Pool allocation classes

Allocation Classes add the ability to have allocation classes in a
pool that are dedicated to serving specific block categories, such
as DDT data, metadata, and small file blocks. A pool can opt-in to
this feature by adding a 'special' or 'dedup' top-level VDEV.

Reviewed by: Pavel Zakharov <[email protected]>
Reviewed-by: Richard Laager <[email protected]>
Reviewed-by: Alek Pinchuk <[email protected]>
Reviewed-by: Håkan Johansson <[email protected]>
Reviewed-by: Andreas Dilger <[email protected]>
Reviewed-by: DHE <[email protected]>
Reviewed-by: Richard Elling <[email protected]>
Reviewed-by: Gregor Kopka <[email protected]>
Reviewed-by: Kash Pande <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Matthew Ahrens <[email protected]>
Signed-off-by: Don Brady <[email protected]>
Closes #5182 

2 files changed, 67 insertions, 0 deletions

diff --git a/lib/libzfs/libzfs_dataset.c b/lib/libzfs/libzfs_dataset.c
index 85b4c5531..76a316a9c 100644
--- a/lib/libzfs/libzfs_dataset.c
+++ b/lib/libzfs/libzfs_dataset.c
@@ -1195,6 +1195,36 @@ zfs_valid_proplist(libzfs_handle_t *hdl, zfs_type_t type, nvlist_t *nvl,
 			}
 			break;
 		}
+
+		case ZFS_PROP_SPECIAL_SMALL_BLOCKS:
+			if (zpool_hdl != NULL) {
+				char state[64] = "";
+
+				/*
+				 * Issue a warning but do not fail so that
+				 * tests for setable properties succeed.
+				 */
+				if (zpool_prop_get_feature(zpool_hdl,
+				    "feature@allocation_classes", state,
+				    sizeof (state)) != 0 ||
+				    strcmp(state, ZFS_FEATURE_ACTIVE) != 0) {
+					(void) fprintf(stderr, gettext(
+					    "%s: property requires a special "
+					    "device in the pool\n"), propname);
+				}
+			}
+			if (intval != 0 &&
+			    (intval < SPA_MINBLOCKSIZE ||
+			    intval > SPA_OLD_MAXBLOCKSIZE || !ISP2(intval))) {
+				zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+				    "invalid '%s=%d' property: must be zero or "
+				    "a power of 2 from 512B to 128K"), propname,
+				    intval);
+				(void) zfs_error(hdl, EZFS_BADPROP, errbuf);
+				goto error;
+			}
+			break;
+
 		case ZFS_PROP_MLSLABEL:
 		{
 #ifdef HAVE_MLSLABEL
diff --git a/lib/libzfs/libzfs_pool.c b/lib/libzfs/libzfs_pool.c
index 0785c3170..fca1a4178 100644
--- a/lib/libzfs/libzfs_pool.c
+++ b/lib/libzfs/libzfs_pool.c
@@ -26,6 +26,7 @@
  * Copyright 2016 Igor Kozhukhov <[email protected]>
  * Copyright (c) 2018 Datto Inc.
  * Copyright (c) 2017 Open-E, Inc. All Rights Reserved.
+ * Copyright (c) 2017, Intel Corporation.
  */
 
 #include <ctype.h>
@@ -720,6 +721,7 @@ zpool_valid_proplist(libzfs_handle_t *hdl, const char *poolname,
 				goto error;
 			}
 			break;
+
 		default:
 			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
 			    "property '%s'(%d) not defined"), propname, prop);
@@ -1173,6 +1175,30 @@ zpool_get_state(zpool_handle_t *zhp)
 }
 
 /*
+ * Check if vdev list contains a special vdev
+ */
+static boolean_t
+zpool_has_special_vdev(nvlist_t *nvroot)
+{
+	nvlist_t **child;
+	uint_t children;
+
+	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN, &child,
+	    &children) == 0) {
+		for (uint_t c = 0; c < children; c++) {
+			char *bias;
+
+			if (nvlist_lookup_string(child[c],
+			    ZPOOL_CONFIG_ALLOCATION_BIAS, &bias) == 0 &&
+			    strcmp(bias, VDEV_ALLOC_BIAS_SPECIAL) == 0) {
+				return (B_TRUE);
+			}
+		}
+	}
+	return (B_FALSE);
+}
+
+/*
  * Create the named pool, using the provided vdev list.  It is assumed
  * that the consumer has already validated the contents of the nvlist, so we
  * don't have to worry about error semantics.
@@ -1220,6 +1246,17 @@ zpool_create(libzfs_handle_t *hdl, const char *pool, nvlist_t *nvroot,
 		    fsprops, zoned, NULL, NULL, B_TRUE, msg)) == NULL) {
 			goto create_failed;
 		}
+
+		if (nvlist_exists(zc_fsprops,
+		    zfs_prop_to_name(ZFS_PROP_SPECIAL_SMALL_BLOCKS)) &&
+		    !zpool_has_special_vdev(nvroot)) {
+			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+			    "%s property requires a special vdev"),
+			    zfs_prop_to_name(ZFS_PROP_SPECIAL_SMALL_BLOCKS));
+			(void) zfs_error(hdl, EZFS_BADPROP, msg);
+			goto create_failed;
+		}
+
 		if (!zc_props &&
 		    (nvlist_alloc(&zc_props, NV_UNIQUE_NAME, 0) != 0)) {
 			goto create_failed;