Revert "blk-mq: fix potential io hang by wrong 'wake_batch'"

This reverts commit 931bd6758b which is
commit 4f1731df60f9033669f024d06ae26a6301260b55 upstream.

It breaks the Android ABI and can be brought back in an abi-safe way in
the future if it is still needed.

Bug: 161946584
Change-Id: I131cbca13e9472d8d8157b64700e1a3db8006ae5
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Greg Kroah-Hartman 2023-09-05 09:42:05 +00:00
parent c057db2f88
commit c0e5631df8
3 changed files with 8 additions and 12 deletions

View File

@ -427,7 +427,7 @@ static void blk_mq_debugfs_tags_show(struct seq_file *m,
seq_printf(m, "nr_tags=%u\n", tags->nr_tags);
seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags);
seq_printf(m, "active_queues=%d\n",
READ_ONCE(tags->active_queues));
atomic_read(&tags->active_queues));
seq_puts(m, "\nbitmap_tags:\n");
sbitmap_queue_show(&tags->bitmap_tags, m);

View File

@ -40,7 +40,6 @@ static void blk_mq_update_wake_batch(struct blk_mq_tags *tags,
void __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
{
unsigned int users;
struct blk_mq_tags *tags = hctx->tags;
/*
* calling test_bit() prior to test_and_set_bit() is intentional,
@ -58,11 +57,9 @@ void __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
return;
}
spin_lock_irq(&tags->lock);
users = tags->active_queues + 1;
WRITE_ONCE(tags->active_queues, users);
blk_mq_update_wake_batch(tags, users);
spin_unlock_irq(&tags->lock);
users = atomic_inc_return(&hctx->tags->active_queues);
blk_mq_update_wake_batch(hctx->tags, users);
}
/*
@ -95,11 +92,9 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
return;
}
spin_lock_irq(&tags->lock);
users = tags->active_queues - 1;
WRITE_ONCE(tags->active_queues, users);
users = atomic_dec_return(&tags->active_queues);
blk_mq_update_wake_batch(tags, users);
spin_unlock_irq(&tags->lock);
blk_mq_tag_wakeup_all(tags, false);
}

View File

@ -750,7 +750,8 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
struct blk_mq_tags {
unsigned int nr_tags;
unsigned int nr_reserved_tags;
unsigned int active_queues;
atomic_t active_queues;
struct sbitmap_queue bitmap_tags;
struct sbitmap_queue breserved_tags;