catalog.c

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/*
 *  linux/fs/hfs/catalog.c
 *
 * Copyright (C) 1995-1997  Paul H. Hargrove
 * (C) 2003 Ardis Technologies <[email protected]>
 * This file may be distributed under the terms of the GNU General Public License.
 *
 * This file contains the functions related to the catalog B-tree.
 *
 * Cache code shamelessly stolen from
 *     linux/fs/inode.c Copyright (C) 1991, 1992  Linus Torvalds
 *     re-shamelessly stolen Copyright (C) 1997 Linus Torvalds
 */

#include "hfs_fs.h"
#include "btree.h"

/*
 * hfs_cat_build_key()
 *
 * Given the ID of the parent and the name build a search key.
 */
void hfs_cat_build_key(struct super_block *sb, btree_key *key, u32 parent, struct qstr *name)
{
    key->cat.reserved = 0;
    key->cat.ParID = cpu_to_be32(parent);
    if (name) {
        hfs_asc2mac(sb, &key->cat.CName, name);
        key->key_len = 6 + key->cat.CName.len;
    } else {
        memset(&key->cat.CName, 0, sizeof(struct hfs_name));
        key->key_len = 6;
    }
}

static int hfs_cat_build_record(hfs_cat_rec *rec, u32 cnid, struct inode *inode)
{
    __be32 mtime = hfs_mtime();

    memset(rec, 0, sizeof(*rec));
    if (S_ISDIR(inode->i_mode)) {
        rec->type = HFS_CDR_DIR;
        rec->dir.DirID = cpu_to_be32(cnid);
        rec->dir.CrDat = mtime;
        rec->dir.MdDat = mtime;
        rec->dir.BkDat = 0;
        rec->dir.UsrInfo.frView = cpu_to_be16(0xff);
        return sizeof(struct hfs_cat_dir);
    } else {
        /* init some fields for the file record */
        rec->type = HFS_CDR_FIL;
        rec->file.Flags = HFS_FIL_USED | HFS_FIL_THD;
        if (!(inode->i_mode & S_IWUSR))
            rec->file.Flags |= HFS_FIL_LOCK;
        rec->file.FlNum = cpu_to_be32(cnid);
        rec->file.CrDat = mtime;
        rec->file.MdDat = mtime;
        rec->file.BkDat = 0;
        rec->file.UsrWds.fdType = HFS_SB(inode->i_sb)->s_type;
        rec->file.UsrWds.fdCreator = HFS_SB(inode->i_sb)->s_creator;
        return sizeof(struct hfs_cat_file);
    }
}

static int hfs_cat_build_thread(struct super_block *sb,
                hfs_cat_rec *rec, int type,
                u32 parentid, struct qstr *name)
{
    rec->type = type;
    memset(rec->thread.reserved, 0, sizeof(rec->thread.reserved));
    rec->thread.ParID = cpu_to_be32(parentid);
    hfs_asc2mac(sb, &rec->thread.CName, name);
    return sizeof(struct hfs_cat_thread);
}

/*
 * create_entry()
 *
 * Add a new file or directory to the catalog B-tree and
 * return a (struct hfs_cat_entry) for it in '*result'.
 */
int hfs_cat_create(u32 cnid, struct inode *dir, struct qstr *str, struct inode *inode)
{
    struct hfs_find_data fd;
    struct super_block *sb;
    union hfs_cat_rec entry;
    int entry_size;
    int err;

    dprint(DBG_CAT_MOD, "create_cat: %s,%u(%d)\n", str->name, cnid, inode->i_nlink);
    if (dir->i_size >= HFS_MAX_VALENCE)
        return -ENOSPC;

    sb = dir->i_sb;
    hfs_find_init(HFS_SB(sb)->cat_tree, &fd);

    hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
    entry_size = hfs_cat_build_thread(sb, &entry, S_ISDIR(inode->i_mode) ?
            HFS_CDR_THD : HFS_CDR_FTH,
            dir->i_ino, str);
    err = hfs_brec_find(&fd);
    if (err != -ENOENT) {
        if (!err)
            err = -EEXIST;
        goto err2;
    }
    err = hfs_brec_insert(&fd, &entry, entry_size);
    if (err)
        goto err2;

    hfs_cat_build_key(sb, fd.search_key, dir->i_ino, str);
    entry_size = hfs_cat_build_record(&entry, cnid, inode);
    err = hfs_brec_find(&fd);
    if (err != -ENOENT) {
        /* panic? */
        if (!err)
            err = -EEXIST;
        goto err1;
    }
    err = hfs_brec_insert(&fd, &entry, entry_size);
    if (err)
        goto err1;

    dir->i_size++;
    dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
    mark_inode_dirty(dir);
    hfs_find_exit(&fd);
    return 0;

err1:
    hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
    if (!hfs_brec_find(&fd))
        hfs_brec_remove(&fd);
err2:
    hfs_find_exit(&fd);
    return err;
}

/*
 * hfs_cat_compare()
 *
 * Description:
 *   This is the comparison function used for the catalog B-tree.  In
 *   comparing catalog B-tree entries, the parent id is the most
 *   significant field (compared as unsigned ints).  The name field is
 *   the least significant (compared in "Macintosh lexical order",
 *   see hfs_strcmp() in string.c)
 * Input Variable(s):
 *   struct hfs_cat_key *key1: pointer to the first key to compare
 *   struct hfs_cat_key *key2: pointer to the second key to compare
 * Output Variable(s):
 *   NONE
 * Returns:
 *   int: negative if key1<key2, positive if key1>key2, and 0 if key1==key2
 * Preconditions:
 *   key1 and key2 point to "valid" (struct hfs_cat_key)s.
 * Postconditions:
 *   This function has no side-effects
 */
int hfs_cat_keycmp(const btree_key *key1, const btree_key *key2)
{
    int retval;

    retval = be32_to_cpu(key1->cat.ParID) - be32_to_cpu(key2->cat.ParID);
    if (!retval)
        retval = hfs_strcmp(key1->cat.CName.name, key1->cat.CName.len,
                    key2->cat.CName.name, key2->cat.CName.len);

    return retval;
}

/* Try to get a catalog entry for given catalog id */
// move to read_super???
int hfs_cat_find_brec(struct super_block *sb, u32 cnid,
              struct hfs_find_data *fd)
{
    hfs_cat_rec rec;
    int res, len, type;

    hfs_cat_build_key(sb, fd->search_key, cnid, NULL);
    res = hfs_brec_read(fd, &rec, sizeof(rec));
    if (res)
        return res;

    type = rec.type;
    if (type != HFS_CDR_THD && type != HFS_CDR_FTH) {
        printk(KERN_ERR "hfs: found bad thread record in catalog\n");
        return -EIO;
    }

    fd->search_key->cat.ParID = rec.thread.ParID;
    len = fd->search_key->cat.CName.len = rec.thread.CName.len;
    if (len > HFS_NAMELEN) {
        printk(KERN_ERR "hfs: bad catalog namelength\n");
        return -EIO;
    }
    memcpy(fd->search_key->cat.CName.name, rec.thread.CName.name, len);
    return hfs_brec_find(fd);
}


/*
 * hfs_cat_delete()
 *
 * Delete the indicated file or directory.
 * The associated thread is also removed unless ('with_thread'==0).
 */
int hfs_cat_delete(u32 cnid, struct inode *dir, struct qstr *str)
{
    struct super_block *sb;
    struct hfs_find_data fd;
    struct list_head *pos;
    int res, type;

    dprint(DBG_CAT_MOD, "delete_cat: %s,%u\n", str ? str->name : NULL, cnid);
    sb = dir->i_sb;
    hfs_find_init(HFS_SB(sb)->cat_tree, &fd);

    hfs_cat_build_key(sb, fd.search_key, dir->i_ino, str);
    res = hfs_brec_find(&fd);
    if (res)
        goto out;

    type = hfs_bnode_read_u8(fd.bnode, fd.entryoffset);
    if (type == HFS_CDR_FIL) {
        struct hfs_cat_file file;
        hfs_bnode_read(fd.bnode, &file, fd.entryoffset, sizeof(file));
        if (be32_to_cpu(file.FlNum) == cnid) {
#if 0
            hfs_free_fork(sb, &file, HFS_FK_DATA);
#endif
            hfs_free_fork(sb, &file, HFS_FK_RSRC);
        }
    }

    list_for_each(pos, &HFS_I(dir)->open_dir_list) {
        struct hfs_readdir_data *rd =
            list_entry(pos, struct hfs_readdir_data, list);
        if (fd.tree->keycmp(fd.search_key, (void *)&rd->key) < 0)
            rd->file->f_pos--;
    }

    res = hfs_brec_remove(&fd);
    if (res)
        goto out;

    hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
    res = hfs_brec_find(&fd);
    if (!res) {
        res = hfs_brec_remove(&fd);
        if (res)
            goto out;
    }

    dir->i_size--;
    dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
    mark_inode_dirty(dir);
    res = 0;
out:
    hfs_find_exit(&fd);

    return res;
}

/*
 * hfs_cat_move()
 *
 * Rename a file or directory, possibly to a new directory.
 * If the destination exists it is removed and a
 * (struct hfs_cat_entry) for it is returned in '*result'.
 */
int hfs_cat_move(u32 cnid, struct inode *src_dir, struct qstr *src_name,
         struct inode *dst_dir, struct qstr *dst_name)
{
    struct super_block *sb;
    struct hfs_find_data src_fd, dst_fd;
    union hfs_cat_rec entry;
    int entry_size, type;
    int err;

    dprint(DBG_CAT_MOD, "rename_cat: %u - %lu,%s - %lu,%s\n", cnid, src_dir->i_ino, src_name->name,
        dst_dir->i_ino, dst_name->name);
    sb = src_dir->i_sb;
    hfs_find_init(HFS_SB(sb)->cat_tree, &src_fd);
    dst_fd = src_fd;

    /* find the old dir entry and read the data */
    hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
    err = hfs_brec_find(&src_fd);
    if (err)
        goto out;
    if (src_fd.entrylength > sizeof(entry) || src_fd.entrylength < 0) {
        err = -EIO;
        goto out;
    }

    hfs_bnode_read(src_fd.bnode, &entry, src_fd.entryoffset,
                src_fd.entrylength);

    /* create new dir entry with the data from the old entry */
    hfs_cat_build_key(sb, dst_fd.search_key, dst_dir->i_ino, dst_name);
    err = hfs_brec_find(&dst_fd);
    if (err != -ENOENT) {
        if (!err)
            err = -EEXIST;
        goto out;
    }

    err = hfs_brec_insert(&dst_fd, &entry, src_fd.entrylength);
    if (err)
        goto out;
    dst_dir->i_size++;
    dst_dir->i_mtime = dst_dir->i_ctime = CURRENT_TIME_SEC;
    mark_inode_dirty(dst_dir);

    /* finally remove the old entry */
    hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
    err = hfs_brec_find(&src_fd);
    if (err)
        goto out;
    err = hfs_brec_remove(&src_fd);
    if (err)
        goto out;
    src_dir->i_size--;
    src_dir->i_mtime = src_dir->i_ctime = CURRENT_TIME_SEC;
    mark_inode_dirty(src_dir);

    type = entry.type;
    if (type == HFS_CDR_FIL && !(entry.file.Flags & HFS_FIL_THD))
        goto out;

    /* remove old thread entry */
    hfs_cat_build_key(sb, src_fd.search_key, cnid, NULL);
    err = hfs_brec_find(&src_fd);
    if (err)
        goto out;
    err = hfs_brec_remove(&src_fd);
    if (err)
        goto out;

    /* create new thread entry */
    hfs_cat_build_key(sb, dst_fd.search_key, cnid, NULL);
    entry_size = hfs_cat_build_thread(sb, &entry, type == HFS_CDR_FIL ? HFS_CDR_FTH : HFS_CDR_THD,
                    dst_dir->i_ino, dst_name);
    err = hfs_brec_find(&dst_fd);
    if (err != -ENOENT) {
        if (!err)
            err = -EEXIST;
        goto out;
    }
    err = hfs_brec_insert(&dst_fd, &entry, entry_size);
out:
    hfs_bnode_put(dst_fd.bnode);
    hfs_find_exit(&src_fd);
    return err;
}