/*
 * Vnode op for reading directories.
 *
 * Convert the on-disk entries to <sys/dirent.h> entries.
 * the problem is that the conversion will blow up some entries by four bytes,
 * so it can't be done in place. This is too bad. Right now the conversion is
 * done entry by entry, the converted entry is sent via uiomove.
 *
 * XXX allocate a buffer, convert as many entries as possible, then send
 * the whole buffer to uiomove
 */
int
ext2fs_readdir(void *v)
{
	struct vop_readdir_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		kauth_cred_t a_cred;
		int **a_eofflag;
		off_t **a_cookies;
		int ncookies;
	} */ *ap = v;
	struct uio *uio = ap->a_uio;
	int error;
	size_t e2fs_count, readcnt;
	struct vnode *vp = ap->a_vp;
	struct m_ext2fs *fs = VTOI(vp)->i_e2fs;

	struct ext2fs_direct *dp;
	struct dirent *dstd;
	struct uio auio;
	struct iovec aiov;
	void *dirbuf;
	off_t off = uio->uio_offset;
	off_t *cookies = NULL;
	int nc = 0, ncookies = 0;
	int e2d_reclen;

	if (vp->v_type != VDIR)
		return (ENOTDIR);

	e2fs_count = uio->uio_resid;
	/* Make sure we don't return partial entries. */
	e2fs_count -= (uio->uio_offset + e2fs_count) & (fs->e2fs_bsize -1);
	if (e2fs_count <= 0)
		return (EINVAL);

	auio = *uio;
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	aiov.iov_len = e2fs_count;
	auio.uio_resid = e2fs_count;
	UIO_SETUP_SYSSPACE(&auio);
	dirbuf = kmem_alloc(e2fs_count, KM_SLEEP);
	dstd = kmem_zalloc(sizeof(struct dirent), KM_SLEEP);
	if (ap->a_ncookies) {
		nc = e2fs_count / _DIRENT_MINSIZE((struct dirent *)0);
		ncookies = nc;
		cookies = malloc(sizeof (off_t) * ncookies, M_TEMP, M_WAITOK);
		*ap->a_cookies = cookies;
	}
	aiov.iov_base = dirbuf;

	error = UFS_BUFRD(ap->a_vp, &auio, 0, ap->a_cred);
	if (error == 0) {
		readcnt = e2fs_count - auio.uio_resid;
		for (dp = (struct ext2fs_direct *)dirbuf;
			(char *)dp < (char *)dirbuf + readcnt; ) {
			e2d_reclen = fs2h16(dp->e2d_reclen);
			if (e2d_reclen == 0) {
				error = EIO;
				break;
			}
			ext2fs_dirconv2ffs(dp, dstd);
			if(dstd->d_reclen > uio->uio_resid) {
				break;
			}
			error = uiomove(dstd, dstd->d_reclen, uio);
			if (error != 0) {
				break;
			}
			off = off + e2d_reclen;
			if (cookies != NULL) {
				*cookies++ = off;
				if (--ncookies <= 0){
					break;  /* out of cookies */
				}
			}
			/* advance dp */
			dp = (struct ext2fs_direct *) ((char *)dp + e2d_reclen);
		}
		/* we need to correct uio_offset */
		uio->uio_offset = off;
	}
	kmem_free(dirbuf, e2fs_count);
	kmem_free(dstd, sizeof(*dstd));
	*ap->a_eofflag = ext2fs_size(VTOI(ap->a_vp)) <= uio->uio_offset;
	if (ap->a_ncookies) {
		if (error) {
			free(*ap->a_cookies, M_TEMP);
			*ap->a_ncookies = 0;
			*ap->a_cookies = NULL;
		} else
			*ap->a_ncookies = nc - ncookies;
	}
	return (error);
}
예제 #2
0
/*
 * Vnode op for reading directories.
 *
 * Convert the on-disk entries to <sys/dirent.h> entries.
 * the problem is that the conversion will blow up some entries by four bytes,
 * so it can't be done in place. This is too bad. Right now the conversion is
 * done entry by entry, the converted entry is sent via uiomove. 
 *
 * XXX allocate a buffer, convert as many entries as possible, then send
 * the whole buffer to uiomove
 */
int
ext2fs_readdir(void *v)
{
	struct vop_readdir_args *ap = v;
	struct uio *uio = ap->a_uio;
	int error;
	size_t e2fs_count, readcnt, entries;
	struct vnode *vp = ap->a_vp;
	struct m_ext2fs *fs = VTOI(vp)->i_e2fs;

	struct ext2fs_direct *dp;
	struct dirent dstd;
	struct uio auio;
	struct iovec aiov;
	caddr_t dirbuf;
	off_t off = uio->uio_offset;
	u_long *cookies = NULL;
	int nc = 0, ncookies = 0;
	int e2d_reclen;

	if (vp->v_type != VDIR)
		return (ENOTDIR);

	e2fs_count = uio->uio_resid;
	entries = (uio->uio_offset + e2fs_count) & (fs->e2fs_bsize - 1);

	/* Make sure we don't return partial entries. */
	if (e2fs_count <= entries)
		return (EINVAL);

	e2fs_count -= entries;
	auio = *uio;
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	auio.uio_segflg = UIO_SYSSPACE;
	aiov.iov_len = e2fs_count;
	auio.uio_resid = e2fs_count;
	dirbuf = malloc(e2fs_count, M_TEMP, M_WAITOK | M_ZERO);
	if (ap->a_ncookies) {
		nc = ncookies = e2fs_count / 16;
		cookies = malloc(sizeof(*cookies) * ncookies, M_TEMP, M_WAITOK);
		*ap->a_cookies = cookies;
	}
	aiov.iov_base = dirbuf;

	error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred);
	if (error == 0) {
		readcnt = e2fs_count - auio.uio_resid;
		for (dp = (struct ext2fs_direct *)dirbuf; 
			(char *)dp < (char *)dirbuf + readcnt; ) {
			e2d_reclen = fs2h16(dp->e2d_reclen);
			if (e2d_reclen == 0) {
				error = EIO;
				break;
			}
			ext2fs_dirconv2ffs(dp, &dstd);
			if(dstd.d_reclen > uio->uio_resid) {
				break;
			}
			if ((error = uiomove((caddr_t)&dstd, dstd.d_reclen, uio)) != 0) {
				break;
			}
			off = off + e2d_reclen;
			if (cookies != NULL) {
				*cookies++ = off;
				if (--ncookies <= 0){
					break;  /* out of cookies */
				}
			}
			/* advance dp */
			dp = (struct ext2fs_direct *) ((char *)dp + e2d_reclen);
		}
		/* we need to correct uio_offset */
		uio->uio_offset = off;
	}
	free(dirbuf, M_TEMP);
	*ap->a_eofflag = ext2fs_size(VTOI(ap->a_vp)) <= uio->uio_offset;
	if (ap->a_ncookies) {
		if (error) {
			free(*ap->a_cookies, M_TEMP);
			*ap->a_ncookies = 0;
			*ap->a_cookies = NULL;
		} else
			*ap->a_ncookies = nc - ncookies;
	}
	return (error);
}