[RFC PATCH 01/10] btrfs: add definitions and constants for remap-tree

[Mark Harmstone <maharmstone@fb.com>]

Add an incompat flag for the new remap-tree feature, and the constants
and definitions needed to support it.

Signed-off-by: Mark Harmstone <maharmstone@fb.com>
---
 fs/btrfs/accessors.h            |  3 +++
 fs/btrfs/sysfs.c                |  2 ++
 fs/btrfs/tree-checker.c         |  6 ++++--
 fs/btrfs/volumes.c              |  1 +
 include/uapi/linux/btrfs.h      |  1 +
 include/uapi/linux/btrfs_tree.h | 12 ++++++++++++
 6 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/accessors.h b/fs/btrfs/accessors.h
index 15ea6348800b..5f5eda8d6f9e 100644
--- a/fs/btrfs/accessors.h
+++ b/fs/btrfs/accessors.h
@@ -1046,6 +1046,9 @@ BTRFS_SETGET_STACK_FUNCS(stack_verity_descriptor_encryption,
 BTRFS_SETGET_STACK_FUNCS(stack_verity_descriptor_size,
 			 struct btrfs_verity_descriptor_item, size, 64);
 
+BTRFS_SETGET_FUNCS(remap_address, struct btrfs_remap, address, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_remap_address, struct btrfs_remap, address, 64);
+
 /* Cast into the data area of the leaf. */
 #define btrfs_item_ptr(leaf, slot, type)				\
 	((type *)(btrfs_item_nr_offset(leaf, 0) + btrfs_item_offset(leaf, slot)))
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 5d93d9dd2c12..3165194f62ab 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -292,6 +292,7 @@ BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
 BTRFS_FEAT_ATTR_INCOMPAT(simple_quota, SIMPLE_QUOTA);
+BTRFS_FEAT_ATTR_INCOMPAT(remap_tree, REMAP_TREE);
 #ifdef CONFIG_BLK_DEV_ZONED
 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
 #endif
@@ -326,6 +327,7 @@ static struct attribute *btrfs_supported_feature_attrs[] = {
 	BTRFS_FEAT_ATTR_PTR(raid1c34),
 	BTRFS_FEAT_ATTR_PTR(block_group_tree),
 	BTRFS_FEAT_ATTR_PTR(simple_quota),
+	BTRFS_FEAT_ATTR_PTR(remap_tree),
 #ifdef CONFIG_BLK_DEV_ZONED
 	BTRFS_FEAT_ATTR_PTR(zoned),
 #endif
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index 8f4703b488b7..a83fb828723a 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -913,11 +913,13 @@ int btrfs_check_chunk_valid(const struct btrfs_fs_info *fs_info,
 		return -EUCLEAN;
 	}
 	if (unlikely(type & ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
-			      BTRFS_BLOCK_GROUP_PROFILE_MASK))) {
+			      BTRFS_BLOCK_GROUP_PROFILE_MASK |
+			      BTRFS_BLOCK_GROUP_REMAPPED))) {
 		chunk_err(fs_info, leaf, chunk, logical,
 			  "unrecognized chunk type: 0x%llx",
 			  ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
-			    BTRFS_BLOCK_GROUP_PROFILE_MASK) & type);
+			    BTRFS_BLOCK_GROUP_PROFILE_MASK |
+			    BTRFS_BLOCK_GROUP_REMAPPED) & type);
 		return -EUCLEAN;
 	}
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 89835071cfea..e041964d03c8 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -234,6 +234,7 @@ void btrfs_describe_block_groups(u64 bg_flags, char *buf, u32 size_buf)
 	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_DATA, "data");
 	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_SYSTEM, "system");
 	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_METADATA, "metadata");
+	DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_REMAPPED, "remapped");
 
 	DESCRIBE_FLAG(BTRFS_AVAIL_ALLOC_BIT_SINGLE, "single");
 	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index dd02160015b2..d857cdc7694a 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -336,6 +336,7 @@ struct btrfs_ioctl_fs_info_args {
 #define BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2	(1ULL << 13)
 #define BTRFS_FEATURE_INCOMPAT_RAID_STRIPE_TREE	(1ULL << 14)
 #define BTRFS_FEATURE_INCOMPAT_SIMPLE_QUOTA	(1ULL << 16)
+#define BTRFS_FEATURE_INCOMPAT_REMAP_TREE	(1ULL << 17)
 
 struct btrfs_ioctl_feature_flags {
 	__u64 compat_flags;
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index fc29d273845d..4439d77a7252 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -76,6 +76,9 @@
 /* Tracks RAID stripes in block groups. */
 #define BTRFS_RAID_STRIPE_TREE_OBJECTID 12ULL
 
+/* Holds details of remapped addresses after relocation. */
+#define BTRFS_REMAP_TREE_OBJECTID 13ULL
+
 /* device stats in the device tree */
 #define BTRFS_DEV_STATS_OBJECTID 0ULL
 
@@ -282,6 +285,10 @@
 
 #define BTRFS_RAID_STRIPE_KEY	230
 
+#define BTRFS_IDENTITY_REMAP_KEY 	234
+#define BTRFS_REMAP_KEY		 	235
+#define BTRFS_REMAP_BACKREF_KEY	 	236
+
 /*
  * Records the overall state of the qgroups.
  * There's only one instance of this key present,
@@ -1161,6 +1168,7 @@ struct btrfs_dev_replace_item {
 #define BTRFS_BLOCK_GROUP_RAID6         (1ULL << 8)
 #define BTRFS_BLOCK_GROUP_RAID1C3       (1ULL << 9)
 #define BTRFS_BLOCK_GROUP_RAID1C4       (1ULL << 10)
+#define BTRFS_BLOCK_GROUP_REMAPPED      (1ULL << 11)
 #define BTRFS_BLOCK_GROUP_RESERVED	(BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
 					 BTRFS_SPACE_INFO_GLOBAL_RSV)
 
@@ -1323,4 +1331,8 @@ struct btrfs_verity_descriptor_item {
 	__u8 encryption;
 } __attribute__ ((__packed__));
 
+struct btrfs_remap {
+	__le64 address;
+} __attribute__ ((__packed__));
+
 #endif /* _BTRFS_CTREE_H_ */
-- 
2.49.0