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src.rivoreo.one / yaboot / a5141a38c8aacc04e7c7673d2cb522a085245d68 / . / second / fs_reiserfs.c
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/*
* fs_reiserfs.c - an implementation for the Reiser filesystem
*
* Copyright (C) 2001 Jeffrey Mahoney (jeffm@suse.com)
*
* Adapted from Grub
*
* Copyright (C) 2000, 2001 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "types.h"
#include "ctype.h"
#include "string.h"
#include "stdlib.h"
#include "fs.h"
#include "errors.h"
#include "debug.h"
#include "reiserfs/reiserfs.h"
/* Exported in struct fs_t */
static int reiserfs_open( struct boot_file_t *file, const char *dev_name,
struct partition_t *part, const char *file_name );
static int reiserfs_read( struct boot_file_t *file, unsigned int size,
void *buffer );
static int reiserfs_seek( struct boot_file_t *file, unsigned int newpos );
static int reiserfs_close( struct boot_file_t *file );
struct fs_t reiserfs_filesystem = {
name:"reiserfs",
open:reiserfs_open,
read:reiserfs_read,
seek:reiserfs_seek,
close:reiserfs_close
};
static int reiserfs_read_super( void );
static int reiserfs_open_file( char *dirname );
static int reiserfs_read_data( char *buf, __u32 len );
static struct reiserfs_state reiserfs;
static struct reiserfs_state *INFO = &reiserfs;
/* Adapted from GRUB: */
static char FSYS_BUF[FSYSREISER_CACHE_SIZE];
int errnum;
static int
reiserfs_open( struct boot_file_t *file, const char *dev_name,
struct partition_t *part, const char *file_name )
{
static char buffer[1024];
DEBUG_ENTER;
DEBUG_OPEN;
memset( INFO, 0, sizeof(struct reiserfs_state) );
INFO->file = file;
if (part)
{
DEBUG_F( "Determining offset for partition %d\n", part->part_number );
INFO->partition_offset = ((uint64_t)part->part_start) * part->blocksize;
DEBUG_F( "%Lu = %lu * %hu\n", INFO->partition_offset,
part->part_start,
part->blocksize );
}
else
INFO->partition_offset = 0;
sprintf( buffer, "%s:%d", dev_name, 0 ); /* 0 is full disk in OF */
file->of_device = prom_open( buffer );
DEBUG_F( "Trying to open dev_name=%s; filename=%s; partition offset=%Lu\n",
buffer, file_name, INFO->partition_offset );
if ( file->of_device == PROM_INVALID_HANDLE || file->of_device == NULL )
{
DEBUG_F( "Can't open device %p\n", file->of_device );
DEBUG_LEAVE(FILE_ERR_BADDEV);
return FILE_ERR_BADDEV;
}
DEBUG_F("%p was successfully opened\n", file->of_device);
if ( reiserfs_read_super() != 1 )
{
DEBUG_F( "Couldn't open ReiserFS @ %s/%Lu\n", buffer, INFO->partition_offset );
prom_close( file->of_device );
DEBUG_LEAVE(FILE_ERR_BAD_FSYS);
return FILE_ERR_BAD_FSYS;
}
DEBUG_F( "Attempting to open %s\n", file_name );
strcpy(buffer, file_name); /* reiserfs_open_file modifies argument */
if (reiserfs_open_file(buffer) == 0)
{
DEBUG_F( "reiserfs_open_file failed. errnum = %d\n", errnum );
prom_close( file->of_device );
DEBUG_LEAVE_F(errnum);
return errnum;
}
DEBUG_F( "Successfully opened %s\n", file_name );
DEBUG_LEAVE(FILE_ERR_OK);
DEBUG_SLEEP;
return FILE_ERR_OK;
}
static int
reiserfs_read( struct boot_file_t *file, unsigned int size, void *buffer )
{
return reiserfs_read_data( buffer, size );
}
static int
reiserfs_seek( struct boot_file_t *file, unsigned int newpos )
{
file->pos = newpos;
return FILE_ERR_OK;
}
static int
reiserfs_close( struct boot_file_t *file )
{
if( file->of_device )
{
prom_close(file->of_device);
file->of_device = 0;
DEBUG_F("reiserfs_close called\n");
}
return FILE_ERR_OK;
}
static __inline__ __u32
log2( __u32 word )
{
int i = 0;
while( word && (word & (1 << ++i)) == 0 );
return i;
}
static __inline__ int
is_power_of_two( unsigned long word )
{
return ( word & -word ) == word;
}
static int
read_disk_block( struct boot_file_t *file, __u32 block, __u32 start,
__u32 length, void *buf )
{
__u16 fs_blocksize = INFO->blocksize == 0 ? REISERFS_OLD_BLOCKSIZE
: INFO->blocksize;
unsigned long long pos = (unsigned long long)block * (unsigned long long)fs_blocksize;
pos += (unsigned long long)INFO->partition_offset + (unsigned long long)start;
DEBUG_F( "Reading %u bytes, starting at block %u, disk offset %Lu\n",
length, block, pos );
if (!prom_lseek( file->of_device, pos )) {
DEBUG_F("prom_lseek failed\n");
return 0;
}
return prom_read( file->of_device, buf, length );
}
static int
journal_read( __u32 block, __u32 len, char *buffer )
{
return read_disk_block( INFO->file,
(INFO->journal_block + block), 0,
len, buffer );
}
/* 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 );
}
/* Init the journal data structure. We try to cache as much as
* possible in the JOURNAL_START-JOURNAL_END space, but if it is full
* we can still read the rest from the disk on demand.
*
* The first number of valid transactions and the descriptor block of the
* first valid transaction are held in INFO. The transactions are all
* adjacent, but we must take care of the journal wrap around.
*/
static int
journal_init( void )
{
struct reiserfs_journal_header header;
struct reiserfs_journal_desc desc;
struct reiserfs_journal_commit commit;
__u32 block_count = INFO->journal_block_count;
__u32 desc_block;
__u32 commit_block;
__u32 next_trans_id;
__u32 *journal_table = JOURNAL_START;
journal_read( block_count, sizeof ( header ), ( char * ) &header );
desc_block = le32_to_cpu(header.j_first_unflushed_offset);
if ( desc_block >= block_count )
return 0;
INFO->journal_transactions = 0;
INFO->journal_first_desc = desc_block;
next_trans_id = le32_to_cpu(header.j_last_flush_trans_id) + 1;
DEBUG_F( "journal_init: last flushed %u\n", le32_to_cpu(header.j_last_flush_trans_id) );
while ( 1 )
{
journal_read( desc_block, sizeof(desc), (char *) &desc );
if ( strcmp( JOURNAL_DESC_MAGIC, desc.j_magic ) != 0
|| desc.j_trans_id != next_trans_id
|| desc.j_mount_id != header.j_mount_id )
/* no more valid transactions */
break;
commit_block = ( desc_block + le32_to_cpu(desc.j_len) + 1 ) & ( block_count - 1 );
journal_read( commit_block, sizeof(commit), (char *) &commit );
if ( desc.j_trans_id != commit.j_trans_id
|| desc.j_len != commit.j_len )
/* no more valid transactions */
break;
DEBUG_F( "Found valid transaction %u/%u at %u.\n",
le32_to_cpu(desc.j_trans_id), le32_to_cpu(desc.j_mount_id),
desc_block );
next_trans_id++;
if ( journal_table < JOURNAL_END )
{
if ( ( journal_table + 1 + le32_to_cpu(desc.j_len) ) >= JOURNAL_END )
{
/* The table is almost full; mark the end of the cached * *
* journal. */
*journal_table = 0xffffffff;
journal_table = JOURNAL_END;
}
else
{
int i;
/* Cache the length and the realblock numbers in the table. *
* The block number of descriptor can easily be computed. *
* and need not to be stored here. */
*journal_table++ = desc.j_len;
for ( i = 0; i < le32_to_cpu(desc.j_len) && i < JOURNAL_TRANS_HALF; i++ )
{
*journal_table++ = desc.j_realblock[i];
DEBUG_F( "block %u is in journal %u.\n",
le32_to_cpu(desc.j_realblock[i]), desc_block );
}
for ( ; i < le32_to_cpu(desc.j_len); i++ )
{
*journal_table++ =
commit.j_realblock[i - JOURNAL_TRANS_HALF];
DEBUG_F( "block %u is in journal %u.\n",
le32_to_cpu(commit.j_realblock[i - JOURNAL_TRANS_HALF]),
desc_block );
}
}
}
desc_block = (commit_block + 1) & (block_count - 1);
}
DEBUG_F( "Transaction %u/%u at %u isn't valid.\n",
le32_to_cpu(desc.j_trans_id), le32_to_cpu(desc.j_mount_id),
desc_block );
INFO->journal_transactions
= next_trans_id - le32_to_cpu(header.j_last_flush_trans_id) - 1;
return (errnum == 0);
}
/* 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;
}
/***************** TREE ACCESSING METHODS *****************************/
/* I assume you are familiar with the ReiserFS tree, if not go to
* http://devlinux.com/projects/reiserfs/
*
* My tree node cache is organized as following
* 0 ROOT node
* 1 LEAF node (if the ROOT is also a LEAF it is copied here
* 2-n other nodes on current path from bottom to top.
* if there is not enough space in the cache, the top most are
* omitted.
*
* I have only two methods to find a key in the tree:
* search_stat(dir_id, objectid) searches for the stat entry (always
* the first entry) of an object.
* next_key() gets the next key in tree order.
*
* This means, that I can only sequential reads of files are
* efficient, but this really doesn't hurt for grub.
*/
/* Read in the node at the current path and depth into the node cache.
* You must set INFO->blocks[depth] before.
*/
static char *
read_tree_node( __u32 blockNr, __u16 depth )
{
char *cache = CACHE(depth);
int num_cached = INFO->cached_slots;
errnum = 0;
if ( depth < num_cached )
{
/* This is the cached part of the path.
Check if same block is needed. */
if ( blockNr == INFO->blocks[depth] )
return cache;
}
else
cache = CACHE(num_cached);
DEBUG_F( " next read_in: block=%u (depth=%u)\n", blockNr, depth );
if ( !block_read( blockNr, 0, INFO->blocksize, cache ) )
{
DEBUG_F( "block_read failed\n" );
return 0;
}
DEBUG_F( "FOUND: blk_level=%u, blk_nr_item=%u, blk_free_space=%u\n",
blkh_level(BLOCKHEAD(cache)),
blkh_nr_item(BLOCKHEAD(cache)),
le16_to_cpu(BLOCKHEAD(cache)->blk_free_space) );
/* Make sure it has the right node level */
if ( blkh_level(BLOCKHEAD(cache)) != depth )
{
DEBUG_F( "depth = %u != %u\n", blkh_level(BLOCKHEAD(cache)), depth );
DEBUG_LEAVE(FILE_ERR_BAD_FSYS);
errnum = FILE_ERR_BAD_FSYS;
return 0;
}
INFO->blocks[depth] = blockNr;
return cache;
}
/* Get the next key, i.e. the key following the last retrieved key in
* tree order. INFO->current_ih and
* INFO->current_info are adapted accordingly. */
static int
next_key( void )
{
__u16 depth;
struct item_head *ih = INFO->current_ih + 1;
char *cache;
DEBUG_F( "next_key:\n old ih: key %u:%u:%u:%u version:%u\n",
le32_to_cpu(INFO->current_ih->ih_key.k_dir_id),
le32_to_cpu(INFO->current_ih->ih_key.k_objectid),
le32_to_cpu(INFO->current_ih->ih_key.u.k_offset_v1.k_offset),
le32_to_cpu(INFO->current_ih->ih_key.u.k_offset_v1.k_uniqueness),
ih_version(INFO->current_ih) );
if ( ih == &ITEMHEAD[blkh_nr_item(BLOCKHEAD( LEAF ))] )
{
depth = BLKH_LEVEL_LEAF;
/* The last item, was the last in the leaf node. * Read in the next
* * block */
do
{
if ( depth == INFO->tree_depth )
{
/* There are no more keys at all. * Return a dummy item with
* * MAX_KEY */
ih =
( struct item_head * )
&BLOCKHEAD( LEAF )->blk_right_delim_key;
goto found;
}
depth++;
DEBUG_F( " depth=%u, i=%u\n", depth, INFO->next_key_nr[depth] );
}
while ( INFO->next_key_nr[depth] == 0 );
if ( depth == INFO->tree_depth )
cache = ROOT;
else if ( depth <= INFO->cached_slots )
cache = CACHE( depth );
else
{
cache = read_tree_node( INFO->blocks[depth], --depth );
if ( !cache )
return 0;
}
do
{
__u16 nr_item = blkh_nr_item(BLOCKHEAD( cache ));
int key_nr = INFO->next_key_nr[depth]++;
DEBUG_F( " depth=%u, i=%u/%u\n", depth, key_nr, nr_item );
if ( key_nr == nr_item )
/* This is the last item in this block, set the next_key_nr *
* to 0 */
INFO->next_key_nr[depth] = 0;
cache =
read_tree_node( dc_block_number( &(DC( cache )[key_nr])),
--depth );
if ( !cache )
return 0;
}
while ( depth > BLKH_LEVEL_LEAF );
ih = ITEMHEAD;
}
found:
INFO->current_ih = ih;
INFO->current_item = &LEAF[ih_location(ih)];
DEBUG_F( " new ih: key %u:%u:%u:%u version:%u\n",
le32_to_cpu(INFO->current_ih->ih_key.k_dir_id),
le32_to_cpu(INFO->current_ih->ih_key.k_objectid),
le32_to_cpu(INFO->current_ih->ih_key.u.k_offset_v1.k_offset),
le32_to_cpu(INFO->current_ih->ih_key.u.k_offset_v1.k_uniqueness),
ih_version(INFO->current_ih) );
return 1;
}
/* preconditions: reiserfs_read_super already executed, therefore
* INFO block is valid
* returns: 0 if error (errnum is set),
* nonzero iff we were able to find the key successfully.
* postconditions: on a nonzero return, the current_ih and
* current_item fields describe the key that equals the
* searched key. INFO->next_key contains the next key after
* the searched key.
* side effects: messes around with the cache.
*/
static int
search_stat( __u32 dir_id, __u32 objectid )
{
char *cache;
int depth;
int nr_item;
int i;
struct item_head *ih;
errnum = 0;
DEBUG_F( "search_stat:\n key %u:%u:0:0\n", le32_to_cpu(dir_id),
le32_to_cpu(objectid) );
depth = INFO->tree_depth;
cache = ROOT;
DEBUG_F( "depth = %d\n", depth );
while ( depth > BLKH_LEVEL_LEAF )
{
struct key *key;
nr_item = blkh_nr_item(BLOCKHEAD( cache ));
key = KEY( cache );
for ( i = 0; i < nr_item; i++ )
{
if (le32_to_cpu(key->k_dir_id) > le32_to_cpu(dir_id)
|| (key->k_dir_id == dir_id
&& (le32_to_cpu(key->k_objectid) > le32_to_cpu(objectid)
|| (key->k_objectid == objectid
&& (key->u.k_offset_v1.k_offset
| key->u.k_offset_v1.k_uniqueness) > 0))))
break;
key++;
}
DEBUG_F( " depth=%d, i=%d/%d\n", depth, i, nr_item );
INFO->next_key_nr[depth] = ( i == nr_item ) ? 0 : i + 1;
cache = read_tree_node( dc_block_number(&(DC(cache)[i])), --depth );
if ( !cache )
return 0;
}
/* cache == LEAF */
nr_item = blkh_nr_item(BLOCKHEAD(LEAF));
ih = ITEMHEAD;
DEBUG_F( "nr_item = %d\n", nr_item );
for ( i = 0; i < nr_item; i++ )
{
if ( ih->ih_key.k_dir_id == dir_id
&& ih->ih_key.k_objectid == objectid
&& ih->ih_key.u.k_offset_v1.k_offset == 0
&& ih->ih_key.u.k_offset_v1.k_uniqueness == 0 )
{
DEBUG_F( " depth=%d, i=%d/%d\n", depth, i, nr_item );
INFO->current_ih = ih;
INFO->current_item = &LEAF[ih_location(ih)];
return 1;
}
ih++;
}
DEBUG_LEAVE(FILE_ERR_BAD_FSYS);
errnum = FILE_ERR_BAD_FSYS;
return 0;
}
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();
}
done:
return (errnum != 0) ? 0 : buf - prev_buf;
}
/* preconditions: reiserfs_read_super already executed, therefore
* INFO block is valid
* returns: 0 if error, nonzero iff we were able to find the file successfully
* postconditions: on a nonzero return, INFO->fileinfo contains the info
* of the file we were trying to look up, filepos is 0 and filemax is
* the size of the file.
*/
static int
reiserfs_open_file( char *dirname )
{
struct reiserfs_de_head *de_head;
char *rest, ch;
__u32 dir_id, objectid, parent_dir_id = 0, parent_objectid = 0;
char linkbuf[PATH_MAX]; /* buffer for following symbolic links */
int link_count = 0;
int mode;
errnum = 0;
dir_id = cpu_to_le32(REISERFS_ROOT_PARENT_OBJECTID);
objectid = cpu_to_le32(REISERFS_ROOT_OBJECTID);
while ( 1 )
{
DEBUG_F( "dirname=%s\n", dirname );
/* Search for the stat info first. */
if ( !search_stat( dir_id, objectid ) )
return 0;
DEBUG_F( "sd_mode=0%o sd_size=%Lu\n",
sd_mode((struct stat_data *) INFO->current_item ),
sd_size(INFO->current_ih, INFO->current_item ));
mode = sd_mode((struct stat_data *)INFO->current_item);
/* If we've got a symbolic link, then chase it. */
if ( S_ISLNK( mode ) )
{
int len = 0;
DEBUG_F("link count = %d\n", link_count);
DEBUG_SLEEP;
if ( ++link_count > MAX_LINK_COUNT )
{
DEBUG_F("Symlink loop\n");
errnum = FILE_ERR_SYMLINK_LOOP;
return 0;
}
/* Get the symlink size. */
INFO->file->len = sd_size(INFO->current_ih, INFO->current_item);
/* Find out how long our remaining name is. */
while ( dirname[len] && !isspace( dirname[len] ) )
len++;
if ( INFO->file->len + len > sizeof ( linkbuf ) - 1 )
{
errnum = FILE_ERR_LENGTH;
return 0;
}
/* Copy the remaining name to the end of the symlink data. Note *
* that DIRNAME and LINKBUF may overlap! */
memmove( linkbuf + INFO->file->len, dirname, len + 1 );
INFO->fileinfo.k_dir_id = dir_id;
INFO->fileinfo.k_objectid = objectid;
INFO->file->pos = 0;
if ( !next_key()
|| reiserfs_read_data( linkbuf, INFO->file->len ) != INFO->file->len ) {
DEBUG_F("reiserfs_open_file - if !next_key || reiserfs_read_data\n");
DEBUG_SLEEP;
errnum = FILE_IOERR;
return 0;
}
DEBUG_F( "symlink=%s\n", linkbuf );
DEBUG_SLEEP;
dirname = linkbuf;
if ( *dirname == '/' )
{
/* It's an absolute link, so look it up in root. */
dir_id = cpu_to_le32(REISERFS_ROOT_PARENT_OBJECTID);
objectid = cpu_to_le32(REISERFS_ROOT_OBJECTID);
}
else
{
/* Relative, so look it up in our parent directory. */
dir_id = parent_dir_id;
objectid = parent_objectid;
}
/* Now lookup the new name. */
continue;
}
/* if we have a real file (and we're not just printing *
* possibilities), then this is where we want to exit */
if ( !*dirname || isspace( *dirname ) )
{
if ( !S_ISREG( mode ) )
{
errnum = FILE_ERR_BAD_TYPE;
return 0;
}
INFO->file->pos = 0;
INFO->file->len = sd_size(INFO->current_ih, INFO->current_item);
INFO->fileinfo.k_dir_id = dir_id;
INFO->fileinfo.k_objectid = objectid;
return next_key();
}
/* continue with the file/directory name interpretation */
while ( *dirname == '/' )
dirname++;
if ( !S_ISDIR( mode ) )
{
errnum = FILE_ERR_NOTDIR;
return 0;
}
for ( rest = dirname; ( ch = *rest ) && !isspace( ch ) && ch != '/';
rest++ ) ;
*rest = 0;
while ( 1 )
{
char *name_end;
int num_entries;
if ( !next_key() )
return 0;
if ( INFO->current_ih->ih_key.k_objectid != objectid )
break;
name_end = INFO->current_item + ih_item_len(INFO->current_ih);
de_head = ( struct reiserfs_de_head * ) INFO->current_item;
num_entries = ih_entry_count(INFO->current_ih);
while ( num_entries > 0 )
{
char *filename = INFO->current_item + deh_location(de_head);
char tmp = *name_end;
if( deh_state(de_head) & (1 << DEH_Visible))
{
int cmp;
/* Directory names in ReiserFS are not null * terminated.
* We write a temporary 0 behind it. * NOTE: that this
* may overwrite the first block in * the tree cache.
* That doesn't hurt as long as we * don't call next_key
* () in between. */
*name_end = 0;
cmp = strcmp( dirname, filename );
*name_end = tmp;
if ( cmp == 0 )
goto found;
}
/* The beginning of this name marks the end of the next name.
*/
name_end = filename;
de_head++;
num_entries--;
}
}
errnum = FILE_ERR_NOTFOUND;
*rest = ch;
return 0;
found:
*rest = ch;
dirname = rest;
parent_dir_id = dir_id;
parent_objectid = objectid;
dir_id = de_head->deh_dir_id; /* LE */
objectid = de_head->deh_objectid; /* LE */
}
}
#ifndef __LITTLE_ENDIAN
typedef union {
struct offset_v2 offset_v2;
__u64 linear;
} offset_v2_esafe_overlay;
inline __u16
offset_v2_k_type( struct offset_v2 *v2 )
{
offset_v2_esafe_overlay tmp = *(offset_v2_esafe_overlay *)v2;
tmp.linear = le64_to_cpu( tmp.linear );
return tmp.offset_v2.k_type;
}
inline loff_t
offset_v2_k_offset( struct offset_v2 *v2 )
{
offset_v2_esafe_overlay tmp = *(offset_v2_esafe_overlay *)v2;
tmp.linear = le64_to_cpu( tmp.linear );
return tmp.offset_v2.k_offset;
}
#endif
inline int
uniqueness2type (__u32 uniqueness)
{
switch (uniqueness) {
case V1_SD_UNIQUENESS: return TYPE_STAT_DATA;
case V1_INDIRECT_UNIQUENESS: return TYPE_INDIRECT;
case V1_DIRECT_UNIQUENESS: return TYPE_DIRECT;
case V1_DIRENTRY_UNIQUENESS: return TYPE_DIRENTRY;
}
return TYPE_ANY;
}
/*
* Local variables:
* c-file-style: "k&r"
* c-basic-offset: 5
* End:
*/