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 <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Mike Christie 2017-11-28 12:40:29 -06:00 committed by Nicholas Bellinger
parent bf99ec1332
commit 89ec9cfd3b

View File

@ -1973,12 +1973,79 @@ 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;
mutex_lock(&root_udev_mutex);
list_for_each_entry(udev, &root_udev, node) {
mutex_lock(&udev->cmdr_lock);
/* Try to complete the finished commands first */
tcmu_handle_completions(udev);
/* Skip the udevs waiting the global pool or in idle */
if (udev->waiting_global || !udev->dbi_thresh) {
mutex_unlock(&udev->cmdr_lock);
continue;
}
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;
}
/* 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);
/* Release the block pages */
tcmu_blocks_release(&udev->data_blocks, start, end);
mutex_unlock(&udev->cmdr_lock);
}
mutex_unlock(&root_udev_mutex);
}
static void run_cmdr_queues(void)
{
struct tcmu_dev *udev;
/*
* 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);
wake_up(&udev->wait_cmdr);
}
mutex_unlock(&root_udev_mutex);
}
static int unmap_thread_fn(void *data)
{
while (!kthread_should_stop()) {
DEFINE_WAIT(__wait);
@ -1989,55 +2056,8 @@ static int unmap_thread_fn(void *data)
if (kthread_should_stop())
break;
mutex_lock(&root_udev_mutex);
list_for_each_entry(udev, &root_udev, node) {
mutex_lock(&udev->cmdr_lock);
/* Try to complete the finished commands first */
tcmu_handle_completions(udev);
/* Skip the udevs waiting the global pool or in idle */
if (udev->waiting_global || !udev->dbi_thresh) {
mutex_unlock(&udev->cmdr_lock);
continue;
}
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;
}
/* 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);
/* Release the block pages */
tcmu_blocks_release(&udev->data_blocks, start, end);
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);
find_free_blocks();
run_cmdr_queues();
}
return 0;