[PATCH v2 6/8] fs: simplify rwlock to spinlock

[Christian Brauner <brauner@kernel.org>]

We're not taking the read_lock() anymore now that all lookup is losless.
Just use a simple spinlock.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 fs/namespace.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/namespace.c b/fs/namespace.c
index a5e1b166be9430d47c295159292cb9028b2e2339..984ec416ca7618260a38b86a16b66dcdba6e62ed 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -78,8 +78,8 @@ 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_SPINLOCK(mnt_ns_tree_lock);
+static seqcount_spinlock_t mnt_ns_tree_seqcount = SEQCNT_SPINLOCK_ZERO(mnt_ns_tree_seqcount, &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 +131,14 @@ 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);
+	spin_lock(&mnt_ns_tree_lock);
 	write_seqcount_begin(&mnt_ns_tree_seqcount);
 }
 
 static inline void mnt_ns_tree_write_unlock(void)
 {
 	write_seqcount_end(&mnt_ns_tree_seqcount);
-	write_unlock(&mnt_ns_tree_lock);
+	spin_unlock(&mnt_ns_tree_lock);
 }
 
 static void mnt_ns_tree_add(struct mnt_namespace *ns)

-- 
2.45.2