From 6fddcb775477bb2213bd76ab62145645eb570f33 Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Tue, 28 Nov 2017 12:40:32 -0600 Subject: tcmu: remove commands_lock No need for the commands_lock. The cmdr_lock is already held during idr addition and deletion, so just grab it during traversal. Note: This also fixes a issue where we should have been using at least _bh locking in tcmu_handle_completions when taking the commands lock to prevent the case where tcmu_handle_completions could be interrupted by a timer softirq while the commands_lock is held. Signed-off-by: Mike Christie Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_user.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) (limited to 'drivers/target/target_core_user.c') diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 2ccc8e61449b..43583a792439 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -139,7 +139,6 @@ struct tcmu_dev { struct radix_tree_root data_blocks; struct idr commands; - spinlock_t commands_lock; struct timer_list timeout; unsigned int cmd_time_out; @@ -1014,10 +1013,7 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) } WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD); - spin_lock(&udev->commands_lock); cmd = idr_remove(&udev->commands, entry->hdr.cmd_id); - spin_unlock(&udev->commands_lock); - if (!cmd) { pr_err("cmd_id not found, ring is broken\n"); set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags); @@ -1115,7 +1111,6 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) INIT_LIST_HEAD(&udev->timedout_entry); idr_init(&udev->commands); - spin_lock_init(&udev->commands_lock); timer_setup(&udev->timeout, tcmu_device_timedout, 0); @@ -1333,16 +1328,14 @@ static void tcmu_dev_kref_release(struct kref *kref) spin_unlock_bh(&timed_out_udevs_lock); /* Upper layer should drain all requests before calling this */ - spin_lock_irq(&udev->commands_lock); + mutex_lock(&udev->cmdr_lock); idr_for_each_entry(&udev->commands, cmd, i) { if (tcmu_check_and_free_pending_cmd(cmd) != 0) all_expired = false; } idr_destroy(&udev->commands); - spin_unlock_irq(&udev->commands_lock); WARN_ON(!all_expired); - mutex_lock(&udev->cmdr_lock); tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1); mutex_unlock(&udev->cmdr_lock); @@ -2060,9 +2053,9 @@ static void check_timedout_devices(void) list_del_init(&udev->timedout_entry); spin_unlock_bh(&timed_out_udevs_lock); - spin_lock(&udev->commands_lock); + mutex_lock(&udev->cmdr_lock); idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL); - spin_unlock(&udev->commands_lock); + mutex_unlock(&udev->cmdr_lock); spin_lock_bh(&timed_out_udevs_lock); } -- cgit v1.2.3-59-g8ed1b