[deliverable/linux.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->extent_state & HFSPLUS_EXT_NEW) {
		if (res != -ENOENT)
			return;
		hfs_brec_insert(fd, hip->cached_extents,
				sizeof(hfsplus_extent_rec));
		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
	} else {
		if (res)
			return;
		hfs_bnode_write(fd->bnode, hip->cached_extents,
				fd->entryoffset, fd->entrylength);
		hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
	}

	/*
	 * We can't just use hfsplus_mark_inode_dirty here, because we
	 * also get called from hfsplus_write_inode, which should not
	 * redirty the inode.  Instead the callers have to be careful
	 * to explicily mark the inode dirty, too.
	 */
	set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
}

static void hfsplus_ext_write_extent_locked(struct inode *inode)
{
	if (HFSPLUS_I(inode)->extent_state & HFSPLUS_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->extent_state & HFSPLUS_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->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_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 was_dirty = 0;
	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);

	/*
	 * hfsplus_ext_read_extent will write out a cached extent into
	 * the extents btree.  In that case we may have to mark the inode
	 * dirty even for a pure read of an extent here.
	 */
	was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
	res = hfsplus_ext_read_extent(inode, ablock);
	if (res) {
		mutex_unlock(&hip->extents_lock);
		return -EIO;
	}
	dblock = hfsplus_ext_find_block(hip->cached_extents,
					ablock - hip->cached_start);
	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);
	}
	if (create || was_dirty)
		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->extent_state |= HFSPLUS_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;
		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
	}
	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->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_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->extent_state |= HFSPLUS_EXT_DIRTY;
			break;
		}
		alloc_cnt = start;
		hip->cached_start = hip->cached_blocks = 0;
		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_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);
	hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
}
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);
b33b7921	98	if (hip->extent_state & HFSPLUS_EXT_NEW) {
1da177e4 LT	99	if (res != -ENOENT)
1da177e4 LT	100	return;
6af502de CH	101	hfs_brec_insert(fd, hip->cached_extents,
6af502de CH	102	sizeof(hfsplus_extent_rec));
b33b7921	103	hip->extent_state &= ~(HFSPLUS_EXT_DIRTY \| HFSPLUS_EXT_NEW);
1da177e4 LT	104	} else {
	105	if (res)
	106	return;
6af502de CH	107	hfs_bnode_write(fd->bnode, hip->cached_extents,
6af502de CH	108	fd->entryoffset, fd->entrylength);
b33b7921	109	hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
1da177e4	110	}
e3494705 CH	111
	112	/*
	113	* We can't just use hfsplus_mark_inode_dirty here, because we
	114	* also get called from hfsplus_write_inode, which should not
	115	* redirty the inode. Instead the callers have to be careful
	116	* to explicily mark the inode dirty, too.
	117	*/
	118	set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
1da177e4 LT	119	}
1da177e4 LT	120
7fcc99f4	121	static void hfsplus_ext_write_extent_locked(struct inode *inode)
1da177e4	122	{
b33b7921	123	if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
1da177e4 LT	124	struct hfs_find_data fd;
1da177e4 LT	125
dd73a01a	126	hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
1da177e4 LT	127	__hfsplus_ext_write_extent(inode, &fd);
	128	hfs_find_exit(&fd);
	129	}
	130	}
	131
7fcc99f4 CH	132	void hfsplus_ext_write_extent(struct inode *inode)
	133	{
	134	mutex_lock(&HFSPLUS_I(inode)->extents_lock);
	135	hfsplus_ext_write_extent_locked(inode);
	136	mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
	137	}
	138
1da177e4 LT	139	static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
	140	struct hfsplus_extent *extent,
	141	u32 cnid, u32 block, u8 type)
	142	{
	143	int res;
	144
	145	hfsplus_ext_build_key(fd->search_key, cnid, block, type);
	146	fd->key->ext.cnid = 0;
	147	res = hfs_brec_find(fd);
	148	if (res && res != -ENOENT)
	149	return res;
	150	if (fd->key->ext.cnid != fd->search_key->ext.cnid \|\|
	151	fd->key->ext.fork_type != fd->search_key->ext.fork_type)
	152	return -ENOENT;
	153	if (fd->entrylength != sizeof(hfsplus_extent_rec))
	154	return -EIO;
	155	hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec));
	156	return 0;
	157	}
	158
	159	static inline int __hfsplus_ext_cache_extent(struct hfs_find_data fd, struct inode inode, u32 block)
	160	{
6af502de	161	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	162	int res;
1da177e4 LT	163
7fcc99f4 CH	164	WARN_ON(!mutex_is_locked(&hip->extents_lock));
7fcc99f4 CH	165
b33b7921	166	if (hip->extent_state & HFSPLUS_EXT_DIRTY)
1da177e4 LT	167	__hfsplus_ext_write_extent(inode, fd);
1da177e4 LT	168
6af502de CH	169	res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
	170	block, HFSPLUS_IS_RSRC(inode) ?
	171	HFSPLUS_TYPE_RSRC :
	172	HFSPLUS_TYPE_DATA);
1da177e4	173	if (!res) {
6af502de CH	174	hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
6af502de CH	175	hip->cached_blocks = hfsplus_ext_block_count(hip->cached_extents);
1da177e4	176	} else {
6af502de	177	hip->cached_start = hip->cached_blocks = 0;
b33b7921	178	hip->extent_state &= ~(HFSPLUS_EXT_DIRTY \| HFSPLUS_EXT_NEW);
1da177e4 LT	179	}
	180	return res;
	181	}
	182
	183	static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
	184	{
6af502de	185	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	186	struct hfs_find_data fd;
	187	int res;
	188
6af502de CH	189	if (block >= hip->cached_start &&
6af502de CH	190	block < hip->cached_start + hip->cached_blocks)
1da177e4 LT	191	return 0;
1da177e4 LT	192
dd73a01a	193	hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
1da177e4 LT	194	res = __hfsplus_ext_cache_extent(&fd, inode, block);
	195	hfs_find_exit(&fd);
	196	return res;
	197	}
	198
	199	/* Get a block at iblock for inode, possibly allocating if create */
	200	int hfsplus_get_block(struct inode *inode, sector_t iblock,
	201	struct buffer_head *bh_result, int create)
	202	{
dd73a01a CH	203	struct super_block *sb = inode->i_sb;
dd73a01a CH	204	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
6af502de	205	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	206	int res = -EIO;
1da177e4 LT	207	u32 ablock, dblock, mask;
e3494705	208	int was_dirty = 0;
1da177e4 LT	209	int shift;
1da177e4 LT	210
1da177e4	211	/* Convert inode block to disk allocation block */
dd73a01a CH	212	shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
dd73a01a CH	213	ablock = iblock >> sbi->fs_shift;
1da177e4	214
6af502de CH	215	if (iblock >= hip->fs_blocks) {
6af502de CH	216	if (iblock > hip->fs_blocks \|\| !create)
1da177e4	217	return -EIO;
6af502de	218	if (ablock >= hip->alloc_blocks) {
1da177e4 LT	219	res = hfsplus_file_extend(inode);
	220	if (res)
	221	return res;
	222	}
	223	} else
	224	create = 0;
	225
6af502de CH	226	if (ablock < hip->first_blocks) {
6af502de CH	227	dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
1da177e4 LT	228	goto done;
	229	}
	230
248736c2 ES	231	if (inode->i_ino == HFSPLUS_EXT_CNID)
	232	return -EIO;
	233
6af502de	234	mutex_lock(&hip->extents_lock);
e3494705 CH	235
	236	/*
	237	* hfsplus_ext_read_extent will write out a cached extent into
	238	* the extents btree. In that case we may have to mark the inode
	239	* dirty even for a pure read of an extent here.
	240	*/
	241	was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
1da177e4	242	res = hfsplus_ext_read_extent(inode, ablock);
e3494705	243	if (res) {
6af502de	244	mutex_unlock(&hip->extents_lock);
1da177e4 LT	245	return -EIO;
1da177e4 LT	246	}
e3494705 CH	247	dblock = hfsplus_ext_find_block(hip->cached_extents,
e3494705 CH	248	ablock - hip->cached_start);
6af502de	249	mutex_unlock(&hip->extents_lock);
1da177e4 LT	250
	251	done:
	252	dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
dd73a01a CH	253	mask = (1 << sbi->fs_shift) - 1;
dd73a01a CH	254	map_bh(bh_result, sb, (dblock << sbi->fs_shift) + sbi->blockoffset + (iblock & mask));
1da177e4 LT	255	if (create) {
1da177e4 LT	256	set_buffer_new(bh_result);
6af502de CH	257	hip->phys_size += sb->s_blocksize;
6af502de CH	258	hip->fs_blocks++;
1da177e4	259	inode_add_bytes(inode, sb->s_blocksize);
1da177e4	260	}
e3494705 CH	261	if (create \|\| was_dirty)
e3494705 CH	262	mark_inode_dirty(inode);
1da177e4 LT	263	return 0;
	264	}
	265
	266	static void hfsplus_dump_extent(struct hfsplus_extent *extent)
	267	{
	268	int i;
	269
	270	dprint(DBG_EXTENT, " ");
	271	for (i = 0; i < 8; i++)
	272	dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
	273	be32_to_cpu(extent[i].block_count));
	274	dprint(DBG_EXTENT, "\n");
	275	}
	276
	277	static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
	278	u32 alloc_block, u32 block_count)
	279	{
	280	u32 count, start;
	281	int i;
	282
	283	hfsplus_dump_extent(extent);
	284	for (i = 0; i < 8; extent++, i++) {
	285	count = be32_to_cpu(extent->block_count);
	286	if (offset == count) {
	287	start = be32_to_cpu(extent->start_block);
	288	if (alloc_block != start + count) {
	289	if (++i >= 8)
	290	return -ENOSPC;
	291	extent++;
	292	extent->start_block = cpu_to_be32(alloc_block);
	293	} else
	294	block_count += count;
	295	extent->block_count = cpu_to_be32(block_count);
	296	return 0;
	297	} else if (offset < count)
	298	break;
	299	offset -= count;
	300	}
	301	/* panic? */
	302	return -EIO;
	303	}
	304
	305	static int hfsplus_free_extents(struct super_block *sb,
	306	struct hfsplus_extent *extent,
	307	u32 offset, u32 block_nr)
	308	{
	309	u32 count, start;
	310	int i;
	311
	312	hfsplus_dump_extent(extent);
	313	for (i = 0; i < 8; extent++, i++) {
	314	count = be32_to_cpu(extent->block_count);
	315	if (offset == count)
	316	goto found;
	317	else if (offset < count)
	318	break;
	319	offset -= count;
	320	}
	321	/* panic? */
	322	return -EIO;
	323	found:
	324	for (;;) {
	325	start = be32_to_cpu(extent->start_block);
	326	if (count <= block_nr) {
327	hfsplus_block_free(sb, start, count);
328	extent->block_count = 0;
329	extent->start_block = 0;
330	block_nr -= count;
331	} else {
332	count -= block_nr;
333	hfsplus_block_free(sb, start + count, block_nr);
334	extent->block_count = cpu_to_be32(count);
335	block_nr = 0;
336	}
337	if (!block_nr \|\| !i)
338	return 0;
339	i--;
340	extent--;
341	count = be32_to_cpu(extent->block_count);
342	}
343	}
344
345	int hfsplus_free_fork(struct super_block sb, u32 cnid, struct hfsplus_fork_raw fork, int type)
346	{
347	struct hfs_find_data fd;
348	hfsplus_extent_rec ext_entry;
349	u32 total_blocks, blocks, start;
350	int res, i;
351
352	total_blocks = be32_to_cpu(fork->total_blocks);
353	if (!total_blocks)
354	return 0;
355
356	blocks = 0;
357	for (i = 0; i < 8; i++)
358	blocks += be32_to_cpu(fork->extents[i].block_count);
359
360	res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
361	if (res)
362	return res;
363	if (total_blocks == blocks)
364	return 0;
365
dd73a01a	366	hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
1da177e4 LT	367	do {
	368	res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
	369	total_blocks, type);
	370	if (res)
	371	break;
	372	start = be32_to_cpu(fd.key->ext.start_block);
	373	hfsplus_free_extents(sb, ext_entry,
	374	total_blocks - start,
	375	total_blocks);
	376	hfs_brec_remove(&fd);
	377	total_blocks = start;
	378	} while (total_blocks > blocks);
	379	hfs_find_exit(&fd);
	380
	381	return res;
	382	}
	383
	384	int hfsplus_file_extend(struct inode *inode)
	385	{
	386	struct super_block *sb = inode->i_sb;
dd73a01a	387	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
6af502de	388	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	389	u32 start, len, goal;
	390	int res;
	391
dd73a01a CH	392	if (sbi->alloc_file->i_size * 8 <
dd73a01a CH	393	sbi->total_blocks - sbi->free_blocks + 8) {
1da177e4	394	// extend alloc file
dd73a01a CH	395	printk(KERN_ERR "hfs: extend alloc file! (%Lu,%u,%u)\n",
	396	sbi->alloc_file->i_size * 8,
	397	sbi->total_blocks, sbi->free_blocks);
1da177e4	398	return -ENOSPC;
1da177e4 LT	399	}
1da177e4 LT	400
6af502de CH	401	mutex_lock(&hip->extents_lock);
	402	if (hip->alloc_blocks == hip->first_blocks)
	403	goal = hfsplus_ext_lastblock(hip->first_extents);
1da177e4	404	else {
6af502de	405	res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
1da177e4 LT	406	if (res)
1da177e4 LT	407	goto out;
6af502de	408	goal = hfsplus_ext_lastblock(hip->cached_extents);
1da177e4 LT	409	}
1da177e4 LT	410
6af502de	411	len = hip->clump_blocks;
dd73a01a CH	412	start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
dd73a01a CH	413	if (start >= sbi->total_blocks) {
1da177e4 LT	414	start = hfsplus_block_allocate(sb, goal, 0, &len);
	415	if (start >= goal) {
	416	res = -ENOSPC;
	417	goto out;
	418	}
	419	}
	420
	421	dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
6af502de CH	422
	423	if (hip->alloc_blocks <= hip->first_blocks) {
	424	if (!hip->first_blocks) {
1da177e4 LT	425	dprint(DBG_EXTENT, "first extents\n");
1da177e4 LT	426	/* no extents yet */
6af502de CH	427	hip->first_extents[0].start_block = cpu_to_be32(start);
6af502de CH	428	hip->first_extents[0].block_count = cpu_to_be32(len);
1da177e4 LT	429	res = 0;
	430	} else {
	431	/* try to append to extents in inode */
6af502de CH	432	res = hfsplus_add_extent(hip->first_extents,
6af502de CH	433	hip->alloc_blocks,
1da177e4 LT	434	start, len);
	435	if (res == -ENOSPC)
	436	goto insert_extent;
	437	}
	438	if (!res) {
6af502de CH	439	hfsplus_dump_extent(hip->first_extents);
6af502de CH	440	hip->first_blocks += len;
1da177e4 LT	441	}
1da177e4 LT	442	} else {
6af502de CH	443	res = hfsplus_add_extent(hip->cached_extents,
6af502de CH	444	hip->alloc_blocks - hip->cached_start,
1da177e4 LT	445	start, len);
1da177e4 LT	446	if (!res) {
6af502de	447	hfsplus_dump_extent(hip->cached_extents);
b33b7921	448	hip->extent_state \|= HFSPLUS_EXT_DIRTY;
6af502de	449	hip->cached_blocks += len;
1da177e4 LT	450	} else if (res == -ENOSPC)
	451	goto insert_extent;
	452	}
	453	out:
6af502de	454	mutex_unlock(&hip->extents_lock);
1da177e4	455	if (!res) {
6af502de	456	hip->alloc_blocks += len;
e3494705	457	hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
1da177e4 LT	458	}
	459	return res;
	460
	461	insert_extent:
	462	dprint(DBG_EXTENT, "insert new extent\n");
7fcc99f4	463	hfsplus_ext_write_extent_locked(inode);
1da177e4	464
6af502de CH	465	memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
	466	hip->cached_extents[0].start_block = cpu_to_be32(start);
	467	hip->cached_extents[0].block_count = cpu_to_be32(len);
	468	hfsplus_dump_extent(hip->cached_extents);
b33b7921	469	hip->extent_state \|= HFSPLUS_EXT_DIRTY \| HFSPLUS_EXT_NEW;
6af502de CH	470	hip->cached_start = hip->alloc_blocks;
6af502de CH	471	hip->cached_blocks = len;
1da177e4 LT	472
	473	res = 0;
	474	goto out;
	475	}
	476
	477	void hfsplus_file_truncate(struct inode *inode)
	478	{
	479	struct super_block *sb = inode->i_sb;
6af502de	480	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	481	struct hfs_find_data fd;
	482	u32 alloc_cnt, blk_cnt, start;
	483	int res;
	484
6af502de CH	485	dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n",
	486	inode->i_ino, (long long)hip->phys_size, inode->i_size);
	487
	488	if (inode->i_size > hip->phys_size) {
1da177e4 LT	489	struct address_space *mapping = inode->i_mapping;
1da177e4 LT	490	struct page *page;
7c0efc62 NP	491	void *fsdata;
7c0efc62 NP	492	u32 size = inode->i_size;
1da177e4 LT	493	int res;
1da177e4 LT	494
7c0efc62 NP	495	res = pagecache_write_begin(NULL, mapping, size, 0,
	496	AOP_FLAG_UNINTERRUPTIBLE,
	497	&page, &fsdata);
1da177e4	498	if (res)
7c0efc62 NP	499	return;
	500	res = pagecache_write_end(NULL, mapping, size, 0, 0, page, fsdata);
	501	if (res < 0)
	502	return;
1da177e4 LT	503	mark_inode_dirty(inode);
1da177e4 LT	504	return;
6af502de	505	} else if (inode->i_size == hip->phys_size)
f76d28d2 RZ	506	return;
f76d28d2 RZ	507
dd73a01a CH	508	blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
dd73a01a CH	509	HFSPLUS_SB(sb)->alloc_blksz_shift;
6af502de	510	alloc_cnt = hip->alloc_blocks;
1da177e4 LT	511	if (blk_cnt == alloc_cnt)
	512	goto out;
	513
6af502de	514	mutex_lock(&hip->extents_lock);
dd73a01a	515	hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
1da177e4	516	while (1) {
6af502de CH	517	if (alloc_cnt == hip->first_blocks) {
6af502de CH	518	hfsplus_free_extents(sb, hip->first_extents,
1da177e4	519	alloc_cnt, alloc_cnt - blk_cnt);
6af502de CH	520	hfsplus_dump_extent(hip->first_extents);
6af502de CH	521	hip->first_blocks = blk_cnt;
1da177e4 LT	522	break;
	523	}
	524	res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
	525	if (res)
	526	break;
6af502de CH	527	start = hip->cached_start;
6af502de CH	528	hfsplus_free_extents(sb, hip->cached_extents,
1da177e4	529	alloc_cnt - start, alloc_cnt - blk_cnt);
6af502de	530	hfsplus_dump_extent(hip->cached_extents);
1da177e4	531	if (blk_cnt > start) {
b33b7921	532	hip->extent_state \|= HFSPLUS_EXT_DIRTY;
1da177e4 LT	533	break;
	534	}
	535	alloc_cnt = start;
6af502de	536	hip->cached_start = hip->cached_blocks = 0;
b33b7921	537	hip->extent_state &= ~(HFSPLUS_EXT_DIRTY \| HFSPLUS_EXT_NEW);
1da177e4 LT	538	hfs_brec_remove(&fd);
	539	}
	540	hfs_find_exit(&fd);
6af502de	541	mutex_unlock(&hip->extents_lock);
1da177e4	542
6af502de	543	hip->alloc_blocks = blk_cnt;
1da177e4	544	out:
6af502de CH	545	hip->phys_size = inode->i_size;
	546	hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
	547	inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
e3494705	548	hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
1da177e4	549	}