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 

1 files changed, 11 insertions, 0 deletions

diff --git a/include/sys/fs/zfs.h b/include/sys/fs/zfs.h
index c8c7cebae..6bbf84346 100644
--- a/include/sys/fs/zfs.h
+++ b/include/sys/fs/zfs.h
@@ -26,6 +26,7 @@
  * Copyright (c) 2013, 2017 Joyent, Inc. All rights reserved.
  * Copyright (c) 2014 Integros [integros.com]
  * Copyright (c) 2017 Datto Inc.
+ * Copyright (c) 2017, Intel Corporation.
  */
 
 /* Portions Copyright 2010 Robert Milkowski */
@@ -181,6 +182,7 @@ typedef enum {
 	ZFS_PROP_KEY_GUID,
 	ZFS_PROP_KEYSTATUS,
 	ZFS_PROP_REMAPTXG,		/* not exposed to the user */
+	ZFS_PROP_SPECIAL_SMALL_BLOCKS,
 	ZFS_NUM_PROPS
 } zfs_prop_t;
 
@@ -713,6 +715,7 @@ typedef struct zpool_load_policy {
 #define	ZPOOL_CONFIG_MMP_TXG		"mmp_txg"	/* not stored on disk */
 #define	ZPOOL_CONFIG_MMP_HOSTNAME	"mmp_hostname"	/* not stored on disk */
 #define	ZPOOL_CONFIG_MMP_HOSTID		"mmp_hostid"	/* not stored on disk */
+#define	ZPOOL_CONFIG_ALLOCATION_BIAS	"alloc_bias"	/* not stored on disk */
 
 /*
  * The persistent vdev state is stored as separate values rather than a single
@@ -759,6 +762,14 @@ typedef struct zpool_load_policy {
 #define	VDEV_TOP_ZAP_POOL_CHECKPOINT_SM \
 	"com.delphix:pool_checkpoint_sm"
 
+#define	VDEV_TOP_ZAP_ALLOCATION_BIAS \
+	"org.zfsonlinux:allocation_bias"
+
+/* vdev metaslab allocation bias */
+#define	VDEV_ALLOC_BIAS_LOG		"log"
+#define	VDEV_ALLOC_BIAS_SPECIAL		"special"
+#define	VDEV_ALLOC_BIAS_DEDUP		"dedup"
+
 /*
  * This is needed in userland to report the minimum necessary device size.
  */