int nextchar()
{
int c=dbuf[fwd];
if(c!=EOF)
{
fwd++;
return c;
}
if(end_of_first_half(fwd)) //then load next buffer
{
read_disk_block(dbuf+SINGLE_BUF_SIZE);
++fwd;
c=dbuf[fwd];
fwd++;
return c;
}
else if(end_of_second_half(fwd)) //then load first buffer
{
read_disk_block(dbuf);
fwd=0;
c=dbuf[fwd];
fwd++;
return c;
}
else
return EOF;
}
static int
journal_read( __u32 block, __u32 len, char *buffer )
{
return read_disk_block( INFO->file,
(INFO->journal_block + block), 0,
len, buffer );
}
init_dbuf(const char*filename)
{
dbuf[SINGLE_BUF_SIZE-1]=EOF;
dbuf[2*SINGLE_BUF_SIZE-1]=EOF;
fp=fopen(filename,"r");
if(!fp)
{
fprintf(stderr,"Cannot open %s",filename);
perror(" ");
return 1;
}
read_disk_block(dbuf);
}
static int
reiserfs_read_data( char *buf, __u32 len )
{
__u32 blocksize;
__u32 offset;
__u32 to_read;
char *prev_buf = buf;
errnum = 0;
DEBUG_F( "reiserfs_read_data: INFO->file->pos=%Lu len=%u, offset=%Lu\n",
INFO->file->pos, len, (__u64) IH_KEY_OFFSET(INFO->current_ih) - 1 );
if ( INFO->current_ih->ih_key.k_objectid != INFO->fileinfo.k_objectid
|| IH_KEY_OFFSET( INFO->current_ih ) > INFO->file->pos + 1 )
{
search_stat( INFO->fileinfo.k_dir_id, INFO->fileinfo.k_objectid );
goto get_next_key;
}
while ( errnum == 0 )
{
if ( INFO->current_ih->ih_key.k_objectid != INFO->fileinfo.k_objectid )
break;
offset = INFO->file->pos - IH_KEY_OFFSET( INFO->current_ih ) + 1;
blocksize = ih_item_len(INFO->current_ih);
DEBUG_F( " loop: INFO->file->pos=%Lu len=%u, offset=%u blocksize=%u\n",
INFO->file->pos, len, offset, blocksize );
if ( IH_KEY_ISTYPE( INFO->current_ih, TYPE_DIRECT )
&& offset < blocksize )
{
to_read = blocksize - offset;
if ( to_read > len )
to_read = len;
memcpy( buf, INFO->current_item + offset, to_read );
goto update_buf_len;
}
else if ( IH_KEY_ISTYPE( INFO->current_ih, TYPE_INDIRECT ) )
{
blocksize = ( blocksize >> 2 ) << INFO->blocksize_shift;
while ( offset < blocksize )
{
__u32 blocknr = le32_to_cpu(((__u32 *)
INFO->current_item)[offset >> INFO->blocksize_shift]);
int blk_offset = offset & (INFO->blocksize - 1);
to_read = INFO->blocksize - blk_offset;
if ( to_read > len )
to_read = len;
/* Journal is only for meta data.
Data blocks can be read directly without using block_read */
read_disk_block( INFO->file, blocknr, blk_offset, to_read,
buf );
update_buf_len:
len -= to_read;
buf += to_read;
offset += to_read;
INFO->file->pos += to_read;
if ( len == 0 )
goto done;
}
}
get_next_key:
next_key();
}
/* check filesystem types and read superblock into memory buffer */
static int
reiserfs_read_super( void )
{
struct reiserfs_super_block super;
__u64 superblock = REISERFS_SUPERBLOCK_BLOCK;
if (read_disk_block(INFO->file, superblock, 0, sizeof(super), &super) != sizeof(super)) {
DEBUG_F("read_disk_block failed!\n");
return 0;
}
DEBUG_F( "Found super->magic: \"%s\"\n", super.s_magic );
if( strcmp( REISER2FS_SUPER_MAGIC_STRING, super.s_magic ) != 0 &&
strcmp( REISERFS_SUPER_MAGIC_STRING, super.s_magic ) != 0 )
{
/* Try old super block position */
superblock = REISERFS_OLD_SUPERBLOCK_BLOCK;
if (read_disk_block( INFO->file, superblock, 0, sizeof (super), &super ) != sizeof(super)) {
DEBUG_F("read_disk_block failed!\n");
return 0;
}
if ( strcmp( REISER2FS_SUPER_MAGIC_STRING, super.s_magic ) != 0 &&
strcmp( REISERFS_SUPER_MAGIC_STRING, super.s_magic ) != 0 )
{
/* pre journaling super block - untested */
if ( strcmp( REISERFS_SUPER_MAGIC_STRING,
(char *) ((__u32) &super + 20 ) ) != 0 )
return 0;
super.s_blocksize = cpu_to_le16(REISERFS_OLD_BLOCKSIZE);
super.s_journal_block = 0;
super.s_version = 0;
}
}
DEBUG_F( "ReiserFS superblock data:\n" );
DEBUG_F( "Block count: %u\n", le32_to_cpu(super.s_block_count) )
DEBUG_F( "Free blocks: %u\n", le32_to_cpu(super.s_free_blocks) );
DEBUG_F( "Journal block: %u\n", le32_to_cpu(super.s_journal_block) );
DEBUG_F( "Journal size (in blocks): %u\n",
le32_to_cpu(super.s_orig_journal_size) );
DEBUG_F( "Root block: %u\n\n", le32_to_cpu(super.s_root_block) );
INFO->version = le16_to_cpu(super.s_version);
INFO->blocksize = le16_to_cpu(super.s_blocksize);
INFO->blocksize_shift = log2( INFO->blocksize );
INFO->journal_block = le32_to_cpu(super.s_journal_block);
INFO->journal_block_count = le32_to_cpu(super.s_orig_journal_size);
INFO->cached_slots = (FSYSREISER_CACHE_SIZE >> INFO->blocksize_shift) - 1;
/* At this point, we've found a valid superblock. If we run into problems
* mounting the FS, the user should probably know. */
/* A few sanity checks ... */
if ( INFO->version > REISERFS_MAX_SUPPORTED_VERSION )
{
prom_printf( "ReiserFS: Unsupported version field: %u\n",
INFO->version );
return 0;
}
if ( INFO->blocksize < FSYSREISER_MIN_BLOCKSIZE
|| INFO->blocksize > FSYSREISER_MAX_BLOCKSIZE )
{
prom_printf( "ReiserFS: Unsupported block size: %u\n",
INFO->blocksize );
return 0;
}
/* Setup the journal.. */
if ( INFO->journal_block != 0 )
{
if ( !is_power_of_two( INFO->journal_block_count ) )
{
prom_printf( "ReiserFS: Unsupported journal size, "
"not a power of 2: %u\n",
INFO->journal_block_count );
return 0;
}
journal_init();
/* Read in super block again, maybe it is in the journal */
block_read( superblock, 0, sizeof (struct reiserfs_super_block),
(char *) &super );
}
/* Read in the root block */
if ( !block_read( le32_to_cpu(super.s_root_block), 0,
INFO->blocksize, ROOT ) )
{
prom_printf( "ReiserFS: Failed to read in root block\n" );
return 0;
}
/* The root node is always the "deepest", so we can
determine the hieght of the tree using it. */
INFO->tree_depth = blkh_level(BLOCKHEAD(ROOT));
DEBUG_F( "root read_in: block=%u, depth=%u\n",
le32_to_cpu(super.s_root_block), INFO->tree_depth );
if ( INFO->tree_depth >= REISERFS_MAX_TREE_HEIGHT )
{
prom_printf( "ReiserFS: Unsupported tree depth (too deep): %u\n",
INFO->tree_depth );
return 0;
}
if ( INFO->tree_depth == BLKH_LEVEL_LEAF )
{
/* There is only one node in the whole filesystem, which is
simultanously leaf and root */
memcpy( LEAF, ROOT, INFO->blocksize );
}
return 1;
}
/* Read a block from ReiserFS file system, taking the journal into
* account. If the block nr is in the journal, the block from the
* journal taken.
*/
static int
block_read( __u32 blockNr, __u32 start, __u32 len, char *buffer )
{
__u32 transactions = INFO->journal_transactions;
__u32 desc_block = INFO->journal_first_desc;
__u32 journal_mask = INFO->journal_block_count - 1;
__u32 translatedNr = blockNr;
__u32 *journal_table = JOURNAL_START;
// DEBUG_F( "block_read( %u, %u, %u, ..)\n", blockNr, start, len );
while ( transactions-- > 0 )
{
int i = 0;
int j_len;
if ( *journal_table != 0xffffffff )
{
/* Search for the blockNr in cached journal */
j_len = le32_to_cpu(*journal_table++);
while ( i++ < j_len )
{
if ( le32_to_cpu(*journal_table++) == blockNr )
{
journal_table += j_len - i;
goto found;
}
}
}
else
{
/* This is the end of cached journal marker. The remaining
* transactions are still on disk. */
struct reiserfs_journal_desc desc;
struct reiserfs_journal_commit commit;
if ( !journal_read( desc_block, sizeof(desc), (char *) &desc ) )
return 0;
j_len = le32_to_cpu(desc.j_len);
while ( i < j_len && i < JOURNAL_TRANS_HALF )
if ( le32_to_cpu(desc.j_realblock[i++]) == blockNr )
goto found;
if ( j_len >= JOURNAL_TRANS_HALF )
{
int commit_block = ( desc_block + 1 + j_len ) & journal_mask;
if ( !journal_read( commit_block,
sizeof(commit), (char *) &commit ) )
return 0;
while ( i < j_len )
if ( le32_to_cpu(commit.j_realblock[i++ - JOURNAL_TRANS_HALF]) == blockNr )
goto found;
}
}
goto not_found;
found:
translatedNr =
INFO->journal_block + ( ( desc_block + i ) & journal_mask );
DEBUG_F( "block_read: block %u is mapped to journal block %u.\n",
blockNr, translatedNr - INFO->journal_block );
/* We must continue the search, as this block may be overwritten in
* later transactions. */
not_found:
desc_block = (desc_block + 2 + j_len) & journal_mask;
}
return read_disk_block( INFO->file, translatedNr, start, len, buffer );
}
