[net-next-2.6.git] / fs / hfsplus / extents.c

/*
 *  linux/fs/hfsplus/extents.c
 *
 * Copyright (C) 2001
 * Brad Boyer (flar@allandria.com)
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 *
 * Handling of Extents both in catalog and extents overflow trees
 */

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/pagemap.h>

#include "hfsplus_fs.h"
#include "hfsplus_raw.h"

/* Compare two extents keys, returns 0 on same, pos/neg for difference */
int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
			const hfsplus_btree_key *k2)
{
	__be32 k1id, k2id;
	__be32 k1s, k2s;

	k1id = k1->ext.cnid;
	k2id = k2->ext.cnid;
	if (k1id != k2id)
		return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;

	if (k1->ext.fork_type != k2->ext.fork_type)
		return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;

	k1s = k1->ext.start_block;
	k2s = k2->ext.start_block;
	if (k1s == k2s)
		return 0;
	return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
}

static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
				  u32 block, u8 type)
{
	key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
	key->ext.cnid = cpu_to_be32(cnid);
	key->ext.start_block = cpu_to_be32(block);
	key->ext.fork_type = type;
	key->ext.pad = 0;
}

static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
{
	int i;
	u32 count;

	for (i = 0; i < 8; ext++, i++) {
		count = be32_to_cpu(ext->block_count);
		if (off < count)
			return be32_to_cpu(ext->start_block) + off;
		off -= count;
	}
	/* panic? */
	return 0;
}

static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
{
	int i;
	u32 count = 0;

	for (i = 0; i < 8; ext++, i++)
		count += be32_to_cpu(ext->block_count);
	return count;
}

static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
{
	int i;

	ext += 7;
	for (i = 0; i < 7; ext--, i++)
		if (ext->block_count)
			break;
	return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
}

static void __hfsplus_ext_write_extent(struct inode *inode, struct hfs_find_data *fd)
{
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	int res;

	WARN_ON(!mutex_is_locked(&hip->extents_lock));

	hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
			      HFSPLUS_IS_RSRC(inode) ?
				HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);

	res = hfs_brec_find(fd);
	if (hip->flags & HFSPLUS_FLG_EXT_NEW) {
		if (res != -ENOENT)
			return;
		hfs_brec_insert(fd, hip->cached_extents,
				sizeof(hfsplus_extent_rec));
		hip->flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
	} else {
		if (res)
			return;
		hfs_bnode_write(fd->bnode, hip->cached_extents,
				fd->entryoffset, fd->entrylength);
		hip->flags &= ~HFSPLUS_FLG_EXT_DIRTY;
	}
}

static void hfsplus_ext_write_extent_locked(struct inode *inode)
{
	if (HFSPLUS_I(inode)->flags & HFSPLUS_FLG_EXT_DIRTY) {
		struct hfs_find_data fd;

		hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
		__hfsplus_ext_write_extent(inode, &fd);
		hfs_find_exit(&fd);
	}
}

void hfsplus_ext_write_extent(struct inode *inode)
{
	mutex_lock(&HFSPLUS_I(inode)->extents_lock);
	hfsplus_ext_write_extent_locked(inode);
	mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
}

static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
					    struct hfsplus_extent *extent,
					    u32 cnid, u32 block, u8 type)
{
	int res;

	hfsplus_ext_build_key(fd->search_key, cnid, block, type);
	fd->key->ext.cnid = 0;
	res = hfs_brec_find(fd);
	if (res && res != -ENOENT)
		return res;
	if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
	    fd->key->ext.fork_type != fd->search_key->ext.fork_type)
		return -ENOENT;
	if (fd->entrylength != sizeof(hfsplus_extent_rec))
		return -EIO;
	hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec));
	return 0;
}

static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block)
{
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	int res;

	WARN_ON(!mutex_is_locked(&hip->extents_lock));

	if (hip->flags & HFSPLUS_FLG_EXT_DIRTY)
		__hfsplus_ext_write_extent(inode, fd);

	res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
					block, HFSPLUS_IS_RSRC(inode) ?
						HFSPLUS_TYPE_RSRC :
						HFSPLUS_TYPE_DATA);
	if (!res) {
		hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
		hip->cached_blocks = hfsplus_ext_block_count(hip->cached_extents);
	} else {
		hip->cached_start = hip->cached_blocks = 0;
		hip->flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
	}
	return res;
}

static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
{
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	struct hfs_find_data fd;
	int res;

	if (block >= hip->cached_start &&
	    block < hip->cached_start + hip->cached_blocks)
		return 0;

	hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
	res = __hfsplus_ext_cache_extent(&fd, inode, block);
	hfs_find_exit(&fd);
	return res;
}

/* Get a block at iblock for inode, possibly allocating if create */
int hfsplus_get_block(struct inode *inode, sector_t iblock,
		      struct buffer_head *bh_result, int create)
{
	struct super_block *sb = inode->i_sb;
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	int res = -EIO;
	u32 ablock, dblock, mask;
	int shift;

	/* Convert inode block to disk allocation block */
	shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
	ablock = iblock >> sbi->fs_shift;

	if (iblock >= hip->fs_blocks) {
		if (iblock > hip->fs_blocks || !create)
			return -EIO;
		if (ablock >= hip->alloc_blocks) {
			res = hfsplus_file_extend(inode);
			if (res)
				return res;
		}
	} else
		create = 0;

	if (ablock < hip->first_blocks) {
		dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
		goto done;
	}

	if (inode->i_ino == HFSPLUS_EXT_CNID)
		return -EIO;

	mutex_lock(&hip->extents_lock);
	res = hfsplus_ext_read_extent(inode, ablock);
	if (!res) {
		dblock = hfsplus_ext_find_block(hip->cached_extents,
						ablock - hip->cached_start);
	} else {
		mutex_unlock(&hip->extents_lock);
		return -EIO;
	}
	mutex_unlock(&hip->extents_lock);

done:
	dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
	mask = (1 << sbi->fs_shift) - 1;
	map_bh(bh_result, sb, (dblock << sbi->fs_shift) + sbi->blockoffset + (iblock & mask));
	if (create) {
		set_buffer_new(bh_result);
		hip->phys_size += sb->s_blocksize;
		hip->fs_blocks++;
		inode_add_bytes(inode, sb->s_blocksize);
		mark_inode_dirty(inode);
	}
	return 0;
}

static void hfsplus_dump_extent(struct hfsplus_extent *extent)
{
	int i;

	dprint(DBG_EXTENT, "   ");
	for (i = 0; i < 8; i++)
		dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
				 be32_to_cpu(extent[i].block_count));
	dprint(DBG_EXTENT, "\n");
}

static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
			      u32 alloc_block, u32 block_count)
{
	u32 count, start;
	int i;

	hfsplus_dump_extent(extent);
	for (i = 0; i < 8; extent++, i++) {
		count = be32_to_cpu(extent->block_count);
		if (offset == count) {
			start = be32_to_cpu(extent->start_block);
			if (alloc_block != start + count) {
				if (++i >= 8)
					return -ENOSPC;
				extent++;
				extent->start_block = cpu_to_be32(alloc_block);
			} else
				block_count += count;
			extent->block_count = cpu_to_be32(block_count);
			return 0;
		} else if (offset < count)
			break;
		offset -= count;
	}
	/* panic? */
	return -EIO;
}

static int hfsplus_free_extents(struct super_block *sb,
				struct hfsplus_extent *extent,
				u32 offset, u32 block_nr)
{
	u32 count, start;
	int i;

	hfsplus_dump_extent(extent);
	for (i = 0; i < 8; extent++, i++) {
		count = be32_to_cpu(extent->block_count);
		if (offset == count)
			goto found;
		else if (offset < count)
			break;
		offset -= count;
	}
	/* panic? */
	return -EIO;
found:
	for (;;) {
		start = be32_to_cpu(extent->start_block);
		if (count <= block_nr) {
			hfsplus_block_free(sb, start, count);
			extent->block_count = 0;
			extent->start_block = 0;
			block_nr -= count;
		} else {
			count -= block_nr;
			hfsplus_block_free(sb, start + count, block_nr);
			extent->block_count = cpu_to_be32(count);
			block_nr = 0;
		}
		if (!block_nr || !i)
			return 0;
		i--;
		extent--;
		count = be32_to_cpu(extent->block_count);
	}
}

int hfsplus_free_fork(struct super_block *sb, u32 cnid, struct hfsplus_fork_raw *fork, int type)
{
	struct hfs_find_data fd;
	hfsplus_extent_rec ext_entry;
	u32 total_blocks, blocks, start;
	int res, i;

	total_blocks = be32_to_cpu(fork->total_blocks);
	if (!total_blocks)
		return 0;

	blocks = 0;
	for (i = 0; i < 8; i++)
		blocks += be32_to_cpu(fork->extents[i].block_count);

	res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
	if (res)
		return res;
	if (total_blocks == blocks)
		return 0;

	hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
	do {
		res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
						total_blocks, type);
		if (res)
			break;
		start = be32_to_cpu(fd.key->ext.start_block);
		hfsplus_free_extents(sb, ext_entry,
				     total_blocks - start,
				     total_blocks);
		hfs_brec_remove(&fd);
		total_blocks = start;
	} while (total_blocks > blocks);
	hfs_find_exit(&fd);

	return res;
}

int hfsplus_file_extend(struct inode *inode)
{
	struct super_block *sb = inode->i_sb;
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	u32 start, len, goal;
	int res;

	if (sbi->alloc_file->i_size * 8 <
	    sbi->total_blocks - sbi->free_blocks + 8) {
		// extend alloc file
		printk(KERN_ERR "hfs: extend alloc file! (%Lu,%u,%u)\n",
				sbi->alloc_file->i_size * 8,
				sbi->total_blocks, sbi->free_blocks);
		return -ENOSPC;
	}

	mutex_lock(&hip->extents_lock);
	if (hip->alloc_blocks == hip->first_blocks)
		goal = hfsplus_ext_lastblock(hip->first_extents);
	else {
		res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
		if (res)
			goto out;
		goal = hfsplus_ext_lastblock(hip->cached_extents);
	}

	len = hip->clump_blocks;
	start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
	if (start >= sbi->total_blocks) {
		start = hfsplus_block_allocate(sb, goal, 0, &len);
		if (start >= goal) {
			res = -ENOSPC;
			goto out;
		}
	}

	dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);

	if (hip->alloc_blocks <= hip->first_blocks) {
		if (!hip->first_blocks) {
			dprint(DBG_EXTENT, "first extents\n");
			/* no extents yet */
			hip->first_extents[0].start_block = cpu_to_be32(start);
			hip->first_extents[0].block_count = cpu_to_be32(len);
			res = 0;
		} else {
			/* try to append to extents in inode */
			res = hfsplus_add_extent(hip->first_extents,
						 hip->alloc_blocks,
						 start, len);
			if (res == -ENOSPC)
				goto insert_extent;
		}
		if (!res) {
			hfsplus_dump_extent(hip->first_extents);
			hip->first_blocks += len;
		}
	} else {
		res = hfsplus_add_extent(hip->cached_extents,
					 hip->alloc_blocks - hip->cached_start,
					 start, len);
		if (!res) {
			hfsplus_dump_extent(hip->cached_extents);
			hip->flags |= HFSPLUS_FLG_EXT_DIRTY;
			hip->cached_blocks += len;
		} else if (res == -ENOSPC)
			goto insert_extent;
	}
out:
	mutex_unlock(&hip->extents_lock);
	if (!res) {
		hip->alloc_blocks += len;
		mark_inode_dirty(inode);
	}
	return res;

insert_extent:
	dprint(DBG_EXTENT, "insert new extent\n");
	hfsplus_ext_write_extent_locked(inode);

	memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
	hip->cached_extents[0].start_block = cpu_to_be32(start);
	hip->cached_extents[0].block_count = cpu_to_be32(len);
	hfsplus_dump_extent(hip->cached_extents);
	hip->flags |= HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW;
	hip->cached_start = hip->alloc_blocks;
	hip->cached_blocks = len;

	res = 0;
	goto out;
}

void hfsplus_file_truncate(struct inode *inode)
{
	struct super_block *sb = inode->i_sb;
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	struct hfs_find_data fd;
	u32 alloc_cnt, blk_cnt, start;
	int res;

	dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n",
		inode->i_ino, (long long)hip->phys_size, inode->i_size);

	if (inode->i_size > hip->phys_size) {
		struct address_space *mapping = inode->i_mapping;
		struct page *page;
		void *fsdata;
		u32 size = inode->i_size;
		int res;

		res = pagecache_write_begin(NULL, mapping, size, 0,
						AOP_FLAG_UNINTERRUPTIBLE,
						&page, &fsdata);
		if (res)
			return;
		res = pagecache_write_end(NULL, mapping, size, 0, 0, page, fsdata);
		if (res < 0)
			return;
		mark_inode_dirty(inode);
		return;
	} else if (inode->i_size == hip->phys_size)
		return;

	blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
			HFSPLUS_SB(sb)->alloc_blksz_shift;
	alloc_cnt = hip->alloc_blocks;
	if (blk_cnt == alloc_cnt)
		goto out;

	mutex_lock(&hip->extents_lock);
	hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
	while (1) {
		if (alloc_cnt == hip->first_blocks) {
			hfsplus_free_extents(sb, hip->first_extents,
					     alloc_cnt, alloc_cnt - blk_cnt);
			hfsplus_dump_extent(hip->first_extents);
			hip->first_blocks = blk_cnt;
			break;
		}
		res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
		if (res)
			break;
		start = hip->cached_start;
		hfsplus_free_extents(sb, hip->cached_extents,
				     alloc_cnt - start, alloc_cnt - blk_cnt);
		hfsplus_dump_extent(hip->cached_extents);
		if (blk_cnt > start) {
			hip->flags |= HFSPLUS_FLG_EXT_DIRTY;
			break;
		}
		alloc_cnt = start;
		hip->cached_start = hip->cached_blocks = 0;
		hip->flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
		hfs_brec_remove(&fd);
	}
	hfs_find_exit(&fd);
	mutex_unlock(&hip->extents_lock);

	hip->alloc_blocks = blk_cnt;
out:
	hip->phys_size = inode->i_size;
	hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
	inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
	mark_inode_dirty(inode);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/hfsplus/extents.c
	3	*
	4	* Copyright (C) 2001
	5	* Brad Boyer (flar@allandria.com)
	6	* (C) 2003 Ardis Technologies <roman@ardistech.com>
	7	*
	8	* Handling of Extents both in catalog and extents overflow trees
	9	*/
	10
	11	#include <linux/errno.h>
	12	#include <linux/fs.h>
	13	#include <linux/pagemap.h>
1da177e4 LT	14
	15	#include "hfsplus_fs.h"
	16	#include "hfsplus_raw.h"
	17
	18	/* Compare two extents keys, returns 0 on same, pos/neg for difference */
2179d372 DE	19	int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
2179d372 DE	20	const hfsplus_btree_key *k2)
1da177e4 LT	21	{
	22	__be32 k1id, k2id;
	23	__be32 k1s, k2s;
	24
	25	k1id = k1->ext.cnid;
	26	k2id = k2->ext.cnid;
	27	if (k1id != k2id)
	28	return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
	29
	30	if (k1->ext.fork_type != k2->ext.fork_type)
	31	return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
	32
	33	k1s = k1->ext.start_block;
	34	k2s = k2->ext.start_block;
	35	if (k1s == k2s)
	36	return 0;
	37	return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
	38	}
	39
	40	static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
	41	u32 block, u8 type)
	42	{
	43	key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
	44	key->ext.cnid = cpu_to_be32(cnid);
	45	key->ext.start_block = cpu_to_be32(block);
	46	key->ext.fork_type = type;
	47	key->ext.pad = 0;
	48	}
	49
	50	static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
	51	{
	52	int i;
	53	u32 count;
	54
	55	for (i = 0; i < 8; ext++, i++) {
	56	count = be32_to_cpu(ext->block_count);
	57	if (off < count)
	58	return be32_to_cpu(ext->start_block) + off;
	59	off -= count;
	60	}
	61	/* panic? */
	62	return 0;
	63	}
	64
	65	static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
	66	{
	67	int i;
	68	u32 count = 0;
	69
	70	for (i = 0; i < 8; ext++, i++)
	71	count += be32_to_cpu(ext->block_count);
	72	return count;
	73	}
	74
	75	static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
	76	{
	77	int i;
	78
	79	ext += 7;
	80	for (i = 0; i < 7; ext--, i++)
	81	if (ext->block_count)
	82	break;
	83	return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
	84	}
85
86	static void __hfsplus_ext_write_extent(struct inode inode, struct hfs_find_data fd)
87	{
6af502de	88	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	89	int res;
1da177e4 LT	90
7fcc99f4 CH	91	WARN_ON(!mutex_is_locked(&hip->extents_lock));
7fcc99f4 CH	92
6af502de CH	93	hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
	94	HFSPLUS_IS_RSRC(inode) ?
	95	HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
	96
1da177e4	97	res = hfs_brec_find(fd);
6af502de	98	if (hip->flags & HFSPLUS_FLG_EXT_NEW) {
1da177e4 LT	99	if (res != -ENOENT)
1da177e4 LT	100	return;
6af502de CH	101	hfs_brec_insert(fd, hip->cached_extents,
	102	sizeof(hfsplus_extent_rec));
	103	hip->flags &= ~(HFSPLUS_FLG_EXT_DIRTY \| HFSPLUS_FLG_EXT_NEW);
1da177e4 LT	104	} else {
	105	if (res)
	106	return;
6af502de CH	107	hfs_bnode_write(fd->bnode, hip->cached_extents,
	108	fd->entryoffset, fd->entrylength);
	109	hip->flags &= ~HFSPLUS_FLG_EXT_DIRTY;
1da177e4 LT	110	}
	111	}
	112
7fcc99f4	113	static void hfsplus_ext_write_extent_locked(struct inode *inode)
1da177e4	114	{
6af502de	115	if (HFSPLUS_I(inode)->flags & HFSPLUS_FLG_EXT_DIRTY) {
1da177e4 LT	116	struct hfs_find_data fd;
1da177e4 LT	117
dd73a01a	118	hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
1da177e4 LT	119	__hfsplus_ext_write_extent(inode, &fd);
	120	hfs_find_exit(&fd);
	121	}
	122	}
	123
7fcc99f4 CH	124	void hfsplus_ext_write_extent(struct inode *inode)
	125	{
	126	mutex_lock(&HFSPLUS_I(inode)->extents_lock);
	127	hfsplus_ext_write_extent_locked(inode);
	128	mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
	129	}
	130
1da177e4 LT	131	static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
	132	struct hfsplus_extent *extent,
	133	u32 cnid, u32 block, u8 type)
	134	{
	135	int res;
	136
	137	hfsplus_ext_build_key(fd->search_key, cnid, block, type);
	138	fd->key->ext.cnid = 0;
	139	res = hfs_brec_find(fd);
	140	if (res && res != -ENOENT)
	141	return res;
	142	if (fd->key->ext.cnid != fd->search_key->ext.cnid \|\|
	143	fd->key->ext.fork_type != fd->search_key->ext.fork_type)
	144	return -ENOENT;
	145	if (fd->entrylength != sizeof(hfsplus_extent_rec))
	146	return -EIO;
	147	hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec));
	148	return 0;
	149	}
	150
	151	static inline int __hfsplus_ext_cache_extent(struct hfs_find_data fd, struct inode inode, u32 block)
	152	{
6af502de	153	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	154	int res;
1da177e4 LT	155
7fcc99f4 CH	156	WARN_ON(!mutex_is_locked(&hip->extents_lock));
7fcc99f4 CH	157
6af502de	158	if (hip->flags & HFSPLUS_FLG_EXT_DIRTY)
1da177e4 LT	159	__hfsplus_ext_write_extent(inode, fd);
1da177e4 LT	160
6af502de CH	161	res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
	162	block, HFSPLUS_IS_RSRC(inode) ?
	163	HFSPLUS_TYPE_RSRC :
	164	HFSPLUS_TYPE_DATA);
1da177e4	165	if (!res) {
6af502de CH	166	hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
6af502de CH	167	hip->cached_blocks = hfsplus_ext_block_count(hip->cached_extents);
1da177e4	168	} else {
6af502de CH	169	hip->cached_start = hip->cached_blocks = 0;
6af502de CH	170	hip->flags &= ~(HFSPLUS_FLG_EXT_DIRTY \| HFSPLUS_FLG_EXT_NEW);
1da177e4 LT	171	}
	172	return res;
	173	}
	174
	175	static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
	176	{
6af502de	177	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	178	struct hfs_find_data fd;
	179	int res;
	180
6af502de CH	181	if (block >= hip->cached_start &&
6af502de CH	182	block < hip->cached_start + hip->cached_blocks)
1da177e4 LT	183	return 0;
1da177e4 LT	184
dd73a01a	185	hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
1da177e4 LT	186	res = __hfsplus_ext_cache_extent(&fd, inode, block);
	187	hfs_find_exit(&fd);
	188	return res;
	189	}
	190
	191	/* Get a block at iblock for inode, possibly allocating if create */
	192	int hfsplus_get_block(struct inode *inode, sector_t iblock,
	193	struct buffer_head *bh_result, int create)
	194	{
dd73a01a CH	195	struct super_block *sb = inode->i_sb;
dd73a01a CH	196	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
6af502de	197	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	198	int res = -EIO;
	199	u32 ablock, dblock, mask;
	200	int shift;
	201
1da177e4	202	/* Convert inode block to disk allocation block */
dd73a01a CH	203	shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
dd73a01a CH	204	ablock = iblock >> sbi->fs_shift;
1da177e4	205
6af502de CH	206	if (iblock >= hip->fs_blocks) {
6af502de CH	207	if (iblock > hip->fs_blocks \|\| !create)
1da177e4	208	return -EIO;
6af502de	209	if (ablock >= hip->alloc_blocks) {
1da177e4 LT	210	res = hfsplus_file_extend(inode);
	211	if (res)
	212	return res;
	213	}
	214	} else
	215	create = 0;
	216
6af502de CH	217	if (ablock < hip->first_blocks) {
6af502de CH	218	dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
1da177e4 LT	219	goto done;
	220	}
	221
248736c2 ES	222	if (inode->i_ino == HFSPLUS_EXT_CNID)
	223	return -EIO;
	224
6af502de	225	mutex_lock(&hip->extents_lock);
1da177e4 LT	226	res = hfsplus_ext_read_extent(inode, ablock);
1da177e4 LT	227	if (!res) {
6af502de CH	228	dblock = hfsplus_ext_find_block(hip->cached_extents,
6af502de CH	229	ablock - hip->cached_start);
1da177e4	230	} else {
6af502de	231	mutex_unlock(&hip->extents_lock);
1da177e4 LT	232	return -EIO;
1da177e4 LT	233	}
6af502de	234	mutex_unlock(&hip->extents_lock);
1da177e4 LT	235
	236	done:
	237	dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
dd73a01a CH	238	mask = (1 << sbi->fs_shift) - 1;
dd73a01a CH	239	map_bh(bh_result, sb, (dblock << sbi->fs_shift) + sbi->blockoffset + (iblock & mask));
1da177e4 LT	240	if (create) {
1da177e4 LT	241	set_buffer_new(bh_result);
6af502de CH	242	hip->phys_size += sb->s_blocksize;
6af502de CH	243	hip->fs_blocks++;
1da177e4 LT	244	inode_add_bytes(inode, sb->s_blocksize);
	245	mark_inode_dirty(inode);
	246	}
	247	return 0;
	248	}
	249
	250	static void hfsplus_dump_extent(struct hfsplus_extent *extent)
	251	{
	252	int i;
	253
	254	dprint(DBG_EXTENT, " ");
	255	for (i = 0; i < 8; i++)
	256	dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
	257	be32_to_cpu(extent[i].block_count));
	258	dprint(DBG_EXTENT, "\n");
	259	}
	260
	261	static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
	262	u32 alloc_block, u32 block_count)
	263	{
	264	u32 count, start;
	265	int i;
	266
	267	hfsplus_dump_extent(extent);
	268	for (i = 0; i < 8; extent++, i++) {
	269	count = be32_to_cpu(extent->block_count);
	270	if (offset == count) {
	271	start = be32_to_cpu(extent->start_block);
	272	if (alloc_block != start + count) {
	273	if (++i >= 8)
	274	return -ENOSPC;
	275	extent++;
	276	extent->start_block = cpu_to_be32(alloc_block);
	277	} else
	278	block_count += count;
	279	extent->block_count = cpu_to_be32(block_count);
	280	return 0;
	281	} else if (offset < count)
	282	break;
	283	offset -= count;
	284	}
	285	/* panic? */
	286	return -EIO;
	287	}
	288
	289	static int hfsplus_free_extents(struct super_block *sb,
	290	struct hfsplus_extent *extent,
	291	u32 offset, u32 block_nr)
	292	{
	293	u32 count, start;
	294	int i;
	295
	296	hfsplus_dump_extent(extent);
	297	for (i = 0; i < 8; extent++, i++) {
	298	count = be32_to_cpu(extent->block_count);
	299	if (offset == count)
	300	goto found;
	301	else if (offset < count)
	302	break;
	303	offset -= count;
	304	}
	305	/* panic? */
	306	return -EIO;
	307	found:
308	for (;;) {
309	start = be32_to_cpu(extent->start_block);
310	if (count <= block_nr) {
311	hfsplus_block_free(sb, start, count);
312	extent->block_count = 0;
313	extent->start_block = 0;
314	block_nr -= count;
315	} else {
316	count -= block_nr;
317	hfsplus_block_free(sb, start + count, block_nr);
318	extent->block_count = cpu_to_be32(count);
319	block_nr = 0;
320	}
321	if (!block_nr \|\| !i)
322	return 0;
323	i--;
324	extent--;
325	count = be32_to_cpu(extent->block_count);
326	}
327	}
328
329	int hfsplus_free_fork(struct super_block sb, u32 cnid, struct hfsplus_fork_raw fork, int type)
330	{
331	struct hfs_find_data fd;
332	hfsplus_extent_rec ext_entry;
333	u32 total_blocks, blocks, start;
334	int res, i;
335
336	total_blocks = be32_to_cpu(fork->total_blocks);
337	if (!total_blocks)
338	return 0;
339
340	blocks = 0;
341	for (i = 0; i < 8; i++)
342	blocks += be32_to_cpu(fork->extents[i].block_count);
343
344	res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
345	if (res)
346	return res;
347	if (total_blocks == blocks)
348	return 0;
349
dd73a01a	350	hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
1da177e4 LT	351	do {
	352	res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
	353	total_blocks, type);
	354	if (res)
	355	break;
	356	start = be32_to_cpu(fd.key->ext.start_block);
	357	hfsplus_free_extents(sb, ext_entry,
	358	total_blocks - start,
	359	total_blocks);
	360	hfs_brec_remove(&fd);
	361	total_blocks = start;
	362	} while (total_blocks > blocks);
	363	hfs_find_exit(&fd);
	364
	365	return res;
	366	}
	367
	368	int hfsplus_file_extend(struct inode *inode)
	369	{
	370	struct super_block *sb = inode->i_sb;
dd73a01a	371	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
6af502de	372	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	373	u32 start, len, goal;
	374	int res;
	375
dd73a01a CH	376	if (sbi->alloc_file->i_size * 8 <
dd73a01a CH	377	sbi->total_blocks - sbi->free_blocks + 8) {
1da177e4	378	// extend alloc file
dd73a01a CH	379	printk(KERN_ERR "hfs: extend alloc file! (%Lu,%u,%u)\n",
	380	sbi->alloc_file->i_size * 8,
	381	sbi->total_blocks, sbi->free_blocks);
1da177e4	382	return -ENOSPC;
1da177e4 LT	383	}
1da177e4 LT	384
6af502de CH	385	mutex_lock(&hip->extents_lock);
	386	if (hip->alloc_blocks == hip->first_blocks)
	387	goal = hfsplus_ext_lastblock(hip->first_extents);
1da177e4	388	else {
6af502de	389	res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
1da177e4 LT	390	if (res)
1da177e4 LT	391	goto out;
6af502de	392	goal = hfsplus_ext_lastblock(hip->cached_extents);
1da177e4 LT	393	}
1da177e4 LT	394
6af502de	395	len = hip->clump_blocks;
dd73a01a CH	396	start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
dd73a01a CH	397	if (start >= sbi->total_blocks) {
1da177e4 LT	398	start = hfsplus_block_allocate(sb, goal, 0, &len);
	399	if (start >= goal) {
	400	res = -ENOSPC;
	401	goto out;
	402	}
	403	}
	404
	405	dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
6af502de CH	406
	407	if (hip->alloc_blocks <= hip->first_blocks) {
	408	if (!hip->first_blocks) {
1da177e4 LT	409	dprint(DBG_EXTENT, "first extents\n");
1da177e4 LT	410	/* no extents yet */
6af502de CH	411	hip->first_extents[0].start_block = cpu_to_be32(start);
6af502de CH	412	hip->first_extents[0].block_count = cpu_to_be32(len);
1da177e4 LT	413	res = 0;
	414	} else {
	415	/* try to append to extents in inode */
6af502de CH	416	res = hfsplus_add_extent(hip->first_extents,
6af502de CH	417	hip->alloc_blocks,
1da177e4 LT	418	start, len);
	419	if (res == -ENOSPC)
	420	goto insert_extent;
	421	}
	422	if (!res) {
6af502de CH	423	hfsplus_dump_extent(hip->first_extents);
6af502de CH	424	hip->first_blocks += len;
1da177e4 LT	425	}
1da177e4 LT	426	} else {
6af502de CH	427	res = hfsplus_add_extent(hip->cached_extents,
6af502de CH	428	hip->alloc_blocks - hip->cached_start,
1da177e4 LT	429	start, len);
1da177e4 LT	430	if (!res) {
6af502de CH	431	hfsplus_dump_extent(hip->cached_extents);
	432	hip->flags \|= HFSPLUS_FLG_EXT_DIRTY;
	433	hip->cached_blocks += len;
1da177e4 LT	434	} else if (res == -ENOSPC)
	435	goto insert_extent;
	436	}
	437	out:
6af502de	438	mutex_unlock(&hip->extents_lock);
1da177e4	439	if (!res) {
6af502de	440	hip->alloc_blocks += len;
1da177e4 LT	441	mark_inode_dirty(inode);
	442	}
	443	return res;
	444
	445	insert_extent:
	446	dprint(DBG_EXTENT, "insert new extent\n");
7fcc99f4	447	hfsplus_ext_write_extent_locked(inode);
1da177e4	448
6af502de CH	449	memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
	450	hip->cached_extents[0].start_block = cpu_to_be32(start);
	451	hip->cached_extents[0].block_count = cpu_to_be32(len);
	452	hfsplus_dump_extent(hip->cached_extents);
	453	hip->flags \|= HFSPLUS_FLG_EXT_DIRTY \| HFSPLUS_FLG_EXT_NEW;
	454	hip->cached_start = hip->alloc_blocks;
	455	hip->cached_blocks = len;
1da177e4 LT	456
	457	res = 0;
	458	goto out;
	459	}
	460
	461	void hfsplus_file_truncate(struct inode *inode)
	462	{
	463	struct super_block *sb = inode->i_sb;
6af502de	464	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	465	struct hfs_find_data fd;
	466	u32 alloc_cnt, blk_cnt, start;
	467	int res;
	468
6af502de CH	469	dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n",
	470	inode->i_ino, (long long)hip->phys_size, inode->i_size);
	471
	472	if (inode->i_size > hip->phys_size) {
1da177e4 LT	473	struct address_space *mapping = inode->i_mapping;
1da177e4 LT	474	struct page *page;
7c0efc62 NP	475	void *fsdata;
7c0efc62 NP	476	u32 size = inode->i_size;
1da177e4 LT	477	int res;
1da177e4 LT	478
7c0efc62 NP	479	res = pagecache_write_begin(NULL, mapping, size, 0,
	480	AOP_FLAG_UNINTERRUPTIBLE,
	481	&page, &fsdata);
1da177e4	482	if (res)
7c0efc62 NP	483	return;
	484	res = pagecache_write_end(NULL, mapping, size, 0, 0, page, fsdata);
	485	if (res < 0)
	486	return;
1da177e4 LT	487	mark_inode_dirty(inode);
1da177e4 LT	488	return;
6af502de	489	} else if (inode->i_size == hip->phys_size)
f76d28d2 RZ	490	return;
f76d28d2 RZ	491
dd73a01a CH	492	blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
dd73a01a CH	493	HFSPLUS_SB(sb)->alloc_blksz_shift;
6af502de	494	alloc_cnt = hip->alloc_blocks;
1da177e4 LT	495	if (blk_cnt == alloc_cnt)
	496	goto out;
	497
6af502de	498	mutex_lock(&hip->extents_lock);
dd73a01a	499	hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
1da177e4	500	while (1) {
6af502de CH	501	if (alloc_cnt == hip->first_blocks) {
6af502de CH	502	hfsplus_free_extents(sb, hip->first_extents,
1da177e4	503	alloc_cnt, alloc_cnt - blk_cnt);
6af502de CH	504	hfsplus_dump_extent(hip->first_extents);
6af502de CH	505	hip->first_blocks = blk_cnt;
1da177e4 LT	506	break;
	507	}
	508	res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
	509	if (res)
	510	break;
6af502de CH	511	start = hip->cached_start;
6af502de CH	512	hfsplus_free_extents(sb, hip->cached_extents,
1da177e4	513	alloc_cnt - start, alloc_cnt - blk_cnt);
6af502de	514	hfsplus_dump_extent(hip->cached_extents);
1da177e4	515	if (blk_cnt > start) {
6af502de	516	hip->flags \|= HFSPLUS_FLG_EXT_DIRTY;
1da177e4 LT	517	break;
	518	}
	519	alloc_cnt = start;
6af502de CH	520	hip->cached_start = hip->cached_blocks = 0;
6af502de CH	521	hip->flags &= ~(HFSPLUS_FLG_EXT_DIRTY \| HFSPLUS_FLG_EXT_NEW);
1da177e4 LT	522	hfs_brec_remove(&fd);
	523	}
	524	hfs_find_exit(&fd);
6af502de	525	mutex_unlock(&hip->extents_lock);
1da177e4	526
6af502de	527	hip->alloc_blocks = blk_cnt;
1da177e4	528	out:
6af502de CH	529	hip->phys_size = inode->i_size;
	530	hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
	531	inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
1da177e4 LT	532	mark_inode_dirty(inode);
1da177e4 LT	533	}