btrfs: remove unused logic of limiting async delalloc pages

A proposed patch in https://marc.info/?l=linux-btrfs&m=147859791003837
pointed out bad limit threshold in cow_file_range_async, but it turned
out that the whole logic is not necessary and is done by writeback. We
agreed to remove it.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2017-01-06 13:27:00 +01:00
parent 26d30f8529
commit 95995dbbe6

View file

@ -1167,7 +1167,6 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page,
struct btrfs_root *root = BTRFS_I(inode)->root;
unsigned long nr_pages;
u64 cur_end;
int limit = 10 * SZ_1M;
clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1, 0, NULL, GFP_NOFS);
@ -1199,12 +1198,6 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page,
btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
if (atomic_read(&fs_info->async_delalloc_pages) > limit) {
wait_event(fs_info->async_submit_wait,
(atomic_read(&fs_info->async_delalloc_pages) <
limit));
}
while (atomic_read(&fs_info->async_submit_draining) &&
atomic_read(&fs_info->async_delalloc_pages)) {
wait_event(fs_info->async_submit_wait,