patch-2.4.22 linux-2.4.22/fs/hfsplus/extents.c

• Lines: 513
• Date: 2003-08-25 04:44:43.000000000 -0700
• Orig file: linux-2.4.21/fs/hfsplus/extents.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.21/fs/hfsplus/extents.c linux-2.4.22/fs/hfsplus/extents.c
@@ -0,0 +1,512 @@
+/*
+ *  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>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0)
+#include <linux/buffer_head.h>
+#endif
+
+#include "hfsplus_fs.h"
+#include "hfsplus_raw.h"
+
+/* Compare two extents keys, returns 0 on same, pos/neg for difference */
+int hfsplus_cmp_ext_key(hfsplus_btree_key *k1, hfsplus_btree_key *k2)
+{
+	u32 k1id, k2id;
+	u32 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;
+}
+
+void hfsplus_fill_ext_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_find_extent(hfsplus_extent *extent, u32 off)
+{
+	int i;
+	u32 count;
+
+	for (i = 0; i < 8; extent++, i++) {
+		count = be32_to_cpu(extent->block_count);
+		if (off < count)
+			return be32_to_cpu(extent->start_block) + off;
+		off -= count;
+	}
+	/* panic? */
+	return 0;
+}
+
+static int hfsplus_find_extentry(struct hfsplus_find_data *fd,
+				 hfsplus_extent *extent)
+{
+	int res;
+
+	fd->key->ext.cnid = 0;
+	res = hfsplus_btree_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 != ext_key_size)...
+	hfsplus_bnode_readbytes(fd->bnode, extent, fd->entryoffset, fd->entrylength);
+	return 0;
+}
+
+/* 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;
+	hfsplus_extent_rec ext_entry;
+	struct hfsplus_find_data fd;
+	int err = -EIO;
+	u32 ablock, dblock = 0;
+
+	sb = inode->i_sb;
+
+	/* Convert inode block to disk allocation block */
+	ablock = iblock;
+
+	if (ablock >= HFSPLUS_I(inode).total_blocks) {
+		if (ablock > HFSPLUS_I(inode).total_blocks || !create)
+			return -EIO;
+		if (ablock >= HFSPLUS_I(inode).alloc_blocks) {
+			err = hfsplus_extend_file(inode);
+			if (err)
+				return err;
+		}
+		HFSPLUS_I(inode).mmu_private += sb->s_blocksize;
+		HFSPLUS_I(inode).total_blocks++;
+		mark_inode_dirty(inode);
+	} else
+		create = 0;
+
+	if (ablock < HFSPLUS_I(inode).extent_blocks) {
+		dblock = hfsplus_find_extent(HFSPLUS_I(inode).extents, ablock);
+	} else {
+		hfsplus_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
+		hfsplus_fill_ext_key(fd.search_key, inode->i_ino, ablock, HFSPLUS_IS_RSRC(inode) ?
+				     HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
+		err = hfsplus_find_extentry(&fd, ext_entry);
+		if (!err)
+			dblock = hfsplus_find_extent(ext_entry, ablock -
+						    be32_to_cpu(fd.key->ext.start_block));
+		hfsplus_find_exit(&fd);
+		if (err)
+			return err;
+	}
+
+	if (!dblock)
+		return -EIO;
+	dprint(DBG_EXTENT, "get_block(%lu): %lu - %u\n", inode->i_ino, iblock, dblock);
+
+	map_bh(bh_result, sb, dblock + HFSPLUS_SB(sb).blockoffset);
+	if (create)
+		set_buffer_new(bh_result);
+	return 0;
+}
+
+static void hfsplus_dump_extent(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(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;
+}
+
+void hfsplus_free_blocks(struct super_block *sb, u32 start, u32 count)
+{
+	struct inode *anode;
+	struct buffer_head *bh;
+	int size, blk, off;
+	unsigned long *data, word, m;
+
+	anode = HFSPLUS_SB(sb).alloc_file;
+	size = sb->s_blocksize / sizeof(unsigned long);
+	blk = (start >> sb->s_blocksize_bits) / 8;
+	off = (start & (sb->s_blocksize * 8 - 1)) / 8 / sizeof(unsigned long);
+	m = 1 << (~start & (8 * sizeof(unsigned long) - 1));
+
+	HFSPLUS_SB(sb).free_blocks += count;
+	sb->s_dirt = 1;
+
+	while (count) {
+		bh = hfsplus_getblk(anode, blk);
+		data = (unsigned long *)bh->b_data;
+		do {
+			word = ~be32_to_cpu(data[off]);
+			for (;;) {
+				if (word & m)
+					printk("freeing free block %u\n", start);
+				word |= m;
+				start++;
+				if (!--count) {
+					data[off] = cpu_to_be32(~word);
+					goto done;
+				}
+				if (!(m >>= 1))
+					break;
+			}
+			data[off] = cpu_to_be32(~word);
+			m = 1UL << (8 * sizeof(unsigned long) - 1);
+		} while (++off < size);
+	done:
+		mark_buffer_dirty_inode(bh, anode);
+		brelse(bh);
+		if (++blk >= anode->i_blocks)
+			break;
+		off = 0;
+	}
+	if (count)
+		printk("%u block left to free\n", count);
+}
+
+int hfsplus_free_extents(struct super_block *sb, 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_free_blocks(sb, start, count);
+			extent->block_count = 0;
+			extent->start_block = 0;
+			block_nr -= count;
+		} else {
+			count -= block_nr;
+			hfsplus_free_blocks(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, hfsplus_fork_raw *fork, int type)
+{
+	struct hfsplus_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;
+
+	hfsplus_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
+	do {
+		hfsplus_fill_ext_key(fd.search_key, cnid,
+				     total_blocks, type);
+		res = hfsplus_find_extentry(&fd, ext_entry);
+		if (res)
+			break;
+		start = be32_to_cpu(fd.key->ext.start_block);
+		hfsplus_free_extents(sb, ext_entry,
+				     total_blocks - start,
+				     total_blocks);
+		hfsplus_bnode_remove_rec(&fd);
+		total_blocks = start;
+	} while (total_blocks > blocks);
+	hfsplus_find_exit(&fd);
+
+	return res;
+}
+
+int hfsplus_extend_file(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct inode *anode = HFSPLUS_SB(sb).alloc_file;
+	struct hfsplus_find_data fd;
+	hfsplus_extent_rec ext_entry;
+	struct buffer_head *bh;
+	u32 blk, blk1, ablock, block_count;
+	unsigned long *data, word, m;
+	int res, size, off, i;
+
+	if (anode->i_size * 8 < HFSPLUS_SB(sb).total_blocks - HFSPLUS_SB(sb).free_blocks + 8) {
+		// extend alloc file
+		BUG();
+	}
+	blk = blk1 = (HFSPLUS_SB(sb).next_alloc >> sb->s_blocksize_bits) / 8;
+	off = (HFSPLUS_SB(sb).next_alloc & (sb->s_blocksize * 8 - 1)) / sizeof(unsigned long) / 8;
+
+	for (;;) {
+		// ignore first off for now...
+		off = 0;
+		bh = hfsplus_getblk(anode, blk);
+		if (blk == anode->i_blocks - 1)
+			size = (HFSPLUS_SB(sb).total_blocks &
+				(sb->s_blocksize * 8 - 1)) /
+				8 / sizeof(unsigned long);
+		else
+			size = sb->s_blocksize / sizeof(unsigned long);
+		data = (unsigned long *)bh->b_data;
+		do {
+			word = be32_to_cpu(data[off]);
+			if (!~word)
+				continue;
+			m = 1UL << (sizeof(unsigned long) * 8 - 1);
+			for (i = 0; m; i++, m >>= 1) {
+				if (word & m)
+					continue;
+				ablock = (blk << sb->s_blocksize_bits) * 8 +
+					off * sizeof(unsigned long) * 8 + i;
+				block_count = 1;
+				word |= m;
+#if 0
+				while ((m >>= 1) && !(word & m)) {
+					block_count++;
+					word |= m;
+				}
+#endif
+				data[off] = cpu_to_be32(word);
+				mark_buffer_dirty_inode(bh, anode);
+				brelse(bh);
+				goto found;
+			}
+		} while (++off < size);
+		brelse(bh);
+		if (++blk >= anode->i_blocks)
+			blk = 0;
+		if (blk == blk1)
+			return -ENOSPC;
+	}
+
+found:
+	dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, ablock, block_count);
+	if (HFSPLUS_I(inode).alloc_blocks <= HFSPLUS_I(inode).extent_blocks) {
+		if (!HFSPLUS_I(inode).extent_blocks) {
+			dprint(DBG_EXTENT, "first extents\n");
+			/* no extents yet */
+			HFSPLUS_I(inode).extents[0].start_block = cpu_to_be32(ablock);
+			HFSPLUS_I(inode).extents[0].block_count = cpu_to_be32(block_count);
+			res = 0;
+		} else
+			/* try to append to extents in inode */
+			res = hfsplus_add_extent(HFSPLUS_I(inode).extents,
+						 HFSPLUS_I(inode).alloc_blocks,
+						 ablock, block_count);
+		if (!res) {
+			hfsplus_dump_extent(HFSPLUS_I(inode).extents);
+			HFSPLUS_I(inode).extent_blocks += block_count;
+		} else if (res == -ENOSPC) {
+			/* create new extent, so find place to insert it */
+			hfsplus_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
+			hfsplus_fill_ext_key(fd.search_key, inode->i_ino,
+					     HFSPLUS_I(inode).alloc_blocks,
+					     HFSPLUS_IS_RSRC(inode) ?
+					     HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
+			res = hfsplus_find_extentry(&fd, ext_entry);
+			if (res && res != -ENOENT) {
+				hfsplus_find_exit(&fd);
+				goto out;
+			}
+			goto insert_extent;
+		}
+	} else {
+		hfsplus_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
+		hfsplus_fill_ext_key(fd.search_key, inode->i_ino,
+				     HFSPLUS_I(inode).alloc_blocks,
+				     HFSPLUS_IS_RSRC(inode) ?
+				     HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
+		res = hfsplus_find_extentry(&fd, ext_entry);
+		if (res) {
+			hfsplus_find_exit(&fd);
+			goto out;
+		}
+
+		res = hfsplus_add_extent(ext_entry, HFSPLUS_I(inode).alloc_blocks -
+					 be32_to_cpu(fd.key->ext.start_block),
+					 ablock, block_count);
+		if (!res) {
+			hfsplus_dump_extent(ext_entry);
+			hfsplus_bnode_writebytes(fd.bnode, &ext_entry,
+						 fd.entryoffset,
+						 sizeof(ext_entry));
+		} else if (res == -ENOSPC)
+			goto insert_extent;
+		hfsplus_find_exit(&fd);
+	}
+out:
+	if (!res) {
+		HFSPLUS_I(inode).alloc_blocks += block_count;
+		mark_inode_dirty(inode);
+		HFSPLUS_SB(sb).free_blocks -= block_count;
+		sb->s_dirt = 1;
+	}
+	return res;
+
+insert_extent:
+	dprint(DBG_EXTENT, "insert new extent\n");
+	memset(ext_entry, 0, sizeof(ext_entry));
+	ext_entry[0].start_block = cpu_to_be32(ablock);
+	ext_entry[0].block_count = cpu_to_be32(block_count);
+
+	hfsplus_bnode_insert_rec(&fd, ext_entry, sizeof(ext_entry));
+	hfsplus_find_exit(&fd);
+	res = 0;
+	goto out;
+}
+
+void hfsplus_truncate(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct hfsplus_find_data fd;
+	hfsplus_extent_rec ext_entry;
+	u32 blk_cnt, start;
+	int res;
+
+	dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n", inode->i_ino,
+	       (long long)HFSPLUS_I(inode).mmu_private, inode->i_size);
+	if (inode->i_size == HFSPLUS_I(inode).mmu_private)
+		return;
+	if (inode->i_size > HFSPLUS_I(inode).mmu_private) {
+		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).mmu_private;
+		unlock_page(page);
+		page_cache_release(page);
+		mark_inode_dirty(inode);
+		return;
+	}
+	blk_cnt = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+
+	while (1) {
+		if (HFSPLUS_I(inode).alloc_blocks <= HFSPLUS_I(inode).extent_blocks) {
+			hfsplus_free_extents(sb, HFSPLUS_I(inode).extents,
+					     HFSPLUS_I(inode).alloc_blocks,
+					     HFSPLUS_I(inode).alloc_blocks - blk_cnt);
+			hfsplus_dump_extent(HFSPLUS_I(inode).extents);
+			HFSPLUS_I(inode).extent_blocks = blk_cnt;
+			break;
+		}
+		hfsplus_find_init(HFSPLUS_SB(sb).ext_tree, &fd);
+		hfsplus_fill_ext_key(fd.search_key, inode->i_ino,
+				     HFSPLUS_I(inode).alloc_blocks,
+				     HFSPLUS_IS_RSRC(inode) ?
+				     HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
+		res = hfsplus_find_extentry(&fd, ext_entry);
+		if (res) {
+			hfsplus_find_exit(&fd);
+			break;
+		}
+		start = be32_to_cpu(fd.key->ext.start_block);
+		hfsplus_free_extents(sb, ext_entry,
+				     HFSPLUS_I(inode).alloc_blocks - start,
+				     HFSPLUS_I(inode).alloc_blocks - blk_cnt);
+		hfsplus_dump_extent(ext_entry);
+		if (blk_cnt > start) {
+			hfsplus_bnode_writebytes(fd.bnode, &ext_entry,
+						 fd.entryoffset,
+						 sizeof(ext_entry));
+			hfsplus_find_exit(&fd);
+			break;
+		}
+		HFSPLUS_I(inode).alloc_blocks = start;
+		hfsplus_bnode_remove_rec(&fd);
+		hfsplus_find_exit(&fd);
+	}
+	HFSPLUS_I(inode).mmu_private = inode->i_size;
+	HFSPLUS_I(inode).alloc_blocks = HFSPLUS_I(inode).total_blocks = blk_cnt;
+}