From: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Date: Mon, 20 Feb 2023 03:41:53 +0000 (-0500)
Subject: btrfs: add flags to give an hint to the chunk allocator (rebased on v6.2)
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e7c38acba9db78eb5e5c57e8b7cbdf1d0baaaa80;p=linux

btrfs: add flags to give an hint to the chunk allocator (rebased on v6.2)

Add the following flags to give an hint about which chunk should be
allocated in which a disk.
The following flags are created:

- BTRFS_DEV_ALLOCATION_PREFERRED_DATA
  preferred data chunk, but metadata chunk allowed
- BTRFS_DEV_ALLOCATION_PREFERRED_METADATA
  preferred metadata chunk, but data chunk allowed
- BTRFS_DEV_ALLOCATION_METADATA_ONLY
  only metadata chunk allowed
- BTRFS_DEV_ALLOCATION_DATA_ONLY
  only data chunk allowed

Signed-off-by: Goffredo Baroncelli <kreijack@inwid.it>
---

diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index fc29d273845d8..71c6135dc7cfb 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -578,6 +578,20 @@ struct btrfs_node {
 	struct btrfs_key_ptr ptrs[];
 } __attribute__ ((__packed__));
 
+/* dev_item.type */
+
+/* btrfs chunk allocation hints */
+#define BTRFS_DEV_ALLOCATION_MASK_BIT_COUNT	3
+/* preferred data chunk, but metadata chunk allowed */
+#define BTRFS_DEV_ALLOCATION_PREFERRED_DATA	(0ULL)
+/* preferred metadata chunk, but data chunk allowed */
+#define BTRFS_DEV_ALLOCATION_PREFERRED_METADATA	(1ULL)
+/* only metadata chunk are allowed */
+#define BTRFS_DEV_ALLOCATION_METADATA_ONLY	(2ULL)
+/* only data chunk allowed */
+#define BTRFS_DEV_ALLOCATION_DATA_ONLY		(3ULL)
+/* 5..7 are unused values */
+
 struct btrfs_dev_item {
 	/* the internal btrfs device id */
 	__le64 devid;