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From: Wei Yang <richard.weiyang@gmail.com>
To: akpm@linux-foundation.org, Liam.Howlett@oracle.com
Cc: maple-tree@lists.infradead.org, linux-mm@kvack.org,
	Wei Yang <richard.weiyang@gmail.com>,
	"Liam R . Howlett" <Liam.Howlett@Oracle.com>,
	Sidhartha Kumar <sidhartha.kumar@oracle.com>,
	Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Subject: [PATCH v4 3/5] maple_tree: not necessary to check index/last again
Date: Sat, 19 Oct 2024 02:37:14 +0000	[thread overview]
Message-ID: <20241019023716.4516-4-richard.weiyang@gmail.com> (raw)
In-Reply-To: <20241019023716.4516-1-richard.weiyang@gmail.com>

Before calling mas_new_root(), the range has been checked.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Liam R. Howlett <Liam.Howlett@Oracle.com>
CC: Sidhartha Kumar <sidhartha.kumar@oracle.com>
CC: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

---
v4: add WARN_ON_ONCE() to check mis-usage.
---
 lib/maple_tree.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 517ddf2950e6..2226e77c00cb 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3662,7 +3662,9 @@ static inline void mas_new_root(struct ma_state *mas, void *entry)
 	void __rcu **slots;
 	unsigned long *pivots;
 
-	if (!entry && !mas->index && mas->last == ULONG_MAX) {
+	WARN_ON_ONCE(mas->index || mas->last != ULONG_MAX);
+
+	if (!entry) {
 		mas->depth = 0;
 		mas_set_height(mas);
 		rcu_assign_pointer(mas->tree->ma_root, entry);
-- 
2.34.1



  parent reply	other threads:[~2024-10-19  2:37 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-19  2:37 [PATCH v4 0/5] refine storing NULL Wei Yang
2024-10-19  2:37 ` [PATCH v4 1/5] maple_tree: print empty for an empty tree on mt_dump() Wei Yang
2024-10-29 15:23   ` Liam R. Howlett
2024-10-19  2:37 ` [PATCH v4 2/5] maple_tree: the return value of mas_root_expand() is not used Wei Yang
2024-10-29 15:23   ` Liam R. Howlett
2024-10-19  2:37 ` Wei Yang [this message]
2024-10-29 15:23   ` [PATCH v4 3/5] maple_tree: not necessary to check index/last again Liam R. Howlett
2024-10-19  2:37 ` [PATCH v4 4/5] maple_tree: refine mas_store_root() on storing NULL Wei Yang
2024-10-29 15:24   ` Liam R. Howlett
2024-10-19  2:37 ` [PATCH v4 5/5] maple_tree: add a test checking storing null Wei Yang
2024-10-22 17:37   ` kernel test robot
2024-10-22 23:32     ` Wei Yang
2024-10-29 15:29       ` Liam R. Howlett
2024-10-31  8:02         ` Wei Yang
2024-10-31 11:17           ` Liam R. Howlett
2024-10-31 23:04             ` Wei Yang
2024-10-29 15:17   ` Liam R. Howlett
2024-10-29 15:22     ` Liam R. Howlett
2024-10-19  2:42 ` [PATCH v4 0/5] refine storing NULL Wei Yang

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