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* grub-core/fs/btrfs.c (grub_btrfs_lzo_decompress): Random fixes and some

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cleanup.
This commit is contained in:
Szymon Janc 2011-08-23 19:49:01 +02:00
parent 1f0e4eed6b
commit 00b98c9b2e
1 changed files with 56 additions and 64 deletions
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120
grub-core/fs/btrfs.c
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@ -31,7 +31,17 @@
GRUB_MOD_LICENSE ("GPLv3+");
#define GRUB_BTRFS_SIGNATURE "_BHRfS_M"
/* From http://www.oberhumer.com/opensource/lzo/lzofaq.php
* LZO will expand incompressible data by a little amount. I still haven't
* computed the exact values, but I suggest using these formulas for
* a worst-case expansion calculation:
*
* output_block_size = input_block_size + (input_block_size / 16) + 64 + 3
* */
#define GRUB_BTRFS_LZO_BLOCK_SIZE 4096
#define GRUB_BTRFS_LZO_BLOCK_MAX_CSIZE (GRUB_BTRFS_LZO_BLOCK_SIZE + \
(GRUB_BTRFS_LZO_BLOCK_SIZE / 16) + 64 + 3)
typedef grub_uint8_t grub_btrfs_checksum_t[0x20];
typedef grub_uint16_t grub_btrfs_uuid_t[8];
@ -880,11 +890,11 @@ grub_btrfs_read_inode (struct grub_btrfs_data *data,
return grub_btrfs_read_logical (data, elemaddr, inode, sizeof (*inode));
}
static int
static grub_ssize_t
grub_btrfs_lzo_decompress(char *ibuf, grub_size_t isize, grub_off_t off,
char *obuf, grub_size_t osize)
{
grub_uint32_t total_size, cblock_size;
grub_uint32_t total_size, cblock_size, uncompressed = 0;
unsigned char buf[GRUB_BTRFS_LZO_BLOCK_SIZE];
total_size = grub_le_to_cpu32 (grub_get_unaligned32 (ibuf));
@ -893,62 +903,54 @@ grub_btrfs_lzo_decompress(char *ibuf, grub_size_t isize, grub_off_t off,
if (isize < total_size)
return -1;
while (osize != 0)
/* Jump forward to first block with requested data. */
while (off >= GRUB_BTRFS_LZO_BLOCK_SIZE)
{
cblock_size = grub_le_to_cpu32 (grub_get_unaligned32 (ibuf));
ibuf += sizeof (cblock_size);
off -= GRUB_BTRFS_LZO_BLOCK_SIZE;
ibuf += cblock_size;
}
while (osize > 0)
{
lzo_uint usize = GRUB_BTRFS_LZO_BLOCK_SIZE;
cblock_size = grub_le_to_cpu32 (grub_get_unaligned32 (ibuf));
ibuf += sizeof (cblock_size);
if (cblock_size > GRUB_BTRFS_LZO_BLOCK_SIZE)
return -1;
/* Jump forward to first block with requested data. */
if (off >= GRUB_BTRFS_LZO_BLOCK_SIZE)
/* Block partially filled with requested data. */
if (off > 0 || osize < GRUB_BTRFS_LZO_BLOCK_SIZE)
{
off -= GRUB_BTRFS_LZO_BLOCK_SIZE;
ibuf += cblock_size;
continue;
}
grub_size_t to_copy = grub_min(osize, GRUB_BTRFS_LZO_BLOCK_SIZE - off);
/* First block partially filled with requested data. */
if (off > 0)
{
if (lzo1x_decompress_safe ((lzo_bytep)ibuf, cblock_size, buf, &usize,
NULL) != LZO_E_OK)
return -1;
grub_memcpy(obuf, buf + off, usize - off);
grub_memcpy(obuf, buf + off, to_copy);
osize -= usize - off;
obuf += usize - off;
osize -= to_copy;
uncompressed += to_copy;
obuf += to_copy;
ibuf += cblock_size;
off = 0;
continue;
}
/* 'Main' case, decompress whole block directly to output buffer. */
if (osize >= GRUB_BTRFS_LZO_BLOCK_SIZE)
{
if (lzo1x_decompress_safe ((lzo_bytep)ibuf, cblock_size,
(lzo_bytep)obuf, &usize, NULL) != LZO_E_OK)
return -1;
if (lzo1x_decompress_safe ((lzo_bytep)ibuf, cblock_size, (lzo_bytep)obuf,
&usize, NULL) != LZO_E_OK)
return -1;
osize -= usize;
obuf += usize;
ibuf += cblock_size;
}
else /* Last possible block partially filled with requested data. */
{
if (lzo1x_decompress_safe ((lzo_bytep)ibuf, cblock_size, buf, &usize,
NULL) != LZO_E_OK)
return -1;
grub_memcpy(obuf, buf, osize);
break;
}
osize -= usize;
uncompressed += usize;
obuf += usize;
ibuf += cblock_size;
}
return 0;
return uncompressed;
}
static grub_ssize_t
@ -1060,7 +1062,8 @@ grub_btrfs_extent_read (struct grub_btrfs_data *data,
if (grub_btrfs_lzo_decompress(data->extent->inl, data->extsize -
((grub_uint8_t *) data->extent->inl
- (grub_uint8_t *) data->extent),
extoff, buf, csize) < 0)
extoff, buf, csize)
!= (grub_ssize_t) csize)
return -1;
}
else
@ -1075,8 +1078,10 @@ grub_btrfs_extent_read (struct grub_btrfs_data *data,
if (data->extent->compression != GRUB_BTRFS_COMPRESSION_NONE)
{
void *tmp;
char *tmp;
grub_uint64_t zsize;
grub_ssize_t ret;
zsize = grub_le_to_cpu64 (data->extent->compressed_size);
tmp = grub_malloc (zsize);
if (!tmp)
@ -1091,36 +1096,23 @@ grub_btrfs_extent_read (struct grub_btrfs_data *data,
}
if (data->extent->compression == GRUB_BTRFS_COMPRESSION_ZLIB)
{
grub_ssize_t ret;
ret = grub_zlib_decompress (tmp, zsize, extoff
+ grub_le_to_cpu64 (data->extent->offset),
buf, csize);
grub_free (tmp);
if (ret != (grub_ssize_t) csize)
return -1;
break;
}
else if (data->extent->compression == GRUB_BTRFS_COMPRESSION_LZO)
{
int ret ;
ret = grub_btrfs_lzo_decompress (tmp, zsize, extoff
ret = grub_zlib_decompress (tmp, zsize, extoff
+ grub_le_to_cpu64 (data->extent->offset),
buf, csize);
else if (data->extent->compression == GRUB_BTRFS_COMPRESSION_LZO)
ret = grub_btrfs_lzo_decompress (tmp, zsize, extoff
+ grub_le_to_cpu64 (data->extent->offset),
buf, csize);
else
ret = -1;
grub_free(tmp);
grub_free(tmp);
if (ret < 0)
return -1;
if (ret != (grub_ssize_t) csize)
return -1;
break;
}
}
break;
}
err = grub_btrfs_read_logical (data,
grub_le_to_cpu64 (data->extent->laddr)
+ grub_le_to_cpu64 (data->extent->offset)