This was intended to congest higher layers to not send bios, but as
1) the congested bit has been taken by writeback
2) and no one is waiting for %nr_async_bios down to zero,
we can safely remove this now.
Signed-off-by: Liu Bo <bo.li.liu@xxxxxxxxxx>
---
fs/btrfs/ctree.h | 1 -
fs/btrfs/disk-io.c | 1 -
fs/btrfs/volumes.c | 14 --------------
3 files changed, 16 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3f3eb7b..27cd882 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -881,7 +881,6 @@ struct btrfs_fs_info {
atomic_t nr_async_submits;
atomic_t async_submit_draining;
- atomic_t nr_async_bios;
atomic_t async_delalloc_pages;
atomic_t open_ioctl_trans;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f45b61f..95583e2 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2657,7 +2657,6 @@ int open_ctree(struct super_block *sb,
atomic_set(&fs_info->nr_async_submits, 0);
atomic_set(&fs_info->async_delalloc_pages, 0);
atomic_set(&fs_info->async_submit_draining, 0);
- atomic_set(&fs_info->nr_async_bios, 0);
atomic_set(&fs_info->defrag_running, 0);
atomic_set(&fs_info->qgroup_op_seq, 0);
atomic_set(&fs_info->reada_works_cnt, 0);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index bd679bc..6e9df4d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -450,13 +450,6 @@ static noinline void run_scheduled_bios(struct btrfs_device *device)
pending = pending->bi_next;
cur->bi_next = NULL;
- /*
- * atomic_dec_return implies a barrier for waitqueue_active
- */
- if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
- waitqueue_active(&fs_info->async_submit_wait))
- wake_up(&fs_info->async_submit_wait);
-
BUG_ON(atomic_read(&cur->__bi_cnt) == 0);
/*
@@ -6132,13 +6125,6 @@ static noinline void btrfs_schedule_bio(struct btrfs_device *device,
return;
}
- /*
- * nr_async_bios allows us to reliably return congestion to the
- * higher layers. Otherwise, the async bio makes it appear we have
- * made progress against dirty pages when we've really just put it
- * on a queue for later
- */
- atomic_inc(&fs_info->nr_async_bios);
WARN_ON(bio->bi_next);
bio->bi_next = NULL;
--
2.9.4
--
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