From 89ec9cfd3b644fbc36047e36776509130d2fc1ec Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Tue, 28 Nov 2017 12:40:29 -0600 Subject: tcmu: split unmap_thread_fn Separate unmap_thread_fn to make it easier to read. Note: this patch does not fix the bug where we might miss a wake up call. The next patch will fix that. This patch only separates the code into functions. Signed-off-by: Mike Christie Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_user.c | 120 ++++++++++++++++++++++---------------- 1 file changed, 70 insertions(+), 50 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 d9fd91ee8282..cab6c72eb012 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -1973,71 +1973,91 @@ static struct target_backend_ops tcmu_ops = { .tb_dev_attrib_attrs = NULL, }; -static int unmap_thread_fn(void *data) + +static void find_free_blocks(void) { struct tcmu_dev *udev; loff_t off; uint32_t start, end, block; - while (!kthread_should_stop()) { - DEFINE_WAIT(__wait); - - prepare_to_wait(&unmap_wait, &__wait, TASK_INTERRUPTIBLE); - schedule(); - finish_wait(&unmap_wait, &__wait); + mutex_lock(&root_udev_mutex); + list_for_each_entry(udev, &root_udev, node) { + mutex_lock(&udev->cmdr_lock); - if (kthread_should_stop()) - break; + /* Try to complete the finished commands first */ + tcmu_handle_completions(udev); - mutex_lock(&root_udev_mutex); - list_for_each_entry(udev, &root_udev, node) { - mutex_lock(&udev->cmdr_lock); + /* Skip the udevs waiting the global pool or in idle */ + if (udev->waiting_global || !udev->dbi_thresh) { + mutex_unlock(&udev->cmdr_lock); + continue; + } - /* Try to complete the finished commands first */ - tcmu_handle_completions(udev); + end = udev->dbi_max + 1; + block = find_last_bit(udev->data_bitmap, end); + if (block == udev->dbi_max) { + /* + * The last bit is dbi_max, so there is + * no need to shrink any blocks. + */ + mutex_unlock(&udev->cmdr_lock); + continue; + } else if (block == end) { + /* The current udev will goto idle state */ + udev->dbi_thresh = start = 0; + udev->dbi_max = 0; + } else { + udev->dbi_thresh = start = block + 1; + udev->dbi_max = block; + } - /* Skip the udevs waiting the global pool or in idle */ - if (udev->waiting_global || !udev->dbi_thresh) { - mutex_unlock(&udev->cmdr_lock); - continue; - } + /* Here will truncate the data area from off */ + off = udev->data_off + start * DATA_BLOCK_SIZE; + unmap_mapping_range(udev->inode->i_mapping, off, 0, 1); - end = udev->dbi_max + 1; - block = find_last_bit(udev->data_bitmap, end); - if (block == udev->dbi_max) { - /* - * The last bit is dbi_max, so there is - * no need to shrink any blocks. - */ - mutex_unlock(&udev->cmdr_lock); - continue; - } else if (block == end) { - /* The current udev will goto idle state */ - udev->dbi_thresh = start = 0; - udev->dbi_max = 0; - } else { - udev->dbi_thresh = start = block + 1; - udev->dbi_max = block; - } + /* Release the block pages */ + tcmu_blocks_release(&udev->data_blocks, start, end); + mutex_unlock(&udev->cmdr_lock); + } + mutex_unlock(&root_udev_mutex); +} - /* Here will truncate the data area from off */ - off = udev->data_off + start * DATA_BLOCK_SIZE; - unmap_mapping_range(udev->inode->i_mapping, off, 0, 1); +static void run_cmdr_queues(void) +{ + struct tcmu_dev *udev; - /* Release the block pages */ - tcmu_blocks_release(&udev->data_blocks, start, end); + /* + * Try to wake up the udevs who are waiting + * for the global data block pool. + */ + mutex_lock(&root_udev_mutex); + list_for_each_entry(udev, &root_udev, node) { + mutex_lock(&udev->cmdr_lock); + if (!udev->waiting_global) { mutex_unlock(&udev->cmdr_lock); + break; } + mutex_unlock(&udev->cmdr_lock); - /* - * Try to wake up the udevs who are waiting - * for the global data pool. - */ - list_for_each_entry(udev, &root_udev, node) { - if (udev->waiting_global) - wake_up(&udev->wait_cmdr); - } - mutex_unlock(&root_udev_mutex); + wake_up(&udev->wait_cmdr); + } + mutex_unlock(&root_udev_mutex); +} + +static int unmap_thread_fn(void *data) +{ + while (!kthread_should_stop()) { + DEFINE_WAIT(__wait); + + prepare_to_wait(&unmap_wait, &__wait, TASK_INTERRUPTIBLE); + schedule(); + finish_wait(&unmap_wait, &__wait); + + if (kthread_should_stop()) + break; + + find_free_blocks(); + run_cmdr_queues(); } return 0; -- cgit v1.2.3-59-g8ed1b