknr);
7b9c0976	150	kunmap_atomic(kaddr);
a17564f5 KS	151
	152	nilfs_dat_commit_entry(dat, req);
	153	}
	154
a17564f5 KS	155	int nilfs_dat_prepare_end(struct inode dat, struct nilfs_palloc_req req)
	156	{
	157	struct nilfs_dat_entry *entry;
	158	__u64 start;
	159	sector_t blocknr;
	160	void *kaddr;
	161	int ret;
	162
	163	ret = nilfs_dat_prepare_entry(dat, req, 0);
	164	if (ret < 0) {
1f5abe7e	165	WARN_ON(ret == -ENOENT);
a17564f5 KS	166	return ret;
	167	}
	168
7b9c0976	169	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	170	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
	171	req->pr_entry_bh, kaddr);
	172	start = le64_to_cpu(entry->de_start);
	173	blocknr = le64_to_cpu(entry->de_blocknr);
7b9c0976	174	kunmap_atomic(kaddr);
a17564f5 KS	175
	176	if (blocknr == 0) {
	177	ret = nilfs_palloc_prepare_free_entry(dat, req);
	178	if (ret < 0) {
	179	nilfs_dat_abort_entry(dat, req);
	180	return ret;
	181	}
	182	}
	183
	184	return 0;
	185	}
	186
	187	void nilfs_dat_commit_end(struct inode dat, struct nilfs_palloc_req req,
	188	int dead)
	189	{
	190	struct nilfs_dat_entry *entry;
	191	__u64 start, end;
	192	sector_t blocknr;
	193	void *kaddr;
	194
7b9c0976	195	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	196	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
	197	req->pr_entry_bh, kaddr);
	198	end = start = le64_to_cpu(entry->de_start);
	199	if (!dead) {
	200	end = nilfs_mdt_cno(dat);
1f5abe7e	201	WARN_ON(start > end);
a17564f5 KS	202	}
	203	entry->de_end = cpu_to_le64(end);
	204	blocknr = le64_to_cpu(entry->de_blocknr);
7b9c0976	205	kunmap_atomic(kaddr);
a17564f5 KS	206
	207	if (blocknr == 0)
	208	nilfs_dat_commit_free(dat, req);
	209	else
	210	nilfs_dat_commit_entry(dat, req);
	211	}
	212
	213	void nilfs_dat_abort_end(struct inode dat, struct nilfs_palloc_req req)
	214	{
	215	struct nilfs_dat_entry *entry;
	216	__u64 start;
	217	sector_t blocknr;
	218	void *kaddr;
	219
7b9c0976	220	kaddr = kmap_atomic(req->pr_entry_bh->b_page);
a17564f5 KS	221	entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr,
	222	req->pr_entry_bh, kaddr);
	223	start = le64_to_cpu(entry->de_start);
	224	blocknr = le64_to_cpu(entry->de_blocknr);
7b9c0976	225	kunmap_atomic(kaddr);
a17564f5 KS	226
	227	if (start == nilfs_mdt_cno(dat) && blocknr == 0)
	228	nilfs_palloc_abort_free_entry(dat, req);
	229	nilfs_dat_abort_entry(dat, req);
	230	}
	231
bd8169ef RK	232	int nilfs_dat_prepare_update(struct inode *dat,
	233	struct nilfs_palloc_req *oldreq,
	234	struct nilfs_palloc_req *newreq)
	235	{
	236	int ret;
	237
	238	ret = nilfs_dat_prepare_end(dat, oldreq);
	239	if (!ret) {
	240	ret = nilfs_dat_prepare_alloc(dat, newreq);
	241	if (ret < 0)
	242	nilfs_dat_abort_end(dat, oldreq);
	243	}
	244	return ret;
	245	}
	246
	247	void nilfs_dat_commit_update(struct inode *dat,
	248	struct nilfs_palloc_req *oldreq,
	249	struct nilfs_palloc_req *newreq, int dead)
	250	{
	251	nilfs_dat_commit_end(dat, oldreq, dead);
	252	nilfs_dat_commit_alloc(dat, newreq);
	253	}
	254
	255	void nilfs_dat_abort_update(struct inode *dat,
	256	struct nilfs_palloc_req *oldreq,
	257	struct nilfs_palloc_req *newreq)
	258	{
	259	nilfs_dat_abort_end(dat, oldreq);
	260	nilfs_dat_abort_alloc(dat, newreq);
	261	}
	262
a17564f5 KS	263	/**
	264	* nilfs_dat_mark_dirty -
	265	* @dat: DAT file inode
	266	* @vblocknr: virtual block number
	267	*
	268	* Description:
	269	*
	270	* Return Value: On success, 0 is returned. On error, one of the following
	271	* negative error codes is returned.
	272	*
	273	* %-EIO - I/O error.
	274	*
	275	* %-ENOMEM - Insufficient amount of memory available.
	276	*/
	277	int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
	278	{
	279	struct nilfs_palloc_req req;
	280	int ret;
	281
	282	req.pr_entry_nr = vblocknr;
	283	ret = nilfs_dat_prepare_entry(dat, &req, 0);
	284	if (ret == 0)
	285	nilfs_dat_commit_entry(dat, &req);
	286	return ret;
	287	}
	288
	289	/**
	290	* nilfs_dat_freev - free virtual block numbers
	291	* @dat: DAT file inode
	292	* @vblocknrs: array of virtual block numbers
	293	* @nitems: number of virtual block numbers
	294	*
	295	* Description: nilfs_dat_freev() frees the virtual block numbers specified by
	296	* @vblocknrs and @nitems.
	297	*
	298	* Return Value: On success, 0 is returned. On error, one of the following
7a65004b	299	* negative error codes is returned.
a17564f5 KS	300	*
	301	* %-EIO - I/O error.
	302	*
	303	* %-ENOMEM - Insufficient amount of memory available.
	304	*
	305	* %-ENOENT - The virtual block number have not been allocated.
	306	*/
	307	int nilfs_dat_freev(struct inode dat, __u64 vblocknrs, size_t nitems)
	308	{
	309	return nilfs_palloc_freev(dat, vblocknrs, nitems);
	310	}
	311
	312	/**
	313	* nilfs_dat_move - change a block number
	314	* @dat: DAT file inode
	315	* @vblocknr: virtual block number
	316	* @blocknr: block number
	317	*
	318	* Description: nilfs_dat_move() changes the block number associated with
	319	* @vblocknr to @blocknr.
	320	*
	321	* Return Value: On success, 0 is returned. On error, one of the following
	322	* negative error codes is returned.
	323	*
	324	* %-EIO - I/O error.
	325	*
	326	* %-ENOMEM - Insufficient amount of memory available.
	327	*/
	328	int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
	329	{
	330	struct buffer_head *entry_bh;
	331	struct nilfs_dat_entry *entry;
	332	void *kaddr;
	333	int ret;
	334
	335	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
	336	if (ret < 0)
	337	return ret;
c1c1d709 RK	338
	339	/*
	340	* The given disk block number (blocknr) is not yet written to
	341	* the device at this point.
	342	*
	343	* To prevent nilfs_dat_translate() from returning the
f6c26ec5	344	* uncommitted block number, this makes a copy of the entry
c1c1d709 RK	345	* buffer and redirects nilfs_dat_translate() to the copy.
	346	*/
	347	if (!buffer_nilfs_redirected(entry_bh)) {
	348	ret = nilfs_mdt_freeze_buffer(dat, entry_bh);
	349	if (ret) {
	350	brelse(entry_bh);
	351	return ret;
	352	}
	353	}
	354
7b9c0976	355	kaddr = kmap_atomic(entry_bh->b_page);
a17564f5	356	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
1f5abe7e	357	if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
a17564f5 KS	358	printk(KERN_CRIT "%s: vbn = %llu, [%llu, %llu)\n", __func__,
	359	(unsigned long long)vblocknr,
	360	(unsigned long long)le64_to_cpu(entry->de_start),
	361	(unsigned long long)le64_to_cpu(entry->de_end));
7b9c0976	362	kunmap_atomic(kaddr);
1f5abe7e RK	363	brelse(entry_bh);
1f5abe7e RK	364	return -EINVAL;
a17564f5	365	}
1f5abe7e	366	WARN_ON(blocknr == 0);
a17564f5	367	entry->de_blocknr = cpu_to_le64(blocknr);
7b9c0976	368	kunmap_atomic(kaddr);
a17564f5	369
5fc7b141	370	mark_buffer_dirty(entry_bh);
a17564f5 KS	371	nilfs_mdt_mark_dirty(dat);
	372
	373	brelse(entry_bh);
	374
	375	return 0;
	376	}
	377
	378	/**
	379	* nilfs_dat_translate - translate a virtual block number to a block number
	380	* @dat: DAT file inode
	381	* @vblocknr: virtual block number
	382	* @blocknrp: pointer to a block number
	383	*
	384	* Description: nilfs_dat_translate() maps the virtual block number @vblocknr
	385	* to the corresponding block number.
	386	*
	387	* Return Value: On success, 0 is returned and the block number associated
	388	* with @vblocknr is stored in the place pointed by @blocknrp. On error, one
	389	* of the following negative error codes is returned.
	390	*
	391	* %-EIO - I/O error.
	392	*
	393	* %-ENOMEM - Insufficient amount of memory available.
	394	*
	395	* %-ENOENT - A block number associated with @vblocknr does not exist.
	396	*/
	397	int nilfs_dat_translate(struct inode dat, __u64 vblocknr, sector_t blocknrp)
	398	{
c1c1d709	399	struct buffer_head entry_bh, bh;
a17564f5 KS	400	struct nilfs_dat_entry *entry;
	401	sector_t blocknr;
	402	void *kaddr;
	403	int ret;
	404
	405	ret = nilfs_palloc_get_entry_block(dat, vblocknr, 0, &entry_bh);
	406	if (ret < 0)
	407	return ret;
	408
c1c1d709 RK	409	if (!nilfs_doing_gc() && buffer_nilfs_redirected(entry_bh)) {
	410	bh = nilfs_mdt_get_frozen_buffer(dat, entry_bh);
	411	if (bh) {
	412	WARN_ON(!buffer_uptodate(bh));
	413	brelse(entry_bh);
	414	entry_bh = bh;
	415	}
	416	}
	417
7b9c0976	418	kaddr = kmap_atomic(entry_bh->b_page);
a17564f5 KS	419	entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
	420	blocknr = le64_to_cpu(entry->de_blocknr);
	421	if (blocknr == 0) {
	422	ret = -ENOENT;
	423	goto out;
	424	}
086d1764	425	*blocknrp = blocknr;
a17564f5 KS	426
a17564f5 KS	427	out:
7b9c0976	428	kunmap_atomic(kaddr);
a17564f5 KS	429	brelse(entry_bh);
	430	return ret;
	431	}
	432
003ff182	433	ssize_t nilfs_dat_get_vinfo(struct inode dat, void buf, unsigned visz,
a17564f5 KS	434	size_t nvi)
	435	{
	436	struct buffer_head *entry_bh;
	437	struct nilfs_dat_entry *entry;
003ff182	438	struct nilfs_vinfo *vinfo = buf;
a17564f5 KS	439	__u64 first, last;
	440	void *kaddr;
	441	unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block;
	442	int i, j, n, ret;
	443
	444	for (i = 0; i < nvi; i += n) {
003ff182	445	ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr,
a17564f5 KS	446	0, &entry_bh);
	447	if (ret < 0)
	448	return ret;
7b9c0976	449	kaddr = kmap_atomic(entry_bh->b_page);
a17564f5	450	/* last virtual block number in this block */
003ff182	451	first = vinfo->vi_vblocknr;
a17564f5 KS	452	do_div(first, entries_per_block);
	453	first *= entries_per_block;
	454	last = first + entries_per_block - 1;
	455	for (j = i, n = 0;
003ff182 RK	456	j < nvi && vinfo->vi_vblocknr >= first &&
	457	vinfo->vi_vblocknr <= last;
	458	j++, n++, vinfo = (void *)vinfo + visz) {
a17564f5	459	entry = nilfs_palloc_block_get_entry(
003ff182 RK	460	dat, vinfo->vi_vblocknr, entry_bh, kaddr);
	461	vinfo->vi_start = le64_to_cpu(entry->de_start);
	462	vinfo->vi_end = le64_to_cpu(entry->de_end);
	463	vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr);
a17564f5	464	}
7b9c0976	465	kunmap_atomic(kaddr);
a17564f5 KS	466	brelse(entry_bh);
	467	}
	468
	469	return nvi;
	470	}
79739565	471
8707df38	472	/**
f1e89c86 RK	473	* nilfs_dat_read - read or get dat inode
f1e89c86 RK	474	* @sb: super block instance
79739565	475	* @entry_size: size of a dat entry
f1e89c86 RK	476	* @raw_inode: on-disk dat inode
f1e89c86 RK	477	* @inodep: buffer to store the inode
79739565	478	*/
f1e89c86 RK	479	int nilfs_dat_read(struct super_block *sb, size_t entry_size,
f1e89c86 RK	480	struct nilfs_inode raw_inode, struct inode *inodep)
79739565 RK	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
f1e89c86 RK	487	dat = nilfs_iget_locked(sb, NULL, NILFS_DAT_INO);
	488	if (unlikely(!dat))
	489	return -ENOMEM;
	490	if (!(dat->i_state & I_NEW))
	491	goto out;
8908b2f7	492
f1e89c86 RK	493	err = nilfs_mdt_init(dat, NILFS_MDT_GFP, sizeof(*di));
	494	if (err)
	495	goto failed;
	496
	497	err = nilfs_palloc_init_blockgroup(dat, entry_size);
	498	if (err)
	499	goto failed;
	500
	501	di = NILFS_DAT_I(dat);
	502	lockdep_set_class(&di->mi.mi_sem, &dat_lock_key);
	503	nilfs_palloc_setup_cache(dat, &di->palloc_cache);
	504	nilfs_mdt_setup_shadow_map(dat, &di->shadow);
	505
	506	err = nilfs_read_inode_common(dat, raw_inode);
	507	if (err)
	508	goto failed;
	509
	510	unlock_new_inode(dat);
	511	out:
	512	*inodep = dat;
	513	return 0;
	514	failed:
	515	iget_failed(dat);
	516	return err;
79739565	517	}