[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(hfsplus_btree_key *k1, 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)
{
	int res;

	hfsplus_ext_build_key(fd->search_key, inode->i_ino, HFSPLUS_I(inode).cached_start,
			      HFSPLUS_IS_RSRC(inode) ?  HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
	res = hfs_brec_find(fd);
	if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_NEW) {
		if (res != -ENOENT)
			return;
		hfs_brec_insert(fd, HFSPLUS_I(inode).cached_extents, sizeof(hfsplus_extent_rec));
		HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
	} else {
		if (res)
			return;
		hfs_bnode_write(fd->bnode, HFSPLUS_I(inode).cached_extents, fd->entryoffset, fd->entrylength);
		HFSPLUS_I(inode).flags &= ~HFSPLUS_FLG_EXT_DIRTY;
	}
}

void hfsplus_ext_write_extent(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);
	}
}

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)
{
	int res;

	if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY)
		__hfsplus_ext_write_extent(inode, fd);

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

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

	if (block >= HFSPLUS_I(inode).cached_start &&
	    block < HFSPLUS_I(inode).cached_start + HFSPLUS_I(inode).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;
	int res = -EIO;
	u32 ablock, dblock, mask;
	int shift;

	sb = inode->i_sb;

	/* Convert inode block to disk allocation block */
	shift = HFSPLUS_SB(sb).alloc_blksz_shift - sb->s_blocksize_bits;
	ablock = iblock >> HFSPLUS_SB(sb).fs_shift;

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

	if (ablock < HFSPLUS_I(inode).first_blocks) {
		dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).first_extents, ablock);
		goto done;
	}

	down(&HFSPLUS_I(inode).extents_lock);
	res = hfsplus_ext_read_extent(inode, ablock);
	if (!res) {
		dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).cached_extents, ablock -
					     HFSPLUS_I(inode).cached_start);
	} else {
		up(&HFSPLUS_I(inode).extents_lock);
		return -EIO;
	}
	up(&HFSPLUS_I(inode).extents_lock);

done:
	dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
	mask = (1 << HFSPLUS_SB(sb).fs_shift) - 1;
	map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask));
	if (create) {
		set_buffer_new(bh_result);
		HFSPLUS_I(inode).phys_size += sb->s_blocksize;
		HFSPLUS_I(inode).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;
	u32 start, len, goal;
	int res;

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

	down(&HFSPLUS_I(inode).extents_lock);
	if (HFSPLUS_I(inode).alloc_blocks == HFSPLUS_I(inode).first_blocks)
		goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).first_extents);
	else {
		res = hfsplus_ext_read_extent(inode, HFSPLUS_I(inode).alloc_blocks);
		if (res)
			goto out;
		goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).cached_extents);
	}

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

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

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

	res = 0;
	goto out;
}

void hfsplus_file_truncate(struct inode *inode)
{
	struct super_block *sb = inode->i_sb;
	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)HFSPLUS_I(inode).phys_size, inode->i_size);
	if (inode->i_size > HFSPLUS_I(inode).phys_size) {
		struct address_space *mapping = inode->i_mapping;
		struct page *page;
		u32 size = inode->i_size - 1;
		int res;

		page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT);
		if (!page)
			return;
		size &= PAGE_CACHE_SIZE - 1;
		size++;
		res = mapping->a_ops->prepare_write(NULL, page, size, size);
		if (!res)
			res = mapping->a_ops->commit_write(NULL, page, size, size);
		if (res)
			inode->i_size = HFSPLUS_I(inode).phys_size;
		unlock_page(page);
		page_cache_release(page);
		mark_inode_dirty(inode);
		return;
	} else if (inode->i_size == HFSPLUS_I(inode).phys_size)
		return;

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

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

	HFSPLUS_I(inode).alloc_blocks = blk_cnt;
out:
	HFSPLUS_I(inode).phys_size = inode->i_size;
	HFSPLUS_I(inode).fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
	inode_set_bytes(inode, HFSPLUS_I(inode).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 */
	19	int hfsplus_ext_cmp_key(hfsplus_btree_key k1, hfsplus_btree_key k2)
	20	{
	21	__be32 k1id, k2id;
	22	__be32 k1s, k2s;
	23
	24	k1id = k1->ext.cnid;
	25	k2id = k2->ext.cnid;
	26	if (k1id != k2id)
	27	return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
	28
	29	if (k1->ext.fork_type != k2->ext.fork_type)
	30	return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
	31
	32	k1s = k1->ext.start_block;
	33	k2s = k2->ext.start_block;
	34	if (k1s == k2s)
	35	return 0;
	36	return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
	37	}
	38
	39	static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
	40	u32 block, u8 type)
	41	{
	42	key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
	43	key->ext.cnid = cpu_to_be32(cnid);
	44	key->ext.start_block = cpu_to_be32(block);
	45	key->ext.fork_type = type;
	46	key->ext.pad = 0;
	47	}
	48
	49	static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
	50	{
	51	int i;
	52	u32 count;
	53
	54	for (i = 0; i < 8; ext++, i++) {
	55	count = be32_to_cpu(ext->block_count);
	56	if (off < count)
	57	return be32_to_cpu(ext->start_block) + off;
	58	off -= count;
	59	}
	60	/* panic? */
	61	return 0;
	62	}
	63
	64	static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
	65	{
	66	int i;
	67	u32 count = 0;
	68
	69	for (i = 0; i < 8; ext++, i++)
	70	count += be32_to_cpu(ext->block_count);
	71	return count;
	72	}
	73
	74	static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
	75	{
	76	int i;
	77
78	ext += 7;
79	for (i = 0; i < 7; ext--, i++)
80	if (ext->block_count)
81	break;
82	return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
83	}
84
85	static void __hfsplus_ext_write_extent(struct inode inode, struct hfs_find_data fd)
86	{
87	int res;
88
89	hfsplus_ext_build_key(fd->search_key, inode->i_ino, HFSPLUS_I(inode).cached_start,
90	HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
91	res = hfs_brec_find(fd);
92	if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_NEW) {
93	if (res != -ENOENT)
94	return;
95	hfs_brec_insert(fd, HFSPLUS_I(inode).cached_extents, sizeof(hfsplus_extent_rec));
96	HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY \| HFSPLUS_FLG_EXT_NEW);
97	} else {
98	if (res)
99	return;
100	hfs_bnode_write(fd->bnode, HFSPLUS_I(inode).cached_extents, fd->entryoffset, fd->entrylength);
101	HFSPLUS_I(inode).flags &= ~HFSPLUS_FLG_EXT_DIRTY;
102	}
103	}
104
105	void hfsplus_ext_write_extent(struct inode *inode)
106	{
107	if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY) {
108	struct hfs_find_data fd;
109
110	hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
111	__hfsplus_ext_write_extent(inode, &fd);
112	hfs_find_exit(&fd);
113	}
114	}
115
116	static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
117	struct hfsplus_extent *extent,
118	u32 cnid, u32 block, u8 type)
119	{
120	int res;
121
122	hfsplus_ext_build_key(fd->search_key, cnid, block, type);
123	fd->key->ext.cnid = 0;
124	res = hfs_brec_find(fd);
125	if (res && res != -ENOENT)
126	return res;
127	if (fd->key->ext.cnid != fd->search_key->ext.cnid \|\|
128	fd->key->ext.fork_type != fd->search_key->ext.fork_type)
129	return -ENOENT;
130	if (fd->entrylength != sizeof(hfsplus_extent_rec))
131	return -EIO;
132	hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec));
133	return 0;
134	}
135
136	static inline int __hfsplus_ext_cache_extent(struct hfs_find_data fd, struct inode inode, u32 block)
137	{
138	int res;
139
140	if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY)
141	__hfsplus_ext_write_extent(inode, fd);
142
143	res = __hfsplus_ext_read_extent(fd, HFSPLUS_I(inode).cached_extents, inode->i_ino,
144	block, HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
145	if (!res) {
146	HFSPLUS_I(inode).cached_start = be32_to_cpu(fd->key->ext.start_block);
147	HFSPLUS_I(inode).cached_blocks = hfsplus_ext_block_count(HFSPLUS_I(inode).cached_extents);
148	} else {
149	HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0;
150	HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY \| HFSPLUS_FLG_EXT_NEW);
151	}
152	return res;
153	}
154
155	static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
156	{
157	struct hfs_find_data fd;
158	int res;
159
160	if (block >= HFSPLUS_I(inode).cached_start &&
161	block < HFSPLUS_I(inode).cached_start + HFSPLUS_I(inode).cached_blocks)
162	return 0;
163
164	hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
165	res = __hfsplus_ext_cache_extent(&fd, inode, block);
166	hfs_find_exit(&fd);
167	return res;
168	}
169
170	/* Get a block at iblock for inode, possibly allocating if create */
171	int hfsplus_get_block(struct inode *inode, sector_t iblock,
172	struct buffer_head *bh_result, int create)
173	{
174	struct super_block *sb;
175	int res = -EIO;
176	u32 ablock, dblock, mask;
177	int shift;
178
179	sb = inode->i_sb;
180
181	/* Convert inode block to disk allocation block */
182	shift = HFSPLUS_SB(sb).alloc_blksz_shift - sb->s_blocksize_bits;
183	ablock = iblock >> HFSPLUS_SB(sb).fs_shift;
184
185	if (iblock >= HFSPLUS_I(inode).fs_blocks) {
186	if (iblock > HFSPLUS_I(inode).fs_blocks \|\| !create)
187	return -EIO;
188	if (ablock >= HFSPLUS_I(inode).alloc_blocks) {
189	res = hfsplus_file_extend(inode);
190	if (res)
191	return res;
192	}
193	} else
194	create = 0;
195
196	if (ablock < HFSPLUS_I(inode).first_blocks) {
197	dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).first_extents, ablock);
198	goto done;
199	}
200
201	down(&HFSPLUS_I(inode).extents_lock);
202	res = hfsplus_ext_read_extent(inode, ablock);
203	if (!res) {
204	dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).cached_extents, ablock -
205	HFSPLUS_I(inode).cached_start);
206	} else {
207	up(&HFSPLUS_I(inode).extents_lock);
208	return -EIO;
209	}
210	up(&HFSPLUS_I(inode).extents_lock);
211
212	done:
213	dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
214	mask = (1 << HFSPLUS_SB(sb).fs_shift) - 1;
215	map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask));
216	if (create) {
217	set_buffer_new(bh_result);
218	HFSPLUS_I(inode).phys_size += sb->s_blocksize;
219	HFSPLUS_I(inode).fs_blocks++;
220	inode_add_bytes(inode, sb->s_blocksize);
221	mark_inode_dirty(inode);
222	}
223	return 0;
224	}
225
226	static void hfsplus_dump_extent(struct hfsplus_extent *extent)
227	{
228	int i;
229
230	dprint(DBG_EXTENT, " ");
231	for (i = 0; i < 8; i++)
232	dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
233	be32_to_cpu(extent[i].block_count));
234	dprint(DBG_EXTENT, "\n");
235	}
236
237	static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
238	u32 alloc_block, u32 block_count)
239	{
240	u32 count, start;
241	int i;
242
243	hfsplus_dump_extent(extent);
244	for (i = 0; i < 8; extent++, i++) {
245	count = be32_to_cpu(extent->block_count);
246	if (offset == count) {
247	start = be32_to_cpu(extent->start_block);
248	if (alloc_block != start + count) {
249	if (++i >= 8)
250	return -ENOSPC;
251	extent++;
252	extent->start_block = cpu_to_be32(alloc_block);
253	} else
254	block_count += count;
255	extent->block_count = cpu_to_be32(block_count);
256	return 0;
257	} else if (offset < count)
258	break;
259	offset -= count;
260	}
261	/* panic? */
262	return -EIO;
263	}
264
265	static int hfsplus_free_extents(struct super_block *sb,
266	struct hfsplus_extent *extent,
267	u32 offset, u32 block_nr)
268	{
269	u32 count, start;
270	int i;
271
272	hfsplus_dump_extent(extent);
273	for (i = 0; i < 8; extent++, i++) {
274	count = be32_to_cpu(extent->block_count);
275	if (offset == count)
276	goto found;
277	else if (offset < count)
278	break;
279	offset -= count;
280	}
281	/* panic? */
282	return -EIO;
283	found:
284	for (;;) {
285	start = be32_to_cpu(extent->start_block);
286	if (count <= block_nr) {
287	hfsplus_block_free(sb, start, count);
288	extent->block_count = 0;
289	extent->start_block = 0;
290	block_nr -= count;
291	} else {
292	count -= block_nr;
293	hfsplus_block_free(sb, start + count, block_nr);
294	extent->block_count = cpu_to_be32(count);
295	block_nr = 0;
296	}
297	if (!block_nr \|\| !i)
298	return 0;
299	i--;
300	extent--;
301	count = be32_to_cpu(extent->block_count);
302	}
303	}
304
305	int hfsplus_free_fork(struct super_block sb, u32 cnid, struct hfsplus_fork_raw fork, int type)
306	{
307	struct hfs_find_data fd;
308	hfsplus_extent_rec ext_entry;
309	u32 total_blocks, blocks, start;
310	int res, i;
311
312	total_blocks = be32_to_cpu(fork->total_blocks);
313	if (!total_blocks)
314	return 0;
315
316	blocks = 0;
317	for (i = 0; i < 8; i++)
318	blocks += be32_to_cpu(fork->extents[i].block_count);
319
320	res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
321	if (res)
322	return res;
323	if (total_blocks == blocks)
324	return 0;
325
326	hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
327	do {
328	res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
329	total_blocks, type);
330	if (res)
331	break;
332	start = be32_to_cpu(fd.key->ext.start_block);
333	hfsplus_free_extents(sb, ext_entry,
334	total_blocks - start,
335	total_blocks);
336	hfs_brec_remove(&fd);
337	total_blocks = start;
338	} while (total_blocks > blocks);
339	hfs_find_exit(&fd);
340
341	return res;
342	}
343
344	int hfsplus_file_extend(struct inode *inode)
345	{
346	struct super_block *sb = inode->i_sb;
347	u32 start, len, goal;
348	int res;
349
350	if (HFSPLUS_SB(sb).alloc_file->i_size * 8 < HFSPLUS_SB(sb).total_blocks - HFSPLUS_SB(sb).free_blocks + 8) {
351	// extend alloc file
634725a9	352	printk(KERN_ERR "hfs: extend alloc file! (%Lu,%u,%u)\n", HFSPLUS_SB(sb).alloc_file->i_size * 8,
1da177e4 LT	353	HFSPLUS_SB(sb).total_blocks, HFSPLUS_SB(sb).free_blocks);
1da177e4 LT	354	return -ENOSPC;
1da177e4 LT	355	}
	356
	357	down(&HFSPLUS_I(inode).extents_lock);
	358	if (HFSPLUS_I(inode).alloc_blocks == HFSPLUS_I(inode).first_blocks)
	359	goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).first_extents);
	360	else {
	361	res = hfsplus_ext_read_extent(inode, HFSPLUS_I(inode).alloc_blocks);
	362	if (res)
	363	goto out;
	364	goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).cached_extents);
	365	}
	366
	367	len = HFSPLUS_I(inode).clump_blocks;
	368	start = hfsplus_block_allocate(sb, HFSPLUS_SB(sb).total_blocks, goal, &len);
	369	if (start >= HFSPLUS_SB(sb).total_blocks) {
	370	start = hfsplus_block_allocate(sb, goal, 0, &len);
	371	if (start >= goal) {
	372	res = -ENOSPC;
	373	goto out;
	374	}
	375	}
	376
	377	dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
	378	if (HFSPLUS_I(inode).alloc_blocks <= HFSPLUS_I(inode).first_blocks) {
	379	if (!HFSPLUS_I(inode).first_blocks) {
	380	dprint(DBG_EXTENT, "first extents\n");
	381	/* no extents yet */
	382	HFSPLUS_I(inode).first_extents[0].start_block = cpu_to_be32(start);
	383	HFSPLUS_I(inode).first_extents[0].block_count = cpu_to_be32(len);
	384	res = 0;
	385	} else {
	386	/* try to append to extents in inode */
	387	res = hfsplus_add_extent(HFSPLUS_I(inode).first_extents,
	388	HFSPLUS_I(inode).alloc_blocks,
	389	start, len);
	390	if (res == -ENOSPC)
	391	goto insert_extent;
	392	}
	393	if (!res) {
	394	hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
	395	HFSPLUS_I(inode).first_blocks += len;
	396	}
	397	} else {
	398	res = hfsplus_add_extent(HFSPLUS_I(inode).cached_extents,
	399	HFSPLUS_I(inode).alloc_blocks -
	400	HFSPLUS_I(inode).cached_start,
	401	start, len);
	402	if (!res) {
	403	hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
	404	HFSPLUS_I(inode).flags \|= HFSPLUS_FLG_EXT_DIRTY;
	405	HFSPLUS_I(inode).cached_blocks += len;
	406	} else if (res == -ENOSPC)
	407	goto insert_extent;
	408	}
	409	out:
	410	up(&HFSPLUS_I(inode).extents_lock);
	411	if (!res) {
	412	HFSPLUS_I(inode).alloc_blocks += len;
	413	mark_inode_dirty(inode);
	414	}
	415	return res;
	416
	417	insert_extent:
	418	dprint(DBG_EXTENT, "insert new extent\n");
419	hfsplus_ext_write_extent(inode);
420
421	memset(HFSPLUS_I(inode).cached_extents, 0, sizeof(hfsplus_extent_rec));
422	HFSPLUS_I(inode).cached_extents[0].start_block = cpu_to_be32(start);
423	HFSPLUS_I(inode).cached_extents[0].block_count = cpu_to_be32(len);
424	hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
425	HFSPLUS_I(inode).flags \|= HFSPLUS_FLG_EXT_DIRTY \| HFSPLUS_FLG_EXT_NEW;
426	HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).alloc_blocks;
427	HFSPLUS_I(inode).cached_blocks = len;
428
429	res = 0;
430	goto out;
431	}
432
433	void hfsplus_file_truncate(struct inode *inode)
434	{
435	struct super_block *sb = inode->i_sb;
436	struct hfs_find_data fd;
437	u32 alloc_cnt, blk_cnt, start;
438	int res;
439
440	dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n", inode->i_ino,
441	(long long)HFSPLUS_I(inode).phys_size, inode->i_size);
442	if (inode->i_size > HFSPLUS_I(inode).phys_size) {
443	struct address_space *mapping = inode->i_mapping;
444	struct page *page;
445	u32 size = inode->i_size - 1;
446	int res;
447
448	page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT);
449	if (!page)
450	return;
451	size &= PAGE_CACHE_SIZE - 1;
452	size++;
453	res = mapping->a_ops->prepare_write(NULL, page, size, size);
454	if (!res)
455	res = mapping->a_ops->commit_write(NULL, page, size, size);
456	if (res)
457	inode->i_size = HFSPLUS_I(inode).phys_size;
458	unlock_page(page);
459	page_cache_release(page);
460	mark_inode_dirty(inode);
461	return;
f76d28d2 RZ	462	} else if (inode->i_size == HFSPLUS_I(inode).phys_size)
	463	return;
	464
1da177e4 LT	465	blk_cnt = (inode->i_size + HFSPLUS_SB(sb).alloc_blksz - 1) >> HFSPLUS_SB(sb).alloc_blksz_shift;
	466	alloc_cnt = HFSPLUS_I(inode).alloc_blocks;
	467	if (blk_cnt == alloc_cnt)
	468	goto out;
	469
	470	down(&HFSPLUS_I(inode).extents_lock);
	471	hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
	472	while (1) {
	473	if (alloc_cnt == HFSPLUS_I(inode).first_blocks) {
	474	hfsplus_free_extents(sb, HFSPLUS_I(inode).first_extents,
	475	alloc_cnt, alloc_cnt - blk_cnt);
	476	hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
	477	HFSPLUS_I(inode).first_blocks = blk_cnt;
	478	break;
	479	}
	480	res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
	481	if (res)
	482	break;
	483	start = HFSPLUS_I(inode).cached_start;
	484	hfsplus_free_extents(sb, HFSPLUS_I(inode).cached_extents,
	485	alloc_cnt - start, alloc_cnt - blk_cnt);
	486	hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
	487	if (blk_cnt > start) {
	488	HFSPLUS_I(inode).flags \|= HFSPLUS_FLG_EXT_DIRTY;
	489	break;
	490	}
	491	alloc_cnt = start;
	492	HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0;
	493	HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY \| HFSPLUS_FLG_EXT_NEW);
	494	hfs_brec_remove(&fd);
	495	}
	496	hfs_find_exit(&fd);
	497	up(&HFSPLUS_I(inode).extents_lock);
	498
	499	HFSPLUS_I(inode).alloc_blocks = blk_cnt;
	500	out:
	501	HFSPLUS_I(inode).phys_size = inode->i_size;
	502	HFSPLUS_I(inode).fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
	503	inode_set_bytes(inode, HFSPLUS_I(inode).fs_blocks << sb->s_blocksize_bits);
	504	mark_inode_dirty(inode);
	505	}