From 298ab06ae475d8f4ba81b360d8fe4193143ae757 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Mon, 10 Nov 2025 16:08:19 +0100 Subject: [PATCH] nstree: use guards for ns_tree_lock Make use of the guard infrastructure for ns_tree_lock. Link: https://patch.msgid.link/20251110-work-namespace-nstree-fixes-v1-7-e8a9264e0fb9@kernel.org Signed-off-by: Christian Brauner --- kernel/nstree.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/kernel/nstree.c b/kernel/nstree.c index 476dd738d653..5270e0fa67a2 100644 --- a/kernel/nstree.c +++ b/kernel/nstree.c @@ -10,6 +10,14 @@ static __cacheline_aligned_in_smp DEFINE_SEQLOCK(ns_tree_lock); +DEFINE_LOCK_GUARD_0(ns_tree_writer, + write_seqlock(&ns_tree_lock), + write_sequnlock(&ns_tree_lock)) + +DEFINE_LOCK_GUARD_0(ns_tree_locked_reader, + read_seqlock_excl(&ns_tree_lock), + read_sequnlock_excl(&ns_tree_lock)) + static struct ns_tree_root ns_unified_root = { /* protected by ns_tree_lock */ .ns_rb = RB_ROOT, .ns_list_head = LIST_HEAD_INIT(ns_unified_root.ns_list_head), @@ -193,7 +201,7 @@ void __ns_tree_add_raw(struct ns_common *ns, struct ns_tree_root *ns_tree) VFS_WARN_ON_ONCE(!ns->ns_id); - write_seqlock(&ns_tree_lock); + guard(ns_tree_writer)(); /* Add to per-type tree and list */ node = ns_tree_node_add(&ns->ns_tree_node, ns_tree, ns_cmp); @@ -218,7 +226,6 @@ void __ns_tree_add_raw(struct ns_common *ns, struct ns_tree_root *ns_tree) VFS_WARN_ON_ONCE(ns != to_ns_common(&init_user_ns)); } } - write_sequnlock(&ns_tree_lock); VFS_WARN_ON_ONCE(node); } @@ -461,9 +468,9 @@ static struct ns_common *lookup_ns_owner_at(u64 ns_id, struct ns_common *owner) VFS_WARN_ON_ONCE(owner->ns_type != CLONE_NEWUSER); - read_seqlock_excl(&ns_tree_lock); - node = owner->ns_owner_root.ns_rb.rb_node; + guard(ns_tree_locked_reader)(); + node = owner->ns_owner_root.ns_rb.rb_node; while (node) { struct ns_common *ns; @@ -480,7 +487,6 @@ static struct ns_common *lookup_ns_owner_at(u64 ns_id, struct ns_common *owner) if (ret) ret = ns_get_unless_inactive(ret); - read_sequnlock_excl(&ns_tree_lock); return ret; } @@ -648,7 +654,8 @@ static struct ns_common *lookup_ns_id_at(u64 ns_id, int ns_type) return NULL; } - read_seqlock_excl(&ns_tree_lock); + guard(ns_tree_locked_reader)(); + if (ns_tree) node = ns_tree->ns_rb.rb_node; else @@ -677,7 +684,6 @@ static struct ns_common *lookup_ns_id_at(u64 ns_id, int ns_type) if (ret) ret = ns_get_unless_inactive(ret); - read_sequnlock_excl(&ns_tree_lock); return ret; } -- 2.47.3