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/root-tree.c | 128 +++++++++++++++++++++++++++---------------
1 files changed, 82 insertions(+), 46 deletions(-)
diff --git a/kernel/fs/btrfs/root-tree.c b/kernel/fs/btrfs/root-tree.c
index b309f29..e9e8ca4 100644
--- a/kernel/fs/btrfs/root-tree.c
+++ b/kernel/fs/btrfs/root-tree.c
@@ -9,6 +9,8 @@
#include "transaction.h"
#include "disk-io.h"
#include "print-tree.h"
+#include "qgroup.h"
+#include "space-info.h"
/*
* Read a root item from the tree. In case we detect a root item smaller then
@@ -20,13 +22,12 @@
static void btrfs_read_root_item(struct extent_buffer *eb, int slot,
struct btrfs_root_item *item)
{
- uuid_le uuid;
- int len;
+ u32 len;
int need_reset = 0;
len = btrfs_item_size_nr(eb, slot);
read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot),
- min_t(int, len, (int)sizeof(*item)));
+ min_t(u32, len, sizeof(*item)));
if (len < sizeof(*item))
need_reset = 1;
if (!need_reset && btrfs_root_generation(item)
@@ -42,8 +43,7 @@
sizeof(*item) - offsetof(struct btrfs_root_item,
generation_v2));
- uuid_le_gen(&uuid);
- memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE);
+ generate_random_guid(item->uuid);
}
}
@@ -210,7 +210,6 @@
struct extent_buffer *leaf;
struct btrfs_path *path;
struct btrfs_key key;
- struct btrfs_key root_key;
struct btrfs_root *root;
int err = 0;
int ret;
@@ -223,10 +222,9 @@
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = 0;
- root_key.type = BTRFS_ROOT_ITEM_KEY;
- root_key.offset = (u64)-1;
-
while (1) {
+ u64 root_objectid;
+
ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
if (ret < 0) {
err = ret;
@@ -250,26 +248,10 @@
key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
- root_key.objectid = key.offset;
+ root_objectid = key.offset;
key.offset++;
- /*
- * The root might have been inserted already, as before we look
- * for orphan roots, log replay might have happened, which
- * triggers a transaction commit and qgroup accounting, which
- * in turn reads and inserts fs roots while doing backref
- * walking.
- */
- root = btrfs_lookup_fs_root(fs_info, root_key.objectid);
- if (root) {
- WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
- &root->state));
- if (btrfs_root_refs(&root->root_item) == 0)
- btrfs_add_dead_root(root);
- continue;
- }
-
- root = btrfs_read_fs_root(tree_root, &root_key);
+ root = btrfs_get_fs_root(fs_info, root_objectid, false);
err = PTR_ERR_OR_ZERO(root);
if (err && err != -ENOENT) {
break;
@@ -286,7 +268,7 @@
break;
}
err = btrfs_del_orphan_item(trans, tree_root,
- root_key.objectid);
+ root_objectid);
btrfs_end_transaction(trans);
if (err) {
btrfs_handle_fs_error(fs_info, err,
@@ -296,23 +278,12 @@
continue;
}
- err = btrfs_init_fs_root(root);
- if (err) {
- btrfs_free_fs_root(root);
- break;
- }
-
- set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
-
- err = btrfs_insert_fs_root(fs_info, root);
- if (err) {
- BUG_ON(err == -EEXIST);
- btrfs_free_fs_root(root);
- break;
- }
-
- if (btrfs_root_refs(&root->root_item) == 0)
+ WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state));
+ if (btrfs_root_refs(&root->root_item) == 0) {
+ set_bit(BTRFS_ROOT_DEAD_TREE, &root->state);
btrfs_add_dead_root(root);
+ }
+ btrfs_put_root(root);
}
btrfs_free_path(path);
@@ -365,8 +336,10 @@
key.offset = ref_id;
again:
ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
- BUG_ON(ret < 0);
- if (ret == 0) {
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ } else if (ret == 0) {
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_root_ref);
@@ -495,3 +468,66 @@
btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);
spin_unlock(&root->root_item_lock);
}
+
+/*
+ * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
+ * root: the root of the parent directory
+ * rsv: block reservation
+ * items: the number of items that we need do reservation
+ * use_global_rsv: allow fallback to the global block reservation
+ *
+ * This function is used to reserve the space for snapshot/subvolume
+ * creation and deletion. Those operations are different with the
+ * common file/directory operations, they change two fs/file trees
+ * and root tree, the number of items that the qgroup reserves is
+ * different with the free space reservation. So we can not use
+ * the space reservation mechanism in start_transaction().
+ */
+int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv, int items,
+ bool use_global_rsv)
+{
+ u64 qgroup_num_bytes = 0;
+ u64 num_bytes;
+ int ret;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+
+ if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
+ /* One for parent inode, two for dir entries */
+ qgroup_num_bytes = 3 * fs_info->nodesize;
+ ret = btrfs_qgroup_reserve_meta_prealloc(root,
+ qgroup_num_bytes, true);
+ if (ret)
+ return ret;
+ }
+
+ num_bytes = btrfs_calc_insert_metadata_size(fs_info, items);
+ rsv->space_info = btrfs_find_space_info(fs_info,
+ BTRFS_BLOCK_GROUP_METADATA);
+ ret = btrfs_block_rsv_add(root, rsv, num_bytes,
+ BTRFS_RESERVE_FLUSH_ALL);
+
+ if (ret == -ENOSPC && use_global_rsv)
+ ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes, true);
+
+ if (ret && qgroup_num_bytes)
+ btrfs_qgroup_free_meta_prealloc(root, qgroup_num_bytes);
+
+ if (!ret) {
+ spin_lock(&rsv->lock);
+ rsv->qgroup_rsv_reserved += qgroup_num_bytes;
+ spin_unlock(&rsv->lock);
+ }
+ return ret;
+}
+
+void btrfs_subvolume_release_metadata(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ u64 qgroup_to_release;
+
+ btrfs_block_rsv_release(fs_info, rsv, (u64)-1, &qgroup_to_release);
+ btrfs_qgroup_convert_reserved_meta(root, qgroup_to_release);
+}
--
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