mirror_zfs/module/zfs/zfs_znode.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or https://opensource.org/licenses/CDDL-1.0.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
 * Copyright (c) 2014 Integros [integros.com]
 */

/* Portions Copyright 2007 Jeremy Teo */
/* Portions Copyright 2011 Martin Matuska <mm@FreeBSD.org> */

#include <sys/dmu.h>
#include <sys/dmu_objset.h>
#include <sys/dmu_tx.h>
#include <sys/zfs_refcount.h>
#include <sys/stat.h>
#include <sys/zap.h>
#include <sys/zfs_znode.h>
#include <sys/sa.h>
#include <sys/zfs_sa.h>
#include <sys/zfs_stat.h>

#include "zfs_prop.h"
#include "zfs_comutil.h"

static int
zfs_sa_setup(objset_t *osp, sa_attr_type_t **sa_table)
{
	uint64_t sa_obj = 0;
	int error;

	error = zap_lookup(osp, MASTER_NODE_OBJ, ZFS_SA_ATTRS, 8, 1, &sa_obj);
	if (error != 0 && error != ENOENT)
		return (error);

	error = sa_setup(osp, sa_obj, zfs_attr_table, ZPL_END, sa_table);
	return (error);
}

static int
zfs_grab_sa_handle(objset_t *osp, uint64_t obj, sa_handle_t **hdlp,
    dmu_buf_t **db, const void *tag)
{
	dmu_object_info_t doi;
	int error;

	if ((error = sa_buf_hold(osp, obj, tag, db)) != 0)
		return (error);

	dmu_object_info_from_db(*db, &doi);
	if ((doi.doi_bonus_type != DMU_OT_SA &&
	    doi.doi_bonus_type != DMU_OT_ZNODE) ||
	    (doi.doi_bonus_type == DMU_OT_ZNODE &&
	    doi.doi_bonus_size < sizeof (znode_phys_t))) {
		sa_buf_rele(*db, tag);
		return (SET_ERROR(ENOTSUP));
	}

	error = sa_handle_get(osp, obj, NULL, SA_HDL_PRIVATE, hdlp);
	if (error != 0) {
		sa_buf_rele(*db, tag);
		return (error);
	}

	return (0);
}

static void
zfs_release_sa_handle(sa_handle_t *hdl, dmu_buf_t *db, const void *tag)
{
	sa_handle_destroy(hdl);
	sa_buf_rele(db, tag);
}

/*
 * Given an object number, return its parent object number and whether
 * or not the object is an extended attribute directory.
 */
int
zfs_obj_to_pobj(objset_t *osp, sa_handle_t *hdl, sa_attr_type_t *sa_table,
    uint64_t *pobjp, int *is_xattrdir)
{
	uint64_t parent;
	uint64_t pflags;
	uint64_t mode;
	uint64_t parent_mode;
	sa_bulk_attr_t bulk[3];
	sa_handle_t *sa_hdl;
	dmu_buf_t *sa_db;
	int count = 0;
	int error;

	SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_PARENT], NULL,
	    &parent, sizeof (parent));
	SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_FLAGS], NULL,
	    &pflags, sizeof (pflags));
	SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_MODE], NULL,
	    &mode, sizeof (mode));

	if ((error = sa_bulk_lookup(hdl, bulk, count)) != 0)
		return (error);

	/*
	 * When a link is removed its parent pointer is not changed and will
	 * be invalid.  There are two cases where a link is removed but the
	 * file stays around, when it goes to the delete queue and when there
	 * are additional links.
	 */
	error = zfs_grab_sa_handle(osp, parent, &sa_hdl, &sa_db, FTAG);
	if (error != 0)
		return (error);

	error = sa_lookup(sa_hdl, ZPL_MODE, &parent_mode, sizeof (parent_mode));
	zfs_release_sa_handle(sa_hdl, sa_db, FTAG);
	if (error != 0)
		return (error);

	*is_xattrdir = ((pflags & ZFS_XATTR) != 0) && S_ISDIR(mode);

	/*
	 * Extended attributes can be applied to files, directories, etc.
	 * Otherwise the parent must be a directory.
	 */
	if (!*is_xattrdir && !S_ISDIR(parent_mode))
		return (SET_ERROR(EINVAL));

	*pobjp = parent;

	return (0);
}

/*
 * Given an object number, return some zpl level statistics
 */
static int
zfs_obj_to_stats_impl(sa_handle_t *hdl, sa_attr_type_t *sa_table,
    zfs_stat_t *sb)
{
	sa_bulk_attr_t bulk[4];
	int count = 0;

	SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_MODE], NULL,
	    &sb->zs_mode, sizeof (sb->zs_mode));
	SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_GEN], NULL,
	    &sb->zs_gen, sizeof (sb->zs_gen));
	SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_LINKS], NULL,
	    &sb->zs_links, sizeof (sb->zs_links));
	SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_CTIME], NULL,
	    &sb->zs_ctime, sizeof (sb->zs_ctime));

	return (sa_bulk_lookup(hdl, bulk, count));
}

static int
zfs_obj_to_path_impl(objset_t *osp, uint64_t obj, sa_handle_t *hdl,
    sa_attr_type_t *sa_table, char *buf, int len)
{
	sa_handle_t *sa_hdl;
	sa_handle_t *prevhdl = NULL;
	dmu_buf_t *prevdb = NULL;
	dmu_buf_t *sa_db = NULL;
	char *path = buf + len - 1;
	int error;

	*path = '\0';
	sa_hdl = hdl;

	uint64_t deleteq_obj;
	VERIFY0(zap_lookup(osp, MASTER_NODE_OBJ,
	    ZFS_UNLINKED_SET, sizeof (uint64_t), 1, &deleteq_obj));
	error = zap_lookup_int(osp, deleteq_obj, obj);
	if (error == 0) {
		return (ESTALE);
	} else if (error != ENOENT) {
		return (error);
	}

	for (;;) {
		uint64_t pobj = 0;
		char component[MAXNAMELEN + 2];
		size_t complen;
		int is_xattrdir = 0;

		if (prevdb) {
			ASSERT3P(prevhdl, !=, NULL);
			zfs_release_sa_handle(prevhdl, prevdb, FTAG);
		}

		if ((error = zfs_obj_to_pobj(osp, sa_hdl, sa_table, &pobj,
		    &is_xattrdir)) != 0)
			break;

		if (pobj == obj) {
			if (path[0] != '/')
				*--path = '/';
			break;
		}

		component[0] = '/';
		if (is_xattrdir) {
			strcpy(component + 1, "<xattrdir>");
		} else {
			error = zap_value_search(osp, pobj, obj,
			    ZFS_DIRENT_OBJ(-1ULL), component + 1);
			if (error != 0)
				break;
		}

		complen = strlen(component);
		path -= complen;
		ASSERT3P(path, >=, buf);
		memcpy(path, component, complen);
		obj = pobj;

		if (sa_hdl != hdl) {
			prevhdl = sa_hdl;
			prevdb = sa_db;
		}
		error = zfs_grab_sa_handle(osp, obj, &sa_hdl, &sa_db, FTAG);
		if (error != 0) {
			sa_hdl = prevhdl;
			sa_db = prevdb;
			break;
		}
	}

	if (sa_hdl != NULL && sa_hdl != hdl) {
		ASSERT3P(sa_db, !=, NULL);
		zfs_release_sa_handle(sa_hdl, sa_db, FTAG);
	}

	if (error == 0)
		(void) memmove(buf, path, buf + len - path);

	return (error);
}

int
zfs_obj_to_path(objset_t *osp, uint64_t obj, char *buf, int len)
{
	sa_attr_type_t *sa_table;
	sa_handle_t *hdl;
	dmu_buf_t *db;
	int error;

	error = zfs_sa_setup(osp, &sa_table);
	if (error != 0)
		return (error);

	error = zfs_grab_sa_handle(osp, obj, &hdl, &db, FTAG);
	if (error != 0)
		return (error);

	error = zfs_obj_to_path_impl(osp, obj, hdl, sa_table, buf, len);

	zfs_release_sa_handle(hdl, db, FTAG);
	return (error);
}

int
zfs_obj_to_stats(objset_t *osp, uint64_t obj, zfs_stat_t *sb,
    char *buf, int len)
{
	char *path = buf + len - 1;
	sa_attr_type_t *sa_table;
	sa_handle_t *hdl;
	dmu_buf_t *db;
	int error;

	*path = '\0';

	error = zfs_sa_setup(osp, &sa_table);
	if (error != 0)
		return (error);

	error = zfs_grab_sa_handle(osp, obj, &hdl, &db, FTAG);
	if (error != 0)
		return (error);

	error = zfs_obj_to_stats_impl(hdl, sa_table, sb);
	if (error != 0) {
		zfs_release_sa_handle(hdl, db, FTAG);
		return (error);
	}

	error = zfs_obj_to_path_impl(osp, obj, hdl, sa_table, buf, len);

	zfs_release_sa_handle(hdl, db, FTAG);
	return (error);
}

/*
 * Read a property stored within the master node.
 */
int
zfs_get_zplprop(objset_t *os, zfs_prop_t prop, uint64_t *value)
{
	uint64_t *cached_copy = NULL;

	/*
	 * Figure out where in the objset_t the cached copy would live, if it
	 * is available for the requested property.
	 */
	if (os != NULL) {
		switch (prop) {
		case ZFS_PROP_VERSION:
			cached_copy = &os->os_version;
			break;
		case ZFS_PROP_NORMALIZE:
			cached_copy = &os->os_normalization;
			break;
		case ZFS_PROP_UTF8ONLY:
			cached_copy = &os->os_utf8only;
			break;
		case ZFS_PROP_CASE:
			cached_copy = &os->os_casesensitivity;
			break;
		default:
			break;
		}
	}
	if (cached_copy != NULL && *cached_copy != OBJSET_PROP_UNINITIALIZED) {
		*value = *cached_copy;
		return (0);
	}

	/*
	 * If the property wasn't cached, look up the file system's value for
	 * the property. For the version property, we look up a slightly
	 * different string.
	 */
	const char *pname;
	int error = ENOENT;
	if (prop == ZFS_PROP_VERSION)
		pname = ZPL_VERSION_STR;
	else
		pname = zfs_prop_to_name(prop);

	if (os != NULL) {
		ASSERT3U(os->os_phys->os_type, ==, DMU_OST_ZFS);
		error = zap_lookup(os, MASTER_NODE_OBJ, pname, 8, 1, value);
	}

	if (error == ENOENT) {
		/* No value set, use the default value */
		switch (prop) {
		case ZFS_PROP_VERSION:
			*value = ZPL_VERSION;
			break;
		case ZFS_PROP_NORMALIZE:
		case ZFS_PROP_UTF8ONLY:
			*value = 0;
			break;
		case ZFS_PROP_CASE:
			*value = ZFS_CASE_SENSITIVE;
			break;
		case ZFS_PROP_ACLTYPE:
#ifdef __FreeBSD__
			*value = ZFS_ACLTYPE_NFSV4;
#else
			*value = ZFS_ACLTYPE_OFF;
#endif
			break;
		default:
			return (error);
		}
		error = 0;
	}

	/*
	 * If one of the methods for getting the property value above worked,
	 * copy it into the objset_t's cache.
	 */
	if (error == 0 && cached_copy != NULL) {
		*cached_copy = *value;
	}

	return (error);
}