[mirror_ubuntu-zesty-kernel.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 int hfsplus_ext_write_extent_locked(struct inode *inode)
{
	int res;

	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;
		__hfsplus_ext_write_extent(inode, &fd);
		hfs_find_exit(&fd);
	}
	return 0;
}

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);
	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;

	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:
	dprint(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;

	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;

	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 */
		printk(KERN_ERR "hfs: 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;
		}
	}

	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");
	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;

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