From 4452226ea276e74fc3e252c88d9bb7e8f8e44bf0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 22 May 2015 17:13:26 -0400 Subject: [PATCH] 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 Reviewed-by: Jan Kara Cc: Jens Axboe Cc: Wu Fengguang Cc: drbd-dev@lists.linbit.com Cc: Neil Brown Cc: Alasdair Kergon Cc: Mike Snitzer Signed-off-by: Jens Axboe --- block/blk-core.c | 1 - drivers/block/drbd/drbd_main.c | 10 +++++----- drivers/md/dm.c | 2 +- drivers/md/raid1.c | 4 ++-- drivers/md/raid10.c | 2 +- fs/fs-writeback.c | 14 +++++++------- include/linux/backing-dev.h | 24 ++++++++++++------------ mm/backing-dev.c | 20 ++++++++++---------- 8 files changed, 38 insertions(+), 39 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 4afac14d4499..c3ba9c3b08d4 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -621,7 +621,6 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) q->backing_dev_info.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; - q->backing_dev_info.state = 0; q->backing_dev_info.capabilities = 0; q->backing_dev_info.name = "block"; q->node = node_id; diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 81fde9ef7f8e..a1518539b858 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -2359,7 +2359,7 @@ static void drbd_cleanup(void) * @congested_data: User data * @bdi_bits: Bits the BDI flusher thread is currently interested in * - * Returns 1<connection->flags)) { - r |= (1 << BDI_async_congested); + r |= (1 << WB_async_congested); /* Without good local data, we would need to read from remote, * and that would need the worker thread as well, which is * currently blocked waiting for that usermode helper to * finish. */ if (!get_ldev_if_state(device, D_UP_TO_DATE)) - r |= (1 << BDI_sync_congested); + r |= (1 << WB_sync_congested); else put_ldev(device); r &= bdi_bits; @@ -2399,9 +2399,9 @@ static int drbd_congested(void *congested_data, int bdi_bits) reason = 'b'; } - if (bdi_bits & (1 << BDI_async_congested) && + if (bdi_bits & (1 << WB_async_congested) && test_bit(NET_CONGESTED, &first_peer_device(device)->connection->flags)) { - r |= (1 << BDI_async_congested); + r |= (1 << WB_async_congested); reason = reason == 'b' ? 'a' : 'n'; } diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 38837f8ea327..2161ed9329c4 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2074,7 +2074,7 @@ static int dm_any_congested(void *congested_data, int bdi_bits) * the query about congestion status of request_queue */ if (dm_request_based(md)) - r = md->queue->backing_dev_info.state & + r = md->queue->backing_dev_info.wb.state & bdi_bits; else r = dm_table_any_congested(map, bdi_bits); diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 9157a29c8dbf..f80f1af61ce7 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -745,7 +745,7 @@ static int raid1_congested(struct mddev *mddev, int bits) struct r1conf *conf = mddev->private; int i, ret = 0; - if ((bits & (1 << BDI_async_congested)) && + if ((bits & (1 << WB_async_congested)) && conf->pending_count >= max_queued_requests) return 1; @@ -760,7 +760,7 @@ static int raid1_congested(struct mddev *mddev, int bits) /* Note the '|| 1' - when read_balance prefers * non-congested targets, it can be removed */ - if ((bits & (1<backing_dev_info, bits); else ret &= bdi_congested(&q->backing_dev_info, bits); diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index e793ab6b3570..fca825718f29 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -914,7 +914,7 @@ static int raid10_congested(struct mddev *mddev, int bits) struct r10conf *conf = mddev->private; int i, ret = 0; - if ((bits & (1 << BDI_async_congested)) && + if ((bits & (1 << WB_async_congested)) && conf->pending_count >= max_queued_requests) return 1; diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 32a8bbd7a9ad..983312cea245 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -74,7 +74,7 @@ unsigned int dirtytime_expire_interval = 12 * 60 * 60; */ 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 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(wbc_writepage); 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 @@ static void bdi_queue_work(struct backing_dev_info *bdi, 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 @@ static long wb_do_writeback(struct bdi_writeback *wb) 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 @@ static long wb_do_writeback(struct bdi_writeback *wb) */ 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 @@ void bdi_writeback_workfn(struct work_struct *work) 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 @@ void __mark_inode_dirty(struct inode *inode, int flags) 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); /* diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index aff923ae8c4b..eb14f988a63e 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -25,13 +25,13 @@ struct device; struct dentry; /* - * Bits in backing_dev_info.state + * Bits in bdi_writeback.state */ -enum bdi_state { - BDI_async_congested, /* The async (write) queue is getting full */ - BDI_sync_congested, /* The sync queue is getting full */ - BDI_registered, /* bdi_register() was done */ - BDI_writeback_running, /* Writeback is in progress */ +enum wb_state { + WB_async_congested, /* The async (write) queue is getting full */ + WB_sync_congested, /* The sync queue is getting full */ + WB_registered, /* bdi_register() was done */ + WB_writeback_running, /* Writeback is in progress */ }; typedef int (congested_fn)(void *, int); @@ -49,6 +49,7 @@ enum bdi_stat_item { struct bdi_writeback { struct backing_dev_info *bdi; /* our parent bdi */ + unsigned long state; /* Always use atomic bitops on this */ unsigned long last_old_flush; /* last old data flush */ struct delayed_work dwork; /* work item used for writeback */ @@ -62,7 +63,6 @@ struct bdi_writeback { struct backing_dev_info { struct list_head bdi_list; unsigned long ra_pages; /* max readahead in PAGE_CACHE_SIZE units */ - unsigned long state; /* Always use atomic bitops on this */ unsigned int capabilities; /* Device capabilities */ congested_fn *congested_fn; /* Function pointer if device is md/dm */ void *congested_data; /* Pointer to aux data for congested func */ @@ -250,23 +250,23 @@ static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits) { if (bdi->congested_fn) return bdi->congested_fn(bdi->congested_data, bdi_bits); - return (bdi->state & bdi_bits); + return (bdi->wb.state & bdi_bits); } static inline int bdi_read_congested(struct backing_dev_info *bdi) { - return bdi_congested(bdi, 1 << BDI_sync_congested); + return bdi_congested(bdi, 1 << WB_sync_congested); } static inline int bdi_write_congested(struct backing_dev_info *bdi) { - return bdi_congested(bdi, 1 << BDI_async_congested); + return bdi_congested(bdi, 1 << WB_async_congested); } static inline int bdi_rw_congested(struct backing_dev_info *bdi) { - return bdi_congested(bdi, (1 << BDI_sync_congested) | - (1 << BDI_async_congested)); + return bdi_congested(bdi, (1 << WB_sync_congested) | + (1 << WB_async_congested)); } enum { diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 6dc4580df2af..b23cf0ea5912 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -96,7 +96,7 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) nr_io, nr_more_io, nr_dirty_time, - !list_empty(&bdi->bdi_list), bdi->state); + !list_empty(&bdi->bdi_list), bdi->wb.state); #undef K return 0; @@ -280,7 +280,7 @@ void bdi_wakeup_thread_delayed(struct backing_dev_info *bdi) timeout = msecs_to_jiffies(dirty_writeback_interval * 10); spin_lock_bh(&bdi->wb_lock); - if (test_bit(BDI_registered, &bdi->state)) + if (test_bit(WB_registered, &bdi->wb.state)) queue_delayed_work(bdi_wq, &bdi->wb.dwork, timeout); spin_unlock_bh(&bdi->wb_lock); } @@ -315,7 +315,7 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, bdi->dev = dev; bdi_debug_register(bdi, dev_name(dev)); - set_bit(BDI_registered, &bdi->state); + set_bit(WB_registered, &bdi->wb.state); spin_lock_bh(&bdi_lock); list_add_tail_rcu(&bdi->bdi_list, &bdi_list); @@ -339,7 +339,7 @@ static void bdi_wb_shutdown(struct backing_dev_info *bdi) { /* Make sure nobody queues further work */ spin_lock_bh(&bdi->wb_lock); - if (!test_and_clear_bit(BDI_registered, &bdi->state)) { + if (!test_and_clear_bit(WB_registered, &bdi->wb.state)) { spin_unlock_bh(&bdi->wb_lock); return; } @@ -492,11 +492,11 @@ static atomic_t nr_bdi_congested[2]; void clear_bdi_congested(struct backing_dev_info *bdi, int sync) { - enum bdi_state bit; + enum wb_state bit; wait_queue_head_t *wqh = &congestion_wqh[sync]; - bit = sync ? BDI_sync_congested : BDI_async_congested; - if (test_and_clear_bit(bit, &bdi->state)) + bit = sync ? WB_sync_congested : WB_async_congested; + if (test_and_clear_bit(bit, &bdi->wb.state)) atomic_dec(&nr_bdi_congested[sync]); smp_mb__after_atomic(); if (waitqueue_active(wqh)) @@ -506,10 +506,10 @@ EXPORT_SYMBOL(clear_bdi_congested); void set_bdi_congested(struct backing_dev_info *bdi, int sync) { - enum bdi_state bit; + enum wb_state bit; - bit = sync ? BDI_sync_congested : BDI_async_congested; - if (!test_and_set_bit(bit, &bdi->state)) + bit = sync ? WB_sync_congested : WB_async_congested; + if (!test_and_set_bit(bit, &bdi->wb.state)) atomic_inc(&nr_bdi_congested[sync]); } EXPORT_SYMBOL(set_bdi_congested); -- 2.20.1