writeback: make congestion functions per bdi_writeback

Currently, all congestion functions take bdi (backing_dev_info) and
always operate on the root wb (bdi->wb) and the congestion state from
the block layer is propagated only for the root blkcg.  This patch
introduces {set|clear}_wb_congested() and wb_congested() which take a
bdi_writeback_congested and bdi_writeback respectively.  The bdi
counteparts are now wrappers invoking the wb based functions on
@bdi->wb.

While converting clear_bdi_congested() to clear_wb_congested(), the
local variable declaration order between @wqh and @bit is swapped for
cosmetic reason.

This patch just adds the new wb based functions.  The following
patches will apply them.

v2: Updated for bdi_writeback_congested.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Tejun Heo 2015-05-22 17:13:41 -04:00 committed by Jens Axboe
parent dfb8ae5678
commit ec8a6f2643
3 changed files with 49 additions and 32 deletions

View file

@ -163,7 +163,17 @@ enum {
BLK_RW_SYNC = 1,
};
void clear_bdi_congested(struct backing_dev_info *bdi, int sync);
void set_bdi_congested(struct backing_dev_info *bdi, int sync);
void clear_wb_congested(struct bdi_writeback_congested *congested, int sync);
void set_wb_congested(struct bdi_writeback_congested *congested, int sync);
static inline void clear_bdi_congested(struct backing_dev_info *bdi, int sync)
{
clear_wb_congested(bdi->wb.congested, sync);
}
static inline void set_bdi_congested(struct backing_dev_info *bdi, int sync)
{
set_wb_congested(bdi->wb.congested, sync);
}
#endif /* __LINUX_BACKING_DEV_DEFS_H */