[RFC ONLY 1/8] btrfs: add raid stripe tree definitions

Johannes Thumshirn
2022-05-16T14:31:55Z

Add definitions for the raid-stripe-tree. This tree will hold informatioin
about the on-disk layout of the stripes in a RAID set.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
fs/btrfs/ctree.h | 28 ++++++++++++++++++++++++++++
include/uapi/linux/btrfs_tree.h | 17 +++++++++++++++++
2 files changed, 45 insertions(+)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 7328fb17b7f5..20aa2ebac7cd 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1878,6 +1878,34 @@ BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_timespec, nsec, 32);
BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec, sec, 64);
BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec, nsec, 32);

+BTRFS_SETGET_FUNCS(stripe_extent_devid, struct btrfs_stripe_extent, devid, 64);
+BTRFS_SETGET_FUNCS(stripe_extent_offset, struct btrfs_stripe_extent, offset, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_stripe_extent_devid, struct btrfs_stripe_extent, devid, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_stripe_extent_offset, struct btrfs_stripe_extent, offset, 64);
+
+static inline struct btrfs_stripe_extent *btrfs_stripe_extent_nr(
+ struct btrfs_dp_stripe *dps, int nr)
+{
+ unsigned long offset = (unsigned long)dps;
+ offset += offsetof(struct btrfs_dp_stripe, extents);
+ offset += nr * sizeof(struct btrfs_stripe_extent);
+ return (struct btrfs_stripe_extent *)offset;
+}
+
+static inline u64 btrfs_stripe_extent_devid_nr(const struct extent_buffer *eb,
+ struct btrfs_dp_stripe *dps,
+ int nr)
+{
+ return btrfs_stripe_extent_devid(eb, btrfs_stripe_extent_nr(dps, nr));
+}
+
+static inline u64 btrfs_stripe_extent_offset_nr(const struct extent_buffer *eb,
+ struct btrfs_dp_stripe *dps,
+ int nr)
+{
+ return btrfs_stripe_extent_offset(eb, btrfs_stripe_extent_nr(dps, nr));
+}
+
/* struct btrfs_dev_extent */
BTRFS_SETGET_FUNCS(dev_extent_chunk_tree, struct btrfs_dev_extent,
chunk_tree, 64);
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index b069752a8ecf..a2d28d83cc96 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -56,6 +56,9 @@
/* Holds the block group items for extent tree v2. */
#define BTRFS_BLOCK_GROUP_TREE_OBJECTID 11ULL

+/* tracks RAID stripes in block groups. */
+#define BTRFS_RAID_STRIPE_TREE_OBJECTID 12ULL
+
/* device stats in the device tree */
#define BTRFS_DEV_STATS_OBJECTID 0ULL

@@ -264,6 +267,8 @@
*/
#define BTRFS_QGROUP_RELATION_KEY 246

+#define BTRFS_RAID_STRIPE_KEY 247
+
/*
* Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY.
*/
@@ -488,6 +493,18 @@ struct btrfs_free_space_header {
__le64 num_bitmaps;
} __attribute__ ((__packed__));

+struct btrfs_stripe_extent {
+ /* btrfs device-id this raid extent lives on */
+ __le64 devid;
+ /* offset from the devextent start */
+ __le64 offset;
+} __attribute__ ((__packed__));
+
+struct btrfs_dp_stripe {
+ /* array of stripe extents this stripe is comprised of */
+ struct btrfs_stripe_extent extents;
+} __attribute__ ((__packed__));
+
#define BTRFS_HEADER_FLAG_WRITTEN (1ULL << 0)
#define BTRFS_HEADER_FLAG_RELOC (1ULL << 1)

--
2.35.1