From 4911e3ccbec047ed1f728e19a70ad87729a3fb01 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 13 Sep 2011 23:08:42 +0200 Subject: [PATCH] target: simplify transport_put_cmd Inline two simple functions only used by it, and replace a goto with a simple if else construct. Note that the code moved from transport_dec_and_check seems fairly buggy - the atomic_read check on a variable where we'd do an atomic_dec_and_test looks racy if we'll ever get someone increment it without the lock held around them (which it looks like we do), and not decrementing the second counter if the first one doesn't hit zero also at least needs an explanation. (nab: Fix transport_put_cmd breakage) Signed-off-by: Christoph Hellwig Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 61 +++++++++++----------------------- 1 file changed, 20 insertions(+), 41 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index bee923f..a650100 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -3732,36 +3732,6 @@ static inline void transport_free_pages(struct se_cmd *cmd) cmd->t_bidi_data_nents = 0; } -static inline void transport_release_tasks(struct se_cmd *cmd) -{ - transport_free_dev_tasks(cmd); -} - -static inline int transport_dec_and_check(struct se_cmd *cmd) -{ - unsigned long flags; - - spin_lock_irqsave(&cmd->t_state_lock, flags); - if (atomic_read(&cmd->t_fe_count)) { - if (!atomic_dec_and_test(&cmd->t_fe_count)) { - spin_unlock_irqrestore(&cmd->t_state_lock, - flags); - return 1; - } - } - - if (atomic_read(&cmd->t_se_count)) { - if (!atomic_dec_and_test(&cmd->t_se_count)) { - spin_unlock_irqrestore(&cmd->t_state_lock, - flags); - return 1; - } - } - spin_unlock_irqrestore(&cmd->t_state_lock, flags); - - return 0; -} - /** * transport_put_cmd - release a reference to a command * @cmd: command to release @@ -3771,26 +3741,35 @@ static inline int transport_dec_and_check(struct se_cmd *cmd) static bool transport_put_cmd(struct se_cmd *cmd) { unsigned long flags; - - if (transport_dec_and_check(cmd)) - return false; + int free_tasks = 0; spin_lock_irqsave(&cmd->t_state_lock, flags); - if (!atomic_read(&cmd->transport_dev_active)) { - spin_unlock_irqrestore(&cmd->t_state_lock, flags); - goto free_pages; + if (atomic_read(&cmd->t_fe_count)) { + if (!atomic_dec_and_test(&cmd->t_fe_count)) + goto out_busy; + } + + if (atomic_read(&cmd->t_se_count)) { + if (!atomic_dec_and_test(&cmd->t_se_count)) + goto out_busy; + } + + if (atomic_read(&cmd->transport_dev_active)) { + atomic_set(&cmd->transport_dev_active, 0); + transport_all_task_dev_remove_state(cmd); + free_tasks = 1; } - atomic_set(&cmd->transport_dev_active, 0); - transport_all_task_dev_remove_state(cmd); spin_unlock_irqrestore(&cmd->t_state_lock, flags); - transport_release_tasks(cmd); - return true; + if (free_tasks != 0) + transport_free_dev_tasks(cmd); -free_pages: transport_free_pages(cmd); transport_release_cmd(cmd); return true; +out_busy: + spin_unlock_irqrestore(&cmd->t_state_lock, flags); + return false; } static int -- 2.7.4