From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/fs/btrfs/qgroup.h | 147 +++++++++++++++++++++++++++++++++++++++++++------
1 files changed, 129 insertions(+), 18 deletions(-)
diff --git a/kernel/fs/btrfs/qgroup.h b/kernel/fs/btrfs/qgroup.h
index 4bbcc1e..7283e4f 100644
--- a/kernel/fs/btrfs/qgroup.h
+++ b/kernel/fs/btrfs/qgroup.h
@@ -6,6 +6,9 @@
#ifndef BTRFS_QGROUP_H
#define BTRFS_QGROUP_H
+#include <linux/spinlock.h>
+#include <linux/rbtree.h>
+#include <linux/kobject.h>
#include "ulist.h"
#include "delayed-ref.h"
@@ -38,6 +41,66 @@
*/
/*
+ * Special performance optimization for balance.
+ *
+ * For balance, we need to swap subtree of subvolume and reloc trees.
+ * In theory, we need to trace all subtree blocks of both subvolume and reloc
+ * trees, since their owner has changed during such swap.
+ *
+ * However since balance has ensured that both subtrees are containing the
+ * same contents and have the same tree structures, such swap won't cause
+ * qgroup number change.
+ *
+ * But there is a race window between subtree swap and transaction commit,
+ * during that window, if we increase/decrease tree level or merge/split tree
+ * blocks, we still need to trace the original subtrees.
+ *
+ * So for balance, we use a delayed subtree tracing, whose workflow is:
+ *
+ * 1) Record the subtree root block get swapped.
+ *
+ * During subtree swap:
+ * O = Old tree blocks
+ * N = New tree blocks
+ * reloc tree subvolume tree X
+ * Root Root
+ * / \ / \
+ * NA OB OA OB
+ * / | | \ / | | \
+ * NC ND OE OF OC OD OE OF
+ *
+ * In this case, NA and OA are going to be swapped, record (NA, OA) into
+ * subvolume tree X.
+ *
+ * 2) After subtree swap.
+ * reloc tree subvolume tree X
+ * Root Root
+ * / \ / \
+ * OA OB NA OB
+ * / | | \ / | | \
+ * OC OD OE OF NC ND OE OF
+ *
+ * 3a) COW happens for OB
+ * If we are going to COW tree block OB, we check OB's bytenr against
+ * tree X's swapped_blocks structure.
+ * If it doesn't fit any, nothing will happen.
+ *
+ * 3b) COW happens for NA
+ * Check NA's bytenr against tree X's swapped_blocks, and get a hit.
+ * Then we do subtree scan on both subtrees OA and NA.
+ * Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND).
+ *
+ * Then no matter what we do to subvolume tree X, qgroup numbers will
+ * still be correct.
+ * Then NA's record gets removed from X's swapped_blocks.
+ *
+ * 4) Transaction commit
+ * Any record in X's swapped_blocks gets removed, since there is no
+ * modification to the swapped subtrees, no need to trigger heavy qgroup
+ * subtree rescan for them.
+ */
+
+/*
* Record a dirty extent, and info qgroup to update quota on it
* TODO: Use kmem cache to alloc it.
*/
@@ -45,7 +108,36 @@
struct rb_node node;
u64 bytenr;
u64 num_bytes;
+
+ /*
+ * For qgroup reserved data space freeing.
+ *
+ * @data_rsv_refroot and @data_rsv will be recorded after
+ * BTRFS_ADD_DELAYED_EXTENT is called.
+ * And will be used to free reserved qgroup space at
+ * transaction commit time.
+ */
+ u32 data_rsv; /* reserved data space needs to be freed */
+ u64 data_rsv_refroot; /* which root the reserved data belongs to */
struct ulist *old_roots;
+};
+
+struct btrfs_qgroup_swapped_block {
+ struct rb_node node;
+
+ int level;
+ bool trace_leaf;
+
+ /* bytenr/generation of the tree block in subvolume tree after swap */
+ u64 subvol_bytenr;
+ u64 subvol_generation;
+
+ /* bytenr/generation of the tree block in reloc tree after swap */
+ u64 reloc_bytenr;
+ u64 reloc_generation;
+
+ u64 last_snapshot;
+ struct btrfs_key first_key;
};
/*
@@ -70,7 +162,7 @@
* be converted into META_PERTRANS.
*/
enum btrfs_qgroup_rsv_type {
- BTRFS_QGROUP_RSV_DATA = 0,
+ BTRFS_QGROUP_RSV_DATA,
BTRFS_QGROUP_RSV_META_PERTRANS,
BTRFS_QGROUP_RSV_META_PREALLOC,
BTRFS_QGROUP_RSV_LAST,
@@ -81,10 +173,10 @@
*
* Each type should have different reservation behavior.
* E.g, data follows its io_tree flag modification, while
- * *currently* meta is just reserve-and-clear during transcation.
+ * *currently* meta is just reserve-and-clear during transaction.
*
* TODO: Add new type for reservation which can survive transaction commit.
- * Currect metadata reservation behavior is not suitable for such case.
+ * Current metadata reservation behavior is not suitable for such case.
*/
struct btrfs_qgroup_rsv {
u64 values[BTRFS_QGROUP_RSV_LAST];
@@ -132,7 +224,17 @@
*/
u64 old_refcnt;
u64 new_refcnt;
+
+ /*
+ * Sysfs kobjectid
+ */
+ struct kobject kobj;
};
+
+static inline u64 btrfs_qgroup_subvolid(u64 qgroupid)
+{
+ return (qgroupid & ((1ULL << BTRFS_QGROUP_LEVEL_SHIFT) - 1));
+}
/*
* For qgroup event trace points only
@@ -246,15 +348,6 @@
void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info,
u64 ref_root, u64 num_bytes,
enum btrfs_qgroup_rsv_type type);
-static inline void btrfs_qgroup_free_delayed_ref(struct btrfs_fs_info *fs_info,
- u64 ref_root, u64 num_bytes)
-{
- if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
- return;
- trace_btrfs_qgroup_free_delayed_ref(fs_info, ref_root, num_bytes);
- btrfs_qgroup_free_refroot(fs_info, ref_root, num_bytes,
- BTRFS_QGROUP_RSV_DATA);
-}
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
@@ -262,12 +355,14 @@
#endif
/* New io_tree based accurate qgroup reserve API */
-int btrfs_qgroup_reserve_data(struct inode *inode,
+int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
struct extent_changeset **reserved, u64 start, u64 len);
-int btrfs_qgroup_release_data(struct inode *inode, u64 start, u64 len);
-int btrfs_qgroup_free_data(struct inode *inode,
- struct extent_changeset *reserved, u64 start, u64 len);
-
+int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len);
+int btrfs_qgroup_free_data(struct btrfs_inode *inode,
+ struct extent_changeset *reserved, u64 start,
+ u64 len);
+int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
+ enum btrfs_qgroup_rsv_type type, bool enforce);
int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
enum btrfs_qgroup_rsv_type type, bool enforce);
/* Reserve metadata space for pertrans and prealloc type */
@@ -317,6 +412,22 @@
*/
void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes);
-void btrfs_qgroup_check_reserved_leak(struct inode *inode);
+void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode);
+
+/* btrfs_qgroup_swapped_blocks related functions */
+void btrfs_qgroup_init_swapped_blocks(
+ struct btrfs_qgroup_swapped_blocks *swapped_blocks);
+
+void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root);
+int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans,
+ struct btrfs_root *subvol_root,
+ struct btrfs_block_group *bg,
+ struct extent_buffer *subvol_parent, int subvol_slot,
+ struct extent_buffer *reloc_parent, int reloc_slot,
+ u64 last_snapshot);
+int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *eb);
+void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans);
+bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info);
#endif
--
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