move Rust sources to top level, C sources into c_src

This moves the Rust sources out of rust_src/ and into the top level.
Running the bcachefs executable out of the development tree is now:

$ ./target/release/bcachefs command
or
$ cargo run --profile release -- command

instead of "./bcachefs command".

Building and installing is still:

$ make && make install

Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 0 insertions, 867 deletions

diff --git a/libbcachefs/six.c b/libbcachefs/six.c
deleted file mode 100644
index 3a494c5d..00000000
--- a/libbcachefs/six.c
+++ /dev/null
@@ -1,867 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-#include <linux/export.h>
-#include <linux/log2.h>
-#include <linux/percpu.h>
-#include <linux/preempt.h>
-#include <linux/rcupdate.h>
-#include <linux/sched.h>
-#include <linux/sched/clock.h>
-#include <linux/sched/rt.h>
-#include <linux/sched/task.h>
-#include <linux/slab.h>
-
-#include <trace/events/lock.h>
-
-#include "six.h"
-
-#ifdef DEBUG
-#define EBUG_ON(cond)			BUG_ON(cond)
-#else
-#define EBUG_ON(cond)			do {} while (0)
-#endif
-
-#define six_acquire(l, t, r, ip)	lock_acquire(l, 0, t, r, 1, NULL, ip)
-#define six_release(l, ip)		lock_release(l, ip)
-
-static void do_six_unlock_type(struct six_lock *lock, enum six_lock_type type);
-
-#define SIX_LOCK_HELD_read_OFFSET	0
-#define SIX_LOCK_HELD_read		~(~0U << 26)
-#define SIX_LOCK_HELD_intent		(1U << 26)
-#define SIX_LOCK_HELD_write		(1U << 27)
-#define SIX_LOCK_WAITING_read		(1U << (28 + SIX_LOCK_read))
-#define SIX_LOCK_WAITING_write		(1U << (28 + SIX_LOCK_write))
-#define SIX_LOCK_NOSPIN			(1U << 31)
-
-struct six_lock_vals {
-	/* Value we add to the lock in order to take the lock: */
-	u32			lock_val;
-
-	/* If the lock has this value (used as a mask), taking the lock fails: */
-	u32			lock_fail;
-
-	/* Mask that indicates lock is held for this type: */
-	u32			held_mask;
-
-	/* Waitlist we wakeup when releasing the lock: */
-	enum six_lock_type	unlock_wakeup;
-};
-
-static const struct six_lock_vals l[] = {
-	[SIX_LOCK_read] = {
-		.lock_val	= 1U << SIX_LOCK_HELD_read_OFFSET,
-		.lock_fail	= SIX_LOCK_HELD_write,
-		.held_mask	= SIX_LOCK_HELD_read,
-		.unlock_wakeup	= SIX_LOCK_write,
-	},
-	[SIX_LOCK_intent] = {
-		.lock_val	= SIX_LOCK_HELD_intent,
-		.lock_fail	= SIX_LOCK_HELD_intent,
-		.held_mask	= SIX_LOCK_HELD_intent,
-		.unlock_wakeup	= SIX_LOCK_intent,
-	},
-	[SIX_LOCK_write] = {
-		.lock_val	= SIX_LOCK_HELD_write,
-		.lock_fail	= SIX_LOCK_HELD_read,
-		.held_mask	= SIX_LOCK_HELD_write,
-		.unlock_wakeup	= SIX_LOCK_read,
-	},
-};
-
-static inline void six_set_bitmask(struct six_lock *lock, u32 mask)
-{
-	if ((atomic_read(&lock->state) & mask) != mask)
-		atomic_or(mask, &lock->state);
-}
-
-static inline void six_clear_bitmask(struct six_lock *lock, u32 mask)
-{
-	if (atomic_read(&lock->state) & mask)
-		atomic_and(~mask, &lock->state);
-}
-
-static inline void six_set_owner(struct six_lock *lock, enum six_lock_type type,
-				 u32 old, struct task_struct *owner)
-{
-	if (type != SIX_LOCK_intent)
-		return;
-
-	if (!(old & SIX_LOCK_HELD_intent)) {
-		EBUG_ON(lock->owner);
-		lock->owner = owner;
-	} else {
-		EBUG_ON(lock->owner != current);
-	}
-}
-
-static inline unsigned pcpu_read_count(struct six_lock *lock)
-{
-	unsigned read_count = 0;
-	int cpu;
-
-	for_each_possible_cpu(cpu)
-		read_count += *per_cpu_ptr(lock->readers, cpu);
-	return read_count;
-}
-
-/*
- * __do_six_trylock() - main trylock routine
- *
- * Returns 1 on success, 0 on failure
- *
- * In percpu reader mode, a failed trylock may cause a spurious trylock failure
- * for anoter thread taking the competing lock type, and we may havve to do a
- * wakeup: when a wakeup is required, we return -1 - wakeup_type.
- */
-static int __do_six_trylock(struct six_lock *lock, enum six_lock_type type,
-			    struct task_struct *task, bool try)
-{
-	int ret;
-	u32 old;
-
-	EBUG_ON(type == SIX_LOCK_write && lock->owner != task);
-	EBUG_ON(type == SIX_LOCK_write &&
-		(try != !(atomic_read(&lock->state) & SIX_LOCK_HELD_write)));
-
-	/*
-	 * Percpu reader mode:
-	 *
-	 * The basic idea behind this algorithm is that you can implement a lock
-	 * between two threads without any atomics, just memory barriers:
-	 *
-	 * For two threads you'll need two variables, one variable for "thread a
-	 * has the lock" and another for "thread b has the lock".
-	 *
-	 * To take the lock, a thread sets its variable indicating that it holds
-	 * the lock, then issues a full memory barrier, then reads from the
-	 * other thread's variable to check if the other thread thinks it has
-	 * the lock. If we raced, we backoff and retry/sleep.
-	 *
-	 * Failure to take the lock may cause a spurious trylock failure in
-	 * another thread, because we temporarily set the lock to indicate that
-	 * we held it. This would be a problem for a thread in six_lock(), when
-	 * they are calling trylock after adding themself to the waitlist and
-	 * prior to sleeping.
-	 *
-	 * Therefore, if we fail to get the lock, and there were waiters of the
-	 * type we conflict with, we will have to issue a wakeup.
-	 *
-	 * Since we may be called under wait_lock (and by the wakeup code
-	 * itself), we return that the wakeup has to be done instead of doing it
-	 * here.
-	 */
-	if (type == SIX_LOCK_read && lock->readers) {
-		preempt_disable();
-		this_cpu_inc(*lock->readers); /* signal that we own lock */
-
-		smp_mb();
-
-		old = atomic_read(&lock->state);
-		ret = !(old & l[type].lock_fail);
-
-		this_cpu_sub(*lock->readers, !ret);
-		preempt_enable();
-
-		if (!ret) {
-			smp_mb();
-			if (atomic_read(&lock->state) & SIX_LOCK_WAITING_write)
-				ret = -1 - SIX_LOCK_write;
-		}
-	} else if (type == SIX_LOCK_write && lock->readers) {
-		if (try) {
-			atomic_add(SIX_LOCK_HELD_write, &lock->state);
-			smp_mb__after_atomic();
-		}
-
-		ret = !pcpu_read_count(lock);
-
-		if (try && !ret) {
-			old = atomic_sub_return(SIX_LOCK_HELD_write, &lock->state);
-			if (old & SIX_LOCK_WAITING_read)
-				ret = -1 - SIX_LOCK_read;
-		}
-	} else {
-		old = atomic_read(&lock->state);
-		do {
-			ret = !(old & l[type].lock_fail);
-			if (!ret || (type == SIX_LOCK_write && !try)) {
-				smp_mb();
-				break;
-			}
-		} while (!atomic_try_cmpxchg_acquire(&lock->state, &old, old + l[type].lock_val));
-
-		EBUG_ON(ret && !(atomic_read(&lock->state) & l[type].held_mask));
-	}
-
-	if (ret > 0)
-		six_set_owner(lock, type, old, task);
-
-	EBUG_ON(type == SIX_LOCK_write && try && ret <= 0 &&
-		(atomic_read(&lock->state) & SIX_LOCK_HELD_write));
-
-	return ret;
-}
-
-static void __six_lock_wakeup(struct six_lock *lock, enum six_lock_type lock_type)
-{
-	struct six_lock_waiter *w, *next;
-	struct task_struct *task;
-	bool saw_one;
-	int ret;
-again:
-	ret = 0;
-	saw_one = false;
-	raw_spin_lock(&lock->wait_lock);
-
-	list_for_each_entry_safe(w, next, &lock->wait_list, list) {
-		if (w->lock_want != lock_type)
-			continue;
-
-		if (saw_one && lock_type != SIX_LOCK_read)
-			goto unlock;
-		saw_one = true;
-
-		ret = __do_six_trylock(lock, lock_type, w->task, false);
-		if (ret <= 0)
-			goto unlock;
-
-		/*
-		 * Similar to percpu_rwsem_wake_function(), we need to guard
-		 * against the wakee noticing w->lock_acquired, returning, and
-		 * then exiting before we do the wakeup:
-		 */
-		task = get_task_struct(w->task);
-		__list_del(w->list.prev, w->list.next);
-		/*
-		 * The release barrier here ensures the ordering of the
-		 * __list_del before setting w->lock_acquired; @w is on the
-		 * stack of the thread doing the waiting and will be reused
-		 * after it sees w->lock_acquired with no other locking:
-		 * pairs with smp_load_acquire() in six_lock_slowpath()
-		 */
-		smp_store_release(&w->lock_acquired, true);
-		wake_up_process(task);
-		put_task_struct(task);
-	}
-
-	six_clear_bitmask(lock, SIX_LOCK_WAITING_read << lock_type);
-unlock:
-	raw_spin_unlock(&lock->wait_lock);
-
-	if (ret < 0) {
-		lock_type = -ret - 1;
-		goto again;
-	}
-}
-
-__always_inline
-static void six_lock_wakeup(struct six_lock *lock, u32 state,
-			    enum six_lock_type lock_type)
-{
-	if (lock_type == SIX_LOCK_write && (state & SIX_LOCK_HELD_read))
-		return;
-
-	if (!(state & (SIX_LOCK_WAITING_read << lock_type)))
-		return;
-
-	__six_lock_wakeup(lock, lock_type);
-}
-
-__always_inline
-static bool do_six_trylock(struct six_lock *lock, enum six_lock_type type, bool try)
-{
-	int ret;
-
-	ret = __do_six_trylock(lock, type, current, try);
-	if (ret < 0)
-		__six_lock_wakeup(lock, -ret - 1);
-
-	return ret > 0;
-}
-
-/**
- * six_trylock_ip - attempt to take a six lock without blocking
- * @lock:	lock to take
- * @type:	SIX_LOCK_read, SIX_LOCK_intent, or SIX_LOCK_write
- * @ip:		ip parameter for lockdep/lockstat, i.e. _THIS_IP_
- *
- * Return: true on success, false on failure.
- */
-bool six_trylock_ip(struct six_lock *lock, enum six_lock_type type, unsigned long ip)
-{
-	if (!do_six_trylock(lock, type, true))
-		return false;
-
-	if (type != SIX_LOCK_write)
-		six_acquire(&lock->dep_map, 1, type == SIX_LOCK_read, ip);
-	return true;
-}
-EXPORT_SYMBOL_GPL(six_trylock_ip);
-
-/**
- * six_relock_ip - attempt to re-take a lock that was held previously
- * @lock:	lock to take
- * @type:	SIX_LOCK_read, SIX_LOCK_intent, or SIX_LOCK_write
- * @seq:	lock sequence number obtained from six_lock_seq() while lock was
- *		held previously
- * @ip:		ip parameter for lockdep/lockstat, i.e. _THIS_IP_
- *
- * Return: true on success, false on failure.
- */
-bool six_relock_ip(struct six_lock *lock, enum six_lock_type type,
-		   unsigned seq, unsigned long ip)
-{
-	if (six_lock_seq(lock) != seq || !six_trylock_ip(lock, type, ip))
-		return false;
-
-	if (six_lock_seq(lock) != seq) {
-		six_unlock_ip(lock, type, ip);
-		return false;
-	}
-
-	return true;
-}
-EXPORT_SYMBOL_GPL(six_relock_ip);
-
-#ifdef CONFIG_BCACHEFS_SIX_OPTIMISTIC_SPIN
-
-static inline bool six_owner_running(struct six_lock *lock)
-{
-	/*
-	 * When there's no owner, we might have preempted between the owner
-	 * acquiring the lock and setting the owner field. If we're an RT task
-	 * that will live-lock because we won't let the owner complete.
-	 */
-	rcu_read_lock();
-	struct task_struct *owner = READ_ONCE(lock->owner);
-	bool ret = owner ? owner_on_cpu(owner) : !rt_task(current);
-	rcu_read_unlock();
-
-	return ret;
-}
-
-static inline bool six_optimistic_spin(struct six_lock *lock,
-				       struct six_lock_waiter *wait,
-				       enum six_lock_type type)
-{
-	unsigned loop = 0;
-	u64 end_time;
-
-	if (type == SIX_LOCK_write)
-		return false;
-
-	if (lock->wait_list.next != &wait->list)
-		return false;
-
-	if (atomic_read(&lock->state) & SIX_LOCK_NOSPIN)
-		return false;
-
-	preempt_disable();
-	end_time = sched_clock() + 10 * NSEC_PER_USEC;
-
-	while (!need_resched() && six_owner_running(lock)) {
-		/*
-		 * Ensures that writes to the waitlist entry happen after we see
-		 * wait->lock_acquired: pairs with the smp_store_release in
-		 * __six_lock_wakeup
-		 */
-		if (smp_load_acquire(&wait->lock_acquired)) {
-			preempt_enable();
-			return true;
-		}
-
-		if (!(++loop & 0xf) && (time_after64(sched_clock(), end_time))) {
-			six_set_bitmask(lock, SIX_LOCK_NOSPIN);
-			break;
-		}
-
-		/*
-		 * The cpu_relax() call is a compiler barrier which forces
-		 * everything in this loop to be re-loaded. We don't need
-		 * memory barriers as we'll eventually observe the right
-		 * values at the cost of a few extra spins.
-		 */
-		cpu_relax();
-	}
-
-	preempt_enable();
-	return false;
-}
-
-#else /* CONFIG_LOCK_SPIN_ON_OWNER */
-
-static inline bool six_optimistic_spin(struct six_lock *lock,
-				       struct six_lock_waiter *wait,
-				       enum six_lock_type type)
-{
-	return false;
-}
-
-#endif
-
-noinline
-static int six_lock_slowpath(struct six_lock *lock, enum six_lock_type type,
-			     struct six_lock_waiter *wait,
-			     six_lock_should_sleep_fn should_sleep_fn, void *p,
-			     unsigned long ip)
-{
-	int ret = 0;
-
-	if (type == SIX_LOCK_write) {
-		EBUG_ON(atomic_read(&lock->state) & SIX_LOCK_HELD_write);
-		atomic_add(SIX_LOCK_HELD_write, &lock->state);
-		smp_mb__after_atomic();
-	}
-
-	trace_contention_begin(lock, 0);
-	lock_contended(&lock->dep_map, ip);
-
-	wait->task		= current;
-	wait->lock_want		= type;
-	wait->lock_acquired	= false;
-
-	raw_spin_lock(&lock->wait_lock);
-	six_set_bitmask(lock, SIX_LOCK_WAITING_read << type);
-	/*
-	 * Retry taking the lock after taking waitlist lock, in case we raced
-	 * with an unlock:
-	 */
-	ret = __do_six_trylock(lock, type, current, false);
-	if (ret <= 0) {
-		wait->start_time = local_clock();
-
-		if (!list_empty(&lock->wait_list)) {
-			struct six_lock_waiter *last =
-				list_last_entry(&lock->wait_list,
-					struct six_lock_waiter, list);
-
-			if (time_before_eq64(wait->start_time, last->start_time))
-				wait->start_time = last->start_time + 1;
-		}
-
-		list_add_tail(&wait->list, &lock->wait_list);
-	}
-	raw_spin_unlock(&lock->wait_lock);
-
-	if (unlikely(ret > 0)) {
-		ret = 0;
-		goto out;
-	}
-
-	if (unlikely(ret < 0)) {
-		__six_lock_wakeup(lock, -ret - 1);
-		ret = 0;
-	}
-
-	if (six_optimistic_spin(lock, wait, type))
-		goto out;
-
-	while (1) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-
-		/*
-		 * Ensures that writes to the waitlist entry happen after we see
-		 * wait->lock_acquired: pairs with the smp_store_release in
-		 * __six_lock_wakeup
-		 */
-		if (smp_load_acquire(&wait->lock_acquired))
-			break;
-
-		ret = should_sleep_fn ? should_sleep_fn(lock, p) : 0;
-		if (unlikely(ret)) {
-			bool acquired;
-
-			/*
-			 * If should_sleep_fn() returns an error, we are
-			 * required to return that error even if we already
-			 * acquired the lock - should_sleep_fn() might have
-			 * modified external state (e.g. when the deadlock cycle
-			 * detector in bcachefs issued a transaction restart)
-			 */
-			raw_spin_lock(&lock->wait_lock);
-			acquired = wait->lock_acquired;
-			if (!acquired)
-				list_del(&wait->list);
-			raw_spin_unlock(&lock->wait_lock);
-
-			if (unlikely(acquired))
-				do_six_unlock_type(lock, type);
-			break;
-		}
-
-		schedule();
-	}
-
-	__set_current_state(TASK_RUNNING);
-out:
-	if (ret && type == SIX_LOCK_write) {
-		six_clear_bitmask(lock, SIX_LOCK_HELD_write);
-		six_lock_wakeup(lock, atomic_read(&lock->state), SIX_LOCK_read);
-	}
-	trace_contention_end(lock, 0);
-
-	return ret;
-}
-
-/**
- * six_lock_ip_waiter - take a lock, with full waitlist interface
- * @lock:	lock to take
- * @type:	SIX_LOCK_read, SIX_LOCK_intent, or SIX_LOCK_write
- * @wait:	pointer to wait object, which will be added to lock's waitlist
- * @should_sleep_fn: callback run after adding to waitlist, immediately prior
- *		to scheduling
- * @p:		passed through to @should_sleep_fn
- * @ip:		ip parameter for lockdep/lockstat, i.e. _THIS_IP_
- *
- * This is the most general six_lock() variant, with parameters to support full
- * cycle detection for deadlock avoidance.
- *
- * The code calling this function must implement tracking of held locks, and the
- * @wait object should be embedded into the struct that tracks held locks -
- * which must also be accessible in a thread-safe way.
- *
- * @should_sleep_fn should invoke the cycle detector; it should walk each
- * lock's waiters, and for each waiter recursively walk their held locks.
- *
- * When this function must block, @wait will be added to @lock's waitlist before
- * calling trylock, and before calling @should_sleep_fn, and @wait will not be
- * removed from the lock waitlist until the lock has been successfully acquired,
- * or we abort.
- *
- * @wait.start_time will be monotonically increasing for any given waitlist, and
- * thus may be used as a loop cursor.
- *
- * Return: 0 on success, or the return code from @should_sleep_fn on failure.
- */
-int six_lock_ip_waiter(struct six_lock *lock, enum six_lock_type type,
-		       struct six_lock_waiter *wait,
-		       six_lock_should_sleep_fn should_sleep_fn, void *p,
-		       unsigned long ip)
-{
-	int ret;
-
-	wait->start_time = 0;
-
-	if (type != SIX_LOCK_write)
-		six_acquire(&lock->dep_map, 0, type == SIX_LOCK_read, ip);
-
-	ret = do_six_trylock(lock, type, true) ? 0
-		: six_lock_slowpath(lock, type, wait, should_sleep_fn, p, ip);
-
-	if (ret && type != SIX_LOCK_write)
-		six_release(&lock->dep_map, ip);
-	if (!ret)
-		lock_acquired(&lock->dep_map, ip);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(six_lock_ip_waiter);
-
-__always_inline
-static void do_six_unlock_type(struct six_lock *lock, enum six_lock_type type)
-{
-	u32 state;
-
-	if (type == SIX_LOCK_intent)
-		lock->owner = NULL;
-
-	if (type == SIX_LOCK_read &&
-	    lock->readers) {
-		smp_mb(); /* unlock barrier */
-		this_cpu_dec(*lock->readers);
-		smp_mb(); /* between unlocking and checking for waiters */
-		state = atomic_read(&lock->state);
-	} else {
-		u32 v = l[type].lock_val;
-
-		if (type != SIX_LOCK_read)
-			v += atomic_read(&lock->state) & SIX_LOCK_NOSPIN;
-
-		EBUG_ON(!(atomic_read(&lock->state) & l[type].held_mask));
-		state = atomic_sub_return_release(v, &lock->state);
-	}
-
-	six_lock_wakeup(lock, state, l[type].unlock_wakeup);
-}
-
-/**
- * six_unlock_ip - drop a six lock
- * @lock:	lock to unlock
- * @type:	SIX_LOCK_read, SIX_LOCK_intent, or SIX_LOCK_write
- * @ip:		ip parameter for lockdep/lockstat, i.e. _THIS_IP_
- *
- * When a lock is held multiple times (because six_lock_incement()) was used),
- * this decrements the 'lock held' counter by one.
- *
- * For example:
- * six_lock_read(&foo->lock);				read count 1
- * six_lock_increment(&foo->lock, SIX_LOCK_read);	read count 2
- * six_lock_unlock(&foo->lock, SIX_LOCK_read);		read count 1
- * six_lock_unlock(&foo->lock, SIX_LOCK_read);		read count 0
- */
-void six_unlock_ip(struct six_lock *lock, enum six_lock_type type, unsigned long ip)
-{
-	EBUG_ON(type == SIX_LOCK_write &&
-		!(atomic_read(&lock->state) & SIX_LOCK_HELD_intent));
-	EBUG_ON((type == SIX_LOCK_write ||
-		 type == SIX_LOCK_intent) &&
-		lock->owner != current);
-
-	if (type != SIX_LOCK_write)
-		six_release(&lock->dep_map, ip);
-	else
-		lock->seq++;
-
-	if (type == SIX_LOCK_intent &&
-	    lock->intent_lock_recurse) {
-		--lock->intent_lock_recurse;
-		return;
-	}
-
-	do_six_unlock_type(lock, type);
-}
-EXPORT_SYMBOL_GPL(six_unlock_ip);
-
-/**
- * six_lock_downgrade - convert an intent lock to a read lock
- * @lock:	lock to dowgrade
- *
- * @lock will have read count incremented and intent count decremented
- */
-void six_lock_downgrade(struct six_lock *lock)
-{
-	six_lock_increment(lock, SIX_LOCK_read);
-	six_unlock_intent(lock);
-}
-EXPORT_SYMBOL_GPL(six_lock_downgrade);
-
-/**
- * six_lock_tryupgrade - attempt to convert read lock to an intent lock
- * @lock:	lock to upgrade
- *
- * On success, @lock will have intent count incremented and read count
- * decremented
- *
- * Return: true on success, false on failure
- */
-bool six_lock_tryupgrade(struct six_lock *lock)
-{
-	u32 old = atomic_read(&lock->state), new;
-
-	do {
-		new = old;
-
-		if (new & SIX_LOCK_HELD_intent)
-			return false;
-
-		if (!lock->readers) {
-			EBUG_ON(!(new & SIX_LOCK_HELD_read));
-			new -= l[SIX_LOCK_read].lock_val;
-		}
-
-		new |= SIX_LOCK_HELD_intent;
-	} while (!atomic_try_cmpxchg_acquire(&lock->state, &old, new));
-
-	if (lock->readers)
-		this_cpu_dec(*lock->readers);
-
-	six_set_owner(lock, SIX_LOCK_intent, old, current);
-
-	return true;
-}
-EXPORT_SYMBOL_GPL(six_lock_tryupgrade);
-
-/**
- * six_trylock_convert - attempt to convert a held lock from one type to another
- * @lock:	lock to upgrade
- * @from:	SIX_LOCK_read or SIX_LOCK_intent
- * @to:		SIX_LOCK_read or SIX_LOCK_intent
- *
- * On success, @lock will have intent count incremented and read count
- * decremented
- *
- * Return: true on success, false on failure
- */
-bool six_trylock_convert(struct six_lock *lock,
-			 enum six_lock_type from,
-			 enum six_lock_type to)
-{
-	EBUG_ON(to == SIX_LOCK_write || from == SIX_LOCK_write);
-
-	if (to == from)
-		return true;
-
-	if (to == SIX_LOCK_read) {
-		six_lock_downgrade(lock);
-		return true;
-	} else {
-		return six_lock_tryupgrade(lock);
-	}
-}
-EXPORT_SYMBOL_GPL(six_trylock_convert);
-
-/**
- * six_lock_increment - increase held lock count on a lock that is already held
- * @lock:	lock to increment
- * @type:	SIX_LOCK_read or SIX_LOCK_intent
- *
- * @lock must already be held, with a lock type that is greater than or equal to
- * @type
- *
- * A corresponding six_unlock_type() call will be required for @lock to be fully
- * unlocked.
- */
-void six_lock_increment(struct six_lock *lock, enum six_lock_type type)
-{
-	six_acquire(&lock->dep_map, 0, type == SIX_LOCK_read, _RET_IP_);
-
-	/* XXX: assert already locked, and that we don't overflow: */
-
-	switch (type) {
-	case SIX_LOCK_read:
-		if (lock->readers) {
-			this_cpu_inc(*lock->readers);
-		} else {
-			EBUG_ON(!(atomic_read(&lock->state) &
-				  (SIX_LOCK_HELD_read|
-				   SIX_LOCK_HELD_intent)));
-			atomic_add(l[type].lock_val, &lock->state);
-		}
-		break;
-	case SIX_LOCK_intent:
-		EBUG_ON(!(atomic_read(&lock->state) & SIX_LOCK_HELD_intent));
-		lock->intent_lock_recurse++;
-		break;
-	case SIX_LOCK_write:
-		BUG();
-		break;
-	}
-}
-EXPORT_SYMBOL_GPL(six_lock_increment);
-
-/**
- * six_lock_wakeup_all - wake up all waiters on @lock
- * @lock:	lock to wake up waiters for
- *
- * Wakeing up waiters will cause them to re-run should_sleep_fn, which may then
- * abort the lock operation.
- *
- * This function is never needed in a bug-free program; it's only useful in
- * debug code, e.g. to determine if a cycle detector is at fault.
- */
-void six_lock_wakeup_all(struct six_lock *lock)
-{
-	u32 state = atomic_read(&lock->state);
-	struct six_lock_waiter *w;
-
-	six_lock_wakeup(lock, state, SIX_LOCK_read);
-	six_lock_wakeup(lock, state, SIX_LOCK_intent);
-	six_lock_wakeup(lock, state, SIX_LOCK_write);
-
-	raw_spin_lock(&lock->wait_lock);
-	list_for_each_entry(w, &lock->wait_list, list)
-		wake_up_process(w->task);
-	raw_spin_unlock(&lock->wait_lock);
-}
-EXPORT_SYMBOL_GPL(six_lock_wakeup_all);
-
-/**
- * six_lock_counts - return held lock counts, for each lock type
- * @lock:	lock to return counters for
- *
- * Return: the number of times a lock is held for read, intent and write.
- */
-struct six_lock_count six_lock_counts(struct six_lock *lock)
-{
-	struct six_lock_count ret;
-
-	ret.n[SIX_LOCK_read]	= !lock->readers
-		? atomic_read(&lock->state) & SIX_LOCK_HELD_read
-		: pcpu_read_count(lock);
-	ret.n[SIX_LOCK_intent]	= !!(atomic_read(&lock->state) & SIX_LOCK_HELD_intent) +
-		lock->intent_lock_recurse;
-	ret.n[SIX_LOCK_write]	= !!(atomic_read(&lock->state) & SIX_LOCK_HELD_write);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(six_lock_counts);
-
-/**
- * six_lock_readers_add - directly manipulate reader count of a lock
- * @lock:	lock to add/subtract readers for
- * @nr:		reader count to add/subtract
- *
- * When an upper layer is implementing lock reentrency, we may have both read
- * and intent locks on the same lock.
- *
- * When we need to take a write lock, the read locks will cause self-deadlock,
- * because six locks themselves do not track which read locks are held by the
- * current thread and which are held by a different thread - it does no
- * per-thread tracking of held locks.
- *
- * The upper layer that is tracking held locks may however, if trylock() has
- * failed, count up its own read locks, subtract them, take the write lock, and
- * then re-add them.
- *
- * As in any other situation when taking a write lock, @lock must be held for
- * intent one (or more) times, so @lock will never be left unlocked.
- */
-void six_lock_readers_add(struct six_lock *lock, int nr)
-{
-	if (lock->readers) {
-		this_cpu_add(*lock->readers, nr);
-	} else {
-		EBUG_ON((int) (atomic_read(&lock->state) & SIX_LOCK_HELD_read) + nr < 0);
-		/* reader count starts at bit 0 */
-		atomic_add(nr, &lock->state);
-	}
-}
-EXPORT_SYMBOL_GPL(six_lock_readers_add);
-
-/**
- * six_lock_exit - release resources held by a lock prior to freeing
- * @lock:	lock to exit
- *
- * When a lock was initialized in percpu mode (SIX_OLCK_INIT_PCPU), this is
- * required to free the percpu read counts.
- */
-void six_lock_exit(struct six_lock *lock)
-{
-	WARN_ON(lock->readers && pcpu_read_count(lock));
-	WARN_ON(atomic_read(&lock->state) & SIX_LOCK_HELD_read);
-
-	free_percpu(lock->readers);
-	lock->readers = NULL;
-}
-EXPORT_SYMBOL_GPL(six_lock_exit);
-
-void __six_lock_init(struct six_lock *lock, const char *name,
-		     struct lock_class_key *key, enum six_lock_init_flags flags)
-{
-	atomic_set(&lock->state, 0);
-	raw_spin_lock_init(&lock->wait_lock);
-	INIT_LIST_HEAD(&lock->wait_list);
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-	debug_check_no_locks_freed((void *) lock, sizeof(*lock));
-	lockdep_init_map(&lock->dep_map, name, key, 0);
-#endif
-
-	/*
-	 * Don't assume that we have real percpu variables available in
-	 * userspace:
-	 */
-#ifdef __KERNEL__
-	if (flags & SIX_LOCK_INIT_PCPU) {
-		/*
-		 * We don't return an error here on memory allocation failure
-		 * since percpu is an optimization, and locks will work with the
-		 * same semantics in non-percpu mode: callers can check for
-		 * failure if they wish by checking lock->readers, but generally
-		 * will not want to treat it as an error.
-		 */
-		lock->readers = alloc_percpu(unsigned);
-	}
-#endif
-}
-EXPORT_SYMBOL_GPL(__six_lock_init);