writeback: move backing_dev_info->state into bdi_writeback
Currently, a bdi (backing_dev_info) embeds single wb (bdi_writeback)
and the role of the separation is unclear. For cgroup support for
writeback IOs, a bdi will be updated to host multiple wb's where each
wb serves writeback IOs of a different cgroup on the bdi. To achieve
that, a wb should carry all states necessary for servicing writeback
IOs for a cgroup independently.
This patch moves bdi->state into wb.
* enum bdi_state is renamed to wb_state and the prefix of all enums is
changed from BDI_ to WB_.
* Explicit zeroing of bdi->state is removed without adding zeoring of
wb->state as the whole data structure is zeroed on init anyway.
* As there's still only one bdi_writeback per backing_dev_info, all
uses of bdi->state are mechanically replaced with bdi->wb.state
introducing no behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: drbd-dev@lists.linbit.com
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 32a8bbd..983312c 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -74,7 +74,7 @@
*/
int writeback_in_progress(struct backing_dev_info *bdi)
{
- return test_bit(BDI_writeback_running, &bdi->state);
+ return test_bit(WB_writeback_running, &bdi->wb.state);
}
EXPORT_SYMBOL(writeback_in_progress);
@@ -112,7 +112,7 @@
static void bdi_wakeup_thread(struct backing_dev_info *bdi)
{
spin_lock_bh(&bdi->wb_lock);
- if (test_bit(BDI_registered, &bdi->state))
+ if (test_bit(WB_registered, &bdi->wb.state))
mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0);
spin_unlock_bh(&bdi->wb_lock);
}
@@ -123,7 +123,7 @@
trace_writeback_queue(bdi, work);
spin_lock_bh(&bdi->wb_lock);
- if (!test_bit(BDI_registered, &bdi->state)) {
+ if (!test_bit(WB_registered, &bdi->wb.state)) {
if (work->done)
complete(work->done);
goto out_unlock;
@@ -1057,7 +1057,7 @@
struct wb_writeback_work *work;
long wrote = 0;
- set_bit(BDI_writeback_running, &wb->bdi->state);
+ set_bit(WB_writeback_running, &wb->state);
while ((work = get_next_work_item(bdi)) != NULL) {
trace_writeback_exec(bdi, work);
@@ -1079,7 +1079,7 @@
*/
wrote += wb_check_old_data_flush(wb);
wrote += wb_check_background_flush(wb);
- clear_bit(BDI_writeback_running, &wb->bdi->state);
+ clear_bit(WB_writeback_running, &wb->state);
return wrote;
}
@@ -1099,7 +1099,7 @@
current->flags |= PF_SWAPWRITE;
if (likely(!current_is_workqueue_rescuer() ||
- !test_bit(BDI_registered, &bdi->state))) {
+ !test_bit(WB_registered, &wb->state))) {
/*
* The normal path. Keep writing back @bdi until its
* work_list is empty. Note that this path is also taken
@@ -1323,7 +1323,7 @@
spin_unlock(&inode->i_lock);
spin_lock(&bdi->wb.list_lock);
if (bdi_cap_writeback_dirty(bdi)) {
- WARN(!test_bit(BDI_registered, &bdi->state),
+ WARN(!test_bit(WB_registered, &bdi->wb.state),
"bdi-%s not registered\n", bdi->name);
/*