[PATCH 06/11] maple_tree: Introduce mas_replace_entry() to directly replace an entry
From: Peng Zhang <hidden>
Date: 2023-07-26 08:23:16
Also in:
linux-fsdevel, linux-mm, lkml
Subsystem:
library code, maple tree, the rest · Maintainers:
Andrew Morton, Liam R. Howlett, Linus Torvalds
If mas has located a specific entry, it may be need to replace this entry, so introduce mas_replace_entry() to do this. mas_replace_entry() will be more efficient than mas_store*() because it doesn't do many unnecessary checks. This function should be inline, but more functions need to be moved to the header file, so I didn't do it for the time being. Signed-off-by: Peng Zhang <redacted> --- include/linux/maple_tree.h | 1 + lib/maple_tree.c | 25 +++++++++++++++++++++++++ 2 files changed, 26 insertions(+)
diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h
index 229fe78e4c89..a05e9827d761 100644
--- a/include/linux/maple_tree.h
+++ b/include/linux/maple_tree.h@@ -462,6 +462,7 @@ struct ma_wr_state { void *mas_walk(struct ma_state *mas); void *mas_store(struct ma_state *mas, void *entry); +void mas_replace_entry(struct ma_state *mas, void *entry); void *mas_erase(struct ma_state *mas); int mas_store_gfp(struct ma_state *mas, void *entry, gfp_t gfp); void mas_store_prealloc(struct ma_state *mas, void *entry);
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index efac6761ae37..d58572666a00 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c@@ -5600,6 +5600,31 @@ void *mas_store(struct ma_state *mas, void *entry) } EXPORT_SYMBOL_GPL(mas_store); +/** + * mas_replace_entry() - Replace an entry that already exists in the maple tree + * @mas: The maple state + * @entry: The entry to store + * + * Please note that mas must already locate an existing entry, and the new entry + * must not be NULL. If these two points cannot be guaranteed, please use + * mas_store*() instead, otherwise it will cause an internal error in the maple + * tree. This function does not need to allocate memory, so it must succeed. + */ +void mas_replace_entry(struct ma_state *mas, void *entry) +{ + void __rcu **slots; + +#ifdef CONFIG_DEBUG_MAPLE_TREE + MAS_WARN_ON(mas, !mte_is_leaf(mas->node)); + MAS_WARN_ON(mas, !entry); + MAS_WARN_ON(mas, mas->offset >= mt_slots[mte_node_type(mas->node)]); +#endif + + slots = ma_slots(mte_to_node(mas->node), mte_node_type(mas->node)); + rcu_assign_pointer(slots[mas->offset], entry); +} +EXPORT_SYMBOL_GPL(mas_replace_entry); + /** * mas_store_gfp() - Store a value into the tree. * @mas: The maple state
--
2.20.1