Convert to lockless lists - intermix with regular list due to
that next pointer in both list_head and llist_head is the first
field, and prev is not used. Do this so we can make babysteps
forward.
Signed-off-by: Alexander Atanasov <alexander.atana...@virtuozzo.com>
---
drivers/md/dm-ploop-bat.c | 3 +--
drivers/md/dm-ploop-map.c | 48 +++++++++++++++++++-----------------
drivers/md/dm-ploop-target.c | 2 +-
drivers/md/dm-ploop.h | 6 ++---
4 files changed, 31 insertions(+), 28 deletions(-)
diff --git a/drivers/md/dm-ploop-bat.c b/drivers/md/dm-ploop-bat.c
index 886a05cdd23a..655d0e4c91ab 100644
--- a/drivers/md/dm-ploop-bat.c
+++ b/drivers/md/dm-ploop-bat.c
@@ -80,8 +80,7 @@ static struct md_page *ploop_alloc_md_page(u32 id)
page = alloc_page(GFP_KERNEL);
if (!page)
goto err_page;
- INIT_LIST_HEAD(&md->wait_list);
- INIT_LIST_HEAD(&md->wb_link);
+ init_llist_head(&md->wait_llist);
md->status = 0;
md->bat_levels = levels;
diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index e50e4ff58902..f848c66ab8e7 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -382,13 +382,14 @@ static bool ploop_delay_if_md_busy(struct ploop *ploop,
struct md_page *md,
WARN_ON_ONCE(!list_empty(&pio->list));
- write_lock_irqsave(&ploop->bat_rwlock, flags);
+ /* lock protects piwb */
+ read_lock_irqsave(&ploop->bat_rwlock, flags);
piwb = md->piwb;
if (piwb && (piwb->type != type || test_bit(MD_WRITEBACK,
&md->status))) {
- list_add_tail(&pio->list, &md->wait_list);
+ llist_add((struct llist_node *)(&pio->list), &md->wait_llist);
busy = true;
}
- write_unlock_irqrestore(&ploop->bat_rwlock, flags);
+ read_unlock_irqrestore(&ploop->bat_rwlock, flags);
return busy;
}
@@ -547,16 +548,13 @@ static void ploop_unlink_completed_pio(struct ploop
*ploop, struct pio *pio)
static bool ploop_md_make_dirty(struct ploop *ploop, struct md_page *md)
{
- unsigned long flags;
bool new = false;
- write_lock_irqsave(&ploop->bat_rwlock, flags);
WARN_ON_ONCE(test_bit(MD_WRITEBACK, &md->status));
if (!test_and_set_bit(MD_DIRTY, &md->status)) {
- list_add_tail(&md->wb_link, &ploop->wb_batch_list);
+ llist_add(&md->wb_llink, &ploop->wb_batch_llist);
new = true;
}
- write_unlock_irqrestore(&ploop->bat_rwlock, flags);
return new;
}
@@ -758,7 +756,9 @@ static void ploop_advance_local_after_bat_wb(struct ploop
*ploop,
map_index_t *dst_clu, off;
unsigned long flags;
LIST_HEAD(list);
-
+ struct llist_node *wait_llist_pending;
+ struct pio *pio;
+ struct llist_node *pos, *t;
BUG_ON(!md);
bat_entries = md->kmpage;
@@ -775,7 +775,6 @@ static void ploop_advance_local_after_bat_wb(struct ploop
*ploop,
i = PLOOP_MAP_OFFSET;
dst_clu = piwb->kmpage;
- write_lock_irqsave(&ploop->bat_rwlock, flags);
for (; i < last; i++) {
if (piwb->type == PIWB_TYPE_DISCARD) {
@@ -802,10 +801,20 @@ static void ploop_advance_local_after_bat_wb(struct ploop
*ploop,
WARN_ON_ONCE(!test_bit(MD_WRITEBACK, &md->status));
clear_bit(MD_WRITEBACK, &md->status);
+ /* protect piwb */
+ write_lock_irqsave(&ploop->bat_rwlock, flags);
md->piwb = NULL;
- list_splice_tail_init(&md->wait_list, &list);
write_unlock_irqrestore(&ploop->bat_rwlock, flags);
+ wait_llist_pending = llist_del_all(&md->wait_llist);
+ if (wait_llist_pending) {
+ wait_llist_pending = llist_reverse_order(wait_llist_pending);
+ llist_for_each_safe(pos, t, wait_llist_pending) {
+ pio = list_entry((struct list_head *)pos, typeof(*pio),
list);
+ list_add(&pio->list, &list);
+ }
+ }
+
if (!list_empty(&list))
ploop_dispatch_pios(ploop, NULL, &list);
}
@@ -1758,22 +1767,17 @@ static void ploop_process_resubmit_pios(struct ploop
*ploop,
static void ploop_submit_metadata_writeback(struct ploop *ploop)
{
struct md_page *md;
- while (1) {
- write_lock_irq(&ploop->bat_rwlock);
- md = list_first_entry_or_null(&ploop->wb_batch_list,
- struct md_page, wb_link);
- if (!md) {
- write_unlock_irq(&ploop->bat_rwlock);
- break;
- }
- list_del_init(&md->wb_link);
- /* L1L2 mustn't be redirtyed, when wb in-flight! */
+ struct md_page *t;
+ struct llist_node *wbl;
+ wbl = llist_del_all(&ploop->wb_batch_llist);
+ if (!wbl)
+ return;
+ wbl = llist_reverse_order(wbl);
+ llist_for_each_entry_safe(md, t, wbl, wb_llink) {
WARN_ON_ONCE(!test_bit(MD_DIRTY, &md->status));
WARN_ON_ONCE(test_bit(MD_WRITEBACK, &md->status));
set_bit(MD_WRITEBACK, &md->status);
clear_bit(MD_DIRTY, &md->status);
- write_unlock_irq(&ploop->bat_rwlock);
-
ploop_index_wb_submit(ploop, md->piwb);
}
}
diff --git a/drivers/md/dm-ploop-target.c b/drivers/md/dm-ploop-target.c
index 8b3b840dea66..b66ae3a9a4b0 100644
--- a/drivers/md/dm-ploop-target.c
+++ b/drivers/md/dm-ploop-target.c
@@ -378,7 +378,7 @@ static int ploop_ctr(struct dm_target *ti, unsigned int
argc, char **argv)
INIT_LIST_HEAD(&ploop->resubmit_pios);
INIT_LIST_HEAD(&ploop->enospc_pios);
INIT_LIST_HEAD(&ploop->cluster_lk_list);
- INIT_LIST_HEAD(&ploop->wb_batch_list);
+ init_llist_head(&ploop->wb_batch_llist);
ploop->bat_entries = RB_ROOT;
timer_setup(&ploop->enospc_timer, ploop_enospc_timer, 0);
diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h
index 5fa176affc4e..4a64a06d0713 100644
--- a/drivers/md/dm-ploop.h
+++ b/drivers/md/dm-ploop.h
@@ -121,9 +121,9 @@ struct md_page {
struct page *page;
void *kmpage;
u8 *bat_levels;
- struct list_head wait_list;
+ struct llist_head wait_llist;
- struct list_head wb_link;
+ struct llist_node wb_llink;
struct ploop_index_wb *piwb;
};
@@ -166,7 +166,7 @@ struct ploop {
u32 hb_nr; /* holes_bitmap size in bits */
rwlock_t bat_rwlock;
- struct list_head wb_batch_list;
+ struct llist_head wb_batch_llist;
/*
* Hash table to link non-exclusive submitted bios.
--
2.43.0
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