OpenZFS 7431 - ZFS Channel Programs

Authored by: Chris Williamson <[email protected]>
Reviewed by: Matthew Ahrens <[email protected]>
Reviewed by: George Wilson <[email protected]>
Reviewed by: John Kennedy <[email protected]>
Reviewed by: Dan Kimmel <[email protected]>
Approved by: Garrett D'Amore <[email protected]>
Ported-by: Don Brady <[email protected]>
Ported-by: John Kennedy <[email protected]>

OpenZFS-issue: https://www.illumos.org/issues/7431
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/dfc11533

Porting Notes:
* The CLI long option arguments for '-t' and '-m' don't parse on linux
* Switched from kmem_alloc to vmem_alloc in zcp_lua_alloc
* Lua implementation is built as its own module (zlua.ko)
* Lua headers consumed directly by zfs code moved to 'include/sys/lua/'
* There is no native setjmp/longjump available in stock Linux kernel.
  Brought over implementations from illumos and FreeBSD
* The get_temporary_prop() was adapted due to VFS platform differences
* Use of inline functions in lua parser to reduce stack usage per C call
* Skip some ZFS Test Suite ZCP tests on sparc64 to avoid stack overflow

1 files changed, 531 insertions, 0 deletions

diff --git a/module/zfs/zcp_iter.c b/module/zfs/zcp_iter.c
new file mode 100644
index 000000000..d37172c88
--- /dev/null
+++ b/module/zfs/zcp_iter.c
@@ -0,0 +1,531 @@
+/*
+ * CDDL HEADER START
+ *
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2016 by Delphix. All rights reserved.
+ */
+
+#include <sys/lua/lua.h>
+#include <sys/lua/lauxlib.h>
+
+#include <sys/dmu.h>
+#include <sys/dsl_prop.h>
+#include <sys/dsl_synctask.h>
+#include <sys/dsl_dataset.h>
+#include <sys/dsl_pool.h>
+#include <sys/dmu_tx.h>
+#include <sys/dmu_objset.h>
+#include <sys/zap.h>
+#include <sys/dsl_dir.h>
+#include <sys/zcp_prop.h>
+
+#include <sys/zcp.h>
+
+typedef int (zcp_list_func_t)(lua_State *);
+typedef struct zcp_list_info {
+	const char *name;
+	zcp_list_func_t *func;
+	zcp_list_func_t *gc;
+	const zcp_arg_t pargs[4];
+	const zcp_arg_t kwargs[2];
+} zcp_list_info_t;
+
+static int
+zcp_clones_iter(lua_State *state)
+{
+	int err;
+	char clonename[ZFS_MAX_DATASET_NAME_LEN];
+	uint64_t dsobj = lua_tonumber(state, lua_upvalueindex(1));
+	uint64_t cursor = lua_tonumber(state, lua_upvalueindex(2));
+	dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
+	dsl_dataset_t *ds, *clone;
+	zap_attribute_t za;
+	zap_cursor_t zc;
+
+	err = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
+	if (err == ENOENT) {
+		return (0);
+	} else if (err != 0) {
+		return (luaL_error(state,
+		    "unexpected error %d from dsl_dataset_hold_obj(dsobj)",
+		    err));
+	}
+
+	if (dsl_dataset_phys(ds)->ds_next_clones_obj == 0) {
+		dsl_dataset_rele(ds, FTAG);
+		return (0);
+	}
+
+	zap_cursor_init_serialized(&zc, dp->dp_meta_objset,
+	    dsl_dataset_phys(ds)->ds_next_clones_obj, cursor);
+	dsl_dataset_rele(ds, FTAG);
+
+	err = zap_cursor_retrieve(&zc, &za);
+	if (err != 0) {
+		zap_cursor_fini(&zc);
+		if (err != ENOENT) {
+			return (luaL_error(state,
+			    "unexpected error %d from zap_cursor_retrieve()",
+			    err));
+		}
+		return (0);
+	}
+	zap_cursor_advance(&zc);
+	cursor = zap_cursor_serialize(&zc);
+	zap_cursor_fini(&zc);
+
+	err = dsl_dataset_hold_obj(dp, za.za_first_integer, FTAG, &clone);
+	if (err != 0) {
+		return (luaL_error(state,
+		    "unexpected error %d from "
+		    "dsl_dataset_hold_obj(za_first_integer)", err));
+	}
+
+	dsl_dir_name(clone->ds_dir, clonename);
+	dsl_dataset_rele(clone, FTAG);
+
+	lua_pushnumber(state, cursor);
+	lua_replace(state, lua_upvalueindex(2));
+
+	(void) lua_pushstring(state, clonename);
+	return (1);
+}
+
+static int zcp_clones_list(lua_State *);
+static zcp_list_info_t zcp_clones_list_info = {
+	.name = "clones",
+	.func = zcp_clones_list,
+	.gc = NULL,
+	.pargs = {
+	    { .za_name = "snapshot", .za_lua_type = LUA_TSTRING},
+	    {NULL, 0}
+	},
+	.kwargs = {
+	    {NULL, 0}
+	}
+};
+
+static int
+zcp_clones_list(lua_State *state)
+{
+	const char *snapname = lua_tostring(state, 1);
+	dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
+	boolean_t issnap;
+	uint64_t dsobj, cursor;
+
+	/*
+	 * zcp_dataset_hold will either successfully return the requested
+	 * dataset or throw a lua error and longjmp out of the zfs.list.clones
+	 * call without returning.
+	 */
+	dsl_dataset_t *ds = zcp_dataset_hold(state, dp, snapname, FTAG);
+	if (ds == NULL)
+		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
+	cursor = 0;
+	issnap = ds->ds_is_snapshot;
+	dsobj = ds->ds_object;
+	dsl_dataset_rele(ds, FTAG);
+
+	if (!issnap) {
+		return (zcp_argerror(state, 1, "%s is not a snapshot",
+		    snapname));
+	}
+
+	lua_pushnumber(state, dsobj);
+	lua_pushnumber(state, cursor);
+	lua_pushcclosure(state, &zcp_clones_iter, 2);
+	return (1);
+}
+
+static int
+zcp_snapshots_iter(lua_State *state)
+{
+	int err;
+	char snapname[ZFS_MAX_DATASET_NAME_LEN];
+	uint64_t dsobj = lua_tonumber(state, lua_upvalueindex(1));
+	uint64_t cursor = lua_tonumber(state, lua_upvalueindex(2));
+	dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
+	dsl_dataset_t *ds;
+	objset_t *os;
+	char *p;
+
+	err = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
+	if (err != 0) {
+		return (luaL_error(state,
+		    "unexpected error %d from dsl_dataset_hold_obj(dsobj)",
+		    err));
+	}
+
+	dsl_dataset_name(ds, snapname);
+	VERIFY3U(sizeof (snapname), >,
+	    strlcat(snapname, "@", sizeof (snapname)));
+
+	p = strchr(snapname, '\0');
+	VERIFY0(dmu_objset_from_ds(ds, &os));
+	err = dmu_snapshot_list_next(os,
+	    sizeof (snapname) - (p - snapname), p, NULL, &cursor, NULL);
+	dsl_dataset_rele(ds, FTAG);
+
+	if (err == ENOENT) {
+		return (0);
+	} else if (err != 0) {
+		return (luaL_error(state,
+		    "unexpected error %d from dmu_snapshot_list_next()", err));
+	}
+
+	lua_pushnumber(state, cursor);
+	lua_replace(state, lua_upvalueindex(2));
+
+	(void) lua_pushstring(state, snapname);
+	return (1);
+}
+
+static int zcp_snapshots_list(lua_State *);
+static zcp_list_info_t zcp_snapshots_list_info = {
+	.name = "snapshots",
+	.func = zcp_snapshots_list,
+	.gc = NULL,
+	.pargs = {
+	    { .za_name = "filesystem | volume", .za_lua_type = LUA_TSTRING},
+	    {NULL, 0}
+	},
+	.kwargs = {
+	    {NULL, 0}
+	}
+};
+
+static int
+zcp_snapshots_list(lua_State *state)
+{
+	const char *fsname = lua_tostring(state, 1);
+	dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
+	boolean_t issnap;
+	uint64_t dsobj;
+
+	dsl_dataset_t *ds = zcp_dataset_hold(state, dp, fsname, FTAG);
+	if (ds == NULL)
+		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
+	issnap = ds->ds_is_snapshot;
+	dsobj = ds->ds_object;
+	dsl_dataset_rele(ds, FTAG);
+
+	if (issnap) {
+		return (zcp_argerror(state, 1,
+		    "argument %s cannot be a snapshot", fsname));
+	}
+
+	lua_pushnumber(state, dsobj);
+	lua_pushnumber(state, 0);
+	lua_pushcclosure(state, &zcp_snapshots_iter, 2);
+	return (1);
+}
+
+/*
+ * Note: channel programs only run in the global zone, so all datasets
+ * are visible to this zone.
+ */
+static boolean_t
+dataset_name_hidden(const char *name)
+{
+	if (strchr(name, '$') != NULL)
+		return (B_TRUE);
+	if (strchr(name, '%') != NULL)
+		return (B_TRUE);
+	return (B_FALSE);
+}
+
+static int
+zcp_children_iter(lua_State *state)
+{
+	int err;
+	char childname[ZFS_MAX_DATASET_NAME_LEN];
+	uint64_t dsobj = lua_tonumber(state, lua_upvalueindex(1));
+	uint64_t cursor = lua_tonumber(state, lua_upvalueindex(2));
+	zcp_run_info_t *ri = zcp_run_info(state);
+	dsl_pool_t *dp = ri->zri_pool;
+	dsl_dataset_t *ds;
+	objset_t *os;
+	char *p;
+
+	err = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
+	if (err != 0) {
+		return (luaL_error(state,
+		    "unexpected error %d from dsl_dataset_hold_obj(dsobj)",
+		    err));
+	}
+
+	dsl_dataset_name(ds, childname);
+	VERIFY3U(sizeof (childname), >,
+	    strlcat(childname, "/", sizeof (childname)));
+	p = strchr(childname, '\0');
+
+	VERIFY0(dmu_objset_from_ds(ds, &os));
+	do {
+		err = dmu_dir_list_next(os,
+		    sizeof (childname) - (p - childname), p, NULL, &cursor);
+	} while (err == 0 && dataset_name_hidden(childname));
+	dsl_dataset_rele(ds, FTAG);
+
+	if (err == ENOENT) {
+		return (0);
+	} else if (err != 0) {
+		return (luaL_error(state,
+		    "unexpected error %d from dmu_dir_list_next()",
+		    err));
+	}
+
+	lua_pushnumber(state, cursor);
+	lua_replace(state, lua_upvalueindex(2));
+
+	(void) lua_pushstring(state, childname);
+	return (1);
+}
+
+static int zcp_children_list(lua_State *);
+static zcp_list_info_t zcp_children_list_info = {
+	.name = "children",
+	.func = zcp_children_list,
+	.gc = NULL,
+	.pargs = {
+	    { .za_name = "filesystem | volume", .za_lua_type = LUA_TSTRING},
+	    {NULL, 0}
+	},
+	.kwargs = {
+	    {NULL, 0}
+	}
+};
+
+static int
+zcp_children_list(lua_State *state)
+{
+	const char *fsname = lua_tostring(state, 1);
+	dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
+	boolean_t issnap;
+	uint64_t dsobj;
+
+	dsl_dataset_t *ds = zcp_dataset_hold(state, dp, fsname, FTAG);
+	if (ds == NULL)
+		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
+
+	issnap = ds->ds_is_snapshot;
+	dsobj = ds->ds_object;
+	dsl_dataset_rele(ds, FTAG);
+
+	if (issnap) {
+		return (zcp_argerror(state, 1,
+		    "argument %s cannot be a snapshot", fsname));
+	}
+
+	lua_pushnumber(state, dsobj);
+	lua_pushnumber(state, 0);
+	lua_pushcclosure(state, &zcp_children_iter, 2);
+	return (1);
+}
+
+static int
+zcp_props_list_gc(lua_State *state)
+{
+	nvlist_t **props = lua_touserdata(state, 1);
+	if (*props != NULL)
+		fnvlist_free(*props);
+	return (0);
+}
+
+static int
+zcp_props_iter(lua_State *state)
+{
+	char *source, *val;
+	nvlist_t *nvprop;
+	nvlist_t **props = lua_touserdata(state, lua_upvalueindex(1));
+	nvpair_t *pair = lua_touserdata(state, lua_upvalueindex(2));
+
+	do {
+		pair = nvlist_next_nvpair(*props, pair);
+		if (pair == NULL) {
+			fnvlist_free(*props);
+			*props = NULL;
+			return (0);
+		}
+	} while (!zfs_prop_user(nvpair_name(pair)));
+
+	lua_pushlightuserdata(state, pair);
+	lua_replace(state, lua_upvalueindex(2));
+
+	nvprop = fnvpair_value_nvlist(pair);
+	val = fnvlist_lookup_string(nvprop, ZPROP_VALUE);
+	source = fnvlist_lookup_string(nvprop, ZPROP_SOURCE);
+
+	(void) lua_pushstring(state, nvpair_name(pair));
+	(void) lua_pushstring(state, val);
+	(void) lua_pushstring(state, source);
+	return (3);
+}
+
+static int zcp_props_list(lua_State *);
+static zcp_list_info_t zcp_props_list_info = {
+	.name = "properties",
+	.func = zcp_props_list,
+	.gc = zcp_props_list_gc,
+	.pargs = {
+	    { .za_name = "filesystem | snapshot | volume",
+	    .za_lua_type = LUA_TSTRING},
+	    {NULL, 0}
+	},
+	.kwargs = {
+	    {NULL, 0}
+	}
+};
+
+static int
+zcp_props_list(lua_State *state)
+{
+	const char *dsname = lua_tostring(state, 1);
+	dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
+	objset_t *os;
+	nvlist_t **props = lua_newuserdata(state, sizeof (nvlist_t *));
+
+	dsl_dataset_t *ds = zcp_dataset_hold(state, dp, dsname, FTAG);
+	if (ds == NULL)
+		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
+	VERIFY0(dmu_objset_from_ds(ds, &os));
+	VERIFY0(dsl_prop_get_all(os, props));
+	dsl_dataset_rele(ds, FTAG);
+
+	/*
+	 * Set the metatable for the properties list to free it on completion.
+	 */
+	luaL_getmetatable(state, zcp_props_list_info.name);
+	(void) lua_setmetatable(state, -2);
+
+	lua_pushlightuserdata(state, NULL);
+	lua_pushcclosure(state, &zcp_props_iter, 2);
+	return (1);
+}
+
+
+/*
+ * Populate nv with all valid properties and their values for the given
+ * dataset.
+ */
+static void
+zcp_dataset_props(dsl_dataset_t *ds, nvlist_t *nv)
+{
+	for (int prop = ZFS_PROP_TYPE; prop < ZFS_NUM_PROPS; prop++) {
+		/* Do not display hidden props */
+		if (!zfs_prop_visible(prop))
+			continue;
+		/* Do not display props not valid for this dataset */
+		if (!prop_valid_for_ds(ds, prop))
+			continue;
+		fnvlist_add_boolean(nv, zfs_prop_to_name(prop));
+	}
+}
+
+static int zcp_system_props_list(lua_State *);
+static zcp_list_info_t zcp_system_props_list_info = {
+	.name = "system_properties",
+	.func = zcp_system_props_list,
+	.pargs = {
+	    { .za_name = "dataset", .za_lua_type = LUA_TSTRING},
+	    {NULL, 0}
+	},
+	.kwargs = {
+	    {NULL, 0}
+	}
+};
+
+/*
+ * Get a list of all visble properties and their values for a given dataset.
+ * Returned on the stack as a Lua table.
+ */
+static int
+zcp_system_props_list(lua_State *state)
+{
+	int error;
+	char errbuf[128];
+	const char *dataset_name;
+	dsl_pool_t *dp = zcp_run_info(state)->zri_pool;
+	zcp_list_info_t *libinfo = &zcp_system_props_list_info;
+	zcp_parse_args(state, libinfo->name, libinfo->pargs, libinfo->kwargs);
+	dataset_name = lua_tostring(state, 1);
+	nvlist_t *nv = fnvlist_alloc();
+
+	dsl_dataset_t *ds = zcp_dataset_hold(state, dp, dataset_name, FTAG);
+	if (ds == NULL)
+		return (1); /* not reached; zcp_dataset_hold() longjmp'd */
+
+	/* Get the names of all valid properties for this dataset */
+	zcp_dataset_props(ds, nv);
+	dsl_dataset_rele(ds, FTAG);
+
+	/* push list as lua table */
+	error = zcp_nvlist_to_lua(state, nv, errbuf, sizeof (errbuf));
+	nvlist_free(nv);
+	if (error != 0) {
+		return (luaL_error(state,
+		    "Error returning nvlist: %s", errbuf));
+	}
+	return (1);
+}
+
+static int
+zcp_list_func(lua_State *state)
+{
+	zcp_list_info_t *info = lua_touserdata(state, lua_upvalueindex(1));
+
+	zcp_parse_args(state, info->name, info->pargs, info->kwargs);
+
+	return (info->func(state));
+}
+
+int
+zcp_load_list_lib(lua_State *state)
+{
+	int i;
+	zcp_list_info_t *zcp_list_funcs[] = {
+		&zcp_children_list_info,
+		&zcp_snapshots_list_info,
+		&zcp_props_list_info,
+		&zcp_clones_list_info,
+		&zcp_system_props_list_info,
+		NULL
+	};
+
+	lua_newtable(state);
+
+	for (i = 0; zcp_list_funcs[i] != NULL; i++) {
+		zcp_list_info_t *info = zcp_list_funcs[i];
+
+		if (info->gc != NULL) {
+			/*
+			 * If the function requires garbage collection, create
+			 * a metatable with its name and register the __gc
+			 * function.
+			 */
+			(void) luaL_newmetatable(state, info->name);
+			(void) lua_pushstring(state, "__gc");
+			lua_pushcfunction(state, info->gc);
+			lua_settable(state, -3);
+			lua_pop(state, 1);
+		}
+
+		lua_pushlightuserdata(state, info);
+		lua_pushcclosure(state, &zcp_list_func, 1);
+		lua_setfield(state, -2, info->name);
+		info++;
+	}
+
+	return (1);
+}