[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 int __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, hfs_find_rec_by_key);
	if (hip->extent_state & HFSPLUS_EXT_NEW) {
		if (res != -ENOENT)
			return res;
		hfs_brec_insert(fd, hip->cached_extents,
				sizeof(hfsplus_extent_rec));
		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
	} else {
		if (res)
			return res;
		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);

	return 0;
}

static int hfsplus_ext_write_extent_locked(struct inode *inode)
{
	int res = 0;

	if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
		struct hfs_find_data fd;

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

int hfsplus_ext_write_extent(struct inode *inode)
{
	int res;

	mutex_lock(&HFSPLUS_I(inode)->extents_lock);
	res = hfsplus_ext_write_extent_locked(inode);
	mutex_unlock(&HFSPLUS_I(inode)->extents_lock);

	return res;
}

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, hfs_find_rec_by_key);
	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) {
		res = __hfsplus_ext_write_extent(inode, fd);
		if (res)
			return res;
	}

	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;

	res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
	if (!res) {
		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;
	sector_t sector;
	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:
	hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
		inode->i_ino, (long long)iblock, dblock);

	mask = (1 << sbi->fs_shift) - 1;
	sector = ((sector_t)dblock << sbi->fs_shift) +
		  sbi->blockoffset + (iblock & mask);
	map_bh(bh_result, sb, sector);

	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;

	hfs_dbg(EXTENT, "   ");
	for (i = 0; i < 8; i++)
		hfs_dbg_cont(EXTENT, " %u:%u",
			     be32_to_cpu(extent[i].start_block),
			     be32_to_cpu(extent[i].block_count));
	hfs_dbg_cont(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;
	int err = 0;

	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) {
			err = hfsplus_block_free(sb, start, count);
			if (err) {
				pr_err("can't free extent\n");
				hfs_dbg(EXTENT, " start: %u count: %u\n",
					start, count);
			}
			extent->block_count = 0;
			extent->start_block = 0;
			block_nr -= count;
		} else {
			count -= block_nr;
			err = hfsplus_block_free(sb, start + count, block_nr);
			if (err) {
				pr_err("can't free extent\n");
				hfs_dbg(EXTENT, " start: %u count: %u\n",
					start, count);
			}
			extent->block_count = cpu_to_be32(count);
			block_nr = 0;
		}
		if (!block_nr || !i) {
			/*
			 * Try to free all extents and
			 * return only last error
			 */
			return err;
		}
		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;

	res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
	if (res)
		return res;
	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 */
		pr_err("extend alloc file! "
				"(%llu,%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;
		}
	}

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

	if (hip->alloc_blocks <= hip->first_blocks) {
		if (!hip->first_blocks) {
			hfs_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:
	hfs_dbg(EXTENT, "insert new extent\n");
	res = hfsplus_ext_write_extent_locked(inode);
	if (res)
		goto out;

	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;

	hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\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;
		loff_t size = inode->i_size;

		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);
	res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
	if (res) {
		mutex_unlock(&hip->extents_lock);
		/* XXX: We lack error handling of hfsplus_file_truncate() */
		return;
	}
	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
d7a475d0	86	static int __hfsplus_ext_write_extent(struct inode *inode,
2753cc28	87	struct hfs_find_data *fd)
1da177e4	88	{
6af502de	89	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	90	int res;
1da177e4 LT	91
7fcc99f4 CH	92	WARN_ON(!mutex_is_locked(&hip->extents_lock));
7fcc99f4 CH	93
6af502de CH	94	hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
	95	HFSPLUS_IS_RSRC(inode) ?
	96	HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
	97
324ef39a	98	res = hfs_brec_find(fd, hfs_find_rec_by_key);
b33b7921	99	if (hip->extent_state & HFSPLUS_EXT_NEW) {
1da177e4	100	if (res != -ENOENT)
d7a475d0	101	return res;
6af502de CH	102	hfs_brec_insert(fd, hip->cached_extents,
6af502de CH	103	sizeof(hfsplus_extent_rec));
b33b7921	104	hip->extent_state &= ~(HFSPLUS_EXT_DIRTY \| HFSPLUS_EXT_NEW);
1da177e4 LT	105	} else {
1da177e4 LT	106	if (res)
d7a475d0	107	return res;
6af502de CH	108	hfs_bnode_write(fd->bnode, hip->cached_extents,
6af502de CH	109	fd->entryoffset, fd->entrylength);
b33b7921	110	hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
1da177e4	111	}
e3494705 CH	112
	113	/*
	114	* We can't just use hfsplus_mark_inode_dirty here, because we
	115	* also get called from hfsplus_write_inode, which should not
	116	* redirty the inode. Instead the callers have to be careful
	117	* to explicily mark the inode dirty, too.
	118	*/
	119	set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
d7a475d0 AK	120
d7a475d0 AK	121	return 0;
1da177e4 LT	122	}
1da177e4 LT	123
dd7f3d54	124	static int hfsplus_ext_write_extent_locked(struct inode *inode)
1da177e4	125	{
d7a475d0	126	int res = 0;
dd7f3d54	127
b33b7921	128	if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
1da177e4 LT	129	struct hfs_find_data fd;
1da177e4 LT	130
dd7f3d54 AK	131	res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
	132	if (res)
	133	return res;
d7a475d0	134	res = __hfsplus_ext_write_extent(inode, &fd);
dd7f3d54	135	hfs_find_exit(&fd);
1da177e4	136	}
d7a475d0	137	return res;
1da177e4 LT	138	}
1da177e4 LT	139
dd7f3d54	140	int hfsplus_ext_write_extent(struct inode *inode)
7fcc99f4	141	{
dd7f3d54 AK	142	int res;
dd7f3d54 AK	143
7fcc99f4	144	mutex_lock(&HFSPLUS_I(inode)->extents_lock);
dd7f3d54	145	res = hfsplus_ext_write_extent_locked(inode);
7fcc99f4	146	mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
dd7f3d54 AK	147
dd7f3d54 AK	148	return res;
7fcc99f4 CH	149	}
7fcc99f4 CH	150
1da177e4 LT	151	static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
	152	struct hfsplus_extent *extent,
	153	u32 cnid, u32 block, u8 type)
	154	{
	155	int res;
	156
	157	hfsplus_ext_build_key(fd->search_key, cnid, block, type);
	158	fd->key->ext.cnid = 0;
324ef39a	159	res = hfs_brec_find(fd, hfs_find_rec_by_key);
1da177e4 LT	160	if (res && res != -ENOENT)
	161	return res;
	162	if (fd->key->ext.cnid != fd->search_key->ext.cnid \|\|
	163	fd->key->ext.fork_type != fd->search_key->ext.fork_type)
	164	return -ENOENT;
	165	if (fd->entrylength != sizeof(hfsplus_extent_rec))
	166	return -EIO;
2753cc28 AS	167	hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
2753cc28 AS	168	sizeof(hfsplus_extent_rec));
1da177e4 LT	169	return 0;
	170	}
	171
2753cc28 AS	172	static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
2753cc28 AS	173	struct inode *inode, u32 block)
1da177e4	174	{
6af502de	175	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	176	int res;
1da177e4 LT	177
7fcc99f4 CH	178	WARN_ON(!mutex_is_locked(&hip->extents_lock));
7fcc99f4 CH	179
d7a475d0 AK	180	if (hip->extent_state & HFSPLUS_EXT_DIRTY) {
	181	res = __hfsplus_ext_write_extent(inode, fd);
	182	if (res)
	183	return res;
	184	}
1da177e4	185
6af502de CH	186	res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
	187	block, HFSPLUS_IS_RSRC(inode) ?
	188	HFSPLUS_TYPE_RSRC :
	189	HFSPLUS_TYPE_DATA);
1da177e4	190	if (!res) {
6af502de	191	hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
2753cc28 AS	192	hip->cached_blocks =
2753cc28 AS	193	hfsplus_ext_block_count(hip->cached_extents);
1da177e4	194	} else {
6af502de	195	hip->cached_start = hip->cached_blocks = 0;
b33b7921	196	hip->extent_state &= ~(HFSPLUS_EXT_DIRTY \| HFSPLUS_EXT_NEW);
1da177e4 LT	197	}
	198	return res;
	199	}
	200
	201	static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
	202	{
6af502de	203	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	204	struct hfs_find_data fd;
	205	int res;
	206
6af502de CH	207	if (block >= hip->cached_start &&
6af502de CH	208	block < hip->cached_start + hip->cached_blocks)
1da177e4 LT	209	return 0;
1da177e4 LT	210
5bd9d99d AK	211	res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
	212	if (!res) {
	213	res = __hfsplus_ext_cache_extent(&fd, inode, block);
	214	hfs_find_exit(&fd);
	215	}
1da177e4 LT	216	return res;
	217	}
	218
	219	/* Get a block at iblock for inode, possibly allocating if create */
	220	int hfsplus_get_block(struct inode *inode, sector_t iblock,
	221	struct buffer_head *bh_result, int create)
	222	{
dd73a01a CH	223	struct super_block *sb = inode->i_sb;
dd73a01a CH	224	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
6af502de	225	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	226	int res = -EIO;
1da177e4 LT	227	u32 ablock, dblock, mask;
bf1a1b31	228	sector_t sector;
e3494705	229	int was_dirty = 0;
1da177e4 LT	230	int shift;
1da177e4 LT	231
1da177e4	232	/* Convert inode block to disk allocation block */
dd73a01a CH	233	shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
dd73a01a CH	234	ablock = iblock >> sbi->fs_shift;
1da177e4	235
6af502de CH	236	if (iblock >= hip->fs_blocks) {
6af502de CH	237	if (iblock > hip->fs_blocks \|\| !create)
1da177e4	238	return -EIO;
6af502de	239	if (ablock >= hip->alloc_blocks) {
1da177e4 LT	240	res = hfsplus_file_extend(inode);
	241	if (res)
	242	return res;
	243	}
	244	} else
	245	create = 0;
	246
6af502de CH	247	if (ablock < hip->first_blocks) {
6af502de CH	248	dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
1da177e4 LT	249	goto done;
	250	}
	251
248736c2 ES	252	if (inode->i_ino == HFSPLUS_EXT_CNID)
	253	return -EIO;
	254
6af502de	255	mutex_lock(&hip->extents_lock);
e3494705 CH	256
	257	/*
	258	* hfsplus_ext_read_extent will write out a cached extent into
	259	* the extents btree. In that case we may have to mark the inode
	260	* dirty even for a pure read of an extent here.
	261	*/
	262	was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
1da177e4	263	res = hfsplus_ext_read_extent(inode, ablock);
e3494705	264	if (res) {
6af502de	265	mutex_unlock(&hip->extents_lock);
1da177e4 LT	266	return -EIO;
1da177e4 LT	267	}
e3494705 CH	268	dblock = hfsplus_ext_find_block(hip->cached_extents,
e3494705 CH	269	ablock - hip->cached_start);
6af502de	270	mutex_unlock(&hip->extents_lock);
1da177e4 LT	271
1da177e4 LT	272	done:
c2b3e1f7	273	hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
2753cc28	274	inode->i_ino, (long long)iblock, dblock);
bf1a1b31	275
dd73a01a	276	mask = (1 << sbi->fs_shift) - 1;
bf1a1b31 CH	277	sector = ((sector_t)dblock << sbi->fs_shift) +
	278	sbi->blockoffset + (iblock & mask);
	279	map_bh(bh_result, sb, sector);
	280
1da177e4 LT	281	if (create) {
1da177e4 LT	282	set_buffer_new(bh_result);
6af502de CH	283	hip->phys_size += sb->s_blocksize;
6af502de CH	284	hip->fs_blocks++;
1da177e4	285	inode_add_bytes(inode, sb->s_blocksize);
1da177e4	286	}
e3494705 CH	287	if (create \|\| was_dirty)
e3494705 CH	288	mark_inode_dirty(inode);
1da177e4 LT	289	return 0;
	290	}
	291
	292	static void hfsplus_dump_extent(struct hfsplus_extent *extent)
	293	{
	294	int i;
	295
c2b3e1f7	296	hfs_dbg(EXTENT, " ");
1da177e4	297	for (i = 0; i < 8; i++)
c2b3e1f7 JP	298	hfs_dbg_cont(EXTENT, " %u:%u",
	299	be32_to_cpu(extent[i].start_block),
	300	be32_to_cpu(extent[i].block_count));
	301	hfs_dbg_cont(EXTENT, "\n");
1da177e4 LT	302	}
	303
	304	static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
	305	u32 alloc_block, u32 block_count)
	306	{
	307	u32 count, start;
	308	int i;
	309
	310	hfsplus_dump_extent(extent);
	311	for (i = 0; i < 8; extent++, i++) {
	312	count = be32_to_cpu(extent->block_count);
	313	if (offset == count) {
	314	start = be32_to_cpu(extent->start_block);
	315	if (alloc_block != start + count) {
	316	if (++i >= 8)
	317	return -ENOSPC;
	318	extent++;
	319	extent->start_block = cpu_to_be32(alloc_block);
	320	} else
	321	block_count += count;
	322	extent->block_count = cpu_to_be32(block_count);
	323	return 0;
	324	} else if (offset < count)
	325	break;
	326	offset -= count;
	327	}
	328	/* panic? */
	329	return -EIO;
	330	}
	331
	332	static int hfsplus_free_extents(struct super_block *sb,
	333	struct hfsplus_extent *extent,
	334	u32 offset, u32 block_nr)
	335	{
	336	u32 count, start;
	337	int i;
1b243fd3	338	int err = 0;
1da177e4 LT	339
	340	hfsplus_dump_extent(extent);
	341	for (i = 0; i < 8; extent++, i++) {
	342	count = be32_to_cpu(extent->block_count);
	343	if (offset == count)
	344	goto found;
	345	else if (offset < count)
	346	break;
	347	offset -= count;
	348	}
	349	/* panic? */
	350	return -EIO;
	351	found:
	352	for (;;) {
	353	start = be32_to_cpu(extent->start_block);
	354	if (count <= block_nr) {
1b243fd3 VD	355	err = hfsplus_block_free(sb, start, count);
1b243fd3 VD	356	if (err) {
d6142673	357	pr_err("can't free extent\n");
c2b3e1f7	358	hfs_dbg(EXTENT, " start: %u count: %u\n",
1b243fd3 VD	359	start, count);
1b243fd3 VD	360	}
1da177e4 LT	361	extent->block_count = 0;
	362	extent->start_block = 0;
	363	block_nr -= count;
	364	} else {
	365	count -= block_nr;
1b243fd3 VD	366	err = hfsplus_block_free(sb, start + count, block_nr);
1b243fd3 VD	367	if (err) {
d6142673	368	pr_err("can't free extent\n");
c2b3e1f7	369	hfs_dbg(EXTENT, " start: %u count: %u\n",
1b243fd3 VD	370	start, count);
1b243fd3 VD	371	}
1da177e4 LT	372	extent->block_count = cpu_to_be32(count);
	373	block_nr = 0;
	374	}
1b243fd3 VD	375	if (!block_nr \|\| !i) {
	376	/*
	377	* Try to free all extents and
	378	* return only last error
	379	*/
	380	return err;
	381	}
1da177e4 LT	382	i--;
	383	extent--;
	384	count = be32_to_cpu(extent->block_count);
	385	}
	386	}
	387
2753cc28 AS	388	int hfsplus_free_fork(struct super_block *sb, u32 cnid,
2753cc28 AS	389	struct hfsplus_fork_raw *fork, int type)
1da177e4 LT	390	{
	391	struct hfs_find_data fd;
	392	hfsplus_extent_rec ext_entry;
	393	u32 total_blocks, blocks, start;
	394	int res, i;
	395
	396	total_blocks = be32_to_cpu(fork->total_blocks);
	397	if (!total_blocks)
	398	return 0;
	399
	400	blocks = 0;
	401	for (i = 0; i < 8; i++)
	402	blocks += be32_to_cpu(fork->extents[i].block_count);
	403
	404	res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
	405	if (res)
	406	return res;
	407	if (total_blocks == blocks)
	408	return 0;
	409
5bd9d99d AK	410	res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
	411	if (res)
	412	return res;
1da177e4 LT	413	do {
	414	res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
	415	total_blocks, type);
	416	if (res)
	417	break;
	418	start = be32_to_cpu(fd.key->ext.start_block);
	419	hfsplus_free_extents(sb, ext_entry,
	420	total_blocks - start,
	421	total_blocks);
	422	hfs_brec_remove(&fd);
	423	total_blocks = start;
	424	} while (total_blocks > blocks);
	425	hfs_find_exit(&fd);
	426
	427	return res;
	428	}
	429
	430	int hfsplus_file_extend(struct inode *inode)
	431	{
	432	struct super_block *sb = inode->i_sb;
dd73a01a	433	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
6af502de	434	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	435	u32 start, len, goal;
	436	int res;
	437
1065348d CH	438	if (sbi->alloc_file->i_size * 8 <
1065348d CH	439	sbi->total_blocks - sbi->free_blocks + 8) {
21f2296a	440	/* extend alloc file */
d6142673	441	pr_err("extend alloc file! "
b2837fcf AS	442	"(%llu,%u,%u)\n",
	443	sbi->alloc_file->i_size * 8,
	444	sbi->total_blocks, sbi->free_blocks);
1da177e4	445	return -ENOSPC;
1da177e4 LT	446	}
1da177e4 LT	447
6af502de CH	448	mutex_lock(&hip->extents_lock);
	449	if (hip->alloc_blocks == hip->first_blocks)
	450	goal = hfsplus_ext_lastblock(hip->first_extents);
1da177e4	451	else {
6af502de	452	res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
1da177e4 LT	453	if (res)
1da177e4 LT	454	goto out;
6af502de	455	goal = hfsplus_ext_lastblock(hip->cached_extents);
1da177e4 LT	456	}
1da177e4 LT	457
6af502de	458	len = hip->clump_blocks;
dd73a01a CH	459	start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
dd73a01a CH	460	if (start >= sbi->total_blocks) {
1da177e4 LT	461	start = hfsplus_block_allocate(sb, goal, 0, &len);
	462	if (start >= goal) {
	463	res = -ENOSPC;
	464	goto out;
	465	}
	466	}
	467
c2b3e1f7	468	hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
6af502de CH	469
	470	if (hip->alloc_blocks <= hip->first_blocks) {
	471	if (!hip->first_blocks) {
c2b3e1f7	472	hfs_dbg(EXTENT, "first extents\n");
1da177e4	473	/* no extents yet */
6af502de CH	474	hip->first_extents[0].start_block = cpu_to_be32(start);
6af502de CH	475	hip->first_extents[0].block_count = cpu_to_be32(len);
1da177e4 LT	476	res = 0;
	477	} else {
	478	/* try to append to extents in inode */
6af502de CH	479	res = hfsplus_add_extent(hip->first_extents,
6af502de CH	480	hip->alloc_blocks,
1da177e4 LT	481	start, len);
	482	if (res == -ENOSPC)
	483	goto insert_extent;
	484	}
	485	if (!res) {
6af502de CH	486	hfsplus_dump_extent(hip->first_extents);
6af502de CH	487	hip->first_blocks += len;
1da177e4 LT	488	}
1da177e4 LT	489	} else {
6af502de CH	490	res = hfsplus_add_extent(hip->cached_extents,
6af502de CH	491	hip->alloc_blocks - hip->cached_start,
1da177e4 LT	492	start, len);
1da177e4 LT	493	if (!res) {
6af502de	494	hfsplus_dump_extent(hip->cached_extents);
b33b7921	495	hip->extent_state \|= HFSPLUS_EXT_DIRTY;
6af502de	496	hip->cached_blocks += len;
1da177e4 LT	497	} else if (res == -ENOSPC)
	498	goto insert_extent;
	499	}
	500	out:
6af502de	501	mutex_unlock(&hip->extents_lock);
1da177e4	502	if (!res) {
6af502de	503	hip->alloc_blocks += len;
e3494705	504	hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
1da177e4 LT	505	}
	506	return res;
	507
	508	insert_extent:
c2b3e1f7	509	hfs_dbg(EXTENT, "insert new extent\n");
dd7f3d54 AK	510	res = hfsplus_ext_write_extent_locked(inode);
	511	if (res)
	512	goto out;
1da177e4	513
6af502de CH	514	memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
	515	hip->cached_extents[0].start_block = cpu_to_be32(start);
	516	hip->cached_extents[0].block_count = cpu_to_be32(len);
	517	hfsplus_dump_extent(hip->cached_extents);
b33b7921	518	hip->extent_state \|= HFSPLUS_EXT_DIRTY \| HFSPLUS_EXT_NEW;
6af502de CH	519	hip->cached_start = hip->alloc_blocks;
6af502de CH	520	hip->cached_blocks = len;
1da177e4 LT	521
	522	res = 0;
	523	goto out;
	524	}
	525
	526	void hfsplus_file_truncate(struct inode *inode)
	527	{
	528	struct super_block *sb = inode->i_sb;
6af502de	529	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	530	struct hfs_find_data fd;
	531	u32 alloc_cnt, blk_cnt, start;
	532	int res;
	533
c2b3e1f7 JP	534	hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
c2b3e1f7 JP	535	inode->i_ino, (long long)hip->phys_size, inode->i_size);
6af502de CH	536
6af502de CH	537	if (inode->i_size > hip->phys_size) {
1da177e4 LT	538	struct address_space *mapping = inode->i_mapping;
1da177e4 LT	539	struct page *page;
7c0efc62	540	void *fsdata;
12f267a2	541	loff_t size = inode->i_size;
1da177e4	542
7c0efc62 NP	543	res = pagecache_write_begin(NULL, mapping, size, 0,
	544	AOP_FLAG_UNINTERRUPTIBLE,
	545	&page, &fsdata);
1da177e4	546	if (res)
7c0efc62	547	return;
2753cc28 AS	548	res = pagecache_write_end(NULL, mapping, size,
2753cc28 AS	549	0, 0, page, fsdata);
7c0efc62 NP	550	if (res < 0)
7c0efc62 NP	551	return;
1da177e4 LT	552	mark_inode_dirty(inode);
1da177e4 LT	553	return;
6af502de	554	} else if (inode->i_size == hip->phys_size)
f76d28d2 RZ	555	return;
f76d28d2 RZ	556
dd73a01a CH	557	blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
dd73a01a CH	558	HFSPLUS_SB(sb)->alloc_blksz_shift;
6af502de	559	alloc_cnt = hip->alloc_blocks;
1da177e4 LT	560	if (blk_cnt == alloc_cnt)
	561	goto out;
	562
6af502de	563	mutex_lock(&hip->extents_lock);
5bd9d99d AK	564	res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
	565	if (res) {
	566	mutex_unlock(&hip->extents_lock);
	567	/* XXX: We lack error handling of hfsplus_file_truncate() */
	568	return;
	569	}
1da177e4	570	while (1) {
6af502de CH	571	if (alloc_cnt == hip->first_blocks) {
6af502de CH	572	hfsplus_free_extents(sb, hip->first_extents,
1da177e4	573	alloc_cnt, alloc_cnt - blk_cnt);
6af502de CH	574	hfsplus_dump_extent(hip->first_extents);
6af502de CH	575	hip->first_blocks = blk_cnt;
1da177e4 LT	576	break;
	577	}
	578	res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
	579	if (res)
	580	break;
6af502de CH	581	start = hip->cached_start;
6af502de CH	582	hfsplus_free_extents(sb, hip->cached_extents,
1da177e4	583	alloc_cnt - start, alloc_cnt - blk_cnt);
6af502de	584	hfsplus_dump_extent(hip->cached_extents);
1da177e4	585	if (blk_cnt > start) {
b33b7921	586	hip->extent_state \|= HFSPLUS_EXT_DIRTY;
1da177e4 LT	587	break;
	588	}
	589	alloc_cnt = start;
6af502de	590	hip->cached_start = hip->cached_blocks = 0;
b33b7921	591	hip->extent_state &= ~(HFSPLUS_EXT_DIRTY \| HFSPLUS_EXT_NEW);
1da177e4 LT	592	hfs_brec_remove(&fd);
	593	}
	594	hfs_find_exit(&fd);
6af502de	595	mutex_unlock(&hip->extents_lock);
1da177e4	596
6af502de	597	hip->alloc_blocks = blk_cnt;
1da177e4	598	out:
6af502de	599	hip->phys_size = inode->i_size;
2753cc28 AS	600	hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
2753cc28 AS	601	sb->s_blocksize_bits;
6af502de	602	inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
e3494705	603	hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
1da177e4	604	}