--- /dev/null
+/* fsys_reiserfs.c - an implementation for the ReiserFS filesystem */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * 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., 51 Franklin Street - Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#ifdef FSYS_REISERFS
+#include "shared.h"
+#include "filesys.h"
+
+#undef REISERDEBUG
+
+/* Some parts of this code (mainly the structures and defines) are
+ * from the original reiser fs code, as found in the linux kernel.
+ */
+
+/* include/asm-i386/types.h */
+typedef __signed__ char __s8;
+typedef unsigned char __u8;
+typedef __signed__ short __s16;
+typedef unsigned short __u16;
+typedef __signed__ int __s32;
+typedef unsigned int __u32;
+typedef unsigned long long __u64;
+
+/* linux/posix_type.h */
+typedef long linux_off_t;
+
+#include "libc/byteorder.h"
+
+/* include/linux/reiser_fs.h */
+/* This is the new super block of a journaling reiserfs system */
+struct reiserfs_super_block
+{
+ __u32 s_block_count; /* blocks count */
+ __u32 s_free_blocks; /* free blocks count */
+ __u32 s_root_block; /* root block number */
+ __u32 s_journal_block; /* journal block number */
+ __u32 s_journal_dev; /* journal device number */
+ __u32 s_journal_size; /* size of the journal on FS creation. used to make sure they don't overflow it */
+ __u32 s_journal_trans_max; /* max number of blocks in a transaction. */
+ __u32 s_journal_magic; /* random value made on fs creation */
+ __u32 s_journal_max_batch; /* max number of blocks to batch into a trans */
+ __u32 s_journal_max_commit_age; /* in seconds, how old can an async commit be */
+ __u32 s_journal_max_trans_age; /* in seconds, how old can a transaction be */
+ __u16 s_blocksize; /* block size */
+ __u16 s_oid_maxsize; /* max size of object id array */
+ __u16 s_oid_cursize; /* current size of object id array */
+ __u16 s_state; /* valid or error */
+ char s_magic[16]; /* reiserfs magic string indicates that file system is reiserfs */
+ __u16 s_tree_height; /* height of disk tree */
+ __u16 s_bmap_nr; /* amount of bitmap blocks needed to address each block of file system */
+ __u16 s_version;
+ char s_unused[128]; /* zero filled by mkreiserfs */
+};
+
+#define REISERFS_MAX_SUPPORTED_VERSION 2
+#define REISERFS_SUPER_MAGIC_STRING "ReIsErFs"
+#define REISER2FS_SUPER_MAGIC_STRING "ReIsEr2Fs"
+
+#define MAX_HEIGHT 7
+
+/* must be correct to keep the desc and commit structs at 4k */
+#define JOURNAL_TRANS_HALF 1018
+
+/* first block written in a commit. */
+struct reiserfs_journal_desc {
+ __u32 j_trans_id; /* id of commit */
+ __u32 j_len; /* length of commit. len +1 is the commit block */
+ __u32 j_mount_id; /* mount id of this trans*/
+ __u32 j_realblock[JOURNAL_TRANS_HALF]; /* real locations for the first blocks */
+ char j_magic[12];
+};
+
+/* last block written in a commit */
+struct reiserfs_journal_commit {
+ __u32 j_trans_id; /* must match j_trans_id from the desc block */
+ __u32 j_len; /* ditto */
+ __u32 j_realblock[JOURNAL_TRANS_HALF]; /* real locations for the last blocks */
+ char j_digest[16]; /* md5 sum of all the blocks involved, including desc and commit. not used, kill it */
+};
+
+/* this header block gets written whenever a transaction is considered
+ fully flushed, and is more recent than the last fully flushed
+ transaction.
+ fully flushed means all the log blocks and all the real blocks are
+ on disk, and this transaction does not need to be replayed.
+*/
+struct reiserfs_journal_header {
+ /* id of last fully flushed transaction */
+ __u32 j_last_flush_trans_id;
+ /* offset in the log of where to start replay after a crash */
+ __u32 j_first_unflushed_offset;
+ /* mount id to detect very old transactions */
+ __u32 j_mount_id;
+};
+
+/* magic string to find desc blocks in the journal */
+#define JOURNAL_DESC_MAGIC "ReIsErLB"
+
+
+/*
+ * directories use this key as well as old files
+ */
+struct offset_v1
+{
+ /*
+ * for regular files this is the offset to the first byte of the
+ * body, contained in the object-item, as measured from the start of
+ * the entire body of the object.
+ *
+ * for directory entries, k_offset consists of hash derived from
+ * hashing the name and using few bits (23 or more) of the resulting
+ * hash, and generation number that allows distinguishing names with
+ * hash collisions. If number of collisions overflows generation
+ * number, we return EEXIST. High order bit is 0 always
+ */
+ __u32 k_offset;
+ __u32 k_uniqueness;
+};
+
+struct offset_v2
+{
+ /*
+ * for regular files this is the offset to the first byte of the
+ * body, contained in the object-item, as measured from the start of
+ * the entire body of the object.
+ *
+ * for directory entries, k_offset consists of hash derived from
+ * hashing the name and using few bits (23 or more) of the resulting
+ * hash, and generation number that allows distinguishing names with
+ * hash collisions. If number of collisions overflows generation
+ * number, we return EEXIST. High order bit is 0 always
+ */
+ __u64 k_offset:60;
+ __u64 k_type: 4;
+};
+
+
+struct key
+{
+ /* packing locality: by default parent directory object id */
+ __u32 k_dir_id;
+ /* object identifier */
+ __u32 k_objectid;
+ /* the offset and node type (old and new form) */
+ union
+ {
+ struct offset_v1 v1;
+ struct offset_v2 v2;
+ }
+ u;
+};
+
+#define KEY_SIZE (sizeof (struct key))
+
+/* Header of a disk block. More precisely, header of a formatted leaf
+ or internal node, and not the header of an unformatted node. */
+struct block_head
+{
+ __u16 blk_level; /* Level of a block in the tree. */
+ __u16 blk_nr_item; /* Number of keys/items in a block. */
+ __u16 blk_free_space; /* Block free space in bytes. */
+ struct key blk_right_delim_key; /* Right delimiting key for this block (supported for leaf level nodes
+ only) */
+};
+#define BLKH_SIZE (sizeof (struct block_head))
+#define DISK_LEAF_NODE_LEVEL 1 /* Leaf node level. */
+
+struct item_head
+{
+ struct key ih_key; /* Everything in the tree is found by searching for it based on its key.*/
+
+ union
+ {
+ __u16 ih_free_space; /* The free space in the last unformatted node of an indirect item if this
+ is an indirect item. This equals 0xFFFF iff this is a direct item or
+ stat data item. Note that the key, not this field, is used to determine
+ the item type, and thus which field this union contains. */
+ __u16 ih_entry_count; /* Iff this is a directory item, this field equals the number of directory
+ entries in the directory item. */
+ }
+ u;
+ __u16 ih_item_len; /* total size of the item body */
+ __u16 ih_item_location; /* an offset to the item body within the block */
+ __u16 ih_version; /* ITEM_VERSION_1 for all old items,
+ ITEM_VERSION_2 for new ones.
+ Highest bit is set by fsck
+ temporary, cleaned after all done */
+};
+/* size of item header */
+#define IH_SIZE (sizeof (struct item_head))
+
+#define ITEM_VERSION_1 0
+#define ITEM_VERSION_2 1
+#define IH_KEY_OFFSET(ih) ((ih)->ih_version == ITEM_VERSION_1 \
+ ? (ih)->ih_key.u.v1.k_offset \
+ : (ih)->ih_key.u.v2.k_offset)
+
+#define IH_KEY_ISTYPE(ih, type) ((ih)->ih_version == ITEM_VERSION_1 \
+ ? (ih)->ih_key.u.v1.k_uniqueness == V1_##type \
+ : (ih)->ih_key.u.v2.k_type == V2_##type)
+
+/* FIXME these types look wrong. */
+struct disk_child
+{
+ unsigned long dc_block_number; /* Disk child's block number. */
+ unsigned short dc_size; /* Disk child's used space. */
+};
+
+#define DC_SIZE (sizeof (struct disk_child))
+
+/* Stat Data on disk.
+ *
+ * Note that reiserfs has two different forms of stat data. Luckily
+ * the fields needed by grub are at the same position.
+ */
+struct stat_data
+{
+ __u16 sd_mode; /* file type, permissions */
+ __u16 sd_notused1[3]; /* fields not needed by reiserfs */
+ __u32 sd_size; /* file size */
+ __u32 sd_size_hi; /* file size high 32 bits (since version 2) */
+};
+
+struct reiserfs_de_head
+{
+ __u32 deh_offset; /* third component of the directory entry key */
+ __u32 deh_dir_id; /* objectid of the parent directory of the
+ object, that is referenced by directory entry */
+ __u32 deh_objectid;/* objectid of the object, that is referenced by
+ directory entry */
+ __u16 deh_location;/* offset of name in the whole item */
+ __u16 deh_state; /* whether 1) entry contains stat data (for
+ future), and 2) whether entry is hidden
+ (unlinked) */
+};
+
+#define DEH_SIZE (sizeof (struct reiserfs_de_head))
+
+#define DEH_Statdata (1 << 0) /* not used now */
+#define DEH_Visible (1 << 2)
+
+#define SD_OFFSET 0
+#define SD_UNIQUENESS 0
+#define DOT_OFFSET 1
+#define DOT_DOT_OFFSET 2
+#define DIRENTRY_UNIQUENESS 500
+
+#define V1_TYPE_STAT_DATA 0x0
+#define V1_TYPE_DIRECT 0xffffffff
+#define V1_TYPE_INDIRECT 0xfffffffe
+#define V1_TYPE_DIRECTORY_MAX 0xfffffffd
+#define V2_TYPE_STAT_DATA 0
+#define V2_TYPE_INDIRECT 1
+#define V2_TYPE_DIRECT 2
+#define V2_TYPE_DIRENTRY 3
+
+#define REISERFS_ROOT_OBJECTID 2
+#define REISERFS_ROOT_PARENT_OBJECTID 1
+#define REISERFS_DISK_OFFSET_IN_BYTES (64 * 1024)
+/* the spot for the super in versions 3.5 - 3.5.11 (inclusive) */
+#define REISERFS_OLD_DISK_OFFSET_IN_BYTES (8 * 1024)
+#define REISERFS_OLD_BLOCKSIZE 4096
+
+#define S_ISREG(mode) (((mode) & 0170000) == 0100000)
+#define S_ISDIR(mode) (((mode) & 0170000) == 0040000)
+#define S_ISLNK(mode) (((mode) & 0170000) == 0120000)
+
+#define PATH_MAX 1024 /* include/linux/limits.h */
+#define MAX_LINK_COUNT 5 /* number of symbolic links to follow */
+
+/* The size of the node cache */
+#define FSYSREISER_CACHE_SIZE 24*1024
+#define FSYSREISER_MIN_BLOCKSIZE SECTOR_SIZE
+#define FSYSREISER_MAX_BLOCKSIZE FSYSREISER_CACHE_SIZE / 3
+
+/* Info about currently opened file */
+struct fsys_reiser_fileinfo
+{
+ __u32 k_dir_id;
+ __u32 k_objectid;
+};
+
+/* In memory info about the currently mounted filesystem */
+struct fsys_reiser_info
+{
+ /* The last read item head */
+ struct item_head *current_ih;
+ /* The last read item */
+ char *current_item;
+ /* The information for the currently opened file */
+ struct fsys_reiser_fileinfo fileinfo;
+ /* The start of the journal */
+ __u32 journal_block;
+ /* The size of the journal */
+ __u32 journal_block_count;
+ /* The first valid descriptor block in journal
+ (relative to journal_block) */
+ __u32 journal_first_desc;
+
+ /* The ReiserFS version. */
+ __u16 version;
+ /* The current depth of the reiser tree. */
+ __u16 tree_depth;
+ /* SECTOR_SIZE << blocksize_shift == blocksize. */
+ __u8 blocksize_shift;
+ /* 1 << full_blocksize_shift == blocksize. */
+ __u8 fullblocksize_shift;
+ /* The reiserfs block size (must be a power of 2) */
+ __u16 blocksize;
+ /* The number of cached tree nodes */
+ __u16 cached_slots;
+ /* The number of valid transactions in journal */
+ __u16 journal_transactions;
+
+ unsigned int blocks[MAX_HEIGHT];
+ unsigned int next_key_nr[MAX_HEIGHT];
+};
+
+/* The cached s+tree blocks in FSYS_BUF, see below
+ * for a more detailed description.
+ */
+#define ROOT ((char *)FSYS_BUF)
+#define CACHE(i) (ROOT + ((i) << INFO->fullblocksize_shift))
+#define LEAF CACHE (DISK_LEAF_NODE_LEVEL)
+
+#define BLOCKHEAD(cache) ((struct block_head *) cache)
+#define ITEMHEAD ((struct item_head *) ((char *) LEAF + BLKH_SIZE))
+#define KEY(cache) ((struct key *) ((char *) cache + BLKH_SIZE))
+#define DC(cache) ((struct disk_child *) \
+ ((char *) cache + BLKH_SIZE + KEY_SIZE * nr_item))
+/* The fsys_reiser_info block.
+ */
+#define INFO \
+ ((struct fsys_reiser_info *) ((char *) FSYS_BUF + FSYSREISER_CACHE_SIZE))
+/*
+ * The journal cache. For each transaction it contains the number of
+ * blocks followed by the real block numbers of this transaction.
+ *
+ * If the block numbers of some transaction won't fit in this space,
+ * this list is stopped with a 0xffffffff marker and the remaining
+ * uncommitted transactions aren't cached.
+ */
+#define JOURNAL_START ((__u32 *) (INFO + 1))
+#define JOURNAL_END ((__u32 *) (FSYS_BUF + FSYS_BUFLEN))
+
+static __inline__ int
+is_power_of_two (unsigned long word)
+{
+ return (word & -word) == word;
+}
+
+static int
+journal_read (int block, int len, char *buffer)
+{
+ return devread ((INFO->journal_block + block) << INFO->blocksize_shift,
+ 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 (int blockNr, int start, int len, char *buffer)
+{
+ int transactions = INFO->journal_transactions;
+ int desc_block = INFO->journal_first_desc;
+ int journal_mask = INFO->journal_block_count - 1;
+ int translatedNr = blockNr;
+ __u32 *journal_table = JOURNAL_START;
+ while (transactions-- > 0)
+ {
+ int i = 0;
+ int j_len;
+ if (*journal_table != 0xffffffff)
+ {
+ /* Search for the blockNr in cached journal */
+ j_len = *journal_table++;
+ while (i++ < j_len)
+ {
+ if (*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 = desc.j_len;
+ while (i < j_len && i < JOURNAL_TRANS_HALF)
+ if (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 (commit.j_realblock[i++ - JOURNAL_TRANS_HALF] == blockNr)
+ goto found;
+ }
+ }
+ goto not_found;
+
+ found:
+ translatedNr = INFO->journal_block + ((desc_block + i) & journal_mask);
+#ifdef REISERDEBUG
+ printf ("block_read: block %d is mapped to journal block %d.\n",
+ blockNr, translatedNr - INFO->journal_block);
+#endif
+ /* 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 devread (translatedNr << INFO->blocksize_shift, 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)
+{
+ unsigned int block_count = INFO->journal_block_count;
+ unsigned int desc_block;
+ unsigned int commit_block;
+ unsigned int next_trans_id;
+ struct reiserfs_journal_header header;
+ struct reiserfs_journal_desc desc;
+ struct reiserfs_journal_commit commit;
+ __u32 *journal_table = JOURNAL_START;
+
+ journal_read (block_count, sizeof (header), (char *) &header);
+ desc_block = header.j_first_unflushed_offset;
+ if (desc_block >= block_count)
+ return 0;
+
+ INFO->journal_first_desc = desc_block;
+ next_trans_id = header.j_last_flush_trans_id + 1;
+
+#ifdef REISERDEBUG
+ printf ("journal_init: last flushed %d\n",
+ header.j_last_flush_trans_id);
+#endif
+
+ while (1)
+ {
+ journal_read (desc_block, sizeof (desc), (char *) &desc);
+ if (substring (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 + 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;
+
+#ifdef REISERDEBUG
+ printf ("Found valid transaction %d/%d at %d.\n",
+ desc.j_trans_id, desc.j_mount_id, desc_block);
+#endif
+
+ next_trans_id++;
+ if (journal_table < JOURNAL_END)
+ {
+ if ((journal_table + 1 + 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 < desc.j_len && i < JOURNAL_TRANS_HALF; i++)
+ {
+ *journal_table++ = desc.j_realblock[i];
+#ifdef REISERDEBUG
+ printf ("block %d is in journal %d.\n",
+ desc.j_realblock[i], desc_block);
+#endif
+ }
+ for ( ; i < desc.j_len; i++)
+ {
+ *journal_table++ = commit.j_realblock[i-JOURNAL_TRANS_HALF];
+#ifdef REISERDEBUG
+ printf ("block %d is in journal %d.\n",
+ commit.j_realblock[i-JOURNAL_TRANS_HALF],
+ desc_block);
+#endif
+ }
+ }
+ }
+ desc_block = (commit_block + 1) & (block_count - 1);
+ }
+#ifdef REISERDEBUG
+ printf ("Transaction %d/%d at %d isn't valid.\n",
+ desc.j_trans_id, desc.j_mount_id, desc_block);
+#endif
+
+ INFO->journal_transactions
+ = next_trans_id - header.j_last_flush_trans_id - 1;
+ return errnum == 0;
+}
+
+/* check filesystem types and read superblock into memory buffer */
+int
+reiserfs_mount (void)
+{
+ struct reiserfs_super_block super;
+ int superblock = REISERFS_DISK_OFFSET_IN_BYTES >> SECTOR_BITS;
+
+ if (part_length < superblock + (sizeof (super) >> SECTOR_BITS)
+ || ! devread (superblock, 0, sizeof (struct reiserfs_super_block),
+ (char *) &super)
+ || (substring (REISER2FS_SUPER_MAGIC_STRING, super.s_magic) > 0
+ && substring (REISERFS_SUPER_MAGIC_STRING, super.s_magic) > 0)
+ || (/* check that this is not a copy inside the journal log */
+ super.s_journal_block * super.s_blocksize
+ <= REISERFS_DISK_OFFSET_IN_BYTES))
+ {
+ /* Try old super block position */
+ superblock = REISERFS_OLD_DISK_OFFSET_IN_BYTES >> SECTOR_BITS;
+ if (part_length < superblock + (sizeof (super) >> SECTOR_BITS)
+ || ! devread (superblock, 0, sizeof (struct reiserfs_super_block),
+ (char *) &super))
+ return 0;
+
+ if (substring (REISER2FS_SUPER_MAGIC_STRING, super.s_magic) > 0
+ && substring (REISERFS_SUPER_MAGIC_STRING, super.s_magic) > 0)
+ {
+ /* pre journaling super block ? */
+ if (substring (REISERFS_SUPER_MAGIC_STRING,
+ (char*) ((char *) &super + 20)) > 0)
+ return 0;
+
+ super.s_blocksize = REISERFS_OLD_BLOCKSIZE;
+ super.s_journal_block = 0;
+ super.s_version = 0;
+ }
+ }
+
+ /* check the version number. */
+ if (super.s_version > REISERFS_MAX_SUPPORTED_VERSION)
+ return 0;
+
+ INFO->version = super.s_version;
+ INFO->blocksize = super.s_blocksize;
+ INFO->fullblocksize_shift = log2 (super.s_blocksize);
+ INFO->blocksize_shift = INFO->fullblocksize_shift - SECTOR_BITS;
+ INFO->cached_slots =
+ (FSYSREISER_CACHE_SIZE >> INFO->fullblocksize_shift) - 1;
+
+#ifdef REISERDEBUG
+ printf ("reiserfs_mount: version=%d, blocksize=%d\n",
+ INFO->version, INFO->blocksize);
+#endif /* REISERDEBUG */
+
+ /* Clear node cache. */
+ memset (INFO->blocks, 0, sizeof (INFO->blocks));
+
+ if (super.s_blocksize < FSYSREISER_MIN_BLOCKSIZE
+ || super.s_blocksize > FSYSREISER_MAX_BLOCKSIZE
+ || (SECTOR_SIZE << INFO->blocksize_shift) != super.s_blocksize)
+ return 0;
+
+ /* Initialize journal code. If something fails we end with zero
+ * journal_transactions, so we don't access the journal at all.
+ */
+ INFO->journal_transactions = 0;
+ if (super.s_journal_block != 0 && super.s_journal_dev == 0)
+ {
+ INFO->journal_block = super.s_journal_block;
+ INFO->journal_block_count = super.s_journal_size;
+ if (is_power_of_two (INFO->journal_block_count))
+ journal_init ();
+
+ /* Read in super block again, maybe it is in the journal */
+ block_read (superblock >> INFO->blocksize_shift,
+ 0, sizeof (struct reiserfs_super_block), (char *) &super);
+ }
+
+ if (! block_read (super.s_root_block, 0, INFO->blocksize, (char*) ROOT))
+ return 0;
+
+ INFO->tree_depth = BLOCKHEAD (ROOT)->blk_level;
+
+#ifdef REISERDEBUG
+ printf ("root read_in: block=%d, depth=%d\n",
+ super.s_root_block, INFO->tree_depth);
+#endif /* REISERDEBUG */
+
+ if (INFO->tree_depth >= MAX_HEIGHT)
+ return 0;
+ if (INFO->tree_depth == DISK_LEAF_NODE_LEVEL)
+ {
+ /* 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://www.namesys.com/content_table.html
+ *
+ * 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 (unsigned int blockNr, int depth)
+{
+ char* cache = CACHE(depth);
+ int num_cached = INFO->cached_slots;
+ 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);
+
+#ifdef REISERDEBUG
+ printf (" next read_in: block=%d (depth=%d)\n",
+ blockNr, depth);
+#endif /* REISERDEBUG */
+ if (! block_read (blockNr, 0, INFO->blocksize, cache))
+ return NULL;
+ /* Make sure it has the right node level */
+ if (BLOCKHEAD (cache)->blk_level != depth)
+ {
+ errnum = ERR_FSYS_CORRUPT;
+ return NULL;
+ }
+
+ 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)
+{
+ int depth;
+ struct item_head *ih = INFO->current_ih + 1;
+ char *cache;
+
+#ifdef REISERDEBUG
+ printf ("next_key:\n old ih: key %d:%d:%d:%d version:%d\n",
+ INFO->current_ih->ih_key.k_dir_id,
+ INFO->current_ih->ih_key.k_objectid,
+ INFO->current_ih->ih_key.u.v1.k_offset,
+ INFO->current_ih->ih_key.u.v1.k_uniqueness,
+ INFO->current_ih->ih_version);
+#endif /* REISERDEBUG */
+
+ if (ih == &ITEMHEAD[BLOCKHEAD (LEAF)->blk_nr_item])
+ {
+ depth = DISK_LEAF_NODE_LEVEL;
+ /* 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++;
+#ifdef REISERDEBUG
+ printf (" depth=%d, i=%d\n", depth, INFO->next_key_nr[depth]);
+#endif /* REISERDEBUG */
+ }
+ 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
+ {
+ int nr_item = BLOCKHEAD (cache)->blk_nr_item;
+ int key_nr = INFO->next_key_nr[depth]++;
+#ifdef REISERDEBUG
+ printf (" depth=%d, i=%d/%d\n", depth, key_nr, nr_item);
+#endif /* REISERDEBUG */
+ 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 (cache)[key_nr].dc_block_number, --depth);
+ if (! cache)
+ return 0;
+ }
+ while (depth > DISK_LEAF_NODE_LEVEL);
+
+ ih = ITEMHEAD;
+ }
+ found:
+ INFO->current_ih = ih;
+ INFO->current_item = &LEAF[ih->ih_item_location];
+#ifdef REISERDEBUG
+ printf (" new ih: key %d:%d:%d:%d version:%d\n",
+ INFO->current_ih->ih_key.k_dir_id,
+ INFO->current_ih->ih_key.k_objectid,
+ INFO->current_ih->ih_key.u.v1.k_offset,
+ INFO->current_ih->ih_key.u.v1.k_uniqueness,
+ INFO->current_ih->ih_version);
+#endif /* REISERDEBUG */
+ return 1;
+}
+
+/* preconditions: reiserfs_mount 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;
+#ifdef REISERDEBUG
+ printf ("search_stat:\n key %d:%d:0:0\n", dir_id, objectid);
+#endif /* REISERDEBUG */
+
+ depth = INFO->tree_depth;
+ cache = ROOT;
+
+ while (depth > DISK_LEAF_NODE_LEVEL)
+ {
+ struct key *key;
+ nr_item = BLOCKHEAD (cache)->blk_nr_item;
+
+ key = KEY (cache);
+
+ for (i = 0; i < nr_item; i++)
+ {
+ if (key->k_dir_id > dir_id
+ || (key->k_dir_id == dir_id
+ && (key->k_objectid > objectid
+ || (key->k_objectid == objectid
+ && (key->u.v1.k_offset
+ | key->u.v1.k_uniqueness) > 0))))
+ break;
+ key++;
+ }
+
+#ifdef REISERDEBUG
+ printf (" depth=%d, i=%d/%d\n", depth, i, nr_item);
+#endif /* REISERDEBUG */
+ INFO->next_key_nr[depth] = (i == nr_item) ? 0 : i+1;
+ cache = read_tree_node (DC (cache)[i].dc_block_number, --depth);
+ if (! cache)
+ return 0;
+ }
+
+ /* cache == LEAF */
+ nr_item = BLOCKHEAD (LEAF)->blk_nr_item;
+ ih = ITEMHEAD;
+ 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.v1.k_offset == 0
+ && ih->ih_key.u.v1.k_uniqueness == 0)
+ {
+#ifdef REISERDEBUG
+ printf (" depth=%d, i=%d/%d\n", depth, i, nr_item);
+#endif /* REISERDEBUG */
+ INFO->current_ih = ih;
+ INFO->current_item = &LEAF[ih->ih_item_location];
+ return 1;
+ }
+ ih++;
+ }
+ errnum = ERR_FSYS_CORRUPT;
+ return 0;
+}
+
+int
+reiserfs_read (char *buf, int len)
+{
+ unsigned int blocksize;
+ unsigned int offset;
+ unsigned int to_read;
+ char *prev_buf = buf;
+
+#ifdef REISERDEBUG
+ printf ("reiserfs_read: filepos=%d len=%d, offset=%x:%x\n",
+ filepos, len, (__u64) IH_KEY_OFFSET (INFO->current_ih) - 1);
+#endif /* REISERDEBUG */
+
+ if (INFO->current_ih->ih_key.k_objectid != INFO->fileinfo.k_objectid
+ || IH_KEY_OFFSET (INFO->current_ih) > filepos + 1)
+ {
+ search_stat (INFO->fileinfo.k_dir_id, INFO->fileinfo.k_objectid);
+ goto get_next_key;
+ }
+
+ while (! errnum)
+ {
+ if (INFO->current_ih->ih_key.k_objectid != INFO->fileinfo.k_objectid)
+ break;
+
+ offset = filepos - IH_KEY_OFFSET (INFO->current_ih) + 1;
+ blocksize = INFO->current_ih->ih_item_len;
+
+#ifdef REISERDEBUG
+ printf (" loop: filepos=%d len=%d, offset=%d blocksize=%d\n",
+ filepos, len, offset, blocksize);
+#endif /* REISERDEBUG */
+
+ if (IH_KEY_ISTYPE(INFO->current_ih, TYPE_DIRECT)
+ && offset < blocksize)
+ {
+#ifdef REISERDEBUG
+ printf ("direct_read: offset=%d, blocksize=%d\n",
+ offset, blocksize);
+#endif /* REISERDEBUG */
+ to_read = blocksize - offset;
+ if (to_read > len)
+ to_read = len;
+
+ if (disk_read_hook != NULL)
+ {
+ disk_read_func = disk_read_hook;
+
+ block_read (INFO->blocks[DISK_LEAF_NODE_LEVEL],
+ (INFO->current_item - LEAF + offset), to_read, buf);
+
+ disk_read_func = NULL;
+ }
+ else
+ 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->fullblocksize_shift;
+#ifdef REISERDEBUG
+ printf ("indirect_read: offset=%d, blocksize=%d\n",
+ offset, blocksize);
+#endif /* REISERDEBUG */
+
+ while (offset < blocksize)
+ {
+ __u32 blocknr = ((__u32 *) INFO->current_item)
+ [offset >> INFO->fullblocksize_shift];
+ int blk_offset = offset & (INFO->blocksize-1);
+
+ to_read = INFO->blocksize - blk_offset;
+ if (to_read > len)
+ to_read = len;
+
+ disk_read_func = disk_read_hook;
+
+ /* Journal is only for meta data. Data blocks can be read
+ * directly without using block_read
+ */
+ devread (blocknr << INFO->blocksize_shift,
+ blk_offset, to_read, buf);
+
+ disk_read_func = NULL;
+ update_buf_len:
+ len -= to_read;
+ buf += to_read;
+ offset += to_read;
+ filepos += to_read;
+ if (len == 0)
+ goto done;
+ }
+ }
+ get_next_key:
+ next_key ();
+ }
+ done:
+ return errnum ? 0 : buf - prev_buf;
+}
+
+
+/* preconditions: reiserfs_mount 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.
+ */
+int
+reiserfs_dir (char *dirname)
+{
+ struct reiserfs_de_head *de_head;
+ char *rest, ch;
+ __u32 dir_id, objectid, parent_dir_id = 0, parent_objectid = 0;
+#ifndef STAGE1_5
+ int do_possibilities = 0;
+#endif /* ! STAGE1_5 */
+ char linkbuf[PATH_MAX]; /* buffer for following symbolic links */
+ int link_count = 0;
+ int mode;
+
+ dir_id = REISERFS_ROOT_PARENT_OBJECTID;
+ objectid = REISERFS_ROOT_OBJECTID;
+
+ while (1)
+ {
+#ifdef REISERDEBUG
+ printf ("dirname=%s\n", dirname);
+#endif /* REISERDEBUG */
+
+ /* Search for the stat info first. */
+ if (! search_stat (dir_id, objectid))
+ return 0;
+
+#ifdef REISERDEBUG
+ printf ("sd_mode=%x sd_size=%d\n",
+ ((struct stat_data *) INFO->current_item)->sd_mode,
+ ((struct stat_data *) INFO->current_item)->sd_size);
+#endif /* REISERDEBUG */
+
+ mode = ((struct stat_data *) INFO->current_item)->sd_mode;
+
+ /* If we've got a symbolic link, then chase it. */
+ if (S_ISLNK (mode))
+ {
+ int len;
+ if (++link_count > MAX_LINK_COUNT)
+ {
+ errnum = ERR_SYMLINK_LOOP;
+ return 0;
+ }
+
+ /* Get the symlink size. */
+ filemax = ((struct stat_data *) INFO->current_item)->sd_size;
+
+ /* Find out how long our remaining name is. */
+ len = 0;
+ while (dirname[len] && !isspace (dirname[len]))
+ len++;
+
+ if (filemax + len > sizeof (linkbuf) - 1)
+ {
+ errnum = ERR_FILELENGTH;
+ return 0;
+ }
+
+ /* Copy the remaining name to the end of the symlink data.
+ Note that DIRNAME and LINKBUF may overlap! */
+ grub_memmove (linkbuf + filemax, dirname, len+1);
+
+ INFO->fileinfo.k_dir_id = dir_id;
+ INFO->fileinfo.k_objectid = objectid;
+ filepos = 0;
+ if (! next_key ()
+ || reiserfs_read (linkbuf, filemax) != filemax)
+ {
+ if (! errnum)
+ errnum = ERR_FSYS_CORRUPT;
+ return 0;
+ }
+
+#ifdef REISERDEBUG
+ printf ("symlink=%s\n", linkbuf);
+#endif /* REISERDEBUG */
+
+ dirname = linkbuf;
+ if (*dirname == '/')
+ {
+ /* It's an absolute link, so look it up in root. */
+ dir_id = REISERFS_ROOT_PARENT_OBJECTID;
+ objectid = 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 = ERR_BAD_FILETYPE;
+ return 0;
+ }
+
+ filepos = 0;
+ filemax = ((struct stat_data *) INFO->current_item)->sd_size;
+
+ /* If this is a new stat data and size is > 4GB set filemax to
+ * maximum
+ */
+ if (INFO->current_ih->ih_version == ITEM_VERSION_2
+ && ((struct stat_data *) INFO->current_item)->sd_size_hi > 0)
+ filemax = 0xffffffff;
+
+ 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 = ERR_BAD_FILETYPE;
+ return 0;
+ }
+ for (rest = dirname; (ch = *rest) && ! isspace (ch) && ch != '/'; rest++);
+ *rest = 0;
+
+# ifndef STAGE1_5
+ if (print_possibilities && ch != '/')
+ do_possibilities = 1;
+# endif /* ! STAGE1_5 */
+
+ while (1)
+ {
+ char *name_end;
+ int num_entries;
+
+ if (! next_key ())
+ return 0;
+#ifdef REISERDEBUG
+ printf ("ih: key %d:%d:%d:%d version:%d\n",
+ INFO->current_ih->ih_key.k_dir_id,
+ INFO->current_ih->ih_key.k_objectid,
+ INFO->current_ih->ih_key.u.v1.k_offset,
+ INFO->current_ih->ih_key.u.v1.k_uniqueness,
+ INFO->current_ih->ih_version);
+#endif /* REISERDEBUG */
+
+ if (INFO->current_ih->ih_key.k_objectid != objectid)
+ break;
+
+ name_end = INFO->current_item + INFO->current_ih->ih_item_len;
+ de_head = (struct reiserfs_de_head *) INFO->current_item;
+ num_entries = INFO->current_ih->u.ih_entry_count;
+ while (num_entries > 0)
+ {
+ char *filename = INFO->current_item + de_head->deh_location;
+ char tmp = *name_end;
+ if ((de_head->deh_state & 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 = substring (dirname, filename);
+ *name_end = tmp;
+# ifndef STAGE1_5
+ if (do_possibilities)
+ {
+ if (cmp <= 0)
+ {
+ if (print_possibilities > 0)
+ print_possibilities = -print_possibilities;
+ *name_end = 0;
+ print_a_completion (filename);
+ *name_end = tmp;
+ }
+ }
+ else
+# endif /* ! STAGE1_5 */
+ if (cmp == 0)
+ goto found;
+ }
+ /* The beginning of this name marks the end of the next name.
+ */
+ name_end = filename;
+ de_head++;
+ num_entries--;
+ }
+ }
+
+# ifndef STAGE1_5
+ if (print_possibilities < 0)
+ return 1;
+# endif /* ! STAGE1_5 */
+
+ errnum = ERR_FILE_NOT_FOUND;
+ *rest = ch;
+ return 0;
+
+ found:
+
+ *rest = ch;
+ dirname = rest;
+
+ parent_dir_id = dir_id;
+ parent_objectid = objectid;
+ dir_id = de_head->deh_dir_id;
+ objectid = de_head->deh_objectid;
+ }
+}
+
+int
+reiserfs_embed (int *start_sector, int needed_sectors)
+{
+ struct reiserfs_super_block super;
+ int num_sectors;
+
+ if (! devread (REISERFS_DISK_OFFSET_IN_BYTES >> SECTOR_BITS, 0,
+ sizeof (struct reiserfs_super_block), (char *) &super))
+ return 0;
+
+ *start_sector = 1; /* reserve first sector for stage1 */
+ if ((substring (REISERFS_SUPER_MAGIC_STRING, super.s_magic) <= 0
+ || substring (REISER2FS_SUPER_MAGIC_STRING, super.s_magic) <= 0)
+ && (/* check that this is not a super block copy inside
+ * the journal log */
+ super.s_journal_block * super.s_blocksize
+ > REISERFS_DISK_OFFSET_IN_BYTES))
+ num_sectors = (REISERFS_DISK_OFFSET_IN_BYTES >> SECTOR_BITS) - 1;
+ else
+ num_sectors = (REISERFS_OLD_DISK_OFFSET_IN_BYTES >> SECTOR_BITS) - 1;
+
+ return (needed_sectors <= num_sectors);
+}
+#endif /* FSYS_REISERFS */
Code Review / kvmfornfv.git / blobdiff