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| author | Tao Guo <glorioustao@gmail.com> | 2012-06-13 21:17:21 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-07-16 09:04:08 -0700 |
| commit | 31b1da2a2ae8a053c33e1fd5b87ec3ea39e81b99 (patch) | |
| tree | 275d8a1753d9ab4b551bccab723f692fbc985027 | |
| parent | 8c890e34f58fc8d3c0eafecf0bdc92c4161b1679 (diff) | |
| download | linux-3.10-31b1da2a2ae8a053c33e1fd5b87ec3ea39e81b99.tar.gz linux-3.10-31b1da2a2ae8a053c33e1fd5b87ec3ea39e81b99.tar.bz2 linux-3.10-31b1da2a2ae8a053c33e1fd5b87ec3ea39e81b99.zip | |
umem: fix up unplugging
commit 32587371ad3db2f9d335de10dbd8cffd4fff5669 upstream.
Fix a regression introduced by 7eaceaccab5f40 ("block: remove per-queue
plugging"). In that patch, Jens removed the whole mm_unplug_device()
function, which used to be the trigger to make umem start to work.
We need to implement unplugging to make umem start to work, or I/O will
never be triggered.
Signed-off-by: Tao Guo <Tao.Guo@emc.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Shaohua Li <shli@kernel.org>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/block/umem.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/block/umem.c b/drivers/block/umem.c index aa2712060bf..9a72277a31d 100644 --- a/drivers/block/umem.c +++ b/drivers/block/umem.c @@ -513,6 +513,44 @@ static void process_page(unsigned long data) } } +struct mm_plug_cb { + struct blk_plug_cb cb; + struct cardinfo *card; +}; + +static void mm_unplug(struct blk_plug_cb *cb) +{ + struct mm_plug_cb *mmcb = container_of(cb, struct mm_plug_cb, cb); + + spin_lock_irq(&mmcb->card->lock); + activate(mmcb->card); + spin_unlock_irq(&mmcb->card->lock); + kfree(mmcb); +} + +static int mm_check_plugged(struct cardinfo *card) +{ + struct blk_plug *plug = current->plug; + struct mm_plug_cb *mmcb; + + if (!plug) + return 0; + + list_for_each_entry(mmcb, &plug->cb_list, cb.list) { + if (mmcb->cb.callback == mm_unplug && mmcb->card == card) + return 1; + } + /* Not currently on the callback list */ + mmcb = kmalloc(sizeof(*mmcb), GFP_ATOMIC); + if (!mmcb) + return 0; + + mmcb->card = card; + mmcb->cb.callback = mm_unplug; + list_add(&mmcb->cb.list, &plug->cb_list); + return 1; +} + static void mm_make_request(struct request_queue *q, struct bio *bio) { struct cardinfo *card = q->queuedata; @@ -523,6 +561,8 @@ static void mm_make_request(struct request_queue *q, struct bio *bio) *card->biotail = bio; bio->bi_next = NULL; card->biotail = &bio->bi_next; + if (bio->bi_rw & REQ_SYNC || !mm_check_plugged(card)) + activate(card); spin_unlock_irq(&card->lock); return; |