diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-core.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index dd134d834d58..177ddcf356e6 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2927,6 +2927,31 @@ static void flush_plug_callbacks(struct blk_plug *plug) } } +struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, void *data, + int size) +{ + struct blk_plug *plug = current->plug; + struct blk_plug_cb *cb; + + if (!plug) + return NULL; + + list_for_each_entry(cb, &plug->cb_list, list) + if (cb->callback == unplug && cb->data == data) + return cb; + + /* Not currently on the callback list */ + BUG_ON(size < sizeof(*cb)); + cb = kzalloc(size, GFP_ATOMIC); + if (cb) { + cb->data = data; + cb->callback = unplug; + list_add(&cb->list, &plug->cb_list); + } + return cb; +} +EXPORT_SYMBOL(blk_check_plugged); + void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) { struct request_queue *q; |