From c7329eff72aa237d6bedef6dc57c93dc048d2a16 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 11 Jul 2018 12:10:51 -0400 Subject: dm crypt: use wake_up_process() instead of a wait queue This is a small simplification of dm-crypt - use wake_up_process() instead of a wait queue in a case where only one process may be waiting. dm-writecache uses a similar pattern. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-crypt.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index b61b069c33af..c406767cb9b7 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -144,7 +144,7 @@ struct crypt_config { struct workqueue_struct *io_queue; struct workqueue_struct *crypt_queue; - wait_queue_head_t write_thread_wait; + spinlock_t write_thread_lock; struct task_struct *write_thread; struct rb_root write_tree; @@ -1620,36 +1620,31 @@ static int dmcrypt_write(void *data) struct rb_root write_tree; struct blk_plug plug; - DECLARE_WAITQUEUE(wait, current); - - spin_lock_irq(&cc->write_thread_wait.lock); + spin_lock_irq(&cc->write_thread_lock); continue_locked: if (!RB_EMPTY_ROOT(&cc->write_tree)) goto pop_from_list; set_current_state(TASK_INTERRUPTIBLE); - __add_wait_queue(&cc->write_thread_wait, &wait); - spin_unlock_irq(&cc->write_thread_wait.lock); + spin_unlock_irq(&cc->write_thread_lock); if (unlikely(kthread_should_stop())) { set_current_state(TASK_RUNNING); - remove_wait_queue(&cc->write_thread_wait, &wait); break; } schedule(); set_current_state(TASK_RUNNING); - spin_lock_irq(&cc->write_thread_wait.lock); - __remove_wait_queue(&cc->write_thread_wait, &wait); + spin_lock_irq(&cc->write_thread_lock); goto continue_locked; pop_from_list: write_tree = cc->write_tree; cc->write_tree = RB_ROOT; - spin_unlock_irq(&cc->write_thread_wait.lock); + spin_unlock_irq(&cc->write_thread_lock); BUG_ON(rb_parent(write_tree.rb_node)); @@ -1693,7 +1688,9 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) return; } - spin_lock_irqsave(&cc->write_thread_wait.lock, flags); + spin_lock_irqsave(&cc->write_thread_lock, flags); + if (RB_EMPTY_ROOT(&cc->write_tree)) + wake_up_process(cc->write_thread); rbp = &cc->write_tree.rb_node; parent = NULL; sector = io->sector; @@ -1706,9 +1703,7 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) } rb_link_node(&io->rb_node, parent, rbp); rb_insert_color(&io->rb_node, &cc->write_tree); - - wake_up_locked(&cc->write_thread_wait); - spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags); + spin_unlock_irqrestore(&cc->write_thread_lock, flags); } static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) @@ -2831,7 +2826,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) goto bad; } - init_waitqueue_head(&cc->write_thread_wait); + spin_lock_init(&cc->write_thread_lock); cc->write_tree = RB_ROOT; cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write"); -- cgit v1.2.3-59-g8ed1b