From 9cbb17508808f8a6bdd83354b61e126ac4fa6fed Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 31 Jul 2012 09:08:14 +0200 Subject: blk: centralize non-request unplug handling. Both md and umem has similar code for getting notified on an blk_finish_plug event. Centralize this code in block/ and allow each driver to provide its distinctive difference. Signed-off-by: NeilBrown Signed-off-by: Jens Axboe --- drivers/md/md.c | 56 +++++--------------------------------------------------- drivers/md/md.h | 8 +++++++- 2 files changed, 12 insertions(+), 52 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/md.c b/drivers/md/md.c index 34381172a947..b493fa417387 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -498,59 +498,13 @@ void md_flush_request(struct mddev *mddev, struct bio *bio) } EXPORT_SYMBOL(md_flush_request); -/* Support for plugging. - * This mirrors the plugging support in request_queue, but does not - * require having a whole queue or request structures. - * We allocate an md_plug_cb for each md device and each thread it gets - * plugged on. This links tot the private plug_handle structure in the - * personality data where we keep a count of the number of outstanding - * plugs so other code can see if a plug is active. - */ -struct md_plug_cb { - struct blk_plug_cb cb; - struct mddev *mddev; -}; - -static void plugger_unplug(struct blk_plug_cb *cb) +void md_unplug(struct blk_plug_cb *cb) { - struct md_plug_cb *mdcb = container_of(cb, struct md_plug_cb, cb); - md_wakeup_thread(mdcb->mddev->thread); - kfree(mdcb); -} - -/* Check that an unplug wakeup will come shortly. - * If not, wakeup the md thread immediately - */ -int mddev_check_plugged(struct mddev *mddev) -{ - struct blk_plug *plug = current->plug; - struct md_plug_cb *mdcb; - - if (!plug) - return 0; - - list_for_each_entry(mdcb, &plug->cb_list, cb.list) { - if (mdcb->cb.callback == plugger_unplug && - mdcb->mddev == mddev) { - /* Already on the list, move to top */ - if (mdcb != list_first_entry(&plug->cb_list, - struct md_plug_cb, - cb.list)) - list_move(&mdcb->cb.list, &plug->cb_list); - return 1; - } - } - /* Not currently on the callback list */ - mdcb = kmalloc(sizeof(*mdcb), GFP_ATOMIC); - if (!mdcb) - return 0; - - mdcb->mddev = mddev; - mdcb->cb.callback = plugger_unplug; - list_add(&mdcb->cb.list, &plug->cb_list); - return 1; + struct mddev *mddev = cb->data; + md_wakeup_thread(mddev->thread); + kfree(cb); } -EXPORT_SYMBOL_GPL(mddev_check_plugged); +EXPORT_SYMBOL(md_unplug); static inline struct mddev *mddev_get(struct mddev *mddev) { diff --git a/drivers/md/md.h b/drivers/md/md.h index 91786c46b85c..8f998e08fb87 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -627,6 +627,12 @@ extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask, struct mddev *mddev); extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs, struct mddev *mddev); -extern int mddev_check_plugged(struct mddev *mddev); extern void md_trim_bio(struct bio *bio, int offset, int size); + +extern void md_unplug(struct blk_plug_cb *cb); +static inline int mddev_check_plugged(struct mddev *mddev) +{ + return !!blk_check_plugged(md_unplug, mddev, + sizeof(struct blk_plug_cb)); +} #endif /* _MD_MD_H */ -- cgit v1.2.3