From 0faa8cca883bbc6a0919e3c89128672659b75820 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Thu, 14 Apr 2011 17:58:19 -0400 Subject: [PATCH] xen/blkback: remove per-queue plugging commit 7eaceaccab5f40bbfda044629a6298616aeaed50 ("block: remove per-queue plugging") added two new interfaces to plug and unplug: blk_start_plug and blk_finish_plug. Lets use those. Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/blkback/blkback.c | 44 +++++++---------------------------- drivers/xen/blkback/common.h | 1 - 2 files changed, 9 insertions(+), 36 deletions(-) diff --git a/drivers/xen/blkback/blkback.c b/drivers/xen/blkback/blkback.c index 2d413930f235..464f2e0b5a61 100644 --- a/drivers/xen/blkback/blkback.c +++ b/drivers/xen/blkback/blkback.c @@ -166,38 +166,6 @@ static void free_req(struct pending_req *req) wake_up(&blkbk->pending_free_wq); } -/* - * Give back a reference count on the underlaying storage. - * It is OK to make multiple calls in this function as it - * resets the plug to NULL when it is done on the first call. - */ -static void unplug_queue(struct blkif_st *blkif) -{ - if (blkif->plug == NULL) - return; - if (blkif->plug->unplug_fn) - blkif->plug->unplug_fn(blkif->plug); - blk_put_queue(blkif->plug); - blkif->plug = NULL; -} - -/* - * Take a reference count on the underlaying storage. - * It is OK to call this multiple times as we check to make sure - * not to double reference. We also give back a reference count - * if it corresponds to another queue. - */ -static void plug_queue(struct blkif_st *blkif, struct block_device *bdev) -{ - struct request_queue *q = bdev_get_queue(bdev); - - if (q == blkif->plug) - return; - unplug_queue(blkif); - blk_get_queue(q); - blkif->plug = q; -} - /* * Unmap the grant references, and also remove the M2P over-rides * used in the 'pending_req'. @@ -280,7 +248,6 @@ int blkif_schedule(void *arg) if (do_block_io_op(blkif)) blkif->waiting_reqs = 1; - unplug_queue(blkif); if (log_stats && time_after(jiffies, blkif->st_print)) print_stats(blkif); @@ -456,6 +423,8 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, struct bio *bio = NULL; int ret, i; int operation; + struct blk_plug plug; + struct request_queue *q; switch (req->operation) { case BLKIF_OP_READ: @@ -561,7 +530,8 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, } /* Get a reference count for the disk queue and start sending I/O */ - plug_queue(blkif, preq.bdev); + blk_get_queue(q); + blk_start_plug(&plug); /* We set it one so that the last submit_bio does not have to call * atomic_inc. @@ -620,11 +590,14 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, else if (operation == WRITE || operation == WRITE_BARRIER) blkif->st_wr_sect += preq.nr_sects; + blk_finish_plug(&plug); + blk_put_queue(q); return; fail_flush: fast_flush_area(pending_req); fail_response: + /* Haven't submitted any bio's yet. */ make_response(blkif, req->id, req->operation, BLKIF_RSP_ERROR); free_req(pending_req); msleep(1); /* back off a bit */ @@ -634,7 +607,8 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, __end_block_io_op(pending_req, -EINVAL); if (bio) bio_put(bio); - unplug_queue(blkif); + blk_finish_plug(&plug); + blk_put_queue(q); msleep(1); /* back off a bit */ return; } diff --git a/drivers/xen/blkback/common.h b/drivers/xen/blkback/common.h index be3fc93d8a31..6257c1106591 100644 --- a/drivers/xen/blkback/common.h +++ b/drivers/xen/blkback/common.h @@ -79,7 +79,6 @@ struct blkif_st { /* One thread per one blkif. */ struct task_struct *xenblkd; unsigned int waiting_reqs; - struct request_queue *plug; /* statistics */ unsigned long st_print; -- 2.34.1