1 files changed, 505 insertions, 0 deletions

diff --git a/fs/hfsplus/extents.c b/fs/hfsplus/extents.c
new file mode 100644
index 0000000..376498c
--- /dev/null
+++ b/fs/hfsplus/extents.c
@@ -0,0 +1,505 @@
+/*
+ *  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 <linux/version.h>
+
+#include "hfsplus_fs.h"
+#include "hfsplus_raw.h"
+
+/* Compare two extents keys, returns 0 on same, pos/neg for difference */
+int hfsplus_ext_cmp_key(hfsplus_btree_key *k1, hfsplus_btree_key *k2)
+{
+	__be32 k1id, k2id;
+	__be32 k1s, k2s;
+
+	k1id = k1->ext.cnid;
+	k2id = k2->ext.cnid;
+	if (k1id != k2id)
+		return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;
+
+	if (k1->ext.fork_type != k2->ext.fork_type)
+		return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;
+
+	k1s = k1->ext.start_block;
+	k2s = k2->ext.start_block;
+	if (k1s == k2s)
+		return 0;
+	return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
+}
+
+static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
+				  u32 block, u8 type)
+{
+	key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
+	key->ext.cnid = cpu_to_be32(cnid);
+	key->ext.start_block = cpu_to_be32(block);
+	key->ext.fork_type = type;
+	key->ext.pad = 0;
+}
+
+static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
+{
+	int i;
+	u32 count;
+
+	for (i = 0; i < 8; ext++, i++) {
+		count = be32_to_cpu(ext->block_count);
+		if (off < count)
+			return be32_to_cpu(ext->start_block) + off;
+		off -= count;
+	}
+	/* panic? */
+	return 0;
+}
+
+static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
+{
+	int i;
+	u32 count = 0;
+
+	for (i = 0; i < 8; ext++, i++)
+		count += be32_to_cpu(ext->block_count);
+	return count;
+}
+
+static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
+{
+	int i;
+
+	ext += 7;
+	for (i = 0; i < 7; ext--, i++)
+		if (ext->block_count)
+			break;
+	return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
+}
+
+static void __hfsplus_ext_write_extent(struct inode *inode, struct hfs_find_data *fd)
+{
+	int res;
+
+	hfsplus_ext_build_key(fd->search_key, inode->i_ino, HFSPLUS_I(inode).cached_start,
+			      HFSPLUS_IS_RSRC(inode) ?  HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
+	res = hfs_brec_find(fd);
+	if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_NEW) {
+		if (res != -ENOENT)
+			return;
+		hfs_brec_insert(fd, HFSPLUS_I(inode).cached_extents, sizeof(hfsplus_extent_rec));
+		HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
+	} else {
+		if (res)
+			return;
+		hfs_bnode_write(fd->bnode, HFSPLUS_I(inode).cached_extents, fd->entryoffset, fd->entrylength);
+		HFSPLUS_I(inode).flags &= ~HFSPLUS_FLG_EXT_DIRTY;
+	}
+}
+
+void hfsplus_ext_write_extent(struct inode *inode)
+{
+	if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY) {
+		struct hfs_find_data fd;
+
+		hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
+		__hfsplus_ext_write_extent(inode, &fd);
+		hfs_find_exit(&fd);
+	}
+}
+
+static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
+					    struct hfsplus_extent *extent,
+					    u32 cnid, u32 block, u8 type)
+{
+	int res;
+
+	hfsplus_ext_build_key(fd->search_key, cnid, block, type);
+	fd->key->ext.cnid = 0;
+	res = hfs_brec_find(fd);
+	if (res && res != -ENOENT)
+		return res;
+	if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
+	    fd->key->ext.fork_type != fd->search_key->ext.fork_type)
+		return -ENOENT;
+	if (fd->entrylength != sizeof(hfsplus_extent_rec))
+		return -EIO;
+	hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfsplus_extent_rec));
+	return 0;
+}
+
+static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block)
+{
+	int res;
+
+	if (HFSPLUS_I(inode).flags & HFSPLUS_FLG_EXT_DIRTY)
+		__hfsplus_ext_write_extent(inode, fd);
+
+	res = __hfsplus_ext_read_extent(fd, HFSPLUS_I(inode).cached_extents, inode->i_ino,
+					block, HFSPLUS_IS_RSRC(inode) ? HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
+	if (!res) {
+		HFSPLUS_I(inode).cached_start = be32_to_cpu(fd->key->ext.start_block);
+		HFSPLUS_I(inode).cached_blocks = hfsplus_ext_block_count(HFSPLUS_I(inode).cached_extents);
+	} else {
+		HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0;
+		HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
+	}
+	return res;
+}
+
+static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
+{
+	struct hfs_find_data fd;
+	int res;
+
+	if (block >= HFSPLUS_I(inode).cached_start &&
+	    block < HFSPLUS_I(inode).cached_start + HFSPLUS_I(inode).cached_blocks)
+		return 0;
+
+	hfs_find_init(HFSPLUS_SB(inode->i_sb).ext_tree, &fd);
+	res = __hfsplus_ext_cache_extent(&fd, inode, block);
+	hfs_find_exit(&fd);
+	return res;
+}
+
+/* Get a block at iblock for inode, possibly allocating if create */
+int hfsplus_get_block(struct inode *inode, sector_t iblock,
+		      struct buffer_head *bh_result, int create)
+{
+	struct super_block *sb;
+	int res = -EIO;
+	u32 ablock, dblock, mask;
+	int shift;
+
+	sb = inode->i_sb;
+
+	/* Convert inode block to disk allocation block */
+	shift = HFSPLUS_SB(sb).alloc_blksz_shift - sb->s_blocksize_bits;
+	ablock = iblock >> HFSPLUS_SB(sb).fs_shift;
+
+	if (iblock >= HFSPLUS_I(inode).fs_blocks) {
+		if (iblock > HFSPLUS_I(inode).fs_blocks || !create)
+			return -EIO;
+		if (ablock >= HFSPLUS_I(inode).alloc_blocks) {
+			res = hfsplus_file_extend(inode);
+			if (res)
+				return res;
+		}
+	} else
+		create = 0;
+
+	if (ablock < HFSPLUS_I(inode).first_blocks) {
+		dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).first_extents, ablock);
+		goto done;
+	}
+
+	down(&HFSPLUS_I(inode).extents_lock);
+	res = hfsplus_ext_read_extent(inode, ablock);
+	if (!res) {
+		dblock = hfsplus_ext_find_block(HFSPLUS_I(inode).cached_extents, ablock -
+					     HFSPLUS_I(inode).cached_start);
+	} else {
+		up(&HFSPLUS_I(inode).extents_lock);
+		return -EIO;
+	}
+	up(&HFSPLUS_I(inode).extents_lock);
+
+done:
+	dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n", inode->i_ino, (long long)iblock, dblock);
+	mask = (1 << HFSPLUS_SB(sb).fs_shift) - 1;
+	map_bh(bh_result, sb, (dblock << HFSPLUS_SB(sb).fs_shift) + HFSPLUS_SB(sb).blockoffset + (iblock & mask));
+	if (create) {
+		set_buffer_new(bh_result);
+		HFSPLUS_I(inode).phys_size += sb->s_blocksize;
+		HFSPLUS_I(inode).fs_blocks++;
+		inode_add_bytes(inode, sb->s_blocksize);
+		mark_inode_dirty(inode);
+	}
+	return 0;
+}
+
+static void hfsplus_dump_extent(struct hfsplus_extent *extent)
+{
+	int i;
+
+	dprint(DBG_EXTENT, "   ");
+	for (i = 0; i < 8; i++)
+		dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
+				 be32_to_cpu(extent[i].block_count));
+	dprint(DBG_EXTENT, "\n");
+}
+
+static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
+			      u32 alloc_block, u32 block_count)
+{
+	u32 count, start;
+	int i;
+
+	hfsplus_dump_extent(extent);
+	for (i = 0; i < 8; extent++, i++) {
+		count = be32_to_cpu(extent->block_count);
+		if (offset == count) {
+			start = be32_to_cpu(extent->start_block);
+			if (alloc_block != start + count) {
+				if (++i >= 8)
+					return -ENOSPC;
+				extent++;
+				extent->start_block = cpu_to_be32(alloc_block);
+			} else
+				block_count += count;
+			extent->block_count = cpu_to_be32(block_count);
+			return 0;
+		} else if (offset < count)
+			break;
+		offset -= count;
+	}
+	/* panic? */
+	return -EIO;
+}
+
+static int hfsplus_free_extents(struct super_block *sb,
+				struct hfsplus_extent *extent,
+				u32 offset, u32 block_nr)
+{
+	u32 count, start;
+	int i;
+
+	hfsplus_dump_extent(extent);
+	for (i = 0; i < 8; extent++, i++) {
+		count = be32_to_cpu(extent->block_count);
+		if (offset == count)
+			goto found;
+		else if (offset < count)
+			break;
+		offset -= count;
+	}
+	/* panic? */
+	return -EIO;
+found:
+	for (;;) {
+		start = be32_to_cpu(extent->start_block);
+		if (count <= block_nr) {
+			hfsplus_block_free(sb, start, count);
+			extent->block_count = 0;
+			extent->start_block = 0;
+			block_nr -= count;
+		} else {
+			count -= block_nr;
+			hfsplus_block_free(sb, start + count, block_nr);
+			extent->block_count = cpu_to_be32(count);
+			block_nr = 0;
+		}
+		if (!block_nr || !i)
+			return 0;
+		i--;
+		extent--;
+		count = be32_to_cpu(extent->block_count);
+	}
+}
+
+int hfsplus_free_fork(struct super_block *sb, u32 cnid, struct hfsplus_fork_raw *fork, int type)
+{
+	struct hfs_find_data fd;
+	hfsplus_extent_rec ext_entry;
+	u32 total_blocks, blocks, start;
+	int res, i;
+
+	total_blocks = be32_to_cpu(fork->total_blocks);
+	if (!total_blocks)
+		return 0;
+
+	blocks = 0;
+	for (i = 0; i < 8; i++)
+		blocks += be32_to_cpu(fork->extents[i].block_count);
+
+	res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
+	if (res)
+		return res;
+	if (total_blocks == blocks)
+		return 0;
+
+	hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
+	do {
+		res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
+						total_blocks, type);
+		if (res)
+			break;
+		start = be32_to_cpu(fd.key->ext.start_block);
+		hfsplus_free_extents(sb, ext_entry,
+				     total_blocks - start,
+				     total_blocks);
+		hfs_brec_remove(&fd);
+		total_blocks = start;
+	} while (total_blocks > blocks);
+	hfs_find_exit(&fd);
+
+	return res;
+}
+
+int hfsplus_file_extend(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	u32 start, len, goal;
+	int res;
+
+	if (HFSPLUS_SB(sb).alloc_file->i_size * 8 < HFSPLUS_SB(sb).total_blocks - HFSPLUS_SB(sb).free_blocks + 8) {
+		// extend alloc file
+		printk("extend alloc file! (%Lu,%u,%u)\n", HFSPLUS_SB(sb).alloc_file->i_size * 8,
+			HFSPLUS_SB(sb).total_blocks, HFSPLUS_SB(sb).free_blocks);
+		return -ENOSPC;
+		//BUG();
+	}
+
+	down(&HFSPLUS_I(inode).extents_lock);
+	if (HFSPLUS_I(inode).alloc_blocks == HFSPLUS_I(inode).first_blocks)
+		goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).first_extents);
+	else {
+		res = hfsplus_ext_read_extent(inode, HFSPLUS_I(inode).alloc_blocks);
+		if (res)
+			goto out;
+		goal = hfsplus_ext_lastblock(HFSPLUS_I(inode).cached_extents);
+	}
+
+	len = HFSPLUS_I(inode).clump_blocks;
+	start = hfsplus_block_allocate(sb, HFSPLUS_SB(sb).total_blocks, goal, &len);
+	if (start >= HFSPLUS_SB(sb).total_blocks) {
+		start = hfsplus_block_allocate(sb, goal, 0, &len);
+		if (start >= goal) {
+			res = -ENOSPC;
+			goto out;
+		}
+	}
+
+	dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
+	if (HFSPLUS_I(inode).alloc_blocks <= HFSPLUS_I(inode).first_blocks) {
+		if (!HFSPLUS_I(inode).first_blocks) {
+			dprint(DBG_EXTENT, "first extents\n");
+			/* no extents yet */
+			HFSPLUS_I(inode).first_extents[0].start_block = cpu_to_be32(start);
+			HFSPLUS_I(inode).first_extents[0].block_count = cpu_to_be32(len);
+			res = 0;
+		} else {
+			/* try to append to extents in inode */
+			res = hfsplus_add_extent(HFSPLUS_I(inode).first_extents,
+						 HFSPLUS_I(inode).alloc_blocks,
+						 start, len);
+			if (res == -ENOSPC)
+				goto insert_extent;
+		}
+		if (!res) {
+			hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
+			HFSPLUS_I(inode).first_blocks += len;
+		}
+	} else {
+		res = hfsplus_add_extent(HFSPLUS_I(inode).cached_extents,
+					 HFSPLUS_I(inode).alloc_blocks -
+					 HFSPLUS_I(inode).cached_start,
+					 start, len);
+		if (!res) {
+			hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
+			HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY;
+			HFSPLUS_I(inode).cached_blocks += len;
+		} else if (res == -ENOSPC)
+			goto insert_extent;
+	}
+out:
+	up(&HFSPLUS_I(inode).extents_lock);
+	if (!res) {
+		HFSPLUS_I(inode).alloc_blocks += len;
+		mark_inode_dirty(inode);
+	}
+	return res;
+
+insert_extent:
+	dprint(DBG_EXTENT, "insert new extent\n");
+	hfsplus_ext_write_extent(inode);
+
+	memset(HFSPLUS_I(inode).cached_extents, 0, sizeof(hfsplus_extent_rec));
+	HFSPLUS_I(inode).cached_extents[0].start_block = cpu_to_be32(start);
+	HFSPLUS_I(inode).cached_extents[0].block_count = cpu_to_be32(len);
+	hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
+	HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW;
+	HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).alloc_blocks;
+	HFSPLUS_I(inode).cached_blocks = len;
+
+	res = 0;
+	goto out;
+}
+
+void hfsplus_file_truncate(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct hfs_find_data fd;
+	u32 alloc_cnt, blk_cnt, start;
+	int res;
+
+	dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n", inode->i_ino,
+	       (long long)HFSPLUS_I(inode).phys_size, inode->i_size);
+	if (inode->i_size > HFSPLUS_I(inode).phys_size) {
+		struct address_space *mapping = inode->i_mapping;
+		struct page *page;
+		u32 size = inode->i_size - 1;
+		int res;
+
+		page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT);
+		if (!page)
+			return;
+		size &= PAGE_CACHE_SIZE - 1;
+		size++;
+		res = mapping->a_ops->prepare_write(NULL, page, size, size);
+		if (!res)
+			res = mapping->a_ops->commit_write(NULL, page, size, size);
+		if (res)
+			inode->i_size = HFSPLUS_I(inode).phys_size;
+		unlock_page(page);
+		page_cache_release(page);
+		mark_inode_dirty(inode);
+		return;
+	}
+	blk_cnt = (inode->i_size + HFSPLUS_SB(sb).alloc_blksz - 1) >> HFSPLUS_SB(sb).alloc_blksz_shift;
+	alloc_cnt = HFSPLUS_I(inode).alloc_blocks;
+	if (blk_cnt == alloc_cnt)
+		goto out;
+
+	down(&HFSPLUS_I(inode).extents_lock);
+	hfs_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
+	while (1) {
+		if (alloc_cnt == HFSPLUS_I(inode).first_blocks) {
+			hfsplus_free_extents(sb, HFSPLUS_I(inode).first_extents,
+					     alloc_cnt, alloc_cnt - blk_cnt);
+			hfsplus_dump_extent(HFSPLUS_I(inode).first_extents);
+			HFSPLUS_I(inode).first_blocks = blk_cnt;
+			break;
+		}
+		res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
+		if (res)
+			break;
+		start = HFSPLUS_I(inode).cached_start;
+		hfsplus_free_extents(sb, HFSPLUS_I(inode).cached_extents,
+				     alloc_cnt - start, alloc_cnt - blk_cnt);
+		hfsplus_dump_extent(HFSPLUS_I(inode).cached_extents);
+		if (blk_cnt > start) {
+			HFSPLUS_I(inode).flags |= HFSPLUS_FLG_EXT_DIRTY;
+			break;
+		}
+		alloc_cnt = start;
+		HFSPLUS_I(inode).cached_start = HFSPLUS_I(inode).cached_blocks = 0;
+		HFSPLUS_I(inode).flags &= ~(HFSPLUS_FLG_EXT_DIRTY | HFSPLUS_FLG_EXT_NEW);
+		hfs_brec_remove(&fd);
+	}
+	hfs_find_exit(&fd);
+	up(&HFSPLUS_I(inode).extents_lock);
+
+	HFSPLUS_I(inode).alloc_blocks = blk_cnt;
+out:
+	HFSPLUS_I(inode).phys_size = inode->i_size;
+	HFSPLUS_I(inode).fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+	inode_set_bytes(inode, HFSPLUS_I(inode).fs_blocks << sb->s_blocksize_bits);
+	mark_inode_dirty(inode);
+}