1 files changed, 5 insertions, 63 deletions

diff --git a/include/spl/sys/rwlock.h b/include/spl/sys/rwlock.h
index 408defac2..5e052b532 100644
--- a/include/spl/sys/rwlock.h
+++ b/include/spl/sys/rwlock.h
@@ -78,15 +78,9 @@ typedef enum {
 	RW_READER	= 2
 } krw_t;
 
-/*
- * If CONFIG_RWSEM_SPIN_ON_OWNER is defined, rw_semaphore will have an owner
- * field, so we don't need our own.
- */
 typedef struct {
 	struct rw_semaphore rw_rwlock;
-#ifndef CONFIG_RWSEM_SPIN_ON_OWNER
 	kthread_t *rw_owner;
-#endif
 #ifdef CONFIG_LOCKDEP
 	krw_type_t	rw_type;
 #endif /* CONFIG_LOCKDEP */
@@ -97,31 +91,19 @@ typedef struct {
 static inline void
 spl_rw_set_owner(krwlock_t *rwp)
 {
-/*
- * If CONFIG_RWSEM_SPIN_ON_OWNER is defined, down_write, up_write,
- * downgrade_write and __init_rwsem will set/clear owner for us.
- */
-#ifndef CONFIG_RWSEM_SPIN_ON_OWNER
 	rwp->rw_owner = current;
-#endif
 }
 
 static inline void
 spl_rw_clear_owner(krwlock_t *rwp)
 {
-#ifndef CONFIG_RWSEM_SPIN_ON_OWNER
 	rwp->rw_owner = NULL;
-#endif
 }
 
 static inline kthread_t *
 rw_owner(krwlock_t *rwp)
 {
-#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
-	return (SEM(rwp)->owner);
-#else
 	return (rwp->rw_owner);
-#endif
 }
 
 #ifdef CONFIG_LOCKDEP
@@ -148,62 +130,22 @@ spl_rw_lockdep_on_maybe(krwlock_t *rwp)			\
 #define	spl_rw_lockdep_on_maybe(rwp)
 #endif /* CONFIG_LOCKDEP */
 
-
 static inline int
-RW_WRITE_HELD(krwlock_t *rwp)
+RW_LOCK_HELD(krwlock_t *rwp)
 {
-	return (rw_owner(rwp) == current);
+	return (spl_rwsem_is_locked(SEM(rwp)));
 }
 
 static inline int
-RW_LOCK_HELD(krwlock_t *rwp)
+RW_WRITE_HELD(krwlock_t *rwp)
 {
-	return (spl_rwsem_is_locked(SEM(rwp)));
+	return (rw_owner(rwp) == current);
 }
 
 static inline int
 RW_READ_HELD(krwlock_t *rwp)
 {
-	if (!RW_LOCK_HELD(rwp))
-		return (0);
-
-	/*
-	 * rw_semaphore cheat sheet:
-	 *
-	 * < 3.16:
-	 * There's no rw_semaphore.owner, so use rwp.owner instead.
-	 * If rwp.owner == NULL then it's a reader
-	 *
-	 * 3.16 - 4.7:
-	 * rw_semaphore.owner added (https://lwn.net/Articles/596656/)
-	 * and CONFIG_RWSEM_SPIN_ON_OWNER introduced.
-	 * If rw_semaphore.owner == NULL then it's a reader
-	 *
-	 * 4.8 - 4.16.16:
-	 * RWSEM_READER_OWNED added as an internal #define.
-	 * (https://lore.kernel.org/patchwork/patch/678590/)
-	 * If rw_semaphore.owner == 1 then it's a reader
-	 *
-	 * 4.16.17 - 4.19:
-	 * RWSEM_OWNER_UNKNOWN introduced as ((struct task_struct *)-1L)
-	 * (https://do-db2.lkml.org/lkml/2018/5/15/985)
-	 * If rw_semaphore.owner == 1 then it's a reader.
-	 *
-	 * 4.20+:
-	 * RWSEM_OWNER_UNKNOWN changed to ((struct task_struct *)-2L)
-	 * (https://lkml.org/lkml/2018/9/6/986)
-	 * If rw_semaphore.owner & 1 then it's a reader, and also the reader's
-	 * task_struct may be embedded in rw_semaphore->owner.
-	 */
-#if	defined(CONFIG_RWSEM_SPIN_ON_OWNER) && defined(RWSEM_OWNER_UNKNOWN)
-	if (RWSEM_OWNER_UNKNOWN == (struct task_struct *)-2L) {
-		/* 4.20+ kernels with CONFIG_RWSEM_SPIN_ON_OWNER */
-		return ((unsigned long) SEM(rwp)->owner & 1);
-	}
-#endif
-
-	/* < 4.20 kernel or !CONFIG_RWSEM_SPIN_ON_OWNER */
-	return (rw_owner(rwp) == NULL || (unsigned long) rw_owner(rwp) == 1);
+	return (RW_LOCK_HELD(rwp) && rw_owner(rwp) == NULL);
 }
 
 /*