balloc.c 21.5 KB
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/*
 * 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"

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#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
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static int read_block_bitmap(struct super_block *sb,
			     struct udf_bitmap *bitmap, unsigned int block,
			     unsigned long bitmap_nr)
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{
	struct buffer_head *bh = NULL;
	int retval = 0;
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	struct kernel_lb_addr loc;
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	loc.logicalBlockNum = bitmap->s_extPosition;
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	loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
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	bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block));
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	if (!bh)
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		retval = -EIO;
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	bitmap->s_block_bitmap[bitmap_nr] = bh;
	return retval;
}

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static int __load_block_bitmap(struct super_block *sb,
			       struct udf_bitmap *bitmap,
			       unsigned int block_group)
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{
	int retval = 0;
	int nr_groups = bitmap->s_nr_groups;

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	if (block_group >= nr_groups) {
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		udf_debug("block_group (%d) > nr_groups (%d)\n",
			  block_group, nr_groups);
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	}

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	if (bitmap->s_block_bitmap[block_group]) {
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		return block_group;
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	} else {
		retval = read_block_bitmap(sb, bitmap, block_group,
					   block_group);
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		if (retval < 0)
			return retval;
		return block_group;
	}
}

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static inline int load_block_bitmap(struct super_block *sb,
				    struct udf_bitmap *bitmap,
				    unsigned int block_group)
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{
	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;
}

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static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
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{
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	struct udf_sb_info *sbi = UDF_SB(sb);
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	struct logicalVolIntegrityDesc *lvid;

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	if (!sbi->s_lvid_bh)
		return;
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	lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
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	le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
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	udf_updated_lvid(sb);
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}

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static void udf_bitmap_free_blocks(struct super_block *sb,
				   struct inode *inode,
				   struct udf_bitmap *bitmap,
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				   struct kernel_lb_addr *bloc,
				   uint32_t offset,
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				   uint32_t count)
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{
	struct udf_sb_info *sbi = UDF_SB(sb);
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	struct buffer_head *bh = NULL;
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	struct udf_part_map *partmap;
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	unsigned long block;
	unsigned long block_group;
	unsigned long bit;
	unsigned long i;
	int bitmap_nr;
	unsigned long overflow;

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	mutex_lock(&sbi->s_alloc_mutex);
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	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
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	if (bloc->logicalBlockNum + count < count ||
	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
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		udf_debug("%d < %d || %d + %d > %d\n",
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			  bloc->logicalBlockNum, 0,
			  bloc->logicalBlockNum, count,
			  partmap->s_partition_len);
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		goto error_return;
	}

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	block = bloc->logicalBlockNum + offset +
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		(sizeof(struct spaceBitmapDesc) << 3);
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	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;
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		}
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		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",
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					  ((char *)bh->b_data)[(bit + i) >> 3]);
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			}
		}
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		udf_add_free_space(sb, sbi->s_partition, count);
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		mark_buffer_dirty(bh);
		if (overflow) {
			block += count;
			count = overflow;
		}
	} while (overflow);

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error_return:
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	mutex_unlock(&sbi->s_alloc_mutex);
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}

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static int udf_bitmap_prealloc_blocks(struct super_block *sb,
				      struct inode *inode,
				      struct udf_bitmap *bitmap,
				      uint16_t partition, uint32_t first_block,
				      uint32_t block_count)
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{
	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;
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	__u32 part_len;
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	mutex_lock(&sbi->s_alloc_mutex);
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	part_len = sbi->s_partmaps[partition].s_partition_len;
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	if (first_block >= part_len)
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		goto out;

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	if (first_block + block_count > part_len)
		block_count = part_len - first_block;
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	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);
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		bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
		if (bitmap_nr < 0)
			goto out;
		bh = bitmap->s_block_bitmap[bitmap_nr];
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		bit = block % (sb->s_blocksize << 3);
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		while (bit < (sb->s_blocksize << 3) && block_count > 0) {
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			if (!udf_clear_bit(bit, bh->b_data))
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				goto out;
			block_count--;
			alloc_count++;
			bit++;
			block++;
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		}
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		mark_buffer_dirty(bh);
	} while (block_count > 0);

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out:
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	udf_add_free_space(sb, partition, -alloc_count);
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	mutex_unlock(&sbi->s_alloc_mutex);
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	return alloc_count;
}

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static int udf_bitmap_new_block(struct super_block *sb,
				struct inode *inode,
				struct udf_bitmap *bitmap, uint16_t partition,
				uint32_t goal, int *err)
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{
	struct udf_sb_info *sbi = UDF_SB(sb);
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	int newbit, bit = 0, block, block_group, group_start;
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	int end_goal, nr_groups, bitmap_nr, i;
	struct buffer_head *bh = NULL;
	char *ptr;
	int newblock = 0;

	*err = -ENOSPC;
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	mutex_lock(&sbi->s_alloc_mutex);
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repeat:
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	if (goal >= sbi->s_partmaps[partition].s_partition_len)
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		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];
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	ptr = memscan((char *)bh->b_data + group_start, 0xFF,
		      sb->s_blocksize - group_start);
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	if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
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		bit = block % (sb->s_blocksize << 3);
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		if (udf_test_bit(bit, bh->b_data))
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			goto got_block;
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		end_goal = (bit + 63) & ~63;
		bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
		if (bit < end_goal)
			goto got_block;
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		ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
			      sb->s_blocksize - ((bit + 7) >> 3));
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		newbit = (ptr - ((char *)bh->b_data)) << 3;
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		if (newbit < sb->s_blocksize << 3) {
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			bit = newbit;
			goto search_back;
		}
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		newbit = udf_find_next_one_bit(bh->b_data,
					       sb->s_blocksize << 3, bit);
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		if (newbit < sb->s_blocksize << 3) {
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			bit = newbit;
			goto got_block;
		}
	}

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	for (i = 0; i < (nr_groups * 2); i++) {
		block_group++;
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		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];
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		if (i < nr_groups) {
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			ptr = memscan((char *)bh->b_data + group_start, 0xFF,
				      sb->s_blocksize - group_start);
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			if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
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				bit = (ptr - ((char *)bh->b_data)) << 3;
				break;
			}
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		} else {
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			bit = udf_find_next_one_bit(bh->b_data,
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						    sb->s_blocksize << 3,
						    group_start << 3);
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			if (bit < sb->s_blocksize << 3)
				break;
		}
	}
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	if (i >= (nr_groups * 2)) {
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		mutex_unlock(&sbi->s_alloc_mutex);
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		return newblock;
	}
	if (bit < sb->s_blocksize << 3)
		goto search_back;
	else
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		bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
					    group_start << 3);
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	if (bit >= sb->s_blocksize << 3) {
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		mutex_unlock(&sbi->s_alloc_mutex);
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		return 0;
	}

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search_back:
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	i = 0;
	while (i < 7 && bit > (group_start << 3) &&
	       udf_test_bit(bit - 1, bh->b_data)) {
		++i;
		--bit;
	}
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got_block:
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	newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
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		(sizeof(struct spaceBitmapDesc) << 3);
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	if (!udf_clear_bit(bit, bh->b_data)) {
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		udf_debug("bit already cleared for block %d\n", bit);
		goto repeat;
	}

	mark_buffer_dirty(bh);

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	udf_add_free_space(sb, partition, -1);
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	mutex_unlock(&sbi->s_alloc_mutex);
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	*err = 0;
	return newblock;

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error_return:
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	*err = -EIO;
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	mutex_unlock(&sbi->s_alloc_mutex);
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	return 0;
}

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static void udf_table_free_blocks(struct super_block *sb,
				  struct inode *inode,
				  struct inode *table,
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				  struct kernel_lb_addr *bloc,
				  uint32_t offset,
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				  uint32_t count)
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{
	struct udf_sb_info *sbi = UDF_SB(sb);
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	struct udf_part_map *partmap;
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	uint32_t start, end;
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	uint32_t elen;
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	struct kernel_lb_addr eloc;
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	struct extent_position oepos, epos;
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	int8_t etype;
	int i;
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	struct udf_inode_info *iinfo;
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	mutex_lock(&sbi->s_alloc_mutex);
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	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
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	if (bloc->logicalBlockNum + count < count ||
	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
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		udf_debug("%d < %d || %d + %d > %d\n",
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			  bloc->logicalBlockNum, 0,
			  bloc->logicalBlockNum, count,
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			  partmap->s_partition_len);
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		goto error_return;
	}

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	iinfo = UDF_I(table);
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	udf_add_free_space(sb, sbi->s_partition, count);
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	start = bloc->logicalBlockNum + offset;
	end = bloc->logicalBlockNum + offset + count - 1;
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	epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
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	elen = 0;
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	epos.block = oepos.block = iinfo->i_location;
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	epos.bh = oepos.bh = NULL;
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	while (count &&
	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
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		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);
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			} else {
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				elen = (etype << 30) |
					(elen +
					(count << sb->s_blocksize_bits));
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				start += count;
				count = 0;
			}
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			udf_write_aext(table, &oepos, &eloc, elen, 1);
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		} else if (eloc.logicalBlockNum == (end + 1)) {
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			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);
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			} else {
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				eloc.logicalBlockNum = start;
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				elen = (etype << 30) |
					(elen +
					(count << sb->s_blocksize_bits));
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				end -= count;
				count = 0;
			}
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			udf_write_aext(table, &oepos, &eloc, elen, 1);
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		}

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		if (epos.bh != oepos.bh) {
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			i = -1;
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			oepos.block = epos.block;
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			brelse(oepos.bh);
			get_bh(epos.bh);
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			oepos.bh = epos.bh;
			oepos.offset = 0;
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		} else {
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			oepos.offset = epos.offset;
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		}
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	}

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	if (count) {
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		/*
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		 * 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 :)
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		 *
		 * 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.
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		 */
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		int adsize;
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		struct short_ad *sad = NULL;
		struct long_ad *lad = NULL;
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		struct allocExtDesc *aed;

		eloc.logicalBlockNum = start;
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		elen = EXT_RECORDED_ALLOCATED |
			(count << sb->s_blocksize_bits);
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		if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
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			adsize = sizeof(struct short_ad);
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		else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
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			adsize = sizeof(struct long_ad);
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		else {
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			brelse(oepos.bh);
			brelse(epos.bh);
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			goto error_return;
		}

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		if (epos.offset + (2 * adsize) > sb->s_blocksize) {
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			unsigned char *sptr, *dptr;
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			int loffset;
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			brelse(oepos.bh);
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			oepos = epos;
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			/* Steal a block from the extent being free'd */
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			epos.block.logicalBlockNum = eloc.logicalBlockNum;
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			eloc.logicalBlockNum++;
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			elen -= sb->s_blocksize;

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			epos.bh = udf_tread(sb,
489
					udf_get_lb_pblock(sb, &epos.block, 0));
M
Marcin Slusarz 已提交
490
			if (!epos.bh) {
J
Jan Kara 已提交
491
				brelse(oepos.bh);
L
Linus Torvalds 已提交
492 493
				goto error_return;
			}
J
Jan Kara 已提交
494
			aed = (struct allocExtDesc *)(epos.bh->b_data);
M
Marcin Slusarz 已提交
495 496
			aed->previousAllocExtLocation =
				cpu_to_le32(oepos.block.logicalBlockNum);
497
			if (epos.offset + adsize > sb->s_blocksize) {
J
Jan Kara 已提交
498
				loffset = epos.offset;
L
Linus Torvalds 已提交
499
				aed->lengthAllocDescs = cpu_to_le32(adsize);
500
				sptr = iinfo->i_ext.i_data + epos.offset
501
								- adsize;
M
Marcin Slusarz 已提交
502 503
				dptr = epos.bh->b_data +
					sizeof(struct allocExtDesc);
L
Linus Torvalds 已提交
504
				memcpy(dptr, sptr, adsize);
M
Marcin Slusarz 已提交
505 506
				epos.offset = sizeof(struct allocExtDesc) +
						adsize;
507
			} else {
J
Jan Kara 已提交
508
				loffset = epos.offset + adsize;
L
Linus Torvalds 已提交
509
				aed->lengthAllocDescs = cpu_to_le32(0);
510
				if (oepos.bh) {
511
					sptr = oepos.bh->b_data + epos.offset;
M
Marcin Slusarz 已提交
512 513
					aed = (struct allocExtDesc *)
						oepos.bh->b_data;
514 515
					le32_add_cpu(&aed->lengthAllocDescs,
							adsize);
516
				} else {
517
					sptr = iinfo->i_ext.i_data +
518
								epos.offset;
519
					iinfo->i_lenAlloc += adsize;
L
Linus Torvalds 已提交
520 521
					mark_inode_dirty(table);
				}
522
				epos.offset = sizeof(struct allocExtDesc);
L
Linus Torvalds 已提交
523
			}
M
Marcin Slusarz 已提交
524
			if (sbi->s_udfrev >= 0x0200)
M
Marcin Slusarz 已提交
525 526
				udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
					    3, 1, epos.block.logicalBlockNum,
527
					    sizeof(struct tag));
L
Linus Torvalds 已提交
528
			else
M
Marcin Slusarz 已提交
529 530
				udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
					    2, 1, epos.block.logicalBlockNum,
531
					    sizeof(struct tag));
532

533
			switch (iinfo->i_alloc_type) {
M
Marcin Slusarz 已提交
534
			case ICBTAG_FLAG_AD_SHORT:
535
				sad = (struct short_ad *)sptr;
M
Marcin Slusarz 已提交
536 537 538 539 540 541 542
				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:
543
				lad = (struct long_ad *)sptr;
M
Marcin Slusarz 已提交
544 545 546 547 548 549
				lad->extLength = cpu_to_le32(
					EXT_NEXT_EXTENT_ALLOCDECS |
					sb->s_blocksize);
				lad->extLocation =
					cpu_to_lelb(epos.block);
				break;
L
Linus Torvalds 已提交
550
			}
551
			if (oepos.bh) {
J
Jan Kara 已提交
552 553
				udf_update_tag(oepos.bh->b_data, loffset);
				mark_buffer_dirty(oepos.bh);
554
			} else {
L
Linus Torvalds 已提交
555
				mark_inode_dirty(table);
556
			}
L
Linus Torvalds 已提交
557 558
		}

M
Marcin Slusarz 已提交
559 560
		/* It's possible that stealing the block emptied the extent */
		if (elen) {
561
			udf_write_aext(table, &epos, &eloc, elen, 1);
L
Linus Torvalds 已提交
562

563
			if (!epos.bh) {
564
				iinfo->i_lenAlloc += adsize;
L
Linus Torvalds 已提交
565
				mark_inode_dirty(table);
566
			} else {
J
Jan Kara 已提交
567
				aed = (struct allocExtDesc *)epos.bh->b_data;
568
				le32_add_cpu(&aed->lengthAllocDescs, adsize);
J
Jan Kara 已提交
569 570
				udf_update_tag(epos.bh->b_data, epos.offset);
				mark_buffer_dirty(epos.bh);
L
Linus Torvalds 已提交
571 572 573 574
			}
		}
	}

J
Jan Kara 已提交
575 576
	brelse(epos.bh);
	brelse(oepos.bh);
L
Linus Torvalds 已提交
577

578
error_return:
I
Ingo Molnar 已提交
579
	mutex_unlock(&sbi->s_alloc_mutex);
L
Linus Torvalds 已提交
580 581 582
	return;
}

583 584 585 586
static int udf_table_prealloc_blocks(struct super_block *sb,
				     struct inode *inode,
				     struct inode *table, uint16_t partition,
				     uint32_t first_block, uint32_t block_count)
L
Linus Torvalds 已提交
587 588 589
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	int alloc_count = 0;
J
Jan Kara 已提交
590
	uint32_t elen, adsize;
591
	struct kernel_lb_addr eloc;
J
Jan Kara 已提交
592
	struct extent_position epos;
L
Linus Torvalds 已提交
593
	int8_t etype = -1;
594
	struct udf_inode_info *iinfo;
L
Linus Torvalds 已提交
595

596
	if (first_block >= sbi->s_partmaps[partition].s_partition_len)
L
Linus Torvalds 已提交
597 598
		return 0;

599 600
	iinfo = UDF_I(table);
	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
601
		adsize = sizeof(struct short_ad);
602
	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
603
		adsize = sizeof(struct long_ad);
L
Linus Torvalds 已提交
604 605 606
	else
		return 0;

I
Ingo Molnar 已提交
607
	mutex_lock(&sbi->s_alloc_mutex);
J
Jan Kara 已提交
608
	epos.offset = sizeof(struct unallocSpaceEntry);
609
	epos.block = iinfo->i_location;
J
Jan Kara 已提交
610
	epos.bh = NULL;
L
Linus Torvalds 已提交
611 612
	eloc.logicalBlockNum = 0xFFFFFFFF;

613 614
	while (first_block != eloc.logicalBlockNum &&
	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
L
Linus Torvalds 已提交
615
		udf_debug("eloc=%d, elen=%d, first_block=%d\n",
616
			  eloc.logicalBlockNum, elen, first_block);
617
		; /* empty loop body */
L
Linus Torvalds 已提交
618 619
	}

620
	if (first_block == eloc.logicalBlockNum) {
J
Jan Kara 已提交
621
		epos.offset -= adsize;
L
Linus Torvalds 已提交
622 623

		alloc_count = (elen >> sb->s_blocksize_bits);
J
Jan Kara 已提交
624
		if (alloc_count > block_count) {
L
Linus Torvalds 已提交
625 626 627
			alloc_count = block_count;
			eloc.logicalBlockNum += alloc_count;
			elen -= (alloc_count << sb->s_blocksize_bits);
628
			udf_write_aext(table, &epos, &eloc,
M
Marcin Slusarz 已提交
629 630 631 632
					(etype << 30) | elen, 1);
		} else
			udf_delete_aext(table, epos, eloc,
					(etype << 30) | elen);
633
	} else {
L
Linus Torvalds 已提交
634
		alloc_count = 0;
635
	}
L
Linus Torvalds 已提交
636

J
Jan Kara 已提交
637
	brelse(epos.bh);
L
Linus Torvalds 已提交
638

639 640
	if (alloc_count)
		udf_add_free_space(sb, partition, -alloc_count);
I
Ingo Molnar 已提交
641
	mutex_unlock(&sbi->s_alloc_mutex);
L
Linus Torvalds 已提交
642 643 644
	return alloc_count;
}

645 646 647 648
static int udf_table_new_block(struct super_block *sb,
			       struct inode *inode,
			       struct inode *table, uint16_t partition,
			       uint32_t goal, int *err)
L
Linus Torvalds 已提交
649 650 651 652
{
	struct udf_sb_info *sbi = UDF_SB(sb);
	uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
	uint32_t newblock = 0, adsize;
J
Jan Kara 已提交
653
	uint32_t elen, goal_elen = 0;
654
	struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
J
Jan Kara 已提交
655
	struct extent_position epos, goal_epos;
L
Linus Torvalds 已提交
656
	int8_t etype;
657
	struct udf_inode_info *iinfo = UDF_I(table);
L
Linus Torvalds 已提交
658 659 660

	*err = -ENOSPC;

661
	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
662
		adsize = sizeof(struct short_ad);
663
	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
664
		adsize = sizeof(struct long_ad);
L
Linus Torvalds 已提交
665 666 667
	else
		return newblock;

I
Ingo Molnar 已提交
668
	mutex_lock(&sbi->s_alloc_mutex);
669
	if (goal >= sbi->s_partmaps[partition].s_partition_len)
L
Linus Torvalds 已提交
670 671
		goal = 0;

M
Marcin Slusarz 已提交
672 673 674 675
	/* 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.
676
	 */
J
Jan Kara 已提交
677
	epos.offset = sizeof(struct unallocSpaceEntry);
678
	epos.block = iinfo->i_location;
J
Jan Kara 已提交
679
	epos.bh = goal_epos.bh = NULL;
L
Linus Torvalds 已提交
680

681 682
	while (spread &&
	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
683
		if (goal >= eloc.logicalBlockNum) {
M
Marcin Slusarz 已提交
684 685
			if (goal < eloc.logicalBlockNum +
					(elen >> sb->s_blocksize_bits))
L
Linus Torvalds 已提交
686 687 688
				nspread = 0;
			else
				nspread = goal - eloc.logicalBlockNum -
689 690
					(elen >> sb->s_blocksize_bits);
		} else {
L
Linus Torvalds 已提交
691
			nspread = eloc.logicalBlockNum - goal;
692
		}
L
Linus Torvalds 已提交
693

694
		if (nspread < spread) {
L
Linus Torvalds 已提交
695
			spread = nspread;
696
			if (goal_epos.bh != epos.bh) {
J
Jan Kara 已提交
697
				brelse(goal_epos.bh);
J
Jan Kara 已提交
698
				goal_epos.bh = epos.bh;
J
Jan Kara 已提交
699
				get_bh(goal_epos.bh);
L
Linus Torvalds 已提交
700
			}
J
Jan Kara 已提交
701 702
			goal_epos.block = epos.block;
			goal_epos.offset = epos.offset - adsize;
L
Linus Torvalds 已提交
703 704 705 706 707
			goal_eloc = eloc;
			goal_elen = (etype << 30) | elen;
		}
	}

J
Jan Kara 已提交
708
	brelse(epos.bh);
L
Linus Torvalds 已提交
709

710
	if (spread == 0xFFFFFFFF) {
J
Jan Kara 已提交
711
		brelse(goal_epos.bh);
I
Ingo Molnar 已提交
712
		mutex_unlock(&sbi->s_alloc_mutex);
L
Linus Torvalds 已提交
713 714 715 716 717 718 719 720 721
		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;
722
	goal_eloc.logicalBlockNum++;
L
Linus Torvalds 已提交
723 724 725
	goal_elen -= sb->s_blocksize;

	if (goal_elen)
726
		udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
L
Linus Torvalds 已提交
727
	else
J
Jan Kara 已提交
728
		udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
J
Jan Kara 已提交
729
	brelse(goal_epos.bh);
L
Linus Torvalds 已提交
730

731
	udf_add_free_space(sb, partition, -1);
L
Linus Torvalds 已提交
732

I
Ingo Molnar 已提交
733
	mutex_unlock(&sbi->s_alloc_mutex);
L
Linus Torvalds 已提交
734 735 736 737
	*err = 0;
	return newblock;
}

738 739 740
void udf_free_blocks(struct super_block *sb, struct inode *inode,
		     struct kernel_lb_addr *bloc, uint32_t offset,
		     uint32_t count)
L
Linus Torvalds 已提交
741
{
742
	uint16_t partition = bloc->partitionReferenceNum;
M
Marcin Slusarz 已提交
743
	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
L
Linus Torvalds 已提交
744

M
Marcin Slusarz 已提交
745
	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
J
Jan Kara 已提交
746 747
		udf_bitmap_free_blocks(sb, inode, map->s_uspace.s_bitmap,
				       bloc, offset, count);
M
Marcin Slusarz 已提交
748
	} else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
J
Jan Kara 已提交
749 750
		udf_table_free_blocks(sb, inode, map->s_uspace.s_table,
				      bloc, offset, count);
M
Marcin Slusarz 已提交
751
	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
J
Jan Kara 已提交
752 753
		udf_bitmap_free_blocks(sb, inode, map->s_fspace.s_bitmap,
				       bloc, offset, count);
M
Marcin Slusarz 已提交
754
	} else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
J
Jan Kara 已提交
755 756
		udf_table_free_blocks(sb, inode, map->s_fspace.s_table,
				      bloc, offset, count);
757
	}
L
Linus Torvalds 已提交
758 759
}

760 761 762 763
inline int udf_prealloc_blocks(struct super_block *sb,
			       struct inode *inode,
			       uint16_t partition, uint32_t first_block,
			       uint32_t block_count)
L
Linus Torvalds 已提交
764
{
M
Marcin Slusarz 已提交
765 766
	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];

M
Marcin Slusarz 已提交
767
	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
L
Linus Torvalds 已提交
768
		return udf_bitmap_prealloc_blocks(sb, inode,
M
Marcin Slusarz 已提交
769
						  map->s_uspace.s_bitmap,
M
Marcin Slusarz 已提交
770 771 772
						  partition, first_block,
						  block_count);
	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
L
Linus Torvalds 已提交
773
		return udf_table_prealloc_blocks(sb, inode,
M
Marcin Slusarz 已提交
774
						 map->s_uspace.s_table,
M
Marcin Slusarz 已提交
775 776 777
						 partition, first_block,
						 block_count);
	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
L
Linus Torvalds 已提交
778
		return udf_bitmap_prealloc_blocks(sb, inode,
M
Marcin Slusarz 已提交
779
						  map->s_fspace.s_bitmap,
M
Marcin Slusarz 已提交
780 781 782
						  partition, first_block,
						  block_count);
	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
L
Linus Torvalds 已提交
783
		return udf_table_prealloc_blocks(sb, inode,
M
Marcin Slusarz 已提交
784
						 map->s_fspace.s_table,
M
Marcin Slusarz 已提交
785 786 787
						 partition, first_block,
						 block_count);
	else
L
Linus Torvalds 已提交
788 789 790
		return 0;
}

791 792 793
inline int udf_new_block(struct super_block *sb,
			 struct inode *inode,
			 uint16_t partition, uint32_t goal, int *err)
L
Linus Torvalds 已提交
794
{
M
Marcin Slusarz 已提交
795
	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
J
Jan Kara 已提交
796

M
Marcin Slusarz 已提交
797 798
	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
		return udf_bitmap_new_block(sb, inode,
M
Marcin Slusarz 已提交
799
					   map->s_uspace.s_bitmap,
800
					   partition, goal, err);
M
Marcin Slusarz 已提交
801
	else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
L
Linus Torvalds 已提交
802
		return udf_table_new_block(sb, inode,
M
Marcin Slusarz 已提交
803
					   map->s_uspace.s_table,
804
					   partition, goal, err);
M
Marcin Slusarz 已提交
805
	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
L
Linus Torvalds 已提交
806
		return udf_bitmap_new_block(sb, inode,
M
Marcin Slusarz 已提交
807
					    map->s_fspace.s_bitmap,
808
					    partition, goal, err);
M
Marcin Slusarz 已提交
809
	else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
L
Linus Torvalds 已提交
810
		return udf_table_new_block(sb, inode,
M
Marcin Slusarz 已提交
811
					   map->s_fspace.s_table,
812
					   partition, goal, err);
M
Marcin Slusarz 已提交
813
	else {
L
Linus Torvalds 已提交
814 815 816 817
		*err = -EIO;
		return 0;
	}
}