C++ HFS_I函数代码示例

/*
 * build_key()
 *
 * Build a key for a file by the given name in the given directory.
 * If the name matches one of the reserved names returns 1 otherwise 0.
 */
static int build_key(struct hfs_cat_key *key, struct inode *dir,
		     const char *name, int len)
{
	struct hfs_name cname;
	const struct hfs_name *reserved;

	/* mangle the name */
	hfs_nameout(dir, &cname, name, len);

	/* check against reserved names */
	reserved = HFS_SB(dir->i_sb)->s_reserved1;
	while (reserved->Len) {
		if (hfs_streq(reserved, &cname)) {
			return 1;
		}
		++reserved;
	}

	/* check against the names reserved only in the root directory */
	if (HFS_I(dir)->entry->cnid == htonl(HFS_ROOT_CNID)) {
		reserved = HFS_SB(dir->i_sb)->s_reserved2;
		while (reserved->Len) {
			if (hfs_streq(reserved, &cname)) {
				return 1;
			}
			++reserved;
		}
	}

	/* build the key */
	hfs_cat_build_key(HFS_I(dir)->entry->cnid, &cname, key);

	return 0;
}

/*
 * init_file_inode()
 *
 * Given an HFS catalog entry initialize an inode for a file.
 */
static void init_file_inode(struct inode *inode, hfs_u8 fork)
{
    struct hfs_fork *fk;
    struct hfs_cat_entry *entry = HFS_I(inode)->entry;

    if (fork == HFS_FK_DATA) {
        inode->i_mode = S_IRWXUGO | S_IFREG;
    } else {
        inode->i_mode = S_IRUGO | S_IWUGO | S_IFREG;
    }

    if (fork == HFS_FK_DATA) {
#if 0 /* XXX: disable crlf translations for now */
        hfs_u32 type = hfs_get_nl(entry->info.file.finfo.fdType);

        HFS_I(inode)->convert =
            ((HFS_SB(inode->i_sb)->s_conv == 't') ||
             ((HFS_SB(inode->i_sb)->s_conv == 'a') &&
              ((type == htonl(0x54455854)) ||   /* "TEXT" */
               (type == htonl(0x7474726f)))));  /* "ttro" */
#else
        HFS_I(inode)->convert = 0;
#endif
        fk = &entry->u.file.data_fork;
    } else {
        fk = &entry->u.file.rsrc_fork;
        HFS_I(inode)->convert = 0;
    }
    HFS_I(inode)->fork = fk;
    inode->i_size = fk->lsize;
    inode->i_blocks = fk->psize;
    inode->i_nlink = 1;
}

/*
 * 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.
 */
int hfs_create(struct inode * dir, const char * name, int len, int mode,
	       struct inode ** result)
{
	struct hfs_cat_entry *entry = HFS_I(dir)->entry;
	struct hfs_cat_entry *new;
	struct hfs_cat_key key;
	int error;

	*result = NULL;

	/* build the key, checking against reserved names */
	if (build_key(&key, dir, name, len)) {
		error = -EEXIST;
	} else {
		/* try to create the file */
		error = hfs_cat_create(entry, &key, 
				       (mode & S_IWUSR) ? 0 : HFS_FIL_LOCK,
				       HFS_SB(dir->i_sb)->s_type,
				       HFS_SB(dir->i_sb)->s_creator, &new);
	}

	if (!error) {
		update_dirs_plus(entry, 0);

		/* create an inode for the new file */
		*result = __hfs_iget(new, HFS_I(dir)->file_type, 0);
		if (!(*result)) {
			/* XXX correct error? */
			error = -EIO;
		}
	}

/*
 * cap_lookup()
 *
 * This is the lookup() entry in the inode_operations structure for
 * HFS directories in the CAP scheme.  The purpose is to generate the
 * inode corresponding to an entry in a directory, given the inode for
 * the directory and the name (and its length) of the entry.
 */
static struct dentry *cap_lookup(struct inode * dir, struct dentry *dentry)
{
	ino_t dtype;
	struct hfs_name cname;
	struct hfs_cat_entry *entry;
	struct hfs_cat_key key;
	struct inode *inode = NULL;

	dentry->d_op = &hfs_dentry_operations;
	entry = HFS_I(dir)->entry;
	dtype = HFS_ITYPE(dir->i_ino);

	/* Perform name-mangling */
	hfs_nameout(dir, &cname, dentry->d_name.name, 
		    dentry->d_name.len);

	/* no need to check for "."  or ".." */

	/* Check for special directories if in a normal directory.
	   Note that cap_dupdir() does an iput(dir). */
	if (dtype==HFS_CAP_NDIR) {
		/* Check for ".resource", ".finderinfo" and ".rootinfo" */
		if (hfs_streq(cname.Name, cname.Len, 
			      DOT_RESOURCE->Name, DOT_RESOURCE_LEN)) {
			++entry->count; /* __hfs_iget() eats one */
			inode = hfs_iget(entry, HFS_CAP_RDIR, dentry);
			goto done;
		} else if (hfs_streq(cname.Name, cname.Len, 
				     DOT_FINDERINFO->Name, 
				     DOT_FINDERINFO_LEN)) {
			++entry->count; /* __hfs_iget() eats one */
			inode = hfs_iget(entry, HFS_CAP_FDIR, dentry);
			goto done;
		} else if ((entry->cnid == htonl(HFS_ROOT_CNID)) &&
			   hfs_streq(cname.Name, cname.Len, 
				     DOT_ROOTINFO->Name, DOT_ROOTINFO_LEN)) {
			++entry->count; /* __hfs_iget() eats one */
			inode = hfs_iget(entry, HFS_CAP_FNDR, dentry);
			goto done;
		}
	}

	/* Do an hfs_iget() on the mangled name. */
	hfs_cat_build_key(entry->cnid, &cname, &key);
	inode = hfs_iget(hfs_cat_get(entry->mdb, &key),
			 HFS_I(dir)->file_type, dentry);

	/* Don't return a resource fork for a directory */
	if (inode && (dtype == HFS_CAP_RDIR) && 
	    (HFS_I(inode)->entry->type == HFS_CDR_DIR)) {
	        iput(inode); /* this does an hfs_cat_put */
		inode = NULL;
	}

done:
	d_add(dentry, inode);
	return NULL;
}

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

/*
 * hfs_put_inode()
 *
 * This is the put_inode() entry in the super_operations for HFS
 * filesystems.  The purpose is to perform any filesystem-dependent 
 * cleanup necessary when the use-count of an inode falls to zero.
 */
void hfs_put_inode(struct inode * inode)
{
	struct hfs_cat_entry *entry = HFS_I(inode)->entry;

	hfs_cat_put(entry);
	if (inode->i_count == 1) {
	  struct hfs_hdr_layout *tmp = HFS_I(inode)->layout;

	  if (tmp) {
		HFS_I(inode)->layout = NULL;
		HFS_DELETE(tmp);
	  }
	}
}

/*
 * hfs_put_inode()
 *
 * This is the put_inode() entry in the super_operations for HFS
 * filesystems.  The purpose is to perform any filesystem-dependent
 * cleanup necessary when the use-count of an inode falls to zero.
 */
void hfs_put_inode(struct inode * inode)
{
    struct hfs_cat_entry *entry = HFS_I(inode)->entry;

    lock_kernel();
    hfs_cat_put(entry);
    if (atomic_read(&inode->i_count) == 1) {
        struct hfs_hdr_layout *tmp = HFS_I(inode)->layout;

        if (tmp) {
            HFS_I(inode)->layout = NULL;
            HFS_DELETE(tmp);
        }
    }
    unlock_kernel();
}

/*
 * 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,
		      unsigned int flags)
{
	int res;

	if (flags & ~RENAME_NOREPLACE)
		return -EINVAL;

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

	res = hfs_cat_move(d_inode(old_dentry)->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(d_inode(old_dentry))->cat_key,
				  new_dir->i_ino, &new_dentry->d_name);
	return res;
}

/*
 * nat_hdr_unlink()
 *
 * This is the unlink() entry in the inode_operations structure for
 * Netatalk .AppleDouble directories.  The purpose is to delete an
 * existing file, given the inode for the parent directory and the name
 * (and its length) of the existing file.
 *
 * WE DON'T ACTUALLY DELETE HEADER THE FILE.
 * In non-afpd-compatible mode:
 *   We return -EPERM.
 * In afpd-compatible mode:
 *   We return success if the file exists or is .Parent.
 *   Otherwise we return -ENOENT.
 */
static int nat_hdr_unlink(struct inode *dir, const char *name, int len)
{
	struct hfs_cat_entry *entry = HFS_I(dir)->entry;
	int error = 0;

	if (!HFS_SB(dir->i_sb)->s_afpd) {
		/* Not in AFPD compatibility mode */
		error = -EPERM;
	} else {
		struct hfs_name cname;

		hfs_nameout(dir, &cname, name, len);
		if (!hfs_streq(&cname, DOT_PARENT)) {
			struct hfs_cat_entry *victim;
			struct hfs_cat_key key;

			hfs_cat_build_key(entry->cnid, &cname, &key);
			victim = hfs_cat_get(entry->mdb, &key);

			if (victim) {
				/* pretend to succeed */
				hfs_cat_put(victim);
			} else {
				error = -ENOENT;
			}
		}
	}
	iput(dir);
	return error;
}

/*
 * cap_info_read()
 *
 * This is the read() entry in the file_operations structure for CAP
 * metadata files.  The purpose is to transfer up to 'count' bytes
 * from the file corresponding to 'inode' beginning at offset
 * 'file->f_pos' to user-space at the address 'buf'.  The return value
 * is the number of bytes actually transferred.
 */
static hfs_rwret_t cap_info_read(struct file *filp, char *buf,
				 hfs_rwarg_t count, loff_t *ppos)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct hfs_cat_entry *entry = HFS_I(inode)->entry;
	hfs_s32 left, size, read = 0;
	hfs_u32 pos;

	if (!S_ISREG(inode->i_mode)) {
		hfs_warn("hfs_cap_info_read: mode = %07o\n", inode->i_mode);
		return -EINVAL;
	}

	pos = *ppos;
	if (pos > HFS_FORK_MAX) {
		return 0;
	}
	size = inode->i_size;
	if (pos > size) {
		left = 0;
	} else {
		left = size - pos;
	}
	if (left > count) {
		left = count;
	}
	if (left <= 0) {
		return 0;
	}

	if (pos < sizeof(struct hfs_cap_info)) {
		int memcount = sizeof(struct hfs_cap_info) - pos;
		struct hfs_cap_info meta;

		if (memcount > left) {
			memcount = left;
		}
		cap_build_meta(&meta, entry);
		memcount -= copy_to_user(buf, ((char *)&meta) + pos, memcount);
		left -= memcount;
		read += memcount;
		pos += memcount;
		buf += memcount;
	}

	if (left > 0) {
		clear_user(buf, left);
	        pos += left;
	}

	if (read) {
		inode->i_atime = CURRENT_TIME;
		*ppos = pos;
		mark_inode_dirty(inode);
	}

	return read;
}

static int hfs_revalidate_dentry(struct dentry *dentry, struct nameidata *nd)
{
    struct inode *inode = dentry->d_inode;
    int diff;

    if(!inode)
        return 1;

    /* fix up inode on a timezone change */
    diff = sys_tz.tz_minuteswest * 60 - HFS_I(inode)->tz_secondswest;
    if (diff) {
        inode->i_ctime.tv_sec += diff;
        inode->i_atime.tv_sec += diff;
        inode->i_mtime.tv_sec += diff;
        HFS_I(inode)->tz_secondswest += diff;
    }
    return 1;
}

static int hfs_write_begin(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
{
	*pagep = NULL;
	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
				hfs_get_block,
				&HFS_I(mapping->host)->phys_size);
}

/* 
 * hfs_dbl_ifill()
 *
 * This function serves the same purpose as a read_inode() function does
 * in other filesystems.  It is called by __hfs_iget() to fill in
 * the missing fields of an uninitialized inode under the AppleDouble
 * scheme.
 */
void hfs_dbl_ifill(struct inode * inode, ino_t type, const int version)
{
	struct hfs_cat_entry *entry = HFS_I(inode)->entry;

	HFS_I(inode)->d_drop_op = hfs_dbl_drop_dentry;
	if (type == HFS_DBL_HDR) {
		if (entry->type == HFS_CDR_FIL) {
			init_file_inode(inode, HFS_FK_RSRC);
			inode->i_size += HFS_DBL_HDR_LEN;
			HFS_I(inode)->default_layout = &hfs_dbl_fil_hdr_layout;
		} else {
			inode->i_size = HFS_DBL_HDR_LEN;
			inode->i_mode = S_IRUGO | S_IWUGO | S_IFREG;
			inode->i_nlink = 1;
			HFS_I(inode)->default_layout = &hfs_dbl_dir_hdr_layout;
		}
		inode->i_op = &hfs_hdr_inode_operations;
	} else if (entry->type == HFS_CDR_FIL) {
		init_file_inode(inode, HFS_FK_DATA);
		inode->i_op = &hfs_file_inode_operations;
	} else { /* Directory */
		struct hfs_dir *hdir = &entry->u.dir;

		inode->i_blocks = 0;
		inode->i_nlink = hdir->dirs + 2;
		inode->i_size = 3 + 2 * (hdir->dirs + hdir->files);
		inode->i_mode = S_IRWXUGO | S_IFDIR;
		inode->i_op = &hfs_dbl_dir_inode_operations;
		HFS_I(inode)->file_type = HFS_DBL_NORM;
		HFS_I(inode)->dir_size = 2;
	}
}

/*
 * cap_info_write()
 *
 * This is the write() entry in the file_operations structure for CAP
 * metadata files.  The purpose is to transfer up to 'count' bytes
 * to the file corresponding to 'inode' beginning at offset
 * '*ppos' from user-space at the address 'buf'.
 * The return value is the number of bytes actually transferred.
 */
static hfs_rwret_t cap_info_write(struct file *filp, const char *buf, 
				  hfs_rwarg_t count, loff_t *ppos)
{
        struct inode *inode = filp->f_dentry->d_inode;
	hfs_u32 pos;

	if (!S_ISREG(inode->i_mode)) {
		hfs_warn("hfs_file_write: mode = %07o\n", inode->i_mode);
		return -EINVAL;
	}
	if (count <= 0) {
		return 0;
	}
	
	pos = (filp->f_flags & O_APPEND) ? inode->i_size : *ppos;

	if (pos > HFS_FORK_MAX) {
		return 0;
	}

	*ppos += count;
	if (*ppos > HFS_FORK_MAX) {
		*ppos = HFS_FORK_MAX;
		count = HFS_FORK_MAX - pos;
	}

	if (*ppos > inode->i_size)
	        inode->i_size = *ppos;

	/* Only deal with the part we store in memory */
	if (pos < sizeof(struct hfs_cap_info)) {
		int end, mem_count;
		struct hfs_cat_entry *entry = HFS_I(inode)->entry;
		struct hfs_cap_info meta;

		mem_count = sizeof(struct hfs_cap_info) - pos;
		if (mem_count > count) {
			mem_count = count;
		}
		end = pos + mem_count;

		cap_build_meta(&meta, entry);
		mem_count -= copy_from_user(((char *)&meta) + pos, buf, mem_count);

		/* Update finder attributes if changed */
		if (OVERLAPS(pos, end, struct hfs_cap_info, fi_fndr)) {
			memcpy(&entry->info, meta.fi_fndr, 32);
			hfs_cat_mark_dirty(entry);
		}

static ssize_t __hfs_getxattr(struct inode *inode, enum hfs_xattr_type type,
			      void *value, size_t size)
{
	struct hfs_find_data fd;
	hfs_cat_rec rec;
	struct hfs_cat_file *file;
	ssize_t res = 0;

	if (!S_ISREG(inode->i_mode) || HFS_IS_RSRC(inode))
		return -EOPNOTSUPP;

	if (size) {
		res = hfs_find_init(HFS_SB(inode->i_sb)->cat_tree, &fd);
		if (res)
			return res;
		fd.search_key->cat = HFS_I(inode)->cat_key;
		res = hfs_brec_find(&fd);
		if (res)
			goto out;
		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
				sizeof(struct hfs_cat_file));
	}
	file = &rec.file;

	switch (type) {
	case HFS_TYPE:
		if (size >= 4) {
			memcpy(value, &file->UsrWds.fdType, 4);
			res = 4;
		} else
			res = size ? -ERANGE : 4;
		break;

	case HFS_CREATOR:
		if (size >= 4) {
			memcpy(value, &file->UsrWds.fdCreator, 4);
			res = 4;
		} else
			res = size ? -ERANGE : 4;
		break;
	}

out:
	if (size)
		hfs_find_exit(&fd);
	return res;
}