Fixed MTP to work with TWRP

fs/udf/balloc.c

@@ -0,0 +1,825 @@
+/*
+ * balloc.c
+ *
+ * PURPOSE
+ *	Block allocation handling routines for the OSTA-UDF(tm) filesystem.
+ *
+ * COPYRIGHT
+ *	This file is distributed under the terms of the GNU General Public
+ *	License (GPL). Copies of the GPL can be obtained from:
+ *		ftp://prep.ai.mit.edu/pub/gnu/GPL
+ *	Each contributing author retains all rights to their own work.
+ *
+ *  (C) 1999-2001 Ben Fennema
+ *  (C) 1999 Stelias Computing Inc
+ *
+ * HISTORY
+ *
+ *  02/24/99 blf  Created.
+ *
+ */
+
+#include "udfdecl.h"
+
+#include <linux/buffer_head.h>
+#include <linux/bitops.h>
+
+#include "udf_i.h"
+#include "udf_sb.h"
+
+#define udf_clear_bit	__test_and_clear_bit_le
+#define udf_set_bit	__test_and_set_bit_le
+#define udf_test_bit	test_bit_le
+#define udf_find_next_one_bit	find_next_bit_le
+
+static int read_block_bitmap(struct super_block *sb,
+			     struct udf_bitmap *bitmap, unsigned int block,
+			     unsigned long bitmap_nr)
+{
+	struct buffer_head *bh = NULL;
+	int retval = 0;
+	struct kernel_lb_addr loc;
+
+	loc.logicalBlockNum = bitmap->s_extPosition;
+	loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
+
+	bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block));
+	if (!bh)
+		retval = -EIO;
+
+	bitmap->s_block_bitmap[bitmap_nr] = bh;
+	return retval;
+}
+
+static int __load_block_bitmap(struct super_block *sb,
+			       struct udf_bitmap *bitmap,
+			       unsigned int block_group)
+{
+	int retval = 0;
+	int nr_groups = bitmap->s_nr_groups;
+
+	if (block_group >= nr_groups) {
+		udf_debug("block_group (%d) > nr_groups (%d)\n",
+			  block_group, nr_groups);
+	}
+
+	if (bitmap->s_block_bitmap[block_group]) {
+		return block_group;
+	} else {
+		retval = read_block_bitmap(sb, bitmap, block_group,
+					   block_group);
+		if (retval < 0)
+			return retval;
+		return block_group;
+	}
+}
+
+static inline int load_block_bitmap(struct super_block *sb,
+				    struct udf_bitmap *bitmap,
+				    unsigned int block_group)
+{
+	int slot;
+
+	slot = __load_block_bitmap(sb, bitmap, block_group);
+
+	if (slot < 0)
+		return slot;
+
+	if (!bitmap->s_block_bitmap[slot])
+		return -EIO;
+
+	return slot;
+}
+
+static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
+{
+	struct udf_sb_info *sbi = UDF_SB(sb);
+	struct logicalVolIntegrityDesc *lvid;
+
+	if (!sbi->s_lvid_bh)
+		return;
+
+	lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
+	le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
+	udf_updated_lvid(sb);
+}
+
+static void udf_bitmap_free_blocks(struct super_block *sb,
+				   struct udf_bitmap *bitmap,
+				   struct kernel_lb_addr *bloc,
+				   uint32_t offset,
+				   uint32_t count)
+{
+	struct udf_sb_info *sbi = UDF_SB(sb);
+	struct buffer_head *bh = NULL;
+	struct udf_part_map *partmap;
+	unsigned long block;
+	unsigned long block_group;
+	unsigned long bit;
+	unsigned long i;
+	int bitmap_nr;
+	unsigned long overflow;
+
+	mutex_lock(&sbi->s_alloc_mutex);
+	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
+	if (bloc->logicalBlockNum + count < count ||
+	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
+		udf_debug("%d < %d || %d + %d > %d\n",
+			  bloc->logicalBlockNum, 0,
+			  bloc->logicalBlockNum, count,
+			  partmap->s_partition_len);
+		goto error_return;
+	}
+
+	block = bloc->logicalBlockNum + offset +
+		(sizeof(struct spaceBitmapDesc) << 3);
+
+	do {
+		overflow = 0;
+		block_group = block >> (sb->s_blocksize_bits + 3);
+		bit = block % (sb->s_blocksize << 3);
+
+		/*
+		* Check to see if we are freeing blocks across a group boundary.
+		*/
+		if (bit + count > (sb->s_blocksize << 3)) {
+			overflow = bit + count - (sb->s_blocksize << 3);
+			count -= overflow;
+		}
+		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
+		if (bitmap_nr < 0)
+			goto error_return;
+
+		bh = bitmap->s_block_bitmap[bitmap_nr];
+		for (i = 0; i < count; i++) {
+			if (udf_set_bit(bit + i, bh->b_data)) {
+				udf_debug("bit %ld already set\n", bit + i);
+				udf_debug("byte=%2x\n",
+					  ((char *)bh->b_data)[(bit + i) >> 3]);
+			}
+		}
+		udf_add_free_space(sb, sbi->s_partition, count);
+		mark_buffer_dirty(bh);
+		if (overflow) {
+			block += count;
+			count = overflow;
+		}
+	} while (overflow);
+
+error_return:
+	mutex_unlock(&sbi->s_alloc_mutex);
+}
+
+static int udf_bitmap_prealloc_blocks(struct super_block *sb,
+				      struct udf_bitmap *bitmap,
+				      uint16_t partition, uint32_t first_block,
+				      uint32_t block_count)
+{
+	struct udf_sb_info *sbi = UDF_SB(sb);
+	int alloc_count = 0;
+	int bit, block, block_group, group_start;
+	int nr_groups, bitmap_nr;
+	struct buffer_head *bh;
+	__u32 part_len;
+
+	mutex_lock(&sbi->s_alloc_mutex);
+	part_len = sbi->s_partmaps[partition].s_partition_len;
+	if (first_block >= part_len)
+		goto out;
+
+	if (first_block + block_count > part_len)
+		block_count = part_len - first_block;
+
+	do {
+		nr_groups = udf_compute_nr_groups(sb, partition);
+		block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
+		block_group = block >> (sb->s_blocksize_bits + 3);
+		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
+
+		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
+		if (bitmap_nr < 0)
+			goto out;
+		bh = bitmap->s_block_bitmap[bitmap_nr];
+
+		bit = block % (sb->s_blocksize << 3);
+
+		while (bit < (sb->s_blocksize << 3) && block_count > 0) {
+			if (!udf_clear_bit(bit, bh->b_data))
+				goto out;
+			block_count--;
+			alloc_count++;
+			bit++;
+			block++;
+		}
+		mark_buffer_dirty(bh);
+	} while (block_count > 0);
+
+out:
+	udf_add_free_space(sb, partition, -alloc_count);
+	mutex_unlock(&sbi->s_alloc_mutex);
+	return alloc_count;
+}
+
+static int udf_bitmap_new_block(struct super_block *sb,
+				struct udf_bitmap *bitmap, uint16_t partition,
+				uint32_t goal, int *err)
+{
+	struct udf_sb_info *sbi = UDF_SB(sb);
+	int newbit, bit = 0, block, block_group, group_start;
+	int end_goal, nr_groups, bitmap_nr, i;
+	struct buffer_head *bh = NULL;
+	char *ptr;
+	int newblock = 0;
+
+	*err = -ENOSPC;
+	mutex_lock(&sbi->s_alloc_mutex);
+
+repeat:
+	if (goal >= sbi->s_partmaps[partition].s_partition_len)
+		goal = 0;
+
+	nr_groups = bitmap->s_nr_groups;
+	block = goal + (sizeof(struct spaceBitmapDesc) << 3);
+	block_group = block >> (sb->s_blocksize_bits + 3);
+	group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
+
+	bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
+	if (bitmap_nr < 0)
+		goto error_return;
+	bh = bitmap->s_block_bitmap[bitmap_nr];
+	ptr = memscan((char *)bh->b_data + group_start, 0xFF,
+		      sb->s_blocksize - group_start);
+
+	if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
+		bit = block % (sb->s_blocksize << 3);
+		if (udf_test_bit(bit, bh->b_data))
+			goto got_block;
+
+		end_goal = (bit + 63) & ~63;
+		bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
+		if (bit < end_goal)
+			goto got_block;
+
+		ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
+			      sb->s_blocksize - ((bit + 7) >> 3));
+		newbit = (ptr - ((char *)bh->b_data)) << 3;
+		if (newbit < sb->s_blocksize << 3) {
+			bit = newbit;
+			goto search_back;
+		}
+
+		newbit = udf_find_next_one_bit(bh->b_data,
+					       sb->s_blocksize << 3, bit);
+		if (newbit < sb->s_blocksize << 3) {
+			bit = newbit;
+			goto got_block;
+		}
+	}
+
+	for (i = 0; i < (nr_groups * 2); i++) {
+		block_group++;
+		if (block_group >= nr_groups)
+			block_group = 0;
+		group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
+
+		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
+		if (bitmap_nr < 0)
+			goto error_return;
+		bh = bitmap->s_block_bitmap[bitmap_nr];
+		if (i < nr_groups) {
+			ptr = memscan((char *)bh->b_data + group_start, 0xFF,
+				      sb->s_blocksize - group_start);
+			if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
+				bit = (ptr - ((char *)bh->b_data)) << 3;
+				break;
+			}
+		} else {
+			bit = udf_find_next_one_bit(bh->b_data,
+						    sb->s_blocksize << 3,
+						    group_start << 3);
+			if (bit < sb->s_blocksize << 3)
+				break;
+		}
+	}
+	if (i >= (nr_groups * 2)) {
+		mutex_unlock(&sbi->s_alloc_mutex);
+		return newblock;
+	}
+	if (bit < sb->s_blocksize << 3)
+		goto search_back;
+	else
+		bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
+					    group_start << 3);
+	if (bit >= sb->s_blocksize << 3) {
+		mutex_unlock(&sbi->s_alloc_mutex);
+		return 0;
+	}
+
+search_back:
+	i = 0;
+	while (i < 7 && bit > (group_start << 3) &&
+	       udf_test_bit(bit - 1, bh->b_data)) {
+		++i;
+		--bit;
+	}
+
+got_block:
+	newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
+		(sizeof(struct spaceBitmapDesc) << 3);
+
+	if (!udf_clear_bit(bit, bh->b_data)) {
+		udf_debug("bit already cleared for block %d\n", bit);
+		goto repeat;
+	}
+
+	mark_buffer_dirty(bh);
+
+	udf_add_free_space(sb, partition, -1);
+	mutex_unlock(&sbi->s_alloc_mutex);
+	*err = 0;
+	return newblock;
+
+error_return:
+	*err = -EIO;
+	mutex_unlock(&sbi->s_alloc_mutex);
+	return 0;
+}
+
+static void udf_table_free_blocks(struct super_block *sb,
+				  struct inode *table,
+				  struct kernel_lb_addr *bloc,
+				  uint32_t offset,
+				  uint32_t count)
+{
+	struct udf_sb_info *sbi = UDF_SB(sb);
+	struct udf_part_map *partmap;
+	uint32_t start, end;
+	uint32_t elen;
+	struct kernel_lb_addr eloc;
+	struct extent_position oepos, epos;
+	int8_t etype;
+	int i;
+	struct udf_inode_info *iinfo;
+
+	mutex_lock(&sbi->s_alloc_mutex);
+	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
+	if (bloc->logicalBlockNum + count < count ||
+	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
+		udf_debug("%d < %d || %d + %d > %d\n",
+			  bloc->logicalBlockNum, 0,
+			  bloc->logicalBlockNum, count,
+			  partmap->s_partition_len);
+		goto error_return;
+	}
+
+	iinfo = UDF_I(table);
+	udf_add_free_space(sb, sbi->s_partition, count);
+
+	start = bloc->logicalBlockNum + offset;
+	end = bloc->logicalBlockNum + offset + count - 1;
+
+	epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
+	elen = 0;
+	epos.block = oepos.block = iinfo->i_location;
+	epos.bh = oepos.bh = NULL;
+
+	while (count &&
+	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
+		if (((eloc.logicalBlockNum +
+			(elen >> sb->s_blocksize_bits)) == start)) {
+			if ((0x3FFFFFFF - elen) <
+					(count << sb->s_blocksize_bits)) {
+				uint32_t tmp = ((0x3FFFFFFF - elen) >>
+							sb->s_blocksize_bits);
+				count -= tmp;
+				start += tmp;
+				elen = (etype << 30) |
+					(0x40000000 - sb->s_blocksize);
+			} else {
+				elen = (etype << 30) |
+					(elen +
+					(count << sb->s_blocksize_bits));
+				start += count;
+				count = 0;
+			}
+			udf_write_aext(table, &oepos, &eloc, elen, 1);
+		} else if (eloc.logicalBlockNum == (end + 1)) {
+			if ((0x3FFFFFFF - elen) <
+					(count << sb->s_blocksize_bits)) {
+				uint32_t tmp = ((0x3FFFFFFF - elen) >>
+						sb->s_blocksize_bits);
+				count -= tmp;
+				end -= tmp;
+				eloc.logicalBlockNum -= tmp;
+				elen = (etype << 30) |
+					(0x40000000 - sb->s_blocksize);
+			} else {
+				eloc.logicalBlockNum = start;
+				elen = (etype << 30) |
+					(elen +
+					(count << sb->s_blocksize_bits));
+				end -= count;
+				count = 0;
+			}
+			udf_write_aext(table, &oepos, &eloc, elen, 1);
+		}
+
+		if (epos.bh != oepos.bh) {
+			i = -1;
+			oepos.block = epos.block;
+			brelse(oepos.bh);
+			get_bh(epos.bh);
+			oepos.bh = epos.bh;
+			oepos.offset = 0;
+		} else {
+			oepos.offset = epos.offset;
+		}
+	}
+
+	if (count) {
+		/*
+		 * NOTE: we CANNOT use udf_add_aext here, as it can try to
+		 * allocate a new block, and since we hold the super block
+		 * lock already very bad things would happen :)
+		 *
+		 * We copy the behavior of udf_add_aext, but instead of
+		 * trying to allocate a new block close to the existing one,
+		 * we just steal a block from the extent we are trying to add.
+		 *
+		 * It would be nice if the blocks were close together, but it
+		 * isn't required.
+		 */
+
+		int adsize;
+		struct short_ad *sad = NULL;
+		struct long_ad *lad = NULL;
+		struct allocExtDesc *aed;
+
+		eloc.logicalBlockNum = start;
+		elen = EXT_RECORDED_ALLOCATED |
+			(count << sb->s_blocksize_bits);
+
+		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
+			adsize = sizeof(struct short_ad);
+		else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
+			adsize = sizeof(struct long_ad);
+		else {
+			brelse(oepos.bh);
+			brelse(epos.bh);
+			goto error_return;
+		}
+
+		if (epos.offset + (2 * adsize) > sb->s_blocksize) {
+			unsigned char *sptr, *dptr;
+			int loffset;
+
+			brelse(oepos.bh);
+			oepos = epos;
+
+			/* Steal a block from the extent being free'd */
+			epos.block.logicalBlockNum = eloc.logicalBlockNum;
+			eloc.logicalBlockNum++;
+			elen -= sb->s_blocksize;
+
+			epos.bh = udf_tread(sb,
+					udf_get_lb_pblock(sb, &epos.block, 0));
+			if (!epos.bh) {
+				brelse(oepos.bh);
+				goto error_return;
+			}
+			aed = (struct allocExtDesc *)(epos.bh->b_data);
+			aed->previousAllocExtLocation =
+				cpu_to_le32(oepos.block.logicalBlockNum);
+			if (epos.offset + adsize > sb->s_blocksize) {
+				loffset = epos.offset;
+				aed->lengthAllocDescs = cpu_to_le32(adsize);
+				sptr = iinfo->i_ext.i_data + epos.offset
+								- adsize;
+				dptr = epos.bh->b_data +
+					sizeof(struct allocExtDesc);
+				memcpy(dptr, sptr, adsize);
+				epos.offset = sizeof(struct allocExtDesc) +
+						adsize;
+			} else {
+				loffset = epos.offset + adsize;
+				aed->lengthAllocDescs = cpu_to_le32(0);
+				if (oepos.bh) {
+					sptr = oepos.bh->b_data + epos.offset;
+					aed = (struct allocExtDesc *)
+						oepos.bh->b_data;
+					le32_add_cpu(&aed->lengthAllocDescs,
+							adsize);
+				} else {
+					sptr = iinfo->i_ext.i_data +
+								epos.offset;
+					iinfo->i_lenAlloc += adsize;
+					mark_inode_dirty(table);
+				}
+				epos.offset = sizeof(struct allocExtDesc);
+			}
+			if (sbi->s_udfrev >= 0x0200)
+				udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
+					    3, 1, epos.block.logicalBlockNum,
+					    sizeof(struct tag));
+			else
+				udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
+					    2, 1, epos.block.logicalBlockNum,
+					    sizeof(struct tag));
+
+			switch (iinfo->i_alloc_type) {
+			case ICBTAG_FLAG_AD_SHORT:
+				sad = (struct short_ad *)sptr;
+				sad->extLength = cpu_to_le32(
+					EXT_NEXT_EXTENT_ALLOCDECS |
+					sb->s_blocksize);
+				sad->extPosition =
+					cpu_to_le32(epos.block.logicalBlockNum);
+				break;
+			case ICBTAG_FLAG_AD_LONG:
+				lad = (struct long_ad *)sptr;
+				lad->extLength = cpu_to_le32(
+					EXT_NEXT_EXTENT_ALLOCDECS |
+					sb->s_blocksize);
+				lad->extLocation =
+					cpu_to_lelb(epos.block);
+				break;
+			}
+			if (oepos.bh) {
+				udf_update_tag(oepos.bh->b_data, loffset);
+				mark_buffer_dirty(oepos.bh);
+			} else {
+				mark_inode_dirty(table);
+			}
+		}
+
+		/* It's possible that stealing the block emptied the extent */
+		if (elen) {
+			udf_write_aext(table, &epos, &eloc, elen, 1);
+
+			if (!epos.bh) {
+				iinfo->i_lenAlloc += adsize;
+				mark_inode_dirty(table);
+			} else {
+				aed = (struct allocExtDesc *)epos.bh->b_data;
+				le32_add_cpu(&aed->lengthAllocDescs, adsize);
+				udf_update_tag(epos.bh->b_data, epos.offset);
+				mark_buffer_dirty(epos.bh);
+			}
+		}
+	}
+
+	brelse(epos.bh);
+	brelse(oepos.bh);
+
+error_return:
+	mutex_unlock(&sbi->s_alloc_mutex);
+	return;
+}
+
+static int udf_table_prealloc_blocks(struct super_block *sb,
+				     struct inode *table, uint16_t partition,
+				     uint32_t first_block, uint32_t block_count)
+{
+	struct udf_sb_info *sbi = UDF_SB(sb);
+	int alloc_count = 0;
+	uint32_t elen, adsize;
+	struct kernel_lb_addr eloc;
+	struct extent_position epos;
+	int8_t etype = -1;
+	struct udf_inode_info *iinfo;
+
+	if (first_block >= sbi->s_partmaps[partition].s_partition_len)
+		return 0;
+
+	iinfo = UDF_I(table);
+	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
+		adsize = sizeof(struct short_ad);
+	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
+		adsize = sizeof(struct long_ad);
+	else
+		return 0;
+
+	mutex_lock(&sbi->s_alloc_mutex);
+	epos.offset = sizeof(struct unallocSpaceEntry);
+	epos.block = iinfo->i_location;
+	epos.bh = NULL;
+	eloc.logicalBlockNum = 0xFFFFFFFF;
+
+	while (first_block != eloc.logicalBlockNum &&
+	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
+		udf_debug("eloc=%d, elen=%d, first_block=%d\n",
+			  eloc.logicalBlockNum, elen, first_block);
+		; /* empty loop body */
+	}
+
+	if (first_block == eloc.logicalBlockNum) {
+		epos.offset -= adsize;
+
+		alloc_count = (elen >> sb->s_blocksize_bits);
+		if (alloc_count > block_count) {
+			alloc_count = block_count;
+			eloc.logicalBlockNum += alloc_count;
+			elen -= (alloc_count << sb->s_blocksize_bits);
+			udf_write_aext(table, &epos, &eloc,
+					(etype << 30) | elen, 1);
+		} else
+			udf_delete_aext(table, epos, eloc,
+					(etype << 30) | elen);
+	} else {
+		alloc_count = 0;
+	}
+
+	brelse(epos.bh);
+
+	if (alloc_count)
+		udf_add_free_space(sb, partition, -alloc_count);
+	mutex_unlock(&sbi->s_alloc_mutex);
+	return alloc_count;
+}
+
+static int udf_table_new_block(struct super_block *sb,
+			       struct inode *table, uint16_t partition,
+			       uint32_t goal, int *err)
+{
+	struct udf_sb_info *sbi = UDF_SB(sb);
+	uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
+	uint32_t newblock = 0, adsize;
+	uint32_t elen, goal_elen = 0;
+	struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
+	struct extent_position epos, goal_epos;
+	int8_t etype;
+	struct udf_inode_info *iinfo = UDF_I(table);
+
+	*err = -ENOSPC;
+
+	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
+		adsize = sizeof(struct short_ad);
+	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
+		adsize = sizeof(struct long_ad);
+	else
+		return newblock;
+
+	mutex_lock(&sbi->s_alloc_mutex);
+	if (goal >= sbi->s_partmaps[partition].s_partition_len)
+		goal = 0;
+
+	/* We search for the closest matching block to goal. If we find
+	   a exact hit, we stop. Otherwise we keep going till we run out
+	   of extents. We store the buffer_head, bloc, and extoffset
+	   of the current closest match and use that when we are done.
+	 */
+	epos.offset = sizeof(struct unallocSpaceEntry);
+	epos.block = iinfo->i_location;
+	epos.bh = goal_epos.bh = NULL;
+
+	while (spread &&
+	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
+		if (goal >= eloc.logicalBlockNum) {
+			if (goal < eloc.logicalBlockNum +
+					(elen >> sb->s_blocksize_bits))
+				nspread = 0;
+			else
+				nspread = goal - eloc.logicalBlockNum -
+					(elen >> sb->s_blocksize_bits);
+		} else {
+			nspread = eloc.logicalBlockNum - goal;
+		}
+
+		if (nspread < spread) {
+			spread = nspread;
+			if (goal_epos.bh != epos.bh) {
+				brelse(goal_epos.bh);
+				goal_epos.bh = epos.bh;
+				get_bh(goal_epos.bh);
+			}
+			goal_epos.block = epos.block;
+			goal_epos.offset = epos.offset - adsize;
+			goal_eloc = eloc;
+			goal_elen = (etype << 30) | elen;
+		}
+	}
+
+	brelse(epos.bh);
+
+	if (spread == 0xFFFFFFFF) {
+		brelse(goal_epos.bh);
+		mutex_unlock(&sbi->s_alloc_mutex);
+		return 0;
+	}
+
+	/* Only allocate blocks from the beginning of the extent.
+	   That way, we only delete (empty) extents, never have to insert an
+	   extent because of splitting */
+	/* This works, but very poorly.... */
+
+	newblock = goal_eloc.logicalBlockNum;
+	goal_eloc.logicalBlockNum++;
+	goal_elen -= sb->s_blocksize;
+
+	if (goal_elen)
+		udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
+	else
+		udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
+	brelse(goal_epos.bh);
+
+	udf_add_free_space(sb, partition, -1);
+
+	mutex_unlock(&sbi->s_alloc_mutex);
+	*err = 0;
+	return newblock;
+}
+
+void udf_free_blocks(struct super_block *sb, struct inode *inode,
+		     struct kernel_lb_addr *bloc, uint32_t offset,
+		     uint32_t count)
+{
+	uint16_t partition = bloc->partitionReferenceNum;
+	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
+
+	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
+		udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,
+				       bloc, offset, count);
+	} else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
+		udf_table_free_blocks(sb, map->s_uspace.s_table,
+				      bloc, offset, count);
+	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
+		udf_bitmap_free_blocks(sb, map->s_fspace.s_bitmap,
+				       bloc, offset, count);
+	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
+		udf_table_free_blocks(sb, map->s_fspace.s_table,
+				      bloc, offset, count);
+	}
+
+	if (inode) {
+		inode_sub_bytes(inode,
+				((sector_t)count) << sb->s_blocksize_bits);
+	}
+}
+
+inline int udf_prealloc_blocks(struct super_block *sb,
+			       struct inode *inode,
+			       uint16_t partition, uint32_t first_block,
+			       uint32_t block_count)
+{
+	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
+	sector_t allocated;
+
+	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
+		allocated = udf_bitmap_prealloc_blocks(sb,
+						       map->s_uspace.s_bitmap,
+						       partition, first_block,
+						       block_count);
+	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
+		allocated = udf_table_prealloc_blocks(sb,
+						      map->s_uspace.s_table,
+						      partition, first_block,
+						      block_count);
+	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
+		allocated = udf_bitmap_prealloc_blocks(sb,
+						       map->s_fspace.s_bitmap,
+						       partition, first_block,
+						       block_count);
+	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
+		allocated = udf_table_prealloc_blocks(sb,
+						      map->s_fspace.s_table,
+						      partition, first_block,
+						      block_count);
+	else
+		return 0;
+
+	if (inode && allocated > 0)
+		inode_add_bytes(inode, allocated << sb->s_blocksize_bits);
+	return allocated;
+}
+
+inline int udf_new_block(struct super_block *sb,
+			 struct inode *inode,
+			 uint16_t partition, uint32_t goal, int *err)
+{
+	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
+	int block;
+
+	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
+		block = udf_bitmap_new_block(sb,
+					     map->s_uspace.s_bitmap,
+					     partition, goal, err);
+	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
+		block = udf_table_new_block(sb,
+					    map->s_uspace.s_table,
+					    partition, goal, err);
+	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
+		block = udf_bitmap_new_block(sb,
+					     map->s_fspace.s_bitmap,
+					     partition, goal, err);
+	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
+		block = udf_table_new_block(sb,
+					    map->s_fspace.s_table,
+					    partition, goal, err);
+	else {
+		*err = -EIO;
+		return 0;
+	}
+	if (inode && block)
+		inode_add_bytes(inode, sb->s_blocksize);
+	return block;
+}