C++ (Cpp) dmu_read_uio Examples

Example #1

File: zvol.c Project: koplover/zfs

static int
zvol_read(struct bio *bio)
{
	zvol_state_t *zv = bio->bi_bdev->bd_disk->private_data;
	uint64_t offset = BIO_BI_SECTOR(bio) << 9;
	uint64_t size = BIO_BI_SIZE(bio);
	int error;
	rl_t *rl;
	uio_t uio;

	if (size == 0)
		return (0);

	uio.uio_bvec = &bio->bi_io_vec[BIO_BI_IDX(bio)];
	uio.uio_skip = BIO_BI_SKIP(bio);
	uio.uio_resid = size;
	uio.uio_iovcnt = bio->bi_vcnt - BIO_BI_IDX(bio);
	uio.uio_loffset = offset;
	uio.uio_limit = MAXOFFSET_T;
	uio.uio_segflg = UIO_BVEC;

	rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_READER);

	error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, &uio, size);

	zfs_range_unlock(rl);

	/* convert checksum errors into IO errors */
	if (error == ECKSUM)
		error = SET_ERROR(EIO);

	return (error);
}

Example #2

File: zfs_vnops_osx_lib.c Project: RJVB/zfs

void getfinderinfo(znode_t *zp, cred_t *cr, finderinfo_t *fip)
{
	vnode_t	*xdvp = NULLVP;
	vnode_t	*xvp = NULLVP;
	struct uio		*auio = NULL;
	struct componentname  cn;
	int		error;
    uint64_t xattr = 0;

    if (sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zp->z_zfsvfs),
                   &xattr, sizeof(xattr)) ||
        (xattr == 0)) {
        goto nodata;
    }

	auio = uio_create(1, 0, UIO_SYSSPACE, UIO_READ);
	if (auio == NULL) {
		goto nodata;
	}
	uio_addiov(auio, CAST_USER_ADDR_T(fip), sizeof (finderinfo_t));

	/*
	 * Grab the hidden attribute directory vnode.
	 *
	 * XXX - switch to embedded Finder Info when it becomes available
	 */
	if ((error = zfs_get_xattrdir(zp, &xdvp, cr, 0))) {
		goto out;
	}

	bzero(&cn, sizeof (cn));
	cn.cn_nameiop = LOOKUP;
	cn.cn_flags = ISLASTCN;
	cn.cn_nameptr = XATTR_FINDERINFO_NAME;
	cn.cn_namelen = strlen(cn.cn_nameptr);

	if ((error = zfs_dirlook(VTOZ(xdvp), cn.cn_nameptr, &xvp, 0, NULL, &cn))) {
		goto out;
	}
	error = dmu_read_uio(zp->z_zfsvfs->z_os, VTOZ(xvp)->z_id, auio,
	                     sizeof (finderinfo_t));
out:
	if (auio)
		uio_free(auio);
	if (xvp)
		vnode_put(xvp);
	if (xdvp)
		vnode_put(xdvp);
	if (error == 0)
		return;
nodata:
	bzero(fip, sizeof (finderinfo_t));
}