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linux/fs/udf/balloc.c
Jan Kara f5cc15dac5 Fix possible NULL pointer dereference in udf_table_free_blocks() 
Fix possible NULL pointer dereference when freeing blocks in case table of
free space is used.  Also fix handling of the case when we need to move
extent from one block to another one to make space for indirect extent.
BTW: Nobody seem to have ever used this code.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31 01:42:22 -07:00

868 lines
24 KiB
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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/quotaops.h>
#include <linux/buffer_head.h>
#include <linux/bitops.h>
#include "udf_i.h"
#include "udf_sb.h"
#define udf_clear_bit(nr,addr) ext2_clear_bit(nr,addr)
#define udf_set_bit(nr,addr) ext2_set_bit(nr,addr)
#define udf_test_bit(nr, addr) ext2_test_bit(nr, addr)
#define udf_find_first_one_bit(addr, size) find_first_one_bit(addr, size)
#define udf_find_next_one_bit(addr, size, offset) find_next_one_bit(addr, size, offset)
#define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x)
#define leNUM_to_cpup(x,y) xleNUM_to_cpup(x,y)
#define xleNUM_to_cpup(x,y) (le ## x ## _to_cpup(y))
#define uintBPL_t uint(BITS_PER_LONG)
#define uint(x) xuint(x)
#define xuint(x) __le ## x
static inline int find_next_one_bit(void *addr, int size, int offset)
{
uintBPL_t *p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG);
int result = offset & ~(BITS_PER_LONG - 1);
unsigned long tmp;
if (offset >= size)
return size;
size -= result;
offset &= (BITS_PER_LONG - 1);
if (offset) {
tmp = leBPL_to_cpup(p++);
tmp &= ~0UL << offset;
if (size < BITS_PER_LONG)
goto found_first;
if (tmp)
goto found_middle;
size -= BITS_PER_LONG;
result += BITS_PER_LONG;
}
while (size & ~(BITS_PER_LONG - 1)) {
if ((tmp = leBPL_to_cpup(p++)))
goto found_middle;
result += BITS_PER_LONG;
size -= BITS_PER_LONG;
}
if (!size)
return result;
tmp = leBPL_to_cpup(p);
found_first:
tmp &= ~0UL >> (BITS_PER_LONG - size);
found_middle:
return result + ffz(~tmp);
}
#define find_first_one_bit(addr, size)\
find_next_one_bit((addr), (size), 0)
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;
kernel_lb_addr loc;
loc.logicalBlockNum = bitmap->s_extPosition;
loc.partitionReferenceNum = UDF_SB_PARTITION(sb);
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_bitmap_free_blocks(struct super_block *sb,
struct inode *inode,
struct udf_bitmap *bitmap,
kernel_lb_addr bloc, uint32_t offset,
uint32_t count)
{
struct udf_sb_info *sbi = UDF_SB(sb);
struct buffer_head *bh = NULL;
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);
if (bloc.logicalBlockNum < 0 ||
(bloc.logicalBlockNum + count) > UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum)) {
udf_debug("%d < %d || %d + %d > %d\n",
bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum));
goto error_return;
}
block = bloc.logicalBlockNum + offset + (sizeof(struct spaceBitmapDesc) << 3);
do_more:
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]);
} else {
if (inode)
DQUOT_FREE_BLOCK(inode, 1);
if (UDF_SB_LVIDBH(sb)) {
UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)] =
cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)]) + 1);
}
}
}
mark_buffer_dirty(bh);
if (overflow) {
block += count;
count = overflow;
goto do_more;
}
error_return:
sb->s_dirt = 1;
if (UDF_SB_LVIDBH(sb))
mark_buffer_dirty(UDF_SB_LVIDBH(sb));
mutex_unlock(&sbi->s_alloc_mutex);
return;
}
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)
{
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;
mutex_lock(&sbi->s_alloc_mutex);
if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
goto out;
if (first_block + block_count > UDF_SB_PARTLEN(sb, partition))
block_count = UDF_SB_PARTLEN(sb, partition) - first_block;
repeat:
nr_groups = (UDF_SB_PARTLEN(sb, partition) +
(sizeof(struct spaceBitmapDesc) << 3) +
(sb->s_blocksize * 8) - 1) / (sb->s_blocksize * 8);
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_test_bit(bit, bh->b_data)) {
goto out;
} else if (DQUOT_PREALLOC_BLOCK(inode, 1)) {
goto out;
} else if (!udf_clear_bit(bit, bh->b_data)) {
udf_debug("bit already cleared for block %d\n", bit);
DQUOT_FREE_BLOCK(inode, 1);
goto out;
}
block_count--;
alloc_count++;
bit++;
block++;
}
mark_buffer_dirty(bh);
if (block_count > 0)
goto repeat;
out:
if (UDF_SB_LVIDBH(sb)) {
UDF_SB_LVID(sb)->freeSpaceTable[partition] =
cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition]) - alloc_count);
mark_buffer_dirty(UDF_SB_LVIDBH(sb));
}
sb->s_dirt = 1;
mutex_unlock(&sbi->s_alloc_mutex);
return alloc_count;
}
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)
{
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 < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
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((char *)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:
for (i = 0; i < 7 && bit > (group_start << 3) && udf_test_bit(bit - 1, bh->b_data); i++, bit--)
; /* empty loop */
got_block:
/*
* Check quota for allocation of this block.
*/
if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
mutex_unlock(&sbi->s_alloc_mutex);
*err = -EDQUOT;
return 0;
}
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);
if (UDF_SB_LVIDBH(sb)) {
UDF_SB_LVID(sb)->freeSpaceTable[partition] =
cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition]) - 1);
mark_buffer_dirty(UDF_SB_LVIDBH(sb));
}
sb->s_dirt = 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 *inode,
struct inode *table,
kernel_lb_addr bloc, uint32_t offset,
uint32_t count)
{
struct udf_sb_info *sbi = UDF_SB(sb);
uint32_t start, end;
uint32_t elen;
kernel_lb_addr eloc;
struct extent_position oepos, epos;
int8_t etype;
int i;
mutex_lock(&sbi->s_alloc_mutex);
if (bloc.logicalBlockNum < 0 ||
(bloc.logicalBlockNum + count) > UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum)) {
udf_debug("%d < %d || %d + %d > %d\n",
bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum));
goto error_return;
}
/* We do this up front - There are some error conditions that could occure,
but.. oh well */
if (inode)
DQUOT_FREE_BLOCK(inode, count);
if (UDF_SB_LVIDBH(sb)) {
UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)] =
cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)]) + count);
mark_buffer_dirty(UDF_SB_LVIDBH(sb));
}
start = bloc.logicalBlockNum + offset;
end = bloc.logicalBlockNum + offset + count - 1;
epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
elen = 0;
epos.block = oepos.block = UDF_I_LOCATION(table);
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)) {
count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
start += ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
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)) {
count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
end -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
eloc.logicalBlockNum -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
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;
short_ad *sad = NULL;
long_ad *lad = NULL;
struct allocExtDesc *aed;
eloc.logicalBlockNum = start;
elen = EXT_RECORDED_ALLOCATED |
(count << sb->s_blocksize_bits);
if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT) {
adsize = sizeof(short_ad);
} else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG) {
adsize = sizeof(long_ad);
} else {
brelse(oepos.bh);
brelse(epos.bh);
goto error_return;
}
if (epos.offset + (2 * adsize) > sb->s_blocksize) {
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;
if (!(epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, epos.block, 0)))) {
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 = UDF_I_DATA(table) + 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;
aed->lengthAllocDescs =
cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
} else {
sptr = UDF_I_DATA(table) + epos.offset;
UDF_I_LENALLOC(table) += adsize;
mark_inode_dirty(table);
}
epos.offset = sizeof(struct allocExtDesc);
}
if (UDF_SB_UDFREV(sb) >= 0x0200)
udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 3, 1,
epos.block.logicalBlockNum, sizeof(tag));
else
udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 2, 1,
epos.block.logicalBlockNum, sizeof(tag));
switch (UDF_I_ALLOCTYPE(table)) {
case ICBTAG_FLAG_AD_SHORT:
sad = (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 = (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);
}
}
if (elen) { /* It's possible that stealing the block emptied the extent */
udf_write_aext(table, &epos, eloc, elen, 1);
if (!epos.bh) {
UDF_I_LENALLOC(table) += adsize;
mark_inode_dirty(table);
} else {
aed = (struct allocExtDesc *)epos.bh->b_data;
aed->lengthAllocDescs =
cpu_to_le32(le32_to_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:
sb->s_dirt = 1;
mutex_unlock(&sbi->s_alloc_mutex);
return;
}
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)
{
struct udf_sb_info *sbi = UDF_SB(sb);
int alloc_count = 0;
uint32_t elen, adsize;
kernel_lb_addr eloc;
struct extent_position epos;
int8_t etype = -1;
if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
return 0;
if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
adsize = sizeof(short_ad);
else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
adsize = sizeof(long_ad);
else
return 0;
mutex_lock(&sbi->s_alloc_mutex);
epos.offset = sizeof(struct unallocSpaceEntry);
epos.block = UDF_I_LOCATION(table);
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 (inode && DQUOT_PREALLOC_BLOCK(inode, alloc_count > block_count ? block_count : alloc_count)) {
alloc_count = 0;
} else 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_SB_LVIDBH(sb)) {
UDF_SB_LVID(sb)->freeSpaceTable[partition] =
cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition]) - alloc_count);
mark_buffer_dirty(UDF_SB_LVIDBH(sb));
sb->s_dirt = 1;
}
mutex_unlock(&sbi->s_alloc_mutex);
return alloc_count;
}
static int udf_table_new_block(struct super_block *sb,
struct inode *inode,
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;
kernel_lb_addr eloc, goal_eloc;
struct extent_position epos, goal_epos;
int8_t etype;
*err = -ENOSPC;
if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
adsize = sizeof(short_ad);
else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
adsize = sizeof(long_ad);
else
return newblock;
mutex_lock(&sbi->s_alloc_mutex);
if (goal < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
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 = UDF_I_LOCATION(table);
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 (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
brelse(goal_epos.bh);
mutex_unlock(&sbi->s_alloc_mutex);
*err = -EDQUOT;
return 0;
}
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);
if (UDF_SB_LVIDBH(sb)) {
UDF_SB_LVID(sb)->freeSpaceTable[partition] =
cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition]) - 1);
mark_buffer_dirty(UDF_SB_LVIDBH(sb));
}
sb->s_dirt = 1;
mutex_unlock(&sbi->s_alloc_mutex);
*err = 0;
return newblock;
}
inline void udf_free_blocks(struct super_block *sb,
struct inode *inode,
kernel_lb_addr bloc, uint32_t offset,
uint32_t count)
{
uint16_t partition = bloc.partitionReferenceNum;
if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP) {
return udf_bitmap_free_blocks(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
bloc, offset, count);
} else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE) {
return udf_table_free_blocks(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
bloc, offset, count);
} else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP) {
return udf_bitmap_free_blocks(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
bloc, offset, count);
} else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE) {
return udf_table_free_blocks(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
bloc, offset, count);
} else {
return;
}
}
inline int udf_prealloc_blocks(struct super_block *sb,
struct inode *inode,
uint16_t partition, uint32_t first_block,
uint32_t block_count)
{
if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP) {
return udf_bitmap_prealloc_blocks(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
partition, first_block, block_count);
} else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE) {
return udf_table_prealloc_blocks(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
partition, first_block, block_count);
} else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP) {
return udf_bitmap_prealloc_blocks(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
partition, first_block, block_count);
} else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE) {
return udf_table_prealloc_blocks(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
partition, first_block, block_count);
} else {
return 0;
}
}
inline int udf_new_block(struct super_block *sb,
struct inode *inode,
uint16_t partition, uint32_t goal, int *err)
{
int ret;
if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP) {
ret = udf_bitmap_new_block(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
partition, goal, err);
return ret;
} else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE) {
return udf_table_new_block(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
partition, goal, err);
} else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP) {
return udf_bitmap_new_block(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
partition, goal, err);
} else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE) {
return udf_table_new_block(sb, inode,
UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
partition, goal, err);
} else {
*err = -EIO;
return 0;
}
}
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