dir.c

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/*
 *  linux/fs/hfs/dir.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 directory-related functions independent of which
 * scheme is being used to represent forks.
 *
 * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
 */

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

/*
 * hfs_lookup()
 */
static struct dentry *hfs_lookup(struct inode *dir, struct dentry *dentry,
                 unsigned int flags)
{
    hfs_cat_rec rec;
    struct hfs_find_data fd;
    struct inode *inode = NULL;
    int res;

    hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
    hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name);
    res = hfs_brec_read(&fd, &rec, sizeof(rec));
    if (res) {
        hfs_find_exit(&fd);
        if (res == -ENOENT) {
            /* No such entry */
            inode = NULL;
            goto done;
        }
        return ERR_PTR(res);
    }
    inode = hfs_iget(dir->i_sb, &fd.search_key->cat, &rec);
    hfs_find_exit(&fd);
    if (!inode)
        return ERR_PTR(-EACCES);
done:
    d_add(dentry, inode);
    return NULL;
}

/*
 * hfs_readdir
 */
static int hfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
    struct inode *inode = filp->f_path.dentry->d_inode;
    struct super_block *sb = inode->i_sb;
    int len, err;
    char strbuf[HFS_MAX_NAMELEN];
    union hfs_cat_rec entry;
    struct hfs_find_data fd;
    struct hfs_readdir_data *rd;
    u16 type;

    if (filp->f_pos >= inode->i_size)
        return 0;

    hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
    hfs_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
    err = hfs_brec_find(&fd);
    if (err)
        goto out;

    switch ((u32)filp->f_pos) {
    case 0:
        /* This is completely artificial... */
        if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR))
            goto out;
        filp->f_pos++;
        /* fall through */
    case 1:
        if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
            err = -EIO;
            goto out;
        }

        hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
        if (entry.type != HFS_CDR_THD) {
            printk(KERN_ERR "hfs: bad catalog folder thread\n");
            err = -EIO;
            goto out;
        }
        //if (fd.entrylength < HFS_MIN_THREAD_SZ) {
        //  printk(KERN_ERR "hfs: truncated catalog thread\n");
        //  err = -EIO;
        //  goto out;
        //}
        if (filldir(dirent, "..", 2, 1,
                be32_to_cpu(entry.thread.ParID), DT_DIR))
            goto out;
        filp->f_pos++;
        /* fall through */
    default:
        if (filp->f_pos >= inode->i_size)
            goto out;
        err = hfs_brec_goto(&fd, filp->f_pos - 1);
        if (err)
            goto out;
    }

    for (;;) {
        if (be32_to_cpu(fd.key->cat.ParID) != inode->i_ino) {
            printk(KERN_ERR "hfs: walked past end of dir\n");
            err = -EIO;
            goto out;
        }

        if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
            err = -EIO;
            goto out;
        }

        hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
        type = entry.type;
        len = hfs_mac2asc(sb, strbuf, &fd.key->cat.CName);
        if (type == HFS_CDR_DIR) {
            if (fd.entrylength < sizeof(struct hfs_cat_dir)) {
                printk(KERN_ERR "hfs: small dir entry\n");
                err = -EIO;
                goto out;
            }
            if (filldir(dirent, strbuf, len, filp->f_pos,
                    be32_to_cpu(entry.dir.DirID), DT_DIR))
                break;
        } else if (type == HFS_CDR_FIL) {
            if (fd.entrylength < sizeof(struct hfs_cat_file)) {
                printk(KERN_ERR "hfs: small file entry\n");
                err = -EIO;
                goto out;
            }
            if (filldir(dirent, strbuf, len, filp->f_pos,
                    be32_to_cpu(entry.file.FlNum), DT_REG))
                break;
        } else {
            printk(KERN_ERR "hfs: bad catalog entry type %d\n", type);
            err = -EIO;
            goto out;
        }
        filp->f_pos++;
        if (filp->f_pos >= inode->i_size)
            goto out;
        err = hfs_brec_goto(&fd, 1);
        if (err)
            goto out;
    }
    rd = filp->private_data;
    if (!rd) {
        rd = kmalloc(sizeof(struct hfs_readdir_data), GFP_KERNEL);
        if (!rd) {
            err = -ENOMEM;
            goto out;
        }
        filp->private_data = rd;
        rd->file = filp;
        list_add(&rd->list, &HFS_I(inode)->open_dir_list);
    }
    memcpy(&rd->key, &fd.key, sizeof(struct hfs_cat_key));
out:
    hfs_find_exit(&fd);
    return err;
}

static int hfs_dir_release(struct inode *inode, struct file *file)
{
    struct hfs_readdir_data *rd = file->private_data;
    if (rd) {
        list_del(&rd->list);
        kfree(rd);
    }
    return 0;
}

/*
 * hfs_create()
 *
 * This is the create() entry in the inode_operations structure for
 * regular HFS directories.  The purpose is to create a new file in
 * a directory and return a corresponding inode, given the inode for
 * the directory and the name (and its length) of the new file.
 */
static int hfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
              bool excl)
{
    struct inode *inode;
    int res;

    inode = hfs_new_inode(dir, &dentry->d_name, mode);
    if (!inode)
        return -ENOSPC;

    res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
    if (res) {
        clear_nlink(inode);
        hfs_delete_inode(inode);
        iput(inode);
        return res;
    }
    d_instantiate(dentry, inode);
    mark_inode_dirty(inode);
    return 0;
}

/*
 * hfs_mkdir()
 *
 * This is the mkdir() entry in the inode_operations structure for
 * regular HFS directories.  The purpose is to create a new directory
 * in a directory, given the inode for the parent directory and the
 * name (and its length) of the new directory.
 */
static int hfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
    struct inode *inode;
    int res;

    inode = hfs_new_inode(dir, &dentry->d_name, S_IFDIR | mode);
    if (!inode)
        return -ENOSPC;

    res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
    if (res) {
        clear_nlink(inode);
        hfs_delete_inode(inode);
        iput(inode);
        return res;
    }
    d_instantiate(dentry, inode);
    mark_inode_dirty(inode);
    return 0;
}

/*
 * hfs_remove()
 *
 * This serves as both unlink() and rmdir() in the inode_operations
 * structure for regular HFS directories.  The purpose is to delete
 * an existing child, given the inode for the parent directory and
 * the name (and its length) of the existing directory.
 *
 * HFS does not have hardlinks, so both rmdir and unlink set the
 * link count to 0.  The only difference is the emptiness check.
 */
static int hfs_remove(struct inode *dir, struct dentry *dentry)
{
    struct inode *inode = dentry->d_inode;
    int res;

    if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
        return -ENOTEMPTY;
    res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
    if (res)
        return res;
    clear_nlink(inode);
    inode->i_ctime = CURRENT_TIME_SEC;
    hfs_delete_inode(inode);
    mark_inode_dirty(inode);
    return 0;
}

/*
 * hfs_rename()
 *
 * This is the rename() entry in the inode_operations structure for
 * regular HFS directories.  The purpose is to rename an existing
 * file or directory, given the inode for the current directory and
 * the name (and its length) of the existing file/directory and the
 * inode for the new directory and the name (and its length) of the
 * new file/directory.
 * XXX: how do you handle must_be dir?
 */
static int hfs_rename(struct inode *old_dir, struct dentry *old_dentry,
              struct inode *new_dir, struct dentry *new_dentry)
{
    int res;

    /* Unlink destination if it already exists */
    if (new_dentry->d_inode) {
        res = hfs_remove(new_dir, new_dentry);
        if (res)
            return res;
    }

    res = hfs_cat_move(old_dentry->d_inode->i_ino,
               old_dir, &old_dentry->d_name,
               new_dir, &new_dentry->d_name);
    if (!res)
        hfs_cat_build_key(old_dir->i_sb,
                  (btree_key *)&HFS_I(old_dentry->d_inode)->cat_key,
                  new_dir->i_ino, &new_dentry->d_name);
    return res;
}

const struct file_operations hfs_dir_operations = {
    .read       = generic_read_dir,
    .readdir    = hfs_readdir,
    .llseek     = generic_file_llseek,
    .release    = hfs_dir_release,
};

const struct inode_operations hfs_dir_inode_operations = {
    .create     = hfs_create,
    .lookup     = hfs_lookup,
    .unlink     = hfs_remove,
    .mkdir      = hfs_mkdir,
    .rmdir      = hfs_remove,
    .rename     = hfs_rename,
    .setattr    = hfs_inode_setattr,
};