[mirror_ubuntu-artful-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 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;

	/* Convert inode block to disk allocation block */
	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, false);
			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, bool zeroout)
{
	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;
		}
	}

	if (zeroout) {
		res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
		if (res)
			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:
	if (!res) {
		hip->alloc_blocks += len;
		mutex_unlock(&hip->extents_lock);
		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
		return 0;
	}
	mutex_unlock(&hip->extents_lock);
	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, 0,
					    &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;

	mutex_lock(&hip->extents_lock);

	alloc_cnt = hip->alloc_blocks;
	if (blk_cnt == alloc_cnt)
		goto out_unlock;

	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);

	hip->alloc_blocks = blk_cnt;
out_unlock:
	mutex_unlock(&hip->extents_lock);
	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	230
1da177e4	231	/* Convert inode block to disk allocation block */
dd73a01a	232	ablock = iblock >> sbi->fs_shift;
1da177e4	233
6af502de CH	234	if (iblock >= hip->fs_blocks) {
6af502de CH	235	if (iblock > hip->fs_blocks \|\| !create)
1da177e4	236	return -EIO;
6af502de	237	if (ablock >= hip->alloc_blocks) {
2cd282a1	238	res = hfsplus_file_extend(inode, false);
1da177e4 LT	239	if (res)
	240	return res;
	241	}
	242	} else
	243	create = 0;
	244
6af502de CH	245	if (ablock < hip->first_blocks) {
6af502de CH	246	dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
1da177e4 LT	247	goto done;
	248	}
	249
248736c2 ES	250	if (inode->i_ino == HFSPLUS_EXT_CNID)
	251	return -EIO;
	252
6af502de	253	mutex_lock(&hip->extents_lock);
e3494705 CH	254
	255	/*
	256	* hfsplus_ext_read_extent will write out a cached extent into
	257	* the extents btree. In that case we may have to mark the inode
	258	* dirty even for a pure read of an extent here.
	259	*/
	260	was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
1da177e4	261	res = hfsplus_ext_read_extent(inode, ablock);
e3494705	262	if (res) {
6af502de	263	mutex_unlock(&hip->extents_lock);
1da177e4 LT	264	return -EIO;
1da177e4 LT	265	}
e3494705 CH	266	dblock = hfsplus_ext_find_block(hip->cached_extents,
e3494705 CH	267	ablock - hip->cached_start);
6af502de	268	mutex_unlock(&hip->extents_lock);
1da177e4 LT	269
1da177e4 LT	270	done:
c2b3e1f7	271	hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n",
2753cc28	272	inode->i_ino, (long long)iblock, dblock);
bf1a1b31	273
dd73a01a	274	mask = (1 << sbi->fs_shift) - 1;
bf1a1b31 CH	275	sector = ((sector_t)dblock << sbi->fs_shift) +
	276	sbi->blockoffset + (iblock & mask);
	277	map_bh(bh_result, sb, sector);
	278
1da177e4 LT	279	if (create) {
1da177e4 LT	280	set_buffer_new(bh_result);
6af502de CH	281	hip->phys_size += sb->s_blocksize;
6af502de CH	282	hip->fs_blocks++;
1da177e4	283	inode_add_bytes(inode, sb->s_blocksize);
1da177e4	284	}
e3494705 CH	285	if (create \|\| was_dirty)
e3494705 CH	286	mark_inode_dirty(inode);
1da177e4 LT	287	return 0;
	288	}
	289
	290	static void hfsplus_dump_extent(struct hfsplus_extent *extent)
	291	{
	292	int i;
	293
c2b3e1f7	294	hfs_dbg(EXTENT, " ");
1da177e4	295	for (i = 0; i < 8; i++)
c2b3e1f7 JP	296	hfs_dbg_cont(EXTENT, " %u:%u",
	297	be32_to_cpu(extent[i].start_block),
	298	be32_to_cpu(extent[i].block_count));
	299	hfs_dbg_cont(EXTENT, "\n");
1da177e4 LT	300	}
	301
	302	static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
	303	u32 alloc_block, u32 block_count)
	304	{
	305	u32 count, start;
	306	int i;
	307
	308	hfsplus_dump_extent(extent);
	309	for (i = 0; i < 8; extent++, i++) {
	310	count = be32_to_cpu(extent->block_count);
	311	if (offset == count) {
	312	start = be32_to_cpu(extent->start_block);
	313	if (alloc_block != start + count) {
	314	if (++i >= 8)
	315	return -ENOSPC;
	316	extent++;
	317	extent->start_block = cpu_to_be32(alloc_block);
	318	} else
	319	block_count += count;
	320	extent->block_count = cpu_to_be32(block_count);
	321	return 0;
	322	} else if (offset < count)
	323	break;
	324	offset -= count;
	325	}
	326	/* panic? */
	327	return -EIO;
	328	}
	329
	330	static int hfsplus_free_extents(struct super_block *sb,
	331	struct hfsplus_extent *extent,
	332	u32 offset, u32 block_nr)
	333	{
	334	u32 count, start;
	335	int i;
1b243fd3	336	int err = 0;
1da177e4 LT	337
	338	hfsplus_dump_extent(extent);
	339	for (i = 0; i < 8; extent++, i++) {
	340	count = be32_to_cpu(extent->block_count);
	341	if (offset == count)
	342	goto found;
	343	else if (offset < count)
	344	break;
	345	offset -= count;
	346	}
	347	/* panic? */
	348	return -EIO;
	349	found:
	350	for (;;) {
	351	start = be32_to_cpu(extent->start_block);
	352	if (count <= block_nr) {
1b243fd3 VD	353	err = hfsplus_block_free(sb, start, count);
1b243fd3 VD	354	if (err) {
d6142673	355	pr_err("can't free extent\n");
c2b3e1f7	356	hfs_dbg(EXTENT, " start: %u count: %u\n",
1b243fd3 VD	357	start, count);
1b243fd3 VD	358	}
1da177e4 LT	359	extent->block_count = 0;
	360	extent->start_block = 0;
	361	block_nr -= count;
	362	} else {
	363	count -= block_nr;
1b243fd3 VD	364	err = hfsplus_block_free(sb, start + count, block_nr);
1b243fd3 VD	365	if (err) {
d6142673	366	pr_err("can't free extent\n");
c2b3e1f7	367	hfs_dbg(EXTENT, " start: %u count: %u\n",
1b243fd3 VD	368	start, count);
1b243fd3 VD	369	}
1da177e4 LT	370	extent->block_count = cpu_to_be32(count);
	371	block_nr = 0;
	372	}
1b243fd3 VD	373	if (!block_nr \|\| !i) {
	374	/*
	375	* Try to free all extents and
	376	* return only last error
	377	*/
	378	return err;
	379	}
1da177e4 LT	380	i--;
	381	extent--;
	382	count = be32_to_cpu(extent->block_count);
	383	}
	384	}
	385
2753cc28 AS	386	int hfsplus_free_fork(struct super_block *sb, u32 cnid,
2753cc28 AS	387	struct hfsplus_fork_raw *fork, int type)
1da177e4 LT	388	{
	389	struct hfs_find_data fd;
	390	hfsplus_extent_rec ext_entry;
	391	u32 total_blocks, blocks, start;
	392	int res, i;
	393
	394	total_blocks = be32_to_cpu(fork->total_blocks);
	395	if (!total_blocks)
	396	return 0;
	397
	398	blocks = 0;
	399	for (i = 0; i < 8; i++)
	400	blocks += be32_to_cpu(fork->extents[i].block_count);
	401
	402	res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
	403	if (res)
	404	return res;
	405	if (total_blocks == blocks)
	406	return 0;
	407
5bd9d99d AK	408	res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
	409	if (res)
	410	return res;
1da177e4 LT	411	do {
	412	res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
	413	total_blocks, type);
	414	if (res)
	415	break;
	416	start = be32_to_cpu(fd.key->ext.start_block);
	417	hfsplus_free_extents(sb, ext_entry,
	418	total_blocks - start,
	419	total_blocks);
	420	hfs_brec_remove(&fd);
	421	total_blocks = start;
	422	} while (total_blocks > blocks);
	423	hfs_find_exit(&fd);
	424
	425	return res;
	426	}
	427
2cd282a1	428	int hfsplus_file_extend(struct inode *inode, bool zeroout)
1da177e4 LT	429	{
1da177e4 LT	430	struct super_block *sb = inode->i_sb;
dd73a01a	431	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
6af502de	432	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	433	u32 start, len, goal;
	434	int res;
	435
1065348d CH	436	if (sbi->alloc_file->i_size * 8 <
1065348d CH	437	sbi->total_blocks - sbi->free_blocks + 8) {
21f2296a	438	/* extend alloc file */
b73f3d0e FF	439	pr_err("extend alloc file! (%llu,%u,%u)\n",
	440	sbi->alloc_file->i_size * 8,
	441	sbi->total_blocks, sbi->free_blocks);
1da177e4	442	return -ENOSPC;
1da177e4 LT	443	}
1da177e4 LT	444
6af502de CH	445	mutex_lock(&hip->extents_lock);
	446	if (hip->alloc_blocks == hip->first_blocks)
	447	goal = hfsplus_ext_lastblock(hip->first_extents);
1da177e4	448	else {
6af502de	449	res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
1da177e4 LT	450	if (res)
1da177e4 LT	451	goto out;
6af502de	452	goal = hfsplus_ext_lastblock(hip->cached_extents);
1da177e4 LT	453	}
1da177e4 LT	454
6af502de	455	len = hip->clump_blocks;
dd73a01a CH	456	start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
dd73a01a CH	457	if (start >= sbi->total_blocks) {
1da177e4 LT	458	start = hfsplus_block_allocate(sb, goal, 0, &len);
	459	if (start >= goal) {
	460	res = -ENOSPC;
	461	goto out;
	462	}
	463	}
	464
2cd282a1 SA	465	if (zeroout) {
	466	res = sb_issue_zeroout(sb, start, len, GFP_NOFS);
	467	if (res)
	468	goto out;
	469	}
	470
c2b3e1f7	471	hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
6af502de CH	472
	473	if (hip->alloc_blocks <= hip->first_blocks) {
	474	if (!hip->first_blocks) {
c2b3e1f7	475	hfs_dbg(EXTENT, "first extents\n");
1da177e4	476	/* no extents yet */
6af502de CH	477	hip->first_extents[0].start_block = cpu_to_be32(start);
6af502de CH	478	hip->first_extents[0].block_count = cpu_to_be32(len);
1da177e4 LT	479	res = 0;
	480	} else {
	481	/* try to append to extents in inode */
6af502de CH	482	res = hfsplus_add_extent(hip->first_extents,
6af502de CH	483	hip->alloc_blocks,
1da177e4 LT	484	start, len);
	485	if (res == -ENOSPC)
	486	goto insert_extent;
	487	}
	488	if (!res) {
6af502de CH	489	hfsplus_dump_extent(hip->first_extents);
6af502de CH	490	hip->first_blocks += len;
1da177e4 LT	491	}
1da177e4 LT	492	} else {
6af502de CH	493	res = hfsplus_add_extent(hip->cached_extents,
6af502de CH	494	hip->alloc_blocks - hip->cached_start,
1da177e4 LT	495	start, len);
1da177e4 LT	496	if (!res) {
6af502de	497	hfsplus_dump_extent(hip->cached_extents);
b33b7921	498	hip->extent_state \|= HFSPLUS_EXT_DIRTY;
6af502de	499	hip->cached_blocks += len;
1da177e4 LT	500	} else if (res == -ENOSPC)
	501	goto insert_extent;
	502	}
	503	out:
1da177e4	504	if (!res) {
6af502de	505	hip->alloc_blocks += len;
d7bdb996	506	mutex_unlock(&hip->extents_lock);
e3494705	507	hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
d7bdb996	508	return 0;
1da177e4	509	}
d7bdb996	510	mutex_unlock(&hip->extents_lock);
1da177e4 LT	511	return res;
	512
	513	insert_extent:
c2b3e1f7	514	hfs_dbg(EXTENT, "insert new extent\n");
dd7f3d54 AK	515	res = hfsplus_ext_write_extent_locked(inode);
	516	if (res)
	517	goto out;
1da177e4	518
6af502de CH	519	memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
	520	hip->cached_extents[0].start_block = cpu_to_be32(start);
	521	hip->cached_extents[0].block_count = cpu_to_be32(len);
	522	hfsplus_dump_extent(hip->cached_extents);
b33b7921	523	hip->extent_state \|= HFSPLUS_EXT_DIRTY \| HFSPLUS_EXT_NEW;
6af502de CH	524	hip->cached_start = hip->alloc_blocks;
6af502de CH	525	hip->cached_blocks = len;
1da177e4 LT	526
	527	res = 0;
	528	goto out;
	529	}
	530
	531	void hfsplus_file_truncate(struct inode *inode)
	532	{
	533	struct super_block *sb = inode->i_sb;
6af502de	534	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
1da177e4 LT	535	struct hfs_find_data fd;
	536	u32 alloc_cnt, blk_cnt, start;
	537	int res;
	538
c2b3e1f7 JP	539	hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n",
c2b3e1f7 JP	540	inode->i_ino, (long long)hip->phys_size, inode->i_size);
6af502de CH	541
6af502de CH	542	if (inode->i_size > hip->phys_size) {
1da177e4 LT	543	struct address_space *mapping = inode->i_mapping;
1da177e4 LT	544	struct page *page;
7c0efc62	545	void *fsdata;
12f267a2	546	loff_t size = inode->i_size;
1da177e4	547
c718a975 TH	548	res = pagecache_write_begin(NULL, mapping, size, 0, 0,
c718a975 TH	549	&page, &fsdata);
1da177e4	550	if (res)
7c0efc62	551	return;
2753cc28 AS	552	res = pagecache_write_end(NULL, mapping, size,
2753cc28 AS	553	0, 0, page, fsdata);
7c0efc62 NP	554	if (res < 0)
7c0efc62 NP	555	return;
1da177e4 LT	556	mark_inode_dirty(inode);
1da177e4 LT	557	return;
6af502de	558	} else if (inode->i_size == hip->phys_size)
f76d28d2 RZ	559	return;
f76d28d2 RZ	560
dd73a01a CH	561	blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
dd73a01a CH	562	HFSPLUS_SB(sb)->alloc_blksz_shift;
d7bdb996 SS	563
	564	mutex_lock(&hip->extents_lock);
	565
6af502de	566	alloc_cnt = hip->alloc_blocks;
1da177e4	567	if (blk_cnt == alloc_cnt)
d7bdb996	568	goto out_unlock;
1da177e4	569
5bd9d99d AK	570	res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
	571	if (res) {
	572	mutex_unlock(&hip->extents_lock);
	573	/* XXX: We lack error handling of hfsplus_file_truncate() */
	574	return;
	575	}
1da177e4	576	while (1) {
6af502de CH	577	if (alloc_cnt == hip->first_blocks) {
6af502de CH	578	hfsplus_free_extents(sb, hip->first_extents,
1da177e4	579	alloc_cnt, alloc_cnt - blk_cnt);
6af502de CH	580	hfsplus_dump_extent(hip->first_extents);
6af502de CH	581	hip->first_blocks = blk_cnt;
1da177e4 LT	582	break;
	583	}
	584	res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
	585	if (res)
	586	break;
6af502de CH	587	start = hip->cached_start;
6af502de CH	588	hfsplus_free_extents(sb, hip->cached_extents,
1da177e4	589	alloc_cnt - start, alloc_cnt - blk_cnt);
6af502de	590	hfsplus_dump_extent(hip->cached_extents);
1da177e4	591	if (blk_cnt > start) {
b33b7921	592	hip->extent_state \|= HFSPLUS_EXT_DIRTY;
1da177e4 LT	593	break;
	594	}
	595	alloc_cnt = start;
6af502de	596	hip->cached_start = hip->cached_blocks = 0;
b33b7921	597	hip->extent_state &= ~(HFSPLUS_EXT_DIRTY \| HFSPLUS_EXT_NEW);
1da177e4 LT	598	hfs_brec_remove(&fd);
	599	}
	600	hfs_find_exit(&fd);
1da177e4	601
6af502de	602	hip->alloc_blocks = blk_cnt;
d7bdb996 SS	603	out_unlock:
d7bdb996 SS	604	mutex_unlock(&hip->extents_lock);
6af502de	605	hip->phys_size = inode->i_size;
2753cc28 AS	606	hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
2753cc28 AS	607	sb->s_blocksize_bits;
6af502de	608	inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
e3494705	609	hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
1da177e4	610	}