brain-hackers_pepepper-mirror
/
linux-brain
mirror of https://github.com/brain-hackers/linux-brain.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
Tejun Heo 2015-05-22 17:13:26 -04:00 committed by Jens Axboe
parent ad7fa852d3
commit 4452226ea2
8 changed files with 38 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
block/blk-core.c
View File

@ -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;

10
drivers/block/drbd/drbd_main.c
View File

@ -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<<BDI_async_congested and/or 1<<BDI_sync_congested if we are congested.
* Returns 1<<WB_async_congested and/or 1<<WB_sync_congested if we are congested.
*/
static int drbd_congested(void *congested_data, int bdi_bits)
{
@ -2376,14 +2376,14 @@ static int drbd_congested(void *congested_data, int bdi_bits)
}
if (test_bit(CALLBACK_PENDING, &first_peer_device(device)->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';
}

2
drivers/md/dm.c
View File

@ -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);

4
drivers/md/raid1.c
View File

@ -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<<BDI_async_congested)) || 1)
if ((bits & (1 << WB_async_congested)) || 1)
ret |= bdi_congested(&q->backing_dev_info, bits);
else
ret &= bdi_congested(&q->backing_dev_info, bits);

2
drivers/md/raid10.c
View File

@ -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;

14
fs/fs-writeback.c
View File

@ -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);
/*

24
include/linux/backing-dev.h
View File

@ -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 {

20
mm/backing-dev.c
View File

@ -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);