diff options
| author | Christian Brauner <brauner@kernel.org> | 2024-12-13 00:03:45 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-01-09 16:58:52 +0100 |
| commit | e7c8dde36818ffa101045cfc887c49cd631048ee (patch) | |
| tree | 78cac646a51ddf2615430a84e42a63540f9110f7 /fs/namespace.c | |
| parent | 4368898b271ad4ea3b6ae64f5cd16486a6d65430 (diff) | |
fs: simplify rwlock to spinlock
We're not taking the read_lock() anymore now that all lookup is
lockless. Just use a simple spinlock.
Link: https://lore.kernel.org/r/20241213-work-mount-rbtree-lockless-v3-6-6e3cdaf9b280@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 8b50b26024fa..a382be402f62 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -78,8 +78,7 @@ static struct kmem_cache *mnt_cache __ro_after_init; static DECLARE_RWSEM(namespace_sem); static HLIST_HEAD(unmounted); /* protected by namespace_sem */ static LIST_HEAD(ex_mountpoints); /* protected by namespace_sem */ -static DEFINE_RWLOCK(mnt_ns_tree_lock); -static seqcount_rwlock_t mnt_ns_tree_seqcount = SEQCNT_RWLOCK_ZERO(mnt_ns_tree_seqcount, &mnt_ns_tree_lock); +static DEFINE_SEQLOCK(mnt_ns_tree_lock); static struct rb_root mnt_ns_tree = RB_ROOT; /* protected by mnt_ns_tree_lock */ static LIST_HEAD(mnt_ns_list); /* protected by mnt_ns_tree_lock */ @@ -131,14 +130,12 @@ static int mnt_ns_cmp(struct rb_node *a, const struct rb_node *b) static inline void mnt_ns_tree_write_lock(void) { - write_lock(&mnt_ns_tree_lock); - write_seqcount_begin(&mnt_ns_tree_seqcount); + write_seqlock(&mnt_ns_tree_lock); } static inline void mnt_ns_tree_write_unlock(void) { - write_seqcount_end(&mnt_ns_tree_seqcount); - write_unlock(&mnt_ns_tree_lock); + write_sequnlock(&mnt_ns_tree_lock); } static void mnt_ns_tree_add(struct mnt_namespace *ns) @@ -163,7 +160,7 @@ static void mnt_ns_tree_add(struct mnt_namespace *ns) static void mnt_ns_release(struct mnt_namespace *ns) { - lockdep_assert_not_held(&mnt_ns_tree_lock); + lockdep_assert_not_held(&mnt_ns_tree_lock.lock); /* keep alive for {list,stat}mount() */ if (refcount_dec_and_test(&ns->passive)) { @@ -225,11 +222,11 @@ static struct mnt_namespace *lookup_mnt_ns(u64 mnt_ns_id) guard(rcu)(); do { - seq = read_seqcount_begin(&mnt_ns_tree_seqcount); + seq = read_seqbegin(&mnt_ns_tree_lock); node = rb_find_rcu(&mnt_ns_id, &mnt_ns_tree, mnt_ns_find); if (node) break; - } while (read_seqcount_retry(&mnt_ns_tree_seqcount, seq)); + } while (read_seqretry(&mnt_ns_tree_lock, seq)); if (!node) return NULL; |